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Subject: Re: [PATCH 3/3] drm/mediatek: add mt8183 dsi driver support
From:   Jitao Shi <jitao.shi@mediatek.com>
To:     Nicolas Boichat <drinkcat@chromium.org>
CC:     Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
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        Sean Paul <seanpaul@chromium.org>,
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        Philipp Zabel <p.zabel@pengutronix.de>,
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        <linux-mediatek@lists.infradead.org>,
        <srv_heupstream@mediatek.com>,
        Sascha Hauer <kernel@pengutronix.de>,
        "Yingjoe Chen" <yingjoe.chen@mediatek.com>,
        Eddie Huang <eddie.huang@mediatek.com>,
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        Bibby Hsieh =?UTF-8?Q?=28=E8=AC=9D=E6=BF=9F=E9=81=A0=29?= 
        <bibby.hsieh@mediatek.com>, CK HU <ck.hu@mediatek.com>,
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Date:   Sun, 17 Feb 2019 22:48:12 +0800
In-Reply-To: <CANMq1KBR-CpjAtj6qTEjK8PA2DUW3w_-OP_EyE7uoaojGLoGLg@mail.gmail.com>
References: <20190214044243.129920-1-jitao.shi@mediatek.com>
         <20190214044243.129920-3-jitao.shi@mediatek.com>
         <CANMq1KBR-CpjAtj6qTEjK8PA2DUW3w_-OP_EyE7uoaojGLoGLg@mail.gmail.com>
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On Thu, 2019-02-14 at 13:54 +0800, Nicolas Boichat wrote:
> On Thu, Feb 14, 2019 at 12:43 PM Jitao Shi <jitao.shi@mediatek.com> wrote:
> >
> > MT8183 dsi has two changes with mt8173.
> > 1. Add the register double buffer control, but we no need it, So make
> >    it default off.
> 
> Can you describe a little bit more what this is about? That's shadow
> registers, right?
> 

Yes, it is shadow registers.

Jitao

> > 2. Add picture size control.
> >
> > Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_dsi.c | 20 +++++++++++++++++++-
> >  1 file changed, 19 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > index 80db02a25cb0..20cb53f05d42 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > @@ -78,6 +78,7 @@
> >  #define DSI_VBP_NL             0x24
> >  #define DSI_VFP_NL             0x28
> >  #define DSI_VACT_NL            0x2C
> > +#define DSI_SIZE_CON           0x38
> >  #define DSI_HSA_WC             0x50
> >  #define DSI_HBP_WC             0x54
> >  #define DSI_HFP_WC             0x58
> > @@ -131,7 +132,10 @@
> >  #define VM_CMD_EN                      BIT(0)
> >  #define TS_VFP_EN                      BIT(5)
> >
> > -#define DSI_CMDQ0              0x180
> 
> As I said earlier, move this to 2/3.
> 

Thank for you review.
I'll move it to 2/3 next version.

Best Regards
Jitao

> > +#define DSI_SHADOW_DEBUG       0x190U
> > +#define FORCE_COMMIT           BIT(0)
> > +#define BYPASS_SHADOW          BIT(1)
> > +
> >  #define CONFIG                         (0xff << 0)
> >  #define SHORT_PACKET                   0
> >  #define LONG_PACKET                    2
> > @@ -158,6 +162,7 @@ struct phy;
> >
> >  struct mtk_dsi_driver_data {
> >         const u32 reg_cmdq_off;
> > +       bool has_size_ctl;
> >  };
> >
> >  struct mtk_dsi {
> > @@ -426,6 +431,9 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
> >         writel(vm->vfront_porch, dsi->regs + DSI_VFP_NL);
> >         writel(vm->vactive, dsi->regs + DSI_VACT_NL);
> >
> > +       if (dsi->driver_data->has_size_ctl)
> > +               writel(vm->vactive << 16 | vm->hactive, dsi->regs + DSI_SIZE_CON);
> > +
> >         horizontal_sync_active_byte = (vm->hsync_len * dsi_tmp_buf_bpp - 10);
> >
> >         if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
> > @@ -595,6 +603,9 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
> >         }
> >
> >         mtk_dsi_enable(dsi);
> > +
> > +       /* DSI no need this double buffer, disable it when writing register */
> 
> "DSI does not need double buffering, disable it when writing register"
> 

I'll fix it next version.


> > +       writel(FORCE_COMMIT | BYPASS_SHADOW, dsi->regs + DSI_SHADOW_DEBUG);
> 
> So you do this on all MT* variants, is that ok?
> 
> >         mtk_dsi_reset_engine(dsi);
> >         mtk_dsi_phy_timconfig(dsi);
> >
> > @@ -1090,11 +1101,18 @@ static const struct mtk_dsi_driver_data mt2701_dsi_driver_data = {
> >         .reg_cmdq_off = 0x180,
> >  };
> >
> > +static const struct mtk_dsi_driver_data mt8183_dsi_driver_data = {
> > +       .reg_cmdq_off = 0x200,
> > +       .has_size_ctl = true,
> > +};
> > +
> >  static const struct of_device_id mtk_dsi_of_match[] = {
> >         { .compatible = "mediatek,mt2701-dsi",
> >           .data = &mt2701_dsi_driver_data },
> >         { .compatible = "mediatek,mt8173-dsi",
> >           .data = &mt8173_dsi_driver_data },
> > +       { .compatible = "mediatek,mt8183-dsi",
> > +         .data = &mt8183_dsi_driver_data },
> >         { },
> >  };
> >
> > --
> > 2.20.1
> >