Commit 6da93a67 authored by Irina Tirdea's avatar Irina Tirdea Committed by Jonathan Cameron
Browse files

iio: accel: mma9551: Add runtime pm support 



Add support for runtime pm to reduce the power consumed by the device
when not used.

If CONFIG_PM is not enabled, the device will be powered on at
init and only powered off on system suspend.

If CONFIG_PM is enabled, runtime pm autosuspend is used:
- for raw reads will keep the device on for a specified time
- for events it will keep the device on as long as we have at least
one event active

Signed-off-by: default avatarIrina Tirdea <irina.tirdea@intel.com>
Reviewed-by: default avatarVlad Dogaru <vlad.dogaru@intel.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 17a2cbc2

drivers/iio/accel/mma9551.c

+139 −23
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/iio/events.h>

#include <linux/pm_runtime.h>



#define MMA9551_DRV_NAME		"mma9551"

#define MMA9551_IRQ_NAME		"mma9551_event"
@@ -71,6 +72,7 @@ enum mma9551_gpio_pin { 
/* Sleep/Wake application */

#define MMA9551_SLEEP_CFG		0x06

#define MMA9551_SLEEP_CFG_SNCEN		BIT(0)

#define MMA9551_SLEEP_CFG_FLEEN		BIT(1)

#define MMA9551_SLEEP_CFG_SCHEN		BIT(2)



/* AFE application */
@@ -114,6 +116,9 @@ enum mma9551_tilt_axis { 
#define MMA9551_I2C_READ_RETRIES	5

#define MMA9551_I2C_READ_DELAY	50	/* us */



#define MMA9551_DEFAULT_SAMPLE_RATE	122	/* Hz */

#define MMA9551_AUTO_SUSPEND_DELAY_MS	2000



struct mma9551_mbox_request {

	u8 start_mbox;		/* Always 0. */

	u8 app_id;
@@ -387,16 +392,55 @@ static int mma9551_read_version(struct i2c_client *client) 
}



/*

 * Power on chip and enable doze mode.

 * Use 'false' as the second parameter to cause the device to enter

 * sleep.

 */

static int mma9551_set_device_state(struct i2c_client *client,

				    bool enable)

static int mma9551_set_device_state(struct i2c_client *client, bool enable)

{

	return mma9551_update_config_bits(client, MMA9551_APPID_SLEEP_WAKE,

					  MMA9551_SLEEP_CFG,

					  MMA9551_SLEEP_CFG_SNCEN,

					  enable ? 0 : MMA9551_SLEEP_CFG_SNCEN);

					  MMA9551_SLEEP_CFG_SNCEN |

					  MMA9551_SLEEP_CFG_FLEEN |

					  MMA9551_SLEEP_CFG_SCHEN,

					  enable ? MMA9551_SLEEP_CFG_SCHEN |

					  MMA9551_SLEEP_CFG_FLEEN :

					  MMA9551_SLEEP_CFG_SNCEN);

}



static int mma9551_set_power_state(struct i2c_client *client, bool on)

{

#ifdef CONFIG_PM

	int ret;



	if (on)

		ret = pm_runtime_get_sync(&client->dev);

	else {

		pm_runtime_mark_last_busy(&client->dev);

		ret = pm_runtime_put_autosuspend(&client->dev);

	}



	if (ret < 0) {

		dev_err(&client->dev,

			"failed to change power state to %d\n", on);

		if (on)

			pm_runtime_put_noidle(&client->dev);



		return ret;

	}

#endif



	return 0;

}



static void mma9551_sleep(int freq)

{

	int sleep_val = 1000 / freq;



	if (sleep_val < 20)

		usleep_range(sleep_val * 1000, 20000);

	else

		msleep_interruptible(sleep_val);

}



static int mma9551_read_incli_chan(struct i2c_client *client,
@@ -424,15 +468,19 @@ static int mma9551_read_incli_chan(struct i2c_client *client, 
		return -EINVAL;

	}



	ret = mma9551_set_power_state(client, true);

	if (ret < 0)

		return ret;



	ret = mma9551_read_status_byte(client, MMA9551_APPID_TILT,

				       reg_addr, &angle);

	if (ret < 0)

		return ret;

		goto out_poweroff;



	ret = mma9551_read_status_byte(client, MMA9551_APPID_TILT,

				       MMA9551_TILT_QUAD_REG, &quadrant);

	if (ret < 0)

		return ret;

		goto out_poweroff;



	angle &= ~MMA9551_TILT_ANGFLG;

	quadrant = (quadrant >> quad_shift) & 0x03;
@@ -442,7 +490,11 @@ static int mma9551_read_incli_chan(struct i2c_client *client, 
	else

		*val = angle + 90 * quadrant;



	return IIO_VAL_INT;

	ret = IIO_VAL_INT;



out_poweroff:

	mma9551_set_power_state(client, false);

	return ret;

}



static int mma9551_read_accel_chan(struct i2c_client *client,
@@ -467,14 +519,22 @@ static int mma9551_read_accel_chan(struct i2c_client *client, 
		return -EINVAL;

	}



	ret = mma9551_set_power_state(client, true);

	if (ret < 0)

		return ret;



	ret = mma9551_read_status_word(client, MMA9551_APPID_AFE,

				       reg_addr, &raw_accel);

	if (ret < 0)

		return ret;

		goto out_poweroff;



	*val = raw_accel;



	return IIO_VAL_INT;

	ret = IIO_VAL_INT;



out_poweroff:

	mma9551_set_power_state(client, false);

	return ret;

}



static int mma9551_read_raw(struct iio_dev *indio_dev,
@@ -556,6 +616,10 @@ static int mma9551_config_incli_event(struct iio_dev *indio_dev, 
					  MMA9551_APPID_NONE, 0, 0);

		if (ret < 0)

			return ret;



		ret = mma9551_set_power_state(data->client, false);

		if (ret < 0)

			return ret;

	} else {

		int bitnum;
@@ -574,12 +638,19 @@ static int mma9551_config_incli_event(struct iio_dev *indio_dev, 
			return -EINVAL;

		}





		ret = mma9551_set_power_state(data->client, true);

		if (ret < 0)

			return ret;



		ret = mma9551_gpio_config(data->client,

					  (enum mma9551_gpio_pin)mma_axis,

					  MMA9551_APPID_TILT, bitnum, 0);

		if (ret < 0)

		if (ret < 0) {

			mma9551_set_power_state(data->client, false);

			return ret;

		}

	}



	data->event_enabled[mma_axis] = state;
@@ -771,12 +842,7 @@ static int mma9551_init(struct mma9551_data *data) 
	if (ret)

		return ret;



	/* Power on chip and enable doze mode. */

	return mma9551_update_config_bits(data->client,

			 MMA9551_APPID_SLEEP_WAKE,

			 MMA9551_SLEEP_CFG,

			 MMA9551_SLEEP_CFG_SCHEN | MMA9551_SLEEP_CFG_SNCEN,

			 MMA9551_SLEEP_CFG_SCHEN);

	return mma9551_set_device_state(data->client, true);

}



static int mma9551_gpio_probe(struct iio_dev *indio_dev)
@@ -869,8 +935,19 @@ static int mma9551_probe(struct i2c_client *client, 
		goto out_poweroff;

	}



	ret = pm_runtime_set_active(&client->dev);

	if (ret < 0)

		goto out_iio_unregister;



	pm_runtime_enable(&client->dev);

	pm_runtime_set_autosuspend_delay(&client->dev,

					 MMA9551_AUTO_SUSPEND_DELAY_MS);

	pm_runtime_use_autosuspend(&client->dev);



	return 0;



out_iio_unregister:

	iio_device_unregister(indio_dev);

out_poweroff:

	mma9551_set_device_state(client, false);
@@ -882,6 +959,10 @@ static int mma9551_remove(struct i2c_client *client) 
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	struct mma9551_data *data = iio_priv(indio_dev);



	pm_runtime_disable(&client->dev);

	pm_runtime_set_suspended(&client->dev);

	pm_runtime_put_noidle(&client->dev);



	iio_device_unregister(indio_dev);

	mutex_lock(&data->mutex);

	mma9551_set_device_state(data->client, false);
@@ -890,37 +971,72 @@ static int mma9551_remove(struct i2c_client *client) 
	return 0;

}



#ifdef CONFIG_PM

static int mma9551_runtime_suspend(struct device *dev)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));

	struct mma9551_data *data = iio_priv(indio_dev);

	int ret;



	mutex_lock(&data->mutex);

	ret = mma9551_set_device_state(data->client, false);

	mutex_unlock(&data->mutex);

	if (ret < 0) {

		dev_err(&data->client->dev, "powering off device failed\n");

		return -EAGAIN;

	}



	return 0;

}



static int mma9551_runtime_resume(struct device *dev)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));

	struct mma9551_data *data = iio_priv(indio_dev);

	int ret;



	ret = mma9551_set_device_state(data->client, true);

	if (ret < 0)

		return ret;



	mma9551_sleep(MMA9551_DEFAULT_SAMPLE_RATE);



	return 0;

}

#endif



#ifdef CONFIG_PM_SLEEP

static int mma9551_suspend(struct device *dev)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));

	struct mma9551_data *data = iio_priv(indio_dev);

	int ret;



	mutex_lock(&data->mutex);

	mma9551_set_device_state(data->client, false);

	ret = mma9551_set_device_state(data->client, false);

	mutex_unlock(&data->mutex);



	return 0;

	return ret;

}



static int mma9551_resume(struct device *dev)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));

	struct mma9551_data *data = iio_priv(indio_dev);

	int ret;



	mutex_lock(&data->mutex);

	mma9551_set_device_state(data->client, true);

	ret = mma9551_set_device_state(data->client, true);

	mutex_unlock(&data->mutex);



	return 0;

	return ret;

}

#else

#define mma9551_suspend NULL

#define mma9551_resume NULL

#endif



static const struct dev_pm_ops mma9551_pm_ops = {

	SET_SYSTEM_SLEEP_PM_OPS(mma9551_suspend, mma9551_resume)

	SET_RUNTIME_PM_OPS(mma9551_runtime_suspend,

			   mma9551_runtime_resume, NULL)

};



static const struct acpi_device_id mma9551_acpi_match[] = {

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