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/usb.h> 28 #include <linux/backlight.h> 29 #include <linux/timer.h> 30 #include <linux/workqueue.h> 31 #include <asm/atomic.h> 32 #include <asm/semaphore.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 struct usb_device_id appledisplay_table [] = { 62 { APPLEDISPLAY_DEVICE(0x9218) }, 63 { APPLEDISPLAY_DEVICE(0x9219) }, 64 { APPLEDISPLAY_DEVICE(0x921d) }, 65 66 /* Terminating entry */ 67 { } 68 }; 69 MODULE_DEVICE_TABLE(usb, appledisplay_table); 70 71 /* Structure to hold all of our device specific stuff */ 72 struct appledisplay { 73 struct usb_device *udev; /* usb device */ 74 struct urb *urb; /* usb request block */ 75 struct backlight_device *bd; /* backlight device */ 76 char *urbdata; /* interrupt URB data buffer */ 77 char *msgdata; /* control message data buffer */ 78 79 struct delayed_work work; 80 int button_pressed; 81 spinlock_t lock; 82 }; 83 84 static atomic_t count_displays = ATOMIC_INIT(0); 85 static struct workqueue_struct *wq; 86 87 static void appledisplay_complete(struct urb *urb) 88 { 89 struct appledisplay *pdata = urb->context; 90 unsigned long flags; 91 int retval; 92 93 switch (urb->status) { 94 case 0: 95 /* success */ 96 break; 97 case -EOVERFLOW: 98 printk(KERN_ERR "appletouch: OVERFLOW with data " 99 "length %d, actual length is %d\n", 100 ACD_URB_BUFFER_LEN, pdata->urb->actual_length); 101 case -ECONNRESET: 102 case -ENOENT: 103 case -ESHUTDOWN: 104 /* This urb is terminated, clean up */ 105 dbg("%s - urb shutting down with status: %d", 106 __FUNCTION__, urb->status); 107 return; 108 default: 109 dbg("%s - nonzero urb status received: %d", 110 __FUNCTION__, urb->status); 111 goto exit; 112 } 113 114 spin_lock_irqsave(&pdata->lock, flags); 115 116 switch(pdata->urbdata[1]) { 117 case ACD_BTN_BRIGHT_UP: 118 case ACD_BTN_BRIGHT_DOWN: 119 pdata->button_pressed = 1; 120 queue_delayed_work(wq, &pdata->work, 0); 121 break; 122 case ACD_BTN_NONE: 123 default: 124 pdata->button_pressed = 0; 125 break; 126 } 127 128 spin_unlock_irqrestore(&pdata->lock, flags); 129 130 exit: 131 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC); 132 if (retval) { 133 err("%s - usb_submit_urb failed with result %d", 134 __FUNCTION__, retval); 135 } 136 } 137 138 static int appledisplay_bl_update_status(struct backlight_device *bd) 139 { 140 struct appledisplay *pdata = class_get_devdata(&bd->class_dev); 141 int retval; 142 143 pdata->msgdata[0] = 0x10; 144 pdata->msgdata[1] = bd->props->brightness; 145 146 retval = usb_control_msg( 147 pdata->udev, 148 usb_sndctrlpipe(pdata->udev, 0), 149 USB_REQ_SET_REPORT, 150 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 151 ACD_USB_BRIGHTNESS, 152 0, 153 pdata->msgdata, 2, 154 ACD_USB_TIMEOUT); 155 156 return retval; 157 } 158 159 static int appledisplay_bl_get_brightness(struct backlight_device *bd) 160 { 161 struct appledisplay *pdata = class_get_devdata(&bd->class_dev); 162 int retval; 163 164 retval = usb_control_msg( 165 pdata->udev, 166 usb_rcvctrlpipe(pdata->udev, 0), 167 USB_REQ_GET_REPORT, 168 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 169 ACD_USB_BRIGHTNESS, 170 0, 171 pdata->msgdata, 2, 172 ACD_USB_TIMEOUT); 173 174 if (retval < 0) 175 return retval; 176 else 177 return pdata->msgdata[1]; 178 } 179 180 static struct backlight_properties appledisplay_bl_data = { 181 .owner = THIS_MODULE, 182 .get_brightness = appledisplay_bl_get_brightness, 183 .update_status = appledisplay_bl_update_status, 184 .max_brightness = 0xFF 185 }; 186 187 static void appledisplay_work(struct work_struct *work) 188 { 189 struct appledisplay *pdata = 190 container_of(work, struct appledisplay, work.work); 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 && 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 err("Could not find int-in endpoint"); 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 err("Out of memory"); 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 err("appledisplay: Allocating buffer for control messages " 249 "failed"); 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 err("appledisplay: Allocating URB failed"); 258 goto error; 259 } 260 261 /* Allocate buffer for interrupt data */ 262 pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN, 263 GFP_KERNEL, &pdata->urb->transfer_dma); 264 if (!pdata->urbdata) { 265 retval = -ENOMEM; 266 err("appledisplay: Allocating URB buffer failed"); 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 err("appledisplay: Submitting URB failed"); 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 pdata->bd = backlight_device_register(bl_name, NULL, NULL, 285 &appledisplay_bl_data); 286 if (IS_ERR(pdata->bd)) { 287 err("appledisplay: Backlight registration failed"); 288 goto error; 289 } 290 291 /* Try to get brightness */ 292 up(&pdata->bd->sem); 293 brightness = appledisplay_bl_get_brightness(pdata->bd); 294 down(&pdata->bd->sem); 295 296 if (brightness < 0) { 297 retval = brightness; 298 err("appledisplay: Error while getting initial brightness: %d", retval); 299 goto error; 300 } 301 302 /* Set brightness in backlight device */ 303 up(&pdata->bd->sem); 304 pdata->bd->props->brightness = brightness; 305 down(&pdata->bd->sem); 306 307 /* save our data pointer in the interface device */ 308 usb_set_intfdata(iface, pdata); 309 310 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n"); 311 312 return 0; 313 314 error: 315 if (pdata) { 316 if (pdata->urb) { 317 usb_kill_urb(pdata->urb); 318 if (pdata->urbdata) 319 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN, 320 pdata->urbdata, pdata->urb->transfer_dma); 321 usb_free_urb(pdata->urb); 322 } 323 if (pdata->bd) 324 backlight_device_unregister(pdata->bd); 325 kfree(pdata->msgdata); 326 } 327 usb_set_intfdata(iface, NULL); 328 kfree(pdata); 329 return retval; 330 } 331 332 static void appledisplay_disconnect(struct usb_interface *iface) 333 { 334 struct appledisplay *pdata = usb_get_intfdata(iface); 335 336 if (pdata) { 337 usb_kill_urb(pdata->urb); 338 cancel_delayed_work(&pdata->work); 339 backlight_device_unregister(pdata->bd); 340 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN, 341 pdata->urbdata, pdata->urb->transfer_dma); 342 usb_free_urb(pdata->urb); 343 kfree(pdata->msgdata); 344 kfree(pdata); 345 } 346 347 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n"); 348 } 349 350 static struct usb_driver appledisplay_driver = { 351 .name = "appledisplay", 352 .probe = appledisplay_probe, 353 .disconnect = appledisplay_disconnect, 354 .id_table = appledisplay_table, 355 }; 356 357 static int __init appledisplay_init(void) 358 { 359 wq = create_singlethread_workqueue("appledisplay"); 360 if (!wq) { 361 err("Could not create work queue\n"); 362 return -ENOMEM; 363 } 364 365 return usb_register(&appledisplay_driver); 366 } 367 368 static void __exit appledisplay_exit(void) 369 { 370 flush_workqueue(wq); 371 destroy_workqueue(wq); 372 usb_deregister(&appledisplay_driver); 373 } 374 375 MODULE_AUTHOR("Michael Hanselmann"); 376 MODULE_DESCRIPTION("Apple Cinema Display driver"); 377 MODULE_LICENSE("GPL"); 378 379 module_init(appledisplay_init); 380 module_exit(appledisplay_exit); 381