mmc: sdhci-s3c: Add device tree support

Add device tree based discovery support for Samsung's sdhci controller.

Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 152 insertions, 6 deletions

diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index 00969ba03277..0c77b10d2619 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -34,6 +34,9 @@
 
 #define MAX_BUS_CLK     (4)
 
+/* Number of gpio's used is max data bus width + command and clock lines */
+#define NUM_GPIOS(x)    (x + 2)
+
 /**
  * struct sdhci_s3c - S3C SDHCI instance
  * @host: The SDHCI host created
@@ -41,6 +44,7 @@
  * @ioarea: The resource created when we claimed the IO area.
  * @pdata: The platform data for this controller.
  * @cur_clk: The index of the current bus clock.
+ * @gpios: List of gpio numbers parsed from device tree.
  * @clk_io: The clock for the internal bus interface.
  * @clk_bus: The clocks that are available for the SD/MMC bus clock.
  */
@@ -52,6 +56,7 @@ struct sdhci_s3c {
         unsigned int            cur_clk;
         int                     ext_cd_irq;
         int                     ext_cd_gpio;
+        int                     *gpios;
 
         struct clk              *clk_io;
         struct clk              *clk_bus[MAX_BUS_CLK];
@@ -422,9 +427,121 @@ static void sdhci_s3c_setup_card_detect_gpio(struct sdhci_s3c *sc)
         }
 }
 
+#ifdef CONFIG_OF
+static int __devinit sdhci_s3c_parse_dt(struct device *dev,
+                struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
+{
+        struct device_node *node = dev->of_node;
+        struct sdhci_s3c *ourhost = to_s3c(host);
+        u32 max_width;
+        int gpio, cnt, ret;
+
+        /* if the bus-width property is not specified, assume width as 1 */
+        if (of_property_read_u32(node, "bus-width", &max_width))
+                max_width = 1;
+        pdata->max_width = max_width;
+
+        ourhost->gpios = devm_kzalloc(dev, NUM_GPIOS(pdata->max_width) *
+                                sizeof(int), GFP_KERNEL);
+        if (!ourhost->gpios)
+                return -ENOMEM;
+
+        /* get the card detection method */
+        if (of_get_property(node, "broken-cd", 0)) {
+                pdata->cd_type = S3C_SDHCI_CD_NONE;
+                goto setup_bus;
+        }
+
+        if (of_get_property(node, "non-removable", 0)) {
+                pdata->cd_type = S3C_SDHCI_CD_PERMANENT;
+                goto setup_bus;
+        }
+
+        gpio = of_get_named_gpio(node, "cd-gpios", 0);
+        if (gpio_is_valid(gpio)) {
+                pdata->cd_type = S3C_SDHCI_CD_GPIO;
+                goto found_cd;
+        } else if (gpio != -ENOENT) {
+                dev_err(dev, "invalid card detect gpio specified\n");
+                return -EINVAL;
+        }
+
+        gpio = of_get_named_gpio(node, "samsung,cd-pinmux-gpio", 0);
+        if (gpio_is_valid(gpio)) {
+                pdata->cd_type = S3C_SDHCI_CD_INTERNAL;
+                goto found_cd;
+        } else if (gpio != -ENOENT) {
+                dev_err(dev, "invalid card detect gpio specified\n");
+                return -EINVAL;
+        }
+
+        dev_info(dev, "assuming no card detect line available\n");
+        pdata->cd_type = S3C_SDHCI_CD_NONE;
+
+ found_cd:
+        if (pdata->cd_type == S3C_SDHCI_CD_GPIO) {
+                pdata->ext_cd_gpio = gpio;
+                ourhost->ext_cd_gpio = -1;
+                if (of_get_property(node, "cd-inverted", NULL))
+                        pdata->ext_cd_gpio_invert = 1;
+        } else if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL) {
+                ret = gpio_request(gpio, "sdhci-cd");
+                if (ret) {
+                        dev_err(dev, "card detect gpio request failed\n");
+                        return -EINVAL;
+                }
+                ourhost->ext_cd_gpio = gpio;
+        }
+
+ setup_bus:
+        /* get the gpios for command, clock and data lines */
+        for (cnt = 0; cnt < NUM_GPIOS(pdata->max_width); cnt++) {
+                gpio = of_get_gpio(node, cnt);
+                if (!gpio_is_valid(gpio)) {
+                        dev_err(dev, "invalid gpio[%d]\n", cnt);
+                        goto err_free_dt_cd_gpio;
+                }
+                ourhost->gpios[cnt] = gpio;
+        }
+
+        for (cnt = 0; cnt < NUM_GPIOS(pdata->max_width); cnt++) {
+                ret = gpio_request(ourhost->gpios[cnt], "sdhci-gpio");
+                if (ret) {
+                        dev_err(dev, "gpio[%d] request failed\n", cnt);
+                        goto err_free_dt_gpios;
+                }
+        }
+
+        return 0;
+
+ err_free_dt_gpios:
+        while (--cnt >= 0)
+                gpio_free(ourhost->gpios[cnt]);
+ err_free_dt_cd_gpio:
+        if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL)
+                gpio_free(ourhost->ext_cd_gpio);
+        return -EINVAL;
+}
+#else
+static int __devinit sdhci_s3c_parse_dt(struct device *dev,
+                struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
+{
+        return -EINVAL;
+}
+#endif
+
+static const struct of_device_id sdhci_s3c_dt_match[];
+
 static inline struct sdhci_s3c_drv_data *sdhci_s3c_get_driver_data(
                         struct platform_device *pdev)
 {
+#ifdef CONFIG_OF
+        if (pdev->dev.of_node) {
+                const struct of_device_id *match;
+                match = of_match_node(sdhci_s3c_dt_match, pdev->dev.of_node);
+                return (struct sdhci_s3c_drv_data *)match->data;
+        }
+#endif
         return (struct sdhci_s3c_drv_data *)
                         platform_get_device_id(pdev)->driver_data;
 }
@@ -439,7 +556,7 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
         struct resource *res;
         int ret, irq, ptr, clks;
 
-        if (!pdev->dev.platform_data) {
+        if (!pdev->dev.platform_data && !pdev->dev.of_node) {
                 dev_err(dev, "no device data specified\n");
                 return -ENOENT;
         }
@@ -455,21 +572,28 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
                 dev_err(dev, "sdhci_alloc_host() failed\n");
                 return PTR_ERR(host);
         }
+        sc = sdhci_priv(host);
 
         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
         if (!pdata) {
                 ret = -ENOMEM;
-                goto err_io_clk;
+                goto err_pdata;
+        }
+
+        if (pdev->dev.of_node) {
+                ret = sdhci_s3c_parse_dt(&pdev->dev, host, pdata);
+                if (ret)
+                        goto err_pdata;
+        } else {
+                memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
+                sc->ext_cd_gpio = -1; /* invalid gpio number */
         }
-        memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
 
         drv_data = sdhci_s3c_get_driver_data(pdev);
-        sc = sdhci_priv(host);
 
         sc->host = host;
         sc->pdev = pdev;
         sc->pdata = pdata;
-        sc->ext_cd_gpio = -1; /* invalid gpio number */
 
         platform_set_drvdata(pdev, host);
 
@@ -633,6 +757,12 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
         clk_put(sc->clk_io);
 
  err_io_clk:
+        for (ptr = 0; ptr < NUM_GPIOS(sc->pdata->max_width); ptr++)
+                gpio_free(sc->gpios[ptr]);
+        if (pdata->cd_type == S3C_SDHCI_CD_INTERNAL)
+                gpio_free(sc->ext_cd_gpio);
+
+ err_pdata:
         sdhci_free_host(host);
 
         return ret;
@@ -640,9 +770,9 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
 
 static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
 {
-        struct s3c_sdhci_platdata *pdata = pdev->dev.platform_data;
         struct sdhci_host *host =  platform_get_drvdata(pdev);
         struct sdhci_s3c *sc = sdhci_priv(host);
+        struct s3c_sdhci_platdata *pdata = sc->pdata;
         int ptr;
 
         if (pdata->cd_type == S3C_SDHCI_CD_EXTERNAL && pdata->ext_cd_cleanup)
@@ -667,6 +797,11 @@ static int __devexit sdhci_s3c_remove(struct platform_device *pdev)
         clk_disable(sc->clk_io);
         clk_put(sc->clk_io);
 
+        if (pdev->dev.of_node) {
+                for (ptr = 0; ptr < NUM_GPIOS(sc->pdata->max_width); ptr++)
+                        gpio_free(sc->gpios[ptr]);
+        }
+
         sdhci_free_host(host);
         platform_set_drvdata(pdev, NULL);
 
@@ -739,6 +874,16 @@ static struct platform_device_id sdhci_s3c_driver_ids[] = {
 };
 MODULE_DEVICE_TABLE(platform, sdhci_s3c_driver_ids);
 
+#ifdef CONFIG_OF
+static const struct of_device_id sdhci_s3c_dt_match[] = {
+        { .compatible = "samsung,s3c6410-sdhci", },
+        { .compatible = "samsung,exynos4210-sdhci",
+                .data = (void *)EXYNOS4_SDHCI_DRV_DATA },
+        {},
+};
+MODULE_DEVICE_TABLE(of, sdhci_s3c_dt_match);
+#endif
+
 static struct platform_driver sdhci_s3c_driver = {
         .probe          = sdhci_s3c_probe,
         .remove         = __devexit_p(sdhci_s3c_remove),
@@ -746,6 +891,7 @@ static struct platform_driver sdhci_s3c_driver = {
         .driver         = {
                 .owner  = THIS_MODULE,
                 .name   = "s3c-sdhci",
+                .of_match_table = of_match_ptr(sdhci_s3c_dt_match),
                 .pm     = SDHCI_S3C_PMOPS,
         },
 };