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authorHans de Goede <hdegoede@redhat.com>2019-12-16 23:51:18 +0300
committerLinus Walleij <linus.walleij@linaro.org>2019-12-30 16:27:17 +0300
commitc72bed23b9e45accdeab626cf2cb2bd08d846f3e (patch)
treeb37cf3ea67f0e49c3d25faf1584f81f70c24e981 /drivers/pinctrl/core.c
parente42617b825f8073569da76dc4510bfa019b1c35a (diff)
downloadlinux-c72bed23b9e45accdeab626cf2cb2bd08d846f3e.tar.xz
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>
Diffstat (limited to 'drivers/pinctrl/core.c')
-rw-r--r--drivers/pinctrl/core.c41
1 files changed, 16 insertions, 25 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 2bbd8ee93507..b0eea728455d 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -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;
}
+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