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