[PATCH v6 5/6] spi: rockchip: Support cs-gpio

Jon Lin
2021-06-07T11:21:18Z

1.Add standard cs-gpio support
2.Refer to spi-controller.yaml for details

Signed-off-by: Jon Lin <jon.lin@rock-chips.com>
---

Changes in v6: None
Changes in v5: None
Changes in v4: None
Changes in v3: None

drivers/spi/spi-rockchip.c | 61 ++++++++++++++++++++++++++++++++++----
1 file changed, 56 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index 950d3bce443b..48b666d42d8a 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -6,6 +6,7 @@

#include <linux/clk.h>
#include <linux/dmaengine.h>
+#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -157,7 +158,8 @@
*/
#define ROCKCHIP_SPI_MAX_TRANLEN 0xffff

-#define ROCKCHIP_SPI_MAX_CS_NUM 2
+/* 2 for native cs, 2 for cs-gpio */
+#define ROCKCHIP_SPI_MAX_CS_NUM 4
#define ROCKCHIP_SPI_VER2_TYPE1 0x05EC0002
#define ROCKCHIP_SPI_VER2_TYPE2 0x00110002

@@ -191,6 +193,7 @@ struct rockchip_spi {
bool cs_asserted[ROCKCHIP_SPI_MAX_CS_NUM];

bool slave_abort;
+ bool gpio_requested;
};

static inline void spi_enable_chip(struct rockchip_spi *rs, bool enable)
@@ -245,11 +248,15 @@ static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
/* Keep things powered as long as CS is asserted */
pm_runtime_get_sync(rs->dev);

- ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER,
- BIT(spi->chip_select));
+ if (gpio_is_valid(spi->cs_gpio))
+ ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
+ else
+ ROCKCHIP_SPI_SET_BITS(rs->regs + ROCKCHIP_SPI_SER, BIT(spi->chip_select));
} else {
- ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER,
- BIT(spi->chip_select));
+ if (gpio_is_valid(spi->cs_gpio))
+ ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, 1);
+ else
+ ROCKCHIP_SPI_CLR_BITS(rs->regs + ROCKCHIP_SPI_SER, BIT(spi->chip_select));

/* Drop reference from when we first asserted CS */
pm_runtime_put(rs->dev);
@@ -632,6 +639,47 @@ static bool rockchip_spi_can_dma(struct spi_controller *ctlr,
return xfer->len / bytes_per_word >= rs->fifo_len;
}

+static int rockchip_spi_setup(struct spi_device *spi)
+{
+
+ int ret = -EINVAL;
+ struct rockchip_spi *rs = spi_controller_get_devdata(spi->controller);
+
+ if (spi->cs_gpio == -ENOENT)
+ return 0;
+
+ if (!rs->gpio_requested && gpio_is_valid(spi->cs_gpio)) {
+ ret = gpio_request_one(spi->cs_gpio,
+ (spi->mode & SPI_CS_HIGH) ?
+ GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH,
+ dev_name(&spi->dev));
+ if (ret)
+ dev_err(&spi->dev, "can't request chipselect gpio %d\n",
+ spi->cs_gpio);
+ else
+ rs->gpio_requested = true;
+ } else {
+ if (gpio_is_valid(spi->cs_gpio)) {
+ int mode = ((spi->mode & SPI_CS_HIGH) ? 0 : 1);
+
+ ret = gpio_direction_output(spi->cs_gpio, mode);
+ if (ret)
+ dev_err(&spi->dev, "chipselect gpio %d setup failed (%d)\n",
+ spi->cs_gpio, ret);
+ }
+ }
+
+ return ret;
+}
+
+static void rockchip_spi_cleanup(struct spi_device *spi)
+{
+ struct rockchip_spi *rs = spi_controller_get_devdata(spi->controller);
+
+ if (rs->gpio_requested)
+ gpio_free(spi->cs_gpio);
+}
+
static int rockchip_spi_probe(struct platform_device *pdev)
{
int ret;
@@ -706,6 +754,7 @@ static int rockchip_spi_probe(struct platform_device *pdev)

rs->dev = &pdev->dev;
rs->freq = clk_get_rate(rs->spiclk);
+ rs->gpio_requested = false;

if (!of_property_read_u32(pdev->dev.of_node, "rx-sample-delay-ns",
&rsd_nsecs)) {
@@ -759,6 +808,8 @@ static int rockchip_spi_probe(struct platform_device *pdev)
ctlr->max_speed_hz = min(rs->freq / BAUDR_SCKDV_MIN, MAX_SCLK_OUT);

ctlr->set_cs = rockchip_spi_set_cs;
+ ctlr->setup = rockchip_spi_setup;
+ ctlr->cleanup = rockchip_spi_cleanup;
ctlr->transfer_one = rockchip_spi_transfer_one;
ctlr->max_transfer_size = rockchip_spi_max_transfer_size;
ctlr->handle_err = rockchip_spi_handle_err;