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Subject[PATCH 1/4] gpio: of: Support regulator nonstandard GPIO properties
Date
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>
---
This patch is preperatory work for converting fixed and GPIO
regulators to deal only with GPIO descriptors.
---
drivers/gpio/gpiolib-of.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index e0d59e61b52f..9686922310a4 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -117,6 +117,41 @@ int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
}
EXPORT_SYMBOL(of_get_named_gpio_flags);

+/*
+ * 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)
@@ -126,6 +161,7 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
struct gpio_desc *desc;
unsigned int i;

+ /* Try GPIO property "foo-gpios" and "foo-gpio" */
for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
if (con_id)
snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
@@ -140,6 +176,10 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
break;
}

+ /* 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;

--
2.14.3
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