Re: [PATCH 2/2] arm64: dts: rockchip: add eMMC's power domain support for rk3399

[Elaine Zhang]

On 08/27/2016 11:05 PM, Shawn Lin wrote:
> On 2016/8/27 21:41, Ziyuan Xu wrote:
> > Control power domain for eMMC via genpd to reduce power consumption.
> >
> > Signed-off-by: Elaine Zhang <zhangqing@xxxxxxxxxxxxxx>
> > Signed-off-by: Ziyuan Xu <xzy.xu@xxxxxxxxxxxxxx>
>
> It looks nice to me. But this should be merged after applying that[0]
> as your patch will break bind/unbind test for sdhci-of-arasan on rk3399
> without it[0]. Moreover, Elaine should make sure that upstreamed
> rockchip power domain stuff would not off pd for emmc, *otherwise*, I
> should update my patch to make sure we update clkmul every time when
> doing suspend 2 resume..
Forgot to say:
If use pd, Although there is no call to power odd the pd_emmc,
it will be power off when the system doing suspend 2 resume.
(Because the system call 
__device_suspend_noirq->pm_genpd_suspend_noirq->rockchip_pd_power_off)

And it's important to note:
If the pd has been power off, some grf regs will be back to the default 
value.(which grf regs in this pd)
So if the pd support power off , this grf regs need to save and restore 
or reinit.
For example:
pd_emmc
	aclk_emmc_grf

If the pd is always on,and this pd have wakeup func.
The device need to add device_init_wakeup() to make the pd always on 
when the system doing suspend 2 resume.

> [0]: https://patchwork.kernel.org/patch/9300971/
>
> > ---
> >
> >  arch/arm64/boot/dts/rockchip/rk3399.dtsi | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> > b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> > index 32aebc8..71733d4 100644
> > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi
> > @@ -239,6 +239,7 @@
> >          #clock-cells = <0>;
> >          phys = <&emmc_phy>;
> >          phy-names = "phy_arasan";
> > +        power-domains = <&power RK3399_PD_EMMC>;
> >          status = "disabled";
> >      };
> >
> > @@ -611,6 +612,11 @@
> >          status = "disabled";
> >      };
> >
> > +    qos_emmc: qos@ffa58000 {
> > +        compatible = "syscon";
> > +        reg = <0x0 0xffa58000 0x0 0x20>;
> > +    };
> > +
> >      qos_hdcp: qos@ffa90000 {
> >          compatible = "syscon";
> >          reg = <0x0 0xffa90000 0x0 0x20>;
> > @@ -739,6 +745,11 @@
> >              };
> >
> >              /* These power domains are grouped by VD_LOGIC */
> > +            pd_emmc@RK3399_PD_EMMC {
> > +                reg = <RK3399_PD_EMMC>;
> > +                clocks = <&cru ACLK_EMMC>;
> > +                pm_qos = <&qos_emmc>;
> > +            };
> >              pd_vio@RK3399_PD_VIO {
> >                  reg = <RK3399_PD_VIO>;
> >                  #address-cells = <1>;