import of bmp280 code from mainline kernel

linux_kernel_modules/bmp280/Kconfig

+#
+# Pressure drivers
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "BMP 280 Pressure sensor"
+
+config BMP280
+	tristate "Bosch Sensortec BMP180/BMP280 pressure sensor I2C driver"
+	depends on (I2C || SPI_MASTER)
+	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 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
+	depends on BMP280
+	depends on I2C
+	select REGMAP_I2C
+
+config BMP280_SPI
+	tristate
+	depends on BMP280
+	depends on SPI_MASTER
+	select REGMAP
+
+endmenu

linux_kernel_modules/bmp280/Makefile

+#
+# Makefile for industrial I/O pressure drivers
+#
+
+# When adding new entries keep the list in alphabetical order
+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

linux_kernel_modules/bmp280/README.md

+BMP280 Linux Kernel Driver
+==========================
+
+This version of the BMP280 Linux kernel driver has been extracted from the mainline kernel at
+revision e6925852d5b862bac749fab9c8d26491cda99e4e.  The files were taken from `drivers/iio/pressure`.

linux_kernel_modules/bmp280/bmp280-i2c.c

+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/acpi.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#include "bmp280.h"
+
+static int bmp280_i2c_probe(struct i2c_client *client,
+			    const struct i2c_device_id *id)
+{
+	struct regmap *regmap;
+	const struct regmap_config *regmap_config;
+
+	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_i2c(client, regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "failed to allocate register map\n");
+		return PTR_ERR(regmap);
+	}
+
+	return bmp280_common_probe(&client->dev,
+				   regmap,
+				   id->driver_data,
+				   id->name,
+				   client->irq);
+}
+
+static int bmp280_i2c_remove(struct i2c_client *client)
+{
+	return bmp280_common_remove(&client->dev);
+}
+
+static const struct acpi_device_id bmp280_acpi_i2c_match[] = {
+	{"BMP0280", BMP280_CHIP_ID },
+	{"BMP0180", BMP180_CHIP_ID },
+	{"BMP0085", BMP180_CHIP_ID },
+	{"BME0280", BME280_CHIP_ID },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, bmp280_acpi_i2c_match);
+
+#ifdef CONFIG_OF
+static const struct of_device_id bmp280_of_i2c_match[] = {
+	{ .compatible = "bosch,bme280", .data = (void *)BME280_CHIP_ID },
+	{ .compatible = "bosch,bmp280", .data = (void *)BMP280_CHIP_ID },
+	{ .compatible = "bosch,bmp180", .data = (void *)BMP180_CHIP_ID },
+	{ .compatible = "bosch,bmp085", .data = (void *)BMP180_CHIP_ID },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, bmp280_of_i2c_match);
+#else
+#define bmp280_of_i2c_match NULL
+#endif
+
+static const struct i2c_device_id bmp280_i2c_id[] = {
+	{"bmp280", BMP280_CHIP_ID },
+	{"bmp180", BMP180_CHIP_ID },
+	{"bmp085", BMP180_CHIP_ID },
+	{"bme280", BME280_CHIP_ID },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, bmp280_i2c_id);
+
+static struct i2c_driver bmp280_i2c_driver = {
+	.driver = {
+		.name	= "bmp280",
+		.acpi_match_table = ACPI_PTR(bmp280_acpi_i2c_match),
+		.of_match_table = of_match_ptr(bmp280_of_i2c_match),
+		.pm = &bmp280_dev_pm_ops,
+	},
+	.probe		= bmp280_i2c_probe,
+	.remove		= bmp280_i2c_remove,
+	.id_table	= bmp280_i2c_id,
+};
+module_i2c_driver(bmp280_i2c_driver);
+
+MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
+MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor");
+MODULE_LICENSE("GPL v2");

linux_kernel_modules/bmp280/bmp280-regmap.c

+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include "bmp280.h"
+
+static bool bmp180_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMP280_REG_CTRL_MEAS:
+	case BMP280_REG_RESET:
+		return true;
+	default:
+		return false;
+	};
+}
+
+static bool bmp180_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMP180_REG_OUT_XLSB:
+	case BMP180_REG_OUT_LSB:
+	case BMP180_REG_OUT_MSB:
+	case BMP280_REG_CTRL_MEAS:
+		return true;
+	default:
+		return false;
+	}
+}
+
+const struct regmap_config bmp180_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = BMP180_REG_OUT_XLSB,
+	.cache_type = REGCACHE_RBTREE,
+
+	.writeable_reg = bmp180_is_writeable_reg,
+	.volatile_reg = bmp180_is_volatile_reg,
+};
+EXPORT_SYMBOL(bmp180_regmap_config);
+
+static bool bmp280_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMP280_REG_CONFIG:
+	case BMP280_REG_CTRL_HUMIDITY:
+	case BMP280_REG_CTRL_MEAS:
+	case BMP280_REG_RESET:
+		return true;
+	default:
+		return false;
+	};
+}
+
+static bool bmp280_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMP280_REG_HUMIDITY_LSB:
+	case BMP280_REG_HUMIDITY_MSB:
+	case BMP280_REG_TEMP_XLSB:
+	case BMP280_REG_TEMP_LSB:
+	case BMP280_REG_TEMP_MSB:
+	case BMP280_REG_PRESS_XLSB:
+	case BMP280_REG_PRESS_LSB:
+	case BMP280_REG_PRESS_MSB:
+	case BMP280_REG_STATUS:
+		return true;
+	default:
+		return false;
+	}
+}
+
+const struct regmap_config bmp280_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = BMP280_REG_HUMIDITY_LSB,
+	.cache_type = REGCACHE_RBTREE,
+
+	.writeable_reg = bmp280_is_writeable_reg,
+	.volatile_reg = bmp280_is_volatile_reg,
+};
+EXPORT_SYMBOL(bmp280_regmap_config);

linux_kernel_modules/bmp280/bmp280-spi.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");

linux_kernel_modules/bmp280/bmp280.h

+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/regmap.h>
+
+/* BMP280 specific registers */
+#define BMP280_REG_HUMIDITY_LSB		0xFE
+#define BMP280_REG_HUMIDITY_MSB		0xFD
+#define BMP280_REG_TEMP_XLSB		0xFC
+#define BMP280_REG_TEMP_LSB		0xFB
+#define BMP280_REG_TEMP_MSB		0xFA
+#define BMP280_REG_PRESS_XLSB		0xF9
+#define BMP280_REG_PRESS_LSB		0xF8
+#define BMP280_REG_PRESS_MSB		0xF7
+
+#define BMP280_REG_CONFIG		0xF5
+#define BMP280_REG_CTRL_MEAS		0xF4
+#define BMP280_REG_STATUS		0xF3
+#define BMP280_REG_CTRL_HUMIDITY	0xF2
+
+/* Due to non linear mapping, and data sizes we can't do a bulk read */
+#define BMP280_REG_COMP_H1		0xA1
+#define BMP280_REG_COMP_H2		0xE1
+#define BMP280_REG_COMP_H3		0xE3
+#define BMP280_REG_COMP_H4		0xE4
+#define BMP280_REG_COMP_H5		0xE5
+#define BMP280_REG_COMP_H6		0xE7
+
+#define BMP280_REG_COMP_TEMP_START	0x88
+#define BMP280_COMP_TEMP_REG_COUNT	6
+
+#define BMP280_REG_COMP_PRESS_START	0x8E
+#define BMP280_COMP_PRESS_REG_COUNT	18
+
+#define BMP280_FILTER_MASK		(BIT(4) | BIT(3) | BIT(2))
+#define BMP280_FILTER_OFF		0
+#define BMP280_FILTER_2X		BIT(2)
+#define BMP280_FILTER_4X		BIT(3)
+#define BMP280_FILTER_8X		(BIT(3) | BIT(2))
+#define BMP280_FILTER_16X		BIT(4)
+
+#define BMP280_OSRS_HUMIDITY_MASK	(BIT(2) | BIT(1) | BIT(0))
+#define BMP280_OSRS_HUMIDITIY_X(osrs_h)	((osrs_h) << 0)
+#define BMP280_OSRS_HUMIDITY_SKIP	0
+#define BMP280_OSRS_HUMIDITY_1X		BMP280_OSRS_HUMIDITIY_X(1)
+#define BMP280_OSRS_HUMIDITY_2X		BMP280_OSRS_HUMIDITIY_X(2)
+#define BMP280_OSRS_HUMIDITY_4X		BMP280_OSRS_HUMIDITIY_X(3)
+#define BMP280_OSRS_HUMIDITY_8X		BMP280_OSRS_HUMIDITIY_X(4)
+#define BMP280_OSRS_HUMIDITY_16X	BMP280_OSRS_HUMIDITIY_X(5)
+
+#define BMP280_OSRS_TEMP_MASK		(BIT(7) | BIT(6) | BIT(5))
+#define BMP280_OSRS_TEMP_SKIP		0
+#define BMP280_OSRS_TEMP_X(osrs_t)	((osrs_t) << 5)
+#define BMP280_OSRS_TEMP_1X		BMP280_OSRS_TEMP_X(1)
+#define BMP280_OSRS_TEMP_2X		BMP280_OSRS_TEMP_X(2)
+#define BMP280_OSRS_TEMP_4X		BMP280_OSRS_TEMP_X(3)
+#define BMP280_OSRS_TEMP_8X		BMP280_OSRS_TEMP_X(4)
+#define BMP280_OSRS_TEMP_16X		BMP280_OSRS_TEMP_X(5)
+
+#define BMP280_OSRS_PRESS_MASK		(BIT(4) | BIT(3) | BIT(2))
+#define BMP280_OSRS_PRESS_SKIP		0
+#define BMP280_OSRS_PRESS_X(osrs_p)	((osrs_p) << 2)
+#define BMP280_OSRS_PRESS_1X		BMP280_OSRS_PRESS_X(1)
+#define BMP280_OSRS_PRESS_2X		BMP280_OSRS_PRESS_X(2)
+#define BMP280_OSRS_PRESS_4X		BMP280_OSRS_PRESS_X(3)
+#define BMP280_OSRS_PRESS_8X		BMP280_OSRS_PRESS_X(4)
+#define BMP280_OSRS_PRESS_16X		BMP280_OSRS_PRESS_X(5)
+
+#define BMP280_MODE_MASK		(BIT(1) | BIT(0))
+#define BMP280_MODE_SLEEP		0
+#define BMP280_MODE_FORCED		BIT(0)
+#define BMP280_MODE_NORMAL		(BIT(1) | BIT(0))
+
+/* BMP180 specific registers */
+#define BMP180_REG_OUT_XLSB		0xF8
+#define BMP180_REG_OUT_LSB		0xF7
+#define BMP180_REG_OUT_MSB		0xF6
+
+#define BMP180_REG_CALIB_START		0xAA
+#define BMP180_REG_CALIB_COUNT		22
+
+#define BMP180_MEAS_SCO			BIT(5)
+#define BMP180_MEAS_TEMP		(0x0E | BMP180_MEAS_SCO)
+#define BMP180_MEAS_PRESS_X(oss)	((oss) << 6 | 0x14 | BMP180_MEAS_SCO)
+#define BMP180_MEAS_PRESS_1X		BMP180_MEAS_PRESS_X(0)
+#define BMP180_MEAS_PRESS_2X		BMP180_MEAS_PRESS_X(1)
+#define BMP180_MEAS_PRESS_4X		BMP180_MEAS_PRESS_X(2)
+#define BMP180_MEAS_PRESS_8X		BMP180_MEAS_PRESS_X(3)
+
+/* BMP180 and BMP280 common registers */
+#define BMP280_REG_CTRL_MEAS		0xF4
+#define BMP280_REG_RESET		0xE0
+#define BMP280_REG_ID			0xD0
+
+#define BMP180_CHIP_ID			0x55
+#define BMP280_CHIP_ID			0x58
+#define BME280_CHIP_ID			0x60
+#define BMP280_SOFT_RESET_VAL		0xB6
+
+/* Regmap configurations */
+extern const struct regmap_config bmp180_regmap_config;
+extern const struct regmap_config bmp280_regmap_config;
+
+/* Probe called from different transports */
+int bmp280_common_probe(struct device *dev,
+			struct regmap *regmap,
+			unsigned int chip,
+			const char *name,
+			int irq);
+int bmp280_common_remove(struct device *dev);
+
+/* PM ops */
+extern const struct dev_pm_ops bmp280_dev_pm_ops;