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 const struct usb_device_id appledisplay_table[] = {
  61         { APPLEDISPLAY_DEVICE(0x9218) },
  62         { APPLEDISPLAY_DEVICE(0x9219) },
  63         { APPLEDISPLAY_DEVICE(0x921c) },
  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         u8 *urbdata;                    /* interrupt URB data buffer */
  77         u8 *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                         __func__, status);
 108                 return;
 109         default:
 110                 dbg("%s - nonzero urb status received: %d",
 111                         __func__, 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                 dev_err(&pdata->udev->dev,
 135                         "%s - usb_submit_urb failed with result %d\n",
 136                         __func__, retval);
 137         }
 138 }
 139
 140 static int appledisplay_bl_update_status(struct backlight_device *bd)
 141 {
 142         struct appledisplay *pdata = bl_get_data(bd);
 143         int retval;
 144
 145         pdata->msgdata[0] = 0x10;
 146         pdata->msgdata[1] = bd->props.brightness;
 147
 148         retval = usb_control_msg(
 149                 pdata->udev,
 150                 usb_sndctrlpipe(pdata->udev, 0),
 151                 USB_REQ_SET_REPORT,
 152                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 153                 ACD_USB_BRIGHTNESS,
 154                 0,
 155                 pdata->msgdata, 2,
 156                 ACD_USB_TIMEOUT);
 157
 158         return retval;
 159 }
 160
 161 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
 162 {
 163         struct appledisplay *pdata = bl_get_data(bd);
 164         int retval;
 165
 166         retval = usb_control_msg(
 167                 pdata->udev,
 168                 usb_rcvctrlpipe(pdata->udev, 0),
 169                 USB_REQ_GET_REPORT,
 170                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 171                 ACD_USB_BRIGHTNESS,
 172                 0,
 173                 pdata->msgdata, 2,
 174                 ACD_USB_TIMEOUT);
 175
 176         if (retval < 0)
 177                 return retval;
 178         else
 179                 return pdata->msgdata[1];
 180 }
 181
 182 static const struct backlight_ops appledisplay_bl_data = {
 183         .get_brightness = appledisplay_bl_get_brightness,
 184         .update_status  = appledisplay_bl_update_status,
 185 };
 186
 187 static void appledisplay_work(struct work_struct *work)
 188 {
 189         struct appledisplay *pdata =
 190                 container_of(work, struct appledisplay, work.work);
 191         int retval;
 192
 193         retval = appledisplay_bl_get_brightness(pdata->bd);
 194         if (retval >= 0)
 195                 pdata->bd->props.brightness = retval;
 196
 197         /* Poll again in about 125ms if there's still a button pressed */
 198         if (pdata->button_pressed)
 199                 schedule_delayed_work(&pdata->work, HZ / 8);
 200 }
 201
 202 static int appledisplay_probe(struct usb_interface *iface,
 203         const struct usb_device_id *id)
 204 {
 205         struct backlight_properties props;
 206         struct appledisplay *pdata;
 207         struct usb_device *udev = interface_to_usbdev(iface);
 208         struct usb_host_interface *iface_desc;
 209         struct usb_endpoint_descriptor *endpoint;
 210         int int_in_endpointAddr = 0;
 211         int i, retval = -ENOMEM, brightness;
 212         char bl_name[20];
 213
 214         /* set up the endpoint information */
 215         /* use only the first interrupt-in endpoint */
 216         iface_desc = iface->cur_altsetting;
 217         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 218                 endpoint = &iface_desc->endpoint[i].desc;
 219                 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
 220                         /* we found an interrupt in endpoint */
 221                         int_in_endpointAddr = endpoint->bEndpointAddress;
 222                         break;
 223                 }
 224         }
 225         if (!int_in_endpointAddr) {
 226                 dev_err(&iface->dev, "Could not find int-in endpoint\n");
 227                 return -EIO;
 228         }
 229
 230         /* allocate memory for our device state and initialize it */
 231         pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
 232         if (!pdata) {
 233                 retval = -ENOMEM;
 234                 dev_err(&iface->dev, "Out of memory\n");
 235                 goto error;
 236         }
 237
 238         pdata->udev = udev;
 239
 240         spin_lock_init(&pdata->lock);
 241         INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
 242
 243         /* Allocate buffer for control messages */
 244         pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
 245         if (!pdata->msgdata) {
 246                 retval = -ENOMEM;
 247                 dev_err(&iface->dev,
 248                         "Allocating buffer for control messages failed\n");
 249                 goto error;
 250         }
 251
 252         /* Allocate interrupt URB */
 253         pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
 254         if (!pdata->urb) {
 255                 retval = -ENOMEM;
 256                 dev_err(&iface->dev, "Allocating URB failed\n");
 257                 goto error;
 258         }
 259
 260         /* Allocate buffer for interrupt data */
 261         pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN,
 262                 GFP_KERNEL, &pdata->urb->transfer_dma);
 263         if (!pdata->urbdata) {
 264                 retval = -ENOMEM;
 265                 dev_err(&iface->dev, "Allocating URB buffer failed\n");
 266                 goto error;
 267         }
 268
 269         /* Configure interrupt URB */
 270         usb_fill_int_urb(pdata->urb, udev,
 271                 usb_rcvintpipe(udev, int_in_endpointAddr),
 272                 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
 273                 pdata, 1);
 274         if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
 275                 retval = -EIO;
 276                 dev_err(&iface->dev, "Submitting URB failed\n");
 277                 goto error;
 278         }
 279
 280         /* Register backlight device */
 281         snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
 282                 atomic_inc_return(&count_displays) - 1);
 283         memset(&props, 0, sizeof(struct backlight_properties));
 284         props.max_brightness = 0xff;
 285         pdata->bd = backlight_device_register(bl_name, NULL, pdata,
 286                                               &appledisplay_bl_data, &props);
 287         if (IS_ERR(pdata->bd)) {
 288                 dev_err(&iface->dev, "Backlight registration failed\n");
 289                 retval = PTR_ERR(pdata->bd);
 290                 goto error;
 291         }
 292
 293         /* Try to get brightness */
 294         brightness = appledisplay_bl_get_brightness(pdata->bd);
 295
 296         if (brightness < 0) {
 297                 retval = brightness;
 298                 dev_err(&iface->dev,
 299                         "Error while getting initial brightness: %d\n", retval);
 300                 goto error;
 301         }
 302
 303         /* Set brightness in backlight device */
 304         pdata->bd->props.brightness = brightness;
 305
 306         /* save our data pointer in the interface device */
 307         usb_set_intfdata(iface, pdata);
 308
 309         printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
 310
 311         return 0;
 312
 313 error:
 314         if (pdata) {
 315                 if (pdata->urb) {
 316                         usb_kill_urb(pdata->urb);
 317                         if (pdata->urbdata)
 318                                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 319                                         pdata->urbdata, pdata->urb->transfer_dma);
 320                         usb_free_urb(pdata->urb);
 321                 }
 322                 if (pdata->bd && !IS_ERR(pdata->bd))
 323                         backlight_device_unregister(pdata->bd);
 324                 kfree(pdata->msgdata);
 325         }
 326         usb_set_intfdata(iface, NULL);
 327         kfree(pdata);
 328         return retval;
 329 }
 330
 331 static void appledisplay_disconnect(struct usb_interface *iface)
 332 {
 333         struct appledisplay *pdata = usb_get_intfdata(iface);
 334
 335         if (pdata) {
 336                 usb_kill_urb(pdata->urb);
 337                 cancel_delayed_work(&pdata->work);
 338                 backlight_device_unregister(pdata->bd);
 339                 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
 340                         pdata->urbdata, pdata->urb->transfer_dma);
 341                 usb_free_urb(pdata->urb);
 342                 kfree(pdata->msgdata);
 343                 kfree(pdata);
 344         }
 345
 346         printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
 347 }
 348
 349 static struct usb_driver appledisplay_driver = {
 350         .name           = "appledisplay",
 351         .probe          = appledisplay_probe,
 352         .disconnect     = appledisplay_disconnect,
 353         .id_table       = appledisplay_table,
 354 };
 355
 356 static int __init appledisplay_init(void)
 357 {
 358         wq = create_singlethread_workqueue("appledisplay");
 359         if (!wq) {
 360                 printk(KERN_ERR "appledisplay: Could not create work queue\n");
 361                 return -ENOMEM;
 362         }
 363
 364         return usb_register(&appledisplay_driver);
 365 }
 366
 367 static void __exit appledisplay_exit(void)
 368 {
 369         flush_workqueue(wq);
 370         destroy_workqueue(wq);
 371         usb_deregister(&appledisplay_driver);
 372 }
 373
 374 MODULE_AUTHOR("Michael Hanselmann");
 375 MODULE_DESCRIPTION("Apple Cinema Display driver");
 376 MODULE_LICENSE("GPL");
 377
 378 module_init(appledisplay_init);
 379 module_exit(appledisplay_exit);