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(0x9222) },
67 { APPLEDISPLAY_DEVICE(0x9226) },
68 { APPLEDISPLAY_DEVICE(0x9236) },
70 /* Terminating entry */
73 MODULE_DEVICE_TABLE(usb, appledisplay_table);
75 /* Structure to hold all of our device specific stuff */
77 struct usb_device *udev; /* usb device */
78 struct urb *urb; /* usb request block */
79 struct backlight_device *bd; /* backlight device */
80 u8 *urbdata; /* interrupt URB data buffer */
81 u8 *msgdata; /* control message data buffer */
83 struct delayed_work work;
86 struct mutex sysfslock; /* concurrent read and write */
89 static atomic_t count_displays = ATOMIC_INIT(0);
91 static void appledisplay_complete(struct urb *urb)
93 struct appledisplay *pdata = urb->context;
94 struct device *dev = &pdata->udev->dev;
96 int status = urb->status;
105 "OVERFLOW with data length %d, actual length is %d\n",
106 ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
110 /* This urb is terminated, clean up */
111 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
115 dev_dbg(dev, "%s - nonzero urb status received: %d\n",
120 spin_lock_irqsave(&pdata->lock, flags);
122 switch(pdata->urbdata[1]) {
123 case ACD_BTN_BRIGHT_UP:
124 case ACD_BTN_BRIGHT_DOWN:
125 pdata->button_pressed = 1;
126 schedule_delayed_work(&pdata->work, 0);
130 pdata->button_pressed = 0;
134 spin_unlock_irqrestore(&pdata->lock, flags);
137 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
139 dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
144 static int appledisplay_bl_update_status(struct backlight_device *bd)
146 struct appledisplay *pdata = bl_get_data(bd);
149 mutex_lock(&pdata->sysfslock);
150 pdata->msgdata[0] = 0x10;
151 pdata->msgdata[1] = bd->props.brightness;
153 retval = usb_control_msg(
155 usb_sndctrlpipe(pdata->udev, 0),
157 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
162 mutex_unlock(&pdata->sysfslock);
170 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
172 struct appledisplay *pdata = bl_get_data(bd);
173 int retval, brightness;
175 mutex_lock(&pdata->sysfslock);
176 retval = usb_control_msg(
178 usb_rcvctrlpipe(pdata->udev, 0),
180 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
189 brightness = pdata->msgdata[1];
191 mutex_unlock(&pdata->sysfslock);
199 static const struct backlight_ops appledisplay_bl_data = {
200 .get_brightness = appledisplay_bl_get_brightness,
201 .update_status = appledisplay_bl_update_status,
204 static void appledisplay_work(struct work_struct *work)
206 struct appledisplay *pdata =
207 container_of(work, struct appledisplay, work.work);
210 retval = appledisplay_bl_get_brightness(pdata->bd);
212 pdata->bd->props.brightness = retval;
214 /* Poll again in about 125ms if there's still a button pressed */
215 if (pdata->button_pressed)
216 schedule_delayed_work(&pdata->work, HZ / 8);
219 static int appledisplay_probe(struct usb_interface *iface,
220 const struct usb_device_id *id)
222 struct backlight_properties props;
223 struct appledisplay *pdata;
224 struct usb_device *udev = interface_to_usbdev(iface);
225 struct usb_endpoint_descriptor *endpoint;
226 int int_in_endpointAddr = 0;
227 int retval, brightness;
230 /* set up the endpoint information */
231 /* use only the first interrupt-in endpoint */
232 retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint);
234 dev_err(&iface->dev, "Could not find int-in endpoint\n");
238 int_in_endpointAddr = endpoint->bEndpointAddress;
240 /* allocate memory for our device state and initialize it */
241 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
249 spin_lock_init(&pdata->lock);
250 INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
251 mutex_init(&pdata->sysfslock);
253 /* Allocate buffer for control messages */
254 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
255 if (!pdata->msgdata) {
260 /* Allocate interrupt URB */
261 pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
267 /* Allocate buffer for interrupt data */
268 pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
269 GFP_KERNEL, &pdata->urb->transfer_dma);
270 if (!pdata->urbdata) {
272 dev_err(&iface->dev, "Allocating URB buffer failed\n");
276 /* Configure interrupt URB */
277 usb_fill_int_urb(pdata->urb, udev,
278 usb_rcvintpipe(udev, int_in_endpointAddr),
279 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
281 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
283 dev_err(&iface->dev, "Submitting URB failed\n");
287 /* Register backlight device */
288 snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
289 atomic_inc_return(&count_displays) - 1);
290 memset(&props, 0, sizeof(struct backlight_properties));
291 props.type = BACKLIGHT_RAW;
292 props.max_brightness = 0xff;
293 pdata->bd = backlight_device_register(bl_name, NULL, pdata,
294 &appledisplay_bl_data, &props);
295 if (IS_ERR(pdata->bd)) {
296 dev_err(&iface->dev, "Backlight registration failed\n");
297 retval = PTR_ERR(pdata->bd);
301 /* Try to get brightness */
302 brightness = appledisplay_bl_get_brightness(pdata->bd);
304 if (brightness < 0) {
307 "Error while getting initial brightness: %d\n", retval);
311 /* Set brightness in backlight device */
312 pdata->bd->props.brightness = brightness;
314 /* save our data pointer in the interface device */
315 usb_set_intfdata(iface, pdata);
317 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
324 usb_kill_urb(pdata->urb);
325 cancel_delayed_work_sync(&pdata->work);
327 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
328 pdata->urbdata, pdata->urb->transfer_dma);
329 usb_free_urb(pdata->urb);
331 if (!IS_ERR(pdata->bd))
332 backlight_device_unregister(pdata->bd);
333 kfree(pdata->msgdata);
335 usb_set_intfdata(iface, NULL);
340 static void appledisplay_disconnect(struct usb_interface *iface)
342 struct appledisplay *pdata = usb_get_intfdata(iface);
345 usb_kill_urb(pdata->urb);
346 cancel_delayed_work_sync(&pdata->work);
347 backlight_device_unregister(pdata->bd);
348 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
349 pdata->urbdata, pdata->urb->transfer_dma);
350 usb_free_urb(pdata->urb);
351 kfree(pdata->msgdata);
355 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
358 static struct usb_driver appledisplay_driver = {
359 .name = "appledisplay",
360 .probe = appledisplay_probe,
361 .disconnect = appledisplay_disconnect,
362 .id_table = appledisplay_table,
365 static int __init appledisplay_init(void)
367 return usb_register(&appledisplay_driver);
370 static void __exit appledisplay_exit(void)
372 usb_deregister(&appledisplay_driver);
375 MODULE_AUTHOR("Michael Hanselmann");
376 MODULE_DESCRIPTION("Apple Cinema Display driver");
377 MODULE_LICENSE("GPL");
379 module_init(appledisplay_init);
380 module_exit(appledisplay_exit);