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
  14 static 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
  31 static 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
  40 static 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
  47 static 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
  89 static 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 };
  97 MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);
  98
  99 static 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 };
 106 MODULE_DEVICE_TABLE(spi, bmp280_spi_id);
 107
 108 static 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 };
 117 module_spi_driver(bmp280_spi_driver);
 118
 119 MODULE_DESCRIPTION("BMP280 SPI bus driver");
 120 MODULE_LICENSE("GPL");