drivers/usb/misc/appledisplay.c

   1 /*
   2  * Apple Cinema Display driver
   3  *
   4  * Copyright (C) 2006  Michael Hanselmann (linux-kernel@hansmi.ch)
   5  *
   6  * Thanks to Caskey L. Dickson for his work with acdctl.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  21  */
  22
  23 #include <linux/config.h>
  24 #include <linux/kernel.h>
  25 #include <linux/errno.h>
  26 #include <linux/init.h>
  27 #include <linux/module.h>
  28 #include <linux/usb.h>
  29 #include <linux/backlight.h>
  30 #include <linux/timer.h>
  31 #include <linux/workqueue.h>
  32 #include <asm/atomic.h>
  33 #include <asm/semaphore.h>
  34
  35 #define APPLE_VENDOR_ID         0x05AC
  36
  37 #define USB_REQ_GET_REPORT      0x01
  38 #define USB_REQ_SET_REPORT      0x09
  39
  40 #define ACD_USB_TIMEOUT         250
  41
  42 #define ACD_USB_EDID            0x0302
  43 #define ACD_USB_BRIGHTNESS      0x0310
  44
  45 #define ACD_BTN_NONE            0
  46 #define ACD_BTN_BRIGHT_UP       3
  47 #define ACD_BTN_BRIGHT_DOWN     4
  48
  49 #define ACD_URB_BUFFER_LEN      2
  50 #define ACD_MSG_BUFFER_LEN      2
  51
  52 #define APPLEDISPLAY_DEVICE(prod)                               \
  53         .match_flags = USB_DEVICE_ID_MATCH_DEVICE |             \
  54                        USB_DEVICE_ID_MATCH_INT_CLASS |          \
  55                        USB_DEVICE_ID_MATCH_INT_PROTOCOL,        \
  56         .idVendor = APPLE_VENDOR_ID,                            \
  57         .idProduct = (prod),                                    \
  58         .bInterfaceClass = USB_CLASS_HID,                       \
  59         .bInterfaceProtocol = 0x00
  60
  61 /* table of devices that work with this driver */
  62 static struct usb_device_id appledisplay_table [] = {
  63         { APPLEDISPLAY_DEVICE(0x9218) },
  64         { APPLEDISPLAY_DEVICE(0x9219) },
  65         { APPLEDISPLAY_DEVICE(0x921d) },
  66
  67         /* Terminating entry */
  68         { }
  69 };
  70 MODULE_DEVICE_TABLE(usb, appledisplay_table);
  71
  72 /* Structure to hold all of our device specific stuff */
  73 struct appledisplay {
  74         struct usb_device *udev;        /* usb device */
  75         struct urb *urb;                /* usb request block */
  76         struct backlight_device *bd;    /* backlight device */
  77         char *urbdata;                  /* interrupt URB data buffer */
  78         char *msgdata;                  /* control message data buffer */
  79
  80         struct work_struct work;
  81         int button_pressed;
  82         spinlock_t lock;
  83 };
  84
  85 static atomic_t count_displays = ATOMIC_INIT(0);
  86 static struct workqueue_struct *wq;
  87
  88 static void appledisplay_complete(struct urb *urb, struct pt_regs *regs)
  89 {
  90         struct appledisplay *pdata = urb->context;
  91         unsigned long flags;
  92         int retval;
  93
  94         switch (urb->status) {
  95         case 0:
  96                 /* success */
  97                 break;
  98         case -EOVERFLOW:
  99                 printk(KERN_ERR "appletouch: OVERFLOW with data "
 100                         "length %d, actual length is %d\n",
 101                         ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
 102         case -ECONNRESET:
 103         case -ENOENT:
 104         case -ESHUTDOWN:
 105                 /* This urb is terminated, clean up */
 106                 dbg("%s - urb shutting down with status: %d",
 107                         __FUNCTION__, urb->status);
 108                 return;
 109         default:
 110                 dbg("%s - nonzero urb status received: %d",
 111                         __FUNCTION__, urb->status);
 112                 goto exit;
 113         }
 114
 115         spin_lock_irqsave(&pdata->lock, flags);
 116
 117         switch(pdata->urbdata[1]) {
 118         case ACD_BTN_BRIGHT_UP:
 119         case ACD_BTN_BRIGHT_DOWN:
 120                 pdata->button_pressed = 1;
 121                 queue_work(wq, &pdata->work);
 122                 break;
 123         case ACD_BTN_NONE:
 124         default:
 125                 pdata->button_pressed = 0;
 126                 break;
 127         }
 128
 129         spin_unlock_irqrestore(&pdata->lock, flags);
 130
 131 exit:
 132         retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
 133         if (retval) {
 134                 err("%s - usb_submit_urb failed with result %d",
 135                         __FUNCTION__, retval);
 136         }
 137 }
 138
 139 static int appledisplay_bl_update_status(struct backlight_device *bd)
 140 {
 141         struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
 142         int retval;
 143
 144         pdata->msgdata[0] = 0x10;
 145         pdata->msgdata[1] = bd->props->brightness;
 146
 147         retval = usb_control_msg(
 148                 pdata->udev,
 149                 usb_sndctrlpipe(pdata->udev, 0),
 150                 USB_REQ_SET_REPORT,
 151                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 152                 ACD_USB_BRIGHTNESS,
 153                 0,
 154                 pdata->msgdata, 2,
 155                 ACD_USB_TIMEOUT);
 156
 157         return retval;
 158 }
 159
 160 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
 161 {
 162         struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
 163         int retval;
 164
 165         retval = usb_control_msg(
 166                 pdata->udev,
 167                 usb_rcvctrlpipe(pdata->udev, 0),
 168                 USB_REQ_GET_REPORT,
 169                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 170                 ACD_USB_BRIGHTNESS,
 171                 0,
 172                 pdata->msgdata, 2,
 173                 ACD_USB_TIMEOUT);
 174
 175         if (retval < 0)
 176                 return retval;
 177         else
 178                 return pdata->msgdata[1];
 179 }
 180
 181 static struct backlight_properties appledisplay_bl_data = {
 182         .owner          = THIS_MODULE,
 183         .get_brightness = appledisplay_bl_get_brightness,
 184         .update_status  = appledisplay_bl_update_status,
 185         .max_brightness = 0xFF
 186 };
 187
 188 static void appledisplay_work(void *private)
 189 {
 190         struct appledisplay *pdata = private;
 191         int retval;
 192
 193         up(&pdata->bd->sem);
 194         retval = appledisplay_bl_get_brightness(pdata->bd);
 195         if (retval >= 0)
 196                 pdata->bd->props->brightness = retval;
 197         down(&pdata->bd->sem);
 198
 199         /* Poll again in about 125ms if there's still a button pressed */
 200         if (pdata->button_pressed)
 201                 schedule_delayed_work(&pdata->work, HZ / 8);
 202 }
 203
 204 static int appledisplay_probe(struct usb_interface *iface,
 205         const struct usb_device_id *id)
 206 {
 207         struct appledisplay *pdata;
 208         struct usb_device *udev = interface_to_usbdev(iface);
 209         struct usb_host_interface *iface_desc;
 210         struct usb_endpoint_descriptor *endpoint;
 211         int int_in_endpointAddr = 0;
 212         int i, retval = -ENOMEM, brightness;
 213         char bl_name[20];
 214
 215         /* set up the endpoint information */
 216         /* use only the first interrupt-in endpoint */
 217         iface_desc = iface->cur_altsetting;
 218         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 219                 endpoint = &iface_desc->endpoint[i].desc;
 220                 if (!int_in_endpointAddr &&
 221                     (endpoint->bEndpointAddress & USB_DIR_IN) &&
 222                     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
 223                      USB_ENDPOINT_XFER_INT)) {
 224                         /* we found an interrupt in endpoint */
 225                         int_in_endpointAddr = endpoint->bEndpointAddress;
 226                         break;
 227                 }
 228         }
 229         if (!int_in_endpointAddr) {
 230                 err("Could not find int-in endpoint");
 231                 return -EIO;
 232         }
 233
 234         /* allocate memory for our device state and initialize it */
 235         pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
 236         if (!pdata) {
 237                 retval = -ENOMEM;
 238                 err("Out of memory");
 239                 goto error;
 240         }
 241
 242         pdata->udev = udev;
 243
 244         spin_lock_init(&pdata->lock);
 245         INIT_WORK(&pdata->work, appledisplay_work, pdata);
 246
 247         /* Allocate buffer for control messages */
 248         pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
 249         if (!pdata->msgdata) {
 250                 retval = -ENOMEM;
 251                 err("appledisplay: Allocating buffer for control messages "
 252                         "failed");
 253                 goto error;
 254         }
 255
 256         /* Allocate interrupt URB */
 257         pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
 258         if (!pdata->urb) {
 259                 retval = -ENOMEM;
 260                 err("appledisplay: Allocating URB failed");
 261                 goto error;
 262         }
 263
 264         /* Allocate buffer for interrupt data */
 265         pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN,
 266                 GFP_KERNEL, &pdata->urb->transfer_dma);
 267         if (!pdata->urbdata) {
 268                 retval = -ENOMEM;
 269                 err("appledisplay: Allocating URB buffer failed");
 270                 goto error;
 271         }
 272
 273         /* Configure interrupt URB */
 274         usb_fill_int_urb(pdata->urb, udev,
 275                 usb_rcvintpipe(udev, int_in_endpointAddr),
 276                 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
 277                 pdata, 1);
 278         if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
 279                 retval = -EIO;
 280                 err("appledisplay: Submitting URB failed");
 281                 goto error;
 282         }
 283
 284         /* Register backlight device */
 285         snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
 286                 atomic_inc_return(&count_displays) - 1);
 287         pdata->bd = backlight_device_register(bl_name, pdata,
 288                                                 &appledisplay_bl_data);
 289         if (IS_ERR(pdata->bd)) {
 290                 err("appledisplay: Backlight registration failed");
 291                 goto error;
 292         }
 293
 294         /* Try to get brightness */
 295         up(&pdata->bd->sem);
 296         brightness = appledisplay_bl_get_brightness(pdata->bd);
 297         down(&pdata->bd->sem);
 298
 299         if (brightness < 0) {
 300                 retval = brightness;
 301                 err("appledisplay: Error while getting initial brightness: %d", retval);
 302                 goto error;
 303         }
 304
 305         /* Set brightness in backlight device */
 306         up(&pdata->bd->sem);
 307         pdata->bd->props->brightness = brightness;
 308         down(&pdata->bd->sem);
 309
 310         /* save our data pointer in the interface device */
 311         usb_set_intfdata(iface, pdata);
 312
 313         printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
 314
 315         return 0;
 316
 317 error:
 318         if (pdata) {
 319                 if (pdata->urb) {
 320                         usb_kill_urb(pdata->urb);
 321                         if (pdata->urbdata)
 322                                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 323                                         pdata->urbdata, pdata->urb->transfer_dma);
 324                         usb_free_urb(pdata->urb);
 325                 }
 326                 if (pdata->bd)
 327                         backlight_device_unregister(pdata->bd);
 328                 kfree(pdata->msgdata);
 329         }
 330         usb_set_intfdata(iface, NULL);
 331         kfree(pdata);
 332         return retval;
 333 }
 334
 335 static void appledisplay_disconnect(struct usb_interface *iface)
 336 {
 337         struct appledisplay *pdata = usb_get_intfdata(iface);
 338
 339         if (pdata) {
 340                 usb_kill_urb(pdata->urb);
 341                 cancel_delayed_work(&pdata->work);
 342                 backlight_device_unregister(pdata->bd);
 343                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 344                         pdata->urbdata, pdata->urb->transfer_dma);
 345                 usb_free_urb(pdata->urb);
 346                 kfree(pdata->msgdata);
 347                 kfree(pdata);
 348         }
 349
 350         printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
 351 }
 352
 353 static struct usb_driver appledisplay_driver = {
 354         .name           = "appledisplay",
 355         .probe          = appledisplay_probe,
 356         .disconnect     = appledisplay_disconnect,
 357         .id_table       = appledisplay_table,
 358 };
 359
 360 static int __init appledisplay_init(void)
 361 {
 362         wq = create_singlethread_workqueue("appledisplay");
 363         if (!wq) {
 364                 err("Could not create work queue\n");
 365                 return -ENOMEM;
 366         }
 367
 368         return usb_register(&appledisplay_driver);
 369 }
 370
 371 static void __exit appledisplay_exit(void)
 372 {
 373         flush_workqueue(wq);
 374         destroy_workqueue(wq);
 375         usb_deregister(&appledisplay_driver);
 376 }
 377
 378 MODULE_AUTHOR("Michael Hanselmann");
 379 MODULE_DESCRIPTION("Apple Cinema Display driver");
 380 MODULE_LICENSE("GPL");
 381
 382 module_init(appledisplay_init);
 383 module_exit(appledisplay_exit);