From 484c314b90ae240fb8e6e2924722deb92c756d93 Mon Sep 17 00:00:00 2001 From: Mikko Koivunen Date: Thu, 18 May 2017 15:12:51 +0300 Subject: [PATCH] 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: Mikko Koivunen Acked-by: Daniel Baluta Signed-off-by: Jonathan Cameron --- drivers/iio/light/rpr0521.c | 70 +++++++++++++++++++++++++++++---------------- 1 file changed, 46 insertions(+), 24 deletions(-) diff --git a/drivers/iio/light/rpr0521.c b/drivers/iio/light/rpr0521.c index 84d8d40..9219819 100644 --- a/drivers/iio/light/rpr0521.c +++ b/drivers/iio/light/rpr0521.c @@ -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 @@ -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_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; - } - - if (update_mask) { - ret = regmap_update_bits(data->regmap, RPR0521_REG_MODE_CTRL, - update_mask, update_mask); - if (ret < 0) - return ret; + data->pxs_ps_need_en = on; + data->pxs_need_dis = !on; } + /* + * 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; } -- 2.7.4