diff options
author | Mark Brown <broonie@linaro.org> | 2014-08-27 19:14:25 +0100 |
---|---|---|
committer | Mark Brown <broonie@linaro.org> | 2014-08-27 19:14:25 +0100 |
commit | e94b8f50907c063de25ca52072e54b0581614995 (patch) | |
tree | 483ee5c8d176e58bde09e9e14565d25bd35d3f3b | |
parent | 38c6e4bb67760db1392b9c5ee0082af07c0db20d (diff) | |
parent | cf673fbc6342b1c2310cdfdc4ed99f18f866b8e4 (diff) | |
download | op-kernel-dev-e94b8f50907c063de25ca52072e54b0581614995.zip op-kernel-dev-e94b8f50907c063de25ca52072e54b0581614995.tar.gz |
Merge tag 'dt-endian' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap into asoc-fsl
regmap: Device tree endianness support
This adds generic support for specifying endianess for register map in
the DT.
-rw-r--r-- | Documentation/devicetree/bindings/regmap/regmap.txt | 47 | ||||
-rw-r--r-- | drivers/base/regmap/regmap-i2c.c | 2 | ||||
-rw-r--r-- | drivers/base/regmap/regmap-spi.c | 2 | ||||
-rw-r--r-- | drivers/base/regmap/regmap.c | 74 |
4 files changed, 114 insertions, 11 deletions
diff --git a/Documentation/devicetree/bindings/regmap/regmap.txt b/Documentation/devicetree/bindings/regmap/regmap.txt new file mode 100644 index 0000000..b494f8b --- /dev/null +++ b/Documentation/devicetree/bindings/regmap/regmap.txt @@ -0,0 +1,47 @@ +Device-Tree binding for regmap + +The endianness mode of CPU & Device scenarios: +Index Device Endianness properties +--------------------------------------------------- +1 BE 'big-endian' +2 LE 'little-endian' + +For one device driver, which will run in different scenarios above +on different SoCs using the devicetree, we need one way to simplify +this. + +Required properties: +- {big,little}-endian: these are boolean properties, if absent + meaning that the CPU and the Device are in the same endianness mode, + these properties are for register values and all the buffers only. + +Examples: +Scenario 1 : CPU in LE mode & device in LE mode. +dev: dev@40031000 { + compatible = "name"; + reg = <0x40031000 0x1000>; + ... +}; + +Scenario 2 : CPU in LE mode & device in BE mode. +dev: dev@40031000 { + compatible = "name"; + reg = <0x40031000 0x1000>; + ... + big-endian; +}; + +Scenario 3 : CPU in BE mode & device in BE mode. +dev: dev@40031000 { + compatible = "name"; + reg = <0x40031000 0x1000>; + ... +}; + +Scenario 4 : CPU in BE mode & device in LE mode. +dev: dev@40031000 { + compatible = "name"; + reg = <0x40031000 0x1000>; + ... + little-endian; +}; diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c index ca193d1..053150a 100644 --- a/drivers/base/regmap/regmap-i2c.c +++ b/drivers/base/regmap/regmap-i2c.c @@ -168,6 +168,8 @@ static struct regmap_bus regmap_i2c = { .write = regmap_i2c_write, .gather_write = regmap_i2c_gather_write, .read = regmap_i2c_read, + .reg_format_endian_default = REGMAP_ENDIAN_BIG, + .val_format_endian_default = REGMAP_ENDIAN_BIG, }; static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c, diff --git a/drivers/base/regmap/regmap-spi.c b/drivers/base/regmap/regmap-spi.c index 0eb3097..53d1148 100644 --- a/drivers/base/regmap/regmap-spi.c +++ b/drivers/base/regmap/regmap-spi.c @@ -109,6 +109,8 @@ static struct regmap_bus regmap_spi = { .async_alloc = regmap_spi_async_alloc, .read = regmap_spi_read, .read_flag_mask = 0x80, + .reg_format_endian_default = REGMAP_ENDIAN_BIG, + .val_format_endian_default = REGMAP_ENDIAN_BIG, }; /** diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 78f43fb..01ae4b8 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -15,6 +15,7 @@ #include <linux/export.h> #include <linux/mutex.h> #include <linux/err.h> +#include <linux/of.h> #include <linux/rbtree.h> #include <linux/sched.h> @@ -448,6 +449,66 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, } EXPORT_SYMBOL_GPL(regmap_attach_dev); +static enum regmap_endian regmap_get_reg_endian(const struct regmap_bus *bus, + const struct regmap_config *config) +{ + enum regmap_endian endian; + + /* Retrieve the endianness specification from the regmap config */ + endian = config->reg_format_endian; + + /* If the regmap config specified a non-default value, use that */ + if (endian != REGMAP_ENDIAN_DEFAULT) + return endian; + + /* Retrieve the endianness specification from the bus config */ + if (bus && bus->reg_format_endian_default) + endian = bus->reg_format_endian_default; + + /* If the bus specified a non-default value, use that */ + if (endian != REGMAP_ENDIAN_DEFAULT) + return endian; + + /* Use this if no other value was found */ + 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) +{ + struct device_node *np = dev->of_node; + enum regmap_endian endian; + + /* Retrieve the endianness specification from the regmap config */ + endian = config->val_format_endian; + + /* If the regmap config specified a non-default value, use that */ + if (endian != REGMAP_ENDIAN_DEFAULT) + return endian; + + /* Parse the device's DT node for an endianness specification */ + if (of_property_read_bool(np, "big-endian")) + endian = REGMAP_ENDIAN_BIG; + else if (of_property_read_bool(np, "little-endian")) + endian = REGMAP_ENDIAN_LITTLE; + + /* If the endianness was specified in DT, use that */ + if (endian != REGMAP_ENDIAN_DEFAULT) + return endian; + + /* Retrieve the endianness specification from the bus config */ + if (bus && bus->val_format_endian_default) + endian = bus->val_format_endian_default; + + /* If the bus specified a non-default value, use that */ + if (endian != REGMAP_ENDIAN_DEFAULT) + return endian; + + /* Use this if no other value was found */ + return REGMAP_ENDIAN_BIG; +} + /** * regmap_init(): Initialise register map * @@ -551,17 +612,8 @@ struct regmap *regmap_init(struct device *dev, map->reg_read = _regmap_bus_read; } - 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; + reg_endian = regmap_get_reg_endian(bus, config); + val_endian = regmap_get_val_endian(dev, bus, config); switch (config->reg_bits + map->reg_shift) { case 2: |