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 33 #define APPLE_VENDOR_ID 0x05AC 34 35 #define USB_REQ_GET_REPORT 0x01 36 #define USB_REQ_SET_REPORT 0x09 37 38 #define ACD_USB_TIMEOUT 250 39 40 #define ACD_USB_EDID 0x0302 41 #define ACD_USB_BRIGHTNESS 0x0310 42 43 #define ACD_BTN_NONE 0 44 #define ACD_BTN_BRIGHT_UP 3 45 #define ACD_BTN_BRIGHT_DOWN 4 46 47 #define ACD_URB_BUFFER_LEN 2 48 #define ACD_MSG_BUFFER_LEN 2 49 50 #define APPLEDISPLAY_DEVICE(prod) \ 51 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \ 52 USB_DEVICE_ID_MATCH_INT_CLASS | \ 53 USB_DEVICE_ID_MATCH_INT_PROTOCOL, \ 54 .idVendor = APPLE_VENDOR_ID, \ 55 .idProduct = (prod), \ 56 .bInterfaceClass = USB_CLASS_HID, \ 57 .bInterfaceProtocol = 0x00 58 59 /* table of devices that work with this driver */ 60 static struct usb_device_id appledisplay_table [] = { 61 { APPLEDISPLAY_DEVICE(0x9218) }, 62 { APPLEDISPLAY_DEVICE(0x9219) }, 63 { APPLEDISPLAY_DEVICE(0x921d) }, 64 65 /* Terminating entry */ 66 { } 67 }; 68 MODULE_DEVICE_TABLE(usb, appledisplay_table); 69 70 /* Structure to hold all of our device specific stuff */ 71 struct appledisplay { 72 struct usb_device *udev; /* usb device */ 73 struct urb *urb; /* usb request block */ 74 struct backlight_device *bd; /* backlight device */ 75 char *urbdata; /* interrupt URB data buffer */ 76 char *msgdata; /* control message data buffer */ 77 78 struct delayed_work work; 79 int button_pressed; 80 spinlock_t lock; 81 }; 82 83 static atomic_t count_displays = ATOMIC_INIT(0); 84 static struct workqueue_struct *wq; 85 86 static void appledisplay_complete(struct urb *urb) 87 { 88 struct appledisplay *pdata = urb->context; 89 unsigned long flags; 90 int status = urb->status; 91 int retval; 92 93 switch (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 shuttingdown with status: %d", 106 __func__, status); 107 return; 108 default: 109 dbg("%s - nonzero urb status received: %d", 110 __func__, 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 __func__, retval); 135 } 136 } 137 138 static int appledisplay_bl_update_status(struct backlight_device *bd) 139 { 140 struct appledisplay *pdata = bl_get_data(bd); 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 = bl_get_data(bd); 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_ops appledisplay_bl_data = { 181 .get_brightness = appledisplay_bl_get_brightness, 182 .update_status = appledisplay_bl_update_status, 183 }; 184 185 static void appledisplay_work(struct work_struct *work) 186 { 187 struct appledisplay *pdata = 188 container_of(work, struct appledisplay, work.work); 189 int retval; 190 191 retval = appledisplay_bl_get_brightness(pdata->bd); 192 if (retval >= 0) 193 pdata->bd->props.brightness = retval; 194 195 /* Poll again in about 125ms if there's still a button pressed */ 196 if (pdata->button_pressed) 197 schedule_delayed_work(&pdata->work, HZ / 8); 198 } 199 200 static int appledisplay_probe(struct usb_interface *iface, 201 const struct usb_device_id *id) 202 { 203 struct appledisplay *pdata; 204 struct usb_device *udev = interface_to_usbdev(iface); 205 struct usb_host_interface *iface_desc; 206 struct usb_endpoint_descriptor *endpoint; 207 int int_in_endpointAddr = 0; 208 int i, retval = -ENOMEM, brightness; 209 char bl_name[20]; 210 211 /* set up the endpoint information */ 212 /* use only the first interrupt-in endpoint */ 213 iface_desc = iface->cur_altsetting; 214 for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) { 215 endpoint = &iface_desc->endpoint[i].desc; 216 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) { 217 /* we found an interrupt in endpoint */ 218 int_in_endpointAddr = endpoint->bEndpointAddress; 219 break; 220 } 221 } 222 if (!int_in_endpointAddr) { 223 err("Could not find int-in endpoint"); 224 return -EIO; 225 } 226 227 /* allocate memory for our device state and initialize it */ 228 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL); 229 if (!pdata) { 230 retval = -ENOMEM; 231 err("Out of memory"); 232 goto error; 233 } 234 235 pdata->udev = udev; 236 237 spin_lock_init(&pdata->lock); 238 INIT_DELAYED_WORK(&pdata->work, appledisplay_work); 239 240 /* Allocate buffer for control messages */ 241 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL); 242 if (!pdata->msgdata) { 243 retval = -ENOMEM; 244 err("appledisplay: Allocating buffer for control messages " 245 "failed"); 246 goto error; 247 } 248 249 /* Allocate interrupt URB */ 250 pdata->urb = usb_alloc_urb(0, GFP_KERNEL); 251 if (!pdata->urb) { 252 retval = -ENOMEM; 253 err("appledisplay: Allocating URB failed"); 254 goto error; 255 } 256 257 /* Allocate buffer for interrupt data */ 258 pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN, 259 GFP_KERNEL, &pdata->urb->transfer_dma); 260 if (!pdata->urbdata) { 261 retval = -ENOMEM; 262 err("appledisplay: Allocating URB buffer failed"); 263 goto error; 264 } 265 266 /* Configure interrupt URB */ 267 usb_fill_int_urb(pdata->urb, udev, 268 usb_rcvintpipe(udev, int_in_endpointAddr), 269 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete, 270 pdata, 1); 271 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) { 272 retval = -EIO; 273 err("appledisplay: Submitting URB failed"); 274 goto error; 275 } 276 277 /* Register backlight device */ 278 snprintf(bl_name, sizeof(bl_name), "appledisplay%d", 279 atomic_inc_return(&count_displays) - 1); 280 pdata->bd = backlight_device_register(bl_name, NULL, pdata, 281 &appledisplay_bl_data); 282 if (IS_ERR(pdata->bd)) { 283 err("appledisplay: Backlight registration failed"); 284 goto error; 285 } 286 287 pdata->bd->props.max_brightness = 0xff; 288 289 /* Try to get brightness */ 290 brightness = appledisplay_bl_get_brightness(pdata->bd); 291 292 if (brightness < 0) { 293 retval = brightness; 294 err("appledisplay: Error while getting initial brightness: %d", retval); 295 goto error; 296 } 297 298 /* Set brightness in backlight device */ 299 pdata->bd->props.brightness = brightness; 300 301 /* save our data pointer in the interface device */ 302 usb_set_intfdata(iface, pdata); 303 304 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n"); 305 306 return 0; 307 308 error: 309 if (pdata) { 310 if (pdata->urb) { 311 usb_kill_urb(pdata->urb); 312 if (pdata->urbdata) 313 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN, 314 pdata->urbdata, pdata->urb->transfer_dma); 315 usb_free_urb(pdata->urb); 316 } 317 if (pdata->bd) 318 backlight_device_unregister(pdata->bd); 319 kfree(pdata->msgdata); 320 } 321 usb_set_intfdata(iface, NULL); 322 kfree(pdata); 323 return retval; 324 } 325 326 static void appledisplay_disconnect(struct usb_interface *iface) 327 { 328 struct appledisplay *pdata = usb_get_intfdata(iface); 329 330 if (pdata) { 331 usb_kill_urb(pdata->urb); 332 cancel_delayed_work(&pdata->work); 333 backlight_device_unregister(pdata->bd); 334 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN, 335 pdata->urbdata, pdata->urb->transfer_dma); 336 usb_free_urb(pdata->urb); 337 kfree(pdata->msgdata); 338 kfree(pdata); 339 } 340 341 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n"); 342 } 343 344 static struct usb_driver appledisplay_driver = { 345 .name = "appledisplay", 346 .probe = appledisplay_probe, 347 .disconnect = appledisplay_disconnect, 348 .id_table = appledisplay_table, 349 }; 350 351 static int __init appledisplay_init(void) 352 { 353 wq = create_singlethread_workqueue("appledisplay"); 354 if (!wq) { 355 err("Could not create work queue\n"); 356 return -ENOMEM; 357 } 358 359 return usb_register(&appledisplay_driver); 360 } 361 362 static void __exit appledisplay_exit(void) 363 { 364 flush_workqueue(wq); 365 destroy_workqueue(wq); 366 usb_deregister(&appledisplay_driver); 367 } 368 369 MODULE_AUTHOR("Michael Hanselmann"); 370 MODULE_DESCRIPTION("Apple Cinema Display driver"); 371 MODULE_LICENSE("GPL"); 372 373 module_init(appledisplay_init); 374 module_exit(appledisplay_exit); 375