[PATCH] ns16550: add device tree support

[NISHIMOTO Hiroki]

Sebastian,

Thanks for your reviwing.
I will re-send as v2.

NISHIMOTO Hiroki


> 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"
> 
> Hiroki,
> 
> 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.
> 
> Sebastian
>