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References: <20180419093225.614-1-wens@csie.org> <20180419093225.614-5-wens@csie.org>
 <58ce9e3b-00ee-87d2-f05b-b9f1414d1cfa@micronovasrl.com>
From:   Chen-Yu Tsai <wens@csie.org>
Date:   Thu, 19 Apr 2018 20:45:14 +0800
Message-ID: <CAGb2v65tH_8_J27Xmx4TeEYhpHLJf4m0AzXJoGXZYMfJH=51xQ@mail.gmail.com>
Subject: Re: [PATCH 4/6] drm/panel: simple: Add support for Banana Pi 7"
 S070WV20-CT16 panel
To:     Giulio Benetti <giulio.benetti@micronovasrl.com>
Cc:     Maxime Ripard <maxime.ripard@bootlin.com>,
        David Airlie <airlied@linux.ie>,
        Thierry Reding <thierry.reding@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        Jonathan Liu <net147@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org
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On Thu, Apr 19, 2018 at 8:31 PM, Giulio Benetti
<giulio.benetti@micronovasrl.com> wrote:
> Hi,
>
> Il 19/04/2018 11:32, Chen-Yu Tsai ha scritto:
>>
>> This panel is marketed as Banana Pi 7" LCD display. On the back is
>> a sticker denoting the model name S070WV20-CT16.
>
>
> Judging from the code, the real vendor should be CDTech.
> Take a look at their website:
> http://www.cdtech-lcd.com/en/standardscreen.html
>
> I point you my patch for inserting another similar panel:
> https://patchwork.freedesktop.org/patch/211914/
>
> Maybe it would make sense to use CDTech as the vendor,
> because maybe Bananapi resells only it.
> Or maybe it is a custom panel done for them,
> but the same is for other panels I've submitted patches.
> Micronova srl custom, but vendor is CDTech.
>
> What do you think?

That might be true. But for people without access to the vendors,
this is horribly hard to figure out. People are only going to look
at whatever marking there is on the LCD panel, and whatever the
seller says. This panel has the model number stickered on, but the
PCB attached to it only has the Banana Pi logo.

And given it's a custom piece, probably OEM or ODM, the real
manufacturer matters less. You don't mention "Foxconn" as the
vendor of the iPhone, do you?

ChenYu

>
> --
> Giulio Benetti
> CTO
>
> MICRONOVA SRL
> Sede: Via A. Niedda 3 - 35010 Vigonza (PD)
> Tel. 049/8931563 - Fax 049/8931346
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> Numero R.E.A. 258642
>
>
>>
>> This is a 7" 800x480 panel connected through a 24-bit RGB interface.
>> However the panel only does 262k colors.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>>   .../display/panel/bananapi,s070wv20-ct16.txt  |  7 ++++++
>>   drivers/gpu/drm/panel/panel-simple.c          | 25 +++++++++++++++++++
>>   2 files changed, 32 insertions(+)
>>   create mode 100644
>> Documentation/devicetree/bindings/display/panel/bananapi,s070wv20-ct16.txt
>>
>> diff --git
>> a/Documentation/devicetree/bindings/display/panel/bananapi,s070wv20-ct16.txt
>> b/Documentation/devicetree/bindings/display/panel/bananapi,s070wv20-ct16.txt
>> new file mode 100644
>> index 000000000000..2ec35ce36e9a
>> --- /dev/null
>> +++
>> b/Documentation/devicetree/bindings/display/panel/bananapi,s070wv20-ct16.txt
>> @@ -0,0 +1,7 @@
>> +Banana Pi 7" (S070WV20-CT16) TFT LCD Panel
>> +
>> +Required properties:
>> +- compatible: should be "bananapi,s070wv20-ct16"
>> +
>> +This binding is compatible with the simple-panel binding, which is
>> specified
>> +in simple-panel.txt in this directory.
>> diff --git a/drivers/gpu/drm/panel/panel-simple.c
>> b/drivers/gpu/drm/panel/panel-simple.c
>> index cbf1ab404ee7..9bc037f74d6c 100644
>> --- a/drivers/gpu/drm/panel/panel-simple.c
>> +++ b/drivers/gpu/drm/panel/panel-simple.c
>> @@ -745,6 +745,28 @@ static const struct panel_desc avic_tm070ddh03 = {
>>         },
>>   };
>>   +static const struct drm_display_mode bananapi_s070wv20_ct16_mode = {
>> +       .clock = 30000,
>> +       .hdisplay = 800,
>> +       .hsync_start = 800 + 40,
>> +       .hsync_end = 800 + 40 + 48,
>> +       .htotal = 800 + 40 + 48 + 40,
>> +       .vdisplay = 480,
>> +       .vsync_start = 480 + 13,
>> +       .vsync_end = 480 + 13 + 3,
>> +       .vtotal = 480 + 13 + 3 + 29,
>> +};
>> +
>> +static const struct panel_desc bananapi_s070wv20_ct16 = {
>> +       .modes = &bananapi_s070wv20_ct16_mode,
>> +       .num_modes = 1,
>> +       .bpc = 6,
>> +       .size = {
>> +               .width = 154,
>> +               .height = 86,
>> +       },
>> +};
>> +
>>   static const struct drm_display_mode boe_nv101wxmn51_modes[] = {
>>         {
>>                 .clock = 71900,
>> @@ -2112,6 +2134,9 @@ static const struct of_device_id platform_of_match[]
>> = {
>>         }, {
>>                 .compatible = "avic,tm070ddh03",
>>                 .data = &avic_tm070ddh03,
>> +       }, {
>> +               .compatible = "bananapi,s070wv20-ct16",
>> +               .data = &bananapi_s070wv20_ct16,
>>         }, {
>>                 .compatible = "boe,nv101wxmn51",
>>                 .data = &boe_nv101wxmn51,
>>
>
>
>