diff mbox

[3/5] dt-bindings: stm32-dma: Add property to handle STM32 DMAMUX

Message ID 1489414561-28912-4-git-send-email-cedric.madianga@gmail.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

M'boumba Cedric Madianga March 13, 2017, 2:15 p.m. UTC
This patch adds an optional property needed for STM32 DMA controller
addressed via STM32 DMAMUX.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
---
 Documentation/devicetree/bindings/dma/stm32-dma.txt | 3 +++
 1 file changed, 3 insertions(+)

Comments

Rob Herring (Arm) March 20, 2017, 9:37 p.m. UTC | #1
On Mon, Mar 13, 2017 at 03:15:59PM +0100, M'boumba Cedric Madianga wrote:
> This patch adds an optional property needed for STM32 DMA controller
> addressed via STM32 DMAMUX.
> 
> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
> ---
>  Documentation/devicetree/bindings/dma/stm32-dma.txt | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt
> index 4408af6..7b5e91a 100644
> --- a/Documentation/devicetree/bindings/dma/stm32-dma.txt
> +++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt
> @@ -16,6 +16,9 @@ Optional properties:
>  - resets: Reference to a reset controller asserting the DMA controller
>  - st,mem2mem: boolean; if defined, it indicates that the controller supports
>    memory-to-memory transfer
> +- st,dmamux: boolean; if defined, it indicates that the controller is behind a
> +  DMA multiplexer. In that case, using dma instances doesn't work for DMA
> +  clients. They have to use dma-router instances.

This should not be needed for the same reason we don't need anything 
like this for chained interrupt controllers.

Also, the compatible string should be specific enough to provide this 
information.

Rob
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Pierre Yves MORDRET April 26, 2017, 9:23 a.m. UTC | #2
On 03/20/2017 10:37 PM, Rob Herring wrote:
> On Mon, Mar 13, 2017 at 03:15:59PM +0100, M'boumba Cedric Madianga wrote:
>> This patch adds an optional property needed for STM32 DMA controller
>> addressed via STM32 DMAMUX.
>>
>> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
>> ---
>>  Documentation/devicetree/bindings/dma/stm32-dma.txt | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt
>> index 4408af6..7b5e91a 100644
>> --- a/Documentation/devicetree/bindings/dma/stm32-dma.txt
>> +++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt
>> @@ -16,6 +16,9 @@ Optional properties:
>>  - resets: Reference to a reset controller asserting the DMA controller
>>  - st,mem2mem: boolean; if defined, it indicates that the controller supports
>>    memory-to-memory transfer
>> +- st,dmamux: boolean; if defined, it indicates that the controller is behind a
>> +  DMA multiplexer. In that case, using dma instances doesn't work for DMA
>> +  clients. They have to use dma-router instances.
>
> This should not be needed for the same reason we don't need anything
> like this for chained interrupt controllers.
>
> Also, the compatible string should be specific enough to provide this
> information.
>
> Rob

I don't understand what you're meant here. Our DMAs can work with or 
without DMAMUX driver. Driver uses this binding to use it or not.

Py

>
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>
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt
index 4408af6..7b5e91a 100644
--- a/Documentation/devicetree/bindings/dma/stm32-dma.txt
+++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt
@@ -16,6 +16,9 @@  Optional properties:
 - resets: Reference to a reset controller asserting the DMA controller
 - st,mem2mem: boolean; if defined, it indicates that the controller supports
   memory-to-memory transfer
+- st,dmamux: boolean; if defined, it indicates that the controller is behind a
+  DMA multiplexer. In that case, using dma instances doesn't work for DMA
+  clients. They have to use dma-router instances.
 
 Example: