regmap: Add trace event for successful cache reads

Currently we only trace physical reads, there's no instrumentation if
the read is satisfied from cache.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

2 files changed, 19 insertions, 2 deletions

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 1ca2d7a1051f..1ead66186b7c 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -193,13 +193,21 @@ void regcache_exit(struct regmap *map)
 int regcache_read(struct regmap *map,
                   unsigned int reg, unsigned int *value)
 {
+        int ret;
+
         if (map->cache_type == REGCACHE_NONE)
                 return -ENOSYS;
 
         BUG_ON(!map->cache_ops);
 
-        if (!regmap_volatile(map, reg))
-                return map->cache_ops->read(map, reg, value);
+        if (!regmap_volatile(map, reg)) {
+                ret = map->cache_ops->read(map, reg, value);
+
+                if (ret == 0)
+                        trace_regmap_reg_read_cache(map->dev, reg, *value);
+
+                return ret;
+        }
 
         return -EINVAL;
 }
diff --git a/include/trace/events/regmap.h b/include/trace/events/regmap.h
index 1e3193b8fcc8..12fbf43524e9 100644
--- a/include/trace/events/regmap.h
+++ b/include/trace/events/regmap.h
@@ -55,6 +55,15 @@ DEFINE_EVENT(regmap_reg, regmap_reg_read,
 
 );
 
+DEFINE_EVENT(regmap_reg, regmap_reg_read_cache,
+
+        TP_PROTO(struct device *dev, unsigned int reg,
+                 unsigned int val),
+
+        TP_ARGS(dev, reg, val)
+
+);
+
 DECLARE_EVENT_CLASS(regmap_block,
 
         TP_PROTO(struct device *dev, unsigned int reg, int count),