Re: [PATCH 1/2] serial: support register interface with 16-bit stride for console

[Masahiro Yamada]

Hi Peter,

2015-10-20 4:50 GMT+09:00 Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>:
> On 10/19/2015 01:40 AM, Masahiro Yamada wrote:
>> Currently, 8-bit (MMIO) and 32-bit (MMIO32) strides are supported for
>> the 8250 console, but 16-bit (MMIO16) stride is not.  The 8250 UART
>> device on my board has 16-bit stride (reg-shift = <1>) and I am eager
>> to use earlycon with it.
>>
>> Refer to arch/arm/boot/dts/uniphier-support-card.dtsi:
>>
>>         serialsc: uart@000b0000 {
>>                 compatible = "ns16550a";
>>                 reg = <0x000b0000 0x20>;
>>                 clock-frequency = <12288000>;
>>                 reg-shift = <1>;
>>         };
>>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
>> ---
>>
>>  Documentation/kernel-parameters.txt  |  9 +++++----
>>  drivers/tty/serial/8250/8250_early.c |  5 +++++
>>  drivers/tty/serial/8250/8250_port.c  | 20 ++++++++++++++++++++
>>  drivers/tty/serial/earlycon.c        | 15 +++++++++++----
>>  drivers/tty/serial/serial_core.c     |  9 +++++++--
>>  include/linux/serial_core.h          |  1 +
>>  include/uapi/linux/serial.h          |  9 +++++----
>>  7 files changed, 54 insertions(+), 14 deletions(-)
>>
>
> [...]
>
>> diff --git a/include/uapi/linux/serial.h b/include/uapi/linux/serial.h
>> index 25331f9..1d20d9c 100644
>> --- a/include/uapi/linux/serial.h
>> +++ b/include/uapi/linux/serial.h
>> @@ -65,10 +65,11 @@ struct serial_struct {
>>  #define SERIAL_IO_PORT       0
>>  #define SERIAL_IO_HUB6       1
>>  #define SERIAL_IO_MEM        2
>> -#define SERIAL_IO_MEM32        3
>> -#define SERIAL_IO_AU   4
>> -#define SERIAL_IO_TSI          5
>> -#define SERIAL_IO_MEM32BE 6
>> +#define SERIAL_IO_MEM16      3
>> +#define SERIAL_IO_MEM32        4
>> +#define SERIAL_IO_AU   5
>> +#define SERIAL_IO_TSI          6
>> +#define SERIAL_IO_MEM32BE 7
>
> The existing values cannot be re-defined since they're userspace visible.

Thanks, I've sent v2.


-- 
Best Regards
Masahiro Yamada
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