| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * I2C driver for Bosch BMI323 6-Axis IMU. |
| * |
| * Copyright (C) 2023, Jagath Jog J <jagathjog1996@gmail.com> |
| */ |
| |
| #include <linux/i2c.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/module.h> |
| #include <linux/regmap.h> |
| |
| #include "bmi323.h" |
| |
| struct bmi323_i2c_priv { |
| struct i2c_client *i2c; |
| u8 i2c_rx_buffer[BMI323_FIFO_LENGTH_IN_BYTES + BMI323_I2C_DUMMY]; |
| }; |
| |
| /* |
| * From BMI323 datasheet section 4: Notes on the Serial Interface Support. |
| * Each I2C register read operation requires to read two dummy bytes before |
| * the actual payload. |
| */ |
| static int bmi323_regmap_i2c_read(void *context, const void *reg_buf, |
| size_t reg_size, void *val_buf, |
| size_t val_size) |
| { |
| struct bmi323_i2c_priv *priv = context; |
| struct i2c_msg msgs[2]; |
| int ret; |
| |
| msgs[0].addr = priv->i2c->addr; |
| msgs[0].flags = priv->i2c->flags; |
| msgs[0].len = reg_size; |
| msgs[0].buf = (u8 *)reg_buf; |
| |
| msgs[1].addr = priv->i2c->addr; |
| msgs[1].len = val_size + BMI323_I2C_DUMMY; |
| msgs[1].buf = priv->i2c_rx_buffer; |
| msgs[1].flags = priv->i2c->flags | I2C_M_RD; |
| |
| ret = i2c_transfer(priv->i2c->adapter, msgs, ARRAY_SIZE(msgs)); |
| if (ret < 0) |
| return -EIO; |
| |
| memcpy(val_buf, priv->i2c_rx_buffer + BMI323_I2C_DUMMY, val_size); |
| |
| return 0; |
| } |
| |
| static int bmi323_regmap_i2c_write(void *context, const void *data, |
| size_t count) |
| { |
| struct bmi323_i2c_priv *priv = context; |
| u8 reg; |
| |
| reg = *(u8 *)data; |
| return i2c_smbus_write_i2c_block_data(priv->i2c, reg, |
| count - sizeof(u8), |
| data + sizeof(u8)); |
| } |
| |
| static struct regmap_bus bmi323_regmap_bus = { |
| .read = bmi323_regmap_i2c_read, |
| .write = bmi323_regmap_i2c_write, |
| }; |
| |
| static const struct regmap_config bmi323_i2c_regmap_config = { |
| .reg_bits = 8, |
| .val_bits = 16, |
| .max_register = BMI323_CFG_RES_REG, |
| .val_format_endian = REGMAP_ENDIAN_LITTLE, |
| }; |
| |
| static int bmi323_i2c_probe(struct i2c_client *i2c) |
| { |
| struct device *dev = &i2c->dev; |
| struct bmi323_i2c_priv *priv; |
| struct regmap *regmap; |
| |
| priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); |
| if (!priv) |
| return -ENOMEM; |
| |
| priv->i2c = i2c; |
| regmap = devm_regmap_init(dev, &bmi323_regmap_bus, priv, |
| &bmi323_i2c_regmap_config); |
| if (IS_ERR(regmap)) |
| return dev_err_probe(dev, PTR_ERR(regmap), |
| "Failed to initialize I2C Regmap\n"); |
| |
| return bmi323_core_probe(dev); |
| } |
| |
| static const struct i2c_device_id bmi323_i2c_ids[] = { |
| { "bmi323" }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, bmi323_i2c_ids); |
| |
| static const struct of_device_id bmi323_of_i2c_match[] = { |
| { .compatible = "bosch,bmi323" }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, bmi323_of_i2c_match); |
| |
| static struct i2c_driver bmi323_i2c_driver = { |
| .driver = { |
| .name = "bmi323", |
| .of_match_table = bmi323_of_i2c_match, |
| }, |
| .probe = bmi323_i2c_probe, |
| .id_table = bmi323_i2c_ids, |
| }; |
| module_i2c_driver(bmi323_i2c_driver); |
| |
| MODULE_DESCRIPTION("Bosch BMI323 IMU driver"); |
| MODULE_AUTHOR("Jagath Jog J <jagathjog1996@gmail.com>"); |
| MODULE_LICENSE("GPL"); |
| MODULE_IMPORT_NS(IIO_BMI323); |