diff mbox

[v3,2/3] PM / OPP: Initialize OPP table from device tree

Message ID 1344577046-14847-3-git-send-email-shawn.guo@linaro.org (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Shawn Guo Aug. 10, 2012, 5:37 a.m. UTC
With a lot of devices booting from device tree nowadays, it requires
that OPP table can be initialized from device tree.  The patch adds
a helper function of_init_opp_table together with a binding doc for
that purpose.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
 Documentation/devicetree/bindings/power/opp.txt |   25 ++++++++++++
 drivers/base/power/opp.c                        |   47 +++++++++++++++++++++++
 include/linux/opp.h                             |    8 ++++
 3 files changed, 80 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/power/opp.txt

Comments

Rafael Wysocki Aug. 16, 2012, 9:05 p.m. UTC | #1
On Friday, August 10, 2012, Shawn Guo wrote:
> With a lot of devices booting from device tree nowadays, it requires
> that OPP table can be initialized from device tree.  The patch adds
> a helper function of_init_opp_table together with a binding doc for
> that purpose.
> 
> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

I need an ACK from whoever maintains the DT bindings for that.

Thanks,
Rafael


> ---
>  Documentation/devicetree/bindings/power/opp.txt |   25 ++++++++++++
>  drivers/base/power/opp.c                        |   47 +++++++++++++++++++++++
>  include/linux/opp.h                             |    8 ++++
>  3 files changed, 80 insertions(+), 0 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/power/opp.txt
> 
> diff --git a/Documentation/devicetree/bindings/power/opp.txt b/Documentation/devicetree/bindings/power/opp.txt
> new file mode 100644
> index 0000000..74499e5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/opp.txt
> @@ -0,0 +1,25 @@
> +* Generic OPP Interface
> +
> +SoCs have a standard set of tuples consisting of frequency and
> +voltage pairs that the device will support per voltage domain. These
> +are called Operating Performance Points or OPPs.
> +
> +Properties:
> +- operating-points: An array of 2-tuples items, and each item consists
> +  of frequency and voltage like <freq-kHz vol-uV>.
> +	freq: clock frequency in kHz
> +	vol: voltage in microvolt
> +
> +Examples:
> +
> +cpu@0 {
> +	compatible = "arm,cortex-a9";
> +	reg = <0>;
> +	next-level-cache = <&L2>;
> +	operating-points = <
> +		/* kHz    uV */
> +		792000  1100000
> +		396000  950000
> +		198000  850000
> +	>;
> +};
> diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
> index ac993ea..d946864 100644
> --- a/drivers/base/power/opp.c
> +++ b/drivers/base/power/opp.c
> @@ -22,6 +22,7 @@
>  #include <linux/rculist.h>
>  #include <linux/rcupdate.h>
>  #include <linux/opp.h>
> +#include <linux/of.h>
>  
>  /*
>   * Internal data structure organization with the OPP layer library is as
> @@ -674,3 +675,49 @@ struct srcu_notifier_head *opp_get_notifier(struct device *dev)
>  
>  	return &dev_opp->head;
>  }
> +
> +#ifdef CONFIG_OF
> +/**
> + * of_init_opp_table() - Initialize opp table from device tree
> + * @dev:	device pointer used to lookup device OPPs.
> + *
> + * Register the initial OPP table with the OPP library for given device.
> + */
> +int of_init_opp_table(struct device *dev)
> +{
> +	const struct property *prop;
> +	const __be32 *val;
> +	int nr;
> +
> +	prop = of_find_property(dev->of_node, "operating-points", NULL);
> +	if (!prop)
> +		return -ENODEV;
> +	if (!prop->value)
> +		return -ENODATA;
> +
> +	/*
> +	 * 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) {
> +		dev_err(dev, "%s: Invalid OPP list\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	val = prop->value;
> +	while (nr) {
> +		unsigned long freq = be32_to_cpup(val++) * 1000;
> +		unsigned long volt = be32_to_cpup(val++);
> +
> +		if (opp_add(dev, freq, volt)) {
> +			dev_warn(dev, "%s: Failed to add OPP %ld\n",
> +				 __func__, freq);
> +			continue;
> +		}
> +		nr -= 2;
> +	}
> +
> +	return 0;
> +}
> +#endif
> diff --git a/include/linux/opp.h b/include/linux/opp.h
> index 2a4e5fa..214e0eb 100644
> --- a/include/linux/opp.h
> +++ b/include/linux/opp.h
> @@ -48,6 +48,14 @@ int opp_disable(struct device *dev, unsigned long freq);
>  
>  struct srcu_notifier_head *opp_get_notifier(struct device *dev);
>  
> +#ifdef CONFIG_OF
> +int of_init_opp_table(struct device *dev);
> +#else
> +static inline int of_init_opp_table(struct device *dev)
> +{
> +	return -EINVAL;
> +}
> +#endif /* CONFIG_OF */
>  #else
>  static inline unsigned long opp_get_voltage(struct opp *opp)
>  {
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Shawn Guo Aug. 17, 2012, 12:52 a.m. UTC | #2
On Thu, Aug 16, 2012 at 11:05:54PM +0200, Rafael J. Wysocki wrote:
> On Friday, August 10, 2012, Shawn Guo wrote:
> > With a lot of devices booting from device tree nowadays, it requires
> > that OPP table can be initialized from device tree.  The patch adds
> > a helper function of_init_opp_table together with a binding doc for
> > that purpose.
> > 
> > Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> 
> I need an ACK from whoever maintains the DT bindings for that.
> 
Rob, please?
Rob Herring Aug. 17, 2012, 1:53 a.m. UTC | #3
On 08/16/2012 07:52 PM, Shawn Guo wrote:
> On Thu, Aug 16, 2012 at 11:05:54PM +0200, Rafael J. Wysocki wrote:
>> On Friday, August 10, 2012, Shawn Guo wrote:
>>> With a lot of devices booting from device tree nowadays, it requires
>>> that OPP table can be initialized from device tree.  The patch adds
>>> a helper function of_init_opp_table together with a binding doc for
>>> that purpose.
>>>
>>> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
>>
>> I need an ACK from whoever maintains the DT bindings for that.
>>
> Rob, please?

Acked-by: Rob Herring <rob.herring@calxeda.com>
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Rafael Wysocki Sept. 4, 2012, 11:27 p.m. UTC | #4
On Friday, August 17, 2012, Rob Herring wrote:
> On 08/16/2012 07:52 PM, Shawn Guo wrote:
> > On Thu, Aug 16, 2012 at 11:05:54PM +0200, Rafael J. Wysocki wrote:
> >> On Friday, August 10, 2012, Shawn Guo wrote:
> >>> With a lot of devices booting from device tree nowadays, it requires
> >>> that OPP table can be initialized from device tree.  The patch adds
> >>> a helper function of_init_opp_table together with a binding doc for
> >>> that purpose.
> >>>
> >>> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> >>
> >> I need an ACK from whoever maintains the DT bindings for that.
> >>
> > Rob, please?
> 
> Acked-by: Rob Herring <rob.herring@calxeda.com>

Applied to the linux-next branch of the linux-pm.git tree as v3.7 material.

Thanks,
Rafael

--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/power/opp.txt b/Documentation/devicetree/bindings/power/opp.txt
new file mode 100644
index 0000000..74499e5
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/opp.txt
@@ -0,0 +1,25 @@ 
+* Generic OPP Interface
+
+SoCs have a standard set of tuples consisting of frequency and
+voltage pairs that the device will support per voltage domain. These
+are called Operating Performance Points or OPPs.
+
+Properties:
+- operating-points: An array of 2-tuples items, and each item consists
+  of frequency and voltage like <freq-kHz vol-uV>.
+	freq: clock frequency in kHz
+	vol: voltage in microvolt
+
+Examples:
+
+cpu@0 {
+	compatible = "arm,cortex-a9";
+	reg = <0>;
+	next-level-cache = <&L2>;
+	operating-points = <
+		/* kHz    uV */
+		792000  1100000
+		396000  950000
+		198000  850000
+	>;
+};
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index ac993ea..d946864 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -22,6 +22,7 @@ 
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 #include <linux/opp.h>
+#include <linux/of.h>
 
 /*
  * Internal data structure organization with the OPP layer library is as
@@ -674,3 +675,49 @@  struct srcu_notifier_head *opp_get_notifier(struct device *dev)
 
 	return &dev_opp->head;
 }
+
+#ifdef CONFIG_OF
+/**
+ * of_init_opp_table() - Initialize opp table from device tree
+ * @dev:	device pointer used to lookup device OPPs.
+ *
+ * Register the initial OPP table with the OPP library for given device.
+ */
+int of_init_opp_table(struct device *dev)
+{
+	const struct property *prop;
+	const __be32 *val;
+	int nr;
+
+	prop = of_find_property(dev->of_node, "operating-points", NULL);
+	if (!prop)
+		return -ENODEV;
+	if (!prop->value)
+		return -ENODATA;
+
+	/*
+	 * 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) {
+		dev_err(dev, "%s: Invalid OPP list\n", __func__);
+		return -EINVAL;
+	}
+
+	val = prop->value;
+	while (nr) {
+		unsigned long freq = be32_to_cpup(val++) * 1000;
+		unsigned long volt = be32_to_cpup(val++);
+
+		if (opp_add(dev, freq, volt)) {
+			dev_warn(dev, "%s: Failed to add OPP %ld\n",
+				 __func__, freq);
+			continue;
+		}
+		nr -= 2;
+	}
+
+	return 0;
+}
+#endif
diff --git a/include/linux/opp.h b/include/linux/opp.h
index 2a4e5fa..214e0eb 100644
--- a/include/linux/opp.h
+++ b/include/linux/opp.h
@@ -48,6 +48,14 @@  int opp_disable(struct device *dev, unsigned long freq);
 
 struct srcu_notifier_head *opp_get_notifier(struct device *dev);
 
+#ifdef CONFIG_OF
+int of_init_opp_table(struct device *dev);
+#else
+static inline int of_init_opp_table(struct device *dev)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_OF */
 #else
 static inline unsigned long opp_get_voltage(struct opp *opp)
 {