diff options
| -rw-r--r-- | drivers/base/regmap/Kconfig | 4 | ||||
| -rw-r--r-- | drivers/base/regmap/Makefile | 1 | ||||
| -rw-r--r-- | drivers/base/regmap/regmap-sccb.c | 128 | ||||
| -rw-r--r-- | include/linux/regmap.h | 35 |
4 files changed, 168 insertions, 0 deletions
diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig index aff34c0c2a3e..6ad5ef48b61e 100644 --- a/drivers/base/regmap/Kconfig +++ b/drivers/base/regmap/Kconfig @@ -45,3 +45,7 @@ config REGMAP_IRQ config REGMAP_SOUNDWIRE tristate depends on SOUNDWIRE_BUS + +config REGMAP_SCCB + tristate + depends on I2C diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile index 5ed0023fabda..f5b4e8851d00 100644 --- a/drivers/base/regmap/Makefile +++ b/drivers/base/regmap/Makefile @@ -15,3 +15,4 @@ obj-$(CONFIG_REGMAP_MMIO) += regmap-mmio.o obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o obj-$(CONFIG_REGMAP_W1) += regmap-w1.o obj-$(CONFIG_REGMAP_SOUNDWIRE) += regmap-sdw.o +obj-$(CONFIG_REGMAP_SCCB) += regmap-sccb.o diff --git a/drivers/base/regmap/regmap-sccb.c b/drivers/base/regmap/regmap-sccb.c new file mode 100644 index 000000000000..b6eb876ea819 --- /dev/null +++ b/drivers/base/regmap/regmap-sccb.c @@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0 +// Register map access API - SCCB support + +#include <linux/regmap.h> +#include <linux/i2c.h> +#include <linux/module.h> + +#include "internal.h" + +/** + * sccb_is_available - Check if the adapter supports SCCB protocol + * @adap: I2C adapter + * + * Return true if the I2C adapter is capable of using SCCB helper functions, + * false otherwise. + */ +static bool sccb_is_available(struct i2c_adapter *adap) +{ + u32 needed_funcs = I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE_DATA; + + /* + * If we ever want support for hardware doing SCCB natively, we will + * introduce a sccb_xfer() callback to struct i2c_algorithm and check + * for it here. + */ + + return (i2c_get_functionality(adap) & needed_funcs) == needed_funcs; +} + +/** + * regmap_sccb_read - Read data from SCCB slave device + * @context: Device that will be interacted wit + * @reg: Register to be read from + * @val: Pointer to store read value + * + * This executes the 2-phase write transmission cycle that is followed by a + * 2-phase read transmission cycle, returning negative errno else zero on + * success. + */ +static int regmap_sccb_read(void *context, unsigned int reg, unsigned int *val) +{ + struct device *dev = context; + struct i2c_client *i2c = to_i2c_client(dev); + int ret; + union i2c_smbus_data data; + + i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT); + + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, + I2C_SMBUS_WRITE, reg, I2C_SMBUS_BYTE, NULL); + if (ret < 0) + goto out; + + ret = __i2c_smbus_xfer(i2c->adapter, i2c->addr, i2c->flags, + I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &data); + if (ret < 0) + goto out; + + *val = data.byte; +out: + i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT); + + return ret; +} + +/** + * regmap_sccb_write - Write data to SCCB slave device + * @context: Device that will be interacted wit + * @reg: Register to write to + * @val: Value to be written + * + * This executes the SCCB 3-phase write transmission cycle, returning negative + * errno else zero on success. + */ +static int regmap_sccb_write(void *context, unsigned int reg, unsigned int val) +{ + struct device *dev = context; + struct i2c_client *i2c = to_i2c_client(dev); + + return i2c_smbus_write_byte_data(i2c, reg, val); +} + +static struct regmap_bus regmap_sccb_bus = { + .reg_write = regmap_sccb_write, + .reg_read = regmap_sccb_read, +}; + +static const struct regmap_bus *regmap_get_sccb_bus(struct i2c_client *i2c, + const struct regmap_config *config) +{ + if (config->val_bits == 8 && config->reg_bits == 8 && + sccb_is_available(i2c->adapter)) + return ®map_sccb_bus; + + return ERR_PTR(-ENOTSUPP); +} + +struct regmap *__regmap_init_sccb(struct i2c_client *i2c, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + const struct regmap_bus *bus = regmap_get_sccb_bus(i2c, config); + + if (IS_ERR(bus)) + return ERR_CAST(bus); + + return __regmap_init(&i2c->dev, bus, &i2c->dev, config, + lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__regmap_init_sccb); + +struct regmap *__devm_regmap_init_sccb(struct i2c_client *i2c, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + const struct regmap_bus *bus = regmap_get_sccb_bus(i2c, config); + + if (IS_ERR(bus)) + return ERR_CAST(bus); + + return __devm_regmap_init(&i2c->dev, bus, &i2c->dev, config, + lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__devm_regmap_init_sccb); + +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 4f38068ffb71..52bf358e2c73 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -514,6 +514,10 @@ struct regmap *__regmap_init_i2c(struct i2c_client *i2c, const struct regmap_config *config, struct lock_class_key *lock_key, const char *lock_name); +struct regmap *__regmap_init_sccb(struct i2c_client *i2c, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name); struct regmap *__regmap_init_slimbus(struct slim_device *slimbus, const struct regmap_config *config, struct lock_class_key *lock_key, @@ -558,6 +562,10 @@ struct regmap *__devm_regmap_init_i2c(struct i2c_client *i2c, const struct regmap_config *config, struct lock_class_key *lock_key, const char *lock_name); +struct regmap *__devm_regmap_init_sccb(struct i2c_client *i2c, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name); struct regmap *__devm_regmap_init_spi(struct spi_device *dev, const struct regmap_config *config, struct lock_class_key *lock_key, @@ -646,6 +654,19 @@ int regmap_attach_dev(struct device *dev, struct regmap *map, i2c, config) /** + * regmap_init_sccb() - Initialise register map + * + * @i2c: Device that will be interacted with + * @config: Configuration for register map + * + * The return value will be an ERR_PTR() on error or a valid pointer to + * a struct regmap. + */ +#define regmap_init_sccb(i2c, config) \ + __regmap_lockdep_wrapper(__regmap_init_sccb, #config, \ + i2c, config) + +/** * regmap_init_slimbus() - Initialise register map * * @slimbus: Device that will be interacted with @@ -798,6 +819,20 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg); i2c, config) /** + * devm_regmap_init_sccb() - Initialise managed register map + * + * @i2c: Device that will be interacted with + * @config: Configuration for register map + * + * The return value will be an ERR_PTR() on error or a valid pointer + * to a struct regmap. The regmap will be automatically freed by the + * device management code. + */ +#define devm_regmap_init_sccb(i2c, config) \ + __regmap_lockdep_wrapper(__devm_regmap_init_sccb, #config, \ + i2c, config) + +/** * devm_regmap_init_spi() - Initialise register map * * @dev: Device that will be interacted with |