Re: [PATCH linux-next 1/4] ARM: at91/dt: add new DT properties for Atmel usart
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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH linux-next 1/4] ARM: at91/dt: add new DT properties for Atmel usart
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. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH linux-next 1/4] ARM: at91/dt: add new DT properties for Atmel usart
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 --- Documentation/devicetree/bindings/serial/atmel-usart.txt | 15 +++ 1 file changed, 15 insertions(+) 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. compatible description: - at91rm9200: legacy USART support -- 1.8.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH linux-next 1/4] ARM: at91/dt: add new DT properties for Atmel usart
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.pitc...@atmel.com --- Documentation/devicetree/bindings/serial/atmel-usart.txt | 15 +++ 1 file changed, 15 insertions(+) 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 -- 1.8.2.2 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
