[PATCH v3 2/3] iio: add MEMSensing MSA311 3-axis accelerometer driver

From: Dmitry Rokosov
Date: Thu Jun 16 2022 - 06:42:49 EST


MSA311 is a tri-axial, low-g accelerometer with I2C digital output for
sensitivity consumer applications. It has dynamical user selectable full
scales range of +-2g/+-4g/+-8g/+-16g and allows acceleration measurements
with output data rates from 1Hz to 1000Hz.

Datasheet can be found at following URL:
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@xxxxxxxxxxxxxx>
---
MAINTAINERS | 6 +
drivers/iio/accel/Kconfig | 13 +
drivers/iio/accel/Makefile | 2 +
drivers/iio/accel/msa311.c | 1312 ++++++++++++++++++++++++++++++++++++
4 files changed, 1333 insertions(+)
create mode 100644 drivers/iio/accel/msa311.c

diff --git a/MAINTAINERS b/MAINTAINERS
index d9b2f1731ee0..55aeb25c004c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12478,6 +12478,12 @@ F: drivers/mtd/
F: include/linux/mtd/
F: include/uapi/mtd/

+MEMSENSING MICROSYSTEMS MSA311 ACCELEROMETER DRIVER
+M: Dmitry Rokosov <ddrokosov@xxxxxxxxxxxxxx>
+L: linux-iio@xxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/iio/accel/msa311.c
+
MEN A21 WATCHDOG DRIVER
M: Johannes Thumshirn <morbidrsa@xxxxxxxxx>
L: linux-watchdog@xxxxxxxxxxxxxxx
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 49587c992a6d..88a265b75eed 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -508,6 +508,19 @@ 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 d03e2f6bba08..b1ddcaa811b6 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -55,6 +55,8 @@ 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..f8a8ed064f21
--- /dev/null
+++ b/drivers/iio/accel/msa311.c
@@ -0,0 +1,1312 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * msa311.c - MEMSensing digital 3-Axis accelerometer
+ *
+ * MSA311 is a tri-axial, low-g accelerometer with I2C digital output for
+ * sensitivity consumer applications. It has dynamical 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@xxxxxxxxxxxxxx>
+ */
+
+#include <linux/i2c.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>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+/* Register map */
+
+#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 {
+ F_SOFT_RESET_I2C, F_SOFT_RESET_SPI,
+
+ F_ORIENT_INT, F_S_TAP_INT, F_D_TAP_INT, F_ACTIVE_INT, F_FREEFALL_INT,
+
+ F_NEW_DATA_INT,
+
+ 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,
+
+ F_ORIENT_Z, F_ORIENT_X_Y,
+
+ F_FS,
+
+ F_X_AXIS_DIS, F_Y_AXIS_DIS, F_Z_AXIS_DIS, F_ODR,
+
+ F_PWR_MODE, F_LOW_POWER_BW,
+
+ F_X_POLARITY, F_Y_POLARITY, F_Z_POLARITY, F_X_Y_SWAP,
+
+ 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,
+
+ F_NEW_DATA_INT_EN, F_FREEFALL_INT_EN,
+
+ F_INT1_ORIENT, F_INT1_S_TAP, F_INT1_D_TAP, F_INT1_ACTIVE,
+ F_INT1_FREEFALL,
+
+ F_INT1_NEW_DATA,
+
+ F_INT1_OD, F_INT1_LVL,
+
+ F_RESET_INT, F_LATCH_INT,
+
+ F_FREEFALL_MODE, F_FREEFALL_HY,
+
+ F_ACTIVE_DUR,
+
+ F_TAP_QUIET, F_TAP_SHOCK, F_TAP_DUR,
+
+ F_TAP_TH,
+
+ F_ORIENT_HYST, F_ORIENT_BLOCKING, F_ORIENT_MODE,
+
+ F_Z_BLOCKING,
+
+ 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_SUSPEND 0b11
+
+/* 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(field) _field = (field); \
+ GENMASK(msa311_reg_fields[_field].msb, \
+ msa311_reg_fields[_field].lsb); \
+})
+
+/**
+ * struct msa311_priv - MSA311 internal private state
+ * @i2c: I2C client object
+ * @lock: Protects msa311 device state between setup and data access routines
+ * (power transitions, samp_freq/scale tune, retrieving axes data, etc)
+ * @new_data_trig: Optional NEW_DATA interrupt driven trigger used
+ * to notify external consumers a new sample is ready
+ * @regs: Underlying I2C bus adapter used to abstract slave
+ * register accesses
+ * @fields: Abstract objects for each registers fields access
+ */
+struct msa311_priv {
+ struct i2c_client *i2c;
+ struct mutex lock; /* state guard */
+
+ struct iio_trigger *new_data_trig;
+
+ struct regmap *regs;
+ struct regmap_field *fields[F_MAX_FIELDS];
+};
+
+/* Channels */
+
+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_all = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .info_mask_shared_by_all_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->i2c->dev;
+ const char *mode = NULL;
+ 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 */
+ switch (pwr_mode) {
+ case MSA311_PWR_MODE_NORMAL:
+ mode = "normal";
+ good_odr = (odr > MSA311_ODR_1_95_HZ);
+ break;
+ case MSA311_PWR_MODE_SUSPEND:
+ mode = "suspend";
+ break;
+ default:
+ mode = "unknown";
+ break;
+ }
+
+ if (!good_odr) {
+ dev_err(dev,
+ "failed to set odr %u.%uHz, not available in %s mode\n",
+ msa311_odr_table[odr].val,
+ msa311_odr_table[odr].val2 / 1000, 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 int unintr_thresh_ms = 20;
+ struct device *dev = &msa311->i2c->dev;
+ unsigned int odr;
+ unsigned long wait_ms;
+ unsigned long freq_uhz;
+ int err;
+
+ err = msa311_get_odr(msa311, &odr);
+ if (err) {
+ dev_err(dev, "cannot get actual freq (%d)\n", 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 * USEC_PER_SEC +
+ msa311_odr_table[odr].val2;
+ wait_ms = (USEC_PER_SEC * MSEC_PER_SEC) / freq_uhz;
+
+ 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->i2c->dev;
+ unsigned int prev_mode;
+ int err;
+
+ dev_dbg(dev, "transition to %s mode\n",
+ (mode == MSA311_PWR_MODE_NORMAL) ? "normal" :
+ (mode == MSA311_PWR_MODE_SUSPEND) ? "suspend" :
+ "unknown");
+
+ 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 wakeup */
+ 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->i2c->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->i2c->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 (%d)\n",
+ chan->datasheet_name, 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->i2c->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 (%d)\n", 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->i2c->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 freq (%d)\n", 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->i2c->dev;
+ unsigned int fs;
+ int err;
+
+ /* We do not have fs >= 1, so skip such values */
+ if (val != 0)
+ return 0;
+
+ err = pm_runtime_resume_and_get(dev);
+ if (err)
+ return err;
+
+ err = -EINVAL;
+ mutex_lock(&msa311->lock);
+ 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) {
+ err = regmap_field_write(msa311->fields[F_FS], fs);
+ if (err) {
+ dev_err(dev, "cannot update scale (%d)\n", err);
+ goto failed;
+ }
+
+ break;
+ }
+
+failed:
+ mutex_unlock(&msa311->lock);
+
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ 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->i2c->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;
+ mutex_lock(&msa311->lock);
+ for (odr = 0; odr < ARRAY_SIZE(msa311_odr_table); ++odr)
+ if (val == msa311_odr_table[odr].val &&
+ val2 == msa311_odr_table[odr].val2) {
+ err = msa311_set_odr(msa311, odr);
+ if (err) {
+ dev_err(dev, "cannot update freq (%d)\n", err);
+ goto failed;
+ }
+
+ break;
+ }
+
+failed:
+ mutex_unlock(&msa311->lock);
+
+ iio_device_release_direct_mode(indio_dev);
+
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ 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->i2c->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_write(msa311->regs, reg, writeval);
+ else
+ err = regmap_read(msa311->regs, reg, readval);
+
+ 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 (%d)\n",
+ (!readval) ? "write" : "read", reg, 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->i2c->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->i2c->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->i2c->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 (%d)\n",
+ state ? "enable" : "disable", 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) ? -EINVAL : 0;
+}
+
+static irqreturn_t msa311_buffer_thread(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct msa311_priv *msa311 = iio_priv(indio_dev);
+ struct device *dev = &msa311->i2c->dev;
+ const struct iio_chan_spec *chan;
+ __le16 axis;
+ int bit = 0, err, i = 0;
+
+ /* Ensure correct alignment of time stamp when present */
+ 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 (%d)\n",
+ chan->datasheet_name, 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);
+ struct device *dev = &msa311->i2c->dev;
+ unsigned int new_data_int_enabled;
+ int err;
+
+ mutex_lock(&msa311->lock);
+
+ /*
+ * We do not check NEW_DATA int status, because of based on
+ * 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);
+
+ /* TODO: check motion interrupts status */
+
+ mutex_unlock(&msa311->lock);
+
+ if (err) {
+ dev_err(dev, "cannot read new_data int state (%d)\n", err);
+ return IRQ_NONE;
+ }
+
+ if (new_data_int_enabled)
+ iio_trigger_poll_chained(msa311->new_data_trig);
+
+ /* TODO: send motion events if needed */
+
+ 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->i2c->dev;
+ unsigned int partid;
+ int err;
+
+ err = regmap_read(msa311->regs, MSA311_PARTID_REG, &partid);
+ if (err) {
+ dev_err(dev, "failed to read partid (%d)\n", err);
+ return err;
+ }
+
+ dev_dbg(dev, "Found MSA311 compatible chip[%#x]\n", partid);
+
+ if (partid != MSA311_WHO_AM_I)
+ dev_warn(dev, "invalid partid (%#x), expected (%#x)\n",
+ partid, MSA311_WHO_AM_I);
+
+ return 0;
+}
+
+static int msa311_chip_init(struct msa311_priv *msa311)
+{
+ struct device *dev = &msa311->i2c->dev;
+ int err;
+
+ err = msa311_check_partid(msa311);
+ if (err)
+ return err;
+
+ /* Soft reset */
+ 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");
+
+ err = msa311_set_pwr_mode(msa311, MSA311_PWR_MODE_NORMAL);
+ if (err)
+ return dev_err_probe(dev, err, "bad normal mode transition\n");
+
+ 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 intrs\n");
+
+ err = regmap_write(msa311->regs, MSA311_INT_SET_1_REG, 0);
+ if (err)
+ return dev_err_probe(dev, err, "cannot disable set1 intrs\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 intrs\n");
+
+ err = regmap_write(msa311->regs, MSA311_INT_MAP_1_REG, 0);
+ if (err)
+ return dev_err_probe(dev, err, "failed to unmap map1 intrs\n");
+
+ /* Disable all axis 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 freq\n");
+
+ return 0;
+}
+
+static int msa311_setup_interrupts(struct msa311_priv *msa311)
+{
+ struct iio_trigger *trig;
+ struct i2c_client *i2c = msa311->i2c;
+ struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
+ struct device *dev = &i2c->dev;
+ int err;
+
+ err = devm_request_threaded_irq(dev, i2c->irq,
+ NULL, msa311_irq_thread,
+ IRQF_ONESHOT,
+ i2c->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", i2c->name);
+ if (!trig)
+ return dev_err_probe(dev, -ENOMEM,
+ "cannot allocate newdata trig\n");
+
+ msa311->new_data_trig = trig;
+ msa311->new_data_trig->dev.parent = dev;
+ 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 trig\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 int\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 int 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 int\n");
+
+ err = regmap_field_write(msa311->fields[F_RESET_INT], 1);
+ if (err)
+ return dev_err_probe(dev, err, "cannot reset int\n");
+
+ err = regmap_field_write(msa311->fields[F_INT1_NEW_DATA], 1);
+ if (err)
+ return dev_err_probe(dev, err, "cannot map new data int\n");
+
+ return 0;
+}
+
+static int msa311_regmap_init(struct msa311_priv *msa311)
+{
+ struct regmap_field **fields = msa311->fields;
+ struct device *dev = &msa311->i2c->dev;
+ struct regmap *regmap;
+ int i;
+
+ regmap = devm_regmap_init_i2c(msa311->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 reg field[%d]\n", i);
+ }
+ }
+
+ return 0;
+}
+
+static void msa311_powerdown(void *dev)
+{
+ /* Resume device if any */
+ pm_runtime_get_sync(dev);
+
+ /* Suspend device right now */
+ pm_runtime_put_sync_suspend(dev);
+}
+
+static int msa311_probe(struct i2c_client *i2c)
+{
+ struct msa311_priv *msa311;
+ struct iio_dev *indio_dev;
+ struct device *dev = &i2c->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->i2c = i2c;
+ i2c_set_clientdata(i2c, indio_dev);
+
+ err = msa311_regmap_init(msa311);
+ if (err)
+ return err;
+
+ mutex_init(&msa311->lock);
+
+ err = devm_pm_runtime_enable(dev);
+ if (err)
+ return err;
+
+ /* Resume msa311 logic before any interactions with registers */
+ err = pm_runtime_resume_and_get(dev);
+ if (err)
+ return err;
+
+ 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; /* setup buffered mode later */
+ indio_dev->channels = msa311_channels;
+ indio_dev->num_channels = ARRAY_SIZE(msa311_channels);
+ indio_dev->name = i2c->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 trig buf\n");
+
+ if (i2c->irq > 0) {
+ err = msa311_setup_interrupts(msa311);
+ if (err)
+ return err;
+ }
+
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+
+ /*
+ * 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, dev);
+ if (err)
+ return dev_err_probe(dev, err, "cannot add powerdown action\n");
+
+ 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;
+
+ dev_dbg(dev, "suspending %s\n", dev->driver->name);
+
+ 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 (%d)\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+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;
+
+ dev_dbg(dev, "resuming %s\n", dev->driver->name);
+
+ 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 (%d)\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+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@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("MEMSensing MSA311 3-axis accelerometer driver");
+MODULE_LICENSE("GPL v2");
--
2.36.0