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 retval;
  92
  93         switch (urb->status) {
  94         case 0:
  95                 /* success */
  96                 break;
  97         case -EOVERFLOW:
  98                 printk(KERN_ERR "appletouch: OVERFLOW with data "
  99                         "length %d, actual length is %d\n",
 100                         ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
 101         case -ECONNRESET:
 102         case -ENOENT:
 103         case -ESHUTDOWN:
 104                 /* This urb is terminated, clean up */
 105                 dbg("%s - urb shutting down with status: %d",
 106                         __FUNCTION__, urb->status);
 107                 return;
 108         default:
 109                 dbg("%s - nonzero urb status received: %d",
 110                         __FUNCTION__, urb->status);
 111                 goto exit;
 112         }
 113
 114         spin_lock_irqsave(&pdata->lock, flags);
 115
 116         switch(pdata->urbdata[1]) {
 117         case ACD_BTN_BRIGHT_UP:
 118         case ACD_BTN_BRIGHT_DOWN:
 119                 pdata->button_pressed = 1;
 120                 queue_delayed_work(wq, &pdata->work, 0);
 121                 break;
 122         case ACD_BTN_NONE:
 123         default:
 124                 pdata->button_pressed = 0;
 125                 break;
 126         }
 127
 128         spin_unlock_irqrestore(&pdata->lock, flags);
 129
 130 exit:
 131         retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
 132         if (retval) {
 133                 err("%s - usb_submit_urb failed with result %d",
 134                         __FUNCTION__, retval);
 135         }
 136 }
 137
 138 static int appledisplay_bl_update_status(struct backlight_device *bd)
 139 {
 140         struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
 141         int retval;
 142
 143         pdata->msgdata[0] = 0x10;
 144         pdata->msgdata[1] = bd->props.brightness;
 145
 146         retval = usb_control_msg(
 147                 pdata->udev,
 148                 usb_sndctrlpipe(pdata->udev, 0),
 149                 USB_REQ_SET_REPORT,
 150                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 151                 ACD_USB_BRIGHTNESS,
 152                 0,
 153                 pdata->msgdata, 2,
 154                 ACD_USB_TIMEOUT);
 155
 156         return retval;
 157 }
 158
 159 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
 160 {
 161         struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
 162         int retval;
 163
 164         retval = usb_control_msg(
 165                 pdata->udev,
 166                 usb_rcvctrlpipe(pdata->udev, 0),
 167                 USB_REQ_GET_REPORT,
 168                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 169                 ACD_USB_BRIGHTNESS,
 170                 0,
 171                 pdata->msgdata, 2,
 172                 ACD_USB_TIMEOUT);
 173
 174         if (retval < 0)
 175                 return retval;
 176         else
 177                 return pdata->msgdata[1];
 178 }
 179
 180 static struct backlight_ops appledisplay_bl_data = {
 181         .get_brightness = appledisplay_bl_get_brightness,
 182         .update_status  = appledisplay_bl_update_status,
 183 };
 184
 185 static void appledisplay_work(struct work_struct *work)
 186 {
 187         struct appledisplay *pdata =
 188                 container_of(work, struct appledisplay, work.work);
 189         int retval;
 190
 191         retval = appledisplay_bl_get_brightness(pdata->bd);
 192         if (retval >= 0)
 193                 pdata->bd->props.brightness = retval;
 194
 195         /* Poll again in about 125ms if there's still a button pressed */
 196         if (pdata->button_pressed)
 197                 schedule_delayed_work(&pdata->work, HZ / 8);
 198 }
 199
 200 static int appledisplay_probe(struct usb_interface *iface,
 201         const struct usb_device_id *id)
 202 {
 203         struct appledisplay *pdata;
 204         struct usb_device *udev = interface_to_usbdev(iface);
 205         struct usb_host_interface *iface_desc;
 206         struct usb_endpoint_descriptor *endpoint;
 207         int int_in_endpointAddr = 0;
 208         int i, retval = -ENOMEM, brightness;
 209         char bl_name[20];
 210
 211         /* set up the endpoint information */
 212         /* use only the first interrupt-in endpoint */
 213         iface_desc = iface->cur_altsetting;
 214         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 215                 endpoint = &iface_desc->endpoint[i].desc;
 216                 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
 217                         /* we found an interrupt in endpoint */
 218                         int_in_endpointAddr = endpoint->bEndpointAddress;
 219                         break;
 220                 }
 221         }
 222         if (!int_in_endpointAddr) {
 223                 err("Could not find int-in endpoint");
 224                 return -EIO;
 225         }
 226
 227         /* allocate memory for our device state and initialize it */
 228         pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
 229         if (!pdata) {
 230                 retval = -ENOMEM;
 231                 err("Out of memory");
 232                 goto error;
 233         }
 234
 235         pdata->udev = udev;
 236
 237         spin_lock_init(&pdata->lock);
 238         INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
 239
 240         /* Allocate buffer for control messages */
 241         pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
 242         if (!pdata->msgdata) {
 243                 retval = -ENOMEM;
 244                 err("appledisplay: Allocating buffer for control messages "
 245                         "failed");
 246                 goto error;
 247         }
 248
 249         /* Allocate interrupt URB */
 250         pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
 251         if (!pdata->urb) {
 252                 retval = -ENOMEM;
 253                 err("appledisplay: Allocating URB failed");
 254                 goto error;
 255         }
 256
 257         /* Allocate buffer for interrupt data */
 258         pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN,
 259                 GFP_KERNEL, &pdata->urb->transfer_dma);
 260         if (!pdata->urbdata) {
 261                 retval = -ENOMEM;
 262                 err("appledisplay: Allocating URB buffer failed");
 263                 goto error;
 264         }
 265
 266         /* Configure interrupt URB */
 267         usb_fill_int_urb(pdata->urb, udev,
 268                 usb_rcvintpipe(udev, int_in_endpointAddr),
 269                 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
 270                 pdata, 1);
 271         if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
 272                 retval = -EIO;
 273                 err("appledisplay: Submitting URB failed");
 274                 goto error;
 275         }
 276
 277         /* Register backlight device */
 278         snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
 279                 atomic_inc_return(&count_displays) - 1);
 280         pdata->bd = backlight_device_register(bl_name, NULL, pdata,
 281                                                 &appledisplay_bl_data);
 282         if (IS_ERR(pdata->bd)) {
 283                 err("appledisplay: Backlight registration failed");
 284                 goto error;
 285         }
 286
 287         pdata->bd->props.max_brightness = 0xff;
 288
 289         /* Try to get brightness */
 290         brightness = appledisplay_bl_get_brightness(pdata->bd);
 291
 292         if (brightness < 0) {
 293                 retval = brightness;
 294                 err("appledisplay: Error while getting initial brightness: %d", retval);
 295                 goto error;
 296         }
 297
 298         /* Set brightness in backlight device */
 299         pdata->bd->props.brightness = brightness;
 300
 301         /* save our data pointer in the interface device */
 302         usb_set_intfdata(iface, pdata);
 303
 304         printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
 305
 306         return 0;
 307
 308 error:
 309         if (pdata) {
 310                 if (pdata->urb) {
 311                         usb_kill_urb(pdata->urb);
 312                         if (pdata->urbdata)
 313                                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 314                                         pdata->urbdata, pdata->urb->transfer_dma);
 315                         usb_free_urb(pdata->urb);
 316                 }
 317                 if (pdata->bd)
 318                         backlight_device_unregister(pdata->bd);
 319                 kfree(pdata->msgdata);
 320         }
 321         usb_set_intfdata(iface, NULL);
 322         kfree(pdata);
 323         return retval;
 324 }
 325
 326 static void appledisplay_disconnect(struct usb_interface *iface)
 327 {
 328         struct appledisplay *pdata = usb_get_intfdata(iface);
 329
 330         if (pdata) {
 331                 usb_kill_urb(pdata->urb);
 332                 cancel_delayed_work(&pdata->work);
 333                 backlight_device_unregister(pdata->bd);
 334                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 335                         pdata->urbdata, pdata->urb->transfer_dma);
 336                 usb_free_urb(pdata->urb);
 337                 kfree(pdata->msgdata);
 338                 kfree(pdata);
 339         }
 340
 341         printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
 342 }
 343
 344 static struct usb_driver appledisplay_driver = {
 345         .name           = "appledisplay",
 346         .probe          = appledisplay_probe,
 347         .disconnect     = appledisplay_disconnect,
 348         .id_table       = appledisplay_table,
 349 };
 350
 351 static int __init appledisplay_init(void)
 352 {
 353         wq = create_singlethread_workqueue("appledisplay");
 354         if (!wq) {
 355                 err("Could not create work queue\n");
 356                 return -ENOMEM;
 357         }
 358
 359         return usb_register(&appledisplay_driver);
 360 }
 361
 362 static void __exit appledisplay_exit(void)
 363 {
 364         flush_workqueue(wq);
 365         destroy_workqueue(wq);
 366         usb_deregister(&appledisplay_driver);
 367 }
 368
 369 MODULE_AUTHOR("Michael Hanselmann");
 370 MODULE_DESCRIPTION("Apple Cinema Display driver");
 371 MODULE_LICENSE("GPL");
 372
 373 module_init(appledisplay_init);
 374 module_exit(appledisplay_exit);