2011-02-06 02:55:56

by Thomas Chou

Subject: [PATCH v5] spi: add OpenCores tiny SPI driver

This patch adds support of OpenCores tiny SPI driver.

http://opencores.org/project,tiny_spi

Signed-off-by: Thomas Chou <[email protected]>
---
v2 minor cleanup, same as Grant suggest for spi_altera.
v3 rename driver to spi_oc_tiny as Grant suggested.
set version to tiny-spi-rtlsvn2 as Jonas suggested.
v4 add dts binding doc.
v5 use devm_* to help cleanup.
add of gpio support.

.../devicetree/bindings/spi/spi_oc_tiny.txt | 12 +
drivers/spi/Kconfig | 8 +
drivers/spi/Makefile | 1 +
drivers/spi/spi_oc_tiny.c | 423 ++++++++++++++++++++
include/linux/spi/spi_oc_tiny.h | 18 +
5 files changed, 462 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
create mode 100644 drivers/spi/spi_oc_tiny.c
create mode 100644 include/linux/spi/spi_oc_tiny.h

diff --git a/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
new file mode 100644
index 0000000..d95c0b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
@@ -0,0 +1,12 @@
+OpenCores tiny SPI
+
+Required properties:
+- compatible : should be "opencores,tiny-spi-rtlsvn2".
+- gpios : should specify GPIOs used for chipselect.
+Optional properties:
+- clock-frequency : input clock frequency to the core.
+- baud-width: width, in bits, of the programmable divider used to scale
+ the input clock to SCLK.
+
+The clock-frequency and baud-width properties are needed only if the divider
+is programmable. They are not needed if the divider is fixed.
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index bb233a9..43d2a7c 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -231,6 +231,14 @@ config SPI_FSL_ESPI
From MPC8536, 85xx platform uses the controller, and all P10xx,
P20xx, P30xx,P40xx, P50xx uses this controller.

+config SPI_OC_TINY
+ tristate "OpenCores tiny SPI"
+ default n
+ depends on GENERIC_GPIO
+ select SPI_BITBANG
+ help
+ This is the driver for OpenCores tiny SPI master controller.
+
config SPI_OMAP_UWIRE
tristate "OMAP1 MicroWire"
depends on ARCH_OMAP1
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 86d1b5f..c7e4c23 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_IMX) += spi_imx.o
obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o
obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o
obj-$(CONFIG_SPI_PXA2XX_PCI) += pxa2xx_spi_pci.o
+obj-$(CONFIG_SPI_OC_TINY) += spi_oc_tiny.o
obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o
obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o
obj-$(CONFIG_SPI_OMAP_100K) += omap_spi_100k.o
diff --git a/drivers/spi/spi_oc_tiny.c b/drivers/spi/spi_oc_tiny.c
new file mode 100644
index 0000000..47d38f6
--- /dev/null
+++ b/drivers/spi/spi_oc_tiny.c
@@ -0,0 +1,423 @@
+/*
+ * OpenCores tiny SPI master driver
+ *
+ * http://opencores.org/project,tiny_spi
+ *
+ * Copyright (C) 2011 Thomas Chou <[email protected]>
+ *
+ * Based on spi_s3c24xx.c, which is:
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ * Ben Dooks <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/spi_oc_tiny.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+
+#define DRV_NAME "spi_oc_tiny"
+
+#define TINY_SPI_RXDATA 0
+#define TINY_SPI_TXDATA 4
+#define TINY_SPI_STATUS 8
+#define TINY_SPI_CONTROL 12
+#define TINY_SPI_BAUD 16
+
+#define TINY_SPI_STATUS_TXE 0x1
+#define TINY_SPI_STATUS_TXR 0x2
+
+struct tiny_spi {
+ /* bitbang has to be first */
+ struct spi_bitbang bitbang;
+ struct completion done;
+
+ void __iomem *base;
+ int irq;
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int baud;
+ unsigned int speed_hz;
+ unsigned int mode;
+ unsigned int len;
+ unsigned int txc, rxc;
+ const u8 *txp;
+ u8 *rxp;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev)
+{
+ return spi_master_get_devdata(sdev->master);
+}
+
+static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
+}
+
+static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (hw->gpio_cs_count) {
+ gpio_set_value(hw->gpio_cs[spi->chip_select],
+ (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
+ }
+}
+
+static int tiny_spi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ unsigned int baud = hw->baud;
+
+ if (t) {
+ if (t->speed_hz && t->speed_hz != hw->speed_hz)
+ baud = tiny_spi_baud(spi, t->speed_hz);
+ }
+ writel(baud, hw->base + TINY_SPI_BAUD);
+ writel(hw->mode, hw->base + TINY_SPI_CONTROL);
+ return 0;
+}
+
+static int tiny_spi_setup(struct spi_device *spi)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (spi->max_speed_hz != hw->speed_hz) {
+ hw->speed_hz = spi->max_speed_hz;
+ hw->baud = tiny_spi_baud(spi, hw->speed_hz);
+ }
+ hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
+ return 0;
+}
+
+static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXR))
+ cpu_relax();
+}
+
+static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXE))
+ cpu_relax();
+}
+
+static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ const u8 *txp = t->tx_buf;
+ u8 *rxp = t->rx_buf;
+ unsigned int i;
+
+ if (hw->irq >= 0) {
+ /* use intrrupt driven data transfer */
+ hw->len = t->len;
+ hw->txp = t->tx_buf;
+ hw->rxp = t->rx_buf;
+ hw->txc = 0;
+ hw->rxc = 0;
+
+ /* send the first byte */
+ if (t->len > 1) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
+ }
+
+ wait_for_completion(&hw->done);
+ } else if (txp && rxp) {
+ /* we need to tighten the transfer loop */
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx, tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (rxp) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0,
+ hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (txp) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ } else {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ tiny_spi_wait_txr(hw);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ }
+ return t->len;
+}
+
+static irqreturn_t tiny_spi_irq(int irq, void *dev)
+{
+ struct tiny_spi *hw = dev;
+
+ writeb(0, hw->base + TINY_SPI_STATUS);
+ if (hw->rxc + 1 == hw->len) {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ hw->rxc++;
+ complete(&hw->done);
+ } else {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ hw->rxc++;
+ if (hw->txc < hw->len) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR,
+ hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(TINY_SPI_STATUS_TXE,
+ hw->base + TINY_SPI_STATUS);
+ }
+ }
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_OF
+#include <linux/of_gpio.h>
+
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct device_node *np = pdev->dev.of_node;
+ unsigned int i;
+ const __be32 *val;
+
+ if (!np)
+ return 0;
+ hw->gpio_cs_count = of_gpio_count(np);
+ if (hw->gpio_cs_count) {
+ hw->gpio_cs = devm_kzalloc(&pdev->dev,
+ hw->gpio_cs_count * sizeof(unsigned int),
+ GFP_KERNEL);
+ if (!hw->gpio_cs)
+ return -ENOMEM;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ hw->gpio_cs[i] = of_get_gpio_flags(np, i, NULL);
+ if (hw->gpio_cs[i] < 0)
+ return -ENODEV;
+ }
+ hw->bitbang.master->dev.of_node = pdev->dev.of_node;
+ val = of_get_property(pdev->dev.of_node,
+ "clock-frequency", NULL);
+ if (val)
+ hw->freq = be32_to_cpup(val);
+ val = of_get_property(pdev->dev.of_node, "baud-width", NULL);
+ if (val)
+ hw->baudwidth = be32_to_cpup(val);
+ return 0;
+}
+#else /* !CONFIG_OF */
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ return 0;
+}
+#endif /* CONFIG_OF */
+
+static int __devinit tiny_spi_probe(struct platform_device *pdev)
+{
+ struct tiny_spi_platform_data *platp = pdev->dev.platform_data;
+ struct tiny_spi *hw;
+ struct spi_master *master;
+ struct resource *res;
+ unsigned int i;
+ int err = -ENODEV;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
+ if (!master)
+ return err;
+
+ /* setup the master state. */
+ master->bus_num = pdev->id;
+ master->num_chipselect = 255;
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ master->setup = tiny_spi_setup;
+
+ hw = spi_master_get_devdata(master);
+ platform_set_drvdata(pdev, hw);
+
+ /* setup the state for the bitbang driver */
+ hw->bitbang.master = spi_master_get(master);
+ if (!hw->bitbang.master)
+ return err;
+ hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
+ hw->bitbang.chipselect = tiny_spi_chipselect;
+ hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;
+
+ /* find and map our resources */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ goto exit_busy;
+ if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
+ pdev->name))
+ goto exit_busy;
+ hw->base = devm_ioremap_nocache(&pdev->dev, res->start,
+ resource_size(res));
+ if (!hw->base)
+ goto exit_busy;
+ /* irq is optional */
+ hw->irq = platform_get_irq(pdev, 0);
+ if (hw->irq >= 0) {
+ init_completion(&hw->done);
+ err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
+ pdev->name, hw);
+ if (err)
+ goto exit;
+ }
+ /* find platform data */
+ if (platp) {
+ hw->gpio_cs_count = platp->gpio_cs_count;
+ hw->gpio_cs = platp->gpio_cs;
+ if (platp->gpio_cs_count && !platp->gpio_cs)
+ goto exit_busy;
+ hw->freq = platp->freq;
+ hw->baudwidth = platp->baudwidth;
+ } else {
+ err = tiny_spi_of_probe(pdev);
+ if (err)
+ goto exit;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
+ if (err)
+ goto exit_gpio;
+ gpio_direction_output(hw->gpio_cs[i], 1);
+ }
+ if (hw->gpio_cs_count)
+ hw->bitbang.master->num_chipselect = hw->gpio_cs_count;
+ else
+ hw->bitbang.master->num_chipselect = 1; /* no chipselect pin */
+
+ /* register our spi controller */
+ err = spi_bitbang_start(&hw->bitbang);
+ if (err)
+ goto exit;
+ dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
+
+ return 0;
+
+exit_gpio:
+ while (i-- > 0)
+ gpio_free(hw->gpio_cs[i]);
+exit_busy:
+ err = -EBUSY;
+exit:
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return err;
+}
+
+static int __devexit tiny_spi_remove(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct spi_master *master = hw->bitbang.master;
+ unsigned int i;
+
+ spi_bitbang_stop(&hw->bitbang);
+ for (i = 0; i < hw->gpio_cs_count; i++)
+ gpio_free(hw->gpio_cs[i]);
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return 0;
+}
+
+static const struct of_device_id tiny_spi_match[] = {
+ { .compatible = "opencores,tiny-spi-rtlsvn2", },
+ {},
+}
+MODULE_DEVICE_TABLE(of, tiny_spi_match);
+
+static struct platform_driver tiny_spi_driver = {
+ .probe = tiny_spi_probe,
+ .remove = __devexit_p(tiny_spi_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .pm = NULL,
+ .of_match_table = tiny_spi_match,
+ },
+};
+
+static int __init tiny_spi_init(void)
+{
+ return platform_driver_register(&tiny_spi_driver);
+}
+module_init(tiny_spi_init);
+
+static void __exit tiny_spi_exit(void)
+{
+ platform_driver_unregister(&tiny_spi_driver);
+}
+module_exit(tiny_spi_exit);
+
+MODULE_DESCRIPTION("OpenCores tiny SPI driver");
+MODULE_AUTHOR("Thomas Chou <[email protected]>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/include/linux/spi/spi_oc_tiny.h b/include/linux/spi/spi_oc_tiny.h
new file mode 100644
index 0000000..94bd099
--- /dev/null
+++ b/include/linux/spi/spi_oc_tiny.h
@@ -0,0 +1,18 @@
+#ifndef _LINUX_SPI_SPI_OC_TINY_H
+#define _LINUX_SPI_SPI_OC_TINY_H
+
+/*
+ * struct tiny_spi_platform_data - platform data of the OpenCores tiny SPI
+ * @freq: input clock freq to the core.
+ * @baudwidth: baud rate divider width of the core.
+ * @gpio_cs_count: number of gpio pins used for chipselect.
+ * @gpio_cs: array of gpio pins used for chipselect.
+ */
+struct tiny_spi_platform_data {
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+#endif /* _LINUX_SPI_SPI_OC_TINY_H */
--
1.7.3.5

2011-02-06 03:47:27

by Thomas Chou

Subject: [PATCH v6] spi: add OpenCores tiny SPI driver

This patch adds support of OpenCores tiny SPI driver.

http://opencores.org/project,tiny_spi

Signed-off-by: Thomas Chou <[email protected]>
---
v2 minor cleanup, same as Grant suggest for spi_altera.
v3 rename driver to spi_oc_tiny as Grant suggested.
set version to tiny-spi-rtlsvn2 as Jonas suggested.
v4 add dts binding doc.
v5 use devm_* to help cleanup.
add of gpio support.
v6 check len from of_get_property.
fix kerneldoc in header.

.../devicetree/bindings/spi/spi_oc_tiny.txt | 12 +
drivers/spi/Kconfig | 8 +
drivers/spi/Makefile | 1 +
drivers/spi/spi_oc_tiny.c | 424 ++++++++++++++++++++
include/linux/spi/spi_oc_tiny.h | 20 +
5 files changed, 465 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
create mode 100644 drivers/spi/spi_oc_tiny.c
create mode 100644 include/linux/spi/spi_oc_tiny.h

diff --git a/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
new file mode 100644
index 0000000..d95c0b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
@@ -0,0 +1,12 @@
+OpenCores tiny SPI
+
+Required properties:
+- compatible : should be "opencores,tiny-spi-rtlsvn2".
+- gpios : should specify GPIOs used for chipselect.
+Optional properties:
+- clock-frequency : input clock frequency to the core.
+- baud-width: width, in bits, of the programmable divider used to scale
+ the input clock to SCLK.
+
+The clock-frequency and baud-width properties are needed only if the divider
+is programmable. They are not needed if the divider is fixed.
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index bb233a9..43d2a7c 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -231,6 +231,14 @@ config SPI_FSL_ESPI
From MPC8536, 85xx platform uses the controller, and all P10xx,
P20xx, P30xx,P40xx, P50xx uses this controller.

+config SPI_OC_TINY
+ tristate "OpenCores tiny SPI"
+ default n
+ depends on GENERIC_GPIO
+ select SPI_BITBANG
+ help
+ This is the driver for OpenCores tiny SPI master controller.
+
config SPI_OMAP_UWIRE
tristate "OMAP1 MicroWire"
depends on ARCH_OMAP1
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 86d1b5f..c7e4c23 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_IMX) += spi_imx.o
obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o
obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o
obj-$(CONFIG_SPI_PXA2XX_PCI) += pxa2xx_spi_pci.o
+obj-$(CONFIG_SPI_OC_TINY) += spi_oc_tiny.o
obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o
obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o
obj-$(CONFIG_SPI_OMAP_100K) += omap_spi_100k.o
diff --git a/drivers/spi/spi_oc_tiny.c b/drivers/spi/spi_oc_tiny.c
new file mode 100644
index 0000000..62a5267
--- /dev/null
+++ b/drivers/spi/spi_oc_tiny.c
@@ -0,0 +1,424 @@
+/*
+ * OpenCores tiny SPI master driver
+ *
+ * http://opencores.org/project,tiny_spi
+ *
+ * Copyright (C) 2011 Thomas Chou <[email protected]>
+ *
+ * Based on spi_s3c24xx.c, which is:
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ * Ben Dooks <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/spi_oc_tiny.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+
+#define DRV_NAME "spi_oc_tiny"
+
+#define TINY_SPI_RXDATA 0
+#define TINY_SPI_TXDATA 4
+#define TINY_SPI_STATUS 8
+#define TINY_SPI_CONTROL 12
+#define TINY_SPI_BAUD 16
+
+#define TINY_SPI_STATUS_TXE 0x1
+#define TINY_SPI_STATUS_TXR 0x2
+
+struct tiny_spi {
+ /* bitbang has to be first */
+ struct spi_bitbang bitbang;
+ struct completion done;
+
+ void __iomem *base;
+ int irq;
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int baud;
+ unsigned int speed_hz;
+ unsigned int mode;
+ unsigned int len;
+ unsigned int txc, rxc;
+ const u8 *txp;
+ u8 *rxp;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev)
+{
+ return spi_master_get_devdata(sdev->master);
+}
+
+static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
+}
+
+static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (hw->gpio_cs_count) {
+ gpio_set_value(hw->gpio_cs[spi->chip_select],
+ (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
+ }
+}
+
+static int tiny_spi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ unsigned int baud = hw->baud;
+
+ if (t) {
+ if (t->speed_hz && t->speed_hz != hw->speed_hz)
+ baud = tiny_spi_baud(spi, t->speed_hz);
+ }
+ writel(baud, hw->base + TINY_SPI_BAUD);
+ writel(hw->mode, hw->base + TINY_SPI_CONTROL);
+ return 0;
+}
+
+static int tiny_spi_setup(struct spi_device *spi)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (spi->max_speed_hz != hw->speed_hz) {
+ hw->speed_hz = spi->max_speed_hz;
+ hw->baud = tiny_spi_baud(spi, hw->speed_hz);
+ }
+ hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
+ return 0;
+}
+
+static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXR))
+ cpu_relax();
+}
+
+static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXE))
+ cpu_relax();
+}
+
+static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ const u8 *txp = t->tx_buf;
+ u8 *rxp = t->rx_buf;
+ unsigned int i;
+
+ if (hw->irq >= 0) {
+ /* use intrrupt driven data transfer */
+ hw->len = t->len;
+ hw->txp = t->tx_buf;
+ hw->rxp = t->rx_buf;
+ hw->txc = 0;
+ hw->rxc = 0;
+
+ /* send the first byte */
+ if (t->len > 1) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
+ }
+
+ wait_for_completion(&hw->done);
+ } else if (txp && rxp) {
+ /* we need to tighten the transfer loop */
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx, tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (rxp) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0,
+ hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (txp) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ } else {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ tiny_spi_wait_txr(hw);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ }
+ return t->len;
+}
+
+static irqreturn_t tiny_spi_irq(int irq, void *dev)
+{
+ struct tiny_spi *hw = dev;
+
+ writeb(0, hw->base + TINY_SPI_STATUS);
+ if (hw->rxc + 1 == hw->len) {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ hw->rxc++;
+ complete(&hw->done);
+ } else {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ hw->rxc++;
+ if (hw->txc < hw->len) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR,
+ hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(TINY_SPI_STATUS_TXE,
+ hw->base + TINY_SPI_STATUS);
+ }
+ }
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_OF
+#include <linux/of_gpio.h>
+
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct device_node *np = pdev->dev.of_node;
+ unsigned int i;
+ const __be32 *val;
+ int len;
+
+ if (!np)
+ return 0;
+ hw->gpio_cs_count = of_gpio_count(np);
+ if (hw->gpio_cs_count) {
+ hw->gpio_cs = devm_kzalloc(&pdev->dev,
+ hw->gpio_cs_count * sizeof(unsigned int),
+ GFP_KERNEL);
+ if (!hw->gpio_cs)
+ return -ENOMEM;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ hw->gpio_cs[i] = of_get_gpio_flags(np, i, NULL);
+ if (hw->gpio_cs[i] < 0)
+ return -ENODEV;
+ }
+ hw->bitbang.master->dev.of_node = pdev->dev.of_node;
+ val = of_get_property(pdev->dev.of_node,
+ "clock-frequency", &len);
+ if (val && len >= sizeof(__be32))
+ hw->freq = be32_to_cpup(val);
+ val = of_get_property(pdev->dev.of_node, "baud-width", &len);
+ if (val && len >= sizeof(__be32))
+ hw->baudwidth = be32_to_cpup(val);
+ return 0;
+}
+#else /* !CONFIG_OF */
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ return 0;
+}
+#endif /* CONFIG_OF */
+
+static int __devinit tiny_spi_probe(struct platform_device *pdev)
+{
+ struct tiny_spi_platform_data *platp = pdev->dev.platform_data;
+ struct tiny_spi *hw;
+ struct spi_master *master;
+ struct resource *res;
+ unsigned int i;
+ int err = -ENODEV;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
+ if (!master)
+ return err;
+
+ /* setup the master state. */
+ master->bus_num = pdev->id;
+ master->num_chipselect = 255;
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ master->setup = tiny_spi_setup;
+
+ hw = spi_master_get_devdata(master);
+ platform_set_drvdata(pdev, hw);
+
+ /* setup the state for the bitbang driver */
+ hw->bitbang.master = spi_master_get(master);
+ if (!hw->bitbang.master)
+ return err;
+ hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
+ hw->bitbang.chipselect = tiny_spi_chipselect;
+ hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;
+
+ /* find and map our resources */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ goto exit_busy;
+ if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
+ pdev->name))
+ goto exit_busy;
+ hw->base = devm_ioremap_nocache(&pdev->dev, res->start,
+ resource_size(res));
+ if (!hw->base)
+ goto exit_busy;
+ /* irq is optional */
+ hw->irq = platform_get_irq(pdev, 0);
+ if (hw->irq >= 0) {
+ init_completion(&hw->done);
+ err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
+ pdev->name, hw);
+ if (err)
+ goto exit;
+ }
+ /* find platform data */
+ if (platp) {
+ hw->gpio_cs_count = platp->gpio_cs_count;
+ hw->gpio_cs = platp->gpio_cs;
+ if (platp->gpio_cs_count && !platp->gpio_cs)
+ goto exit_busy;
+ hw->freq = platp->freq;
+ hw->baudwidth = platp->baudwidth;
+ } else {
+ err = tiny_spi_of_probe(pdev);
+ if (err)
+ goto exit;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
+ if (err)
+ goto exit_gpio;
+ gpio_direction_output(hw->gpio_cs[i], 1);
+ }
+ if (hw->gpio_cs_count)
+ hw->bitbang.master->num_chipselect = hw->gpio_cs_count;
+ else
+ hw->bitbang.master->num_chipselect = 1; /* no chipselect pin */
+
+ /* register our spi controller */
+ err = spi_bitbang_start(&hw->bitbang);
+ if (err)
+ goto exit;
+ dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
+
+ return 0;
+
+exit_gpio:
+ while (i-- > 0)
+ gpio_free(hw->gpio_cs[i]);
+exit_busy:
+ err = -EBUSY;
+exit:
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return err;
+}
+
+static int __devexit tiny_spi_remove(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct spi_master *master = hw->bitbang.master;
+ unsigned int i;
+
+ spi_bitbang_stop(&hw->bitbang);
+ for (i = 0; i < hw->gpio_cs_count; i++)
+ gpio_free(hw->gpio_cs[i]);
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return 0;
+}
+
+static const struct of_device_id tiny_spi_match[] = {
+ { .compatible = "opencores,tiny-spi-rtlsvn2", },
+ {},
+}
+MODULE_DEVICE_TABLE(of, tiny_spi_match);
+
+static struct platform_driver tiny_spi_driver = {
+ .probe = tiny_spi_probe,
+ .remove = __devexit_p(tiny_spi_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .pm = NULL,
+ .of_match_table = tiny_spi_match,
+ },
+};
+
+static int __init tiny_spi_init(void)
+{
+ return platform_driver_register(&tiny_spi_driver);
+}
+module_init(tiny_spi_init);
+
+static void __exit tiny_spi_exit(void)
+{
+ platform_driver_unregister(&tiny_spi_driver);
+}
+module_exit(tiny_spi_exit);
+
+MODULE_DESCRIPTION("OpenCores tiny SPI driver");
+MODULE_AUTHOR("Thomas Chou <[email protected]>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/include/linux/spi/spi_oc_tiny.h b/include/linux/spi/spi_oc_tiny.h
new file mode 100644
index 0000000..1ac529c
--- /dev/null
+++ b/include/linux/spi/spi_oc_tiny.h
@@ -0,0 +1,20 @@
+#ifndef _LINUX_SPI_SPI_OC_TINY_H
+#define _LINUX_SPI_SPI_OC_TINY_H
+
+/**
+ * struct tiny_spi_platform_data - platform data of the OpenCores tiny SPI
+ * @freq: input clock freq to the core.
+ * @baudwidth: baud rate divider width of the core.
+ * @gpio_cs_count: number of gpio pins used for chipselect.
+ * @gpio_cs: array of gpio pins used for chipselect.
+ *
+ * freq and baudwidth are used only if the divider is programmable.
+ */
+struct tiny_spi_platform_data {
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+#endif /* _LINUX_SPI_SPI_OC_TINY_H */
--
1.7.3.5

2011-02-08 05:40:52

by Thomas Chou

Subject: [PATCH v7] spi: add OpenCores tiny SPI driver

This patch adds support of OpenCores tiny SPI driver.

http://opencores.org/project,tiny_spi

Signed-off-by: Thomas Chou <[email protected]>
---
v2 minor cleanup, same as Grant suggest for spi_altera.
v3 rename driver to spi_oc_tiny as Grant suggested.
set version to tiny-spi-rtlsvn2 as Jonas suggested.
v4 add dts binding doc.
v5 use devm_* to help cleanup.
add of gpio support.
v6 check len from of_get_property.
fix kerneldoc in header.
v7 remove default n from Kconfig.

.../devicetree/bindings/spi/spi_oc_tiny.txt | 12 +
drivers/spi/Kconfig | 7 +
drivers/spi/Makefile | 1 +
drivers/spi/spi_oc_tiny.c | 421 ++++++++++++++++++++
include/linux/spi/spi_oc_tiny.h | 20 +
5 files changed, 461 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
create mode 100644 drivers/spi/spi_oc_tiny.c
create mode 100644 include/linux/spi/spi_oc_tiny.h

diff --git a/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
new file mode 100644
index 0000000..d95c0b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
@@ -0,0 +1,12 @@
+OpenCores tiny SPI
+
+Required properties:
+- compatible : should be "opencores,tiny-spi-rtlsvn2".
+- gpios : should specify GPIOs used for chipselect.
+Optional properties:
+- clock-frequency : input clock frequency to the core.
+- baud-width: width, in bits, of the programmable divider used to scale
+ the input clock to SCLK.
+
+The clock-frequency and baud-width properties are needed only if the divider
+is programmable. They are not needed if the divider is fixed.
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index bb233a9..8faa57a 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -231,6 +231,13 @@ config SPI_FSL_ESPI
From MPC8536, 85xx platform uses the controller, and all P10xx,
P20xx, P30xx,P40xx, P50xx uses this controller.

+config SPI_OC_TINY
+ tristate "OpenCores tiny SPI"
+ depends on GENERIC_GPIO
+ select SPI_BITBANG
+ help
+ This is the driver for OpenCores tiny SPI master controller.
+
config SPI_OMAP_UWIRE
tristate "OMAP1 MicroWire"
depends on ARCH_OMAP1
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 86d1b5f..c7e4c23 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_IMX) += spi_imx.o
obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o
obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o
obj-$(CONFIG_SPI_PXA2XX_PCI) += pxa2xx_spi_pci.o
+obj-$(CONFIG_SPI_OC_TINY) += spi_oc_tiny.o
obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o
obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o
obj-$(CONFIG_SPI_OMAP_100K) += omap_spi_100k.o
diff --git a/drivers/spi/spi_oc_tiny.c b/drivers/spi/spi_oc_tiny.c
new file mode 100644
index 0000000..fa82b90
--- /dev/null
+++ b/drivers/spi/spi_oc_tiny.c
@@ -0,0 +1,421 @@
+/*
+ * OpenCores tiny SPI master driver
+ *
+ * http://opencores.org/project,tiny_spi
+ *
+ * Copyright (C) 2011 Thomas Chou <[email protected]>
+ *
+ * Based on spi_s3c24xx.c, which is:
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ * Ben Dooks <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/spi_oc_tiny.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+
+#define DRV_NAME "spi_oc_tiny"
+
+#define TINY_SPI_RXDATA 0
+#define TINY_SPI_TXDATA 4
+#define TINY_SPI_STATUS 8
+#define TINY_SPI_CONTROL 12
+#define TINY_SPI_BAUD 16
+
+#define TINY_SPI_STATUS_TXE 0x1
+#define TINY_SPI_STATUS_TXR 0x2
+
+struct tiny_spi {
+ /* bitbang has to be first */
+ struct spi_bitbang bitbang;
+ struct completion done;
+
+ void __iomem *base;
+ int irq;
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int baud;
+ unsigned int speed_hz;
+ unsigned int mode;
+ unsigned int len;
+ unsigned int txc, rxc;
+ const u8 *txp;
+ u8 *rxp;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev)
+{
+ return spi_master_get_devdata(sdev->master);
+}
+
+static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
+}
+
+static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (hw->gpio_cs_count) {
+ gpio_set_value(hw->gpio_cs[spi->chip_select],
+ (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
+ }
+}
+
+static int tiny_spi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ unsigned int baud = hw->baud;
+
+ if (t) {
+ if (t->speed_hz && t->speed_hz != hw->speed_hz)
+ baud = tiny_spi_baud(spi, t->speed_hz);
+ }
+ writel(baud, hw->base + TINY_SPI_BAUD);
+ writel(hw->mode, hw->base + TINY_SPI_CONTROL);
+ return 0;
+}
+
+static int tiny_spi_setup(struct spi_device *spi)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (spi->max_speed_hz != hw->speed_hz) {
+ hw->speed_hz = spi->max_speed_hz;
+ hw->baud = tiny_spi_baud(spi, hw->speed_hz);
+ }
+ hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
+ return 0;
+}
+
+static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXR))
+ cpu_relax();
+}
+
+static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXE))
+ cpu_relax();
+}
+
+static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ const u8 *txp = t->tx_buf;
+ u8 *rxp = t->rx_buf;
+ unsigned int i;
+
+ if (hw->irq >= 0) {
+ /* use intrrupt driven data transfer */
+ hw->len = t->len;
+ hw->txp = t->tx_buf;
+ hw->rxp = t->rx_buf;
+ hw->txc = 0;
+ hw->rxc = 0;
+
+ /* send the first byte */
+ if (t->len > 1) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
+ }
+
+ wait_for_completion(&hw->done);
+ } else if (txp && rxp) {
+ /* we need to tighten the transfer loop */
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx, tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (rxp) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0,
+ hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (txp) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ } else {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ tiny_spi_wait_txr(hw);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ }
+ return t->len;
+}
+
+static irqreturn_t tiny_spi_irq(int irq, void *dev)
+{
+ struct tiny_spi *hw = dev;
+
+ writeb(0, hw->base + TINY_SPI_STATUS);
+ if (hw->rxc + 1 == hw->len) {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ hw->rxc++;
+ complete(&hw->done);
+ } else {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ hw->rxc++;
+ if (hw->txc < hw->len) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR,
+ hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(TINY_SPI_STATUS_TXE,
+ hw->base + TINY_SPI_STATUS);
+ }
+ }
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_OF
+#include <linux/of_gpio.h>
+
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct device_node *np = pdev->dev.of_node;
+ unsigned int i;
+ const __be32 *val;
+ int len;
+
+ if (!np)
+ return 0;
+ hw->gpio_cs_count = of_gpio_count(np);
+ if (hw->gpio_cs_count) {
+ hw->gpio_cs = devm_kzalloc(&pdev->dev,
+ hw->gpio_cs_count * sizeof(unsigned int),
+ GFP_KERNEL);
+ if (!hw->gpio_cs)
+ return -ENOMEM;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ hw->gpio_cs[i] = of_get_gpio_flags(np, i, NULL);
+ if (hw->gpio_cs[i] < 0)
+ return -ENODEV;
+ }
+ hw->bitbang.master->dev.of_node = pdev->dev.of_node;
+ val = of_get_property(pdev->dev.of_node,
+ "clock-frequency", &len);
+ if (val && len >= sizeof(__be32))
+ hw->freq = be32_to_cpup(val);
+ val = of_get_property(pdev->dev.of_node, "baud-width", &len);
+ if (val && len >= sizeof(__be32))
+ hw->baudwidth = be32_to_cpup(val);
+ return 0;
+}
+#else /* !CONFIG_OF */
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ return 0;
+}
+#endif /* CONFIG_OF */
+
+static int __devinit tiny_spi_probe(struct platform_device *pdev)
+{
+ struct tiny_spi_platform_data *platp = pdev->dev.platform_data;
+ struct tiny_spi *hw;
+ struct spi_master *master;
+ struct resource *res;
+ unsigned int i;
+ int err = -ENODEV;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
+ if (!master)
+ return err;
+
+ /* setup the master state. */
+ master->bus_num = pdev->id;
+ master->num_chipselect = 255;
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ master->setup = tiny_spi_setup;
+
+ hw = spi_master_get_devdata(master);
+ platform_set_drvdata(pdev, hw);
+
+ /* setup the state for the bitbang driver */
+ hw->bitbang.master = spi_master_get(master);
+ if (!hw->bitbang.master)
+ return err;
+ hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
+ hw->bitbang.chipselect = tiny_spi_chipselect;
+ hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;
+
+ /* find and map our resources */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ goto exit_busy;
+ if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
+ pdev->name))
+ goto exit_busy;
+ hw->base = devm_ioremap_nocache(&pdev->dev, res->start,
+ resource_size(res));
+ if (!hw->base)
+ goto exit_busy;
+ /* irq is optional */
+ hw->irq = platform_get_irq(pdev, 0);
+ if (hw->irq >= 0) {
+ init_completion(&hw->done);
+ err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
+ pdev->name, hw);
+ if (err)
+ goto exit;
+ }
+ /* find platform data */
+ if (platp) {
+ hw->gpio_cs_count = platp->gpio_cs_count;
+ hw->gpio_cs = platp->gpio_cs;
+ if (platp->gpio_cs_count && !platp->gpio_cs)
+ goto exit_busy;
+ hw->freq = platp->freq;
+ hw->baudwidth = platp->baudwidth;
+ } else {
+ err = tiny_spi_of_probe(pdev);
+ if (err)
+ goto exit;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
+ if (err)
+ goto exit_gpio;
+ gpio_direction_output(hw->gpio_cs[i], 1);
+ }
+ hw->bitbang.master->num_chipselect = max(1U, hw->gpio_cs_count);
+
+ /* register our spi controller */
+ err = spi_bitbang_start(&hw->bitbang);
+ if (err)
+ goto exit;
+ dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
+
+ return 0;
+
+exit_gpio:
+ while (i-- > 0)
+ gpio_free(hw->gpio_cs[i]);
+exit_busy:
+ err = -EBUSY;
+exit:
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return err;
+}
+
+static int __devexit tiny_spi_remove(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct spi_master *master = hw->bitbang.master;
+ unsigned int i;
+
+ spi_bitbang_stop(&hw->bitbang);
+ for (i = 0; i < hw->gpio_cs_count; i++)
+ gpio_free(hw->gpio_cs[i]);
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return 0;
+}
+
+static const struct of_device_id tiny_spi_match[] = {
+ { .compatible = "opencores,tiny-spi-rtlsvn2", },
+ {},
+}
+MODULE_DEVICE_TABLE(of, tiny_spi_match);
+
+static struct platform_driver tiny_spi_driver = {
+ .probe = tiny_spi_probe,
+ .remove = __devexit_p(tiny_spi_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .pm = NULL,
+ .of_match_table = tiny_spi_match,
+ },
+};
+
+static int __init tiny_spi_init(void)
+{
+ return platform_driver_register(&tiny_spi_driver);
+}
+module_init(tiny_spi_init);
+
+static void __exit tiny_spi_exit(void)
+{
+ platform_driver_unregister(&tiny_spi_driver);
+}
+module_exit(tiny_spi_exit);
+
+MODULE_DESCRIPTION("OpenCores tiny SPI driver");
+MODULE_AUTHOR("Thomas Chou <[email protected]>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/include/linux/spi/spi_oc_tiny.h b/include/linux/spi/spi_oc_tiny.h
new file mode 100644
index 0000000..1ac529c
--- /dev/null
+++ b/include/linux/spi/spi_oc_tiny.h
@@ -0,0 +1,20 @@
+#ifndef _LINUX_SPI_SPI_OC_TINY_H
+#define _LINUX_SPI_SPI_OC_TINY_H
+
+/**
+ * struct tiny_spi_platform_data - platform data of the OpenCores tiny SPI
+ * @freq: input clock freq to the core.
+ * @baudwidth: baud rate divider width of the core.
+ * @gpio_cs_count: number of gpio pins used for chipselect.
+ * @gpio_cs: array of gpio pins used for chipselect.
+ *
+ * freq and baudwidth are used only if the divider is programmable.
+ */
+struct tiny_spi_platform_data {
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+#endif /* _LINUX_SPI_SPI_OC_TINY_H */
--
1.7.4

2011-02-12 09:31:35

by Grant Likely

Subject: Re: [PATCH v7] spi: add OpenCores tiny SPI driver

On Tue, Feb 08, 2011 at 01:43:23PM +0800, Thomas Chou wrote:
> This patch adds support of OpenCores tiny SPI driver.
>
> http://opencores.org/project,tiny_spi
>
> Signed-off-by: Thomas Chou <[email protected]>
> ---
> v2 minor cleanup, same as Grant suggest for spi_altera.
> v3 rename driver to spi_oc_tiny as Grant suggested.
> set version to tiny-spi-rtlsvn2 as Jonas suggested.
> v4 add dts binding doc.
> v5 use devm_* to help cleanup.
> add of gpio support.
> v6 check len from of_get_property.
> fix kerneldoc in header.
> v7 remove default n from Kconfig.
>
> .../devicetree/bindings/spi/spi_oc_tiny.txt | 12 +
> drivers/spi/Kconfig | 7 +
> drivers/spi/Makefile | 1 +
> drivers/spi/spi_oc_tiny.c | 421 ++++++++++++++++++++
> include/linux/spi/spi_oc_tiny.h | 20 +
> 5 files changed, 461 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
> create mode 100644 drivers/spi/spi_oc_tiny.c
> create mode 100644 include/linux/spi/spi_oc_tiny.h

Hi Thomas

Still need documentation on the binding in
Documentation/devicetree/bindings before I pick up this driver. This
goes for all the new drivers with dt bindings.

g.

>
> diff --git a/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
> new file mode 100644
> index 0000000..d95c0b3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
> @@ -0,0 +1,12 @@
> +OpenCores tiny SPI
> +
> +Required properties:
> +- compatible : should be "opencores,tiny-spi-rtlsvn2".
> +- gpios : should specify GPIOs used for chipselect.
> +Optional properties:
> +- clock-frequency : input clock frequency to the core.
> +- baud-width: width, in bits, of the programmable divider used to scale
> + the input clock to SCLK.
> +
> +The clock-frequency and baud-width properties are needed only if the divider
> +is programmable. They are not needed if the divider is fixed.
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index bb233a9..8faa57a 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -231,6 +231,13 @@ config SPI_FSL_ESPI
> From MPC8536, 85xx platform uses the controller, and all P10xx,
> P20xx, P30xx,P40xx, P50xx uses this controller.
>
> +config SPI_OC_TINY
> + tristate "OpenCores tiny SPI"
> + depends on GENERIC_GPIO
> + select SPI_BITBANG
> + help
> + This is the driver for OpenCores tiny SPI master controller.
> +
> config SPI_OMAP_UWIRE
> tristate "OMAP1 MicroWire"
> depends on ARCH_OMAP1
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index 86d1b5f..c7e4c23 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_IMX) += spi_imx.o
> obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o
> obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o
> obj-$(CONFIG_SPI_PXA2XX_PCI) += pxa2xx_spi_pci.o
> +obj-$(CONFIG_SPI_OC_TINY) += spi_oc_tiny.o
> obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o
> obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o
> obj-$(CONFIG_SPI_OMAP_100K) += omap_spi_100k.o
> diff --git a/drivers/spi/spi_oc_tiny.c b/drivers/spi/spi_oc_tiny.c
> new file mode 100644
> index 0000000..fa82b90
> --- /dev/null
> +++ b/drivers/spi/spi_oc_tiny.c
> @@ -0,0 +1,421 @@
> +/*
> + * OpenCores tiny SPI master driver
> + *
> + * http://opencores.org/project,tiny_spi
> + *
> + * Copyright (C) 2011 Thomas Chou <[email protected]>
> + *
> + * Based on spi_s3c24xx.c, which is:
> + * Copyright (c) 2006 Ben Dooks
> + * Copyright (c) 2006 Simtec Electronics
> + * Ben Dooks <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/errno.h>
> +#include <linux/platform_device.h>
> +#include <linux/spi/spi.h>
> +#include <linux/spi/spi_bitbang.h>
> +#include <linux/spi/spi_oc_tiny.h>
> +#include <linux/io.h>
> +#include <linux/gpio.h>
> +#include <linux/of.h>
> +
> +#define DRV_NAME "spi_oc_tiny"
> +
> +#define TINY_SPI_RXDATA 0
> +#define TINY_SPI_TXDATA 4
> +#define TINY_SPI_STATUS 8
> +#define TINY_SPI_CONTROL 12
> +#define TINY_SPI_BAUD 16
> +
> +#define TINY_SPI_STATUS_TXE 0x1
> +#define TINY_SPI_STATUS_TXR 0x2
> +
> +struct tiny_spi {
> + /* bitbang has to be first */
> + struct spi_bitbang bitbang;
> + struct completion done;
> +
> + void __iomem *base;
> + int irq;
> + unsigned int freq;
> + unsigned int baudwidth;
> + unsigned int baud;
> + unsigned int speed_hz;
> + unsigned int mode;
> + unsigned int len;
> + unsigned int txc, rxc;
> + const u8 *txp;
> + u8 *rxp;
> + unsigned int gpio_cs_count;
> + int *gpio_cs;
> +};
> +
> +static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev)
> +{
> + return spi_master_get_devdata(sdev->master);
> +}
> +
> +static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> +
> + return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
> +}
> +
> +static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> +
> + if (hw->gpio_cs_count) {
> + gpio_set_value(hw->gpio_cs[spi->chip_select],
> + (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
> + }
> +}
> +
> +static int tiny_spi_setup_transfer(struct spi_device *spi,
> + struct spi_transfer *t)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> + unsigned int baud = hw->baud;
> +
> + if (t) {
> + if (t->speed_hz && t->speed_hz != hw->speed_hz)
> + baud = tiny_spi_baud(spi, t->speed_hz);
> + }
> + writel(baud, hw->base + TINY_SPI_BAUD);
> + writel(hw->mode, hw->base + TINY_SPI_CONTROL);
> + return 0;
> +}
> +
> +static int tiny_spi_setup(struct spi_device *spi)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> +
> + if (spi->max_speed_hz != hw->speed_hz) {
> + hw->speed_hz = spi->max_speed_hz;
> + hw->baud = tiny_spi_baud(spi, hw->speed_hz);
> + }
> + hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
> + return 0;
> +}
> +
> +static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
> +{
> + while (!(readb(hw->base + TINY_SPI_STATUS) &
> + TINY_SPI_STATUS_TXR))
> + cpu_relax();
> +}
> +
> +static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
> +{
> + while (!(readb(hw->base + TINY_SPI_STATUS) &
> + TINY_SPI_STATUS_TXE))
> + cpu_relax();
> +}
> +
> +static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> + const u8 *txp = t->tx_buf;
> + u8 *rxp = t->rx_buf;
> + unsigned int i;
> +
> + if (hw->irq >= 0) {
> + /* use intrrupt driven data transfer */
> + hw->len = t->len;
> + hw->txp = t->tx_buf;
> + hw->rxp = t->rx_buf;
> + hw->txc = 0;
> + hw->rxc = 0;
> +
> + /* send the first byte */
> + if (t->len > 1) {
> + writeb(hw->txp ? *hw->txp++ : 0,
> + hw->base + TINY_SPI_TXDATA);
> + hw->txc++;
> + writeb(hw->txp ? *hw->txp++ : 0,
> + hw->base + TINY_SPI_TXDATA);
> + hw->txc++;
> + writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
> + } else {
> + writeb(hw->txp ? *hw->txp++ : 0,
> + hw->base + TINY_SPI_TXDATA);
> + hw->txc++;
> + writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
> + }
> +
> + wait_for_completion(&hw->done);
> + } else if (txp && rxp) {
> + /* we need to tighten the transfer loop */
> + writeb(*txp++, hw->base + TINY_SPI_TXDATA);
> + if (t->len > 1) {
> + writeb(*txp++, hw->base + TINY_SPI_TXDATA);
> + for (i = 2; i < t->len; i++) {
> + u8 rx, tx = *txp++;
> + tiny_spi_wait_txr(hw);
> + rx = readb(hw->base + TINY_SPI_TXDATA);
> + writeb(tx, hw->base + TINY_SPI_TXDATA);
> + *rxp++ = rx;
> + }
> + tiny_spi_wait_txr(hw);
> + *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
> + }
> + tiny_spi_wait_txe(hw);
> + *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
> + } else if (rxp) {
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + if (t->len > 1) {
> + writeb(0,
> + hw->base + TINY_SPI_TXDATA);
> + for (i = 2; i < t->len; i++) {
> + u8 rx;
> + tiny_spi_wait_txr(hw);
> + rx = readb(hw->base + TINY_SPI_TXDATA);
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + *rxp++ = rx;
> + }
> + tiny_spi_wait_txr(hw);
> + *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
> + }
> + tiny_spi_wait_txe(hw);
> + *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
> + } else if (txp) {
> + writeb(*txp++, hw->base + TINY_SPI_TXDATA);
> + if (t->len > 1) {
> + writeb(*txp++, hw->base + TINY_SPI_TXDATA);
> + for (i = 2; i < t->len; i++) {
> + u8 tx = *txp++;
> + tiny_spi_wait_txr(hw);
> + writeb(tx, hw->base + TINY_SPI_TXDATA);
> + }
> + }
> + tiny_spi_wait_txe(hw);
> + } else {
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + if (t->len > 1) {
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + for (i = 2; i < t->len; i++) {
> + tiny_spi_wait_txr(hw);
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + }
> + }
> + tiny_spi_wait_txe(hw);
> + }
> + return t->len;
> +}
> +
> +static irqreturn_t tiny_spi_irq(int irq, void *dev)
> +{
> + struct tiny_spi *hw = dev;
> +
> + writeb(0, hw->base + TINY_SPI_STATUS);
> + if (hw->rxc + 1 == hw->len) {
> + if (hw->rxp)
> + *hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
> + hw->rxc++;
> + complete(&hw->done);
> + } else {
> + if (hw->rxp)
> + *hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
> + hw->rxc++;
> + if (hw->txc < hw->len) {
> + writeb(hw->txp ? *hw->txp++ : 0,
> + hw->base + TINY_SPI_TXDATA);
> + hw->txc++;
> + writeb(TINY_SPI_STATUS_TXR,
> + hw->base + TINY_SPI_STATUS);
> + } else {
> + writeb(TINY_SPI_STATUS_TXE,
> + hw->base + TINY_SPI_STATUS);
> + }
> + }
> + return IRQ_HANDLED;
> +}
> +
> +#ifdef CONFIG_OF
> +#include <linux/of_gpio.h>
> +
> +static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
> +{
> + struct tiny_spi *hw = platform_get_drvdata(pdev);
> + struct device_node *np = pdev->dev.of_node;
> + unsigned int i;
> + const __be32 *val;
> + int len;
> +
> + if (!np)
> + return 0;
> + hw->gpio_cs_count = of_gpio_count(np);
> + if (hw->gpio_cs_count) {
> + hw->gpio_cs = devm_kzalloc(&pdev->dev,
> + hw->gpio_cs_count * sizeof(unsigned int),
> + GFP_KERNEL);
> + if (!hw->gpio_cs)
> + return -ENOMEM;
> + }
> + for (i = 0; i < hw->gpio_cs_count; i++) {
> + hw->gpio_cs[i] = of_get_gpio_flags(np, i, NULL);
> + if (hw->gpio_cs[i] < 0)
> + return -ENODEV;
> + }
> + hw->bitbang.master->dev.of_node = pdev->dev.of_node;
> + val = of_get_property(pdev->dev.of_node,
> + "clock-frequency", &len);
> + if (val && len >= sizeof(__be32))
> + hw->freq = be32_to_cpup(val);
> + val = of_get_property(pdev->dev.of_node, "baud-width", &len);
> + if (val && len >= sizeof(__be32))
> + hw->baudwidth = be32_to_cpup(val);
> + return 0;
> +}
> +#else /* !CONFIG_OF */
> +static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
> +{
> + return 0;
> +}
> +#endif /* CONFIG_OF */
> +
> +static int __devinit tiny_spi_probe(struct platform_device *pdev)
> +{
> + struct tiny_spi_platform_data *platp = pdev->dev.platform_data;
> + struct tiny_spi *hw;
> + struct spi_master *master;
> + struct resource *res;
> + unsigned int i;
> + int err = -ENODEV;
> +
> + master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
> + if (!master)
> + return err;
> +
> + /* setup the master state. */
> + master->bus_num = pdev->id;
> + master->num_chipselect = 255;
> + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
> + master->setup = tiny_spi_setup;
> +
> + hw = spi_master_get_devdata(master);
> + platform_set_drvdata(pdev, hw);
> +
> + /* setup the state for the bitbang driver */
> + hw->bitbang.master = spi_master_get(master);
> + if (!hw->bitbang.master)
> + return err;
> + hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
> + hw->bitbang.chipselect = tiny_spi_chipselect;
> + hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;
> +
> + /* find and map our resources */
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + goto exit_busy;
> + if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
> + pdev->name))
> + goto exit_busy;
> + hw->base = devm_ioremap_nocache(&pdev->dev, res->start,
> + resource_size(res));
> + if (!hw->base)
> + goto exit_busy;
> + /* irq is optional */
> + hw->irq = platform_get_irq(pdev, 0);
> + if (hw->irq >= 0) {
> + init_completion(&hw->done);
> + err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
> + pdev->name, hw);
> + if (err)
> + goto exit;
> + }
> + /* find platform data */
> + if (platp) {
> + hw->gpio_cs_count = platp->gpio_cs_count;
> + hw->gpio_cs = platp->gpio_cs;
> + if (platp->gpio_cs_count && !platp->gpio_cs)
> + goto exit_busy;
> + hw->freq = platp->freq;
> + hw->baudwidth = platp->baudwidth;
> + } else {
> + err = tiny_spi_of_probe(pdev);
> + if (err)
> + goto exit;
> + }
> + for (i = 0; i < hw->gpio_cs_count; i++) {
> + err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
> + if (err)
> + goto exit_gpio;
> + gpio_direction_output(hw->gpio_cs[i], 1);
> + }
> + hw->bitbang.master->num_chipselect = max(1U, hw->gpio_cs_count);
> +
> + /* register our spi controller */
> + err = spi_bitbang_start(&hw->bitbang);
> + if (err)
> + goto exit;
> + dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
> +
> + return 0;
> +
> +exit_gpio:
> + while (i-- > 0)
> + gpio_free(hw->gpio_cs[i]);
> +exit_busy:
> + err = -EBUSY;
> +exit:
> + platform_set_drvdata(pdev, NULL);
> + spi_master_put(master);
> + return err;
> +}
> +
> +static int __devexit tiny_spi_remove(struct platform_device *pdev)
> +{
> + struct tiny_spi *hw = platform_get_drvdata(pdev);
> + struct spi_master *master = hw->bitbang.master;
> + unsigned int i;
> +
> + spi_bitbang_stop(&hw->bitbang);
> + for (i = 0; i < hw->gpio_cs_count; i++)
> + gpio_free(hw->gpio_cs[i]);
> + platform_set_drvdata(pdev, NULL);
> + spi_master_put(master);
> + return 0;
> +}
> +
> +static const struct of_device_id tiny_spi_match[] = {
> + { .compatible = "opencores,tiny-spi-rtlsvn2", },
> + {},
> +}
> +MODULE_DEVICE_TABLE(of, tiny_spi_match);
> +
> +static struct platform_driver tiny_spi_driver = {
> + .probe = tiny_spi_probe,
> + .remove = __devexit_p(tiny_spi_remove),
> + .driver = {
> + .name = DRV_NAME,
> + .owner = THIS_MODULE,
> + .pm = NULL,
> + .of_match_table = tiny_spi_match,
> + },
> +};
> +
> +static int __init tiny_spi_init(void)
> +{
> + return platform_driver_register(&tiny_spi_driver);
> +}
> +module_init(tiny_spi_init);
> +
> +static void __exit tiny_spi_exit(void)
> +{
> + platform_driver_unregister(&tiny_spi_driver);
> +}
> +module_exit(tiny_spi_exit);
> +
> +MODULE_DESCRIPTION("OpenCores tiny SPI driver");
> +MODULE_AUTHOR("Thomas Chou <[email protected]>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:" DRV_NAME);
> diff --git a/include/linux/spi/spi_oc_tiny.h b/include/linux/spi/spi_oc_tiny.h
> new file mode 100644
> index 0000000..1ac529c
> --- /dev/null
> +++ b/include/linux/spi/spi_oc_tiny.h
> @@ -0,0 +1,20 @@
> +#ifndef _LINUX_SPI_SPI_OC_TINY_H
> +#define _LINUX_SPI_SPI_OC_TINY_H
> +
> +/**
> + * struct tiny_spi_platform_data - platform data of the OpenCores tiny SPI
> + * @freq: input clock freq to the core.
> + * @baudwidth: baud rate divider width of the core.
> + * @gpio_cs_count: number of gpio pins used for chipselect.
> + * @gpio_cs: array of gpio pins used for chipselect.
> + *
> + * freq and baudwidth are used only if the divider is programmable.
> + */
> +struct tiny_spi_platform_data {
> + unsigned int freq;
> + unsigned int baudwidth;
> + unsigned int gpio_cs_count;
> + int *gpio_cs;
> +};
> +
> +#endif /* _LINUX_SPI_SPI_OC_TINY_H */
> --
> 1.7.4
>

2011-02-12 09:35:21

by Grant Likely

Subject: Re: [PATCH v7] spi: add OpenCores tiny SPI driver

On Sat, Feb 12, 2011 at 2:31 AM, Grant Likely <[email protected]> wrote:
> On Tue, Feb 08, 2011 at 01:43:23PM +0800, Thomas Chou wrote:
>> This patch adds support of OpenCores tiny SPI driver.
>>
>> http://opencores.org/project,tiny_spi
>>
>> Signed-off-by: Thomas Chou <[email protected]>
>> ---
>> v2 minor cleanup, same as Grant suggest for spi_altera.
>> v3 rename driver to spi_oc_tiny as Grant suggested.
>> set version to tiny-spi-rtlsvn2 as Jonas suggested.
>> v4 add dts binding doc.
>> v5 use devm_* to help cleanup.
>> add of gpio support.
>> v6 check len from of_get_property.
>> fix kerneldoc in header.
>> v7 remove default n from Kconfig.
>>
>> .../devicetree/bindings/spi/spi_oc_tiny.txt | 12 +
>> drivers/spi/Kconfig | 7 +
>> drivers/spi/Makefile | 1 +
>> drivers/spi/spi_oc_tiny.c | 421 ++++++++++++++++++++
>> include/linux/spi/spi_oc_tiny.h | 20 +
>> 5 files changed, 461 insertions(+), 0 deletions(-)
>> create mode 100644 Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
>> create mode 100644 drivers/spi/spi_oc_tiny.c
>> create mode 100644 include/linux/spi/spi_oc_tiny.h
>
> Hi Thomas
>
> Still need documentation on the binding in
> Documentation/devicetree/bindings before I pick up this driver. This
> goes for all the new drivers with dt bindings.

Oops, nevermind. I see it. Sorry for the noise.

g.

2011-02-14 02:13:09

by Thomas Chou

Subject: [PATCH v8] spi: add OpenCores tiny SPI driver

This patch adds support of OpenCores tiny SPI driver.

http://opencores.org/project,tiny_spi

Signed-off-by: Thomas Chou <[email protected]>
---
v2 minor cleanup, same as Grant suggest for spi_altera.
v3 rename driver to spi_oc_tiny as Grant suggested.
set version to tiny-spi-rtlsvn2 as Jonas suggested.
v4 add dts binding doc.
v5 use devm_* to help cleanup.
add of gpio support.
v6 check len from of_get_property.
fix kerneldoc in header.
v7 remove default n from Kconfig.
v8 condition module device table export for of.

.../devicetree/bindings/spi/spi_oc_tiny.txt | 12 +
drivers/spi/Kconfig | 7 +
drivers/spi/Makefile | 1 +
drivers/spi/spi_oc_tiny.c | 421 ++++++++++++++++++++
include/linux/spi/spi_oc_tiny.h | 20 +
5 files changed, 461 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
create mode 100644 drivers/spi/spi_oc_tiny.c
create mode 100644 include/linux/spi/spi_oc_tiny.h

diff --git a/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
new file mode 100644
index 0000000..d95c0b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
@@ -0,0 +1,12 @@
+OpenCores tiny SPI
+
+Required properties:
+- compatible : should be "opencores,tiny-spi-rtlsvn2".
+- gpios : should specify GPIOs used for chipselect.
+Optional properties:
+- clock-frequency : input clock frequency to the core.
+- baud-width: width, in bits, of the programmable divider used to scale
+ the input clock to SCLK.
+
+The clock-frequency and baud-width properties are needed only if the divider
+is programmable. They are not needed if the divider is fixed.
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index bb233a9..8faa57a 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -231,6 +231,13 @@ config SPI_FSL_ESPI
From MPC8536, 85xx platform uses the controller, and all P10xx,
P20xx, P30xx,P40xx, P50xx uses this controller.

+config SPI_OC_TINY
+ tristate "OpenCores tiny SPI"
+ depends on GENERIC_GPIO
+ select SPI_BITBANG
+ help
+ This is the driver for OpenCores tiny SPI master controller.
+
config SPI_OMAP_UWIRE
tristate "OMAP1 MicroWire"
depends on ARCH_OMAP1
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 86d1b5f..c7e4c23 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_IMX) += spi_imx.o
obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o
obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o
obj-$(CONFIG_SPI_PXA2XX_PCI) += pxa2xx_spi_pci.o
+obj-$(CONFIG_SPI_OC_TINY) += spi_oc_tiny.o
obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o
obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o
obj-$(CONFIG_SPI_OMAP_100K) += omap_spi_100k.o
diff --git a/drivers/spi/spi_oc_tiny.c b/drivers/spi/spi_oc_tiny.c
new file mode 100644
index 0000000..fa82b90
--- /dev/null
+++ b/drivers/spi/spi_oc_tiny.c
@@ -0,0 +1,421 @@
+/*
+ * OpenCores tiny SPI master driver
+ *
+ * http://opencores.org/project,tiny_spi
+ *
+ * Copyright (C) 2011 Thomas Chou <[email protected]>
+ *
+ * Based on spi_s3c24xx.c, which is:
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ * Ben Dooks <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/spi_oc_tiny.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+
+#define DRV_NAME "spi_oc_tiny"
+
+#define TINY_SPI_RXDATA 0
+#define TINY_SPI_TXDATA 4
+#define TINY_SPI_STATUS 8
+#define TINY_SPI_CONTROL 12
+#define TINY_SPI_BAUD 16
+
+#define TINY_SPI_STATUS_TXE 0x1
+#define TINY_SPI_STATUS_TXR 0x2
+
+struct tiny_spi {
+ /* bitbang has to be first */
+ struct spi_bitbang bitbang;
+ struct completion done;
+
+ void __iomem *base;
+ int irq;
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int baud;
+ unsigned int speed_hz;
+ unsigned int mode;
+ unsigned int len;
+ unsigned int txc, rxc;
+ const u8 *txp;
+ u8 *rxp;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev)
+{
+ return spi_master_get_devdata(sdev->master);
+}
+
+static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
+}
+
+static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (hw->gpio_cs_count) {
+ gpio_set_value(hw->gpio_cs[spi->chip_select],
+ (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
+ }
+}
+
+static int tiny_spi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ unsigned int baud = hw->baud;
+
+ if (t) {
+ if (t->speed_hz && t->speed_hz != hw->speed_hz)
+ baud = tiny_spi_baud(spi, t->speed_hz);
+ }
+ writel(baud, hw->base + TINY_SPI_BAUD);
+ writel(hw->mode, hw->base + TINY_SPI_CONTROL);
+ return 0;
+}
+
+static int tiny_spi_setup(struct spi_device *spi)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (spi->max_speed_hz != hw->speed_hz) {
+ hw->speed_hz = spi->max_speed_hz;
+ hw->baud = tiny_spi_baud(spi, hw->speed_hz);
+ }
+ hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
+ return 0;
+}
+
+static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXR))
+ cpu_relax();
+}
+
+static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXE))
+ cpu_relax();
+}
+
+static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ const u8 *txp = t->tx_buf;
+ u8 *rxp = t->rx_buf;
+ unsigned int i;
+
+ if (hw->irq >= 0) {
+ /* use intrrupt driven data transfer */
+ hw->len = t->len;
+ hw->txp = t->tx_buf;
+ hw->rxp = t->rx_buf;
+ hw->txc = 0;
+ hw->rxc = 0;
+
+ /* send the first byte */
+ if (t->len > 1) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
+ }
+
+ wait_for_completion(&hw->done);
+ } else if (txp && rxp) {
+ /* we need to tighten the transfer loop */
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx, tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (rxp) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0,
+ hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (txp) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ } else {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ tiny_spi_wait_txr(hw);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ }
+ return t->len;
+}
+
+static irqreturn_t tiny_spi_irq(int irq, void *dev)
+{
+ struct tiny_spi *hw = dev;
+
+ writeb(0, hw->base + TINY_SPI_STATUS);
+ if (hw->rxc + 1 == hw->len) {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ hw->rxc++;
+ complete(&hw->done);
+ } else {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ hw->rxc++;
+ if (hw->txc < hw->len) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR,
+ hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(TINY_SPI_STATUS_TXE,
+ hw->base + TINY_SPI_STATUS);
+ }
+ }
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_OF
+#include <linux/of_gpio.h>
+
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct device_node *np = pdev->dev.of_node;
+ unsigned int i;
+ const __be32 *val;
+ int len;
+
+ if (!np)
+ return 0;
+ hw->gpio_cs_count = of_gpio_count(np);
+ if (hw->gpio_cs_count) {
+ hw->gpio_cs = devm_kzalloc(&pdev->dev,
+ hw->gpio_cs_count * sizeof(unsigned int),
+ GFP_KERNEL);
+ if (!hw->gpio_cs)
+ return -ENOMEM;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ hw->gpio_cs[i] = of_get_gpio_flags(np, i, NULL);
+ if (hw->gpio_cs[i] < 0)
+ return -ENODEV;
+ }
+ hw->bitbang.master->dev.of_node = pdev->dev.of_node;
+ val = of_get_property(pdev->dev.of_node,
+ "clock-frequency", &len);
+ if (val && len >= sizeof(__be32))
+ hw->freq = be32_to_cpup(val);
+ val = of_get_property(pdev->dev.of_node, "baud-width", &len);
+ if (val && len >= sizeof(__be32))
+ hw->baudwidth = be32_to_cpup(val);
+ return 0;
+}
+#else /* !CONFIG_OF */
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ return 0;
+}
+#endif /* CONFIG_OF */
+
+static int __devinit tiny_spi_probe(struct platform_device *pdev)
+{
+ struct tiny_spi_platform_data *platp = pdev->dev.platform_data;
+ struct tiny_spi *hw;
+ struct spi_master *master;
+ struct resource *res;
+ unsigned int i;
+ int err = -ENODEV;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
+ if (!master)
+ return err;
+
+ /* setup the master state. */
+ master->bus_num = pdev->id;
+ master->num_chipselect = 255;
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ master->setup = tiny_spi_setup;
+
+ hw = spi_master_get_devdata(master);
+ platform_set_drvdata(pdev, hw);
+
+ /* setup the state for the bitbang driver */
+ hw->bitbang.master = spi_master_get(master);
+ if (!hw->bitbang.master)
+ return err;
+ hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
+ hw->bitbang.chipselect = tiny_spi_chipselect;
+ hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;
+
+ /* find and map our resources */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ goto exit_busy;
+ if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
+ pdev->name))
+ goto exit_busy;
+ hw->base = devm_ioremap_nocache(&pdev->dev, res->start,
+ resource_size(res));
+ if (!hw->base)
+ goto exit_busy;
+ /* irq is optional */
+ hw->irq = platform_get_irq(pdev, 0);
+ if (hw->irq >= 0) {
+ init_completion(&hw->done);
+ err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
+ pdev->name, hw);
+ if (err)
+ goto exit;
+ }
+ /* find platform data */
+ if (platp) {
+ hw->gpio_cs_count = platp->gpio_cs_count;
+ hw->gpio_cs = platp->gpio_cs;
+ if (platp->gpio_cs_count && !platp->gpio_cs)
+ goto exit_busy;
+ hw->freq = platp->freq;
+ hw->baudwidth = platp->baudwidth;
+ } else {
+ err = tiny_spi_of_probe(pdev);
+ if (err)
+ goto exit;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
+ if (err)
+ goto exit_gpio;
+ gpio_direction_output(hw->gpio_cs[i], 1);
+ }
+ hw->bitbang.master->num_chipselect = max(1U, hw->gpio_cs_count);
+
+ /* register our spi controller */
+ err = spi_bitbang_start(&hw->bitbang);
+ if (err)
+ goto exit;
+ dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
+
+ return 0;
+
+exit_gpio:
+ while (i-- > 0)
+ gpio_free(hw->gpio_cs[i]);
+exit_busy:
+ err = -EBUSY;
+exit:
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return err;
+}
+
+static int __devexit tiny_spi_remove(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct spi_master *master = hw->bitbang.master;
+ unsigned int i;
+
+ spi_bitbang_stop(&hw->bitbang);
+ for (i = 0; i < hw->gpio_cs_count; i++)
+ gpio_free(hw->gpio_cs[i]);
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return 0;
+}
+
+static const struct of_device_id tiny_spi_match[] = {
+ { .compatible = "opencores,tiny-spi-rtlsvn2", },
+ {},
+}
+MODULE_DEVICE_TABLE(of, tiny_spi_match);
+
+static struct platform_driver tiny_spi_driver = {
+ .probe = tiny_spi_probe,
+ .remove = __devexit_p(tiny_spi_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .pm = NULL,
+ .of_match_table = tiny_spi_match,
+ },
+};
+
+static int __init tiny_spi_init(void)
+{
+ return platform_driver_register(&tiny_spi_driver);
+}
+module_init(tiny_spi_init);
+
+static void __exit tiny_spi_exit(void)
+{
+ platform_driver_unregister(&tiny_spi_driver);
+}
+module_exit(tiny_spi_exit);
+
+MODULE_DESCRIPTION("OpenCores tiny SPI driver");
+MODULE_AUTHOR("Thomas Chou <[email protected]>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/include/linux/spi/spi_oc_tiny.h b/include/linux/spi/spi_oc_tiny.h
new file mode 100644
index 0000000..1ac529c
--- /dev/null
+++ b/include/linux/spi/spi_oc_tiny.h
@@ -0,0 +1,20 @@
+#ifndef _LINUX_SPI_SPI_OC_TINY_H
+#define _LINUX_SPI_SPI_OC_TINY_H
+
+/**
+ * struct tiny_spi_platform_data - platform data of the OpenCores tiny SPI
+ * @freq: input clock freq to the core.
+ * @baudwidth: baud rate divider width of the core.
+ * @gpio_cs_count: number of gpio pins used for chipselect.
+ * @gpio_cs: array of gpio pins used for chipselect.
+ *
+ * freq and baudwidth are used only if the divider is programmable.
+ */
+struct tiny_spi_platform_data {
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+#endif /* _LINUX_SPI_SPI_OC_TINY_H */
--
1.7.4

2011-02-14 02:17:52

by Thomas Chou

Subject: [PATCH v8 resend] spi: add OpenCores tiny SPI driver

This patch adds support of OpenCores tiny SPI driver.

http://opencores.org/project,tiny_spi

Signed-off-by: Thomas Chou <[email protected]>
---
v2 minor cleanup, same as Grant suggest for spi_altera.
v3 rename driver to spi_oc_tiny as Grant suggested.
set version to tiny-spi-rtlsvn2 as Jonas suggested.
v4 add dts binding doc.
v5 use devm_* to help cleanup.
add of gpio support.
v6 check len from of_get_property.
fix kerneldoc in header.
v7 remove default n from Kconfig.
v8 condition module device table export for of.

Sorry, forget to commit the last change.

.../devicetree/bindings/spi/spi_oc_tiny.txt | 12 +
drivers/spi/Kconfig | 7 +
drivers/spi/Makefile | 1 +
drivers/spi/spi_oc_tiny.c | 425 ++++++++++++++++++++
include/linux/spi/spi_oc_tiny.h | 20 +
5 files changed, 465 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
create mode 100644 drivers/spi/spi_oc_tiny.c
create mode 100644 include/linux/spi/spi_oc_tiny.h

diff --git a/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
new file mode 100644
index 0000000..d95c0b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
@@ -0,0 +1,12 @@
+OpenCores tiny SPI
+
+Required properties:
+- compatible : should be "opencores,tiny-spi-rtlsvn2".
+- gpios : should specify GPIOs used for chipselect.
+Optional properties:
+- clock-frequency : input clock frequency to the core.
+- baud-width: width, in bits, of the programmable divider used to scale
+ the input clock to SCLK.
+
+The clock-frequency and baud-width properties are needed only if the divider
+is programmable. They are not needed if the divider is fixed.
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index bb233a9..8faa57a 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -231,6 +231,13 @@ config SPI_FSL_ESPI
From MPC8536, 85xx platform uses the controller, and all P10xx,
P20xx, P30xx,P40xx, P50xx uses this controller.

+config SPI_OC_TINY
+ tristate "OpenCores tiny SPI"
+ depends on GENERIC_GPIO
+ select SPI_BITBANG
+ help
+ This is the driver for OpenCores tiny SPI master controller.
+
config SPI_OMAP_UWIRE
tristate "OMAP1 MicroWire"
depends on ARCH_OMAP1
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 86d1b5f..c7e4c23 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_IMX) += spi_imx.o
obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o
obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o
obj-$(CONFIG_SPI_PXA2XX_PCI) += pxa2xx_spi_pci.o
+obj-$(CONFIG_SPI_OC_TINY) += spi_oc_tiny.o
obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o
obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o
obj-$(CONFIG_SPI_OMAP_100K) += omap_spi_100k.o
diff --git a/drivers/spi/spi_oc_tiny.c b/drivers/spi/spi_oc_tiny.c
new file mode 100644
index 0000000..e99e545
--- /dev/null
+++ b/drivers/spi/spi_oc_tiny.c
@@ -0,0 +1,425 @@
+/*
+ * OpenCores tiny SPI master driver
+ *
+ * http://opencores.org/project,tiny_spi
+ *
+ * Copyright (C) 2011 Thomas Chou <[email protected]>
+ *
+ * Based on spi_s3c24xx.c, which is:
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ * Ben Dooks <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/spi_oc_tiny.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/of.h>
+
+#define DRV_NAME "spi_oc_tiny"
+
+#define TINY_SPI_RXDATA 0
+#define TINY_SPI_TXDATA 4
+#define TINY_SPI_STATUS 8
+#define TINY_SPI_CONTROL 12
+#define TINY_SPI_BAUD 16
+
+#define TINY_SPI_STATUS_TXE 0x1
+#define TINY_SPI_STATUS_TXR 0x2
+
+struct tiny_spi {
+ /* bitbang has to be first */
+ struct spi_bitbang bitbang;
+ struct completion done;
+
+ void __iomem *base;
+ int irq;
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int baud;
+ unsigned int speed_hz;
+ unsigned int mode;
+ unsigned int len;
+ unsigned int txc, rxc;
+ const u8 *txp;
+ u8 *rxp;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev)
+{
+ return spi_master_get_devdata(sdev->master);
+}
+
+static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
+}
+
+static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (hw->gpio_cs_count) {
+ gpio_set_value(hw->gpio_cs[spi->chip_select],
+ (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
+ }
+}
+
+static int tiny_spi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ unsigned int baud = hw->baud;
+
+ if (t) {
+ if (t->speed_hz && t->speed_hz != hw->speed_hz)
+ baud = tiny_spi_baud(spi, t->speed_hz);
+ }
+ writel(baud, hw->base + TINY_SPI_BAUD);
+ writel(hw->mode, hw->base + TINY_SPI_CONTROL);
+ return 0;
+}
+
+static int tiny_spi_setup(struct spi_device *spi)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+
+ if (spi->max_speed_hz != hw->speed_hz) {
+ hw->speed_hz = spi->max_speed_hz;
+ hw->baud = tiny_spi_baud(spi, hw->speed_hz);
+ }
+ hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
+ return 0;
+}
+
+static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXR))
+ cpu_relax();
+}
+
+static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
+{
+ while (!(readb(hw->base + TINY_SPI_STATUS) &
+ TINY_SPI_STATUS_TXE))
+ cpu_relax();
+}
+
+static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct tiny_spi *hw = tiny_spi_to_hw(spi);
+ const u8 *txp = t->tx_buf;
+ u8 *rxp = t->rx_buf;
+ unsigned int i;
+
+ if (hw->irq >= 0) {
+ /* use intrrupt driven data transfer */
+ hw->len = t->len;
+ hw->txp = t->tx_buf;
+ hw->rxp = t->rx_buf;
+ hw->txc = 0;
+ hw->rxc = 0;
+
+ /* send the first byte */
+ if (t->len > 1) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
+ }
+
+ wait_for_completion(&hw->done);
+ } else if (txp && rxp) {
+ /* we need to tighten the transfer loop */
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx, tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (rxp) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0,
+ hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 rx;
+ tiny_spi_wait_txr(hw);
+ rx = readb(hw->base + TINY_SPI_TXDATA);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ *rxp++ = rx;
+ }
+ tiny_spi_wait_txr(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ }
+ tiny_spi_wait_txe(hw);
+ *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ } else if (txp) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(*txp++, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ u8 tx = *txp++;
+ tiny_spi_wait_txr(hw);
+ writeb(tx, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ } else {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ if (t->len > 1) {
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ for (i = 2; i < t->len; i++) {
+ tiny_spi_wait_txr(hw);
+ writeb(0, hw->base + TINY_SPI_TXDATA);
+ }
+ }
+ tiny_spi_wait_txe(hw);
+ }
+ return t->len;
+}
+
+static irqreturn_t tiny_spi_irq(int irq, void *dev)
+{
+ struct tiny_spi *hw = dev;
+
+ writeb(0, hw->base + TINY_SPI_STATUS);
+ if (hw->rxc + 1 == hw->len) {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
+ hw->rxc++;
+ complete(&hw->done);
+ } else {
+ if (hw->rxp)
+ *hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
+ hw->rxc++;
+ if (hw->txc < hw->len) {
+ writeb(hw->txp ? *hw->txp++ : 0,
+ hw->base + TINY_SPI_TXDATA);
+ hw->txc++;
+ writeb(TINY_SPI_STATUS_TXR,
+ hw->base + TINY_SPI_STATUS);
+ } else {
+ writeb(TINY_SPI_STATUS_TXE,
+ hw->base + TINY_SPI_STATUS);
+ }
+ }
+ return IRQ_HANDLED;
+}
+
+#ifdef CONFIG_OF
+#include <linux/of_gpio.h>
+
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct device_node *np = pdev->dev.of_node;
+ unsigned int i;
+ const __be32 *val;
+ int len;
+
+ if (!np)
+ return 0;
+ hw->gpio_cs_count = of_gpio_count(np);
+ if (hw->gpio_cs_count) {
+ hw->gpio_cs = devm_kzalloc(&pdev->dev,
+ hw->gpio_cs_count * sizeof(unsigned int),
+ GFP_KERNEL);
+ if (!hw->gpio_cs)
+ return -ENOMEM;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ hw->gpio_cs[i] = of_get_gpio_flags(np, i, NULL);
+ if (hw->gpio_cs[i] < 0)
+ return -ENODEV;
+ }
+ hw->bitbang.master->dev.of_node = pdev->dev.of_node;
+ val = of_get_property(pdev->dev.of_node,
+ "clock-frequency", &len);
+ if (val && len >= sizeof(__be32))
+ hw->freq = be32_to_cpup(val);
+ val = of_get_property(pdev->dev.of_node, "baud-width", &len);
+ if (val && len >= sizeof(__be32))
+ hw->baudwidth = be32_to_cpup(val);
+ return 0;
+}
+#else /* !CONFIG_OF */
+static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
+{
+ return 0;
+}
+#endif /* CONFIG_OF */
+
+static int __devinit tiny_spi_probe(struct platform_device *pdev)
+{
+ struct tiny_spi_platform_data *platp = pdev->dev.platform_data;
+ struct tiny_spi *hw;
+ struct spi_master *master;
+ struct resource *res;
+ unsigned int i;
+ int err = -ENODEV;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
+ if (!master)
+ return err;
+
+ /* setup the master state. */
+ master->bus_num = pdev->id;
+ master->num_chipselect = 255;
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ master->setup = tiny_spi_setup;
+
+ hw = spi_master_get_devdata(master);
+ platform_set_drvdata(pdev, hw);
+
+ /* setup the state for the bitbang driver */
+ hw->bitbang.master = spi_master_get(master);
+ if (!hw->bitbang.master)
+ return err;
+ hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
+ hw->bitbang.chipselect = tiny_spi_chipselect;
+ hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;
+
+ /* find and map our resources */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ goto exit_busy;
+ if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
+ pdev->name))
+ goto exit_busy;
+ hw->base = devm_ioremap_nocache(&pdev->dev, res->start,
+ resource_size(res));
+ if (!hw->base)
+ goto exit_busy;
+ /* irq is optional */
+ hw->irq = platform_get_irq(pdev, 0);
+ if (hw->irq >= 0) {
+ init_completion(&hw->done);
+ err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
+ pdev->name, hw);
+ if (err)
+ goto exit;
+ }
+ /* find platform data */
+ if (platp) {
+ hw->gpio_cs_count = platp->gpio_cs_count;
+ hw->gpio_cs = platp->gpio_cs;
+ if (platp->gpio_cs_count && !platp->gpio_cs)
+ goto exit_busy;
+ hw->freq = platp->freq;
+ hw->baudwidth = platp->baudwidth;
+ } else {
+ err = tiny_spi_of_probe(pdev);
+ if (err)
+ goto exit;
+ }
+ for (i = 0; i < hw->gpio_cs_count; i++) {
+ err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
+ if (err)
+ goto exit_gpio;
+ gpio_direction_output(hw->gpio_cs[i], 1);
+ }
+ hw->bitbang.master->num_chipselect = max(1U, hw->gpio_cs_count);
+
+ /* register our spi controller */
+ err = spi_bitbang_start(&hw->bitbang);
+ if (err)
+ goto exit;
+ dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
+
+ return 0;
+
+exit_gpio:
+ while (i-- > 0)
+ gpio_free(hw->gpio_cs[i]);
+exit_busy:
+ err = -EBUSY;
+exit:
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return err;
+}
+
+static int __devexit tiny_spi_remove(struct platform_device *pdev)
+{
+ struct tiny_spi *hw = platform_get_drvdata(pdev);
+ struct spi_master *master = hw->bitbang.master;
+ unsigned int i;
+
+ spi_bitbang_stop(&hw->bitbang);
+ for (i = 0; i < hw->gpio_cs_count; i++)
+ gpio_free(hw->gpio_cs[i]);
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id tiny_spi_match[] = {
+ { .compatible = "opencores,tiny-spi-rtlsvn2", },
+ {},
+}
+MODULE_DEVICE_TABLE(of, tiny_spi_match);
+#else /* CONFIG_OF */
+#define tiny_spi_match NULL
+#endif /* CONFIG_OF */
+
+static struct platform_driver tiny_spi_driver = {
+ .probe = tiny_spi_probe,
+ .remove = __devexit_p(tiny_spi_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ .pm = NULL,
+ .of_match_table = tiny_spi_match,
+ },
+};
+
+static int __init tiny_spi_init(void)
+{
+ return platform_driver_register(&tiny_spi_driver);
+}
+module_init(tiny_spi_init);
+
+static void __exit tiny_spi_exit(void)
+{
+ platform_driver_unregister(&tiny_spi_driver);
+}
+module_exit(tiny_spi_exit);
+
+MODULE_DESCRIPTION("OpenCores tiny SPI driver");
+MODULE_AUTHOR("Thomas Chou <[email protected]>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/include/linux/spi/spi_oc_tiny.h b/include/linux/spi/spi_oc_tiny.h
new file mode 100644
index 0000000..1ac529c
--- /dev/null
+++ b/include/linux/spi/spi_oc_tiny.h
@@ -0,0 +1,20 @@
+#ifndef _LINUX_SPI_SPI_OC_TINY_H
+#define _LINUX_SPI_SPI_OC_TINY_H
+
+/**
+ * struct tiny_spi_platform_data - platform data of the OpenCores tiny SPI
+ * @freq: input clock freq to the core.
+ * @baudwidth: baud rate divider width of the core.
+ * @gpio_cs_count: number of gpio pins used for chipselect.
+ * @gpio_cs: array of gpio pins used for chipselect.
+ *
+ * freq and baudwidth are used only if the divider is programmable.
+ */
+struct tiny_spi_platform_data {
+ unsigned int freq;
+ unsigned int baudwidth;
+ unsigned int gpio_cs_count;
+ int *gpio_cs;
+};
+
+#endif /* _LINUX_SPI_SPI_OC_TINY_H */
--
1.7.4

2011-02-16 02:51:29

by Grant Likely

Subject: Re: [PATCH v8 resend] spi: add OpenCores tiny SPI driver

On Mon, Feb 14, 2011 at 10:20:39AM +0800, Thomas Chou wrote:
> This patch adds support of OpenCores tiny SPI driver.
>
> http://opencores.org/project,tiny_spi
>
> Signed-off-by: Thomas Chou <[email protected]>

Applied, thanks.

g.

> ---
> v2 minor cleanup, same as Grant suggest for spi_altera.
> v3 rename driver to spi_oc_tiny as Grant suggested.
> set version to tiny-spi-rtlsvn2 as Jonas suggested.
> v4 add dts binding doc.
> v5 use devm_* to help cleanup.
> add of gpio support.
> v6 check len from of_get_property.
> fix kerneldoc in header.
> v7 remove default n from Kconfig.
> v8 condition module device table export for of.
>
> Sorry, forget to commit the last change.
>
> .../devicetree/bindings/spi/spi_oc_tiny.txt | 12 +
> drivers/spi/Kconfig | 7 +
> drivers/spi/Makefile | 1 +
> drivers/spi/spi_oc_tiny.c | 425 ++++++++++++++++++++
> include/linux/spi/spi_oc_tiny.h | 20 +
> 5 files changed, 465 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
> create mode 100644 drivers/spi/spi_oc_tiny.c
> create mode 100644 include/linux/spi/spi_oc_tiny.h
>
> diff --git a/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
> new file mode 100644
> index 0000000..d95c0b3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/spi_oc_tiny.txt
> @@ -0,0 +1,12 @@
> +OpenCores tiny SPI
> +
> +Required properties:
> +- compatible : should be "opencores,tiny-spi-rtlsvn2".
> +- gpios : should specify GPIOs used for chipselect.
> +Optional properties:
> +- clock-frequency : input clock frequency to the core.
> +- baud-width: width, in bits, of the programmable divider used to scale
> + the input clock to SCLK.
> +
> +The clock-frequency and baud-width properties are needed only if the divider
> +is programmable. They are not needed if the divider is fixed.
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index bb233a9..8faa57a 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -231,6 +231,13 @@ config SPI_FSL_ESPI
> From MPC8536, 85xx platform uses the controller, and all P10xx,
> P20xx, P30xx,P40xx, P50xx uses this controller.
>
> +config SPI_OC_TINY
> + tristate "OpenCores tiny SPI"
> + depends on GENERIC_GPIO
> + select SPI_BITBANG
> + help
> + This is the driver for OpenCores tiny SPI master controller.
> +
> config SPI_OMAP_UWIRE
> tristate "OMAP1 MicroWire"
> depends on ARCH_OMAP1
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index 86d1b5f..c7e4c23 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_SPI_IMX) += spi_imx.o
> obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o
> obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o
> obj-$(CONFIG_SPI_PXA2XX_PCI) += pxa2xx_spi_pci.o
> +obj-$(CONFIG_SPI_OC_TINY) += spi_oc_tiny.o
> obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o
> obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o
> obj-$(CONFIG_SPI_OMAP_100K) += omap_spi_100k.o
> diff --git a/drivers/spi/spi_oc_tiny.c b/drivers/spi/spi_oc_tiny.c
> new file mode 100644
> index 0000000..e99e545
> --- /dev/null
> +++ b/drivers/spi/spi_oc_tiny.c
> @@ -0,0 +1,425 @@
> +/*
> + * OpenCores tiny SPI master driver
> + *
> + * http://opencores.org/project,tiny_spi
> + *
> + * Copyright (C) 2011 Thomas Chou <[email protected]>
> + *
> + * Based on spi_s3c24xx.c, which is:
> + * Copyright (c) 2006 Ben Dooks
> + * Copyright (c) 2006 Simtec Electronics
> + * Ben Dooks <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/errno.h>
> +#include <linux/platform_device.h>
> +#include <linux/spi/spi.h>
> +#include <linux/spi/spi_bitbang.h>
> +#include <linux/spi/spi_oc_tiny.h>
> +#include <linux/io.h>
> +#include <linux/gpio.h>
> +#include <linux/of.h>
> +
> +#define DRV_NAME "spi_oc_tiny"
> +
> +#define TINY_SPI_RXDATA 0
> +#define TINY_SPI_TXDATA 4
> +#define TINY_SPI_STATUS 8
> +#define TINY_SPI_CONTROL 12
> +#define TINY_SPI_BAUD 16
> +
> +#define TINY_SPI_STATUS_TXE 0x1
> +#define TINY_SPI_STATUS_TXR 0x2
> +
> +struct tiny_spi {
> + /* bitbang has to be first */
> + struct spi_bitbang bitbang;
> + struct completion done;
> +
> + void __iomem *base;
> + int irq;
> + unsigned int freq;
> + unsigned int baudwidth;
> + unsigned int baud;
> + unsigned int speed_hz;
> + unsigned int mode;
> + unsigned int len;
> + unsigned int txc, rxc;
> + const u8 *txp;
> + u8 *rxp;
> + unsigned int gpio_cs_count;
> + int *gpio_cs;
> +};
> +
> +static inline struct tiny_spi *tiny_spi_to_hw(struct spi_device *sdev)
> +{
> + return spi_master_get_devdata(sdev->master);
> +}
> +
> +static unsigned int tiny_spi_baud(struct spi_device *spi, unsigned int hz)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> +
> + return min(DIV_ROUND_UP(hw->freq, hz * 2), (1U << hw->baudwidth)) - 1;
> +}
> +
> +static void tiny_spi_chipselect(struct spi_device *spi, int is_active)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> +
> + if (hw->gpio_cs_count) {
> + gpio_set_value(hw->gpio_cs[spi->chip_select],
> + (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
> + }
> +}
> +
> +static int tiny_spi_setup_transfer(struct spi_device *spi,
> + struct spi_transfer *t)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> + unsigned int baud = hw->baud;
> +
> + if (t) {
> + if (t->speed_hz && t->speed_hz != hw->speed_hz)
> + baud = tiny_spi_baud(spi, t->speed_hz);
> + }
> + writel(baud, hw->base + TINY_SPI_BAUD);
> + writel(hw->mode, hw->base + TINY_SPI_CONTROL);
> + return 0;
> +}
> +
> +static int tiny_spi_setup(struct spi_device *spi)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> +
> + if (spi->max_speed_hz != hw->speed_hz) {
> + hw->speed_hz = spi->max_speed_hz;
> + hw->baud = tiny_spi_baud(spi, hw->speed_hz);
> + }
> + hw->mode = spi->mode & (SPI_CPOL | SPI_CPHA);
> + return 0;
> +}
> +
> +static inline void tiny_spi_wait_txr(struct tiny_spi *hw)
> +{
> + while (!(readb(hw->base + TINY_SPI_STATUS) &
> + TINY_SPI_STATUS_TXR))
> + cpu_relax();
> +}
> +
> +static inline void tiny_spi_wait_txe(struct tiny_spi *hw)
> +{
> + while (!(readb(hw->base + TINY_SPI_STATUS) &
> + TINY_SPI_STATUS_TXE))
> + cpu_relax();
> +}
> +
> +static int tiny_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
> +{
> + struct tiny_spi *hw = tiny_spi_to_hw(spi);
> + const u8 *txp = t->tx_buf;
> + u8 *rxp = t->rx_buf;
> + unsigned int i;
> +
> + if (hw->irq >= 0) {
> + /* use intrrupt driven data transfer */
> + hw->len = t->len;
> + hw->txp = t->tx_buf;
> + hw->rxp = t->rx_buf;
> + hw->txc = 0;
> + hw->rxc = 0;
> +
> + /* send the first byte */
> + if (t->len > 1) {
> + writeb(hw->txp ? *hw->txp++ : 0,
> + hw->base + TINY_SPI_TXDATA);
> + hw->txc++;
> + writeb(hw->txp ? *hw->txp++ : 0,
> + hw->base + TINY_SPI_TXDATA);
> + hw->txc++;
> + writeb(TINY_SPI_STATUS_TXR, hw->base + TINY_SPI_STATUS);
> + } else {
> + writeb(hw->txp ? *hw->txp++ : 0,
> + hw->base + TINY_SPI_TXDATA);
> + hw->txc++;
> + writeb(TINY_SPI_STATUS_TXE, hw->base + TINY_SPI_STATUS);
> + }
> +
> + wait_for_completion(&hw->done);
> + } else if (txp && rxp) {
> + /* we need to tighten the transfer loop */
> + writeb(*txp++, hw->base + TINY_SPI_TXDATA);
> + if (t->len > 1) {
> + writeb(*txp++, hw->base + TINY_SPI_TXDATA);
> + for (i = 2; i < t->len; i++) {
> + u8 rx, tx = *txp++;
> + tiny_spi_wait_txr(hw);
> + rx = readb(hw->base + TINY_SPI_TXDATA);
> + writeb(tx, hw->base + TINY_SPI_TXDATA);
> + *rxp++ = rx;
> + }
> + tiny_spi_wait_txr(hw);
> + *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
> + }
> + tiny_spi_wait_txe(hw);
> + *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
> + } else if (rxp) {
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + if (t->len > 1) {
> + writeb(0,
> + hw->base + TINY_SPI_TXDATA);
> + for (i = 2; i < t->len; i++) {
> + u8 rx;
> + tiny_spi_wait_txr(hw);
> + rx = readb(hw->base + TINY_SPI_TXDATA);
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + *rxp++ = rx;
> + }
> + tiny_spi_wait_txr(hw);
> + *rxp++ = readb(hw->base + TINY_SPI_TXDATA);
> + }
> + tiny_spi_wait_txe(hw);
> + *rxp++ = readb(hw->base + TINY_SPI_RXDATA);
> + } else if (txp) {
> + writeb(*txp++, hw->base + TINY_SPI_TXDATA);
> + if (t->len > 1) {
> + writeb(*txp++, hw->base + TINY_SPI_TXDATA);
> + for (i = 2; i < t->len; i++) {
> + u8 tx = *txp++;
> + tiny_spi_wait_txr(hw);
> + writeb(tx, hw->base + TINY_SPI_TXDATA);
> + }
> + }
> + tiny_spi_wait_txe(hw);
> + } else {
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + if (t->len > 1) {
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + for (i = 2; i < t->len; i++) {
> + tiny_spi_wait_txr(hw);
> + writeb(0, hw->base + TINY_SPI_TXDATA);
> + }
> + }
> + tiny_spi_wait_txe(hw);
> + }
> + return t->len;
> +}
> +
> +static irqreturn_t tiny_spi_irq(int irq, void *dev)
> +{
> + struct tiny_spi *hw = dev;
> +
> + writeb(0, hw->base + TINY_SPI_STATUS);
> + if (hw->rxc + 1 == hw->len) {
> + if (hw->rxp)
> + *hw->rxp++ = readb(hw->base + TINY_SPI_RXDATA);
> + hw->rxc++;
> + complete(&hw->done);
> + } else {
> + if (hw->rxp)
> + *hw->rxp++ = readb(hw->base + TINY_SPI_TXDATA);
> + hw->rxc++;
> + if (hw->txc < hw->len) {
> + writeb(hw->txp ? *hw->txp++ : 0,
> + hw->base + TINY_SPI_TXDATA);
> + hw->txc++;
> + writeb(TINY_SPI_STATUS_TXR,
> + hw->base + TINY_SPI_STATUS);
> + } else {
> + writeb(TINY_SPI_STATUS_TXE,
> + hw->base + TINY_SPI_STATUS);
> + }
> + }
> + return IRQ_HANDLED;
> +}
> +
> +#ifdef CONFIG_OF
> +#include <linux/of_gpio.h>
> +
> +static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
> +{
> + struct tiny_spi *hw = platform_get_drvdata(pdev);
> + struct device_node *np = pdev->dev.of_node;
> + unsigned int i;
> + const __be32 *val;
> + int len;
> +
> + if (!np)
> + return 0;
> + hw->gpio_cs_count = of_gpio_count(np);
> + if (hw->gpio_cs_count) {
> + hw->gpio_cs = devm_kzalloc(&pdev->dev,
> + hw->gpio_cs_count * sizeof(unsigned int),
> + GFP_KERNEL);
> + if (!hw->gpio_cs)
> + return -ENOMEM;
> + }
> + for (i = 0; i < hw->gpio_cs_count; i++) {
> + hw->gpio_cs[i] = of_get_gpio_flags(np, i, NULL);
> + if (hw->gpio_cs[i] < 0)
> + return -ENODEV;
> + }
> + hw->bitbang.master->dev.of_node = pdev->dev.of_node;
> + val = of_get_property(pdev->dev.of_node,
> + "clock-frequency", &len);
> + if (val && len >= sizeof(__be32))
> + hw->freq = be32_to_cpup(val);
> + val = of_get_property(pdev->dev.of_node, "baud-width", &len);
> + if (val && len >= sizeof(__be32))
> + hw->baudwidth = be32_to_cpup(val);
> + return 0;
> +}
> +#else /* !CONFIG_OF */
> +static int __devinit tiny_spi_of_probe(struct platform_device *pdev)
> +{
> + return 0;
> +}
> +#endif /* CONFIG_OF */
> +
> +static int __devinit tiny_spi_probe(struct platform_device *pdev)
> +{
> + struct tiny_spi_platform_data *platp = pdev->dev.platform_data;
> + struct tiny_spi *hw;
> + struct spi_master *master;
> + struct resource *res;
> + unsigned int i;
> + int err = -ENODEV;
> +
> + master = spi_alloc_master(&pdev->dev, sizeof(struct tiny_spi));
> + if (!master)
> + return err;
> +
> + /* setup the master state. */
> + master->bus_num = pdev->id;
> + master->num_chipselect = 255;
> + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
> + master->setup = tiny_spi_setup;
> +
> + hw = spi_master_get_devdata(master);
> + platform_set_drvdata(pdev, hw);
> +
> + /* setup the state for the bitbang driver */
> + hw->bitbang.master = spi_master_get(master);
> + if (!hw->bitbang.master)
> + return err;
> + hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
> + hw->bitbang.chipselect = tiny_spi_chipselect;
> + hw->bitbang.txrx_bufs = tiny_spi_txrx_bufs;
> +
> + /* find and map our resources */
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + goto exit_busy;
> + if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
> + pdev->name))
> + goto exit_busy;
> + hw->base = devm_ioremap_nocache(&pdev->dev, res->start,
> + resource_size(res));
> + if (!hw->base)
> + goto exit_busy;
> + /* irq is optional */
> + hw->irq = platform_get_irq(pdev, 0);
> + if (hw->irq >= 0) {
> + init_completion(&hw->done);
> + err = devm_request_irq(&pdev->dev, hw->irq, tiny_spi_irq, 0,
> + pdev->name, hw);
> + if (err)
> + goto exit;
> + }
> + /* find platform data */
> + if (platp) {
> + hw->gpio_cs_count = platp->gpio_cs_count;
> + hw->gpio_cs = platp->gpio_cs;
> + if (platp->gpio_cs_count && !platp->gpio_cs)
> + goto exit_busy;
> + hw->freq = platp->freq;
> + hw->baudwidth = platp->baudwidth;
> + } else {
> + err = tiny_spi_of_probe(pdev);
> + if (err)
> + goto exit;
> + }
> + for (i = 0; i < hw->gpio_cs_count; i++) {
> + err = gpio_request(hw->gpio_cs[i], dev_name(&pdev->dev));
> + if (err)
> + goto exit_gpio;
> + gpio_direction_output(hw->gpio_cs[i], 1);
> + }
> + hw->bitbang.master->num_chipselect = max(1U, hw->gpio_cs_count);
> +
> + /* register our spi controller */
> + err = spi_bitbang_start(&hw->bitbang);
> + if (err)
> + goto exit;
> + dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
> +
> + return 0;
> +
> +exit_gpio:
> + while (i-- > 0)
> + gpio_free(hw->gpio_cs[i]);
> +exit_busy:
> + err = -EBUSY;
> +exit:
> + platform_set_drvdata(pdev, NULL);
> + spi_master_put(master);
> + return err;
> +}
> +
> +static int __devexit tiny_spi_remove(struct platform_device *pdev)
> +{
> + struct tiny_spi *hw = platform_get_drvdata(pdev);
> + struct spi_master *master = hw->bitbang.master;
> + unsigned int i;
> +
> + spi_bitbang_stop(&hw->bitbang);
> + for (i = 0; i < hw->gpio_cs_count; i++)
> + gpio_free(hw->gpio_cs[i]);
> + platform_set_drvdata(pdev, NULL);
> + spi_master_put(master);
> + return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id tiny_spi_match[] = {
> + { .compatible = "opencores,tiny-spi-rtlsvn2", },
> + {},
> +}
> +MODULE_DEVICE_TABLE(of, tiny_spi_match);
> +#else /* CONFIG_OF */
> +#define tiny_spi_match NULL
> +#endif /* CONFIG_OF */
> +
> +static struct platform_driver tiny_spi_driver = {
> + .probe = tiny_spi_probe,
> + .remove = __devexit_p(tiny_spi_remove),
> + .driver = {
> + .name = DRV_NAME,
> + .owner = THIS_MODULE,
> + .pm = NULL,
> + .of_match_table = tiny_spi_match,
> + },
> +};
> +
> +static int __init tiny_spi_init(void)
> +{
> + return platform_driver_register(&tiny_spi_driver);
> +}
> +module_init(tiny_spi_init);
> +
> +static void __exit tiny_spi_exit(void)
> +{
> + platform_driver_unregister(&tiny_spi_driver);
> +}
> +module_exit(tiny_spi_exit);
> +
> +MODULE_DESCRIPTION("OpenCores tiny SPI driver");
> +MODULE_AUTHOR("Thomas Chou <[email protected]>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:" DRV_NAME);
> diff --git a/include/linux/spi/spi_oc_tiny.h b/include/linux/spi/spi_oc_tiny.h
> new file mode 100644
> index 0000000..1ac529c
> --- /dev/null
> +++ b/include/linux/spi/spi_oc_tiny.h
> @@ -0,0 +1,20 @@
> +#ifndef _LINUX_SPI_SPI_OC_TINY_H
> +#define _LINUX_SPI_SPI_OC_TINY_H
> +
> +/**
> + * struct tiny_spi_platform_data - platform data of the OpenCores tiny SPI
> + * @freq: input clock freq to the core.
> + * @baudwidth: baud rate divider width of the core.
> + * @gpio_cs_count: number of gpio pins used for chipselect.
> + * @gpio_cs: array of gpio pins used for chipselect.
> + *
> + * freq and baudwidth are used only if the divider is programmable.
> + */
> +struct tiny_spi_platform_data {
> + unsigned int freq;
> + unsigned int baudwidth;
> + unsigned int gpio_cs_count;
> + int *gpio_cs;
> +};
> +
> +#endif /* _LINUX_SPI_SPI_OC_TINY_H */
> --
> 1.7.4
>