spi: gpio: Don't request CS GPIO in DT use-case

DT use-case already relies on SPI core to control CS (requested by
of_spi_register_master() and controlled spi_set_cs()), so there's no
need to try to request those GPIO in spi-gpio code. Change the code
such that spi-gpio's CS related code is only used if device is probed
via pdata.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Healy <cphealy@gmail.com>
Cc: linux-spi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c
index c8fe87ebf8c8fbae949276aab42a6eea767eedbf..3d05c6a71706b092a3599c081243bd99bceb597c 100644 (file)
--- a/drivers/spi/spi-gpio.c
+++ b/drivers/spi/spi-gpio.c
@@ -46,7 +46,6 @@ struct spi_gpio {
        struct gpio_desc                *miso;
        struct gpio_desc                *mosi;
        struct gpio_desc                **cs_gpios;
-       bool                            has_cs;
 };
 
 /*----------------------------------------------------------------------*/
@@ -216,7 +215,7 @@ static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
                gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL);
 
        /* Drive chip select line, if we have one */
-       if (spi_gpio->has_cs) {
+       if (spi_gpio->cs_gpios) {
                struct gpio_desc *cs = spi_gpio->cs_gpios[spi->chip_select];
 
                /* SPI chip selects are normally active-low */
@@ -234,10 +233,12 @@ static int spi_gpio_setup(struct spi_device *spi)
         * The CS GPIOs have already been
         * initialized from the descriptor lookup.
         */
-       cs = spi_gpio->cs_gpios[spi->chip_select];
-       if (!spi->controller_state && cs)
-               status = gpiod_direction_output(cs,
-                                               !(spi->mode & SPI_CS_HIGH));
+       if (spi_gpio->cs_gpios) {
+               cs = spi_gpio->cs_gpios[spi->chip_select];
+               if (!spi->controller_state && cs)
+                       status = gpiod_direction_output(cs,
+                                                 !(spi->mode & SPI_CS_HIGH));
+       }
 
        if (!status)
                status = spi_bitbang_setup(spi);
@@ -290,11 +291,8 @@ static void spi_gpio_cleanup(struct spi_device *spi)
  */
 static int spi_gpio_request(struct device *dev,
                            struct spi_gpio *spi_gpio,
-                           unsigned int num_chipselects,
                            u16 *mflags)
 {
-       int i;
-
        spi_gpio->mosi = devm_gpiod_get_optional(dev, "mosi", GPIOD_OUT_LOW);
        if (IS_ERR(spi_gpio->mosi))
                return PTR_ERR(spi_gpio->mosi);
@@ -315,13 +313,6 @@ static int spi_gpio_request(struct device *dev,
        if (IS_ERR(spi_gpio->sck))
                return PTR_ERR(spi_gpio->sck);
 
-       for (i = 0; i < num_chipselects; i++) {
-               spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs",
-                                                            i, GPIOD_OUT_HIGH);
-               if (IS_ERR(spi_gpio->cs_gpios[i]))
-                       return PTR_ERR(spi_gpio->cs_gpios[i]);
-       }
-
        return 0;
 }
 
@@ -332,90 +323,87 @@ static const struct of_device_id spi_gpio_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids);
 
-static int spi_gpio_probe_dt(struct platform_device *pdev)
+static int spi_gpio_probe_dt(struct platform_device *pdev,
+                            struct spi_master *master)
 {
-       int ret;
-       u32 tmp;
-       struct spi_gpio_platform_data   *pdata;
-       struct device_node *np = pdev->dev.of_node;
-       const struct of_device_id *of_id =
-                       of_match_device(spi_gpio_dt_ids, &pdev->dev);
-
-       if (!of_id)
-               return 0;
+       master->dev.of_node = pdev->dev.of_node;
+       master->use_gpio_descriptors = true;
 
-       pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
-       if (!pdata)
-               return -ENOMEM;
+       return 0;
+}
+#else
+static inline int spi_gpio_probe_dt(struct platform_device *pdev,
+                                   struct spi_master *master)
+{
+       return 0;
+}
+#endif
 
+static int spi_gpio_probe_pdata(struct platform_device *pdev,
+                               struct spi_master *master)
+{
+       struct device *dev = &pdev->dev;
+       struct spi_gpio_platform_data *pdata = dev_get_platdata(dev);
+       struct spi_gpio *spi_gpio = spi_master_get_devdata(master);
+       int i;
 
-       ret = of_property_read_u32(np, "num-chipselects", &tmp);
-       if (ret < 0) {
-               dev_err(&pdev->dev, "num-chipselects property not found\n");
-               goto error_free;
-       }
+#ifdef GENERIC_BITBANG
+       if (!pdata || !pdata->num_chipselect)
+               return -ENODEV;
+#endif
+       /*
+        * The master needs to think there is a chipselect even if not
+        * connected
+        */
+       master->num_chipselect = pdata->num_chipselect ?: 1;
 
-       pdata->num_chipselect = tmp;
-       pdev->dev.platform_data = pdata;
+       spi_gpio->cs_gpios = devm_kcalloc(dev, master->num_chipselect,
+                                         sizeof(*spi_gpio->cs_gpios),
+                                         GFP_KERNEL);
+       if (!spi_gpio->cs_gpios)
+               return -ENOMEM;
 
-       return 1;
+       for (i = 0; i < master->num_chipselect; i++) {
+               spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs", i,
+                                                            GPIOD_OUT_HIGH);
+               if (IS_ERR(spi_gpio->cs_gpios[i]))
+                       return PTR_ERR(spi_gpio->cs_gpios[i]);
+       }
 
-error_free:
-       devm_kfree(&pdev->dev, pdata);
-       return ret;
-}
-#else
-static inline int spi_gpio_probe_dt(struct platform_device *pdev)
-{
        return 0;
 }
-#endif
 
 static int spi_gpio_probe(struct platform_device *pdev)
 {
        int                             status;
        struct spi_master               *master;
        struct spi_gpio                 *spi_gpio;
-       struct spi_gpio_platform_data   *pdata;
        struct device                   *dev = &pdev->dev;
        struct spi_bitbang              *bb;
+       const struct of_device_id       *of_id;
        u16 master_flags = 0;
-       bool use_of = 0;
-
-       status = spi_gpio_probe_dt(pdev);
-       if (status < 0)
-               return status;
-       if (status > 0)
-               use_of = 1;
 
-       pdata = dev_get_platdata(dev);
-#ifdef GENERIC_BITBANG
-       if (!pdata || (!use_of && !pdata->num_chipselect))
-               return -ENODEV;
-#endif
+       of_id = of_match_device(spi_gpio_dt_ids, &pdev->dev);
 
        master = spi_alloc_master(dev, sizeof(*spi_gpio));
        if (!master)
                return -ENOMEM;
 
-       spi_gpio = spi_master_get_devdata(master);
+       if (of_id)
+               status = spi_gpio_probe_dt(pdev, master);
+       else
+               status = spi_gpio_probe_pdata(pdev, master);
 
-       spi_gpio->cs_gpios = devm_kcalloc(dev,
-                               pdata->num_chipselect,
-                               sizeof(*spi_gpio->cs_gpios),
-                               GFP_KERNEL);
-       if (!spi_gpio->cs_gpios)
-               return -ENOMEM;
+       if (status)
+               return status;
 
-       platform_set_drvdata(pdev, spi_gpio);
+       spi_gpio = spi_master_get_devdata(master);
 
-       /* Determine if we have chip selects connected */
-       spi_gpio->has_cs = !!pdata->num_chipselect;
+       platform_set_drvdata(pdev, spi_gpio);
 
        spi_gpio->pdev = pdev;
 
-       status = spi_gpio_request(dev, spi_gpio,
-                                 pdata->num_chipselect, &master_flags);
+       status = spi_gpio_request(dev, spi_gpio, &master_flags);
        if (status)
                return status;
 
@@ -424,13 +412,9 @@ static int spi_gpio_probe(struct platform_device *pdev)
                            SPI_CS_HIGH;
        master->flags = master_flags;
        master->bus_num = pdev->id;
-       /* The master needs to think there is a chipselect even if not connected */
-       master->num_chipselect = spi_gpio->has_cs ? pdata->num_chipselect : 1;
        master->setup = spi_gpio_setup;
        master->cleanup = spi_gpio_cleanup;
-#ifdef CONFIG_OF
-       master->dev.of_node = dev->of_node;
-#endif
+
        bb = &spi_gpio->bitbang;
        bb->master = master;
        bb->chipselect = spi_gpio_chipselect;