Commit dea046e7 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpio: remove machine hogs 



With no more users, remove legacy machine hog API from the kernel.

Reviewed-by: default avatarLinus Walleij <linusw@kernel.org>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260309-gpio-hog-fwnode-v2-5-4e61f3dbf06a@oss.qualcomm.com


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
parent e627fc9f

Documentation/driver-api/gpio/board.rst

+0 −16
Original line number Diff line number Diff line
@@ -239,22 +239,6 @@ mapping and is thus transparent to GPIO consumers. 
A set of functions such as gpiod_set_value() is available to work with

the new descriptor-oriented interface.



Boards using platform data can also hog GPIO lines by defining GPIO hog tables.



.. code-block:: c



        struct gpiod_hog gpio_hog_table[] = {

                GPIO_HOG("gpio.0", 10, "foo", GPIO_ACTIVE_LOW, GPIOD_OUT_HIGH),

                { }

        };



And the table can be added to the board code as follows::



        gpiod_add_hogs(gpio_hog_table);



The line will be hogged as soon as the gpiochip is created or - in case the

chip was created earlier - when the hog table is registered.



Arrays of pins

--------------

In addition to requesting pins belonging to a function one by one, a device may

drivers/gpio/gpiolib.c

+0 −71
Original line number Diff line number Diff line
@@ -103,9 +103,6 @@ static DEFINE_MUTEX(gpio_devices_lock); 
/* Ensures coherence during read-only accesses to the list of GPIO devices. */

DEFINE_STATIC_SRCU(gpio_devices_srcu);



static DEFINE_MUTEX(gpio_machine_hogs_mutex);

static LIST_HEAD(gpio_machine_hogs);



const char *const gpio_suffixes[] = { "gpios", "gpio", NULL };



static void gpiochip_free_hogs(struct gpio_chip *gc);
@@ -930,36 +927,6 @@ static int gpiochip_setup_dev(struct gpio_chip *gc) 
	return ret;

}



static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)

{

	struct gpio_desc *desc;

	int rv;



	desc = gpiochip_get_desc(gc, hog->chip_hwnum);

	if (IS_ERR(desc)) {

		gpiochip_err(gc, "%s: unable to get GPIO desc: %ld\n",

			     __func__, PTR_ERR(desc));

		return;

	}



	rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);

	if (rv)

		gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",

			  __func__, gc->label, hog->chip_hwnum, rv);

}



static void gpiochip_machine_hog_lines(struct gpio_chip *gc)

{

	struct gpiod_hog *hog;



	guard(mutex)(&gpio_machine_hogs_mutex);



	list_for_each_entry(hog, &gpio_machine_hogs, list) {

		if (!strcmp(gc->label, hog->chip_label))

			gpiochip_machine_hog(gc, hog);

	}

}



int gpiochip_add_hog(struct gpio_chip *gc, struct fwnode_handle *fwnode)

{

	struct fwnode_handle *gc_node = dev_fwnode(&gc->gpiodev->dev);
@@ -1047,8 +1014,6 @@ static int gpiochip_hog_lines(struct gpio_chip *gc) 
			return ret;

	}



	gpiochip_machine_hog_lines(gc);



	return 0;

}
@@ -4578,42 +4543,6 @@ void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) 
}

EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);



/**

 * gpiod_add_hogs() - register a set of GPIO hogs from machine code

 * @hogs: table of gpio hog entries with a zeroed sentinel at the end

 */

void gpiod_add_hogs(struct gpiod_hog *hogs)

{

	struct gpiod_hog *hog;



	guard(mutex)(&gpio_machine_hogs_mutex);



	for (hog = &hogs[0]; hog->chip_label; hog++) {

		list_add_tail(&hog->list, &gpio_machine_hogs);



		/*

		 * The chip may have been registered earlier, so check if it

		 * exists and, if so, try to hog the line now.

		 */

		struct gpio_device *gdev __free(gpio_device_put) =

				gpio_device_find_by_label(hog->chip_label);

		if (gdev)

			gpiochip_machine_hog(gpio_device_get_chip(gdev), hog);

	}

}

EXPORT_SYMBOL_GPL(gpiod_add_hogs);



void gpiod_remove_hogs(struct gpiod_hog *hogs)

{

	struct gpiod_hog *hog;



	guard(mutex)(&gpio_machine_hogs_mutex);



	for (hog = &hogs[0]; hog->chip_label; hog++)

		list_del(&hog->list);

}

EXPORT_SYMBOL_GPL(gpiod_remove_hogs);



static bool gpiod_match_lookup_table(struct device *dev,

				     const struct gpiod_lookup_table *table)

{

include/linux/gpio/machine.h

+0 −33
Original line number Diff line number Diff line
@@ -46,23 +46,6 @@ struct gpiod_lookup_table { 
	struct gpiod_lookup table[];

};



/**

 * struct gpiod_hog - GPIO line hog table

 * @chip_label: name of the chip the GPIO belongs to

 * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO

 * @line_name: consumer name for the hogged line

 * @lflags: bitmask of gpio_lookup_flags GPIO_* values

 * @dflags: GPIO flags used to specify the direction and value

 */

struct gpiod_hog {

	struct list_head list;

	const char *chip_label;

	u16 chip_hwnum;

	const char *line_name;

	unsigned long lflags;

	int dflags;

};



/*

 * Helper for lookup tables with just one single lookup for a device.

 */
@@ -95,24 +78,10 @@ static struct gpiod_lookup_table _name = { \ 
	.flags = _flags,                                                  \

}



/*

 * Simple definition of a single GPIO hog in an array.

 */

#define GPIO_HOG(_chip_label, _chip_hwnum, _line_name, _lflags, _dflags)  \

(struct gpiod_hog) {                                                      \

	.chip_label = _chip_label,                                        \

	.chip_hwnum = _chip_hwnum,                                        \

	.line_name = _line_name,                                          \

	.lflags = _lflags,                                                \

	.dflags = _dflags,                                                \

}



#ifdef CONFIG_GPIOLIB

void gpiod_add_lookup_table(struct gpiod_lookup_table *table);

void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n);

void gpiod_remove_lookup_table(struct gpiod_lookup_table *table);

void gpiod_add_hogs(struct gpiod_hog *hogs);

void gpiod_remove_hogs(struct gpiod_hog *hogs);

#else /* ! CONFIG_GPIOLIB */

static inline

void gpiod_add_lookup_table(struct gpiod_lookup_table *table) {}
@@ -120,8 +89,6 @@ static inline 
void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) {}

static inline

void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) {}

static inline void gpiod_add_hogs(struct gpiod_hog *hogs) {}

static inline void gpiod_remove_hogs(struct gpiod_hog *hogs) {}

#endif /* CONFIG_GPIOLIB */



#endif /* __LINUX_GPIO_MACHINE_H */