diff mbox series

[v3,2/5] dt: bindings: add mt7621-clk device tree binding documentation

Message ID 20201113154632.24973-3-sergio.paracuellos@gmail.com (mailing list archive)
State Superseded
Headers show
Series MIPS: ralink: add CPU clock detection and clock gate driver for MT7621 | expand

Commit Message

Sergio Paracuellos Nov. 13, 2020, 3:46 p.m. UTC 
Adds device tree binding documentation for clocks in the
MT7621 SOC.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
---
 .../bindings/clock/mediatek,mt7621-clk.yaml   | 61 +++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml

Comments

Rob Herring Nov. 21, 2020, 1:34 p.m. UTC | #1 
On Fri, Nov 13, 2020 at 04:46:29PM +0100, Sergio Paracuellos wrote:
> Adds device tree binding documentation for clocks in the
> MT7621 SOC.
> 
> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
> ---
>  .../bindings/clock/mediatek,mt7621-clk.yaml   | 61 +++++++++++++++++++
>  1 file changed, 61 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
> 
> diff --git a/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml b/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
> new file mode 100644
> index 000000000000..363bd9880e29
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
> @@ -0,0 +1,61 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/clock/mediatek,mt7621-clk.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: MT7621 Clock Device Tree Bindings
> +
> +maintainers:
> +  - Sergio Paracuellos <sergio.paracuellos@gmail.com>
> +
> +description: |
> +  The MT7621 has a PLL controller from where the cpu clock is provided
> +  as well as derived clocks for the bus and the peripherals. It also
> +  can gate SoC device clocks.
> +
> +  Each clock is assigned an identifier and client nodes use this identifier
> +  to specify the clock which they consume.
> +
> +  All these identifiers could be found in:
> +  [1]: <include/dt-bindings/clock/mt7621-clk.h>.
> +
> +properties:
> +  compatible:
> +    const: mediatek,mt7621-clk
> +
> +  ralink,sysctl:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description:
> +      phandle to the syscon which is in the same address area with syscon
> +      device.
> +
> +  "#clock-cells":
> +    description:
> +      The first cell indicates the clock gate number, see [1] for available
> +      clocks.
> +    const: 1
> +
> +  clock-output-names:
> +    maxItems: 8
> +
> +required:
> +  - compatible
> +  - ralink,sysctl
> +  - '#clock-cells'
> +  - clock-output-names
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/mt7621-clk.h>
> +
> +    pll {
> +      compatible = "mediatek,mt7621-clk";
> +      ralink,sysctl = <&sysc>;

If this is the only control interface, then make this a child of 'sysc'. 
And use 'reg' if there's a dedicated range of registers.

> +      #clock-cells = <1>;
> +      clock-output-names = "xtal", "cpu", "bus",
> +                           "50m", "125m", "150m",
> +                           "250m", "270m";
> +    };
> -- 
> 2.25.1
>
Sergio Paracuellos Nov. 21, 2020, 2:50 p.m. UTC | #2 
Hi Rob,

Thanks for the review.

On Sat, Nov 21, 2020 at 2:34 PM Rob Herring <robh@kernel.org> wrote:
>
> On Fri, Nov 13, 2020 at 04:46:29PM +0100, Sergio Paracuellos wrote:
> > Adds device tree binding documentation for clocks in the
> > MT7621 SOC.
> >
> > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
> > ---
> >  .../bindings/clock/mediatek,mt7621-clk.yaml   | 61 +++++++++++++++++++
> >  1 file changed, 61 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml b/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
> > new file mode 100644
> > index 000000000000..363bd9880e29
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
> > @@ -0,0 +1,61 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/clock/mediatek,mt7621-clk.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: MT7621 Clock Device Tree Bindings
> > +
> > +maintainers:
> > +  - Sergio Paracuellos <sergio.paracuellos@gmail.com>
> > +
> > +description: |
> > +  The MT7621 has a PLL controller from where the cpu clock is provided
> > +  as well as derived clocks for the bus and the peripherals. It also
> > +  can gate SoC device clocks.
> > +
> > +  Each clock is assigned an identifier and client nodes use this identifier
> > +  to specify the clock which they consume.
> > +
> > +  All these identifiers could be found in:
> > +  [1]: <include/dt-bindings/clock/mt7621-clk.h>.
> > +
> > +properties:
> > +  compatible:
> > +    const: mediatek,mt7621-clk
> > +
> > +  ralink,sysctl:
> > +    $ref: /schemas/types.yaml#/definitions/phandle
> > +    description:
> > +      phandle to the syscon which is in the same address area with syscon
> > +      device.
> > +
> > +  "#clock-cells":
> > +    description:
> > +      The first cell indicates the clock gate number, see [1] for available
> > +      clocks.
> > +    const: 1
> > +
> > +  clock-output-names:
> > +    maxItems: 8
> > +
> > +required:
> > +  - compatible
> > +  - ralink,sysctl
> > +  - '#clock-cells'
> > +  - clock-output-names
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/mt7621-clk.h>
> > +
> > +    pll {
> > +      compatible = "mediatek,mt7621-clk";
> > +      ralink,sysctl = <&sysc>;
>
> If this is the only control interface, then make this a child of 'sysc'.
> And use 'reg' if there's a dedicated range of registers.

This is the only one now in the device tree which is still in staging
but there are several places where this sys control registers are
accessed from. In the case of the clocks we need:

#define SYSC_REG_SYSTEM_CONFIG0         0x10
#define SYSC_REG_SYSTEM_CONFIG1         0x14
#define SYSC_REG_CLKCFG0                0x2c
#define SYSC_REG_CLKCFG1                0x30
#define SYSC_REG_CUR_CLK_STS            0x44

where there is not a range as it is but several different registers
from where we need to read or write things. I wrote the driver using
syscon and regmap because I thought in that way it might be more
maintainable but this architecture also has operations to read and
write registers from sysc and not using regmap at all. This operations
are defined in arch/mips/include/asm/mach-ralink/ralink_regs.h. But
because this sysc is currently mapped I cannot request its registers
using reg in the device tree. If you prefer me to avoid the use of
this syscon and regmap and use operations defined in ralink_regs.h,
this will become in a node without "regs" or  "ralink,sysctl"
property:

pll {
    compatible = "mediatek,mt7621-clk";
    #clock-cells = <1>;
    clock-output-names = "xtal", "cpu", "bus",
                      "50m", "125m", "150m",
                       "250m", "270m";
};

What should I do then?

Best regards,
    Sergio Paracuellos

>
> > +      #clock-cells = <1>;
> > +      clock-output-names = "xtal", "cpu", "bus",
> > +                           "50m", "125m", "150m",
> > +                           "250m", "270m";
> > +    };
> > --
> > 2.25.1
> >
Sergio Paracuellos Nov. 21, 2020, 4:22 p.m. UTC | #3 
On Sat, Nov 21, 2020 at 3:50 PM Sergio Paracuellos
<sergio.paracuellos@gmail.com> wrote:
>
> Hi Rob,
>
> Thanks for the review.
>
> On Sat, Nov 21, 2020 at 2:34 PM Rob Herring <robh@kernel.org> wrote:
> >
> > On Fri, Nov 13, 2020 at 04:46:29PM +0100, Sergio Paracuellos wrote:
> > > Adds device tree binding documentation for clocks in the
> > > MT7621 SOC.
> > >
> > > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
> > > ---
> > >  .../bindings/clock/mediatek,mt7621-clk.yaml   | 61 +++++++++++++++++++
> > >  1 file changed, 61 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml b/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
> > > new file mode 100644
> > > index 000000000000..363bd9880e29
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
> > > @@ -0,0 +1,61 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/clock/mediatek,mt7621-clk.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: MT7621 Clock Device Tree Bindings
> > > +
> > > +maintainers:
> > > +  - Sergio Paracuellos <sergio.paracuellos@gmail.com>
> > > +
> > > +description: |
> > > +  The MT7621 has a PLL controller from where the cpu clock is provided
> > > +  as well as derived clocks for the bus and the peripherals. It also
> > > +  can gate SoC device clocks.
> > > +
> > > +  Each clock is assigned an identifier and client nodes use this identifier
> > > +  to specify the clock which they consume.
> > > +
> > > +  All these identifiers could be found in:
> > > +  [1]: <include/dt-bindings/clock/mt7621-clk.h>.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: mediatek,mt7621-clk
> > > +
> > > +  ralink,sysctl:
> > > +    $ref: /schemas/types.yaml#/definitions/phandle
> > > +    description:
> > > +      phandle to the syscon which is in the same address area with syscon
> > > +      device.
> > > +
> > > +  "#clock-cells":
> > > +    description:
> > > +      The first cell indicates the clock gate number, see [1] for available
> > > +      clocks.
> > > +    const: 1
> > > +
> > > +  clock-output-names:
> > > +    maxItems: 8
> > > +
> > > +required:
> > > +  - compatible
> > > +  - ralink,sysctl
> > > +  - '#clock-cells'
> > > +  - clock-output-names
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/clock/mt7621-clk.h>
> > > +
> > > +    pll {
> > > +      compatible = "mediatek,mt7621-clk";
> > > +      ralink,sysctl = <&sysc>;
> >
> > If this is the only control interface, then make this a child of 'sysc'.
> > And use 'reg' if there's a dedicated range of registers.
>
> This is the only one now in the device tree which is still in staging
> but there are several places where this sys control registers are
> accessed from. In the case of the clocks we need:
>
> #define SYSC_REG_SYSTEM_CONFIG0         0x10
> #define SYSC_REG_SYSTEM_CONFIG1         0x14
> #define SYSC_REG_CLKCFG0                0x2c
> #define SYSC_REG_CLKCFG1                0x30
> #define SYSC_REG_CUR_CLK_STS            0x44
>
> where there is not a range as it is but several different registers
> from where we need to read or write things. I wrote the driver using
> syscon and regmap because I thought in that way it might be more
> maintainable but this architecture also has operations to read and
> write registers from sysc and not using regmap at all. This operations
> are defined in arch/mips/include/asm/mach-ralink/ralink_regs.h. But
> because this sysc is currently mapped I cannot request its registers
> using reg in the device tree. If you prefer me to avoid the use of
> this syscon and regmap and use operations defined in ralink_regs.h,
> this will become in a node without "regs" or  "ralink,sysctl"
> property:
>
> pll {
>     compatible = "mediatek,mt7621-clk";
>     #clock-cells = <1>;
>     clock-output-names = "xtal", "cpu", "bus",
>                       "50m", "125m", "150m",
>                        "250m", "270m";
> };
>
> What should I do then?

Ok, I think I understand now what you are saying. You meant just move
this as a child if 'sysc' and
avoid the phandle:

    sysc: sysc@0 {
            compatible = "mtk,mt7621-sysc", "syscon";
            reg = <0x0 0x100>;

            pll: pll {
                compatible = "mediatek,mt7621-clk";
                #clock-cells = <1>;
                clock-output-names = "xtal", "cpu", "bus",
                                  "50m", "125m", "150m",
                                 "250m", "270m";
            };
        };

And because there is not a range of registers 'reg' property is not
needed, right?

And in the driver side make use of 'syscon_node_to_regmap(node->parent)' instead
of 'syscon_regmap_lookup_by_phandle(node, "ralink,sysctl")'.

Ok, thanks for the clarification. Will change when v4 is sent.

Best regards,
    Sergio Paracuellos
>
> Best regards,
>     Sergio Paracuellos
>
> >
> > > +      #clock-cells = <1>;
> > > +      clock-output-names = "xtal", "cpu", "bus",
> > > +                           "50m", "125m", "150m",
> > > +                           "250m", "270m";
> > > +    };
> > > --
> > > 2.25.1
> > >
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml b/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
new file mode 100644
index 000000000000..363bd9880e29
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/mediatek,mt7621-clk.yaml
@@ -0,0 +1,61 @@ 
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/mediatek,mt7621-clk.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MT7621 Clock Device Tree Bindings
+
+maintainers:
+  - Sergio Paracuellos <sergio.paracuellos@gmail.com>
+
+description: |
+  The MT7621 has a PLL controller from where the cpu clock is provided
+  as well as derived clocks for the bus and the peripherals. It also
+  can gate SoC device clocks.
+
+  Each clock is assigned an identifier and client nodes use this identifier
+  to specify the clock which they consume.
+
+  All these identifiers could be found in:
+  [1]: <include/dt-bindings/clock/mt7621-clk.h>.
+
+properties:
+  compatible:
+    const: mediatek,mt7621-clk
+
+  ralink,sysctl:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      phandle to the syscon which is in the same address area with syscon
+      device.
+
+  "#clock-cells":
+    description:
+      The first cell indicates the clock gate number, see [1] for available
+      clocks.
+    const: 1
+
+  clock-output-names:
+    maxItems: 8
+
+required:
+  - compatible
+  - ralink,sysctl
+  - '#clock-cells'
+  - clock-output-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/mt7621-clk.h>
+
+    pll {
+      compatible = "mediatek,mt7621-clk";
+      ralink,sysctl = <&sysc>;
+      #clock-cells = <1>;
+      clock-output-names = "xtal", "cpu", "bus",
+                           "50m", "125m", "150m",
+                           "250m", "270m";
+    };