drivers/iio/pressure/bmp280-spi.c

   1 /*
   2  * SPI interface for the BMP280 driver
   3  *
   4  * Inspired by the older BMP085 driver drivers/misc/bmp085-spi.c
   5  */
   6 #include <linux/module.h>
   7 #include <linux/spi/spi.h>
   8 #include <linux/err.h>
   9 #include <linux/regmap.h>
  10
  11 #include "bmp280.h"
  12
  13 static int bmp280_regmap_spi_write(void *context, const void *data,
  14                                    size_t count)
  15 {
  16         struct device *dev = context;
  17         struct spi_device *spi = to_spi_device(dev);
  18         u8 buf[2];
  19
  20         memcpy(buf, data, 2);
  21         /*
  22          * The SPI register address (= full register address without bit 7) and
  23          * the write command (bit7 = RW = '0')
  24          */
  25         buf[0] &= ~0x80;
  26
  27         return spi_write_then_read(spi, buf, 2, NULL, 0);
  28 }
  29
  30 static int bmp280_regmap_spi_read(void *context, const void *reg,
  31                                   size_t reg_size, void *val, size_t val_size)
  32 {
  33         struct device *dev = context;
  34         struct spi_device *spi = to_spi_device(dev);
  35
  36         return spi_write_then_read(spi, reg, reg_size, val, val_size);
  37 }
  38
  39 static struct regmap_bus bmp280_regmap_bus = {
  40         .write = bmp280_regmap_spi_write,
  41         .read = bmp280_regmap_spi_read,
  42         .reg_format_endian_default = REGMAP_ENDIAN_BIG,
  43         .val_format_endian_default = REGMAP_ENDIAN_BIG,
  44 };
  45
  46 static int bmp280_spi_probe(struct spi_device *spi)
  47 {
  48         const struct spi_device_id *id = spi_get_device_id(spi);
  49         struct regmap *regmap;
  50         const struct regmap_config *regmap_config;
  51         int ret;
  52
  53         spi->bits_per_word = 8;
  54         ret = spi_setup(spi);
  55         if (ret < 0) {
  56                 dev_err(&spi->dev, "spi_setup failed!\n");
  57                 return ret;
  58         }
  59
  60         switch (id->driver_data) {
  61         case BMP180_CHIP_ID:
  62                 regmap_config = &bmp180_regmap_config;
  63                 break;
  64         case BMP280_CHIP_ID:
  65         case BME280_CHIP_ID:
  66                 regmap_config = &bmp280_regmap_config;
  67                 break;
  68         default:
  69                 return -EINVAL;
  70         }
  71
  72         regmap = devm_regmap_init(&spi->dev,
  73                                   &bmp280_regmap_bus,
  74                                   &spi->dev,
  75                                   regmap_config);
  76         if (IS_ERR(regmap)) {
  77                 dev_err(&spi->dev, "failed to allocate register map\n");
  78                 return PTR_ERR(regmap);
  79         }
  80
  81         return bmp280_common_probe(&spi->dev,
  82                                    regmap,
  83                                    id->driver_data,
  84                                    id->name,
  85                                    spi->irq);
  86 }
  87
  88 static int bmp280_spi_remove(struct spi_device *spi)
  89 {
  90         return bmp280_common_remove(&spi->dev);
  91 }
  92
  93 static const struct of_device_id bmp280_of_spi_match[] = {
  94         { .compatible = "bosch,bmp085", },
  95         { .compatible = "bosch,bmp180", },
  96         { .compatible = "bosch,bmp181", },
  97         { .compatible = "bosch,bmp280", },
  98         { .compatible = "bosch,bme280", },
  99         { },
 100 };
 101 MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);
 102
 103 static const struct spi_device_id bmp280_spi_id[] = {
 104         { "bmp180", BMP180_CHIP_ID },
 105         { "bmp181", BMP180_CHIP_ID },
 106         { "bmp280", BMP280_CHIP_ID },
 107         { "bme280", BME280_CHIP_ID },
 108         { }
 109 };
 110 MODULE_DEVICE_TABLE(spi, bmp280_spi_id);
 111
 112 static struct spi_driver bmp280_spi_driver = {
 113         .driver = {
 114                 .name = "bmp280",
 115                 .of_match_table = bmp280_of_spi_match,
 116                 .pm = &bmp280_dev_pm_ops,
 117         },
 118         .id_table = bmp280_spi_id,
 119         .probe = bmp280_spi_probe,
 120         .remove = bmp280_spi_remove,
 121 };
 122 module_spi_driver(bmp280_spi_driver);
 123
 124 MODULE_DESCRIPTION("BMP280 SPI bus driver");
 125 MODULE_LICENSE("GPL");