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SubjectRe: [PATCH v2 1/3] devicetree: bindings: bd718x7: document HW state related ROHM specific properties
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Hi Matti,

On 2019-02-13 01:50, Matti Vaittinen wrote:
> Add ROHM BD71837 / BD71847 specific device tree bindings for
> controlling the PMIC shutdown/reset states and voltages for
> different HW states. The PMIC was designed to be used with NXP
> i.MX8 SoC and it supports SNVS low power state which seems to
> be typical for NXP i.MX SoCs. However, when SNVS is used we must
> not allow SW to control enabling/disabling those regulators which
> are crucial for system to boot as there is a HW limitation which
> causes SW controlled regulators to be kept shut down after SNVS
> reset.
>
> Allow setting the SNVS to be used as reset target state and allow
> marking those regulators which are critical for boot.
>
> Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
> ---
> .../devicetree/bindings/mfd/rohm,bd71837-pmic.txt | 15 +++++++++++
> .../bindings/regulator/rohm,bd71837-regulator.txt | 30
> ++++++++++++++++++++++
> 2 files changed, 45 insertions(+)
>
> diff --git
> a/Documentation/devicetree/bindings/mfd/rohm,bd71837-pmic.txt
> b/Documentation/devicetree/bindings/mfd/rohm,bd71837-pmic.txt
> index a4b056761eaa..f07c32975315 100644
> --- a/Documentation/devicetree/bindings/mfd/rohm,bd71837-pmic.txt
> +++ b/Documentation/devicetree/bindings/mfd/rohm,bd71837-pmic.txt
> @@ -23,6 +23,21 @@ Required properties:
>
> Optional properties:
> - clock-output-names : Should contain name for output clock.
> +- rohm,reset-snvs-powered : Transfer BD718x7 to SNVS state at reset.
> +
> +The BD718x7 supports two different HW states as reset target states.
> States
> +are called as SNVS and READY. At READY state all the PMIC power
> outputs go
> +down and OTP is reload. At the SNVS state all other logic and external
> +devices apart from the SNVS power domain are shut off. Please refer to
> NXP
> +i.MX8 documentation for further information regarding SNVS state. When
> a
> +reset is done via SNVS state the PMIC OTP data is not reload. This
> cause
> +

It looks like there is some text missing here.

> +There is a HW quirk in BD718x7 which causes power outputs that have
> been
> +under SW control to stay down when reset has switched power state to
> SNVS.
> +If reset is done via READY state the power outputs will be set to HW
> control
> +by OTP loading. Thus the reset target state is set to READY by
> default. If
> +SNVS state is used the boot crucial regulators must have the
> +regulator-always-on and regulator-boot-on properties set in regulator
> node.
>
> Example:
>
> diff --git
> a/Documentation/devicetree/bindings/regulator/rohm,bd71837-regulator.txt
> b/Documentation/devicetree/bindings/regulator/rohm,bd71837-regulator.txt
> index 4b98ca26e61a..4a05cbf915ee 100644
> ---
> a/Documentation/devicetree/bindings/regulator/rohm,bd71837-regulator.txt
> +++
> b/Documentation/devicetree/bindings/regulator/rohm,bd71837-regulator.txt
> @@ -27,8 +27,38 @@ BUCK1, BUCK2, BUCK3, BUCK4, BUCK5, BUCK6
> LDO1, LDO2, LDO3, LDO4, LDO5, LDO6
>
> Optional properties:
> +- rohm,dvs-run-voltage : PMIC default "RUN" state voltage in uV.
> + See below table for bucks which support this.
> +- rohm,dvs-idle-voltage : PMIC default "IDLE" state voltage in uV.
> + See below table for bucks which support this.
> +- rohm,dvs-suspend-voltage : PMIC default "SUSPEND" state voltage in
> uV.
> + See below table for bucks which support this.
> - Any optional property defined in bindings/regulator/regulator.txt
>
> +Supported default DVS states:
> +
> +BD71837:
> +buck | dvs-run-voltage | dvs-idle-voltage | dvs-suspend-voltage
> +-----------------------------------------------------------------------------
> +1 | supported | supported | supported
> +----------------------------------------------------------------------------
> +2 | supported | supported | not supported
> +----------------------------------------------------------------------------
> +3 | supported | not supported | not supported
> +----------------------------------------------------------------------------
> +4 | supported | not supported | not supported
> +----------------------------------------------------------------------------
> +rest | not supported | not supported | not supported
> +
> +BD71847:
> +buck | dvs-run-voltage | dvs-idle-voltage | dvs-suspend-voltage
> +-----------------------------------------------------------------------------
> +1 | supported | supported | supported
> +----------------------------------------------------------------------------
> +2 | supported | supported | not supported
> +----------------------------------------------------------------------------
> +rest | not supported | not supported | not supported
> +
> Example:

Could you add an example of the optional properties ?

Thanks
Angus

> regulators {
> buck1: BUCK1 {
> --
> 2.14.3

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