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      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
     21 extern "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 
     33 struct usb_host_context;
     34 struct usb_endpoint_descriptor;
     35 
     36 struct usb_descriptor_iter {
     37     unsigned char*  config;
     38     unsigned char*  config_end;
     39     unsigned char*  curr_desc;
     40 };
     41 
     42 struct 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     int endpoint;
     51     void *client_data;  /* free for use by client */
     52 };
     53 
     54 /* Callback for notification when new USB devices are attached.
     55  * Return true to exit from usb_host_run.
     56  */
     57 typedef int (* usb_device_added_cb)(const char *dev_name, void *client_data);
     58 
     59 /* Callback for notification when USB devices are removed.
     60  * Return true to exit from usb_host_run.
     61  */
     62 typedef int (* usb_device_removed_cb)(const char *dev_name, void *client_data);
     63 
     64 /* Callback indicating that initial device discovery is done.
     65  * Return true to exit from usb_host_run.
     66  */
     67 typedef int (* usb_discovery_done_cb)(void *client_data);
     68 
     69 /* Call this to initialize the USB host library. */
     70 struct usb_host_context *usb_host_init(void);
     71 
     72 /* Call this to cleanup the USB host library. */
     73 void usb_host_cleanup(struct usb_host_context *context);
     74 
     75 /* Call this to get the inotify file descriptor. */
     76 int usb_host_get_fd(struct usb_host_context *context);
     77 
     78 /* Call this to initialize the usb host context. */
     79 int usb_host_load(struct usb_host_context *context,
     80                   usb_device_added_cb added_cb,
     81                   usb_device_removed_cb removed_cb,
     82                   usb_discovery_done_cb discovery_done_cb,
     83                   void *client_data);
     84 
     85 /* Call this to read and handle occuring usb event. */
     86 int usb_host_read_event(struct usb_host_context *context);
     87 
     88 /* Call this to monitor the USB bus for new and removed devices.
     89  * This is intended to be called from a dedicated thread,
     90  * as it will not return until one of the callbacks returns true.
     91  * added_cb will be called immediately for each existing USB device,
     92  * and subsequently each time a new device is added.
     93  * removed_cb is called when USB devices are removed from the bus.
     94  * discovery_done_cb is called after the initial discovery of already
     95  * connected devices is complete.
     96  */
     97 void usb_host_run(struct usb_host_context *context,
     98                   usb_device_added_cb added_cb,
     99                   usb_device_removed_cb removed_cb,
    100                   usb_discovery_done_cb discovery_done_cb,
    101                   void *client_data);
    102 
    103 /* Creates a usb_device object for a USB device */
    104 struct usb_device *usb_device_open(const char *dev_name);
    105 
    106 /* Releases all resources associated with the USB device */
    107 void usb_device_close(struct usb_device *device);
    108 
    109 /* Creates a usb_device object for already open USB device */
    110 struct usb_device *usb_device_new(const char *dev_name, int fd);
    111 
    112 /* Returns the file descriptor for the usb_device */
    113 int usb_device_get_fd(struct usb_device *device);
    114 
    115 /* Returns the name for the USB device, which is the same as
    116  * the dev_name passed to usb_device_open()
    117  */
    118 const char* usb_device_get_name(struct usb_device *device);
    119 
    120 /* Returns a unique ID for the device.
    121  *Currently this is generated from the dev_name path.
    122  */
    123 int usb_device_get_unique_id(struct usb_device *device);
    124 
    125 /* Returns a unique ID for the device name.
    126  * Currently this is generated from the device path.
    127  */
    128 int usb_device_get_unique_id_from_name(const char* name);
    129 
    130 /* Returns the device name for the unique ID.
    131  * Call free() to deallocate the returned string */
    132 char* usb_device_get_name_from_unique_id(int id);
    133 
    134 /* Returns the USB vendor ID from the device descriptor for the USB device */
    135 uint16_t usb_device_get_vendor_id(struct usb_device *device);
    136 
    137 /* Returns the USB product ID from the device descriptor for the USB device */
    138 uint16_t usb_device_get_product_id(struct usb_device *device);
    139 
    140 /* Returns a pointer to device descriptor */
    141 const struct usb_device_descriptor* usb_device_get_device_descriptor(struct usb_device *device);
    142 
    143 /* Returns a USB descriptor string for the given string ID.
    144  * Return value: < 0 on error.  0 on success.
    145  * The string is returned in ucs2_out in USB-native UCS-2 encoding.
    146  *
    147  * parameters:
    148  *  id - the string descriptor index.
    149  *  timeout - in milliseconds (see Documentation/driver-api/usb/usb.rst)
    150  *  ucs2_out - Must point to null on call.
    151  *             Will be filled in with a buffer on success.
    152  *             If this is non-null on return, it must be free()d.
    153  *  response_size - size, in bytes, of ucs-2 string in ucs2_out.
    154  *                  The size isn't guaranteed to include null termination.
    155  * Call free() to free the result when you are done with it.
    156  */
    157 int usb_device_get_string_ucs2(struct usb_device* device, int id, int timeout, void** ucs2_out,
    158                                size_t* response_size);
    159 
    160 /* Returns the length in bytes read into the raw descriptors array */
    161 size_t usb_device_get_descriptors_length(const struct usb_device* device);
    162 
    163 /* Returns a pointer to the raw descriptors array */
    164 const unsigned char* usb_device_get_raw_descriptors(const struct usb_device* device);
    165 
    166 /* Returns a USB descriptor string for the given string ID.
    167  * Used to implement usb_device_get_manufacturer_name,
    168  * usb_device_get_product_name and usb_device_get_serial.
    169  * Returns ascii - non ascii characters will be replaced with '?'.
    170  * Call free() to free the result when you are done with it.
    171  */
    172 char* usb_device_get_string(struct usb_device *device, int id, int timeout);
    173 
    174 /* Returns the manufacturer name for the USB device.
    175  * Call free() to free the result when you are done with it.
    176  */
    177 char* usb_device_get_manufacturer_name(struct usb_device *device, int timeout);
    178 
    179 /* Returns the product name for the USB device.
    180  * Call free() to free the result when you are done with it.
    181  */
    182 char* usb_device_get_product_name(struct usb_device *device, int timeout);
    183 
    184 /* Returns the version number for the USB device.
    185  */
    186 int usb_device_get_version(struct usb_device *device);
    187 
    188 /* Returns the USB serial number for the USB device.
    189  * Call free() to free the result when you are done with it.
    190  */
    191 char* usb_device_get_serial(struct usb_device *device, int timeout);
    192 
    193 /* Returns true if we have write access to the USB device,
    194  * and false if we only have access to the USB device configuration.
    195  */
    196 int usb_device_is_writeable(struct usb_device *device);
    197 
    198 /* Initializes a usb_descriptor_iter, which can be used to iterate through all
    199  * the USB descriptors for a USB device.
    200  */
    201 void usb_descriptor_iter_init(struct usb_device *device, struct usb_descriptor_iter *iter);
    202 
    203 /* Returns the next USB descriptor for a device, or NULL if we have reached the
    204  * end of the list.
    205  */
    206 struct usb_descriptor_header *usb_descriptor_iter_next(struct usb_descriptor_iter *iter);
    207 
    208 /* Claims the specified interface of a USB device */
    209 int usb_device_claim_interface(struct usb_device *device, unsigned int interface);
    210 
    211 /* Releases the specified interface of a USB device */
    212 int usb_device_release_interface(struct usb_device *device, unsigned int interface);
    213 
    214 /* Requests the kernel to connect or disconnect its driver for the specified interface.
    215  * This can be used to ask the kernel to disconnect its driver for a device
    216  * so usb_device_claim_interface can claim it instead.
    217  */
    218 int usb_device_connect_kernel_driver(struct usb_device *device,
    219         unsigned int interface, int connect);
    220 
    221 /* Sets the current configuration for the device to the specified configuration */
    222 int usb_device_set_configuration(struct usb_device *device, int configuration);
    223 
    224 /* Sets the specified interface of a USB device */
    225 int usb_device_set_interface(struct usb_device *device, unsigned int interface,
    226                             unsigned int alt_setting);
    227 
    228 /* Sends a control message to the specified device on endpoint zero */
    229 int usb_device_control_transfer(struct usb_device *device,
    230                             int requestType,
    231                             int request,
    232                             int value,
    233                             int index,
    234                             void* buffer,
    235                             int length,
    236                             unsigned int timeout);
    237 
    238 /* Reads or writes on a bulk endpoint.
    239  * Returns number of bytes transferred, or negative value for error.
    240  */
    241 int usb_device_bulk_transfer(struct usb_device *device,
    242                             int endpoint,
    243                             void* buffer,
    244                             unsigned int length,
    245                             unsigned int timeout);
    246 
    247 /** Reset USB bus for the device */
    248 int usb_device_reset(struct usb_device *device);
    249 
    250 /* Creates a new usb_request. */
    251 struct usb_request *usb_request_new(struct usb_device *dev,
    252         const struct usb_endpoint_descriptor *ep_desc);
    253 
    254 /* Releases all resources associated with the request */
    255 void usb_request_free(struct usb_request *req);
    256 
    257 /* Submits a read or write request on the specified device */
    258 int usb_request_queue(struct usb_request *req);
    259 
    260  /* Waits for the results of a previous usb_request_queue operation. timeoutMillis == -1 requests
    261   * to wait forever.
    262   * Returns a usb_request, or NULL for error.
    263   */
    264 struct usb_request *usb_request_wait(struct usb_device *dev, int timeoutMillis);
    265 
    266 /* Cancels a pending usb_request_queue() operation. */
    267 int usb_request_cancel(struct usb_request *req);
    268 
    269 #ifdef __cplusplus
    270 }
    271 #endif
    272 #endif /* __USB_HOST_H */
    273