[PATCH 1/4] regmap: Add support for discarding parts of the register cache

From: Mark Brown
Date: Wed May 08 2013 - 08:59:28 EST


Allow drivers to discard parts of the register cache, for example if part
of the hardware has been reset.

Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
---
drivers/base/regmap/internal.h | 1 +
drivers/base/regmap/regcache.c | 37 +++++++++++++++++++++++++++++++++++++
include/linux/regmap.h | 9 +++++++++
include/trace/events/regmap.h | 23 +++++++++++++++++++++++
4 files changed, 70 insertions(+)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index c130536..b33a4ff 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -148,6 +148,7 @@ struct regcache_ops {
int (*read)(struct regmap *map, unsigned int reg, unsigned int *value);
int (*write)(struct regmap *map, unsigned int reg, unsigned int value);
int (*sync)(struct regmap *map, unsigned int min, unsigned int max);
+ int (*drop)(struct regmap *map, unsigned int min, unsigned int max);
};

bool regmap_writeable(struct regmap *map, unsigned int reg);
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 1196c21..14c6eef 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -359,6 +359,43 @@ out:
EXPORT_SYMBOL_GPL(regcache_sync_region);

/**
+ * regcache_drop_region: Discard part of the register cache
+ *
+ * @map: map to operate on
+ * @min: first register to discard
+ * @max: last register to discard
+ *
+ * Discard part of the register cache.
+ *
+ * Return a negative value on failure, 0 on success.
+ */
+int regcache_drop_region(struct regmap *map, unsigned int min,
+ unsigned int max)
+{
+ unsigned int reg;
+ int ret = 0;
+
+ if (!map->cache_present && !(map->cache_ops && map->cache_ops->drop))
+ return -EINVAL;
+
+ map->lock(map);
+
+ trace_regcache_drop_region(map->dev, min, max);
+
+ if (map->cache_present)
+ for (reg = min; reg < max + 1; reg++)
+ clear_bit(reg, map->cache_present);
+
+ if (map->cache_ops && map->cache_ops->drop)
+ ret = map->cache_ops->drop(map, min, max);
+
+ map->unlock(map);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regcache_drop_region);
+
+/**
* regcache_cache_only: Put a register map into cache only mode
*
* @map: map to configure
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 02d84e2..5067ee9 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -394,6 +394,8 @@ bool regmap_can_raw_write(struct regmap *map);
int regcache_sync(struct regmap *map);
int regcache_sync_region(struct regmap *map, unsigned int min,
unsigned int max);
+int regcache_drop_region(struct regmap *map, unsigned int min,
+ unsigned int max);
void regcache_cache_only(struct regmap *map, bool enable);
void regcache_cache_bypass(struct regmap *map, bool enable);
void regcache_mark_dirty(struct regmap *map);
@@ -562,6 +564,13 @@ static inline int regcache_sync_region(struct regmap *map, unsigned int min,
return -EINVAL;
}

+static inline int regcache_drop_region(struct regmap *map, unsigned int min,
+ unsigned int max)
+{
+ WARN_ONCE(1, "regmap API is disabled");
+ return -EINVAL;
+}
+
static inline void regcache_cache_only(struct regmap *map, bool enable)
{
WARN_ONCE(1, "regmap API is disabled");
diff --git a/include/trace/events/regmap.h b/include/trace/events/regmap.h
index a43a2f6..23d5615 100644
--- a/include/trace/events/regmap.h
+++ b/include/trace/events/regmap.h
@@ -223,6 +223,29 @@ DEFINE_EVENT(regmap_async, regmap_async_complete_done,

);

+TRACE_EVENT(regcache_drop_region,
+
+ TP_PROTO(struct device *dev, unsigned int from,
+ unsigned int to),
+
+ TP_ARGS(dev, from, to),
+
+ TP_STRUCT__entry(
+ __string( name, dev_name(dev) )
+ __field( unsigned int, from )
+ __field( unsigned int, to )
+ ),
+
+ TP_fast_assign(
+ __assign_str(name, dev_name(dev));
+ __entry->from = from;
+ __entry->to = to;
+ ),
+
+ TP_printk("%s %u-%u", __get_str(name), (unsigned int)__entry->from,
+ (unsigned int)__entry->to)
+);
+
#endif /* _TRACE_REGMAP_H */

/* This part must be outside protection */
--
1.7.10.4

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