On Mon, Sep 17, 2018 at 6:03 PM Akinobu Mita <akinobu.m...@gmail.com> wrote:
>
> AMG88xx has a register for setting operating mode. This adds support
> runtime PM by changing the operating mode.
>
> The instruction for changing sleep mode to normal mode is from the
> reference specifications.
>
> https://docid81hrs3j1.cloudfront.net/medialibrary/2017/11/PANA-S-A0002141979-1.pdf
>
> Cc: Matt Ranostay <matt.ranos...@konsulko.com>
> Cc: Sakari Ailus <sakari.ai...@linux.intel.com>
> Cc: Hans Verkuil <hansv...@cisco.com>
> Cc: Mauro Carvalho Chehab <mche...@kernel.org>
> Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com>
> ---
> drivers/media/i2c/video-i2c.c | 140
> +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 138 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/i2c/video-i2c.c b/drivers/media/i2c/video-i2c.c
> index 916f36e..93822f4 100644
> --- a/drivers/media/i2c/video-i2c.c
> +++ b/drivers/media/i2c/video-i2c.c
> @@ -17,6 +17,7 @@
> #include <linux/module.h>
> #include <linux/mutex.h>
> #include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
> #include <linux/regmap.h>
> #include <linux/sched.h>
> #include <linux/slab.h>
> @@ -94,6 +95,9 @@ struct video_i2c_chip {
> /* xfer function */
> int (*xfer)(struct video_i2c_data *data, char *buf);
>
> + /* power control function */
> + int (*set_power)(struct video_i2c_data *data, bool on);
> +
> /* hwmon init function */
> int (*hwmon_init)(struct video_i2c_data *data);
> };
> @@ -104,6 +108,14 @@ static int amg88xx_xfer(struct video_i2c_data *data,
> char *buf)
> data->chip->buffer_size);
> }
>
> +#define AMG88XX_REG_PCTL 0x00
> +#define AMG88XX_PCTL_NORMAL 0x00
> +#define AMG88XX_PCTL_SLEEP 0x10
> +
> +#define AMG88XX_REG_RST 0x01
> +#define AMG88XX_RST_FLAG 0x30
> +#define AMG88XX_RST_INIT 0x3f
> +
> #define AMG88XX_REG_FPSC 0x02
> #define AMG88XX_FPSC_1FPS BIT(0)
>
> @@ -120,6 +132,59 @@ static int amg88xx_setup(struct video_i2c_data *data)
> return regmap_update_bits(data->regmap, AMG88XX_REG_FPSC, mask, val);
> }
>
> +static int amg88xx_set_power_on(struct video_i2c_data *data)
> +{
> + int ret;
> +
> + ret = regmap_write(data->regmap, AMG88XX_REG_PCTL,
> AMG88XX_PCTL_NORMAL);
> + if (ret)
> + return ret;
> +
> + msleep(50);
> +
> + ret = regmap_write(data->regmap, AMG88XX_REG_RST, AMG88XX_RST_INIT);
> + if (ret)
> + return ret;
> +
> + msleep(2);
> +
> + ret = regmap_write(data->regmap, AMG88XX_REG_RST, AMG88XX_RST_FLAG);
> + if (ret)
> + return ret;
> +
> + /*
> + * Wait two frames before reading thermistor and temperature registers
> + */
> + msleep(200);
> +
> + return 0;
> +}
> +
> +static int amg88xx_set_power_off(struct video_i2c_data *data)
> +{
> + int ret;
> +
> + ret = regmap_write(data->regmap, AMG88XX_REG_PCTL,
> AMG88XX_PCTL_SLEEP);
> + if (ret)
> + return ret;
> + /*
> + * Wait for a while to avoid resuming normal mode immediately after
> + * entering sleep mode, otherwise the device occasionally goes wrong
> + * (thermistor and temperature registers are not updated at all)
> + */
> + msleep(100);
> +
> + return 0;
> +}
> +
> +static int amg88xx_set_power(struct video_i2c_data *data, bool on)
> +{
> + if (on)
> + return amg88xx_set_power_on(data);
> +
> + return amg88xx_set_power_off(data);
> +}
> +
> #if IS_ENABLED(CONFIG_HWMON)
>
> static const u32 amg88xx_temp_config[] = {
> @@ -151,7 +216,15 @@ static int amg88xx_read(struct device *dev, enum
> hwmon_sensor_types type,
> __le16 buf;
> int tmp;
>
> + tmp = pm_runtime_get_sync(regmap_get_device(data->regmap));
> + if (tmp < 0) {
> + pm_runtime_put_noidle(regmap_get_device(data->regmap));
> + return tmp;
> + }
> +
> tmp = regmap_bulk_read(data->regmap, 0x0e, &buf, 2);
> + pm_runtime_mark_last_busy(regmap_get_device(data->regmap));
> + pm_runtime_put_autosuspend(regmap_get_device(data->regmap));
> if (tmp)
> return tmp;
>
> @@ -210,6 +283,7 @@ static const struct video_i2c_chip video_i2c_chip[] = {
> .regmap_config = &amg88xx_regmap_config,
> .setup = &amg88xx_setup,
> .xfer = &amg88xx_xfer,
> + .set_power = amg88xx_set_power,
> .hwmon_init = amg88xx_hwmon_init,
> },
> };
> @@ -336,14 +410,21 @@ static void video_i2c_del_list(struct vb2_queue *vq,
> enum vb2_buffer_state state
> static int start_streaming(struct vb2_queue *vq, unsigned int count)
> {
> struct video_i2c_data *data = vb2_get_drv_priv(vq);
> + struct device *dev = regmap_get_device(data->regmap);
> int ret;
>
> if (data->kthread_vid_cap)
> return 0;
>
> + ret = pm_runtime_get_sync(dev);
> + if (ret < 0) {
> + pm_runtime_put_noidle(dev);
> + goto error_del_list;
> + }
> +
> ret = data->chip->setup(data);
> if (ret)
> - goto error_del_list;
> + goto error_rpm_put;
>
> data->sequence = 0;
> data->kthread_vid_cap = kthread_run(video_i2c_thread_vid_cap, data,
> @@ -352,6 +433,9 @@ static int start_streaming(struct vb2_queue *vq, unsigned
> int count)
> if (!ret)
> return 0;
>
> +error_rpm_put:
> + pm_runtime_mark_last_busy(dev);
> + pm_runtime_put_autosuspend(dev);
> error_del_list:
> video_i2c_del_list(vq, VB2_BUF_STATE_QUEUED);
>
> @@ -367,6 +451,8 @@ static void stop_streaming(struct vb2_queue *vq)
>
> kthread_stop(data->kthread_vid_cap);
> data->kthread_vid_cap = NULL;
> + pm_runtime_mark_last_busy(regmap_get_device(data->regmap));
> + pm_runtime_put_autosuspend(regmap_get_device(data->regmap));
>
> video_i2c_del_list(vq, VB2_BUF_STATE_ERROR);
> }
> @@ -627,6 +713,18 @@ static int video_i2c_probe(struct i2c_client *client,
> video_set_drvdata(&data->vdev, data);
> i2c_set_clientdata(client, data);
>
> + ret = data->chip->set_power(data, true);
> + if (ret)
> + goto error_unregister_device;
> +
> + pm_runtime_get_noresume(&client->dev);
> + pm_runtime_set_active(&client->dev);
> + pm_runtime_enable(&client->dev);
> + pm_runtime_set_autosuspend_delay(&client->dev, 2000);
2 seconds arbitrary for runtime suspending? I could be blind (or that
I can't read the part English + Japanese datasheet) but not sure how
much power is saved in low-power mode.
In any case looks fine to me.
- Matt
Reviewed-by: Matt Ranostay <matt.ranos...@konsulko.com>
> + pm_runtime_use_autosuspend(&client->dev);
> + pm_runtime_mark_last_busy(&client->dev);
> + pm_runtime_put_autosuspend(&client->dev);
> +
> if (data->chip->hwmon_init) {
> ret = data->chip->hwmon_init(data);
> if (ret < 0) {
> @@ -637,10 +735,17 @@ static int video_i2c_probe(struct i2c_client *client,
>
> ret = video_register_device(&data->vdev, VFL_TYPE_GRABBER, -1);
> if (ret < 0)
> - goto error_unregister_device;
> + goto error_pm_disable;
>
> return 0;
>
> +error_pm_disable:
> + pm_runtime_get_sync(&client->dev);
> + pm_runtime_disable(&client->dev);
> + pm_runtime_set_suspended(&client->dev);
> + pm_runtime_put_noidle(&client->dev);
> + data->chip->set_power(data, false);
> +
> error_unregister_device:
> v4l2_device_unregister(v4l2_dev);
> mutex_destroy(&data->lock);
> @@ -654,6 +759,13 @@ static int video_i2c_remove(struct i2c_client *client)
> struct video_i2c_data *data = i2c_get_clientdata(client);
>
> video_unregister_device(&data->vdev);
> +
> + pm_runtime_get_sync(&client->dev);
> + pm_runtime_disable(&client->dev);
> + pm_runtime_set_suspended(&client->dev);
> + pm_runtime_put_noidle(&client->dev);
> + data->chip->set_power(data, false);
> +
> v4l2_device_unregister(&data->v4l2_dev);
>
> mutex_destroy(&data->lock);
> @@ -662,6 +774,29 @@ static int video_i2c_remove(struct i2c_client *client)
> return 0;
> }
>
> +#ifdef CONFIG_PM
> +
> +static int video_i2c_pm_runtime_suspend(struct device *dev)
> +{
> + struct video_i2c_data *data = i2c_get_clientdata(to_i2c_client(dev));
> +
> + return data->chip->set_power(data, false);
> +}
> +
> +static int video_i2c_pm_runtime_resume(struct device *dev)
> +{
> + struct video_i2c_data *data = i2c_get_clientdata(to_i2c_client(dev));
> +
> + return data->chip->set_power(data, true);
> +}
> +
> +#endif
> +
> +static const struct dev_pm_ops video_i2c_pm_ops = {
> + SET_RUNTIME_PM_OPS(video_i2c_pm_runtime_suspend,
> + video_i2c_pm_runtime_resume, NULL)
> +};
> +
> static const struct i2c_device_id video_i2c_id_table[] = {
> { "amg88xx", AMG88XX },
> {}
> @@ -678,6 +813,7 @@ static struct i2c_driver video_i2c_driver = {
> .driver = {
> .name = VIDEO_I2C_DRIVER,
> .of_match_table = video_i2c_of_match,
> + .pm = &video_i2c_pm_ops,
> },
> .probe = video_i2c_probe,
> .remove = video_i2c_remove,
> --
> 2.7.4
>
