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Diffstat (limited to 'Documentation/devicetree/bindings/power')
| -rw-r--r-- | Documentation/devicetree/bindings/power/power_domain.txt | 49 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/power/rockchip-io-domain.txt | 83 |
2 files changed, 132 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt new file mode 100644 index 000000000000..98c16672ab5f --- /dev/null +++ b/Documentation/devicetree/bindings/power/power_domain.txt @@ -0,0 +1,49 @@ +* Generic PM domains + +System on chip designs are often divided into multiple PM domains that can be +used for power gating of selected IP blocks for power saving by reduced leakage +current. + +This device tree binding can be used to bind PM domain consumer devices with +their PM domains provided by PM domain providers. A PM domain provider can be +represented by any node in the device tree and can provide one or more PM +domains. A consumer node can refer to the provider by a phandle and a set of +phandle arguments (so called PM domain specifiers) of length specified by the +#power-domain-cells property in the PM domain provider node. + +==PM domain providers== + +Required properties: + - #power-domain-cells : Number of cells in a PM domain specifier; + Typically 0 for nodes representing a single PM domain and 1 for nodes + providing multiple PM domains (e.g. power controllers), but can be any value + as specified by device tree binding documentation of particular provider. + +Example: + + power: power-controller@12340000 { + compatible = "foo,power-controller"; + reg = <0x12340000 0x1000>; + #power-domain-cells = <1>; + }; + +The node above defines a power controller that is a PM domain provider and +expects one cell as its phandle argument. + +==PM domain consumers== + +Required properties: + - power-domains : A phandle and PM domain specifier as defined by bindings of + the power controller specified by phandle. + +Example: + + leaky-device@12350000 { + compatible = "foo,i-leak-current"; + reg = <0x12350000 0x1000>; + power-domains = <&power 0>; + }; + +The node above defines a typical PM domain consumer device, which is located +inside a PM domain with index 0 of a power controller represented by a node +with the label "power". diff --git a/Documentation/devicetree/bindings/power/rockchip-io-domain.txt b/Documentation/devicetree/bindings/power/rockchip-io-domain.txt new file mode 100644 index 000000000000..6fbf6e7ecde6 --- /dev/null +++ b/Documentation/devicetree/bindings/power/rockchip-io-domain.txt @@ -0,0 +1,83 @@ +Rockchip SRAM for IO Voltage Domains: +------------------------------------- + +IO domain voltages on some Rockchip SoCs are variable but need to be +kept in sync between the regulators and the SoC using a special +register. + +A specific example using rk3288: +- If the regulator hooked up to a pin like SDMMC0_VDD is 3.3V then + bit 7 of GRF_IO_VSEL needs to be 0. If the regulator hooked up to + that same pin is 1.8V then bit 7 of GRF_IO_VSEL needs to be 1. + +Said another way, this driver simply handles keeping bits in the SoC's +general register file (GRF) in sync with the actual value of a voltage +hooked up to the pins. + +Note that this driver specifically doesn't include: +- any logic for deciding what voltage we should set regulators to +- any logic for deciding whether regulators (or internal SoC blocks) + should have power or not have power + +If there were some other software that had the smarts of making +decisions about regulators, it would work in conjunction with this +driver. When that other software adjusted a regulator's voltage then +this driver would handle telling the SoC about it. A good example is +vqmmc for SD. In that case the dw_mmc driver simply is told about a +regulator. It changes the regulator between 3.3V and 1.8V at the +right time. This driver notices the change and makes sure that the +SoC is on the same page. + + +Required properties: +- compatible: should be one of: + - "rockchip,rk3188-io-voltage-domain" for rk3188 + - "rockchip,rk3288-io-voltage-domain" for rk3288 +- rockchip,grf: phandle to the syscon managing the "general register files" + + +You specify supplies using the standard regulator bindings by including +a phandle the the relevant regulator. All specified supplies must be able +to report their voltage. The IO Voltage Domain for any non-specified +supplies will be not be touched. + +Possible supplies for rk3188: +- ap0-supply: The supply connected to AP0_VCC. +- ap1-supply: The supply connected to AP1_VCC. +- cif-supply: The supply connected to CIF_VCC. +- flash-supply: The supply connected to FLASH_VCC. +- lcdc0-supply: The supply connected to LCD0_VCC. +- lcdc1-supply: The supply connected to LCD1_VCC. +- vccio0-supply: The supply connected to VCCIO0. +- vccio1-supply: The supply connected to VCCIO1. + Sometimes also labeled VCCIO1 and VCCIO2. + +Possible supplies for rk3288: +- audio-supply: The supply connected to APIO4_VDD. +- bb-supply: The supply connected to APIO5_VDD. +- dvp-supply: The supply connected to DVPIO_VDD. +- flash0-supply: The supply connected to FLASH0_VDD. Typically for eMMC +- flash1-supply: The supply connected to FLASH1_VDD. Also known as SDIO1. +- gpio30-supply: The supply connected to APIO1_VDD. +- gpio1830 The supply connected to APIO2_VDD. +- lcdc-supply: The supply connected to LCDC_VDD. +- sdcard-supply: The supply connected to SDMMC0_VDD. +- wifi-supply: The supply connected to APIO3_VDD. Also known as SDIO0. + + +Example: + + io-domains { + compatible = "rockchip,rk3288-io-voltage-domain"; + rockchip,grf = <&grf>; + + audio-supply = <&vcc18_codec>; + bb-supply = <&vcc33_io>; + dvp-supply = <&vcc_18>; + flash0-supply = <&vcc18_flashio>; + gpio1830-supply = <&vcc33_io>; + gpio30-supply = <&vcc33_pmuio>; + lcdc-supply = <&vcc33_lcd>; + sdcard-supply = <&vccio_sd>; + wifi-supply = <&vcc18_wl>; + }; |
