linux-kernel - Re: [PATCH v7 9/9] drm/mediatek: add support for Mediatek SoC MT2701

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Message-ID: <1473744743.28437.26.camel@mtksdaap41>
Date:   Tue, 13 Sep 2016 13:32:23 +0800
From:   CK Hu <ck.hu@...iatek.com>
To:     YT Shen <yt.shen@...iatek.com>
CC:     <dri-devel@...ts.freedesktop.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        David Airlie <airlied@...ux.ie>,
        Matthias Brugger <matthias.bgg@...il.com>,
        Daniel Kurtz <djkurtz@...omium.org>,
        Mao Huang <littlecvr@...omium.org>,
        Bibby Hsieh <bibby.hsieh@...iatek.com>,
        "Daniel Vetter" <daniel.vetter@...ll.ch>,
        Thierry Reding <thierry.reding@...il.com>,
        Jie Qiu <jie.qiu@...iatek.com>,
        Maxime Ripard <maxime.ripard@...e-electrons.com>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        shaoming chen <shaoming.chen@...iatek.com>,
        Jitao Shi <jitao.shi@...iatek.com>,
        Boris Brezillon <boris.brezillon@...e-electrons.com>,
        Dan Carpenter <dan.carpenter@...cle.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <srv_heupstream@...iatek.com>,
        Sascha Hauer <kernel@...gutronix.de>,
        <yingjoe.chen@...iatek.com>, <emil.l.velikov@...il.com>
Subject: Re: [PATCH v7 9/9] drm/mediatek: add support for Mediatek SoC MT2701

Hi, YT:

On Mon, 2016-09-12 at 18:16 +0800, YT Shen wrote:
> Hi CK,
> 
> On Wed, 2016-09-07 at 13:37 +0800, CK Hu wrote:
> > Hi, YT:
> > 
> > On Fri, 2016-09-02 at 19:24 +0800, YT Shen wrote:
> > > This patch add support for the Mediatek MT2701 DISP subsystem.
> > > There is only one OVL engine in MT2701.
> > > 
> > > Signed-off-by: YT Shen <yt.shen@...iatek.com>
> > 
> > [snip...]
> > 
> > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > > index 4b4e449..465819b 100644
> > > --- a/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > > +++ b/drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c
> > > @@ -112,6 +112,7 @@ struct mtk_ddp_comp_match {
> > >  
> > >  static const struct mtk_ddp_comp_match mtk_ddp_matches[DDP_COMPONENT_ID_MAX] = {
> > >  	[DDP_COMPONENT_AAL]	= { MTK_DISP_AAL,	0, NULL },
> > > +	[DDP_COMPONENT_BLS]	= { MTK_DISP_PWM,	0, NULL },
> > 
> > I think BLS is different than PWM, so this statement should be
> > 
> > [DDP_COMPONENT_BLS] = { MTK_DISP_BLS, 0, NULL };
> The BLS module actually is a multifunction device, one of them is the
> PWM function.  We only upstream PWM function [1] now, and it is
> accepted.  When there are real use case (gamma function), we will update
> this part.  What do you think?

I think BLS = PWM + GAMMA and the device with register range from
0x1400a000 to 0x1400afff should be called BLS. I think this device is
called PWM in [1] because it just use its PWM function and it's not
suitable. At least in DRM driver, we should use the term BLS rather than
PWM. Maybe we should define as below:

[DDP_COMPONENT_BLS] = { MTK_DISP_BLS, 0, NULL };

and

{ .compatible = "mediatek,mt2701-disp-pwm",   .data = (void
*)MTK_DISP_BLS },


Regards,
CK

[1] https://patchwork.kernel.org/patch/9223001/

> 
> Regards,
> yt.shen
> 
> [1] https://patchwork.kernel.org/patch/9223001/
> 
> > 
> > 
> > >  	[DDP_COMPONENT_COLOR0]	= { MTK_DISP_COLOR,	0, &ddp_color },
> > >  	[DDP_COMPONENT_COLOR1]	= { MTK_DISP_COLOR,	1, &ddp_color },
> > >  	[DDP_COMPONENT_DPI0]	= { MTK_DPI,		0, NULL },
> > 
> > Regards,
> > CK
> > 
> > 
> 
>