The SPI controller has the following characteristics:
- Full-duplex synchronous serial data transmission
- Support up to 4 variable length byte transmission
- Main mode support
- Mode failure generates an error flag and issues an interrupt request
- Double buffer receiver
- Serial clock with programmable polarity and phase
- SPI can be controlled in wait mode
- Support boot from SPI
Use mtd_debug tool to earse/write/read /dev/mtd0 on development.
eg:
[root@linux mtd-utils-1.0.0]# mtd_debug erase /dev/mtd0 0x20000 0x40000
Erased 262144 bytes from address 0x00020000 in flash
[root@linux mtd-utils-1.0.0]# mtd_debug write /dev/mtd0 0x20000 13 1.img
Copied 13 bytes from 1.img to address 0x00020000 in flash
[root@linux mtd-utils-1.0.0]# mtd_debug read /dev/mtd0 0x20000 13 2.img
Copied 13 bytes from address 0x00020000 in flash to 2.img
[root@linux mtd-utils-1.0.0]# cmp -l 1.img 2.img
Signed-off-by: Qing Zhang <[email protected]>
---
v2:
- keep Kconfig and Makefile sorted
- make the entire comment a C++ one so things look more intentional
- Fix unclear indentation
- make conditional statements to improve legibility
- Don't use static inline
- the core handle message queue
- Add a new binding document
- Fix probe part mixed pdev and PCI
v3:
- expose set_cs to the core and let it handle things
- replace transfer_one_message to transfer_one
- replace spi_alloc_master to devm_spi_alloc_master
- split out into prepare/unprepare_message
- releases pci regions before unregister master
v4:
- names used in the manual
- rename ls7a_spi_do_transfer to ls7a_spi_setup_transfer
- change read the spcr and sper outside of this function
- mode configuration moved to prepare instead
- remove redundancy code about unprepare/prepare_message
- used 0x4 instead of 0x1,WFEMPTY instead of RFEMPTY
v5:
- remove unnecessary blank lines
---
drivers/spi/Kconfig | 7 ++
drivers/spi/Makefile | 1 +
drivers/spi/spi-ls7a.c | 280 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 288 insertions(+)
create mode 100644 drivers/spi/spi-ls7a.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index aadaea0..af7c0d4 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -413,6 +413,13 @@ config SPI_LP8841_RTC
Say N here unless you plan to run the kernel on an ICP DAS
LP-8x4x industrial computer.
+config SPI_LS7A
+ tristate "Loongson LS7A SPI Controller Support"
+ depends on CPU_LOONGSON64 || COMPILE_TEST
+ help
+ This drivers supports the Loongson LS7A SPI controller in master
+ SPI mode.
+
config SPI_MPC52xx
tristate "Freescale MPC52xx SPI (non-PSC) controller support"
depends on PPC_MPC52xx
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 6fea582..d015cf2 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_SPI_LANTIQ_SSC) += spi-lantiq-ssc.o
obj-$(CONFIG_SPI_JCORE) += spi-jcore.o
obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o
obj-$(CONFIG_SPI_LP8841_RTC) += spi-lp8841-rtc.o
+obj-$(CONFIG_SPI_LS7A) += spi-ls7a.o
obj-$(CONFIG_SPI_MESON_SPICC) += spi-meson-spicc.o
obj-$(CONFIG_SPI_MESON_SPIFC) += spi-meson-spifc.o
obj-$(CONFIG_SPI_MPC512x_PSC) += spi-mpc512x-psc.o
diff --git a/drivers/spi/spi-ls7a.c b/drivers/spi/spi-ls7a.c
new file mode 100644
index 0000000..d24b6d91
--- /dev/null
+++ b/drivers/spi/spi-ls7a.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Loongson LS7A SPI Controller driver
+//
+// Copyright (C) 2020 Loongson Technology Corporation Limited.
+//
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/spi/spi.h>
+
+/* define spi register */
+#define SPCR 0x00
+#define SPSR 0x01
+#define FIFO 0x02
+#define SPER 0x03
+#define SFC_PARAM 0x04
+#define SFC_SOFTCS 0x05
+#define SFC_TIMING 0x06
+
+struct ls7a_spi {
+ struct spi_master *master;
+ void __iomem *base;
+ unsigned int hz;
+ unsigned int mode;
+};
+
+static void ls7a_spi_write_reg(struct ls7a_spi *spi,
+ unsigned char reg,
+ unsigned char data)
+{
+ writeb(data, spi->base + reg);
+}
+
+static char ls7a_spi_read_reg(struct ls7a_spi *spi, unsigned char reg)
+{
+ return readb(spi->base + reg);
+}
+
+static int ls7a_spi_prepare_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct ls7a_spi *ls7a_spi;
+ struct spi_device *spi = msg->spi;
+ unsigned char val;
+
+ ls7a_spi = spi_master_get_devdata(master);
+
+ if (ls7a_spi->mode != spi->mode) {
+ val = ls7a_spi_read_reg(ls7a_spi, SPCR);
+ val &= ~0xc;
+ if (spi->mode & SPI_CPOL)
+ val |= 8;
+ if (spi->mode & SPI_CPHA)
+ val |= 4;
+ ls7a_spi_write_reg(ls7a_spi, SPCR, val);
+ val = ls7a_spi_read_reg(ls7a_spi, SPER);
+ ls7a_spi_write_reg(ls7a_spi, SPER, val);
+ ls7a_spi->mode = spi->mode;
+ }
+ return 0;
+}
+
+static void ls7a_spi_set_cs(struct spi_device *spi, bool enable)
+{
+ struct ls7a_spi *ls7a_spi;
+ int cs;
+
+ ls7a_spi = spi_master_get_devdata(spi->master);
+
+ cs = ls7a_spi_read_reg(ls7a_spi, SFC_SOFTCS) & ~(0x11 << spi->chip_select);
+
+ if (!!(spi->mode & SPI_CS_HIGH) == enable)
+ ls7a_spi_write_reg(ls7a_spi, SFC_SOFTCS, (0x1 << spi->chip_select) | cs);
+ else
+ ls7a_spi_write_reg(ls7a_spi, SFC_SOFTCS, (0x11 << spi->chip_select) | cs);
+}
+
+static int ls7a_spi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ unsigned int hz;
+ unsigned int div, div_tmp;
+ unsigned int bit;
+ unsigned long clk;
+ unsigned char val;
+ unsigned char spcr, sper;
+ const char rdiv[12] = {0, 1, 4, 2, 3, 5, 6, 7, 8, 9, 10, 11};
+ struct ls7a_spi *ls7a_spi;
+
+ ls7a_spi = spi_master_get_devdata(spi->master);
+
+ if (t) {
+ hz = t->speed_hz;
+ if (!hz)
+ hz = spi->max_speed_hz;
+ } else {
+ hz = spi->max_speed_hz;
+ }
+
+ if (hz & (ls7a_spi->hz != hz)) {
+ clk = 100000000;
+
+ div = DIV_ROUND_UP(clk, hz);
+ if (div < 2)
+ div = 2;
+ if (div > 4096)
+ div = 4096;
+
+ bit = fls(div) - 1;
+ if ((1 << bit) == div)
+ bit--;
+ div_tmp = rdiv[bit];
+
+ dev_dbg(&spi->dev, "clk = %ld hz = %d div_tmp = %d bit = %d\n",
+ clk, hz, div_tmp, bit);
+
+ ls7a_spi->hz = hz;
+ spcr = div_tmp & 3;
+ sper = (div_tmp >> 2) & 3;
+
+ val = ls7a_spi_read_reg(ls7a_spi, SPCR);
+ ls7a_spi_write_reg(ls7a_spi, SPCR, (val & ~3) | spcr);
+ val = ls7a_spi_read_reg(ls7a_spi, SPER);
+ ls7a_spi_write_reg(ls7a_spi, SPER, (val & ~3) | sper);
+ }
+ return 0;
+}
+
+static int ls7a_spi_setup(struct spi_device *spi)
+{
+ return ls7a_spi_setup_transfer(spi, NULL);
+}
+
+static int ls7a_spi_write_read_8bit(struct spi_device *spi,
+ const u8 **tx_buf, u8 **rx_buf,
+ unsigned int num)
+{
+ struct ls7a_spi *ls7a_spi;
+
+ ls7a_spi = spi_master_get_devdata(spi->master);
+
+ if (tx_buf && *tx_buf) {
+ ls7a_spi_write_reg(ls7a_spi, FIFO, *((*tx_buf)++));
+
+ while ((ls7a_spi_read_reg(ls7a_spi, SPSR) & 0x4) == 1)
+ ;
+ } else {
+ ls7a_spi_write_reg(ls7a_spi, FIFO, 0);
+
+ while ((ls7a_spi_read_reg(ls7a_spi, SPSR) & 0x1) == 1)
+ ;
+ }
+
+ if (rx_buf && *rx_buf)
+ *(*rx_buf)++ = ls7a_spi_read_reg(ls7a_spi, FIFO);
+ else
+ ls7a_spi_read_reg(ls7a_spi, FIFO);
+
+ return 1;
+}
+
+static unsigned int ls7a_spi_write_read(struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ unsigned int count;
+ const u8 *tx = xfer->tx_buf;
+ u8 *rx = xfer->rx_buf;
+
+ count = xfer->len;
+
+ do {
+ if (ls7a_spi_write_read_8bit(spi, &tx, &rx, count) < 0)
+ goto out;
+ count--;
+ } while (count);
+
+out:
+ return xfer->len - count;
+}
+
+static int ls7a_spi_transfer_one(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ int status = 0;
+
+ status = ls7a_spi_setup_transfer(spi, t);
+ if (status < 0)
+ return status;
+
+ if (t->len)
+ ls7a_spi_write_read(spi, t);
+
+ return status;
+}
+
+static int ls7a_spi_pci_probe(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ struct spi_master *master;
+ struct ls7a_spi *spi;
+ int ret;
+
+ master = devm_spi_alloc_master(&pdev->dev, sizeof(*spi));
+ if (!master)
+ return -ENOMEM;
+
+ spi = spi_master_get_devdata(master);
+ ret = pcim_enable_device(pdev);
+ if (ret)
+ goto err_free_master;
+
+ ret = pci_request_regions(pdev, "ls7a-spi");
+ if (ret)
+ goto err_free_master;
+
+ spi->base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
+ if (!spi->base) {
+ ret = -EINVAL;
+ goto err_free_master;
+ }
+ ls7a_spi_write_reg(spi, SPCR, 0x51);
+ ls7a_spi_write_reg(spi, SPER, 0x00);
+ ls7a_spi_write_reg(spi, SFC_TIMING, 0x01);
+ ls7a_spi_write_reg(spi, SFC_PARAM, 0x40);
+ spi->mode = 0;
+
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ master->set_cs = ls7a_spi_set_cs;
+ master->prepare_message = ls7a_spi_prepare_message;
+ master->setup = ls7a_spi_setup;
+ master->transfer_one = ls7a_spi_transfer_one;
+ master->bits_per_word_mask = SPI_BPW_MASK(8);
+ master->num_chipselect = 4;
+ master->dev.of_node = pdev->dev.of_node;
+
+ spi->master = master;
+
+ pci_set_drvdata(pdev, master);
+
+ ret = spi_register_master(master);
+ if (ret)
+ goto err_free_master;
+
+ return 0;
+
+err_free_master:
+ pci_release_regions(pdev);
+ return ret;
+}
+
+static void ls7a_spi_pci_remove(struct pci_dev *pdev)
+{
+ struct spi_master *master = pci_get_drvdata(pdev);
+
+ spi_unregister_master(master);
+ pci_release_regions(pdev);
+}
+
+static const struct pci_device_id ls7a_spi_pci_id_table[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x7a0b) },
+ { 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, ls7a_spi_pci_id_table);
+
+static struct pci_driver ls7a_spi_pci_driver = {
+ .name = "ls7a-spi",
+ .id_table = ls7a_spi_pci_id_table,
+ .probe = ls7a_spi_pci_probe,
+ .remove = ls7a_spi_pci_remove,
+};
+
+module_pci_driver(ls7a_spi_pci_driver);
+
+MODULE_AUTHOR("Juxin Gao <[email protected]>");
+MODULE_AUTHOR("Qing Zhang <[email protected]>");
+MODULE_DESCRIPTION("Loongson LS7A SPI controller driver");
+MODULE_LICENSE("GPL v2");
--
2.1.0
Switch the DT binding to a YAML schema to enable the DT validation.
Signed-off-by: Qing Zhang <[email protected]>
---
v4:
- fix warnings/errors about running 'make dt_binding_check'
v5:
- remove num-chipelects
---
.../devicetree/bindings/spi/loongson,spi-ls7a.yaml | 44 ++++++++++++++++++++++
1 file changed, 44 insertions(+)
create mode 100644 Documentation/devicetree/bindings/spi/loongson,spi-ls7a.yaml
diff --git a/Documentation/devicetree/bindings/spi/loongson,spi-ls7a.yaml b/Documentation/devicetree/bindings/spi/loongson,spi-ls7a.yaml
new file mode 100644
index 0000000..b90b28b
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/loongson,spi-ls7a.yaml
@@ -0,0 +1,44 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/loongson,spi-ls7a.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Loongson LS7A PCH SPI Controller
+
+maintainers:
+ - Qing Zhang <[email protected]>
+
+description: |
+ This controller can be found in Loongson-3 systems with LS7A PCH.
+
+properties:
+ compatible:
+ const: loongson,ls7a-spi
+
+ reg:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ pci {
+ #address-cells = <3>;
+ #size-cells = <2>;
+
+ spi@16,0 {
+ compatible = "pci0014,7a0b.0",
+ "pci0014,7a0b",
+ "pciclass088000",
+ "pciclass0800";
+
+ reg = <0xb000 0x0 0x0 0x0 0x0>;
+ };
+ };
+
+...
--
2.1.0
Reviewed-by: Huacai Chen <[email protected]>
On Sat, Dec 26, 2020 at 5:13 PM Qing Zhang <[email protected]> wrote:
>
> Switch the DT binding to a YAML schema to enable the DT validation.
>
> Signed-off-by: Qing Zhang <[email protected]>
> ---
>
> v4:
> - fix warnings/errors about running 'make dt_binding_check'
>
> v5:
> - remove num-chipelects
>
> ---
> .../devicetree/bindings/spi/loongson,spi-ls7a.yaml | 44 ++++++++++++++++++++++
> 1 file changed, 44 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/spi/loongson,spi-ls7a.yaml
>
> diff --git a/Documentation/devicetree/bindings/spi/loongson,spi-ls7a.yaml b/Documentation/devicetree/bindings/spi/loongson,spi-ls7a.yaml
> new file mode 100644
> index 0000000..b90b28b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/loongson,spi-ls7a.yaml
> @@ -0,0 +1,44 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/spi/loongson,spi-ls7a.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Loongson LS7A PCH SPI Controller
> +
> +maintainers:
> + - Qing Zhang <[email protected]>
> +
> +description: |
> + This controller can be found in Loongson-3 systems with LS7A PCH.
> +
> +properties:
> + compatible:
> + const: loongson,ls7a-spi
> +
> + reg:
> + maxItems: 1
> +
> +required:
> + - compatible
> + - reg
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + pci {
> + #address-cells = <3>;
> + #size-cells = <2>;
> +
> + spi@16,0 {
> + compatible = "pci0014,7a0b.0",
> + "pci0014,7a0b",
> + "pciclass088000",
> + "pciclass0800";
> +
> + reg = <0xb000 0x0 0x0 0x0 0x0>;
> + };
> + };
> +
> +...
> --
> 2.1.0
>
Hi, Qing,
On Sat, Dec 26, 2020 at 5:13 PM Qing Zhang <[email protected]> wrote:
>
> The SPI controller has the following characteristics:
>
> - Full-duplex synchronous serial data transmission
> - Support up to 4 variable length byte transmission
> - Main mode support
> - Mode failure generates an error flag and issues an interrupt request
> - Double buffer receiver
> - Serial clock with programmable polarity and phase
> - SPI can be controlled in wait mode
> - Support boot from SPI
>
> Use mtd_debug tool to earse/write/read /dev/mtd0 on development.
>
> eg:
>
> [root@linux mtd-utils-1.0.0]# mtd_debug erase /dev/mtd0 0x20000 0x40000
> Erased 262144 bytes from address 0x00020000 in flash
> [root@linux mtd-utils-1.0.0]# mtd_debug write /dev/mtd0 0x20000 13 1.img
> Copied 13 bytes from 1.img to address 0x00020000 in flash
> [root@linux mtd-utils-1.0.0]# mtd_debug read /dev/mtd0 0x20000 13 2.img
> Copied 13 bytes from address 0x00020000 in flash to 2.img
> [root@linux mtd-utils-1.0.0]# cmp -l 1.img 2.img
>
> Signed-off-by: Qing Zhang <[email protected]>
> ---
>
> v2:
> - keep Kconfig and Makefile sorted
> - make the entire comment a C++ one so things look more intentional
> - Fix unclear indentation
> - make conditional statements to improve legibility
> - Don't use static inline
> - the core handle message queue
> - Add a new binding document
> - Fix probe part mixed pdev and PCI
>
> v3:
> - expose set_cs to the core and let it handle things
> - replace transfer_one_message to transfer_one
> - replace spi_alloc_master to devm_spi_alloc_master
> - split out into prepare/unprepare_message
> - releases pci regions before unregister master
>
> v4:
> - names used in the manual
> - rename ls7a_spi_do_transfer to ls7a_spi_setup_transfer
> - change read the spcr and sper outside of this function
> - mode configuration moved to prepare instead
> - remove redundancy code about unprepare/prepare_message
> - used 0x4 instead of 0x1,WFEMPTY instead of RFEMPTY
>
> v5:
> - remove unnecessary blank lines
>
> ---
> drivers/spi/Kconfig | 7 ++
> drivers/spi/Makefile | 1 +
> drivers/spi/spi-ls7a.c | 280 +++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 288 insertions(+)
> create mode 100644 drivers/spi/spi-ls7a.c
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index aadaea0..af7c0d4 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -413,6 +413,13 @@ config SPI_LP8841_RTC
> Say N here unless you plan to run the kernel on an ICP DAS
> LP-8x4x industrial computer.
>
> +config SPI_LS7A
> + tristate "Loongson LS7A SPI Controller Support"
> + depends on CPU_LOONGSON64 || COMPILE_TEST
> + help
> + This drivers supports the Loongson LS7A SPI controller in master
> + SPI mode.
> +
> config SPI_MPC52xx
> tristate "Freescale MPC52xx SPI (non-PSC) controller support"
> depends on PPC_MPC52xx
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index 6fea582..d015cf2 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -61,6 +61,7 @@ obj-$(CONFIG_SPI_LANTIQ_SSC) += spi-lantiq-ssc.o
> obj-$(CONFIG_SPI_JCORE) += spi-jcore.o
> obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o
> obj-$(CONFIG_SPI_LP8841_RTC) += spi-lp8841-rtc.o
> +obj-$(CONFIG_SPI_LS7A) += spi-ls7a.o
> obj-$(CONFIG_SPI_MESON_SPICC) += spi-meson-spicc.o
> obj-$(CONFIG_SPI_MESON_SPIFC) += spi-meson-spifc.o
> obj-$(CONFIG_SPI_MPC512x_PSC) += spi-mpc512x-psc.o
> diff --git a/drivers/spi/spi-ls7a.c b/drivers/spi/spi-ls7a.c
> new file mode 100644
> index 0000000..d24b6d91
> --- /dev/null
> +++ b/drivers/spi/spi-ls7a.c
> @@ -0,0 +1,280 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +//
> +// Loongson LS7A SPI Controller driver
> +//
> +// Copyright (C) 2020 Loongson Technology Corporation Limited.
> +//
> +
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/spi/spi.h>
> +
> +/* define spi register */
> +#define SPCR 0x00
> +#define SPSR 0x01
> +#define FIFO 0x02
> +#define SPER 0x03
> +#define SFC_PARAM 0x04
> +#define SFC_SOFTCS 0x05
> +#define SFC_TIMING 0x06
> +
> +struct ls7a_spi {
> + struct spi_master *master;
> + void __iomem *base;
> + unsigned int hz;
> + unsigned int mode;
> +};
> +
> +static void ls7a_spi_write_reg(struct ls7a_spi *spi,
> + unsigned char reg,
> + unsigned char data)
> +{
> + writeb(data, spi->base + reg);
> +}
> +
> +static char ls7a_spi_read_reg(struct ls7a_spi *spi, unsigned char reg)
> +{
> + return readb(spi->base + reg);
> +}
> +
> +static int ls7a_spi_prepare_message(struct spi_master *master,
> + struct spi_message *msg)
> +{
> + struct ls7a_spi *ls7a_spi;
> + struct spi_device *spi = msg->spi;
> + unsigned char val;
> +
> + ls7a_spi = spi_master_get_devdata(master);
> +
> + if (ls7a_spi->mode != spi->mode) {
> + val = ls7a_spi_read_reg(ls7a_spi, SPCR);
> + val &= ~0xc;
> + if (spi->mode & SPI_CPOL)
> + val |= 8;
> + if (spi->mode & SPI_CPHA)
> + val |= 4;
> + ls7a_spi_write_reg(ls7a_spi, SPCR, val);
> + val = ls7a_spi_read_reg(ls7a_spi, SPER);
> + ls7a_spi_write_reg(ls7a_spi, SPER, val);
> + ls7a_spi->mode = spi->mode;
> + }
> + return 0;
I'm sorry that I hadn't review very carefully in V4 and you need to
send another new version. In kernel code we usually keep a blank line
before the last "return xxx" in a function, and there are several
other places with the same problem.
Huacai
> +}
> +
> +static void ls7a_spi_set_cs(struct spi_device *spi, bool enable)
> +{
> + struct ls7a_spi *ls7a_spi;
> + int cs;
> +
> + ls7a_spi = spi_master_get_devdata(spi->master);
> +
> + cs = ls7a_spi_read_reg(ls7a_spi, SFC_SOFTCS) & ~(0x11 << spi->chip_select);
> +
> + if (!!(spi->mode & SPI_CS_HIGH) == enable)
> + ls7a_spi_write_reg(ls7a_spi, SFC_SOFTCS, (0x1 << spi->chip_select) | cs);
> + else
> + ls7a_spi_write_reg(ls7a_spi, SFC_SOFTCS, (0x11 << spi->chip_select) | cs);
> +}
> +
> +static int ls7a_spi_setup_transfer(struct spi_device *spi,
> + struct spi_transfer *t)
> +{
> + unsigned int hz;
> + unsigned int div, div_tmp;
> + unsigned int bit;
> + unsigned long clk;
> + unsigned char val;
> + unsigned char spcr, sper;
> + const char rdiv[12] = {0, 1, 4, 2, 3, 5, 6, 7, 8, 9, 10, 11};
> + struct ls7a_spi *ls7a_spi;
> +
> + ls7a_spi = spi_master_get_devdata(spi->master);
> +
> + if (t) {
> + hz = t->speed_hz;
> + if (!hz)
> + hz = spi->max_speed_hz;
> + } else {
> + hz = spi->max_speed_hz;
> + }
> +
> + if (hz & (ls7a_spi->hz != hz)) {
> + clk = 100000000;
> +
> + div = DIV_ROUND_UP(clk, hz);
> + if (div < 2)
> + div = 2;
> + if (div > 4096)
> + div = 4096;
> +
> + bit = fls(div) - 1;
> + if ((1 << bit) == div)
> + bit--;
> + div_tmp = rdiv[bit];
> +
> + dev_dbg(&spi->dev, "clk = %ld hz = %d div_tmp = %d bit = %d\n",
> + clk, hz, div_tmp, bit);
> +
> + ls7a_spi->hz = hz;
> + spcr = div_tmp & 3;
> + sper = (div_tmp >> 2) & 3;
> +
> + val = ls7a_spi_read_reg(ls7a_spi, SPCR);
> + ls7a_spi_write_reg(ls7a_spi, SPCR, (val & ~3) | spcr);
> + val = ls7a_spi_read_reg(ls7a_spi, SPER);
> + ls7a_spi_write_reg(ls7a_spi, SPER, (val & ~3) | sper);
> + }
> + return 0;
> +}
> +
> +static int ls7a_spi_setup(struct spi_device *spi)
> +{
> + return ls7a_spi_setup_transfer(spi, NULL);
> +}
> +
> +static int ls7a_spi_write_read_8bit(struct spi_device *spi,
> + const u8 **tx_buf, u8 **rx_buf,
> + unsigned int num)
> +{
> + struct ls7a_spi *ls7a_spi;
> +
> + ls7a_spi = spi_master_get_devdata(spi->master);
> +
> + if (tx_buf && *tx_buf) {
> + ls7a_spi_write_reg(ls7a_spi, FIFO, *((*tx_buf)++));
> +
> + while ((ls7a_spi_read_reg(ls7a_spi, SPSR) & 0x4) == 1)
> + ;
> + } else {
> + ls7a_spi_write_reg(ls7a_spi, FIFO, 0);
> +
> + while ((ls7a_spi_read_reg(ls7a_spi, SPSR) & 0x1) == 1)
> + ;
> + }
> +
> + if (rx_buf && *rx_buf)
> + *(*rx_buf)++ = ls7a_spi_read_reg(ls7a_spi, FIFO);
> + else
> + ls7a_spi_read_reg(ls7a_spi, FIFO);
> +
> + return 1;
> +}
> +
> +static unsigned int ls7a_spi_write_read(struct spi_device *spi,
> + struct spi_transfer *xfer)
> +{
> + unsigned int count;
> + const u8 *tx = xfer->tx_buf;
> + u8 *rx = xfer->rx_buf;
> +
> + count = xfer->len;
> +
> + do {
> + if (ls7a_spi_write_read_8bit(spi, &tx, &rx, count) < 0)
> + goto out;
> + count--;
> + } while (count);
> +
> +out:
> + return xfer->len - count;
> +}
> +
> +static int ls7a_spi_transfer_one(struct spi_master *master,
> + struct spi_device *spi,
> + struct spi_transfer *t)
> +{
> + int status = 0;
> +
> + status = ls7a_spi_setup_transfer(spi, t);
> + if (status < 0)
> + return status;
> +
> + if (t->len)
> + ls7a_spi_write_read(spi, t);
> +
> + return status;
> +}
> +
> +static int ls7a_spi_pci_probe(struct pci_dev *pdev,
> + const struct pci_device_id *ent)
> +{
> + struct spi_master *master;
> + struct ls7a_spi *spi;
> + int ret;
> +
> + master = devm_spi_alloc_master(&pdev->dev, sizeof(*spi));
> + if (!master)
> + return -ENOMEM;
> +
> + spi = spi_master_get_devdata(master);
> + ret = pcim_enable_device(pdev);
> + if (ret)
> + goto err_free_master;
> +
> + ret = pci_request_regions(pdev, "ls7a-spi");
> + if (ret)
> + goto err_free_master;
> +
> + spi->base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
> + if (!spi->base) {
> + ret = -EINVAL;
> + goto err_free_master;
> + }
> + ls7a_spi_write_reg(spi, SPCR, 0x51);
> + ls7a_spi_write_reg(spi, SPER, 0x00);
> + ls7a_spi_write_reg(spi, SFC_TIMING, 0x01);
> + ls7a_spi_write_reg(spi, SFC_PARAM, 0x40);
> + spi->mode = 0;
> +
> + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
> + master->set_cs = ls7a_spi_set_cs;
> + master->prepare_message = ls7a_spi_prepare_message;
> + master->setup = ls7a_spi_setup;
> + master->transfer_one = ls7a_spi_transfer_one;
> + master->bits_per_word_mask = SPI_BPW_MASK(8);
> + master->num_chipselect = 4;
> + master->dev.of_node = pdev->dev.of_node;
> +
> + spi->master = master;
> +
> + pci_set_drvdata(pdev, master);
> +
> + ret = spi_register_master(master);
> + if (ret)
> + goto err_free_master;
> +
> + return 0;
> +
> +err_free_master:
> + pci_release_regions(pdev);
> + return ret;
> +}
> +
> +static void ls7a_spi_pci_remove(struct pci_dev *pdev)
> +{
> + struct spi_master *master = pci_get_drvdata(pdev);
> +
> + spi_unregister_master(master);
> + pci_release_regions(pdev);
> +}
> +
> +static const struct pci_device_id ls7a_spi_pci_id_table[] = {
> + { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x7a0b) },
> + { 0, }
> +};
> +
> +MODULE_DEVICE_TABLE(pci, ls7a_spi_pci_id_table);
> +
> +static struct pci_driver ls7a_spi_pci_driver = {
> + .name = "ls7a-spi",
> + .id_table = ls7a_spi_pci_id_table,
> + .probe = ls7a_spi_pci_probe,
> + .remove = ls7a_spi_pci_remove,
> +};
> +
> +module_pci_driver(ls7a_spi_pci_driver);
> +
> +MODULE_AUTHOR("Juxin Gao <[email protected]>");
> +MODULE_AUTHOR("Qing Zhang <[email protected]>");
> +MODULE_DESCRIPTION("Loongson LS7A SPI controller driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.1.0
>
Hi, Huacai
On 12/28/2020 08:32 AM, Huacai Chen wrote:
> Hi, Qing,
>
> On Sat, Dec 26, 2020 at 5:13 PM Qing Zhang <[email protected]> wrote:
>> The SPI controller has the following characteristics:
>>
>> - Full-duplex synchronous serial data transmission
>> - Support up to 4 variable length byte transmission
>> - Main mode support
>> - Mode failure generates an error flag and issues an interrupt request
>> - Double buffer receiver
>> - Serial clock with programmable polarity and phase
>> - SPI can be controlled in wait mode
>> - Support boot from SPI
>>
>> Use mtd_debug tool to earse/write/read /dev/mtd0 on development.
>>
>> eg:
>>
>> [root@linux mtd-utils-1.0.0]# mtd_debug erase /dev/mtd0 0x20000 0x40000
>> Erased 262144 bytes from address 0x00020000 in flash
>> [root@linux mtd-utils-1.0.0]# mtd_debug write /dev/mtd0 0x20000 13 1.img
>> Copied 13 bytes from 1.img to address 0x00020000 in flash
>> [root@linux mtd-utils-1.0.0]# mtd_debug read /dev/mtd0 0x20000 13 2.img
>> Copied 13 bytes from address 0x00020000 in flash to 2.img
>> [root@linux mtd-utils-1.0.0]# cmp -l 1.img 2.img
>>
>> Signed-off-by: Qing Zhang <[email protected]>
>> ---
>>
>> v2:
>> - keep Kconfig and Makefile sorted
>> - make the entire comment a C++ one so things look more intentional
>> - Fix unclear indentation
>> - make conditional statements to improve legibility
>> - Don't use static inline
>> - the core handle message queue
>> - Add a new binding document
>> - Fix probe part mixed pdev and PCI
>>
>> v3:
>> - expose set_cs to the core and let it handle things
>> - replace transfer_one_message to transfer_one
>> - replace spi_alloc_master to devm_spi_alloc_master
>> - split out into prepare/unprepare_message
>> - releases pci regions before unregister master
>>
>> v4:
>> - names used in the manual
>> - rename ls7a_spi_do_transfer to ls7a_spi_setup_transfer
>> - change read the spcr and sper outside of this function
>> - mode configuration moved to prepare instead
>> - remove redundancy code about unprepare/prepare_message
>> - used 0x4 instead of 0x1,WFEMPTY instead of RFEMPTY
>>
>> v5:
>> - remove unnecessary blank lines
>>
>> ---
>> drivers/spi/Kconfig | 7 ++
>> drivers/spi/Makefile | 1 +
>> drivers/spi/spi-ls7a.c | 280 +++++++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 288 insertions(+)
>> create mode 100644 drivers/spi/spi-ls7a.c
>>
>> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
>> index aadaea0..af7c0d4 100644
>> --- a/drivers/spi/Kconfig
>> +++ b/drivers/spi/Kconfig
>> @@ -413,6 +413,13 @@ config SPI_LP8841_RTC
>> Say N here unless you plan to run the kernel on an ICP DAS
>> LP-8x4x industrial computer.
>>
>> +config SPI_LS7A
>> + tristate "Loongson LS7A SPI Controller Support"
>> + depends on CPU_LOONGSON64 || COMPILE_TEST
>> + help
>> + This drivers supports the Loongson LS7A SPI controller in master
>> + SPI mode.
>> +
>> config SPI_MPC52xx
>> tristate "Freescale MPC52xx SPI (non-PSC) controller support"
>> depends on PPC_MPC52xx
>> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
>> index 6fea582..d015cf2 100644
>> --- a/drivers/spi/Makefile
>> +++ b/drivers/spi/Makefile
>> @@ -61,6 +61,7 @@ obj-$(CONFIG_SPI_LANTIQ_SSC) += spi-lantiq-ssc.o
>> obj-$(CONFIG_SPI_JCORE) += spi-jcore.o
>> obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o
>> obj-$(CONFIG_SPI_LP8841_RTC) += spi-lp8841-rtc.o
>> +obj-$(CONFIG_SPI_LS7A) += spi-ls7a.o
>> obj-$(CONFIG_SPI_MESON_SPICC) += spi-meson-spicc.o
>> obj-$(CONFIG_SPI_MESON_SPIFC) += spi-meson-spifc.o
>> obj-$(CONFIG_SPI_MPC512x_PSC) += spi-mpc512x-psc.o
>> diff --git a/drivers/spi/spi-ls7a.c b/drivers/spi/spi-ls7a.c
>> new file mode 100644
>> index 0000000..d24b6d91
>> --- /dev/null
>> +++ b/drivers/spi/spi-ls7a.c
>> @@ -0,0 +1,280 @@
>> +// SPDX-License-Identifier: GPL-2.0-only
>> +//
>> +// Loongson LS7A SPI Controller driver
>> +//
>> +// Copyright (C) 2020 Loongson Technology Corporation Limited.
>> +//
>> +
>> +#include <linux/module.h>
>> +#include <linux/pci.h>
>> +#include <linux/spi/spi.h>
>> +
>> +/* define spi register */
>> +#define SPCR 0x00
>> +#define SPSR 0x01
>> +#define FIFO 0x02
>> +#define SPER 0x03
>> +#define SFC_PARAM 0x04
>> +#define SFC_SOFTCS 0x05
>> +#define SFC_TIMING 0x06
>> +
>> +struct ls7a_spi {
>> + struct spi_master *master;
>> + void __iomem *base;
>> + unsigned int hz;
>> + unsigned int mode;
>> +};
>> +
>> +static void ls7a_spi_write_reg(struct ls7a_spi *spi,
>> + unsigned char reg,
>> + unsigned char data)
>> +{
>> + writeb(data, spi->base + reg);
>> +}
>> +
>> +static char ls7a_spi_read_reg(struct ls7a_spi *spi, unsigned char reg)
>> +{
>> + return readb(spi->base + reg);
>> +}
>> +
>> +static int ls7a_spi_prepare_message(struct spi_master *master,
>> + struct spi_message *msg)
>> +{
>> + struct ls7a_spi *ls7a_spi;
>> + struct spi_device *spi = msg->spi;
>> + unsigned char val;
>> +
>> + ls7a_spi = spi_master_get_devdata(master);
>> +
>> + if (ls7a_spi->mode != spi->mode) {
>> + val = ls7a_spi_read_reg(ls7a_spi, SPCR);
>> + val &= ~0xc;
>> + if (spi->mode & SPI_CPOL)
>> + val |= 8;
>> + if (spi->mode & SPI_CPHA)
>> + val |= 4;
>> + ls7a_spi_write_reg(ls7a_spi, SPCR, val);
>> + val = ls7a_spi_read_reg(ls7a_spi, SPER);
>> + ls7a_spi_write_reg(ls7a_spi, SPER, val);
>> + ls7a_spi->mode = spi->mode;
>> + }
>> + return 0;
> I'm sorry that I hadn't review very carefully in V4 and you need to
> send another new version. In kernel code we usually keep a blank line
> before the last "return xxx" in a function, and there are several
> other places with the same problem.
>
> Huacai
Thank you again for your reply and suggestions,
I will send v6 in the soon.
Thanks,
-Qing
>
>> +}
>> +
>> +static void ls7a_spi_set_cs(struct spi_device *spi, bool enable)
>> +{
>> + struct ls7a_spi *ls7a_spi;
>> + int cs;
>> +
>> + ls7a_spi = spi_master_get_devdata(spi->master);
>> +
>> + cs = ls7a_spi_read_reg(ls7a_spi, SFC_SOFTCS) & ~(0x11 << spi->chip_select);
>> +
>> + if (!!(spi->mode & SPI_CS_HIGH) == enable)
>> + ls7a_spi_write_reg(ls7a_spi, SFC_SOFTCS, (0x1 << spi->chip_select) | cs);
>> + else
>> + ls7a_spi_write_reg(ls7a_spi, SFC_SOFTCS, (0x11 << spi->chip_select) | cs);
>> +}
>> +
>> +static int ls7a_spi_setup_transfer(struct spi_device *spi,
>> + struct spi_transfer *t)
>> +{
>> + unsigned int hz;
>> + unsigned int div, div_tmp;
>> + unsigned int bit;
>> + unsigned long clk;
>> + unsigned char val;
>> + unsigned char spcr, sper;
>> + const char rdiv[12] = {0, 1, 4, 2, 3, 5, 6, 7, 8, 9, 10, 11};
>> + struct ls7a_spi *ls7a_spi;
>> +
>> + ls7a_spi = spi_master_get_devdata(spi->master);
>> +
>> + if (t) {
>> + hz = t->speed_hz;
>> + if (!hz)
>> + hz = spi->max_speed_hz;
>> + } else {
>> + hz = spi->max_speed_hz;
>> + }
>> +
>> + if (hz & (ls7a_spi->hz != hz)) {
>> + clk = 100000000;
>> +
>> + div = DIV_ROUND_UP(clk, hz);
>> + if (div < 2)
>> + div = 2;
>> + if (div > 4096)
>> + div = 4096;
>> +
>> + bit = fls(div) - 1;
>> + if ((1 << bit) == div)
>> + bit--;
>> + div_tmp = rdiv[bit];
>> +
>> + dev_dbg(&spi->dev, "clk = %ld hz = %d div_tmp = %d bit = %d\n",
>> + clk, hz, div_tmp, bit);
>> +
>> + ls7a_spi->hz = hz;
>> + spcr = div_tmp & 3;
>> + sper = (div_tmp >> 2) & 3;
>> +
>> + val = ls7a_spi_read_reg(ls7a_spi, SPCR);
>> + ls7a_spi_write_reg(ls7a_spi, SPCR, (val & ~3) | spcr);
>> + val = ls7a_spi_read_reg(ls7a_spi, SPER);
>> + ls7a_spi_write_reg(ls7a_spi, SPER, (val & ~3) | sper);
>> + }
>> + return 0;
>> +}
>> +
>> +static int ls7a_spi_setup(struct spi_device *spi)
>> +{
>> + return ls7a_spi_setup_transfer(spi, NULL);
>> +}
>> +
>> +static int ls7a_spi_write_read_8bit(struct spi_device *spi,
>> + const u8 **tx_buf, u8 **rx_buf,
>> + unsigned int num)
>> +{
>> + struct ls7a_spi *ls7a_spi;
>> +
>> + ls7a_spi = spi_master_get_devdata(spi->master);
>> +
>> + if (tx_buf && *tx_buf) {
>> + ls7a_spi_write_reg(ls7a_spi, FIFO, *((*tx_buf)++));
>> +
>> + while ((ls7a_spi_read_reg(ls7a_spi, SPSR) & 0x4) == 1)
>> + ;
>> + } else {
>> + ls7a_spi_write_reg(ls7a_spi, FIFO, 0);
>> +
>> + while ((ls7a_spi_read_reg(ls7a_spi, SPSR) & 0x1) == 1)
>> + ;
>> + }
>> +
>> + if (rx_buf && *rx_buf)
>> + *(*rx_buf)++ = ls7a_spi_read_reg(ls7a_spi, FIFO);
>> + else
>> + ls7a_spi_read_reg(ls7a_spi, FIFO);
>> +
>> + return 1;
>> +}
>> +
>> +static unsigned int ls7a_spi_write_read(struct spi_device *spi,
>> + struct spi_transfer *xfer)
>> +{
>> + unsigned int count;
>> + const u8 *tx = xfer->tx_buf;
>> + u8 *rx = xfer->rx_buf;
>> +
>> + count = xfer->len;
>> +
>> + do {
>> + if (ls7a_spi_write_read_8bit(spi, &tx, &rx, count) < 0)
>> + goto out;
>> + count--;
>> + } while (count);
>> +
>> +out:
>> + return xfer->len - count;
>> +}
>> +
>> +static int ls7a_spi_transfer_one(struct spi_master *master,
>> + struct spi_device *spi,
>> + struct spi_transfer *t)
>> +{
>> + int status = 0;
>> +
>> + status = ls7a_spi_setup_transfer(spi, t);
>> + if (status < 0)
>> + return status;
>> +
>> + if (t->len)
>> + ls7a_spi_write_read(spi, t);
>> +
>> + return status;
>> +}
>> +
>> +static int ls7a_spi_pci_probe(struct pci_dev *pdev,
>> + const struct pci_device_id *ent)
>> +{
>> + struct spi_master *master;
>> + struct ls7a_spi *spi;
>> + int ret;
>> +
>> + master = devm_spi_alloc_master(&pdev->dev, sizeof(*spi));
>> + if (!master)
>> + return -ENOMEM;
>> +
>> + spi = spi_master_get_devdata(master);
>> + ret = pcim_enable_device(pdev);
>> + if (ret)
>> + goto err_free_master;
>> +
>> + ret = pci_request_regions(pdev, "ls7a-spi");
>> + if (ret)
>> + goto err_free_master;
>> +
>> + spi->base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
>> + if (!spi->base) {
>> + ret = -EINVAL;
>> + goto err_free_master;
>> + }
>> + ls7a_spi_write_reg(spi, SPCR, 0x51);
>> + ls7a_spi_write_reg(spi, SPER, 0x00);
>> + ls7a_spi_write_reg(spi, SFC_TIMING, 0x01);
>> + ls7a_spi_write_reg(spi, SFC_PARAM, 0x40);
>> + spi->mode = 0;
>> +
>> + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
>> + master->set_cs = ls7a_spi_set_cs;
>> + master->prepare_message = ls7a_spi_prepare_message;
>> + master->setup = ls7a_spi_setup;
>> + master->transfer_one = ls7a_spi_transfer_one;
>> + master->bits_per_word_mask = SPI_BPW_MASK(8);
>> + master->num_chipselect = 4;
>> + master->dev.of_node = pdev->dev.of_node;
>> +
>> + spi->master = master;
>> +
>> + pci_set_drvdata(pdev, master);
>> +
>> + ret = spi_register_master(master);
>> + if (ret)
>> + goto err_free_master;
>> +
>> + return 0;
>> +
>> +err_free_master:
>> + pci_release_regions(pdev);
>> + return ret;
>> +}
>> +
>> +static void ls7a_spi_pci_remove(struct pci_dev *pdev)
>> +{
>> + struct spi_master *master = pci_get_drvdata(pdev);
>> +
>> + spi_unregister_master(master);
>> + pci_release_regions(pdev);
>> +}
>> +
>> +static const struct pci_device_id ls7a_spi_pci_id_table[] = {
>> + { PCI_DEVICE(PCI_VENDOR_ID_LOONGSON, 0x7a0b) },
>> + { 0, }
>> +};
>> +
>> +MODULE_DEVICE_TABLE(pci, ls7a_spi_pci_id_table);
>> +
>> +static struct pci_driver ls7a_spi_pci_driver = {
>> + .name = "ls7a-spi",
>> + .id_table = ls7a_spi_pci_id_table,
>> + .probe = ls7a_spi_pci_probe,
>> + .remove = ls7a_spi_pci_remove,
>> +};
>> +
>> +module_pci_driver(ls7a_spi_pci_driver);
>> +
>> +MODULE_AUTHOR("Juxin Gao <[email protected]>");
>> +MODULE_AUTHOR("Qing Zhang <[email protected]>");
>> +MODULE_DESCRIPTION("Loongson LS7A SPI controller driver");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 2.1.0
>>