hi Ulf,
On 2016年09月17日 16:49, Ulf Hansson wrote:
On 17 September 2016 at 04:32, Ziyuan Xu <xzy.xu@xxxxxxxxxxxxxx> wrote:
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
Signed-off-by: Ziyuan Xu <xzy.xu@xxxxxxxxxxxxxx>
Acked-by: Rob Herring <robh@xxxxxxxxxx>
---
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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