drivers/iio/imu/bmi270/bmi270_spi.c

   1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2
   3 #include <linux/iio/iio.h>
   4 #include <linux/mod_devicetable.h>
   5 #include <linux/module.h>
   6 #include <linux/regmap.h>
   7 #include <linux/spi/spi.h>
   8
   9 #include "bmi270.h"
  10
  11 /*
  12  * The following two functions are taken from the BMI323 spi driver code.
  13  * In section 6.4 of the BMI270 data it specifies that after a read
  14  * operation the first data byte from the device is a dummy byte
  15  */
  16 static int bmi270_regmap_spi_read(void *spi, const void *reg_buf,
  17                                   size_t reg_size, void *val_buf,
  18                                   size_t val_size)
  19 {
  20         return spi_write_then_read(spi, reg_buf, reg_size, val_buf, val_size);
  21 }
  22
  23 static int bmi270_regmap_spi_write(void *spi, const void *data,
  24                                    size_t count)
  25 {
  26         u8 *data_buff = (u8 *)data;
  27
  28         /*
  29          * Remove the extra pad byte since its only needed for the read
  30          * operation
  31          */
  32         data_buff[1] = data_buff[0];
  33         return spi_write_then_read(spi, data_buff + 1, count - 1, NULL, 0);
  34 }
  35
  36 static const struct regmap_bus bmi270_regmap_bus = {
  37         .read = bmi270_regmap_spi_read,
  38         .write = bmi270_regmap_spi_write,
  39 };
  40
  41 static const struct regmap_config bmi270_spi_regmap_config = {
  42         .reg_bits = 8,
  43         .val_bits = 8,
  44         .pad_bits = 8,
  45         .read_flag_mask = BIT(7),
  46 };
  47
  48 static int bmi270_spi_probe(struct spi_device *spi)
  49 {
  50         struct regmap *regmap;
  51         struct device *dev = &spi->dev;
  52         const struct bmi270_chip_info *chip_info;
  53
  54         chip_info = spi_get_device_match_data(spi);
  55         if (!chip_info)
  56                 return -ENODEV;
  57
  58         regmap = devm_regmap_init(dev, &bmi270_regmap_bus, dev,
  59                                   &bmi270_spi_regmap_config);
  60         if (IS_ERR(regmap))
  61                 return dev_err_probe(dev, PTR_ERR(regmap),
  62                                      "Failed to init i2c regmap");
  63
  64         return bmi270_core_probe(dev, regmap, chip_info);
  65 }
  66
  67 static const struct spi_device_id bmi270_spi_id[] = {
  68         { "bmi260", (kernel_ulong_t)&bmi260_chip_info },
  69         { "bmi270", (kernel_ulong_t)&bmi270_chip_info },
  70         { }
  71 };
  72
  73 static const struct of_device_id bmi270_of_match[] = {
  74         { .compatible = "bosch,bmi260", .data = &bmi260_chip_info },
  75         { .compatible = "bosch,bmi270", .data = &bmi270_chip_info },
  76         { }
  77 };
  78
  79 static struct spi_driver bmi270_spi_driver = {
  80         .driver = {
  81                 .name = "bmi270",
  82                 .of_match_table = bmi270_of_match,
  83         },
  84         .probe = bmi270_spi_probe,
  85         .id_table = bmi270_spi_id,
  86 };
  87 module_spi_driver(bmi270_spi_driver);
  88
  89 MODULE_AUTHOR("Alex Lanzano");
  90 MODULE_DESCRIPTION("BMI270 driver");
  91 MODULE_LICENSE("GPL");
  92 MODULE_IMPORT_NS("IIO_BMI270");