| Message ID | 20170112034121.27697-6-f.fainelli@gmail.com |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Florian Fainelli <f.fainelli@gmail.com> Date: Wed, 11 Jan 2017 19:41:16 -0800 > Add a helper function to lookup a device reference given a class name. > This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and > make it more generic. > > Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> > --- > drivers/base/core.c | 19 +++++++++++++++++++ > include/linux/device.h | 1 + > 2 files changed, 20 insertions(+) > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index 020ea7f05520..3dd6047c10d8 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -2065,6 +2065,25 @@ struct device *device_find_child(struct device *parent, void *data, > } > EXPORT_SYMBOL_GPL(device_find_child); > > +static int dev_is_class(struct device *dev, void *class) I know you are just moving code, but this class argumnet is a string and thus should be "char *" or even "const char *".
On 01/12/2017 01:21 PM, David Miller wrote: > From: Florian Fainelli <f.fainelli@gmail.com> > Date: Wed, 11 Jan 2017 19:41:16 -0800 > >> Add a helper function to lookup a device reference given a class name. >> This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and >> make it more generic. >> >> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> >> --- >> drivers/base/core.c | 19 +++++++++++++++++++ >> include/linux/device.h | 1 + >> 2 files changed, 20 insertions(+) >> >> diff --git a/drivers/base/core.c b/drivers/base/core.c >> index 020ea7f05520..3dd6047c10d8 100644 >> --- a/drivers/base/core.c >> +++ b/drivers/base/core.c >> @@ -2065,6 +2065,25 @@ struct device *device_find_child(struct device *parent, void *data, >> } >> EXPORT_SYMBOL_GPL(device_find_child); >> >> +static int dev_is_class(struct device *dev, void *class) > > I know you are just moving code, but this class argumnet is a string > and thus should be "char *" or even "const char *". Well, this is really so that we don't need to cast the arguments passed to device_find_child(), which takes a void *data as well. If we made that a const char *class, we'd get warnings that look like these: drivers/base/core.c: In function 'device_find_class': drivers/base/core.c:2083:2: warning: passing argument 2 of 'device_find_child' discards 'const' qualifier from pointer target type [enabled by default] return device_find_child(parent, class, dev_is_class); ^ drivers/base/core.c:2050:16: note: expected 'void *' but argument is of type 'const char *' struct device *device_find_child(struct device *parent, void *data, ^ drivers/base/core.c:2083:2: warning: passing argument 3 of 'device_find_child' from incompatible pointer type [enabled by default] return device_find_child(parent, class, dev_is_class); ^ drivers/base/core.c:2050:16: note: expected 'int (*)(struct device *, void *)' but argument is of type 'int (*)(struct device *, const char *)' struct device *device_find_child(struct device *parent, void *data, ^
From: Florian Fainelli <f.fainelli@gmail.com> Date: Thu, 12 Jan 2017 14:50:39 -0800 > Well, this is really so that we don't need to cast the arguments passed > to device_find_child(), which takes a void *data as well. Aha, I didn't catch that, my bad.
From: Florian Fainelli > Sent: 12 January 2017 22:51 > On 01/12/2017 01:21 PM, David Miller wrote: > > From: Florian Fainelli <f.fainelli@gmail.com> > > Date: Wed, 11 Jan 2017 19:41:16 -0800 > > > >> Add a helper function to lookup a device reference given a class name. > >> This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and > >> make it more generic. ... > >> +static int dev_is_class(struct device *dev, void *class) > > > > I know you are just moving code, but this class argumnet is a string > > and thus should be "char *" or even "const char *". > > Well, this is really so that we don't need to cast the arguments passed > to device_find_child(), which takes a void *data as well. If we made > that a const char *class, we'd get warnings that look like these: > > drivers/base/core.c: In function 'device_find_class': > drivers/base/core.c:2083:2: warning: passing argument 2 of > 'device_find_child' discards 'const' qualifier from pointer target type > [enabled by default] > return device_find_child(parent, class, dev_is_class); > ^ > drivers/base/core.c:2050:16: note: expected 'void *' but argument is of > type 'const char *' > struct device *device_find_child(struct device *parent, void *data, > ^ ... Maybe device_find_child() needs changing to take 'const void *' ? David
On 01/13/2017 02:55 AM, David Laight wrote: > From: Florian Fainelli >> Sent: 12 January 2017 22:51 >> On 01/12/2017 01:21 PM, David Miller wrote: >>> From: Florian Fainelli <f.fainelli@gmail.com> >>> Date: Wed, 11 Jan 2017 19:41:16 -0800 >>> >>>> Add a helper function to lookup a device reference given a class name. >>>> This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and >>>> make it more generic. > ... >>>> +static int dev_is_class(struct device *dev, void *class) >>> >>> I know you are just moving code, but this class argumnet is a string >>> and thus should be "char *" or even "const char *". >> >> Well, this is really so that we don't need to cast the arguments passed >> to device_find_child(), which takes a void *data as well. If we made >> that a const char *class, we'd get warnings that look like these: >> >> drivers/base/core.c: In function 'device_find_class': >> drivers/base/core.c:2083:2: warning: passing argument 2 of >> 'device_find_child' discards 'const' qualifier from pointer target type >> [enabled by default] >> return device_find_child(parent, class, dev_is_class); >> ^ >> drivers/base/core.c:2050:16: note: expected 'void *' but argument is of >> type 'const char *' >> struct device *device_find_child(struct device *parent, void *data, >> ^ > ... > > Maybe device_find_child() needs changing to take 'const void *' ? As a separate patch set, sure, I will add that to my TODO. Thanks!
diff --git a/drivers/base/core.c b/drivers/base/core.c index 020ea7f05520..3dd6047c10d8 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2065,6 +2065,25 @@ struct device *device_find_child(struct device *parent, void *data, } EXPORT_SYMBOL_GPL(device_find_child); +static int dev_is_class(struct device *dev, void *class) +{ + if (dev->class != NULL && !strcmp(dev->class->name, class)) + return 1; + + return 0; +} + +struct device *device_find_class(struct device *parent, char *class) +{ + if (dev_is_class(parent, class)) { + get_device(parent); + return parent; + } + + return device_find_child(parent, class, dev_is_class); +} +EXPORT_SYMBOL_GPL(device_find_class); + int __init devices_init(void) { devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL); diff --git a/include/linux/device.h b/include/linux/device.h index 491b4c0ca633..8d37f5ecb972 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1120,6 +1120,7 @@ extern int device_for_each_child_reverse(struct device *dev, void *data, int (*fn)(struct device *dev, void *data)); extern struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); +extern struct device *device_find_class(struct device *parent, char *class); extern int device_rename(struct device *dev, const char *new_name); extern int device_move(struct device *dev, struct device *new_parent, enum dpm_order dpm_order);
Add a helper function to lookup a device reference given a class name. This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and make it more generic. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> --- drivers/base/core.c | 19 +++++++++++++++++++ include/linux/device.h | 1 + 2 files changed, 20 insertions(+)