[v10,2/5] media: renesas: vsp1: Add support to deassert/assert reset line

  As the resets DT property is mandatory, and is present in all .dtsi
in mainline, add support to perform deassert/assert using reference
counted reset handle.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
v9->v10:
 * Moved {deassert,assert} calls to vsp1_pm_runtime_{resume,suspend}
v8->v9:
 * No change
v7->v8:
 * No Change
v6->v7:
 * No change
v5->v6:
 * Rebased to media_staging and updated commit header
 * Added Rb tag from Laurent
 * Added forward declaration for struct reset_control
 * Updated vsp1_device_get() with changes suggested by Laurent
 * Updated error message for reset_control_get form ctrl->control.
v4->v5:
 * Added Rb tag from Geert
v3->v4:
 * Restored error check for pm_runtime_resume_and_get and calls
   assert() in case of failure.
v2->v3:
 * Added Rb tag from Philipp
 * If reset_control_deassert() failed, return ret directly. 
v1->v2:
 * Used reference counted reset handle to perform deassert/assert
RFC->v1:
 * Added reset support as separate patch
 * Moved rstc just after the bus_master field in struct vsp1_device
RFC:
 * https://patchwork.kernel.org/project/linux-renesas-soc/patch/20220112174612.10773-21-biju.das.jz@bp.renesas.com/
---
 drivers/media/platform/renesas/vsp1/vsp1.h     |  2 ++
 drivers/media/platform/renesas/vsp1/vsp1_drv.c | 17 ++++++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)
  

Hi Biju,

On Wed, May 4, 2022 at 9:06 PM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> As the resets DT property is mandatory, and is present in all .dtsi
> in mainline, add support to perform deassert/assert using reference
> counted reset handle.
>
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> v9->v10:
>  * Moved {deassert,assert} calls to vsp1_pm_runtime_{resume,suspend}

Thanks for the update!

> --- a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> +++ b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> @@ -631,13 +633,21 @@ static int __maybe_unused vsp1_pm_runtime_resume(struct device *dev)
>         struct vsp1_device *vsp1 = dev_get_drvdata(dev);
>         int ret;
>
> +       ret = reset_control_deassert(vsp1->rstc);
> +       if (ret < 0)
> +               return ret;
> +
>         if (vsp1->info) {
>                 ret = vsp1_device_init(vsp1);
>                 if (ret < 0)

Missing reset_control_assert().

>                         return ret;
>         }
>
> -       return rcar_fcp_enable(vsp1->fcp);
> +       ret = rcar_fcp_enable(vsp1->fcp);
> +       if (ret < 0)
> +               reset_control_assert(vsp1->rstc);
> +
> +       return ret;
>  }
>
>  static const struct dev_pm_ops vsp1_pm_ops = {

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
  

Hi Geert,

Thanks for the feedback.

> Subject: Re: [PATCH v10 2/5] media: renesas: vsp1: Add support to
> deassert/assert reset line
> 
> Hi Biju,
> 
> On Wed, May 4, 2022 at 9:06 PM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> > As the resets DT property is mandatory, and is present in all .dtsi in
> > mainline, add support to perform deassert/assert using reference
> > counted reset handle.
> >
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> > v9->v10:
> >  * Moved {deassert,assert} calls to vsp1_pm_runtime_{resume,suspend}
> 
> Thanks for the update!
> 
> > --- a/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > +++ b/drivers/media/platform/renesas/vsp1/vsp1_drv.c
> > @@ -631,13 +633,21 @@ static int __maybe_unused
> vsp1_pm_runtime_resume(struct device *dev)
> >         struct vsp1_device *vsp1 = dev_get_drvdata(dev);
> >         int ret;
> >
> > +       ret = reset_control_deassert(vsp1->rstc);
> > +       if (ret < 0)
> > +               return ret;
> > +
> >         if (vsp1->info) {
> >                 ret = vsp1_device_init(vsp1);
> >                 if (ret < 0)
> 
> Missing reset_control_assert().

OK, will fix this, by adding goto statement, which can be used for below error
handling as well.

Cheers,
Biju

> 
> >                         return ret;
> >         }
> >
> > -       return rcar_fcp_enable(vsp1->fcp);
> > +       ret = rcar_fcp_enable(vsp1->fcp);
> > +       if (ret < 0)
> > +               reset_control_assert(vsp1->rstc);
> > +
> > +       return ret;
> >  }
> >
> >  static const struct dev_pm_ops vsp1_pm_ops = {
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
> 
> In personal conversations with technical people, I call myself a hacker.
> But when I'm talking to journalists I just say "programmer" or something
> like that.
>                                 -- Linus Torvalds