[U-Boot] [RFC PATCH 7/8] serial: actions: add uart support for s700

[André Przywara]

On 05/01/2019 18:20, Manivannan Sadhasivam wrote:
> On Thu, Jan 03, 2019 at 06:56:22PM +0530, Amit Singh Tomar wrote:
>> UART controller present on S700 is compatible with existing
>> S900 UART, this patch simply adds a proper compatible string
>> so that S900 uart driver can be reused for S700.
>>
>> Signed-off-by: Amit Singh Tomar <amittomer25 at gmail.com>
>> ---
>>  drivers/serial/serial_owl.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/serial/serial_owl.c b/drivers/serial/serial_owl.c
>> index 7ead73e..76995bf 100644
>> --- a/drivers/serial/serial_owl.c
>> +++ b/drivers/serial/serial_owl.c
>> @@ -121,6 +121,7 @@ static const struct dm_serial_ops owl_serial_ops = {
>>  
>>  static const struct udevice_id owl_serial_ids[] = {
>>  	{ .compatible =	"actions,s900-serial" },
>> +	{ .compatible =	"actions,owl-uart" },
> 
> "owl" is the family name for S series SoCs from Actions Semi. There are
> 3 SoCs so far, S500, S700 and S900. Reason for naming s900-serial was
> that there are hw difference between S500 (ARMv7) and S900/S700 (ARMv8).
> So, this should be "actions,s700-serial".

Huh, how so? The Linux DT bindings, which should be authoritative, do
not describe a s700 device. Also the Linux DTs use the s900 name. The
only difference between the S500 and S900 type seems to be the FIFO
size, which U-Boot doesn't care about.
As all the DTs I see in the Linux tree have owl-uart in their compatible
list, it would actually be sufficient to list just that. This is what
Linux' earlycon relies on.
But to play safe we could list both here, maybe even add s500-serial,
for the sake of completeness.

But we should not invent a new compatible string here.

Cheers,
Andre.


> 
> Thanks,
> Mani
> 
>>  	{ }
>>  };
>>  
>> -- 
>> 2.7.4
>>