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

[Manivannan Sadhasivam]

On Sun, Jan 06, 2019 at 01:12:53AM +0000, André Przywara wrote:
> 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.
>

My argument above was based on the fact that Amit didn't remove
"actions,s900-serial" compatible but added "actions,owl-serial".
I'm okay with having "actions,owl-serial" for _all_ S series boards.

Thanks,
Mani

> But we should not invent a new compatible string here.
> 
> Cheers,
> Andre.
> 
> 
> > 
> > Thanks,
> > Mani
> > 
> >>  	{ }
> >>  };
> >>  
> >> -- 
> >> 2.7.4
> >>
>