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Commit 484c314b authored by Mikko Koivunen's avatar Mikko Koivunen Committed by Jonathan Cameron
Browse files

iio: light: rpr0521 on-off sequence change for CONFIG_PM 



Refactor _set_power_state(), _resume() and _suspend().
Enable measurement only when needed, not in _init(). System can suspend
during measurement and measurement is continued on resume.
Pm turns off measurement when both ps and als measurements are disabled for
2 seconds. During off-time the power save is 20-500mA, typically 180mA.

Signed-off-by: default avatarMikko Koivunen <mikko.koivunen@fi.rohmeurope.com>
Acked-by: default avatarDaniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 12d74949

drivers/iio/light/rpr0521.c

+46 −24
Original line number Diff line number Diff line
@@ -9,7 +9,7 @@ 
 *

 * IIO driver for RPR-0521RS (7-bit I2C slave address 0x38).

 *

 * TODO: illuminance channel, PM support, buffer

 * TODO: illuminance channel, buffer

 */



#include <linux/module.h>
@@ -142,9 +142,11 @@ struct rpr0521_data { 
	bool als_dev_en;

	bool pxs_dev_en;



	/* optimize runtime pm ops - enable device only if needed */

	/* optimize runtime pm ops - enable/disable device only if needed */

	bool als_ps_need_en;

	bool pxs_ps_need_en;

	bool als_need_dis;

	bool pxs_need_dis;



	struct regmap *regmap;

};
@@ -230,40 +232,32 @@ static int rpr0521_pxs_enable(struct rpr0521_data *data, u8 status) 
 * @on: state to be set for devices in @device_mask

 * @device_mask: bitmask specifying for which device we need to update @on state

 *

 * We rely on rpr0521_runtime_resume to enable our @device_mask devices, but

 * if (for example) PXS was enabled (pxs_dev_en = true) by a previous call to

 * rpr0521_runtime_resume and we want to enable ALS we MUST set ALS enable

 * bit of RPR0521_REG_MODE_CTRL here because rpr0521_runtime_resume will not

 * be called twice.

 * Calls for this function must be balanced so that each ON should have matching

 * OFF. Otherwise pm usage_count gets out of sync.

 */

static int rpr0521_set_power_state(struct rpr0521_data *data, bool on,

				   u8 device_mask)

{

#ifdef CONFIG_PM

	int ret;

	u8 update_mask = 0;



	if (device_mask & RPR0521_MODE_ALS_MASK) {

		if (on && !data->als_ps_need_en && data->pxs_dev_en)

			update_mask |= RPR0521_MODE_ALS_MASK;

		else

		data->als_ps_need_en = on;

		data->als_need_dis = !on;

	}



	if (device_mask & RPR0521_MODE_PXS_MASK) {

		if (on && !data->pxs_ps_need_en && data->als_dev_en)

			update_mask |= RPR0521_MODE_PXS_MASK;

		else

		data->pxs_ps_need_en = on;

		data->pxs_need_dis = !on;

	}



	if (update_mask) {

		ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL,

					 update_mask, update_mask);

		if (ret < 0)

			return ret;

	}



	/*

	 * On: _resume() is called only when we are suspended

	 * Off: _suspend() is called after delay if _resume() is not

	 * called before that.

	 * Note: If either measurement is re-enabled before _suspend(),

	 * both stay enabled until _suspend().

	 */

	if (on) {

		ret = pm_runtime_get_sync(&data->client->dev);

	} else {
@@ -279,6 +273,23 @@ static int rpr0521_set_power_state(struct rpr0521_data *data, bool on, 


		return ret;

	}



	if (on) {

		/* If _resume() was not called, enable measurement now. */

		if (data->als_ps_need_en) {

			ret = rpr0521_als_enable(data, RPR0521_MODE_ALS_ENABLE);

			if (ret)

				return ret;

			data->als_ps_need_en = false;

		}



		if (data->pxs_ps_need_en) {

			ret = rpr0521_pxs_enable(data, RPR0521_MODE_PXS_ENABLE);

			if (ret)

				return ret;

			data->pxs_ps_need_en = false;

		}

	}

#endif

	return 0;

}
@@ -425,12 +436,14 @@ static int rpr0521_init(struct rpr0521_data *data) 
		return ret;

	}



#ifndef CONFIG_PM

	ret = rpr0521_als_enable(data, RPR0521_MODE_ALS_ENABLE);

	if (ret < 0)

		return ret;

	ret = rpr0521_pxs_enable(data, RPR0521_MODE_PXS_ENABLE);

	if (ret < 0)

		return ret;

#endif



	return 0;

}
@@ -560,9 +573,16 @@ static int rpr0521_runtime_suspend(struct device *dev) 
	struct rpr0521_data *data = iio_priv(indio_dev);

	int ret;



	/* disable channels and sets {als,pxs}_dev_en to false */

	mutex_lock(&data->lock);

	/* If measurements are enabled, enable them on resume */

	if (!data->als_need_dis)

		data->als_ps_need_en = data->als_dev_en;

	if (!data->pxs_need_dis)

		data->pxs_ps_need_en = data->pxs_dev_en;



	/* disable channels and sets {als,pxs}_dev_en to false */

	ret = rpr0521_poweroff(data);

	regcache_mark_dirty(data->regmap);

	mutex_unlock(&data->lock);



	return ret;
@@ -574,6 +594,7 @@ static int rpr0521_runtime_resume(struct device *dev) 
	struct rpr0521_data *data = iio_priv(indio_dev);

	int ret;



	regcache_sync(data->regmap);

	if (data->als_ps_need_en) {

		ret = rpr0521_als_enable(data, RPR0521_MODE_ALS_ENABLE);

		if (ret < 0)
@@ -587,6 +608,7 @@ static int rpr0521_runtime_resume(struct device *dev) 
			return ret;

		data->pxs_ps_need_en = false;

	}

	msleep(100);	//wait for first measurement result



	return 0;

}