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 static struct workqueue_struct *wq; 89 90 static void appledisplay_complete(struct urb *urb) 91 { 92 struct appledisplay *pdata = urb->context; 93 struct device *dev = &pdata->udev->dev; 94 unsigned long flags; 95 int status = urb->status; 96 int retval; 97 98 switch (status) { 99 case 0: 100 /* success */ 101 break; 102 case -EOVERFLOW: 103 dev_err(dev, 104 "OVERFLOW with data length %d, actual length is %d\n", 105 ACD_URB_BUFFER_LEN, pdata->urb->actual_length); 106 case -ECONNRESET: 107 case -ENOENT: 108 case -ESHUTDOWN: 109 /* This urb is terminated, clean up */ 110 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n", 111 __func__, status); 112 return; 113 default: 114 dev_dbg(dev, "%s - nonzero urb status received: %d\n", 115 __func__, status); 116 goto exit; 117 } 118 119 spin_lock_irqsave(&pdata->lock, flags); 120 121 switch(pdata->urbdata[1]) { 122 case ACD_BTN_BRIGHT_UP: 123 case ACD_BTN_BRIGHT_DOWN: 124 pdata->button_pressed = 1; 125 queue_delayed_work(wq, &pdata->work, 0); 126 break; 127 case ACD_BTN_NONE: 128 default: 129 pdata->button_pressed = 0; 130 break; 131 } 132 133 spin_unlock_irqrestore(&pdata->lock, flags); 134 135 exit: 136 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC); 137 if (retval) { 138 dev_err(dev, "%s - usb_submit_urb failed with result %d\n", 139 __func__, retval); 140 } 141 } 142 143 static int appledisplay_bl_update_status(struct backlight_device *bd) 144 { 145 struct appledisplay *pdata = bl_get_data(bd); 146 int retval; 147 148 mutex_lock(&pdata->sysfslock); 149 pdata->msgdata[0] = 0x10; 150 pdata->msgdata[1] = bd->props.brightness; 151 152 retval = usb_control_msg( 153 pdata->udev, 154 usb_sndctrlpipe(pdata->udev, 0), 155 USB_REQ_SET_REPORT, 156 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 157 ACD_USB_BRIGHTNESS, 158 0, 159 pdata->msgdata, 2, 160 ACD_USB_TIMEOUT); 161 mutex_unlock(&pdata->sysfslock); 162 163 return retval; 164 } 165 166 static int appledisplay_bl_get_brightness(struct backlight_device *bd) 167 { 168 struct appledisplay *pdata = bl_get_data(bd); 169 int retval, brightness; 170 171 mutex_lock(&pdata->sysfslock); 172 retval = usb_control_msg( 173 pdata->udev, 174 usb_rcvctrlpipe(pdata->udev, 0), 175 USB_REQ_GET_REPORT, 176 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 177 ACD_USB_BRIGHTNESS, 178 0, 179 pdata->msgdata, 2, 180 ACD_USB_TIMEOUT); 181 brightness = pdata->msgdata[1]; 182 mutex_unlock(&pdata->sysfslock); 183 184 if (retval < 0) 185 return retval; 186 else 187 return brightness; 188 } 189 190 static const struct backlight_ops appledisplay_bl_data = { 191 .get_brightness = appledisplay_bl_get_brightness, 192 .update_status = appledisplay_bl_update_status, 193 }; 194 195 static void appledisplay_work(struct work_struct *work) 196 { 197 struct appledisplay *pdata = 198 container_of(work, struct appledisplay, work.work); 199 int retval; 200 201 retval = appledisplay_bl_get_brightness(pdata->bd); 202 if (retval >= 0) 203 pdata->bd->props.brightness = retval; 204 205 /* Poll again in about 125ms if there's still a button pressed */ 206 if (pdata->button_pressed) 207 schedule_delayed_work(&pdata->work, HZ / 8); 208 } 209 210 static int appledisplay_probe(struct usb_interface *iface, 211 const struct usb_device_id *id) 212 { 213 struct backlight_properties props; 214 struct appledisplay *pdata; 215 struct usb_device *udev = interface_to_usbdev(iface); 216 struct usb_host_interface *iface_desc; 217 struct usb_endpoint_descriptor *endpoint; 218 int int_in_endpointAddr = 0; 219 int i, retval = -ENOMEM, brightness; 220 char bl_name[20]; 221 222 /* set up the endpoint information */ 223 /* use only the first interrupt-in endpoint */ 224 iface_desc = iface->cur_altsetting; 225 for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) { 226 endpoint = &iface_desc->endpoint[i].desc; 227 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) { 228 /* we found an interrupt in endpoint */ 229 int_in_endpointAddr = endpoint->bEndpointAddress; 230 break; 231 } 232 } 233 if (!int_in_endpointAddr) { 234 dev_err(&iface->dev, "Could not find int-in endpoint\n"); 235 return -EIO; 236 } 237 238 /* allocate memory for our device state and initialize it */ 239 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL); 240 if (!pdata) { 241 retval = -ENOMEM; 242 dev_err(&iface->dev, "Out of memory\n"); 243 goto error; 244 } 245 246 pdata->udev = udev; 247 248 spin_lock_init(&pdata->lock); 249 INIT_DELAYED_WORK(&pdata->work, appledisplay_work); 250 mutex_init(&pdata->sysfslock); 251 252 /* Allocate buffer for control messages */ 253 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL); 254 if (!pdata->msgdata) { 255 retval = -ENOMEM; 256 dev_err(&iface->dev, 257 "Allocating buffer for control messages failed\n"); 258 goto error; 259 } 260 261 /* Allocate interrupt URB */ 262 pdata->urb = usb_alloc_urb(0, GFP_KERNEL); 263 if (!pdata->urb) { 264 retval = -ENOMEM; 265 dev_err(&iface->dev, "Allocating URB failed\n"); 266 goto error; 267 } 268 269 /* Allocate buffer for interrupt data */ 270 pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 271 GFP_KERNEL, &pdata->urb->transfer_dma); 272 if (!pdata->urbdata) { 273 retval = -ENOMEM; 274 dev_err(&iface->dev, "Allocating URB buffer failed\n"); 275 goto error; 276 } 277 278 /* Configure interrupt URB */ 279 usb_fill_int_urb(pdata->urb, udev, 280 usb_rcvintpipe(udev, int_in_endpointAddr), 281 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete, 282 pdata, 1); 283 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) { 284 retval = -EIO; 285 dev_err(&iface->dev, "Submitting URB failed\n"); 286 goto error; 287 } 288 289 /* Register backlight device */ 290 snprintf(bl_name, sizeof(bl_name), "appledisplay%d", 291 atomic_inc_return(&count_displays) - 1); 292 memset(&props, 0, sizeof(struct backlight_properties)); 293 props.type = BACKLIGHT_RAW; 294 props.max_brightness = 0xff; 295 pdata->bd = backlight_device_register(bl_name, NULL, pdata, 296 &appledisplay_bl_data, &props); 297 if (IS_ERR(pdata->bd)) { 298 dev_err(&iface->dev, "Backlight registration failed\n"); 299 retval = PTR_ERR(pdata->bd); 300 goto error; 301 } 302 303 /* Try to get brightness */ 304 brightness = appledisplay_bl_get_brightness(pdata->bd); 305 306 if (brightness < 0) { 307 retval = brightness; 308 dev_err(&iface->dev, 309 "Error while getting initial brightness: %d\n", retval); 310 goto error; 311 } 312 313 /* Set brightness in backlight device */ 314 pdata->bd->props.brightness = brightness; 315 316 /* save our data pointer in the interface device */ 317 usb_set_intfdata(iface, pdata); 318 319 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n"); 320 321 return 0; 322 323 error: 324 if (pdata) { 325 if (pdata->urb) { 326 usb_kill_urb(pdata->urb); 327 if (pdata->urbdata) 328 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 329 pdata->urbdata, pdata->urb->transfer_dma); 330 usb_free_urb(pdata->urb); 331 } 332 if (!IS_ERR(pdata->bd)) 333 backlight_device_unregister(pdata->bd); 334 kfree(pdata->msgdata); 335 } 336 usb_set_intfdata(iface, NULL); 337 kfree(pdata); 338 return retval; 339 } 340 341 static void appledisplay_disconnect(struct usb_interface *iface) 342 { 343 struct appledisplay *pdata = usb_get_intfdata(iface); 344 345 if (pdata) { 346 usb_kill_urb(pdata->urb); 347 cancel_delayed_work(&pdata->work); 348 backlight_device_unregister(pdata->bd); 349 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN, 350 pdata->urbdata, pdata->urb->transfer_dma); 351 usb_free_urb(pdata->urb); 352 kfree(pdata->msgdata); 353 kfree(pdata); 354 } 355 356 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n"); 357 } 358 359 static struct usb_driver appledisplay_driver = { 360 .name = "appledisplay", 361 .probe = appledisplay_probe, 362 .disconnect = appledisplay_disconnect, 363 .id_table = appledisplay_table, 364 }; 365 366 static int __init appledisplay_init(void) 367 { 368 wq = create_singlethread_workqueue("appledisplay"); 369 if (!wq) { 370 printk(KERN_ERR "appledisplay: Could not create work queue\n"); 371 return -ENOMEM; 372 } 373 374 return usb_register(&appledisplay_driver); 375 } 376 377 static void __exit appledisplay_exit(void) 378 { 379 flush_workqueue(wq); 380 destroy_workqueue(wq); 381 usb_deregister(&appledisplay_driver); 382 } 383 384 MODULE_AUTHOR("Michael Hanselmann"); 385 MODULE_DESCRIPTION("Apple Cinema Display driver"); 386 MODULE_LICENSE("GPL"); 387 388 module_init(appledisplay_init); 389 module_exit(appledisplay_exit); 390