gpio: remove of_get_named_gpio() and <linux/of_gpio.h>

All in-tree consumers have been converted to the descriptor-based API.
Remove the deprecated of_get_named_gpio() helper, delete the
<linux/of_gpio.h> header, and drop the corresponding entry from
MAINTAINERS.

Also remove the completed TODO item for this cleanup.

Signed-off-by: Jialu Xu <xujialu@vimux.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Link: https://patch.msgid.link/02ABDA1F9E3FAF1F+20260307030623.3495092-6-xujialu@vimux.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

Author: vimuxx

MAINTAINERS

@@ -10959,7 +10959,6 @@ F:	drivers/gpio/
 F:	include/dt-bindings/gpio/
 F:	include/linux/gpio.h
 F:	include/linux/gpio/
-F:	include/linux/of_gpio.h
 K:	(devm_)?gpio_(request|free|direction|get|set)
 K:	GPIOD_FLAGS_BIT_NONEXCLUSIVE
 K:	devm_gpiod_unhinge

drivers/gpio/TODO

@@ -58,34 +58,6 @@ Work items:
 
 -------------------------------------------------------------------------------
 
-Get rid of <linux/of_gpio.h>
-
-This header and helpers appeared at one point when there was no proper
-driver infrastructure for doing simpler MMIO GPIO devices and there was
-no core support for parsing device tree GPIOs from the core library with
-the [devm_]gpiod_get() calls we have today that will implicitly go into
-the device tree back-end. It is legacy and should not be used in new code.
-
-Work items:
-
-- Change all consumer drivers that #include <linux/of_gpio.h> to
-  #include <linux/gpio/consumer.h> and stop doing custom parsing of the
-  GPIO lines from the device tree. This can be tricky and often involves
-  changing board files, etc.
-
-- Pull semantics for legacy device tree (OF) GPIO lookups into
-  gpiolib-of.c: in some cases subsystems are doing custom flags and
-  lookups for polarity inversion, open drain and what not. As we now
-  handle this with generic OF bindings, pull all legacy handling into
-  gpiolib so the library API becomes narrow and deep and handle all
-  legacy bindings internally. (See e.g. commits 6953c57ab172,
-  6a537d48461d etc)
-
-- Delete <linux/of_gpio.h> when all the above is complete and everything
-  uses <linux/gpio/consumer.h> or <linux/gpio/driver.h> instead.
-
--------------------------------------------------------------------------------
-
 Collect drivers
 
 Collect GPIO drivers from arch/* and other places that should be placed

drivers/gpio/gpiolib-of.c

@@ -14,7 +14,6 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
-#include <linux/of_gpio.h>
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/slab.h>
 #include <linux/string.h>
@@ -446,32 +445,6 @@ static struct gpio_desc *of_get_named_gpiod_flags(const struct device_node *np,
 	return desc;
 }
 
-/**
- * of_get_named_gpio() - Get a GPIO number to use with GPIO API
- * @np:		device node to get GPIO from
- * @propname:	Name of property containing gpio specifier(s)
- * @index:	index of the GPIO
- *
- * **DEPRECATED** This function is deprecated and must not be used in new code.
- *
- * Returns:
- * GPIO number to use with Linux generic GPIO API, or one of the errno
- * value on the error condition.
- */
-int of_get_named_gpio(const struct device_node *np, const char *propname,
-		      int index)
-{
-	struct gpio_desc *desc;
-
-	desc = of_get_named_gpiod_flags(np, propname, index, NULL);
-
-	if (IS_ERR(desc))
-		return PTR_ERR(desc);
-	else
-		return desc_to_gpio(desc);
-}
-EXPORT_SYMBOL_GPL(of_get_named_gpio);
-
 /* Converts gpio_lookup_flags into bitmask of GPIO_* values */
 static unsigned long of_convert_gpio_flags(enum of_gpio_flags flags)
 {