diff mbox series

[v5,6/7] iio: add MEMSensing MSA311 3-axis accelerometer driver

Message ID 20220812165243.22177-7-ddrokosov@sberdevices.ru
State Superseded
Headers show
Series iio: accel: add MSA311 accelerometer driver | expand

Commit Message

Dmitry Rokosov Aug. 12, 2022, 4:52 p.m. UTC
MSA311 is a tri-axial, low-g accelerometer with I2C digital output for
sensitivity consumer applications. It has dynamic user-selectable full
scales range of +-2g/+-4g/+-8g/+-16g and allows acceleration measurements
with output data rates from 1Hz to 1000Hz.

Spec: https://cdn-shop.adafruit.com/product-files/5309/MSA311-V1.1-ENG.pdf

This driver supports following MSA311 features:
    - IIO interface
    - Different power modes: NORMAL and SUSPEND (using pm_runtime)
    - ODR (Output Data Rate) selection
    - Scale and samp_freq selection
    - IIO triggered buffer, IIO reg access
    - NEW_DATA interrupt + trigger

Below features to be done:
    - Motion Events: ACTIVE, TAP, ORIENT, FREEFALL
    - Low Power mode

Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
---
 MAINTAINERS                |    6 +
 drivers/iio/accel/Kconfig  |   13 +
 drivers/iio/accel/Makefile |    2 +
 drivers/iio/accel/msa311.c | 1339 ++++++++++++++++++++++++++++++++++++
 4 files changed, 1360 insertions(+)
 create mode 100644 drivers/iio/accel/msa311.c

Comments

Andy Shevchenko Aug. 12, 2022, 10:34 p.m. UTC | #1
On Fri, Aug 12, 2022 at 7:52 PM Dmitry Rokosov <DDRokosov@sberdevices.ru> wrote:
>
> MSA311 is a tri-axial, low-g accelerometer with I2C digital output for
> sensitivity consumer applications. It has dynamic user-selectable full
> scales range of +-2g/+-4g/+-8g/+-16g and allows acceleration measurements
> with output data rates from 1Hz to 1000Hz.

> Spec: https://cdn-shop.adafruit.com/product-files/5309/MSA311-V1.1-ENG.pdf

Can you use Datasheet: tag below (just before your SoB tag)?

> This driver supports following MSA311 features:
>     - IIO interface
>     - Different power modes: NORMAL and SUSPEND (using pm_runtime)
>     - ODR (Output Data Rate) selection
>     - Scale and samp_freq selection
>     - IIO triggered buffer, IIO reg access
>     - NEW_DATA interrupt + trigger
>
> Below features to be done:
>     - Motion Events: ACTIVE, TAP, ORIENT, FREEFALL
>     - Low Power mode

...

> +static const struct {
> +       int val;
> +       int val2;
> +} msa311_fs_table[] = {
> +       {0, 9580}, {0, 19160}, {0, 38320}, {0, 76641}
> +};

At least you may deduplicate the type definition for these data structures, like

struct iio_float {
  int integer;
  int fract;
};

...

> +               dev_err(dev,
> +                       "cannot set odr %u.%luHz, not available in %s mode\n",
> +                       msa311_odr_table[odr].val,
> +                       msa311_odr_table[odr].val2 / MILLIHZ_PER_HZ,

Logically it's MICROHZ_PER_MILLIHZ.

> +                       msa311_pwr_modes[pwr_mode]);

...

> +       freq_uhz = msa311_odr_table[odr].val * MICROHZ_PER_HZ +
> +                  msa311_odr_table[odr].val2;
> +       wait_ms = (MICROHZ_PER_HZ / freq_uhz) * MSEC_PER_SEC;

On the contrary this seems correct.

...

> +       err = iio_device_claim_direct_mode(indio_dev);
> +       if (err)
> +               return err;
> +
> +       mutex_lock(&msa311->lock);
> +       err = msa311_get_axis(msa311, chan, &axis);
> +       mutex_unlock(&msa311->lock);
> +
> +       iio_device_release_direct_mode(indio_dev);
> +
> +       if (err) {
> +               dev_err(dev, "cannot get axis %s (%pe)\n",
> +                       chan->datasheet_name, ERR_PTR(err));
> +               return err;
> +       }
> +
> +       pm_runtime_mark_last_busy(dev);
> +       pm_runtime_put_autosuspend(dev);

All error cases above miss the PM restoration. Is it on purpose?
Otherwise fix it here and check everywhere else.

...

> +       used = scnprintf(msa311->chip_name, sizeof(msa311->chip_name),
> +                        "msa311-%hhx", partid);

> +       msa311->chip_name[used] = '\0';

What is this for exactly?

...

> +       /* Disable all interrupts by default */
> +       err = regmap_write(msa311->regs, MSA311_INT_SET_0_REG, 0);
> +       if (err)
> +               return dev_err_probe(dev, err,
> +                                    "cannot disable set0 interrupts\n");
> +
> +       err = regmap_write(msa311->regs, MSA311_INT_SET_1_REG, 0);
> +       if (err)
> +               return dev_err_probe(dev, err,
> +                                    "cannot disable set1 interrupts\n");

Wondering if the above can be combined to bulk write.

...

> +       /* Unmap all INT1 interrupts by default */
> +       err = regmap_write(msa311->regs, MSA311_INT_MAP_0_REG, 0);
> +       if (err)
> +               return dev_err_probe(dev, err,
> +                                    "failed to unmap map0 interrupts\n");
> +
> +       err = regmap_write(msa311->regs, MSA311_INT_MAP_1_REG, 0);
> +       if (err)
> +               return dev_err_probe(dev, err,
> +                                    "failed to unmap map1 interrupts\n");

Ditto.

...

> +       /* Keep going without interrupts if no initialized I2C irq */

IRQ

...

> +                                    "cannot allocate newdata trigger\n");

In case you wish to make them shorter, you can use "can't".

...

> +                                    "can't register newdata trigger\n");

...esp. if you already do this in the other message, but not in all.
So, some consistency would be good to have.

...

I avoided commenting on the points that were not addressed and you
explained why.
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 64379c699903..010e7d854bf7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12992,6 +12992,12 @@  F:	drivers/mtd/
 F:	include/linux/mtd/
 F:	include/uapi/mtd/
 
+MEMSENSING MICROSYSTEMS MSA311 DRIVER
+M:	Dmitry Rokosov <ddrokosov@sberdevices.ru>
+L:	linux-iio@vger.kernel.org
+S:	Maintained
+F:	drivers/iio/accel/msa311.c
+
 MEN A21 WATCHDOG DRIVER
 M:	Johannes Thumshirn <morbidrsa@gmail.com>
 L:	linux-watchdog@vger.kernel.org
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index b53f010f3e40..36a5ddf631ef 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -539,6 +539,19 @@  config MMA9553
 	  To compile this driver as a module, choose M here: the module
 	  will be called mma9553.
 
+config MSA311
+	tristate "MEMSensing Digital 3-Axis Accelerometer Driver"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select REGMAP_I2C
+	help
+	  Say yes here to build support for the MEMSensing MSA311
+	  accelerometer driver.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called msa311.
+
 config MXC4005
 	tristate "Memsic MXC4005XC 3-Axis Accelerometer Driver"
 	depends on I2C
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 4d8792668838..5e45b5fa5ab5 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -58,6 +58,8 @@  obj-$(CONFIG_MMA9551_CORE)	+= mma9551_core.o
 obj-$(CONFIG_MMA9551)		+= mma9551.o
 obj-$(CONFIG_MMA9553)		+= mma9553.o
 
+obj-$(CONFIG_MSA311)		+= msa311.o
+
 obj-$(CONFIG_MXC4005)		+= mxc4005.o
 obj-$(CONFIG_MXC6255)		+= mxc6255.o
 
diff --git a/drivers/iio/accel/msa311.c b/drivers/iio/accel/msa311.c
new file mode 100644
index 000000000000..6b992f7c0745
--- /dev/null
+++ b/drivers/iio/accel/msa311.c
@@ -0,0 +1,1339 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MEMSensing digital 3-Axis accelerometer
+ *
+ * MSA311 is a tri-axial, low-g accelerometer with I2C digital output for
+ * sensitivity consumer applications. It has dynamic user-selectable full
+ * scales range of +-2g/+-4g/+-8g/+-16g and allows acceleration measurements
+ * with output data rates from 1Hz to 1000Hz.
+ *
+ * MSA311 is available in an ultra small (2mm x 2mm, height 0.95mm) LGA package
+ * and is guaranteed to operate over -40C to +85C.
+ *
+ * This driver supports following MSA311 features:
+ *     - IIO interface
+ *     - Different power modes: NORMAL, SUSPEND
+ *     - ODR (Output Data Rate) selection
+ *     - Scale selection
+ *     - IIO triggered buffer
+ *     - NEW_DATA interrupt + trigger
+ *
+ * Below features to be done:
+ *     - Motion Events: ACTIVE, TAP, ORIENT, FREEFALL
+ *     - Low Power mode
+ *
+ * Copyright (c) 2022, SberDevices. All Rights Reserved.
+ *
+ * Author: Dmitry Rokosov <ddrokosov@sberdevices.ru>
+ */
+
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/string_helpers.h>
+#include <linux/units.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define MSA311_SOFT_RESET_REG     0x00
+#define MSA311_PARTID_REG         0x01
+#define MSA311_ACC_X_REG          0x02
+#define MSA311_ACC_Y_REG          0x04
+#define MSA311_ACC_Z_REG          0x06
+#define MSA311_MOTION_INT_REG     0x09
+#define MSA311_DATA_INT_REG       0x0A
+#define MSA311_TAP_ACTIVE_STS_REG 0x0B
+#define MSA311_ORIENT_STS_REG     0x0C
+#define MSA311_RANGE_REG          0x0F
+#define MSA311_ODR_REG            0x10
+#define MSA311_PWR_MODE_REG       0x11
+#define MSA311_SWAP_POLARITY_REG  0x12
+#define MSA311_INT_SET_0_REG      0x16
+#define MSA311_INT_SET_1_REG      0x17
+#define MSA311_INT_MAP_0_REG      0x19
+#define MSA311_INT_MAP_1_REG      0x1A
+#define MSA311_INT_CONFIG_REG     0x20
+#define MSA311_INT_LATCH_REG      0x21
+#define MSA311_FREEFALL_DUR_REG   0x22
+#define MSA311_FREEFALL_TH_REG    0x23
+#define MSA311_FREEFALL_HY_REG    0x24
+#define MSA311_ACTIVE_DUR_REG     0x27
+#define MSA311_ACTIVE_TH_REG      0x28
+#define MSA311_TAP_DUR_REG        0x2A
+#define MSA311_TAP_TH_REG         0x2B
+#define MSA311_ORIENT_HY_REG      0x2C
+#define MSA311_Z_BLOCK_REG        0x2D
+#define MSA311_OFFSET_X_REG       0x38
+#define MSA311_OFFSET_Y_REG       0x39
+#define MSA311_OFFSET_Z_REG       0x3A
+
+enum msa311_fields {
+	/* Soft_Reset */
+	F_SOFT_RESET_I2C, F_SOFT_RESET_SPI,
+	/* Motion_Interrupt */
+	F_ORIENT_INT, F_S_TAP_INT, F_D_TAP_INT, F_ACTIVE_INT, F_FREEFALL_INT,
+	/* Data_Interrupt */
+	F_NEW_DATA_INT,
+	/* Tap_Active_Status */
+	F_TAP_SIGN, F_TAP_FIRST_X, F_TAP_FIRST_Y, F_TAP_FIRST_Z, F_ACTV_SIGN,
+	F_ACTV_FIRST_X, F_ACTV_FIRST_Y, F_ACTV_FIRST_Z,
+	/* Orientation_Status */
+	F_ORIENT_Z, F_ORIENT_X_Y,
+	/* Range */
+	F_FS,
+	/* ODR */
+	F_X_AXIS_DIS, F_Y_AXIS_DIS, F_Z_AXIS_DIS, F_ODR,
+	/* Power Mode/Bandwidth */
+	F_PWR_MODE, F_LOW_POWER_BW,
+	/* Swap_Polarity */
+	F_X_POLARITY, F_Y_POLARITY, F_Z_POLARITY, F_X_Y_SWAP,
+	/* Int_Set_0 */
+	F_ORIENT_INT_EN, F_S_TAP_INT_EN, F_D_TAP_INT_EN, F_ACTIVE_INT_EN_Z,
+	F_ACTIVE_INT_EN_Y, F_ACTIVE_INT_EN_X,
+	/* Int_Set_1 */
+	F_NEW_DATA_INT_EN, F_FREEFALL_INT_EN,
+	/* Int_Map_0 */
+	F_INT1_ORIENT, F_INT1_S_TAP, F_INT1_D_TAP, F_INT1_ACTIVE,
+	F_INT1_FREEFALL,
+	/* Int_Map_1 */
+	F_INT1_NEW_DATA,
+	/* Int_Config */
+	F_INT1_OD, F_INT1_LVL,
+	/* Int_Latch */
+	F_RESET_INT, F_LATCH_INT,
+	/* Freefall_Hy */
+	F_FREEFALL_MODE, F_FREEFALL_HY,
+	/* Active_Dur */
+	F_ACTIVE_DUR,
+	/* Tap_Dur */
+	F_TAP_QUIET, F_TAP_SHOCK, F_TAP_DUR,
+	/* Tap_Th */
+	F_TAP_TH,
+	/* Orient_Hy */
+	F_ORIENT_HYST, F_ORIENT_BLOCKING, F_ORIENT_MODE,
+	/* Z_Block */
+	F_Z_BLOCKING,
+	/* Offset_compensation */
+	F_MAX_FIELDS,
+};
+
+static const struct reg_field msa311_reg_fields[] = {
+	[F_SOFT_RESET_I2C] = REG_FIELD(MSA311_SOFT_RESET_REG, 2, 2),
+	[F_SOFT_RESET_SPI] = REG_FIELD(MSA311_SOFT_RESET_REG, 5, 5),
+
+	[F_ORIENT_INT] = REG_FIELD(MSA311_MOTION_INT_REG, 6, 6),
+	[F_S_TAP_INT] = REG_FIELD(MSA311_MOTION_INT_REG, 5, 5),
+	[F_D_TAP_INT] = REG_FIELD(MSA311_MOTION_INT_REG, 4, 4),
+	[F_ACTIVE_INT] = REG_FIELD(MSA311_MOTION_INT_REG, 2, 2),
+	[F_FREEFALL_INT] = REG_FIELD(MSA311_MOTION_INT_REG, 0, 0),
+
+	[F_NEW_DATA_INT] = REG_FIELD(MSA311_DATA_INT_REG, 0, 0),
+
+	[F_TAP_SIGN] = REG_FIELD(MSA311_TAP_ACTIVE_STS_REG, 7, 7),
+	[F_TAP_FIRST_X] = REG_FIELD(MSA311_TAP_ACTIVE_STS_REG, 6, 6),
+	[F_TAP_FIRST_Y] = REG_FIELD(MSA311_TAP_ACTIVE_STS_REG, 5, 5),
+	[F_TAP_FIRST_Z] = REG_FIELD(MSA311_TAP_ACTIVE_STS_REG, 4, 4),
+	[F_ACTV_SIGN] = REG_FIELD(MSA311_TAP_ACTIVE_STS_REG, 3, 3),
+	[F_ACTV_FIRST_X] = REG_FIELD(MSA311_TAP_ACTIVE_STS_REG, 2, 2),
+	[F_ACTV_FIRST_Y] = REG_FIELD(MSA311_TAP_ACTIVE_STS_REG, 1, 1),
+	[F_ACTV_FIRST_Z] = REG_FIELD(MSA311_TAP_ACTIVE_STS_REG, 0, 0),
+
+	[F_ORIENT_Z] = REG_FIELD(MSA311_ORIENT_STS_REG, 6, 6),
+	[F_ORIENT_X_Y] = REG_FIELD(MSA311_ORIENT_STS_REG, 4, 5),
+
+	[F_FS] = REG_FIELD(MSA311_RANGE_REG, 0, 1),
+
+	[F_X_AXIS_DIS] = REG_FIELD(MSA311_ODR_REG, 7, 7),
+	[F_Y_AXIS_DIS] = REG_FIELD(MSA311_ODR_REG, 6, 6),
+	[F_Z_AXIS_DIS] = REG_FIELD(MSA311_ODR_REG, 5, 5),
+	[F_ODR] = REG_FIELD(MSA311_ODR_REG, 0, 3),
+
+	[F_PWR_MODE] = REG_FIELD(MSA311_PWR_MODE_REG, 6, 7),
+	[F_LOW_POWER_BW] = REG_FIELD(MSA311_PWR_MODE_REG, 1, 4),
+
+	[F_X_POLARITY] = REG_FIELD(MSA311_SWAP_POLARITY_REG, 3, 3),
+	[F_Y_POLARITY] = REG_FIELD(MSA311_SWAP_POLARITY_REG, 2, 2),
+	[F_Z_POLARITY] = REG_FIELD(MSA311_SWAP_POLARITY_REG, 1, 1),
+	[F_X_Y_SWAP] = REG_FIELD(MSA311_SWAP_POLARITY_REG, 0, 0),
+
+	[F_ORIENT_INT_EN] = REG_FIELD(MSA311_INT_SET_0_REG, 6, 6),
+	[F_S_TAP_INT_EN] = REG_FIELD(MSA311_INT_SET_0_REG, 5, 5),
+	[F_D_TAP_INT_EN] = REG_FIELD(MSA311_INT_SET_0_REG, 4, 4),
+	[F_ACTIVE_INT_EN_Z] = REG_FIELD(MSA311_INT_SET_0_REG, 2, 2),
+	[F_ACTIVE_INT_EN_Y] = REG_FIELD(MSA311_INT_SET_0_REG, 1, 1),
+	[F_ACTIVE_INT_EN_X] = REG_FIELD(MSA311_INT_SET_0_REG, 0, 0),
+
+	[F_NEW_DATA_INT_EN] = REG_FIELD(MSA311_INT_SET_1_REG, 4, 4),
+	[F_FREEFALL_INT_EN] = REG_FIELD(MSA311_INT_SET_1_REG, 3, 3),
+
+	[F_INT1_ORIENT] = REG_FIELD(MSA311_INT_MAP_0_REG, 6, 6),
+	[F_INT1_S_TAP] = REG_FIELD(MSA311_INT_MAP_0_REG, 5, 5),
+	[F_INT1_D_TAP] = REG_FIELD(MSA311_INT_MAP_0_REG, 4, 4),
+	[F_INT1_ACTIVE] = REG_FIELD(MSA311_INT_MAP_0_REG, 2, 2),
+	[F_INT1_FREEFALL] = REG_FIELD(MSA311_INT_MAP_0_REG, 0, 0),
+
+	[F_INT1_NEW_DATA] = REG_FIELD(MSA311_INT_MAP_1_REG, 0, 0),
+
+	[F_INT1_OD] = REG_FIELD(MSA311_INT_CONFIG_REG, 1, 1),
+	[F_INT1_LVL] = REG_FIELD(MSA311_INT_CONFIG_REG, 0, 0),
+
+	[F_RESET_INT] = REG_FIELD(MSA311_INT_LATCH_REG, 7, 7),
+	[F_LATCH_INT] = REG_FIELD(MSA311_INT_LATCH_REG, 0, 3),
+
+	[F_FREEFALL_MODE] = REG_FIELD(MSA311_FREEFALL_HY_REG, 2, 2),
+	[F_FREEFALL_HY] = REG_FIELD(MSA311_FREEFALL_HY_REG, 0, 1),
+
+	[F_ACTIVE_DUR] = REG_FIELD(MSA311_ACTIVE_DUR_REG, 0, 1),
+
+	[F_TAP_QUIET] = REG_FIELD(MSA311_TAP_DUR_REG, 7, 7),
+	[F_TAP_SHOCK] = REG_FIELD(MSA311_TAP_DUR_REG, 6, 6),
+	[F_TAP_DUR] = REG_FIELD(MSA311_TAP_DUR_REG, 0, 2),
+
+	[F_TAP_TH] = REG_FIELD(MSA311_TAP_TH_REG, 0, 4),
+
+	[F_ORIENT_HYST] = REG_FIELD(MSA311_ORIENT_HY_REG, 4, 6),
+	[F_ORIENT_BLOCKING] = REG_FIELD(MSA311_ORIENT_HY_REG, 2, 3),
+	[F_ORIENT_MODE] = REG_FIELD(MSA311_ORIENT_HY_REG, 0, 1),
+
+	[F_Z_BLOCKING] = REG_FIELD(MSA311_Z_BLOCK_REG, 0, 3),
+};
+
+#define MSA311_WHO_AM_I 0x13
+
+/*
+ * Possible Full Scale ranges
+ *
+ * Axis data is 12-bit signed value, so
+ *
+ * fs0 = (2 + 2) * 9.81 / (2^11) = 0.009580
+ * fs1 = (4 + 4) * 9.81 / (2^11) = 0.019160
+ * fs2 = (8 + 8) * 9.81 / (2^11) = 0.038320
+ * fs3 = (16 + 16) * 9.81 / (2^11) = 0.076641
+ */
+enum {
+	MSA311_FS_2G,
+	MSA311_FS_4G,
+	MSA311_FS_8G,
+	MSA311_FS_16G,
+};
+
+static const struct {
+	int val;
+	int val2;
+} msa311_fs_table[] = {
+	{0, 9580}, {0, 19160}, {0, 38320}, {0, 76641}
+};
+
+/* Possible Output Data Rate values */
+enum {
+	MSA311_ODR_1_HZ,
+	MSA311_ODR_1_95_HZ,
+	MSA311_ODR_3_9_HZ,
+	MSA311_ODR_7_81_HZ,
+	MSA311_ODR_15_63_HZ,
+	MSA311_ODR_31_25_HZ,
+	MSA311_ODR_62_5_HZ,
+	MSA311_ODR_125_HZ,
+	MSA311_ODR_250_HZ,
+	MSA311_ODR_500_HZ,
+	MSA311_ODR_1000_HZ,
+};
+
+static const struct {
+	int val;
+	int val2;
+} msa311_odr_table[] = {
+	{1, 0}, {1, 950000}, {3, 900000}, {7, 810000}, {15, 630000},
+	{31, 250000}, {62, 500000}, {125, 0}, {250, 0}, {500, 0}, {1000, 0}
+};
+
+/* All supported power modes */
+#define MSA311_PWR_MODE_NORMAL  0b00
+#define MSA311_PWR_MODE_LOW     0b01
+#define MSA311_PWR_MODE_UNKNOWN 0b10
+#define MSA311_PWR_MODE_SUSPEND 0b11
+static const char * const msa311_pwr_modes[] = {
+	[MSA311_PWR_MODE_NORMAL] = "normal",
+	[MSA311_PWR_MODE_LOW] = "low",
+	[MSA311_PWR_MODE_UNKNOWN] = "unknown",
+	[MSA311_PWR_MODE_SUSPEND] = "suspend",
+};
+
+/* Autosuspend delay */
+#define MSA311_PWR_SLEEP_DELAY_MS 2000
+
+/* Possible INT1 types and levels */
+enum {
+	MSA311_INT1_OD_PUSH_PULL,
+	MSA311_INT1_OD_OPEN_DRAIN,
+};
+
+enum {
+	MSA311_INT1_LVL_LOW,
+	MSA311_INT1_LVL_HIGH,
+};
+
+/* Latch INT modes */
+#define MSA311_LATCH_INT_NOT_LATCHED 0b0000
+#define MSA311_LATCH_INT_250MS       0b0001
+#define MSA311_LATCH_INT_500MS       0b0010
+#define MSA311_LATCH_INT_1S          0b0011
+#define MSA311_LATCH_INT_2S          0b0100
+#define MSA311_LATCH_INT_4S          0b0101
+#define MSA311_LATCH_INT_8S          0b0110
+#define MSA311_LATCH_INT_1MS         0b1010
+#define MSA311_LATCH_INT_2MS         0b1011
+#define MSA311_LATCH_INT_25MS        0b1100
+#define MSA311_LATCH_INT_50MS        0b1101
+#define MSA311_LATCH_INT_100MS       0b1110
+#define MSA311_LATCH_INT_LATCHED     0b0111
+
+static const struct regmap_range msa311_readonly_registers[] = {
+	regmap_reg_range(MSA311_PARTID_REG, MSA311_ORIENT_STS_REG),
+};
+
+static const struct regmap_access_table msa311_writeable_table = {
+	.no_ranges = msa311_readonly_registers,
+	.n_no_ranges = ARRAY_SIZE(msa311_readonly_registers),
+};
+
+static const struct regmap_range msa311_writeonly_registers[] = {
+	regmap_reg_range(MSA311_SOFT_RESET_REG, MSA311_SOFT_RESET_REG),
+};
+
+static const struct regmap_access_table msa311_readable_table = {
+	.no_ranges = msa311_writeonly_registers,
+	.n_no_ranges = ARRAY_SIZE(msa311_writeonly_registers),
+};
+
+static const struct regmap_range msa311_volatile_registers[] = {
+	regmap_reg_range(MSA311_ACC_X_REG, MSA311_ORIENT_STS_REG),
+};
+
+static const struct regmap_access_table msa311_volatile_table = {
+	.yes_ranges = msa311_volatile_registers,
+	.n_yes_ranges = ARRAY_SIZE(msa311_volatile_registers),
+};
+
+static const struct regmap_config msa311_regmap_config = {
+	.name = "msa311",
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MSA311_OFFSET_Z_REG,
+	.wr_table = &msa311_writeable_table,
+	.rd_table = &msa311_readable_table,
+	.volatile_table = &msa311_volatile_table,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+#define MSA311_GENMASK(field) ({                \
+	typeof(&(msa311_reg_fields)[0]) _field; \
+	_field = &msa311_reg_fields[(field)];   \
+	GENMASK(_field->msb, _field->lsb);      \
+})
+
+/**
+ * struct msa311_priv - MSA311 internal private state
+ * @regs: Underlying I2C bus adapter used to abstract slave
+ *        register accesses
+ * @fields: Abstract objects for each registers fields access
+ * @dev: Device handler associated with appropriate bus client
+ * @lock: Protects msa311 device state between setup and data access routines
+ *        (power transitions, samp_freq/scale tune, retrieving axes data, etc)
+ * @chip_name: Chip name in the format "msa311-%hhx" % partid
+ * @new_data_trig: Optional NEW_DATA interrupt driven trigger used
+ *                 to notify external consumers a new sample is ready
+ * @vdd: Optional external voltage regulator for the device power supply
+ */
+struct msa311_priv {
+	struct regmap *regs;
+	struct regmap_field *fields[F_MAX_FIELDS];
+
+	struct device *dev;
+	struct mutex lock;
+	char chip_name[10];
+
+	struct iio_trigger *new_data_trig;
+	struct regulator *vdd;
+};
+
+enum msa311_si {
+	MSA311_SI_X,
+	MSA311_SI_Y,
+	MSA311_SI_Z,
+	MSA311_SI_TIMESTAMP,
+};
+
+#define MSA311_ACCEL_CHANNEL(axis) {                                        \
+	.type = IIO_ACCEL,                                                  \
+	.modified = 1,                                                      \
+	.channel2 = IIO_MOD_##axis,                                         \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                       \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |              \
+				    BIT(IIO_CHAN_INFO_SAMP_FREQ),           \
+	.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SCALE) |    \
+					      BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+	.scan_index = MSA311_SI_##axis,                                     \
+	.scan_type = {                                                      \
+		.sign = 's',                                                \
+		.realbits = 12,                                             \
+		.storagebits = 16,                                          \
+		.shift = 4,                                                 \
+		.endianness = IIO_LE,                                       \
+	},                                                                  \
+	.datasheet_name = "ACC_"#axis,                                      \
+}
+
+static const struct iio_chan_spec msa311_channels[] = {
+	MSA311_ACCEL_CHANNEL(X),
+	MSA311_ACCEL_CHANNEL(Y),
+	MSA311_ACCEL_CHANNEL(Z),
+	IIO_CHAN_SOFT_TIMESTAMP(MSA311_SI_TIMESTAMP),
+};
+
+/**
+ * msa311_get_odr() - Read Output Data Rate (ODR) value from MSA311 accel
+ * @msa311: MSA311 internal private state
+ * @odr: output ODR value
+ *
+ * This function should be called under msa311->lock.
+ *
+ * Return: 0 on success, -ERRNO in other failures
+ */
+static inline int msa311_get_odr(struct msa311_priv *msa311, unsigned int *odr)
+{
+	int err;
+
+	err = regmap_field_read(msa311->fields[F_ODR], odr);
+	if (err)
+		return err;
+
+	/*
+	 * Filter the same 1000Hz ODR register values based on datasheet info.
+	 * ODR can be equal to 1010-1111 for 1000Hz, but function returns 1010
+	 * all the time.
+	 */
+	if (*odr > MSA311_ODR_1000_HZ)
+		*odr = MSA311_ODR_1000_HZ;
+
+	return 0;
+}
+
+/**
+ * msa311_set_odr() - Setup Output Data Rate (ODR) value for MSA311 accel
+ * @msa311: MSA311 internal private state
+ * @odr: requested ODR value
+ *
+ * This function should be called under msa311->lock. Possible ODR values:
+ *     - 1Hz (not available in normal mode)
+ *     - 1.95Hz (not available in normal mode)
+ *     - 3.9Hz
+ *     - 7.81Hz
+ *     - 15.63Hz
+ *     - 31.25Hz
+ *     - 62.5Hz
+ *     - 125Hz
+ *     - 250Hz
+ *     - 500Hz
+ *     - 1000Hz
+ *
+ * Return: 0 on success, -EINVAL for bad ODR value in the certain power mode,
+ *         -ERRNO in other failures
+ */
+static inline int msa311_set_odr(struct msa311_priv *msa311, unsigned int odr)
+{
+	struct device *dev = msa311->dev;
+	unsigned int pwr_mode;
+	bool good_odr = false;
+	int err;
+
+	err = regmap_field_read(msa311->fields[F_PWR_MODE], &pwr_mode);
+	if (err)
+		return err;
+
+	/* Filter bad ODR values */
+	if (pwr_mode == MSA311_PWR_MODE_NORMAL)
+		good_odr = (odr > MSA311_ODR_1_95_HZ);
+
+	if (!good_odr) {
+		dev_err(dev,
+			"cannot set odr %u.%luHz, not available in %s mode\n",
+			msa311_odr_table[odr].val,
+			msa311_odr_table[odr].val2 / MILLIHZ_PER_HZ,
+			msa311_pwr_modes[pwr_mode]);
+		return -EINVAL;
+	}
+
+	return regmap_field_write(msa311->fields[F_ODR], odr);
+}
+
+/**
+ * msa311_wait_for_next_data() - Wait next accel data available after resume
+ * @msa311: MSA311 internal private state
+ *
+ * Return: 0 on success, -EINTR if msleep() was interrupted,
+ *         -ERRNO in other failures
+ */
+static int msa311_wait_for_next_data(struct msa311_priv *msa311)
+{
+	static const unsigned int unintr_thresh_ms = 20;
+	struct device *dev = msa311->dev;
+	unsigned long freq_uhz;
+	unsigned long wait_ms;
+	unsigned int odr;
+	int err;
+
+	err = msa311_get_odr(msa311, &odr);
+	if (err) {
+		dev_err(dev, "cannot get actual frequency (%pe)\n",
+			ERR_PTR(err));
+		return err;
+	}
+
+	/*
+	 * After msa311 resuming is done, we need to wait for data
+	 * to be refreshed by accel logic.
+	 * A certain timeout is calculated based on the current ODR value.
+	 * If requested timeout isn't so long (let's assume 20ms),
+	 * we can wait for next data in uninterruptible sleep.
+	 */
+	freq_uhz = msa311_odr_table[odr].val * MICROHZ_PER_HZ +
+		   msa311_odr_table[odr].val2;
+	wait_ms = (MICROHZ_PER_HZ / freq_uhz) * MSEC_PER_SEC;
+
+	if (wait_ms < unintr_thresh_ms)
+		usleep_range(wait_ms * USEC_PER_MSEC,
+			     unintr_thresh_ms * USEC_PER_MSEC);
+	else
+		return msleep_interruptible(wait_ms) ? -EINTR : 0;
+
+	return 0;
+}
+
+/**
+ * msa311_set_pwr_mode() - Install certain MSA311 power mode
+ * @msa311: MSA311 internal private state
+ * @mode: Power mode can be equal to NORMAL or SUSPEND
+ *
+ * This function should be called under msa311->lock.
+ *
+ * Return: 0 on success, -ERRNO on failure
+ */
+static int msa311_set_pwr_mode(struct msa311_priv *msa311, unsigned int mode)
+{
+	struct device *dev = msa311->dev;
+	unsigned int prev_mode;
+	int err;
+
+	if (mode >= ARRAY_SIZE(msa311_pwr_modes))
+		return -EINVAL;
+
+	dev_dbg(dev, "transition to %s mode\n", msa311_pwr_modes[mode]);
+
+	err = regmap_field_read(msa311->fields[F_PWR_MODE], &prev_mode);
+	if (err)
+		return err;
+
+	err = regmap_field_write(msa311->fields[F_PWR_MODE], mode);
+	if (err)
+		return err;
+
+	/* Wait actual data if we wake up */
+	if (prev_mode == MSA311_PWR_MODE_SUSPEND &&
+	    mode == MSA311_PWR_MODE_NORMAL)
+		return msa311_wait_for_next_data(msa311);
+
+	return 0;
+}
+
+/**
+ * msa311_get_axis() - Read MSA311 accel data for certain IIO channel axis spec
+ * @msa311: MSA311 internal private state
+ * @chan: IIO channel specification
+ * @axis: Output accel axis data for requested IIO channel spec
+ *
+ * This function should be called under msa311->lock.
+ *
+ * Return: 0 on success, -EINVAL for unknown IIO channel specification,
+ *         -ERRNO in other failures
+ */
+static int msa311_get_axis(struct msa311_priv *msa311,
+			   const struct iio_chan_spec * const chan,
+			   __le16 *axis)
+{
+	struct device *dev = msa311->dev;
+	unsigned int axis_reg;
+
+	if (chan->scan_index < MSA311_SI_X || chan->scan_index > MSA311_SI_Z) {
+		dev_err(dev, "invalid scan_index value [%d]\n",
+			chan->scan_index);
+		return -EINVAL;
+	}
+
+	/* Axes data layout has 2 byte gap for each axis starting from X axis */
+	axis_reg = MSA311_ACC_X_REG + (chan->scan_index << 1);
+
+	return regmap_bulk_read(msa311->regs, axis_reg, axis, sizeof(*axis));
+}
+
+static int msa311_read_raw_data(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2)
+{
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	struct device *dev = msa311->dev;
+	__le16 axis;
+	int err;
+
+	err = pm_runtime_resume_and_get(dev);
+	if (err)
+		return err;
+
+	err = iio_device_claim_direct_mode(indio_dev);
+	if (err)
+		return err;
+
+	mutex_lock(&msa311->lock);
+	err = msa311_get_axis(msa311, chan, &axis);
+	mutex_unlock(&msa311->lock);
+
+	iio_device_release_direct_mode(indio_dev);
+
+	if (err) {
+		dev_err(dev, "cannot get axis %s (%pe)\n",
+			chan->datasheet_name, ERR_PTR(err));
+		return err;
+	}
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	/*
+	 * Axis data format is:
+	 * ACC_X = (ACC_X_MSB[7:0] << 4) | ACC_X_LSB[7:4]
+	 */
+	*val = sign_extend32(le16_to_cpu(axis) >> chan->scan_type.shift,
+			     chan->scan_type.realbits - 1);
+
+	return IIO_VAL_INT;
+}
+
+static int msa311_read_scale(struct iio_dev *indio_dev, int *val, int *val2)
+{
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	struct device *dev = msa311->dev;
+	unsigned int fs;
+	int err;
+
+	mutex_lock(&msa311->lock);
+	err = regmap_field_read(msa311->fields[F_FS], &fs);
+	mutex_unlock(&msa311->lock);
+	if (err) {
+		dev_err(dev, "cannot get actual scale (%pe)\n", ERR_PTR(err));
+		return err;
+	}
+
+	*val = msa311_fs_table[fs].val;
+	*val2 = msa311_fs_table[fs].val2;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int msa311_read_samp_freq(struct iio_dev *indio_dev,
+				 int *val, int *val2)
+{
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	struct device *dev = msa311->dev;
+	unsigned int odr;
+	int err;
+
+	mutex_lock(&msa311->lock);
+	err = msa311_get_odr(msa311, &odr);
+	mutex_unlock(&msa311->lock);
+	if (err) {
+		dev_err(dev, "cannot get actual frequency (%pe)\n",
+			ERR_PTR(err));
+		return err;
+	}
+
+	*val = msa311_odr_table[odr].val;
+	*val2 = msa311_odr_table[odr].val2;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int msa311_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		return msa311_read_raw_data(indio_dev, chan, val, val2);
+
+	case IIO_CHAN_INFO_SCALE:
+		return msa311_read_scale(indio_dev, val, val2);
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		return msa311_read_samp_freq(indio_dev, val, val2);
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int msa311_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type,
+			     int *length, long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*vals = (int *)msa311_odr_table;
+		*type = IIO_VAL_INT_PLUS_MICRO;
+		/* ODR value has 2 ints (integer and fractional parts) */
+		*length = ARRAY_SIZE(msa311_odr_table) * 2;
+		return IIO_AVAIL_LIST;
+
+	case IIO_CHAN_INFO_SCALE:
+		*vals = (int *)msa311_fs_table;
+		*type = IIO_VAL_INT_PLUS_MICRO;
+		/* FS value has 2 ints (integer and fractional parts) */
+		*length = ARRAY_SIZE(msa311_fs_table) * 2;
+		return IIO_AVAIL_LIST;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int msa311_write_scale(struct iio_dev *indio_dev, int val, int val2)
+{
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	struct device *dev = msa311->dev;
+	unsigned int fs;
+	int err;
+
+	/* We do not have fs >= 1, so skip such values */
+	if (val)
+		return 0;
+
+	err = pm_runtime_resume_and_get(dev);
+	if (err)
+		return err;
+
+	err = -EINVAL;
+	for (fs = 0; fs < ARRAY_SIZE(msa311_fs_table); fs++)
+		/* Do not check msa311_fs_table[fs].val, it's always 0 */
+		if (val2 == msa311_fs_table[fs].val2) {
+			mutex_lock(&msa311->lock);
+			err = regmap_field_write(msa311->fields[F_FS], fs);
+			mutex_unlock(&msa311->lock);
+			break;
+		}
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	if (err)
+		dev_err(dev, "cannot update scale (%pe)\n", ERR_PTR(err));
+
+	return err;
+}
+
+static int msa311_write_samp_freq(struct iio_dev *indio_dev, int val, int val2)
+{
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	struct device *dev = msa311->dev;
+	unsigned int odr;
+	int err;
+
+	err = pm_runtime_resume_and_get(dev);
+	if (err)
+		return err;
+
+	/*
+	 * Sampling frequency changing is prohibited when buffer mode is
+	 * enabled, because sometimes MSA311 chip returns outliers during
+	 * frequency values growing up in the read operation moment.
+	 */
+	err = iio_device_claim_direct_mode(indio_dev);
+	if (err)
+		return err;
+
+	err = -EINVAL;
+	for (odr = 0; odr < ARRAY_SIZE(msa311_odr_table); odr++)
+		if (val == msa311_odr_table[odr].val &&
+		    val2 == msa311_odr_table[odr].val2) {
+			mutex_lock(&msa311->lock);
+			err = msa311_set_odr(msa311, odr);
+			mutex_unlock(&msa311->lock);
+			break;
+		}
+
+	iio_device_release_direct_mode(indio_dev);
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	if (err)
+		dev_err(dev, "cannot update frequency (%pe)\n", ERR_PTR(err));
+
+	return err;
+}
+
+static int msa311_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val, int val2, long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		return msa311_write_scale(indio_dev, val, val2);
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		return msa311_write_samp_freq(indio_dev, val, val2);
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int msa311_debugfs_reg_access(struct iio_dev *indio_dev,
+				     unsigned int reg, unsigned int writeval,
+				     unsigned int *readval)
+{
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	struct device *dev = msa311->dev;
+	int err;
+
+	if (reg > regmap_get_max_register(msa311->regs))
+		return -EINVAL;
+
+	err = pm_runtime_resume_and_get(dev);
+	if (err)
+		return err;
+
+	mutex_lock(&msa311->lock);
+
+	if (readval)
+		err = regmap_read(msa311->regs, reg, readval);
+	else
+		err = regmap_write(msa311->regs, reg, writeval);
+
+	mutex_unlock(&msa311->lock);
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	if (err)
+		dev_err(dev, "cannot %s register %u from debugfs (%pe)\n",
+			str_read_write(readval), reg, ERR_PTR(err));
+
+	return err;
+}
+
+static int msa311_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	struct device *dev = msa311->dev;
+
+	return pm_runtime_resume_and_get(dev);
+}
+
+static int msa311_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	struct device *dev = msa311->dev;
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return 0;
+}
+
+static int msa311_set_new_data_trig_state(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	struct device *dev = msa311->dev;
+	int err;
+
+	mutex_lock(&msa311->lock);
+	err = regmap_field_write(msa311->fields[F_NEW_DATA_INT_EN], state);
+	mutex_unlock(&msa311->lock);
+	if (err)
+		dev_err(dev,
+			"cannot %s buffer due to new_data_int failure (%pe)\n",
+			str_enable_disable(state), ERR_PTR(err));
+
+	return err;
+}
+
+static int msa311_validate_device(struct iio_trigger *trig,
+				  struct iio_dev *indio_dev)
+{
+	return iio_trigger_get_drvdata(trig) == indio_dev ? 0 : -EINVAL;
+}
+
+static irqreturn_t msa311_buffer_thread(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct msa311_priv *msa311 = iio_priv(pf->indio_dev);
+	struct iio_dev *indio_dev = pf->indio_dev;
+	const struct iio_chan_spec *chan;
+	struct device *dev = msa311->dev;
+	int bit, err, i = 0;
+	__le16 axis;
+	struct {
+		__le16 channels[MSA311_SI_Z + 1];
+		s64 ts __aligned(8);
+	} buf;
+
+	memset(&buf, 0, sizeof(buf));
+
+	mutex_lock(&msa311->lock);
+
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
+			 indio_dev->masklength) {
+		chan = &msa311_channels[bit];
+
+		err = msa311_get_axis(msa311, chan, &axis);
+		if (err) {
+			mutex_unlock(&msa311->lock);
+			dev_err(dev, "cannot get axis %s (%pe)\n",
+				chan->datasheet_name, ERR_PTR(err));
+			goto err;
+		}
+
+		buf.channels[i++] = axis;
+	}
+
+	mutex_unlock(&msa311->lock);
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &buf,
+					   iio_get_time_ns(indio_dev));
+
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t msa311_irq_thread(int irq, void *p)
+{
+	struct msa311_priv *msa311 = iio_priv(p);
+	unsigned int new_data_int_enabled;
+	struct device *dev = msa311->dev;
+	int err;
+
+	mutex_lock(&msa311->lock);
+
+	/*
+	 * We do not check NEW_DATA int status, because based on the
+	 * specification it's cleared automatically after a fixed time.
+	 * So just check that is enabled by driver logic.
+	 */
+	err = regmap_field_read(msa311->fields[F_NEW_DATA_INT_EN],
+				&new_data_int_enabled);
+
+	mutex_unlock(&msa311->lock);
+	if (err) {
+		dev_err(dev, "cannot read new_data interrupt state (%pe)\n",
+			ERR_PTR(err));
+		return IRQ_NONE;
+	}
+
+	if (new_data_int_enabled)
+		iio_trigger_poll_chained(msa311->new_data_trig);
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_info msa311_info = {
+	.read_raw = msa311_read_raw,
+	.read_avail = msa311_read_avail,
+	.write_raw = msa311_write_raw,
+	.debugfs_reg_access = msa311_debugfs_reg_access,
+};
+
+static const struct iio_buffer_setup_ops msa311_buffer_setup_ops = {
+	.preenable = msa311_buffer_preenable,
+	.postdisable = msa311_buffer_postdisable,
+};
+
+static const struct iio_trigger_ops msa311_new_data_trig_ops = {
+	.set_trigger_state = msa311_set_new_data_trig_state,
+	.validate_device = msa311_validate_device,
+};
+
+static int msa311_check_partid(struct msa311_priv *msa311)
+{
+	struct device *dev = msa311->dev;
+	unsigned int partid;
+	int used, err;
+
+	err = regmap_read(msa311->regs, MSA311_PARTID_REG, &partid);
+	if (err)
+		return dev_err_probe(dev, err, "failed to read partid\n");
+
+	if (partid != MSA311_WHO_AM_I)
+		dev_warn(dev, "invalid partid (%#x), expected (%#x)\n",
+			 partid, MSA311_WHO_AM_I);
+
+	used = scnprintf(msa311->chip_name, sizeof(msa311->chip_name),
+			 "msa311-%hhx", partid);
+	msa311->chip_name[used] = '\0';
+
+	return 0;
+}
+
+static int msa311_soft_reset(struct msa311_priv *msa311)
+{
+	struct device *dev = msa311->dev;
+	int err;
+
+	err = regmap_write(msa311->regs, MSA311_SOFT_RESET_REG,
+			   MSA311_GENMASK(F_SOFT_RESET_I2C) |
+			   MSA311_GENMASK(F_SOFT_RESET_SPI));
+	if (err)
+		return dev_err_probe(dev, err, "cannot soft reset all logic\n");
+
+	return 0;
+}
+
+static int msa311_chip_init(struct msa311_priv *msa311)
+{
+	struct device *dev = msa311->dev;
+	int err;
+
+	err = regmap_write(msa311->regs, MSA311_RANGE_REG, MSA311_FS_16G);
+	if (err)
+		return dev_err_probe(dev, err, "failed to setup accel range\n");
+
+	/* Disable all interrupts by default */
+	err = regmap_write(msa311->regs, MSA311_INT_SET_0_REG, 0);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "cannot disable set0 interrupts\n");
+
+	err = regmap_write(msa311->regs, MSA311_INT_SET_1_REG, 0);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "cannot disable set1 interrupts\n");
+
+	/* Unmap all INT1 interrupts by default */
+	err = regmap_write(msa311->regs, MSA311_INT_MAP_0_REG, 0);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "failed to unmap map0 interrupts\n");
+
+	err = regmap_write(msa311->regs, MSA311_INT_MAP_1_REG, 0);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "failed to unmap map1 interrupts\n");
+
+	/* Disable all axes by default */
+	err = regmap_update_bits(msa311->regs, MSA311_ODR_REG,
+				 MSA311_GENMASK(F_X_AXIS_DIS) |
+				 MSA311_GENMASK(F_Y_AXIS_DIS) |
+				 MSA311_GENMASK(F_Z_AXIS_DIS), 0);
+	if (err)
+		return dev_err_probe(dev, err, "cannot enable all axes\n");
+
+	err = msa311_set_odr(msa311, MSA311_ODR_125_HZ);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "failed to set accel frequency\n");
+
+	return 0;
+}
+
+static int msa311_setup_interrupts(struct msa311_priv *msa311)
+{
+	struct device *dev = msa311->dev;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
+	struct iio_trigger *trig;
+	int err;
+
+	/* Keep going without interrupts if no initialized I2C irq */
+	if (i2c->irq <= 0)
+		return 0;
+
+	err = devm_request_threaded_irq(&i2c->dev, i2c->irq,
+					NULL, msa311_irq_thread,
+					IRQF_ONESHOT,
+					msa311->chip_name,
+					indio_dev);
+	if (err)
+		return dev_err_probe(dev, err, "failed to request IRQ\n");
+
+	trig = devm_iio_trigger_alloc(dev, "%s-new-data", msa311->chip_name);
+	if (!trig)
+		return dev_err_probe(dev, -ENOMEM,
+				     "cannot allocate newdata trigger\n");
+
+	msa311->new_data_trig = trig;
+	msa311->new_data_trig->ops = &msa311_new_data_trig_ops;
+	iio_trigger_set_drvdata(msa311->new_data_trig, indio_dev);
+
+	err = devm_iio_trigger_register(dev, msa311->new_data_trig);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "can't register newdata trigger\n");
+
+	err = regmap_field_write(msa311->fields[F_INT1_OD],
+				 MSA311_INT1_OD_PUSH_PULL);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "cannot enable push-pull interrupt\n");
+
+	err = regmap_field_write(msa311->fields[F_INT1_LVL],
+				 MSA311_INT1_LVL_HIGH);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "cannot set active interrupt level\n");
+
+	err = regmap_field_write(msa311->fields[F_LATCH_INT],
+				 MSA311_LATCH_INT_LATCHED);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "cannot latch interrupt\n");
+
+	err = regmap_field_write(msa311->fields[F_RESET_INT], 1);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "cannot reset interrupt\n");
+
+	err = regmap_field_write(msa311->fields[F_INT1_NEW_DATA], 1);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "cannot map new data interrupt\n");
+
+	return 0;
+}
+
+static int msa311_regmap_init(struct msa311_priv *msa311)
+{
+	struct regmap_field **fields = msa311->fields;
+	struct device *dev = msa311->dev;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct regmap *regmap;
+	int i;
+
+	regmap = devm_regmap_init_i2c(i2c, &msa311_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap),
+				     "failed to register i2c regmap\n");
+
+	msa311->regs = regmap;
+
+	for (i = 0; i < F_MAX_FIELDS; i++) {
+		fields[i] = devm_regmap_field_alloc(dev,
+						    msa311->regs,
+						    msa311_reg_fields[i]);
+		if (IS_ERR(msa311->fields[i]))
+			return dev_err_probe(dev, PTR_ERR(msa311->fields[i]),
+					     "cannot alloc field[%d]\n", i);
+	}
+
+	return 0;
+}
+
+static void msa311_powerdown(void *msa311)
+{
+	msa311_set_pwr_mode(msa311, MSA311_PWR_MODE_SUSPEND);
+}
+
+static void msa311_vdd_disable(void *vdd)
+{
+	regulator_disable(vdd);
+}
+
+static int msa311_probe(struct i2c_client *i2c)
+{
+	struct device *dev = &i2c->dev;
+	struct msa311_priv *msa311;
+	struct iio_dev *indio_dev;
+	int err;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*msa311));
+	if (!indio_dev)
+		return dev_err_probe(dev, -ENOMEM,
+				     "IIO device allocation failed\n");
+
+	msa311 = iio_priv(indio_dev);
+	msa311->dev = dev;
+	i2c_set_clientdata(i2c, indio_dev);
+
+	err = msa311_regmap_init(msa311);
+	if (err)
+		return err;
+
+	mutex_init(&msa311->lock);
+
+	msa311->vdd = devm_regulator_get_optional(dev, "vdd");
+	if (IS_ERR(msa311->vdd)) {
+		err = PTR_ERR(msa311->vdd);
+		if (err == -ENODEV)
+			msa311->vdd = NULL;
+		else
+			return dev_err_probe(dev, PTR_ERR(msa311->vdd),
+					     "cannot get vdd supply\n");
+	}
+
+	if (msa311->vdd) {
+		err = regulator_enable(msa311->vdd);
+		if (err)
+			return dev_err_probe(dev, err,
+					     "cannot enable vdd supply\n");
+
+		err = devm_add_action_or_reset(dev, msa311_vdd_disable,
+					       msa311->vdd);
+		if (err) {
+			return dev_err_probe(dev, err,
+					     "cannot add vdd disable action\n");
+		}
+	}
+
+	err = msa311_check_partid(msa311);
+	if (err)
+		return err;
+
+	err = msa311_soft_reset(msa311);
+	if (err)
+		return err;
+
+	err = msa311_set_pwr_mode(msa311, MSA311_PWR_MODE_NORMAL);
+	if (err)
+		return dev_err_probe(dev, err, "failed to power on device\n");
+
+	/*
+	 * Register powerdown deferred callback which suspends the chip
+	 * after module unloaded.
+	 *
+	 * MSA311 should be in SUSPEND mode in the two cases:
+	 * 1) When driver is loaded, but we do not have any data or
+	 *    configuration requests to it (we are solving it using
+	 *    autosuspend feature).
+	 * 2) When driver is unloaded and device is not used (devm action is
+	 *    used in this case).
+	 */
+	err = devm_add_action_or_reset(dev, msa311_powerdown, msa311);
+	if (err)
+		return dev_err_probe(dev, err, "cannot add powerdown action\n");
+
+	err = pm_runtime_set_active(dev);
+	if (err)
+		return err;
+
+	err = devm_pm_runtime_enable(dev);
+	if (err)
+		return err;
+
+	pm_runtime_get_noresume(dev);
+	pm_runtime_set_autosuspend_delay(dev, MSA311_PWR_SLEEP_DELAY_MS);
+	pm_runtime_use_autosuspend(dev);
+
+	err = msa311_chip_init(msa311);
+	if (err)
+		return err;
+
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = msa311_channels;
+	indio_dev->num_channels = ARRAY_SIZE(msa311_channels);
+	indio_dev->name = msa311->chip_name;
+	indio_dev->info = &msa311_info;
+
+	err = devm_iio_triggered_buffer_setup(dev,
+					      indio_dev,
+					      iio_pollfunc_store_time,
+					      msa311_buffer_thread,
+					      &msa311_buffer_setup_ops);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "cannot setup IIO trigger buffer\n");
+
+	err = msa311_setup_interrupts(msa311);
+	if (err)
+		return err;
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	err = devm_iio_device_register(dev, indio_dev);
+	if (err)
+		return dev_err_probe(dev, err, "IIO device register failed\n");
+
+	return 0;
+}
+
+static int msa311_runtime_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	int err;
+
+	mutex_lock(&msa311->lock);
+	err = msa311_set_pwr_mode(msa311, MSA311_PWR_MODE_SUSPEND);
+	mutex_unlock(&msa311->lock);
+	if (err)
+		dev_err(dev, "failed to power off device (%pe)\n",
+			ERR_PTR(err));
+
+	return err;
+}
+
+static int msa311_runtime_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct msa311_priv *msa311 = iio_priv(indio_dev);
+	int err;
+
+	mutex_lock(&msa311->lock);
+	err = msa311_set_pwr_mode(msa311, MSA311_PWR_MODE_NORMAL);
+	mutex_unlock(&msa311->lock);
+	if (err)
+		dev_err(dev, "failed to power on device (%pe)\n",
+			ERR_PTR(err));
+
+	return err;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(msa311_pm_ops, msa311_runtime_suspend,
+				 msa311_runtime_resume, NULL);
+
+static const struct i2c_device_id msa311_i2c_id[] = {
+	{ .name = "msa311" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, msa311_i2c_id);
+
+static const struct of_device_id msa311_of_match[] = {
+	{ .compatible = "memsensing,msa311" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, msa311_of_match);
+
+static struct i2c_driver msa311_driver = {
+	.driver = {
+		.name = "msa311",
+		.owner = THIS_MODULE,
+		.of_match_table = msa311_of_match,
+		.pm = pm_ptr(&msa311_pm_ops),
+	},
+	.probe_new	= msa311_probe,
+	.id_table	= msa311_i2c_id,
+};
+module_i2c_driver(msa311_driver);
+
+MODULE_AUTHOR("Dmitry Rokosov <ddrokosov@sberdevices.ru>");
+MODULE_DESCRIPTION("MEMSensing MSA311 3-axis accelerometer driver");
+MODULE_LICENSE("GPL");