gpio-rcar: Add DT support

Add DT bindings for the gpio-rcar driver and read the device
configuration from the DT node at probe time if available.

Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

1 files changed, 56 insertions, 10 deletions

diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c
index d173d56dbb8c..5a693dd0ac7a 100644
--- a/drivers/gpio/gpio-rcar.c
+++ b/drivers/gpio/gpio-rcar.c
@@ -51,6 +51,8 @@ struct gpio_rcar_priv {
 #define FILONOFF 0x28
 #define BOTHEDGE 0x4c
 
+#define RCAR_MAX_GPIO_PER_BANK          32
+
 static inline u32 gpio_rcar_read(struct gpio_rcar_priv *p, int offs)
 {
         return ioread32(p->base + offs);
@@ -274,9 +276,39 @@ static struct irq_domain_ops gpio_rcar_irq_domain_ops = {
         .map    = gpio_rcar_irq_domain_map,
 };
 
+static void gpio_rcar_parse_pdata(struct gpio_rcar_priv *p)
+{
+        struct gpio_rcar_config *pdata = p->pdev->dev.platform_data;
+#ifdef CONFIG_OF
+        struct device_node *np = p->pdev->dev.of_node;
+        struct of_phandle_args args;
+        int ret;
+#endif
+
+        if (pdata)
+                p->config = *pdata;
+#ifdef CONFIG_OF
+        else if (np) {
+                ret = of_parse_phandle_with_args(np, "gpio-ranges",
+                                "#gpio-range-cells", 0, &args);
+                p->config.number_of_pins = ret == 0 && args.args_count == 3
+                                         ? args.args[2]
+                                         : RCAR_MAX_GPIO_PER_BANK;
+                p->config.gpio_base = -1;
+        }
+#endif
+
+        if (p->config.number_of_pins == 0 ||
+            p->config.number_of_pins > RCAR_MAX_GPIO_PER_BANK) {
+                dev_warn(&p->pdev->dev,
+                         "Invalid number of gpio lines %u, using %u\n",
+                         p->config.number_of_pins, RCAR_MAX_GPIO_PER_BANK);
+                p->config.number_of_pins = RCAR_MAX_GPIO_PER_BANK;
+        }
+}
+
 static int gpio_rcar_probe(struct platform_device *pdev)
 {
-        struct gpio_rcar_config *pdata = pdev->dev.platform_data;
         struct gpio_rcar_priv *p;
         struct resource *io, *irq;
         struct gpio_chip *gpio_chip;
@@ -291,14 +323,14 @@ static int gpio_rcar_probe(struct platform_device *pdev)
                 goto err0;
         }
 
-        /* deal with driver instance configuration */
-        if (pdata)
-                p->config = *pdata;
-
         p->pdev = pdev;
-        platform_set_drvdata(pdev, p);
         spin_lock_init(&p->lock);
 
+        /* Get device configuration from DT node or platform data. */
+        gpio_rcar_parse_pdata(p);
+
+        platform_set_drvdata(pdev, p);
+
         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 
@@ -325,6 +357,7 @@ static int gpio_rcar_probe(struct platform_device *pdev)
         gpio_chip->set = gpio_rcar_set;
         gpio_chip->to_irq = gpio_rcar_to_irq;
         gpio_chip->label = name;
+        gpio_chip->dev = &pdev->dev;
         gpio_chip->owner = THIS_MODULE;
         gpio_chip->base = p->config.gpio_base;
         gpio_chip->ngpio = p->config.number_of_pins;
@@ -371,10 +404,12 @@ static int gpio_rcar_probe(struct platform_device *pdev)
                                  p->config.irq_base, ret);
         }
 
-        ret = gpiochip_add_pin_range(gpio_chip, p->config.pctl_name, 0,
-                                     gpio_chip->base, gpio_chip->ngpio);
-        if (ret < 0)
-                dev_warn(&pdev->dev, "failed to add pin range\n");
+        if (p->config.pctl_name) {
+                ret = gpiochip_add_pin_range(gpio_chip, p->config.pctl_name, 0,
+                                             gpio_chip->base, gpio_chip->ngpio);
+                if (ret < 0)
+                        dev_warn(&pdev->dev, "failed to add pin range\n");
+        }
 
         return 0;
 
@@ -397,11 +432,22 @@ static int gpio_rcar_remove(struct platform_device *pdev)
         return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id gpio_rcar_of_table[] = {
+        {
+                .compatible = "renesas,gpio-rcar",
+        },
+};
+
+MODULE_DEVICE_TABLE(of, gpio_rcar_of_table);
+#endif
+
 static struct platform_driver gpio_rcar_device_driver = {
         .probe          = gpio_rcar_probe,
         .remove         = gpio_rcar_remove,
         .driver         = {
                 .name   = "gpio_rcar",
+                .of_match_table = of_match_ptr(gpio_rcar_of_table),
         }
 };