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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /Documentation/devicetree/bindings/rtc/isil,isl12057.txt | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/devicetree/bindings/rtc/isil,isl12057.txt')
-rw-r--r-- | Documentation/devicetree/bindings/rtc/isil,isl12057.txt | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/rtc/isil,isl12057.txt b/Documentation/devicetree/bindings/rtc/isil,isl12057.txt new file mode 100644 index 000000000..ff7c43555 --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/isil,isl12057.txt @@ -0,0 +1,74 @@ +Intersil ISL12057 I2C RTC/Alarm chip + +ISL12057 is a trivial I2C device (it has simple device tree bindings, +consisting of a compatible field, an address and possibly an interrupt +line). + +Nonetheless, it also supports an option boolean property +("wakeup-source") to handle the specific use-case found +on at least three in-tree users of the chip (NETGEAR ReadyNAS 102, 104 +and 2120 ARM-based NAS); On those devices, the IRQ#2 pin of the chip +(associated with the alarm supported by the driver) is not connected +to the SoC but to a PMIC. It allows the device to be powered up when +RTC alarm rings. In order to mark the device has a wakeup source and +get access to the 'wakealarm' sysfs entry, this specific property can +be set when the IRQ#2 pin of the chip is not connected to the SoC but +can wake up the device. + +Required properties supported by the device: + + - "compatible": must be "isil,isl12057" + - "reg": I2C bus address of the device + +Optional properties: + + - "wakeup-source": mark the chip as a wakeup source, independently of + the availability of an IRQ line connected to the SoC. + + +Example isl12057 node without IRQ#2 pin connected (no alarm support): + + isl12057: isl12057@68 { + compatible = "isil,isl12057"; + reg = <0x68>; + }; + + +Example isl12057 node with IRQ#2 pin connected to main SoC via MPP6 (note +that the pinctrl-related properties below are given for completeness and +may not be required or may be different depending on your system or +SoC, and the main function of the MPP used as IRQ line, i.e. +"interrupt-parent" and "interrupts" are usually sufficient): + + pinctrl { + ... + + rtc_alarm_pin: rtc_alarm_pin { + marvell,pins = "mpp6"; + marvell,function = "gpio"; + }; + + ... + + }; + + ... + + isl12057: isl12057@68 { + compatible = "isil,isl12057"; + reg = <0x68>; + pinctrl-0 = <&rtc_alarm_pin>; + pinctrl-names = "default"; + interrupt-parent = <&gpio0>; + interrupts = <6 IRQ_TYPE_EDGE_FALLING>; + }; + + +Example isl12057 node without IRQ#2 pin connected to the SoC but to a +PMIC, allowing the device to be started based on configured alarm: + + isl12057: isl12057@68 { + compatible = "isil,isl12057"; + reg = <0x68>; + wakeup-source; + }; |