[PATCH v2 03/15] dt-bindings: devfreq: rk3399_dmc: Fix Hz units
Chanwoo Choi
cw00.choi at samsung.com
Thu Feb 3 17:59:22 PST 2022
On 1/28/22 8:07 AM, Brian Norris wrote:
> The driver and all downstream device trees [1] are using Hz units, but
> the document claims MHz. DRAM frequency for these systems can't possibly
> exceed 2^32-1 Hz, so the choice of unit doesn't really matter than much.
>
> Rather than add unnecessary risk in getting the units wrong, let's just
> go with the unofficial convention and make the docs match reality.
>
> A sub-1MHz frequency is extremely unlikely, so include a minimum in the
> schema, to help catch anybody who might have believed this was MHz.
>
> [1] And notably, also those trying to upstream them:
> https://protect2.fireeye.com/v1/url?k=0a7de78e-55e6dec8-0a7c6cc1-0cc47a3003e8-4f0969a9fa7b496e&q=1&e=6129c5df-8bd2-4072-86ef-79b79b36ec89&u=https%3A%2F%2Flore.kernel.org%2Flkml%2F20210308233858.24741-3-daniel.lezcano%40linaro.org%2F
>
> Signed-off-by: Brian Norris <briannorris at chromium.org>
> ---
>
> (no changes since v1)
>
> .../bindings/devfreq/rk3399_dmc.yaml | 24 +++++++++----------
> 1 file changed, 12 insertions(+), 12 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/devfreq/rk3399_dmc.yaml b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.yaml
> index fd62a8cd62d5..8bb778df92ae 100644
> --- a/Documentation/devicetree/bindings/devfreq/rk3399_dmc.yaml
> +++ b/Documentation/devicetree/bindings/devfreq/rk3399_dmc.yaml
> @@ -116,11 +116,11 @@ properties:
>
> rockchip,ddr3_odt_dis_freq:
> $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 1000000 # In case anyone thought this was MHz.
> description:
> When the DRAM type is DDR3, this parameter defines the ODT disable
> - frequency in MHz (Mega Hz). When the DDR frequency is less then
> - ddr3_odt_dis_freq, the ODT on the DRAM side and controller side are both
> - disabled.
> + frequency in Hz. When the DDR frequency is less then ddr3_odt_dis_freq,
> + the ODT on the DRAM side and controller side are both disabled.
>
> rockchip,ddr3_drv:
> deprecated: true
> @@ -160,11 +160,11 @@ properties:
>
> rockchip,lpddr3_odt_dis_freq:
> $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 1000000 # In case anyone thought this was MHz.
> description:
> When the DRAM type is LPDDR3, this parameter defines then ODT disable
> - frequency in MHz (Mega Hz). When DDR frequency is less then
> - ddr3_odt_dis_freq, the ODT on the DRAM side and controller side are both
> - disabled.
> + frequency in Hz. When DDR frequency is less then ddr3_odt_dis_freq, the
> + ODT on the DRAM side and controller side are both disabled.
>
> rockchip,lpddr3_drv:
> deprecated: true
> @@ -204,11 +204,11 @@ properties:
>
> rockchip,lpddr4_odt_dis_freq:
> $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 1000000 # In case anyone thought this was MHz.
> description:
> When the DRAM type is LPDDR4, this parameter defines the ODT disable
> - frequency in MHz (Mega Hz). When the DDR frequency is less then
> - ddr3_odt_dis_freq, the ODT on the DRAM side and controller side are both
> - disabled.
> + frequency in Hz. When the DDR frequency is less then ddr3_odt_dis_freq,
> + the ODT on the DRAM side and controller side are both disabled.
>
> rockchip,lpddr4_drv:
> deprecated: true
> @@ -287,7 +287,7 @@ examples:
> rockchip,sr_mc_gate_idle = <0x3>;
> rockchip,srpd_lite_idle = <0x4>;
> rockchip,standby_idle = <0x2000>;
> - rockchip,ddr3_odt_dis_freq = <333>;
> - rockchip,lpddr3_odt_dis_freq = <333>;
> - rockchip,lpddr4_odt_dis_freq = <333>;
> + rockchip,ddr3_odt_dis_freq = <333000000>;
> + rockchip,lpddr3_odt_dis_freq = <333000000>;
> + rockchip,lpddr4_odt_dis_freq = <333000000>;
> };
>
Acked-by: Chanwoo Choi <cw00.choi at samsung.com>
--
Best Regards,
Chanwoo Choi
Samsung Electronics
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