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/usb.h>
28 #include <linux/backlight.h>
29 #include <linux/timer.h>
30 #include <linux/workqueue.h>
31 #include <asm/atomic.h>
32 #include <asm/semaphore.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 struct usb_device_id appledisplay_table [] = {
62 { APPLEDISPLAY_DEVICE(0x9218) },
63 { APPLEDISPLAY_DEVICE(0x9219) },
64 { APPLEDISPLAY_DEVICE(0x921d) },
66 /* Terminating entry */
69 MODULE_DEVICE_TABLE(usb, appledisplay_table);
71 /* Structure to hold all of our device specific stuff */
73 struct usb_device *udev; /* usb device */
74 struct urb *urb; /* usb request block */
75 struct backlight_device *bd; /* backlight device */
76 char *urbdata; /* interrupt URB data buffer */
77 char *msgdata; /* control message data buffer */
79 struct delayed_work work;
84 static atomic_t count_displays = ATOMIC_INIT(0);
85 static struct workqueue_struct *wq;
87 static void appledisplay_complete(struct urb *urb)
89 struct appledisplay *pdata = urb->context;
93 switch (urb->status) {
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);
104 /* This urb is terminated, clean up */
105 dbg("%s - urb shutting down with status: %d",
106 __FUNCTION__, urb->status);
109 dbg("%s - nonzero urb status received: %d",
110 __FUNCTION__, urb->status);
114 spin_lock_irqsave(&pdata->lock, flags);
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);
124 pdata->button_pressed = 0;
128 spin_unlock_irqrestore(&pdata->lock, flags);
131 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
133 err("%s - usb_submit_urb failed with result %d",
134 __FUNCTION__, retval);
138 static int appledisplay_bl_update_status(struct backlight_device *bd)
140 struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
143 pdata->msgdata[0] = 0x10;
144 pdata->msgdata[1] = bd->props->brightness;
146 retval = usb_control_msg(
148 usb_sndctrlpipe(pdata->udev, 0),
150 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
159 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
161 struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
164 retval = usb_control_msg(
166 usb_rcvctrlpipe(pdata->udev, 0),
168 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
177 return pdata->msgdata[1];
180 static struct backlight_properties appledisplay_bl_data = {
181 .get_brightness = appledisplay_bl_get_brightness,
182 .update_status = appledisplay_bl_update_status,
183 .max_brightness = 0xFF
186 static void appledisplay_work(struct work_struct *work)
188 struct appledisplay *pdata =
189 container_of(work, struct appledisplay, work.work);
193 retval = appledisplay_bl_get_brightness(pdata->bd);
195 pdata->bd->props->brightness = retval;
196 down(&pdata->bd->sem);
198 /* Poll again in about 125ms if there's still a button pressed */
199 if (pdata->button_pressed)
200 schedule_delayed_work(&pdata->work, HZ / 8);
203 static int appledisplay_probe(struct usb_interface *iface,
204 const struct usb_device_id *id)
206 struct appledisplay *pdata;
207 struct usb_device *udev = interface_to_usbdev(iface);
208 struct usb_host_interface *iface_desc;
209 struct usb_endpoint_descriptor *endpoint;
210 int int_in_endpointAddr = 0;
211 int i, retval = -ENOMEM, brightness;
214 /* set up the endpoint information */
215 /* use only the first interrupt-in endpoint */
216 iface_desc = iface->cur_altsetting;
217 for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
218 endpoint = &iface_desc->endpoint[i].desc;
219 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
220 /* we found an interrupt in endpoint */
221 int_in_endpointAddr = endpoint->bEndpointAddress;
225 if (!int_in_endpointAddr) {
226 err("Could not find int-in endpoint");
230 /* allocate memory for our device state and initialize it */
231 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
234 err("Out of memory");
240 spin_lock_init(&pdata->lock);
241 INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
243 /* Allocate buffer for control messages */
244 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
245 if (!pdata->msgdata) {
247 err("appledisplay: Allocating buffer for control messages "
252 /* Allocate interrupt URB */
253 pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
256 err("appledisplay: Allocating URB failed");
260 /* Allocate buffer for interrupt data */
261 pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN,
262 GFP_KERNEL, &pdata->urb->transfer_dma);
263 if (!pdata->urbdata) {
265 err("appledisplay: Allocating URB buffer failed");
269 /* Configure interrupt URB */
270 usb_fill_int_urb(pdata->urb, udev,
271 usb_rcvintpipe(udev, int_in_endpointAddr),
272 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
274 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
276 err("appledisplay: Submitting URB failed");
280 /* Register backlight device */
281 snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
282 atomic_inc_return(&count_displays) - 1);
283 pdata->bd = backlight_device_register(bl_name, NULL, pdata,
284 &appledisplay_bl_data);
285 if (IS_ERR(pdata->bd)) {
286 err("appledisplay: Backlight registration failed");
290 /* Try to get brightness */
292 brightness = appledisplay_bl_get_brightness(pdata->bd);
293 down(&pdata->bd->sem);
295 if (brightness < 0) {
297 err("appledisplay: Error while getting initial brightness: %d", retval);
301 /* Set brightness in backlight device */
303 pdata->bd->props->brightness = brightness;
304 down(&pdata->bd->sem);
306 /* save our data pointer in the interface device */
307 usb_set_intfdata(iface, pdata);
309 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
316 usb_kill_urb(pdata->urb);
318 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
319 pdata->urbdata, pdata->urb->transfer_dma);
320 usb_free_urb(pdata->urb);
323 backlight_device_unregister(pdata->bd);
324 kfree(pdata->msgdata);
326 usb_set_intfdata(iface, NULL);
331 static void appledisplay_disconnect(struct usb_interface *iface)
333 struct appledisplay *pdata = usb_get_intfdata(iface);
336 usb_kill_urb(pdata->urb);
337 cancel_delayed_work(&pdata->work);
338 backlight_device_unregister(pdata->bd);
339 usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
340 pdata->urbdata, pdata->urb->transfer_dma);
341 usb_free_urb(pdata->urb);
342 kfree(pdata->msgdata);
346 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
349 static struct usb_driver appledisplay_driver = {
350 .name = "appledisplay",
351 .probe = appledisplay_probe,
352 .disconnect = appledisplay_disconnect,
353 .id_table = appledisplay_table,
356 static int __init appledisplay_init(void)
358 wq = create_singlethread_workqueue("appledisplay");
360 err("Could not create work queue\n");
364 return usb_register(&appledisplay_driver);
367 static void __exit appledisplay_exit(void)
370 destroy_workqueue(wq);
371 usb_deregister(&appledisplay_driver);
374 MODULE_AUTHOR("Michael Hanselmann");
375 MODULE_DESCRIPTION("Apple Cinema Display driver");
376 MODULE_LICENSE("GPL");
378 module_init(appledisplay_init);
379 module_exit(appledisplay_exit);