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.
+ 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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