RE: [PATCH v4 1/5] dt-bindings: phy: Document Samsung UFS PHY bindings

[Alim Akhtar]

Hi Rob,

> -----Original Message-----
> From: Rob Herring <robh@xxxxxxxxxx>
> Sent: 05 April 2020 07:24
> To: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> Cc: devicetree@xxxxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx;
krzk@xxxxxxxxxx;
> avri.altman@xxxxxxx; martin.petersen@xxxxxxxxxx;
> kwmad.kim@xxxxxxxxxxx; stanley.chu@xxxxxxxxxxxx;
> cang@xxxxxxxxxxxxxx; linux-samsung-soc@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v4 1/5] dt-bindings: phy: Document Samsung UFS PHY
> bindings
> 
> On Fri, Mar 27, 2020 at 10:36:34PM +0530, Alim Akhtar wrote:
> > This patch documents Samsung UFS PHY device tree bindings
> >
> > Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> > ---
> >  .../bindings/phy/samsung,ufs-phy.yaml         | 67 +++++++++++++++++++
> >  1 file changed, 67 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/phy/samsung,ufs-phy.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/phy/samsung,ufs-phy.yaml
> > b/Documentation/devicetree/bindings/phy/samsung,ufs-phy.yaml
> > new file mode 100644
> > index 000000000000..41ba481ecc76
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/phy/samsung,ufs-phy.yaml
> > @@ -0,0 +1,67 @@
> > +# SPDX-License-Identifier: (GPL-2.0)
> 
> Dual license new bindings:
> 
> (GPL-2.0-only OR BSD-2-Clause)
> 
Sure will update.

> > +%YAML 1.2
> > +---
> > +$id:
> > +https://protect2.fireeye.com/url?k=91cb53a2-cc1b5b6e-91cad8ed-000babf
> > +f3793-
> 448c7d85bdf69f5a&q=1&u=http%3A%2F%2Fdevicetree.org%2Fschemas%2F
> > +phy%2Fsamsung%2Cufs-phy.yaml%23
> > +$schema:
> > +https://protect2.fireeye.com/url?k=a8ce57c7-f51e5f0b-a8cfdc88-000babf
> > +f3793-fbe649ab0853d701&q=1&u=http%3A%2F%2Fdevicetree.org%2Fmeta-
> schem
> > +as%2Fcore.yaml%23
> > +
> > +title: Samsung SoC series UFS PHY Device Tree Bindings
> > +
> > +maintainers:
> > +  - Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
> > +
> > +properties:
> > +  "#phy-cells":
> > +    const: 0
> > +
> > +  compatible:
> > +    enum:
> > +      - samsung,exynos7-ufs-phy
> > +
> > +  reg:
> > +    maxItems: 1
> > +    description: PHY base register address
> > +
> > +  reg-names:
> > +    items:
> > +      - const: phy-pma
> > +
> > +  clocks:
> > +    items:
> > +      - description: PLL reference clock
> > +      - description: Referencec clock parrent
> > +
> > +  clock-names:
> > +    items:
> > +      - const: ref_clk_parent
> > +      - const: ref_clk
> 
> Doesn't match what 'clocks' says.
> 
Will correct.

> Also, why do you need the parent in DT? Just use clk_get_parent(). DT
should
> reflect actual h/w clock connections (not what the driver happens to
need).
> Also, there's the assigned-clocks binding.
> 
Some of the platform deviates from the normal clock trees and need to force
a different parent. To get such parent added this.
I will explore a bit more on this, and check about assigned-clocks binding.
This is also an optional clock, so will change accordingly

> > +
> > +  samsung,pmu-syscon:
> > +    $ref: '/schemas/types.yaml#/definitions/phandle'
> > +    description: phandle for PMU system controller interface, used to
> > +                 control pmu registers for power isolation
> 
> We have a binding for power domains. Use that for power isolation.
> 
Let me have a look on that, if power domains bindings can be use here, this
is same way other Exynos binding is defined w.r.t. pmu-syscon.

> > +
> > +required:
> > +  - "#phy-cells"
> > +  - compatible
> > +  - reg
> > +  - reg-names
> > +  - clocks
> > +  - clock-names
> > +  - samsung,pmu-syscon
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/exynos7-clk.h>
> > +
> > +    ufs_phy: ufs-phy@15571800 {
> > +        compatible = "samsung,exynos7-ufs-phy";
> > +        reg = <0x15571800 0x240>;
> > +        reg-names = "phy-pma";
> > +        samsung,pmu-syscon = <&pmu_system_controller>;
> > +        #phy-cells = <0>;
> > +        clocks = <&clock_fsys1 MOUT_FSYS1_PHYCLK_SEL1>,
> > +                 <&clock_top1 CLK_SCLK_PHY_FSYS1_26M>;
> > +        clock-names = "ref_clk_parent",
> > +                      "ref_clk";
> > +    };
> > +...
> >
> > base-commit: fb33c6510d5595144d585aa194d377cf74d31911
> > --
> > 2.17.1
> >