usbhost.h revision 120b57a3d9703bccba534af335aa94dd3a41be2f
1/* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#ifndef __USB_HOST_H 18#define __USB_HOST_H 19 20#ifdef __cplusplus 21extern "C" { 22#endif 23 24#include <stdint.h> 25 26#include <linux/version.h> 27#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 20) 28#include <linux/usb/ch9.h> 29#else 30#include <linux/usb_ch9.h> 31#endif 32 33struct usb_host_context; 34struct usb_endpoint_descriptor; 35 36struct usb_descriptor_iter { 37 unsigned char* config; 38 unsigned char* config_end; 39 unsigned char* curr_desc; 40}; 41 42struct usb_request 43{ 44 struct usb_device *dev; 45 void* buffer; 46 int buffer_length; 47 int actual_length; 48 int max_packet_size; 49 void *private_data; /* struct usbdevfs_urb* */ 50 void *client_data; /* free for use by client */ 51}; 52 53/* Callback for notification when new USB devices are attached. 54 * Return true to exit from usb_host_run. 55 */ 56typedef int (* usb_device_added_cb)(const char *dev_name, void *client_data); 57 58/* Callback for notification when USB devices are removed. 59 * Return true to exit from usb_host_run. 60 */ 61typedef int (* usb_device_removed_cb)(const char *dev_name, void *client_data); 62 63/* Callback indicating that initial device discovery is done. 64 * Return true to exit from usb_host_run. 65 */ 66typedef int (* usb_discovery_done_cb)(void *client_data); 67 68/* Call this to initialize the USB host library. */ 69struct usb_host_context *usb_host_init(void); 70 71/* Call this to cleanup the USB host library. */ 72void usb_host_cleanup(struct usb_host_context *context); 73 74/* Call this to monitor the USB bus for new and removed devices. 75 * This is intended to be called from a dedicated thread, 76 * as it will not return until one of the callbacks returns true. 77 * added_cb will be called immediately for each existing USB device, 78 * and subsequently each time a new device is added. 79 * removed_cb is called when USB devices are removed from the bus. 80 * discovery_done_cb is called after the initial discovery of already 81 * connected devices is complete. 82 */ 83void usb_host_run(struct usb_host_context *context, 84 usb_device_added_cb added_cb, 85 usb_device_removed_cb removed_cb, 86 usb_discovery_done_cb discovery_done_cb, 87 void *client_data); 88 89/* Creates a usb_device object for a USB device */ 90struct usb_device *usb_device_open(const char *dev_name); 91 92/* Releases all resources associated with the USB device */ 93void usb_device_close(struct usb_device *device); 94 95/* Creates a usb_device object for already open USB device */ 96struct usb_device *usb_device_new(const char *dev_name, int fd); 97 98/* Returns the file descriptor for the usb_device */ 99int usb_device_get_fd(struct usb_device *device); 100 101/* Returns the name for the USB device, which is the same as 102 * the dev_name passed to usb_device_open() 103 */ 104const char* usb_device_get_name(struct usb_device *device); 105 106/* Returns a unique ID for the device. 107 *Currently this is generated from the dev_name path. 108 */ 109int usb_device_get_unique_id(struct usb_device *device); 110 111/* Returns a unique ID for the device name. 112 * Currently this is generated from the device path. 113 */ 114int usb_device_get_unique_id_from_name(const char* name); 115 116/* Returns the device name for the unique ID. 117 * Call free() to deallocate the returned string */ 118char* usb_device_get_name_from_unique_id(int id); 119 120/* Returns the USB vendor ID from the device descriptor for the USB device */ 121uint16_t usb_device_get_vendor_id(struct usb_device *device); 122 123/* Returns the USB product ID from the device descriptor for the USB device */ 124uint16_t usb_device_get_product_id(struct usb_device *device); 125 126const struct usb_device_descriptor* usb_device_get_device_descriptor(struct usb_device *device); 127 128/* Returns a USB descriptor string for the given string ID. 129 * Used to implement usb_device_get_manufacturer_name, 130 * usb_device_get_product_name and usb_device_get_serial. 131 * Call free() to free the result when you are done with it. 132 */ 133char* usb_device_get_string(struct usb_device *device, int id); 134 135/* Returns the manufacturer name for the USB device. 136 * Call free() to free the result when you are done with it. 137 */ 138char* usb_device_get_manufacturer_name(struct usb_device *device); 139 140/* Returns the product name for the USB device. 141 * Call free() to free the result when you are done with it. 142 */ 143char* usb_device_get_product_name(struct usb_device *device); 144 145/* Returns the USB serial number for the USB device. 146 * Call free() to free the result when you are done with it. 147 */ 148char* usb_device_get_serial(struct usb_device *device); 149 150/* Returns true if we have write access to the USB device, 151 * and false if we only have access to the USB device configuration. 152 */ 153int usb_device_is_writeable(struct usb_device *device); 154 155/* Initializes a usb_descriptor_iter, which can be used to iterate through all 156 * the USB descriptors for a USB device. 157 */ 158void usb_descriptor_iter_init(struct usb_device *device, struct usb_descriptor_iter *iter); 159 160/* Returns the next USB descriptor for a device, or NULL if we have reached the 161 * end of the list. 162 */ 163struct usb_descriptor_header *usb_descriptor_iter_next(struct usb_descriptor_iter *iter); 164 165/* Claims the specified interface of a USB device */ 166int usb_device_claim_interface(struct usb_device *device, unsigned int interface); 167 168/* Releases the specified interface of a USB device */ 169int usb_device_release_interface(struct usb_device *device, unsigned int interface); 170 171/* Requests the kernel to connect or disconnect its driver for the specified interface. 172 * This can be used to ask the kernel to disconnect its driver for a device 173 * so usb_device_claim_interface can claim it instead. 174 */ 175int usb_device_connect_kernel_driver(struct usb_device *device, 176 unsigned int interface, int connect); 177 178/* Sends a control message to the specified device on endpoint zero */ 179int usb_device_control_transfer(struct usb_device *device, 180 int requestType, 181 int request, 182 int value, 183 int index, 184 void* buffer, 185 int length, 186 unsigned int timeout); 187 188/* Reads or writes on a bulk endpoint */ 189int usb_device_bulk_transfer(struct usb_device *device, 190 int endpoint, 191 void* buffer, 192 int length, 193 unsigned int timeout); 194 195/* Creates a new usb_request. */ 196struct usb_request *usb_request_new(struct usb_device *dev, 197 const struct usb_endpoint_descriptor *ep_desc); 198 199/* Releases all resources associated with the request */ 200void usb_request_free(struct usb_request *req); 201 202/* Submits a read or write request on the specified device */ 203int usb_request_queue(struct usb_request *req); 204 205 /* Waits for the results of a previous usb_request_queue operation. 206 * Returns a usb_request, or NULL for error. 207 */ 208struct usb_request *usb_request_wait(struct usb_device *dev); 209 210/* Cancels a pending usb_request_queue() operation. */ 211int usb_request_cancel(struct usb_request *req); 212 213#ifdef __cplusplus 214} 215#endif 216#endif /* __USB_HOST_H */ 217