Merge tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO updates from Greg KH:
 "Here is the big staging and IIO driver pull request for 4.9-rc1.

  There are a lot of patches in here, the majority due to the
  drivers/staging/greybus/ subsystem being merged in with full
  development history that went back a few years, in order to preserve
  the work that those developers did over time.

  Lots and lots of tiny cleanups happened in the tree as well, due to
  the Outreachy application process and lots of other developers showing
  up for the first time to clean code up.  Along with those changes, we
  deleted a wireless driver, and added a raspberrypi driver (currently
  marked broken), and lots of new iio drivers.

  Overall the tree still shrunk with more lines removed than added,
  about 10 thousand lines removed in total. Full details are in the very
  long shortlog below.

  All of this has been in the linux-next tree with no issues. There will
  be some merge problems with other subsystem trees, but those are all
  minor problems and shouldn't be hard to work out when they happen
  (MAINTAINERS and some lustre build problems with the IB tree)"

And furter from me asking for clarification about greybus:
 "Right now there is a phone from Motorola shipping with this code (a
  slightly older version, but the same tree), so even though Ara is not
  alive in the same form, the functionality is happening. We are working
  with the developers of that phone to merge the newer stuff in with
  their fork so they can use the upstream version in future versions of
  their phone product line.

  Toshiba has at least one chip shipping in their catalog that
  needs/uses this protocol over a Unipro link, and rumor has it that
  there might be more in the future.

  There are also other users of the greybus protocols, there is a talk
  next week at ELC that shows how it is being used across a network
  connection to control a device, and previous ELC talks have showed the
  protocol stack being used over USB to drive embedded Linux boards.
  I've also talked to some people who are starting to work to add a host
  controller driver to control arduinos as the greybus PHY protocols are
  very useful to control a serial/i2c/spio/whatever device across a
  random physical link, as it is a way to have a self-describing device
  be attached to a host without needing manual configuration.

  So yes, people are using it, and there is still the chance that it
  will show up in a phone/laptop/tablet/whatever from Google in the
  future as well, the tech isn't dead, even if the original large phone
  project happens to be"

* tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (3703 commits)
  Staging: fbtft: Fix bug in fbtft-core
  staging: rtl8188eu: fix double unlock error in rtw_resume_process()
  staging:r8188eu: remove GEN_MLME_EXT_HANDLER macro
  staging:r8188eu: remove GEN_DRV_CMD_HANDLER macro
  staging:r8188eu: remove GEN_EVT_CODE macro
  staging:r8188eu: remove GEN_CMD_CODE macro
  staging:r8188eu: remove pkt_newalloc member of the recv_buf structure
  staging:r8188eu: remove rtw_handle_dualmac declaration
  staging:r8188eu: remove (RGTRY|BSSID)_(OFT|SZ) macros
  staging:r8188eu: change rtl8188e_process_phy_info function argument type
  Staging: fsl-mc: Remove blank lines
  Staging: fsl-mc: Fix unaligned * in block comments
  Staging: comedi: Align the * in block comments
  Staging : ks7010 : Fix block comments warninig
  Staging: vt6655: Remove explicit NULL comparison using Coccinelle
  staging: rtl8188eu: core: rtw_xmit: Use macros instead of constants
  staging: rtl8188eu: core: rtw_xmit: Move constant of the right side
  staging: dgnc: Fix lines longer than 80 characters
  Staging: dgnc: constify attribute_group structures
  Staging: most: hdm-dim2: constify attribute_group structures
  ...

1 files changed, 860 insertions, 0 deletions

diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c
new file mode 100644
index 0000000..2173531
--- /dev/null
+++ b/drivers/iio/magnetometer/ak8974.c
@@ -0,0 +1,860 @@
+/*
+ * Driver for the Asahi Kasei EMD Corporation AK8974
+ * and Aichi Steel AMI305 magnetometer chips.
+ * Based on a patch from Samu Onkalo and the AK8975 IIO driver.
+ *
+ * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+ * Copyright (c) 2010 NVIDIA Corporation.
+ * Copyright (C) 2016 Linaro Ltd.
+ *
+ * Author: Samu Onkalo <samu.p.onkalo@nokia.com>
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h> /* For irq_get_irq_data() */
+#include <linux/completion.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/bitops.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/pm_runtime.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+/*
+ * 16-bit registers are little-endian. LSB is at the address defined below
+ * and MSB is at the next higher address.
+ */
+
+/* These registers are common for AK8974 and AMI305 */
+#define AK8974_SELFTEST		0x0C
+#define AK8974_SELFTEST_IDLE	0x55
+#define AK8974_SELFTEST_OK	0xAA
+
+#define AK8974_INFO		0x0D
+
+#define AK8974_WHOAMI		0x0F
+#define AK8974_WHOAMI_VALUE_AMI305 0x47
+#define AK8974_WHOAMI_VALUE_AK8974 0x48
+
+#define AK8974_DATA_X		0x10
+#define AK8974_DATA_Y		0x12
+#define AK8974_DATA_Z		0x14
+#define AK8974_INT_SRC		0x16
+#define AK8974_STATUS		0x18
+#define AK8974_INT_CLEAR	0x1A
+#define AK8974_CTRL1		0x1B
+#define AK8974_CTRL2		0x1C
+#define AK8974_CTRL3		0x1D
+#define AK8974_INT_CTRL		0x1E
+#define AK8974_INT_THRES	0x26  /* Absolute any axis value threshold */
+#define AK8974_PRESET		0x30
+
+/* AK8974-specific offsets */
+#define AK8974_OFFSET_X		0x20
+#define AK8974_OFFSET_Y		0x22
+#define AK8974_OFFSET_Z		0x24
+/* AMI305-specific offsets */
+#define AMI305_OFFSET_X		0x6C
+#define AMI305_OFFSET_Y		0x72
+#define AMI305_OFFSET_Z		0x78
+
+/* Different temperature registers */
+#define AK8974_TEMP		0x31
+#define AMI305_TEMP		0x60
+
+#define AK8974_INT_X_HIGH	BIT(7) /* Axis over +threshold  */
+#define AK8974_INT_Y_HIGH	BIT(6)
+#define AK8974_INT_Z_HIGH	BIT(5)
+#define AK8974_INT_X_LOW	BIT(4) /* Axis below -threshold	*/
+#define AK8974_INT_Y_LOW	BIT(3)
+#define AK8974_INT_Z_LOW	BIT(2)
+#define AK8974_INT_RANGE	BIT(1) /* Range overflow (any axis) */
+
+#define AK8974_STATUS_DRDY	BIT(6) /* Data ready */
+#define AK8974_STATUS_OVERRUN	BIT(5) /* Data overrun */
+#define AK8974_STATUS_INT	BIT(4) /* Interrupt occurred */
+
+#define AK8974_CTRL1_POWER	BIT(7) /* 0 = standby; 1 = active */
+#define AK8974_CTRL1_RATE	BIT(4) /* 0 = 10 Hz; 1 = 20 Hz	 */
+#define AK8974_CTRL1_FORCE_EN	BIT(1) /* 0 = normal; 1 = force	 */
+#define AK8974_CTRL1_MODE2	BIT(0) /* 0 */
+
+#define AK8974_CTRL2_INT_EN	BIT(4)  /* 1 = enable interrupts	      */
+#define AK8974_CTRL2_DRDY_EN	BIT(3)  /* 1 = enable data ready signal */
+#define AK8974_CTRL2_DRDY_POL	BIT(2)  /* 1 = data ready active high   */
+#define AK8974_CTRL2_RESDEF	(AK8974_CTRL2_DRDY_POL)
+
+#define AK8974_CTRL3_RESET	BIT(7) /* Software reset		  */
+#define AK8974_CTRL3_FORCE	BIT(6) /* Start forced measurement */
+#define AK8974_CTRL3_SELFTEST	BIT(4) /* Set selftest register	  */
+#define AK8974_CTRL3_RESDEF	0x00
+
+#define AK8974_INT_CTRL_XEN	BIT(7) /* Enable interrupt for this axis */
+#define AK8974_INT_CTRL_YEN	BIT(6)
+#define AK8974_INT_CTRL_ZEN	BIT(5)
+#define AK8974_INT_CTRL_XYZEN	(BIT(7)|BIT(6)|BIT(5))
+#define AK8974_INT_CTRL_POL	BIT(3) /* 0 = active low; 1 = active high */
+#define AK8974_INT_CTRL_PULSE	BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
+#define AK8974_INT_CTRL_RESDEF	(AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
+
+/* The AMI305 has elaborate FW version and serial number registers */
+#define AMI305_VER		0xE8
+#define AMI305_SN		0xEA
+
+#define AK8974_MAX_RANGE	2048
+
+#define AK8974_POWERON_DELAY	50
+#define AK8974_ACTIVATE_DELAY	1
+#define AK8974_SELFTEST_DELAY	1
+/*
+ * Set the autosuspend to two orders of magnitude larger than the poweron
+ * delay to make sane reasonable power tradeoff savings (5 seconds in
+ * this case).
+ */
+#define AK8974_AUTOSUSPEND_DELAY 5000
+
+#define AK8974_MEASTIME		3
+
+#define AK8974_PWR_ON		1
+#define AK8974_PWR_OFF		0
+
+/**
+ * struct ak8974 - state container for the AK8974 driver
+ * @i2c: parent I2C client
+ * @orientation: mounting matrix, flipped axis etc
+ * @map: regmap to access the AK8974 registers over I2C
+ * @regs: the avdd and dvdd power regulators
+ * @name: the name of the part
+ * @variant: the whoami ID value (for selecting code paths)
+ * @lock: locks the magnetometer for exclusive use during a measurement
+ * @drdy_irq: uses the DRDY IRQ line
+ * @drdy_complete: completion for DRDY
+ * @drdy_active_low: the DRDY IRQ is active low
+ */
+struct ak8974 {
+	struct i2c_client *i2c;
+	struct iio_mount_matrix orientation;
+	struct regmap *map;
+	struct regulator_bulk_data regs[2];
+	const char *name;
+	u8 variant;
+	struct mutex lock;
+	bool drdy_irq;
+	struct completion drdy_complete;
+	bool drdy_active_low;
+};
+
+static const char ak8974_reg_avdd[] = "avdd";
+static const char ak8974_reg_dvdd[] = "dvdd";
+
+static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
+{
+	int ret;
+	u8 val;
+
+	val = mode ? AK8974_CTRL1_POWER : 0;
+	val |= AK8974_CTRL1_FORCE_EN;
+	ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
+	if (ret < 0)
+		return ret;
+
+	if (mode)
+		msleep(AK8974_ACTIVATE_DELAY);
+
+	return 0;
+}
+
+static int ak8974_reset(struct ak8974 *ak8974)
+{
+	int ret;
+
+	/* Power on to get register access. Sets CTRL1 reg to reset state */
+	ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
+	if (ret)
+		return ret;
+	ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
+	if (ret)
+		return ret;
+	ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
+	if (ret)
+		return ret;
+	ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
+			   AK8974_INT_CTRL_RESDEF);
+	if (ret)
+		return ret;
+
+	/* After reset, power off is default state */
+	return ak8974_set_power(ak8974, AK8974_PWR_OFF);
+}
+
+static int ak8974_configure(struct ak8974 *ak8974)
+{
+	int ret;
+
+	ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN |
+			   AK8974_CTRL2_INT_EN);
+	if (ret)
+		return ret;
+	ret = regmap_write(ak8974->map, AK8974_CTRL3, 0);
+	if (ret)
+		return ret;
+	ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
+	if (ret)
+		return ret;
+
+	return regmap_write(ak8974->map, AK8974_PRESET, 0);
+}
+
+static int ak8974_trigmeas(struct ak8974 *ak8974)
+{
+	unsigned int clear;
+	u8 mask;
+	u8 val;
+	int ret;
+
+	/* Clear any previous measurement overflow status */
+	ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear);
+	if (ret)
+		return ret;
+
+	/* If we have a DRDY IRQ line, use it */
+	if (ak8974->drdy_irq) {
+		mask = AK8974_CTRL2_INT_EN |
+			AK8974_CTRL2_DRDY_EN |
+			AK8974_CTRL2_DRDY_POL;
+		val = AK8974_CTRL2_DRDY_EN;
+
+		if (!ak8974->drdy_active_low)
+			val |= AK8974_CTRL2_DRDY_POL;
+
+		init_completion(&ak8974->drdy_complete);
+		ret = regmap_update_bits(ak8974->map, AK8974_CTRL2,
+					 mask, val);
+		if (ret)
+			return ret;
+	}
+
+	/* Force a measurement */
+	return regmap_update_bits(ak8974->map,
+				  AK8974_CTRL3,
+				  AK8974_CTRL3_FORCE,
+				  AK8974_CTRL3_FORCE);
+}
+
+static int ak8974_await_drdy(struct ak8974 *ak8974)
+{
+	int timeout = 2;
+	unsigned int val;
+	int ret;
+
+	if (ak8974->drdy_irq) {
+		ret = wait_for_completion_timeout(&ak8974->drdy_complete,
+					1 + msecs_to_jiffies(1000));
+		if (!ret) {
+			dev_err(&ak8974->i2c->dev,
+				"timeout waiting for DRDY IRQ\n");
+			return -ETIMEDOUT;
+		}
+		return 0;
+	}
+
+	/* Default delay-based poll loop */
+	do {
+		msleep(AK8974_MEASTIME);
+		ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
+		if (ret < 0)
+			return ret;
+		if (val & AK8974_STATUS_DRDY)
+			return 0;
+	} while (--timeout);
+	if (!timeout) {
+		dev_err(&ak8974->i2c->dev,
+			"timeout waiting for DRDY\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int ak8974_getresult(struct ak8974 *ak8974, s16 *result)
+{
+	unsigned int src;
+	int ret;
+
+	ret = ak8974_await_drdy(ak8974);
+	if (ret)
+		return ret;
+	ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
+	if (ret < 0)
+		return ret;
+
+	/* Out of range overflow! Strong magnet close? */
+	if (src & AK8974_INT_RANGE) {
+		dev_err(&ak8974->i2c->dev,
+			"range overflow in sensor\n");
+		return -ERANGE;
+	}
+
+	ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
+	if (ret)
+		return ret;
+
+	return ret;
+}
+
+static irqreturn_t ak8974_drdy_irq(int irq, void *d)
+{
+	struct ak8974 *ak8974 = d;
+
+	if (!ak8974->drdy_irq)
+		return IRQ_NONE;
+
+	/* TODO: timestamp here to get good measurement stamps */
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
+{
+	struct ak8974 *ak8974 = d;
+	unsigned int val;
+	int ret;
+
+	/* Check if this was a DRDY from us */
+	ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
+	if (ret < 0) {
+		dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
+		return IRQ_HANDLED;
+	}
+	if (val & AK8974_STATUS_DRDY) {
+		/* Yes this was our IRQ */
+		complete(&ak8974->drdy_complete);
+		return IRQ_HANDLED;
+	}
+
+	/* We may be on a shared IRQ, let the next client check */
+	return IRQ_NONE;
+}
+
+static int ak8974_selftest(struct ak8974 *ak8974)
+{
+	struct device *dev = &ak8974->i2c->dev;
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
+	if (ret)
+		return ret;
+	if (val != AK8974_SELFTEST_IDLE) {
+		dev_err(dev, "selftest not idle before test\n");
+		return -EIO;
+	}
+
+	/* Trigger self-test */
+	ret = regmap_update_bits(ak8974->map,
+			AK8974_CTRL3,
+			AK8974_CTRL3_SELFTEST,
+			AK8974_CTRL3_SELFTEST);
+	if (ret) {
+		dev_err(dev, "could not write CTRL3\n");
+		return ret;
+	}
+
+	msleep(AK8974_SELFTEST_DELAY);
+
+	ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
+	if (ret)
+		return ret;
+	if (val != AK8974_SELFTEST_OK) {
+		dev_err(dev, "selftest result NOT OK (%02x)\n", val);
+		return -EIO;
+	}
+
+	ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
+	if (ret)
+		return ret;
+	if (val != AK8974_SELFTEST_IDLE) {
+		dev_err(dev, "selftest not idle after test (%02x)\n", val);
+		return -EIO;
+	}
+	dev_dbg(dev, "passed self-test\n");
+
+	return 0;
+}
+
+static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
+{
+	int ret;
+	u16 bulk;
+
+	ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
+	if (ret)
+		return ret;
+	*val = le16_to_cpu(bulk);
+
+	return 0;
+}
+
+static int ak8974_detect(struct ak8974 *ak8974)
+{
+	unsigned int whoami;
+	const char *name;
+	int ret;
+	unsigned int fw;
+	u16 sn;
+
+	ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
+	if (ret)
+		return ret;
+
+	switch (whoami) {
+	case AK8974_WHOAMI_VALUE_AMI305:
+		name = "ami305";
+		ret = regmap_read(ak8974->map, AMI305_VER, &fw);
+		if (ret)
+			return ret;
+		fw &= 0x7f; /* only bits 0 thru 6 valid */
+		ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
+		if (ret)
+			return ret;
+		dev_info(&ak8974->i2c->dev,
+			 "detected %s, FW ver %02x, S/N: %04x\n",
+			 name, fw, sn);
+		break;
+	case AK8974_WHOAMI_VALUE_AK8974:
+		name = "ak8974";
+		dev_info(&ak8974->i2c->dev, "detected AK8974\n");
+		break;
+	default:
+		dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
+			whoami);
+		return -ENODEV;
+	}
+
+	ak8974->name = name;
+	ak8974->variant = whoami;
+
+	return 0;
+}
+
+static int ak8974_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2,
+			   long mask)
+{
+	struct ak8974 *ak8974 = iio_priv(indio_dev);
+	s16 hw_values[3];
+	int ret = -EINVAL;
+
+	pm_runtime_get_sync(&ak8974->i2c->dev);
+	mutex_lock(&ak8974->lock);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (chan->address > 2) {
+			dev_err(&ak8974->i2c->dev, "faulty channel address\n");
+			ret = -EIO;
+			goto out_unlock;
+		}
+		ret = ak8974_trigmeas(ak8974);
+		if (ret)
+			goto out_unlock;
+		ret = ak8974_getresult(ak8974, hw_values);
+		if (ret)
+			goto out_unlock;
+
+		/*
+		 * We read all axes and discard all but one, for optimized
+		 * reading, use the triggered buffer.
+		 */
+		*val = le16_to_cpu(hw_values[chan->address]);
+
+		ret = IIO_VAL_INT;
+	}
+
+ out_unlock:
+	mutex_unlock(&ak8974->lock);
+	pm_runtime_mark_last_busy(&ak8974->i2c->dev);
+	pm_runtime_put_autosuspend(&ak8974->i2c->dev);
+
+	return ret;
+}
+
+static void ak8974_fill_buffer(struct iio_dev *indio_dev)
+{
+	struct ak8974 *ak8974 = iio_priv(indio_dev);
+	int ret;
+	s16 hw_values[8]; /* Three axes + 64bit padding */
+
+	pm_runtime_get_sync(&ak8974->i2c->dev);
+	mutex_lock(&ak8974->lock);
+
+	ret = ak8974_trigmeas(ak8974);
+	if (ret) {
+		dev_err(&ak8974->i2c->dev, "error triggering measure\n");
+		goto out_unlock;
+	}
+	ret = ak8974_getresult(ak8974, hw_values);
+	if (ret) {
+		dev_err(&ak8974->i2c->dev, "error getting measures\n");
+		goto out_unlock;
+	}
+
+	iio_push_to_buffers_with_timestamp(indio_dev, hw_values,
+					   iio_get_time_ns(indio_dev));
+
+ out_unlock:
+	mutex_unlock(&ak8974->lock);
+	pm_runtime_mark_last_busy(&ak8974->i2c->dev);
+	pm_runtime_put_autosuspend(&ak8974->i2c->dev);
+}
+
+static irqreturn_t ak8974_handle_trigger(int irq, void *p)
+{
+	const struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+
+	ak8974_fill_buffer(indio_dev);
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_mount_matrix *
+ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
+			const struct iio_chan_spec *chan)
+{
+	struct ak8974 *ak8974 = iio_priv(indio_dev);
+
+	return &ak8974->orientation;
+}
+
+static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
+	IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
+	{ },
+};
+
+#define AK8974_AXIS_CHANNEL(axis, index)				\
+	{								\
+		.type = IIO_MAGN,					\
+		.modified = 1,						\
+		.channel2 = IIO_MOD_##axis,				\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+		.ext_info = ak8974_ext_info,				\
+		.address = index,					\
+		.scan_index = index,					\
+		.scan_type = {						\
+			.sign = 's',					\
+			.realbits = 16,					\
+			.storagebits = 16,				\
+			.endianness = IIO_LE				\
+		},							\
+	}
+
+static const struct iio_chan_spec ak8974_channels[] = {
+	AK8974_AXIS_CHANNEL(X, 0),
+	AK8974_AXIS_CHANNEL(Y, 1),
+	AK8974_AXIS_CHANNEL(Z, 2),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
+
+static const struct iio_info ak8974_info = {
+	.read_raw = &ak8974_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
+	struct ak8974 *ak8974 = iio_priv(indio_dev);
+
+	switch (reg) {
+	case AK8974_CTRL1:
+	case AK8974_CTRL2:
+	case AK8974_CTRL3:
+	case AK8974_INT_CTRL:
+	case AK8974_INT_THRES:
+	case AK8974_INT_THRES + 1:
+	case AK8974_PRESET:
+	case AK8974_PRESET + 1:
+		return true;
+	case AK8974_OFFSET_X:
+	case AK8974_OFFSET_X + 1:
+	case AK8974_OFFSET_Y:
+	case AK8974_OFFSET_Y + 1:
+	case AK8974_OFFSET_Z:
+	case AK8974_OFFSET_Z + 1:
+		if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974)
+			return true;
+		return false;
+	case AMI305_OFFSET_X:
+	case AMI305_OFFSET_X + 1:
+	case AMI305_OFFSET_Y:
+	case AMI305_OFFSET_Y + 1:
+	case AMI305_OFFSET_Z:
+	case AMI305_OFFSET_Z + 1:
+		if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI305)
+			return true;
+		return false;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config ak8974_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xff,
+	.writeable_reg = ak8974_writeable_reg,
+};
+
+static int ak8974_probe(struct i2c_client *i2c,
+			const struct i2c_device_id *id)
+{
+	struct iio_dev *indio_dev;
+	struct ak8974 *ak8974;
+	unsigned long irq_trig;
+	int irq = i2c->irq;
+	int ret;
+
+	/* Register with IIO */
+	indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	ak8974 = iio_priv(indio_dev);
+	i2c_set_clientdata(i2c, indio_dev);
+	ak8974->i2c = i2c;
+	mutex_init(&ak8974->lock);
+
+	ret = of_iio_read_mount_matrix(&i2c->dev,
+				       "mount-matrix",
+				       &ak8974->orientation);
+	if (ret)
+		return ret;
+
+	ak8974->regs[0].supply = ak8974_reg_avdd;
+	ak8974->regs[1].supply = ak8974_reg_dvdd;
+
+	ret = devm_regulator_bulk_get(&i2c->dev,
+				      ARRAY_SIZE(ak8974->regs),
+				      ak8974->regs);
+	if (ret < 0) {
+		dev_err(&i2c->dev, "cannot get regulators\n");
+		return ret;
+	}
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
+	if (ret < 0) {
+		dev_err(&i2c->dev, "cannot enable regulators\n");
+		return ret;
+	}
+
+	/* Take runtime PM online */
+	pm_runtime_get_noresume(&i2c->dev);
+	pm_runtime_set_active(&i2c->dev);
+	pm_runtime_enable(&i2c->dev);
+
+	ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
+	if (IS_ERR(ak8974->map)) {
+		dev_err(&i2c->dev, "failed to allocate register map\n");
+		return PTR_ERR(ak8974->map);
+	}
+
+	ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
+	if (ret) {
+		dev_err(&i2c->dev, "could not power on\n");
+		goto power_off;
+	}
+
+	ret = ak8974_detect(ak8974);
+	if (ret) {
+		dev_err(&i2c->dev, "neither AK8974 nor AMI305 found\n");
+		goto power_off;
+	}
+
+	ret = ak8974_selftest(ak8974);
+	if (ret)
+		dev_err(&i2c->dev, "selftest failed (continuing anyway)\n");
+
+	ret = ak8974_reset(ak8974);
+	if (ret) {
+		dev_err(&i2c->dev, "AK8974 reset failed\n");
+		goto power_off;
+	}
+
+	pm_runtime_set_autosuspend_delay(&i2c->dev,
+					 AK8974_AUTOSUSPEND_DELAY);
+	pm_runtime_use_autosuspend(&i2c->dev);
+	pm_runtime_put(&i2c->dev);
+
+	indio_dev->dev.parent = &i2c->dev;
+	indio_dev->channels = ak8974_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ak8974_channels);
+	indio_dev->info = &ak8974_info;
+	indio_dev->available_scan_masks = ak8974_scan_masks;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->name = ak8974->name;
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+					 ak8974_handle_trigger,
+					 NULL);
+	if (ret) {
+		dev_err(&i2c->dev, "triggered buffer setup failed\n");
+		goto disable_pm;
+	}
+
+	/* If we have a valid DRDY IRQ, make use of it */
+	if (irq > 0) {
+		irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
+		if (irq_trig == IRQF_TRIGGER_RISING) {
+			dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n");
+		} else if (irq_trig == IRQF_TRIGGER_FALLING) {
+			ak8974->drdy_active_low = true;
+			dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n");
+		} else {
+			irq_trig = IRQF_TRIGGER_RISING;
+		}
+		irq_trig |= IRQF_ONESHOT;
+		irq_trig |= IRQF_SHARED;
+
+		ret = devm_request_threaded_irq(&i2c->dev,
+						irq,
+						ak8974_drdy_irq,
+						ak8974_drdy_irq_thread,
+						irq_trig,
+						ak8974->name,
+						ak8974);
+		if (ret) {
+			dev_err(&i2c->dev, "unable to request DRDY IRQ "
+				"- proceeding without IRQ\n");
+			goto no_irq;
+		}
+		ak8974->drdy_irq = true;
+	}
+
+no_irq:
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(&i2c->dev, "device register failed\n");
+		goto cleanup_buffer;
+	}
+
+	return 0;
+
+cleanup_buffer:
+	iio_triggered_buffer_cleanup(indio_dev);
+disable_pm:
+	pm_runtime_put_noidle(&i2c->dev);
+	pm_runtime_disable(&i2c->dev);
+	ak8974_set_power(ak8974, AK8974_PWR_OFF);
+power_off:
+	regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
+
+	return ret;
+}
+
+static int __exit ak8974_remove(struct i2c_client *i2c)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
+	struct ak8974 *ak8974 = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	pm_runtime_get_sync(&i2c->dev);
+	pm_runtime_put_noidle(&i2c->dev);
+	pm_runtime_disable(&i2c->dev);
+	ak8974_set_power(ak8974, AK8974_PWR_OFF);
+	regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
+
+	return 0;
+}
+
+static int __maybe_unused ak8974_runtime_suspend(struct device *dev)
+{
+	struct ak8974 *ak8974 =
+		iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+	ak8974_set_power(ak8974, AK8974_PWR_OFF);
+	regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
+
+	return 0;
+}
+
+static int __maybe_unused ak8974_runtime_resume(struct device *dev)
+{
+	struct ak8974 *ak8974 =
+		iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+	int ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
+	if (ret)
+		return ret;
+	msleep(AK8974_POWERON_DELAY);
+	ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
+	if (ret)
+		goto out_regulator_disable;
+
+	ret = ak8974_configure(ak8974);
+	if (ret)
+		goto out_disable_power;
+
+	return 0;
+
+out_disable_power:
+	ak8974_set_power(ak8974, AK8974_PWR_OFF);
+out_regulator_disable:
+	regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
+
+	return ret;
+}
+
+static const struct dev_pm_ops ak8974_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(ak8974_runtime_suspend,
+			   ak8974_runtime_resume, NULL)
+};
+
+static const struct i2c_device_id ak8974_id[] = {
+	{"ami305", 0 },
+	{"ak8974", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, ak8974_id);
+
+static const struct of_device_id ak8974_of_match[] = {
+	{ .compatible = "asahi-kasei,ak8974", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, ak8974_of_match);
+
+static struct i2c_driver ak8974_driver = {
+	.driver	 = {
+		.name	= "ak8974",
+		.pm = &ak8974_dev_pm_ops,
+		.of_match_table = of_match_ptr(ak8974_of_match),
+	},
+	.probe	  = ak8974_probe,
+	.remove	  = __exit_p(ak8974_remove),
+	.id_table = ak8974_id,
+};
+module_i2c_driver(ak8974_driver);
+
+MODULE_DESCRIPTION("AK8974 and AMI305 3-axis magnetometer driver");
+MODULE_AUTHOR("Samu Onkalo");
+MODULE_AUTHOR("Linus Walleij");
+MODULE_LICENSE("GPL v2");