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