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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * SPI interface for the BMP280 driver4 *5 * Inspired by the older BMP085 driver drivers/misc/bmp085-spi.c6 */7#include <linux/bits.h>8#include <linux/err.h>9#include <linux/module.h>10#include <linux/regmap.h>11#include <linux/spi/spi.h>12 13#include "bmp280.h"14 15static int bmp280_regmap_spi_write(void *context, const void *data,16 size_t count)17{18 struct spi_device *spi = to_spi_device(context);19 u8 buf[2];20 21 memcpy(buf, data, 2);22 /*23 * The SPI register address (= full register address without bit 7) and24 * 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 spi_device *spi = to_spi_device(context);35 36 return spi_write_then_read(spi, reg, reg_size, val, val_size);37}38 39static int bmp380_regmap_spi_read(void *context, const void *reg,40 size_t reg_size, void *val, size_t val_size)41{42 struct spi_device *spi = to_spi_device(context);43 u8 rx_buf[BME280_BURST_READ_BYTES + 1];44 ssize_t status;45 46 if (val_size > BME280_BURST_READ_BYTES)47 return -EINVAL;48 49 /*50 * According to the BMP3xx datasheets, for a basic SPI read opertion,51 * the first byte needs to be dropped and the rest are the requested52 * data.53 */54 status = spi_write_then_read(spi, reg, 1, rx_buf, val_size + 1);55 if (status)56 return status;57 58 memcpy(val, rx_buf + 1, val_size);59 60 return 0;61}62 63static const struct regmap_bus bmp280_regmap_bus = {64 .write = bmp280_regmap_spi_write,65 .read = bmp280_regmap_spi_read,66 .reg_format_endian_default = REGMAP_ENDIAN_BIG,67 .val_format_endian_default = REGMAP_ENDIAN_BIG,68};69 70static const struct regmap_bus bmp380_regmap_bus = {71 .write = bmp280_regmap_spi_write,72 .read = bmp380_regmap_spi_read,73 .read_flag_mask = BIT(7),74 .reg_format_endian_default = REGMAP_ENDIAN_BIG,75 .val_format_endian_default = REGMAP_ENDIAN_BIG,76};77 78static int bmp280_spi_probe(struct spi_device *spi)79{80 const struct spi_device_id *id = spi_get_device_id(spi);81 const struct bmp280_chip_info *chip_info;82 struct regmap_bus const *bmp_regmap_bus;83 struct regmap *regmap;84 int ret;85 86 spi->bits_per_word = 8;87 ret = spi_setup(spi);88 if (ret < 0) {89 dev_err(&spi->dev, "spi_setup failed!\n");90 return ret;91 }92 93 chip_info = spi_get_device_match_data(spi);94 95 if (chip_info->spi_read_extra_byte)96 bmp_regmap_bus = &bmp380_regmap_bus;97 else98 bmp_regmap_bus = &bmp280_regmap_bus;99 100 regmap = devm_regmap_init(&spi->dev,101 bmp_regmap_bus,102 &spi->dev,103 chip_info->regmap_config);104 if (IS_ERR(regmap)) {105 dev_err(&spi->dev, "failed to allocate register map\n");106 return PTR_ERR(regmap);107 }108 109 return bmp280_common_probe(&spi->dev,110 regmap,111 chip_info,112 id->name,113 spi->irq);114}115 116static const struct of_device_id bmp280_of_spi_match[] = {117 { .compatible = "bosch,bmp085", .data = &bmp180_chip_info },118 { .compatible = "bosch,bmp180", .data = &bmp180_chip_info },119 { .compatible = "bosch,bmp181", .data = &bmp180_chip_info },120 { .compatible = "bosch,bmp280", .data = &bmp280_chip_info },121 { .compatible = "bosch,bme280", .data = &bme280_chip_info },122 { .compatible = "bosch,bmp380", .data = &bmp380_chip_info },123 { .compatible = "bosch,bmp580", .data = &bmp580_chip_info },124 { },125};126MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);127 128static const struct spi_device_id bmp280_spi_id[] = {129 { "bmp085", (kernel_ulong_t)&bmp180_chip_info },130 { "bmp180", (kernel_ulong_t)&bmp180_chip_info },131 { "bmp181", (kernel_ulong_t)&bmp180_chip_info },132 { "bmp280", (kernel_ulong_t)&bmp280_chip_info },133 { "bme280", (kernel_ulong_t)&bme280_chip_info },134 { "bmp380", (kernel_ulong_t)&bmp380_chip_info },135 { "bmp580", (kernel_ulong_t)&bmp580_chip_info },136 { }137};138MODULE_DEVICE_TABLE(spi, bmp280_spi_id);139 140static struct spi_driver bmp280_spi_driver = {141 .driver = {142 .name = "bmp280",143 .of_match_table = bmp280_of_spi_match,144 .pm = pm_ptr(&bmp280_dev_pm_ops),145 },146 .id_table = bmp280_spi_id,147 .probe = bmp280_spi_probe,148};149module_spi_driver(bmp280_spi_driver);150 151MODULE_DESCRIPTION("BMP280 SPI bus driver");152MODULE_LICENSE("GPL");153MODULE_IMPORT_NS(IIO_BMP280);154