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+ARM Versatile Express system registers
+--------------------------------------
+
+This is a system control registers block, providing multiple low level
+platform functions like board detection and identification, software
+interrupt generation, MMC and NOR Flash control etc.
+
+Required node properties:
+- compatible value : = "arm,vexpress,sysreg";
+- reg : physical base address and the size of the registers window
+- gpio-controller : specifies that the node is a GPIO controller
+- #gpio-cells : size of the GPIO specifier, should be 2:
+ - first cell is the pseudo-GPIO line number:
+ 0 - MMC CARDIN
+ 1 - MMC WPROT
+ 2 - NOR FLASH WPn
+ - second cell can take standard GPIO flags (currently ignored).
+
+Example:
+ v2m_sysreg: sysreg@10000000 {
+ compatible = "arm,vexpress-sysreg";
+ reg = <0x10000000 0x1000>;
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
+
+This block also can also act a bridge to the platform's configuration
+bus via "system control" interface, addressing devices with site number,
+position in the board stack, config controller, function and device
+numbers - see motherboard's TRM for more details.
+
+The node describing a config device must refer to the sysreg node via
+"arm,vexpress,config-bridge" phandle (can be also defined in the node's
+parent) and relies on the board topology properties - see main vexpress
+node documentation for more details. It must must also define the
+following property:
+- arm,vexpress-sysreg,func : must contain two cells:
+ - first cell defines function number (eg. 1 for clock generator,
+ 2 for voltage regulators etc.)
+ - device number (eg. osc 0, osc 1 etc.)
+
+Example:
+ mcc {
+ arm,vexpress,config-bridge = <&v2m_sysreg>;
+
+ osc@0 {
+ compatible = "arm,vexpress-osc";
+ arm,vexpress-sysreg,func = <1 0>;
+ };
+ };