Re: [PATCH V3 1/2] ARM: imx: add vddsoc/pu setpoint info into dts

Re: [PATCH V3 1/2] ARM: imx: add vddsoc/pu setpoint info into dts

[Fabio Estevam]

Hi Anson,

On Wed, Dec 18, 2013 at 7:26 PM, Anson Huang <b20788@freescale.com> wrote:

> +  Documentation/devicetree/bindings/regulator/regulator.txt for details.
> +  arm-supply: vddarm input.
> +  pu-supply: vddpu input.
> +  soc-supply: vddsoc input.

I found these messages confusing, as someone may think that you are
referring to the VDD_ARM_IN/VDD_ARM23_IN and VDD_SOC_IN, which are
really inputs.

What about doing this instead?

arm-supply: VDDARM LDO output
pu-supply:  VDDPU LDO output
soc-supply: VDDSOC LDO output

Regards,

Fabio Estevam

Re: [PATCH V3 1/2] ARM: imx: add vddsoc/pu setpoint info into dts

[Anson.Huang]

Sent from Anson's iPhone

> 在 2013年12月18日，19:08，"Fabio Estevam" <festevam@gmail.com> 写道：
> 
> Hi Anson,
> 
>> On Wed, Dec 18, 2013 at 7:26 PM, Anson Huang <b20788@freescale.com> wrote:
>> 
>> +  Documentation/devicetree/bindings/regulator/regulator.txt for details.
>> +  arm-supply: vddarm input.
>> +  pu-supply: vddpu input.
>> +  soc-supply: vddsoc input.
> 
> I found these messages confusing, as someone may think that you are
> referring to the VDD_ARM_IN/VDD_ARM23_IN and VDD_SOC_IN, which are
> really inputs.
> 
> What about doing this instead?
> 
> arm-supply: VDDARM LDO output
> pu-supply:  VDDPU LDO output
> soc-supply: VDDSOC LDO output

I think they should know these regulators mean the arm, soc/pu's
real working voltage, as you know, our i.MX6 also support LDO bypass mode, then these regulators can be
VDDXXX_IN. that is why I use vddxxx
input, not vddxxx LDO input.Thanks!
> 
> Regards,
> 
> Fabio Estevam
> 
> 

Re: [PATCH V3 1/2] ARM: imx: add vddsoc/pu setpoint info into dts

[Shawn Guo]

On Wed, Dec 18, 2013 at 04:26:49PM -0500, Anson Huang wrote:
> i.MX6Q needs to update vddarm, vddsoc/pu regulators when cpu freq
> is changed, each setpoint has different voltage, so we need to
> pass vddarm, vddsoc/pu's freq-voltage info from dts together.
> 
> Signed-off-by: Anson Huang <b20788@freescale.com>
> ---
>  .../devicetree/bindings/cpufreq/cpufreq-imx6.txt   |   56 ++++++++++++++++++++

As I said in V2 review, the device tree binding doc change should be
part of driver patch (patch #2 in this case) or a separate patch, but
never be in the same patch as DTS change.

Shawn

>  arch/arm/boot/dts/imx6q.dtsi                       |    7 +++
>  2 files changed, 63 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..cf1c5f7
> --- /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: vddarm input.
> +  pu-supply: vddpu input.
> +  soc-supply: vddsoc input.
> +
> +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>;
> +	};
> diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
> index e7e8332..021e0cb 100644
> --- a/arch/arm/boot/dts/imx6q.dtsi
> +++ b/arch/arm/boot/dts/imx6q.dtsi
> @@ -30,6 +30,13 @@
>  				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>;
> -- 
> 1.7.9.5
> 
> 

Re: [PATCH V3 2/2] cpufreq: imx6q: correct VDDSOC/PU voltage scaling when cpufreq is changed

[Shawn Guo]

On Wed, Dec 18, 2013 at 04:26:50PM -0500, Anson Huang wrote:
> on i.MX6Q, cpu freq change need to follow below flows:
> 
> 1. each setpoint has different VDDARM, VDDSOC/PU voltage, get the setpoint
>    table from dts;
> 2. when cpu freq is scaling up, need to increase VDDSOC/PU voltage before
>    VDDARM, if VDDPU is off, no need to change it;
> 3. when cpu freq is scaling down, need to decrease VDDARM voltage before
>    VDDSOC/PU, if VDDPU is off, no need to change it;
> 
> normally dts will pass vddsoc/pu freq/volt info to kernel, if not, will
> use fixed value for vddsoc/pu voltage setting.
> 
> Signed-off-by: Anson Huang <b20788@freescale.com>

Acked-by: Shawn Guo <shawn.guo@linaro.org>

[PATCH V3 1/2] ARM: imx: add vddsoc/pu setpoint info into dts

[Anson Huang]

i.MX6Q needs to update vddarm, vddsoc/pu regulators when cpu freq
is changed, each setpoint has different voltage, so we need to
pass vddarm, vddsoc/pu's freq-voltage info from dts together.

Signed-off-by: Anson Huang <b20788@freescale.com>
---
 .../devicetree/bindings/cpufreq/cpufreq-imx6.txt   |   56 ++++++++++++++++++++
 arch/arm/boot/dts/imx6q.dtsi                       |    7 +++
 2 files changed, 63 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..cf1c5f7
--- /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: vddarm input.
+  pu-supply: vddpu input.
+  soc-supply: vddsoc input.
+
+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>;
+	};
diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
index e7e8332..021e0cb 100644
--- a/arch/arm/boot/dts/imx6q.dtsi
+++ b/arch/arm/boot/dts/imx6q.dtsi
@@ -30,6 +30,13 @@
 				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>;
-- 
1.7.9.5

[PATCH V3 2/2] cpufreq: imx6q: correct VDDSOC/PU voltage scaling when cpufreq is changed

[Anson Huang]

on i.MX6Q, cpu freq change need to follow below flows:

1. each setpoint has different VDDARM, VDDSOC/PU voltage, get the setpoint
   table from dts;
2. when cpu freq is scaling up, need to increase VDDSOC/PU voltage before
   VDDARM, if VDDPU is off, no need to change it;
3. when cpu freq is scaling down, need to decrease VDDARM voltage before
   VDDSOC/PU, if VDDPU is off, no need to change it;

normally dts will pass vddsoc/pu freq/volt info to kernel, if not, will
use fixed value for vddsoc/pu voltage setting.

Signed-off-by: Anson Huang <b20788@freescale.com>
---
 drivers/cpufreq/imx6q-cpufreq.c |  106 ++++++++++++++++++++++++++++-----------
 1 file changed, 77 insertions(+), 29 deletions(-)

diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index 4b3f18e..c29198f 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -35,6 +35,9 @@ static struct device *cpu_dev;
 static struct cpufreq_frequency_table *freq_table;
 static unsigned int transition_latency;
 
+static u32 *imx6_soc_volt;
+static u32 soc_opp_count;
+
 static unsigned int imx6q_get_speed(unsigned int cpu)
 {
 	return clk_get_rate(arm_clk) / 1000;
@@ -69,23 +72,22 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
 
 	/* scaling up?  scale voltage before frequency */
 	if (new_freq > old_freq) {
+		ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
+		if (ret) {
+			dev_err(cpu_dev, "failed to scale vddpu up: %d\n", ret);
+			return ret;
+		}
+		ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
+		if (ret) {
+			dev_err(cpu_dev, "failed to scale vddsoc up: %d\n", ret);
+			return ret;
+		}
 		ret = regulator_set_voltage_tol(arm_reg, volt, 0);
 		if (ret) {
 			dev_err(cpu_dev,
 				"failed to scale vddarm up: %d\n", ret);
 			return ret;
 		}
-
-		/*
-		 * Need to increase vddpu and vddsoc for safety
-		 * if we are about to run at 1.2 GHz.
-		 */
-		if (new_freq == FREQ_1P2_GHZ / 1000) {
-			regulator_set_voltage_tol(pu_reg,
-					PU_SOC_VOLTAGE_HIGH, 0);
-			regulator_set_voltage_tol(soc_reg,
-					PU_SOC_VOLTAGE_HIGH, 0);
-		}
 	}
 
 	/*
@@ -120,12 +122,15 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
 				 "failed to scale vddarm down: %d\n", ret);
 			ret = 0;
 		}
-
-		if (old_freq == FREQ_1P2_GHZ / 1000) {
-			regulator_set_voltage_tol(pu_reg,
-					PU_SOC_VOLTAGE_NORMAL, 0);
-			regulator_set_voltage_tol(soc_reg,
-					PU_SOC_VOLTAGE_NORMAL, 0);
+		ret = regulator_set_voltage_tol(soc_reg, imx6_soc_volt[index], 0);
+		if (ret) {
+			dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret);
+			ret = 0;
+		}
+		ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
+		if (ret) {
+			dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret);
+			ret = 0;
 		}
 	}
 
@@ -153,6 +158,9 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev)
 	struct dev_pm_opp *opp;
 	unsigned long min_volt, max_volt;
 	int num, ret;
+	const struct property *prop;
+	const __be32 *val;
+	u32 nr, i, j;
 
 	cpu_dev = get_cpu_device(0);
 	if (!cpu_dev) {
@@ -201,10 +209,62 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev)
 		goto put_node;
 	}
 
+	/* Make imx6_soc_volt array's size same as arm opp number */
+	imx6_soc_volt = devm_kzalloc(cpu_dev, sizeof(*imx6_soc_volt) * num, GFP_KERNEL);
+	if (imx6_soc_volt == NULL) {
+		ret = -ENOMEM;
+		goto free_freq_table;
+	}
+
+	prop = of_find_property(np, "fsl,soc-operating-points", NULL);
+	if (!prop || !prop->value)
+		goto soc_opp_out;
+
+	/*
+	 * Each OPP is a set of tuples consisting of frequency and
+	 * voltage like <freq-kHz vol-uV>.
+	 */
+	nr = prop->length / sizeof(u32);
+	if (nr % 2 || (nr / 2) < num)
+		goto soc_opp_out;
+
+	for (j = 0; j < num; j++) {
+		val = prop->value;
+		for (i = 0; i < nr / 2; i++) {
+			unsigned long freq = be32_to_cpup(val++);
+			unsigned long volt = be32_to_cpup(val++);
+			if (freq_table[j].frequency == freq) {
+				imx6_soc_volt[soc_opp_count++] = volt;
+				break;
+			}
+		}
+	}
+
+soc_opp_out:
+	/* use fixed soc opp volt if no valid soc opp info found in dtb */
+	if (soc_opp_count != num) {
+		dev_warn(cpu_dev, "can NOT find valid fsl,soc-operating-points property in dtb, use default value!\n");
+		for (j = 0; j < num; j++)
+			imx6_soc_volt[j] = PU_SOC_VOLTAGE_NORMAL;
+		if (freq_table[num - 1].frequency * 1000 == FREQ_1P2_GHZ)
+			imx6_soc_volt[num - 1] = PU_SOC_VOLTAGE_HIGH;
+	}
+
 	if (of_property_read_u32(np, "clock-latency", &transition_latency))
 		transition_latency = CPUFREQ_ETERNAL;
 
 	/*
+	 * Calculate the ramp time for max voltage change in the
+	 * VDDSOC and VDDPU regulators.
+	 */
+	ret = regulator_set_voltage_time(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
+	if (ret > 0)
+		transition_latency += ret * 1000;
+	ret = regulator_set_voltage_time(pu_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
+	if (ret > 0)
+		transition_latency += ret * 1000;
+
+	/*
 	 * OPP is maintained in order of increasing frequency, and
 	 * freq_table initialised from OPP is therefore sorted in the
 	 * same order.
@@ -221,18 +281,6 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev)
 	if (ret > 0)
 		transition_latency += ret * 1000;
 
-	/* Count vddpu and vddsoc latency in for 1.2 GHz support */
-	if (freq_table[num].frequency == FREQ_1P2_GHZ / 1000) {
-		ret = regulator_set_voltage_time(pu_reg, PU_SOC_VOLTAGE_NORMAL,
-						 PU_SOC_VOLTAGE_HIGH);
-		if (ret > 0)
-			transition_latency += ret * 1000;
-		ret = regulator_set_voltage_time(soc_reg, PU_SOC_VOLTAGE_NORMAL,
-						 PU_SOC_VOLTAGE_HIGH);
-		if (ret > 0)
-			transition_latency += ret * 1000;
-	}
-
 	ret = cpufreq_register_driver(&imx6q_cpufreq_driver);
 	if (ret) {
 		dev_err(cpu_dev, "failed register driver: %d\n", ret);
-- 
1.7.9.5

Re: [PATCH V3 1/2] ARM: imx: add vddsoc/pu setpoint info into dts

[Anson.Huang]

Sent from Anson's iPhone

> 在 2013年12月18日，22:21，"Shawn Guo" <shawn.guo@linaro.org> 写道：
> 
>> On Wed, Dec 18, 2013 at 04:26:49PM -0500, Anson Huang wrote:
>> i.MX6Q needs to update vddarm, vddsoc/pu regulators when cpu freq
>> is changed, each setpoint has different voltage, so we need to
>> pass vddarm, vddsoc/pu's freq-voltage info from dts together.
>> 
>> Signed-off-by: Anson Huang <b20788@freescale.com>
>> ---
>> .../devicetree/bindings/cpufreq/cpufreq-imx6.txt   |   56 ++++++++++++++++++++
> 
> As I said in V2 review, the device tree binding doc change should be
> part of driver patch (patch #2 in this case) or a separate patch, but
> never be in the same patch as DTS change.

I missed that one, sorry for that, then I will send out a V4 patch set.
> 
> Shawn
> 
>> arch/arm/boot/dts/imx6q.dtsi                       |    7 +++
>> 2 files changed, 63 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..cf1c5f7
>> --- /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: vddarm input.
>> +  pu-supply: vddpu input.
>> +  soc-supply: vddsoc input.
>> +
>> +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>;
>> +    };
>> diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
>> index e7e8332..021e0cb 100644
>> --- a/arch/arm/boot/dts/imx6q.dtsi
>> +++ b/arch/arm/boot/dts/imx6q.dtsi
>> @@ -30,6 +30,13 @@
>>                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>;
>> -- 
>> 1.7.9.5
> 
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

RE: [PATCH V3 1/2] ARM: imx: add vddsoc/pu setpoint info into dts

[Anson.Huang]

Best Regards.
Anson huang 黄勇才
 
Freescale Semiconductor Shanghai
上海浦东新区亮景路192号A座2楼
201203
Tel:021-28937058


>-----Original Message-----
>From: Huang Yongcai-B20788
>Sent: Wednesday, December 18, 2013 8:01 PM
>To: Fabio Estevam
>Cc: Huang Yongcai-B20788; Shawn Guo; rjw@rjwysocki.net; Viresh Kumar;
>devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
>cpufreq@vger.kernel.org; linux-pm@vger.kernel.org
>Subject: Re: [PATCH V3 1/2] ARM: imx: add vddsoc/pu setpoint info into dts
>
>
>
>Sent from Anson's iPhone
>
>> 在 2013年12月18日，19:08，"Fabio Estevam" <festevam@gmail.com> 写道：
>>
>> Hi Anson,
>>
>>> On Wed, Dec 18, 2013 at 7:26 PM, Anson Huang <b20788@freescale.com> wrote:
>>>
>>> +  Documentation/devicetree/bindings/regulator/regulator.txt for details.
>>> +  arm-supply: vddarm input.
>>> +  pu-supply: vddpu input.
>>> +  soc-supply: vddsoc input.
>>
>> I found these messages confusing, as someone may think that you are
>> referring to the VDD_ARM_IN/VDD_ARM23_IN and VDD_SOC_IN, which are
>> really inputs.
>>
>> What about doing this instead?
>>
>> arm-supply: VDDARM LDO output
>> pu-supply:  VDDPU LDO output
>> soc-supply: VDDSOC LDO output
>
>I think they should know these regulators mean the arm, soc/pu's real working
>voltage, as you know, our i.MX6 also support LDO bypass mode, then these
>regulators can be VDDXXX_IN. that is why I use vddxxx input, not vddxxx LDO
>input.Thanks!

After re-consideration, I think below should be better:
arm-supply: regulator node supplying arm.
pu-supply: regulator node supplying pu.
soc-supply: regulator node supplying soc.

Anson 


>>
>> Regards,
>>
>> Fabio Estevam
>>
>>

Re: [PATCH V3 1/2] ARM: imx: add vddsoc/pu setpoint info into dts

[Fabio Estevam]

On Thu, Dec 19, 2013 at 12:13 AM, Anson.Huang@freescale.com
<Anson.Huang@freescale.com> wrote:
> After re-consideration, I think below should be better:
> arm-supply: regulator node supplying arm.
> pu-supply: regulator node supplying pu.
> soc-supply: regulator node supplying soc.

Yes, this looks better.

Regards,

Fabio Estevam

RE: [PATCH V3 2/2] cpufreq: imx6q: correct VDDSOC/PU voltage scaling when cpufreq is changed

[Anson.Huang]

Ping...

Best Regards.
Anson huang 黄勇才
 
Freescale Semiconductor Shanghai
上海浦东新区亮景路192号A座2楼
201203
Tel:021-28937058


>-----Original Message-----
>From: Shawn Guo [mailto:shawn.guo@linaro.org]
>Sent: Wednesday, December 18, 2013 10:26 PM
>To: Huang Yongcai-B20788
>Cc: rjw@rjwysocki.net; viresh.kumar@linaro.org; cpufreq@vger.kernel.org;
>linux-pm@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
>devicetree@vger.kernel.org
>Subject: Re: [PATCH V3 2/2] cpufreq: imx6q: correct VDDSOC/PU voltage scaling
>when cpufreq is changed
>
>On Wed, Dec 18, 2013 at 04:26:50PM -0500, Anson Huang wrote:
>> on i.MX6Q, cpu freq change need to follow below flows:
>>
>> 1. each setpoint has different VDDARM, VDDSOC/PU voltage, get the setpoint
>>    table from dts;
>> 2. when cpu freq is scaling up, need to increase VDDSOC/PU voltage before
>>    VDDARM, if VDDPU is off, no need to change it; 3. when cpu freq is
>> scaling down, need to decrease VDDARM voltage before
>>    VDDSOC/PU, if VDDPU is off, no need to change it;
>>
>> normally dts will pass vddsoc/pu freq/volt info to kernel, if not,
>> will use fixed value for vddsoc/pu voltage setting.
>>
>> Signed-off-by: Anson Huang <b20788@freescale.com>
>
>Acked-by: Shawn Guo <shawn.guo@linaro.org>