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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/devicetree/bindings/power/rockchip-io-domain.txt
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
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+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 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>;
+ };