[v4,6/9] media: i2c: ov5645: Use runtime PM

  From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Switch to using runtime PM for power management.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
v3->v4
* Fixed comments pointed by Sakari

v2->v3
* Jumped to err_pm_runtime label in case of sd register failure
* Now calling pm_runtime_mark_last_busy() before pm_runtime_put_autosuspend()
  call
* Now calling pm_runtime_put_sync() in case s_stream(1) fails
* In s_stream(0) no calling pm_runtime_mark_last_busy() and
  pm_runtime_put_autosuspend()
* Included RB tag from Laurent.

v1->v2
* Moved pm_runtime_*_autosuspend() calls after registering the subdev.
---
 drivers/media/i2c/ov5645.c | 133 +++++++++++++++++++------------------
 1 file changed, 68 insertions(+), 65 deletions(-)
  

Hi Prabhakar,

On 11/1/22 00:21, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Switch to using runtime PM for power management.
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> v3->v4
> * Fixed comments pointed by Sakari
> 
> v2->v3
> * Jumped to err_pm_runtime label in case of sd register failure
> * Now calling pm_runtime_mark_last_busy() before pm_runtime_put_autosuspend()
>   call
> * Now calling pm_runtime_put_sync() in case s_stream(1) fails
> * In s_stream(0) no calling pm_runtime_mark_last_busy() and
>   pm_runtime_put_autosuspend()
> * Included RB tag from Laurent.
> 
> v1->v2
> * Moved pm_runtime_*_autosuspend() calls after registering the subdev.
> ---
>  drivers/media/i2c/ov5645.c | 133 +++++++++++++++++++------------------
>  1 file changed, 68 insertions(+), 65 deletions(-)
> 
> diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c
> index 47451238ca05..2e6135d0a31a 100644
> --- a/drivers/media/i2c/ov5645.c
> +++ b/drivers/media/i2c/ov5645.c
> @@ -27,6 +27,7 @@
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_graph.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/slab.h>
>  #include <linux/types.h>
> @@ -108,7 +109,6 @@ struct ov5645 {
>  	u8 timing_tc_reg21;
>  
>  	struct mutex power_lock; /* lock to protect power state */
> -	int power_count;
>  
>  	struct gpio_desc *enable_gpio;
>  	struct gpio_desc *rst_gpio;
> @@ -635,8 +635,24 @@ static int ov5645_set_register_array(struct ov5645 *ov5645,
>  	return 0;
>  }
>  
> -static int ov5645_set_power_on(struct ov5645 *ov5645)
> +static int ov5645_set_power_off(struct device *dev)
>  {
> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +	struct ov5645 *ov5645 = to_ov5645(sd);
> +
> +	ov5645_write_reg(ov5645, OV5645_IO_MIPI_CTRL00, 0x58);
> +	gpiod_set_value_cansleep(ov5645->rst_gpio, 1);
> +	gpiod_set_value_cansleep(ov5645->enable_gpio, 0);
> +	clk_disable_unprepare(ov5645->xclk);
> +	regulator_bulk_disable(OV5645_NUM_SUPPLIES, ov5645->supplies);
> +
> +	return 0;
> +}
> +
> +static int ov5645_set_power_on(struct device *dev)
> +{
> +	struct v4l2_subdev *sd = dev_get_drvdata(dev);
> +	struct ov5645 *ov5645 = to_ov5645(sd);
>  	int ret;
>  
>  	ret = regulator_bulk_enable(OV5645_NUM_SUPPLIES, ov5645->supplies);
> @@ -658,57 +674,19 @@ static int ov5645_set_power_on(struct ov5645 *ov5645)
>  
>  	msleep(20);
>  
> -	return 0;
> -}
> -
> -static void ov5645_set_power_off(struct ov5645 *ov5645)
> -{
> -	gpiod_set_value_cansleep(ov5645->rst_gpio, 1);
> -	gpiod_set_value_cansleep(ov5645->enable_gpio, 0);
> -	clk_disable_unprepare(ov5645->xclk);
> -	regulator_bulk_disable(OV5645_NUM_SUPPLIES, ov5645->supplies);
> -}
> -
> -static int ov5645_s_power(struct v4l2_subdev *sd, int on)
> -{
> -	struct ov5645 *ov5645 = to_ov5645(sd);
> -	int ret = 0;
> -
> -	mutex_lock(&ov5645->power_lock);
> -
> -	/* If the power count is modified from 0 to != 0 or from != 0 to 0,
> -	 * update the power state.
> -	 */
> -	if (ov5645->power_count == !on) {
> -		if (on) {
> -			ret = ov5645_set_power_on(ov5645);
> -			if (ret < 0)
> -				goto exit;
> -
> -			ret = ov5645_set_register_array(ov5645,
> -					ov5645_global_init_setting,
> +	ret = ov5645_set_register_array(ov5645, ov5645_global_init_setting,
>  					ARRAY_SIZE(ov5645_global_init_setting));
> -			if (ret < 0) {
> -				dev_err(ov5645->dev,
> -					"could not set init registers\n");
> -				ov5645_set_power_off(ov5645);
> -				goto exit;
> -			}
> -
> -			usleep_range(500, 1000);
> -		} else {
> -			ov5645_write_reg(ov5645, OV5645_IO_MIPI_CTRL00, 0x58);
> -			ov5645_set_power_off(ov5645);
> -		}
> +	if (ret < 0) {
> +		dev_err(ov5645->dev, "could not set init registers\n");
> +		goto exit;
>  	}
>  
> -	/* Update the power count. */
> -	ov5645->power_count += on ? 1 : -1;
> -	WARN_ON(ov5645->power_count < 0);
> +	usleep_range(500, 1000);
>  
> -exit:
> -	mutex_unlock(&ov5645->power_lock);
> +	return 0;
>  
> +exit:
> +	ov5645_set_power_off(dev);
>  	return ret;

smatch gives this warning:

drivers/media/i2c/ov5645.c:687 ov5645_set_power_on() warn: 'ov5645->xclk' from clk_prepare_enable() not released on lines: 687.

Can you take a look?

Thanks!

	Hans

>  }
  

Hi Hans,

On Mon, Nov 28, 2022 at 1:49 PM Hans Verkuil <hverkuil@xs4all.nl> wrote:
>
<snip>
> > +exit:
> > +     ov5645_set_power_off(dev);
> >       return ret;
>
> smatch gives this warning:
>
> drivers/media/i2c/ov5645.c:687 ov5645_set_power_on() warn: 'ov5645->xclk' from clk_prepare_enable() not released on lines: 687.
>
> Can you take a look?
>
Sure I'll have a look at it.

Cheers,
Prabhakar
  

Hi Hans,

On Mon, Nov 28, 2022 at 1:49 PM Hans Verkuil <hverkuil@xs4all.nl> wrote:
>
> Hi Prabhakar,
>
> On 11/1/22 00:21, Prabhakar wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
<snip>
> > -static void ov5645_set_power_off(struct ov5645 *ov5645)
> > -{
> > -     gpiod_set_value_cansleep(ov5645->rst_gpio, 1);
> > -     gpiod_set_value_cansleep(ov5645->enable_gpio, 0);
> > -     clk_disable_unprepare(ov5645->xclk);
> > -     regulator_bulk_disable(OV5645_NUM_SUPPLIES, ov5645->supplies);
> > -}
> > -
> > -static int ov5645_s_power(struct v4l2_subdev *sd, int on)
> > -{
> > -     struct ov5645 *ov5645 = to_ov5645(sd);
> > -     int ret = 0;
> > -
> > -     mutex_lock(&ov5645->power_lock);
> > -
> > -     /* If the power count is modified from 0 to != 0 or from != 0 to 0,
> > -      * update the power state.
> > -      */
> > -     if (ov5645->power_count == !on) {
> > -             if (on) {
> > -                     ret = ov5645_set_power_on(ov5645);
> > -                     if (ret < 0)
> > -                             goto exit;
> > -
> > -                     ret = ov5645_set_register_array(ov5645,
> > -                                     ov5645_global_init_setting,
> > +     ret = ov5645_set_register_array(ov5645, ov5645_global_init_setting,
> >                                       ARRAY_SIZE(ov5645_global_init_setting));
> > -                     if (ret < 0) {
> > -                             dev_err(ov5645->dev,
> > -                                     "could not set init registers\n");
> > -                             ov5645_set_power_off(ov5645);
> > -                             goto exit;
> > -                     }
> > -
> > -                     usleep_range(500, 1000);
> > -             } else {
> > -                     ov5645_write_reg(ov5645, OV5645_IO_MIPI_CTRL00, 0x58);
> > -                     ov5645_set_power_off(ov5645);
> > -             }
> > +     if (ret < 0) {
> > +             dev_err(ov5645->dev, "could not set init registers\n");
> > +             goto exit;
> >       }
> >
> > -     /* Update the power count. */
> > -     ov5645->power_count += on ? 1 : -1;
> > -     WARN_ON(ov5645->power_count < 0);
> > +     usleep_range(500, 1000);
> >
> > -exit:
> > -     mutex_unlock(&ov5645->power_lock);
> > +     return 0;
> >
> > +exit:
> > +     ov5645_set_power_off(dev);
> >       return ret;
>
> smatch gives this warning:
>
> drivers/media/i2c/ov5645.c:687 ov5645_set_power_on() warn: 'ov5645->xclk' from clk_prepare_enable() not released on lines: 687.
>
it's a false positive, as in case of error we jump to the exit label
which calls ov5645_set_power_off() which internally calls
clk_disable_unprepare() for xclk and on success we need to have xclk
ON during s_stream(ON) and eventually the
xclk will be unprepared in s_stream(OFF).

Cheers,
Prabhakar