gpio: add gpio-hog support

add gpio-hog support. GPIO hogging is a mechanism
providing automatic GPIO request and configuration
as part of the gpio-controller's driver probe function.

for more infos see:
doc/device-tree-bindings/gpio/gpio.txt

Signed-off-by: Heiko Schocher <hs@denx.de>
Tested-by: Michal Simek <michal.simek@xilinx.com> (zcu102)
Tested-by: Patrick Delaunay <patrick.delaunay@st.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index d03602696f..37f71e5708 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -349,6 +349,22 @@ const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);
 int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);
 
 /**
+ * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
+ *
+ * @name:	Name to look up
+ * @return:	Returns gpio_desc for gpio
+ */
+struct gpio_desc *gpio_hog_lookup_name(const char *name);
+
+/**
+ * gpio_hog_probe_all() - probe all gpio devices with
+ * gpio-hog subnodes.
+ *
+ * @return:	Returns return value from device_probe()
+ */
+int gpio_hog_probe_all(void);
+
+/**
  * gpio_lookup_name - Look up a GPIO name and return its details
  *
  * This is used to convert a named GPIO into a device, offset and GPIO
@@ -504,6 +520,22 @@ int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
 				    int flags);
 
 /**
+ * gpio_dev_request_index() - request single GPIO from gpio device
+ *
+ * @dev:	GPIO device
+ * @nodename:	Name of node
+ * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
+ * @index:	Index number of the GPIO in that list use request (0=first)
+ * @flags:	GPIOD_* flags
+ * @dtflags:	GPIO flags read from DT
+ * @desc:	GPIO descriotor filled from this function
+ * @return:	return value from gpio_request_tail()
+ */
+int gpio_dev_request_index(struct udevice *dev, const char *nodename,
+			   char *list_name, int index, int flags,
+			   int dtflags, struct gpio_desc *desc);
+
+/**
  * dm_gpio_free() - Free a single GPIO
  *
  * This frees a single GPIOs previously returned from gpio_request_by_name().