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