diff options
Diffstat (limited to 'drivers/base/core.c')
| -rw-r--r-- | drivers/base/core.c | 201 |
1 files changed, 198 insertions, 3 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index 6b355bd7816..b21f864c9ce 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -8,13 +8,13 @@ * */ -#include <linux/config.h> #include <linux/device.h> #include <linux/err.h> #include <linux/init.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/string.h> +#include <linux/kdev_t.h> #include <asm/semaphore.h> @@ -28,6 +28,22 @@ int (*platform_notify_remove)(struct device * dev) = NULL; * sysfs bindings for devices. */ +/** + * dev_driver_string - Return a device's driver name, if at all possible + * @dev: struct device to get the name of + * + * Will return the device's driver's name if it is bound to a device. If + * the device is not bound to a device, it will return the name of the bus + * it is attached to. If it is not attached to a bus either, an empty + * string will be returned. + */ +const char *dev_driver_string(struct device *dev) +{ + return dev->driver ? dev->driver->name : + (dev->bus ? dev->bus->name : ""); +} +EXPORT_SYMBOL_GPL(dev_driver_string); + #define to_dev(obj) container_of(obj, struct device, kobj) #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) @@ -98,6 +114,8 @@ static int dev_uevent_filter(struct kset *kset, struct kobject *kobj) struct device *dev = to_dev(kobj); if (dev->bus) return 1; + if (dev->class) + return 1; } return 0; } @@ -106,7 +124,11 @@ static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj) { struct device *dev = to_dev(kobj); - return dev->bus->name; + if (dev->bus) + return dev->bus->name; + if (dev->class) + return dev->class->name; + return NULL; } static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp, @@ -117,6 +139,16 @@ static int dev_uevent(struct kset *kset, struct kobject *kobj, char **envp, int length = 0; int retval = 0; + /* add the major/minor if present */ + if (MAJOR(dev->devt)) { + add_uevent_var(envp, num_envp, &i, + buffer, buffer_size, &length, + "MAJOR=%u", MAJOR(dev->devt)); + add_uevent_var(envp, num_envp, &i, + buffer, buffer_size, &length, + "MINOR=%u", MINOR(dev->devt)); + } + /* add bus name of physical device */ if (dev->bus) add_uevent_var(envp, num_envp, &i, @@ -161,6 +193,12 @@ static ssize_t store_uevent(struct device *dev, struct device_attribute *attr, return count; } +static ssize_t show_dev(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return print_dev_t(buf, dev->devt); +} + /* * devices_subsys - structure to be registered with kobject core. */ @@ -231,6 +269,7 @@ void device_initialize(struct device *dev) klist_init(&dev->klist_children, klist_children_get, klist_children_put); INIT_LIST_HEAD(&dev->dma_pools); + INIT_LIST_HEAD(&dev->node); init_MUTEX(&dev->sem); device_init_wakeup(dev, 0); } @@ -249,6 +288,7 @@ void device_initialize(struct device *dev) int device_add(struct device *dev) { struct device *parent = NULL; + char *class_name = NULL; int error = -EINVAL; dev = get_device(dev); @@ -274,23 +314,69 @@ int device_add(struct device *dev) dev->uevent_attr.store = store_uevent; device_create_file(dev, &dev->uevent_attr); - kobject_uevent(&dev->kobj, KOBJ_ADD); + if (MAJOR(dev->devt)) { + struct device_attribute *attr; + attr = kzalloc(sizeof(*attr), GFP_KERNEL); + if (!attr) { + error = -ENOMEM; + goto PMError; + } + attr->attr.name = "dev"; + attr->attr.mode = S_IRUGO; + if (dev->driver) + attr->attr.owner = dev->driver->owner; + attr->show = show_dev; + error = device_create_file(dev, attr); + if (error) { + kfree(attr); + goto attrError; + } + + dev->devt_attr = attr; + } + + if (dev->class) { + sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj, + "subsystem"); + sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj, + dev->bus_id); + + sysfs_create_link(&dev->kobj, &dev->parent->kobj, "device"); + class_name = make_class_name(dev->class->name, &dev->kobj); + sysfs_create_link(&dev->parent->kobj, &dev->kobj, class_name); + } + if ((error = device_pm_add(dev))) goto PMError; if ((error = bus_add_device(dev))) goto BusError; + kobject_uevent(&dev->kobj, KOBJ_ADD); + bus_attach_device(dev); if (parent) klist_add_tail(&dev->knode_parent, &parent->klist_children); + if (dev->class) { + /* tie the class to the device */ + down(&dev->class->sem); + list_add_tail(&dev->node, &dev->class->devices); + up(&dev->class->sem); + } + /* notify platform of device entry */ if (platform_notify) platform_notify(dev); Done: + kfree(class_name); put_device(dev); return error; BusError: device_pm_remove(dev); PMError: + if (dev->devt_attr) { + device_remove_file(dev, dev->devt_attr); + kfree(dev->devt_attr); + } + attrError: kobject_uevent(&dev->kobj, KOBJ_REMOVE); kobject_del(&dev->kobj); Error: @@ -362,9 +448,23 @@ void put_device(struct device * dev) void device_del(struct device * dev) { struct device * parent = dev->parent; + char *class_name = NULL; if (parent) klist_del(&dev->knode_parent); + if (dev->devt_attr) + device_remove_file(dev, dev->devt_attr); + if (dev->class) { + sysfs_remove_link(&dev->kobj, "subsystem"); + sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id); + class_name = make_class_name(dev->class->name, &dev->kobj); + sysfs_remove_link(&dev->kobj, "device"); + sysfs_remove_link(&dev->parent->kobj, class_name); + kfree(class_name); + down(&dev->class->sem); + list_del_init(&dev->node); + up(&dev->class->sem); + } device_remove_file(dev, &dev->uevent_attr); /* Notify the platform of the removal, in case they @@ -449,3 +549,98 @@ EXPORT_SYMBOL_GPL(put_device); EXPORT_SYMBOL_GPL(device_create_file); EXPORT_SYMBOL_GPL(device_remove_file); + + +static void device_create_release(struct device *dev) +{ + pr_debug("%s called for %s\n", __FUNCTION__, dev->bus_id); + kfree(dev); +} + +/** + * device_create - creates a device and registers it with sysfs + * @cs: 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. + * @dev: the dev_t for the char device to be added. + * @fmt: string for the class 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. + * 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. + * + * Note: the struct class passed to this function must have previously + * been created with a call to class_create(). + */ +struct device *device_create(struct class *class, struct device *parent, + dev_t devt, char *fmt, ...) +{ + va_list args; + struct device *dev = NULL; + int retval = -ENODEV; + + if (class == NULL || IS_ERR(class)) + goto error; + if (parent == NULL) { + printk(KERN_WARNING "%s does not work yet for NULL parents\n", __FUNCTION__); + 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; + + va_start(args, fmt); + vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args); + va_end(args); + retval = device_register(dev); + if (retval) + goto error; + + return dev; + +error: + kfree(dev); + return ERR_PTR(retval); +} +EXPORT_SYMBOL_GPL(device_create); + +/** + * device_destroy - removes a device that was created with device_create() + * @class: the pointer to the struct class that this device was registered * with. + * @dev: the dev_t of the device that was previously registered. + * + * This call unregisters and cleans up a class device that was created with a + * call to class_device_create() + */ +void device_destroy(struct class *class, dev_t devt) +{ + struct device *dev = NULL; + struct device *dev_tmp; + + down(&class->sem); + list_for_each_entry(dev_tmp, &class->devices, node) { + if (dev_tmp->devt == devt) { + dev = dev_tmp; + break; + } + } + up(&class->sem); + + if (dev) + device_unregister(dev); +} +EXPORT_SYMBOL_GPL(device_destroy); |