gpiolib: introduce fwnode_gpiod_get_index()

This introduces fwnode_gpiod_get_index() that iterates through common gpio
suffixes when trying to locate a GPIO within a given firmware node.

We also switch devm_fwnode_gpiod_get_index() to call
fwnode_gpiod_get_index() instead of iterating through GPIO suffixes on
its own.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20190913032240.50333-3-dmitry.torokhov@gmail.com
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
index 9a0475c..4421be0 100644 (file)
--- a/drivers/gpio/gpiolib-devres.c
+++ b/drivers/gpio/gpiolib-devres.c
@@ -205,29 +205,15 @@ struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
                                              enum gpiod_flags flags,
                                              const char *label)
 {
-       char prop_name[32]; /* 32 is max size of property name */
        struct gpio_desc **dr;
        struct gpio_desc *desc;
-       unsigned int i;
 
        dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
                          GFP_KERNEL);
        if (!dr)
                return ERR_PTR(-ENOMEM);
 
-       for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
-               if (con_id)
-                       snprintf(prop_name, sizeof(prop_name), "%s-%s",
-                                           con_id, gpio_suffixes[i]);
-               else
-                       snprintf(prop_name, sizeof(prop_name), "%s",
-                                           gpio_suffixes[i]);
-
-               desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
-                                             label);
-               if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
-                       break;
-       }
+       desc = fwnode_gpiod_get_index(fwnode, con_id, index, flags, label);
        if (IS_ERR(desc)) {
                devres_free(dr);
                return desc;

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index bdbc164..2342dea 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4324,6 +4324,54 @@ static int platform_gpio_count(struct device *dev, const char *con_id)
        return count;
 }
 
+/**
+ * fwnode_gpiod_get_index - obtain a GPIO from firmware node
+ * @fwnode:    handle of the firmware node
+ * @con_id:    function within the GPIO consumer
+ * @index:     index of the GPIO to obtain for the consumer
+ * @flags:     GPIO initialization flags
+ * @label:     label to attach to the requested GPIO
+ *
+ * This function can be used for drivers that get their configuration
+ * from opaque firmware.
+ *
+ * The function properly finds the corresponding GPIO using whatever is the
+ * underlying firmware interface and then makes sure that the GPIO
+ * descriptor is requested before it is returned to the caller.
+ *
+ * Returns:
+ * On successful request the GPIO pin is configured in accordance with
+ * provided @flags.
+ *
+ * In case of error an ERR_PTR() is returned.
+ */
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+                                        const char *con_id, int index,
+                                        enum gpiod_flags flags,
+                                        const char *label)
+{
+       struct gpio_desc *desc;
+       char prop_name[32]; /* 32 is max size of property name */
+       unsigned int i;
+
+       for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
+               if (con_id)
+                       snprintf(prop_name, sizeof(prop_name), "%s-%s",
+                                           con_id, gpio_suffixes[i]);
+               else
+                       snprintf(prop_name, sizeof(prop_name), "%s",
+                                           gpio_suffixes[i]);
+
+               desc = fwnode_get_named_gpiod(fwnode, prop_name, index, flags,
+                                             label);
+               if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
+                       break;
+       }
+
+       return desc;
+}
+EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
+
 /**
  * gpiod_count - return the number of GPIOs associated with a device / function
  *             or -ENOENT if no GPIO has been assigned to the requested function

diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index dc0ddcd..5215fdb 100644 (file)
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -176,6 +176,10 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
                                         const char *propname, int index,
                                         enum gpiod_flags dflags,
                                         const char *label);
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+                                        const char *con_id, int index,
+                                        enum gpiod_flags flags,
+                                        const char *label);
 struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
                                              struct fwnode_handle *child,
                                              const char *con_id, int index,
@@ -531,6 +535,15 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
        return ERR_PTR(-ENOSYS);
 }
 
+static inline
+struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
+                                        const char *con_id, int index,
+                                        enum gpiod_flags flags,
+                                        const char *label)
+{
+       return ERR_PTR(-ENOSYS);
+}
+
 static inline
 struct gpio_desc *devm_fwnode_gpiod_get_index(struct device *dev,
                                              struct fwnode_handle *fwnode,