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    SubjectRe: [PATCH v2 1/5] tty/serial: RS485 bindings for device tree
    On Wed, Oct 12, 2011 at 06:06:56PM +0200, Nicolas Ferre wrote:
    > Generic bindings for RS485 feature included in some UARTs.
    > Those bindings have to be used withing an UART device tree node.
    > Documentation updated to link to the bindings definition.
    >
    > Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

    Acked-by: Grant Likely <grant.likely@secretlab.ca>

    > ---
    > Documentation/devicetree/bindings/serial/rs485.txt | 31 ++++++++++++++++++++
    > .../devicetree/bindings/tty/serial/atmel-usart.txt | 27 +++++++++++++++++
    > Documentation/serial/serial-rs485.txt | 5 +++
    > 3 files changed, 63 insertions(+), 0 deletions(-)
    > create mode 100644 Documentation/devicetree/bindings/serial/rs485.txt
    > create mode 100644 Documentation/devicetree/bindings/tty/serial/atmel-usart.txt
    >
    > diff --git a/Documentation/devicetree/bindings/serial/rs485.txt b/Documentation/devicetree/bindings/serial/rs485.txt
    > new file mode 100644
    > index 0000000..1e753c6
    > --- /dev/null
    > +++ b/Documentation/devicetree/bindings/serial/rs485.txt
    > @@ -0,0 +1,31 @@
    > +* RS485 serial communications
    > +
    > +The RTS signal is capable of automatically controlling line direction for
    > +the built-in half-duplex mode.
    > +The properties described hereafter shall be given to a half-duplex capable
    > +UART node.
    > +
    > +Required properties:
    > +- rs485-rts-delay: prop-encoded-array <a b> where:
    > + * a is the delay beteween rts signal and beginning of data sent in milliseconds.
    > + it corresponds to the delay before sending data.
    > + * b is the delay between end of data sent and rts signal in milliseconds
    > + it corresponds to the delay after sending data and actual release of the line.
    > +
    > +Optional properties:
    > +- linux,rs485-enabled-at-boot-time: empty property telling to enable the rs485
    > + feature at boot time. It can be disabled later with proper ioctl.
    > +- rs485-rx-during-tx: empty property that enables the receiving of data even
    > + whilst sending data.
    > +
    > +RS485 example for Atmel USART:
    > + usart0: serial@fff8c000 {
    > + compatible = "atmel,at91sam9260-usart";
    > + reg = <0xfff8c000 0x4000>;
    > + interrupts = <7>;
    > + atmel,use-dma-rx;
    > + atmel,use-dma-tx;
    > + linux,rs485-enabled-at-boot-time;
    > + rs485-rts-delay = <0 200>; // in milliseconds
    > + };
    > +
    > diff --git a/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt b/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt
    > new file mode 100644
    > index 0000000..a49d9a1
    > --- /dev/null
    > +++ b/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt
    > @@ -0,0 +1,27 @@
    > +* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)
    > +
    > +Required properties:
    > +- compatible: Should be "atmel,<chip>-usart"
    > + The compatible <chip> indicated will be the first SoC to support an
    > + additional mode or an USART new feature.
    > +- reg: Should contain registers location and length
    > +- interrupts: Should contain interrupt
    > +
    > +Optional properties:
    > +- atmel,use-dma-rx: use of PDC or DMA for receiving data
    > +- atmel,use-dma-tx: use of PDC or DMA for transmitting data
    > +
    > +<chip> compatible description:
    > +- at91rm9200: legacy USART support
    > +- at91sam9260: generic USART implementation for SAM9 SoCs
    > +
    > +Example:
    > +
    > + usart0: serial@fff8c000 {
    > + compatible = "atmel,at91sam9260-usart";
    > + reg = <0xfff8c000 0x4000>;
    > + interrupts = <7>;
    > + atmel,use-dma-rx;
    > + atmel,use-dma-tx;
    > + };
    > +
    > diff --git a/Documentation/serial/serial-rs485.txt b/Documentation/serial/serial-rs485.txt
    > index c8878f8..079cb3d 100644
    > --- a/Documentation/serial/serial-rs485.txt
    > +++ b/Documentation/serial/serial-rs485.txt
    > @@ -28,6 +28,10 @@
    > RS485 communications. This data structure is used to set and configure RS485
    > parameters in the platform data and in ioctls.
    >
    > + The device tree can also provide RS485 boot time parameters (see [2]
    > + for bindings). The driver is in charge of filling this data structure from
    > + the values given by the device tree.
    > +
    > Any driver for devices capable of working both as RS232 and RS485 should
    > provide at least the following ioctls:
    >
    > @@ -121,3 +125,4 @@
    > 5. REFERENCES
    >
    > [1] include/linux/serial.h
    > + [2] Documentation/devicetree/bindings/serial/rs485.txt
    > --
    > 1.7.5.4
    >


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