Re: [PATCH 2/2 v6] iio: magnetometer: Add driver for Yamaha YAS530

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 24 Dec 2020 13:08:20 +0100
Linus Walleij <linus.walleij@linaro.org> wrote:

> This adds an IIO magnetometer driver for the Yamaha
> YAS530 family of magnetometer/compass chips YAS530,
> YAS532 and YAS533.
> 
> A quick survey of the source code released by different
> vendors reveal that we have these variants in the family
> with some deployments listed:
> 
>  * YAS529 MS-3C (2005 Samsung Aries)
>  * YAS530 MS-3E (2011 Samsung Galaxy S Advance)
>  * YAS532 MS-3R (2011 Samsung Galaxy S4)
>  * YAS533 MS-3F (Vivo 1633, 1707, V3, Y21L)
>  * (YAS534 is a magnetic switch)
>  * YAS535 MS-6C
>  * YAS536 MS-3W
>  * YAS537 MS-3T (2015 Samsung Galaxy S6, Note 5)
>  * YAS539 MS-3S (2018 Samsung Galaxy A7 SM-A750FN)
> 
> The YAS529 is so significantly different from the
> YAS53x variants that it will require its own driver.
> The YAS537 and YAS539 have slightly different register
> sets but have strong similarities so a common driver
> patching this one will probably be reasonable.
> 
> The source code for Samsung Galaxy A7's YAS539 is not
> that is significantly different from the YAS530 in the
> Galaxy S Advance, so I believe we will only need this
> one driver with quirks to handle all of them.
> 
> The YAS539 is actively announced on Yamaha's devices
> site:
> https://device.yamaha.com/en/lsi/products/e_compass/
> 
> This is a driver written from scratch using buffered
> IIO and runtime PM handling regulators and reset.
> 
> Thanks to Andy Shevchenko for great help in finding all
> the special kernel infrastructure functions and quirks
> during review of this driver.
> 
> Cc: phone-devel@vger.kernel.org
> Cc: Jonathan Bakker <xc-racer2@live.ca>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Series applied to the togreg branch of iio.git and pushed out as testing
to let the autobuilders work their magic.

Thanks,

Jonathan

> ---
> ChangeLog v5->v6:
> - Fix some build robot warnings (one on errorpath one
>   instance of unreachable code).
> - Fix a double unlock bug in the measurement code.
> - Check all kerneldoc using the scripts/kernel-doc script.
> - Assert reset also on the errorpath of probe().
> - Add some comments on the PM runtime cleanup in remove().
> - Some cosmetics pushing some code segements into a
>   single line.
> - Collect Andy's Review tag.
> ChangeLog v4->v5:
> - Drop the NULL check for the reset GPIO line, as the
>   gpiolib will silently bail out on NULL descriptors
>   anyway.
> - Rename YAS5XX_AUTOSUSPEND_DELAY to
>   YAS5XX_AUTOSUSPEND_DELAY_MS to indicate it is in
>   milliseconds.
> - Use memchr_inv() to check if the calibration is
>   all zeroes.
> - Drop some commas, add some commas for style.
> - Replace the busy wait function with a simple call
>   to regmap_read_poll_timeout().
> - Clarify with a comment in the kerneldoc that the extra
>   mutex in the state is used to serialize multiple
>   regmap operations so these get atomic.
> - Instead of defining *DATA_CENTER as e.g. 2048
>   and *DATA_OVERFLOW as 4095 define *DATA_BITS as
>   e.g. 12 and use the BIT() macro to defins the center
>   and overflow in relation to the number of bits used.
> - Notate the offset ranges like this: [-31 .. 31]
> - Order the includes alphabetically.
> ChangeLog v3->v4:
> - Renamed the driver and everything related to
>   "yas530" taking the name of the first supported
>   part number.
> - Use FIELD_GET() to extract bits from longer words
>   where appropriate. This makes it necessary to tag
>   yas5xx_extract_bit() with __always_inline since
>   FIELD_GET() relies on being resolved at compiletime.
> - Use FIELD_PREP() to conjure the CCK setting.
> - Extract the calibration parameters using a u64 and
>   the linearization parameters using a u32 where we
>   chop out the bits we need.
> - Drop the now unused yas5xx_extract_bits() function,
>   as FIELD_GET() does a better job at what we want to
>   do.
> - Don't mention the YAS529 in the introductory description.
>   It will be handled by a separate driver.
> - Drop unused includes.
> - Drop the struct i2c_client * from the state container: we
>   only ever need the struct device *.
> - Use the define for YAS5XX_MEASURE_DATA_BUSY.
> - Fix the horrible mutex lock bug in yas5xx_measure()
> - Fix up various cosmetic style issues so they are hopefully
>   the way Jonathan likes them.
> - Drop development leftover dummy read of the device ID
>   register.
> - Drop the ,0 parameter to the i2c_device_id
> - Rename the IIO device just "yas530" or "yas532" in
>   lowercase. Keep the verbose prints in dmesg so we know
>   what device we found.
> - Drop surplus newline in the KConfig
> ChangeLog v1->v3:
> - This is posted along with the DT bindings which are
>   in v2 so just number everything as v2.
> ---
>  drivers/iio/magnetometer/Kconfig         |   15 +
>  drivers/iio/magnetometer/Makefile        |    2 +
>  drivers/iio/magnetometer/yamaha-yas530.c | 1049 ++++++++++++++++++++++
>  3 files changed, 1066 insertions(+)
>  create mode 100644 drivers/iio/magnetometer/yamaha-yas530.c
> 
> diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig
> index 1697a8c03506..5d4ffd66032e 100644
> --- a/drivers/iio/magnetometer/Kconfig
> +++ b/drivers/iio/magnetometer/Kconfig
> @@ -205,4 +205,19 @@ config SENSORS_RM3100_SPI
>  	  To compile this driver as a module, choose M here: the module
>  	  will be called rm3100-spi.
>  
> +config YAMAHA_YAS530
> +	tristate "Yamaha YAS530 family of 3-Axis Magnetometers (I2C)"
> +	depends on I2C
> +	select REGMAP_I2C
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	help
> +	  Say Y here to add support for the Yamaha YAS530 series of
> +	  3-Axis Magnetometers. Right now YAS530, YAS532 and YAS533 are
> +	  fully supported.
> +
> +	  This driver can also be compiled as a module.
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called yamaha-yas.
> +
>  endmenu
> diff --git a/drivers/iio/magnetometer/Makefile b/drivers/iio/magnetometer/Makefile
> index ba1bc34b82fa..b9f45b7fafc3 100644
> --- a/drivers/iio/magnetometer/Makefile
> +++ b/drivers/iio/magnetometer/Makefile
> @@ -28,3 +28,5 @@ obj-$(CONFIG_SENSORS_HMC5843_SPI)	+= hmc5843_spi.o
>  obj-$(CONFIG_SENSORS_RM3100)		+= rm3100-core.o
>  obj-$(CONFIG_SENSORS_RM3100_I2C)	+= rm3100-i2c.o
>  obj-$(CONFIG_SENSORS_RM3100_SPI)	+= rm3100-spi.o
> +
> +obj-$(CONFIG_YAMAHA_YAS530)		+= yamaha-yas530.o
> diff --git a/drivers/iio/magnetometer/yamaha-yas530.c b/drivers/iio/magnetometer/yamaha-yas530.c
> new file mode 100644
> index 000000000000..d46f23d82b3d
> --- /dev/null
> +++ b/drivers/iio/magnetometer/yamaha-yas530.c
> @@ -0,0 +1,1049 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Driver for the Yamaha YAS magnetic sensors, often used in Samsung
> + * mobile phones. While all are not yet handled because of lacking
> + * hardware, expand this driver to handle the different variants:
> + *
> + * YAS530 MS-3E (2011 Samsung Galaxy S Advance)
> + * YAS532 MS-3R (2011 Samsung Galaxy S4)
> + * YAS533 MS-3F (Vivo 1633, 1707, V3, Y21L)
> + * (YAS534 is a magnetic switch, not handled)
> + * YAS535 MS-6C
> + * YAS536 MS-3W
> + * YAS537 MS-3T (2015 Samsung Galaxy S6, Note 5, Xiaomi)
> + * YAS539 MS-3S (2018 Samsung Galaxy A7 SM-A750FN)
> + *
> + * Code functions found in the MPU3050 YAS530 and YAS532 drivers
> + * named "inv_compass" in the Tegra Android kernel tree.
> + * Copyright (C) 2012 InvenSense Corporation
> + *
> + * Author: Linus Walleij <linus.walleij@linaro.org>
> + */
> +#include <linux/bitfield.h>
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/mutex.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/random.h>
> +#include <linux/unaligned/be_byteshift.h>
> +
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +
> +/* This register map covers YAS530 and YAS532 but differs in YAS 537 and YAS539 */
> +#define YAS5XX_DEVICE_ID		0x80
> +#define YAS5XX_ACTUATE_INIT_COIL	0x81
> +#define YAS5XX_MEASURE			0x82
> +#define YAS5XX_CONFIG			0x83
> +#define YAS5XX_MEASURE_INTERVAL		0x84
> +#define YAS5XX_OFFSET_X			0x85 /* [-31 .. 31] */
> +#define YAS5XX_OFFSET_Y1		0x86 /* [-31 .. 31] */
> +#define YAS5XX_OFFSET_Y2		0x87 /* [-31 .. 31] */
> +#define YAS5XX_TEST1			0x88
> +#define YAS5XX_TEST2			0x89
> +#define YAS5XX_CAL			0x90
> +#define YAS5XX_MEASURE_DATA		0xB0
> +
> +/* Bits in the YAS5xx config register */
> +#define YAS5XX_CONFIG_INTON		BIT(0) /* Interrupt on? */
> +#define YAS5XX_CONFIG_INTHACT		BIT(1) /* Interrupt active high? */
> +#define YAS5XX_CONFIG_CCK_MASK		GENMASK(4, 2)
> +#define YAS5XX_CONFIG_CCK_SHIFT		2
> +
> +/* Bits in the measure command register */
> +#define YAS5XX_MEASURE_START		BIT(0)
> +#define YAS5XX_MEASURE_LDTC		BIT(1)
> +#define YAS5XX_MEASURE_FORS		BIT(2)
> +#define YAS5XX_MEASURE_DLYMES		BIT(4)
> +
> +/* Bits in the measure data register */
> +#define YAS5XX_MEASURE_DATA_BUSY	BIT(7)
> +
> +#define YAS530_DEVICE_ID		0x01 /* YAS530 (MS-3E) */
> +#define YAS530_VERSION_A		0 /* YAS530 (MS-3E A) */
> +#define YAS530_VERSION_B		1 /* YAS530B (MS-3E B) */
> +#define YAS530_VERSION_A_COEF		380
> +#define YAS530_VERSION_B_COEF		550
> +#define YAS530_DATA_BITS		12
> +#define YAS530_DATA_CENTER		BIT(YAS530_DATA_BITS - 1)
> +#define YAS530_DATA_OVERFLOW		(BIT(YAS530_DATA_BITS) - 1)
> +
> +#define YAS532_DEVICE_ID		0x02 /* YAS532/YAS533 (MS-3R/F) */
> +#define YAS532_VERSION_AB		0 /* YAS532/533 AB (MS-3R/F AB) */
> +#define YAS532_VERSION_AC		1 /* YAS532/533 AC (MS-3R/F AC) */
> +#define YAS532_VERSION_AB_COEF		1800
> +#define YAS532_VERSION_AC_COEF_X	850
> +#define YAS532_VERSION_AC_COEF_Y1	750
> +#define YAS532_VERSION_AC_COEF_Y2	750
> +#define YAS532_DATA_BITS		13
> +#define YAS532_DATA_CENTER		BIT(YAS532_DATA_BITS - 1)
> +#define YAS532_DATA_OVERFLOW		(BIT(YAS532_DATA_BITS) - 1)
> +#define YAS532_20DEGREES		390 /* Looks like Kelvin */
> +
> +/* These variant IDs are known from code dumps */
> +#define YAS537_DEVICE_ID		0x07 /* YAS537 (MS-3T) */
> +#define YAS539_DEVICE_ID		0x08 /* YAS539 (MS-3S) */
> +
> +/* Turn off device regulators etc after 5 seconds of inactivity */
> +#define YAS5XX_AUTOSUSPEND_DELAY_MS	5000
> +
> +struct yas5xx_calibration {
> +	/* Linearization calibration x, y1, y2 */
> +	s32 r[3];
> +	u32 f[3];
> +	/* Temperature compensation calibration */
> +	s32 Cx, Cy1, Cy2;
> +	/* Misc calibration coefficients */
> +	s32 a2, a3, a4, a5, a6, a7, a8, a9, k;
> +	/* clock divider */
> +	u8 dck;
> +};
> +
> +/**
> + * struct yas5xx - state container for the YAS5xx driver
> + * @dev: parent device pointer
> + * @devid: device ID number
> + * @version: device version
> + * @name: device name
> + * @calibration: calibration settings from the OTP storage
> + * @hard_offsets: offsets for each axis measured with initcoil actuated
> + * @orientation: mounting matrix, flipped axis etc
> + * @map: regmap to access the YAX5xx registers over I2C
> + * @regs: the vdd and vddio power regulators
> + * @reset: optional GPIO line used for handling RESET
> + * @lock: locks the magnetometer for exclusive use during a measurement (which
> + * involves several register transactions so the regmap lock is not enough)
> + * so that measurements get serialized in a first-come-first serve manner
> + * @scan: naturally aligned measurements
> + */
> +struct yas5xx {
> +	struct device *dev;
> +	unsigned int devid;
> +	unsigned int version;
> +	char name[16];
> +	struct yas5xx_calibration calibration;
> +	u8 hard_offsets[3];
> +	struct iio_mount_matrix orientation;
> +	struct regmap *map;
> +	struct regulator_bulk_data regs[2];
> +	struct gpio_desc *reset;
> +	struct mutex lock;
> +	/*
> +	 * The scanout is 4 x 32 bits in CPU endianness.
> +	 * Ensure timestamp is naturally aligned
> +	 */
> +	struct {
> +		s32 channels[4];
> +		s64 ts __aligned(8);
> +	} scan;
> +};
> +
> +/* On YAS530 the x, y1 and y2 values are 12 bits */
> +static u16 yas530_extract_axis(u8 *data)
> +{
> +	u16 val;
> +
> +	/*
> +	 * These are the bits used in a 16bit word:
> +	 * 15 14 13 12 11 10 9  8  7  6  5  4  3  2  1  0
> +	 *    x  x  x  x  x  x  x  x  x  x  x  x
> +	 */
> +	val = get_unaligned_be16(&data[0]);
> +	val = FIELD_GET(GENMASK(14, 3), val);
> +	return val;
> +}
> +
> +/* On YAS532 the x, y1 and y2 values are 13 bits */
> +static u16 yas532_extract_axis(u8 *data)
> +{
> +	u16 val;
> +
> +	/*
> +	 * These are the bits used in a 16bit word:
> +	 * 15 14 13 12 11 10 9  8  7  6  5  4  3  2  1  0
> +	 *    x  x  x  x  x  x  x  x  x  x  x  x  x
> +	 */
> +	val = get_unaligned_be16(&data[0]);
> +	val = FIELD_GET(GENMASK(14, 2), val);
> +	return val;
> +}
> +
> +/**
> + * yas5xx_measure() - Make a measure from the hardware
> + * @yas5xx: The device state
> + * @t: the raw temperature measurement
> + * @x: the raw x axis measurement
> + * @y1: the y1 axis measurement
> + * @y2: the y2 axis measurement
> + * @return: 0 on success or error code
> + */
> +static int yas5xx_measure(struct yas5xx *yas5xx, u16 *t, u16 *x, u16 *y1, u16 *y2)
> +{
> +	unsigned int busy;
> +	u8 data[8];
> +	int ret;
> +	u16 val;
> +
> +	mutex_lock(&yas5xx->lock);
> +	ret = regmap_write(yas5xx->map, YAS5XX_MEASURE, YAS5XX_MEASURE_START);
> +	if (ret < 0)
> +		goto out_unlock;
> +
> +	/*
> +	 * Typical time to measure 1500 us, max 2000 us so wait min 500 us
> +	 * and at most 20000 us (one magnitude more than the datsheet max)
> +	 * before timeout.
> +	 */
> +	ret = regmap_read_poll_timeout(yas5xx->map, YAS5XX_MEASURE_DATA, busy,
> +				       !(busy & YAS5XX_MEASURE_DATA_BUSY),
> +				       500, 20000);
> +	if (ret) {
> +		dev_err(yas5xx->dev, "timeout waiting for measurement\n");
> +		goto out_unlock;
> +	}
> +
> +	ret = regmap_bulk_read(yas5xx->map, YAS5XX_MEASURE_DATA,
> +			       data, sizeof(data));
> +	if (ret)
> +		goto out_unlock;
> +
> +	mutex_unlock(&yas5xx->lock);
> +
> +	switch (yas5xx->devid) {
> +	case YAS530_DEVICE_ID:
> +		/*
> +		 * The t value is 9 bits in big endian format
> +		 * These are the bits used in a 16bit word:
> +		 * 15 14 13 12 11 10 9  8  7  6  5  4  3  2  1  0
> +		 *    x  x  x  x  x  x  x  x  x
> +		 */
> +		val = get_unaligned_be16(&data[0]);
> +		val = FIELD_GET(GENMASK(14, 6), val);
> +		*t = val;
> +		*x = yas530_extract_axis(&data[2]);
> +		*y1 = yas530_extract_axis(&data[4]);
> +		*y2 = yas530_extract_axis(&data[6]);
> +		break;
> +	case YAS532_DEVICE_ID:
> +		/*
> +		 * The t value is 10 bits in big endian format
> +		 * These are the bits used in a 16bit word:
> +		 * 15 14 13 12 11 10 9  8  7  6  5  4  3  2  1  0
> +		 *    x  x  x  x  x  x  x  x  x  x
> +		 */
> +		val = get_unaligned_be16(&data[0]);
> +		val = FIELD_GET(GENMASK(14, 5), val);
> +		*t = val;
> +		*x = yas532_extract_axis(&data[2]);
> +		*y1 = yas532_extract_axis(&data[4]);
> +		*y2 = yas532_extract_axis(&data[6]);
> +		break;
> +	default:
> +		dev_err(yas5xx->dev, "unknown data format\n");
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	return ret;
> +
> +out_unlock:
> +	mutex_unlock(&yas5xx->lock);
> +	return ret;
> +}
> +
> +static s32 yas5xx_linearize(struct yas5xx *yas5xx, u16 val, int axis)
> +{
> +	struct yas5xx_calibration *c = &yas5xx->calibration;
> +	static const s32 yas532ac_coef[] = {
> +		YAS532_VERSION_AC_COEF_X,
> +		YAS532_VERSION_AC_COEF_Y1,
> +		YAS532_VERSION_AC_COEF_Y2,
> +	};
> +	s32 coef;
> +
> +	/* Select coefficients */
> +	switch (yas5xx->devid) {
> +	case YAS530_DEVICE_ID:
> +		if (yas5xx->version == YAS530_VERSION_A)
> +			coef = YAS530_VERSION_A_COEF;
> +		else
> +			coef = YAS530_VERSION_B_COEF;
> +		break;
> +	case YAS532_DEVICE_ID:
> +		if (yas5xx->version == YAS532_VERSION_AB)
> +			coef = YAS532_VERSION_AB_COEF;
> +		else
> +			/* Elaborate coefficients */
> +			coef = yas532ac_coef[axis];
> +		break;
> +	default:
> +		dev_err(yas5xx->dev, "unknown device type\n");
> +		return val;
> +	}
> +	/*
> +	 * Linearization formula:
> +	 *
> +	 * x' = x - (3721 + 50 * f) + (xoffset - r) * c
> +	 *
> +	 * Where f and r are calibration values, c is a per-device
> +	 * and sometimes per-axis coefficient.
> +	 */
> +	return val - (3721 + 50 * c->f[axis]) +
> +		(yas5xx->hard_offsets[axis] - c->r[axis]) * coef;
> +}
> +
> +/**
> + * yas5xx_get_measure() - Measure a sample of all axis and process
> + * @yas5xx: The device state
> + * @to: Temperature out
> + * @xo: X axis out
> + * @yo: Y axis out
> + * @zo: Z axis out
> + * @return: 0 on success or error code
> + *
> + * Returned values are in nanotesla according to some code.
> + */
> +static int yas5xx_get_measure(struct yas5xx *yas5xx, s32 *to, s32 *xo, s32 *yo, s32 *zo)
> +{
> +	struct yas5xx_calibration *c = &yas5xx->calibration;
> +	u16 t, x, y1, y2;
> +	/* These are "signed x, signed y1 etc */
> +	s32 sx, sy1, sy2, sy, sz;
> +	int ret;
> +
> +	/* We first get raw data that needs to be translated to [x,y,z] */
> +	ret = yas5xx_measure(yas5xx, &t, &x, &y1, &y2);
> +	if (ret)
> +		return ret;
> +
> +	/* Do some linearization if available */
> +	sx = yas5xx_linearize(yas5xx, x, 0);
> +	sy1 = yas5xx_linearize(yas5xx, y1, 1);
> +	sy2 = yas5xx_linearize(yas5xx, y2, 2);
> +
> +	/*
> +	 * Temperature compensation for x, y1, y2 respectively:
> +	 *
> +	 *          Cx * t
> +	 * x' = x - ------
> +	 *           100
> +	 */
> +	sx = sx - (c->Cx * t) / 100;
> +	sy1 = sy1 - (c->Cy1 * t) / 100;
> +	sy2 = sy2 - (c->Cy2 * t) / 100;
> +
> +	/*
> +	 * Break y1 and y2 into y and z, y1 and y2 are apparently encoding
> +	 * y and z.
> +	 */
> +	sy = sy1 - sy2;
> +	sz = -sy1 - sy2;
> +
> +	/*
> +	 * FIXME: convert to Celsius? Just guessing this is given
> +	 * as 1/10:s of degrees so multiply by 100 to get millicentigrades.
> +	 */
> +	*to = t * 100;
> +	/*
> +	 * Calibrate [x,y,z] with some formulas like this:
> +	 *
> +	 *            100 * x + a_2 * y + a_3 * z
> +	 *  x' = k *  ---------------------------
> +	 *                        10
> +	 *
> +	 *           a_4 * x + a_5 * y + a_6 * z
> +	 *  y' = k * ---------------------------
> +	 *                        10
> +	 *
> +	 *           a_7 * x + a_8 * y + a_9 * z
> +	 *  z' = k * ---------------------------
> +	 *                        10
> +	 */
> +	*xo = c->k * ((100 * sx + c->a2 * sy + c->a3 * sz) / 10);
> +	*yo = c->k * ((c->a4 * sx + c->a5 * sy + c->a6 * sz) / 10);
> +	*zo = c->k * ((c->a7 * sx + c->a8 * sy + c->a9 * sz) / 10);
> +
> +	return 0;
> +}
> +
> +static int yas5xx_read_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan,
> +			   int *val, int *val2,
> +			   long mask)
> +{
> +	struct yas5xx *yas5xx = iio_priv(indio_dev);
> +	s32 t, x, y, z;
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		pm_runtime_get_sync(yas5xx->dev);
> +		ret = yas5xx_get_measure(yas5xx, &t, &x, &y, &z);
> +		pm_runtime_mark_last_busy(yas5xx->dev);
> +		pm_runtime_put_autosuspend(yas5xx->dev);
> +		if (ret)
> +			return ret;
> +		switch (chan->address) {
> +		case 0:
> +			*val = t;
> +			break;
> +		case 1:
> +			*val = x;
> +			break;
> +		case 2:
> +			*val = y;
> +			break;
> +		case 3:
> +			*val = z;
> +			break;
> +		default:
> +			dev_err(yas5xx->dev, "unknown channel\n");
> +			return -EINVAL;
> +		}
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		if (chan->address == 0) {
> +			/* Temperature is unscaled */
> +			*val = 1;
> +			return IIO_VAL_INT;
> +		}
> +		/*
> +		 * The axis values are in nanotesla according to the vendor
> +		 * drivers, but is clearly in microtesla according to
> +		 * experiments. Since 1 uT = 0.01 Gauss, we need to divide
> +		 * by 100000000 (10^8) to get to Gauss from the raw value.
> +		 */
> +		*val = 1;
> +		*val2 = 100000000;
> +		return IIO_VAL_FRACTIONAL;
> +	default:
> +		/* Unknown request */
> +		return -EINVAL;
> +	}
> +}
> +
> +static void yas5xx_fill_buffer(struct iio_dev *indio_dev)
> +{
> +	struct yas5xx *yas5xx = iio_priv(indio_dev);
> +	s32 t, x, y, z;
> +	int ret;
> +
> +	pm_runtime_get_sync(yas5xx->dev);
> +	ret = yas5xx_get_measure(yas5xx, &t, &x, &y, &z);
> +	pm_runtime_mark_last_busy(yas5xx->dev);
> +	pm_runtime_put_autosuspend(yas5xx->dev);
> +	if (ret) {
> +		dev_err(yas5xx->dev, "error refilling buffer\n");
> +		return;
> +	}
> +	yas5xx->scan.channels[0] = t;
> +	yas5xx->scan.channels[1] = x;
> +	yas5xx->scan.channels[2] = y;
> +	yas5xx->scan.channels[3] = z;
> +	iio_push_to_buffers_with_timestamp(indio_dev, &yas5xx->scan,
> +					   iio_get_time_ns(indio_dev));
> +}
> +
> +static irqreturn_t yas5xx_handle_trigger(int irq, void *p)
> +{
> +	const struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +
> +	yas5xx_fill_buffer(indio_dev);
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +
> +static const struct iio_mount_matrix *
> +yas5xx_get_mount_matrix(const struct iio_dev *indio_dev,
> +			const struct iio_chan_spec *chan)
> +{
> +	struct yas5xx *yas5xx = iio_priv(indio_dev);
> +
> +	return &yas5xx->orientation;
> +}
> +
> +static const struct iio_chan_spec_ext_info yas5xx_ext_info[] = {
> +	IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, yas5xx_get_mount_matrix),
> +	{ }
> +};
> +
> +#define YAS5XX_AXIS_CHANNEL(axis, index)				\
> +	{								\
> +		.type = IIO_MAGN,					\
> +		.modified = 1,						\
> +		.channel2 = IIO_MOD_##axis,				\
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
> +			BIT(IIO_CHAN_INFO_SCALE),			\
> +		.ext_info = yas5xx_ext_info,				\
> +		.address = index,					\
> +		.scan_index = index,					\
> +		.scan_type = {						\
> +			.sign = 's',					\
> +			.realbits = 32,					\
> +			.storagebits = 32,				\
> +			.endianness = IIO_CPU,				\
> +		},							\
> +	}
> +
> +static const struct iio_chan_spec yas5xx_channels[] = {
> +	{
> +		.type = IIO_TEMP,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> +		.address = 0,
> +		.scan_index = 0,
> +		.scan_type = {
> +			.sign = 'u',
> +			.realbits = 32,
> +			.storagebits = 32,
> +			.endianness = IIO_CPU,
> +		},
> +	},
> +	YAS5XX_AXIS_CHANNEL(X, 1),
> +	YAS5XX_AXIS_CHANNEL(Y, 2),
> +	YAS5XX_AXIS_CHANNEL(Z, 3),
> +	IIO_CHAN_SOFT_TIMESTAMP(4),
> +};
> +
> +static const unsigned long yas5xx_scan_masks[] = { GENMASK(3, 0), 0 };
> +
> +static const struct iio_info yas5xx_info = {
> +	.read_raw = &yas5xx_read_raw,
> +};
> +
> +static bool yas5xx_volatile_reg(struct device *dev, unsigned int reg)
> +{
> +	return reg == YAS5XX_ACTUATE_INIT_COIL ||
> +		reg == YAS5XX_MEASURE ||
> +		(reg >= YAS5XX_MEASURE_DATA && reg <= YAS5XX_MEASURE_DATA + 8);
> +}
> +
> +/* TODO: enable regmap cache, using mark dirty and sync at runtime resume */
> +static const struct regmap_config yas5xx_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0xff,
> +	.volatile_reg = yas5xx_volatile_reg,
> +};
> +
> +/**
> + * yas53x_extract_calibration() - extracts the a2-a9 and k calibration
> + * @data: the bitfield to use
> + * @c: the calibration to populate
> + */
> +static void yas53x_extract_calibration(u8 *data, struct yas5xx_calibration *c)
> +{
> +	u64 val = get_unaligned_be64(data);
> +
> +	/*
> +	 * Bitfield layout for the axis calibration data, for factor
> +	 * a2 = 2 etc, k = k, c = clock divider
> +	 *
> +	 * n   7 6 5 4 3 2 1 0
> +	 * 0 [ 2 2 2 2 2 2 3 3 ] bits 63 .. 56
> +	 * 1 [ 3 3 4 4 4 4 4 4 ] bits 55 .. 48
> +	 * 2 [ 5 5 5 5 5 5 6 6 ] bits 47 .. 40
> +	 * 3 [ 6 6 6 6 7 7 7 7 ] bits 39 .. 32
> +	 * 4 [ 7 7 7 8 8 8 8 8 ] bits 31 .. 24
> +	 * 5 [ 8 9 9 9 9 9 9 9 ] bits 23 .. 16
> +	 * 6 [ 9 k k k k k c c ] bits 15 .. 8
> +	 * 7 [ c x x x x x x x ] bits  7 .. 0
> +	 */
> +	c->a2 = FIELD_GET(GENMASK_ULL(63, 58), val) - 32;
> +	c->a3 = FIELD_GET(GENMASK_ULL(57, 54), val) - 8;
> +	c->a4 = FIELD_GET(GENMASK_ULL(53, 48), val) - 32;
> +	c->a5 = FIELD_GET(GENMASK_ULL(47, 42), val) + 38;
> +	c->a6 = FIELD_GET(GENMASK_ULL(41, 36), val) - 32;
> +	c->a7 = FIELD_GET(GENMASK_ULL(35, 29), val) - 64;
> +	c->a8 = FIELD_GET(GENMASK_ULL(28, 23), val) - 32;
> +	c->a9 = FIELD_GET(GENMASK_ULL(22, 15), val);
> +	c->k = FIELD_GET(GENMASK_ULL(14, 10), val) + 10;
> +	c->dck = FIELD_GET(GENMASK_ULL(9, 7), val);
> +}
> +
> +static int yas530_get_calibration_data(struct yas5xx *yas5xx)
> +{
> +	struct yas5xx_calibration *c = &yas5xx->calibration;
> +	u8 data[16];
> +	u32 val;
> +	int ret;
> +
> +	/* Dummy read, first read is ALWAYS wrong */
> +	ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data));
> +	if (ret)
> +		return ret;
> +
> +	/* Actual calibration readout */
> +	ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data));
> +	if (ret)
> +		return ret;
> +	dev_dbg(yas5xx->dev, "calibration data: %*ph\n", 14, data);
> +
> +	add_device_randomness(data, sizeof(data));
> +	yas5xx->version = data[15] & GENMASK(1, 0);
> +
> +	/* Extract the calibration from the bitfield */
> +	c->Cx = data[0] * 6 - 768;
> +	c->Cy1 = data[1] * 6 - 768;
> +	c->Cy2 = data[2] * 6 - 768;
> +	yas53x_extract_calibration(&data[3], c);
> +
> +	/*
> +	 * Extract linearization:
> +	 * Linearization layout in the 32 bits at byte 11:
> +	 * The r factors are 6 bit values where bit 5 is the sign
> +	 *
> +	 * n    7  6  5  4  3  2  1  0
> +	 * 0 [ xx xx xx r0 r0 r0 r0 r0 ] bits 31 .. 24
> +	 * 1 [ r0 f0 f0 r1 r1 r1 r1 r1 ] bits 23 .. 16
> +	 * 2 [ r1 f1 f1 r2 r2 r2 r2 r2 ] bits 15 .. 8
> +	 * 3 [ r2 f2 f2 xx xx xx xx xx ] bits  7 .. 0
> +	 */
> +	val = get_unaligned_be32(&data[11]);
> +	c->f[0] = FIELD_GET(GENMASK(22, 21), val);
> +	c->f[1] = FIELD_GET(GENMASK(14, 13), val);
> +	c->f[2] = FIELD_GET(GENMASK(6, 5), val);
> +	c->r[0] = sign_extend32(FIELD_GET(GENMASK(28, 23), val), 5);
> +	c->r[1] = sign_extend32(FIELD_GET(GENMASK(20, 15), val), 5);
> +	c->r[2] = sign_extend32(FIELD_GET(GENMASK(12, 7), val), 5);
> +	return 0;
> +}
> +
> +static int yas532_get_calibration_data(struct yas5xx *yas5xx)
> +{
> +	struct yas5xx_calibration *c = &yas5xx->calibration;
> +	u8 data[14];
> +	u32 val;
> +	int ret;
> +
> +	/* Dummy read, first read is ALWAYS wrong */
> +	ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data));
> +	if (ret)
> +		return ret;
> +	/* Actual calibration readout */
> +	ret = regmap_bulk_read(yas5xx->map, YAS5XX_CAL, data, sizeof(data));
> +	if (ret)
> +		return ret;
> +	dev_dbg(yas5xx->dev, "calibration data: %*ph\n", 14, data);
> +
> +	/* Sanity check, is this all zeroes? */
> +	if (memchr_inv(data, 0x00, 13)) {
> +		if (!(data[13] & BIT(7)))
> +			dev_warn(yas5xx->dev, "calibration is blank!\n");
> +	}
> +
> +	add_device_randomness(data, sizeof(data));
> +	/* Only one bit of version info reserved here as far as we know */
> +	yas5xx->version = data[13] & BIT(0);
> +
> +	/* Extract calibration from the bitfield */
> +	c->Cx = data[0] * 10 - 1280;
> +	c->Cy1 = data[1] * 10 - 1280;
> +	c->Cy2 = data[2] * 10 - 1280;
> +	yas53x_extract_calibration(&data[3], c);
> +	/*
> +	 * Extract linearization:
> +	 * Linearization layout in the 32 bits at byte 10:
> +	 * The r factors are 6 bit values where bit 5 is the sign
> +	 *
> +	 * n    7  6  5  4  3  2  1  0
> +	 * 0 [ xx r0 r0 r0 r0 r0 r0 f0 ] bits 31 .. 24
> +	 * 1 [ f0 r1 r1 r1 r1 r1 r1 f1 ] bits 23 .. 16
> +	 * 2 [ f1 r2 r2 r2 r2 r2 r2 f2 ] bits 15 .. 8
> +	 * 3 [ f2 xx xx xx xx xx xx xx ] bits  7 .. 0
> +	 */
> +	val = get_unaligned_be32(&data[10]);
> +	c->f[0] = FIELD_GET(GENMASK(24, 23), val);
> +	c->f[1] = FIELD_GET(GENMASK(16, 15), val);
> +	c->f[2] = FIELD_GET(GENMASK(8, 7), val);
> +	c->r[0] = sign_extend32(FIELD_GET(GENMASK(30, 25), val), 5);
> +	c->r[1] = sign_extend32(FIELD_GET(GENMASK(22, 17), val), 5);
> +	c->r[2] = sign_extend32(FIELD_GET(GENMASK(14, 7), val), 5);
> +
> +	return 0;
> +}
> +
> +static void yas5xx_dump_calibration(struct yas5xx *yas5xx)
> +{
> +	struct yas5xx_calibration *c = &yas5xx->calibration;
> +
> +	dev_dbg(yas5xx->dev, "f[] = [%d, %d, %d]\n",
> +		c->f[0], c->f[1], c->f[2]);
> +	dev_dbg(yas5xx->dev, "r[] = [%d, %d, %d]\n",
> +		c->r[0], c->r[1], c->r[2]);
> +	dev_dbg(yas5xx->dev, "Cx = %d\n", c->Cx);
> +	dev_dbg(yas5xx->dev, "Cy1 = %d\n", c->Cy1);
> +	dev_dbg(yas5xx->dev, "Cy2 = %d\n", c->Cy2);
> +	dev_dbg(yas5xx->dev, "a2 = %d\n", c->a2);
> +	dev_dbg(yas5xx->dev, "a3 = %d\n", c->a3);
> +	dev_dbg(yas5xx->dev, "a4 = %d\n", c->a4);
> +	dev_dbg(yas5xx->dev, "a5 = %d\n", c->a5);
> +	dev_dbg(yas5xx->dev, "a6 = %d\n", c->a6);
> +	dev_dbg(yas5xx->dev, "a7 = %d\n", c->a7);
> +	dev_dbg(yas5xx->dev, "a8 = %d\n", c->a8);
> +	dev_dbg(yas5xx->dev, "a9 = %d\n", c->a9);
> +	dev_dbg(yas5xx->dev, "k = %d\n", c->k);
> +	dev_dbg(yas5xx->dev, "dck = %d\n", c->dck);
> +}
> +
> +static int yas5xx_set_offsets(struct yas5xx *yas5xx, s8 ox, s8 oy1, s8 oy2)
> +{
> +	int ret;
> +
> +	ret = regmap_write(yas5xx->map, YAS5XX_OFFSET_X, ox);
> +	if (ret)
> +		return ret;
> +	ret = regmap_write(yas5xx->map, YAS5XX_OFFSET_Y1, oy1);
> +	if (ret)
> +		return ret;
> +	return regmap_write(yas5xx->map, YAS5XX_OFFSET_Y2, oy2);
> +}
> +
> +static s8 yas5xx_adjust_offset(s8 old, int bit, u16 center, u16 measure)
> +{
> +	if (measure > center)
> +		return old + BIT(bit);
> +	if (measure < center)
> +		return old - BIT(bit);
> +	return old;
> +}
> +
> +static int yas5xx_meaure_offsets(struct yas5xx *yas5xx)
> +{
> +	int ret;
> +	u16 center;
> +	u16 t, x, y1, y2;
> +	s8 ox, oy1, oy2;
> +	int i;
> +
> +	/* Actuate the init coil and measure offsets */
> +	ret = regmap_write(yas5xx->map, YAS5XX_ACTUATE_INIT_COIL, 0);
> +	if (ret)
> +		return ret;
> +
> +	/* When the initcoil is active this should be around the center */
> +	switch (yas5xx->devid) {
> +	case YAS530_DEVICE_ID:
> +		center = YAS530_DATA_CENTER;
> +		break;
> +	case YAS532_DEVICE_ID:
> +		center = YAS532_DATA_CENTER;
> +		break;
> +	default:
> +		dev_err(yas5xx->dev, "unknown device type\n");
> +		return -EINVAL;
> +	}
> +
> +	/*
> +	 * We set offsets in the interval +-31 by iterating
> +	 * +-16, +-8, +-4, +-2, +-1 adjusting the offsets each
> +	 * time, then writing the final offsets into the
> +	 * registers.
> +	 *
> +	 * NOTE: these offsets are NOT in the same unit or magnitude
> +	 * as the values for [x, y1, y2]. The value is +/-31
> +	 * but the effect on the raw values is much larger.
> +	 * The effect of the offset is to bring the measure
> +	 * rougly to the center.
> +	 */
> +	ox = 0;
> +	oy1 = 0;
> +	oy2 = 0;
> +
> +	for (i = 4; i >= 0; i--) {
> +		ret = yas5xx_set_offsets(yas5xx, ox, oy1, oy2);
> +		if (ret)
> +			return ret;
> +
> +		ret = yas5xx_measure(yas5xx, &t, &x, &y1, &y2);
> +		if (ret)
> +			return ret;
> +		dev_dbg(yas5xx->dev, "measurement %d: x=%d, y1=%d, y2=%d\n",
> +			5-i, x, y1, y2);
> +
> +		ox = yas5xx_adjust_offset(ox, i, center, x);
> +		oy1 = yas5xx_adjust_offset(oy1, i, center, y1);
> +		oy2 = yas5xx_adjust_offset(oy2, i, center, y2);
> +	}
> +
> +	/* Needed for calibration algorithm */
> +	yas5xx->hard_offsets[0] = ox;
> +	yas5xx->hard_offsets[1] = oy1;
> +	yas5xx->hard_offsets[2] = oy2;
> +	ret = yas5xx_set_offsets(yas5xx, ox, oy1, oy2);
> +	if (ret)
> +		return ret;
> +
> +	dev_info(yas5xx->dev, "discovered hard offsets: x=%d, y1=%d, y2=%d\n",
> +		 ox, oy1, oy2);
> +	return 0;
> +}
> +
> +static int yas5xx_power_on(struct yas5xx *yas5xx)
> +{
> +	unsigned int val;
> +	int ret;
> +
> +	/* Zero the test registers */
> +	ret = regmap_write(yas5xx->map, YAS5XX_TEST1, 0);
> +	if (ret)
> +		return ret;
> +	ret = regmap_write(yas5xx->map, YAS5XX_TEST2, 0);
> +	if (ret)
> +		return ret;
> +
> +	/* Set up for no interrupts, calibrated clock divider */
> +	val = FIELD_PREP(YAS5XX_CONFIG_CCK_MASK, yas5xx->calibration.dck);
> +	ret = regmap_write(yas5xx->map, YAS5XX_CONFIG, val);
> +	if (ret)
> +		return ret;
> +
> +	/* Measure interval 0 (back-to-back?)  */
> +	return regmap_write(yas5xx->map, YAS5XX_MEASURE_INTERVAL, 0);
> +}
> +
> +static int yas5xx_probe(struct i2c_client *i2c,
> +			const struct i2c_device_id *id)
> +{
> +	struct iio_dev *indio_dev;
> +	struct device *dev = &i2c->dev;
> +	struct yas5xx *yas5xx;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*yas5xx));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	yas5xx = iio_priv(indio_dev);
> +	i2c_set_clientdata(i2c, indio_dev);
> +	yas5xx->dev = dev;
> +	mutex_init(&yas5xx->lock);
> +
> +	ret = iio_read_mount_matrix(dev, "mount-matrix", &yas5xx->orientation);
> +	if (ret)
> +		return ret;
> +
> +	yas5xx->regs[0].supply = "vdd";
> +	yas5xx->regs[1].supply = "iovdd";
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(yas5xx->regs),
> +				      yas5xx->regs);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "cannot get regulators\n");
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs);
> +	if (ret) {
> +		dev_err(dev, "cannot enable regulators\n");
> +		return ret;
> +	}
> +
> +	/* See comment in runtime resume callback */
> +	usleep_range(31000, 40000);
> +
> +	/* This will take the device out of reset if need be */
> +	yas5xx->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(yas5xx->reset)) {
> +		ret = dev_err_probe(dev, PTR_ERR(yas5xx->reset),
> +				    "failed to get reset line\n");
> +		goto reg_off;
> +	}
> +
> +	yas5xx->map = devm_regmap_init_i2c(i2c, &yas5xx_regmap_config);
> +	if (IS_ERR(yas5xx->map)) {
> +		dev_err(dev, "failed to allocate register map\n");
> +		ret = PTR_ERR(yas5xx->map);
> +		goto assert_reset;
> +	}
> +
> +	ret = regmap_read(yas5xx->map, YAS5XX_DEVICE_ID, &yas5xx->devid);
> +	if (ret)
> +		goto assert_reset;
> +
> +	switch (yas5xx->devid) {
> +	case YAS530_DEVICE_ID:
> +		ret = yas530_get_calibration_data(yas5xx);
> +		if (ret)
> +			goto assert_reset;
> +		dev_info(dev, "detected YAS530 MS-3E %s",
> +			 yas5xx->version ? "B" : "A");
> +		strncpy(yas5xx->name, "yas530", sizeof(yas5xx->name));
> +		break;
> +	case YAS532_DEVICE_ID:
> +		ret = yas532_get_calibration_data(yas5xx);
> +		if (ret)
> +			goto assert_reset;
> +		dev_info(dev, "detected YAS532/YAS533 MS-3R/F %s",
> +			 yas5xx->version ? "AC" : "AB");
> +		strncpy(yas5xx->name, "yas532", sizeof(yas5xx->name));
> +		break;
> +	default:
> +		dev_err(dev, "unhandled device ID %02x\n", yas5xx->devid);
> +		goto assert_reset;
> +	}
> +
> +	yas5xx_dump_calibration(yas5xx);
> +	ret = yas5xx_power_on(yas5xx);
> +	if (ret)
> +		goto assert_reset;
> +	ret = yas5xx_meaure_offsets(yas5xx);
> +	if (ret)
> +		goto assert_reset;
> +
> +	indio_dev->info = &yas5xx_info;
> +	indio_dev->available_scan_masks = yas5xx_scan_masks;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->name = yas5xx->name;
> +	indio_dev->channels = yas5xx_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(yas5xx_channels);
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +					 yas5xx_handle_trigger,
> +					 NULL);
> +	if (ret) {
> +		dev_err(dev, "triggered buffer setup failed\n");
> +		goto assert_reset;
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret) {
> +		dev_err(dev, "device register failed\n");
> +		goto cleanup_buffer;
> +	}
> +
> +	/* Take runtime PM online */
> +	pm_runtime_get_noresume(dev);
> +	pm_runtime_set_active(dev);
> +	pm_runtime_enable(dev);
> +
> +	pm_runtime_set_autosuspend_delay(dev, YAS5XX_AUTOSUSPEND_DELAY_MS);
> +	pm_runtime_use_autosuspend(dev);
> +	pm_runtime_put(dev);
> +
> +	return 0;
> +
> +cleanup_buffer:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +assert_reset:
> +	gpiod_set_value_cansleep(yas5xx->reset, 1);
> +reg_off:
> +	regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs);
> +
> +	return ret;
> +}
> +
> +static int yas5xx_remove(struct i2c_client *i2c)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
> +	struct yas5xx *yas5xx = iio_priv(indio_dev);
> +	struct device *dev = &i2c->dev;
> +
> +	iio_device_unregister(indio_dev);
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	/*
> +	 * Now we can't get any more reads from the device, which would
> +	 * also call pm_runtime* functions and race with our disable
> +	 * code. Disable PM runtime in orderly fashion and power down.
> +	 */
> +	pm_runtime_get_sync(dev);
> +	pm_runtime_put_noidle(dev);
> +	pm_runtime_disable(dev);
> +	gpiod_set_value_cansleep(yas5xx->reset, 1);
> +	regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused yas5xx_runtime_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct yas5xx *yas5xx = iio_priv(indio_dev);
> +
> +	gpiod_set_value_cansleep(yas5xx->reset, 1);
> +	regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused yas5xx_runtime_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> +	struct yas5xx *yas5xx = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs);
> +	if (ret) {
> +		dev_err(dev, "cannot enable regulators\n");
> +		return ret;
> +	}
> +
> +	/*
> +	 * The YAS530 datasheet says TVSKW is up to 30 ms, after that 1 ms
> +	 * for all voltages to settle. The YAS532 is 10ms then 4ms for the
> +	 * I2C to come online. Let's keep it safe and put this at 31ms.
> +	 */
> +	usleep_range(31000, 40000);
> +	gpiod_set_value_cansleep(yas5xx->reset, 0);
> +
> +	ret = yas5xx_power_on(yas5xx);
> +	if (ret) {
> +		dev_err(dev, "cannot power on\n");
> +		goto out_reset;
> +	}
> +
> +	return 0;
> +
> +out_reset:
> +	gpiod_set_value_cansleep(yas5xx->reset, 1);
> +	regulator_bulk_disable(ARRAY_SIZE(yas5xx->regs), yas5xx->regs);
> +
> +	return ret;
> +}
> +
> +static const struct dev_pm_ops yas5xx_dev_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
> +				pm_runtime_force_resume)
> +	SET_RUNTIME_PM_OPS(yas5xx_runtime_suspend,
> +			   yas5xx_runtime_resume, NULL)
> +};
> +
> +static const struct i2c_device_id yas5xx_id[] = {
> +	{"yas530", },
> +	{"yas532", },
> +	{"yas533", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, yas5xx_id);
> +
> +static const struct of_device_id yas5xx_of_match[] = {
> +	{ .compatible = "yamaha,yas530", },
> +	{ .compatible = "yamaha,yas532", },
> +	{ .compatible = "yamaha,yas533", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, yas5xx_of_match);
> +
> +static struct i2c_driver yas5xx_driver = {
> +	.driver	 = {
> +		.name	= "yas5xx",
> +		.of_match_table = yas5xx_of_match,
> +		.pm = &yas5xx_dev_pm_ops,
> +	},
> +	.probe	  = yas5xx_probe,
> +	.remove	  = yas5xx_remove,
> +	.id_table = yas5xx_id,
> +};
> +module_i2c_driver(yas5xx_driver);
> +
> +MODULE_DESCRIPTION("Yamaha YAS53x 3-axis magnetometer driver");
> +MODULE_AUTHOR("Linus Walleij");
> +MODULE_LICENSE("GPL v2");