drivers/media/usb/uvc/uvc_status.c

   1 /*
   2  *      uvc_status.c  --  USB Video Class driver - Status endpoint
   3  *
   4  *      Copyright (C) 2005-2009
   5  *          Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   6  *
   7  *      This program is free software; you can redistribute it and/or modify
   8  *      it under the terms of the GNU General Public License as published by
   9  *      the Free Software Foundation; either version 2 of the License, or
  10  *      (at your option) any later version.
  11  *
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/input.h>
  16 #include <linux/slab.h>
  17 #include <linux/usb.h>
  18 #include <linux/usb/input.h>
  19
  20 #include "uvcvideo.h"
  21
  22 /* --------------------------------------------------------------------------
  23  * Input device
  24  */
  25 #ifdef CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV
  26 static int uvc_input_init(struct uvc_device *dev)
  27 {
  28         struct input_dev *input;
  29         int ret;
  30
  31         input = input_allocate_device();
  32         if (input == NULL)
  33                 return -ENOMEM;
  34
  35         usb_make_path(dev->udev, dev->input_phys, sizeof(dev->input_phys));
  36         strlcat(dev->input_phys, "/button", sizeof(dev->input_phys));
  37
  38         input->name = dev->name;
  39         input->phys = dev->input_phys;
  40         usb_to_input_id(dev->udev, &input->id);
  41         input->dev.parent = &dev->intf->dev;
  42
  43         __set_bit(EV_KEY, input->evbit);
  44         __set_bit(KEY_CAMERA, input->keybit);
  45
  46         if ((ret = input_register_device(input)) < 0)
  47                 goto error;
  48
  49         dev->input = input;
  50         return 0;
  51
  52 error:
  53         input_free_device(input);
  54         return ret;
  55 }
  56
  57 static void uvc_input_unregister(struct uvc_device *dev)
  58 {
  59         if (dev->input)
  60                 input_unregister_device(dev->input);
  61 }
  62
  63 static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
  64         int value)
  65 {
  66         if (dev->input) {
  67                 input_report_key(dev->input, code, value);
  68                 input_sync(dev->input);
  69         }
  70 }
  71
  72 #else
  73 #define uvc_input_init(dev)
  74 #define uvc_input_unregister(dev)
  75 #define uvc_input_report_key(dev, code, value)
  76 #endif /* CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV */
  77
  78 /* --------------------------------------------------------------------------
  79  * Status interrupt endpoint
  80  */
  81 struct uvc_streaming_status {
  82         u8      bStatusType;
  83         u8      bOriginator;
  84         u8      bEvent;
  85         u8      bValue[];
  86 } __packed;
  87
  88 struct uvc_control_status {
  89         u8      bStatusType;
  90         u8      bOriginator;
  91         u8      bEvent;
  92         u8      bSelector;
  93         u8      bAttribute;
  94         u8      bValue[];
  95 } __packed;
  96
  97 static void uvc_event_streaming(struct uvc_device *dev,
  98                                 struct uvc_streaming_status *status, int len)
  99 {
 100         if (len < 3) {
 101                 uvc_trace(UVC_TRACE_STATUS, "Invalid streaming status event "
 102                                 "received.\n");
 103                 return;
 104         }
 105
 106         if (status->bEvent == 0) {
 107                 if (len < 4)
 108                         return;
 109                 uvc_trace(UVC_TRACE_STATUS, "Button (intf %u) %s len %d\n",
 110                           status->bOriginator,
 111                           status->bValue[0] ? "pressed" : "released", len);
 112                 uvc_input_report_key(dev, KEY_CAMERA, status->bValue[0]);
 113         } else {
 114                 uvc_trace(UVC_TRACE_STATUS,
 115                           "Stream %u error event %02x len %d.\n",
 116                           status->bOriginator, status->bEvent, len);
 117         }
 118 }
 119
 120 #define UVC_CTRL_VALUE_CHANGE   0
 121 #define UVC_CTRL_INFO_CHANGE    1
 122 #define UVC_CTRL_FAILURE_CHANGE 2
 123 #define UVC_CTRL_MIN_CHANGE     3
 124 #define UVC_CTRL_MAX_CHANGE     4
 125
 126 static struct uvc_control *uvc_event_entity_find_ctrl(struct uvc_entity *entity,
 127                                                       u8 selector)
 128 {
 129         struct uvc_control *ctrl;
 130         unsigned int i;
 131
 132         for (i = 0, ctrl = entity->controls; i < entity->ncontrols; i++, ctrl++)
 133                 if (ctrl->info.selector == selector)
 134                         return ctrl;
 135
 136         return NULL;
 137 }
 138
 139 static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
 140                                         const struct uvc_control_status *status,
 141                                         struct uvc_video_chain **chain)
 142 {
 143         list_for_each_entry((*chain), &dev->chains, list) {
 144                 struct uvc_entity *entity;
 145                 struct uvc_control *ctrl;
 146
 147                 list_for_each_entry(entity, &(*chain)->entities, chain) {
 148                         if (entity->id != status->bOriginator)
 149                                 continue;
 150
 151                         ctrl = uvc_event_entity_find_ctrl(entity,
 152                                                           status->bSelector);
 153                         if (ctrl)
 154                                 return ctrl;
 155                 }
 156         }
 157
 158         return NULL;
 159 }
 160
 161 static bool uvc_event_control(struct urb *urb,
 162                               const struct uvc_control_status *status, int len)
 163 {
 164         static const char *attrs[] = { "value", "info", "failure", "min", "max" };
 165         struct uvc_device *dev = urb->context;
 166         struct uvc_video_chain *chain;
 167         struct uvc_control *ctrl;
 168
 169         if (len < 6 || status->bEvent != 0 ||
 170             status->bAttribute >= ARRAY_SIZE(attrs)) {
 171                 uvc_trace(UVC_TRACE_STATUS, "Invalid control status event "
 172                                 "received.\n");
 173                 return false;
 174         }
 175
 176         uvc_trace(UVC_TRACE_STATUS, "Control %u/%u %s change len %d.\n",
 177                   status->bOriginator, status->bSelector,
 178                   attrs[status->bAttribute], len);
 179
 180         /* Find the control. */
 181         ctrl = uvc_event_find_ctrl(dev, status, &chain);
 182         if (!ctrl)
 183                 return false;
 184
 185         switch (status->bAttribute) {
 186         case UVC_CTRL_VALUE_CHANGE:
 187                 return uvc_ctrl_status_event(urb, chain, ctrl, status->bValue);
 188
 189         case UVC_CTRL_INFO_CHANGE:
 190         case UVC_CTRL_FAILURE_CHANGE:
 191         case UVC_CTRL_MIN_CHANGE:
 192         case UVC_CTRL_MAX_CHANGE:
 193                 break;
 194         }
 195
 196         return false;
 197 }
 198
 199 static void uvc_status_complete(struct urb *urb)
 200 {
 201         struct uvc_device *dev = urb->context;
 202         int len, ret;
 203
 204         switch (urb->status) {
 205         case 0:
 206                 break;
 207
 208         case -ENOENT:           /* usb_kill_urb() called. */
 209         case -ECONNRESET:       /* usb_unlink_urb() called. */
 210         case -ESHUTDOWN:        /* The endpoint is being disabled. */
 211         case -EPROTO:           /* Device is disconnected (reported by some
 212                                  * host controller). */
 213                 return;
 214
 215         default:
 216                 uvc_printk(KERN_WARNING, "Non-zero status (%d) in status "
 217                         "completion handler.\n", urb->status);
 218                 return;
 219         }
 220
 221         len = urb->actual_length;
 222         if (len > 0) {
 223                 switch (dev->status[0] & 0x0f) {
 224                 case UVC_STATUS_TYPE_CONTROL: {
 225                         struct uvc_control_status *status =
 226                                 (struct uvc_control_status *)dev->status;
 227
 228                         if (uvc_event_control(urb, status, len))
 229                                 /* The URB will be resubmitted in work context. */
 230                                 return;
 231                         break;
 232                 }
 233
 234                 case UVC_STATUS_TYPE_STREAMING: {
 235                         struct uvc_streaming_status *status =
 236                                 (struct uvc_streaming_status *)dev->status;
 237
 238                         uvc_event_streaming(dev, status, len);
 239                         break;
 240                 }
 241
 242                 default:
 243                         uvc_trace(UVC_TRACE_STATUS, "Unknown status event "
 244                                 "type %u.\n", dev->status[0]);
 245                         break;
 246                 }
 247         }
 248
 249         /* Resubmit the URB. */
 250         urb->interval = dev->int_ep->desc.bInterval;
 251         if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
 252                 uvc_printk(KERN_ERR, "Failed to resubmit status URB (%d).\n",
 253                         ret);
 254         }
 255 }
 256
 257 int uvc_status_init(struct uvc_device *dev)
 258 {
 259         struct usb_host_endpoint *ep = dev->int_ep;
 260         unsigned int pipe;
 261         int interval;
 262
 263         if (ep == NULL)
 264                 return 0;
 265
 266         uvc_input_init(dev);
 267
 268         dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL);
 269         if (dev->status == NULL)
 270                 return -ENOMEM;
 271
 272         dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
 273         if (dev->int_urb == NULL) {
 274                 kfree(dev->status);
 275                 return -ENOMEM;
 276         }
 277
 278         pipe = usb_rcvintpipe(dev->udev, ep->desc.bEndpointAddress);
 279
 280         /* For high-speed interrupt endpoints, the bInterval value is used as
 281          * an exponent of two. Some developers forgot about it.
 282          */
 283         interval = ep->desc.bInterval;
 284         if (interval > 16 && dev->udev->speed == USB_SPEED_HIGH &&
 285             (dev->quirks & UVC_QUIRK_STATUS_INTERVAL))
 286                 interval = fls(interval) - 1;
 287
 288         usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
 289                 dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete,
 290                 dev, interval);
 291
 292         return 0;
 293 }
 294
 295 void uvc_status_unregister(struct uvc_device *dev)
 296 {
 297         usb_kill_urb(dev->int_urb);
 298         uvc_input_unregister(dev);
 299 }
 300
 301 void uvc_status_cleanup(struct uvc_device *dev)
 302 {
 303         usb_free_urb(dev->int_urb);
 304         kfree(dev->status);
 305 }
 306
 307 int uvc_status_start(struct uvc_device *dev, gfp_t flags)
 308 {
 309         if (dev->int_urb == NULL)
 310                 return 0;
 311
 312         return usb_submit_urb(dev->int_urb, flags);
 313 }
 314
 315 void uvc_status_stop(struct uvc_device *dev)
 316 {
 317         usb_kill_urb(dev->int_urb);
 318 }