2 * Apple Cinema Display driver
4 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
6 * Thanks to Caskey L. Dickson for his work with acdctl.
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.
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.
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.
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>
34 #define APPLE_VENDOR_ID 0x05AC
36 #define USB_REQ_GET_REPORT 0x01
37 #define USB_REQ_SET_REPORT 0x09
39 #define ACD_USB_TIMEOUT 250
41 #define ACD_USB_EDID 0x0302
42 #define ACD_USB_BRIGHTNESS 0x0310
44 #define ACD_BTN_NONE 0
45 #define ACD_BTN_BRIGHT_UP 3
46 #define ACD_BTN_BRIGHT_DOWN 4
48 #define ACD_URB_BUFFER_LEN 2
49 #define ACD_MSG_BUFFER_LEN 2
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
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) },
68 /* Terminating entry */
71 MODULE_DEVICE_TABLE(usb, appledisplay_table);
73 /* Structure to hold all of our device specific stuff */
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 */
81 struct delayed_work work;
84 struct mutex sysfslock; /* concurrent read and write */
87 static atomic_t count_displays = ATOMIC_INIT(0);
88 static struct workqueue_struct *wq;
90 static void appledisplay_complete(struct urb *urb)
92 struct appledisplay *pdata = urb->context;
93 struct device *dev = &pdata->udev->dev;
95 int status = urb->status;
104 "OVERFLOW with data length %d, actual length is %d\n",
105 ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
109 /* This urb is terminated, clean up */
110 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
114 dev_dbg(dev, "%s - nonzero urb status received: %d\n",
119 spin_lock_irqsave(&pdata->lock, flags);
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);
129 pdata->button_pressed = 0;
133 spin_unlock_irqrestore(&pdata->lock, flags);
136 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
138 dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
143 static int appledisplay_bl_update_status(struct backlight_device *bd)
145 struct appledisplay *pdata = bl_get_data(bd);
148 mutex_lock(&pdata->sysfslock);
149 pdata->msgdata[0] = 0x10;
150 pdata->msgdata[1] = bd->props.brightness;
152 retval = usb_control_msg(
154 usb_sndctrlpipe(pdata->udev, 0),
156 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
161 mutex_unlock(&pdata->sysfslock);
166 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
168 struct appledisplay *pdata = bl_get_data(bd);
169 int retval, brightness;
171 mutex_lock(&pdata->sysfslock);
172 retval = usb_control_msg(
174 usb_rcvctrlpipe(pdata->udev, 0),
176 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
181 brightness = pdata->msgdata[1];
182 mutex_unlock(&pdata->sysfslock);
190 static const struct backlight_ops appledisplay_bl_data = {
191 .get_brightness = appledisplay_bl_get_brightness,
192 .update_status = appledisplay_bl_update_status,
195 static void appledisplay_work(struct work_struct *work)
197 struct appledisplay *pdata =
198 container_of(work, struct appledisplay, work.work);
201 retval = appledisplay_bl_get_brightness(pdata->bd);
203 pdata->bd->props.brightness = retval;
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);
210 static int appledisplay_probe(struct usb_interface *iface,
211 const struct usb_device_id *id)
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;
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;
233 if (!int_in_endpointAddr) {
234 dev_err(&iface->dev, "Could not find int-in endpoint\n");
238 /* allocate memory for our device state and initialize it */
239 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
242 dev_err(&iface->dev, "Out of memory\n");
248 spin_lock_init(&pdata->lock);
249 INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
250 mutex_init(&pdata->sysfslock);
252 /* Allocate buffer for control messages */
253 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
254 if (!pdata->msgdata) {
257 "Allocating buffer for control messages failed\n");
261 /* Allocate interrupt URB */
262 pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
265 dev_err(&iface->dev, "Allocating URB failed\n");
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) {
274 dev_err(&iface->dev, "Allocating URB buffer failed\n");
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,
283 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
285 dev_err(&iface->dev, "Submitting URB failed\n");
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);
303 /* Try to get brightness */
304 brightness = appledisplay_bl_get_brightness(pdata->bd);
306 if (brightness < 0) {
309 "Error while getting initial brightness: %d\n", retval);
313 /* Set brightness in backlight device */
314 pdata->bd->props.brightness = brightness;
316 /* save our data pointer in the interface device */
317 usb_set_intfdata(iface, pdata);
319 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
326 usb_kill_urb(pdata->urb);
328 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
329 pdata->urbdata, pdata->urb->transfer_dma);
330 usb_free_urb(pdata->urb);
332 if (!IS_ERR(pdata->bd))
333 backlight_device_unregister(pdata->bd);
334 kfree(pdata->msgdata);
336 usb_set_intfdata(iface, NULL);
341 static void appledisplay_disconnect(struct usb_interface *iface)
343 struct appledisplay *pdata = usb_get_intfdata(iface);
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);
356 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
359 static struct usb_driver appledisplay_driver = {
360 .name = "appledisplay",
361 .probe = appledisplay_probe,
362 .disconnect = appledisplay_disconnect,
363 .id_table = appledisplay_table,
366 static int __init appledisplay_init(void)
368 wq = create_singlethread_workqueue("appledisplay");
370 printk(KERN_ERR "appledisplay: Could not create work queue\n");
374 return usb_register(&appledisplay_driver);
377 static void __exit appledisplay_exit(void)
380 destroy_workqueue(wq);
381 usb_deregister(&appledisplay_driver);
384 MODULE_AUTHOR("Michael Hanselmann");
385 MODULE_DESCRIPTION("Apple Cinema Display driver");
386 MODULE_LICENSE("GPL");
388 module_init(appledisplay_init);
389 module_exit(appledisplay_exit);