[PATCH v2 1/4] iio: magn: Add support for BMC150 magnetometer

[Irina Tirdea]

Add support for the Bosh BMC150 Magnetometer.
The specification can be downloaded from:
http://ae-bst.resource.bosch.com/media/products/dokumente/bmc150/BST-BMC150-DS000-04.pdf.
The chip contains both an accelerometer and a magnetometer.
This patch adds support only for the magnetometer part.

The temperature compensation formulas are based on bmm050_api.c
authored by contact@xxxxxxxxxxxxxxxxxxxx

Signed-off-by: Irina Tirdea <irina.tirdea@xxxxxxxxx>
---
 drivers/iio/magnetometer/Kconfig       |  14 +
 drivers/iio/magnetometer/Makefile      |   2 +
 drivers/iio/magnetometer/bmc150_magn.c | 986 +++++++++++++++++++++++++++++++++
 3 files changed, 1002 insertions(+)
 create mode 100644 drivers/iio/magnetometer/bmc150_magn.c

diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
index a5d6de7..008baca 100644
--- a/drivers/iio/magnetometer/Kconfig
+++ b/drivers/iio/magnetometer/Kconfig
@@ -76,4 +76,18 @@ config IIO_ST_MAGN_SPI_3AXIS
 	depends on IIO_ST_MAGN_3AXIS
 	depends on IIO_ST_SENSORS_SPI
 
+config BMC150_MAGN
+	tristate "Bosch BMC150 Magnetometer Driver"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for the BMC150 magnetometer.
+
+	  Currently this only supports the device via an i2c interface.
+
+	  This is a combo module with both accelerometer and magnetometer.
+	  This driver is only implementing magnetometer part, which has
+	  its own address and register map.
+
 endmenu
diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile
index 0f5d3c9..e2c3459 100644
--- a/drivers/iio/magnetometer/Makefile
+++ b/drivers/iio/magnetometer/Makefile
@@ -13,3 +13,5 @@ st_magn-$(CONFIG_IIO_BUFFER) += st_magn_buffer.o
 
 obj-$(CONFIG_IIO_ST_MAGN_I2C_3AXIS) += st_magn_i2c.o
 obj-$(CONFIG_IIO_ST_MAGN_SPI_3AXIS) += st_magn_spi.o
+
+obj-$(CONFIG_BMC150_MAGN) += bmc150_magn.o
diff --git a/drivers/iio/magnetometer/bmc150_magn.c b/drivers/iio/magnetometer/bmc150_magn.c
new file mode 100644
index 0000000..b8e4c90
--- /dev/null
+++ b/drivers/iio/magnetometer/bmc150_magn.c
@@ -0,0 +1,986 @@
+/*
+ * Bosch BMC150 three-axis magnetic field sensor driver
+ *
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * This code is based on bmm050_api.c authored by contact@xxxxxxxxxxxxxxxxxxx:
+ *
+ * (C) Copyright 2011~2014 Bosch Sensortec GmbH All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/regmap.h>
+
+#define BMC150_MAGN_DRV_NAME			"bmc150_magn"
+#define BMC150_MAGN_IRQ_NAME			"bmc150_magn_event"
+#define BMC150_MAGN_GPIO_INT			"interrupt"
+
+#define BMC150_MAGN_REG_CHIP_ID			0x40
+#define BMC150_MAGN_CHIP_ID_VAL			0x32
+
+#define BMC150_MAGN_REG_X_L			0x42
+#define BMC150_MAGN_REG_X_M			0x43
+#define BMC150_MAGN_REG_Y_L			0x44
+#define BMC150_MAGN_REG_Y_M			0x45
+#define BMC150_MAGN_SHIFT_XY_L			3
+#define BMC150_MAGN_REG_Z_L			0x46
+#define BMC150_MAGN_REG_Z_M			0x47
+#define BMC150_MAGN_SHIFT_Z_L			1
+#define BMC150_MAGN_REG_RHALL_L			0x48
+#define BMC150_MAGN_REG_RHALL_M			0x49
+#define BMC150_MAGN_SHIFT_RHALL_L		2
+
+#define BMC150_MAGN_REG_INT_STATUS		0x4A
+
+#define BMC150_MAGN_REG_POWER			0x4B
+#define BMC150_MAGN_MASK_POWER_CTL		BIT(0)
+
+#define BMC150_MAGN_REG_OPMODE_ODR		0x4C
+#define BMC150_MAGN_MASK_OPMODE			GENMASK(2, 1)
+#define BMC150_MAGN_SHIFT_OPMODE		1
+#define BMC150_MAGN_MODE_NORMAL			0x00
+#define BMC150_MAGN_MODE_FORCED			0x01
+#define BMC150_MAGN_MODE_SLEEP			0x03
+#define BMC150_MAGN_MASK_ODR			GENMASK(5, 3)
+#define BMC150_MAGN_SHIFT_ODR			3
+
+#define BMC150_MAGN_REG_INT			0x4D
+
+#define BMC150_MAGN_REG_INT_DRDY		0x4E
+#define BMC150_MAGN_MASK_DRDY_EN		BIT(7)
+#define BMC150_MAGN_SHIFT_DRDY_EN		7
+#define BMC150_MAGN_MASK_DRDY_INT3		BIT(6)
+#define BMC150_MAGN_MASK_DRDY_Z_EN		BIT(5)
+#define BMC150_MAGN_MASK_DRDY_Y_EN		BIT(4)
+#define BMC150_MAGN_MASK_DRDY_X_EN		BIT(3)
+#define BMC150_MAGN_MASK_DRDY_DR_POLARITY	BIT(2)
+#define BMC150_MAGN_MASK_DRDY_LATCHING		BIT(1)
+#define BMC150_MAGN_MASK_DRDY_INT3_POLARITY	BIT(0)
+
+#define BMC150_MAGN_REG_LOW_THRESH		0x4F
+#define BMC150_MAGN_REG_HIGH_THRESH		0x50
+#define BMC150_MAGN_REG_REP_XY			0x51
+#define BMC150_MAGN_REG_REP_Z			0x52
+
+#define BMC150_MAGN_REG_TRIM_START		0x5D
+#define BMC150_MAGN_REG_TRIM_END		0x71
+
+#define BMC150_MAGN_XY_OVERFLOW_VAL		-4096
+#define BMC150_MAGN_Z_OVERFLOW_VAL		-16384
+
+/* Time from SUSPEND to SLEEP */
+#define BMC150_MAGN_START_UP_TIME_MS		3
+
+#define BMC150_MAGN_AUTO_SUSPEND_DELAY_MS	2000
+
+#define BMC150_MAGN_REGVAL_TO_REPXY(regval) (((regval) * 2) + 1)
+#define BMC150_MAGN_REGVAL_TO_REPZ(regval) ((regval) + 1)
+#define BMC150_MAGN_REPXY_TO_REGVAL(rep) (((rep) - 1) / 2)
+#define BMC150_MAGN_REPZ_TO_REGVAL(rep) ((rep) - 1)
+
+enum bmc150_magn_axis {
+	AXIS_X,
+	AXIS_Y,
+	AXIS_Z,
+	RHALL,
+	AXIS_XYZ_MAX = RHALL,
+	AXIS_XYZR_MAX,
+};
+
+enum bmc150_magn_power_modes {
+	BMC150_MAGN_POWER_MODE_SUSPEND,
+	BMC150_MAGN_POWER_MODE_SLEEP,
+	BMC150_MAGN_POWER_MODE_NORMAL,
+};
+
+struct bmc150_magn_trim_regs {
+	s8 x1;
+	s8 y1;
+	__le16 reserved1;
+	u8 reserved2;
+	__le16 z4;
+	s8 x2;
+	s8 y2;
+	__le16 reserved3;
+	__le16 z2;
+	__le16 z1;
+	__le16 xyz1;
+	__le16 z3;
+	s8 xy2;
+	u8 xy1;
+} __packed;
+
+struct bmc150_magn_data {
+	struct i2c_client *client;
+	/*
+	 * 1. Protect this structure.
+	 * 2. Serialize sequences that power on/off the device and access HW.
+	 */
+	struct mutex mutex;
+	struct regmap *regmap;
+	/* 4 x 32 bits for x, y z, 4 bytes align, 64 bits timestamp */
+	s32 buffer[6];
+	struct iio_trigger *dready_trig;
+	bool dready_trigger_on;
+};
+
+static const struct {
+	int freq;
+	u8 reg_val;
+} bmc150_magn_samp_freq_table[] = { {2, 0x01},
+				    {6, 0x02},
+				    {8, 0x03},
+				    {10, 0x00},
+				    {15, 0x04},
+				    {20, 0x05},
+				    {25, 0x06},
+				    {30, 0x07} };
+
+enum bmc150_magn_presets {
+	LOW_POWER_PRESET,
+	REGULAR_PRESET,
+	ENHANCED_REGULAR_PRESET,
+	HIGH_ACCURACY_PRESET
+};
+
+static const struct bmc150_magn_preset {
+	u8 rep_xy;
+	u8 rep_z;
+	u8 odr;
+} bmc150_magn_presets_table[] = {
+	[LOW_POWER_PRESET] = {3, 3, 10},
+	[REGULAR_PRESET] =  {9, 15, 10},
+	[ENHANCED_REGULAR_PRESET] =  {15, 27, 10},
+	[HIGH_ACCURACY_PRESET] =  {47, 83, 20},
+};
+
+#define BMC150_MAGN_DEFAULT_PRESET REGULAR_PRESET
+
+static bool bmc150_magn_is_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMC150_MAGN_REG_POWER:
+	case BMC150_MAGN_REG_OPMODE_ODR:
+	case BMC150_MAGN_REG_INT:
+	case BMC150_MAGN_REG_INT_DRDY:
+	case BMC150_MAGN_REG_LOW_THRESH:
+	case BMC150_MAGN_REG_HIGH_THRESH:
+	case BMC150_MAGN_REG_REP_XY:
+	case BMC150_MAGN_REG_REP_Z:
+		return true;
+	default:
+		return false;
+	};
+}
+
+static bool bmc150_magn_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case BMC150_MAGN_REG_X_L:
+	case BMC150_MAGN_REG_X_M:
+	case BMC150_MAGN_REG_Y_L:
+	case BMC150_MAGN_REG_Y_M:
+	case BMC150_MAGN_REG_Z_L:
+	case BMC150_MAGN_REG_Z_M:
+	case BMC150_MAGN_REG_RHALL_L:
+	case BMC150_MAGN_REG_RHALL_M:
+	case BMC150_MAGN_REG_INT_STATUS:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config bmc150_magn_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.max_register = BMC150_MAGN_REG_TRIM_END,
+	.cache_type = REGCACHE_RBTREE,
+
+	.writeable_reg = bmc150_magn_is_writeable_reg,
+	.volatile_reg = bmc150_magn_is_volatile_reg,
+};
+
+static int bmc150_magn_set_power_mode(struct bmc150_magn_data *data,
+				      enum bmc150_magn_power_modes mode,
+				      bool state)
+{
+	int ret;
+
+	switch (mode) {
+	case BMC150_MAGN_POWER_MODE_SUSPEND:
+		ret = regmap_update_bits(data->regmap, BMC150_MAGN_REG_POWER,
+					 BMC150_MAGN_MASK_POWER_CTL, !state);
+		if (ret < 0)
+			return ret;
+		usleep_range(BMC150_MAGN_START_UP_TIME_MS * 1000, 20000);
+		return 0;
+	case BMC150_MAGN_POWER_MODE_SLEEP:
+		return regmap_update_bits(data->regmap,
+					  BMC150_MAGN_REG_OPMODE_ODR,
+					  BMC150_MAGN_MASK_OPMODE,
+					  BMC150_MAGN_MODE_SLEEP <<
+					  BMC150_MAGN_SHIFT_OPMODE);
+	case BMC150_MAGN_POWER_MODE_NORMAL:
+		return regmap_update_bits(data->regmap,
+					  BMC150_MAGN_REG_OPMODE_ODR,
+					  BMC150_MAGN_MASK_OPMODE,
+					  BMC150_MAGN_MODE_NORMAL <<
+					  BMC150_MAGN_SHIFT_OPMODE);
+	}
+
+	return -EINVAL;
+}
+
+static int bmc150_magn_set_power_state(struct bmc150_magn_data *data, bool on)
+{
+#ifdef CONFIG_PM
+	int ret;
+
+	if (on) {
+		ret = pm_runtime_get_sync(&data->client->dev);
+	} else {
+		pm_runtime_mark_last_busy(&data->client->dev);
+		ret = pm_runtime_put_autosuspend(&data->client->dev);
+	}
+
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"failed to change power state to %d\n", on);
+		if (on)
+			pm_runtime_put_noidle(&data->client->dev);
+
+		return ret;
+	}
+#endif
+
+	return 0;
+}
+
+static int bmc150_magn_get_odr(struct bmc150_magn_data *data, int *val)
+{
+	int ret, reg_val;
+	u8 i, odr_val;
+
+	ret = regmap_read(data->regmap, BMC150_MAGN_REG_OPMODE_ODR, &reg_val);
+	if (ret < 0)
+		return ret;
+	odr_val = (reg_val & BMC150_MAGN_MASK_ODR) >> BMC150_MAGN_SHIFT_ODR;
+
+	for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++)
+		if (bmc150_magn_samp_freq_table[i].reg_val == odr_val) {
+			*val = bmc150_magn_samp_freq_table[i].freq;
+			return 0;
+		}
+
+	return -EINVAL;
+}
+
+static int bmc150_magn_set_odr(struct bmc150_magn_data *data, int val)
+{
+	int ret;
+	u8 i;
+
+	for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++) {
+		if (bmc150_magn_samp_freq_table[i].freq == val) {
+			ret = regmap_update_bits(data->regmap,
+						 BMC150_MAGN_REG_OPMODE_ODR,
+						 BMC150_MAGN_MASK_ODR,
+						 bmc150_magn_samp_freq_table[i].
+						 reg_val <<
+						 BMC150_MAGN_SHIFT_ODR);
+			if (ret < 0)
+				return ret;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static s32 bmc150_magn_compensate_x(struct bmc150_magn_trim_regs *tregs, s16 x,
+				    u16 rhall)
+{
+	s16 val;
+	u16 xyz1 = le16_to_cpu(tregs->xyz1);
+
+	if (x == BMC150_MAGN_XY_OVERFLOW_VAL)
+		return S32_MIN;
+
+	if (!rhall)
+		rhall = xyz1;
+
+	val = ((s16)(((u16)((((s32)xyz1) << 14) / rhall)) - ((u16)0x4000)));
+	val = ((s16)((((s32)x) * ((((((((s32)tregs->xy2) * ((((s32)val) *
+	      ((s32)val)) >> 7)) + (((s32)val) *
+	      ((s32)(((s16)tregs->xy1) << 7)))) >> 9) + ((s32)0x100000)) *
+	      ((s32)(((s16)tregs->x2) + ((s16)0xA0)))) >> 12)) >> 13)) +
+	      (((s16)tregs->x1) << 3);
+
+	return (s32)val;
+}
+
+static s32 bmc150_magn_compensate_y(struct bmc150_magn_trim_regs *tregs, s16 y,
+				    u16 rhall)
+{
+	s16 val;
+	u16 xyz1 = le16_to_cpu(tregs->xyz1);
+
+	if (y == BMC150_MAGN_XY_OVERFLOW_VAL)
+		return S32_MIN;
+
+	if (!rhall)
+		rhall = xyz1;
+
+	val = ((s16)(((u16)((((s32)xyz1) << 14) / rhall)) - ((u16)0x4000)));
+	val = ((s16)((((s32)y) * ((((((((s32)tregs->xy2) * ((((s32)val) *
+	      ((s32)val)) >> 7)) + (((s32)val) *
+	      ((s32)(((s16)tregs->xy1) << 7)))) >> 9) + ((s32)0x100000)) *
+	      ((s32)(((s16)tregs->y2) + ((s16)0xA0)))) >> 12)) >> 13)) +
+	      (((s16)tregs->y1) << 3);
+
+	return (s32)val;
+}
+
+static s32 bmc150_magn_compensate_z(struct bmc150_magn_trim_regs *tregs, s16 z,
+				    u16 rhall)
+{
+	s32 val;
+	u16 xyz1 = le16_to_cpu(tregs->xyz1);
+	u16 z1 = le16_to_cpu(tregs->z1);
+	s16 z2 = le16_to_cpu(tregs->z2);
+	s16 z3 = le16_to_cpu(tregs->z3);
+	s16 z4 = le16_to_cpu(tregs->z4);
+
+	if (z == BMC150_MAGN_Z_OVERFLOW_VAL)
+		return S32_MIN;
+
+	val = (((((s32)(z - z4)) << 15) - ((((s32)z3) * ((s32)(((s16)rhall) -
+	      ((s16)xyz1)))) >> 2)) / (z2 + ((s16)(((((s32)z1) *
+	      ((((s16)rhall) << 1))) + (1 << 15)) >> 16))));
+
+	return val;
+}
+
+static int bmc150_magn_read_xyz(struct bmc150_magn_data *data, s32 *buffer)
+{
+	int ret;
+	__le16 values[AXIS_XYZR_MAX];
+	s16 raw_x, raw_y, raw_z;
+	u16 rhall;
+	struct bmc150_magn_trim_regs tregs;
+
+	ret = regmap_bulk_read(data->regmap, BMC150_MAGN_REG_X_L,
+			       values, sizeof(values));
+	if (ret < 0)
+		return ret;
+
+	raw_x = (s16)le16_to_cpu(values[AXIS_X]) >> BMC150_MAGN_SHIFT_XY_L;
+	raw_y = (s16)le16_to_cpu(values[AXIS_Y]) >> BMC150_MAGN_SHIFT_XY_L;
+	raw_z = (s16)le16_to_cpu(values[AXIS_Z]) >> BMC150_MAGN_SHIFT_Z_L;
+	rhall = le16_to_cpu(values[RHALL]) >> BMC150_MAGN_SHIFT_RHALL_L;
+
+	ret = regmap_bulk_read(data->regmap, BMC150_MAGN_REG_TRIM_START,
+			       &tregs, sizeof(tregs));
+	if (ret < 0)
+		return ret;
+
+	buffer[AXIS_X] = bmc150_magn_compensate_x(&tregs, raw_x, rhall);
+	buffer[AXIS_Y] = bmc150_magn_compensate_y(&tregs, raw_y, rhall);
+	buffer[AXIS_Z] = bmc150_magn_compensate_z(&tregs, raw_z, rhall);
+
+	return 0;
+}
+
+static int bmc150_magn_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+	int ret;
+	s32 values[AXIS_XYZ_MAX];
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (iio_buffer_enabled(indio_dev))
+			return -EBUSY;
+		mutex_lock(&data->mutex);
+
+		ret = bmc150_magn_set_power_state(data, true);
+		if (ret < 0) {
+			mutex_unlock(&data->mutex);
+			return ret;
+		}
+
+		ret = bmc150_magn_read_xyz(data, values);
+		if (ret < 0) {
+			bmc150_magn_set_power_state(data, false);
+			mutex_unlock(&data->mutex);
+			return ret;
+		}
+		*val = values[chan->scan_index];
+
+		ret = bmc150_magn_set_power_state(data, false);
+		if (ret < 0) {
+			mutex_unlock(&data->mutex);
+			return ret;
+		}
+
+		mutex_unlock(&data->mutex);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/*
+		 * The API/driver performs an off-chip temperature
+		 * compensation and outputs x/y/z magnetic field data in
+		 * 16 LSB/uT to the upper application layer.
+		 */
+		*val = 0;
+		*val2 = 625;
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = bmc150_magn_get_odr(data, val);
+		if (ret < 0)
+			return ret;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bmc150_magn_write_raw(struct iio_dev *indio_dev,
+				 struct iio_chan_spec const *chan,
+				 int val, int val2, long mask)
+{
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		mutex_lock(&data->mutex);
+		ret = bmc150_magn_set_odr(data, val);
+		mutex_unlock(&data->mutex);
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bmc150_magn_validate_trigger(struct iio_dev *indio_dev,
+					struct iio_trigger *trig)
+{
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+
+	if (data->dready_trig != trig)
+		return -EINVAL;
+
+	return 0;
+}
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("2 6 8 10 15 20 25 30");
+
+static struct attribute *bmc150_magn_attributes[] = {
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group bmc150_magn_attrs_group = {
+	.attrs = bmc150_magn_attributes,
+};
+
+#define BMC150_MAGN_CHANNEL(_axis) {					\
+	.type = IIO_MAGN,						\
+	.modified = 1,							\
+	.channel2 = IIO_MOD_##_axis,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) |	\
+				    BIT(IIO_CHAN_INFO_SCALE),		\
+	.scan_index = AXIS_##_axis,					\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 32,						\
+		.storagebits = 32,					\
+		.shift = 0,						\
+		.endianness = IIO_LE					\
+	},								\
+}
+
+static const struct iio_chan_spec bmc150_magn_channels[] = {
+	BMC150_MAGN_CHANNEL(X),
+	BMC150_MAGN_CHANNEL(Y),
+	BMC150_MAGN_CHANNEL(Z),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static const struct iio_info bmc150_magn_info = {
+	.attrs = &bmc150_magn_attrs_group,
+	.read_raw = bmc150_magn_read_raw,
+	.write_raw = bmc150_magn_write_raw,
+	.validate_trigger = bmc150_magn_validate_trigger,
+	.driver_module = THIS_MODULE,
+};
+
+static const unsigned long bmc150_magn_scan_masks[] = {0x07, 0};
+
+static irqreturn_t bmc150_magn_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = bmc150_magn_read_xyz(data, data->buffer);
+	mutex_unlock(&data->mutex);
+	if (ret < 0)
+		goto err;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+					   pf->timestamp);
+
+err:
+	iio_trigger_notify_done(data->dready_trig);
+
+	return IRQ_HANDLED;
+}
+
+static int bmc150_magn_init(struct bmc150_magn_data *data)
+{
+	int ret, chip_id;
+	struct bmc150_magn_preset preset;
+
+	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND,
+					 false);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"Failed to bring up device from suspend mode\n");
+		return ret;
+	}
+
+	ret = regmap_read(data->regmap, BMC150_MAGN_REG_CHIP_ID, &chip_id);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed reading chip id\n");
+		goto err_poweroff;
+	}
+	if (chip_id != BMC150_MAGN_CHIP_ID_VAL) {
+		dev_err(&data->client->dev, "Invalid chip id 0x%x\n", ret);
+		ret = -ENODEV;
+		goto err_poweroff;
+	}
+	dev_dbg(&data->client->dev, "Chip id %x\n", ret);
+
+	preset = bmc150_magn_presets_table[BMC150_MAGN_DEFAULT_PRESET];
+	ret = bmc150_magn_set_odr(data, preset.odr);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to set ODR to %d\n",
+			preset.odr);
+		goto err_poweroff;
+	}
+
+	ret = regmap_write(data->regmap, BMC150_MAGN_REG_REP_XY,
+			   BMC150_MAGN_REPXY_TO_REGVAL(preset.rep_xy));
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to set REP XY to %d\n",
+			preset.rep_xy);
+		goto err_poweroff;
+	}
+
+	ret = regmap_write(data->regmap, BMC150_MAGN_REG_REP_Z,
+			   BMC150_MAGN_REPZ_TO_REGVAL(preset.rep_z));
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to set REP Z to %d\n",
+			preset.rep_z);
+		goto err_poweroff;
+	}
+
+	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
+					 true);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to power on device\n");
+		goto err_poweroff;
+	}
+
+	return 0;
+
+err_poweroff:
+	bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
+	return ret;
+}
+
+static int bmc150_magn_reset_intr(struct bmc150_magn_data *data)
+{
+	int tmp;
+
+	/*
+	 * Data Ready (DRDY) is always cleared after
+	 * readout of data registers ends.
+	 */
+	return regmap_read(data->regmap, BMC150_MAGN_REG_X_L, &tmp);
+}
+
+static int bmc150_magn_trig_try_reen(struct iio_trigger *trig)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (!data->dready_trigger_on)
+		return 0;
+
+	mutex_lock(&data->mutex);
+	ret = bmc150_magn_reset_intr(data);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int bmc150_magn_data_rdy_trigger_set_state(struct iio_trigger *trig,
+						  bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+	int ret = 0;
+
+	mutex_lock(&data->mutex);
+	if (state == data->dready_trigger_on)
+		goto err_unlock;
+
+	ret = bmc150_magn_set_power_state(data, state);
+	if (ret < 0)
+		goto err_unlock;
+
+	ret = regmap_update_bits(data->regmap, BMC150_MAGN_REG_INT_DRDY,
+				 BMC150_MAGN_MASK_DRDY_EN,
+				 state << BMC150_MAGN_SHIFT_DRDY_EN);
+	if (ret < 0)
+		goto err_poweroff;
+
+	data->dready_trigger_on = state;
+
+	if (state) {
+		ret = bmc150_magn_reset_intr(data);
+		if (ret < 0)
+			goto err_poweroff;
+	}
+	mutex_unlock(&data->mutex);
+
+	return 0;
+
+err_poweroff:
+	bmc150_magn_set_power_state(data, false);
+err_unlock:
+	mutex_unlock(&data->mutex);
+	return ret;
+}
+
+static const struct iio_trigger_ops bmc150_magn_trigger_ops = {
+	.set_trigger_state = bmc150_magn_data_rdy_trigger_set_state,
+	.try_reenable = bmc150_magn_trig_try_reen,
+	.owner = THIS_MODULE,
+};
+
+static int bmc150_magn_gpio_probe(struct i2c_client *client)
+{
+	struct device *dev;
+	struct gpio_desc *gpio;
+	int ret;
+
+	if (!client)
+		return -EINVAL;
+
+	dev = &client->dev;
+
+	/* data ready GPIO interrupt pin */
+	gpio = devm_gpiod_get_index(dev, BMC150_MAGN_GPIO_INT, 0);
+	if (IS_ERR(gpio)) {
+		dev_err(dev, "ACPI GPIO get index failed\n");
+		return PTR_ERR(gpio);
+	}
+
+	ret = gpiod_direction_input(gpio);
+	if (ret)
+		return ret;
+
+	ret = gpiod_to_irq(gpio);
+
+	dev_dbg(dev, "GPIO resource, no:%d irq:%d\n", desc_to_gpio(gpio), ret);
+
+	return ret;
+}
+
+static const char *bmc150_magn_match_acpi_device(struct device *dev)
+{
+	const struct acpi_device_id *id;
+
+	id = acpi_match_device(dev->driver->acpi_match_table, dev);
+	if (!id)
+		return NULL;
+
+	return dev_name(dev);
+}
+
+static int bmc150_magn_probe(struct i2c_client *client,
+			     const struct i2c_device_id *id)
+{
+	struct bmc150_magn_data *data;
+	struct iio_dev *indio_dev;
+	const char *name = NULL;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	if (id)
+		name = id->name;
+	else if (ACPI_HANDLE(&client->dev))
+		name = bmc150_magn_match_acpi_device(&client->dev);
+	else
+		return -ENOSYS;
+
+	mutex_init(&data->mutex);
+	data->regmap = devm_regmap_init_i2c(client, &bmc150_magn_regmap_config);
+	if (IS_ERR(data->regmap)) {
+		dev_err(&client->dev, "Failed to allocate register map\n");
+		return PTR_ERR(data->regmap);
+	}
+
+	ret = bmc150_magn_init(data);
+	if (ret < 0)
+		return ret;
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->channels = bmc150_magn_channels;
+	indio_dev->num_channels = ARRAY_SIZE(bmc150_magn_channels);
+	indio_dev->available_scan_masks = bmc150_magn_scan_masks;
+	indio_dev->name = name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &bmc150_magn_info;
+
+	if (client->irq <= 0)
+		client->irq = bmc150_magn_gpio_probe(client);
+
+	if (client->irq > 0) {
+		data->dready_trig = devm_iio_trigger_alloc(&client->dev,
+							   "%s-dev%d",
+							   indio_dev->name,
+							   indio_dev->id);
+		if (!data->dready_trig) {
+			ret = -ENOMEM;
+			dev_err(&client->dev, "iio trigger alloc failed\n");
+			goto err_poweroff;
+		}
+
+		data->dready_trig->dev.parent = &client->dev;
+		data->dready_trig->ops = &bmc150_magn_trigger_ops;
+		iio_trigger_set_drvdata(data->dready_trig, indio_dev);
+		ret = iio_trigger_register(data->dready_trig);
+		if (ret) {
+			dev_err(&client->dev, "iio trigger register failed\n");
+			goto err_poweroff;
+		}
+
+		ret = iio_triggered_buffer_setup(indio_dev,
+						 &iio_pollfunc_store_time,
+						 bmc150_magn_trigger_handler,
+						 NULL);
+		if (ret < 0) {
+			dev_err(&client->dev,
+				"iio triggered buffer setup failed\n");
+			goto err_trigger_unregister;
+		}
+
+		ret = request_threaded_irq(client->irq,
+					   iio_trigger_generic_data_rdy_poll,
+					   NULL,
+					   IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+					   BMC150_MAGN_IRQ_NAME,
+					   data->dready_trig);
+		if (ret < 0) {
+			dev_err(&client->dev, "request irq %d failed\n",
+				client->irq);
+			goto err_buffer_cleanup;
+		}
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "unable to register iio device\n");
+		goto err_free_irq;
+	}
+
+	ret = pm_runtime_set_active(&client->dev);
+	if (ret)
+		goto err_iio_unregister;
+
+	pm_runtime_enable(&client->dev);
+	pm_runtime_set_autosuspend_delay(&client->dev,
+					 BMC150_MAGN_AUTO_SUSPEND_DELAY_MS);
+	pm_runtime_use_autosuspend(&client->dev);
+
+	dev_dbg(&indio_dev->dev, "Registered device %s\n", name);
+
+	return 0;
+
+err_iio_unregister:
+	iio_device_unregister(indio_dev);
+err_free_irq:
+	if (client->irq > 0)
+		free_irq(client->irq, data->dready_trig);
+err_buffer_cleanup:
+	if (data->dready_trig)
+		iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+	if (data->dready_trig)
+		iio_trigger_unregister(data->dready_trig);
+err_poweroff:
+	bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
+	return ret;
+}
+
+static int bmc150_magn_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+	pm_runtime_put_noidle(&client->dev);
+
+	iio_device_unregister(indio_dev);
+
+	if (client->irq > 0)
+		free_irq(data->client->irq, data->dready_trig);
+
+	if (data->dready_trig) {
+		iio_triggered_buffer_cleanup(indio_dev);
+		iio_trigger_unregister(data->dready_trig);
+	}
+
+	mutex_lock(&data->mutex);
+	bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int bmc150_magn_runtime_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
+					 true);
+	mutex_unlock(&data->mutex);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "powering off device failed\n");
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+static int bmc150_magn_runtime_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+
+	return bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
+					  true);
+}
+#endif
+
+#ifdef CONFIG_PM_SLEEP
+static int bmc150_magn_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
+					 true);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int bmc150_magn_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct bmc150_magn_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
+					 true);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+#endif
+
+static const struct dev_pm_ops bmc150_magn_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(bmc150_magn_suspend, bmc150_magn_resume)
+	SET_RUNTIME_PM_OPS(bmc150_magn_runtime_suspend,
+			   bmc150_magn_runtime_resume, NULL)
+};
+
+static const struct acpi_device_id bmc150_magn_acpi_match[] = {
+	{"BMC150B", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, bmc150_magn_acpi_match);
+
+static const struct i2c_device_id bmc150_magn_id[] = {
+	{"bmc150_magn", 0},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, bmc150_magn_id);
+
+static struct i2c_driver bmc150_magn_driver = {
+	.driver = {
+		   .name = BMC150_MAGN_DRV_NAME,
+		   .acpi_match_table = ACPI_PTR(bmc150_magn_acpi_match),
+		   .pm = &bmc150_magn_pm_ops,
+		   },
+	.probe = bmc150_magn_probe,
+	.remove = bmc150_magn_remove,
+	.id_table = bmc150_magn_id,
+};
+module_i2c_driver(bmc150_magn_driver);
+
+MODULE_AUTHOR("Irina Tirdea <irina.tirdea@xxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BMC150 magnetometer driver");
-- 
1.9.1

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