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: Irina Tirdea <irina.tirdea@xxxxxxxxx>
Reviewed-by: Vlad Dogaru <vlad.dogaru@xxxxxxxxx>
---
drivers/iio/accel/mma9551.c | 161 ++++++++++++++++++++++++++++++++++++-------
1 file changed, 138 insertions(+), 23 deletions(-)
diff --git a/drivers/iio/accel/mma9551.c b/drivers/iio/accel/mma9551.c
index 1be125b..34ee9d6 100644
--- a/drivers/iio/accel/mma9551.c
+++ b/drivers/iio/accel/mma9551.c
@@ -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,
@@ -555,6 +615,10 @@ 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;
@@ -573,10 +637,16 @@ 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, 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;
@@ -769,12 +839,7 @@ 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)
@@ -867,8 +932,19 @@ 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);
@@ -880,6 +956,10 @@ 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);
@@ -888,37 +968,72 @@ 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[] = {
--
1.7.9.5
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
