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

From: Shawn Lin
Date: Sun Aug 28 2016 - 23:26:13 EST

On 2016/8/29 10:50, Elaine Zhang wrote:

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

Thanks for explaining this. I checked the code a bit and actually I
don't need to updata clkmul since it was recorded, although it is still
reset to 0x10 reading from syscon. So for that, we can now pick it
up without waiting for my sdhci-of-arasan's update.

Reviewed-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>

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:

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.



arch/arm64/boot/dts/rockchip/rk3399.dtsi | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/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>;

Best Regards
Shawn Lin