alistair23-linux/drivers/iio/pressure/bmp280-spi.c
Linus Walleij 3d838118c6 iio: pressure: bmp280: add power management
The PM280 has an internal standby-mode, but to really save power
we should shut the sensor down and disconnect the power. With
the proper .pm hooks we can enable both runtime and system power
management of the sensor. We use the *force callbacks from the
system PM hooks. When the sensor comes back we always reconfigure
it to make sure it is ready to roll as expected.

Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-07-03 11:32:14 +01:00

126 lines
2.9 KiB
C

/*
* SPI interface for the BMP280 driver
*
* Inspired by the older BMP085 driver drivers/misc/bmp085-spi.c
*/
#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 device *dev = context;
struct spi_device *spi = to_spi_device(dev);
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 device *dev = context;
struct spi_device *spi = to_spi_device(dev);
return spi_write_then_read(spi, reg, reg_size, val, val_size);
}
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 int bmp280_spi_probe(struct spi_device *spi)
{
const struct spi_device_id *id = spi_get_device_id(spi);
struct regmap *regmap;
const struct regmap_config *regmap_config;
int ret;
spi->bits_per_word = 8;
ret = spi_setup(spi);
if (ret < 0) {
dev_err(&spi->dev, "spi_setup failed!\n");
return ret;
}
switch (id->driver_data) {
case BMP180_CHIP_ID:
regmap_config = &bmp180_regmap_config;
break;
case BMP280_CHIP_ID:
case BME280_CHIP_ID:
regmap_config = &bmp280_regmap_config;
break;
default:
return -EINVAL;
}
regmap = devm_regmap_init(&spi->dev,
&bmp280_regmap_bus,
&spi->dev,
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,
id->driver_data,
id->name,
spi->irq);
}
static int bmp280_spi_remove(struct spi_device *spi)
{
return bmp280_common_remove(&spi->dev);
}
static const struct of_device_id bmp280_of_spi_match[] = {
{ .compatible = "bosch,bmp085", },
{ .compatible = "bosch,bmp180", },
{ .compatible = "bosch,bmp181", },
{ .compatible = "bosch,bmp280", },
{ .compatible = "bosch,bme280", },
{ },
};
MODULE_DEVICE_TABLE(of, bmp280_of_spi_match);
static const struct spi_device_id bmp280_spi_id[] = {
{ "bmp180", BMP180_CHIP_ID },
{ "bmp181", BMP180_CHIP_ID },
{ "bmp280", BMP280_CHIP_ID },
{ "bme280", BME280_CHIP_ID },
{ }
};
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 = &bmp280_dev_pm_ops,
},
.id_table = bmp280_spi_id,
.probe = bmp280_spi_probe,
.remove = bmp280_spi_remove,
};
module_spi_driver(bmp280_spi_driver);
MODULE_DESCRIPTION("BMP280 SPI bus driver");
MODULE_LICENSE("GPL");