From: Jean-Jacques Hiblot jjhiblot@ti.com
A regmap field is an abstraction available in Linux. It provides to access bitfields in a regmap without having to worry about shifts and masks.
Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Reviewed-by: Simon Glass sjg@chromium.org Signed-off-by: Pratyush Yadav p.yadav@ti.com --- drivers/core/regmap.c | 83 ++++++++++++++++++++++++++++ include/regmap.h | 122 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 205 insertions(+)
diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c index a3da0cf7c3..c2bed88eac 100644 --- a/drivers/core/regmap.c +++ b/drivers/core/regmap.c @@ -18,6 +18,20 @@ #include <linux/ioport.h> #include <linux/compat.h> #include <linux/err.h> +#include <linux/bitops.h> + +/* + * Internal representation of a regmap field. Instead of storing the MSB and + * LSB, store the shift and mask. This makes the code a bit cleaner and faster + * because the shift and mask don't have to be calculated every time. + */ +struct regmap_field { + struct regmap *regmap; + unsigned int mask; + /* lsb */ + unsigned int shift; + unsigned int reg; +};
DECLARE_GLOBAL_DATA_PTR;
@@ -547,3 +561,72 @@ int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val)
return regmap_write(map, offset, reg | (val & mask)); } + +int regmap_field_read(struct regmap_field *field, unsigned int *val) +{ + int ret; + unsigned int reg_val; + + ret = regmap_read(field->regmap, field->reg, ®_val); + if (ret != 0) + return ret; + + reg_val &= field->mask; + reg_val >>= field->shift; + *val = reg_val; + + return ret; +} + +int regmap_field_write(struct regmap_field *field, unsigned int val) +{ + return regmap_update_bits(field->regmap, field->reg, field->mask, + val << field->shift); +} + +static void regmap_field_init(struct regmap_field *rm_field, + struct regmap *regmap, + struct reg_field reg_field) +{ + rm_field->regmap = regmap; + rm_field->reg = reg_field.reg; + rm_field->shift = reg_field.lsb; + rm_field->mask = GENMASK(reg_field.msb, reg_field.lsb); +} + +struct regmap_field *devm_regmap_field_alloc(struct udevice *dev, + struct regmap *regmap, + struct reg_field reg_field) +{ + struct regmap_field *rm_field = devm_kzalloc(dev, sizeof(*rm_field), + GFP_KERNEL); + if (!rm_field) + return ERR_PTR(-ENOMEM); + + regmap_field_init(rm_field, regmap, reg_field); + + return rm_field; +} + +void devm_regmap_field_free(struct udevice *dev, struct regmap_field *field) +{ + devm_kfree(dev, field); +} + +struct regmap_field *regmap_field_alloc(struct regmap *regmap, + struct reg_field reg_field) +{ + struct regmap_field *rm_field = kzalloc(sizeof(*rm_field), GFP_KERNEL); + + if (!rm_field) + return ERR_PTR(-ENOMEM); + + regmap_field_init(rm_field, regmap, reg_field); + + return rm_field; +} + +void regmap_field_free(struct regmap_field *field) +{ + kfree(field); +} diff --git a/include/regmap.h b/include/regmap.h index 7a6fcc7f53..c6258face3 100644 --- a/include/regmap.h +++ b/include/regmap.h @@ -312,6 +312,43 @@ int regmap_raw_read_range(struct regmap *map, uint range_num, uint offset, regmap_read_poll_timeout_test(map, addr, val, cond, sleep_us, \ timeout_ms, 0) \
+/** + * regmap_field_read_poll_timeout - Poll until a condition is met or a timeout + * occurs + * + * @field: Regmap field to read from + * @val: Unsigned integer variable to read the value into + * @cond: Break condition (usually involving @val) + * @sleep_us: Maximum time to sleep between reads in us (0 tight-loops). + * @timeout_ms: Timeout in ms, 0 means never timeout + * + * Returns 0 on success and -ETIMEDOUT upon a timeout or the regmap_field_read + * error return value in case of a error read. In the two former cases, + * the last read value at @addr is stored in @val. + * + * This is modelled after the regmap_read_poll_timeout macros in linux but + * with millisecond timeout. + */ +#define regmap_field_read_poll_timeout(field, val, cond, sleep_us, timeout_ms) \ +({ \ + unsigned long __start = get_timer(0); \ + int __ret; \ + for (;;) { \ + __ret = regmap_field_read((field), &(val)); \ + if (__ret) \ + break; \ + if (cond) \ + break; \ + if ((timeout_ms) && get_timer(__start) > (timeout_ms)) { \ + __ret = regmap_field_read((field), &(val)); \ + break; \ + } \ + if ((sleep_us)) \ + udelay((sleep_us)); \ + } \ + __ret ?: ((cond) ? 0 : -ETIMEDOUT); \ +}) + /** * regmap_update_bits() - Perform a read/modify/write using a mask * @@ -407,4 +444,89 @@ void *regmap_get_range(struct regmap *map, unsigned int range_num); */ int regmap_uninit(struct regmap *map);
+/** + * struct reg_field - Description of an register field + * + * @reg: Offset of the register within the regmap bank + * @lsb: lsb of the register field. + * @msb: msb of the register field. + */ +struct reg_field { + unsigned int reg; + unsigned int lsb; + unsigned int msb; +}; + +struct regmap_field; + +/** + * REG_FIELD() - A convenient way to initialize a 'struct reg_feild'. + * + * @_reg: Offset of the register within the regmap bank + * @_lsb: lsb of the register field. + * @_msb: msb of the register field. + * + * Register fields are often described in terms of 3 things: the register it + * belongs to, its LSB, and its MSB. This macro can be used by drivers to + * clearly and easily initialize a 'struct regmap_field'. + * + * For example, say a device has a register at offset DEV_REG1 (0x100) and a + * field of DEV_REG1 is on bits [7:3]. So a driver can initialize a regmap + * field for this by doing: + * struct reg_field field = REG_FIELD(DEV_REG1, 3, 7); + */ +#define REG_FIELD(_reg, _lsb, _msb) { \ + .reg = _reg, \ + .lsb = _lsb, \ + .msb = _msb, \ + } + +/** + * devm_regmap_field_alloc() - Allocate and initialise a register field. + * + * @dev: Device that will be interacted with + * @regmap: regmap bank in which this register field is located. + * @reg_field: Register field with in the bank. + * + * The return value will be an ERR_PTR() on error or a valid pointer + * to a struct regmap_field. The regmap_field will be automatically freed + * by the device management code. + */ +struct regmap_field *devm_regmap_field_alloc(struct udevice *dev, + struct regmap *regmap, + struct reg_field reg_field); +/** + * devm_regmap_field_free() - Free a register field allocated using + * devm_regmap_field_alloc. + * + * @dev: Device that will be interacted with + * @field: regmap field which should be freed. + * + * Free register field allocated using devm_regmap_field_alloc(). Usually + * drivers need not call this function, as the memory allocated via devm + * will be freed as per device-driver life-cyle. + */ +void devm_regmap_field_free(struct udevice *dev, struct regmap_field *field); + +/** + * regmap_field_write() - Write a value to a regmap field + * + * @field: Regmap field to write to + * @val: Data to write to the regmap at the specified offset + * + * Return: 0 if OK, -ve on error + */ +int regmap_field_write(struct regmap_field *field, unsigned int val); + +/** + * regmap_read() - Read a 32-bit value from a regmap + * + * @field: Regmap field to write to + * @valp: Pointer to the buffer to receive the data read from the regmap + * field + * + * Return: 0 if OK, -ve on error + */ +int regmap_field_read(struct regmap_field *field, unsigned int *val); + #endif