On Tue, Nov 10, 2015 at 4:26 AM, Adriana Reus <adriana.reus@xxxxxxxxx> wrote:
>
>
> On 08.11.2015 22:26, Matt Ranostay wrote:
>>
>> Add runtime PM support for the lidar-lite module to enable low power
>> mode when last device requested reading is over a second.
>>
>> Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
>> ---
>> drivers/iio/proximity/pulsedlight-lidar-lite-v2.c | 54
>> ++++++++++++++++++++++-
>> 1 file changed, 53 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
>> b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
>> index 961f9f99..1a5481f 100644
>> --- a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
>> +++ b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
>> @@ -13,7 +13,7 @@
>> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>> * GNU General Public License for more details.
>> *
>> - * TODO: runtime pm, interrupt mode, and signal strength reporting
>> + * TODO: interrupt mode, and signal strength reporting
>> */
>>
>> #include <linux/err.h>
>> @@ -21,6 +21,7 @@
>> #include <linux/i2c.h>
>> #include <linux/delay.h>
>> #include <linux/module.h>
>> +#include <linux/pm_runtime.h>
>> #include <linux/iio/iio.h>
>> #include <linux/iio/sysfs.h>
>> #include <linux/iio/buffer.h>
>> @@ -37,6 +38,7 @@
>>
>> #define LIDAR_REG_DATA_HBYTE 0x0f
>> #define LIDAR_REG_DATA_LBYTE 0x10
>> +#define LIDAR_REG_PWR_CONTROL 0x65
>>
>> #define LIDAR_DRV_NAME "lidar"
>>
>> @@ -90,6 +92,12 @@ static inline int lidar_write_control(struct lidar_data
>> *data, int val)
>> return i2c_smbus_write_byte_data(data->client, LIDAR_REG_CONTROL,
>> val);
>> }
>>
>> +static inline int lidar_write_power(struct lidar_data *data, int val)
>> +{
>> + return i2c_smbus_write_byte_data(data->client,
>> + LIDAR_REG_PWR_CONTROL, val);
>> +}
>> +
>> static int lidar_read_measurement(struct lidar_data *data, u16 *reg)
>> {
>> int ret;
>> @@ -116,6 +124,8 @@ static int lidar_get_measurement(struct lidar_data
>> *data, u16 *reg)
>> int tries = 10;
>> int ret;
>>
>> + pm_runtime_get_sync(&client->dev);
>> +
>> /* start sample */
>> ret = lidar_write_control(data, LIDAR_REG_CONTROL_ACQUIRE);
>> if (ret < 0) {
>> @@ -144,6 +154,8 @@ static int lidar_get_measurement(struct lidar_data
>> *data, u16 *reg)
>> }
>> ret = -EIO;
>> }
>> + pm_runtime_mark_last_busy(&client->dev);
>> + pm_runtime_put_autosuspend(&client->dev);
>>
>> return ret;
>> }
>> @@ -243,6 +255,15 @@ static int lidar_probe(struct i2c_client *client,
>> if (ret)
>> goto error_unreg_buffer;
>>
>> + pm_runtime_set_autosuspend_delay(&client->dev, 1000);
>> + pm_runtime_use_autosuspend(&client->dev);
>> +
>> + pm_runtime_set_active(&client->dev);
>
> pm_runtime_set_active ^ may return an error code.
Ah true. But is the return value really needed in this case?
>
>> + pm_runtime_enable(&client->dev);
>> +
>> + pm_runtime_mark_last_busy(&client->dev);
>> + pm_runtime_idle(&client->dev);
>> +
>> return 0;
>>
>> error_unreg_buffer:
>> @@ -258,6 +279,9 @@ static int lidar_remove(struct i2c_client *client)
>> iio_device_unregister(indio_dev);
>> iio_triggered_buffer_cleanup(indio_dev);
>>
>> + pm_runtime_disable(&client->dev);
>> + pm_runtime_set_suspended(&client->dev);
>> +
>> return 0;
>> }
>>
>> @@ -273,10 +297,38 @@ static const struct of_device_id lidar_dt_ids[] = {
>> };
>> MODULE_DEVICE_TABLE(of, lidar_dt_ids);
>>
>> +#ifdef CONFIG_PM
>> +static int lidar_pm_runtime_suspend(struct device *dev)
>> +{
>> + struct iio_dev *indio_dev =
>> i2c_get_clientdata(to_i2c_client(dev));
>> + struct lidar_data *data = iio_priv(indio_dev);
>> +
>> + return lidar_write_power(data, 0x0f);
>> +}
>> +
>> +static int lidar_pm_runtime_resume(struct device *dev)
>> +{
>> + struct iio_dev *indio_dev =
>> i2c_get_clientdata(to_i2c_client(dev));
>> + struct lidar_data *data = iio_priv(indio_dev);
>> + int ret = lidar_write_power(data, 0);
>> +
>> + /* regulator and FPGA needs settling time */
>> + usleep_range(15000, 20000);
>> +
>> + return ret;
>> +}
>> +#endif
>> +
>> +static const struct dev_pm_ops lidar_pm_ops = {
>> + SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend,
>> + lidar_pm_runtime_resume, NULL)
>> +};
>> +
>> static struct i2c_driver lidar_driver = {
>> .driver = {
>> .name = LIDAR_DRV_NAME,
>> .of_match_table = of_match_ptr(lidar_dt_ids),
>> + .pm = &lidar_pm_ops,
>> },
>> .probe = lidar_probe,
>> .remove = lidar_remove,
>>
>
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