| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | Specifying wakeup capability for devices |
| 2 | ============================================ |
| 3 | |
| 4 | Any device nodes |
| 5 | ---------------- |
| Tom Rini | 93743d2 | 2024-04-01 09:08:13 -0400 | [diff] [blame^] | 6 | Nodes that describe devices which have wakeup capability may contain a |
| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 7 | "wakeup-source" boolean property. |
| 8 | |
| Tom Rini | 93743d2 | 2024-04-01 09:08:13 -0400 | [diff] [blame^] | 9 | If the device is marked as a wakeup-source, interrupt wake capability depends |
| 10 | on the device specific "interrupt-names" property. If no interrupts are labeled |
| 11 | as wake capable, then it is up to the device to determine which interrupts can |
| 12 | wake the system. |
| 13 | |
| 14 | However if a device has a dedicated interrupt as the wakeup source, then it |
| 15 | needs to specify/identify it using a device specific interrupt name. In such |
| 16 | cases only that interrupt can be used as a wakeup interrupt. |
| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 17 | |
| Tom Rini | 93743d2 | 2024-04-01 09:08:13 -0400 | [diff] [blame^] | 18 | While various legacy interrupt names exist, new devices should use "wakeup" as |
| 19 | the canonical interrupt name. |
| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 20 | |
| 21 | List of legacy properties and respective binding document |
| 22 | --------------------------------------------------------- |
| 23 | |
| 24 | 1. "gpio-key,wakeup" Documentation/devicetree/bindings/input/gpio-keys{,-polled}.txt |
| 25 | 2. "has-tpo" Documentation/devicetree/bindings/rtc/rtc-opal.txt |
| 26 | 3. "linux,wakeup" Documentation/devicetree/bindings/input/gpio-matrix-keypad.txt |
| 27 | Documentation/devicetree/bindings/mfd/tc3589x.txt |
| 28 | Documentation/devicetree/bindings/input/touchscreen/ads7846.txt |
| 29 | 4. "linux,keypad-wakeup" Documentation/devicetree/bindings/input/qcom,pm8xxx-keypad.txt |
| 30 | 5. "linux,input-wakeup" Documentation/devicetree/bindings/input/samsung-keypad.txt |
| 31 | 6. "nvidia,wakeup-source" Documentation/devicetree/bindings/input/nvidia,tegra20-kbc.txt |
| 32 | |
| 33 | Examples |
| 34 | -------- |
| 35 | |
| 36 | 1. With "wakeup" interrupt name |
| 37 | |
| 38 | device@10000 { |
| 39 | compatible = "vendor,device-id"; |
| 40 | reg = <0x10000 0x1000>; |
| 41 | interrupts = <0 19 4>, <0 21 4>, <0 22 4>; |
| 42 | interrupt-names = "ack", "err", "wakeup"; |
| 43 | wakeup-source; |
| 44 | }; |
| 45 | |
| 46 | 2. Without "wakeup" interrupt name |
| 47 | |
| 48 | embedded-controller { |
| 49 | compatible = "google,cros-ec-i2c"; |
| 50 | reg = <0x1e>; |
| 51 | interrupts = <6 0>; |
| 52 | interrupt-parent = <&gpx1>; |
| 53 | pinctrl-names = "default"; |
| 54 | pinctrl-0 = <&ec_irq>; |
| 55 | wakeup-source; |
| 56 | }; |
| 57 | |
| 58 | 3. Without interrupts |
| 59 | |
| 60 | gpio_keys { |
| 61 | compatible = "gpio-keys"; |
| 62 | #address-cells = <1>; |
| 63 | #size-cells = <0>; |
| 64 | |
| 65 | button@1 { |
| 66 | debounce-interval = <50>; |
| 67 | wakeup-source; |
| 68 | linux,code = <116>; |
| 69 | label = "POWER"; |
| 70 | gpios = <&iofpga_gpio0 0 0x4>; |
| 71 | }; |
| 72 | [....] |
| 73 | }; |