Merge tag 'iio-5.7a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

First set of new IIO device support, fatures and cleanups for the 5.7 cycle

Includes changes for the counter subsystem

Core Feature
* Explicitly handle sysfs values in dB, including correctly handling the
  needed postfix dB.
* Add a TODO to suggest suitable activities for new contributors to IIO now
  the vast majority of drivers are out of staging (and the remaining ones
  there are 'hard'). Also update the TODO in staging to remove stale entries.

Staging graduations
* ad7192 ADC.

New device support
* ad5770r
  - New driver for this 6 channel DAC including DT bindings.
* ad8366
  - Add supprot for the hmc1119 attenuator.
* al3010
  - New driver supporting this Dyna-image light sensors.
  - Power management and DT bindings added in additional patches.
* atlas-sensor
  - Add support for atlas DO-SM device.  Reads disolved oxygen in a solution.
* gpap002x00f
  - New driver and bindings to support the GP2AP002A00F and GP2AP002S00F light
    and proximity sensors. There is some limited existing support in
    input.  The intent is to drop this driver once IIO driver is in place.
* hmc425a
  - New driver for this attenuator.
* icp10100
  - New driver for this presure sensor.
* ltc2632
  - Add support for the ltc2636 8 channel DAC. Includes bindings and some
    tidying up of the driver.
* inv_mpu6050
  - Support IAM20680, ICM20609, ICM20689 and ICM20690.
    Includes related tidy up and rework of low pass filter bandwidth
    handling to give suitable values for all chips.

Binding conversions to yaml or missing bindings docs.
* atlas-sensor, including consolidation of previous 3 separate docs into 1.
* ad7923, previously no doc.
* max1363, split into max1238 and max1363 to simplify yaml.
* stm32-adc

Features
* (counter) 104-quad-8
  - Support a filter clock prescaler.
  - Support reporting of encoder cable status.
* ad7124
  - Low pass filter support.
  - Debugfs interface to access registers directly.
* ad8366
  - Support control of hardware gain.
* inv_mpu6050
  - Runtime pm with autosuspend.
* npcm adc
  - Add reset support. This is a breaking change if DT is not in sync,
    however this device is a BMC so the ecosystem is closed enought that
    this should not be a problem.
* srf04
  - Add power management with DT bindings for the GPIO.
* stm32-timer-trigger
  - Power management.
* (counter) stm32-timer-cnt
  - Power management.
* vcnl4000
  - Enable runtime PM for devices that don't use on demand measurement.

Cleanups and minor fixes
* core
  - Avoid double read when using debugfs.  Whilst we provide no guarantees
    on lack of side effects using the debugfs interfaces, this one is
    generate unexpected results so let us tidy it up.
* dac/Kconfig
  - Alphabetic order.
* ad5755
  - Grammar and minor other fixes.
* ad7124
  - Fail probe if get_voltage fails as no meaningful readings can be had
    without knowing the external reference.
  - Switch to selection between different channel attributes rather than
    building the arrays at runtime.
  - Remove the spi_device_id table as the driver cannot be probled without
    more information that can be provided without dt.
  - Update sysfs docs to provide more inormation and bring remaining docs for
    this part out of staging.
* ad9292
  - Use new SPI transfer delay structure.
* adis library
  - Add unlocked version of adis_initial_startup and refactor the function.
  - Add a product ID santiy check.
  - Add support for different self test registers.
  - Use new SPI delay structure.
  - Add new docs and tidy up existing.
* adis16136
  - Initialize adis_data statically.
* adis16400
  - Initialize adis_data statically.
* adis16460
  - Use core __adis_initial_Startup now it supports everything needed.
* adis16480
  - Initialize adis_data statically.
  - Use core __adis_initial_startup now it supports everything needed.
* al3320a
  - Add missing DT binding docs.
  - Tidy up code formatting.
  - Simplify error paths using devm_add_action_or_reset.
  - Ensure autoloading works by adding the of_match_table.
* atlas-sensor
  - Drop false requirement for interrupt line, the value can be polled using
    a sysfs or hrtimer type trigger.
* exynos-adc
  - Silence warning message on deferring probe.
* gp2ap002
  - Greatly simplify the Lux LUT.
  - Reorder actions around buffer setup and tear down as part of a sub-system
    wide standardization of these.
* inv_mpu6050
  - Various lttle tidyups.
  - Simpliy I2C aux MUX handling by enabling it only at startup. It never
    needs to be disabled.
  - Simplify polling rate when magnetometer enabled by putting only under
    control of userspace.
  - Always execute full reset on devices supporting spi. It does no harm
    when using i2c and makes for simpler code.
  - Reduce over the top sleep times for vddio regulator power up.
  - Greatly simplify power and engine management.
  - Fix some delays in polled reads (only visible due to other changes)
  - Stop preventing sampling rate changes whilst running as there is no
    adverse consequence of doing so.
  - Prevent attempting to read the temperature if neither accel nor
    gyro is enabled.
* lmp9100
  - Reorder actions around buffer setup and tear down as part of a sub-system
    wide standardization of these.
* max1118
  - Use new SPI transfer delay structure.
* mcp320x
  - Use new SPI transfer delay structure.
* si1133
  - Read full 24 bit signed integer instead o dropping last 8 bits of value.
    Not a critical fix as just adds precision.
* st_sensors
  - Use st_sensors_dev_name_probe instead of open coded version in st_accel
  - Handle potential memory allocation failure.
* st_lsm6dsx
  - Fix some wrong structure element naming in documentation.
  - Add missing return value check.
* stm32_timer_cnt
  - Drop some unused left over IIO headers from this count subsystem driver.
  - Ensure the clock is enabled in master mode.  Theoretical issue rather
    than one known to happen in the wild.
* tlc4541
  - Use new SPI delay structure.

* tag 'iio-5.7a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio: (98 commits)
  iio: dac: Kconfig: sort symbols alphabetically
  iio: light: gp2ap020a00f: fix iio_triggered_buffer_{predisable,postenable} positions
  iio: potentiostat: lmp9100: fix iio_triggered_buffer_{predisable,postenable} positions
  iio: trigger: stm32-timer: add power management support
  iio: trigger: stm32-timer: rename enabled flag
  iio: add a TODO
  counter: 104-quad-8: Support Differential Encoder Cable Status
  counter: 104-quad-8: Support Filter Clock Prescaler
  iio: pressure: icp10100: add driver for InvenSense ICP-101xx
  iio: industrialio-core: Fix debugfs read
  iio: imu: adis: add a note better explaining state_lock
  iio: imu: adis: update 'adis_data' struct doc-string
  iio: imu: adis: add doc-string for 'adis' struct
  iio: imu: adis_buffer: Use new structure for SPI transfer delays
  iio: adc: ti-tlc4541: Use new structure for SPI transfer delays
  iio: adc: mcp320x: Use new structure for SPI transfer delays
  iio: adc: max1118: Use new structure for SPI transfer delays
  iio: adc: ad9292: Use new structure for SPI transfer delays
  iio: adc: exynos: Silence warning about regulators during deferred probe
  staging: iio: update TODO
  ...

1 files changed, 482 insertions, 169 deletions

diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
index 5096fc49012d..7cb9ff3d3e94 100644
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -16,6 +16,8 @@
 #include <linux/acpi.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
 #include "inv_mpu_iio.h"
 #include "inv_mpu_magn.h"
 
@@ -99,9 +101,31 @@ static const struct inv_mpu6050_reg_map reg_set_6050 = {
 };
 
 static const struct inv_mpu6050_chip_config chip_config_6050 = {
+	.clk = INV_CLK_INTERNAL,
 	.fsr = INV_MPU6050_FSR_2000DPS,
 	.lpf = INV_MPU6050_FILTER_20HZ,
-	.divider = INV_MPU6050_FIFO_RATE_TO_DIVIDER(INV_MPU6050_INIT_FIFO_RATE),
+	.divider = INV_MPU6050_FIFO_RATE_TO_DIVIDER(50),
+	.gyro_en = true,
+	.accl_en = true,
+	.temp_en = true,
+	.magn_en = false,
+	.gyro_fifo_enable = false,
+	.accl_fifo_enable = false,
+	.temp_fifo_enable = false,
+	.magn_fifo_enable = false,
+	.accl_fs = INV_MPU6050_FS_02G,
+	.user_ctrl = 0,
+};
+
+static const struct inv_mpu6050_chip_config chip_config_6500 = {
+	.clk = INV_CLK_PLL,
+	.fsr = INV_MPU6050_FSR_2000DPS,
+	.lpf = INV_MPU6050_FILTER_20HZ,
+	.divider = INV_MPU6050_FIFO_RATE_TO_DIVIDER(50),
+	.gyro_en = true,
+	.accl_en = true,
+	.temp_en = true,
+	.magn_en = false,
 	.gyro_fifo_enable = false,
 	.accl_fifo_enable = false,
 	.temp_fifo_enable = false,
@@ -124,7 +148,7 @@ static const struct inv_mpu6050_hw hw_info[] = {
 		.whoami = INV_MPU6500_WHOAMI_VALUE,
 		.name = "MPU6500",
 		.reg = &reg_set_6500,
-		.config = &chip_config_6050,
+		.config = &chip_config_6500,
 		.fifo_size = 512,
 		.temp = {INV_MPU6500_TEMP_OFFSET, INV_MPU6500_TEMP_SCALE},
 	},
@@ -132,7 +156,7 @@ static const struct inv_mpu6050_hw hw_info[] = {
 		.whoami = INV_MPU6515_WHOAMI_VALUE,
 		.name = "MPU6515",
 		.reg = &reg_set_6500,
-		.config = &chip_config_6050,
+		.config = &chip_config_6500,
 		.fifo_size = 512,
 		.temp = {INV_MPU6500_TEMP_OFFSET, INV_MPU6500_TEMP_SCALE},
 	},
@@ -156,7 +180,7 @@ static const struct inv_mpu6050_hw hw_info[] = {
 		.whoami = INV_MPU9250_WHOAMI_VALUE,
 		.name = "MPU9250",
 		.reg = &reg_set_6500,
-		.config = &chip_config_6050,
+		.config = &chip_config_6500,
 		.fifo_size = 512,
 		.temp = {INV_MPU6500_TEMP_OFFSET, INV_MPU6500_TEMP_SCALE},
 	},
@@ -164,7 +188,7 @@ static const struct inv_mpu6050_hw hw_info[] = {
 		.whoami = INV_MPU9255_WHOAMI_VALUE,
 		.name = "MPU9255",
 		.reg = &reg_set_6500,
-		.config = &chip_config_6050,
+		.config = &chip_config_6500,
 		.fifo_size = 512,
 		.temp = {INV_MPU6500_TEMP_OFFSET, INV_MPU6500_TEMP_SCALE},
 	},
@@ -172,104 +196,242 @@ static const struct inv_mpu6050_hw hw_info[] = {
 		.whoami = INV_ICM20608_WHOAMI_VALUE,
 		.name = "ICM20608",
 		.reg = &reg_set_6500,
-		.config = &chip_config_6050,
+		.config = &chip_config_6500,
 		.fifo_size = 512,
 		.temp = {INV_ICM20608_TEMP_OFFSET, INV_ICM20608_TEMP_SCALE},
 	},
 	{
+		.whoami = INV_ICM20609_WHOAMI_VALUE,
+		.name = "ICM20609",
+		.reg = &reg_set_6500,
+		.config = &chip_config_6500,
+		.fifo_size = 4 * 1024,
+		.temp = {INV_ICM20608_TEMP_OFFSET, INV_ICM20608_TEMP_SCALE},
+	},
+	{
+		.whoami = INV_ICM20689_WHOAMI_VALUE,
+		.name = "ICM20689",
+		.reg = &reg_set_6500,
+		.config = &chip_config_6500,
+		.fifo_size = 4 * 1024,
+		.temp = {INV_ICM20608_TEMP_OFFSET, INV_ICM20608_TEMP_SCALE},
+	},
+	{
 		.whoami = INV_ICM20602_WHOAMI_VALUE,
 		.name = "ICM20602",
 		.reg = &reg_set_icm20602,
-		.config = &chip_config_6050,
+		.config = &chip_config_6500,
 		.fifo_size = 1008,
 		.temp = {INV_ICM20608_TEMP_OFFSET, INV_ICM20608_TEMP_SCALE},
 	},
+	{
+		.whoami = INV_ICM20690_WHOAMI_VALUE,
+		.name = "ICM20690",
+		.reg = &reg_set_6500,
+		.config = &chip_config_6500,
+		.fifo_size = 1024,
+		.temp = {INV_ICM20608_TEMP_OFFSET, INV_ICM20608_TEMP_SCALE},
+	},
+	{
+		.whoami = INV_IAM20680_WHOAMI_VALUE,
+		.name = "IAM20680",
+		.reg = &reg_set_6500,
+		.config = &chip_config_6500,
+		.fifo_size = 512,
+		.temp = {INV_ICM20608_TEMP_OFFSET, INV_ICM20608_TEMP_SCALE},
+	},
 };
 
-int inv_mpu6050_switch_engine(struct inv_mpu6050_state *st, bool en, u32 mask)
+static int inv_mpu6050_pwr_mgmt_1_write(struct inv_mpu6050_state *st, bool sleep,
+					int clock, int temp_dis)
 {
-	unsigned int d, mgmt_1;
-	int result;
-	/*
-	 * switch clock needs to be careful. Only when gyro is on, can
-	 * clock source be switched to gyro. Otherwise, it must be set to
-	 * internal clock
-	 */
-	if (mask == INV_MPU6050_BIT_PWR_GYRO_STBY) {
-		result = regmap_read(st->map, st->reg->pwr_mgmt_1, &mgmt_1);
-		if (result)
-			return result;
+	u8 val;
+
+	if (clock < 0)
+		clock = st->chip_config.clk;
+	if (temp_dis < 0)
+		temp_dis = !st->chip_config.temp_en;
 
-		mgmt_1 &= ~INV_MPU6050_BIT_CLK_MASK;
+	val = clock & INV_MPU6050_BIT_CLK_MASK;
+	if (temp_dis)
+		val |= INV_MPU6050_BIT_TEMP_DIS;
+	if (sleep)
+		val |= INV_MPU6050_BIT_SLEEP;
+
+	dev_dbg(regmap_get_device(st->map), "pwr_mgmt_1: 0x%x\n", val);
+	return regmap_write(st->map, st->reg->pwr_mgmt_1, val);
+}
+
+static int inv_mpu6050_clock_switch(struct inv_mpu6050_state *st,
+				    unsigned int clock)
+{
+	int ret;
+
+	switch (st->chip_type) {
+	case INV_MPU6050:
+	case INV_MPU6000:
+	case INV_MPU9150:
+		/* old chips: switch clock manually */
+		ret = inv_mpu6050_pwr_mgmt_1_write(st, false, clock, -1);
+		if (ret)
+			return ret;
+		st->chip_config.clk = clock;
+		break;
+	default:
+		/* automatic clock switching, nothing to do */
+		break;
 	}
 
-	if ((mask == INV_MPU6050_BIT_PWR_GYRO_STBY) && (!en)) {
-		/*
-		 * turning off gyro requires switch to internal clock first.
-		 * Then turn off gyro engine
-		 */
-		mgmt_1 |= INV_CLK_INTERNAL;
-		result = regmap_write(st->map, st->reg->pwr_mgmt_1, mgmt_1);
-		if (result)
-			return result;
+	return 0;
+}
+
+int inv_mpu6050_switch_engine(struct inv_mpu6050_state *st, bool en,
+			      unsigned int mask)
+{
+	unsigned int sleep;
+	u8 pwr_mgmt2, user_ctrl;
+	int ret;
+
+	/* delete useless requests */
+	if (mask & INV_MPU6050_SENSOR_ACCL && en == st->chip_config.accl_en)
+		mask &= ~INV_MPU6050_SENSOR_ACCL;
+	if (mask & INV_MPU6050_SENSOR_GYRO && en == st->chip_config.gyro_en)
+		mask &= ~INV_MPU6050_SENSOR_GYRO;
+	if (mask & INV_MPU6050_SENSOR_TEMP && en == st->chip_config.temp_en)
+		mask &= ~INV_MPU6050_SENSOR_TEMP;
+	if (mask & INV_MPU6050_SENSOR_MAGN && en == st->chip_config.magn_en)
+		mask &= ~INV_MPU6050_SENSOR_MAGN;
+	if (mask == 0)
+		return 0;
+
+	/* turn on/off temperature sensor */
+	if (mask & INV_MPU6050_SENSOR_TEMP) {
+		ret = inv_mpu6050_pwr_mgmt_1_write(st, false, -1, !en);
+		if (ret)
+			return ret;
+		st->chip_config.temp_en = en;
 	}
 
-	result = regmap_read(st->map, st->reg->pwr_mgmt_2, &d);
-	if (result)
-		return result;
-	if (en)
-		d &= ~mask;
-	else
-		d |= mask;
-	result = regmap_write(st->map, st->reg->pwr_mgmt_2, d);
-	if (result)
-		return result;
+	/* update user_crtl for driving magnetometer */
+	if (mask & INV_MPU6050_SENSOR_MAGN) {
+		user_ctrl = st->chip_config.user_ctrl;
+		if (en)
+			user_ctrl |= INV_MPU6050_BIT_I2C_MST_EN;
+		else
+			user_ctrl &= ~INV_MPU6050_BIT_I2C_MST_EN;
+		ret = regmap_write(st->map, st->reg->user_ctrl, user_ctrl);
+		if (ret)
+			return ret;
+		st->chip_config.user_ctrl = user_ctrl;
+		st->chip_config.magn_en = en;
+	}
 
-	if (en) {
-		/* Wait for output to stabilize */
-		msleep(INV_MPU6050_TEMP_UP_TIME);
-		if (mask == INV_MPU6050_BIT_PWR_GYRO_STBY) {
-			/* switch internal clock to PLL */
-			mgmt_1 |= INV_CLK_PLL;
-			result = regmap_write(st->map,
-					      st->reg->pwr_mgmt_1, mgmt_1);
-			if (result)
-				return result;
+	/* manage accel & gyro engines */
+	if (mask & (INV_MPU6050_SENSOR_ACCL | INV_MPU6050_SENSOR_GYRO)) {
+		/* compute power management 2 current value */
+		pwr_mgmt2 = 0;
+		if (!st->chip_config.accl_en)
+			pwr_mgmt2 |= INV_MPU6050_BIT_PWR_ACCL_STBY;
+		if (!st->chip_config.gyro_en)
+			pwr_mgmt2 |= INV_MPU6050_BIT_PWR_GYRO_STBY;
+
+		/* update to new requested value */
+		if (mask & INV_MPU6050_SENSOR_ACCL) {
+			if (en)
+				pwr_mgmt2 &= ~INV_MPU6050_BIT_PWR_ACCL_STBY;
+			else
+				pwr_mgmt2 |= INV_MPU6050_BIT_PWR_ACCL_STBY;
+		}
+		if (mask & INV_MPU6050_SENSOR_GYRO) {
+			if (en)
+				pwr_mgmt2 &= ~INV_MPU6050_BIT_PWR_GYRO_STBY;
+			else
+				pwr_mgmt2 |= INV_MPU6050_BIT_PWR_GYRO_STBY;
+		}
+
+		/* switch clock to internal when turning gyro off */
+		if (mask & INV_MPU6050_SENSOR_GYRO && !en) {
+			ret = inv_mpu6050_clock_switch(st, INV_CLK_INTERNAL);
+			if (ret)
+				return ret;
+		}
+
+		/* update sensors engine */
+		dev_dbg(regmap_get_device(st->map), "pwr_mgmt_2: 0x%x\n",
+			pwr_mgmt2);
+		ret = regmap_write(st->map, st->reg->pwr_mgmt_2, pwr_mgmt2);
+		if (ret)
+			return ret;
+		if (mask & INV_MPU6050_SENSOR_ACCL)
+			st->chip_config.accl_en = en;
+		if (mask & INV_MPU6050_SENSOR_GYRO)
+			st->chip_config.gyro_en = en;
+
+		/* compute required time to have sensors stabilized */
+		sleep = 0;
+		if (en) {
+			if (mask & INV_MPU6050_SENSOR_ACCL) {
+				if (sleep < INV_MPU6050_ACCEL_UP_TIME)
+					sleep = INV_MPU6050_ACCEL_UP_TIME;
+			}
+			if (mask & INV_MPU6050_SENSOR_GYRO) {
+				if (sleep < INV_MPU6050_GYRO_UP_TIME)
+					sleep = INV_MPU6050_GYRO_UP_TIME;
+			}
+		} else {
+			if (mask & INV_MPU6050_SENSOR_GYRO) {
+				if (sleep < INV_MPU6050_GYRO_DOWN_TIME)
+					sleep = INV_MPU6050_GYRO_DOWN_TIME;
+			}
+		}
+		if (sleep)
+			msleep(sleep);
+
+		/* switch clock to PLL when turning gyro on */
+		if (mask & INV_MPU6050_SENSOR_GYRO && en) {
+			ret = inv_mpu6050_clock_switch(st, INV_CLK_PLL);
+			if (ret)
+				return ret;
 		}
 	}
 
 	return 0;
 }
 
-int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on)
+static int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st,
+				     bool power_on)
 {
 	int result;
 
-	if (power_on) {
-		if (!st->powerup_count) {
-			result = regmap_write(st->map, st->reg->pwr_mgmt_1, 0);
-			if (result)
-				return result;
-			usleep_range(INV_MPU6050_REG_UP_TIME_MIN,
-				     INV_MPU6050_REG_UP_TIME_MAX);
-		}
-		st->powerup_count++;
-	} else {
-		if (st->powerup_count == 1) {
-			result = regmap_write(st->map, st->reg->pwr_mgmt_1,
-					      INV_MPU6050_BIT_SLEEP);
-			if (result)
-				return result;
-		}
-		st->powerup_count--;
-	}
+	result = inv_mpu6050_pwr_mgmt_1_write(st, !power_on, -1, -1);
+	if (result)
+		return result;
 
-	dev_dbg(regmap_get_device(st->map), "set power %d, count=%u\n",
-		power_on, st->powerup_count);
+	if (power_on)
+		usleep_range(INV_MPU6050_REG_UP_TIME_MIN,
+			     INV_MPU6050_REG_UP_TIME_MAX);
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(inv_mpu6050_set_power_itg);
+
+static int inv_mpu6050_set_gyro_fsr(struct inv_mpu6050_state *st,
+				    enum inv_mpu6050_fsr_e val)
+{
+	unsigned int gyro_shift;
+	u8 data;
+
+	switch (st->chip_type) {
+	case INV_ICM20690:
+		gyro_shift = INV_ICM20690_GYRO_CONFIG_FSR_SHIFT;
+		break;
+	default:
+		gyro_shift = INV_MPU6050_GYRO_CONFIG_FSR_SHIFT;
+		break;
+	}
+
+	data = val << gyro_shift;
+	return regmap_write(st->map, st->reg->gyro_config, data);
+}
 
 /**
  *  inv_mpu6050_set_lpf_regs() - set low pass filter registers, chip dependent
@@ -286,20 +448,23 @@ static int inv_mpu6050_set_lpf_regs(struct inv_mpu6050_state *st,
 	if (result)
 		return result;
 
+	/* set accel lpf */
 	switch (st->chip_type) {
 	case INV_MPU6050:
 	case INV_MPU6000:
 	case INV_MPU9150:
 		/* old chips, nothing to do */
-		result = 0;
+		return 0;
+	case INV_ICM20689:
+	case INV_ICM20690:
+		/* set FIFO size to maximum value */
+		val |= INV_ICM20689_BITS_FIFO_SIZE_MAX;
 		break;
 	default:
-		/* set accel lpf */
-		result = regmap_write(st->map, st->reg->accel_lpf, val);
 		break;
 	}
 
-	return result;
+	return regmap_write(st->map, st->reg->accel_lpf, val);
 }
 
 /**
@@ -317,35 +482,28 @@ static int inv_mpu6050_init_config(struct iio_dev *indio_dev)
 	u8 d;
 	struct inv_mpu6050_state *st = iio_priv(indio_dev);
 
-	result = inv_mpu6050_set_power_itg(st, true);
+	result = inv_mpu6050_set_gyro_fsr(st, st->chip_config.fsr);
 	if (result)
 		return result;
-	d = (INV_MPU6050_FSR_2000DPS << INV_MPU6050_GYRO_CONFIG_FSR_SHIFT);
-	result = regmap_write(st->map, st->reg->gyro_config, d);
-	if (result)
-		goto error_power_off;
 
-	result = inv_mpu6050_set_lpf_regs(st, INV_MPU6050_FILTER_20HZ);
+	result = inv_mpu6050_set_lpf_regs(st, st->chip_config.lpf);
 	if (result)
-		goto error_power_off;
+		return result;
 
-	d = INV_MPU6050_FIFO_RATE_TO_DIVIDER(INV_MPU6050_INIT_FIFO_RATE);
+	d = st->chip_config.divider;
 	result = regmap_write(st->map, st->reg->sample_rate_div, d);
 	if (result)
-		goto error_power_off;
+		return result;
 
-	d = (INV_MPU6050_FS_02G << INV_MPU6050_ACCL_CONFIG_FSR_SHIFT);
+	d = (st->chip_config.accl_fs << INV_MPU6050_ACCL_CONFIG_FSR_SHIFT);
 	result = regmap_write(st->map, st->reg->accl_config, d);
 	if (result)
-		goto error_power_off;
+		return result;
 
 	result = regmap_write(st->map, st->reg->int_pin_cfg, st->irq_mask);
 	if (result)
 		return result;
 
-	memcpy(&st->chip_config, hw_info[st->chip_type].config,
-	       sizeof(struct inv_mpu6050_chip_config));
-
 	/*
 	 * Internal chip period is 1ms (1kHz).
 	 * Let's use at the beginning the theorical value before measuring
@@ -356,13 +514,9 @@ static int inv_mpu6050_init_config(struct iio_dev *indio_dev)
 	/* magn chip init, noop if not present in the chip */
 	result = inv_mpu_magn_probe(st);
 	if (result)
-		goto error_power_off;
-
-	return inv_mpu6050_set_power_itg(st, false);
+		return result;
 
-error_power_off:
-	inv_mpu6050_set_power_itg(st, false);
-	return result;
+	return 0;
 }
 
 static int inv_mpu6050_sensor_set(struct inv_mpu6050_state  *st, int reg,
@@ -399,45 +553,85 @@ static int inv_mpu6050_read_channel_data(struct iio_dev *indio_dev,
 					 int *val)
 {
 	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+	struct device *pdev = regmap_get_device(st->map);
+	unsigned int freq_hz, period_us, min_sleep_us, max_sleep_us;
 	int result;
 	int ret;
 
-	result = inv_mpu6050_set_power_itg(st, true);
-	if (result)
+	/* compute sample period */
+	freq_hz = INV_MPU6050_DIVIDER_TO_FIFO_RATE(st->chip_config.divider);
+	period_us = 1000000 / freq_hz;
+
+	result = pm_runtime_get_sync(pdev);
+	if (result < 0) {
+		pm_runtime_put_noidle(pdev);
 		return result;
+	}
 
 	switch (chan->type) {
 	case IIO_ANGL_VEL:
-		result = inv_mpu6050_switch_engine(st, true,
-				INV_MPU6050_BIT_PWR_GYRO_STBY);
-		if (result)
-			goto error_power_off;
+		if (!st->chip_config.gyro_en) {
+			result = inv_mpu6050_switch_engine(st, true,
+					INV_MPU6050_SENSOR_GYRO);
+			if (result)
+				goto error_power_off;
+			/* need to wait 2 periods to have first valid sample */
+			min_sleep_us = 2 * period_us;
+			max_sleep_us = 2 * (period_us + period_us / 2);
+			usleep_range(min_sleep_us, max_sleep_us);
+		}
 		ret = inv_mpu6050_sensor_show(st, st->reg->raw_gyro,
 					      chan->channel2, val);
-		result = inv_mpu6050_switch_engine(st, false,
-				INV_MPU6050_BIT_PWR_GYRO_STBY);
-		if (result)
-			goto error_power_off;
 		break;
 	case IIO_ACCEL:
-		result = inv_mpu6050_switch_engine(st, true,
-				INV_MPU6050_BIT_PWR_ACCL_STBY);
-		if (result)
-			goto error_power_off;
+		if (!st->chip_config.accl_en) {
+			result = inv_mpu6050_switch_engine(st, true,
+					INV_MPU6050_SENSOR_ACCL);
+			if (result)
+				goto error_power_off;
+			/* wait 1 period for first sample availability */
+			min_sleep_us = period_us;
+			max_sleep_us = period_us + period_us / 2;
+			usleep_range(min_sleep_us, max_sleep_us);
+		}
 		ret = inv_mpu6050_sensor_show(st, st->reg->raw_accl,
 					      chan->channel2, val);
-		result = inv_mpu6050_switch_engine(st, false,
-				INV_MPU6050_BIT_PWR_ACCL_STBY);
-		if (result)
-			goto error_power_off;
 		break;
 	case IIO_TEMP:
-		/* wait for stablization */
-		msleep(INV_MPU6050_SENSOR_UP_TIME);
+		/* temperature sensor work only with accel and/or gyro */
+		if (!st->chip_config.accl_en && !st->chip_config.gyro_en) {
+			result = -EBUSY;
+			goto error_power_off;
+		}
+		if (!st->chip_config.temp_en) {
+			result = inv_mpu6050_switch_engine(st, true,
+					INV_MPU6050_SENSOR_TEMP);
+			if (result)
+				goto error_power_off;
+			/* wait 1 period for first sample availability */
+			min_sleep_us = period_us;
+			max_sleep_us = period_us + period_us / 2;
+			usleep_range(min_sleep_us, max_sleep_us);
+		}
 		ret = inv_mpu6050_sensor_show(st, st->reg->temperature,
 					      IIO_MOD_X, val);
 		break;
 	case IIO_MAGN:
+		if (!st->chip_config.magn_en) {
+			result = inv_mpu6050_switch_engine(st, true,
+					INV_MPU6050_SENSOR_MAGN);
+			if (result)
+				goto error_power_off;
+			/* frequency is limited for magnetometer */
+			if (freq_hz > INV_MPU_MAGN_FREQ_HZ_MAX) {
+				freq_hz = INV_MPU_MAGN_FREQ_HZ_MAX;
+				period_us = 1000000 / freq_hz;
+			}
+			/* need to wait 2 periods to have first valid sample */
+			min_sleep_us = 2 * period_us;
+			max_sleep_us = 2 * (period_us + period_us / 2);
+			usleep_range(min_sleep_us, max_sleep_us);
+		}
 		ret = inv_mpu_magn_read(st, chan->channel2, val);
 		break;
 	default:
@@ -445,14 +639,13 @@ static int inv_mpu6050_read_channel_data(struct iio_dev *indio_dev,
 		break;
 	}
 
-	result = inv_mpu6050_set_power_itg(st, false);
-	if (result)
-		goto error_power_off;
+	pm_runtime_mark_last_busy(pdev);
+	pm_runtime_put_autosuspend(pdev);
 
 	return ret;
 
 error_power_off:
-	inv_mpu6050_set_power_itg(st, false);
+	pm_runtime_put_autosuspend(pdev);
 	return result;
 }
 
@@ -533,12 +726,10 @@ inv_mpu6050_read_raw(struct iio_dev *indio_dev,
 static int inv_mpu6050_write_gyro_scale(struct inv_mpu6050_state *st, int val)
 {
 	int result, i;
-	u8 d;
 
 	for (i = 0; i < ARRAY_SIZE(gyro_scale_6050); ++i) {
 		if (gyro_scale_6050[i] == val) {
-			d = (i << INV_MPU6050_GYRO_CONFIG_FSR_SHIFT);
-			result = regmap_write(st->map, st->reg->gyro_config, d);
+			result = inv_mpu6050_set_gyro_fsr(st, i);
 			if (result)
 				return result;
 
@@ -593,6 +784,7 @@ static int inv_mpu6050_write_raw(struct iio_dev *indio_dev,
 				 int val, int val2, long mask)
 {
 	struct inv_mpu6050_state  *st = iio_priv(indio_dev);
+	struct device *pdev = regmap_get_device(st->map);
 	int result;
 
 	/*
@@ -604,9 +796,11 @@ static int inv_mpu6050_write_raw(struct iio_dev *indio_dev,
 		return result;
 
 	mutex_lock(&st->lock);
-	result = inv_mpu6050_set_power_itg(st, true);
-	if (result)
+	result = pm_runtime_get_sync(pdev);
+	if (result < 0) {
+		pm_runtime_put_noidle(pdev);
 		goto error_write_raw_unlock;
+	}
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
@@ -644,7 +838,8 @@ static int inv_mpu6050_write_raw(struct iio_dev *indio_dev,
 		break;
 	}
 
-	result |= inv_mpu6050_set_power_itg(st, false);
+	pm_runtime_mark_last_busy(pdev);
+	pm_runtime_put_autosuspend(pdev);
 error_write_raw_unlock:
 	mutex_unlock(&st->lock);
 	iio_device_release_direct_mode(indio_dev);
@@ -655,30 +850,32 @@ error_write_raw_unlock:
 /**
  *  inv_mpu6050_set_lpf() - set low pass filer based on fifo rate.
  *
- *                  Based on the Nyquist principle, the sampling rate must
- *                  exceed twice of the bandwidth of the signal, or there
- *                  would be alising. This function basically search for the
- *                  correct low pass parameters based on the fifo rate, e.g,
- *                  sampling frequency.
+ *                  Based on the Nyquist principle, the bandwidth of the low
+ *                  pass filter must not exceed the signal sampling rate divided
+ *                  by 2, or there would be aliasing.
+ *                  This function basically search for the correct low pass
+ *                  parameters based on the fifo rate, e.g, sampling frequency.
  *
  *  lpf is set automatically when setting sampling rate to avoid any aliases.
  */
 static int inv_mpu6050_set_lpf(struct inv_mpu6050_state *st, int rate)
 {
-	static const int hz[] = {188, 98, 42, 20, 10, 5};
+	static const int hz[] = {400, 200, 90, 40, 20, 10};
 	static const int d[] = {
-		INV_MPU6050_FILTER_188HZ, INV_MPU6050_FILTER_98HZ,
-		INV_MPU6050_FILTER_42HZ, INV_MPU6050_FILTER_20HZ,
+		INV_MPU6050_FILTER_200HZ, INV_MPU6050_FILTER_100HZ,
+		INV_MPU6050_FILTER_45HZ, INV_MPU6050_FILTER_20HZ,
 		INV_MPU6050_FILTER_10HZ, INV_MPU6050_FILTER_5HZ
 	};
-	int i, h, result;
+	int i, result;
 	u8 data;
 
-	h = (rate >> 1);
-	i = 0;
-	while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
-		i++;
-	data = d[i];
+	data = INV_MPU6050_FILTER_5HZ;
+	for (i = 0; i < ARRAY_SIZE(hz); ++i) {
+		if (rate >= hz[i]) {
+			data = d[i];
+			break;
+		}
+	}
 	result = inv_mpu6050_set_lpf_regs(st, data);
 	if (result)
 		return result;
@@ -699,6 +896,7 @@ inv_mpu6050_fifo_rate_store(struct device *dev, struct device_attribute *attr,
 	int result;
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+	struct device *pdev = regmap_get_device(st->map);
 
 	if (kstrtoint(buf, 10, &fifo_rate))
 		return -EINVAL;
@@ -706,10 +904,6 @@ inv_mpu6050_fifo_rate_store(struct device *dev, struct device_attribute *attr,
 	    fifo_rate > INV_MPU6050_MAX_FIFO_RATE)
 		return -EINVAL;
 
-	result = iio_device_claim_direct_mode(indio_dev);
-	if (result)
-		return result;
-
 	/* compute the chip sample rate divider */
 	d = INV_MPU6050_FIFO_RATE_TO_DIVIDER(fifo_rate);
 	/* compute back the fifo rate to handle truncation cases */
@@ -720,9 +914,11 @@ inv_mpu6050_fifo_rate_store(struct device *dev, struct device_attribute *attr,
 		result = 0;
 		goto fifo_rate_fail_unlock;
 	}
-	result = inv_mpu6050_set_power_itg(st, true);
-	if (result)
+	result = pm_runtime_get_sync(pdev);
+	if (result < 0) {
+		pm_runtime_put_noidle(pdev);
 		goto fifo_rate_fail_unlock;
+	}
 
 	result = regmap_write(st->map, st->reg->sample_rate_div, d);
 	if (result)
@@ -738,11 +934,11 @@ inv_mpu6050_fifo_rate_store(struct device *dev, struct device_attribute *attr,
 	if (result)
 		goto fifo_rate_fail_power_off;
 
+	pm_runtime_mark_last_busy(pdev);
 fifo_rate_fail_power_off:
-	result |= inv_mpu6050_set_power_itg(st, false);
+	pm_runtime_put_autosuspend(pdev);
 fifo_rate_fail_unlock:
 	mutex_unlock(&st->lock);
-	iio_device_release_direct_mode(indio_dev);
 	if (result)
 		return result;
 
@@ -1066,11 +1262,13 @@ static const struct iio_info mpu_info = {
 static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
 {
 	int result;
-	unsigned int regval;
+	unsigned int regval, mask;
 	int i;
 
 	st->hw  = &hw_info[st->chip_type];
 	st->reg = hw_info[st->chip_type].reg;
+	memcpy(&st->chip_config, hw_info[st->chip_type].config,
+	       sizeof(st->chip_config));
 
 	/* check chip self-identification */
 	result = regmap_read(st->map, INV_MPU6050_REG_WHOAMI, &regval);
@@ -1102,6 +1300,24 @@ static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
 	if (result)
 		return result;
 	msleep(INV_MPU6050_POWER_UP_TIME);
+	switch (st->chip_type) {
+	case INV_MPU6000:
+	case INV_MPU6500:
+	case INV_MPU6515:
+	case INV_MPU9250:
+	case INV_MPU9255:
+		/* reset signal path (required for spi connection) */
+		regval = INV_MPU6050_BIT_TEMP_RST | INV_MPU6050_BIT_ACCEL_RST |
+			 INV_MPU6050_BIT_GYRO_RST;
+		result = regmap_write(st->map, INV_MPU6050_REG_SIGNAL_PATH_RESET,
+				      regval);
+		if (result)
+			return result;
+		msleep(INV_MPU6050_POWER_UP_TIME);
+		break;
+	default:
+		break;
+	}
 
 	/*
 	 * Turn power on. After reset, the sleep bit could be on
@@ -1112,17 +1328,13 @@ static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
 	result = inv_mpu6050_set_power_itg(st, true);
 	if (result)
 		return result;
-
-	result = inv_mpu6050_switch_engine(st, false,
-					   INV_MPU6050_BIT_PWR_ACCL_STBY);
-	if (result)
-		goto error_power_off;
-	result = inv_mpu6050_switch_engine(st, false,
-					   INV_MPU6050_BIT_PWR_GYRO_STBY);
+	mask = INV_MPU6050_SENSOR_ACCL | INV_MPU6050_SENSOR_GYRO |
+			INV_MPU6050_SENSOR_TEMP | INV_MPU6050_SENSOR_MAGN;
+	result = inv_mpu6050_switch_engine(st, false, mask);
 	if (result)
 		goto error_power_off;
 
-	return inv_mpu6050_set_power_itg(st, false);
+	return 0;
 
 error_power_off:
 	inv_mpu6050_set_power_itg(st, false);
@@ -1139,7 +1351,7 @@ static int inv_mpu_core_enable_regulator_vddio(struct inv_mpu6050_state *st)
 			"Failed to enable vddio regulator: %d\n", result);
 	} else {
 		/* Give the device a little bit of time to start up. */
-		usleep_range(35000, 70000);
+		usleep_range(3000, 5000);
 	}
 
 	return result;
@@ -1170,6 +1382,14 @@ static void inv_mpu_core_disable_regulator_action(void *_data)
 	inv_mpu_core_disable_regulator_vddio(st);
 }
 
+static void inv_mpu_pm_disable(void *data)
+{
+	struct device *dev = data;
+
+	pm_runtime_put_sync_suspend(dev);
+	pm_runtime_disable(dev);
+}
+
 int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
 		int (*inv_mpu_bus_setup)(struct iio_dev *), int chip_type)
 {
@@ -1194,7 +1414,6 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
 	st = iio_priv(indio_dev);
 	mutex_init(&st->lock);
 	st->chip_type = chip_type;
-	st->powerup_count = 0;
 	st->irq = irq;
 	st->map = regmap;
 
@@ -1259,6 +1478,7 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
 		dev_err(dev, "Failed to enable vdd regulator: %d\n", result);
 		return result;
 	}
+	msleep(INV_MPU6050_POWER_UP_TIME);
 
 	result = inv_mpu_core_enable_regulator_vddio(st);
 	if (result) {
@@ -1287,7 +1507,7 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
 	result = inv_mpu6050_init_config(indio_dev);
 	if (result) {
 		dev_err(dev, "Could not initialize device.\n");
-		return result;
+		goto error_power_off;
 	}
 
 	dev_set_drvdata(dev, indio_dev);
@@ -1299,8 +1519,24 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
 		indio_dev->name = dev_name(dev);
 
 	/* requires parent device set in indio_dev */
-	if (inv_mpu_bus_setup)
-		inv_mpu_bus_setup(indio_dev);
+	if (inv_mpu_bus_setup) {
+		result = inv_mpu_bus_setup(indio_dev);
+		if (result)
+			goto error_power_off;
+	}
+
+	/* chip init is done, turning on runtime power management */
+	result = pm_runtime_set_active(dev);
+	if (result)
+		goto error_power_off;
+	pm_runtime_get_noresume(dev);
+	pm_runtime_enable(dev);
+	pm_runtime_set_autosuspend_delay(dev, INV_MPU6050_SUSPEND_DELAY_MS);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_put(dev);
+	result = devm_add_action_or_reset(dev, inv_mpu_pm_disable, dev);
+	if (result)
+		return result;
 
 	switch (chip_type) {
 	case INV_MPU9150:
@@ -1359,14 +1595,17 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
 	}
 
 	return 0;
+
+error_power_off:
+	inv_mpu6050_set_power_itg(st, false);
+	return result;
 }
 EXPORT_SYMBOL_GPL(inv_mpu_core_probe);
 
-#ifdef CONFIG_PM_SLEEP
-
-static int inv_mpu_resume(struct device *dev)
+static int __maybe_unused inv_mpu_resume(struct device *dev)
 {
-	struct inv_mpu6050_state *st = iio_priv(dev_get_drvdata(dev));
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
 	int result;
 
 	mutex_lock(&st->lock);
@@ -1375,27 +1614,101 @@ static int inv_mpu_resume(struct device *dev)
 		goto out_unlock;
 
 	result = inv_mpu6050_set_power_itg(st, true);
+	if (result)
+		goto out_unlock;
+
+	result = inv_mpu6050_switch_engine(st, true, st->suspended_sensors);
+	if (result)
+		goto out_unlock;
+
+	if (iio_buffer_enabled(indio_dev))
+		result = inv_mpu6050_prepare_fifo(st, true);
+
 out_unlock:
 	mutex_unlock(&st->lock);
 
 	return result;
 }
 
-static int inv_mpu_suspend(struct device *dev)
+static int __maybe_unused inv_mpu_suspend(struct device *dev)
 {
-	struct inv_mpu6050_state *st = iio_priv(dev_get_drvdata(dev));
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
 	int result;
 
 	mutex_lock(&st->lock);
+
+	if (iio_buffer_enabled(indio_dev)) {
+		result = inv_mpu6050_prepare_fifo(st, false);
+		if (result)
+			goto out_unlock;
+	}
+
+	st->suspended_sensors = 0;
+	if (st->chip_config.accl_en)
+		st->suspended_sensors |= INV_MPU6050_SENSOR_ACCL;
+	if (st->chip_config.gyro_en)
+		st->suspended_sensors |= INV_MPU6050_SENSOR_GYRO;
+	if (st->chip_config.temp_en)
+		st->suspended_sensors |= INV_MPU6050_SENSOR_TEMP;
+	if (st->chip_config.magn_en)
+		st->suspended_sensors |= INV_MPU6050_SENSOR_MAGN;
+	result = inv_mpu6050_switch_engine(st, false, st->suspended_sensors);
+	if (result)
+		goto out_unlock;
+
 	result = inv_mpu6050_set_power_itg(st, false);
+	if (result)
+		goto out_unlock;