hi Ulf,


On 2016年09月17日 16:49, Ulf Hansson wrote:

On 17 September 2016 at 04:32, Ziyuan Xu [off-list ref] wrote:

quoted

Add power domain as a optional property for sdhci-of-arasan, which can
be turned off in the so-called unused condition, such as suspend and
remove. Aim to lower power requirements.

I assume runtime suspend make sense as well?

Sorry to reply this mail after a long time.

On rk3399 platform, there is a eMMC-phy which is in charge of eMMC's 
logic interface. We should guarantee that phy is ready before cmd/data 
transfer.
I mean that I need to consider about the resume latency, so that I can 
land RPM for arasan-of-sdhci.
I intend to use auto-suspend for arasan-of-sdhci.

Moreover, perhaps you could share a little information here about what
needs to be done at the driver level which controls the mmc IP. More
precisely, what do you need to do at runtime_suspend, suspend,
runtime_resume, and resume?

Invoke sdhci_runtime_suspend_host, disable relevant clock in 
rumtime_suspend, deprocessing in runtime_resume.
Is that ok?

Kind regards
Uffe

quoted

Signed-off-by: Ziyuan Xu <redacted>

Acked-by: Rob Herring <redacted>
---

Changes in v3:
- fix a typo
- add Rob's ack-tag

Changes in v2:
- fix a typo
- add an example code for power-domain

  Documentation/devicetree/bindings/mmc/arasan,sdhci.txt | 7 ++++++-
  1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mmc/arasan,sdhci.txt b/Documentation/devicetree/bindings/mmc/arasan,sdhci.txt
index 3404afa..eb84d29 100644
--- a/Documentation/devicetree/bindings/mmc/arasan,sdhci.txt
+++ b/Documentation/devicetree/bindings/mmc/arasan,sdhci.txt

@@ -1,12 +1,14 @@
  Device Tree Bindings for the Arasan SDHCI Controller

-  The bindings follow the mmc[1], clock[2], interrupt[3] and phy[4] bindings.
+  The bindings follow the mmc[1], clock[2], interrupt[3], phy[4] and power
+  domain[5] bindings.
    Only deviations are documented here.

    [1] Documentation/devicetree/bindings/mmc/mmc.txt
    [2] Documentation/devicetree/bindings/clock/clock-bindings.txt
    [3] Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
    [4] Documentation/devicetree/bindings/phy/phy-bindings.txt
+  [5] Documentation/devicetree/bindings/power/power_domain.txt

  Required Properties:
    - compatible: Compatibility string.  One of:

@@ -36,6 +38,8 @@ Optional Properties:
    - #clock-cells: If specified this should be the value <0>.  With this property
      in place we will export a clock representing the Card Clock.  This clock
      is expected to be consumed by our PHY.  You must also specify
+  - power-domains: A phandle and PM domain as specifier defined by bindings
+    of the power controller specified by phandle.

  Example:
         sdhci@e0100000 {

@@ -71,5 +75,6 @@ Example:
                 phys = <&emmc_phy>;
                 phy-names = "phy_arasan";
                 #clock-cells = <0>;
+               power-domains = <&power RK3399_PD_EMMC>;
                 status = "disabled";
         };
--

2.9.2


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