Hi Laurent,
On Thu, Mar 10, 2016 at 10:40 AM, Laurent Pinchart
<laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
> On Wednesday 09 March 2016 20:18:41 Geert Uytterhoeven wrote:
>> On R-Car H3, some power areas (e.g. A3VP) contain I/O devices, which are
>> also part of the CPG/MSSR Clock Domain. Hook up the CPG/MSSR Clock
>> Domain attach/detach callbacks to enable power management using module
>> clocks.
>>
>> This also allows to support the Clock Domain for devices in the
>> "always-on" power area.
>>
>> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>> --- a/drivers/soc/renesas/rcar-sysc.c
>> +++ b/drivers/soc/renesas/rcar-sysc.c
>> @@ -251,6 +252,15 @@ static void __init rcar_sysc_pd_setup(struct
>> device_node *np, gov = &pm_domain_always_on_gov;
>> }
>>
>> +#ifdef CONFIG_ARCH_R8A7795
>
> This is fine for now as the R8A7795 is the only ARM64 model in the R-Car
> family, but how do you plan to move forward on this ? Will it be enabled for
> ARM64 SoCs straight away, and for ARM32 SoCs when switching from the cpg to
> the always-on power domain ?
>
>> + if (!(pd->flags & (PD_CPU | PD_SCU))) {
>> + /* Enable Clock Domain for I/O devices */
>> + genpd->flags = GENPD_FLAG_PM_CLK;
>> + genpd->attach_dev = cpg_mssr_attach_dev;
>> + genpd->detach_dev = cpg_mssr_detach_dev;
>> + }
>> +#endif
When enabling the always-on power domain for R-Car H1 and Gen2, this
should become:
if (!(pd->flags & (PD_CPU | PD_SCU))) {
/* Enable Clock Domain for I/O devices */
genpd->flags = GENPD_FLAG_PM_CLK;
#ifdef CONFIG_ARCH_R8A7795 /* or CONFIG_ARM64 */
genpd->attach_dev = cpg_mssr_attach_dev;
genpd->detach_dev = cpg_mssr_detach_dev;
#else
genpd->attach_dev = cpg_mstp_attach_dev;
genpd->detach_dev = cpg_mstp_detach_dev;
#endif
It becomes more gory when migrating R-Car H1 and Gen2 to CPG/MSSR, and
maintaining backwards compatibility, as which callbacks to choose will depend
on the presence of "renesas,cpg-mstp-clocks" device nodes in DT, and a new
CONFIG_CLK_RENESAS_LEGACY option.
Needless to say, it'll be more complex if not all SoCs migrate at once...
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
