drivers/iio/imu/bmi323/bmi323_spi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SPI driver for Bosch BMI323 6-Axis IMU.
   4  *
   5  * Copyright (C) 2023, Jagath Jog J <[email protected]>
   6  */
   7
   8 #include <linux/mod_devicetable.h>
   9 #include <linux/module.h>
  10 #include <linux/regmap.h>
  11 #include <linux/spi/spi.h>
  12
  13 #include "bmi323.h"
  14
  15 /*
  16  * From BMI323 datasheet section 4: Notes on the Serial Interface Support.
  17  * Each SPI register read operation requires to read one dummy byte before
  18  * the actual payload.
  19  */
  20 static int bmi323_regmap_spi_read(void *context, const void *reg_buf,
  21                                   size_t reg_size, void *val_buf,
  22                                   size_t val_size)
  23 {
  24         struct spi_device *spi = context;
  25
  26         return spi_write_then_read(spi, reg_buf, reg_size, val_buf, val_size);
  27 }
  28
  29 static int bmi323_regmap_spi_write(void *context, const void *data,
  30                                    size_t count)
  31 {
  32         struct spi_device *spi = context;
  33         u8 *data_buff = (u8 *)data;
  34
  35         data_buff[1] = data_buff[0];
  36         return spi_write(spi, data_buff + 1, count - 1);
  37 }
  38
  39 static const struct regmap_bus bmi323_regmap_bus = {
  40         .read = bmi323_regmap_spi_read,
  41         .write = bmi323_regmap_spi_write,
  42 };
  43
  44 static const struct regmap_config bmi323_spi_regmap_config = {
  45         .reg_bits = 8,
  46         .val_bits = 16,
  47         .pad_bits = 8,
  48         .read_flag_mask = BIT(7),
  49         .max_register = BMI323_CFG_RES_REG,
  50         .val_format_endian = REGMAP_ENDIAN_LITTLE,
  51 };
  52
  53 static int bmi323_spi_probe(struct spi_device *spi)
  54 {
  55         struct device *dev = &spi->dev;
  56         struct regmap *regmap;
  57
  58         regmap = devm_regmap_init(dev, &bmi323_regmap_bus, dev,
  59                                   &bmi323_spi_regmap_config);
  60         if (IS_ERR(regmap))
  61                 return dev_err_probe(dev, PTR_ERR(regmap),
  62                                      "Failed to initialize SPI Regmap\n");
  63
  64         return bmi323_core_probe(dev);
  65 }
  66
  67 static const struct spi_device_id bmi323_spi_ids[] = {
  68         { "bmi323" },
  69         { }
  70 };
  71 MODULE_DEVICE_TABLE(spi, bmi323_spi_ids);
  72
  73 static const struct of_device_id bmi323_of_spi_match[] = {
  74         { .compatible = "bosch,bmi323" },
  75         { }
  76 };
  77 MODULE_DEVICE_TABLE(of, bmi323_of_spi_match);
  78
  79 static struct spi_driver bmi323_spi_driver = {
  80         .driver = {
  81                 .name = "bmi323",
  82                 .pm = pm_ptr(&bmi323_core_pm_ops),
  83                 .of_match_table = bmi323_of_spi_match,
  84         },
  85         .probe = bmi323_spi_probe,
  86         .id_table = bmi323_spi_ids,
  87 };
  88 module_spi_driver(bmi323_spi_driver);
  89
  90 MODULE_DESCRIPTION("Bosch BMI323 IMU driver");
  91 MODULE_AUTHOR("Jagath Jog J <[email protected]>");
  92 MODULE_LICENSE("GPL");
  93 MODULE_IMPORT_NS("IIO_BMI323");