gpio: add ops to get dir flags

Add the ops for GPIO driver get_dir_flags(), allows to get dynamically
the current gpio configuration; it is used by the API function
dm_gpio_get_dir_flags().

When these optional ops are absent, the gpio uclass continues to use
the mandatory ops (direction_output, direction_input, get_value) and
value of desc->flags to manage only the main dir flags:
- GPIOD_IS_IN
- GPIOD_IS_OUT
- GPIOD_IS_OUT_ACTIVE
- GPIOD_ACTIVE_LOW

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 25263994d24033c4b42461193a06f8472096b4a8..84e5013cceb58e4af1c10c81dfa27d7d2fa71dc8 100644 (file)
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -614,19 +614,36 @@ int dm_gpio_set_dir(struct gpio_desc *desc)
 
 int dm_gpio_get_dir_flags(struct gpio_desc *desc, ulong *flags)
 {
-       int ret;
+       struct udevice *dev = desc->dev;
+       int ret, value;
+       struct dm_gpio_ops *ops = gpio_get_ops(dev);
        ulong dir_flags;
 
        ret = check_reserved(desc, "get_dir_flags");
        if (ret)
                return ret;
 
-       dir_flags = desc->flags;
-       /* only GPIOD_IS_OUT_ACTIVE is provided by uclass */
-       dir_flags &= ~GPIOD_IS_OUT_ACTIVE;
-       if ((desc->flags & GPIOD_IS_OUT) && _gpio_get_value(desc))
-               dir_flags |= GPIOD_IS_OUT_ACTIVE;
+       /* GPIOD_ are directly provided by driver except GPIOD_ACTIVE_LOW */
+       if (ops->get_dir_flags) {
+               ret = ops->get_dir_flags(dev, desc->offset, &dir_flags);
+               if (ret)
+                       return ret;
 
+               /* GPIOD_ACTIVE_LOW is saved in desc->flags */
+               value = dir_flags & GPIOD_IS_OUT_ACTIVE ? 1 : 0;
+               if (desc->flags & GPIOD_ACTIVE_LOW)
+                       value = !value;
+               dir_flags &= ~(GPIOD_ACTIVE_LOW | GPIOD_IS_OUT_ACTIVE);
+               dir_flags |= (desc->flags & GPIOD_ACTIVE_LOW);
+               if (value)
+                       dir_flags |= GPIOD_IS_OUT_ACTIVE;
+       } else {
+               dir_flags = desc->flags;
+               /* only GPIOD_IS_OUT_ACTIVE is provided by uclass */
+               dir_flags &= ~GPIOD_IS_OUT_ACTIVE;
+               if ((desc->flags & GPIOD_IS_OUT) && _gpio_get_value(desc))
+                       dir_flags |= GPIOD_IS_OUT_ACTIVE;
+       }
        *flags = dir_flags;
 
        return 0;
@@ -1129,6 +1146,8 @@ static int gpio_post_bind(struct udevice *dev)
                        ops->get_function += gd->reloc_off;
                if (ops->xlate)
                        ops->xlate += gd->reloc_off;
+               if (ops->get_dir_flags)
+                       ops->get_dir_flags += gd->reloc_off;
 
                reloc_done++;
        }

diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 42c9ab29ca8decd812b9b8f01c2da6c681be1bc2..7c1f71b1accb1a31ea690302daf106f0e1401a10 100644 (file)
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -297,6 +297,21 @@ struct dm_gpio_ops {
         */
        int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
                     struct ofnode_phandle_args *args);
+
+       /**
+        * get_dir_flags() - Get GPIO dir flags
+        *
+        * This function return the GPIO direction flags used.
+        *
+        * This method is optional.
+        *
+        * @dev:        GPIO device
+        * @offset:     GPIO offset within that device
+        * @flags:      place to put the used direction flags by GPIO
+        * @return 0 if OK, -ve on error
+        */
+       int (*get_dir_flags)(struct udevice *dev, unsigned int offset,
+                            ulong *flags);
 };
 
 /**