diff options
Diffstat (limited to 'include/linux/device.h')
| -rw-r--r-- | include/linux/device.h | 172 |
1 files changed, 158 insertions, 14 deletions
diff --git a/include/linux/device.h b/include/linux/device.h index ab8dfc095709..c66111affca9 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -47,6 +47,38 @@ extern int __must_check bus_create_file(struct bus_type *, struct bus_attribute *); extern void bus_remove_file(struct bus_type *, struct bus_attribute *); +/** + * struct bus_type - The bus type of the device + * + * @name: The name of the bus. + * @bus_attrs: Default attributes of the bus. + * @dev_attrs: Default attributes of the devices on the bus. + * @drv_attrs: Default attributes of the device drivers on the bus. + * @match: Called, perhaps multiple times, whenever a new device or driver + * is added for this bus. It should return a nonzero value if the + * given device can be handled by the given driver. + * @uevent: Called when a device is added, removed, or a few other things + * that generate uevents to add the environment variables. + * @probe: Called when a new device or driver add to this bus, and callback + * the specific driver's probe to initial the matched device. + * @remove: Called when a device removed from this bus. + * @shutdown: Called at shut-down time to quiesce the device. + * @suspend: Called when a device on this bus wants to go to sleep mode. + * @resume: Called to bring a device on this bus out of sleep mode. + * @pm: Power management operations of this bus, callback the specific + * device driver's pm-ops. + * @p: The private data of the driver core, only the driver core can + * touch this. + * + * A bus is a channel between the processor and one or more devices. For the + * purposes of the device model, all devices are connected via a bus, even if + * it is an internal, virtual, "platform" bus. Buses can plug into each other. + * A USB controller is usually a PCI device, for example. The device model + * represents the actual connections between buses and the devices they control. + * A bus is represented by the bus_type structure. It contains the name, the + * default attributes, the bus' methods, PM operations, and the driver core's + * private data. + */ struct bus_type { const char *name; struct bus_attribute *bus_attrs; @@ -119,6 +151,37 @@ extern int bus_unregister_notifier(struct bus_type *bus, extern struct kset *bus_get_kset(struct bus_type *bus); extern struct klist *bus_get_device_klist(struct bus_type *bus); +/** + * struct device_driver - The basic device driver structure + * @name: Name of the device driver. + * @bus: The bus which the device of this driver belongs to. + * @owner: The module owner. + * @mod_name: Used for built-in modules. + * @suppress_bind_attrs: Disables bind/unbind via sysfs. + * @of_match_table: The open firmware table. + * @probe: Called to query the existence of a specific device, + * whether this driver can work with it, and bind the driver + * to a specific device. + * @remove: Called when the device is removed from the system to + * unbind a device from this driver. + * @shutdown: Called at shut-down time to quiesce the device. + * @suspend: Called to put the device to sleep mode. Usually to a + * low power state. + * @resume: Called to bring a device from sleep mode. + * @groups: Default attributes that get created by the driver core + * automatically. + * @pm: Power management operations of the device which matched + * this driver. + * @p: Driver core's private data, no one other than the driver + * core can touch this. + * + * The device driver-model tracks all of the drivers known to the system. + * The main reason for this tracking is to enable the driver core to match + * up drivers with new devices. Once drivers are known objects within the + * system, however, a number of other things become possible. Device drivers + * can export information and configuration variables that are independent + * of any specific device. + */ struct device_driver { const char *name; struct bus_type *bus; @@ -185,8 +248,34 @@ struct device *driver_find_device(struct device_driver *drv, struct device *start, void *data, int (*match)(struct device *dev, void *data)); -/* - * device classes +/** + * struct class - device classes + * @name: Name of the class. + * @owner: The module owner. + * @class_attrs: Default attributes of this class. + * @dev_attrs: Default attributes of the devices belong to the class. + * @dev_bin_attrs: Default binary attributes of the devices belong to the class. + * @dev_kobj: The kobject that represents this class and links it into the hierarchy. + * @dev_uevent: Called when a device is added, removed from this class, or a + * few other things that generate uevents to add the environment + * variables. + * @devnode: Callback to provide the devtmpfs. + * @class_release: Called to release this class. + * @dev_release: Called to release the device. + * @suspend: Used to put the device to sleep mode, usually to a low power + * state. + * @resume: Used to bring the device from the sleep mode. + * @ns_type: Callbacks so sysfs can detemine namespaces. + * @namespace: Namespace of the device belongs to this class. + * @pm: The default device power management operations of this class. + * @p: The private data of the driver core, no one other than the + * driver core can touch this. + * + * A class is a higher-level view of a device that abstracts out low-level + * implementation details. Drivers may see a SCSI disk or an ATA disk, but, + * at the class level, they are all simply disks. Classes allow user space + * to work with devices based on what they do, rather than how they are + * connected or how they work. */ struct class { const char *name; @@ -401,6 +490,65 @@ struct device_dma_parameters { unsigned long segment_boundary_mask; }; +/** + * struct device - The basic device structure + * @parent: The device's "parent" device, the device to which it is attached. + * In most cases, a parent device is some sort of bus or host + * controller. If parent is NULL, the device, is a top-level device, + * which is not usually what you want. + * @p: Holds the private data of the driver core portions of the device. + * See the comment of the struct device_private for detail. + * @kobj: A top-level, abstract class from which other classes are derived. + * @init_name: Initial name of the device. + * @type: The type of device. + * This identifies the device type and carries type-specific + * information. + * @mutex: Mutex to synchronize calls to its driver. + * @bus: Type of bus device is on. + * @driver: Which driver has allocated this + * @platform_data: Platform data specific to the device. + * Example: For devices on custom boards, as typical of embedded + * and SOC based hardware, Linux often uses platform_data to point + * to board-specific structures describing devices and how they + * are wired. That can include what ports are available, chip + * variants, which GPIO pins act in what additional roles, and so + * on. This shrinks the "Board Support Packages" (BSPs) and + * minimizes board-specific #ifdefs in drivers. + * @power: For device power management. + * See Documentation/power/devices.txt for details. + * @pwr_domain: Provide callbacks that are executed during system suspend, + * hibernation, system resume and during runtime PM transitions + * along with subsystem-level and driver-level callbacks. + * @numa_node: NUMA node this device is close to. + * @dma_mask: Dma mask (if dma'ble device). + * @coherent_dma_mask: Like dma_mask, but for alloc_coherent mapping as not all + * hardware supports 64-bit addresses for consistent allocations + * such descriptors. + * @dma_parms: A low level driver may set these to teach IOMMU code about + * segment limitations. + * @dma_pools: Dma pools (if dma'ble device). + * @dma_mem: Internal for coherent mem override. + * @archdata: For arch-specific additions. + * @of_node: Associated device tree node. + * @of_match: Matching of_device_id from driver. + * @devt: For creating the sysfs "dev". + * @devres_lock: Spinlock to protect the resource of the device. + * @devres_head: The resources list of the device. + * @knode_class: The node used to add the device to the class list. + * @class: The class of the device. + * @groups: Optional attribute groups. + * @release: Callback to free the device after all references have + * gone away. This should be set by the allocator of the + * device (i.e. the bus driver that discovered the device). + * + * At the lowest level, every device in a Linux system is represented by an + * instance of struct device. The device structure contains the information + * that the device model core needs to model the system. Most subsystems, + * however, track additional information about the devices they host. As a + * result, it is rare for devices to be represented by bare device structures; + * instead, that structure, like kobject structures, is usually embedded within + * a higher-level representation of the device. + */ struct device { struct device *parent; @@ -408,7 +556,7 @@ struct device { struct kobject kobj; const char *init_name; /* initial name of the device */ - struct device_type *type; + const struct device_type *type; struct mutex mutex; /* mutex to synchronize calls to * its driver. @@ -442,7 +590,6 @@ struct device { struct dev_archdata archdata; struct device_node *of_node; /* associated device tree node */ - const struct of_device_id *of_match; /* matching of_device_id from driver */ dev_t devt; /* dev_t, creates the sysfs "dev" */ @@ -557,7 +704,7 @@ extern int device_move(struct device *dev, struct device *new_parent, extern const char *device_get_devnode(struct device *dev, mode_t *mode, const char **tmp); extern void *dev_get_drvdata(const struct device *dev); -extern void dev_set_drvdata(struct device *dev, void *data); +extern int dev_set_drvdata(struct device *dev, void *data); /* * Root device objects for grouping under /sys/devices @@ -611,7 +758,7 @@ extern int (*platform_notify)(struct device *dev); extern int (*platform_notify_remove)(struct device *dev); -/** +/* * get_device - atomically increment the reference count for the device. * */ @@ -633,13 +780,6 @@ static inline int devtmpfs_mount(const char *mountpoint) { return 0; } /* drivers/base/power/shutdown.c */ extern void device_shutdown(void); -#ifndef CONFIG_ARCH_NO_SYSDEV_OPS -/* drivers/base/sys.c */ -extern void sysdev_shutdown(void); -#else -static inline void sysdev_shutdown(void) { } -#endif - /* debugging and troubleshooting/diagnostic helpers. */ extern const char *dev_driver_string(const struct device *dev); @@ -742,13 +882,17 @@ do { \ #endif /* - * dev_WARN() acts like dev_printk(), but with the key difference + * dev_WARN*() acts like dev_printk(), but with the key difference * of using a WARN/WARN_ON to get the message out, including the * file/line information and a backtrace. */ #define dev_WARN(dev, format, arg...) \ WARN(1, "Device: %s\n" format, dev_driver_string(dev), ## arg); +#define dev_WARN_ONCE(dev, condition, format, arg...) \ + WARN_ONCE(condition, "Device %s\n" format, \ + dev_driver_string(dev), ## arg) + /* Create alias, so I can be autoloaded. */ #define MODULE_ALIAS_CHARDEV(major,minor) \ MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor)) |