[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAGb2v66DOZbppAOT6yLaxyLSmSQ3t9RT-ESHaNq1vs=Fwbv93Q@mail.gmail.com>
Date: Sat, 20 May 2017 10:01:41 +0800
From: Chen-Yu Tsai <wens@...e.org>
To: Icenowy Zheng <icenowy@...c.io>
Cc: linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
Maxime Ripard <maxime.ripard@...e-electrons.com>,
devicetree <devicetree@...r.kernel.org>,
linux-sunxi <linux-sunxi@...glegroups.com>,
linux-kernel <linux-kernel@...r.kernel.org>,
dri-devel <dri-devel@...ts.freedesktop.org>,
Chen-Yu Tsai <wens@...e.org>, Rob Herring <robh+dt@...nel.org>,
linux-clk <linux-clk@...r.kernel.org>
Subject: Re: [linux-sunxi] Re: [RFC PATCH 01/11] dt-bindings: update the
binding for Allwinner H3 TVE support
On Sat, May 20, 2017 at 2:06 AM, Icenowy Zheng <icenowy@...c.io> wrote:
>
>
> 于 2017年5月20日 GMT+08:00 上午2:02:15, Maxime Ripard <maxime.ripard@...e-electrons.com> 写到:
>>On Thu, May 18, 2017 at 12:43:44AM +0800, Icenowy Zheng wrote:
>>> -On SoCs other than the A33 and V3s, there is one more clock
>>required:
>>> +For the following compatibles:
>>> + * allwinner,sun5i-a13-tcon
>>> + * allwinner,sun6i-a31-tcon
>>> + * allwinner,sun6i-a31s-tcon
>>> + * allwinner,sun8i-a33-tcon
>>> + * allwinner,sun8i-v3s-tcon
>>> +there is one more clock and one more property required:
>>> + - clocks:
>>> + - 'tcon-ch0': The clock driving the TCON channel 0
>>> + - clock-output-names: Name of the pixel clock created
>>> +
>>> +For the following compatibles:
>>> + * allwinner,sun5i-a13-tcon
>>> + * allwinner,sun6i-a31-tcon
>>> + * allwinner,sun6i-a31s-tcon
>>> + * allwinner,sun8i-h3-tcon0
>>> +there is one more clock required:
>>> - 'tcon-ch1': The clock driving the TCON channel 1
>>
>>Putting ID's in the compatible name is usually a bad idea. What is the
>>difference between the two? Only that the second one doesn't have a
>>clock?
>
> Yes.
>
>>
>>That seems highly unlikely. How does it generate the pixel clock
>>frequency?
>
> Yes it seems impossible, but it's also the fact.
>
> There's only one CLK_TCON in H3/5, which is for TCON0.
>
> It's possible that lcd-ch1 clk is CLK_TVE, but it's still a weird situation --
> Although we have a lcd-ch1 clock, we cannot touch it, otherwise
> the TVE will refuse to work (the TVE can only work under 216MHz).
Assuming the TV encoder is like the old one, then it never had a
separate module clock. Instead its timing signals are fed from the
TCON. So CLK_TVE is likely the clock for TCON1 here.
ChenYu
Powered by blists - more mailing lists