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// SPDX-License-Identifier: GPL-2.0-only
/*
* SPI interface for the BMP280 driver
*
* Inspired by the older BMP085 driver drivers/misc/bmp085-spi.c
*/
#include <linux/bits.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/err.h>
#include <linux/regmap.h>
#include "bmp280.h"
static int bmp280_regmap_spi_write(void *context, const void *data,
size_t count)
{
struct spi_device *spi = to_spi_device(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 bmp280_regmap_spi_read(void *context, const void *reg,
size_t reg_size, void *val, size_t val_size)
{
struct spi_device *spi = to_spi_device(context);
return spi_write_then_read(spi, reg, reg_size, val, val_size);
}
static int bmp380_regmap_spi_read(void *context, const void *reg,
size_t reg_size, void *val, size_t val_size)
{
struct spi_device *spi = to_spi_device(context);
u8 rx_buf[4];
ssize_t status;
/*
* Maximum number of consecutive bytes read for a temperature or
* pressure measurement is 3.
*/
if (val_size > 3)
return -EINVAL;
/*
* According to the BMP3xx datasheets, for a basic SPI read opertion,
* the first byte needs to be dropped and the rest are the requested
* data.
*/
status = spi_write_then_read(spi, reg, 1, rx_buf, val_size + 1);
if (status)
return status;
memcpy(val, rx_buf + 1, val_size);
return 0;
}
static struct regmap_bus bmp280_regmap_bus = {
.write = bmp280_regmap_spi_write,
.read = bmp280_regmap_spi_read,
.reg_format_endian_default = REGMAP_ENDIAN_BIG,
.val_format_endian_default = REGMAP_ENDIAN_BIG,
};
static struct regmap_bus bmp380_regmap_bus = {
.write = bmp280_regmap_spi_write,
.read = bmp380_regmap_spi_read,
.read_flag_mask = BIT(7),
.reg_format_endian_default = REGMAP_ENDIAN_BIG,
.val_format_endian_default = REGMAP_ENDIAN_BIG,
};
static int bmp280_spi_probe(struct spi_device *spi)
{
const struct spi_device_id *id = spi_get_device_id(spi);
const struct bmp280_chip_info *chip_info;
struct regmap_bus *bmp_regmap_bus;
struct regmap *regmap;
int ret;
spi->bits_per_word = 8;
ret = spi_setup(spi);
if (ret < 0) {
dev_err(&spi->dev, "spi_setup failed!\n");
return ret;
}
chip_info = spi_get_device_match_data(spi);
if (chip_info->spi_read_extra_byte)
bmp_regmap_bus = &bmp380_regmap_bus;
else
bmp_regmap_bus = &bmp280_regmap_bus;
regmap = devm_regmap_init(&spi->dev,
bmp_regmap_bus,
&spi->dev,
chip_info->regmap_config);
if (IS_ERR(regmap)) {
dev_err(&spi->dev, "failed to allocate register map\n");
return PTR_ERR(regmap);
}
return bmp280_common_probe(&spi->dev,
regmap,
chip_info,
id->name,
spi->irq);
}
static const struct of_device_id bmp280_of_spi_match[] = {
{ .compatible = "bosch,bmp085", .data = &bmp180_chip_info },
{ .compatible = "bosch,bmp180", .data = &bmp180_chip_info },
{ .compatible = "bosch,bmp181", .data = &bmp180_chip_info },
{ .compatible = "bosch,bmp280", .data = &bmp280_chip_info },
{ .compatible = "bosch,bme280", .data = &bme280_chip_info },
{ .compatible = "bosch,bmp380", .data = &bmp380_chip_info },
{ .compatible = "bosch,bmp580", .data = &bmp580_chip_info },
{ },
};
MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);
static const struct spi_device_id bmp280_spi_id[] = {
{ "bmp085", (kernel_ulong_t)&bmp180_chip_info },
{ "bmp180", (kernel_ulong_t)&bmp180_chip_info },
{ "bmp181", (kernel_ulong_t)&bmp180_chip_info },
{ "bmp280", (kernel_ulong_t)&bmp280_chip_info },
{ "bme280", (kernel_ulong_t)&bme280_chip_info },
{ "bmp380", (kernel_ulong_t)&bmp380_chip_info },
{ "bmp580", (kernel_ulong_t)&bmp580_chip_info },
{ }
};
MODULE_DEVICE_TABLE(spi, bmp280_spi_id);
static struct spi_driver bmp280_spi_driver = {
.driver = {
.name = "bmp280",
.of_match_table = bmp280_of_spi_match,
.pm = pm_ptr(&bmp280_dev_pm_ops),
},
.id_table = bmp280_spi_id,
.probe = bmp280_spi_probe,
};
module_spi_driver(bmp280_spi_driver);
MODULE_DESCRIPTION("BMP280 SPI bus driver");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(IIO_BMP280);
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