diff options
| -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 | 117 |
4 files changed, 157 insertions, 11 deletions
diff --git a/Documentation/devicetree/bindings/regmap/regmap.txt b/Documentation/devicetree/bindings/regmap/regmap.txt new file mode 100644 index 000000000000..b494f8b8ef72 --- /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 ca193d1ef47c..053150a7f9f2 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 0eb3097c0d76..53d1148e80a0 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 78f43fb2fe84..e4e567e82b84 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 +449,102 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, } EXPORT_SYMBOL_GPL(regmap_attach_dev); +enum regmap_endian_type { + REGMAP_ENDIAN_REG, + REGMAP_ENDIAN_VAL, +}; + +static int of_regmap_get_endian(struct device *dev, + const struct regmap_bus *bus, + const struct regmap_config *config, + enum regmap_endian_type type, + enum regmap_endian *endian) +{ + struct device_node *np = dev->of_node; + + if (!endian || !config) + return -EINVAL; + + /* + * Firstly, try to parse the endianness from driver's config, + * this is to be compatible with the none DT or the old drivers. + * From the driver's config the endianness value maybe: + * REGMAP_ENDIAN_BIG, + * REGMAP_ENDIAN_LITTLE, + * REGMAP_ENDIAN_NATIVE, + * REGMAP_ENDIAN_DEFAULT. + */ + switch (type) { + case REGMAP_ENDIAN_REG: + *endian = config->reg_format_endian; + break; + case REGMAP_ENDIAN_VAL: + *endian = config->val_format_endian; + break; + default: + return -EINVAL; + } + + /* + * If the endianness parsed from driver config is + * REGMAP_ENDIAN_DEFAULT, that means maybe we are using the DT + * node to specify the endianness information. + */ + if (*endian != REGMAP_ENDIAN_DEFAULT) + return 0; + + /* + * Secondly, try to parse the endianness from DT node if the + * driver config does not specify it. + * From the DT node the endianness value maybe: + * REGMAP_ENDIAN_BIG, + * REGMAP_ENDIAN_LITTLE, + * REGMAP_ENDIAN_NATIVE, + */ + switch (type) { + case REGMAP_ENDIAN_VAL: + 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; + else + *endian = REGMAP_ENDIAN_NATIVE; + break; + case REGMAP_ENDIAN_REG: + break; + default: + return -EINVAL; + } + + /* + * If the endianness parsed from DT node is REGMAP_ENDIAN_NATIVE, that + * maybe means the DT does not care the endianness or it should use + * the regmap bus's default endianness, then we should try to check + * whether the regmap bus has specified the default endianness. + */ + if (*endian != REGMAP_ENDIAN_NATIVE) + return 0; + + /* + * Finally, try to parse the endianness from regmap bus config + * if in device's DT node the endianness property is absent. + */ + switch (type) { + case REGMAP_ENDIAN_REG: + if (bus && bus->reg_format_endian_default) + *endian = bus->reg_format_endian_default; + break; + case REGMAP_ENDIAN_VAL: + if (bus && bus->val_format_endian_default) + *endian = bus->val_format_endian_default; + break; + default: + return -EINVAL; + } + + return 0; +} + /** * regmap_init(): Initialise register map * @@ -551,17 +648,15 @@ 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; + ret = of_regmap_get_endian(dev, bus, config, REGMAP_ENDIAN_REG, + ®_endian); + if (ret) + return ERR_PTR(ret); + + ret = of_regmap_get_endian(dev, bus, config, REGMAP_ENDIAN_VAL, + &val_endian); + if (ret) + return ERR_PTR(ret); switch (config->reg_bits + map->reg_shift) { case 2: |