Cc'ing few people (whom I cc'd last time as well :)).
On 27-07-15, 16:20, Lee Jones wrote:
> These OPPs are used in ST's CPUFreq implementation.
>
> Signed-off-by: Lee Jones <lee.jo...@linaro.org>
> ---
>
> Changelog:
> - None, new patch
>
> Documentation/devicetree/bindings/power/opp-st.txt | 76
> ++++++++++++++++++++++
> 1 file changed, 76 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/power/opp-st.txt
>
> diff --git a/Documentation/devicetree/bindings/power/opp-st.txt
> b/Documentation/devicetree/bindings/power/opp-st.txt
> new file mode 100644
> index 0000000..6eb2a91
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/opp-st.txt
> @@ -0,0 +1,76 @@
> +STMicroelectronics OPP (Operating Performance Points) Bindings
> +--------------------------------------------------------------
> +
> +Frequency Scaling only
> +----------------------
> +
> +Located in CPU's node:
> +
> +- operating-points : [See: ./opp.txt]
> +
> +Example [safe]
> +--------------
> +
> +cpus {
> + cpu@0 {
> + /* kHz uV */
> + operating-points = <1500000 0
> + 1200000 0
> + 800000 0
> + 500000 0>;
> + };
> +};
> +
> +Dynamic Voltage and Frequency Scaling (DVFS)
> +--------------------------------------------
> +
> +Located in 'cpu0-opp-list' node [to be provided ONLY by the bootloader]:
> +
> +- compatible : Should be "operating-points-v2-sti"
> +- opp{1..N} : Each 'oppX' subnode will contain the following
> properties:
Or should we mention:
- opp{1..N} : Each 'oppX' subnode shall contain below properties,
over what ./opp.txt defines:
?
> + - opp-hz : CPU frequency [Hz] for this OPP [See: ./opp.txt]
> + - st,avs : List of available voltages [uV] indexed by process
> code
> + - st,cuts : Cut version this OPP is suitable for [0xFF means ALL]
> + - st,substrate : Substrate version this OPP is suitable for
> [0xFF means ALL]
> +- st,syscfg : Phandle to Major number register
> + First cell: offset to major number
> +- st,syscfg-eng : Phandle to Minor number and Pcode registers
> + First cell: offset to process code
> + Second cell: offset to minor number
> +
> +WARNING: The opp{1..N} nodes will be provided by the bootloader. Do not
> attempt to
> + artificially synthesise the opp{1..N} nodes or any of their
> descendants.
> + They are very platform specific and may damage the hardware if created
> + incorrectly.
> +
> +Example [unsafe]
> +----------------
> +
> +cpus {
> + cpu@0 {
> + operating-points-v2 = <&cpu0_opp_list>;
> + };
> +};
> +
> +/* ############################################################ */
> +/* # WARNING: Do not attempt to copy/replicate this node, # */
> +/* # it is only to be supplied by the bootloader !!! # */
> +/* ############################################################ */
> +cpu0-opp-list {
> + compatible = "operating-points-v2-sti";
> + st,syscfg = <&syscfg [major_offset]>;
> + st,syscfg-eng = <&syscfg_eng [pcode_offset] [minor_offset]>;
> +
> + opp0 {
> + opp-hz = <1200000000>;
> + st,avs = <1110 1150 1100 1080 1040 1020 980 930>;
> + st,substrate = <0xff>;
> + st,cuts = <0xff>;
> + };
> + opp1 {
> + opp-hz = <1500000000>;
> + st,avs = <1200 1200 1200 1200 1170 1140 1100 1070>;
> + st,substrate = <0xff>;
> + st,cuts = <0x2>;
> + };
> +};
I don't see more problems here, unless we can move some of this to the
generic bindings.
@Rob/Stephen: Please respond before it is late :)
--
viresh
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