Linux Audio

Check our new training course

Loading...
v3.1
  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 */
 61static const struct usb_device_id appledisplay_table[] = {
 62	{ APPLEDISPLAY_DEVICE(0x9218) },
 63	{ APPLEDISPLAY_DEVICE(0x9219) },
 64	{ APPLEDISPLAY_DEVICE(0x921c) },
 65	{ APPLEDISPLAY_DEVICE(0x921d) },
 66
 67	/* Terminating entry */
 68	{ }
 69};
 70MODULE_DEVICE_TABLE(usb, appledisplay_table);
 71
 72/* Structure to hold all of our device specific stuff */
 73struct appledisplay {
 74	struct usb_device *udev;	/* usb device */
 75	struct urb *urb;		/* usb request block */
 76	struct backlight_device *bd;	/* backlight device */
 77	u8 *urbdata;			/* interrupt URB data buffer */
 78	u8 *msgdata;			/* control message data buffer */
 79
 80	struct delayed_work work;
 81	int button_pressed;
 82	spinlock_t lock;
 83};
 84
 85static atomic_t count_displays = ATOMIC_INIT(0);
 86static struct workqueue_struct *wq;
 87
 88static void appledisplay_complete(struct urb *urb)
 89{
 90	struct appledisplay *pdata = urb->context;
 
 91	unsigned long flags;
 92	int status = urb->status;
 93	int retval;
 94
 95	switch (status) {
 96	case 0:
 97		/* success */
 98		break;
 99	case -EOVERFLOW:
100		printk(KERN_ERR "appletouch: OVERFLOW with data "
101			"length %d, actual length is %d\n",
102			ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
103	case -ECONNRESET:
104	case -ENOENT:
105	case -ESHUTDOWN:
106		/* This urb is terminated, clean up */
107		dbg("%s - urb shuttingdown with status: %d",
108			__func__, status);
109		return;
110	default:
111		dbg("%s - nonzero urb status received: %d",
112			__func__, status);
113		goto exit;
114	}
115
116	spin_lock_irqsave(&pdata->lock, flags);
117
118	switch(pdata->urbdata[1]) {
119	case ACD_BTN_BRIGHT_UP:
120	case ACD_BTN_BRIGHT_DOWN:
121		pdata->button_pressed = 1;
122		queue_delayed_work(wq, &pdata->work, 0);
123		break;
124	case ACD_BTN_NONE:
125	default:
126		pdata->button_pressed = 0;
127		break;
128	}
129
130	spin_unlock_irqrestore(&pdata->lock, flags);
131
132exit:
133	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
134	if (retval) {
135		dev_err(&pdata->udev->dev,
136			"%s - usb_submit_urb failed with result %d\n",
137			__func__, retval);
138	}
139}
140
141static int appledisplay_bl_update_status(struct backlight_device *bd)
142{
143	struct appledisplay *pdata = bl_get_data(bd);
144	int retval;
145
146	pdata->msgdata[0] = 0x10;
147	pdata->msgdata[1] = bd->props.brightness;
148
149	retval = usb_control_msg(
150		pdata->udev,
151		usb_sndctrlpipe(pdata->udev, 0),
152		USB_REQ_SET_REPORT,
153		USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
154		ACD_USB_BRIGHTNESS,
155		0,
156		pdata->msgdata, 2,
157		ACD_USB_TIMEOUT);
158
159	return retval;
160}
161
162static int appledisplay_bl_get_brightness(struct backlight_device *bd)
163{
164	struct appledisplay *pdata = bl_get_data(bd);
165	int retval;
166
167	retval = usb_control_msg(
168		pdata->udev,
169		usb_rcvctrlpipe(pdata->udev, 0),
170		USB_REQ_GET_REPORT,
171		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
172		ACD_USB_BRIGHTNESS,
173		0,
174		pdata->msgdata, 2,
175		ACD_USB_TIMEOUT);
176
177	if (retval < 0)
178		return retval;
179	else
180		return pdata->msgdata[1];
181}
182
183static const struct backlight_ops appledisplay_bl_data = {
184	.get_brightness	= appledisplay_bl_get_brightness,
185	.update_status	= appledisplay_bl_update_status,
186};
187
188static void appledisplay_work(struct work_struct *work)
189{
190	struct appledisplay *pdata =
191		container_of(work, struct appledisplay, work.work);
192	int retval;
193
194	retval = appledisplay_bl_get_brightness(pdata->bd);
195	if (retval >= 0)
196		pdata->bd->props.brightness = retval;
197
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);
201}
202
203static int appledisplay_probe(struct usb_interface *iface,
204	const struct usb_device_id *id)
205{
206	struct backlight_properties props;
207	struct appledisplay *pdata;
208	struct usb_device *udev = interface_to_usbdev(iface);
209	struct usb_host_interface *iface_desc;
210	struct usb_endpoint_descriptor *endpoint;
211	int int_in_endpointAddr = 0;
212	int i, retval = -ENOMEM, brightness;
213	char bl_name[20];
214
215	/* set up the endpoint information */
216	/* use only the first interrupt-in endpoint */
217	iface_desc = iface->cur_altsetting;
218	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
219		endpoint = &iface_desc->endpoint[i].desc;
220		if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
221			/* we found an interrupt in endpoint */
222			int_in_endpointAddr = endpoint->bEndpointAddress;
223			break;
224		}
225	}
226	if (!int_in_endpointAddr) {
227		dev_err(&iface->dev, "Could not find int-in endpoint\n");
228		return -EIO;
229	}
230
231	/* allocate memory for our device state and initialize it */
232	pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
233	if (!pdata) {
234		retval = -ENOMEM;
235		dev_err(&iface->dev, "Out of memory\n");
236		goto error;
237	}
238
239	pdata->udev = udev;
240
241	spin_lock_init(&pdata->lock);
242	INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
243
244	/* Allocate buffer for control messages */
245	pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
246	if (!pdata->msgdata) {
247		retval = -ENOMEM;
248		dev_err(&iface->dev,
249			"Allocating buffer for control messages failed\n");
250		goto error;
251	}
252
253	/* Allocate interrupt URB */
254	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
255	if (!pdata->urb) {
256		retval = -ENOMEM;
257		dev_err(&iface->dev, "Allocating URB failed\n");
258		goto error;
259	}
260
261	/* Allocate buffer for interrupt data */
262	pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
263		GFP_KERNEL, &pdata->urb->transfer_dma);
264	if (!pdata->urbdata) {
265		retval = -ENOMEM;
266		dev_err(&iface->dev, "Allocating URB buffer failed\n");
267		goto error;
268	}
269
270	/* Configure interrupt URB */
271	usb_fill_int_urb(pdata->urb, udev,
272		usb_rcvintpipe(udev, int_in_endpointAddr),
273		pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
274		pdata, 1);
275	if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
276		retval = -EIO;
277		dev_err(&iface->dev, "Submitting URB failed\n");
278		goto error;
279	}
280
281	/* Register backlight device */
282	snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
283		atomic_inc_return(&count_displays) - 1);
284	memset(&props, 0, sizeof(struct backlight_properties));
285	props.type = BACKLIGHT_RAW;
286	props.max_brightness = 0xff;
287	pdata->bd = backlight_device_register(bl_name, NULL, pdata,
288					      &appledisplay_bl_data, &props);
289	if (IS_ERR(pdata->bd)) {
290		dev_err(&iface->dev, "Backlight registration failed\n");
291		retval = PTR_ERR(pdata->bd);
292		goto error;
293	}
294
295	/* Try to get brightness */
296	brightness = appledisplay_bl_get_brightness(pdata->bd);
297
298	if (brightness < 0) {
299		retval = brightness;
300		dev_err(&iface->dev,
301			"Error while getting initial brightness: %d\n", retval);
302		goto error;
303	}
304
305	/* Set brightness in backlight device */
306	pdata->bd->props.brightness = brightness;
307
308	/* save our data pointer in the interface device */
309	usb_set_intfdata(iface, pdata);
310
311	printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
312
313	return 0;
314
315error:
316	if (pdata) {
317		if (pdata->urb) {
318			usb_kill_urb(pdata->urb);
319			if (pdata->urbdata)
320				usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
321					pdata->urbdata, pdata->urb->transfer_dma);
322			usb_free_urb(pdata->urb);
323		}
324		if (pdata->bd && !IS_ERR(pdata->bd))
325			backlight_device_unregister(pdata->bd);
326		kfree(pdata->msgdata);
327	}
328	usb_set_intfdata(iface, NULL);
329	kfree(pdata);
330	return retval;
331}
332
333static void appledisplay_disconnect(struct usb_interface *iface)
334{
335	struct appledisplay *pdata = usb_get_intfdata(iface);
336
337	if (pdata) {
338		usb_kill_urb(pdata->urb);
339		cancel_delayed_work(&pdata->work);
340		backlight_device_unregister(pdata->bd);
341		usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
342			pdata->urbdata, pdata->urb->transfer_dma);
343		usb_free_urb(pdata->urb);
344		kfree(pdata->msgdata);
345		kfree(pdata);
346	}
347
348	printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
349}
350
351static struct usb_driver appledisplay_driver = {
352	.name		= "appledisplay",
353	.probe		= appledisplay_probe,
354	.disconnect	= appledisplay_disconnect,
355	.id_table	= appledisplay_table,
356};
357
358static int __init appledisplay_init(void)
359{
360	wq = create_singlethread_workqueue("appledisplay");
361	if (!wq) {
362		printk(KERN_ERR "appledisplay: Could not create work queue\n");
363		return -ENOMEM;
364	}
365
366	return usb_register(&appledisplay_driver);
367}
368
369static void __exit appledisplay_exit(void)
370{
371	flush_workqueue(wq);
372	destroy_workqueue(wq);
373	usb_deregister(&appledisplay_driver);
374}
375
376MODULE_AUTHOR("Michael Hanselmann");
377MODULE_DESCRIPTION("Apple Cinema Display driver");
378MODULE_LICENSE("GPL");
379
380module_init(appledisplay_init);
381module_exit(appledisplay_exit);
v3.5.6
  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 */
 61static const struct usb_device_id appledisplay_table[] = {
 62	{ APPLEDISPLAY_DEVICE(0x9218) },
 63	{ APPLEDISPLAY_DEVICE(0x9219) },
 64	{ APPLEDISPLAY_DEVICE(0x921c) },
 65	{ APPLEDISPLAY_DEVICE(0x921d) },
 66
 67	/* Terminating entry */
 68	{ }
 69};
 70MODULE_DEVICE_TABLE(usb, appledisplay_table);
 71
 72/* Structure to hold all of our device specific stuff */
 73struct appledisplay {
 74	struct usb_device *udev;	/* usb device */
 75	struct urb *urb;		/* usb request block */
 76	struct backlight_device *bd;	/* backlight device */
 77	u8 *urbdata;			/* interrupt URB data buffer */
 78	u8 *msgdata;			/* control message data buffer */
 79
 80	struct delayed_work work;
 81	int button_pressed;
 82	spinlock_t lock;
 83};
 84
 85static atomic_t count_displays = ATOMIC_INIT(0);
 86static struct workqueue_struct *wq;
 87
 88static void appledisplay_complete(struct urb *urb)
 89{
 90	struct appledisplay *pdata = urb->context;
 91	struct device *dev = &pdata->udev->dev;
 92	unsigned long flags;
 93	int status = urb->status;
 94	int retval;
 95
 96	switch (status) {
 97	case 0:
 98		/* success */
 99		break;
100	case -EOVERFLOW:
101		dev_err(dev,
102			"OVERFLOW with data length %d, actual length is %d\n",
103			ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
104	case -ECONNRESET:
105	case -ENOENT:
106	case -ESHUTDOWN:
107		/* This urb is terminated, clean up */
108		dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
109			__func__, status);
110		return;
111	default:
112		dev_dbg(dev, "%s - nonzero urb status received: %d/n",
113			__func__, status);
114		goto exit;
115	}
116
117	spin_lock_irqsave(&pdata->lock, flags);
118
119	switch(pdata->urbdata[1]) {
120	case ACD_BTN_BRIGHT_UP:
121	case ACD_BTN_BRIGHT_DOWN:
122		pdata->button_pressed = 1;
123		queue_delayed_work(wq, &pdata->work, 0);
124		break;
125	case ACD_BTN_NONE:
126	default:
127		pdata->button_pressed = 0;
128		break;
129	}
130
131	spin_unlock_irqrestore(&pdata->lock, flags);
132
133exit:
134	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
135	if (retval) {
136		dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
 
137			__func__, retval);
138	}
139}
140
141static int appledisplay_bl_update_status(struct backlight_device *bd)
142{
143	struct appledisplay *pdata = bl_get_data(bd);
144	int retval;
145
146	pdata->msgdata[0] = 0x10;
147	pdata->msgdata[1] = bd->props.brightness;
148
149	retval = usb_control_msg(
150		pdata->udev,
151		usb_sndctrlpipe(pdata->udev, 0),
152		USB_REQ_SET_REPORT,
153		USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
154		ACD_USB_BRIGHTNESS,
155		0,
156		pdata->msgdata, 2,
157		ACD_USB_TIMEOUT);
158
159	return retval;
160}
161
162static int appledisplay_bl_get_brightness(struct backlight_device *bd)
163{
164	struct appledisplay *pdata = bl_get_data(bd);
165	int retval;
166
167	retval = usb_control_msg(
168		pdata->udev,
169		usb_rcvctrlpipe(pdata->udev, 0),
170		USB_REQ_GET_REPORT,
171		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
172		ACD_USB_BRIGHTNESS,
173		0,
174		pdata->msgdata, 2,
175		ACD_USB_TIMEOUT);
176
177	if (retval < 0)
178		return retval;
179	else
180		return pdata->msgdata[1];
181}
182
183static const struct backlight_ops appledisplay_bl_data = {
184	.get_brightness	= appledisplay_bl_get_brightness,
185	.update_status	= appledisplay_bl_update_status,
186};
187
188static void appledisplay_work(struct work_struct *work)
189{
190	struct appledisplay *pdata =
191		container_of(work, struct appledisplay, work.work);
192	int retval;
193
194	retval = appledisplay_bl_get_brightness(pdata->bd);
195	if (retval >= 0)
196		pdata->bd->props.brightness = retval;
197
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);
201}
202
203static int appledisplay_probe(struct usb_interface *iface,
204	const struct usb_device_id *id)
205{
206	struct backlight_properties props;
207	struct appledisplay *pdata;
208	struct usb_device *udev = interface_to_usbdev(iface);
209	struct usb_host_interface *iface_desc;
210	struct usb_endpoint_descriptor *endpoint;
211	int int_in_endpointAddr = 0;
212	int i, retval = -ENOMEM, brightness;
213	char bl_name[20];
214
215	/* set up the endpoint information */
216	/* use only the first interrupt-in endpoint */
217	iface_desc = iface->cur_altsetting;
218	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
219		endpoint = &iface_desc->endpoint[i].desc;
220		if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
221			/* we found an interrupt in endpoint */
222			int_in_endpointAddr = endpoint->bEndpointAddress;
223			break;
224		}
225	}
226	if (!int_in_endpointAddr) {
227		dev_err(&iface->dev, "Could not find int-in endpoint\n");
228		return -EIO;
229	}
230
231	/* allocate memory for our device state and initialize it */
232	pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
233	if (!pdata) {
234		retval = -ENOMEM;
235		dev_err(&iface->dev, "Out of memory\n");
236		goto error;
237	}
238
239	pdata->udev = udev;
240
241	spin_lock_init(&pdata->lock);
242	INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
243
244	/* Allocate buffer for control messages */
245	pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
246	if (!pdata->msgdata) {
247		retval = -ENOMEM;
248		dev_err(&iface->dev,
249			"Allocating buffer for control messages failed\n");
250		goto error;
251	}
252
253	/* Allocate interrupt URB */
254	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
255	if (!pdata->urb) {
256		retval = -ENOMEM;
257		dev_err(&iface->dev, "Allocating URB failed\n");
258		goto error;
259	}
260
261	/* Allocate buffer for interrupt data */
262	pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
263		GFP_KERNEL, &pdata->urb->transfer_dma);
264	if (!pdata->urbdata) {
265		retval = -ENOMEM;
266		dev_err(&iface->dev, "Allocating URB buffer failed\n");
267		goto error;
268	}
269
270	/* Configure interrupt URB */
271	usb_fill_int_urb(pdata->urb, udev,
272		usb_rcvintpipe(udev, int_in_endpointAddr),
273		pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
274		pdata, 1);
275	if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
276		retval = -EIO;
277		dev_err(&iface->dev, "Submitting URB failed\n");
278		goto error;
279	}
280
281	/* Register backlight device */
282	snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
283		atomic_inc_return(&count_displays) - 1);
284	memset(&props, 0, sizeof(struct backlight_properties));
285	props.type = BACKLIGHT_RAW;
286	props.max_brightness = 0xff;
287	pdata->bd = backlight_device_register(bl_name, NULL, pdata,
288					      &appledisplay_bl_data, &props);
289	if (IS_ERR(pdata->bd)) {
290		dev_err(&iface->dev, "Backlight registration failed\n");
291		retval = PTR_ERR(pdata->bd);
292		goto error;
293	}
294
295	/* Try to get brightness */
296	brightness = appledisplay_bl_get_brightness(pdata->bd);
297
298	if (brightness < 0) {
299		retval = brightness;
300		dev_err(&iface->dev,
301			"Error while getting initial brightness: %d\n", retval);
302		goto error;
303	}
304
305	/* Set brightness in backlight device */
306	pdata->bd->props.brightness = brightness;
307
308	/* save our data pointer in the interface device */
309	usb_set_intfdata(iface, pdata);
310
311	printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
312
313	return 0;
314
315error:
316	if (pdata) {
317		if (pdata->urb) {
318			usb_kill_urb(pdata->urb);
319			if (pdata->urbdata)
320				usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
321					pdata->urbdata, pdata->urb->transfer_dma);
322			usb_free_urb(pdata->urb);
323		}
324		if (pdata->bd && !IS_ERR(pdata->bd))
325			backlight_device_unregister(pdata->bd);
326		kfree(pdata->msgdata);
327	}
328	usb_set_intfdata(iface, NULL);
329	kfree(pdata);
330	return retval;
331}
332
333static void appledisplay_disconnect(struct usb_interface *iface)
334{
335	struct appledisplay *pdata = usb_get_intfdata(iface);
336
337	if (pdata) {
338		usb_kill_urb(pdata->urb);
339		cancel_delayed_work(&pdata->work);
340		backlight_device_unregister(pdata->bd);
341		usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
342			pdata->urbdata, pdata->urb->transfer_dma);
343		usb_free_urb(pdata->urb);
344		kfree(pdata->msgdata);
345		kfree(pdata);
346	}
347
348	printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
349}
350
351static struct usb_driver appledisplay_driver = {
352	.name		= "appledisplay",
353	.probe		= appledisplay_probe,
354	.disconnect	= appledisplay_disconnect,
355	.id_table	= appledisplay_table,
356};
357
358static int __init appledisplay_init(void)
359{
360	wq = create_singlethread_workqueue("appledisplay");
361	if (!wq) {
362		printk(KERN_ERR "appledisplay: Could not create work queue\n");
363		return -ENOMEM;
364	}
365
366	return usb_register(&appledisplay_driver);
367}
368
369static void __exit appledisplay_exit(void)
370{
371	flush_workqueue(wq);
372	destroy_workqueue(wq);
373	usb_deregister(&appledisplay_driver);
374}
375
376MODULE_AUTHOR("Michael Hanselmann");
377MODULE_DESCRIPTION("Apple Cinema Display driver");
378MODULE_LICENSE("GPL");
379
380module_init(appledisplay_init);
381module_exit(appledisplay_exit);