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"); 126