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