diff mbox

[V4,3/3] cpufreq: imx6: Add device tree binding document

Message ID 1387462609-13013-3-git-send-email-b20788@freescale.com
State Superseded, archived
Headers show

Commit Message

Anson Huang Dec. 19, 2013, 2:16 p.m. UTC 
This device tree binding document describes the imx6 cpufreq
DT bindings. This document lists all required and optional properties
for imx6 cpufreq.

Signed-off-by: Anson Huang <b20788@freescale.com>
---
 .../devicetree/bindings/cpufreq/cpufreq-imx6.txt   |   56 ++++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt

Comments

Sudeep.KarkadaNagesha@arm.com Dec. 19, 2013, 2:21 p.m. UTC | #1 
On 19/12/13 14:16, Anson Huang wrote:
> This device tree binding document describes the imx6 cpufreq
> DT bindings. This document lists all required and optional properties
> for imx6 cpufreq.
> 
> Signed-off-by: Anson Huang <b20788@freescale.com>
> ---
>  .../devicetree/bindings/cpufreq/cpufreq-imx6.txt   |   56 ++++++++++++++++++++
>  1 file changed, 56 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt
> 
> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt
> new file mode 100644
> index 0000000..a14b895
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt
> @@ -0,0 +1,56 @@
> +i.MX6 cpufreq driver
> +-------------------
> +
> +i.MX6 SoC cpufreq driver for CPU frequency scaling.
> +
> +This binding doc defines properties that must be put in the /cpus/cpu@0 node,
> +please refer to Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> +for detail.
> +
> +Required properties:
> +- operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt
> +  for details.
> +- clocks: Specify clocks that need to be used when cpu frequency is scaled,
> +  refer to Documentation/devicetree/bindings/clock/clock-bindings.txt for
> +  details.
> +- clock-names: List of clock input name strings sorted in the same order as the
> +  clocks property, refer to Documentation/devicetree/bindings/clock/clock-bindings.txt
> +  for details.
> +- xxx-supply: Input voltage supply regulator, refer to
> +  Documentation/devicetree/bindings/regulator/regulator.txt for details.
> +  arm-supply: regulator node supplying arm.
> +  pu-supply: regulator node supplying pu.
> +  soc-supply: regulator node supplying soc.
> +
> +Optional properties:
> +- fsl,soc-operating-points: Specify vddsoc/pu voltage settings that must
> +  go with cpu0's operating-points.
> +- clock-latency: Specify the possible maximum transition latency for clock,
> +  in unit of nanoseconds.
> +

Sorry if I am missing something obvious as I have not followed the previous
versions and corresponding comments.

Should these SoC properties be part of cpu node ? If so which cpu or why cpu0 ?
IIUC it's more a SoC properties which also influences ARM CPU OPPs. IOW other
regulators may depend on pu/soc-supply. In that case it would be cleaner if that
dependency is setup through regulators framework.

> +Examples:
> +
> +	cpu@0 {
> +		operating-points = <
> +			/* kHz    uV */
> +			1200000 1275000
> +			996000  1250000
> +			792000  1150000
> +			396000  975000
> +		>;
> +		fsl,soc-operating-points = <
> +			/* ARM kHz  SOC-PU uV */
> +			1200000 1275000
> +			996000	1250000
> +			792000	1175000
> +			396000	1175000
> +		>;
> +		clock-latency = <61036>; /* two CLK32 periods */
> +		clocks = <&clks 104>, <&clks 6>, <&clks 16>,
> +			 <&clks 17>, <&clks 170>;
> +		clock-names = "arm", "pll2_pfd2_396m", "step",
> +			      "pll1_sw", "pll1_sys";
> +		arm-supply = <&reg_arm>;
> +		pu-supply = <&reg_pu>;
> +		soc-supply = <&reg_soc>;
> +	};
> 


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Anson.Huang@freescale.com Dec. 19, 2013, 3:42 p.m. UTC | #2 
Sent from Anson's iPhone

> 在 2013年12月19日，22:21，"Sudeep KarkadaNagesha" <Sudeep.KarkadaNagesha@arm.com> 写道：

> 

>> On 19/12/13 14:16, Anson Huang wrote:

>> This device tree binding document describes the imx6 cpufreq

>> DT bindings. This document lists all required and optional properties

>> for imx6 cpufreq.

>> 

>> Signed-off-by: Anson Huang <b20788@freescale.com>

>> ---

>> .../devicetree/bindings/cpufreq/cpufreq-imx6.txt   |   56 ++++++++++++++++++++

>> 1 file changed, 56 insertions(+)

>> create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt

>> 

>> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt

>> new file mode 100644

>> index 0000000..a14b895

>> --- /dev/null

>> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt

>> @@ -0,0 +1,56 @@

>> +i.MX6 cpufreq driver

>> +-------------------

>> +

>> +i.MX6 SoC cpufreq driver for CPU frequency scaling.

>> +

>> +This binding doc defines properties that must be put in the /cpus/cpu@0 node,

>> +please refer to Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt

>> +for detail.

>> +

>> +Required properties:

>> +- operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt

>> +  for details.

>> +- clocks: Specify clocks that need to be used when cpu frequency is scaled,

>> +  refer to Documentation/devicetree/bindings/clock/clock-bindings.txt for

>> +  details.

>> +- clock-names: List of clock input name strings sorted in the same order as the

>> +  clocks property, refer to Documentation/devicetree/bindings/clock/clock-bindings.txt

>> +  for details.

>> +- xxx-supply: Input voltage supply regulator, refer to

>> +  Documentation/devicetree/bindings/regulator/regulator.txt for details.

>> +  arm-supply: regulator node supplying arm.

>> +  pu-supply: regulator node supplying pu.

>> +  soc-supply: regulator node supplying soc.

>> +

>> +Optional properties:

>> +- fsl,soc-operating-points: Specify vddsoc/pu voltage settings that must

>> +  go with cpu0's operating-points.

>> +- clock-latency: Specify the possible maximum transition latency for clock,

>> +  in unit of nanoseconds.

>> +

> 

> Sorry if I am missing something obvious as I have not followed the previous

> versions and corresponding comments.

> 

> Should these SoC properties be part of cpu node ? If so which cpu or why cpu0 ?

yes, these properties are for cpufreq function, as on SMP system, all CPUs are running at same freq, cpufreq is tied to cpu0, so we put them in cpu0's node. 


> IIUC it's more a SoC properties which also influences ARM CPU OPPs. IOW other

> regulators may depend on pu/soc-supply. In that case it would be cleaner if that

> dependency is setup through regulators framework.


the truth is that arm power domain has no level shift with sic/pu domain, so when arm domain voltage is changed, soc/pu domain need to be changed too, more like multi OPP concept. there is no other regulators depend on soc/pu supply.

anson.
> 

>> +Examples:

>> +

>> +    cpu@0 {

>> +        operating-points = <

>> +            /* kHz    uV */

>> +            1200000 1275000

>> +            996000  1250000

>> +            792000  1150000

>> +            396000  975000

>> +        >;

>> +        fsl,soc-operating-points = <

>> +            /* ARM kHz  SOC-PU uV */

>> +            1200000 1275000

>> +            996000    1250000

>> +            792000    1175000

>> +            396000    1175000

>> +        >;

>> +        clock-latency = <61036>; /* two CLK32 periods */

>> +        clocks = <&clks 104>, <&clks 6>, <&clks 16>,

>> +             <&clks 17>, <&clks 170>;

>> +        clock-names = "arm", "pll2_pfd2_396m", "step",

>> +                  "pll1_sw", "pll1_sys";

>> +        arm-supply = <&reg_arm>;

>> +        pu-supply = <&reg_pu>;

>> +        soc-supply = <&reg_soc>;

>> +    };

> 

> 

> 

>
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt
new file mode 100644
index 0000000..a14b895
--- /dev/null
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-imx6.txt
@@ -0,0 +1,56 @@ 
+i.MX6 cpufreq driver
+-------------------
+
+i.MX6 SoC cpufreq driver for CPU frequency scaling.
+
+This binding doc defines properties that must be put in the /cpus/cpu@0 node,
+please refer to Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
+for detail.
+
+Required properties:
+- operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt
+  for details.
+- clocks: Specify clocks that need to be used when cpu frequency is scaled,
+  refer to Documentation/devicetree/bindings/clock/clock-bindings.txt for
+  details.
+- clock-names: List of clock input name strings sorted in the same order as the
+  clocks property, refer to Documentation/devicetree/bindings/clock/clock-bindings.txt
+  for details.
+- xxx-supply: Input voltage supply regulator, refer to
+  Documentation/devicetree/bindings/regulator/regulator.txt for details.
+  arm-supply: regulator node supplying arm.
+  pu-supply: regulator node supplying pu.
+  soc-supply: regulator node supplying soc.
+
+Optional properties:
+- fsl,soc-operating-points: Specify vddsoc/pu voltage settings that must
+  go with cpu0's operating-points.
+- clock-latency: Specify the possible maximum transition latency for clock,
+  in unit of nanoseconds.
+
+Examples:
+
+	cpu@0 {
+		operating-points = <
+			/* kHz    uV */
+			1200000 1275000
+			996000  1250000
+			792000  1150000
+			396000  975000
+		>;
+		fsl,soc-operating-points = <
+			/* ARM kHz  SOC-PU uV */
+			1200000 1275000
+			996000	1250000
+			792000	1175000
+			396000	1175000
+		>;
+		clock-latency = <61036>; /* two CLK32 periods */
+		clocks = <&clks 104>, <&clks 6>, <&clks 16>,
+			 <&clks 17>, <&clks 170>;
+		clock-names = "arm", "pll2_pfd2_396m", "step",
+			      "pll1_sw", "pll1_sys";
+		arm-supply = <&reg_arm>;
+		pu-supply = <&reg_pu>;
+		soc-supply = <&reg_soc>;
+	};