Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

[karo-tx-linux.git] / drivers / base / regmap / regcache.c

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 7eb7b3b98794849c6718c068504c7ac1acf3a2c9..b9862d741a56210885638b3cfc9ce8c92f435254 100644 (file)
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -249,6 +249,22 @@ int regcache_write(struct regmap *map,
        return 0;
 }
 
+static bool regcache_reg_needs_sync(struct regmap *map, unsigned int reg,
+                                   unsigned int val)
+{
+       int ret;
+
+       /* If we don't know the chip just got reset, then sync everything. */
+       if (!map->no_sync_defaults)
+               return true;
+
+       /* Is this the hardware default?  If so skip. */
+       ret = regcache_lookup_reg(map, reg);
+       if (ret >= 0 && val == map->reg_defaults[ret].def)
+               return false;
+       return true;
+}
+
 static int regcache_default_sync(struct regmap *map, unsigned int min,
                                 unsigned int max)
 {
@@ -266,9 +282,7 @@ static int regcache_default_sync(struct regmap *map, unsigned int min,
                if (ret)
                        return ret;
 
-               /* Is this the hardware default?  If so skip. */
-               ret = regcache_lookup_reg(map, reg);
-               if (ret >= 0 && val == map->reg_defaults[ret].def)
+               if (!regcache_reg_needs_sync(map, reg, val))
                        continue;
 
                map->cache_bypass = 1;
@@ -342,6 +356,7 @@ out:
        /* Restore the bypass state */
        map->async = false;
        map->cache_bypass = bypass;
+       map->no_sync_defaults = false;
        map->unlock(map->lock_arg);
 
        regmap_async_complete(map);
@@ -397,6 +412,7 @@ out:
        /* Restore the bypass state */
        map->cache_bypass = bypass;
        map->async = false;
+       map->no_sync_defaults = false;
        map->unlock(map->lock_arg);
 
        regmap_async_complete(map);
@@ -461,18 +477,23 @@ void regcache_cache_only(struct regmap *map, bool enable)
 EXPORT_SYMBOL_GPL(regcache_cache_only);
 
 /**
- * regcache_mark_dirty: Mark the register cache as dirty
+ * regcache_mark_dirty: Indicate that HW registers were reset to default values
  *
  * @map: map to mark
  *
- * Mark the register cache as dirty, for example due to the device
- * having been powered down for suspend.  If the cache is not marked
- * as dirty then the cache sync will be suppressed.
+ * Inform regcache that the device has been powered down or reset, so that
+ * on resume, regcache_sync() knows to write out all non-default values
+ * stored in the cache.
+ *
+ * If this function is not called, regcache_sync() will assume that
+ * the hardware state still matches the cache state, modulo any writes that
+ * happened when cache_only was true.
  */
 void regcache_mark_dirty(struct regmap *map)
 {
        map->lock(map->lock_arg);
        map->cache_dirty = true;
+       map->no_sync_defaults = true;
        map->unlock(map->lock_arg);
 }
 EXPORT_SYMBOL_GPL(regcache_mark_dirty);
@@ -613,10 +634,7 @@ static int regcache_sync_block_single(struct regmap *map, void *block,
                        continue;
 
                val = regcache_get_val(map, block, i);
-
-               /* Is this the hardware default?  If so skip. */
-               ret = regcache_lookup_reg(map, regtmp);
-               if (ret >= 0 && val == map->reg_defaults[ret].def)
+               if (!regcache_reg_needs_sync(map, regtmp, val))
                        continue;
 
                map->cache_bypass = 1;
@@ -688,10 +706,7 @@ static int regcache_sync_block_raw(struct regmap *map, void *block,
                }
 
                val = regcache_get_val(map, block, i);
-
-               /* Is this the hardware default?  If so skip. */
-               ret = regcache_lookup_reg(map, regtmp);
-               if (ret >= 0 && val == map->reg_defaults[ret].def) {
+               if (!regcache_reg_needs_sync(map, regtmp, val)) {
                        ret = regcache_sync_block_raw_flush(map, &data,
                                                            base, regtmp);
                        if (ret != 0)