RE: [PATCH 11/17] drm: renesas: rz-du: mipi_dsi: Add OF data support

[Biju Das]

> -----Original Message-----
> From: Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx>
> Sent: 31 March 2025 14:59
> To: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>; Andrzej Hajda <andrzej.hajda@xxxxxxxxx>; Neil
> Armstrong <neil.armstrong@xxxxxxxxxx>; Robert Foss <rfoss@xxxxxxxxxx>; laurent.pinchart
> <laurent.pinchart@xxxxxxxxxxxxxxxx>; Jonas Karlman <jonas@xxxxxxxxx>; Jernej Skrabec
> <jernej.skrabec@xxxxxxxxx>; David Airlie <airlied@xxxxxxxxx>; Simona Vetter <simona@xxxxxxxx>; Maarten
> Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>; Maxime Ripard <mripard@xxxxxxxxxx>; Thomas Zimmermann
> <tzimmermann@xxxxxxx>; Rob Herring <robh@xxxxxxxxxx>; Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>; Conor
> Dooley <conor+dt@xxxxxxxxxx>; Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>; Kieran Bingham
> <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>; Stephen Boyd <sboyd@xxxxxxxxxx>; Philipp Zabel
> <p.zabel@xxxxxxxxxxxxxx>; devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-renesas-
> soc@xxxxxxxxxxxxxxx; linux-media@xxxxxxxxxxxxxxx; linux-clk@xxxxxxxxxxxxxxx; Fabrizio Castro
> <fabrizio.castro.jz@xxxxxxxxxxx>; Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Subject: Re: [PATCH 11/17] drm: renesas: rz-du: mipi_dsi: Add OF data support
> 
> Hi Biju,
> 
> Thank you for the review.
> 
> On Mon, Mar 31, 2025 at 1:38 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> >
> > Hi Prabhakar,
> >
> > Thanks for the patch.
> >
> > > -----Original Message-----
> > > From: Prabhakar <prabhakar.csengg@xxxxxxxxx>
> > > Sent: 30 March 2025 22:07
> > > Subject: [PATCH 11/17] drm: renesas: rz-du: mipi_dsi: Add OF data
> > > support
> > >
> > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > >
> > > In preparation for adding support for the Renesas RZ/V2H(P) SoC,
> > > this patch introduces a mechanism to pass SoC-specific information
> > > via OF data in the DSI driver. This enables the driver to adapt dynamically to various SoC-
> specific requirements without hardcoding configurations.
> > >
> > > The MIPI DSI interface on the RZ/V2H(P) SoC is nearly identical to
> > > the one on the RZ/G2L SoC. While the LINK registers are shared
> > > between the two SoCs, the D-PHY registers differ. Also the VCLK
> > > range differs on both these SoCs. To accommodate these differences `struct rzg2l_mipi_dsi_hw_info`
> is introduced and as now passed as OF data.
> > >
> > > These changes lay the groundwork for the upcoming RZ/V2H(P) SoC
> > > support by allowing SoC-specific data to be passed through OF.
> > >
> <snip>
> > > +
> > >       ret = drm_of_get_data_lanes_count_ep(dsi->dev->of_node, 1, 0, 1, 4);
> > >       if (ret < 0)
> > >               return dev_err_probe(dsi->dev, ret, @@ -729,10 +750,12
> > > @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
> > >       if (IS_ERR(dsi->vclk))
> > >               return PTR_ERR(dsi->vclk);
> > >
> > > -     dsi->rstc = devm_reset_control_get_exclusive(dsi->dev, "rst");
> > > -     if (IS_ERR(dsi->rstc))
> > > -             return dev_err_probe(dsi->dev, PTR_ERR(dsi->rstc),
> > > -                                  "failed to get rst\n");
> > > +     if (dsi->info->has_dphy_rstc) {
> > > +             dsi->rstc = devm_reset_control_get_exclusive(dsi->dev,
> > > + "rst");
> >
> > Maybe use devm_reset_control_get_optional_exclusive by dropping has_dphy_rstc.
> >
> As the dtbs_check doesn't enforce this,  `has_dphy_rstc` flag was added. Recently the same was done
> for the CRU [0] based on the recent comment received.
> 

RZ/V2H has "arst" and "prst". So, If you add "rst" for RZ/V2H then you should get dtbs warning, right?

Cheers,
Biju