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Diffstat (limited to 'Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml')
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diff --git a/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml new file mode 100644 index 000000000..0df41c4f6 --- /dev/null +++ b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml @@ -0,0 +1,175 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/soc/ti/wkup-m3-ipc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Wakeup M3 IPC device + +maintainers: + - Dave Gerlach <d-gerlach@ti.com> + - Drew Fustini <dfustini@baylibre.com> + +description: |+ + The TI AM33xx and AM43xx family of devices use a small Cortex M3 co-processor + (commonly referred to as Wakeup M3 or CM3) to help with various low power tasks + that cannot be controlled from the MPU, like suspend/resume and certain deep + C-states for CPU Idle. Once the wkup_m3_ipc driver uses the wkup_m3_rproc driver + to boot the wkup_m3, it handles communication with the CM3 using IPC registers + present in the SoC's control module and a mailbox. The wkup_m3_ipc exposes an + API to allow the SoC PM code to execute specific PM tasks. + + Wkup M3 Device Node + ==================== + A wkup_m3_ipc device node is used to represent the IPC registers within an + SoC. + + Support for VTT Toggle with GPIO pin + ==================================== + On some boards like the AM335x EVM-SK and the AM437x GP EVM, a GPIO pin is + connected to the enable pin on the DDR VTT regulator. This allows the + regulator to be disabled upon suspend and enabled upon resume. Please note + that the GPIO pin must be part of the GPIO0 module as only this GPIO module + is in the wakeup power domain. + + Support for IO Isolation + ======================== + On AM437x SoCs, certain pins can be forced into an alternate state when IO + isolation is activated. Those pins have pad control registers prefixed by + 'CTRL_CONF_' that contain DS0 (e.g. deep sleep) configuration bits that can + override the pin's existing bias (pull-up/pull-down) and value (high/low) when + IO isolation is active. + + Support for I2C PMIC Voltage Scaling + ==================================== + It is possible to pass the name of a binary file to load into the CM3 memory. + The binary data is the I2C sequences for the CM3 to send out to the PMIC + during low power mode entry. + +properties: + compatible: + enum: + - ti,am3352-wkup-m3-ipc # for AM33xx SoCs + - ti,am4372-wkup-m3-ipc # for AM43xx SoCs + + reg: + description: + The IPC register address space to communicate with the Wakeup M3 processor + maxItems: 1 + + interrupts: + description: wkup_m3 interrupt that signals the MPU + maxItems: 1 + + ti,rproc: + $ref: /schemas/types.yaml#/definitions/phandle + description: + phandle to the wkup_m3 rproc node so the IPC driver can boot it + + mboxes: + description: + phandles used by IPC framework to get correct mbox + channel for communication. Must point to appropriate + mbox_wkupm3 child node. + maxItems: 1 + + firmware-name: + description: + Name of binary file with I2C sequences for PMIC voltage scaling + + ti,vtt-gpio-pin: + $ref: /schemas/types.yaml#/definitions/uint32 + description: GPIO pin connected to enable pin on VTT regulator + + ti,set-io-isolation: + type: boolean + description: + If this property is present, then the wkup_m3_ipc driver will instruct + the CM3 firmware to activate IO isolation when suspending to deep sleep. + This can be leveraged by a board design to put other devices on the board + into a low power state. + +allOf: + - if: + properties: + compatible: + not: + contains: + const: ti,am4372-wkup-m3-ipc + then: + properties: + ti,set-io-isolation: false + +required: + - compatible + - reg + - interrupts + - ti,rproc + - mboxes + +additionalProperties: false + +examples: + - | + /* Example for AM335x SoC */ + soc { + #address-cells = <1>; + #size-cells = <1>; + + am335x_mailbox: mailbox { + #mbox-cells = <1>; + }; + + wkup_m3_ipc@1324 { + compatible = "ti,am3352-wkup-m3-ipc"; + reg = <0x1324 0x24>; + interrupts = <78>; + ti,rproc = <&wkup_m3>; + mboxes = <&am335x_mailbox &mbox_wkupm3>; + ti,vtt-gpio-pin = <7>; + firmware-name = "am335x-evm-scale-data.bin"; + }; + }; + + - | + /* + * Example for AM473x SoC: + * On the AM437x-GP-EVM board, gpio5_7 is wired to enable pin of the DDR VTT + * regulator. The 'ddr_vtt_toggle_default' pinmux node configures gpio5_7 + * for pull-up during normal system operation. However, the DS0 (deep sleep) + * state of the pin is configured for pull-down and thus the VTT regulator + * will be disabled to save power when IO isolation is active. Note that + * this method is an alternative to using the 'ti,vtt-gpio-pin' property. + */ + #include <dt-bindings/pinctrl/am43xx.h> + soc { + #address-cells = <1>; + #size-cells = <1>; + + am437x_mailbox: mailbox { + #mbox-cells = <1>; + }; + + am43xx_pinmux { + pinctrl-names = "default"; + pinctrl-0 = <&ddr3_vtt_toggle_default>; + + ddr3_vtt_toggle_default: ddr_vtt_toggle_default { + pinctrl-single,pins = < + 0x25C (DS0_PULL_UP_DOWN_EN | PIN_OUTPUT_PULLUP | DS0_FORCE_OFF_MODE | MUX_MODE7) + >; + }; + }; + + wkup_m3_ipc@1324 { + compatible = "ti,am4372-wkup-m3-ipc"; + reg = <0x1324 0x24>; + interrupts = <78>; + ti,rproc = <&wkup_m3>; + mboxes = <&am437x_mailbox &mbox_wkupm3>; + ti,set-io-isolation; + firmware-name = "am43x-evm-scale-data.bin"; + }; + }; + +... |