[PATCH] ns16550: add device tree support
sebastian.hesselbarth at gmail.com
Mon Jun 24 11:03:09 EDT 2013
On 06/24/13 14:18, NISHIMOTO Hiroki wrote:
> This patch adds device tree support for serial_ns16550 driver.
> Tested with pcduino (allwinner a10).
> Signed-off-by: NISHIMOTO Hiroki <hiroki.nishimoto.if at gmail.com>
> .../devicetree/bindings/serial/ns16550_serial.txt | 34 ++++++++++++++
> drivers/serial/serial_ns16550.c | 53 ++++++++++++++++++++--
> 2 files changed, 84 insertions(+), 3 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/serial/ns16550_serial.txt
> diff --git a/Documentation/devicetree/bindings/serial/ns16550_serial.txt b/Documentation/devicetree/bindings/serial/ns16550_serial.txt
> new file mode 100644
> index 0000000..848f949
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/serial/ns16550_serial.txt
> @@ -0,0 +1,34 @@
> +* NS16550 UART
> +Required properties:
> +- compatible : "ns16550_serial"
as stated in Documentation/devicetree/bindings/README, barebox uses the
same bindings as "the kernel" which is Linux I guess. Linux already has
a binding for ns16550 compatible serial.
I suggest to use that binding as a reference although it is not
documented but needs to be stripped from its source code.
> +- reg : offset and length of the register set for the device.
> +Optional properties:
> +- clock-frequency : the input clock frequency for the UART.
> +- reg-shift : quantity to shift the register offsets by. If this property is
> + not present then the register offsets are not shifted.
> +- reg-io-width : the size (in bytes) of the IO accesses that should be
> + performed on the device. If this property is not present then single byte
> + accesses are used.
> +- disable-fifo :
> + 0: enable tx/rx fifo (default value)
> + 1: disable tx/rx fifo
> +- console-stdin : activate stdin on this console.
> +- console-stdout : activate stdout on this console.
> +- console-stderr : activate stderr on this console.
ePAPR specification already defines stdout-path and stdin-path.
Moreover, barebox has of_device_is_stdout_path to check if a device is
referenced by stdout-path property.
More information about the barebox