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 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 u8 *urbdata; /* interrupt URB data buffer */ 78 u8 *msgdata; /* control message data buffer */ 79 80 struct delayed_work 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) 89 { 90 struct appledisplay *pdata = urb->context; 91 struct device *dev = &pdata->udev->dev; 92 unsigned long flags; 93 int status = urb->status; 94 int retval; 95 96 switch (status) { 97 case 0: 98 /* success */ 99 break; 100 case -EOVERFLOW: 101 dev_err(dev, 102 "OVERFLOW with data length %d, actual length is %d\n", 103 ACD_URB_BUFFER_LEN, pdata->urb->actual_length); 104 case -ECONNRESET: 105 case -ENOENT: 106 case -ESHUTDOWN: 107 /* This urb is terminated, clean up */ 108 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n", 109 __func__, status); 110 return; 111 default: 112 dev_dbg(dev, "%s - nonzero urb status received: %d/n", 113 __func__, status); 114 goto exit; 115 } 116 117 spin_lock_irqsave(&pdata->lock, flags); 118 119 switch(pdata->urbdata[1]) { 120 case ACD_BTN_BRIGHT_UP: 121 case ACD_BTN_BRIGHT_DOWN: 122 pdata->button_pressed = 1; 123 queue_delayed_work(wq, &pdata->work, 0); 124 break; 125 case ACD_BTN_NONE: 126 default: 127 pdata->button_pressed = 0; 128 break; 129 } 130 131 spin_unlock_irqrestore(&pdata->lock, flags); 132 133 exit: 134 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC); 135 if (retval) { 136 dev_err(dev, "%s - usb_submit_urb failed with result %d\n", 137 __func__, retval); 138 } 139 } 140 141 static int appledisplay_bl_update_status(struct backlight_device *bd) 142 { 143 struct appledisplay *pdata = bl_get_data(bd); 144 int retval; 145 146 pdata->msgdata[0] = 0x10; 147 pdata->msgdata[1] = bd->props.brightness; 148 149 retval = usb_control_msg( 150 pdata->udev, 151 usb_sndctrlpipe(pdata->udev, 0), 152 USB_REQ_SET_REPORT, 153 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 154 ACD_USB_BRIGHTNESS, 155 0, 156 pdata->msgdata, 2, 157 ACD_USB_TIMEOUT); 158 159 return retval; 160 } 161 162 static int appledisplay_bl_get_brightness(struct backlight_device *bd) 163 { 164 struct appledisplay *pdata = bl_get_data(bd); 165 int retval; 166 167 retval = usb_control_msg( 168 pdata->udev, 169 usb_rcvctrlpipe(pdata->udev, 0), 170 USB_REQ_GET_REPORT, 171 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 172 ACD_USB_BRIGHTNESS, 173 0, 174 pdata->msgdata, 2, 175 ACD_USB_TIMEOUT); 176 177 if (retval < 0) 178 return retval; 179 else 180 return pdata->msgdata[1]; 181 } 182 183 static const struct backlight_ops appledisplay_bl_data = { 184 .get_brightness = appledisplay_bl_get_brightness, 185 .update_status = appledisplay_bl_update_status, 186 }; 187 188 static void appledisplay_work(struct work_struct *work) 189 { 190 struct appledisplay *pdata = 191 container_of(work, struct appledisplay, work.work); 192 int retval; 193 194 retval = appledisplay_bl_get_brightness(pdata->bd); 195 if (retval >= 0) 196 pdata->bd->props.brightness = retval; 197 198 /* Poll again in about 125ms if there's still a button pressed */ 199 if (pdata->button_pressed) 200 schedule_delayed_work(&pdata->work, HZ / 8); 201 } 202 203 static int appledisplay_probe(struct usb_interface *iface, 204 const struct usb_device_id *id) 205 { 206 struct backlight_properties props; 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 dev_err(&iface->dev, "Could not find int-in endpoint\n"); 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 dev_err(&iface->dev, "Out of memory\n"); 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 dev_err(&iface->dev, 249 "Allocating buffer for control messages failed\n"); 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 dev_err(&iface->dev, "Allocating URB failed\n"); 258 goto error; 259 } 260 261 /* Allocate buffer for interrupt data */ 262 pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 263 GFP_KERNEL, &pdata->urb->transfer_dma); 264 if (!pdata->urbdata) { 265 retval = -ENOMEM; 266 dev_err(&iface->dev, "Allocating URB buffer failed\n"); 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 dev_err(&iface->dev, "Submitting URB failed\n"); 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 memset(&props, 0, sizeof(struct backlight_properties)); 285 props.type = BACKLIGHT_RAW; 286 props.max_brightness = 0xff; 287 pdata->bd = backlight_device_register(bl_name, NULL, pdata, 288 &appledisplay_bl_data, &props); 289 if (IS_ERR(pdata->bd)) { 290 dev_err(&iface->dev, "Backlight registration failed\n"); 291 retval = PTR_ERR(pdata->bd); 292 goto error; 293 } 294 295 /* Try to get brightness */ 296 brightness = appledisplay_bl_get_brightness(pdata->bd); 297 298 if (brightness < 0) { 299 retval = brightness; 300 dev_err(&iface->dev, 301 "Error while getting initial brightness: %d\n", retval); 302 goto error; 303 } 304 305 /* Set brightness in backlight device */ 306 pdata->bd->props.brightness = brightness; 307 308 /* save our data pointer in the interface device */ 309 usb_set_intfdata(iface, pdata); 310 311 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n"); 312 313 return 0; 314 315 error: 316 if (pdata) { 317 if (pdata->urb) { 318 usb_kill_urb(pdata->urb); 319 if (pdata->urbdata) 320 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 321 pdata->urbdata, pdata->urb->transfer_dma); 322 usb_free_urb(pdata->urb); 323 } 324 if (pdata->bd && !IS_ERR(pdata->bd)) 325 backlight_device_unregister(pdata->bd); 326 kfree(pdata->msgdata); 327 } 328 usb_set_intfdata(iface, NULL); 329 kfree(pdata); 330 return retval; 331 } 332 333 static void appledisplay_disconnect(struct usb_interface *iface) 334 { 335 struct appledisplay *pdata = usb_get_intfdata(iface); 336 337 if (pdata) { 338 usb_kill_urb(pdata->urb); 339 cancel_delayed_work(&pdata->work); 340 backlight_device_unregister(pdata->bd); 341 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 342 pdata->urbdata, pdata->urb->transfer_dma); 343 usb_free_urb(pdata->urb); 344 kfree(pdata->msgdata); 345 kfree(pdata); 346 } 347 348 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n"); 349 } 350 351 static struct usb_driver appledisplay_driver = { 352 .name = "appledisplay", 353 .probe = appledisplay_probe, 354 .disconnect = appledisplay_disconnect, 355 .id_table = appledisplay_table, 356 }; 357 358 static int __init appledisplay_init(void) 359 { 360 wq = create_singlethread_workqueue("appledisplay"); 361 if (!wq) { 362 printk(KERN_ERR "appledisplay: Could not create work queue\n"); 363 return -ENOMEM; 364 } 365 366 return usb_register(&appledisplay_driver); 367 } 368 369 static void __exit appledisplay_exit(void) 370 { 371 flush_workqueue(wq); 372 destroy_workqueue(wq); 373 usb_deregister(&appledisplay_driver); 374 } 375 376 MODULE_AUTHOR("Michael Hanselmann"); 377 MODULE_DESCRIPTION("Apple Cinema Display driver"); 378 MODULE_LICENSE("GPL"); 379 380 module_init(appledisplay_init); 381 module_exit(appledisplay_exit); 382