regcache: Add support for sorting defaults arrays

The defaults array in regcache must be sorted into ascending register
address order, because binary search is used to locate values in
the array. Add a helper to sort the register defaults array which
can be useful for systems that dynamically create a defaults array
based on external information.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Link: https://patch.msgid.link/20250217140159.2288784-2-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index b1f8508c3966df54fe5514d00aa1fdeb392967c4..f7fcf2de1301fe94e57f761f11bb87b72dfa1634 100644 (file)
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -21,6 +21,37 @@ static const struct regcache_ops *cache_types[] = {
        &regcache_flat_ops,
 };
 
+static int regcache_defaults_cmp(const void *a, const void *b)
+{
+       const struct reg_default *x = a;
+       const struct reg_default *y = b;
+
+       if (x->reg > y->reg)
+               return 1;
+       else if (x->reg < y->reg)
+               return -1;
+       else
+               return 0;
+}
+
+static void regcache_defaults_swap(void *a, void *b, int size)
+{
+       struct reg_default *x = a;
+       struct reg_default *y = b;
+       struct reg_default tmp;
+
+       tmp = *x;
+       *x = *y;
+       *y = tmp;
+}
+
+void regcache_sort_defaults(struct reg_default *defaults, unsigned int ndefaults)
+{
+       sort(defaults, ndefaults, sizeof(*defaults),
+            regcache_defaults_cmp, regcache_defaults_swap);
+}
+EXPORT_SYMBOL_GPL(regcache_sort_defaults);
+
 static int regcache_hw_init(struct regmap *map)
 {
        int i, j;

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 3a96d068915f3f200d6a4acd59f6575f6a2d05dc..d17c5ea3d55db5492b1e76d0202c2d7aac46dcc4 100644 (file)
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -1352,6 +1352,7 @@ bool regmap_can_raw_write(struct regmap *map);
 size_t regmap_get_raw_read_max(struct regmap *map);
 size_t regmap_get_raw_write_max(struct regmap *map);
 
+void regcache_sort_defaults(struct reg_default *defaults, unsigned int ndefaults);
 int regcache_sync(struct regmap *map);
 int regcache_sync_region(struct regmap *map, unsigned int min,
                         unsigned int max);
@@ -2043,6 +2044,12 @@ static inline bool regmap_might_sleep(struct regmap *map)
        return true;
 }
 
+static inline void regcache_sort_defaults(struct reg_default *defaults,
+                                         unsigned int ndefaults)
+{
+       WARN_ONCE(1, "regmap API is disabled");
+}
+
 static inline int regcache_sync(struct regmap *map)
 {
        WARN_ONCE(1, "regmap API is disabled");