2018-08-31 14:04:00

by Radu Pirea

[permalink] [raw]
Subject: [RESEND PATCH v11 0/6] Driver for at91 usart in spi mode

Hello,

This is the 11th version of driver. I added a mfd driver which by
default probes atmel_serial driver and if in dt is specified to probe
the spi driver, then the spi-at91-usart driver will be probed. The
compatible for atmel_serial is now the compatible for at91-usart mfd
driver and compatilbe for atmel_serial driver was changed in order to
keep the bindings for serial as they are.

@Lee, could you take this patch series into your tree? I addressed all Mark
remarks.

In this resend I changed my email address from MAINTAINERS file.

Changes in v11:
- removed "depends on HAS_DMA" from drivers/spi/Kconfig because the driver has
no dma support
- changed "selects MFD_AT91_USART" to "depends on MFD_AT91_USART" in
drivers/spi/Kconfig
- changed comment style in spi-at91-usart.c

Changes in v10:
-fixed kbuild test robot warning

Changes in v9:
- minor changes
- rebased on top of broonie/for-4.19

Changes in v8:
- fixed passing an empty mfd cell if "atmel,usart-mode" value is invalid

Changes in v7:
- synced up SPDIX license with module license
- numbering of usart modes starts from 0 insteand of 1

Changes in v6:
- removed unused compatible strings from serial and spi drivers

Changes in v5:
- fixed usage of stdout-path property with atmel_serial driver

Changes in v4:
- modified the spi driver to use cs gpio support form spi subsystem
- fixed dma transfers for serial driver
- squashed binding for spi and serial and moved them to mfd/atmel-usart.txt

Changes in v3:
- fixed spi slaves probing

Changes in v2:
- added at91-usart mfd driver
- modified spi-at91-usart driver to work as mfd driver child
- modified atmel_serial driver to work as mfd driver child

Changes in v1:
- added spi-at91-usart driver

Radu Pirea (6):
MAINTAINERS: add at91 usart mfd driver
dt-bindings: add binding for atmel-usart in SPI mode
mfd: at91-usart: added mfd driver for usart
MAINTAINERS: add at91 usart spi driver
spi: at91-usart: add driver for at91-usart as spi
tty/serial: atmel: change the driver to work under at91-usart mfd

.../bindings/{serial => mfd}/atmel-usart.txt | 25 +-
MAINTAINERS | 16 +
drivers/mfd/Kconfig | 9 +
drivers/mfd/Makefile | 1 +
drivers/mfd/at91-usart.c | 71 +++
drivers/spi/Kconfig | 8 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-at91-usart.c | 432 ++++++++++++++++++
drivers/tty/serial/Kconfig | 1 +
drivers/tty/serial/atmel_serial.c | 42 +-
include/dt-bindings/mfd/at91-usart.h | 17 +
11 files changed, 606 insertions(+), 17 deletions(-)
rename Documentation/devicetree/bindings/{serial => mfd}/atmel-usart.txt (76%)
create mode 100644 drivers/mfd/at91-usart.c
create mode 100644 drivers/spi/spi-at91-usart.c
create mode 100644 include/dt-bindings/mfd/at91-usart.h

--
2.18.0



2018-08-31 13:42:05

by Radu Pirea

[permalink] [raw]
Subject: [RESEND PATCH v11 2/6] dt-bindings: add binding for atmel-usart in SPI mode

This patch moves the bindings for serial from serial/atmel-usart.txt to
mfd/atmel-usart.txt and adds bindings for USART in SPI mode.

Signed-off-by: Radu Pirea <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Acked-for-MFD-by: Lee Jones <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
---
.../bindings/{serial => mfd}/atmel-usart.txt | 25 +++++++++++++++++--
include/dt-bindings/mfd/at91-usart.h | 17 +++++++++++++
2 files changed, 40 insertions(+), 2 deletions(-)
rename Documentation/devicetree/bindings/{serial => mfd}/atmel-usart.txt (76%)
create mode 100644 include/dt-bindings/mfd/at91-usart.h

diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/mfd/atmel-usart.txt
similarity index 76%
rename from Documentation/devicetree/bindings/serial/atmel-usart.txt
rename to Documentation/devicetree/bindings/mfd/atmel-usart.txt
index 7c0d6b2f53e4..0348fef0f497 100644
--- a/Documentation/devicetree/bindings/serial/atmel-usart.txt
+++ b/Documentation/devicetree/bindings/mfd/atmel-usart.txt
@@ -1,6 +1,6 @@
* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)

-Required properties:
+Required properties for USART:
- compatible: Should be "atmel,<chip>-usart" or "atmel,<chip>-dbgu"
The compatible <chip> indicated will be the first SoC to support an
additional mode or an USART new feature.
@@ -11,7 +11,13 @@ Required properties:
Required elements: "usart"
- clocks: phandles to input clocks.

-Optional properties:
+Required properties for USART in SPI mode:
+- #size-cells : Must be <0>
+- #address-cells : Must be <1>
+- cs-gpios: chipselects (internal cs not supported)
+- atmel,usart-mode : Must be <AT91_USART_MODE_SPI> (found in dt-bindings/mfd/at91-usart.h)
+
+Optional properties in serial mode:
- atmel,use-dma-rx: use of PDC or DMA for receiving data
- atmel,use-dma-tx: use of PDC or DMA for transmitting data
- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD line respectively.
@@ -62,3 +68,18 @@ Example:
dma-names = "tx", "rx";
atmel,fifo-size = <32>;
};
+
+- SPI mode:
+ #include <dt-bindings/mfd/at91-usart.h>
+
+ spi0: spi@f001c000 {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ compatible = "atmel,at91rm9200-usart", "atmel,at91sam9260-usart";
+ atmel,usart-mode = <AT91_USART_MODE_SPI>;
+ reg = <0xf001c000 0x100>;
+ interrupts = <12 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&usart0_clk>;
+ clock-names = "usart";
+ cs-gpios = <&pioB 3 0>;
+ };
diff --git a/include/dt-bindings/mfd/at91-usart.h b/include/dt-bindings/mfd/at91-usart.h
new file mode 100644
index 000000000000..2de5bc312e1e
--- /dev/null
+++ b/include/dt-bindings/mfd/at91-usart.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * This header provides macros for AT91 USART DT bindings.
+ *
+ * Copyright (C) 2018 Microchip Technology
+ *
+ * Author: Radu Pirea <[email protected]>
+ *
+ */
+
+#ifndef __DT_BINDINGS_AT91_USART_H__
+#define __DT_BINDINGS_AT91_USART_H__
+
+#define AT91_USART_MODE_SERIAL 0
+#define AT91_USART_MODE_SPI 1
+
+#endif /* __DT_BINDINGS_AT91_USART_H__ */
--
2.18.0


2018-08-31 13:42:13

by Radu Pirea

[permalink] [raw]
Subject: [RESEND PATCH v11 5/6] spi: at91-usart: add driver for at91-usart as spi

This is the driver for at91-usart in spi mode. The USART IP can be configured
to work in many modes and one of them is SPI.

The driver was tested on sama5d3-xplained and sama5d4-xplained boards with
enc28j60 ethernet controller as slave.

Signed-off-by: Radu Pirea <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Reviwed-by: Mark Brown <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
---
drivers/spi/Kconfig | 8 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-at91-usart.c | 432 +++++++++++++++++++++++++++++++++++
3 files changed, 441 insertions(+)
create mode 100644 drivers/spi/spi-at91-usart.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 7580eb76ab18..181b5f2e831d 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -83,6 +83,14 @@ config SPI_ATMEL
This selects a driver for the Atmel SPI Controller, present on
many AT91 ARM chips.

+config SPI_AT91_USART
+ tristate "Atmel USART Controller SPI driver"
+ depends on (ARCH_AT91 || COMPILE_TEST)
+ depends on MFD_AT91_USART
+ help
+ This selects a driver for the AT91 USART Controller as SPI Master,
+ present on AT91 and SAMA5 SoC series.
+
config SPI_AU1550
tristate "Au1550/Au1200/Au1300 SPI Controller"
depends on MIPS_ALCHEMY
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 1920b6cc2b7e..7385bbd37dcf 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_SPI_LOOPBACK_TEST) += spi-loopback-test.o
obj-$(CONFIG_SPI_ALTERA) += spi-altera.o
obj-$(CONFIG_SPI_ARMADA_3700) += spi-armada-3700.o
obj-$(CONFIG_SPI_ATMEL) += spi-atmel.o
+obj-$(CONFIG_SPI_AT91_USART) += spi-at91-usart.o
obj-$(CONFIG_SPI_ATH79) += spi-ath79.o
obj-$(CONFIG_SPI_AU1550) += spi-au1550.o
obj-$(CONFIG_SPI_AXI_SPI_ENGINE) += spi-axi-spi-engine.o
diff --git a/drivers/spi/spi-at91-usart.c b/drivers/spi/spi-at91-usart.c
new file mode 100644
index 000000000000..4712bd470c89
--- /dev/null
+++ b/drivers/spi/spi-at91-usart.c
@@ -0,0 +1,432 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Driver for AT91 USART Controllers as SPI
+//
+// Copyright (C) 2018 Microchip Technology Inc.
+//
+// Author: Radu Pirea <[email protected]>
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+
+#include <linux/spi/spi.h>
+
+#define US_CR 0x00
+#define US_MR 0x04
+#define US_IER 0x08
+#define US_IDR 0x0C
+#define US_CSR 0x14
+#define US_RHR 0x18
+#define US_THR 0x1C
+#define US_BRGR 0x20
+#define US_VERSION 0xFC
+
+#define US_CR_RSTRX BIT(2)
+#define US_CR_RSTTX BIT(3)
+#define US_CR_RXEN BIT(4)
+#define US_CR_RXDIS BIT(5)
+#define US_CR_TXEN BIT(6)
+#define US_CR_TXDIS BIT(7)
+
+#define US_MR_SPI_MASTER 0x0E
+#define US_MR_CHRL GENMASK(7, 6)
+#define US_MR_CPHA BIT(8)
+#define US_MR_CPOL BIT(16)
+#define US_MR_CLKO BIT(18)
+#define US_MR_WRDBT BIT(20)
+#define US_MR_LOOP BIT(15)
+
+#define US_IR_RXRDY BIT(0)
+#define US_IR_TXRDY BIT(1)
+#define US_IR_OVRE BIT(5)
+
+#define US_BRGR_SIZE BIT(16)
+
+#define US_MIN_CLK_DIV 0x06
+#define US_MAX_CLK_DIV BIT(16)
+
+#define US_RESET (US_CR_RSTRX | US_CR_RSTTX)
+#define US_DISABLE (US_CR_RXDIS | US_CR_TXDIS)
+#define US_ENABLE (US_CR_RXEN | US_CR_TXEN)
+#define US_OVRE_RXRDY_IRQS (US_IR_OVRE | US_IR_RXRDY)
+
+#define US_INIT \
+ (US_MR_SPI_MASTER | US_MR_CHRL | US_MR_CLKO | US_MR_WRDBT)
+
+/* Register access macros */
+#define at91_usart_spi_readl(port, reg) \
+ readl_relaxed((port)->regs + US_##reg)
+#define at91_usart_spi_writel(port, reg, value) \
+ writel_relaxed((value), (port)->regs + US_##reg)
+
+#define at91_usart_spi_readb(port, reg) \
+ readb_relaxed((port)->regs + US_##reg)
+#define at91_usart_spi_writeb(port, reg, value) \
+ writeb_relaxed((value), (port)->regs + US_##reg)
+
+struct at91_usart_spi {
+ struct spi_transfer *current_transfer;
+ void __iomem *regs;
+ struct device *dev;
+ struct clk *clk;
+
+ /*used in interrupt to protect data reading*/
+ spinlock_t lock;
+
+ int irq;
+ unsigned int current_tx_remaining_bytes;
+ unsigned int current_rx_remaining_bytes;
+
+ u32 spi_clk;
+ u32 status;
+
+ bool xfer_failed;
+};
+
+static inline u32 at91_usart_spi_tx_ready(struct at91_usart_spi *aus)
+{
+ return aus->status & US_IR_TXRDY;
+}
+
+static inline u32 at91_usart_spi_rx_ready(struct at91_usart_spi *aus)
+{
+ return aus->status & US_IR_RXRDY;
+}
+
+static inline u32 at91_usart_spi_check_overrun(struct at91_usart_spi *aus)
+{
+ return aus->status & US_IR_OVRE;
+}
+
+static inline u32 at91_usart_spi_read_status(struct at91_usart_spi *aus)
+{
+ aus->status = at91_usart_spi_readl(aus, CSR);
+ return aus->status;
+}
+
+static inline void at91_usart_spi_tx(struct at91_usart_spi *aus)
+{
+ unsigned int len = aus->current_transfer->len;
+ unsigned int remaining = aus->current_tx_remaining_bytes;
+ const u8 *tx_buf = aus->current_transfer->tx_buf;
+
+ if (!remaining)
+ return;
+
+ if (at91_usart_spi_tx_ready(aus)) {
+ at91_usart_spi_writeb(aus, THR, tx_buf[len - remaining]);
+ aus->current_tx_remaining_bytes--;
+ }
+}
+
+static inline void at91_usart_spi_rx(struct at91_usart_spi *aus)
+{
+ int len = aus->current_transfer->len;
+ int remaining = aus->current_rx_remaining_bytes;
+ u8 *rx_buf = aus->current_transfer->rx_buf;
+
+ if (!remaining)
+ return;
+
+ rx_buf[len - remaining] = at91_usart_spi_readb(aus, RHR);
+ aus->current_rx_remaining_bytes--;
+}
+
+static inline void
+at91_usart_spi_set_xfer_speed(struct at91_usart_spi *aus,
+ struct spi_transfer *xfer)
+{
+ at91_usart_spi_writel(aus, BRGR,
+ DIV_ROUND_UP(aus->spi_clk, xfer->speed_hz));
+}
+
+static irqreturn_t at91_usart_spi_interrupt(int irq, void *dev_id)
+{
+ struct spi_controller *controller = dev_id;
+ struct at91_usart_spi *aus = spi_master_get_devdata(controller);
+
+ spin_lock(&aus->lock);
+ at91_usart_spi_read_status(aus);
+
+ if (at91_usart_spi_check_overrun(aus)) {
+ aus->xfer_failed = true;
+ at91_usart_spi_writel(aus, IDR, US_IR_OVRE | US_IR_RXRDY);
+ spin_unlock(&aus->lock);
+ return IRQ_HANDLED;
+ }
+
+ if (at91_usart_spi_rx_ready(aus)) {
+ at91_usart_spi_rx(aus);
+ spin_unlock(&aus->lock);
+ return IRQ_HANDLED;
+ }
+
+ spin_unlock(&aus->lock);
+
+ return IRQ_NONE;
+}
+
+static int at91_usart_spi_setup(struct spi_device *spi)
+{
+ struct at91_usart_spi *aus = spi_master_get_devdata(spi->controller);
+ u32 *ausd = spi->controller_state;
+ unsigned int mr = at91_usart_spi_readl(aus, MR);
+ u8 bits = spi->bits_per_word;
+
+ if (bits != 8) {
+ dev_dbg(&spi->dev, "Only 8 bits per word are supported\n");
+ return -EINVAL;
+ }
+
+ if (spi->mode & SPI_CPOL)
+ mr |= US_MR_CPOL;
+ else
+ mr &= ~US_MR_CPOL;
+
+ if (spi->mode & SPI_CPHA)
+ mr |= US_MR_CPHA;
+ else
+ mr &= ~US_MR_CPHA;
+
+ if (spi->mode & SPI_LOOP)
+ mr |= US_MR_LOOP;
+ else
+ mr &= ~US_MR_LOOP;
+
+ if (!ausd) {
+ ausd = kzalloc(sizeof(*ausd), GFP_KERNEL);
+ if (!ausd)
+ return -ENOMEM;
+
+ spi->controller_state = ausd;
+ }
+
+ *ausd = mr;
+
+ dev_dbg(&spi->dev,
+ "setup: bpw %u mode 0x%x -> mr %d %08x\n",
+ bits, spi->mode, spi->chip_select, mr);
+
+ return 0;
+}
+
+int at91_usart_spi_transfer_one(struct spi_controller *ctlr,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);
+
+ at91_usart_spi_set_xfer_speed(aus, xfer);
+ aus->xfer_failed = false;
+ aus->current_transfer = xfer;
+ aus->current_tx_remaining_bytes = xfer->len;
+ aus->current_rx_remaining_bytes = xfer->len;
+
+ while ((aus->current_tx_remaining_bytes ||
+ aus->current_rx_remaining_bytes) && !aus->xfer_failed) {
+ at91_usart_spi_read_status(aus);
+ at91_usart_spi_tx(aus);
+ cpu_relax();
+ }
+
+ if (aus->xfer_failed) {
+ dev_err(aus->dev, "Overrun!\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+int at91_usart_spi_prepare_message(struct spi_controller *ctlr,
+ struct spi_message *message)
+{
+ struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);
+ struct spi_device *spi = message->spi;
+ u32 *ausd = spi->controller_state;
+
+ at91_usart_spi_writel(aus, CR, US_ENABLE);
+ at91_usart_spi_writel(aus, IER, US_OVRE_RXRDY_IRQS);
+ at91_usart_spi_writel(aus, MR, *ausd);
+
+ return 0;
+}
+
+int at91_usart_spi_unprepare_message(struct spi_controller *ctlr,
+ struct spi_message *message)
+{
+ struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);
+
+ at91_usart_spi_writel(aus, CR, US_RESET | US_DISABLE);
+ at91_usart_spi_writel(aus, IDR, US_OVRE_RXRDY_IRQS);
+
+ return 0;
+}
+
+static void at91_usart_spi_cleanup(struct spi_device *spi)
+{
+ struct at91_usart_spi_device *ausd = spi->controller_state;
+
+ spi->controller_state = NULL;
+ kfree(ausd);
+}
+
+static void at91_usart_spi_init(struct at91_usart_spi *aus)
+{
+ at91_usart_spi_writel(aus, MR, US_INIT);
+ at91_usart_spi_writel(aus, CR, US_RESET | US_DISABLE);
+}
+
+static int at91_usart_gpio_setup(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.parent->of_node;
+ int i;
+ int ret;
+ int nb;
+
+ if (!np)
+ return -EINVAL;
+
+ nb = of_gpio_named_count(np, "cs-gpios");
+ for (i = 0; i < nb; i++) {
+ int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
+
+ if (cs_gpio < 0)
+ return cs_gpio;
+
+ if (gpio_is_valid(cs_gpio)) {
+ ret = devm_gpio_request_one(&pdev->dev, cs_gpio,
+ GPIOF_DIR_OUT,
+ dev_name(&pdev->dev));
+ if (ret)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int at91_usart_spi_probe(struct platform_device *pdev)
+{
+ struct resource *regs;
+ struct spi_controller *controller;
+ struct at91_usart_spi *aus;
+ struct clk *clk;
+ int irq;
+ int ret;
+
+ regs = platform_get_resource(to_platform_device(pdev->dev.parent),
+ IORESOURCE_MEM, 0);
+ if (!regs)
+ return -EINVAL;
+
+ irq = platform_get_irq(to_platform_device(pdev->dev.parent), 0);
+ if (irq < 0)
+ return irq;
+
+ clk = devm_clk_get(pdev->dev.parent, "usart");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ ret = -ENOMEM;
+ controller = spi_alloc_master(&pdev->dev, sizeof(*aus));
+ if (!controller)
+ goto at91_usart_spi_probe_fail;
+
+ ret = at91_usart_gpio_setup(pdev);
+ if (ret)
+ goto at91_usart_spi_probe_fail;
+
+ controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH;
+ controller->dev.of_node = pdev->dev.parent->of_node;
+ controller->bits_per_word_mask = SPI_BPW_MASK(8);
+ controller->setup = at91_usart_spi_setup;
+ controller->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX;
+ controller->transfer_one = at91_usart_spi_transfer_one;
+ controller->prepare_message = at91_usart_spi_prepare_message;
+ controller->unprepare_message = at91_usart_spi_unprepare_message;
+ controller->cleanup = at91_usart_spi_cleanup;
+ controller->max_speed_hz = DIV_ROUND_UP(clk_get_rate(clk),
+ US_MIN_CLK_DIV);
+ controller->min_speed_hz = DIV_ROUND_UP(clk_get_rate(clk),
+ US_MAX_CLK_DIV);
+ platform_set_drvdata(pdev, controller);
+
+ aus = spi_master_get_devdata(controller);
+
+ aus->dev = &pdev->dev;
+ aus->regs = devm_ioremap_resource(&pdev->dev, regs);
+ if (IS_ERR(aus->regs)) {
+ ret = PTR_ERR(aus->regs);
+ goto at91_usart_spi_probe_fail;
+ }
+
+ aus->irq = irq;
+ aus->clk = clk;
+
+ ret = devm_request_irq(&pdev->dev, irq, at91_usart_spi_interrupt, 0,
+ dev_name(&pdev->dev), controller);
+ if (ret)
+ goto at91_usart_spi_probe_fail;
+
+ ret = clk_prepare_enable(clk);
+ if (ret)
+ goto at91_usart_spi_probe_fail;
+
+ aus->spi_clk = clk_get_rate(clk);
+ at91_usart_spi_init(aus);
+
+ spin_lock_init(&aus->lock);
+ ret = devm_spi_register_master(&pdev->dev, controller);
+ if (ret)
+ goto at91_usart_fail_register_master;
+
+ dev_info(&pdev->dev,
+ "AT91 USART SPI Controller version 0x%x at %pa (irq %d)\n",
+ at91_usart_spi_readl(aus, VERSION),
+ &regs->start, irq);
+
+ return 0;
+
+at91_usart_fail_register_master:
+ clk_disable_unprepare(clk);
+at91_usart_spi_probe_fail:
+ spi_master_put(controller);
+ return ret;
+}
+
+static int at91_usart_spi_remove(struct platform_device *pdev)
+{
+ struct spi_controller *ctlr = platform_get_drvdata(pdev);
+ struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);
+
+ clk_disable_unprepare(aus->clk);
+
+ return 0;
+}
+
+static const struct of_device_id at91_usart_spi_dt_ids[] = {
+ { .compatible = "microchip,at91sam9g45-usart-spi"},
+ { /* sentinel */}
+};
+
+MODULE_DEVICE_TABLE(of, at91_usart_spi_dt_ids);
+
+static struct platform_driver at91_usart_spi_driver = {
+ .driver = {
+ .name = "at91_usart_spi",
+ },
+ .probe = at91_usart_spi_probe,
+ .remove = at91_usart_spi_remove,
+};
+
+module_platform_driver(at91_usart_spi_driver);
+
+MODULE_DESCRIPTION("Microchip AT91 USART SPI Controller driver");
+MODULE_AUTHOR("Radu Pirea <[email protected]>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:at91_usart_spi");
--
2.18.0


2018-08-31 13:42:25

by Radu Pirea

[permalink] [raw]
Subject: [RESEND PATCH v11 6/6] tty/serial: atmel: change the driver to work under at91-usart mfd

This patch modifies the place where resources and device tree properties
are searched.

Signed-off-by: Radu Pirea <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Acked-by: Richard Genoud <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
---
drivers/tty/serial/Kconfig | 1 +
drivers/tty/serial/atmel_serial.c | 42 ++++++++++++++++++++-----------
2 files changed, 28 insertions(+), 15 deletions(-)

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index df8bd0c7b97d..32886c304641 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -118,6 +118,7 @@ config SERIAL_ATMEL
depends on ARCH_AT91 || COMPILE_TEST
select SERIAL_CORE
select SERIAL_MCTRL_GPIO if GPIOLIB
+ select MFD_AT91_USART
help
This enables the driver for the on-chip UARTs of the Atmel
AT91 processors.
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 8e4428725848..267d4d1de3f8 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -193,8 +193,7 @@ static struct console atmel_console;

#if defined(CONFIG_OF)
static const struct of_device_id atmel_serial_dt_ids[] = {
- { .compatible = "atmel,at91rm9200-usart" },
- { .compatible = "atmel,at91sam9260-usart" },
+ { .compatible = "atmel,at91rm9200-usart-serial" },
{ /* sentinel */ }
};
#endif
@@ -915,6 +914,7 @@ static void atmel_tx_dma(struct uart_port *port)
static int atmel_prepare_tx_dma(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ struct device *mfd_dev = port->dev->parent;
dma_cap_mask_t mask;
struct dma_slave_config config;
int ret, nent;
@@ -922,7 +922,7 @@ static int atmel_prepare_tx_dma(struct uart_port *port)
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);

- atmel_port->chan_tx = dma_request_slave_channel(port->dev, "tx");
+ atmel_port->chan_tx = dma_request_slave_channel(mfd_dev, "tx");
if (atmel_port->chan_tx == NULL)
goto chan_err;
dev_info(port->dev, "using %s for tx DMA transfers\n",
@@ -1093,6 +1093,7 @@ static void atmel_rx_from_dma(struct uart_port *port)
static int atmel_prepare_rx_dma(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ struct device *mfd_dev = port->dev->parent;
struct dma_async_tx_descriptor *desc;
dma_cap_mask_t mask;
struct dma_slave_config config;
@@ -1104,7 +1105,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
dma_cap_zero(mask);
dma_cap_set(DMA_CYCLIC, mask);

- atmel_port->chan_rx = dma_request_slave_channel(port->dev, "rx");
+ atmel_port->chan_rx = dma_request_slave_channel(mfd_dev, "rx");
if (atmel_port->chan_rx == NULL)
goto chan_err;
dev_info(port->dev, "using %s for rx DMA transfers\n",
@@ -2222,8 +2223,8 @@ static const char *atmel_type(struct uart_port *port)
*/
static void atmel_release_port(struct uart_port *port)
{
- struct platform_device *pdev = to_platform_device(port->dev);
- int size = pdev->resource[0].end - pdev->resource[0].start + 1;
+ struct platform_device *mpdev = to_platform_device(port->dev->parent);
+ int size = resource_size(mpdev->resource);

release_mem_region(port->mapbase, size);

@@ -2238,8 +2239,8 @@ static void atmel_release_port(struct uart_port *port)
*/
static int atmel_request_port(struct uart_port *port)
{
- struct platform_device *pdev = to_platform_device(port->dev);
- int size = pdev->resource[0].end - pdev->resource[0].start + 1;
+ struct platform_device *mpdev = to_platform_device(port->dev->parent);
+ int size = resource_size(mpdev->resource);

if (!request_mem_region(port->mapbase, size, "atmel_serial"))
return -EBUSY;
@@ -2341,27 +2342,28 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
{
int ret;
struct uart_port *port = &atmel_port->uart;
+ struct platform_device *mpdev = to_platform_device(pdev->dev.parent);

atmel_init_property(atmel_port, pdev);
atmel_set_ops(port);

- uart_get_rs485_mode(&pdev->dev, &port->rs485);
+ uart_get_rs485_mode(&mpdev->dev, &port->rs485);

port->iotype = UPIO_MEM;
port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
port->ops = &atmel_pops;
port->fifosize = 1;
port->dev = &pdev->dev;
- port->mapbase = pdev->resource[0].start;
- port->irq = pdev->resource[1].start;
+ port->mapbase = mpdev->resource[0].start;
+ port->irq = mpdev->resource[1].start;
port->rs485_config = atmel_config_rs485;
- port->membase = NULL;
+ port->membase = NULL;

memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));

/* for console, the clock could already be configured */
if (!atmel_port->clk) {
- atmel_port->clk = clk_get(&pdev->dev, "usart");
+ atmel_port->clk = clk_get(&mpdev->dev, "usart");
if (IS_ERR(atmel_port->clk)) {
ret = PTR_ERR(atmel_port->clk);
atmel_port->clk = NULL;
@@ -2694,13 +2696,22 @@ static void atmel_serial_probe_fifos(struct atmel_uart_port *atmel_port,
static int atmel_serial_probe(struct platform_device *pdev)
{
struct atmel_uart_port *atmel_port;
- struct device_node *np = pdev->dev.of_node;
+ struct device_node *np = pdev->dev.parent->of_node;
void *data;
int ret = -ENODEV;
bool rs485_enabled;

BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));

+ /*
+ * In device tree there is no node with "atmel,at91rm9200-usart-serial"
+ * as compatible string. This driver is probed by at91-usart mfd driver
+ * which is just a wrapper over the atmel_serial driver and
+ * spi-at91-usart driver. All attributes needed by this driver are
+ * found in of_node of parent.
+ */
+ pdev->dev.of_node = np;
+
ret = of_alias_get_id(np, "serial");
if (ret < 0)
/* port id not found in platform data nor device-tree aliases:
@@ -2836,6 +2847,7 @@ static int atmel_serial_remove(struct platform_device *pdev)

clk_put(atmel_port->clk);
atmel_port->clk = NULL;
+ pdev->dev.of_node = NULL;

return ret;
}
@@ -2846,7 +2858,7 @@ static struct platform_driver atmel_serial_driver = {
.suspend = atmel_serial_suspend,
.resume = atmel_serial_resume,
.driver = {
- .name = "atmel_usart",
+ .name = "atmel_usart_serial",
.of_match_table = of_match_ptr(atmel_serial_dt_ids),
},
};
--
2.18.0


2018-08-31 14:04:02

by Radu Pirea

[permalink] [raw]
Subject: [RESEND PATCH v11 1/6] MAINTAINERS: add at91 usart mfd driver

Added entry for at91 usart mfd driver.

Signed-off-by: Radu Pirea <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
Acked-for-MFD-by: Lee Jones <[email protected]>
---
MAINTAINERS | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index a5b256b25905..94b37382cd2b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9502,6 +9502,7 @@ M: Richard Genoud <[email protected]>
S: Maintained
F: drivers/tty/serial/atmel_serial.c
F: drivers/tty/serial/atmel_serial.h
+F: Documentation/devicetree/bindings/mfd/atmel-usart.txt

MICROCHIP / ATMEL DMA DRIVER
M: Ludovic Desroches <[email protected]>
@@ -9533,6 +9534,14 @@ S: Supported
F: drivers/mtd/nand/raw/atmel/*
F: Documentation/devicetree/bindings/mtd/atmel-nand.txt

+MICROCHIP AT91 USART MFD DRIVER
+M: Radu Pirea <[email protected]>
+L: [email protected]
+S: Supported
+F: drivers/mfd/at91-usart.c
+F: include/dt-bindings/mfd/at91-usart.h
+F: Documentation/devicetree/bindings/mfd/atmel-usart.txt
+
MICROCHIP KSZ SERIES ETHERNET SWITCH DRIVER
M: Woojung Huh <[email protected]>
M: Microchip Linux Driver Support <[email protected]>
--
2.18.0


2018-08-31 14:07:19

by Radu Pirea

[permalink] [raw]
Subject: [RESEND PATCH v11 3/6] mfd: at91-usart: added mfd driver for usart

This mfd driver is just a wrapper over atmel_serial driver and
spi-at91-usart driver. Selection of one of the drivers is based on a
property from device tree. If the property is not specified, the default
driver is atmel_serial.

Signed-off-by: Radu Pirea <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Acked-by: Rob Herring <[email protected]>
Acked-for-MFD-by: Lee Jones <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
---
drivers/mfd/Kconfig | 9 +++++
drivers/mfd/Makefile | 1 +
drivers/mfd/at91-usart.c | 71 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 81 insertions(+)
create mode 100644 drivers/mfd/at91-usart.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 11841f4b7b2b..0b79c5d04cc9 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -99,6 +99,15 @@ config MFD_AAT2870_CORE
additional drivers must be enabled in order to use the
functionality of the device.

+config MFD_AT91_USART
+ tristate "AT91 USART Driver"
+ select MFD_CORE
+ help
+ Select this to get support for AT91 USART IP. This is a wrapper
+ over at91-usart-serial driver and usart-spi-driver. Only one function
+ can be used at a time. The choice is done at boot time by the probe
+ function of this MFD driver according to a device tree property.
+
config MFD_ATMEL_FLEXCOM
tristate "Atmel Flexcom (Flexible Serial Communication Unit)"
select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 5856a9489cbd..12980a4ad460 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -196,6 +196,7 @@ obj-$(CONFIG_MFD_SPMI_PMIC) += qcom-spmi-pmic.o
obj-$(CONFIG_TPS65911_COMPARATOR) += tps65911-comparator.o
obj-$(CONFIG_MFD_TPS65090) += tps65090.o
obj-$(CONFIG_MFD_AAT2870_CORE) += aat2870-core.o
+obj-$(CONFIG_MFD_AT91_USART) += at91-usart.o
obj-$(CONFIG_MFD_ATMEL_FLEXCOM) += atmel-flexcom.o
obj-$(CONFIG_MFD_ATMEL_HLCDC) += atmel-hlcdc.o
obj-$(CONFIG_MFD_ATMEL_SMC) += atmel-smc.o
diff --git a/drivers/mfd/at91-usart.c b/drivers/mfd/at91-usart.c
new file mode 100644
index 000000000000..a4b9929c156f
--- /dev/null
+++ b/drivers/mfd/at91-usart.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for AT91 USART
+ *
+ * Copyright (C) 2018 Microchip Technology
+ *
+ * Author: Radu Pirea <[email protected]>
+ *
+ */
+
+#include <dt-bindings/mfd/at91-usart.h>
+
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/property.h>
+
+static struct mfd_cell at91_usart_spi_subdev = {
+ .name = "at91_usart_spi",
+ .of_compatible = "microchip,at91sam9g45-usart-spi",
+ };
+
+static struct mfd_cell at91_usart_serial_subdev = {
+ .name = "atmel_usart_serial",
+ .of_compatible = "atmel,at91rm9200-usart-serial",
+ };
+
+static int at91_usart_mode_probe(struct platform_device *pdev)
+{
+ struct mfd_cell cell;
+ u32 opmode = AT91_USART_MODE_SERIAL;
+
+ device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);
+
+ switch (opmode) {
+ case AT91_USART_MODE_SPI:
+ cell = at91_usart_spi_subdev;
+ break;
+ case AT91_USART_MODE_SERIAL:
+ cell = at91_usart_serial_subdev;
+ break;
+ default:
+ dev_err(&pdev->dev, "atmel,usart-mode has an invalid value %u\n",
+ opmode);
+ return -EINVAL;
+ }
+
+ return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, &cell, 1,
+ NULL, 0, NULL);
+}
+
+static const struct of_device_id at91_usart_mode_of_match[] = {
+ { .compatible = "atmel,at91rm9200-usart" },
+ { .compatible = "atmel,at91sam9260-usart" },
+ { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, at91_usart_mode_of_match);
+
+static struct platform_driver at91_usart_mfd = {
+ .probe = at91_usart_mode_probe,
+ .driver = {
+ .name = "at91_usart_mode",
+ .of_match_table = at91_usart_mode_of_match,
+ },
+};
+
+module_platform_driver(at91_usart_mfd);
+
+MODULE_AUTHOR("Radu Pirea <[email protected]>");
+MODULE_DESCRIPTION("AT91 USART MFD driver");
+MODULE_LICENSE("GPL v2");
--
2.18.0


2018-08-31 16:19:50

by Radu Pirea

[permalink] [raw]
Subject: [RESEND PATCH v11 4/6] MAINTAINERS: add at91 usart spi driver

Added entry for at91 usart mfd driver.

Signed-off-by: Radu Pirea <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 94b37382cd2b..d58bc2d6bb3d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9542,6 +9542,13 @@ F: drivers/mfd/at91-usart.c
F: include/dt-bindings/mfd/at91-usart.h
F: Documentation/devicetree/bindings/mfd/atmel-usart.txt

+MICROCHIP AT91 USART SPI DRIVER
+M: Radu Pirea <[email protected]>
+L: [email protected]
+S: Supported
+F: drivers/spi/spi-at91-usart.c
+F: Documentation/devicetree/bindings/mfd/atmel-usart.txt
+
MICROCHIP KSZ SERIES ETHERNET SWITCH DRIVER
M: Woojung Huh <[email protected]>
M: Microchip Linux Driver Support <[email protected]>
--
2.18.0


2018-09-02 01:21:48

by kernel test robot

[permalink] [raw]
Subject: Re: [RESEND PATCH v11 5/6] spi: at91-usart: add driver for at91-usart as spi

Hi Radu,

I love your patch! Perhaps something to improve:

[auto build test WARNING on ljones-mfd/for-mfd-next]
[also build test WARNING on v4.19-rc1 next-20180831]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url: https://github.com/0day-ci/linux/commits/Radu-Pirea/Driver-for-at91-usart-in-spi-mode/20180901-165150
base: https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git for-mfd-next
reproduce:
# apt-get install sparse
make ARCH=x86_64 allmodconfig
make C=1 CF=-D__CHECK_ENDIAN__


sparse warnings: (new ones prefixed by >>)

>> drivers/spi/spi-at91-usart.c:218:5: sparse: symbol 'at91_usart_spi_transfer_one' was not declared. Should it be static?
>> drivers/spi/spi-at91-usart.c:245:5: sparse: symbol 'at91_usart_spi_prepare_message' was not declared. Should it be static?
>> drivers/spi/spi-at91-usart.c:259:5: sparse: symbol 'at91_usart_spi_unprepare_message' was not declared. Should it be static?

Please review and possibly fold the followup patch.

---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation

2018-09-02 01:47:39

by Fengguang Wu

[permalink] [raw]
Subject: [RFC PATCH] spi: at91-usart: at91_usart_spi_transfer_one() can be static


Fixes: 5890bab41187 ("spi: at91-usart: add driver for at91-usart as spi")
Signed-off-by: kbuild test robot <[email protected]>
---
spi-at91-usart.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-at91-usart.c b/drivers/spi/spi-at91-usart.c
index 4712bd4..a924657 100644
--- a/drivers/spi/spi-at91-usart.c
+++ b/drivers/spi/spi-at91-usart.c
@@ -215,9 +215,9 @@ static int at91_usart_spi_setup(struct spi_device *spi)
return 0;
}

-int at91_usart_spi_transfer_one(struct spi_controller *ctlr,
- struct spi_device *spi,
- struct spi_transfer *xfer)
+static int at91_usart_spi_transfer_one(struct spi_controller *ctlr,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
{
struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);

@@ -242,8 +242,8 @@ int at91_usart_spi_transfer_one(struct spi_controller *ctlr,
return 0;
}

-int at91_usart_spi_prepare_message(struct spi_controller *ctlr,
- struct spi_message *message)
+static int at91_usart_spi_prepare_message(struct spi_controller *ctlr,
+ struct spi_message *message)
{
struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);
struct spi_device *spi = message->spi;
@@ -256,8 +256,8 @@ int at91_usart_spi_prepare_message(struct spi_controller *ctlr,
return 0;
}

-int at91_usart_spi_unprepare_message(struct spi_controller *ctlr,
- struct spi_message *message)
+static int at91_usart_spi_unprepare_message(struct spi_controller *ctlr,
+ struct spi_message *message)
{
struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);