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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/devicetree/bindings/arm/vexpress-sysreg.txt | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/devicetree/bindings/arm/vexpress-sysreg.txt')
-rw-r--r-- | Documentation/devicetree/bindings/arm/vexpress-sysreg.txt | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/vexpress-sysreg.txt b/Documentation/devicetree/bindings/arm/vexpress-sysreg.txt new file mode 100644 index 000000000..50095802f --- /dev/null +++ b/Documentation/devicetree/bindings/arm/vexpress-sysreg.txt @@ -0,0 +1,103 @@ +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 + +Deprecated properties, replaced by GPIO subnodes (see below): +- 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). + +Control registers providing pseudo-GPIO lines must be represented +by subnodes, each of them requiring the following properties: +- compatible value : one of + "arm,vexpress-sysreg,sys_led" + "arm,vexpress-sysreg,sys_mci" + "arm,vexpress-sysreg,sys_flash" +- gpio-controller : makes the node a GPIO controller +- #gpio-cells : size of the GPIO specifier, must be 2: + - first cell is the function number: + - for sys_led : 0..7 = LED 0..7 + - for sys_mci : 0 = MMC CARDIN, 1 = MMC WPROT + - for sys_flash : 0 = NOR FLASH WPn + - second cell can take standard GPIO flags (currently ignored). + +Example: + v2m_sysreg: sysreg@10000000 { + compatible = "arm,vexpress-sysreg"; + reg = <0x10000000 0x1000>; + + v2m_led_gpios: sys_led@8 { + compatible = "arm,vexpress-sysreg,sys_led"; + gpio-controller; + #gpio-cells = <2>; + }; + + v2m_mmc_gpios: sys_mci@48 { + compatible = "arm,vexpress-sysreg,sys_mci"; + gpio-controller; + #gpio-cells = <2>; + }; + + v2m_flash_gpios: sys_flash@4c { + compatible = "arm,vexpress-sysreg,sys_flash"; + 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. All configuration +controller accessible via this interface must reference the sysreg +node via "arm,vexpress,config-bridge" phandle and define appropriate +topology properties - see main vexpress node documentation for more +details. Each child of such node describes one function and must +define the following properties: +- compatible value : must be one of (corresponding to the TRM): + "arm,vexpress-amp" + "arm,vexpress-dvimode" + "arm,vexpress-energy" + "arm,vexpress-muxfpga" + "arm,vexpress-osc" + "arm,vexpress-power" + "arm,vexpress-reboot" + "arm,vexpress-reset" + "arm,vexpress-scc" + "arm,vexpress-shutdown" + "arm,vexpress-temp" + "arm,vexpress-volt" +- arm,vexpress-sysreg,func : must contain a set of two cells long groups: + - first cell of each group defines the function number + (eg. 1 for clock generator, 2 for voltage regulators etc.) + - second cell of each group defines device number (eg. osc 0, + osc 1 etc.) + - some functions (eg. energy meter, with its 64 bit long counter) + are using more than one function/device number pair + +Example: + mcc { + compatible = "arm,vexpress,config-bus"; + arm,vexpress,config-bridge = <&v2m_sysreg>; + + osc@0 { + compatible = "arm,vexpress-osc"; + arm,vexpress-sysreg,func = <1 0>; + }; + + energy@0 { + compatible = "arm,vexpress-energy"; + arm,vexpress-sysreg,func = <13 0>, <13 1>; + }; + }; |