[PATCH V6 05/11] iio: imu: inv_icm42607: Add PM support for icm42607

[Chris Morgan <macroalpha82@gmail.com>]

From: Chris Morgan <macromorgan@hotmail.com>

Add power management support for the ICM42607 device driver.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
---
 drivers/iio/imu/inv_icm42607/inv_icm42607.h   |  12 ++
 .../iio/imu/inv_icm42607/inv_icm42607_core.c  | 151 ++++++++++++++++++
 .../iio/imu/inv_icm42607/inv_icm42607_i2c.c   |   1 +
 .../iio/imu/inv_icm42607/inv_icm42607_spi.c   |   1 +
 4 files changed, 165 insertions(+)

diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607.h b/drivers/iio/imu/inv_icm42607/inv_icm42607.h
index 2c20e95b237a..5f37999e39a5 100644
--- a/drivers/iio/imu/inv_icm42607/inv_icm42607.h
+++ b/drivers/iio/imu/inv_icm42607/inv_icm42607.h
@@ -10,6 +10,7 @@
 #include <linux/bitops.h>
 #include <linux/iio/iio.h>
 #include <linux/mutex.h>
+#include <linux/pm.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 
@@ -96,24 +97,34 @@ struct inv_icm42607_hw {
 	const struct inv_icm42607_conf *conf;
 };
 
+struct inv_icm42607_suspended {
+	enum inv_icm42607_sensor_mode gyro;
+	enum inv_icm42607_sensor_mode accel;
+	bool temp;
+};
+
 /**
  *  struct inv_icm42607_state - driver state variables
  *  @lock:		lock for serializing multiple registers access.
  *  @hw:		Hardware specific data.
  *  @map:		regmap pointer.
  *  @vddio_supply:	I/O voltage regulator for the chip.
+ *  @vddio_en:		I/O voltage status for runtime PM.
  *  @irq:		chip irq, required to enable/disable and set wakeup
  *  @orientation:	sensor chip orientation relative to main hardware.
  *  @conf:		chip sensors configurations.
+ *  @suspended:		suspended sensors configuration.
  */
 struct inv_icm42607_state {
 	struct mutex lock;
 	const struct inv_icm42607_hw *hw;
 	struct regmap *map;
 	struct regulator *vddio_supply;
+	bool vddio_en;
 	int irq;
 	struct iio_mount_matrix orientation;
 	struct inv_icm42607_conf conf;
+	struct inv_icm42607_suspended suspended;
 };
 
 /* Virtual register addresses: @bank on MSB (4 upper bits), @address on LSB */
@@ -339,6 +350,7 @@ typedef int (*inv_icm42607_bus_setup)(struct inv_icm42607_state *);
 extern const struct regmap_config inv_icm42607_regmap_config;
 extern const struct inv_icm42607_hw inv_icm42607_hw_data;
 extern const struct inv_icm42607_hw inv_icm42607p_hw_data;
+extern const struct dev_pm_ops inv_icm42607_pm_ops;
 
 int inv_icm42607_core_probe(struct regmap *regmap, const struct inv_icm42607_hw *hw,
 			    inv_icm42607_bus_setup bus_setup);
diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
index 6119379ca6a8..dfd2fed7bf1e 100644
--- a/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
+++ b/drivers/iio/imu/inv_icm42607/inv_icm42607_core.c
@@ -9,6 +9,7 @@
 #include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/pm_runtime.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
@@ -72,6 +73,62 @@ const struct inv_icm42607_hw inv_icm42607p_hw_data = {
 };
 EXPORT_SYMBOL_NS_GPL(inv_icm42607p_hw_data, "IIO_ICM42607");
 
+static int inv_icm42607_set_pwr_mgmt0(struct inv_icm42607_state *st,
+				      enum inv_icm42607_sensor_mode gyro,
+				      enum inv_icm42607_sensor_mode accel,
+				      bool temp, unsigned int *sleep_ms)
+{
+	enum inv_icm42607_sensor_mode oldgyro = st->conf.gyro.mode;
+	enum inv_icm42607_sensor_mode oldaccel = st->conf.accel.mode;
+	bool oldtemp = st->conf.temp_en;
+	unsigned int sleepval;
+	unsigned int val;
+	int ret;
+
+	if (gyro == oldgyro && accel == oldaccel && temp == oldtemp)
+		return 0;
+
+	val = FIELD_PREP(INV_ICM42607_PWR_MGMT0_GYRO_MODE_MASK, gyro);
+	val |= FIELD_PREP(INV_ICM42607_PWR_MGMT0_ACCEL_MODE_MASK, accel);
+	if (!temp)
+		val |= INV_ICM42607_PWR_MGMT0_ACCEL_LP_CLK_SEL;
+	ret = regmap_write(st->map, INV_ICM42607_REG_PWR_MGMT0, val);
+	if (ret)
+		return ret;
+
+	st->conf.gyro.mode = gyro;
+	st->conf.accel.mode = accel;
+	st->conf.temp_en = temp;
+
+	sleepval = 0;
+	if (temp && !oldtemp) {
+		if (sleepval < INV_ICM42607_TEMP_STARTUP_TIME_MS)
+			sleepval = INV_ICM42607_TEMP_STARTUP_TIME_MS;
+	}
+	if (accel != oldaccel && oldaccel == INV_ICM42607_SENSOR_MODE_OFF) {
+		usleep_range(200, 300);
+		if (sleepval < INV_ICM42607_ACCEL_STARTUP_TIME_MS)
+			sleepval = INV_ICM42607_ACCEL_STARTUP_TIME_MS;
+	}
+	if (gyro != oldgyro) {
+		if (oldgyro == INV_ICM42607_SENSOR_MODE_OFF) {
+			usleep_range(200, 300);
+			if (sleepval < INV_ICM42607_GYRO_STARTUP_TIME_MS)
+				sleepval = INV_ICM42607_GYRO_STARTUP_TIME_MS;
+		} else if (gyro == INV_ICM42607_SENSOR_MODE_OFF) {
+			if (sleepval < INV_ICM42607_GYRO_STOP_TIME_MS)
+				sleepval = INV_ICM42607_GYRO_STOP_TIME_MS;
+		}
+	}
+
+	if (sleep_ms)
+		*sleep_ms = sleepval;
+	else if (sleepval)
+		msleep(sleepval);
+
+	return 0;
+}
+
 static int inv_icm42607_set_conf(struct inv_icm42607_state *st,
 				 const struct inv_icm42607_conf *conf)
 {
@@ -185,11 +242,15 @@ static int inv_icm42607_enable_vddio_reg(struct inv_icm42607_state *st)
 {
 	int ret;
 
+	if (st->vddio_en)
+		return 0;
+
 	ret = regulator_enable(st->vddio_supply);
 	if (ret)
 		return ret;
 
 	fsleep(INV_ICM42607_POWER_UP_TIME_US);
+	st->vddio_en = 1;
 
 	return 0;
 }
@@ -198,7 +259,10 @@ static void inv_icm42607_disable_vddio_reg(void *_data)
 {
 	struct inv_icm42607_state *st = _data;
 
+	if (!st->vddio_en)
+		return;
 	regulator_disable(st->vddio_supply);
+	st->vddio_en = 0;
 }
 
 int inv_icm42607_core_probe(struct regmap *regmap, const struct inv_icm42607_hw *hw,
@@ -256,10 +320,97 @@ int inv_icm42607_core_probe(struct regmap *regmap, const struct inv_icm42607_hw
 	if (ret)
 		return ret;
 
+	ret = devm_pm_runtime_set_active_enabled(dev);
+	if (ret)
+		return ret;
+
+	pm_runtime_set_autosuspend_delay(dev, INV_ICM42607_SUSPEND_DELAY_MS);
+	pm_runtime_use_autosuspend(dev);
+
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(inv_icm42607_core_probe, "IIO_ICM42607");
 
+/*
+ * Suspend saves sensors state and turns everything off.
+ * Check first if runtime suspend has not already done the job.
+ */
+static int inv_icm42607_suspend(struct device *dev)
+{
+	struct inv_icm42607_state *st = dev_get_drvdata(dev);
+	int ret;
+
+	guard(mutex)(&st->lock);
+
+	if (pm_runtime_suspended(dev))
+		return 0;
+
+	ret = inv_icm42607_set_pwr_mgmt0(st, INV_ICM42607_SENSOR_MODE_OFF,
+					 INV_ICM42607_SENSOR_MODE_OFF,
+					 false, NULL);
+	if (ret)
+		return ret;
+	inv_icm42607_disable_vddio_reg(st);
+
+	return 0;
+}
+
+/*
+ * System resume gets the system back on and restores the sensors state.
+ * Manually put runtime power management in system active state.
+ */
+static int inv_icm42607_resume(struct device *dev)
+{
+	struct inv_icm42607_state *st = dev_get_drvdata(dev);
+	int ret;
+
+	guard(mutex)(&st->lock);
+
+	if (pm_runtime_suspended(dev))
+		return 0;
+
+	ret = inv_icm42607_enable_vddio_reg(st);
+	if (ret)
+		return ret;
+
+	/* Nothing else to restore at this time. */
+
+	return 0;
+}
+
+static int inv_icm42607_runtime_suspend(struct device *dev)
+{
+	struct inv_icm42607_state *st = dev_get_drvdata(dev);
+	int ret = 0;
+
+	guard(mutex)(&st->lock);
+
+	ret = inv_icm42607_set_pwr_mgmt0(st, INV_ICM42607_SENSOR_MODE_OFF,
+					 INV_ICM42607_SENSOR_MODE_OFF, false,
+					 NULL);
+	if (ret)
+		return ret;
+
+	inv_icm42607_disable_vddio_reg(st);
+
+	return 0;
+}
+
+static int inv_icm42607_runtime_resume(struct device *dev)
+{
+	struct inv_icm42607_state *st = dev_get_drvdata(dev);
+
+	guard(mutex)(&st->lock);
+
+	return inv_icm42607_enable_vddio_reg(st);
+}
+
+EXPORT_NS_GPL_DEV_PM_OPS(inv_icm42607_pm_ops, IIO_ICM42607) = {
+	SYSTEM_SLEEP_PM_OPS(inv_icm42607_suspend, inv_icm42607_resume)
+	RUNTIME_PM_OPS(inv_icm42607_runtime_suspend,
+		       inv_icm42607_runtime_resume, NULL)
+};
+
 MODULE_AUTHOR("InvenSense, Inc.");
 MODULE_DESCRIPTION("InvenSense ICM-42607x device driver");
 MODULE_LICENSE("GPL");
diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607_i2c.c b/drivers/iio/imu/inv_icm42607/inv_icm42607_i2c.c
index 8631579a609a..a51c764bf1dc 100644
--- a/drivers/iio/imu/inv_icm42607/inv_icm42607_i2c.c
+++ b/drivers/iio/imu/inv_icm42607/inv_icm42607_i2c.c
@@ -77,6 +77,7 @@ static struct i2c_driver inv_icm42607_driver = {
 	.driver = {
 		.name = "inv-icm42607-i2c",
 		.of_match_table = inv_icm42607_of_matches,
+		.pm = pm_ptr(&inv_icm42607_pm_ops),
 	},
 	.id_table = inv_icm42607_id,
 	.probe = inv_icm42607_probe,
diff --git a/drivers/iio/imu/inv_icm42607/inv_icm42607_spi.c b/drivers/iio/imu/inv_icm42607/inv_icm42607_spi.c
index 49438fa6f867..9ba3dd0c689a 100644
--- a/drivers/iio/imu/inv_icm42607/inv_icm42607_spi.c
+++ b/drivers/iio/imu/inv_icm42607/inv_icm42607_spi.c
@@ -90,6 +90,7 @@ static struct spi_driver inv_icm42607_driver = {
 	.driver = {
 		.name = "inv-icm42607-spi",
 		.of_match_table = inv_icm42607_of_matches,
+		.pm = pm_ptr(&inv_icm42607_pm_ops),
 	},
 	.id_table = inv_icm42607_spi_id_table,
 	.probe = inv_icm42607_probe,
-- 
2.43.0