dm: gpio: Add gpio_get_function() and friends

Add helpers to the uclass to allow finding out the pin function.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index e11c5a69c583fa3c2ab96269d28228bc942cc518..04b7b16fd6b924d81931a6bd4e5659d2af231c1a 100644 (file)
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -283,6 +283,53 @@ const char *gpio_get_bank_info(struct udevice *dev, int *bit_count)
        return priv->bank_name;
 }
 
+static const char * const gpio_function[GPIOF_COUNT] = {
+       "input",
+       "output",
+       "unused",
+       "unknown",
+       "func",
+};
+
+int get_function(struct udevice *dev, int offset, bool skip_unused,
+                const char **namep)
+{
+       struct gpio_dev_priv *uc_priv = dev->uclass_priv;
+       struct dm_gpio_ops *ops = gpio_get_ops(dev);
+
+       BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));
+       if (!device_active(dev))
+               return -ENODEV;
+       if (offset < 0 || offset >= uc_priv->gpio_count)
+               return -EINVAL;
+       if (namep)
+               *namep = uc_priv->name[offset];
+       if (skip_unused && !uc_priv->name[offset])
+               return GPIOF_UNUSED;
+       if (ops->get_function) {
+               int ret;
+
+               ret = ops->get_function(dev, offset);
+               if (ret < 0)
+                       return ret;
+               if (ret >= ARRAY_SIZE(gpio_function))
+                       return -ENODATA;
+               return ret;
+       }
+
+       return GPIOF_UNKNOWN;
+}
+
+int gpio_get_function(struct udevice *dev, int offset, const char **namep)
+{
+       return get_function(dev, offset, true, namep);
+}
+
+int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep)
+{
+       return get_function(dev, offset, false, namep);
+}
+
 /* We need to renumber the GPIOs when any driver is probed/removed */
 static int gpio_renumber(struct udevice *removed_dev)
 {

diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 128249ef89099cbd2cc63ec91910e25768e42c55..71044549ba44c06f5ccd1f4326906533739fb38f 100644 (file)
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -83,7 +83,7 @@ int gpio_get_value(unsigned gpio);
 int gpio_set_value(unsigned gpio, int value);
 
 /* State of a GPIO, as reported by get_function() */
-enum {
+enum gpio_func_t {
        GPIOF_INPUT = 0,
        GPIOF_OUTPUT,
        GPIOF_UNUSED,           /* Not claimed */
@@ -95,6 +95,38 @@ enum {
 
 struct udevice;
 
+/**
+ * gpio_get_function() - get the current function for a GPIO pin
+ *
+ * Note this returns GPIOF_UNUSED if the GPIO is not requested.
+ *
+ * @dev:       Device to check
+ * @offset:    Offset of device GPIO to check
+ * @namep:     If non-NULL, this is set to the nane given when the GPIO
+ *             was requested, or -1 if it has not been requested
+ * @return  -ENODATA if the driver returned an unknown function,
+ * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
+ * GPIOF_UNUSED if the GPIO has not been requested. Otherwise returns the
+ * function from enum gpio_func_t.
+ */
+int gpio_get_function(struct udevice *dev, int offset, const char **namep);
+
+/**
+ * gpio_get_raw_function() - get the current raw function for a GPIO pin
+ *
+ * Note this does not return GPIOF_UNUSED - it will always return the GPIO
+ * driver's view of a pin function, even if it is not correctly set up.
+ *
+ * @dev:       Device to check
+ * @offset:    Offset of device GPIO to check
+ * @namep:     If non-NULL, this is set to the nane given when the GPIO
+ *             was requested, or -1 if it has not been requested
+ * @return  -ENODATA if the driver returned an unknown function,
+ * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
+ * Otherwise returns the function from enum gpio_func_t.
+ */
+int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep);
+
 /**
  * struct struct dm_gpio_ops - Driver model GPIO operations
  *