From mboxrd@z Thu Jan 1 00:00:00 1970 From: f.fainelli@gmail.com (Florian Fainelli) Date: Tue, 17 Jan 2017 15:21:47 -0800 Subject: [PATCH net-next v4 05/10] drivers: base: Add device_find_in_class_name() In-Reply-To: <20170117232152.1661-1-f.fainelli@gmail.com> References: <20170117232152.1661-1-f.fainelli@gmail.com> Message-ID: <20170117232152.1661-6-f.fainelli@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- drivers/base/core.c | 31 +++++++++++++++++++++++++++++++ include/linux/device.h | 2 ++ 2 files changed, 33 insertions(+) diff --git a/drivers/base/core.c b/drivers/base/core.c index 8c25e68e67d7..fb9fced38634 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2058,6 +2058,37 @@ struct device *device_find_child(struct device *parent, void *data, } EXPORT_SYMBOL_GPL(device_find_child); +static int device_class_name_match(struct device *dev, void *class) +{ + if (dev->class != NULL && !strcmp(dev->class->name, class)) + return 1; + + return 0; +} + +/** + * device_find_in_class_name - device iterator for locating a particular device + * within the specified class name + * @parent: parent struct device + * @class_name: Class name to match against + * + * This function returns 1 if the device (specified by @parent), or one of its child + * is in the class whose name is specified by @class_name. Returns 0 otherwise. + * + * NOTE: you will need to drop the reference with put_device() after use. + */ +struct device *device_find_in_class_name(struct device *parent, + char *class_name) +{ + if (device_class_name_match(parent, class_name)) { + get_device(parent); + return parent; + } + + return device_find_child(parent, class_name, device_class_name_match); +} +EXPORT_SYMBOL_GPL(device_find_in_class_name); + 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..fbc2a255f92e 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1120,6 +1120,8 @@ 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_in_class_name(struct device *parent, + char *class_name); 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); -- 2.9.3