* [PATCH v2 1/2] regmap: Export regmap_get_val_endian
@ 2015-02-03 18:01 Guenter Roeck
2015-02-03 18:01 ` [PATCH v2 2/2] regmap: Fix i2c word access when using SMBus access functions Guenter Roeck
2015-02-04 20:48 ` [PATCH v2 1/2] regmap: Export regmap_get_val_endian Mark Brown
0 siblings, 2 replies; 3+ messages in thread
From: Guenter Roeck @ 2015-02-03 18:01 UTC (permalink / raw)
To: Mark Brown; +Cc: linux-kernel, Guenter Roeck, Jean Delvare
We'll need to call it from regmap-i2c.c, which can be built as module.
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: New patch
drivers/base/regmap/internal.h | 4 ++++
drivers/base/regmap/regmap.c | 7 ++++---
2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 0da5865..c49a79e 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -233,6 +233,10 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg,
void regmap_async_complete_cb(struct regmap_async *async, int ret);
+enum regmap_endian regmap_get_val_endian(struct device *dev,
+ const struct regmap_bus *bus,
+ const struct regmap_config *config);
+
extern struct regcache_ops regcache_rbtree_ops;
extern struct regcache_ops regcache_lzo_ops;
extern struct regcache_ops regcache_flat_ops;
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index d2f8a81..f99b098 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -473,9 +473,9 @@ static enum regmap_endian regmap_get_reg_endian(const struct regmap_bus *bus,
return REGMAP_ENDIAN_BIG;
}
-static enum regmap_endian regmap_get_val_endian(struct device *dev,
- const struct regmap_bus *bus,
- const struct regmap_config *config)
+enum regmap_endian regmap_get_val_endian(struct device *dev,
+ const struct regmap_bus *bus,
+ const struct regmap_config *config)
{
struct device_node *np;
enum regmap_endian endian;
@@ -513,6 +513,7 @@ static enum regmap_endian regmap_get_val_endian(struct device *dev,
/* Use this if no other value was found */
return REGMAP_ENDIAN_BIG;
}
+EXPORT_SYMBOL_GPL(regmap_get_val_endian);
/**
* regmap_init(): Initialise register map
--
2.1.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v2 2/2] regmap: Fix i2c word access when using SMBus access functions
2015-02-03 18:01 [PATCH v2 1/2] regmap: Export regmap_get_val_endian Guenter Roeck
@ 2015-02-03 18:01 ` Guenter Roeck
2015-02-04 20:48 ` [PATCH v2 1/2] regmap: Export regmap_get_val_endian Mark Brown
1 sibling, 0 replies; 3+ messages in thread
From: Guenter Roeck @ 2015-02-03 18:01 UTC (permalink / raw)
To: Mark Brown; +Cc: linux-kernel, Guenter Roeck, Jean Delvare
SMBus access functions assume that 16-bit values are formatted as
little endian numbers. The direct i2c access functions in regmap,
however, assume that 16-bit values are formatted as big endian numbers.
As a result, the current code returns different values if an i2c chip's
16-bit registers are accessed through i2c access functions vs. SMBus
access functions.
Use regmap_smbus_read_word_swapped and regmap_smbus_write_word_swapped
for 16-bit SMBus accesses if a chip is configured as REGMAP_ENDIAN_BIG.
If the chip is configured as REGMAP_ENDIAN_LITTLE, keep using
regmap_smbus_write_word_data and regmap_smbus_read_word_data. Otherwise
reject registration if the controller does not support direct i2c accesses.
Cc: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: SMBUs -> SMBus, 16 bit -> 16-bit in commit log
Use regmap_get_val_endian to get configured chip endianness
Only accept REGMAP_ENDIAN_LITTLE and REGMAP_ENDIAN_BIG for SMBus 16-bit
accesses
drivers/base/regmap/regmap-i2c.c | 46 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 45 insertions(+), 1 deletion(-)
diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c
index 053150a..4b76e33 100644
--- a/drivers/base/regmap/regmap-i2c.c
+++ b/drivers/base/regmap/regmap-i2c.c
@@ -14,6 +14,7 @@
#include <linux/i2c.h>
#include <linux/module.h>
+#include "internal.h"
static int regmap_smbus_byte_reg_read(void *context, unsigned int reg,
unsigned int *val)
@@ -87,6 +88,42 @@ static struct regmap_bus regmap_smbus_word = {
.reg_read = regmap_smbus_word_reg_read,
};
+static int regmap_smbus_word_read_swapped(void *context, unsigned int reg,
+ unsigned int *val)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+ int ret;
+
+ if (reg > 0xff)
+ return -EINVAL;
+
+ ret = i2c_smbus_read_word_swapped(i2c, reg);
+ if (ret < 0)
+ return ret;
+
+ *val = ret;
+
+ return 0;
+}
+
+static int regmap_smbus_word_write_swapped(void *context, unsigned int reg,
+ unsigned int val)
+{
+ struct device *dev = context;
+ struct i2c_client *i2c = to_i2c_client(dev);
+
+ if (val > 0xffff || reg > 0xff)
+ return -EINVAL;
+
+ return i2c_smbus_write_word_swapped(i2c, reg, val);
+}
+
+static struct regmap_bus regmap_smbus_word_swapped = {
+ .reg_write = regmap_smbus_word_write_swapped,
+ .reg_read = regmap_smbus_word_read_swapped,
+};
+
static int regmap_i2c_write(void *context, const void *data, size_t count)
{
struct device *dev = context;
@@ -180,7 +217,14 @@ static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c,
else if (config->val_bits == 16 && config->reg_bits == 8 &&
i2c_check_functionality(i2c->adapter,
I2C_FUNC_SMBUS_WORD_DATA))
- return ®map_smbus_word;
+ switch (regmap_get_val_endian(&i2c->dev, NULL, config)) {
+ case REGMAP_ENDIAN_LITTLE:
+ return ®map_smbus_word;
+ case REGMAP_ENDIAN_BIG:
+ return ®map_smbus_word_swapped;
+ default: /* everything else is not supported */
+ break;
+ }
else if (config->val_bits == 8 && config->reg_bits == 8 &&
i2c_check_functionality(i2c->adapter,
I2C_FUNC_SMBUS_BYTE_DATA))
--
2.1.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2 1/2] regmap: Export regmap_get_val_endian
2015-02-03 18:01 [PATCH v2 1/2] regmap: Export regmap_get_val_endian Guenter Roeck
2015-02-03 18:01 ` [PATCH v2 2/2] regmap: Fix i2c word access when using SMBus access functions Guenter Roeck
@ 2015-02-04 20:48 ` Mark Brown
1 sibling, 0 replies; 3+ messages in thread
From: Mark Brown @ 2015-02-04 20:48 UTC (permalink / raw)
To: Guenter Roeck; +Cc: linux-kernel, Jean Delvare
[-- Attachment #1: Type: text/plain, Size: 159 bytes --]
On Tue, Feb 03, 2015 at 10:01:18AM -0800, Guenter Roeck wrote:
> We'll need to call it from regmap-i2c.c, which can be built as module.
Applied both, thanks.
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 473 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-02-03 18:01 [PATCH v2 1/2] regmap: Export regmap_get_val_endian Guenter Roeck
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2015-02-04 20:48 ` [PATCH v2 1/2] regmap: Export regmap_get_val_endian Mark Brown
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