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 dev_err(&pdata->udev->dev, 134 "%s - usb_submit_urb failed with result %d\n", 135 __func__, retval); 136 } 137 } 138 139 static int appledisplay_bl_update_status(struct backlight_device *bd) 140 { 141 struct appledisplay *pdata = bl_get_data(bd); 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 = bl_get_data(bd); 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_ops appledisplay_bl_data = { 182 .get_brightness = appledisplay_bl_get_brightness, 183 .update_status = appledisplay_bl_update_status, 184 }; 185 186 static void appledisplay_work(struct work_struct *work) 187 { 188 struct appledisplay *pdata = 189 container_of(work, struct appledisplay, work.work); 190 int retval; 191 192 retval = appledisplay_bl_get_brightness(pdata->bd); 193 if (retval >= 0) 194 pdata->bd->props.brightness = retval; 195 196 /* Poll again in about 125ms if there's still a button pressed */ 197 if (pdata->button_pressed) 198 schedule_delayed_work(&pdata->work, HZ / 8); 199 } 200 201 static int appledisplay_probe(struct usb_interface *iface, 202 const struct usb_device_id *id) 203 { 204 struct appledisplay *pdata; 205 struct usb_device *udev = interface_to_usbdev(iface); 206 struct usb_host_interface *iface_desc; 207 struct usb_endpoint_descriptor *endpoint; 208 int int_in_endpointAddr = 0; 209 int i, retval = -ENOMEM, brightness; 210 char bl_name[20]; 211 212 /* set up the endpoint information */ 213 /* use only the first interrupt-in endpoint */ 214 iface_desc = iface->cur_altsetting; 215 for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) { 216 endpoint = &iface_desc->endpoint[i].desc; 217 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) { 218 /* we found an interrupt in endpoint */ 219 int_in_endpointAddr = endpoint->bEndpointAddress; 220 break; 221 } 222 } 223 if (!int_in_endpointAddr) { 224 dev_err(&iface->dev, "Could not find int-in endpoint\n"); 225 return -EIO; 226 } 227 228 /* allocate memory for our device state and initialize it */ 229 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL); 230 if (!pdata) { 231 retval = -ENOMEM; 232 dev_err(&iface->dev, "Out of memory\n"); 233 goto error; 234 } 235 236 pdata->udev = udev; 237 238 spin_lock_init(&pdata->lock); 239 INIT_DELAYED_WORK(&pdata->work, appledisplay_work); 240 241 /* Allocate buffer for control messages */ 242 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL); 243 if (!pdata->msgdata) { 244 retval = -ENOMEM; 245 dev_err(&iface->dev, 246 "Allocating buffer for control messages failed\n"); 247 goto error; 248 } 249 250 /* Allocate interrupt URB */ 251 pdata->urb = usb_alloc_urb(0, GFP_KERNEL); 252 if (!pdata->urb) { 253 retval = -ENOMEM; 254 dev_err(&iface->dev, "Allocating URB failed\n"); 255 goto error; 256 } 257 258 /* Allocate buffer for interrupt data */ 259 pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN, 260 GFP_KERNEL, &pdata->urb->transfer_dma); 261 if (!pdata->urbdata) { 262 retval = -ENOMEM; 263 dev_err(&iface->dev, "Allocating URB buffer failed\n"); 264 goto error; 265 } 266 267 /* Configure interrupt URB */ 268 usb_fill_int_urb(pdata->urb, udev, 269 usb_rcvintpipe(udev, int_in_endpointAddr), 270 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete, 271 pdata, 1); 272 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) { 273 retval = -EIO; 274 dev_err(&iface->dev, "Submitting URB failed\n"); 275 goto error; 276 } 277 278 /* Register backlight device */ 279 snprintf(bl_name, sizeof(bl_name), "appledisplay%d", 280 atomic_inc_return(&count_displays) - 1); 281 pdata->bd = backlight_device_register(bl_name, NULL, pdata, 282 &appledisplay_bl_data); 283 if (IS_ERR(pdata->bd)) { 284 dev_err(&iface->dev, "Backlight registration failed\n"); 285 goto error; 286 } 287 288 pdata->bd->props.max_brightness = 0xff; 289 290 /* Try to get brightness */ 291 brightness = appledisplay_bl_get_brightness(pdata->bd); 292 293 if (brightness < 0) { 294 retval = brightness; 295 dev_err(&iface->dev, 296 "Error while getting initial brightness: %d\n", retval); 297 goto error; 298 } 299 300 /* Set brightness in backlight device */ 301 pdata->bd->props.brightness = brightness; 302 303 /* save our data pointer in the interface device */ 304 usb_set_intfdata(iface, pdata); 305 306 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n"); 307 308 return 0; 309 310 error: 311 if (pdata) { 312 if (pdata->urb) { 313 usb_kill_urb(pdata->urb); 314 if (pdata->urbdata) 315 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN, 316 pdata->urbdata, pdata->urb->transfer_dma); 317 usb_free_urb(pdata->urb); 318 } 319 if (pdata->bd && !IS_ERR(pdata->bd)) 320 backlight_device_unregister(pdata->bd); 321 kfree(pdata->msgdata); 322 } 323 usb_set_intfdata(iface, NULL); 324 kfree(pdata); 325 return retval; 326 } 327 328 static void appledisplay_disconnect(struct usb_interface *iface) 329 { 330 struct appledisplay *pdata = usb_get_intfdata(iface); 331 332 if (pdata) { 333 usb_kill_urb(pdata->urb); 334 cancel_delayed_work(&pdata->work); 335 backlight_device_unregister(pdata->bd); 336 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN, 337 pdata->urbdata, pdata->urb->transfer_dma); 338 usb_free_urb(pdata->urb); 339 kfree(pdata->msgdata); 340 kfree(pdata); 341 } 342 343 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n"); 344 } 345 346 static struct usb_driver appledisplay_driver = { 347 .name = "appledisplay", 348 .probe = appledisplay_probe, 349 .disconnect = appledisplay_disconnect, 350 .id_table = appledisplay_table, 351 }; 352 353 static int __init appledisplay_init(void) 354 { 355 wq = create_singlethread_workqueue("appledisplay"); 356 if (!wq) { 357 printk(KERN_ERR "appledisplay: Could not create work queue\n"); 358 return -ENOMEM; 359 } 360 361 return usb_register(&appledisplay_driver); 362 } 363 364 static void __exit appledisplay_exit(void) 365 { 366 flush_workqueue(wq); 367 destroy_workqueue(wq); 368 usb_deregister(&appledisplay_driver); 369 } 370 371 MODULE_AUTHOR("Michael Hanselmann"); 372 MODULE_DESCRIPTION("Apple Cinema Display driver"); 373 MODULE_LICENSE("GPL"); 374 375 module_init(appledisplay_init); 376 module_exit(appledisplay_exit); 377