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Groups > linux.kernel > #1290885

[PATCH v4 06/20] PM / devfreq: Add devfreq_get_devfreq_by_phandle()

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This patch adds the new devfreq_get_devfreq_by_phandle() OF helper function
which can find the instance of devfreq device by using phandle ("devfreq").

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
[linux.amoon: Tested on Odroid U3]
Tested-by: Anand Moon <linux.amoon@gmail.com>
---
 drivers/devfreq/devfreq.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/devfreq.h   |  9 +++++++++
 2 files changed, 53 insertions(+)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 15e58779e4c0..78ea4cdaa82c 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -25,6 +25,7 @@
 #include <linux/list.h>
 #include <linux/printk.h>
 #include <linux/hrtimer.h>
+#include <linux/of.h>
 #include "governor.h"
 
 static struct class *devfreq_class;
@@ -686,6 +687,49 @@ struct devfreq *devm_devfreq_add_device(struct device *dev,
 }
 EXPORT_SYMBOL(devm_devfreq_add_device);
 
+#ifdef CONFIG_OF
+/*
+ * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree
+ * @dev - instance to the given device
+ * @index - index into list of devfreq
+ *
+ * return the instance of devfreq device
+ */
+struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, int index)
+{
+	struct device_node *node;
+	struct devfreq *devfreq;
+
+	if (!dev)
+		return ERR_PTR(-EINVAL);
+
+	if (!dev->of_node)
+		return ERR_PTR(-EINVAL);
+
+	node = of_parse_phandle(dev->of_node, "devfreq", index);
+	if (!node)
+		return ERR_PTR(-ENODEV);
+
+	mutex_lock(&devfreq_list_lock);
+	list_for_each_entry(devfreq, &devfreq_list, node) {
+		if (devfreq->dev.parent
+			&& devfreq->dev.parent->of_node == node) {
+			mutex_unlock(&devfreq_list_lock);
+			return devfreq;
+		}
+	}
+	mutex_unlock(&devfreq_list_lock);
+
+	return ERR_PTR(-EPROBE_DEFER);
+}
+#else
+struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, int index)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif /* CONFIG_OF */
+EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);
+
 /**
  * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
  * @dev:	the device to add devfreq feature.
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 95c54578a1b4..cf972befca2b 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -211,6 +211,9 @@ extern int devm_devfreq_register_opp_notifier(struct device *dev,
 extern void devm_devfreq_unregister_opp_notifier(struct device *dev,
 						struct devfreq *devfreq);
 
+extern struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
+						int index);
+
 /**
  * devfreq_update_stats() - update the last_status pointer in struct devfreq
  * @df:		the devfreq instance whose status needs updating
@@ -322,6 +325,12 @@ static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
 {
 }
 
+static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
+							int index)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline int devfreq_update_stats(struct devfreq *df)
 {
 	return -EINVAL;
-- 
1.9.1

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[PATCH v4 00/20] PM / devferq: Add generic exynos bus frequency driver  and new passive governor Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
  [PATCH v4 04/20] ARM: dts: Add DMC bus frequency for  exynos3250-rinato/monk Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
  [PATCH v4 02/20] PM / devfreq: exynos: Add documentation for generic  exynos bus frequency driver Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
  [PATCH v4 20/20] ARM: dts: Add support of bus frequency for  exynos4412-trats/odroidu3 Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
    Re: [PATCH v4 20/20] ARM: dts: Add support of bus frequency for  exynos4412-trats/odroidu3 Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2015-12-15 01:40 +0100
  [PATCH v4 08/20] PM / devfreq: exynos: Add support of bus frequency of  sub-blocks using passive governor Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
  [PATCH v4 19/20] ARM: dts: Expand the voltage range of buck1/3  regulator for exynos4412-odroidu3 Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
  [PATCH v4 12/20] MAINTAINERS: Add samsung bus frequency driver entry Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
  [PATCH v4 07/20] PM / devfreq: Show the related information according  to governor type Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
  [PATCH v4 06/20] PM / devfreq: Add devfreq_get_devfreq_by_phandle() Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
  [PATCH v4 15/20] ARM: dts: Add bus nodes using VDD_INT for Exynos4x12 Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100
  [PATCH v4 03/20] ARM: dts: Add DMC bus node for Exynos3250 Chanwoo Choi <cw00.choi@samsung.com> - 2015-12-14 07:50 +0100

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