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: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20191216205122.1850923-2-hdegoede@redhat.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Hans de Goede 2019-12-16 21:51:18 +01:00 коммит произвёл Linus Walleij
Родитель e42617b825
Коммит c72bed23b9
5 изменённых файлов: 25 добавлений и 33 удалений

Просмотреть файл

@ -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"),

Просмотреть файл

@ -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->maps = maps;
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;
}
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;
}
/**
* 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
*/
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)
/**
* pinctrl_unregister_mappings() - unregister a set of pin controller mappings
* @maps: the pincontrol mappings table passed to pinctrl_register_mappings()
* when registering the mappings.
*/
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

Просмотреть файл

@ -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);

Просмотреть файл

@ -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);

Просмотреть файл

@ -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)
{
}