spi: stm32: Switch to use GPIO descriptors for CS

This switches the STM32 SPI driver over to using GPIO
descriptors for chip select. Instead of the callbacks for
picking the GPIO lines using the legacy API we just let
the core handle it all using descriptors.

Cc: Fabien Dessenne <fabien.dessenne@st.com>
Cc: Amelie Delaunay <amelie.delaunay@st.com>
Cc: Cezary Gapinski <cezary.gapinski@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20191205083401.27077-1-linus.walleij@linaro.orgSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-stm32.c

@@ -9,7 +9,6 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/dmaengine.h>
-#include <linux/gpio.h>
 #include <linux/interrupt.h>
 #include <linux/iopoll.h>
 #include <linux/module.h>
@@ -973,29 +972,6 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-/**
- * stm32_spi_setup - setup device chip select
- */
-static int stm32_spi_setup(struct spi_device *spi_dev)
-{
-	int ret = 0;
-
-	if (!gpio_is_valid(spi_dev->cs_gpio)) {
-		dev_err(&spi_dev->dev, "%d is not a valid gpio\n",
-			spi_dev->cs_gpio);
-		return -EINVAL;
-	}
-
-	dev_dbg(&spi_dev->dev, "%s: set gpio%d output %s\n", __func__,
-		spi_dev->cs_gpio,
-		(spi_dev->mode & SPI_CS_HIGH) ? "low" : "high");
-
-	ret = gpio_direction_output(spi_dev->cs_gpio,
-				    !(spi_dev->mode & SPI_CS_HIGH));
-
-	return ret;
-}
-
 /**
  * stm32_spi_prepare_msg - set up the controller to transfer a single message
  */
@@ -1810,7 +1786,7 @@ static int stm32_spi_probe(struct platform_device *pdev)
 	struct spi_master *master;
 	struct stm32_spi *spi;
 	struct resource *res;
-	int i, ret;
+	int ret;
 
 	master = spi_alloc_master(&pdev->dev, sizeof(struct stm32_spi));
 	if (!master) {
@@ -1898,7 +1874,7 @@ static int stm32_spi_probe(struct platform_device *pdev)
 	master->bits_per_word_mask = spi->cfg->get_bpw_mask(spi);
 	master->max_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_min;
 	master->min_speed_hz = spi->clk_rate / spi->cfg->baud_rate_div_max;
-	master->setup = stm32_spi_setup;
+	master->use_gpio_descriptors = true;
 	master->prepare_message = stm32_spi_prepare_msg;
 	master->transfer_one = stm32_spi_transfer_one;
 	master->unprepare_message = stm32_spi_unprepare_msg;
@@ -1928,29 +1904,12 @@ static int stm32_spi_probe(struct platform_device *pdev)
 		goto err_dma_release;
 	}
 
-	if (!master->cs_gpios) {
+	if (!master->cs_gpiods) {
 		dev_err(&pdev->dev, "no CS gpios available\n");
 		ret = -EINVAL;
 		goto err_dma_release;
 	}
 
-	for (i = 0; i < master->num_chipselect; i++) {
-		if (!gpio_is_valid(master->cs_gpios[i])) {
-			dev_err(&pdev->dev, "%i is not a valid gpio\n",
-				master->cs_gpios[i]);
-			ret = -EINVAL;
-			goto err_dma_release;
-		}
-
-		ret = devm_gpio_request(&pdev->dev, master->cs_gpios[i],
-					DRIVER_NAME);
-		if (ret) {
-			dev_err(&pdev->dev, "can't get CS gpio %i\n",
-				master->cs_gpios[i]);
-			goto err_dma_release;
-		}
-	}
-
 	dev_info(&pdev->dev, "driver initialized\n");
 
 	return 0;