LXR linux/drivers/iio/pressure/bmp280-spi.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * SPI interface for the BMP280 driver
   4 *
   5 * Inspired by the older BMP085 driver drivers/misc/bmp085-spi.c
   6 */
   7#include <linux/module.h>
   8#include <linux/spi/spi.h>
   9#include <linux/err.h>
  10#include <linux/regmap.h>
  11
  12#include "bmp280.h"
  13
  14static int bmp280_regmap_spi_write(void *context, const void *data,
  15                                   size_t count)
  16{
  17        struct device *dev = context;
  18        struct spi_device *spi = to_spi_device(dev);
  19        u8 buf[2];
  20
  21        memcpy(buf, data, 2);
  22        /*
  23         * The SPI register address (= full register address without bit 7) and
  24         * the write command (bit7 = RW = '0')
  25         */
  26        buf[0] &= ~0x80;
  27
  28        return spi_write_then_read(spi, buf, 2, NULL, 0);
  29}
  30
  31static int bmp280_regmap_spi_read(void *context, const void *reg,
  32                                  size_t reg_size, void *val, size_t val_size)
  33{
  34        struct device *dev = context;
  35        struct spi_device *spi = to_spi_device(dev);
  36
  37        return spi_write_then_read(spi, reg, reg_size, val, val_size);
  38}
  39
  40static struct regmap_bus bmp280_regmap_bus = {
  41        .write = bmp280_regmap_spi_write,
  42        .read = bmp280_regmap_spi_read,
  43        .reg_format_endian_default = REGMAP_ENDIAN_BIG,
  44        .val_format_endian_default = REGMAP_ENDIAN_BIG,
  45};
  46
  47static int bmp280_spi_probe(struct spi_device *spi)
  48{
  49        const struct spi_device_id *id = spi_get_device_id(spi);
  50        struct regmap *regmap;
  51        const struct regmap_config *regmap_config;
  52        int ret;
  53
  54        spi->bits_per_word = 8;
  55        ret = spi_setup(spi);
  56        if (ret < 0) {
  57                dev_err(&spi->dev, "spi_setup failed!\n");
  58                return ret;
  59        }
  60
  61        switch (id->driver_data) {
  62        case BMP180_CHIP_ID:
  63                regmap_config = &bmp180_regmap_config;
  64                break;
  65        case BMP280_CHIP_ID:
  66        case BME280_CHIP_ID:
  67                regmap_config = &bmp280_regmap_config;
  68                break;
  69        default:
  70                return -EINVAL;
  71        }
  72
  73        regmap = devm_regmap_init(&spi->dev,
  74                                  &bmp280_regmap_bus,
  75                                  &spi->dev,
  76                                  regmap_config);
  77        if (IS_ERR(regmap)) {
  78                dev_err(&spi->dev, "failed to allocate register map\n");
  79                return PTR_ERR(regmap);
  80        }
  81
  82        return bmp280_common_probe(&spi->dev,
  83                                   regmap,
  84                                   id->driver_data,
  85                                   id->name,
  86                                   spi->irq);
  87}
  88
  89static const struct of_device_id bmp280_of_spi_match[] = {
  90        { .compatible = "bosch,bmp085", },
  91        { .compatible = "bosch,bmp180", },
  92        { .compatible = "bosch,bmp181", },
  93        { .compatible = "bosch,bmp280", },
  94        { .compatible = "bosch,bme280", },
  95        { },
  96};
  97MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);
  98
  99static const struct spi_device_id bmp280_spi_id[] = {
 100        { "bmp180", BMP180_CHIP_ID },
 101        { "bmp181", BMP180_CHIP_ID },
 102        { "bmp280", BMP280_CHIP_ID },
 103        { "bme280", BME280_CHIP_ID },
 104        { }
 105};
 106MODULE_DEVICE_TABLE(spi, bmp280_spi_id);
 107
 108static struct spi_driver bmp280_spi_driver = {
 109        .driver = {
 110                .name = "bmp280",
 111                .of_match_table = bmp280_of_spi_match,
 112                .pm = &bmp280_dev_pm_ops,
 113        },
 114        .id_table = bmp280_spi_id,
 115        .probe = bmp280_spi_probe,
 116};
 117module_spi_driver(bmp280_spi_driver);
 118
 119MODULE_DESCRIPTION("BMP280 SPI bus driver");
 120MODULE_LICENSE("GPL");
 121