Messages in this thread | | | Subject | Re: [PATCH 1/4] ARM: dts: exynos5250: Add #sound-dai-cells property to hdmi device node | From | Sylwester Nawrocki <> | Date | Fri, 09 Mar 2018 12:52:58 +0100 |
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Hi Inki,
On 03/09/2018 03:40 AM, Inki Dae wrote: > 2018년 03월 08일 02:27에 Sylwester Nawrocki 이(가) 쓴 글: >> This property is required for specifying link between the HDMI IP block >> and the SoC's audio subsystem. >> >> Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> >> --- >> arch/arm/boot/dts/exynos5250.dtsi | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/arch/arm/boot/dts/exynos5250.dtsi b/arch/arm/boot/dts/exynos5250.dtsi >> index 56626d1a4235..71d2ede118e3 100644 >> --- a/arch/arm/boot/dts/exynos5250.dtsi >> +++ b/arch/arm/boot/dts/exynos5250.dtsi >> @@ -700,6 +700,7 @@ >> "sclk_hdmiphy", "mout_hdmi"; >> samsung,syscon-phandle = <&pmu_system_controller>; >> phy = <&hdmiphy>; >> + #sound-dai-cells = <0>; > > This patch adds this property to hdmi device node which is bound by HDMI driver > of Exynos DRM. As we talked about this at other email thread, seems this property > is required mandatorily for Odroid XU3/4 board which uses Exynos5422. > There may be something I'm missing so could you let me know how this property > is required?
It is required to properly interpret the list of DAI specified in the 'sound-dai' property. If a device supports only one DAI it will have #sound-dai-cells = <0> and the sound-dai property values in cpu<->codec link may look like this:
cpu { ... } codec { sound-dai = <&max98090>, <&hdmi>; };
When the CODEC support more DAIs it will have #sound-dai-cells = <1> and we can additionally specify which DAI we exactly refer to, in this case DAI 0:
cpu { ... } codec { sound-dai = <&max98095 0>, <&hdmi>; };
More details can be found in documentation of of_parse_phandle_with_args() function.
The above refers to cpu/codec mapping like I2S0 -> [max9809x, hdmi], on Exynos5433 we have I2S0 -> wm5110 and I2S1 -> hdmi.
-- Regards, Sylwester
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