| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) |
| 2 | %YAML 1.2 |
| 3 | --- |
| 4 | $id: http://devicetree.org/schemas/rtc/amlogic,meson-vrtc.yaml# |
| 5 | $schema: http://devicetree.org/meta-schemas/core.yaml# |
| 6 | |
| 7 | title: Amlogic Virtual RTC (VRTC) |
| 8 | |
| 9 | maintainers: |
| 10 | - Neil Armstrong <neil.armstrong@linaro.org> |
| 11 | |
| 12 | description: | |
| 13 | This is a Linux interface to an RTC managed by firmware, hence it's |
| 14 | virtual from a Linux perspective. The interface is 1 register where |
| 15 | an alarm time (in seconds) is to be written. |
| 16 | The alarm register is a simple scratch register shared between the |
| 17 | application processors (AP) and the secure co-processor (SCP.) When |
| 18 | the AP suspends, the SCP will use the value of this register to |
| 19 | program an always-on timer before going sleep. When the timer expires, |
| 20 | the SCP will wake up and will then wake the AP. |
| 21 | |
| 22 | allOf: |
| 23 | - $ref: rtc.yaml# |
| 24 | |
| 25 | properties: |
| 26 | compatible: |
| 27 | enum: |
| 28 | - amlogic,meson-vrtc |
| 29 | |
| 30 | reg: |
| 31 | maxItems: 1 |
| 32 | |
| 33 | required: |
| 34 | - compatible |
| 35 | - reg |
| 36 | |
| 37 | additionalProperties: false |
| 38 | |
| 39 | examples: |
| 40 | - | |
| 41 | rtc@a8 { |
| 42 | compatible = "amlogic,meson-vrtc"; |
| 43 | reg = <0x000a8 0x4>; |
| 44 | }; |