[PATCH net-next v2 1/2] regmap: Allow installing custom reg_update_bits function

jon
2015-10-01T11:43:48Z

From: Jon Ringle <jringle@gridpoint.com>

This commit allows installing a custom reg_update_bits function for cases where
the hardware provides a mechanism to set or clear register bits without a
read/modify/write cycle. Such is the case with the Microchip ENCX24J600.

Signed-off-by: Jon Ringle <jringle@gridpoint.com>
---
drivers/base/regmap/internal.h | 3 +++
drivers/base/regmap/regmap.c | 25 +++++++++++++++++++++++++
include/linux/regmap.h | 4 ++++
3 files changed, 32 insertions(+)

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index cc55788..4036d7a 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -98,6 +98,9 @@ struct regmap {

int (*reg_read)(void *context, unsigned int reg, unsigned int *val);
int (*reg_write)(void *context, unsigned int reg, unsigned int val);
+ int (*reg_update_bits)(void *context, unsigned int reg,
+ unsigned int mask, unsigned int val,
+ bool *change, bool force_write);

bool defer_caching;

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index afaf562..70387c9 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -619,6 +619,7 @@ struct regmap *__regmap_init(struct device *dev,
goto skip_format_initialization;
} else {
map->reg_read = _regmap_bus_read;
+ map->reg_update_bits = bus->reg_update_bits;
}

reg_endian = regmap_get_reg_endian(bus, config);
@@ -2509,6 +2510,30 @@ static int _regmap_update_bits(struct regmap *map, unsigned int reg,
int ret;
unsigned int tmp, orig;

+ if (map->reg_update_bits) {
+ ret = map->reg_update_bits(map->bus_context, reg, mask, val,
+ change, force_write);
+ if (ret != 0)
+ return ret;
+
+ /* Fix up the cache by read/modify/write */
+ if (!map->cache_bypass && !map->defer_caching) {
+ ret = regcache_read(map, reg, &orig);
+ if (ret != 0)
+ return ret;
+
+ tmp = orig & ~mask;
+ tmp |= val & mask;
+
+ ret = regcache_write(map, reg, tmp);
+ if (ret != 0)
+ return ret;
+ if (map->cache_only)
+ map->cache_dirty = true;
+ }
+ return ret;
+ }
+
ret = _regmap_read(map, reg, &orig);
if (ret != 0)
return ret;
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 8fc0bfd..4d3a3b1 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -296,6 +296,9 @@ typedef int (*regmap_hw_reg_read)(void *context, unsigned int reg,
unsigned int *val);
typedef int (*regmap_hw_reg_write)(void *context, unsigned int reg,
unsigned int val);
+typedef int (*regmap_hw_reg_update_bits)(void *context, unsigned int reg,
+ unsigned int mask, unsigned int val,
+ bool *change, bool force_write);
typedef struct regmap_async *(*regmap_hw_async_alloc)(void);
typedef void (*regmap_hw_free_context)(void *context);

@@ -335,6 +338,7 @@ struct regmap_bus {
regmap_hw_gather_write gather_write;
regmap_hw_async_write async_write;
regmap_hw_reg_write reg_write;
+ regmap_hw_reg_update_bits reg_update_bits;
regmap_hw_read read;
regmap_hw_reg_read reg_read;
regmap_hw_free_context free_context;
--
2.4.1