[PATCH V3 0/2] PM / OPP: Parse opp-supported-hw/opp-<prop>-<name> bindings

[PATCH V3 0/2] PM / OPP: Parse opp-supported-hw/opp-<prop>-<name> bindings

[Viresh Kumar]

Hi Rafael,

These patches parse the newly added opp-supported-hw/opp-<prop>-<name>
bindings.

Rebased over: Latest pm/linux-next
Tested-on: Exynos 5250, dual core A15.

V2->V3:
- Stephen had an interesting point to make for V2, as the patches
  created the dev_opp first and then updated it within the OPP-list
  lock. But a simultaneous reader of the dev_opp list need a rcu way of
  handling this.
- The big difference, why its not a problem here, is that the platform
  needs to call this routine before the OPPs are parsed from DT and the
  opp-list will be empty. And so no-readers.
- It wasn't guaranteed earlier, but now we have installed few WARN_ON()
  to make sure about that there are no OPPs while these routines are
  called.
- It should be pretty safe to get these merged now.
- Lee's work depends on this to be merged,
  http://marc.info/?l=linux-kernel&m=144958553611215&w=2

V1->V2:
- Fixed locking
- NUL terminate strings instead of sprintf
- Remove NULL checkers for the routines
- constify 'versions'
- s/EINVAL/EBUSY
- updated comments over routines
- Use of_property_read_u32_index() instead of allocating arrays
- remove dev_opp for failures

Viresh Kumar (2):
  PM / OPP: Parse 'opp-supported-hw' binding
  PM / OPP: Parse 'opp-<prop>-<name>' bindings

 drivers/base/power/opp/core.c | 313 ++++++++++++++++++++++++++++++++++++++++--
 drivers/base/power/opp/opp.h  |   7 +
 include/linux/pm_opp.h        |  22 +++
 3 files changed, 327 insertions(+), 15 deletions(-)

-- 
2.6.2.198.g614a2ac

[PATCH V3 0/2] PM / OPP: Parse opp-supported-hw/opp-<prop>-<name> bindings

[Viresh Kumar]

Hi Rafael,

These patches parse the newly added opp-supported-hw/opp-<prop>-<name>
bindings.

Rebased over: Latest pm/linux-next
Tested-on: Exynos 5250, dual core A15.

V2->V3:
- Stephen had an interesting point to make for V2, as the patches
  created the dev_opp first and then updated it within the OPP-list
  lock. But a simultaneous reader of the dev_opp list need a rcu way of
  handling this.
- The big difference, why its not a problem here, is that the platform
  needs to call this routine before the OPPs are parsed from DT and the
  opp-list will be empty. And so no-readers.
- It wasn't guaranteed earlier, but now we have installed few WARN_ON()
  to make sure about that there are no OPPs while these routines are
  called.
- It should be pretty safe to get these merged now.
- Lee's work depends on this to be merged,
  http://marc.info/?l=linux-kernel&m=144958553611215&w=2

V1->V2:
- Fixed locking
- NUL terminate strings instead of sprintf
- Remove NULL checkers for the routines
- constify 'versions'
- s/EINVAL/EBUSY
- updated comments over routines
- Use of_property_read_u32_index() instead of allocating arrays
- remove dev_opp for failures

Viresh Kumar (2):
  PM / OPP: Parse 'opp-supported-hw' binding
  PM / OPP: Parse 'opp-<prop>-<name>' bindings

 drivers/base/power/opp/core.c | 313 ++++++++++++++++++++++++++++++++++++++++--
 drivers/base/power/opp/opp.h  |   7 +
 include/linux/pm_opp.h        |  22 +++
 3 files changed, 327 insertions(+), 15 deletions(-)

-- 
2.6.2.198.g614a2ac

[PATCH V3 1/2] PM / OPP: Parse 'opp-supported-hw' binding

[Viresh Kumar]

OPP bindings allow a platform to enable OPPs based on the version of the
hardware they are used for.

Add support to the OPP-core to parse these bindings, by introducing
dev_pm_opp_{set|put}_supported_hw() APIs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp/core.c | 148 ++++++++++++++++++++++++++++++++++++++++++
 drivers/base/power/opp/opp.h  |   5 ++
 include/linux/pm_opp.h        |  13 ++++
 3 files changed, 166 insertions(+)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 6aa172be6e8e..55cf1a99b532 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -559,6 +559,9 @@ static void _remove_device_opp(struct device_opp *dev_opp)
 	if (!list_empty(&dev_opp->opp_list))
 		return;
 
+	if (dev_opp->supported_hw)
+		return;
+
 	list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
 				    node);
 
@@ -834,6 +837,145 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
 }
 
 /**
+ * dev_pm_opp_set_supported_hw() - Set supported platforms
+ * @dev: Device for which supported-hw has to be set.
+ * @versions: Array of hierarchy of versions to match.
+ * @count: Number of elements in the array.
+ *
+ * This is required only for the V2 bindings, and it enables a platform to
+ * specify the hierarchy of versions it supports. OPP layer will then enable
+ * OPPs, which are available for those versions, based on its 'opp-supported-hw'
+ * property.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
+				unsigned int count)
+{
+	struct device_opp *dev_opp;
+	int ret = 0;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	dev_opp = _add_device_opp(dev);
+	if (!dev_opp) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	/* Do we already have a version hierarchy associated with dev_opp? */
+	if (dev_opp->supported_hw) {
+		dev_err(dev, "%s: Already have supported hardware list\n",
+			__func__);
+		ret = -EBUSY;
+		goto err;
+	}
+
+	dev_opp->supported_hw = kmemdup(versions, count * sizeof(*versions),
+					GFP_KERNEL);
+	if (!dev_opp->supported_hw) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	dev_opp->supported_hw_count = count;
+	mutex_unlock(&dev_opp_list_lock);
+	return 0;
+
+err:
+	_remove_device_opp(dev_opp);
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw);
+
+/**
+ * dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw
+ * @dev: Device for which supported-hw has to be set.
+ *
+ * This is required only for the V2 bindings, and is called for a matching
+ * dev_pm_opp_set_supported_hw(). Until this is called, the device_opp structure
+ * will not be freed.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+void dev_pm_opp_put_supported_hw(struct device *dev)
+{
+	struct device_opp *dev_opp;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	/* Check for existing list for 'dev' first */
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp)) {
+		dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	if (!dev_opp->supported_hw) {
+		dev_err(dev, "%s: Doesn't have supported hardware list\n",
+			__func__);
+		goto unlock;
+	}
+
+	kfree(dev_opp->supported_hw);
+	dev_opp->supported_hw = NULL;
+	dev_opp->supported_hw_count = 0;
+
+	/* Try freeing device_opp if this was the last blocking resource */
+	_remove_device_opp(dev_opp);
+
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
+
+static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp,
+			      struct device_node *np)
+{
+	unsigned int count = dev_opp->supported_hw_count;
+	u32 version;
+	int ret;
+
+	if (!dev_opp->supported_hw)
+		return true;
+
+	while (count--) {
+		ret = of_property_read_u32_index(np, "opp-supported-hw", count,
+						 &version);
+		if (ret) {
+			dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
+				 __func__, count, ret);
+			return false;
+		}
+
+		/* Both of these are bitwise masks of the versions */
+		if (!(version & dev_opp->supported_hw[count]))
+			return false;
+	}
+
+	return true;
+}
+
+/**
  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
  * @dev:	device for which we do this operation
  * @np:		device node
@@ -879,6 +1021,12 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 		goto free_opp;
 	}
 
+	/* Check if the OPP supports hardware's hierarchy of versions or not */
+	if (!_opp_is_supported(dev, dev_opp, np)) {
+		dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
+		goto free_opp;
+	}
+
 	/*
 	 * Rate is defined as an unsigned long in clk API, and so casting
 	 * explicitly to its type. Must be fixed once rate is 64 bit
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
index b8880c7f8be1..70f4564a6ab9 100644
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -129,6 +129,8 @@ struct device_list_opp {
  * @clock_latency_ns_max: Max clock latency in nanoseconds.
  * @shared_opp: OPP is shared between multiple devices.
  * @suspend_opp: Pointer to OPP to be used during device suspend.
+ * @supported_hw: Array of version number to support.
+ * @supported_hw_count: Number of elements in supported_hw array.
  * @dentry:	debugfs dentry pointer of the real device directory (not links).
  * @dentry_name: Name of the real dentry.
  *
@@ -153,6 +155,9 @@ struct device_opp {
 	bool shared_opp;
 	struct dev_pm_opp *suspend_opp;
 
+	unsigned int *supported_hw;
+	unsigned int supported_hw_count;
+
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *dentry;
 	char dentry_name[NAME_MAX];
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 9a2e50337af9..3a85110242f0 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -55,6 +55,9 @@ int dev_pm_opp_enable(struct device *dev, unsigned long freq);
 int dev_pm_opp_disable(struct device *dev, unsigned long freq);
 
 struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev);
+int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
+				unsigned int count);
+void dev_pm_opp_put_supported_hw(struct device *dev);
 #else
 static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
 {
@@ -129,6 +132,16 @@ static inline struct srcu_notifier_head *dev_pm_opp_get_notifier(
 {
 	return ERR_PTR(-EINVAL);
 }
+
+static inline int dev_pm_opp_set_supported_hw(struct device *dev,
+					      const u32 *versions,
+					      unsigned int count)
+{
+	return -EINVAL;
+}
+
+static inline void dev_pm_opp_put_supported_hw(struct device *dev) {}
+
 #endif		/* CONFIG_PM_OPP */
 
 #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
-- 
2.6.2.198.g614a2ac

[PATCH V3 1/2] PM / OPP: Parse 'opp-supported-hw' binding

[Viresh Kumar]

OPP bindings allow a platform to enable OPPs based on the version of the
hardware they are used for.

Add support to the OPP-core to parse these bindings, by introducing
dev_pm_opp_{set|put}_supported_hw() APIs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp/core.c | 148 ++++++++++++++++++++++++++++++++++++++++++
 drivers/base/power/opp/opp.h  |   5 ++
 include/linux/pm_opp.h        |  13 ++++
 3 files changed, 166 insertions(+)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 6aa172be6e8e..55cf1a99b532 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -559,6 +559,9 @@ static void _remove_device_opp(struct device_opp *dev_opp)
 	if (!list_empty(&dev_opp->opp_list))
 		return;
 
+	if (dev_opp->supported_hw)
+		return;
+
 	list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
 				    node);
 
@@ -834,6 +837,145 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
 }
 
 /**
+ * dev_pm_opp_set_supported_hw() - Set supported platforms
+ * @dev: Device for which supported-hw has to be set.
+ * @versions: Array of hierarchy of versions to match.
+ * @count: Number of elements in the array.
+ *
+ * This is required only for the V2 bindings, and it enables a platform to
+ * specify the hierarchy of versions it supports. OPP layer will then enable
+ * OPPs, which are available for those versions, based on its 'opp-supported-hw'
+ * property.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
+				unsigned int count)
+{
+	struct device_opp *dev_opp;
+	int ret = 0;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	dev_opp = _add_device_opp(dev);
+	if (!dev_opp) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	/* Do we already have a version hierarchy associated with dev_opp? */
+	if (dev_opp->supported_hw) {
+		dev_err(dev, "%s: Already have supported hardware list\n",
+			__func__);
+		ret = -EBUSY;
+		goto err;
+	}
+
+	dev_opp->supported_hw = kmemdup(versions, count * sizeof(*versions),
+					GFP_KERNEL);
+	if (!dev_opp->supported_hw) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	dev_opp->supported_hw_count = count;
+	mutex_unlock(&dev_opp_list_lock);
+	return 0;
+
+err:
+	_remove_device_opp(dev_opp);
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw);
+
+/**
+ * dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw
+ * @dev: Device for which supported-hw has to be set.
+ *
+ * This is required only for the V2 bindings, and is called for a matching
+ * dev_pm_opp_set_supported_hw(). Until this is called, the device_opp structure
+ * will not be freed.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+void dev_pm_opp_put_supported_hw(struct device *dev)
+{
+	struct device_opp *dev_opp;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	/* Check for existing list for 'dev' first */
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp)) {
+		dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	if (!dev_opp->supported_hw) {
+		dev_err(dev, "%s: Doesn't have supported hardware list\n",
+			__func__);
+		goto unlock;
+	}
+
+	kfree(dev_opp->supported_hw);
+	dev_opp->supported_hw = NULL;
+	dev_opp->supported_hw_count = 0;
+
+	/* Try freeing device_opp if this was the last blocking resource */
+	_remove_device_opp(dev_opp);
+
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
+
+static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp,
+			      struct device_node *np)
+{
+	unsigned int count = dev_opp->supported_hw_count;
+	u32 version;
+	int ret;
+
+	if (!dev_opp->supported_hw)
+		return true;
+
+	while (count--) {
+		ret = of_property_read_u32_index(np, "opp-supported-hw", count,
+						 &version);
+		if (ret) {
+			dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
+				 __func__, count, ret);
+			return false;
+		}
+
+		/* Both of these are bitwise masks of the versions */
+		if (!(version & dev_opp->supported_hw[count]))
+			return false;
+	}
+
+	return true;
+}
+
+/**
  * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
  * @dev:	device for which we do this operation
  * @np:		device node
@@ -879,6 +1021,12 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 		goto free_opp;
 	}
 
+	/* Check if the OPP supports hardware's hierarchy of versions or not */
+	if (!_opp_is_supported(dev, dev_opp, np)) {
+		dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
+		goto free_opp;
+	}
+
 	/*
 	 * Rate is defined as an unsigned long in clk API, and so casting
 	 * explicitly to its type. Must be fixed once rate is 64 bit
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
index b8880c7f8be1..70f4564a6ab9 100644
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -129,6 +129,8 @@ struct device_list_opp {
  * @clock_latency_ns_max: Max clock latency in nanoseconds.
  * @shared_opp: OPP is shared between multiple devices.
  * @suspend_opp: Pointer to OPP to be used during device suspend.
+ * @supported_hw: Array of version number to support.
+ * @supported_hw_count: Number of elements in supported_hw array.
  * @dentry:	debugfs dentry pointer of the real device directory (not links).
  * @dentry_name: Name of the real dentry.
  *
@@ -153,6 +155,9 @@ struct device_opp {
 	bool shared_opp;
 	struct dev_pm_opp *suspend_opp;
 
+	unsigned int *supported_hw;
+	unsigned int supported_hw_count;
+
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *dentry;
 	char dentry_name[NAME_MAX];
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 9a2e50337af9..3a85110242f0 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -55,6 +55,9 @@ int dev_pm_opp_enable(struct device *dev, unsigned long freq);
 int dev_pm_opp_disable(struct device *dev, unsigned long freq);
 
 struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev);
+int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
+				unsigned int count);
+void dev_pm_opp_put_supported_hw(struct device *dev);
 #else
 static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
 {
@@ -129,6 +132,16 @@ static inline struct srcu_notifier_head *dev_pm_opp_get_notifier(
 {
 	return ERR_PTR(-EINVAL);
 }
+
+static inline int dev_pm_opp_set_supported_hw(struct device *dev,
+					      const u32 *versions,
+					      unsigned int count)
+{
+	return -EINVAL;
+}
+
+static inline void dev_pm_opp_put_supported_hw(struct device *dev) {}
+
 #endif		/* CONFIG_PM_OPP */
 
 #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
-- 
2.6.2.198.g614a2ac

Re: [PATCH V3 1/2] PM / OPP: Parse 'opp-supported-hw' binding

[Lee Jones]

On 9 December 2015 at 02:31, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> OPP bindings allow a platform to enable OPPs based on the version of the
> hardware they are used for.
>
> Add support to the OPP-core to parse these bindings, by introducing
> dev_pm_opp_{set|put}_supported_hw() APIs.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
>  drivers/base/power/opp/core.c | 148 ++++++++++++++++++++++++++++++++++++++++++
>  drivers/base/power/opp/opp.h  |   5 ++
>  include/linux/pm_opp.h        |  13 ++++
>  3 files changed, 166 insertions(+)

Tested-by: Lee Jones <lee.jones@linaro.org>

> diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
> index 6aa172be6e8e..55cf1a99b532 100644
> --- a/drivers/base/power/opp/core.c
> +++ b/drivers/base/power/opp/core.c
> @@ -559,6 +559,9 @@ static void _remove_device_opp(struct device_opp *dev_opp)
>         if (!list_empty(&dev_opp->opp_list))
>                 return;
>
> +       if (dev_opp->supported_hw)
> +               return;
> +
>         list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
>                                     node);
>
> @@ -834,6 +837,145 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
>  }
>
>  /**
> + * dev_pm_opp_set_supported_hw() - Set supported platforms
> + * @dev: Device for which supported-hw has to be set.
> + * @versions: Array of hierarchy of versions to match.
> + * @count: Number of elements in the array.
> + *
> + * This is required only for the V2 bindings, and it enables a platform to
> + * specify the hierarchy of versions it supports. OPP layer will then enable
> + * OPPs, which are available for those versions, based on its 'opp-supported-hw'
> + * property.
> + *
> + * Locking: The internal device_opp and opp structures are RCU protected.
> + * Hence this function internally uses RCU updater strategy with mutex locks
> + * to keep the integrity of the internal data structures. Callers should ensure
> + * that this function is *NOT* called under RCU protection or in contexts where
> + * mutex cannot be locked.
> + */
> +int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
> +                               unsigned int count)
> +{
> +       struct device_opp *dev_opp;
> +       int ret = 0;
> +
> +       /* Hold our list modification lock here */
> +       mutex_lock(&dev_opp_list_lock);
> +
> +       dev_opp = _add_device_opp(dev);
> +       if (!dev_opp) {
> +               ret = -ENOMEM;
> +               goto unlock;
> +       }
> +
> +       /* Make sure there are no concurrent readers while updating dev_opp */
> +       WARN_ON(!list_empty(&dev_opp->opp_list));
> +
> +       /* Do we already have a version hierarchy associated with dev_opp? */
> +       if (dev_opp->supported_hw) {
> +               dev_err(dev, "%s: Already have supported hardware list\n",
> +                       __func__);
> +               ret = -EBUSY;
> +               goto err;
> +       }
> +
> +       dev_opp->supported_hw = kmemdup(versions, count * sizeof(*versions),
> +                                       GFP_KERNEL);
> +       if (!dev_opp->supported_hw) {
> +               ret = -ENOMEM;
> +               goto err;
> +       }
> +
> +       dev_opp->supported_hw_count = count;
> +       mutex_unlock(&dev_opp_list_lock);
> +       return 0;
> +
> +err:
> +       _remove_device_opp(dev_opp);
> +unlock:
> +       mutex_unlock(&dev_opp_list_lock);
> +
> +       return ret;
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_opp_set_supported_hw);
> +
> +/**
> + * dev_pm_opp_put_supported_hw() - Releases resources blocked for supported hw
> + * @dev: Device for which supported-hw has to be set.
> + *
> + * This is required only for the V2 bindings, and is called for a matching
> + * dev_pm_opp_set_supported_hw(). Until this is called, the device_opp structure
> + * will not be freed.
> + *
> + * Locking: The internal device_opp and opp structures are RCU protected.
> + * Hence this function internally uses RCU updater strategy with mutex locks
> + * to keep the integrity of the internal data structures. Callers should ensure
> + * that this function is *NOT* called under RCU protection or in contexts where
> + * mutex cannot be locked.
> + */
> +void dev_pm_opp_put_supported_hw(struct device *dev)
> +{
> +       struct device_opp *dev_opp;
> +
> +       /* Hold our list modification lock here */
> +       mutex_lock(&dev_opp_list_lock);
> +
> +       /* Check for existing list for 'dev' first */
> +       dev_opp = _find_device_opp(dev);
> +       if (IS_ERR(dev_opp)) {
> +               dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));
> +               goto unlock;
> +       }
> +
> +       /* Make sure there are no concurrent readers while updating dev_opp */
> +       WARN_ON(!list_empty(&dev_opp->opp_list));
> +
> +       if (!dev_opp->supported_hw) {
> +               dev_err(dev, "%s: Doesn't have supported hardware list\n",
> +                       __func__);
> +               goto unlock;
> +       }
> +
> +       kfree(dev_opp->supported_hw);
> +       dev_opp->supported_hw = NULL;
> +       dev_opp->supported_hw_count = 0;
> +
> +       /* Try freeing device_opp if this was the last blocking resource */
> +       _remove_device_opp(dev_opp);
> +
> +unlock:
> +       mutex_unlock(&dev_opp_list_lock);
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
> +
> +static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp,
> +                             struct device_node *np)
> +{
> +       unsigned int count = dev_opp->supported_hw_count;
> +       u32 version;
> +       int ret;
> +
> +       if (!dev_opp->supported_hw)
> +               return true;
> +
> +       while (count--) {
> +               ret = of_property_read_u32_index(np, "opp-supported-hw", count,
> +                                                &version);
> +               if (ret) {
> +                       dev_warn(dev, "%s: failed to read opp-supported-hw property at index %d: %d\n",
> +                                __func__, count, ret);
> +                       return false;
> +               }
> +
> +               /* Both of these are bitwise masks of the versions */
> +               if (!(version & dev_opp->supported_hw[count]))
> +                       return false;
> +       }
> +
> +       return true;
> +}
> +
> +/**
>   * _opp_add_static_v2() - Allocate static OPPs (As per 'v2' DT bindings)
>   * @dev:       device for which we do this operation
>   * @np:                device node
> @@ -879,6 +1021,12 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
>                 goto free_opp;
>         }
>
> +       /* Check if the OPP supports hardware's hierarchy of versions or not */
> +       if (!_opp_is_supported(dev, dev_opp, np)) {
> +               dev_dbg(dev, "OPP not supported by hardware: %llu\n", rate);
> +               goto free_opp;
> +       }
> +
>         /*
>          * Rate is defined as an unsigned long in clk API, and so casting
>          * explicitly to its type. Must be fixed once rate is 64 bit
> diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
> index b8880c7f8be1..70f4564a6ab9 100644
> --- a/drivers/base/power/opp/opp.h
> +++ b/drivers/base/power/opp/opp.h
> @@ -129,6 +129,8 @@ struct device_list_opp {
>   * @clock_latency_ns_max: Max clock latency in nanoseconds.
>   * @shared_opp: OPP is shared between multiple devices.
>   * @suspend_opp: Pointer to OPP to be used during device suspend.
> + * @supported_hw: Array of version number to support.
> + * @supported_hw_count: Number of elements in supported_hw array.
>   * @dentry:    debugfs dentry pointer of the real device directory (not links).
>   * @dentry_name: Name of the real dentry.
>   *
> @@ -153,6 +155,9 @@ struct device_opp {
>         bool shared_opp;
>         struct dev_pm_opp *suspend_opp;
>
> +       unsigned int *supported_hw;
> +       unsigned int supported_hw_count;
> +
>  #ifdef CONFIG_DEBUG_FS
>         struct dentry *dentry;
>         char dentry_name[NAME_MAX];
> diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
> index 9a2e50337af9..3a85110242f0 100644
> --- a/include/linux/pm_opp.h
> +++ b/include/linux/pm_opp.h
> @@ -55,6 +55,9 @@ int dev_pm_opp_enable(struct device *dev, unsigned long freq);
>  int dev_pm_opp_disable(struct device *dev, unsigned long freq);
>
>  struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev);
> +int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
> +                               unsigned int count);
> +void dev_pm_opp_put_supported_hw(struct device *dev);
>  #else
>  static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
>  {
> @@ -129,6 +132,16 @@ static inline struct srcu_notifier_head *dev_pm_opp_get_notifier(
>  {
>         return ERR_PTR(-EINVAL);
>  }
> +
> +static inline int dev_pm_opp_set_supported_hw(struct device *dev,
> +                                             const u32 *versions,
> +                                             unsigned int count)
> +{
> +       return -EINVAL;
> +}
> +
> +static inline void dev_pm_opp_put_supported_hw(struct device *dev) {}
> +
>  #endif         /* CONFIG_PM_OPP */
>
>  #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
> --
> 2.6.2.198.g614a2ac
>
> _______________________________________________
> linaro-kernel mailing list
> linaro-kernel@lists.linaro.org
> https://lists.linaro.org/mailman/listinfo/linaro-kernel



-- 
Lee Jones
Linaro ST Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

[PATCH V3 2/2] PM / OPP: Parse 'opp-<prop>-<name>' bindings

[Viresh Kumar]

OPP bindings (for few properties) allow a platform to choose a
value/range among a set of available options. The options are present as
opp-<prop>-<name>, where the platform needs to supply the <name> string.

The OPP properties which allow such an option are: opp-microvolt and
opp-microamp.

Add support to the OPP-core to parse these bindings, by introducing
dev_pm_opp_{set|put}_prop_name() APIs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp/core.c | 165 ++++++++++++++++++++++++++++++++++++++----
 drivers/base/power/opp/opp.h  |   2 +
 include/linux/pm_opp.h        |   9 +++
 3 files changed, 161 insertions(+), 15 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 55cf1a99b532..5c01fec1ed14 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -562,6 +562,9 @@ static void _remove_device_opp(struct device_opp *dev_opp)
 	if (dev_opp->supported_hw)
 		return;
 
+	if (dev_opp->prop_name)
+		return;
+
 	list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
 				    node);
 
@@ -794,35 +797,48 @@ static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
 }
 
 /* TODO: Support multiple regulators */
-static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
+static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
+			      struct device_opp *dev_opp)
 {
 	u32 microvolt[3] = {0};
 	u32 val;
 	int count, ret;
+	struct property *prop = NULL;
+	char name[NAME_MAX];
+
+	/* Search for "opp-microvolt-<name>" */
+	if (dev_opp->prop_name) {
+		sprintf(name, "opp-microvolt-%s", dev_opp->prop_name);
+		prop = of_find_property(opp->np, name, NULL);
+	}
+
+	if (!prop) {
+		/* Search for "opp-microvolt" */
+		name[13] = '\0';
+		prop = of_find_property(opp->np, name, NULL);
 
-	/* Missing property isn't a problem, but an invalid entry is */
-	if (!of_find_property(opp->np, "opp-microvolt", NULL))
-		return 0;
+		/* Missing property isn't a problem, but an invalid entry is */
+		if (!prop)
+			return 0;
+	}
 
-	count = of_property_count_u32_elems(opp->np, "opp-microvolt");
+	count = of_property_count_u32_elems(opp->np, name);
 	if (count < 0) {
-		dev_err(dev, "%s: Invalid opp-microvolt property (%d)\n",
-			__func__, count);
+		dev_err(dev, "%s: Invalid %s property (%d)\n",
+			__func__, name, count);
 		return count;
 	}
 
 	/* There can be one or three elements here */
 	if (count != 1 && count != 3) {
-		dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n",
-			__func__, count);
+		dev_err(dev, "%s: Invalid number of elements in %s property (%d)\n",
+			__func__, name, count);
 		return -EINVAL;
 	}
 
-	ret = of_property_read_u32_array(opp->np, "opp-microvolt", microvolt,
-					 count);
+	ret = of_property_read_u32_array(opp->np, name, microvolt, count);
 	if (ret) {
-		dev_err(dev, "%s: error parsing opp-microvolt: %d\n", __func__,
-			ret);
+		dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
 		return -EINVAL;
 	}
 
@@ -830,7 +846,20 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
 	opp->u_volt_min = microvolt[1];
 	opp->u_volt_max = microvolt[2];
 
-	if (!of_property_read_u32(opp->np, "opp-microamp", &val))
+	/* Search for "opp-microamp-<name>" */
+	prop = NULL;
+	if (dev_opp->prop_name) {
+		sprintf(name, "opp-microamp-%s", dev_opp->prop_name);
+		prop = of_find_property(opp->np, name, NULL);
+	}
+
+	if (!prop) {
+		/* Search for "opp-microamp" */
+		name[12] = '\0';
+		prop = of_find_property(opp->np, name, NULL);
+	}
+
+	if (prop && !of_property_read_u32(opp->np, name, &val))
 		opp->u_amp = val;
 
 	return 0;
@@ -948,6 +977,112 @@ void dev_pm_opp_put_supported_hw(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
 
+/**
+ * dev_pm_opp_set_prop_name() - Set prop-extn name
+ * @dev: Device for which the regulator has to be set.
+ * @name: name to postfix to properties.
+ *
+ * This is required only for the V2 bindings, and it enables a platform to
+ * specify the extn to be used for certain property names. The properties to
+ * which the extension will apply are opp-microvolt and opp-microamp. OPP core
+ * should postfix the property name with -<name> while looking for them.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
+{
+	struct device_opp *dev_opp;
+	int ret = 0;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	dev_opp = _add_device_opp(dev);
+	if (!dev_opp) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	/* Do we already have a prop-name associated with dev_opp? */
+	if (dev_opp->prop_name) {
+		dev_err(dev, "%s: Already have prop-name %s\n", __func__,
+			dev_opp->prop_name);
+		ret = -EBUSY;
+		goto err;
+	}
+
+	dev_opp->prop_name = kstrdup(name, GFP_KERNEL);
+	if (!dev_opp->prop_name) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mutex_unlock(&dev_opp_list_lock);
+	return 0;
+
+err:
+	_remove_device_opp(dev_opp);
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);
+
+/**
+ * dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name
+ * @dev: Device for which the regulator has to be set.
+ *
+ * This is required only for the V2 bindings, and is called for a matching
+ * dev_pm_opp_set_prop_name(). Until this is called, the device_opp structure
+ * will not be freed.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+void dev_pm_opp_put_prop_name(struct device *dev)
+{
+	struct device_opp *dev_opp;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	/* Check for existing list for 'dev' first */
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp)) {
+		dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	if (!dev_opp->prop_name) {
+		dev_err(dev, "%s: Doesn't have a prop-name\n", __func__);
+		goto unlock;
+	}
+
+	kfree(dev_opp->prop_name);
+	dev_opp->prop_name = NULL;
+
+	/* Try freeing device_opp if this was the last blocking resource */
+	_remove_device_opp(dev_opp);
+
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
+
 static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp,
 			      struct device_node *np)
 {
@@ -1042,7 +1177,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 	if (!of_property_read_u32(np, "clock-latency-ns", &val))
 		new_opp->clock_latency_ns = val;
 
-	ret = opp_parse_supplies(new_opp, dev);
+	ret = opp_parse_supplies(new_opp, dev, dev_opp);
 	if (ret)
 		goto free_opp;
 
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
index 70f4564a6ab9..690638ef36ee 100644
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -131,6 +131,7 @@ struct device_list_opp {
  * @suspend_opp: Pointer to OPP to be used during device suspend.
  * @supported_hw: Array of version number to support.
  * @supported_hw_count: Number of elements in supported_hw array.
+ * @prop_name: A name to postfix to many DT properties, while parsing them.
  * @dentry:	debugfs dentry pointer of the real device directory (not links).
  * @dentry_name: Name of the real dentry.
  *
@@ -157,6 +158,7 @@ struct device_opp {
 
 	unsigned int *supported_hw;
 	unsigned int supported_hw_count;
+	const char *prop_name;
 
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *dentry;
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 3a85110242f0..95403d2ccaf5 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -58,6 +58,8 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev);
 int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
 				unsigned int count);
 void dev_pm_opp_put_supported_hw(struct device *dev);
+int dev_pm_opp_set_prop_name(struct device *dev, const char *name);
+void dev_pm_opp_put_prop_name(struct device *dev);
 #else
 static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
 {
@@ -142,6 +144,13 @@ static inline int dev_pm_opp_set_supported_hw(struct device *dev,
 
 static inline void dev_pm_opp_put_supported_hw(struct device *dev) {}
 
+static inline int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
+{
+	return -EINVAL;
+}
+
+static inline void dev_pm_opp_put_prop_name(struct device *dev) {}
+
 #endif		/* CONFIG_PM_OPP */
 
 #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
-- 
2.6.2.198.g614a2ac

[PATCH V3 2/2] PM / OPP: Parse 'opp-<prop>-<name>' bindings

[Viresh Kumar]

OPP bindings (for few properties) allow a platform to choose a
value/range among a set of available options. The options are present as
opp-<prop>-<name>, where the platform needs to supply the <name> string.

The OPP properties which allow such an option are: opp-microvolt and
opp-microamp.

Add support to the OPP-core to parse these bindings, by introducing
dev_pm_opp_{set|put}_prop_name() APIs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/base/power/opp/core.c | 165 ++++++++++++++++++++++++++++++++++++++----
 drivers/base/power/opp/opp.h  |   2 +
 include/linux/pm_opp.h        |   9 +++
 3 files changed, 161 insertions(+), 15 deletions(-)

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 55cf1a99b532..5c01fec1ed14 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -562,6 +562,9 @@ static void _remove_device_opp(struct device_opp *dev_opp)
 	if (dev_opp->supported_hw)
 		return;
 
+	if (dev_opp->prop_name)
+		return;
+
 	list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
 				    node);
 
@@ -794,35 +797,48 @@ static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
 }
 
 /* TODO: Support multiple regulators */
-static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
+static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
+			      struct device_opp *dev_opp)
 {
 	u32 microvolt[3] = {0};
 	u32 val;
 	int count, ret;
+	struct property *prop = NULL;
+	char name[NAME_MAX];
+
+	/* Search for "opp-microvolt-<name>" */
+	if (dev_opp->prop_name) {
+		sprintf(name, "opp-microvolt-%s", dev_opp->prop_name);
+		prop = of_find_property(opp->np, name, NULL);
+	}
+
+	if (!prop) {
+		/* Search for "opp-microvolt" */
+		name[13] = '\0';
+		prop = of_find_property(opp->np, name, NULL);
 
-	/* Missing property isn't a problem, but an invalid entry is */
-	if (!of_find_property(opp->np, "opp-microvolt", NULL))
-		return 0;
+		/* Missing property isn't a problem, but an invalid entry is */
+		if (!prop)
+			return 0;
+	}
 
-	count = of_property_count_u32_elems(opp->np, "opp-microvolt");
+	count = of_property_count_u32_elems(opp->np, name);
 	if (count < 0) {
-		dev_err(dev, "%s: Invalid opp-microvolt property (%d)\n",
-			__func__, count);
+		dev_err(dev, "%s: Invalid %s property (%d)\n",
+			__func__, name, count);
 		return count;
 	}
 
 	/* There can be one or three elements here */
 	if (count != 1 && count != 3) {
-		dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n",
-			__func__, count);
+		dev_err(dev, "%s: Invalid number of elements in %s property (%d)\n",
+			__func__, name, count);
 		return -EINVAL;
 	}
 
-	ret = of_property_read_u32_array(opp->np, "opp-microvolt", microvolt,
-					 count);
+	ret = of_property_read_u32_array(opp->np, name, microvolt, count);
 	if (ret) {
-		dev_err(dev, "%s: error parsing opp-microvolt: %d\n", __func__,
-			ret);
+		dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
 		return -EINVAL;
 	}
 
@@ -830,7 +846,20 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
 	opp->u_volt_min = microvolt[1];
 	opp->u_volt_max = microvolt[2];
 
-	if (!of_property_read_u32(opp->np, "opp-microamp", &val))
+	/* Search for "opp-microamp-<name>" */
+	prop = NULL;
+	if (dev_opp->prop_name) {
+		sprintf(name, "opp-microamp-%s", dev_opp->prop_name);
+		prop = of_find_property(opp->np, name, NULL);
+	}
+
+	if (!prop) {
+		/* Search for "opp-microamp" */
+		name[12] = '\0';
+		prop = of_find_property(opp->np, name, NULL);
+	}
+
+	if (prop && !of_property_read_u32(opp->np, name, &val))
 		opp->u_amp = val;
 
 	return 0;
@@ -948,6 +977,112 @@ void dev_pm_opp_put_supported_hw(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
 
+/**
+ * dev_pm_opp_set_prop_name() - Set prop-extn name
+ * @dev: Device for which the regulator has to be set.
+ * @name: name to postfix to properties.
+ *
+ * This is required only for the V2 bindings, and it enables a platform to
+ * specify the extn to be used for certain property names. The properties to
+ * which the extension will apply are opp-microvolt and opp-microamp. OPP core
+ * should postfix the property name with -<name> while looking for them.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
+{
+	struct device_opp *dev_opp;
+	int ret = 0;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	dev_opp = _add_device_opp(dev);
+	if (!dev_opp) {
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	/* Do we already have a prop-name associated with dev_opp? */
+	if (dev_opp->prop_name) {
+		dev_err(dev, "%s: Already have prop-name %s\n", __func__,
+			dev_opp->prop_name);
+		ret = -EBUSY;
+		goto err;
+	}
+
+	dev_opp->prop_name = kstrdup(name, GFP_KERNEL);
+	if (!dev_opp->prop_name) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	mutex_unlock(&dev_opp_list_lock);
+	return 0;
+
+err:
+	_remove_device_opp(dev_opp);
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);
+
+/**
+ * dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name
+ * @dev: Device for which the regulator has to be set.
+ *
+ * This is required only for the V2 bindings, and is called for a matching
+ * dev_pm_opp_set_prop_name(). Until this is called, the device_opp structure
+ * will not be freed.
+ *
+ * Locking: The internal device_opp and opp structures are RCU protected.
+ * Hence this function internally uses RCU updater strategy with mutex locks
+ * to keep the integrity of the internal data structures. Callers should ensure
+ * that this function is *NOT* called under RCU protection or in contexts where
+ * mutex cannot be locked.
+ */
+void dev_pm_opp_put_prop_name(struct device *dev)
+{
+	struct device_opp *dev_opp;
+
+	/* Hold our list modification lock here */
+	mutex_lock(&dev_opp_list_lock);
+
+	/* Check for existing list for 'dev' first */
+	dev_opp = _find_device_opp(dev);
+	if (IS_ERR(dev_opp)) {
+		dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));
+		goto unlock;
+	}
+
+	/* Make sure there are no concurrent readers while updating dev_opp */
+	WARN_ON(!list_empty(&dev_opp->opp_list));
+
+	if (!dev_opp->prop_name) {
+		dev_err(dev, "%s: Doesn't have a prop-name\n", __func__);
+		goto unlock;
+	}
+
+	kfree(dev_opp->prop_name);
+	dev_opp->prop_name = NULL;
+
+	/* Try freeing device_opp if this was the last blocking resource */
+	_remove_device_opp(dev_opp);
+
+unlock:
+	mutex_unlock(&dev_opp_list_lock);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
+
 static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp,
 			      struct device_node *np)
 {
@@ -1042,7 +1177,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 	if (!of_property_read_u32(np, "clock-latency-ns", &val))
 		new_opp->clock_latency_ns = val;
 
-	ret = opp_parse_supplies(new_opp, dev);
+	ret = opp_parse_supplies(new_opp, dev, dev_opp);
 	if (ret)
 		goto free_opp;
 
diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
index 70f4564a6ab9..690638ef36ee 100644
--- a/drivers/base/power/opp/opp.h
+++ b/drivers/base/power/opp/opp.h
@@ -131,6 +131,7 @@ struct device_list_opp {
  * @suspend_opp: Pointer to OPP to be used during device suspend.
  * @supported_hw: Array of version number to support.
  * @supported_hw_count: Number of elements in supported_hw array.
+ * @prop_name: A name to postfix to many DT properties, while parsing them.
  * @dentry:	debugfs dentry pointer of the real device directory (not links).
  * @dentry_name: Name of the real dentry.
  *
@@ -157,6 +158,7 @@ struct device_opp {
 
 	unsigned int *supported_hw;
 	unsigned int supported_hw_count;
+	const char *prop_name;
 
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *dentry;
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 3a85110242f0..95403d2ccaf5 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -58,6 +58,8 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev);
 int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
 				unsigned int count);
 void dev_pm_opp_put_supported_hw(struct device *dev);
+int dev_pm_opp_set_prop_name(struct device *dev, const char *name);
+void dev_pm_opp_put_prop_name(struct device *dev);
 #else
 static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
 {
@@ -142,6 +144,13 @@ static inline int dev_pm_opp_set_supported_hw(struct device *dev,
 
 static inline void dev_pm_opp_put_supported_hw(struct device *dev) {}
 
+static inline int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
+{
+	return -EINVAL;
+}
+
+static inline void dev_pm_opp_put_prop_name(struct device *dev) {}
+
 #endif		/* CONFIG_PM_OPP */
 
 #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
-- 
2.6.2.198.g614a2ac

Re: [PATCH V3 2/2] PM / OPP: Parse 'opp-<prop>-<name>' bindings

[Lee Jones]

On 9 December 2015 at 02:31, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> OPP bindings (for few properties) allow a platform to choose a
> value/range among a set of available options. The options are present as
> opp-<prop>-<name>, where the platform needs to supply the <name> string.
>
> The OPP properties which allow such an option are: opp-microvolt and
> opp-microamp.
>
> Add support to the OPP-core to parse these bindings, by introducing
> dev_pm_opp_{set|put}_prop_name() APIs.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
>  drivers/base/power/opp/core.c | 165 ++++++++++++++++++++++++++++++++++++++----
>  drivers/base/power/opp/opp.h  |   2 +
>  include/linux/pm_opp.h        |   9 +++
>  3 files changed, 161 insertions(+), 15 deletions(-)

Tested-by: Lee Jones <lee.jones@linaro.org>

> diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
> index 55cf1a99b532..5c01fec1ed14 100644
> --- a/drivers/base/power/opp/core.c
> +++ b/drivers/base/power/opp/core.c
> @@ -562,6 +562,9 @@ static void _remove_device_opp(struct device_opp *dev_opp)
>         if (dev_opp->supported_hw)
>                 return;
>
> +       if (dev_opp->prop_name)
> +               return;
> +
>         list_dev = list_first_entry(&dev_opp->dev_list, struct device_list_opp,
>                                     node);
>
> @@ -794,35 +797,48 @@ static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
>  }
>
>  /* TODO: Support multiple regulators */
> -static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
> +static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
> +                             struct device_opp *dev_opp)
>  {
>         u32 microvolt[3] = {0};
>         u32 val;
>         int count, ret;
> +       struct property *prop = NULL;
> +       char name[NAME_MAX];
> +
> +       /* Search for "opp-microvolt-<name>" */
> +       if (dev_opp->prop_name) {
> +               sprintf(name, "opp-microvolt-%s", dev_opp->prop_name);
> +               prop = of_find_property(opp->np, name, NULL);
> +       }
> +
> +       if (!prop) {
> +               /* Search for "opp-microvolt" */
> +               name[13] = '\0';
> +               prop = of_find_property(opp->np, name, NULL);
>
> -       /* Missing property isn't a problem, but an invalid entry is */
> -       if (!of_find_property(opp->np, "opp-microvolt", NULL))
> -               return 0;
> +               /* Missing property isn't a problem, but an invalid entry is */
> +               if (!prop)
> +                       return 0;
> +       }
>
> -       count = of_property_count_u32_elems(opp->np, "opp-microvolt");
> +       count = of_property_count_u32_elems(opp->np, name);
>         if (count < 0) {
> -               dev_err(dev, "%s: Invalid opp-microvolt property (%d)\n",
> -                       __func__, count);
> +               dev_err(dev, "%s: Invalid %s property (%d)\n",
> +                       __func__, name, count);
>                 return count;
>         }
>
>         /* There can be one or three elements here */
>         if (count != 1 && count != 3) {
> -               dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n",
> -                       __func__, count);
> +               dev_err(dev, "%s: Invalid number of elements in %s property (%d)\n",
> +                       __func__, name, count);
>                 return -EINVAL;
>         }
>
> -       ret = of_property_read_u32_array(opp->np, "opp-microvolt", microvolt,
> -                                        count);
> +       ret = of_property_read_u32_array(opp->np, name, microvolt, count);
>         if (ret) {
> -               dev_err(dev, "%s: error parsing opp-microvolt: %d\n", __func__,
> -                       ret);
> +               dev_err(dev, "%s: error parsing %s: %d\n", __func__, name, ret);
>                 return -EINVAL;
>         }
>
> @@ -830,7 +846,20 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
>         opp->u_volt_min = microvolt[1];
>         opp->u_volt_max = microvolt[2];
>
> -       if (!of_property_read_u32(opp->np, "opp-microamp", &val))
> +       /* Search for "opp-microamp-<name>" */
> +       prop = NULL;
> +       if (dev_opp->prop_name) {
> +               sprintf(name, "opp-microamp-%s", dev_opp->prop_name);
> +               prop = of_find_property(opp->np, name, NULL);
> +       }
> +
> +       if (!prop) {
> +               /* Search for "opp-microamp" */
> +               name[12] = '\0';
> +               prop = of_find_property(opp->np, name, NULL);
> +       }
> +
> +       if (prop && !of_property_read_u32(opp->np, name, &val))
>                 opp->u_amp = val;
>
>         return 0;
> @@ -948,6 +977,112 @@ void dev_pm_opp_put_supported_hw(struct device *dev)
>  }
>  EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
>
> +/**
> + * dev_pm_opp_set_prop_name() - Set prop-extn name
> + * @dev: Device for which the regulator has to be set.
> + * @name: name to postfix to properties.
> + *
> + * This is required only for the V2 bindings, and it enables a platform to
> + * specify the extn to be used for certain property names. The properties to
> + * which the extension will apply are opp-microvolt and opp-microamp. OPP core
> + * should postfix the property name with -<name> while looking for them.
> + *
> + * Locking: The internal device_opp and opp structures are RCU protected.
> + * Hence this function internally uses RCU updater strategy with mutex locks
> + * to keep the integrity of the internal data structures. Callers should ensure
> + * that this function is *NOT* called under RCU protection or in contexts where
> + * mutex cannot be locked.
> + */
> +int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
> +{
> +       struct device_opp *dev_opp;
> +       int ret = 0;
> +
> +       /* Hold our list modification lock here */
> +       mutex_lock(&dev_opp_list_lock);
> +
> +       dev_opp = _add_device_opp(dev);
> +       if (!dev_opp) {
> +               ret = -ENOMEM;
> +               goto unlock;
> +       }
> +
> +       /* Make sure there are no concurrent readers while updating dev_opp */
> +       WARN_ON(!list_empty(&dev_opp->opp_list));
> +
> +       /* Do we already have a prop-name associated with dev_opp? */
> +       if (dev_opp->prop_name) {
> +               dev_err(dev, "%s: Already have prop-name %s\n", __func__,
> +                       dev_opp->prop_name);
> +               ret = -EBUSY;
> +               goto err;
> +       }
> +
> +       dev_opp->prop_name = kstrdup(name, GFP_KERNEL);
> +       if (!dev_opp->prop_name) {
> +               ret = -ENOMEM;
> +               goto err;
> +       }
> +
> +       mutex_unlock(&dev_opp_list_lock);
> +       return 0;
> +
> +err:
> +       _remove_device_opp(dev_opp);
> +unlock:
> +       mutex_unlock(&dev_opp_list_lock);
> +
> +       return ret;
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);
> +
> +/**
> + * dev_pm_opp_put_prop_name() - Releases resources blocked for prop-name
> + * @dev: Device for which the regulator has to be set.
> + *
> + * This is required only for the V2 bindings, and is called for a matching
> + * dev_pm_opp_set_prop_name(). Until this is called, the device_opp structure
> + * will not be freed.
> + *
> + * Locking: The internal device_opp and opp structures are RCU protected.
> + * Hence this function internally uses RCU updater strategy with mutex locks
> + * to keep the integrity of the internal data structures. Callers should ensure
> + * that this function is *NOT* called under RCU protection or in contexts where
> + * mutex cannot be locked.
> + */
> +void dev_pm_opp_put_prop_name(struct device *dev)
> +{
> +       struct device_opp *dev_opp;
> +
> +       /* Hold our list modification lock here */
> +       mutex_lock(&dev_opp_list_lock);
> +
> +       /* Check for existing list for 'dev' first */
> +       dev_opp = _find_device_opp(dev);
> +       if (IS_ERR(dev_opp)) {
> +               dev_err(dev, "Failed to find dev_opp: %ld\n", PTR_ERR(dev_opp));
> +               goto unlock;
> +       }
> +
> +       /* Make sure there are no concurrent readers while updating dev_opp */
> +       WARN_ON(!list_empty(&dev_opp->opp_list));
> +
> +       if (!dev_opp->prop_name) {
> +               dev_err(dev, "%s: Doesn't have a prop-name\n", __func__);
> +               goto unlock;
> +       }
> +
> +       kfree(dev_opp->prop_name);
> +       dev_opp->prop_name = NULL;
> +
> +       /* Try freeing device_opp if this was the last blocking resource */
> +       _remove_device_opp(dev_opp);
> +
> +unlock:
> +       mutex_unlock(&dev_opp_list_lock);
> +}
> +EXPORT_SYMBOL_GPL(dev_pm_opp_put_prop_name);
> +
>  static bool _opp_is_supported(struct device *dev, struct device_opp *dev_opp,
>                               struct device_node *np)
>  {
> @@ -1042,7 +1177,7 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np)
>         if (!of_property_read_u32(np, "clock-latency-ns", &val))
>                 new_opp->clock_latency_ns = val;
>
> -       ret = opp_parse_supplies(new_opp, dev);
> +       ret = opp_parse_supplies(new_opp, dev, dev_opp);
>         if (ret)
>                 goto free_opp;
>
> diff --git a/drivers/base/power/opp/opp.h b/drivers/base/power/opp/opp.h
> index 70f4564a6ab9..690638ef36ee 100644
> --- a/drivers/base/power/opp/opp.h
> +++ b/drivers/base/power/opp/opp.h
> @@ -131,6 +131,7 @@ struct device_list_opp {
>   * @suspend_opp: Pointer to OPP to be used during device suspend.
>   * @supported_hw: Array of version number to support.
>   * @supported_hw_count: Number of elements in supported_hw array.
> + * @prop_name: A name to postfix to many DT properties, while parsing them.
>   * @dentry:    debugfs dentry pointer of the real device directory (not links).
>   * @dentry_name: Name of the real dentry.
>   *
> @@ -157,6 +158,7 @@ struct device_opp {
>
>         unsigned int *supported_hw;
>         unsigned int supported_hw_count;
> +       const char *prop_name;
>
>  #ifdef CONFIG_DEBUG_FS
>         struct dentry *dentry;
> diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
> index 3a85110242f0..95403d2ccaf5 100644
> --- a/include/linux/pm_opp.h
> +++ b/include/linux/pm_opp.h
> @@ -58,6 +58,8 @@ struct srcu_notifier_head *dev_pm_opp_get_notifier(struct device *dev);
>  int dev_pm_opp_set_supported_hw(struct device *dev, const u32 *versions,
>                                 unsigned int count);
>  void dev_pm_opp_put_supported_hw(struct device *dev);
> +int dev_pm_opp_set_prop_name(struct device *dev, const char *name);
> +void dev_pm_opp_put_prop_name(struct device *dev);
>  #else
>  static inline unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp)
>  {
> @@ -142,6 +144,13 @@ static inline int dev_pm_opp_set_supported_hw(struct device *dev,
>
>  static inline void dev_pm_opp_put_supported_hw(struct device *dev) {}
>
> +static inline int dev_pm_opp_set_prop_name(struct device *dev, const char *name)
> +{
> +       return -EINVAL;
> +}
> +
> +static inline void dev_pm_opp_put_prop_name(struct device *dev) {}
> +
>  #endif         /* CONFIG_PM_OPP */
>
>  #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
> --
> 2.6.2.198.g614a2ac
>
> _______________________________________________
> linaro-kernel mailing list
> linaro-kernel@lists.linaro.org
> https://lists.linaro.org/mailman/listinfo/linaro-kernel



-- 
Lee Jones
Linaro ST Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH V3 2/2] PM / OPP: Parse 'opp-<prop>-<name>' bindings

[Rafael J. Wysocki]

On Thursday, December 10, 2015 09:54:45 AM Lee Jones wrote:
> On 9 December 2015 at 02:31, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > OPP bindings (for few properties) allow a platform to choose a
> > value/range among a set of available options. The options are present as
> > opp-<prop>-<name>, where the platform needs to supply the <name> string.
> >
> > The OPP properties which allow such an option are: opp-microvolt and
> > opp-microamp.
> >
> > Add support to the OPP-core to parse these bindings, by introducing
> > dev_pm_opp_{set|put}_prop_name() APIs.
> >
> > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > ---
> >  drivers/base/power/opp/core.c | 165 ++++++++++++++++++++++++++++++++++++++----
> >  drivers/base/power/opp/opp.h  |   2 +
> >  include/linux/pm_opp.h        |   9 +++
> >  3 files changed, 161 insertions(+), 15 deletions(-)
> 
> Tested-by: Lee Jones <lee.jones@linaro.org>

OK, so tentatively I can take these two.

What exectly does depend on them and how that thing is intended to be handled?

Thanks,
Rafael

Re: [PATCH V3 2/2] PM / OPP: Parse 'opp-<prop>-<name>' bindings

[Viresh Kumar]

On 10-12-15, 22:45, Rafael J. Wysocki wrote:
> On Thursday, December 10, 2015 09:54:45 AM Lee Jones wrote:
> > On 9 December 2015 at 02:31, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > > OPP bindings (for few properties) allow a platform to choose a
> > > value/range among a set of available options. The options are present as
> > > opp-<prop>-<name>, where the platform needs to supply the <name> string.
> > >
> > > The OPP properties which allow such an option are: opp-microvolt and
> > > opp-microamp.
> > >
> > > Add support to the OPP-core to parse these bindings, by introducing
> > > dev_pm_opp_{set|put}_prop_name() APIs.
> > >
> > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> > > ---
> > >  drivers/base/power/opp/core.c | 165 ++++++++++++++++++++++++++++++++++++++----
> > >  drivers/base/power/opp/opp.h  |   2 +
> > >  include/linux/pm_opp.h        |   9 +++
> > >  3 files changed, 161 insertions(+), 15 deletions(-)
> > 
> > Tested-by: Lee Jones <lee.jones@linaro.org>
> 
> OK, so tentatively I can take these two.
> 
> What exectly does depend on them and how that thing is intended to be handled?

The other two patches from Lee, Perhaps he missed mentioning that in
his cover-letter.

[PICKME 0/2] cpufreq: New ST driver

They must be rebased on my patches as they use the new APIs defined
here.

-- 
viresh

Re: [PATCH V3 2/2] PM / OPP: Parse 'opp-<prop>-<name>' bindings

[Geert Uytterhoeven]

Hi Viresh,

On Wed, Dec 9, 2015 at 3:31 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> OPP bindings (for few properties) allow a platform to choose a
> value/range among a set of available options. The options are present as
> opp-<prop>-<name>, where the platform needs to supply the <name> string.
>
> The OPP properties which allow such an option are: opp-microvolt and
> opp-microamp.
>
> Add support to the OPP-core to parse these bindings, by introducing
> dev_pm_opp_{set|put}_prop_name() APIs.
>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

> @@ -794,35 +797,48 @@ static int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
>  }
>
>  /* TODO: Support multiple regulators */
> -static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
> +static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev,
> +                             struct device_opp *dev_opp)
>  {
>         u32 microvolt[3] = {0};
>         u32 val;
>         int count, ret;
> +       struct property *prop = NULL;
> +       char name[NAME_MAX];
> +
> +       /* Search for "opp-microvolt-<name>" */
> +       if (dev_opp->prop_name) {
> +               sprintf(name, "opp-microvolt-%s", dev_opp->prop_name);

Any chance an attacker can overflow name[] by providing a very long
dev_opp->prop_name?

Better safe than sorry:

        snprintf(name, sizeof(name), ...);

> +               prop = of_find_property(opp->np, name, NULL);
> +       }

> @@ -830,7 +846,20 @@ static int opp_parse_supplies(struct dev_pm_opp *opp, struct device *dev)
>         opp->u_volt_min = microvolt[1];
>         opp->u_volt_max = microvolt[2];
>
> -       if (!of_property_read_u32(opp->np, "opp-microamp", &val))
> +       /* Search for "opp-microamp-<name>" */
> +       prop = NULL;
> +       if (dev_opp->prop_name) {
> +               sprintf(name, "opp-microamp-%s", dev_opp->prop_name);

Likewise

> +               prop = of_find_property(opp->np, name, NULL);
> +       }

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH V3 2/2] PM / OPP: Parse 'opp-<prop>-<name>' bindings

[Viresh Kumar]

On 05-01-16, 11:31, Geert Uytterhoeven wrote:
> Any chance an attacker can overflow name[] by providing a very long
> dev_opp->prop_name?
> 
> Better safe than sorry:
> 
>         snprintf(name, sizeof(name), ...);

Sent a patch to you..

-- 
viresh