These functios allows the driver core to automatically clean up
any allocation made by rtc drivers. Thus, it simplifies the error
paths.
Signed-off-by: Jingoo Han <jg1....@samsung.com>
---
Changes since v2:
- Removed unnecessary WARN_ON() of devm_rtc_device_match()
Changes since v1:
- Simplified 'if' statements using WARN_ON()
- Added a description of the return value of devm_rtc_device_register()
drivers/rtc/class.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/rtc.h | 6 ++++
2 files changed, 76 insertions(+), 0 deletions(-)
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 9b742d3..b72b40b 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -259,6 +259,76 @@ void rtc_device_unregister(struct rtc_device *rtc)
}
EXPORT_SYMBOL_GPL(rtc_device_unregister);
+static void devm_rtc_device_release(struct device *dev, void *res)
+{
+ struct rtc_device *rtc = *(struct rtc_device **)res;
+
+ rtc_device_unregister(rtc);
+}
+
+static int devm_rtc_device_match(struct device *dev, void *res, void *data)
+{
+ struct rtc **r = res;
+
+ return *r == data;
+}
+
+/**
+ * devm_rtc_device_register - resource managed rtc_device_register()
+ * @name: the name of the device
+ * @dev: the device to register
+ * @ops: the rtc operations structure
+ * @owner: the module owner
+ *
+ * @return a struct rtc on success, or an ERR_PTR on error
+ *
+ * Managed rtc_device_register(). The rtc_device returned from this function
+ * are automatically freed on driver detach. See rtc_device_register()
+ * for more information.
+ */
+
+struct rtc_device *devm_rtc_device_register(const char *name,
+ struct device *dev,
+ const struct rtc_class_ops *ops,
+ struct module *owner)
+{
+ struct rtc_device **ptr, *rtc;
+
+ ptr = devres_alloc(devm_rtc_device_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ rtc = rtc_device_register(name, dev, ops, owner);
+ if (!IS_ERR(rtc)) {
+ *ptr = rtc;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return rtc;
+}
+EXPORT_SYMBOL_GPL(devm_rtc_device_register);
+
+/**
+ * devm_rtc_device_unregister - resource managed devm_rtc_device_unregister()
+ * @dev: the device to unregister
+ * @rtc: the RTC class device to unregister
+ *
+ * Deallocated a rtc allocated with devm_rtc_device_register(). Normally this
+ * function will not need to be called and the resource management code will
+ * ensure that the resource is freed.
+ */
+void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc)
+{
+ int rc;
+
+ rc = devres_release(dev, devm_rtc_device_release,
+ devm_rtc_device_match, rtc);
+ WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_rtc_device_unregister);
+
static int __init rtc_init(void)
{
rtc_class = class_create(THIS_MODULE, "rtc");
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 580b24c..d955768 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -133,7 +133,13 @@ extern struct rtc_device *rtc_device_register(const char
*name,
struct device *dev,
const struct rtc_class_ops *ops,
struct module *owner);
+extern struct rtc_device *devm_rtc_device_register(const char *name,
+ struct device *dev,
+ const struct rtc_class_ops *ops,
+ struct module *owner);
extern void rtc_device_unregister(struct rtc_device *rtc);
+extern void devm_rtc_device_unregister(struct device *dev,
+ struct rtc_device *rtc);
extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
--
1.7.2.5
--
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