Re: [PATCHv8 2/9] devfreq: event: Add resource-managed function for devfreq-event device

Re: [PATCHv8 2/9] devfreq: event: Add resource-managed function for devfreq-event device

[MyungJoo Ham]

>   
>  This patch add the resource-managed function for devfreq-event device as
> following functions. The devm_devfreq_event_add_edev() manages automatically
> the memory of devfreq-event device using resource management.
> - devm_devfreq_event_add_edev()
> - devm_devfreq_event_remove_edev()
> 
> Cc: Myungjoo Ham <myungjoo.ham@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.comA

Reviewed-by: MyungJoo Ham <myungjoo.ham@samsung.com>

You may merge this patch with 1/9 as well.
I don't think this is a major change the requires a seperated patch.


Cheers,
MyungJoo

Re: [PATCHv8 2/9] devfreq: event: Add resource-managed function for devfreq-event device

[MyungJoo Ham]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=utf-8, Size: 792 bytes --]

>   
>  This patch add the resource-managed function for devfreq-event device as
> following functions. The devm_devfreq_event_add_edev() manages automatically
> the memory of devfreq-event device using resource management.
> - devm_devfreq_event_add_edev()
> - devm_devfreq_event_remove_edev()
> 
> Cc: Myungjoo Ham <myungjoo.ham@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.comA

Reviewed-by: MyungJoo Ham <myungjoo.ham@samsung.com>

You may merge this patch with 1/9 as well.
I don't think this is a major change the requires a seperated patch.


Cheers,
MyungJoo
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Re: [PATCHv8 2/9] devfreq: event: Add resource-managed function for devfreq-event device

[Chanwoo Choi]

On 01/20/2015 01:46 PM, MyungJoo Ham wrote:
>>   
>>  This patch add the resource-managed function for devfreq-event device as
>> following functions. The devm_devfreq_event_add_edev() manages automatically
>> the memory of devfreq-event device using resource management.
>> - devm_devfreq_event_add_edev()
>> - devm_devfreq_event_remove_edev()
>>
>> Cc: Myungjoo Ham <myungjoo.ham@samsung.com>
>> Cc: Kyungmin Park <kyungmin.park@samsung.com>
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.comA
> 
> Reviewed-by: MyungJoo Ham <myungjoo.ham@samsung.com>
> 
> You may merge this patch with 1/9 as well.
> I don't think this is a major change the requires a seperated patch.

OK. I'll merge it. on patch1.

Best Regards,
Chanwoo Choi

[PATCHv8 2/9] devfreq: event: Add resource-managed function for devfreq-event device

[Chanwoo Choi]

On 01/20/2015 01:46 PM, MyungJoo Ham wrote:
>>   
>>  This patch add the resource-managed function for devfreq-event device as
>> following functions. The devm_devfreq_event_add_edev() manages automatically
>> the memory of devfreq-event device using resource management.
>> - devm_devfreq_event_add_edev()
>> - devm_devfreq_event_remove_edev()
>>
>> Cc: Myungjoo Ham <myungjoo.ham@samsung.com>
>> Cc: Kyungmin Park <kyungmin.park@samsung.com>
>> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.comA
> 
> Reviewed-by: MyungJoo Ham <myungjoo.ham@samsung.com>
> 
> You may merge this patch with 1/9 as well.
> I don't think this is a major change the requires a seperated patch.

OK. I'll merge it. on patch1.

Best Regards,
Chanwoo Choi

[PATCHv8 0/9] devfreq: Add devfreq-event class to provide raw data for devfreq device

[Chanwoo Choi]

This patchset add new devfreq_event class to provide raw data to determine
current utilization of device  which is used for devfreq governor.

The following description explains the feature of two kind of devfreq class:
- devfreq class (existing)
 : devfreq consumer device use raw data from devfreq_event device for
   determining proper current system state and change voltage/frequency
   dynamically using various governors.
- devfreq_event class (new)
 : Provide measured raw data to devfreq device for governor

---------
Changelog:

Changes from v7:
(https://lkml.org/lkml/2015/1/7/795)
- Use EXPORT_SYMBOL_GPL macro instead of EXPORT_SYMBOL
- Fix the binding document of exynos-ppmu.c driver
- Drop the devfreq-event type patch because it isnt' clear
- Fix bug of devfreq_event_add_edev() when fail to execute device_register()
- Modify resource free operation on following functions:
  : devfreq_event_remove_edev()
  : devfreq_event_release_edev()

Changes from v6:
(https://lkml.org/lkml/2014/12/28/139)
- This patchset is based on v3.19-rc3.
1. devfreq-event class driver
- Fix build break if devfreq-event framework is off
- Add resource-managed function for devfreq-event device
: devm_devfreq_event_add_edev()
: devm_devfreq_event_remove_edev()

Changes from v5:
(https://lkml.org/lkml/2014/12/22/527)
- Rebase these patch-set on v3.19-rc1 and Test it.
1. exynos-ppmu.c
- Change the error value when of_iomap() fail to map the memory
- Remove owner setting of platform_driver
- Add exynos_ppmu_disable() function
2. exynos dts file
- Add PPMU node to Exynos3250-based Monk board
- Remove ppmu_cpu node on Exynos4412-based TRATS2 board and add ppmu_leftbus/rightbus node

Changes from v4:
(https://lkml.org/lkml/2014/12/16/511)
1. devfreq-event class driver
- Add devfreq_event_get_edev_count() function
- Modify the simple description of devfreq-event framework in devfreq-event.c
- Minimize the usage range of global lock usage in devfreq_event_add_edev()
- Remove '_is_enabled()' function pointer in devfreq_event_ops structure
- Add separte CONFIG_PM_DEVFREQ_EVENT configuration
- Add new devfreq-event.h header file including devfreq-event helper functions
2. exynos dts file
- Add new patch to support PPMU with DEVFREQ-event on Exynos4412-based TRATS2

Changes from v3:
(https://lkml.org/lkml/2014/12/12/219)
1. devfreq-event class driver
- Fix return value of devfreq_event_get_event()
- Add new structure devfreq_event_data for devfreq_event_get_event()
- Modify the prototype of devfreq_event_get_event() function
- Call of_node_put after calling of_parse_phandle() to decrement refcount
2. exynos-ppmu driver
- Modify usage of devfreq_event_get_event() function
  according to new prototype of this funciton
- Add the additional description to exynos-ppmu.txt how to add PPMU node
  in board dts file
- Use 'PPMU_EVENT' macro to remove duplicate codes
- Add the support of PPMU for Exynos5260
3. exynos dts file
- Add missing PPMU_FSYS node to exynos3250.dtsi
- Fix 'ppmu_mfc_l' node name as 'ppmu_mfc' because exynos3250 has only one MFC IP.
- Add missing PPMU_ACP/G3D to exynos4.dtsi
4. etc
- Fix wrong abbreviation of PPMU (PPMU :Platform Performance Monitoring Unit)
- Add new patch to support the PPMU of Exynos5260 SoC

Changes from v2:
(https://lkml.org/lkml/2014/12/9/304)
1. devfreq-event class driver
- Rename all the helper functions of devfreq-event device
- Add devfreq_event_remove_edev() instead of devfreq_put_event_dev()
- Add devfreq_event_release_edev() to initialize it before put device
- Add the detailed description of devfreq-event API
- Add the attributes of devfreq-event class (enable_count)
- Check the overflow about event/total_event data in devfreq_event_get_event()
- Remove the 'exclusive flag' feature
- Set set_event()/get_event() functions as mandary
- Add missing of_node_put() call
- Change variable type of 'get_event()' funciton from 'int' to 'u64'
2. exynos-ppmu driver
- Remove un-used field (struct devfreq)
- Use 'of_get_child_by_name()' instead of 'of_find_node_by_name()'
- Add missing of_node_put() call
- Fix wrong clock control
- Use devfreq_event_remove_edev() instead of devfreq_remove_device()
- Add the documentation for exynos-ppmu driver
- Remove 'enable/disable/is_enabled/reset' function of exynos-ppmu driver
3. exynos3250-rinato.dts
- Add ppmu_{leftbus|rightbus} dt node and remove ppmu_cpu dt node

Changes from v1:
(https://lkml.org/lkml/2014/9/5/11)
- Code clean
- Add the description of devfreq-event structure
- Add 'is_enabled' function to devfreq_event_ops structure
- Add 'enable_count' field to devfreq_event_dev structure
- Check whether devfreq-event device is enabled or not
  during calling devfreq_event API
- Define the type of devfreq-event device as following
  : DEVFREQ_EVENT_TYPE_RAW_DATA
  : DEVFREQ_EVENT_TYPE_UTILIZATION
  : DEVFREQ_EVENT_TYPE_BANDWIDTH
  : DEVFREQ_EVENT_TYPE_LATENCY
- Add the exclusive feature of devfreq-event device.
  If devfreq-event device is used on only on devfreq driver,
  should used 'devfreq_enable_event_dev_exclusive()' function
- Add new patch6 for test on Exynos3250-based Rinato board

Chanwoo Choi (9):
  devfreq: event: Add new devfreq_event class to provide basic data for devfreq governor
  devfreq: event: Add resource-managed function for devfreq-event device
  devfreq: event: Add exynos-ppmu devfreq-event driver
  devfreq: event: Add documentation for exynos-ppmu devfreq-event driver
  ARM: dts: Add PPMU dt node for Exynos3250 SoC
  ARM: dts: Add PPMU dt node for Exynos4 SoCs
  ARM: dts: Add PPMU dt node for Exynos5260 SoC
  ARM: dts: exynos: Add PPMU node to Exynos3250-based Rinato/Monk board
  ARM: dts: exynos: Add PPMU node for Exynos4412-based TRATS2 board

 .../bindings/devfreq/event/exynos-ppmu.txt         | 110 +++++
 arch/arm/boot/dts/exynos3250-monk.dts              |  40 ++
 arch/arm/boot/dts/exynos3250-rinato.dts            |  40 ++
 arch/arm/boot/dts/exynos3250.dtsi                  |  74 +++
 arch/arm/boot/dts/exynos4.dtsi                     | 108 +++++
 arch/arm/boot/dts/exynos4210.dtsi                  |   8 +
 arch/arm/boot/dts/exynos4412-trats2.dts            |  40 ++
 arch/arm/boot/dts/exynos5260.dtsi                  |  90 ++++
 drivers/devfreq/Kconfig                            |   2 +
 drivers/devfreq/Makefile                           |   6 +-
 drivers/devfreq/devfreq-event.c                    | 511 +++++++++++++++++++++
 drivers/devfreq/event/Kconfig                      |  25 +
 drivers/devfreq/event/Makefile                     |   2 +
 drivers/devfreq/event/exynos-ppmu.c                | 398 ++++++++++++++++
 include/linux/devfreq-event.h                      | 186 ++++++++
 15 files changed, 1639 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/devfreq/event/exynos-ppmu.txt
 create mode 100644 drivers/devfreq/devfreq-event.c
 create mode 100644 drivers/devfreq/event/Kconfig
 create mode 100644 drivers/devfreq/event/Makefile
 create mode 100644 drivers/devfreq/event/exynos-ppmu.c
 create mode 100644 include/linux/devfreq-event.h

-- 
1.8.5.5

[PATCHv8 2/9] devfreq: event: Add resource-managed function for devfreq-event device

[Chanwoo Choi]

This patch add the resource-managed function for devfreq-event device as
following functions. The devm_devfreq_event_add_edev() manages automatically
the memory of devfreq-event device using resource management.
- devm_devfreq_event_add_edev()
- devm_devfreq_event_remove_edev()

Cc: Myungjoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/devfreq-event.c | 63 +++++++++++++++++++++++++++++++++++++++++
 include/linux/devfreq-event.h   | 16 +++++++++++
 2 files changed, 79 insertions(+)

diff --git a/drivers/devfreq/devfreq-event.c b/drivers/devfreq/devfreq-event.c
index 9ba5ba4..57529af 100644
--- a/drivers/devfreq/devfreq-event.c
+++ b/drivers/devfreq/devfreq-event.c
@@ -389,6 +389,69 @@ int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
 }
 EXPORT_SYMBOL_GPL(devfreq_event_remove_edev);
 
+static int devm_devfreq_event_match(struct device *dev, void *res, void *data)
+{
+	struct devfreq_event_dev **r = res;
+
+	if (WARN_ON(!r || !*r))
+		return 0;
+
+	return *r == data;
+}
+
+static void devm_devfreq_event_release(struct device *dev, void *res)
+{
+	devfreq_event_remove_edev(*(struct devfreq_event_dev **)res);
+}
+
+/**
+ * devm_devfreq_event_add_edev() - Resource-managed devfreq_event_add_edev()
+ * @dev		: the device owning the devfreq-event device being created
+ * @desc	: the devfreq-event device's decriptor which include essential
+ *		  data for devfreq-event device.
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management and simplify the free operation
+ * for memory of devfreq-event device.
+ */
+struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
+						struct devfreq_event_desc *desc)
+{
+	struct devfreq_event_dev **ptr, *edev;
+
+	ptr = devres_alloc(devm_devfreq_event_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	edev = devfreq_event_add_edev(dev, desc);
+	if (IS_ERR(edev)) {
+		devres_free(ptr);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	*ptr = edev;
+	devres_add(dev, ptr);
+
+	return edev;
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_add_edev);
+
+/**
+ * devm_devfreq_event_remove_edev()- Resource-managed devfreq_event_remove_edev()
+ * @dev		: the device owning the devfreq-event device being created
+ * @edev	: the devfreq-event device
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management.
+ */
+void devm_devfreq_event_remove_edev(struct device *dev,
+				struct devfreq_event_dev *edev)
+{
+	WARN_ON(devres_release(dev, devm_devfreq_event_release,
+			       devm_devfreq_event_match, edev));
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_remove_edev);
+
 /*
  * Device attributes for devfreq-event class.
  */
diff --git a/include/linux/devfreq-event.h b/include/linux/devfreq-event.h
index b7363f5..b6e3afa 100644
--- a/include/linux/devfreq-event.h
+++ b/include/linux/devfreq-event.h
@@ -106,6 +106,10 @@ extern int devfreq_event_get_edev_count(struct device *dev);
 extern struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
 				struct devfreq_event_desc *desc);
 extern int devfreq_event_remove_edev(struct devfreq_event_dev *edev);
+extern struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
+				struct devfreq_event_desc *desc);
+extern void devm_devfreq_event_remove_edev(struct device *dev,
+				struct devfreq_event_dev *edev);
 
 #else
 static inline int devfreq_event_enable_edev(struct devfreq_event_dev *edev)
@@ -165,6 +169,18 @@ static inline int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
 {
 	return -EINVAL;
 }
+
+static inline struct devfreq_event_dev *devm_devfreq_event_add_edev(
+					struct device *dev,
+					struct devfreq_event_desc *desc)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline void devm_devfreq_event_remove_edev(struct device *dev,
+					struct devfreq_event_dev *edev)
+{
+}
 #endif /* CONFIG_PM_DEVFREQ_EVENT */
 
 #endif /* __LINUX_DEVFREQ_EVENT_H__ */
-- 
1.8.5.5

[PATCHv8 2/9] devfreq: event: Add resource-managed function for devfreq-event device

[Chanwoo Choi]

This patch add the resource-managed function for devfreq-event device as
following functions. The devm_devfreq_event_add_edev() manages automatically
the memory of devfreq-event device using resource management.
- devm_devfreq_event_add_edev()
- devm_devfreq_event_remove_edev()

Cc: Myungjoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/devfreq-event.c | 63 +++++++++++++++++++++++++++++++++++++++++
 include/linux/devfreq-event.h   | 16 +++++++++++
 2 files changed, 79 insertions(+)

diff --git a/drivers/devfreq/devfreq-event.c b/drivers/devfreq/devfreq-event.c
index 9ba5ba4..57529af 100644
--- a/drivers/devfreq/devfreq-event.c
+++ b/drivers/devfreq/devfreq-event.c
@@ -389,6 +389,69 @@ int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
 }
 EXPORT_SYMBOL_GPL(devfreq_event_remove_edev);
 
+static int devm_devfreq_event_match(struct device *dev, void *res, void *data)
+{
+	struct devfreq_event_dev **r = res;
+
+	if (WARN_ON(!r || !*r))
+		return 0;
+
+	return *r == data;
+}
+
+static void devm_devfreq_event_release(struct device *dev, void *res)
+{
+	devfreq_event_remove_edev(*(struct devfreq_event_dev **)res);
+}
+
+/**
+ * devm_devfreq_event_add_edev() - Resource-managed devfreq_event_add_edev()
+ * @dev		: the device owning the devfreq-event device being created
+ * @desc	: the devfreq-event device's decriptor which include essential
+ *		  data for devfreq-event device.
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management and simplify the free operation
+ * for memory of devfreq-event device.
+ */
+struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
+						struct devfreq_event_desc *desc)
+{
+	struct devfreq_event_dev **ptr, *edev;
+
+	ptr = devres_alloc(devm_devfreq_event_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	edev = devfreq_event_add_edev(dev, desc);
+	if (IS_ERR(edev)) {
+		devres_free(ptr);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	*ptr = edev;
+	devres_add(dev, ptr);
+
+	return edev;
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_add_edev);
+
+/**
+ * devm_devfreq_event_remove_edev()- Resource-managed devfreq_event_remove_edev()
+ * @dev		: the device owning the devfreq-event device being created
+ * @edev	: the devfreq-event device
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management.
+ */
+void devm_devfreq_event_remove_edev(struct device *dev,
+				struct devfreq_event_dev *edev)
+{
+	WARN_ON(devres_release(dev, devm_devfreq_event_release,
+			       devm_devfreq_event_match, edev));
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_remove_edev);
+
 /*
  * Device attributes for devfreq-event class.
  */
diff --git a/include/linux/devfreq-event.h b/include/linux/devfreq-event.h
index b7363f5..b6e3afa 100644
--- a/include/linux/devfreq-event.h
+++ b/include/linux/devfreq-event.h
@@ -106,6 +106,10 @@ extern int devfreq_event_get_edev_count(struct device *dev);
 extern struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
 				struct devfreq_event_desc *desc);
 extern int devfreq_event_remove_edev(struct devfreq_event_dev *edev);
+extern struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
+				struct devfreq_event_desc *desc);
+extern void devm_devfreq_event_remove_edev(struct device *dev,
+				struct devfreq_event_dev *edev);
 
 #else
 static inline int devfreq_event_enable_edev(struct devfreq_event_dev *edev)
@@ -165,6 +169,18 @@ static inline int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
 {
 	return -EINVAL;
 }
+
+static inline struct devfreq_event_dev *devm_devfreq_event_add_edev(
+					struct device *dev,
+					struct devfreq_event_desc *desc)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline void devm_devfreq_event_remove_edev(struct device *dev,
+					struct devfreq_event_dev *edev)
+{
+}
 #endif /* CONFIG_PM_DEVFREQ_EVENT */
 
 #endif /* __LINUX_DEVFREQ_EVENT_H__ */
-- 
1.8.5.5

[PATCHv8 2/9] devfreq: event: Add resource-managed function for devfreq-event device

[Chanwoo Choi]

This patch add the resource-managed function for devfreq-event device as
following functions. The devm_devfreq_event_add_edev() manages automatically
the memory of devfreq-event device using resource management.
- devm_devfreq_event_add_edev()
- devm_devfreq_event_remove_edev()

Cc: Myungjoo Ham <myungjoo.ham@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
 drivers/devfreq/devfreq-event.c | 63 +++++++++++++++++++++++++++++++++++++++++
 include/linux/devfreq-event.h   | 16 +++++++++++
 2 files changed, 79 insertions(+)

diff --git a/drivers/devfreq/devfreq-event.c b/drivers/devfreq/devfreq-event.c
index 9ba5ba4..57529af 100644
--- a/drivers/devfreq/devfreq-event.c
+++ b/drivers/devfreq/devfreq-event.c
@@ -389,6 +389,69 @@ int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
 }
 EXPORT_SYMBOL_GPL(devfreq_event_remove_edev);
 
+static int devm_devfreq_event_match(struct device *dev, void *res, void *data)
+{
+	struct devfreq_event_dev **r = res;
+
+	if (WARN_ON(!r || !*r))
+		return 0;
+
+	return *r == data;
+}
+
+static void devm_devfreq_event_release(struct device *dev, void *res)
+{
+	devfreq_event_remove_edev(*(struct devfreq_event_dev **)res);
+}
+
+/**
+ * devm_devfreq_event_add_edev() - Resource-managed devfreq_event_add_edev()
+ * @dev		: the device owning the devfreq-event device being created
+ * @desc	: the devfreq-event device's decriptor which include essential
+ *		  data for devfreq-event device.
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management and simplify the free operation
+ * for memory of devfreq-event device.
+ */
+struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
+						struct devfreq_event_desc *desc)
+{
+	struct devfreq_event_dev **ptr, *edev;
+
+	ptr = devres_alloc(devm_devfreq_event_release, sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return ERR_PTR(-ENOMEM);
+
+	edev = devfreq_event_add_edev(dev, desc);
+	if (IS_ERR(edev)) {
+		devres_free(ptr);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	*ptr = edev;
+	devres_add(dev, ptr);
+
+	return edev;
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_add_edev);
+
+/**
+ * devm_devfreq_event_remove_edev()- Resource-managed devfreq_event_remove_edev()
+ * @dev		: the device owning the devfreq-event device being created
+ * @edev	: the devfreq-event device
+ *
+ * Note that this function manages automatically the memory of devfreq-event
+ * device using device resource management.
+ */
+void devm_devfreq_event_remove_edev(struct device *dev,
+				struct devfreq_event_dev *edev)
+{
+	WARN_ON(devres_release(dev, devm_devfreq_event_release,
+			       devm_devfreq_event_match, edev));
+}
+EXPORT_SYMBOL_GPL(devm_devfreq_event_remove_edev);
+
 /*
  * Device attributes for devfreq-event class.
  */
diff --git a/include/linux/devfreq-event.h b/include/linux/devfreq-event.h
index b7363f5..b6e3afa 100644
--- a/include/linux/devfreq-event.h
+++ b/include/linux/devfreq-event.h
@@ -106,6 +106,10 @@ extern int devfreq_event_get_edev_count(struct device *dev);
 extern struct devfreq_event_dev *devfreq_event_add_edev(struct device *dev,
 				struct devfreq_event_desc *desc);
 extern int devfreq_event_remove_edev(struct devfreq_event_dev *edev);
+extern struct devfreq_event_dev *devm_devfreq_event_add_edev(struct device *dev,
+				struct devfreq_event_desc *desc);
+extern void devm_devfreq_event_remove_edev(struct device *dev,
+				struct devfreq_event_dev *edev);
 
 #else
 static inline int devfreq_event_enable_edev(struct devfreq_event_dev *edev)
@@ -165,6 +169,18 @@ static inline int devfreq_event_remove_edev(struct devfreq_event_dev *edev)
 {
 	return -EINVAL;
 }
+
+static inline struct devfreq_event_dev *devm_devfreq_event_add_edev(
+					struct device *dev,
+					struct devfreq_event_desc *desc)
+{
+	return ERR_PTR(-EINVAL);
+}
+
+static inline void devm_devfreq_event_remove_edev(struct device *dev,
+					struct devfreq_event_dev *edev)
+{
+}
 #endif /* CONFIG_PM_DEVFREQ_EVENT */
 
 #endif /* __LINUX_DEVFREQ_EVENT_H__ */
-- 
1.8.5.5