RE: [PATCH v2 1/2] dt-bindings: Add binding for Renesas 8T49N241
From: Biju Das
Date: Fri Jul 02 2021 - 02:52:30 EST
Hi Alex,
Thanks for the patch.
> -----Original Message-----
> From: Alex Helms <alexander.helms.jy@xxxxxxxxxxx>
> Sent: 02 July 2021 00:23
> To: linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> clk@xxxxxxxxxxxxxxx; linux-renesas-soc@xxxxxxxxxxxxxxx
> Cc: robh+dt@xxxxxxxxxx; sboyd@xxxxxxxxxx; mturquette@xxxxxxxxxxxx;
> geert+renesas@xxxxxxxxx; Alexander Helms <alexander.helms.jy@xxxxxxxxxxx>;
> David Cater <david.cater.jc@xxxxxxxxxxx>; michal.simek@xxxxxxxxxx
> Subject: [PATCH v2 1/2] dt-bindings: Add binding for Renesas 8T49N241
>
> Renesas 8T49N241 has 4 outputs, 1 integral and 3 fractional dividers.
> The 8T49N241 accepts up to two differential or single-ended input clocks
> and a fundamental-mode crystal input. The internal PLL can lock to either
> of the input reference clocks or to the crystal to behave as a frequency
> synthesizer.
>
> Signed-off-by: Alex Helms <alexander.helms.jy@xxxxxxxxxxx>
> ---
> .../bindings/clock/renesas,8t49n241.yaml | 183 ++++++++++++++++++
> MAINTAINERS | 6 +
> 2 files changed, 189 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/clock/renesas,8t49n241.yaml
>
> diff --git a/Documentation/devicetree/bindings/clock/renesas,8t49n241.yaml
> b/Documentation/devicetree/bindings/clock/renesas,8t49n241.yaml
> new file mode 100644
> index 000000000..d817ec46d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/renesas,8t49n241.yaml
> @@ -0,0 +1,183 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2
> +---
> +$id:
> +https://jpn01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevice
> +tree.org%2Fschemas%2Fclock%2Frenesas%2C8t49n24x.yaml%23&data=04%7C0
> +1%7Cbiju.das.jz%40bp.renesas.com%7Ce51e24d06083403a3d0e08d93ce73933%7C5
> +3d82571da1947e49cb4625a166a4a2a%7C0%7C0%7C637607786063741484%7CUnknown%
> +7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXV
> +CI6Mn0%3D%7C1000&sdata=BIKHeHpyG3vloEEO02HzM6TtWqQtDlSGRMifOQVprPI%
> +3D&reserved=0
> +$schema:
> +https://jpn01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdevice
> +tree.org%2Fmeta-schemas%2Fcore.yaml%23&data=04%7C01%7Cbiju.das.jz%4
> +0bp.renesas.com%7Ce51e24d06083403a3d0e08d93ce73933%7C53d82571da1947e49c
> +b4625a166a4a2a%7C0%7C0%7C637607786063751443%7CUnknown%7CTWFpbGZsb3d8eyJ
> +WIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&
> +amp;sdata=3XhlKhlwT3hr0KVjynaiMlqMC94tq3sEYgNH6LMf9Kc%3D&reserved=0
> +
> +title: Binding for Renesas 8T49N241 Universal Frequency Translator
> +
> +description: |
> + The 8T49N241 has one fractional-feedback PLL that can be used as a
> + jitter attenuator and frequency translator. It is equipped with one
> + integer and three fractional output dividers, allowing the generation
> + of up to four different output frequencies, ranging from 8kHz to 1GHz.
> + These frequencies are completely independent of each other, the input
> + reference frequencies and the crystal reference frequency. The device
> + places virtually no constraints on input to output frequency
> +conversion,
> + supporting all FEC rates, including the new revision of ITU-T
> + Recommendation G.709 (2009), most with 0ppm conversion error.
> + The outputs may select among LVPECL, LVDS, HCSL or LVCMOS output
> levels.
> +
> + The driver can read a full register map from the DT, and will use
> + that register map to initialize the attached part (via I2C) when the
> + system boots. Any configuration not supported by the common clock
> + framework must be done via the full register map, including optimized
> settings.
> +
> + The 8T49N241 accepts up to two differential or single-ended input
> + clocks and a fundamental-mode crystal input. The internal PLL can
> + lock to either of the input reference clocks or just to the crystal
> + to behave as a frequency synthesizer. The PLL can use the second
> + input for redundant backup of the primary input reference, but in
> + this case, both input clock references must be related in frequency.
> +
> + All outputs are currently assumed to be LVDS, unless overridden in
> + the full register map in the DT.
> +
> +maintainers:
> + - Alex Helms <alexander.helms.jy@xxxxxxxxxxx>
> + - David Cater <david.cater.jc@xxxxxxxxxxx>
> +
> +properties:
> + compatible:
> + enum:
> + - 8t49n241
> +
> + reg:
> + description: I2C device address
> + enum: [ 0x7c, 0x6c, 0x7d, 0x6d, 0x7e, 0x6e, 0x7f, 0x6f ]
> +
> + '#clock-cells':
> + const: 1
> +
> + clock-names:
> + description: Name of the input clock
> + minItems: 1
> + maxItems: 3
> + items:
> + enum: [ input-xtal, input-clk0, input-clk1 ]
> +
> + clocks:
> + minItems: 1
> + maxItems: 3
> +
> +required:
> + - compatible
> + - reg
> + - '#clock-cells'
> + - clocks
> + - clock-names
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + /* 25MHz reference clock */
> + input_clk0: input_clk0 {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-frequency = <25000000>;
> + };
> +
> + i2c@0 {
> + reg = <0x0 0x100>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + renesas8t49n241_1: clock-generator@6c {
> + compatible = "renesas,8t49n241";
> + reg = <0x6c>;
> + #clock-cells = <1>;
> +
> + clocks = <&input_clk0>;
> + clock-names = "input-clk0";
> + };
> + };
> +
> + /* Consumer referencing the 8T49N241 Q1 */
> + consumer {
> + /* ... */
> + clocks = <&renesas8t49n241_1 1>;
> + /* ... */
> + };
> + - |
> + /* 40MHz crystal */
> + input_xtal: input_xtal {
> + compatible = "fixed-clock";
> + #clock-cells = <0>;
> + clock-frequency = <40000000>;
> + };
> +
> + i2c@0 {
> + reg = <0x0 0x100>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + renesas8t49n241_2: clock-generator@6c {
> + compatible = "renesas,8t49n241";
> + reg = <0x6c>;
> + #clock-cells = <1>;
> +
> + clocks = <&input_xtal>;
> + clock-names = "input-xtal";
> +
> + settings=[
optional or required property?
> + 09 50 00 60 67 C5 6C FF 03 00 30 00 00 01 00 00
> + 01 07 00 00 07 00 00 77 6D 06 00 00 00 00 00 FF
> + FF FF FF 00 3F 00 2A 00 16 33 33 00 01 00 00 D0
> + 00 00 00 00 00 00 00 00 00 04 00 00 00 02 00 00
> + 00 00 00 00 00 00 00 17 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 D7 0A 2B 20 00 00 00 0B
> + 00 00 00 00 00 00 00 00 00 00 27 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + C3 00 08 01 00 00 00 00 00 00 00 00 00 30 00 00
> + 00 0A 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> + 00 00 00 00 85 00 00 9C 01 D4 02 71 07 00 00 00
> + 00 83 00 10 02 08 8C
> + ];
> + };
> + };
> +
One question,
Full regmap or just overriding few registers which is better, assuming the device has default values programmed in OTP.
Again that needs {offset, value}???
Regards,
Biju
> + /* Consumer referencing the 8T49N241 Q1 */
> + consumer {
> + /* ... */
> + clocks = <&renesas8t49n241_2 1>;
> + /* ... */
> + };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0cce91cd5..882d79ead 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -15575,6 +15575,12 @@ F: include/linux/rpmsg/
> F: include/uapi/linux/rpmsg.h
> F: samples/rpmsg/
>
> +RENESAS 8T49N24X DRIVER
> +M: Alex Helms <alexander.helms.jy@xxxxxxxxxxx>
> +M: David Cater <david.cater.jc@xxxxxxxxxxx>
> +S: Odd Fixes
> +F: Documentation/devicetree/bindings/clock/renesas,8t49n241.yaml
> +
> RENESAS CLOCK DRIVERS
> M: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> L: linux-renesas-soc@xxxxxxxxxxxxxxx
> --
> 2.30.2