On Fri, Aug 02, 2013 at 10:01:52PM +0100, Stephen Warren wrote:
> (CCing the other DT maintainers, hence quoting binding in full)
>
> On 08/02/2013 07:23 AM, Bartlomiej Zolnierkiewicz wrote:
> > On EXYNOS5440 power domains are handled in a different way than on
> > the previous EXYNOS SoCs. Add support for them to EXYNOS pm_domains
> > driver. Then add device tree nodes for PCIe (controlling power for
> > PCIe host controller) and Conn2 (controlling power for Ethernet,
> > SATA and USB controllers) power domains to exynos5440.dtsi.
> >
> > Currently if runtime Power Management is enabled and the driver
> > for devices under power domain is disabled then the power domain
> > will be disabled by EXYNOS pm_domains driver. To make more active
> > use of power domains (dynamically enable and disabled them as
> > needed) it is required to add runtime PM support to pci-exynos,
> > stmmac, ahci_platform, ohci-exynos and ehci-s5p drivers (to be
> > done later).
> >
> > Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
> > Signed-off-by: Myungjoo Ham <myungjoo.ham@xxxxxxxxxxx>
> > Cc: Tomasz Figa <t.figa@xxxxxxxxxxx>
> > Cc: Stephen Warren <swarren@xxxxxxxxxxxxx>
> > ---
> > Documentation/devicetree/bindings/arm/exynos/power_domain.txt | 33 ++
> > arch/arm/boot/dts/exynos5440.dtsi | 23 +
> > arch/arm/mach-exynos/Kconfig | 1
> > arch/arm/mach-exynos/common.c | 4
> > arch/arm/mach-exynos/pm_domains.c | 138 +++++++++-
> > 5 files changed, 190 insertions(+), 9 deletions(-)
> >
> > Index: b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
> > ===================================================================
> > --- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt 2013-08-02 14:45:53.551392396 +0200
> > +++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt 2013-08-02 14:46:29.799391845 +0200
> > @@ -5,20 +5,47 @@ to gate power to one or more peripherals
> >
> > Required Properties:
> > - compatible: should be one of the following.
> > - * samsung,exynos4210-pd - for exynos4210 type power domain.
> > + * samsung,exynos4210-pd - for Exynos4210 type power domain.
> > + * samsung,exynos5440-pd - for Exynos5440 type power domain.
> > - reg: physical base address of the controller and length of memory mapped
> > - region.
> > + region (Exynos4210 type power domain) or bit offset in the control
> > + register (Exynos5440 type power domain).
> > +
> > +Additional parent node must be created for Exynos5440 power domains with
> > +the following required properties:
> > +- compatible: samsung,exynos5440-power-domains, simple-bus
> > +- reg: physical base address of the XMU controller and length of memory
> > + mapped region
>
> It's a little odd to describe the child nodes first. Given the 4210 and
> 5440 bindings work so differently, I'd suggest making separate binding
> files for the two; samsung,exynos4210-pd.txt and samsung,exynos5440-pd.txt.
>
> The node being describe here clearly is not a simple-bus; the child
> nodes appear to have a specific need that their parent be compatible =
> "samsung,exynos5440-power-domains", hence they aren't the independent
> devices that simple-bus would usually contain.
+1. This is most definitely not a simple-bus, the child nodes reg
properties cdon't represent the same address space as the
parent's reg property.
How much does the association of bit-offsets to power domains vary?
>
> Note that I only briefly reviewed the low-level structural aspects of
> the binding that I mentioned above; I haven't thought about the binding
> at a higher level of e.g. "does this binding conceptually make sense".
This is unfortunately difficult to do :(
>
> > Node of a device using power domains must have a samsung,power-domain property
> > defined with a phandle to respective power domain.
> >
> > -Example:
> > +Example for Exynos4210 compatible power domain:
> >
> > lcd0: power-domain-lcd0 {
> > compatible = "samsung,exynos4210-pd";
> > reg = <0x10023C00 0x10>;
> > };
> >
> > +Example for Exynos5440 compatible power domains:
> > +
> > + power-domains@00160000 {
> > + compatible = "samsung,exynos5440-power-domains", "simple-bus";
> > + reg = <0x00160000 0x1000>;
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + pd_pcie: pcie-power-domain@6 {
> > + compatible = "samsung,exynos5440-pd";
> > + reg = <6>;
> > + };
> > +
> > + pd_conn2: conn2-power-domain@7 {
> > + compatible = "samsung,exynos5440-pd";
> > + reg = <7>;
> > + };
> > + };
> > +
> > Example of the node using power domain:
> >
> > node {
> > Index: b/arch/arm/boot/dts/exynos5440.dtsi
> > ===================================================================
> > --- a/arch/arm/boot/dts/exynos5440.dtsi 2013-08-02 14:45:53.599392397 +0200
> > +++ b/arch/arm/boot/dts/exynos5440.dtsi 2013-08-02 14:46:29.815391842 +0200
> > @@ -29,6 +29,23 @@
> > #clock-cells = <1>;
> > };
> >
> > + power-domains@00160000 {
> > + compatible = "samsung,exynos5440-power-domains", "simple-bus";
> > + reg = <0x00160000 0x1000>;
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + pd_pcie: pcie-power-domain@6 {
> > + compatible = "samsung,exynos5440-pd";
> > + reg = <6>;
> > + };
> > +
> > + pd_conn2: conn2-power-domain@7 {
> > + compatible = "samsung,exynos5440-pd";
> > + reg = <7>;
> > + };
> > + };
> > +
> > gic:interrupt-controller@2E0000 {
> > compatible = "arm,cortex-a15-gic";
> > #interrupt-cells = <3>;
> > @@ -192,6 +209,7 @@
> > phy-mode = "sgmii";
> > clocks = <&clock 25>;
> > clock-names = "stmmaceth";
> > + samsung,power-domain = <&pd_conn2>;
> > };
This feels like a clock style binding would fit better:
samsung,power-domain = <&pwr 7>;
But there may be a better, more general way of handling this. I'm not
sure how this relates to regulators and so on, and how other vendors
handle this stuff...
Thanks,
Mark.
> >
> > amba {
> > @@ -240,6 +258,7 @@
> > interrupts = <0 30 0>;
> > clocks = <&clock 23>;
> > clock-names = "sata";
> > + samsung,power-domain = <&pd_conn2>;
> > };
> >
> > ohci@220000 {
> > @@ -248,6 +267,7 @@
> > interrupts = <0 29 0>;
> > clocks = <&clock 24>;
> > clock-names = "usbhost";
> > + samsung,power-domain = <&pd_conn2>;
> > };
> >
> > ehci@221000 {
> > @@ -256,6 +276,7 @@
> > interrupts = <0 29 0>;
> > clocks = <&clock 24>;
> > clock-names = "usbhost";
> > + samsung,power-domain = <&pd_conn2>;
> > };
> >
> > pcie@290000 {
> > @@ -275,6 +296,7 @@
> > #interrupt-cells = <1>;
> > interrupt-map-mask = <0 0 0 0>;
> > interrupt-map = <0x0 0 &gic 53>;
> > + samsung,power-domain = <&pd_pcie>;
> > };
> >
> > pcie@2a0000 {
> > @@ -294,5 +316,6 @@
> > #interrupt-cells = <1>;
> > interrupt-map-mask = <0 0 0 0>;
> > interrupt-map = <0x0 0 &gic 56>;
> > + samsung,power-domain = <&pd_pcie>;
> > };
> > };
>
>
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