[PATCH] arm64: dts: rockchip: Add uart dma names to the SoC dtsi for RK356x

[Philipp Puschmann]

Hi Diederik,

Am 10.07.24 um 12:02 schrieb Diederik de Haas:
> On Wednesday, 10 July 2024 11:33:56 CEST Philipp Puschmann wrote:
>> DMA names are required by of_dma_request_slave_channel function that is
>> called during uart probe. So to enable DMA for uarts add the names as in
>> the RK3568 TRM.
> 
> Setting it on channels without flow control apparently causes issues. See
> 
> https://lore.kernel.org/linux-rockchip/20240628120130.24076-1-didi.debian@cknow.org/

Ah is see. The only problem that i have is to enable/disable dmas by having or not having
dma-names properties, where the latter case is followed by kernel error messages. That
is very counterintuitive. Maybe a explicit boolean like dma-broken would be better. That
could be set on dtsi level as default and deleted on board dts if wanted. With such
a boolean we could also prevent the misleading "dma-names property of" error message
and replace it with a hint that dma is disabled on purpose.

Regards,
Philipp Puschmann
> 
>> Signed-off-by: Philipp Puschmann <p.puschmann at pironex.com>
>> ---
>>  arch/arm64/boot/dts/rockchip/rk356x.dtsi | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/rockchip/rk356x.dtsi
>> b/arch/arm64/boot/dts/rockchip/rk356x.dtsi index d8543b5557ee..4ae40661ca6a
>> 100644
>> --- a/arch/arm64/boot/dts/rockchip/rk356x.dtsi
>> +++ b/arch/arm64/boot/dts/rockchip/rk356x.dtsi
>> @@ -489,6 +489,7 @@ uart0: serial at fdd50000 {
>>  		clocks = <&pmucru SCLK_UART0>, <&pmucru PCLK_UART0>;
>>  		clock-names = "baudclk", "apb_pclk";
>>  		dmas = <&dmac0 0>, <&dmac0 1>;
>> +		dma-names = "tx", "rx";
>>  		pinctrl-0 = <&uart0_xfer>;
>>  		pinctrl-names = "default";
>>  		reg-io-width = <4>;
>> @@ -1389,6 +1390,7 @@ uart1: serial at fe650000 {
>>  		clocks = <&cru SCLK_UART1>, <&cru PCLK_UART1>;
>>  		clock-names = "baudclk", "apb_pclk";
>>  		dmas = <&dmac0 2>, <&dmac0 3>;
>> +		dma-names = "tx", "rx";
>>  		pinctrl-0 = <&uart1m0_xfer>;
>>  		pinctrl-names = "default";
>>  		reg-io-width = <4>;
>> ...