gpio: Remove legacy API documentation

In order to discourage people to use old and legacy GPIO APIs
remove the respective documentation completely. It also helps
further cleanups of the legacy GPIO API leftovers, which is
ongoing task.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hu Haowen <2023002089@link.tyut.edu.cn>
Link: https://lore.kernel.org/r/20240508101703.830066-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Documentation/driver-api/gpio/board.rst

@@ -4,12 +4,6 @@ GPIO Mappings
 
 This document explains how GPIOs can be assigned to given devices and functions.
 
-Note that it only applies to the new descriptor-based interface. For a
-description of the deprecated integer-based GPIO interface please refer to
-legacy.rst (actually, there is no real mapping possible with the old
-interface; you just fetch an integer from somewhere and request the
-corresponding GPIO).
-
 All platforms can enable the GPIO library, but if the platform strictly
 requires GPIO functionality to be present, it needs to select GPIOLIB from its
 Kconfig. Then, how GPIOs are mapped depends on what the platform uses to

Documentation/driver-api/gpio/consumer.rst

@@ -2,9 +2,7 @@
 GPIO Descriptor Consumer Interface
 ==================================
 
-This document describes the consumer interface of the GPIO framework. Note that
-it describes the new descriptor-based interface. For a description of the
-deprecated integer-based GPIO interface please refer to legacy.rst.
+This document describes the consumer interface of the GPIO framework.
 
 
 Guidelines for GPIOs consumers

Documentation/driver-api/gpio/index.rst

@@ -13,7 +13,6 @@ Contents:
    consumer
    board
    drivers-on-gpio
-   legacy
    bt8xxgpio
 
 Core

Documentation/driver-api/gpio/intro.rst

@@ -10,18 +10,6 @@ The documents in this directory give detailed instructions on how to access
 GPIOs in drivers, and how to write a driver for a device that provides GPIOs
 itself.
 
-Due to the history of GPIO interfaces in the kernel, there are two different
-ways to obtain and use GPIOs:
-
-  - The descriptor-based interface is the preferred way to manipulate GPIOs,
-    and is described by all the files in this directory excepted legacy.rst.
-  - The legacy integer-based interface which is considered deprecated (but still
-    usable for compatibility reasons) is documented in legacy.rst.
-
-The remainder of this document applies to the new descriptor-based interface.
-legacy.rst contains the same information applied to the legacy
-integer-based interface.
-
 
 What is a GPIO?
 ===============

Documentation/translations/zh_CN/driver-api/gpio/index.rst

@@ -18,8 +18,6 @@
    :caption: 目录
    :maxdepth: 2
 
-   legacy
-
 Todolist:
 
 *   intro

include/linux/gpio.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 /*
- * <linux/gpio.h>
+ * NOTE: This header *must not* be included.
  *
  * This is the LEGACY GPIO bulk include file, including legacy APIs. It is
  * used for GPIO drivers still referencing the global GPIO numberspace,
@@ -16,8 +16,6 @@
 
 struct device;
 
-/* see Documentation/driver-api/gpio/legacy.rst */
-
 /* make these flag values available regardless of GPIO kconfig options */
 #define GPIOF_DIR_OUT	(0 << 0)
 #define GPIOF_DIR_IN	(1 << 0)
@@ -121,8 +119,6 @@ static inline int gpio_to_irq(unsigned gpio)
 
 int gpio_request_one(unsigned gpio, unsigned long flags, const char *label);
 
-/* CONFIG_GPIOLIB: bindings for managed devices that want to request gpios */
-
 int devm_gpio_request(struct device *dev, unsigned gpio, const char *label);
 int devm_gpio_request_one(struct device *dev, unsigned gpio,
 			  unsigned long flags, const char *label);