Dma for usart3 on sam9g25

Discussion around AT91RM9200 and SAM9 Series Products.

Moderator: nferre

okcash
Posts: 1
Joined: Thu Apr 30, 2015 5:55 pm

Dma for usart3 on sam9g25

Thu Apr 30, 2015 6:01 pm

Does someone know how to enable the DMA for usart3 on sam9g25; we can find information only for usart0 ,1, 2.
Thanks
blue_z
Location: USA
Posts: 1560
Joined: Thu Apr 19, 2007 10:15 pm

Re: Dma for usart3 on sam9g25

Thu Apr 30, 2015 8:57 pm

okcash wrote:Does someone know how to enable the DMA for usart3 on sam9g25;
In what environment?
okcash wrote:we can find information only for usart0 ,1, 2.
What is this "information"?
Why is that info not applicable/extensible to USART3?

Regards
aretra4
Posts: 4
Joined: Mon Dec 15, 2014 1:46 am

Re: Dma for usart3 on sam9g25

Tue May 05, 2015 4:01 pm

Code: Select all

			/* /dev/ttyS4 */
			
			usart3: serial@f8028000 {
				status = "okay";
				current-speed = <115200>;
				compatible = "atmel,at91sam9260-usart";
				reg = <0xf8028000 0x200>;
				interrupts = <8 IRQ_TYPE_LEVEL_HIGH 5>;
				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";
				pinctrl-names = "default";
				pinctrl-0 = <&pinctrl_usart3 &pinctrl_usart3_rts &pinctrl_usart3_cts>;
			};
			
the dma-related extra fields inside the usart3 section should suffice
rumcajs666
Posts: 3
Joined: Fri Dec 14, 2007 9:33 am

Re: Dma for usart3 on sam9g25

Fri Feb 05, 2016 3:46 pm

Hi,
I know this is old thread, but i have an issue with dma and usart3.
Do i have to make some more changes in device tree/kernel to make it works?

When i change usart 3's device tree entry like that

Code: Select all

usart3: serial@f8028000 {
            status = "okay";
            current-speed = <115200>;
            compatible = "atmel,at91sam9260-usart";
            reg = <0xf8028000 0x200>;
            interrupts = <8 IRQ_TYPE_LEVEL_HIGH 5>;
            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";
            pinctrl-names = "default";
            pinctrl-0 = <&pinctrl_usart3 &pinctrl_usart3_rts &pinctrl_usart3_cts>;
         };
my cpu freezes.
No kernel panic, nor any erros.
I'm working on kernel 3.10.
Does anyone had similar issue?

Return to “SAM9 ARM9 MPU”

Who is online

Users browsing this forum: No registered users and 1 guest