Linux下驱动的应用

struct usb_device { int devnum; /* Address on USB bus */ char devpath[16]; /* Use in messages: /port/port/... */ enum { USB_SPEED_UNKNOWN = 0, /* enumerating */ USB_SPEED_LOW, USB_SPEED_FULL, /* usb 1.1 */ USB_SPEED_HIGH /* usb 2.0 */ } speed; struct usb_tt *tt; /* low/full speed dev, highspeed hub */ int ttport; /* device port on that tt hub */ atomic_t refcnt; /* Reference count */ struct semaphore serialize; /* * This is our custom open-coded lock, similar to r/w locks in concept. * It prevents drivers and /proc access from simultaneous access. * Type: * 0 - unlocked * 1 - locked for reads * 2 - locked for writes * 3 - locked for everything */ wait_queue_head_t excl_wait; spinlock_t excl_lock; unsigned excl_type; unsigned int toggle[2]; /* one bit for each endpoint ([0] = IN, [1] = OUT) */ unsigned int halted[2]; /* endpoint halts; one bit per endpoint # & direction; */ /* [0] = IN, [1] = OUT */ int epmaxpacketin[16]; /* INput endpoint specific maximums */ int epmaxpacketout[16]; /* OUTput endpoint specific maximums */ struct usb_device *parent; struct usb_bus *bus; /* Bus we're part of */ struct usb_device_descriptor descriptor; /* Descriptor */ struct usb_config_descriptor *config; /* All of the configs */ struct usb_config_descriptor *actconfig; /* the active configuration */ char **rawdescriptors; /* Raw descriptors for each config */ int have_langid; /* whether string_langid is valid yet */ int string_langid; /* language ID for strings */ void *hcpriv; /* Host Controller private data */ /* usbdevfs inode list */ struct list_head inodes; struct list_head filelist; /* * Child devices - these can be either new devices * (if this is a hub device), or different instances * of this same device. * * Each instance needs its own set of data structures. */ int maxchild; /* Number of ports if hub */ struct usb_device *children[USB_MAXCHILDREN]; }; struct usb_bus { int busnum; /* Bus number (in order of reg) */ char *bus_name; /* stable id (PCI slot_name etc) */ #ifdef DEVNUM_ROUND_ROBIN int devnum_next; /* Next open device number in round-robin allocation */ #endif /* DEVNUM_ROUND_ROBIN */ struct usb_devmap devmap; /* Device map */ struct usb_operations *op; /* Operations (specific to the HC) */ struct usb_device *root_hub; /* Root hub */ struct list_head bus_list; void *hcpriv; /* Host Controller private data */ int bandwidth_allocated; /* on this Host Controller; */ /* applies to Int. and Isoc. pipes; */ /* measured in microseconds/frame; */ /* range is 0..900, where 900 = */ /* 90% of a 1-millisecond frame */ int bandwidth_int_reqs; /* number of Interrupt requesters */ int bandwidth_isoc_reqs; /* number of Isoc. requesters */ /* usbdevfs inode list */ struct list_head inodes; atomic_t refcnt; }; struct usb_driver { struct module *owner; const char *name; void *(*probe)(struct usb_device *dev, /* the device */ unsigned intf, /* what interface */ const struct usb_device_id *id /* from id_table */ ); void(*disconnect)(struct usb_device *, void*); struct list_head driver_list; struct file_operations *fops; int minor; struct semaphore serialize; int(*ioctl)(struct usb_device *dev, unsigned int code, void *buf); const struct usb_device_id *id_table; }; struct urb; typedef void(*usb_complete_t)(struct urb*); struct urb { spinlock_t lock; // lock for the URB void *hcpriv; // private data for host controller struct list_head urb_list; // list pointer to all active urbs struct urb *next; // pointer to next URB struct usb_device *dev; // pointer to associated USB device unsigned int pipe; // pipe information int status; // returned status unsigned int transfer_flags; // USB_DISABLE_SPD | USB_ISO_ASAP | etc. void *transfer_buffer; // associated data buffer dma_addr_t transfer_dma; // dma addr for transfer_buffer int transfer_buffer_length; // data buffer length int actual_length; // actual data buffer length int bandwidth; // bandwidth for this transfer request (INT or ISO) unsigned char *setup_packet; // setup packet (control only) dma_addr_t setup_dma; // dma addr for setup_packet // int start_frame; // start frame (iso/irq only) int number_of_packets; // number of packets in this request (iso) int interval; // polling interval (irq only) int error_count; // number of errors in this transfer (iso only) int timeout; // timeout (in jiffies) // void *context; // context for completion routine usb_complete_t complete; // pointer to completion routine // struct iso_packet_descriptor iso_frame_desc[0]; }; /* * urb->transfer_flags: */ #define USB_DISABLE_SPD 0x0001 #define URB_SHORT_NOT_OK USB_DISABLE_SPD #define USB_ISO_ASAP 0x0002 #define USB_ASYNC_UNLINK 0x0008 #define USB_QUEUE_BULK 0x0010 #define USB_NO_FSBR 0x0020 #define USB_ZERO_PACKET 0x0040 // Finish bulk OUTs always with zero length packet #define URB_NO_INTERRUPT 0x0080 /* HINT: no non-error interrupt needed */ /* ... less overhead for QUEUE_BULK */ #define USB_TIMEOUT_KILLED 0x1000 // only set by HCD! 10.3.4 USB内核函数接口分析 int usb_register(struct usb_driver *new_driver) { if (new_driver->fops != NULL) { if (usb_minors[new_driver->minor / 16]) { err("error registering %s driver", new_driver->name); return - EINVAL; } usb_minors[new_driver->minor / 16] = new_driver; } info("registered new driver %s", new_driver->name); init_MUTEX(&new_driver->serialize); /*将新驱动添加到驱动列表*/ list_add_tail(&new_driver->driver_list, &usb_driver_list); /*深度优先搜索设备，使驱动程序驱动它们的接口*/ usb_scan_devices(); return 0; } void usb_deregister(struct usb_driver *driver) { struct list_head *tmp; info("deregistering driver %s", driver->name); if (driver->fops != NULL) usb_minors[driver->minor / 16] = NULL; /* 从双向链表中摘下来 */ list_del(&driver->driver_list); down(&usb_bus_list_lock); tmp = usb_bus_list.next; while (tmp != &usb_bus_list) { struct usb_bus *bus = list_entry(tmp, struct usb_bus, bus_list); tmp = tmp->next; /*断开与设备接口连接，释放资源，为设备接口重新寻找新驱动*/ usb_drivers_purge(driver, bus->root_hub); } up(&usb_bus_list_lock); } int usb_get_class_descriptor(struct usb_device *dev, int ifnum, unsigned char type, unsigned char id, void *buf, int size) { return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), USB_REQ_GET_DESCRIPTOR, USB_RECIP_INTERFACE | USB_DIR_IN, (type << 8) + id, ifnum, buf, size, HZ * GET_TIMEOUT); } int usb_get_protocol(struct usb_device *dev, int ifnum) { unsigned char type; int ret; if ((ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), USB_REQ_GET_PROTOCOL, USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, ifnum, &type, 1, HZ * GET_TIMEOUT)) < 0) return ret; return type; } int usb_set_protocol(struct usb_device *dev, int ifnum, int protocol) { return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_PROTOCOL, USB_TYPE_CLASS | USB_RECIP_INTERFACE, protocol, ifnum, NULL, 0, HZ * SET_TIMEOUT); } int usb_get_report(struct usb_device *dev, int ifnum, unsigned char type, unsigned char id, void *buf, int size) { return usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), USB_REQ_GET_REPORT, USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, (type << 8) + id, ifnum, buf, size, HZ * GET_TIMEOUT); } int usb_set_report(struct usb_device *dev, int ifnum, unsigned char type, unsigned char id, void *buf, int size) { return usb_control_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_REPORT, USB_TYPE_CLASS | USB_RECIP_INTERFAC