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 <mikko.koivunen@xxxxxxxxxxxxxxxxx>
---
Don't enable measurement on _init() when using CONFIG_PM. Enable only
when needed, otherwise it messes up the pm suspend-resume. Polling
enables/disables the measurement anyway.
Save ALS/PS enabled status on _suspend() when called during measurement,
so that measurement can be re-enabled on _resume().
checkpatch.pl OK
Tested on LeMaker HiKey with AOSP7.1 kernel 4.4.
Builds ok with torvalds/linux feb 27.
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 5d077f4..02ce635 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 <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_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;
}
--
1.7.9.5
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