Messages in this thread Patch in this message | | | Date | Sat, 12 Jan 2008 17:47:54 +0800 | From | Dave Young <> | Subject | [PATCH 1/7] driver-core : add class iteration api |
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Add the following class iteration functions for driver use: class_for_each_device class_find_device class_for_each_child class_find_child
Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
--- drivers/base/class.c | 159 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/device.h | 8 ++ 2 files changed, 167 insertions(+)
diff -upr linux/drivers/base/class.c linux.new/drivers/base/class.c --- linux/drivers/base/class.c 2008-01-12 14:42:24.000000000 +0800 +++ linux.new/drivers/base/class.c 2008-01-12 14:42:24.000000000 +0800 @@ -798,6 +798,165 @@ void class_device_put(struct class_devic kobject_put(&class_dev->kobj); } +/** + * class_for_each_device - device iterator + * @class: the class we're iterating + * @data: data for the callback + * @fn: function to be called for each device + * + * Iterate over @class's list of devices, and call @fn for each, + * passing it @data. + * + * We check the return of @fn each time. If it returns anything + * other than 0, we break out and return that value. + */ +int class_for_each_device(struct class *class, void *data, + int (*fn)(struct device *, void *)) +{ + struct device *dev; + int error = 0; + + if (!class) + return -EINVAL; + down(&class->sem); + list_for_each_entry(dev, &class->devices, node) { + dev = get_device(dev); + if (dev) { + error = fn(dev, data); + put_device(dev); + } else + error = -ENODEV; + if (error) + break; + } + up(&class->sem); + + return error; +} +EXPORT_SYMBOL_GPL(class_for_each_device); + +/** + * class_find_device - device iterator for locating a particular device + * @class: the class we're iterating + * @data: data for the match function + * @match: function to check device + * + * This is similar to the class_for_each_dev() function above, but it + * returns a reference to a device that is 'found' for later use, as + * determined by the @match callback. + * + * The callback should return 0 if the device doesn't match and non-zero + * if it does. If the callback returns non-zero, this function will + * return to the caller and not iterate over any more devices. + */ +struct device *class_find_device(struct class *class, void *data, + int (*match)(struct device *, void *)) +{ + struct device *dev; + int error = 1; + + if (!class) + return NULL; + + down(&class->sem); + list_for_each_entry(dev, &class->devices, node) { + dev = get_device(dev); + if (dev) { + if (match(dev, data)) { + error = 0; + break; + } else + put_device(dev); + } else + break; + } + up(&class->sem); + + if (error) + return NULL; + return dev; +} +EXPORT_SYMBOL_GPL(class_find_device); + +/** + * class_for_each_child - class child iterator + * @class: the class we're iterating + * @data: data for the callback + * @fn: function to be called for each child of the class + * + * Iterate over @class's list of children, and call @fn for each, + * passing it @data. + * + * We check the return of @fn each time. If it returns anything + * other than 0, we break out and return that value. + */ +int class_for_each_child(struct class *class, void *data, + int (*fn)(struct class_device *, void *)) +{ + struct class_device *dev; + int error = 0; + + if (!class) + return -EINVAL; + down(&class->sem); + list_for_each_entry(dev, &class->children, node) { + dev = class_device_get(dev); + if (dev) { + error = fn(dev, data); + class_device_put(dev); + } else + error = -ENODEV; + if (error) + break; + } + up(&class->sem); + + return error; +} +EXPORT_SYMBOL_GPL(class_for_each_child); + +/** + * class_find_child - device iterator for locating a particular class_device + * @class: the class we're iterating + * @data: data for the match function + * @match: function to check class_device + * + * This is similar to the class_for_each_child() function above, but it + * returns a reference to a class_device that is 'found' for later use, as + * determined by the @match callback. + * + * The callback should return 0 if the class_device doesn't match and non-zero + * if it does. If the callback returns non-zero, this function will + * return to the caller and not iterate over any more class_devices. + */ +struct class_device *class_find_child(struct class *class, void *data, + int (*match)(struct class_device *, void *)) +{ + struct class_device *dev; + int error = 1; + + if (!class) + return NULL; + + down(&class->sem); + list_for_each_entry(dev, &class->children, node) { + dev = class_device_get(dev); + if (dev) { + if (match(dev, data)) { + error = 0; + break; + } else + class_device_put(dev); + } else + break; + } + up(&class->sem); + + if (error) + return NULL; + return dev; +} +EXPORT_SYMBOL_GPL(class_find_child); int class_interface_register(struct class_interface *class_intf) { diff -upr linux/include/linux/device.h linux.new/include/linux/device.h --- linux/include/linux/device.h 2008-01-12 14:42:24.000000000 +0800 +++ linux.new/include/linux/device.h 2008-01-12 14:42:24.000000000 +0800 @@ -199,6 +199,14 @@ struct class { extern int __must_check class_register(struct class *); extern void class_unregister(struct class *); +extern int class_for_each_device(struct class *class, void *data, + int (*fn)(struct device *dev, void *data)); +extern struct device *class_find_device(struct class *class, void *data, + int (*match)(struct device *, void *)); +extern int class_for_each_child(struct class *class, void *data, + int (*fn)(struct class_device *, void *)); +extern struct class_device *class_find_child(struct class *class, void *data, + int (*match)(struct class_device *, void *)); struct class_attribute {
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