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