Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-26 12:52:30 +00:00
Code Issues Packages Projects Releases Wiki Activity

dt-bindings: mfd: atmel-usart: add DMA bindings for USART in SPI mode

Browse Source 
The bindings for DMA are now common for both drivers of the USART
IP.

The node given as an example for USART in SPI mode has been updated in
order to include DMA bindings.

Signed-off-by: Radu Pirea <radu_nicolae.pirea@upb.ro>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Radu Pirea 2019-05-05 21:06:45 +03:00 committed by Mark Brown
parent e29eaa3c4b
commit f7b99e5948
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 15 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
Documentation/devicetree/bindings/mfd/atmel-usart.txt
View File

@ -17,17 +17,24 @@ Required properties for USART in SPI mode:
- cs-gpios: chipselects (internal cs not supported) - cs-gpios: chipselects (internal cs not supported)
- atmel,usart-mode : Must be <AT91_USART_MODE_SPI> (found in dt-bindings/mfd/at91-usart.h) - atmel,usart-mode : Must be <AT91_USART_MODE_SPI> (found in dt-bindings/mfd/at91-usart.h)
Optional properties in serial and SPI mode:
- dma bindings for dma transfer:
- dmas: DMA specifier, consisting of a phandle to DMA controller node,
memory peripheral interface and USART DMA channel ID, FIFO configuration.
The order of DMA channels is fixed. The first DMA channel must be TX
associated channel and the second one must be RX associated channel.
Refer to dma.txt and atmel-dma.txt for details.
- dma-names: "tx" for TX channel.
"rx" for RX channel.
The order of dma-names is also fixed. The first name must be "tx"
and the second one must be "rx" as in the examples below.
Optional properties in serial mode: Optional properties in serial mode:
- atmel,use-dma-rx: use of PDC or DMA for receiving data - atmel,use-dma-rx: use of PDC or DMA for receiving data
- atmel,use-dma-tx: use of PDC or DMA for transmitting data - atmel,use-dma-tx: use of PDC or DMA for transmitting data
- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD line respectively. - {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD line respectively.
It will use specified PIO instead of the peripheral function pin for the USART feature. It will use specified PIO instead of the peripheral function pin for the USART feature.
If unsure, don't specify this property. If unsure, don't specify this property.
- add dma bindings for dma transfer:
- dmas: DMA specifier, consisting of a phandle to DMA controller node,
memory peripheral interface and USART DMA channel ID, FIFO configuration.
Refer to dma.txt and atmel-dma.txt for details.
- dma-names: "rx" for RX channel, "tx" for TX channel.
- atmel,fifo-size: maximum number of data the RX and TX FIFOs can store for FIFO - atmel,fifo-size: maximum number of data the RX and TX FIFOs can store for FIFO
capable USARTs. capable USARTs.
- rs485-rts-delay, rs485-rx-during-tx, linux,rs485-enabled-at-boot-time: see rs485.txt - rs485-rts-delay, rs485-rx-during-tx, linux,rs485-enabled-at-boot-time: see rs485.txt
@ -81,5 +88,8 @@ Example:
interrupts = <12 IRQ_TYPE_LEVEL_HIGH 5>; interrupts = <12 IRQ_TYPE_LEVEL_HIGH 5>;
clocks = <&usart0_clk>; clocks = <&usart0_clk>;
clock-names = "usart"; clock-names = "usart";
dmas = <&dma0 2 AT91_DMA_CFG_PER_ID(3)>,
<&dma0 2 (AT91_DMA_CFG_PER_ID(4) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
dma-names = "tx", "rx";
cs-gpios = <&pioB 3 0>; cs-gpios = <&pioB 3 0>;
}; };