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/slab.h>
  28 #include <linux/usb.h>
  29 #include <linux/backlight.h>
  30 #include <linux/timer.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/atomic.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 const struct usb_device_id appledisplay_table[] = {
  62         { APPLEDISPLAY_DEVICE(0x9218) },
  63         { APPLEDISPLAY_DEVICE(0x9219) },
  64         { APPLEDISPLAY_DEVICE(0x921c) },
  65         { APPLEDISPLAY_DEVICE(0x921d) },
  66         { APPLEDISPLAY_DEVICE(0x9222) },
  67         { APPLEDISPLAY_DEVICE(0x9226) },
  68         { APPLEDISPLAY_DEVICE(0x9236) },
  69
  70         /* Terminating entry */
  71         { }
  72 };
  73 MODULE_DEVICE_TABLE(usb, appledisplay_table);
  74
  75 /* Structure to hold all of our device specific stuff */
  76 struct appledisplay {
  77         struct usb_device *udev;        /* usb device */
  78         struct urb *urb;                /* usb request block */
  79         struct backlight_device *bd;    /* backlight device */
  80         u8 *urbdata;                    /* interrupt URB data buffer */
  81         u8 *msgdata;                    /* control message data buffer */
  82
  83         struct delayed_work work;
  84         int button_pressed;
  85         spinlock_t lock;
  86         struct mutex sysfslock;         /* concurrent read and write */
  87 };
  88
  89 static atomic_t count_displays = ATOMIC_INIT(0);
  90 static struct workqueue_struct *wq;
  91
  92 static void appledisplay_complete(struct urb *urb)
  93 {
  94         struct appledisplay *pdata = urb->context;
  95         struct device *dev = &pdata->udev->dev;
  96         unsigned long flags;
  97         int status = urb->status;
  98         int retval;
  99
 100         switch (status) {
 101         case 0:
 102                 /* success */
 103                 break;
 104         case -EOVERFLOW:
 105                 dev_err(dev,
 106                         "OVERFLOW with data length %d, actual length is %d\n",
 107                         ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
 108         case -ECONNRESET:
 109         case -ENOENT:
 110         case -ESHUTDOWN:
 111                 /* This urb is terminated, clean up */
 112                 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
 113                         __func__, status);
 114                 return;
 115         default:
 116                 dev_dbg(dev, "%s - nonzero urb status received: %d\n",
 117                         __func__, status);
 118                 goto exit;
 119         }
 120
 121         spin_lock_irqsave(&pdata->lock, flags);
 122
 123         switch(pdata->urbdata[1]) {
 124         case ACD_BTN_BRIGHT_UP:
 125         case ACD_BTN_BRIGHT_DOWN:
 126                 pdata->button_pressed = 1;
 127                 queue_delayed_work(wq, &pdata->work, 0);
 128                 break;
 129         case ACD_BTN_NONE:
 130         default:
 131                 pdata->button_pressed = 0;
 132                 break;
 133         }
 134
 135         spin_unlock_irqrestore(&pdata->lock, flags);
 136
 137 exit:
 138         retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
 139         if (retval) {
 140                 dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
 141                         __func__, retval);
 142         }
 143 }
 144
 145 static int appledisplay_bl_update_status(struct backlight_device *bd)
 146 {
 147         struct appledisplay *pdata = bl_get_data(bd);
 148         int retval;
 149
 150         mutex_lock(&pdata->sysfslock);
 151         pdata->msgdata[0] = 0x10;
 152         pdata->msgdata[1] = bd->props.brightness;
 153
 154         retval = usb_control_msg(
 155                 pdata->udev,
 156                 usb_sndctrlpipe(pdata->udev, 0),
 157                 USB_REQ_SET_REPORT,
 158                 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 159                 ACD_USB_BRIGHTNESS,
 160                 0,
 161                 pdata->msgdata, 2,
 162                 ACD_USB_TIMEOUT);
 163         mutex_unlock(&pdata->sysfslock);
 164
 165         if (retval < 0)
 166                 return retval;
 167         else
 168                 return 0;
 169 }
 170
 171 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
 172 {
 173         struct appledisplay *pdata = bl_get_data(bd);
 174         int retval, brightness;
 175
 176         mutex_lock(&pdata->sysfslock);
 177         retval = usb_control_msg(
 178                 pdata->udev,
 179                 usb_rcvctrlpipe(pdata->udev, 0),
 180                 USB_REQ_GET_REPORT,
 181                 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 182                 ACD_USB_BRIGHTNESS,
 183                 0,
 184                 pdata->msgdata, 2,
 185                 ACD_USB_TIMEOUT);
 186         if (retval < 2) {
 187                 if (retval >= 0)
 188                         retval = -EMSGSIZE;
 189         } else {
 190                 brightness = pdata->msgdata[1];
 191         }
 192         mutex_unlock(&pdata->sysfslock);
 193
 194         if (retval < 0)
 195                 return retval;
 196         else
 197                 return brightness;
 198 }
 199
 200 static const struct backlight_ops appledisplay_bl_data = {
 201         .get_brightness = appledisplay_bl_get_brightness,
 202         .update_status  = appledisplay_bl_update_status,
 203 };
 204
 205 static void appledisplay_work(struct work_struct *work)
 206 {
 207         struct appledisplay *pdata =
 208                 container_of(work, struct appledisplay, work.work);
 209         int retval;
 210
 211         retval = appledisplay_bl_get_brightness(pdata->bd);
 212         if (retval >= 0)
 213                 pdata->bd->props.brightness = retval;
 214
 215         /* Poll again in about 125ms if there's still a button pressed */
 216         if (pdata->button_pressed)
 217                 schedule_delayed_work(&pdata->work, HZ / 8);
 218 }
 219
 220 static int appledisplay_probe(struct usb_interface *iface,
 221         const struct usb_device_id *id)
 222 {
 223         struct backlight_properties props;
 224         struct appledisplay *pdata;
 225         struct usb_device *udev = interface_to_usbdev(iface);
 226         struct usb_host_interface *iface_desc;
 227         struct usb_endpoint_descriptor *endpoint;
 228         int int_in_endpointAddr = 0;
 229         int i, retval = -ENOMEM, brightness;
 230         char bl_name[20];
 231
 232         /* set up the endpoint information */
 233         /* use only the first interrupt-in endpoint */
 234         iface_desc = iface->cur_altsetting;
 235         for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
 236                 endpoint = &iface_desc->endpoint[i].desc;
 237                 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
 238                         /* we found an interrupt in endpoint */
 239                         int_in_endpointAddr = endpoint->bEndpointAddress;
 240                         break;
 241                 }
 242         }
 243         if (!int_in_endpointAddr) {
 244                 dev_err(&iface->dev, "Could not find int-in endpoint\n");
 245                 return -EIO;
 246         }
 247
 248         /* allocate memory for our device state and initialize it */
 249         pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
 250         if (!pdata) {
 251                 retval = -ENOMEM;
 252                 dev_err(&iface->dev, "Out of memory\n");
 253                 goto error;
 254         }
 255
 256         pdata->udev = udev;
 257
 258         spin_lock_init(&pdata->lock);
 259         INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
 260         mutex_init(&pdata->sysfslock);
 261
 262         /* Allocate buffer for control messages */
 263         pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
 264         if (!pdata->msgdata) {
 265                 retval = -ENOMEM;
 266                 dev_err(&iface->dev,
 267                         "Allocating buffer for control messages failed\n");
 268                 goto error;
 269         }
 270
 271         /* Allocate interrupt URB */
 272         pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
 273         if (!pdata->urb) {
 274                 retval = -ENOMEM;
 275                 dev_err(&iface->dev, "Allocating URB failed\n");
 276                 goto error;
 277         }
 278
 279         /* Allocate buffer for interrupt data */
 280         pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
 281                 GFP_KERNEL, &pdata->urb->transfer_dma);
 282         if (!pdata->urbdata) {
 283                 retval = -ENOMEM;
 284                 dev_err(&iface->dev, "Allocating URB buffer failed\n");
 285                 goto error;
 286         }
 287
 288         /* Configure interrupt URB */
 289         usb_fill_int_urb(pdata->urb, udev,
 290                 usb_rcvintpipe(udev, int_in_endpointAddr),
 291                 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
 292                 pdata, 1);
 293         if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
 294                 retval = -EIO;
 295                 dev_err(&iface->dev, "Submitting URB failed\n");
 296                 goto error;
 297         }
 298
 299         /* Register backlight device */
 300         snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
 301                 atomic_inc_return(&count_displays) - 1);
 302         memset(&props, 0, sizeof(struct backlight_properties));
 303         props.type = BACKLIGHT_RAW;
 304         props.max_brightness = 0xff;
 305         pdata->bd = backlight_device_register(bl_name, NULL, pdata,
 306                                               &appledisplay_bl_data, &props);
 307         if (IS_ERR(pdata->bd)) {
 308                 dev_err(&iface->dev, "Backlight registration failed\n");
 309                 retval = PTR_ERR(pdata->bd);
 310                 goto error;
 311         }
 312
 313         /* Try to get brightness */
 314         brightness = appledisplay_bl_get_brightness(pdata->bd);
 315
 316         if (brightness < 0) {
 317                 retval = brightness;
 318                 dev_err(&iface->dev,
 319                         "Error while getting initial brightness: %d\n", retval);
 320                 goto error;
 321         }
 322
 323         /* Set brightness in backlight device */
 324         pdata->bd->props.brightness = brightness;
 325
 326         /* save our data pointer in the interface device */
 327         usb_set_intfdata(iface, pdata);
 328
 329         printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
 330
 331         return 0;
 332
 333 error:
 334         if (pdata) {
 335                 if (pdata->urb) {
 336                         usb_kill_urb(pdata->urb);
 337                         cancel_delayed_work_sync(&pdata->work);
 338                         if (pdata->urbdata)
 339                                 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
 340                                         pdata->urbdata, pdata->urb->transfer_dma);
 341                         usb_free_urb(pdata->urb);
 342                 }
 343                 if (!IS_ERR(pdata->bd))
 344                         backlight_device_unregister(pdata->bd);
 345                 kfree(pdata->msgdata);
 346         }
 347         usb_set_intfdata(iface, NULL);
 348         kfree(pdata);
 349         return retval;
 350 }
 351
 352 static void appledisplay_disconnect(struct usb_interface *iface)
 353 {
 354         struct appledisplay *pdata = usb_get_intfdata(iface);
 355
 356         if (pdata) {
 357                 usb_kill_urb(pdata->urb);
 358                 cancel_delayed_work(&pdata->work);
 359                 backlight_device_unregister(pdata->bd);
 360                 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
 361                         pdata->urbdata, pdata->urb->transfer_dma);
 362                 usb_free_urb(pdata->urb);
 363                 kfree(pdata->msgdata);
 364                 kfree(pdata);
 365         }
 366
 367         printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
 368 }
 369
 370 static struct usb_driver appledisplay_driver = {
 371         .name           = "appledisplay",
 372         .probe          = appledisplay_probe,
 373         .disconnect     = appledisplay_disconnect,
 374         .id_table       = appledisplay_table,
 375 };
 376
 377 static int __init appledisplay_init(void)
 378 {
 379         wq = create_singlethread_workqueue("appledisplay");
 380         if (!wq) {
 381                 printk(KERN_ERR "appledisplay: Could not create work queue\n");
 382                 return -ENOMEM;
 383         }
 384
 385         return usb_register(&appledisplay_driver);
 386 }
 387
 388 static void __exit appledisplay_exit(void)
 389 {
 390         flush_workqueue(wq);
 391         destroy_workqueue(wq);
 392         usb_deregister(&appledisplay_driver);
 393 }
 394
 395 MODULE_AUTHOR("Michael Hanselmann");
 396 MODULE_DESCRIPTION("Apple Cinema Display driver");
 397 MODULE_LICENSE("GPL");
 398
 399 module_init(appledisplay_init);
 400 module_exit(appledisplay_exit);