Re: [PATCH 1/3] dt-bindings: dma: ti: k3-bcdma: Describe cfg register regions

From: Vignesh Raghavendra
Date: Fri Aug 11 2023 - 00:38:45 EST




On 11/08/23 00:05, Conor Dooley wrote:
> On Thu, Aug 10, 2023 at 11:13:53PM +0530, Vignesh Raghavendra wrote:
>> Block copy DMA(BCDMA)module on K3 SoCs have ring cfg, TX and RX
>> channel cfg register regions which are usually configured by a Device
>> Management firmware. But certain entities such as bootloader (like
>> U-Boot) may have to access them directly. Describe this region in the
>> binding documentation for completeness of module description.
>>
>> Keep the binding compatible with existing DTS files by requiring first
>> five regions to be present at least.
>>
>> Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx>
>> ---
>> .../devicetree/bindings/dma/ti/k3-bcdma.yaml | 25 +++++++++++++------
>> 1 file changed, 17 insertions(+), 8 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
>> index 4ca300a42a99..d166e284532b 100644
>> --- a/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
>> +++ b/Documentation/devicetree/bindings/dma/ti/k3-bcdma.yaml
>> @@ -37,11 +37,11 @@ properties:
>>
>> reg:
>> minItems: 3
>> - maxItems: 5
>> + maxItems: 8
>
> How come none of these reg entries have a description? What
> differentiates a "gcfg" from a "cfg" for example?
>

Ok, I will a patch to describe the regions first before adding new ones.

>>
>> reg-names:
>> minItems: 3
>> - maxItems: 5
>> + maxItems: 8
>>
>> "#dma-cells":
>> const: 3
>> @@ -161,14 +161,19 @@ allOf:
>> properties:
>> reg:
>> minItems: 5
>> + maxItems: 8
>>
>> reg-names:
>> + minItems: 5
>> items:
>> - const: gcfg
>> - const: bchanrt
>> - const: rchanrt
>> - const: tchanrt
>> - const: ringrt
>> + - const: cfg
>> + - const: tchan
>> + - const: rchan
>>
>> required:
>> - ti,sci-rm-range-bchan
>> @@ -216,12 +221,16 @@ examples:
>> main_bcdma: dma-controller@485c0100 {
>> compatible = "ti,am64-dmss-bcdma";
>>
>> - reg = <0x0 0x485c0100 0x0 0x100>,
>> - <0x0 0x4c000000 0x0 0x20000>,
>> - <0x0 0x4a820000 0x0 0x20000>,
>> - <0x0 0x4aa40000 0x0 0x20000>,
>> - <0x0 0x4bc00000 0x0 0x100000>;
>> - reg-names = "gcfg", "bchanrt", "rchanrt", "tchanrt", "ringrt";
>> + reg = <0x00 0x485c0100 0x00 0x100>,
>
> Why have you added extra zeros? (0x00)

Sorry, copy paste error, was trying to copy example from real DT that
use 0x00. Will fix. Thanks!

>
> Thanks,
> Conor.
>
>> + <0x00 0x4c000000 0x00 0x20000>,
>> + <0x00 0x4a820000 0x00 0x20000>,
>> + <0x00 0x4aa40000 0x00 0x20000>,
>> + <0x00 0x4bc00000 0x00 0x100000>,
>> + <0x00 0x48600000 0x00 0x8000>,
>> + <0x00 0x484a4000 0x00 0x2000>,
>> + <0x00 0x484c2000 0x00 0x2000>;
>> + reg-names = "gcfg", "bchanrt", "rchanrt", "tchanrt", "ringrt",
>> + "cfg", "tchan", "rchan";
>> msi-parent = <&inta_main_dmss>;
>> #dma-cells = <3>;
>>
>> --
>> 2.41.0
>>

--
Regards
Vignesh