spi: s3c24xx: Convert to GPIO descriptors

This driver has a bunch of custom oldstyle GPIO number-passing
fields and a custom set-up callback.

The good thing is: nothing in the kernel is using it.

Convert the driver to use GPIO descriptors with a SPI_MASTER_GPIO_SS
flag so that the local CS callback also get invoked as the hardware
needs this.

New users of this driver can provide GPIO descriptor tables like
the other converted drivers.

Cc: linux-samsung-soc@vger.kernel.org
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: Sylwester Nawrocki <snawrocki@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20220119000914.192553-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 3 insertions, 49 deletions

diff --git a/drivers/spi/spi-s3c24xx.c b/drivers/spi/spi-s3c24xx.c
index d6f51695ca5b..660aa866af06 100644
--- a/drivers/spi/spi-s3c24xx.c
+++ b/drivers/spi/spi-s3c24xx.c
@@ -12,7 +12,6 @@
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/platform_device.h>
-#include <linux/gpio.h>
 #include <linux/io.h>
 #include <linux/slab.h>
 
@@ -62,9 +61,6 @@ struct s3c24xx_spi {
 	unsigned char		 fiq_inuse;
 	unsigned char		 fiq_claimed;
 
-	void			(*set_cs)(struct s3c2410_spi_info *spi,
-					  int cs, int pol);
-
 	/* data buffers */
 	const unsigned char	*tx;
 	unsigned char		*rx;
@@ -84,29 +80,21 @@ static inline struct s3c24xx_spi *to_hw(struct spi_device *sdev)
 	return spi_master_get_devdata(sdev->master);
 }
 
-static void s3c24xx_spi_gpiocs(struct s3c2410_spi_info *spi, int cs, int pol)
-{
-	gpio_set_value(spi->pin_cs, pol);
-}
-
 static void s3c24xx_spi_chipsel(struct spi_device *spi, int value)
 {
 	struct s3c24xx_spi_devstate *cs = spi->controller_state;
 	struct s3c24xx_spi *hw = to_hw(spi);
-	unsigned int cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
 
 	/* change the chipselect state and the state of the spi engine clock */
 
 	switch (value) {
 	case BITBANG_CS_INACTIVE:
-		hw->set_cs(hw->pdata, spi->chip_select, cspol^1);
 		writeb(cs->spcon, hw->regs + S3C2410_SPCON);
 		break;
 
 	case BITBANG_CS_ACTIVE:
 		writeb(cs->spcon | S3C2410_SPCON_ENSCK,
 		       hw->regs + S3C2410_SPCON);
-		hw->set_cs(hw->pdata, spi->chip_select, cspol);
 		break;
 	}
 }
@@ -452,14 +440,6 @@ static void s3c24xx_spi_initialsetup(struct s3c24xx_spi *hw)
 	writeb(0xff, hw->regs + S3C2410_SPPRE);
 	writeb(SPPIN_DEFAULT, hw->regs + S3C2410_SPPIN);
 	writeb(SPCON_DEFAULT, hw->regs + S3C2410_SPCON);
-
-	if (hw->pdata) {
-		if (hw->set_cs == s3c24xx_spi_gpiocs)
-			gpio_direction_output(hw->pdata->pin_cs, 1);
-
-		if (hw->pdata->gpio_setup)
-			hw->pdata->gpio_setup(hw->pdata, 1);
-	}
 }
 
 static int s3c24xx_spi_probe(struct platform_device *pdev)
@@ -502,6 +482,9 @@ static int s3c24xx_spi_probe(struct platform_device *pdev)
 	master->num_chipselect = hw->pdata->num_cs;
 	master->bus_num = pdata->bus_num;
 	master->bits_per_word_mask = SPI_BPW_MASK(8);
+	/* we need to call the local chipselect callback */
+	master->flags = SPI_MASTER_GPIO_SS;
+	master->use_gpio_descriptors = true;
 
 	/* setup the state for the bitbang driver */
 
@@ -541,27 +524,6 @@ static int s3c24xx_spi_probe(struct platform_device *pdev)
 		goto err_no_pdata;
 	}
 
-	/* setup any gpio we can */
-
-	if (!pdata->set_cs) {
-		if (pdata->pin_cs < 0) {
-			dev_err(&pdev->dev, "No chipselect pin\n");
-			err = -EINVAL;
-			goto err_register;
-		}
-
-		err = devm_gpio_request(&pdev->dev, pdata->pin_cs,
-					dev_name(&pdev->dev));
-		if (err) {
-			dev_err(&pdev->dev, "Failed to get gpio for cs\n");
-			goto err_register;
-		}
-
-		hw->set_cs = s3c24xx_spi_gpiocs;
-		gpio_direction_output(pdata->pin_cs, 1);
-	} else
-		hw->set_cs = pdata->set_cs;
-
 	s3c24xx_spi_initialsetup(hw);
 
 	/* register our spi controller */
@@ -604,9 +566,6 @@ static int s3c24xx_spi_suspend(struct device *dev)
 	if (ret)
 		return ret;
 
-	if (hw->pdata && hw->pdata->gpio_setup)
-		hw->pdata->gpio_setup(hw->pdata, 0);
-
 	clk_disable(hw->clk);
 	return 0;
 }
diff --git a/include/linux/spi/s3c24xx.h b/include/linux/spi/s3c24xx.h
index 440a71593162..9b8bb22d5b0c 100644
--- a/include/linux/spi/s3c24xx.h
+++ b/include/linux/spi/s3c24xx.h
@@ -10,14 +10,9 @@
 #define __LINUX_SPI_S3C24XX_H __FILE__
 
 struct s3c2410_spi_info {
-	int			 pin_cs;	/* simple gpio cs */
 	unsigned int		 num_cs;	/* total chipselects */
 	int			 bus_num;       /* bus number to use. */
-
 	unsigned int		 use_fiq:1;	/* use fiq */
-
-	void (*gpio_setup)(struct s3c2410_spi_info *spi, int enable);
-	void (*set_cs)(struct s3c2410_spi_info *spi, int cs, int pol);
 };
 
 extern int s3c24xx_set_fiq(unsigned int irq, u32 *ack_ptr, bool on);