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
  33 #define APPLE_VENDOR_ID         0x05AC
  34
  35 #define USB_REQ_GET_REPORT      0x01
  36 #define USB_REQ_SET_REPORT      0x09
  37
  38 #define ACD_USB_TIMEOUT         250
  39
  40 #define ACD_USB_EDID            0x0302
  41 #define ACD_USB_BRIGHTNESS      0x0310
  42
  43 #define ACD_BTN_NONE            0
  44 #define ACD_BTN_BRIGHT_UP       3
  45 #define ACD_BTN_BRIGHT_DOWN     4
  46
  47 #define ACD_URB_BUFFER_LEN      2
  48 #define ACD_MSG_BUFFER_LEN      2
  49
  50 #define APPLEDISPLAY_DEVICE(prod)                               \
  51         .match_flags = USB_DEVICE_ID_MATCH_DEVICE |             \
  52                        USB_DEVICE_ID_MATCH_INT_CLASS |          \
  53                        USB_DEVICE_ID_MATCH_INT_PROTOCOL,        \
  54         .idVendor = APPLE_VENDOR_ID,                            \
  55         .idProduct = (prod),                                    \
  56         .bInterfaceClass = USB_CLASS_HID,                       \
  57         .bInterfaceProtocol = 0x00
  58
  59 /* table of devices that work with this driver */
  60 static struct usb_device_id appledisplay_table [] = {
  61         { APPLEDISPLAY_DEVICE(0x9218) },
  62         { APPLEDISPLAY_DEVICE(0x9219) },
  63         { APPLEDISPLAY_DEVICE(0x921d) },
  64
  65         /* Terminating entry */
  66         { }
  67 };
  68 MODULE_DEVICE_TABLE(usb, appledisplay_table);
  69
  70 /* Structure to hold all of our device specific stuff */
  71 struct appledisplay {
  72         struct usb_device *udev;        /* usb device */
  73         struct urb *urb;                /* usb request block */
  74         struct backlight_device *bd;    /* backlight device */
  75         char *urbdata;                  /* interrupt URB data buffer */
  76         char *msgdata;                  /* control message data buffer */
  77
  78         struct delayed_work work;
  79         int button_pressed;
  80         spinlock_t lock;
  81 };
  82
  83 static atomic_t count_displays = ATOMIC_INIT(0);
  84 static struct workqueue_struct *wq;
  85
  86 static void appledisplay_complete(struct urb *urb)
  87 {
  88         struct appledisplay *pdata = urb->context;
  89         unsigned long flags;
  90         int status = urb->status;
  91         int retval;
  92
  93         switch (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 shuttingdown with status: %d",
 106                         __func__, status);
 107                 return;
 108         default:
 109                 dbg("%s - nonzero urb status received: %d",
 110                         __func__, 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                 dev_err(&pdata->udev->dev,
 134                         "%s - usb_submit_urb failed with result %d\n",
 135                         __func__, 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                 dev_err(&iface->dev, "Could not find int-in endpoint\n");
 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                 dev_err(&iface->dev, "Out of memory\n");
 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                 dev_err(&iface->dev,
 246                         "Allocating buffer for control messages failed\n");
 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                 dev_err(&iface->dev, "Allocating URB failed\n");
 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                 dev_err(&iface->dev, "Allocating URB buffer failed\n");
 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                 dev_err(&iface->dev, "Submitting URB failed\n");
 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                 dev_err(&iface->dev, "Backlight registration failed\n");
 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                 dev_err(&iface->dev,
 296                         "Error while getting initial brightness: %d\n", retval);
 297                 goto error;
 298         }
 299
 300         /* Set brightness in backlight device */
 301         pdata->bd->props.brightness = brightness;
 302
 303         /* save our data pointer in the interface device */
 304         usb_set_intfdata(iface, pdata);
 305
 306         printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
 307
 308         return 0;
 309
 310 error:
 311         if (pdata) {
 312                 if (pdata->urb) {
 313                         usb_kill_urb(pdata->urb);
 314                         if (pdata->urbdata)
 315                                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 316                                         pdata->urbdata, pdata->urb->transfer_dma);
 317                         usb_free_urb(pdata->urb);
 318                 }
 319                 if (pdata->bd && !IS_ERR(pdata->bd))
 320                         backlight_device_unregister(pdata->bd);
 321                 kfree(pdata->msgdata);
 322         }
 323         usb_set_intfdata(iface, NULL);
 324         kfree(pdata);
 325         return retval;
 326 }
 327
 328 static void appledisplay_disconnect(struct usb_interface *iface)
 329 {
 330         struct appledisplay *pdata = usb_get_intfdata(iface);
 331
 332         if (pdata) {
 333                 usb_kill_urb(pdata->urb);
 334                 cancel_delayed_work(&pdata->work);
 335                 backlight_device_unregister(pdata->bd);
 336                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 337                         pdata->urbdata, pdata->urb->transfer_dma);
 338                 usb_free_urb(pdata->urb);
 339                 kfree(pdata->msgdata);
 340                 kfree(pdata);
 341         }
 342
 343         printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
 344 }
 345
 346 static struct usb_driver appledisplay_driver = {
 347         .name           = "appledisplay",
 348         .probe          = appledisplay_probe,
 349         .disconnect     = appledisplay_disconnect,
 350         .id_table       = appledisplay_table,
 351 };
 352
 353 static int __init appledisplay_init(void)
 354 {
 355         wq = create_singlethread_workqueue("appledisplay");
 356         if (!wq) {
 357                 printk(KERN_ERR "appledisplay: Could not create work queue\n");
 358                 return -ENOMEM;
 359         }
 360
 361         return usb_register(&appledisplay_driver);
 362 }
 363
 364 static void __exit appledisplay_exit(void)
 365 {
 366         flush_workqueue(wq);
 367         destroy_workqueue(wq);
 368         usb_deregister(&appledisplay_driver);
 369 }
 370
 371 MODULE_AUTHOR("Michael Hanselmann");
 372 MODULE_DESCRIPTION("Apple Cinema Display driver");
 373 MODULE_LICENSE("GPL");
 374
 375 module_init(appledisplay_init);
 376 module_exit(appledisplay_exit);