diff mbox

at91: sam9x5 dt: add usart dma definitions to dt

Message ID 775af3ca3993517ceeb45da786dd69a4d000829b.1412922258.git.jiri.prchal@aksignal.cz (mailing list archive)
State New, archived
Headers show

Commit Message

Jiri Prchal Oct. 10, 2014, 6:35 a.m. UTC 
This patch adds usart dma definitions to both dtsi for sam9x5 chips. Without
usage of dma it's unable to catch all bytes on usart receiver.

Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
---
 arch/arm/boot/dts/at91sam9x5.dtsi        | 20 ++++++++++++++++++++
 arch/arm/boot/dts/at91sam9x5_usart3.dtsi |  5 +++++
 2 files changed, 25 insertions(+)

--
1.9.1

Comments

Ludovic Desroches Oct. 10, 2014, 8:12 a.m. UTC | #1 
Hi,

On Fri, Oct 10, 2014 at 08:35:56AM +0200, Jiri Prchal wrote:
> This patch adds usart dma definitions to both dtsi for sam9x5 chips. Without
> usage of dma it's unable to catch all bytes on usart receiver.
> 

Adding DMA configuration is a good idea. But I think we will have an
issue because we have too many requested channels for DMA0.

Adding usart0, 9 dma channels will be requested. So a choice has to be
done. On DMA0 we have:
- 2 channels for SSC,
- 1 channel for MMC,
- 2 channels for I2C0,
- 2 channels for SPI0,
- 2 channels for USART0.

I have only mentionned enabled devices.

Regards

Ludovic


> Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
> ---
>  arch/arm/boot/dts/at91sam9x5.dtsi        | 20 ++++++++++++++++++++
>  arch/arm/boot/dts/at91sam9x5_usart3.dtsi |  5 +++++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/at91sam9x5.dtsi b/arch/arm/boot/dts/at91sam9x5.dtsi
> index 726274f..f9acf6d 100644
> --- a/arch/arm/boot/dts/at91sam9x5.dtsi
> +++ b/arch/arm/boot/dts/at91sam9x5.dtsi
> @@ -860,6 +860,11 @@
>  				interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
>  				pinctrl-names = "default";
>  				pinctrl-0 = <&pinctrl_dbgu>;
> +				atmel,use-dma-tx;
> +				atmel,use-dma-rx;
> +				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(8)>,
> +				       <&dma1 1 (AT91_DMA_CFG_PER_ID(9) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
> +				dma-names = "tx", "rx";
>  				clocks = <&mck>;
>  				clock-names = "usart";
>  				status = "disabled";
> @@ -871,6 +876,11 @@
>  				interrupts = <5 IRQ_TYPE_LEVEL_HIGH 5>;
>  				pinctrl-names = "default";
>  				pinctrl-0 = <&pinctrl_usart0>;
> +				atmel,use-dma-rx;
> +				atmel,use-dma-tx;
> +				dmas = <&dma0 1 AT91_DMA_CFG_PER_ID(3)>,
> +				       <&dma0 1 (AT91_DMA_CFG_PER_ID(4) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
> +				dma-names = "tx", "rx";
>  				clocks = <&usart0_clk>;
>  				clock-names = "usart";
>  				status = "disabled";
> @@ -882,6 +892,11 @@
>  				interrupts = <6 IRQ_TYPE_LEVEL_HIGH 5>;
>  				pinctrl-names = "default";
>  				pinctrl-0 = <&pinctrl_usart1>;
> +				atmel,use-dma-rx;
> +				atmel,use-dma-tx;
> +				dmas = <&dma0 1 AT91_DMA_CFG_PER_ID(5)>,
> +				       <&dma0 1 (AT91_DMA_CFG_PER_ID(6) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
> +				dma-names = "tx", "rx";
>  				clocks = <&usart1_clk>;
>  				clock-names = "usart";
>  				status = "disabled";
> @@ -893,6 +908,11 @@
>  				interrupts = <7 IRQ_TYPE_LEVEL_HIGH 5>;
>  				pinctrl-names = "default";
>  				pinctrl-0 = <&pinctrl_usart2>;
> +				atmel,use-dma-rx;
> +				atmel,use-dma-tx;
> +				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(12)>,
> +				       <&dma1 1 (AT91_DMA_CFG_PER_ID(13) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
> +				dma-names = "tx", "rx";
>  				clocks = <&usart2_clk>;
>  				clock-names = "usart";
>  				status = "disabled";
> diff --git a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
> index 140217a5..731da0e 100644
> --- a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
> +++ b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
> @@ -57,6 +57,11 @@
>  				interrupts = <8 IRQ_TYPE_LEVEL_HIGH 5>;
>  				pinctrl-names = "default";
>  				pinctrl-0 = <&pinctrl_usart3>;
> +				atmel,use-dma-rx;
> +				atmel,use-dma-tx;
> +				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(14)>,
> +				       <&dma1 1 (AT91_DMA_CFG_PER_ID(15) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
> +				dma-names = "tx", "rx";
>  				clocks = <&usart3_clk>;
>  				clock-names = "usart";
>  				status = "disabled";
> --
> 1.9.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Nicolas Ferre Oct. 10, 2014, 8:39 a.m. UTC | #2 
On 10/10/2014 10:12, Ludovic Desroches :
> Hi,
> 
> On Fri, Oct 10, 2014 at 08:35:56AM +0200, Jiri Prchal wrote:
>> This patch adds usart dma definitions to both dtsi for sam9x5 chips. Without
>> usage of dma it's unable to catch all bytes on usart receiver.

At which speed, with which kind of load on the CPU?

> Adding DMA configuration is a good idea. But I think we will have an
> issue because we have too many requested channels for DMA0.
> 
> Adding usart0, 9 dma channels will be requested. So a choice has to be
> done. On DMA0 we have:
> - 2 channels for SSC,
> - 1 channel for MMC,
> - 2 channels for I2C0,
> - 2 channels for SPI0,
> - 2 channels for USART0.

Yes, so maybe disable the DMA for SPI0. But the decision is pretty
related to the use of the board. So I would not change things...

> I have only mentioned enabled devices.

Yes indeed,

So maybe we can add the "dmas" properties in the files mentioned by
Jiri, but not enable them like you did Ludovic in this patch:

d24cd78399a3625a69887c8124638260c1c37a2b (ARM: at91: sama5d3: add usart
dma configurations)

Bye,


>> Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
>> ---
>>  arch/arm/boot/dts/at91sam9x5.dtsi        | 20 ++++++++++++++++++++
>>  arch/arm/boot/dts/at91sam9x5_usart3.dtsi |  5 +++++
>>  2 files changed, 25 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/at91sam9x5.dtsi b/arch/arm/boot/dts/at91sam9x5.dtsi
>> index 726274f..f9acf6d 100644
>> --- a/arch/arm/boot/dts/at91sam9x5.dtsi
>> +++ b/arch/arm/boot/dts/at91sam9x5.dtsi
>> @@ -860,6 +860,11 @@
>>  				interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
>>  				pinctrl-names = "default";
>>  				pinctrl-0 = <&pinctrl_dbgu>;
>> +				atmel,use-dma-tx;
>> +				atmel,use-dma-rx;
>> +				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(8)>,
>> +				       <&dma1 1 (AT91_DMA_CFG_PER_ID(9) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>> +				dma-names = "tx", "rx";
>>  				clocks = <&mck>;
>>  				clock-names = "usart";
>>  				status = "disabled";
>> @@ -871,6 +876,11 @@
>>  				interrupts = <5 IRQ_TYPE_LEVEL_HIGH 5>;
>>  				pinctrl-names = "default";
>>  				pinctrl-0 = <&pinctrl_usart0>;
>> +				atmel,use-dma-rx;
>> +				atmel,use-dma-tx;
>> +				dmas = <&dma0 1 AT91_DMA_CFG_PER_ID(3)>,
>> +				       <&dma0 1 (AT91_DMA_CFG_PER_ID(4) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>> +				dma-names = "tx", "rx";
>>  				clocks = <&usart0_clk>;
>>  				clock-names = "usart";
>>  				status = "disabled";
>> @@ -882,6 +892,11 @@
>>  				interrupts = <6 IRQ_TYPE_LEVEL_HIGH 5>;
>>  				pinctrl-names = "default";
>>  				pinctrl-0 = <&pinctrl_usart1>;
>> +				atmel,use-dma-rx;
>> +				atmel,use-dma-tx;
>> +				dmas = <&dma0 1 AT91_DMA_CFG_PER_ID(5)>,
>> +				       <&dma0 1 (AT91_DMA_CFG_PER_ID(6) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>> +				dma-names = "tx", "rx";
>>  				clocks = <&usart1_clk>;
>>  				clock-names = "usart";
>>  				status = "disabled";
>> @@ -893,6 +908,11 @@
>>  				interrupts = <7 IRQ_TYPE_LEVEL_HIGH 5>;
>>  				pinctrl-names = "default";
>>  				pinctrl-0 = <&pinctrl_usart2>;
>> +				atmel,use-dma-rx;
>> +				atmel,use-dma-tx;
>> +				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(12)>,
>> +				       <&dma1 1 (AT91_DMA_CFG_PER_ID(13) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>> +				dma-names = "tx", "rx";
>>  				clocks = <&usart2_clk>;
>>  				clock-names = "usart";
>>  				status = "disabled";
>> diff --git a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
>> index 140217a5..731da0e 100644
>> --- a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
>> +++ b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
>> @@ -57,6 +57,11 @@
>>  				interrupts = <8 IRQ_TYPE_LEVEL_HIGH 5>;
>>  				pinctrl-names = "default";
>>  				pinctrl-0 = <&pinctrl_usart3>;
>> +				atmel,use-dma-rx;
>> +				atmel,use-dma-tx;
>> +				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(14)>,
>> +				       <&dma1 1 (AT91_DMA_CFG_PER_ID(15) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>> +				dma-names = "tx", "rx";
>>  				clocks = <&usart3_clk>;
>>  				clock-names = "usart";
>>  				status = "disabled";
>> --
>> 1.9.1
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 
>
Jiri Prchal Oct. 10, 2014, 9:22 a.m. UTC | #3 
Hi,

Dne 10.10.2014 v 10:39 Nicolas Ferre napsal(a):
> On 10/10/2014 10:12, Ludovic Desroches :
>> Hi,
>>
>> On Fri, Oct 10, 2014 at 08:35:56AM +0200, Jiri Prchal wrote:
>>> This patch adds usart dma definitions to both dtsi for sam9x5 chips. Without
>>> usage of dma it's unable to catch all bytes on usart receiver.
>
> At which speed, with which kind of load on the CPU?
At 115200b/s, load aprox. 10% at 400MHz.
>
>> Adding DMA configuration is a good idea. But I think we will have an
>> issue because we have too many requested channels for DMA0.
I discovered that dma has only 8 channels for 15 peripherals right now.
And it makes big problem to me, I need at least 9ch on dma0 since on dma1 need only 6.
>>
>> Adding usart0, 9 dma channels will be requested. So a choice has to be
>> done. On DMA0 we have:
>> - 2 channels for SSC,
>> - 1 channel for MMC,
>> - 2 channels for I2C0,
>> - 2 channels for SPI0,
>> - 2 channels for USART0.
>
> Yes, so maybe disable the DMA for SPI0. But the decision is pretty
> related to the use of the board. So I would not change things...
No, SPI0 need too.
>
>> I have only mentioned enabled devices.
>
> Yes indeed,
>
> So maybe we can add the "dmas" properties in the files mentioned by
> Jiri, but not enable them like you did Ludovic in this patch:
>
> d24cd78399a3625a69887c8124638260c1c37a2b (ARM: at91: sama5d3: add usart
> dma configurations)
>
> Bye,
But is it possible to enable/disable dma at runtime from userspace?
>
>
>>> Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
>>> ---
>>>   arch/arm/boot/dts/at91sam9x5.dtsi        | 20 ++++++++++++++++++++
>>>   arch/arm/boot/dts/at91sam9x5_usart3.dtsi |  5 +++++
>>>   2 files changed, 25 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/at91sam9x5.dtsi b/arch/arm/boot/dts/at91sam9x5.dtsi
>>> index 726274f..f9acf6d 100644
>>> --- a/arch/arm/boot/dts/at91sam9x5.dtsi
>>> +++ b/arch/arm/boot/dts/at91sam9x5.dtsi
>>> @@ -860,6 +860,11 @@
>>>   				interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
>>>   				pinctrl-names = "default";
>>>   				pinctrl-0 = <&pinctrl_dbgu>;
>>> +				atmel,use-dma-tx;
>>> +				atmel,use-dma-rx;
>>> +				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(8)>,
>>> +				       <&dma1 1 (AT91_DMA_CFG_PER_ID(9) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>>> +				dma-names = "tx", "rx";
>>>   				clocks = <&mck>;
>>>   				clock-names = "usart";
>>>   				status = "disabled";
>>> @@ -871,6 +876,11 @@
>>>   				interrupts = <5 IRQ_TYPE_LEVEL_HIGH 5>;
>>>   				pinctrl-names = "default";
>>>   				pinctrl-0 = <&pinctrl_usart0>;
>>> +				atmel,use-dma-rx;
>>> +				atmel,use-dma-tx;
>>> +				dmas = <&dma0 1 AT91_DMA_CFG_PER_ID(3)>,
>>> +				       <&dma0 1 (AT91_DMA_CFG_PER_ID(4) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>>> +				dma-names = "tx", "rx";
>>>   				clocks = <&usart0_clk>;
>>>   				clock-names = "usart";
>>>   				status = "disabled";
>>> @@ -882,6 +892,11 @@
>>>   				interrupts = <6 IRQ_TYPE_LEVEL_HIGH 5>;
>>>   				pinctrl-names = "default";
>>>   				pinctrl-0 = <&pinctrl_usart1>;
>>> +				atmel,use-dma-rx;
>>> +				atmel,use-dma-tx;
>>> +				dmas = <&dma0 1 AT91_DMA_CFG_PER_ID(5)>,
>>> +				       <&dma0 1 (AT91_DMA_CFG_PER_ID(6) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>>> +				dma-names = "tx", "rx";
>>>   				clocks = <&usart1_clk>;
>>>   				clock-names = "usart";
>>>   				status = "disabled";
>>> @@ -893,6 +908,11 @@
>>>   				interrupts = <7 IRQ_TYPE_LEVEL_HIGH 5>;
>>>   				pinctrl-names = "default";
>>>   				pinctrl-0 = <&pinctrl_usart2>;
>>> +				atmel,use-dma-rx;
>>> +				atmel,use-dma-tx;
>>> +				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(12)>,
>>> +				       <&dma1 1 (AT91_DMA_CFG_PER_ID(13) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>>> +				dma-names = "tx", "rx";
>>>   				clocks = <&usart2_clk>;
>>>   				clock-names = "usart";
>>>   				status = "disabled";
>>> diff --git a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
>>> index 140217a5..731da0e 100644
>>> --- a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
>>> +++ b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
>>> @@ -57,6 +57,11 @@
>>>   				interrupts = <8 IRQ_TYPE_LEVEL_HIGH 5>;
>>>   				pinctrl-names = "default";
>>>   				pinctrl-0 = <&pinctrl_usart3>;
>>> +				atmel,use-dma-rx;
>>> +				atmel,use-dma-tx;
>>> +				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(14)>,
>>> +				       <&dma1 1 (AT91_DMA_CFG_PER_ID(15) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
>>> +				dma-names = "tx", "rx";
>>>   				clocks = <&usart3_clk>;
>>>   				clock-names = "usart";
>>>   				status = "disabled";
>>> --
>>> 1.9.1
>>>
>>>
>>> _______________________________________________
>>> linux-arm-kernel mailing list
>>> linux-arm-kernel@lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>>
>>
>
>
diff mbox

Patch

diff --git a/arch/arm/boot/dts/at91sam9x5.dtsi b/arch/arm/boot/dts/at91sam9x5.dtsi
index 726274f..f9acf6d 100644
--- a/arch/arm/boot/dts/at91sam9x5.dtsi
+++ b/arch/arm/boot/dts/at91sam9x5.dtsi
@@ -860,6 +860,11 @@ 
 				interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_dbgu>;
+				atmel,use-dma-tx;
+				atmel,use-dma-rx;
+				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(8)>,
+				       <&dma1 1 (AT91_DMA_CFG_PER_ID(9) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				clocks = <&mck>;
 				clock-names = "usart";
 				status = "disabled";
@@ -871,6 +876,11 @@ 
 				interrupts = <5 IRQ_TYPE_LEVEL_HIGH 5>;
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_usart0>;
+				atmel,use-dma-rx;
+				atmel,use-dma-tx;
+				dmas = <&dma0 1 AT91_DMA_CFG_PER_ID(3)>,
+				       <&dma0 1 (AT91_DMA_CFG_PER_ID(4) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				clocks = <&usart0_clk>;
 				clock-names = "usart";
 				status = "disabled";
@@ -882,6 +892,11 @@ 
 				interrupts = <6 IRQ_TYPE_LEVEL_HIGH 5>;
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_usart1>;
+				atmel,use-dma-rx;
+				atmel,use-dma-tx;
+				dmas = <&dma0 1 AT91_DMA_CFG_PER_ID(5)>,
+				       <&dma0 1 (AT91_DMA_CFG_PER_ID(6) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				clocks = <&usart1_clk>;
 				clock-names = "usart";
 				status = "disabled";
@@ -893,6 +908,11 @@ 
 				interrupts = <7 IRQ_TYPE_LEVEL_HIGH 5>;
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_usart2>;
+				atmel,use-dma-rx;
+				atmel,use-dma-tx;
+				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(12)>,
+				       <&dma1 1 (AT91_DMA_CFG_PER_ID(13) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				clocks = <&usart2_clk>;
 				clock-names = "usart";
 				status = "disabled";
diff --git a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
index 140217a5..731da0e 100644
--- a/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
+++ b/arch/arm/boot/dts/at91sam9x5_usart3.dtsi
@@ -57,6 +57,11 @@ 
 				interrupts = <8 IRQ_TYPE_LEVEL_HIGH 5>;
 				pinctrl-names = "default";
 				pinctrl-0 = <&pinctrl_usart3>;
+				atmel,use-dma-rx;
+				atmel,use-dma-tx;
+				dmas = <&dma1 1 AT91_DMA_CFG_PER_ID(14)>,
+				       <&dma1 1 (AT91_DMA_CFG_PER_ID(15) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
+				dma-names = "tx", "rx";
 				clocks = <&usart3_clk>;
 				clock-names = "usart";
 				status = "disabled";