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Documentation: Add device tree bindings for Freescale i.MX GPC

The i.MX6 contains a power controller that controls power gating and
sequencing for the SoC's power domains.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
This commit is contained in:
Philipp Zabel 2015-02-23 18:40:11 +01:00 committed by Shawn Guo
parent 52c47b6341
commit 58e4a668be

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Freescale i.MX General Power Controller
=======================================
The i.MX6Q General Power Control (GPC) block contains DVFS load tracking
counters and Power Gating Control (PGC) for the CPU and PU (GPU/VPU) power
domains.
Required properties:
- compatible: Should be "fsl,imx6q-gpc" or "fsl,imx6sl-gpc"
- reg: should be register base and length as documented in the
datasheet
- interrupts: Should contain GPC interrupt request 1
- pu-supply: Link to the LDO regulator powering the PU power domain
- clocks: Clock phandles to devices in the PU power domain that need
to be enabled during domain power-up for reset propagation.
- #power-domain-cells: Should be 1, see below:
The gpc node is a power-controller as documented by the generic power domain
bindings in Documentation/devicetree/bindings/power/power_domain.txt.
Example:
gpc: gpc@020dc000 {
compatible = "fsl,imx6q-gpc";
reg = <0x020dc000 0x4000>;
interrupts = <0 89 IRQ_TYPE_LEVEL_HIGH>,
<0 90 IRQ_TYPE_LEVEL_HIGH>;
pu-supply = <&reg_pu>;
clocks = <&clks IMX6QDL_CLK_GPU3D_CORE>,
<&clks IMX6QDL_CLK_GPU3D_SHADER>,
<&clks IMX6QDL_CLK_GPU2D_CORE>,
<&clks IMX6QDL_CLK_GPU2D_AXI>,
<&clks IMX6QDL_CLK_OPENVG_AXI>,
<&clks IMX6QDL_CLK_VPU_AXI>;
#power-domain-cells = <1>;
};
Specifying power domain for IP modules
======================================
IP cores belonging to a power domain should contain a 'power-domains' property
that is a phandle pointing to the gpc device node and a DOMAIN_INDEX specifying
the power domain the device belongs to.
Example of a device that is part of the PU power domain:
vpu: vpu@02040000 {
reg = <0x02040000 0x3c000>;
/* ... */
power-domains = <&gpc 1>;
/* ... */
};
The following DOMAIN_INDEX values are valid for i.MX6Q:
ARM_DOMAIN 0
PU_DOMAIN 1
The following additional DOMAIN_INDEX value is valid for i.MX6SL:
DISPLAY_DOMAIN 2