[PATCH V2 1/2] regmap: allow busses to request formatting with specific endianness
From: Stephen Warren
Date: Thu May 24 2012 - 12:47:50 EST
From: Stephen Warren <swarren@xxxxxxxxxx>
Add a field to struct regmap_bus that allows bus drivers to request that
register addresses and values be formatted with a specific endianness.
The default endianness is unchanged from current operation: Big.
Implement native endian formatting/parsing for 16- and 32-bit values.
This will be enough to support regmap-mmio.c.
Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx>
---
v2: Allow regmap_config to specify endianness, and regmap_bus to specify
a default endianness when it doesn't.
---
drivers/base/regmap/regmap.c | 101 +++++++++++++++++++++++++++++++++++++-----
include/linux/regmap.h | 25 ++++++++++
2 files changed, 115 insertions(+), 11 deletions(-)
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 0bcda48..1cf7214 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -119,13 +119,19 @@ static void regmap_format_8(void *buf, unsigned int val, unsigned int shift)
b[0] = val << shift;
}
-static void regmap_format_16(void *buf, unsigned int val, unsigned int shift)
+static void regmap_format_16_be(void *buf, unsigned int val, unsigned int shift)
{
__be16 *b = buf;
b[0] = cpu_to_be16(val << shift);
}
+static void regmap_format_16_native(void *buf, unsigned int val,
+ unsigned int shift)
+{
+ *(u16 *)buf = val << shift;
+}
+
static void regmap_format_24(void *buf, unsigned int val, unsigned int shift)
{
u8 *b = buf;
@@ -137,13 +143,19 @@ static void regmap_format_24(void *buf, unsigned int val, unsigned int shift)
b[2] = val;
}
-static void regmap_format_32(void *buf, unsigned int val, unsigned int shift)
+static void regmap_format_32_be(void *buf, unsigned int val, unsigned int shift)
{
__be32 *b = buf;
b[0] = cpu_to_be32(val << shift);
}
+static void regmap_format_32_native(void *buf, unsigned int val,
+ unsigned int shift)
+{
+ *(u32 *)buf = val << shift;
+}
+
static unsigned int regmap_parse_8(void *buf)
{
u8 *b = buf;
@@ -151,7 +163,7 @@ static unsigned int regmap_parse_8(void *buf)
return b[0];
}
-static unsigned int regmap_parse_16(void *buf)
+static unsigned int regmap_parse_16_be(void *buf)
{
__be16 *b = buf;
@@ -160,6 +172,11 @@ static unsigned int regmap_parse_16(void *buf)
return b[0];
}
+static unsigned int regmap_parse_16_native(void *buf)
+{
+ return *(u16 *)buf;
+}
+
static unsigned int regmap_parse_24(void *buf)
{
u8 *b = buf;
@@ -170,7 +187,7 @@ static unsigned int regmap_parse_24(void *buf)
return ret;
}
-static unsigned int regmap_parse_32(void *buf)
+static unsigned int regmap_parse_32_be(void *buf)
{
__be32 *b = buf;
@@ -179,6 +196,11 @@ static unsigned int regmap_parse_32(void *buf)
return b[0];
}
+static unsigned int regmap_parse_32_native(void *buf)
+{
+ return *(u32 *)buf;
+}
+
static void regmap_lock_mutex(struct regmap *map)
{
mutex_lock(&map->mutex);
@@ -227,6 +249,7 @@ struct regmap *regmap_init(struct device *dev,
{
struct regmap *map, **m;
int ret = -EINVAL;
+ enum regmap_endian reg_endian, val_endian;
if (!bus || !config)
goto err;
@@ -275,6 +298,18 @@ struct regmap *regmap_init(struct device *dev,
map->read_flag_mask = bus->read_flag_mask;
}
+ reg_endian = config->reg_format_endian;
+ if (reg_endian == REGMAP_ENDIAN_DEFAULT)
+ reg_endian = bus->reg_format_endian_default;
+ if (reg_endian == REGMAP_ENDIAN_DEFAULT)
+ reg_endian = REGMAP_ENDIAN_BIG;
+
+ val_endian = config->val_format_endian;
+ if (val_endian == REGMAP_ENDIAN_DEFAULT)
+ val_endian = bus->val_format_endian_default;
+ if (val_endian == REGMAP_ENDIAN_DEFAULT)
+ val_endian = REGMAP_ENDIAN_BIG;
+
switch (config->reg_bits + map->reg_shift) {
case 2:
switch (config->val_bits) {
@@ -321,11 +356,29 @@ struct regmap *regmap_init(struct device *dev,
break;
case 16:
- map->format.format_reg = regmap_format_16;
+ switch (reg_endian) {
+ case REGMAP_ENDIAN_BIG:
+ map->format.format_reg = regmap_format_16_be;
+ break;
+ case REGMAP_ENDIAN_NATIVE:
+ map->format.format_reg = regmap_format_16_native;
+ break;
+ default:
+ goto err_map;
+ }
break;
case 32:
- map->format.format_reg = regmap_format_32;
+ switch (reg_endian) {
+ case REGMAP_ENDIAN_BIG:
+ map->format.format_reg = regmap_format_32_be;
+ break;
+ case REGMAP_ENDIAN_NATIVE:
+ map->format.format_reg = regmap_format_32_native;
+ break;
+ default:
+ goto err_map;
+ }
break;
default:
@@ -338,21 +391,47 @@ struct regmap *regmap_init(struct device *dev,
map->format.parse_val = regmap_parse_8;
break;
case 16:
- map->format.format_val = regmap_format_16;
- map->format.parse_val = regmap_parse_16;
+ switch (val_endian) {
+ case REGMAP_ENDIAN_BIG:
+ map->format.format_val = regmap_format_16_be;
+ map->format.parse_val = regmap_parse_16_be;
+ break;
+ case REGMAP_ENDIAN_NATIVE:
+ map->format.format_val = regmap_format_16_native;
+ map->format.parse_val = regmap_parse_16_native;
+ break;
+ default:
+ goto err_map;
+ }
break;
case 24:
+ if (val_endian != REGMAP_ENDIAN_BIG)
+ goto err_map;
map->format.format_val = regmap_format_24;
map->format.parse_val = regmap_parse_24;
break;
case 32:
- map->format.format_val = regmap_format_32;
- map->format.parse_val = regmap_parse_32;
+ switch (val_endian) {
+ case REGMAP_ENDIAN_BIG:
+ map->format.format_val = regmap_format_32_be;
+ map->format.parse_val = regmap_parse_32_be;
+ break;
+ case REGMAP_ENDIAN_NATIVE:
+ map->format.format_val = regmap_format_32_native;
+ map->format.parse_val = regmap_parse_32_native;
+ break;
+ default:
+ goto err_map;
+ }
break;
}
- if (map->format.format_write)
+ if (map->format.format_write) {
+ if ((reg_endian != REGMAP_ENDIAN_BIG) ||
+ (val_endian != REGMAP_ENDIAN_BIG))
+ goto err_map;
map->use_single_rw = true;
+ }
if (!map->format.format_write &&
!(map->format.format_reg && map->format.format_val))
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 56af22e..26136b5 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -43,6 +43,14 @@ struct reg_default {
#ifdef CONFIG_REGMAP
+enum regmap_endian {
+ /* Unspecified -> 0 -> Backwards compatible default */
+ REGMAP_ENDIAN_DEFAULT = 0,
+ REGMAP_ENDIAN_BIG,
+ REGMAP_ENDIAN_LITTLE,
+ REGMAP_ENDIAN_NATIVE,
+};
+
/**
* Configuration for the register map of a device.
*
@@ -84,6 +92,12 @@ struct reg_default {
* @reg_defaults_raw: Power on reset values for registers (for use with
* register cache support).
* @num_reg_defaults_raw: Number of elements in reg_defaults_raw.
+ * @reg_format_endian: Endianness for formatted register addresses. If this is
+ * DEFAULT, the @reg_format_endian_default value from the
+ * regmap bus is used.
+ * @val_format_endian: Endianness for formatted register values. If this is
+ * DEFAULT, the @reg_format_endian_default value from the
+ * regmap bus is used.
*/
struct regmap_config {
const char *name;
@@ -109,6 +123,9 @@ struct regmap_config {
u8 write_flag_mask;
bool use_single_rw;
+
+ enum regmap_endian reg_format_endian;
+ enum regmap_endian val_format_endian;
};
typedef int (*regmap_hw_write)(void *context, const void *data,
@@ -133,6 +150,12 @@ typedef void (*regmap_hw_free_context)(void *context);
* data.
* @read_flag_mask: Mask to be set in the top byte of the register when doing
* a read.
+ * @reg_format_endian_default: Default endianness for formatted register
+ * addresses. Used when the regmap_config specifies DEFAULT. If this is
+ * DEFAULT, BIG is assumed.
+ * @val_format_endian_default: Default endianness for formatted register
+ * values. Used when the regmap_config specifies DEFAULT. If this is
+ * DEFAULT, BIG is assumed.
*/
struct regmap_bus {
bool fast_io;
@@ -141,6 +164,8 @@ struct regmap_bus {
regmap_hw_read read;
regmap_hw_free_context free_context;
u8 read_flag_mask;
+ enum regmap_endian reg_format_endian_default;
+ enum regmap_endian val_format_endian_default;
};
struct regmap *regmap_init(struct device *dev,
--
1.7.0.4
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