| // SPDX-License-Identifier: GPL-2.0 |
| // |
| // Register map access API - I2C support |
| // |
| // Copyright 2011 Wolfson Microelectronics plc |
| // |
| // Author: Mark Brown <broonie@opensource.wolfsonmicro.com> |
| |
| #include <linux/regmap.h> |
| #include <linux/i2c.h> |
| #include <linux/module.h> |
| |
| #include "internal.h" |
| |
| static int regmap_smbus_byte_reg_read(void *context, unsigned int reg, |
| unsigned int *val) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| int ret; |
| |
| if (reg > 0xff) |
| return -EINVAL; |
| |
| ret = i2c_smbus_read_byte_data(i2c, reg); |
| if (ret < 0) |
| return ret; |
| |
| *val = ret; |
| |
| return 0; |
| } |
| |
| static int regmap_smbus_byte_reg_write(void *context, unsigned int reg, |
| unsigned int val) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| |
| if (val > 0xff || reg > 0xff) |
| return -EINVAL; |
| |
| return i2c_smbus_write_byte_data(i2c, reg, val); |
| } |
| |
| static const struct regmap_bus regmap_smbus_byte = { |
| .reg_write = regmap_smbus_byte_reg_write, |
| .reg_read = regmap_smbus_byte_reg_read, |
| }; |
| |
| static int regmap_smbus_word_reg_read(void *context, unsigned int reg, |
| unsigned int *val) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| int ret; |
| |
| if (reg > 0xff) |
| return -EINVAL; |
| |
| ret = i2c_smbus_read_word_data(i2c, reg); |
| if (ret < 0) |
| return ret; |
| |
| *val = ret; |
| |
| return 0; |
| } |
| |
| static int regmap_smbus_word_reg_write(void *context, unsigned int reg, |
| unsigned int val) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| |
| if (val > 0xffff || reg > 0xff) |
| return -EINVAL; |
| |
| return i2c_smbus_write_word_data(i2c, reg, val); |
| } |
| |
| static const struct regmap_bus regmap_smbus_word = { |
| .reg_write = regmap_smbus_word_reg_write, |
| .reg_read = regmap_smbus_word_reg_read, |
| }; |
| |
| static int regmap_smbus_word_read_swapped(void *context, unsigned int reg, |
| unsigned int *val) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| int ret; |
| |
| if (reg > 0xff) |
| return -EINVAL; |
| |
| ret = i2c_smbus_read_word_swapped(i2c, reg); |
| if (ret < 0) |
| return ret; |
| |
| *val = ret; |
| |
| return 0; |
| } |
| |
| static int regmap_smbus_word_write_swapped(void *context, unsigned int reg, |
| unsigned int val) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| |
| if (val > 0xffff || reg > 0xff) |
| return -EINVAL; |
| |
| return i2c_smbus_write_word_swapped(i2c, reg, val); |
| } |
| |
| static const struct regmap_bus regmap_smbus_word_swapped = { |
| .reg_write = regmap_smbus_word_write_swapped, |
| .reg_read = regmap_smbus_word_read_swapped, |
| }; |
| |
| static int regmap_i2c_write(void *context, const void *data, size_t count) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| int ret; |
| |
| ret = i2c_master_send(i2c, data, count); |
| if (ret == count) |
| return 0; |
| else if (ret < 0) |
| return ret; |
| else |
| return -EIO; |
| } |
| |
| static int regmap_i2c_gather_write(void *context, |
| const void *reg, size_t reg_size, |
| const void *val, size_t val_size) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| struct i2c_msg xfer[2]; |
| int ret; |
| |
| /* If the I2C controller can't do a gather tell the core, it |
| * will substitute in a linear write for us. |
| */ |
| if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_NOSTART)) |
| return -ENOTSUPP; |
| |
| xfer[0].addr = i2c->addr; |
| xfer[0].flags = 0; |
| xfer[0].len = reg_size; |
| xfer[0].buf = (void *)reg; |
| |
| xfer[1].addr = i2c->addr; |
| xfer[1].flags = I2C_M_NOSTART; |
| xfer[1].len = val_size; |
| xfer[1].buf = (void *)val; |
| |
| ret = i2c_transfer(i2c->adapter, xfer, 2); |
| if (ret == 2) |
| return 0; |
| if (ret < 0) |
| return ret; |
| else |
| return -EIO; |
| } |
| |
| static int regmap_i2c_read(void *context, |
| const void *reg, size_t reg_size, |
| void *val, size_t val_size) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| struct i2c_msg xfer[2]; |
| int ret; |
| |
| xfer[0].addr = i2c->addr; |
| xfer[0].flags = 0; |
| xfer[0].len = reg_size; |
| xfer[0].buf = (void *)reg; |
| |
| xfer[1].addr = i2c->addr; |
| xfer[1].flags = I2C_M_RD; |
| xfer[1].len = val_size; |
| xfer[1].buf = val; |
| |
| ret = i2c_transfer(i2c->adapter, xfer, 2); |
| if (ret == 2) |
| return 0; |
| else if (ret < 0) |
| return ret; |
| else |
| return -EIO; |
| } |
| |
| static const 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 int regmap_i2c_smbus_i2c_write(void *context, const void *data, |
| size_t count) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| |
| if (count < 1) |
| return -EINVAL; |
| |
| --count; |
| return i2c_smbus_write_i2c_block_data(i2c, ((u8 *)data)[0], count, |
| ((u8 *)data + 1)); |
| } |
| |
| static int regmap_i2c_smbus_i2c_read(void *context, const void *reg, |
| size_t reg_size, void *val, |
| size_t val_size) |
| { |
| struct device *dev = context; |
| struct i2c_client *i2c = to_i2c_client(dev); |
| int ret; |
| |
| if (reg_size != 1 || val_size < 1) |
| return -EINVAL; |
| |
| ret = i2c_smbus_read_i2c_block_data(i2c, ((u8 *)reg)[0], val_size, val); |
| if (ret == val_size) |
| return 0; |
| else if (ret < 0) |
| return ret; |
| else |
| return -EIO; |
| } |
| |
| static const struct regmap_bus regmap_i2c_smbus_i2c_block = { |
| .write = regmap_i2c_smbus_i2c_write, |
| .read = regmap_i2c_smbus_i2c_read, |
| .max_raw_read = I2C_SMBUS_BLOCK_MAX, |
| .max_raw_write = I2C_SMBUS_BLOCK_MAX, |
| }; |
| |
| static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c, |
| const struct regmap_config *config) |
| { |
| if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C)) |
| return ®map_i2c; |
| else if (config->val_bits == 8 && config->reg_bits == 8 && |
| i2c_check_functionality(i2c->adapter, |
| I2C_FUNC_SMBUS_I2C_BLOCK)) |
| return ®map_i2c_smbus_i2c_block; |
| else if (config->val_bits == 16 && config->reg_bits == 8 && |
| i2c_check_functionality(i2c->adapter, |
| I2C_FUNC_SMBUS_WORD_DATA)) |
| switch (regmap_get_val_endian(&i2c->dev, NULL, config)) { |
| case REGMAP_ENDIAN_LITTLE: |
| return ®map_smbus_word; |
| case REGMAP_ENDIAN_BIG: |
| return ®map_smbus_word_swapped; |
| default: /* everything else is not supported */ |
| break; |
| } |
| else if (config->val_bits == 8 && config->reg_bits == 8 && |
| i2c_check_functionality(i2c->adapter, |
| I2C_FUNC_SMBUS_BYTE_DATA)) |
| return ®map_smbus_byte; |
| |
| return ERR_PTR(-ENOTSUPP); |
| } |
| |
| struct regmap *__regmap_init_i2c(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_i2c_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_i2c); |
| |
| 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) |
| { |
| const struct regmap_bus *bus = regmap_get_i2c_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_i2c); |
| |
| MODULE_LICENSE("GPL"); |
