* [PATCH V2] rtc: add devm_rtc_device_{register,unregister}()
@ 2013-02-26 1:21 Jingoo Han
2013-02-26 1:23 ` 'Tejun Heo'
2013-02-26 22:33 ` Dmitry Torokhov
0 siblings, 2 replies; 6+ messages in thread
From: Jingoo Han @ 2013-02-26 1:21 UTC (permalink / raw)
To: 'Andrew Morton'
Cc: linux-kernel, 'Tejun Heo', 'Greg KH',
'Alessandro Zummo', rtc-linux, 'Jingoo Han'
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.han@samsung.com>
---
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 | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/rtc.h | 6 ++++
2 files changed, 78 insertions(+), 0 deletions(-)
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 9b742d3..31496bc 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -259,6 +259,78 @@ 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;
+ if (WARN_ON(!r || !*r))
+ return 0;
+
+ 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
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH V2] rtc: add devm_rtc_device_{register,unregister}()
2013-02-26 1:21 [PATCH V2] rtc: add devm_rtc_device_{register,unregister}() Jingoo Han
@ 2013-02-26 1:23 ` 'Tejun Heo'
2013-02-26 1:30 ` 'Tejun Heo'
2013-02-26 22:33 ` Dmitry Torokhov
1 sibling, 1 reply; 6+ messages in thread
From: 'Tejun Heo' @ 2013-02-26 1:23 UTC (permalink / raw)
To: Jingoo Han
Cc: 'Andrew Morton', linux-kernel, 'Greg KH',
'Alessandro Zummo', rtc-linux
Hello,
On Tue, Feb 26, 2013 at 10:21:06AM +0900, Jingoo Han wrote:
> 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.han@samsung.com>
Looks okay to me but
> +static int devm_rtc_device_match(struct device *dev, void *res, void *data)
> +{
> + struct rtc **r = res;
> + if (WARN_ON(!r || !*r))
> + return 0;
> +
> + return *r == data;
> +}
again, why do we need the WARN_ON() at all given that other
devm_*_match() don't do that and the only way to get NULL there would
be bug in devm_rtc*() code itself rather than its users?
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH V2] rtc: add devm_rtc_device_{register,unregister}()
2013-02-26 1:23 ` 'Tejun Heo'
@ 2013-02-26 1:30 ` 'Tejun Heo'
2013-02-26 1:42 ` Jingoo Han
0 siblings, 1 reply; 6+ messages in thread
From: 'Tejun Heo' @ 2013-02-26 1:30 UTC (permalink / raw)
To: Jingoo Han
Cc: 'Andrew Morton', linux-kernel, 'Greg KH',
'Alessandro Zummo', rtc-linux
On Mon, Feb 25, 2013 at 05:23:17PM -0800, 'Tejun Heo' wrote:
> again, why do we need the WARN_ON() at all given that other
> devm_*_match() don't do that and the only way to get NULL there would
> be bug in devm_rtc*() code itself rather than its users?
Ughh... I see that you probably copied the chunk from clk / regulator
implementation. Let's please not copy those. Input validation via
WARN_ON()s is nice when the interface is taking input from outside or
the code in question is complex / fragile. Here, the code involved is
like 20 lines and self-contained.
Thanks.
--
tejun
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH V2] rtc: add devm_rtc_device_{register,unregister}()
2013-02-26 1:30 ` 'Tejun Heo'
@ 2013-02-26 1:42 ` Jingoo Han
0 siblings, 0 replies; 6+ messages in thread
From: Jingoo Han @ 2013-02-26 1:42 UTC (permalink / raw)
To: 'Tejun Heo'
Cc: 'Andrew Morton', linux-kernel, 'Greg KH',
'Alessandro Zummo', rtc-linux, 'Jingoo Han'
On Tuesday, February 26, 2013 10:30 AM, Tejun Heo wrote:
>
> On Mon, Feb 25, 2013 at 05:23:17PM -0800, 'Tejun Heo' wrote:
> > again, why do we need the WARN_ON() at all given that other
> > devm_*_match() don't do that and the only way to get NULL there would
> > be bug in devm_rtc*() code itself rather than its users?
>
> Ughh... I see that you probably copied the chunk from clk / regulator
> implementation. Let's please not copy those. Input validation via
> WARN_ON()s is nice when the interface is taking input from outside or
> the code in question is complex / fragile. Here, the code involved is
> like 20 lines and self-contained.
OK, I see.
Thank you for your comment.
I will send v3 patch soon :)
Best regards,
Jingoo Han
>
> Thanks.
>
> --
> tejun
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH V2] rtc: add devm_rtc_device_{register,unregister}()
2013-02-26 1:21 [PATCH V2] rtc: add devm_rtc_device_{register,unregister}() Jingoo Han
2013-02-26 1:23 ` 'Tejun Heo'
@ 2013-02-26 22:33 ` Dmitry Torokhov
2013-02-27 2:12 ` Jingoo Han
1 sibling, 1 reply; 6+ messages in thread
From: Dmitry Torokhov @ 2013-02-26 22:33 UTC (permalink / raw)
To: Jingoo Han
Cc: 'Andrew Morton', linux-kernel, 'Tejun Heo',
'Greg KH', 'Alessandro Zummo', rtc-linux
On Tue, Feb 26, 2013 at 10:21:06AM +0900, Jingoo Han wrote:
> +/**
> + * 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)
Why do you need a separate function? You can add a flag to struct rtc_device
so it knows whether it is devm-managed or not and behave accordingly.
And then you can do
#define devm_rtc_device_unregister rtc_device_unregister
Thanks.
--
Dmitry
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH V2] rtc: add devm_rtc_device_{register,unregister}()
2013-02-26 22:33 ` Dmitry Torokhov
@ 2013-02-27 2:12 ` Jingoo Han
0 siblings, 0 replies; 6+ messages in thread
From: Jingoo Han @ 2013-02-27 2:12 UTC (permalink / raw)
To: 'Dmitry Torokhov'
Cc: 'Andrew Morton', linux-kernel, 'Tejun Heo',
'Greg KH', 'Alessandro Zummo', rtc-linux,
'Jingoo Han'
On Wednesday, February 27, 2013 7:33 AM, Dmitry Torokhov wrote:
>
> On Tue, Feb 26, 2013 at 10:21:06AM +0900, Jingoo Han wrote:
> > +/**
> > + * 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)
>
> Why do you need a separate function? You can add a flag to struct rtc_device
> so it knows whether it is devm-managed or not and behave accordingly.
> And then you can do
>
> #define devm_rtc_device_unregister rtc_device_unregister
Um, I don't prefer that way using additional a flag.
Also, most of other devm_* functions are using a separate functions
such as devm_pwm_put(), devm_regulator_put(),devm_usb_put_phy(), etc.
>
> Thanks.
>
> --
> Dmitry
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2013-02-27 2:12 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2013-02-26 1:21 [PATCH V2] rtc: add devm_rtc_device_{register,unregister}() Jingoo Han
2013-02-26 1:23 ` 'Tejun Heo'
2013-02-26 1:30 ` 'Tejun Heo'
2013-02-26 1:42 ` Jingoo Han
2013-02-26 22:33 ` Dmitry Torokhov
2013-02-27 2:12 ` Jingoo Han
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