gpio: update dir_flags management

Update the flag management in GPIO uclass: the desc->flags is always
combined with the requested flags and the GPIO descriptor is updated
for further call.

Add a function dm_gpio_get_dir_flags to get dynamically
the current dir_flags (configuration and value).

This patch prepare introduction of the dir flags support with new ops.

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

drivers/gpio/gpio-uclass.c

@@ -141,8 +141,9 @@ int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc,
 	if (args->args_count < 2)
 		return 0;
 
+	desc->flags = 0;
 	if (args->args[1] & GPIO_ACTIVE_LOW)
-		desc->flags = GPIOD_ACTIVE_LOW;
+		desc->flags |= GPIOD_ACTIVE_LOW;
 
 	return 0;
 }
@@ -559,6 +560,8 @@ int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
 	if (ret)
 		return ret;
 
+	/* combine the requested flags (for IN/OUT) and the descriptor flags */
+	flags |= desc->flags;
 	ret = _dm_gpio_set_dir_flags(desc, flags);
 
 	/* update the descriptor flags */
@@ -579,6 +582,26 @@ int dm_gpio_set_dir(struct gpio_desc *desc)
 	return _dm_gpio_set_dir_flags(desc, desc->flags);
 }
 
+int dm_gpio_get_dir_flags(struct gpio_desc *desc, ulong *flags)
+{
+	int ret;
+	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;
+
+	*flags = dir_flags;
+
+	return 0;
+}
+
 /**
  * gpio_get_value() - [COMPAT] Sample GPIO pin and return it's value
  * gpio:	GPIO number
@@ -849,7 +872,7 @@ static int gpio_request_tail(int ret, const char *nodename,
 		debug("%s: dm_gpio_requestf failed\n", __func__);
 		goto err;
 	}
-	ret = dm_gpio_set_dir_flags(desc, flags | desc->flags);
+	ret = dm_gpio_set_dir_flags(desc, flags);
 	if (ret) {
 		debug("%s: dm_gpio_set_dir failed\n", __func__);
 		goto err;

include/asm-generic/gpio.h

@@ -592,8 +592,7 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value);
 /**
  * dm_gpio_set_dir() - Set the direction for a GPIO
  *
- * This sets up the direction according tot the provided flags. It will do
+ * This sets up the direction according to the GPIO flags: desc->flags.
- * nothing unless the direction is actually specified.
  *
  * @desc:	GPIO description containing device, offset and flags,
  *		previously returned by gpio_request_by_name()
@@ -602,11 +601,10 @@ int dm_gpio_set_value(const struct gpio_desc *desc, int value);
 int dm_gpio_set_dir(struct gpio_desc *desc);
 
 /**
- * dm_gpio_set_dir_flags() - Set direction using specific flags
+ * dm_gpio_set_dir_flags() - Set direction using description and added flags
  *
- * This is like dm_gpio_set_dir() except that the flags value is provided
+ * This sets up the direction according to the provided flags and the GPIO
- * instead of being used from desc->flags. This is needed because in many
+ * description (desc->flags) which include direction information.
- * cases the GPIO description does not include direction information.
  * Note that desc->flags is updated by this function.
  *
  * @desc:	GPIO description containing device, offset and flags,
@@ -616,6 +614,18 @@ int dm_gpio_set_dir(struct gpio_desc *desc);
  */
 int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);
 
+/**
+ * dm_gpio_get_dir_flags() - Get direction flags
+ *
+ * read the current direction flags
+ *
+ * @desc:	GPIO description containing device, offset and flags,
+ *		previously returned by gpio_request_by_name()
+ * @flags:	place to put the used flags
+ * @return 0 if OK, -ve on error, in which case desc->flags is not updated
+ */
+int dm_gpio_get_dir_flags(struct gpio_desc *desc, ulong *flags);
+
 /**
  * gpio_get_number() - Get the global GPIO number of a GPIO
  *