[U-Boot] [PATCH] serial: pl01x: Add support for devices with the rate pre-configured.

[Sergei Temerkhanov]

On Sat, Feb 6, 2016 at 12:44 PM, Simon Glass <sjg at chromium.org> wrote:
> Hi Eric,
>
> On 5 February 2016 at 14:43, Eric Anholt <eric at anholt.net> wrote:
>> For Raspberry Pi, we had the input clock rate to the pl011 fixed in
>> the rpi.c file, but it may be changed by firmware due to user changes
>> to config.txt.  Since the firmware always sets up the uart (default
>> 115200 output unless the user changes it), we can just skip our own
>> uart init to simplify the boot process and more reliably get serial
>> output.
>>
>> Signed-off-by: Eric Anholt <eric at anholt.net>
>> ---
>>  board/raspberrypi/rpi/rpi.c             | 3 +--
>>  drivers/serial/serial_pl01x.c           | 4 ++++
>>  include/dm/platform_data/serial_pl01x.h | 1 +
>>  3 files changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/board/raspberrypi/rpi/rpi.c b/board/raspberrypi/rpi/rpi.c
>> index 4b80d7b..1fd3f97 100644
>> --- a/board/raspberrypi/rpi/rpi.c
>> +++ b/board/raspberrypi/rpi/rpi.c
>> @@ -35,8 +35,7 @@ static const struct pl01x_serial_platdata serial_platdata = {
>>  #else
>>         .base = 0x20201000,
>>  #endif
>> -       .type = TYPE_PL011,
>> -       .clock = 3000000,
>> +       .type = TYPE_PL01X_PRECONFIGURED,
>>  };
>>
>>  U_BOOT_DEVICE(bcm2835_serials) = {
>> diff --git a/drivers/serial/serial_pl01x.c b/drivers/serial/serial_pl01x.c
>> index 552c945..7d4d214 100644
>> --- a/drivers/serial/serial_pl01x.c
>> +++ b/drivers/serial/serial_pl01x.c
>> @@ -83,6 +83,8 @@ static int pl01x_generic_serial_init(struct pl01x_regs *regs,
>>                 /* disable everything */
>>                 writel(0, &regs->pl011_cr);
>>                 break;
>> +       case TYPE_PL01X_PRECONFIGURED:
>> +               break;
>>         default:
>>                 return -EINVAL;
>>         }
>> @@ -172,6 +174,8 @@ static int pl01x_generic_setbrg(struct pl01x_regs *regs, enum pl01x_type type,
>>                 writel(UART_PL011_CR_UARTEN | UART_PL011_CR_TXE |
>>                        UART_PL011_CR_RXE | UART_PL011_CR_RTS, &regs->pl011_cr);
>>                 break;
>> +       case TYPE_PL01X_PRECONFIGURED:
>> +               break;
>>         }
>>         default:
>>                 return -EINVAL;
>> diff --git a/include/dm/platform_data/serial_pl01x.h b/include/dm/platform_data/serial_pl01x.h
>> index 5e068f3..ae1bf31 100644
>> --- a/include/dm/platform_data/serial_pl01x.h
>> +++ b/include/dm/platform_data/serial_pl01x.h
>> @@ -9,6 +9,7 @@
>>  enum pl01x_type {
>>         TYPE_PL010,
>>         TYPE_PL011,
>> +       TYPE_PL01X_PRECONFIGURED,
>
> This seems odd. You are not adding a new UART type.
>
> How about a separate bool flag?

I posted a patch with the same purpose a while ago
http://lists.denx.de/pipermail/u-boot/2015-October/230079.html

Regards,
Sergey

>
> Regards,
> Simon
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