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[v4,3/7] Documentation: DT: update atmel SSC with DMA binding

Message ID 1373379933-32749-4-git-send-email-richard.genoud@gmail.com (mailing list archive)
State New, archived
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Commit Message

Richard Genoud July 9, 2013, 2:25 p.m. UTC
As atmel-ssc can be used with DMA, the documentation should be updated.
Also, a configuration DMA example is given.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
---
 .../devicetree/bindings/misc/atmel-ssc.txt         |   20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

Comments

Mark Brown July 9, 2013, 3:05 p.m. UTC | #1
On Tue, Jul 09, 2013 at 04:25:29PM +0200, Richard Genoud wrote:

>  - reg: Should contain SSC registers location and length
>  - interrupts: Should contain SSC interrupt
> +For dma transfer:
> +- dmas: DMA specifier, consisting of a phandle to DMA controller node,
> +  the memory interface and SSC DMA channel ID (for tx and rx).
> +  See Documentation/devicetree/bindings/dma/atmel-dma.txt for details.
> +- dma-names: Must be "tx", "rx".

This is added as a required property so...

> -Example:
> +Examples:
>  ssc0: ssc@fffbc000 {
>  	compatible = "atmel,at91rm9200-ssc";
>  	reg = <0xfffbc000 0x4000>;
>  	interrupts = <14 4 5>;
>  };

...this first example is now invalid and should probably just be being
extended with the new required properties.
Richard Genoud July 10, 2013, 9:48 a.m. UTC | #2
2013/7/9 Mark Brown <broonie@kernel.org>:
> On Tue, Jul 09, 2013 at 04:25:29PM +0200, Richard Genoud wrote:
>
>>  - reg: Should contain SSC registers location and length
>>  - interrupts: Should contain SSC interrupt
>> +For dma transfer:
>> +- dmas: DMA specifier, consisting of a phandle to DMA controller node,
>> +  the memory interface and SSC DMA channel ID (for tx and rx).
>> +  See Documentation/devicetree/bindings/dma/atmel-dma.txt for details.
>> +- dma-names: Must be "tx", "rx".
>
> This is added as a required property so...
>
>> -Example:
>> +Examples:
>>  ssc0: ssc@fffbc000 {
>>       compatible = "atmel,at91rm9200-ssc";
>>       reg = <0xfffbc000 0x4000>;
>>       interrupts = <14 4 5>;
>>  };
>
> ...this first example is now invalid and should probably just be being
> extended with the new required properties.

Well, I have to rewrite that to make it clearer.
The thing is:
with "atmel,at91rm9200-ssc" the SSC doesn't work with DMA.
with "atmel,at91sam9g45-ssc", the SSC work ONLY with DMA.

So the dmas/dma-names properties are only required for g45-ssc, and
useless for rm9200-ssc

Maybe the best will be to write a paragraph for g45-ssc and another
for rm9200-ssc, even if there's some identical lines between them.


Thanks !

Richard.
Mark Brown July 10, 2013, 10:01 a.m. UTC | #3
On Wed, Jul 10, 2013 at 11:48:27AM +0200, Richard Genoud wrote:
> 2013/7/9 Mark Brown <broonie@kernel.org>:

> > ...this first example is now invalid and should probably just be being
> > extended with the new required properties.

> Well, I have to rewrite that to make it clearer.
> The thing is:
> with "atmel,at91rm9200-ssc" the SSC doesn't work with DMA.
> with "atmel,at91sam9g45-ssc", the SSC work ONLY with DMA.

> So the dmas/dma-names properties are only required for g45-ssc, and
> useless for rm9200-ssc

> Maybe the best will be to write a paragraph for g45-ssc and another
> for rm9200-ssc, even if there's some identical lines between them.

OK, or just write a section "Required for devices with compatible X".
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Patch

diff --git a/Documentation/devicetree/bindings/misc/atmel-ssc.txt b/Documentation/devicetree/bindings/misc/atmel-ssc.txt
index 38e51ad..7c320da 100644
--- a/Documentation/devicetree/bindings/misc/atmel-ssc.txt
+++ b/Documentation/devicetree/bindings/misc/atmel-ssc.txt
@@ -6,10 +6,28 @@  Required properties:
 	- atmel,at91sam9g45-ssc: support dma transfer
 - reg: Should contain SSC registers location and length
 - interrupts: Should contain SSC interrupt
+For dma transfer:
+- dmas: DMA specifier, consisting of a phandle to DMA controller node,
+  the memory interface and SSC DMA channel ID (for tx and rx).
+  See Documentation/devicetree/bindings/dma/atmel-dma.txt for details.
+- dma-names: Must be "tx", "rx".
 
-Example:
+Examples:
 ssc0: ssc@fffbc000 {
 	compatible = "atmel,at91rm9200-ssc";
 	reg = <0xfffbc000 0x4000>;
 	interrupts = <14 4 5>;
 };
+
+
+ssc0: ssc@f0010000 {
+      compatible = "atmel,at91sam9g45-ssc";
+      reg = <0xf0010000 0x4000>;
+      interrupts = <28 4 5>;
+      dmas = <&dma0 1 13>,
+	     <&dma0 1 14>;
+      dma-names = "tx", "rx";
+      pinctrl-names = "default";
+      pinctrl-0 = <&pinctrl_ssc0_tx &pinctrl_ssc0_rx>;
+      status = "disabled";
+};