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 = pm_ptr(&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"); 121