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/kernel.h>
  24 #include <linux/errno.h>
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/usb.h>
  28 #include <linux/backlight.h>
  29 #include <linux/timer.h>
  30 #include <linux/workqueue.h>
  31 #include <asm/atomic.h>
  32 #include <asm/semaphore.h>
  33
  34 #define APPLE_VENDOR_ID         0x05AC
  35
  36 #define USB_REQ_GET_REPORT      0x01
  37 #define USB_REQ_SET_REPORT      0x09
  38
  39 #define ACD_USB_TIMEOUT         250
  40
  41 #define ACD_USB_EDID            0x0302
  42 #define ACD_USB_BRIGHTNESS      0x0310
  43
  44 #define ACD_BTN_NONE            0
  45 #define ACD_BTN_BRIGHT_UP       3
  46 #define ACD_BTN_BRIGHT_DOWN     4
  47
  48 #define ACD_URB_BUFFER_LEN      2
  49 #define ACD_MSG_BUFFER_LEN      2
  50
  51 #define APPLEDISPLAY_DEVICE(prod)                               \
  52         .match_flags = USB_DEVICE_ID_MATCH_DEVICE |             \
  53                        USB_DEVICE_ID_MATCH_INT_CLASS |          \
  54                        USB_DEVICE_ID_MATCH_INT_PROTOCOL,        \
  55         .idVendor = APPLE_VENDOR_ID,                            \
  56         .idProduct = (prod),                                    \
  57         .bInterfaceClass = USB_CLASS_HID,                       \
  58         .bInterfaceProtocol = 0x00
  59
  60 /* table of devices that work with this driver */
  61 static struct usb_device_id appledisplay_table [] = {
  62         { APPLEDISPLAY_DEVICE(0x9218) },
  63         { APPLEDISPLAY_DEVICE(0x9219) },
  64         { APPLEDISPLAY_DEVICE(0x921d) },
  65
  66         /* Terminating entry */
  67         { }
  68 };
  69 MODULE_DEVICE_TABLE(usb, appledisplay_table);
  70
  71 /* Structure to hold all of our device specific stuff */
  72 struct appledisplay {
  73         struct usb_device *udev;        /* usb device */
  74         struct urb *urb;                /* usb request block */
  75         struct backlight_device *bd;    /* backlight device */
  76         char *urbdata;                  /* interrupt URB data buffer */
  77         char *msgdata;                  /* control message data buffer */
  78
  79         struct delayed_work work;
  80         int button_pressed;
  81         spinlock_t lock;
  82 };
  83
  84 static atomic_t count_displays = ATOMIC_INIT(0);
  85 static struct workqueue_struct *wq;
  86
  87 static void appledisplay_complete(struct urb *urb)
  88 {
  89         struct appledisplay *pdata = urb->context;
  90         unsigned long flags;
  91         int status = urb->status;
  92         int retval;
  93
  94         switch (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 shuttingdown with status: %d",
 107                         __FUNCTION__, status);
 108                 return;
 109         default:
 110                 dbg("%s - nonzero urb status received: %d",
 111                         __FUNCTION__, 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_delayed_work(wq, &pdata->work, 0);
 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 = bl_get_data(bd);
 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 = bl_get_data(bd);
 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_ops appledisplay_bl_data = {
 182         .get_brightness = appledisplay_bl_get_brightness,
 183         .update_status  = appledisplay_bl_update_status,
 184 };
 185
 186 static void appledisplay_work(struct work_struct *work)
 187 {
 188         struct appledisplay *pdata =
 189                 container_of(work, struct appledisplay, work.work);
 190         int retval;
 191
 192         retval = appledisplay_bl_get_brightness(pdata->bd);
 193         if (retval >= 0)
 194                 pdata->bd->props.brightness = retval;
 195
 196         /* Poll again in about 125ms if there's still a button pressed */
 197         if (pdata->button_pressed)
 198                 schedule_delayed_work(&pdata->work, HZ / 8);
 199 }
 200
 201 static int appledisplay_probe(struct usb_interface *iface,
 202         const struct usb_device_id *id)
 203 {
 204         struct appledisplay *pdata;
 205         struct usb_device *udev = interface_to_usbdev(iface);
 206         struct usb_host_interface *iface_desc;
 207         struct usb_endpoint_descriptor *endpoint;
 208         int int_in_endpointAddr = 0;
 209         int i, retval = -ENOMEM, brightness;
 210         char bl_name[20];
 211
 212         /* set up the endpoint information */
 213         /* use only the first interrupt-in endpoint */
 214         iface_desc = iface->cur_altsetting;
 215         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 216                 endpoint = &iface_desc->endpoint[i].desc;
 217                 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
 218                         /* we found an interrupt in endpoint */
 219                         int_in_endpointAddr = endpoint->bEndpointAddress;
 220                         break;
 221                 }
 222         }
 223         if (!int_in_endpointAddr) {
 224                 err("Could not find int-in endpoint");
 225                 return -EIO;
 226         }
 227
 228         /* allocate memory for our device state and initialize it */
 229         pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
 230         if (!pdata) {
 231                 retval = -ENOMEM;
 232                 err("Out of memory");
 233                 goto error;
 234         }
 235
 236         pdata->udev = udev;
 237
 238         spin_lock_init(&pdata->lock);
 239         INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
 240
 241         /* Allocate buffer for control messages */
 242         pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
 243         if (!pdata->msgdata) {
 244                 retval = -ENOMEM;
 245                 err("appledisplay: Allocating buffer for control messages "
 246                         "failed");
 247                 goto error;
 248         }
 249
 250         /* Allocate interrupt URB */
 251         pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
 252         if (!pdata->urb) {
 253                 retval = -ENOMEM;
 254                 err("appledisplay: Allocating URB failed");
 255                 goto error;
 256         }
 257
 258         /* Allocate buffer for interrupt data */
 259         pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN,
 260                 GFP_KERNEL, &pdata->urb->transfer_dma);
 261         if (!pdata->urbdata) {
 262                 retval = -ENOMEM;
 263                 err("appledisplay: Allocating URB buffer failed");
 264                 goto error;
 265         }
 266
 267         /* Configure interrupt URB */
 268         usb_fill_int_urb(pdata->urb, udev,
 269                 usb_rcvintpipe(udev, int_in_endpointAddr),
 270                 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
 271                 pdata, 1);
 272         if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
 273                 retval = -EIO;
 274                 err("appledisplay: Submitting URB failed");
 275                 goto error;
 276         }
 277
 278         /* Register backlight device */
 279         snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
 280                 atomic_inc_return(&count_displays) - 1);
 281         pdata->bd = backlight_device_register(bl_name, NULL, pdata,
 282                                                 &appledisplay_bl_data);
 283         if (IS_ERR(pdata->bd)) {
 284                 err("appledisplay: Backlight registration failed");
 285                 goto error;
 286         }
 287
 288         pdata->bd->props.max_brightness = 0xff;
 289
 290         /* Try to get brightness */
 291         brightness = appledisplay_bl_get_brightness(pdata->bd);
 292
 293         if (brightness < 0) {
 294                 retval = brightness;
 295                 err("appledisplay: Error while getting initial brightness: %d", retval);
 296                 goto error;
 297         }
 298
 299         /* Set brightness in backlight device */
 300         pdata->bd->props.brightness = brightness;
 301
 302         /* save our data pointer in the interface device */
 303         usb_set_intfdata(iface, pdata);
 304
 305         printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
 306
 307         return 0;
 308
 309 error:
 310         if (pdata) {
 311                 if (pdata->urb) {
 312                         usb_kill_urb(pdata->urb);
 313                         if (pdata->urbdata)
 314                                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 315                                         pdata->urbdata, pdata->urb->transfer_dma);
 316                         usb_free_urb(pdata->urb);
 317                 }
 318                 if (pdata->bd)
 319                         backlight_device_unregister(pdata->bd);
 320                 kfree(pdata->msgdata);
 321         }
 322         usb_set_intfdata(iface, NULL);
 323         kfree(pdata);
 324         return retval;
 325 }
 326
 327 static void appledisplay_disconnect(struct usb_interface *iface)
 328 {
 329         struct appledisplay *pdata = usb_get_intfdata(iface);
 330
 331         if (pdata) {
 332                 usb_kill_urb(pdata->urb);
 333                 cancel_delayed_work(&pdata->work);
 334                 backlight_device_unregister(pdata->bd);
 335                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 336                         pdata->urbdata, pdata->urb->transfer_dma);
 337                 usb_free_urb(pdata->urb);
 338                 kfree(pdata->msgdata);
 339                 kfree(pdata);
 340         }
 341
 342         printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
 343 }
 344
 345 static struct usb_driver appledisplay_driver = {
 346         .name           = "appledisplay",
 347         .probe          = appledisplay_probe,
 348         .disconnect     = appledisplay_disconnect,
 349         .id_table       = appledisplay_table,
 350 };
 351
 352 static int __init appledisplay_init(void)
 353 {
 354         wq = create_singlethread_workqueue("appledisplay");
 355         if (!wq) {
 356                 err("Could not create work queue\n");
 357                 return -ENOMEM;
 358         }
 359
 360         return usb_register(&appledisplay_driver);
 361 }
 362
 363 static void __exit appledisplay_exit(void)
 364 {
 365         flush_workqueue(wq);
 366         destroy_workqueue(wq);
 367         usb_deregister(&appledisplay_driver);
 368 }
 369
 370 MODULE_AUTHOR("Michael Hanselmann");
 371 MODULE_DESCRIPTION("Apple Cinema Display driver");
 372 MODULE_LICENSE("GPL");
 373
 374 module_init(appledisplay_init);
 375 module_exit(appledisplay_exit);