regmap: make lock/unlock functions customizable

It is sometimes convenient for a regmap user to override the standard
regmap lock/unlock functions with custom functions.
For instance this can be useful in case an already existing spinlock
or mutex has to be used for locking a set of registers instead of the
internal regmap spinlock/mutex.
Note that the fast_io field of struct regmap_bus is ignored in case
custom locking functions are used.

Signed-off-by: Davide Ciminaghi <ciminaghi@gnudd.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

2 files changed, 39 insertions, 30 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 80f9ab9c3aa4..b1ee824e2a5f 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -31,14 +31,12 @@ struct regmap_format {
         unsigned int (*parse_val)(void *buf);
 };
 
-typedef void (*regmap_lock)(struct regmap *map);
-typedef void (*regmap_unlock)(struct regmap *map);
-
 struct regmap {
         struct mutex mutex;
         spinlock_t spinlock;
         regmap_lock lock;
         regmap_unlock unlock;
+        void *lock_arg; /* This is passed to lock/unlock functions */
 
         struct device *dev; /* Device we do I/O on */
         void *work_buf;     /* Scratch buffer used to format I/O */
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 52069d29ff12..5d8b75255b50 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -214,23 +214,27 @@ static unsigned int regmap_parse_32_native(void *buf)
         return *(u32 *)buf;
 }
 
-static void regmap_lock_mutex(struct regmap *map)
+static void regmap_lock_mutex(void *__map)
 {
+        struct regmap *map = __map;
         mutex_lock(&map->mutex);
 }
 
-static void regmap_unlock_mutex(struct regmap *map)
+static void regmap_unlock_mutex(void *__map)
 {
+        struct regmap *map = __map;
         mutex_unlock(&map->mutex);
 }
 
-static void regmap_lock_spinlock(struct regmap *map)
+static void regmap_lock_spinlock(void *__map)
 {
+        struct regmap *map = __map;
         spin_lock(&map->spinlock);
 }
 
-static void regmap_unlock_spinlock(struct regmap *map)
+static void regmap_unlock_spinlock(void *__map)
 {
+        struct regmap *map = __map;
         spin_unlock(&map->spinlock);
 }
 
@@ -335,14 +339,21 @@ struct regmap *regmap_init(struct device *dev,
                 goto err;
         }
 
-        if (bus->fast_io) {
-                spin_lock_init(&map->spinlock);
-                map->lock = regmap_lock_spinlock;
-                map->unlock = regmap_unlock_spinlock;
+        if (config->lock && config->unlock) {
+                map->lock = config->lock;
+                map->unlock = config->unlock;
+                map->lock_arg = config->lock_arg;
         } else {
-                mutex_init(&map->mutex);
-                map->lock = regmap_lock_mutex;
-                map->unlock = regmap_unlock_mutex;
+                if (bus->fast_io) {
+                        spin_lock_init(&map->spinlock);
+                        map->lock = regmap_lock_spinlock;
+                        map->unlock = regmap_unlock_spinlock;
+                } else {
+                        mutex_init(&map->mutex);
+                        map->lock = regmap_lock_mutex;
+                        map->unlock = regmap_unlock_mutex;
+                }
+                map->lock_arg = map;
         }
         map->format.reg_bytes = DIV_ROUND_UP(config->reg_bits, 8);
         map->format.pad_bytes = config->pad_bits / 8;
@@ -939,11 +950,11 @@ int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
         if (reg % map->reg_stride)
                 return -EINVAL;
 
-        map->lock(map);
+        map->lock(map->lock_arg);
 
         ret = _regmap_write(map, reg, val);
 
-        map->unlock(map);
+        map->unlock(map->lock_arg);
 
         return ret;
 }
@@ -975,11 +986,11 @@ int regmap_raw_write(struct regmap *map, unsigned int reg,
         if (reg % map->reg_stride)
                 return -EINVAL;
 
-        map->lock(map);
+        map->lock(map->lock_arg);
 
         ret = _regmap_raw_write(map, reg, val, val_len);
 
-        map->unlock(map);
+        map->unlock(map->lock_arg);
 
         return ret;
 }
@@ -1011,7 +1022,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
         if (reg % map->reg_stride)
                 return -EINVAL;
 
-        map->lock(map);
+        map->lock(map->lock_arg);
 
         /* No formatting is require if val_byte is 1 */
         if (val_bytes == 1) {
@@ -1047,7 +1058,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
                 kfree(wval);
 
 out:
-        map->unlock(map);
+        map->unlock(map->lock_arg);
         return ret;
 }
 EXPORT_SYMBOL_GPL(regmap_bulk_write);
@@ -1137,11 +1148,11 @@ int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
         if (reg % map->reg_stride)
                 return -EINVAL;
 
-        map->lock(map);
+        map->lock(map->lock_arg);
 
         ret = _regmap_read(map, reg, val);
 
-        map->unlock(map);
+        map->unlock(map->lock_arg);
 
         return ret;
 }
@@ -1171,7 +1182,7 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
         if (reg % map->reg_stride)
                 return -EINVAL;
 
-        map->lock(map);
+        map->lock(map->lock_arg);
 
         if (regmap_volatile_range(map, reg, val_count) || map->cache_bypass ||
             map->cache_type == REGCACHE_NONE) {
@@ -1193,7 +1204,7 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
         }
 
  out:
-        map->unlock(map);
+        map->unlock(map->lock_arg);
 
         return ret;
 }
@@ -1300,9 +1311,9 @@ int regmap_update_bits(struct regmap *map, unsigned int reg,
         bool change;
         int ret;
 
-        map->lock(map);
+        map->lock(map->lock_arg);
         ret = _regmap_update_bits(map, reg, mask, val, &change);
-        map->unlock(map);
+        map->unlock(map->lock_arg);
 
         return ret;
 }
@@ -1326,9 +1337,9 @@ int regmap_update_bits_check(struct regmap *map, unsigned int reg,
 {
         int ret;
 
-        map->lock(map);
+        map->lock(map->lock_arg);
         ret = _regmap_update_bits(map, reg, mask, val, change);
-        map->unlock(map);
+        map->unlock(map->lock_arg);
         return ret;
 }
 EXPORT_SYMBOL_GPL(regmap_update_bits_check);
@@ -1357,7 +1368,7 @@ int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
         if (map->patch)
                 return -EBUSY;
 
-        map->lock(map);
+        map->lock(map->lock_arg);
 
         bypass = map->cache_bypass;
 
@@ -1385,7 +1396,7 @@ int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
 out:
         map->cache_bypass = bypass;
 
-        map->unlock(map);
+        map->unlock(map->lock_arg);
 
         return ret;
 }