Commit c72bed23 authored by Hans de Goede's avatar Hans de Goede Committed by Linus Walleij
Browse files

pinctrl: Allow modules to use pinctrl_[un]register_mappings 



Currently only the drivers/pinctrl/devicetree.c code allows registering
pinctrl-mappings which may later be unregistered, all other mappings
are assumed to be permanent.

Non-dt platforms may also want to register pinctrl mappings from code which
is build as a module, which requires being able to unregister the mapping
when the module is unloaded to avoid dangling pointers.

To allow unregistering the mappings the devicetree code uses 2 internal
functions: pinctrl_register_map and pinctrl_unregister_map.

pinctrl_register_map allows the devicetree code to tell the core to
not memdup the mappings as it retains ownership of them and
pinctrl_unregister_map does the unregistering, note this only works
when the mappings where not memdupped.

The only code relying on the memdup/shallow-copy done by
pinctrl_register_mappings is arch/arm/mach-u300/core.c this commit
replaces the __initdata with const, so that the shallow-copy is no
longer necessary.

After that we can get rid of the internal pinctrl_unregister_map function
and just use pinctrl_register_mappings directly everywhere.

This commit also renames pinctrl_unregister_map to
pinctrl_unregister_mappings so that its naming matches its
pinctrl_register_mappings counter-part and exports it.

Together these 2 changes will allow non-dt platform code to
register pinctrl-mappings from modules without breaking things on
module unload (as they can now unregister the mapping on unload).

Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20191216205122.1850923-2-hdegoede@redhat.com


Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent e42617b8

arch/arm/mach-u300/core.c

+1 −1
Original line number Diff line number Diff line
@@ -201,7 +201,7 @@ static unsigned long pin_highz_conf[] = { 
};



/* Pin control settings */

static struct pinctrl_map __initdata u300_pinmux_map[] = {

static const struct pinctrl_map u300_pinmux_map[] = {

	/* anonymous maps for chip power and EMIFs */

	PIN_MAP_MUX_GROUP_HOG_DEFAULT("pinctrl-u300", NULL, "power"),

	PIN_MAP_MUX_GROUP_HOG_DEFAULT("pinctrl-u300", NULL, "emif0"),

drivers/pinctrl/core.c

+16 −25
Original line number Diff line number Diff line
@@ -1376,8 +1376,15 @@ void devm_pinctrl_put(struct pinctrl *p) 
}

EXPORT_SYMBOL_GPL(devm_pinctrl_put);



int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps,

			 bool dup)

/**

 * pinctrl_register_mappings() - register a set of pin controller mappings

 * @maps: the pincontrol mappings table to register. Note the pinctrl-core

 *	keeps a reference to the passed in maps, so they should _not_ be

 *	marked with __initdata.

 * @num_maps: the number of maps in the mapping table

 */

int pinctrl_register_mappings(const struct pinctrl_map *maps,

			      unsigned num_maps)

{

	int i, ret;

	struct pinctrl_maps *maps_node;
@@ -1430,17 +1437,8 @@ int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps, 
	if (!maps_node)

		return -ENOMEM;



	maps_node->num_maps = num_maps;

	if (dup) {

		maps_node->maps = kmemdup(maps, sizeof(*maps) * num_maps,

					  GFP_KERNEL);

		if (!maps_node->maps) {

			kfree(maps_node);

			return -ENOMEM;

		}

	} else {

	maps_node->maps = maps;

	}

	maps_node->num_maps = num_maps;



	mutex_lock(&pinctrl_maps_mutex);

	list_add_tail(&maps_node->node, &pinctrl_maps);
@@ -1448,22 +1446,14 @@ int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps, 


	return 0;

}

EXPORT_SYMBOL_GPL(pinctrl_register_mappings);



/**

 * pinctrl_register_mappings() - register a set of pin controller mappings

 * @maps: the pincontrol mappings table to register. This should probably be

 *	marked with __initdata so it can be discarded after boot. This

 *	function will perform a shallow copy for the mapping entries.

 * @num_maps: the number of maps in the mapping table

 * pinctrl_unregister_mappings() - unregister a set of pin controller mappings

 * @maps: the pincontrol mappings table passed to pinctrl_register_mappings()

 *	when registering the mappings.

 */

int pinctrl_register_mappings(const struct pinctrl_map *maps,

			      unsigned num_maps)

{

	return pinctrl_register_map(maps, num_maps, true);

}

EXPORT_SYMBOL_GPL(pinctrl_register_mappings);



void pinctrl_unregister_map(const struct pinctrl_map *map)

void pinctrl_unregister_mappings(const struct pinctrl_map *map)

{

	struct pinctrl_maps *maps_node;
@@ -1478,6 +1468,7 @@ void pinctrl_unregister_map(const struct pinctrl_map *map) 
	}

	mutex_unlock(&pinctrl_maps_mutex);

}

EXPORT_SYMBOL_GPL(pinctrl_unregister_mappings);



/**

 * pinctrl_force_sleep() - turn a given controller device into sleep state

drivers/pinctrl/core.h

+0 −4
Original line number Diff line number Diff line
@@ -236,10 +236,6 @@ extern struct pinctrl_gpio_range * 
pinctrl_find_gpio_range_from_pin_nolock(struct pinctrl_dev *pctldev,

					unsigned int pin);



int pinctrl_register_map(const struct pinctrl_map *maps, unsigned num_maps,

			 bool dup);

void pinctrl_unregister_map(const struct pinctrl_map *map);



extern int pinctrl_force_sleep(struct pinctrl_dev *pctldev);

extern int pinctrl_force_default(struct pinctrl_dev *pctldev);

drivers/pinctrl/devicetree.c

+2 −2
Original line number Diff line number Diff line
@@ -51,7 +51,7 @@ void pinctrl_dt_free_maps(struct pinctrl *p) 
	struct pinctrl_dt_map *dt_map, *n1;



	list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {

		pinctrl_unregister_map(dt_map->map);

		pinctrl_unregister_mappings(dt_map->map);

		list_del(&dt_map->node);

		dt_free_map(dt_map->pctldev, dt_map->map,

			    dt_map->num_maps);
@@ -92,7 +92,7 @@ static int dt_remember_or_free_map(struct pinctrl *p, const char *statename, 
	dt_map->num_maps = num_maps;

	list_add_tail(&dt_map->node, &p->dt_maps);



	return pinctrl_register_map(map, num_maps, false);

	return pinctrl_register_mappings(map, num_maps);



err_free_map:

	dt_free_map(pctldev, map, num_maps);

include/linux/pinctrl/machine.h

+5 −0
Original line number Diff line number Diff line
@@ -153,6 +153,7 @@ struct pinctrl_map { 


extern int pinctrl_register_mappings(const struct pinctrl_map *map,

				unsigned num_maps);

extern void pinctrl_unregister_mappings(const struct pinctrl_map *map);

extern void pinctrl_provide_dummies(void);

#else
@@ -162,6 +163,10 @@ static inline int pinctrl_register_mappings(const struct pinctrl_map *map, 
	return 0;

}



static inline void pinctrl_unregister_mappings(const struct pinctrl_map *map)

{

}



static inline void pinctrl_provide_dummies(void)

{

}

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