[PATCH] ARM: EXYNOS: add power domains support for EXYNOS5440
Stephen Warren
swarren at wwwdotorg.org
Fri Aug 2 17:01:52 EDT 2013
(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 at samsung.com>
> Signed-off-by: Myungjoo Ham <myungjoo.ham at samsung.com>
> Cc: Tomasz Figa <t.figa at samsung.com>
> Cc: Stephen Warren <swarren at wwwdotorg.org>
> ---
> 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.
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".
> 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 at 00160000 {
> + compatible = "samsung,exynos5440-power-domains", "simple-bus";
> + reg = <0x00160000 0x1000>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + pd_pcie: pcie-power-domain at 6 {
> + compatible = "samsung,exynos5440-pd";
> + reg = <6>;
> + };
> +
> + pd_conn2: conn2-power-domain at 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 at 00160000 {
> + compatible = "samsung,exynos5440-power-domains", "simple-bus";
> + reg = <0x00160000 0x1000>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + pd_pcie: pcie-power-domain at 6 {
> + compatible = "samsung,exynos5440-pd";
> + reg = <6>;
> + };
> +
> + pd_conn2: conn2-power-domain at 7 {
> + compatible = "samsung,exynos5440-pd";
> + reg = <7>;
> + };
> + };
> +
> gic:interrupt-controller at 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>;
> };
>
> amba {
> @@ -240,6 +258,7 @@
> interrupts = <0 30 0>;
> clocks = <&clock 23>;
> clock-names = "sata";
> + samsung,power-domain = <&pd_conn2>;
> };
>
> ohci at 220000 {
> @@ -248,6 +267,7 @@
> interrupts = <0 29 0>;
> clocks = <&clock 24>;
> clock-names = "usbhost";
> + samsung,power-domain = <&pd_conn2>;
> };
>
> ehci at 221000 {
> @@ -256,6 +276,7 @@
> interrupts = <0 29 0>;
> clocks = <&clock 24>;
> clock-names = "usbhost";
> + samsung,power-domain = <&pd_conn2>;
> };
>
> pcie at 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 at 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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