From 39ef311204941ddd01ea2950d6220c8ccc710d15 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Sun, 14 Jul 2013 16:05:57 -0700 Subject: [PATCH] driver core: Introduce device_create_groups device_create_groups lets callers create devices as well as associated sysfs attributes with a single call. This avoids race conditions seen if sysfs attributes on new devices are created later. [fixed up comment block placement and add checks for printk buffer formats - gregkh] Signed-off-by: Guenter Roeck Cc: Jean Delvare Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 117 ++++++++++++++++++++++++++++++----------- include/linux/device.h | 5 ++ 2 files changed, 91 insertions(+), 31 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index dc3ea237f086..a8aae1823f73 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -1667,6 +1667,46 @@ static void device_create_release(struct device *dev) kfree(dev); } +static struct device * +device_create_groups_vargs(struct class *class, struct device *parent, + dev_t devt, void *drvdata, + const struct attribute_group **groups, + const char *fmt, va_list args) +{ + struct device *dev = NULL; + int retval = -ENODEV; + + if (class == NULL || IS_ERR(class)) + goto error; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) { + retval = -ENOMEM; + goto error; + } + + dev->devt = devt; + dev->class = class; + dev->parent = parent; + dev->groups = groups; + dev->release = device_create_release; + dev_set_drvdata(dev, drvdata); + + retval = kobject_set_name_vargs(&dev->kobj, fmt, args); + if (retval) + goto error; + + retval = device_register(dev); + if (retval) + goto error; + + return dev; + +error: + put_device(dev); + return ERR_PTR(retval); +} + /** * device_create_vargs - creates a device and registers it with sysfs * @class: pointer to the struct class that this device should be registered to @@ -1696,37 +1736,8 @@ struct device *device_create_vargs(struct class *class, struct device *parent, dev_t devt, void *drvdata, const char *fmt, va_list args) { - struct device *dev = NULL; - int retval = -ENODEV; - - if (class == NULL || IS_ERR(class)) - goto error; - - dev = kzalloc(sizeof(*dev), GFP_KERNEL); - if (!dev) { - retval = -ENOMEM; - goto error; - } - - dev->devt = devt; - dev->class = class; - dev->parent = parent; - dev->release = device_create_release; - dev_set_drvdata(dev, drvdata); - - retval = kobject_set_name_vargs(&dev->kobj, fmt, args); - if (retval) - goto error; - - retval = device_register(dev); - if (retval) - goto error; - - return dev; - -error: - put_device(dev); - return ERR_PTR(retval); + return device_create_groups_vargs(class, parent, devt, drvdata, NULL, + fmt, args); } EXPORT_SYMBOL_GPL(device_create_vargs); @@ -1767,6 +1778,50 @@ struct device *device_create(struct class *class, struct device *parent, } EXPORT_SYMBOL_GPL(device_create); +/** + * device_create_with_groups - creates a device and registers it with sysfs + * @class: pointer to the struct class that this device should be registered to + * @parent: pointer to the parent struct device of this new device, if any + * @devt: the dev_t for the char device to be added + * @drvdata: the data to be added to the device for callbacks + * @groups: NULL-terminated list of attribute groups to be created + * @fmt: string for the device's name + * + * This function can be used by char device classes. A struct device + * will be created in sysfs, registered to the specified class. + * Additional attributes specified in the groups parameter will also + * be created automatically. + * + * A "dev" file will be created, showing the dev_t for the device, if + * the dev_t is not 0,0. + * If a pointer to a parent struct device is passed in, the newly created + * struct device will be a child of that device in sysfs. + * The pointer to the struct device will be returned from the call. + * Any further sysfs files that might be required can be created using this + * pointer. + * + * Returns &struct device pointer on success, or ERR_PTR() on error. + * + * Note: the struct class passed to this function must have previously + * been created with a call to class_create(). + */ +struct device *device_create_with_groups(struct class *class, + struct device *parent, dev_t devt, + void *drvdata, + const struct attribute_group **groups, + const char *fmt, ...) +{ + va_list vargs; + struct device *dev; + + va_start(vargs, fmt); + dev = device_create_groups_vargs(class, parent, devt, drvdata, groups, + fmt, vargs); + va_end(vargs); + return dev; +} +EXPORT_SYMBOL_GPL(device_create_with_groups); + static int __match_devt(struct device *dev, const void *data) { const dev_t *devt = data; diff --git a/include/linux/device.h b/include/linux/device.h index f207a8f49f80..bd5931e89f74 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -938,6 +938,11 @@ extern __printf(5, 6) struct device *device_create(struct class *cls, struct device *parent, dev_t devt, void *drvdata, const char *fmt, ...); +extern __printf(6, 7) +struct device *device_create_with_groups(struct class *cls, + struct device *parent, dev_t devt, void *drvdata, + const struct attribute_group **groups, + const char *fmt, ...); extern void device_destroy(struct class *cls, dev_t devt); /*