[v2,1/3] media: i2c: imx219: Fix power sequence

  When supporting Rpi Camera v2 Module on the RZ/G2E, found the driver had
some issues with rcar mipi-csi driver. The sensor never entered into LP-11
state.

The powerup sequence in the datasheet[1] shows the sensor entering into
LP-11 in streaming mode, so to fix this issue transitions are performed
from "streaming -> standby" in the probe() after power up.

With this commit the sensor is able to enter LP-11 mode during power up,
as expected by some CSI-2 controllers.

[1] https://publiclab.org/system/images/photos/000/023/294/original/
RASPBERRY_PI_CAMERA_V2_DATASHEET_IMX219PQH5_7.0.0_Datasheet_XXX.PDF

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
 drivers/media/i2c/imx219.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
  

Hi Prabhakar.

Thanks for the update.

On Fri, 6 Mar 2020 at 10:32, Lad Prabhakar <prabhakar.csengg@gmail.com> wrote:
>
> When supporting Rpi Camera v2 Module on the RZ/G2E, found the driver had
> some issues with rcar mipi-csi driver. The sensor never entered into LP-11
> state.
>
> The powerup sequence in the datasheet[1] shows the sensor entering into
> LP-11 in streaming mode, so to fix this issue transitions are performed
> from "streaming -> standby" in the probe() after power up.
>
> With this commit the sensor is able to enter LP-11 mode during power up,
> as expected by some CSI-2 controllers.
>
> [1] https://publiclab.org/system/images/photos/000/023/294/original/
> RASPBERRY_PI_CAMERA_V2_DATASHEET_IMX219PQH5_7.0.0_Datasheet_XXX.PDF
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com>


> ---
>  drivers/media/i2c/imx219.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
>
> diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> index f1effb5a5f66..16010ca1781a 100644
> --- a/drivers/media/i2c/imx219.c
> +++ b/drivers/media/i2c/imx219.c
> @@ -1224,6 +1224,23 @@ static int imx219_probe(struct i2c_client *client)
>         /* Set default mode to max resolution */
>         imx219->mode = &supported_modes[0];
>
> +       /* sensor doesn't enter LP-11 state upon power up until and unless
> +        * streaming is started, so upon power up switch the modes to:
> +        * streaming -> standby
> +        */
> +       ret = imx219_write_reg(imx219, IMX219_REG_MODE_SELECT,
> +                              IMX219_REG_VALUE_08BIT, IMX219_MODE_STREAMING);
> +       if (ret < 0)
> +               goto error_power_off;
> +       usleep_range(100, 110);
> +
> +       /* put sensor back to standby mode */
> +       ret = imx219_write_reg(imx219, IMX219_REG_MODE_SELECT,
> +                              IMX219_REG_VALUE_08BIT, IMX219_MODE_STANDBY);
> +       if (ret < 0)
> +               goto error_power_off;
> +       usleep_range(100, 110);
> +
>         ret = imx219_init_controls(imx219);
>         if (ret)
>                 goto error_power_off;
> --
> 2.20.1
>
  

Hi Dave,

On Fri, Mar 6, 2020 at 1:01 PM Dave Stevenson
<dave.stevenson@raspberrypi.com> wrote:
>
> Hi Prabhakar.
>
> Thanks for the update.
>
> On Fri, 6 Mar 2020 at 10:32, Lad Prabhakar <prabhakar.csengg@gmail.com> wrote:
> >
> > When supporting Rpi Camera v2 Module on the RZ/G2E, found the driver had
> > some issues with rcar mipi-csi driver. The sensor never entered into LP-11
> > state.
> >
> > The powerup sequence in the datasheet[1] shows the sensor entering into
> > LP-11 in streaming mode, so to fix this issue transitions are performed
> > from "streaming -> standby" in the probe() after power up.
> >
> > With this commit the sensor is able to enter LP-11 mode during power up,
> > as expected by some CSI-2 controllers.
> >
> > [1] https://publiclab.org/system/images/photos/000/023/294/original/
> > RASPBERRY_PI_CAMERA_V2_DATASHEET_IMX219PQH5_7.0.0_Datasheet_XXX.PDF
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Acked-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
>
Thank you for the Ack.

Cheers,
--Prabhakar

>
> > ---
> >  drivers/media/i2c/imx219.c | 17 +++++++++++++++++
> >  1 file changed, 17 insertions(+)
> >
> > diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> > index f1effb5a5f66..16010ca1781a 100644
> > --- a/drivers/media/i2c/imx219.c
> > +++ b/drivers/media/i2c/imx219.c
> > @@ -1224,6 +1224,23 @@ static int imx219_probe(struct i2c_client *client)
> >         /* Set default mode to max resolution */
> >         imx219->mode = &supported_modes[0];
> >
> > +       /* sensor doesn't enter LP-11 state upon power up until and unless
> > +        * streaming is started, so upon power up switch the modes to:
> > +        * streaming -> standby
> > +        */
> > +       ret = imx219_write_reg(imx219, IMX219_REG_MODE_SELECT,
> > +                              IMX219_REG_VALUE_08BIT, IMX219_MODE_STREAMING);
> > +       if (ret < 0)
> > +               goto error_power_off;
> > +       usleep_range(100, 110);
> > +
> > +       /* put sensor back to standby mode */
> > +       ret = imx219_write_reg(imx219, IMX219_REG_MODE_SELECT,
> > +                              IMX219_REG_VALUE_08BIT, IMX219_MODE_STANDBY);
> > +       if (ret < 0)
> > +               goto error_power_off;
> > +       usleep_range(100, 110);
> > +
> >         ret = imx219_init_controls(imx219);
> >         if (ret)
> >                 goto error_power_off;
> > --
> > 2.20.1
> >