On Thu, Apr 14, 2022 at 12:27:23PM -0700, Drew Fustini wrote:
> Add documentation for the ti,set-io-isolation DT property on the wkup_m3_ipc
> node which tells the wkup_m3_ipc driver to use the wkup_m3 to enable
> IO Isolation during low power mode transitions on am43xx platforms.
>
> Signed-off-by: Dave Gerlach <[email protected]>
> [dfustini: convert to YAML, make DTS example that passes check]
> Signed-off-by: Drew Fustini <[email protected]>
> ---
> Changes from v2:
> - correct indentation of the 'allOf:' block
>
> Changes from v1:
> - correct typo of 'ti,set-io-isolation' property in subject
> - make 'ti,set-io-isolation' only valid for 'ti,am4372-wkup-m3-ipc'
>
> .../bindings/soc/ti/wkup-m3-ipc.yaml | 78 +++++++++++++++++--
> 1 file changed, 73 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
> index 7f4a75c5fcaa..f0ae86250fe4 100644
> --- a/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
> +++ b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
> @@ -24,14 +24,22 @@ description: |+
> A wkup_m3_ipc device node is used to represent the IPC registers within an
> SoC.
>
> - Support for VTT Toggle
> - ==================================
> + 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.
> +
> properties:
> compatible:
> enum:
> @@ -63,6 +71,24 @@ properties:
> $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:
Rob - sorry for the churn. I realize now that there should have been a
blank line before 'allOf:'. Should I send a v4 or (if there are not
other issues) could that just added when applying?
Thank you,
Drew