gpio: Adjust of_xlate API to support multiple GPIO chips

This patch changes the of_xlate API to make it possible for multiple
gpio_chips to refer to the same device tree node.  This is useful for
banked GPIO controllers that use multiple gpio_chips for a single
device.  With this change the core code will try calling of_xlate on
each gpio_chip that references the device_node and will return the
gpio number for the first one to return 'true'.

Tested-by: Roland Stigge <stigge@antcom.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/arch/arm/mach-imx/mach-mx35_3ds.c b/arch/arm/mach-imx/mach-mx35_3ds.c
index 6ae51c6..6a7cf91 100644 (file)
--- a/arch/arm/mach-imx/mach-mx35_3ds.c
+++ b/arch/arm/mach-imx/mach-mx35_3ds.c
@@ -96,8 +96,7 @@ static struct i2c_board_info __initdata i2c_devices_3ds[] = {
 
 static int lcd_power_gpio = -ENXIO;
 
-static int mc9s08dz60_gpiochip_match(struct gpio_chip *chip,
-                                                    const void *data)
+static int mc9s08dz60_gpiochip_match(struct gpio_chip *chip, void *data)
 {
        return !strcmp(chip->label, data);
 }

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index bf984b6..d18068a 100644 (file)
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -15,11 +15,39 @@
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/io.h>
+#include <linux/gpio.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_gpio.h>
 #include <linux/slab.h>
 
+/* Private data structure for of_gpiochip_is_match */
+struct gg_data {
+       enum of_gpio_flags *flags;
+       struct of_phandle_args gpiospec;
+
+       int out_gpio;
+};
+
+/* Private function for resolving node pointer to gpio_chip */
+static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data)
+{
+       struct gg_data *gg_data = data;
+       int ret;
+
+       if ((gc->of_node != gg_data->gpiospec.np) ||
+           (gc->of_gpio_n_cells != gg_data->gpiospec.args_count) ||
+           (!gc->of_xlate))
+               return false;
+
+       ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
+       if (ret < 0)
+               return false;
+
+       gg_data->out_gpio = ret + gc->base;
+       return true;
+}
+
 /**
  * of_get_named_gpio_flags() - Get a GPIO number and flags to use with GPIO API
  * @np:                device node to get GPIO from
@@ -34,46 +62,25 @@
 int of_get_named_gpio_flags(struct device_node *np, const char *propname,
                            int index, enum of_gpio_flags *flags)
 {
+       struct gg_data gg_data = { .flags = flags, .out_gpio = -ENODEV };
        int ret;
-       struct gpio_chip *gc;
-       struct of_phandle_args gpiospec;
+
+       /* .of_xlate might decide to not fill in the flags, so clear it. */
+       if (flags)
+               *flags = 0;
 
        ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
-                                        &gpiospec);
+                                        &gg_data.gpiospec);
        if (ret) {
                pr_debug("%s: can't parse gpios property\n", __func__);
-               goto err0;
-       }
-
-       gc = of_node_to_gpiochip(gpiospec.np);
-       if (!gc) {
-               pr_debug("%s: gpio controller %s isn't registered\n",
-                        np->full_name, gpiospec.np->full_name);
-               ret = -ENODEV;
-               goto err1;
-       }
-
-       if (gpiospec.args_count != gc->of_gpio_n_cells) {
-               pr_debug("%s: wrong #gpio-cells for %s\n",
-                        np->full_name, gpiospec.np->full_name);
-               ret = -EINVAL;
-               goto err1;
+               return -EINVAL;
        }
 
-       /* .xlate might decide to not fill in the flags, so clear it. */
-       if (flags)
-               *flags = 0;
-
-       ret = gc->of_xlate(gc, &gpiospec, flags);
-       if (ret < 0)
-               goto err1;
+       gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);
 
-       ret += gc->base;
-err1:
-       of_node_put(gpiospec.np);
-err0:
+       of_node_put(gg_data.gpiospec.np);
        pr_debug("%s exited with status %d\n", __func__, ret);
-       return ret;
+       return gg_data.out_gpio;
 }
 EXPORT_SYMBOL(of_get_named_gpio_flags);
 
@@ -227,14 +234,3 @@ void of_gpiochip_remove(struct gpio_chip *chip)
        if (chip->of_node)
                of_node_put(chip->of_node);
 }
-
-/* Private function for resolving node pointer to gpio_chip */
-static int of_gpiochip_is_match(struct gpio_chip *chip, const void *data)
-{
-       return chip->of_node == data;
-}
-
-struct gpio_chip *of_node_to_gpiochip(struct device_node *np)
-{
-       return gpiochip_find(np, of_gpiochip_is_match);
-}

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 566d012..38353c0 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1156,7 +1156,7 @@ EXPORT_SYMBOL_GPL(gpiochip_remove);
  */
 struct gpio_chip *gpiochip_find(const void *data,
                                int (*match)(struct gpio_chip *chip,
-                                            const void *data))
+                                            void *data))
 {
        struct gpio_chip *chip = NULL;
        unsigned long flags;

diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 4ead123..1ba08f0 100644 (file)
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -144,7 +144,7 @@ extern int gpiochip_add(struct gpio_chip *chip);
 extern int __must_check gpiochip_remove(struct gpio_chip *chip);
 extern struct gpio_chip *gpiochip_find(const void *data,
                                        int (*match)(struct gpio_chip *chip,
-                                                    const void *data));
+                                                    void *data));
 
 
 /* Always use the library code for GPIO management calls,

diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
index 81733d1..c454f57 100644 (file)
--- a/include/linux/of_gpio.h
+++ b/include/linux/of_gpio.h
@@ -58,7 +58,6 @@ extern int of_mm_gpiochip_add(struct device_node *np,
 
 extern void of_gpiochip_add(struct gpio_chip *gc);
 extern void of_gpiochip_remove(struct gpio_chip *gc);
-extern struct gpio_chip *of_node_to_gpiochip(struct device_node *np);
 extern int of_gpio_simple_xlate(struct gpio_chip *gc,
                                const struct of_phandle_args *gpiospec,
                                u32 *flags);