Re: [PATCH v2 7/9] ARM: STi: DT: STiH407: Add FDMA driver dt nodes.

From: Lee Jones
Date: Fri Sep 11 2015 - 12:27:58 EST


On Fri, 11 Sep 2015, Peter Griffin wrote:

> These nodes are required to get the fdma driver working
> on STiH407 based silicon.
>
> Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
> ---
> arch/arm/boot/dts/stih407-family.dtsi | 51 +++++++++++++++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
>
> diff --git a/arch/arm/boot/dts/stih407-family.dtsi b/arch/arm/boot/dts/stih407-family.dtsi
> index 838b812..da07474b 100644
> --- a/arch/arm/boot/dts/stih407-family.dtsi
> +++ b/arch/arm/boot/dts/stih407-family.dtsi
> @@ -565,5 +565,56 @@
> <&phy_port2 PHY_TYPE_USB3>;
> };
> };
> +
> + fdma0: fdma0-audio@8e20000 {

I'm not familiar with the FDMA driver, so can't comment knowledgeably,
but the <dev> part of <dev>@<base_address> should only describe the
type of hardware. I believe in this case it should just be
dma@08e20000. Also notice the leading zero in the address, which I
believe mitigates possible confusion. Then you be more specific with
the label, so something like 'fdma-audio' seems appropriate here.

> + compatible = "st,stih407-fdma-mpe31";
> + reg = <0x8e20000 0x20000>;

I personally find padding up to 32bits helpful in the addresses.

> + interrupts = <GIC_SPI 5 IRQ_TYPE_NONE>;
> + dma-channels = <16>;
> + #dma-cells = <3>;
> + st,fdma-id = <0>;

We usually shy away from ID properties. What is it required for in
this case?

> + clocks = <&clk_s_c0_flexgen CLK_FDMA>,
> + <&clk_s_c0_flexgen CLK_EXT2F_A9>,
> + <&clk_s_c0_flexgen CLK_EXT2F_A9>,
> + <&clk_s_c0_flexgen CLK_EXT2F_A9>;
> + clock-names = "fdma_slim",
> + "fdma_hi",
> + "fdma_low",
> + "fdma_ic";
> + };
> +
> + fdma1: fdma1-app@8e40000 {
> + compatible = "st,stih407-fdma-mpe31";
> + reg = <0x8e40000 0x20000>;
> + interrupts = <GIC_SPI 7 IRQ_TYPE_NONE>;
> + dma-channels = <16>;
> + #dma-cells = <3>;
> + st,fdma-id = <1>;
> + clocks = <&clk_s_c0_flexgen CLK_FDMA>,
> + <&clk_s_c0_flexgen CLK_TX_ICN_DMU>,
> + <&clk_s_c0_flexgen CLK_TX_ICN_DMU>,
> + <&clk_s_c0_flexgen CLK_EXT2F_A9>;
> + clock-names = "fdma_slim",
> + "fdma_hi",
> + "fdma_low",
> + "fdma_ic";
> + };
> +
> + fdma2: fdma2-free_running@8e60000 {
> + compatible = "st,stih407-fdma-mpe31";
> + reg = <0x8e60000 0x20000>;
> + interrupts = <GIC_SPI 9 IRQ_TYPE_NONE>;
> + dma-channels = <16>;
> + #dma-cells = <3>;
> + st,fdma-id = <2>;
> + clocks = <&clk_s_c0_flexgen CLK_FDMA>,
> + <&clk_s_c0_flexgen CLK_EXT2F_A9>,
> + <&clk_s_c0_flexgen CLK_TX_ICN_DISP_0>,
> + <&clk_s_c0_flexgen CLK_EXT2F_A9>;
> + clock-names = "fdma_slim",
> + "fdma_hi",
> + "fdma_low",
> + "fdma_ic";
> + };
> };
> };

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org â Open source software for ARM SoCs
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