| Message ID | 6fe7914a2c39245ac9a05cdb9962b88c409ec1a4.1433253787.git.cyrille.pitchen@atmel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2 Jun 2015 16:18:21 +0200, Cyrille Pitchen wrote: > +- atmel,rts-low-threshold: when the RX FIFO level, ie the number of data > + available to be read from the RX FIFO, crosses down this threshold the RTS > + line is driven to low level to tell the remote peer that it can (re)start > + sending new data. > +- atmel,rts-high-threshold: when the RX FIFO level crosses up this threshold, > + the RTS line is driven to high level to tell the remote peer that it should > + stop sending new data. Maintainers, are there any guidelines for what is appropriate to put into DT? The parameters above look like they could be programmed at runtime through some user space API like sysfs.
diff --git a/Documentation/devicetree/bindings/serial/atmel-usart.txt b/Documentation/devicetree/bindings/serial/atmel-usart.txt index 90787aa..6158418 100644 --- a/Documentation/devicetree/bindings/serial/atmel-usart.txt +++ b/Documentation/devicetree/bindings/serial/atmel-usart.txt @@ -22,6 +22,21 @@ Optional properties: 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: size of the TX and RX FIFOs. That is to say the maximum + number of data each FIFO can store. A positive size enables FIFO support. + A zero size or a missing property disables FIFO support. +- atmel,rts-low-threshold: when the RX FIFO level, ie the number of data + available to be read from the RX FIFO, crosses down this threshold the RTS + line is driven to low level to tell the remote peer that it can (re)start + sending new data. +- atmel,rts-high-threshold: when the RX FIFO level crosses up this threshold, + the RTS line is driven to high level to tell the remote peer that it should + stop sending new data. + +0 < rts-low-threshold < rts-high-threshold <= fifo-size + +These two thresholds are only used when both the FIFO support and the hardware +handshake mode are enabled. <chip> compatible description: - at91rm9200: legacy USART support
add 3 new properties: - "atmel,fifo-size": to enable FIFO support - "atmel,rts-low-threshold" and "atmel,rts-high-threshold": to control the hardware handshake flow control. Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> --- Documentation/devicetree/bindings/serial/atmel-usart.txt | 15 +++++++++++++++ 1 file changed, 15 insertions(+)