of: create of_phandle_args to simplify return of phandle parsing data

of_parse_phandle_with_args() needs to return quite a bit of data.  Rather
than making each datum a separate **out_ argument, this patch creates
struct of_phandle_args to contain all the returned data and reworks the
user of the function.  This patch also enables of_parse_phandle_with_args()
to return the device node pointer for the phandle node.

This patch also ends up being fairly major surgery to
of_parse_handle_with_args().  The existing structure didn't work well
when extending to use of_phandle_args, and I discovered bugs during testing.
I also took the opportunity to rename the function to be like the
existing of_parse_phandle().

v2: - moved declaration of of_phandle_args to fix compile on non-DT builds
    - fixed incorrect index in example usage
    - fixed incorrect return code handling for empty entries

Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 19 insertions, 24 deletions

diff --git a/drivers/of/gpio.c b/drivers/of/gpio.c
index ea4f2faab22..7e62d15d60f 100644
--- a/drivers/of/gpio.c
+++ b/drivers/of/gpio.c
@@ -35,32 +35,27 @@ int of_get_named_gpio_flags(struct device_node *np, const char *propname,
                            int index, enum of_gpio_flags *flags)
 {
         int ret;
-        struct device_node *gpio_np;
         struct gpio_chip *gc;
-        int size;
-        const void *gpio_spec;
-        const __be32 *gpio_cells;
+        struct of_phandle_args gpiospec;
 
-        ret = of_parse_phandles_with_args(np, propname, "#gpio-cells", index,
-                                          &gpio_np, &gpio_spec);
+        ret = of_parse_phandle_with_args(np, propname, "#gpio-cells", index,
+                                         &gpiospec);
         if (ret) {
                 pr_debug("%s: can't parse gpios property\n", __func__);
                 goto err0;
         }
 
-        gc = of_node_to_gpiochip(gpio_np);
+        gc = of_node_to_gpiochip(gpiospec.np);
         if (!gc) {
                 pr_debug("%s: gpio controller %s isn't registered\n",
-                         np->full_name, gpio_np->full_name);
+                         np->full_name, gpiospec.np->full_name);
                 ret = -ENODEV;
                 goto err1;
         }
 
-        gpio_cells = of_get_property(gpio_np, "#gpio-cells", &size);
-        if (!gpio_cells || size != sizeof(*gpio_cells) ||
-                        be32_to_cpup(gpio_cells) != gc->of_gpio_n_cells) {
+        if (gpiospec.args_count != gc->of_gpio_n_cells) {
                 pr_debug("%s: wrong #gpio-cells for %s\n",
-                         np->full_name, gpio_np->full_name);
+                         np->full_name, gpiospec.np->full_name);
                 ret = -EINVAL;
                 goto err1;
         }
@@ -69,13 +64,13 @@ int of_get_named_gpio_flags(struct device_node *np, const char *propname,
         if (flags)
                 *flags = 0;
 
-        ret = gc->of_xlate(gc, np, gpio_spec, flags);
+        ret = gc->of_xlate(gc, &gpiospec, flags);
         if (ret < 0)
                 goto err1;
 
         ret += gc->base;
 err1:
-        of_node_put(gpio_np);
+        of_node_put(gpiospec.np);
 err0:
         pr_debug("%s exited with status %d\n", __func__, ret);
         return ret;
@@ -105,8 +100,8 @@ unsigned int of_gpio_count(struct device_node *np)
         do {
                 int ret;
 
-                ret = of_parse_phandles_with_args(np, "gpios", "#gpio-cells",
-                                                  cnt, NULL, NULL);
+                ret = of_parse_phandle_with_args(np, "gpios", "#gpio-cells",
+                                                 cnt, NULL);
                 /* A hole in the gpios = <> counts anyway. */
                 if (ret < 0 && ret != -EEXIST)
                         break;
@@ -127,12 +122,9 @@ EXPORT_SYMBOL(of_gpio_count);
  * gpio chips. This function performs only one sanity check: whether gpio
  * is less than ngpios (that is specified in the gpio_chip).
  */
-int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np,
-                         const void *gpio_spec, u32 *flags)
+int of_gpio_simple_xlate(struct gpio_chip *gc,
+                         const struct of_phandle_args *gpiospec, u32 *flags)
 {
-        const __be32 *gpio = gpio_spec;
-        const u32 n = be32_to_cpup(gpio);
-
         /*
          * We're discouraging gpio_cells < 2, since that way you'll have to
          * write your own xlate function (that will have to retrive the GPIO
@@ -144,13 +136,16 @@ int of_gpio_simple_xlate(struct gpio_chip *gc, struct device_node *np,
                 return -EINVAL;
         }
 
-        if (n > gc->ngpio)
+        if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
+                return -EINVAL;
+
+        if (gpiospec->args[0] > gc->ngpio)
                 return -EINVAL;
 
         if (flags)
-                *flags = be32_to_cpu(gpio[1]);
+                *flags = gpiospec->args[1];
 
-        return n;
+        return gpiospec->args[0];
 }
 EXPORT_SYMBOL(of_gpio_simple_xlate);