Commit b26b4e91 authored by Linus Walleij's avatar Linus Walleij Committed by Jonathan Cameron
Browse files

iio: pressure: bmp280: add SPI interface driver 



This patch mimics the SPI functionality found in the misc driver in
drivers/misc/bh085-spi.c to make it possible to reuse the existing
BMP280/BMP180/BMP085 driver with all clients of the other driver.
The adoption is straight-forward since like the other driver, it is
a simple matter of using regmap.

This driver is also so obviously inspired/copied from the old misc
driver in drivers/misc/bmp085.c that I just took the liberty to
add in the authors of the other drivers + self in the core driver
file.

The MISC driver also supports a variant named "BMP181" so include
that here to be complete in comparison to the old driver.

The bus mapping code for SPI was written by Akinobu Mita.

Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Tested-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 17118843

drivers/iio/pressure/Kconfig

+12 −3
Original line number Diff line number Diff line
@@ -7,17 +7,20 @@ menu "Pressure sensors" 


config BMP280

	tristate "Bosch Sensortec BMP180/BMP280 pressure sensor I2C driver"

	depends on I2C

	depends on (I2C || SPI_MASTER)

	depends on !(BMP085_I2C=y || BMP085_I2C=m)

	depends on !(BMP085_SPI=y || BMP085_SPI=m)

	select REGMAP

	select BMP280_I2C if (I2C)

	select BMP280_SPI if (SPI_MASTER)

	help

	  Say yes here to build support for Bosch Sensortec BMP180 and BMP280

	  pressure and temperature sensors. Also supports the BE280 with

	  an additional humidity sensor channel.



	  To compile this driver as a module, choose M here: the modules

	  will be called bmp280-i2c and bmp280.

	  To compile this driver as a module, choose M here: the core module

	  will be called bmp280 and you will also get bmp280-i2c for I2C

	  and/or bmp280-spi for SPI support.



config BMP280_I2C

	tristate
@@ -25,6 +28,12 @@ config BMP280_I2C 
	depends on I2C

	select REGMAP_I2C



config BMP280_SPI

	tristate

	depends on BMP280

	depends on SPI_MASTER

	select REGMAP



config HID_SENSOR_PRESS

	depends on HID_SENSOR_HUB

	select IIO_BUFFER

drivers/iio/pressure/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
obj-$(CONFIG_BMP280) += bmp280.o

bmp280-objs := bmp280-core.o bmp280-regmap.o

obj-$(CONFIG_BMP280_I2C) += bmp280-i2c.o

obj-$(CONFIG_BMP280_SPI) += bmp280-spi.o

obj-$(CONFIG_HID_SENSOR_PRESS)   += hid-sensor-press.o

obj-$(CONFIG_HP03) += hp03.o

obj-$(CONFIG_MPL115) += mpl115.o

drivers/iio/pressure/bmp280-core.c

+4 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2010 Christoph Mair <christoph.mair@gmail.com>

 * Copyright (c) 2012 Bosch Sensortec GmbH

 * Copyright (c) 2012 Unixphere AB

 * Copyright (c) 2014 Intel Corporation

 * Copyright (c) 2016 Linus Walleij <linus.walleij@linaro.org>

 *

 * Driver for Bosch Sensortec BMP180 and BMP280 digital pressure sensor.

 *

drivers/iio/pressure/bmp280-spi.c

0 → 100644
+123 −0
Original line number Diff line number Diff line 
/*

 * 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);

}



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,

	},

	.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");

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