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/config.h> 24 #include <linux/kernel.h> 25 #include <linux/errno.h> 26 #include <linux/init.h> 27 #include <linux/module.h> 28 #include <linux/usb.h> 29 #include <linux/backlight.h> 30 #include <linux/timer.h> 31 #include <linux/workqueue.h> 32 #include <asm/atomic.h> 33 #include <asm/semaphore.h> 34 35 #define APPLE_VENDOR_ID 0x05AC 36 37 #define USB_REQ_GET_REPORT 0x01 38 #define USB_REQ_SET_REPORT 0x09 39 40 #define ACD_USB_TIMEOUT 250 41 42 #define ACD_USB_EDID 0x0302 43 #define ACD_USB_BRIGHTNESS 0x0310 44 45 #define ACD_BTN_NONE 0 46 #define ACD_BTN_BRIGHT_UP 3 47 #define ACD_BTN_BRIGHT_DOWN 4 48 49 #define ACD_URB_BUFFER_LEN 2 50 #define ACD_MSG_BUFFER_LEN 2 51 52 #define APPLEDISPLAY_DEVICE(prod) \ 53 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \ 54 USB_DEVICE_ID_MATCH_INT_CLASS | \ 55 USB_DEVICE_ID_MATCH_INT_PROTOCOL, \ 56 .idVendor = APPLE_VENDOR_ID, \ 57 .idProduct = (prod), \ 58 .bInterfaceClass = USB_CLASS_HID, \ 59 .bInterfaceProtocol = 0x00 60 61 /* table of devices that work with this driver */ 62 static struct usb_device_id appledisplay_table [] = { 63 { APPLEDISPLAY_DEVICE(0x9218) }, 64 { APPLEDISPLAY_DEVICE(0x9219) }, 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 char *urbdata; /* interrupt URB data buffer */ 78 char *msgdata; /* control message data buffer */ 79 80 struct work_struct 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, struct pt_regs *regs) 89 { 90 struct appledisplay *pdata = urb->context; 91 unsigned long flags; 92 int retval; 93 94 switch (urb->status) { 95 case 0: 96 /* success */ 97 break; 98 case -EOVERFLOW: 99 printk(KERN_ERR "appletouch: OVERFLOW with data " 100 "length %d, actual length is %d\n", 101 ACD_URB_BUFFER_LEN, pdata->urb->actual_length); 102 case -ECONNRESET: 103 case -ENOENT: 104 case -ESHUTDOWN: 105 /* This urb is terminated, clean up */ 106 dbg("%s - urb shutting down with status: %d", 107 __FUNCTION__, urb->status); 108 return; 109 default: 110 dbg("%s - nonzero urb status received: %d", 111 __FUNCTION__, urb->status); 112 goto exit; 113 } 114 115 spin_lock_irqsave(&pdata->lock, flags); 116 117 switch(pdata->urbdata[1]) { 118 case ACD_BTN_BRIGHT_UP: 119 case ACD_BTN_BRIGHT_DOWN: 120 pdata->button_pressed = 1; 121 queue_work(wq, &pdata->work); 122 break; 123 case ACD_BTN_NONE: 124 default: 125 pdata->button_pressed = 0; 126 break; 127 } 128 129 spin_unlock_irqrestore(&pdata->lock, flags); 130 131 exit: 132 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC); 133 if (retval) { 134 err("%s - usb_submit_urb failed with result %d", 135 __FUNCTION__, retval); 136 } 137 } 138 139 static int appledisplay_bl_update_status(struct backlight_device *bd) 140 { 141 struct appledisplay *pdata = class_get_devdata(&bd->class_dev); 142 int retval; 143 144 pdata->msgdata[0] = 0x10; 145 pdata->msgdata[1] = bd->props->brightness; 146 147 retval = usb_control_msg( 148 pdata->udev, 149 usb_sndctrlpipe(pdata->udev, 0), 150 USB_REQ_SET_REPORT, 151 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 152 ACD_USB_BRIGHTNESS, 153 0, 154 pdata->msgdata, 2, 155 ACD_USB_TIMEOUT); 156 157 return retval; 158 } 159 160 static int appledisplay_bl_get_brightness(struct backlight_device *bd) 161 { 162 struct appledisplay *pdata = class_get_devdata(&bd->class_dev); 163 int retval; 164 165 retval = usb_control_msg( 166 pdata->udev, 167 usb_rcvctrlpipe(pdata->udev, 0), 168 USB_REQ_GET_REPORT, 169 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 170 ACD_USB_BRIGHTNESS, 171 0, 172 pdata->msgdata, 2, 173 ACD_USB_TIMEOUT); 174 175 if (retval < 0) 176 return retval; 177 else 178 return pdata->msgdata[1]; 179 } 180 181 static struct backlight_properties appledisplay_bl_data = { 182 .owner = THIS_MODULE, 183 .get_brightness = appledisplay_bl_get_brightness, 184 .update_status = appledisplay_bl_update_status, 185 .max_brightness = 0xFF 186 }; 187 188 static void appledisplay_work(void *private) 189 { 190 struct appledisplay *pdata = private; 191 int retval; 192 193 up(&pdata->bd->sem); 194 retval = appledisplay_bl_get_brightness(pdata->bd); 195 if (retval >= 0) 196 pdata->bd->props->brightness = retval; 197 down(&pdata->bd->sem); 198 199 /* Poll again in about 125ms if there's still a button pressed */ 200 if (pdata->button_pressed) 201 schedule_delayed_work(&pdata->work, HZ / 8); 202 } 203 204 static int appledisplay_probe(struct usb_interface *iface, 205 const struct usb_device_id *id) 206 { 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 && 221 (endpoint->bEndpointAddress & USB_DIR_IN) && 222 ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == 223 USB_ENDPOINT_XFER_INT)) { 224 /* we found an interrupt in endpoint */ 225 int_in_endpointAddr = endpoint->bEndpointAddress; 226 break; 227 } 228 } 229 if (!int_in_endpointAddr) { 230 err("Could not find int-in endpoint"); 231 return -EIO; 232 } 233 234 /* allocate memory for our device state and initialize it */ 235 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL); 236 if (!pdata) { 237 retval = -ENOMEM; 238 err("Out of memory"); 239 goto error; 240 } 241 242 pdata->udev = udev; 243 244 spin_lock_init(&pdata->lock); 245 INIT_WORK(&pdata->work, appledisplay_work, pdata); 246 247 /* Allocate buffer for control messages */ 248 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL); 249 if (!pdata->msgdata) { 250 retval = -ENOMEM; 251 err("appledisplay: Allocating buffer for control messages " 252 "failed"); 253 goto error; 254 } 255 256 /* Allocate interrupt URB */ 257 pdata->urb = usb_alloc_urb(0, GFP_KERNEL); 258 if (!pdata->urb) { 259 retval = -ENOMEM; 260 err("appledisplay: Allocating URB failed"); 261 goto error; 262 } 263 264 /* Allocate buffer for interrupt data */ 265 pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN, 266 GFP_KERNEL, &pdata->urb->transfer_dma); 267 if (!pdata->urbdata) { 268 retval = -ENOMEM; 269 err("appledisplay: Allocating URB buffer failed"); 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 err("appledisplay: Submitting URB failed"); 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 pdata->bd = backlight_device_register(bl_name, pdata, 288 &appledisplay_bl_data); 289 if (IS_ERR(pdata->bd)) { 290 err("appledisplay: Backlight registration failed"); 291 goto error; 292 } 293 294 /* Try to get brightness */ 295 up(&pdata->bd->sem); 296 brightness = appledisplay_bl_get_brightness(pdata->bd); 297 down(&pdata->bd->sem); 298 299 if (brightness < 0) { 300 retval = brightness; 301 err("appledisplay: Error while getting initial brightness: %d", retval); 302 goto error; 303 } 304 305 /* Set brightness in backlight device */ 306 up(&pdata->bd->sem); 307 pdata->bd->props->brightness = brightness; 308 down(&pdata->bd->sem); 309 310 /* save our data pointer in the interface device */ 311 usb_set_intfdata(iface, pdata); 312 313 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n"); 314 315 return 0; 316 317 error: 318 if (pdata) { 319 if (pdata->urb) { 320 usb_kill_urb(pdata->urb); 321 if (pdata->urbdata) 322 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN, 323 pdata->urbdata, pdata->urb->transfer_dma); 324 usb_free_urb(pdata->urb); 325 } 326 if (pdata->bd) 327 backlight_device_unregister(pdata->bd); 328 kfree(pdata->msgdata); 329 } 330 usb_set_intfdata(iface, NULL); 331 kfree(pdata); 332 return retval; 333 } 334 335 static void appledisplay_disconnect(struct usb_interface *iface) 336 { 337 struct appledisplay *pdata = usb_get_intfdata(iface); 338 339 if (pdata) { 340 usb_kill_urb(pdata->urb); 341 cancel_delayed_work(&pdata->work); 342 backlight_device_unregister(pdata->bd); 343 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN, 344 pdata->urbdata, pdata->urb->transfer_dma); 345 usb_free_urb(pdata->urb); 346 kfree(pdata->msgdata); 347 kfree(pdata); 348 } 349 350 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n"); 351 } 352 353 static struct usb_driver appledisplay_driver = { 354 .name = "appledisplay", 355 .probe = appledisplay_probe, 356 .disconnect = appledisplay_disconnect, 357 .id_table = appledisplay_table, 358 }; 359 360 static int __init appledisplay_init(void) 361 { 362 wq = create_singlethread_workqueue("appledisplay"); 363 if (!wq) { 364 err("Could not create work queue\n"); 365 return -ENOMEM; 366 } 367 368 return usb_register(&appledisplay_driver); 369 } 370 371 static void __exit appledisplay_exit(void) 372 { 373 flush_workqueue(wq); 374 destroy_workqueue(wq); 375 usb_deregister(&appledisplay_driver); 376 } 377 378 MODULE_AUTHOR("Michael Hanselmann"); 379 MODULE_DESCRIPTION("Apple Cinema Display driver"); 380 MODULE_LICENSE("GPL"); 381 382 module_init(appledisplay_init); 383 module_exit(appledisplay_exit); 384