Re: [PATCH v1 1/2] scsi: dt-bindings: ufs: Add vcc-voltage-level for UFS

From: Rob Herring
Date: Mon Sep 14 2020 - 14:35:39 EST


On Mon, Aug 31, 2020 at 11:00:47PM -0700, Bao D. Nguyen wrote:
> UFS's specifications supports a range of Vcc operating
> voltage levels. Add documentation for the UFS's Vcc voltage
> levels setting.
>
> Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
> Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
> Signed-off-by: Bao D. Nguyen <nguyenb@xxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
> index 415ccdd..7257b32 100644
> --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
> +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
> @@ -23,6 +23,8 @@ Optional properties:
> with "phys" attribute, provides phandle to UFS PHY node
> - vdd-hba-supply : phandle to UFS host controller supply regulator node
> - vcc-supply : phandle to VCC supply regulator node
> +- vcc-voltage-level : specifies voltage levels for VCC supply.
> + Should be specified in pairs (min, max), units uV.

The expectation is the regulator pointed to by 'vcc-supply' has the
voltage constraints. Those constraints are supposed to be the board
constraints, not the regulator operating design constraints. If that
doesn't work for your case, then it should be addressed in a common way
for the regulator binding.

Also, properties with units must have a unit suffix.

Rob