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// SPDX-License-Identifier: GPL-2.0
/*
* BME680 - SPI Driver
*
* Copyright (C) 2018 Himanshu Jha <himanshujha199640@gmail.com>
*/
#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>
#include "bme680.h"
static int bme680_regmap_spi_write(void *context, const void *data,
size_t count)
{
struct spi_device *spi = context;
u8 buf[2];
memcpy(buf, data, 2);
/*
* The SPI register address (= full register address without bit 7)
* and the write command (bit7 = RW = '0')
*/
buf[0] &= ~0x80;
return spi_write_then_read(spi, buf, 2, NULL, 0);
}
static int bme680_regmap_spi_read(void *context, const void *reg,
size_t reg_size, void *val, size_t val_size)
{
struct spi_device *spi = context;
return spi_write_then_read(spi, reg, reg_size, val, val_size);
}
static struct regmap_bus bme680_regmap_bus = {
.write = bme680_regmap_spi_write,
.read = bme680_regmap_spi_read,
.reg_format_endian_default = REGMAP_ENDIAN_BIG,
.val_format_endian_default = REGMAP_ENDIAN_BIG,
};
static int bme680_spi_probe(struct spi_device *spi)
{
const struct spi_device_id *id = spi_get_device_id(spi);
struct regmap *regmap;
unsigned int val;
int ret;
spi->bits_per_word = 8;
ret = spi_setup(spi);
if (ret < 0) {
dev_err(&spi->dev, "spi_setup failed!\n");
return ret;
}
regmap = devm_regmap_init(&spi->dev, &bme680_regmap_bus,
&spi->dev, &bme680_regmap_config);
if (IS_ERR(regmap)) {
dev_err(&spi->dev, "Failed to register spi regmap %d\n",
(int)PTR_ERR(regmap));
return PTR_ERR(regmap);
}
ret = regmap_write(regmap, BME680_REG_SOFT_RESET_SPI,
BME680_CMD_SOFTRESET);
if (ret < 0) {
dev_err(&spi->dev, "Failed to reset chip\n");
return ret;
}
/* after power-on reset, Page 0(0x80-0xFF) of spi_mem_page is active */
ret = regmap_read(regmap, BME680_REG_CHIP_SPI_ID, &val);
if (ret < 0) {
dev_err(&spi->dev, "Error reading SPI chip ID\n");
return ret;
}
if (val != BME680_CHIP_ID_VAL) {
dev_err(&spi->dev, "Wrong chip ID, got %x expected %x\n",
val, BME680_CHIP_ID_VAL);
return -ENODEV;
}
/*
* select Page 1 of spi_mem_page to enable access to
* to registers from address 0x00 to 0x7F.
*/
ret = regmap_write_bits(regmap, BME680_REG_STATUS,
BME680_SPI_MEM_PAGE_BIT,
BME680_SPI_MEM_PAGE_1_VAL);
if (ret < 0) {
dev_err(&spi->dev, "failed to set page 1 of spi_mem_page\n");
return ret;
}
return bme680_core_probe(&spi->dev, regmap, id->name);
}
static const struct spi_device_id bme680_spi_id[] = {
{"bme680", 0},
{},
};
MODULE_DEVICE_TABLE(spi, bme680_spi_id);
static const struct acpi_device_id bme680_acpi_match[] = {
{"BME0680", 0},
{},
};
MODULE_DEVICE_TABLE(acpi, bme680_acpi_match);
static struct spi_driver bme680_spi_driver = {
.driver = {
.name = "bme680_spi",
.acpi_match_table = ACPI_PTR(bme680_acpi_match),
},
.probe = bme680_spi_probe,
.id_table = bme680_spi_id,
};
module_spi_driver(bme680_spi_driver);
MODULE_AUTHOR("Himanshu Jha <himanshujha199640@gmail.com>");
MODULE_DESCRIPTION("Bosch BME680 SPI driver");
MODULE_LICENSE("GPL v2");
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