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Message-ID: <169412ca-9167-b214-d613-4fe0e76ad36a@flygoat.com>
Date:   Sun, 27 Mar 2022 13:54:04 +0100
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Subject: Re: [PATCH v12 3/6] dt-bindings: display: Add Loongson display
 controller
Content-Language: en-GB
To:     Sui Jingfeng <15330273260@189.cn>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Roland Scheidegger <sroland@vmware.com>,
        Zack Rusin <zackr@vmware.com>,
        Christian Gmeiner <christian.gmeiner@gmail.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        "David S . Miller" <davem@davemloft.net>,
        Lucas Stach <l.stach@pengutronix.de>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Ilia Mirkin <imirkin@alum.mit.edu>,
        Qing Zhang <zhangqing@loongson.cn>,
        suijingfeng <suijingfeng@loongson.cn>
Cc:     linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org
References: <20220327113846.2498146-1-15330273260@189.cn>
 <20220327113846.2498146-4-15330273260@189.cn>
From:   Jiaxun Yang <jiaxun.yang@flygoat.com>
In-Reply-To: <20220327113846.2498146-4-15330273260@189.cn>
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Precedence: bulk


在 2022/3/27 12:38, Sui Jingfeng 写道:
> Add DT bindings and simple usages for Loongson display controller
> found in LS7A1000 bridges chip and LS2k1000 SoC.
>
> Signed-off-by: Sui Jingfeng <15330273260@189.cn>
[...]
> +
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    bus {
> +
> +        #address-cells = <3>;
> +        #size-cells = <2>;
> +        #interrupt-cells = <2>;
> +
> +        display-controller@6,1 {
> +            compatible = "loongson,ls7a1000-dc";
> +            reg = <0x3100 0x0 0x0 0x0 0x0>;
> +            interrupts = <28 IRQ_TYPE_LEVEL_HIGH>;
> +
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            i2c@6 {
> +                compatible = "loongson,gpio-i2c";
> +                reg = <0x00001650 0x00000020>;
Hi Jingfeng,

Thanks for your patch.

Just curious about what is this "reg" for?
> +                loongson,nr = <6>;
Why nr start from 6?

The approach you are handling I2C seems to be wired..

Actually you can reference how network subsystem is handling
MDIO controller built-in into Ethernet controller [1] in this case. It is
basically the same problem.

[1]: 
https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/net/snps,dwmac.yaml

Thanks.
- Jiaxun

> +                loongson,sda = <0>;
> +                loongson,scl = <1>;
> +                loongson,udelay = <5>;
> +                loongson,timeout = <2200>;
> +            };
> +
> +            i2c@7 {
> +                compatible = "loongson,gpio-i2c";
> +                reg = <0x00001650 0x00000020>;
> +                loongson,nr = <7>;
> +                loongson,sda = <2>;
> +                loongson,scl = <3>;
> +                loongson,udelay = <5>;
> +                loongson,timeout = <2200>;
> +            };
> +
> +            ports {
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +                port@0 {
> +                    reg = <0>;
> +                    endpoint {
> +                            remote-endpoint = <&vga_encoder_in>;
> +                    };
> +                };
> +
> +                port@1 {
> +                    reg = <1>;
> +                    endpoint {
> +                            remote-endpoint = <&dvi_encoder_in>;
> +                    };
> +                };
> +            };
> +        };
> +    };
> +
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    bus {
> +
> +        #address-cells = <3>;
> +        #size-cells = <2>;
> +        #interrupt-cells = <2>;
> +
> +        display-controller@6,0 {
> +            compatible = "loongson,ls2k1000-dc";
> +            reg = <0x3100 0x0 0x0 0x0 0x0>;
> +            interrupts = <28 IRQ_TYPE_LEVEL_HIGH>;
> +
> +            ports {
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +                port@0 {
> +                    reg = <0>;
> +                    endpoint {
> +                            remote-endpoint = <&panel_in>;
> +                    };
> +                };
> +
> +                port@1 {
> +                    reg = <1>;
> +                    endpoint {
> +                            remote-endpoint = <&hdmi_encoder_in>;
> +                    };
> +                };
> +            };
> +        };
> +    };
> +...