[U-Boot] [PATCH] dm: ns16550: Add support for reg-offset property

[Adam Ford]

On Sat, Mar 12, 2016 at 7:54 PM, Simon Glass <sjg at chromium.org> wrote:
> Hi,
>
> On 28 February 2016 at 15:39, Alexander Graf <agraf at suse.de> wrote:
>>
>>
>> On 02/25/2016 02:38 PM, Derald D. Woods wrote:
>>>
>>> On Thu, Feb 25, 2016 at 09:11:24AM +0100, Michal Simek wrote:
>>>>
>>>> On 25.2.2016 05:47, Derald D. Woods wrote:
>>>>>
>>>>> On Wed, Feb 24, 2016 at 12:26:09PM +0100, Michal Simek wrote:
>>>>>>
>>>>>> On 24.2.2016 11:56, Adam Ford wrote:
>>>>>>>
>>>>>>> On Tue, Feb 23, 2016 at 12:38 AM, Simon Glass <sjg at chromium.org>
>>>>>>> wrote:
>>>>>>>>
>>>>>>>> Hi Michal,
>>>>>>>>
>>>>>>>> On 22 February 2016 at 00:40, Michal Simek <michal.simek at xilinx.com>
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>> On 19.2.2016 21:55, Simon Glass wrote:
>>>>>>>>>>
>>>>>>>>>> Hi Michal,
>>>>>>>>>>
>>>>>>>>>> On 16 February 2016 at 08:17, Michal Simek
>>>>>>>>>> <michal.simek at xilinx.com> wrote:
>>>>>>>>>>>
>>>>>>>>>>> reg-offset is the part of standard 8250 binding in the kernel.
>>>>>>>>>>> It is shifting start of address space by reg-offset.
>>>>>>>>>>> On Xilinx platform this offset is typically 0x1000.
>>>>>>>>>>>
>>>>>>>>>>> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
>>>>>>>>>>> ---
>>>>>>>>>>>
>>>>>>>>>>>   drivers/serial/ns16550.c | 6 ++++--
>>>>>>>>>>>   include/ns16550.h        | 1 +
>>>>>>>>>>>   2 files changed, 5 insertions(+), 2 deletions(-)
>>>>>>>>>>
>>>>>>>>>> Reviewed-by: Simon Glass <sjg at chromium.org>
>>>>>>>>>>
>>>>>>>>>> Do you support the debug UART feature on your boards?
>>>>>>>>>
>>>>>>>>> yes. I do support it but there you can put just address plus offset
>>>>>>>>> and
>>>>>>>>> there is no reason to add one more option to Kconfig.
>>>>>>>>> But let me know if you think that this is incorrect flow.
>>>>>>>
>>>>>>> This patch seems to break my OMAP3 board.  Does anyone know if I need
>>>>>>> to set a certain offset for OMAP3 to make this work (and where is the
>>>>>>> right place for it) ?
>>>>>>
>>>>>> Are you using DT init? Check your DT description if there is reg-offset
>>>>>> property. I expect if your board worked before and you remove this
>>>>>> property it will start to work again.
>>>>>>
>>>>> I am seeing the same problem with my BeagleBoard Rev. C4. There is
>>>>> something common, to more than one board, happening with this commit.
>>>>
>>>> You should enable debug console and send the log.
>>>> Do you have enough space for malloc?
>>>>
>>> I will have little time this weekend to go further. Some things will
>>> need to be un-configured to have enough space. I am around 7 KiB over
>>> with DEBUG enabled.
>>
>>
>> I'm not quite sure what exactly is going wrong here - maybe some asm code is
>> accessing the fields without proper offset generation?
>>
>> Either way, the patch below seems to fix the issue for me (on beaglebone):
>>
>> diff --git a/include/ns16550.h b/include/ns16550.h
>> index 5eeacd6..1311f4c 100644
>> --- a/include/ns16550.h
>> +++ b/include/ns16550.h
>> @@ -54,9 +54,9 @@
>>   */
>>  struct ns16550_platdata {
>>         unsigned long base;
>> -       int reg_offset;
>>         int reg_shift;
>>         int clock;
>> +       int reg_offset;
>>  };
>>
>>  struct udevice;
>>
>
> I picked up Alexander's suggestion: Still, we should fix everything up
> to use member names.
>

As far as I know a bunch of impacted boards should be fixed now.
http://git.denx.de/?p=u-boot.git;a=commitdiff;h=2f6ed3b89a1760ffa73123fb266de3d56eb5d88e

I think Alexander's patch shouldn't impact anything else.

adam

> Applied to u-boot-dm/next, thanks!
>
> - Simon
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