gpio: of: Support regulator nonstandard GPIO properties

Before it was clearly established that all GPIO properties in the
device tree shall be named "foo-gpios" (with the deprecated variant
"foo-gpio" for single lines) we unfortunately merged a few bindings
for regulators with random phandle names.

As we want to switch the GPIO regulator driver to using descriptors,
we need devm_gpiod_get() to return something reasonable when looking
up these in the device tree.

Put in a special #ifdef:ed kludge to do this special lookup only
for the regulator case and gets compiled out if we're not enabling
regulators. Supply a whitelist with properties we accept.

Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 13acd03..d2a6656 100644 (file)
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -147,6 +147,41 @@ static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id
        return desc;
 }
 
+/*
+ * Some regulator bindings happened before we managed to establish that GPIO
+ * properties should be named "foo-gpios" so we have this special kludge for
+ * them.
+ */
+static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
+                                               enum of_gpio_flags *of_flags)
+{
+       /* These are the connection IDs we accept as legacy GPIO phandles */
+       const char *whitelist[] = {
+               "wlf,ldoena", /* Arizona */
+               "wlf,ldo1ena", /* WM8994 */
+               "wlf,ldo2ena", /* WM8994 */
+       };
+       struct device_node *np = dev->of_node;
+       struct gpio_desc *desc;
+       int i;
+
+       if (!IS_ENABLED(CONFIG_REGULATOR))
+               return ERR_PTR(-ENOENT);
+
+       if (!con_id)
+               return ERR_PTR(-ENOENT);
+
+       for (i = 0; i < ARRAY_SIZE(whitelist); i++)
+               if (!strcmp(con_id, whitelist[i]))
+                       break;
+
+       if (i == ARRAY_SIZE(whitelist))
+               return ERR_PTR(-ENOENT);
+
+       desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
+       return desc;
+}
+
 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
                               unsigned int idx,
                               enum gpio_lookup_flags *flags)
@@ -175,6 +210,10 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
        if (IS_ERR(desc))
                desc = of_find_spi_gpio(dev, con_id, &of_flags);
 
+       /* Special handling for regulator GPIOs if used */
+       if (IS_ERR(desc))
+               desc = of_find_regulator_gpio(dev, con_id, &of_flags);
+
        if (IS_ERR(desc))
                return desc;