[mirror_ubuntu-jammy-kernel.git] / drivers / usb / misc / appledisplay.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Apple Cinema Display driver
 *
 * Copyright (C) 2006  Michael Hanselmann (linux-kernel@hansmi.ch)
 *
 * Thanks to Caskey L. Dickson for his work with acdctl.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/backlight.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/atomic.h>

#define APPLE_VENDOR_ID		0x05AC

#define USB_REQ_GET_REPORT	0x01
#define USB_REQ_SET_REPORT	0x09

#define ACD_USB_TIMEOUT		250

#define ACD_USB_EDID		0x0302
#define ACD_USB_BRIGHTNESS	0x0310

#define ACD_BTN_NONE		0
#define ACD_BTN_BRIGHT_UP	3
#define ACD_BTN_BRIGHT_DOWN	4

#define ACD_URB_BUFFER_LEN	2
#define ACD_MSG_BUFFER_LEN	2

#define APPLEDISPLAY_DEVICE(prod)				\
	.match_flags = USB_DEVICE_ID_MATCH_DEVICE |		\
		       USB_DEVICE_ID_MATCH_INT_CLASS |		\
		       USB_DEVICE_ID_MATCH_INT_PROTOCOL,	\
	.idVendor = APPLE_VENDOR_ID,				\
	.idProduct = (prod),					\
	.bInterfaceClass = USB_CLASS_HID,			\
	.bInterfaceProtocol = 0x00

/* table of devices that work with this driver */
static const struct usb_device_id appledisplay_table[] = {
	{ APPLEDISPLAY_DEVICE(0x9218) },
	{ APPLEDISPLAY_DEVICE(0x9219) },
	{ APPLEDISPLAY_DEVICE(0x921c) },
	{ APPLEDISPLAY_DEVICE(0x921d) },
	{ APPLEDISPLAY_DEVICE(0x9236) },

	/* Terminating entry */
	{ }
};
MODULE_DEVICE_TABLE(usb, appledisplay_table);

/* Structure to hold all of our device specific stuff */
struct appledisplay {
	struct usb_device *udev;	/* usb device */
	struct urb *urb;		/* usb request block */
	struct backlight_device *bd;	/* backlight device */
	u8 *urbdata;			/* interrupt URB data buffer */
	u8 *msgdata;			/* control message data buffer */

	struct delayed_work work;
	int button_pressed;
	spinlock_t lock;
	struct mutex sysfslock;		/* concurrent read and write */
};

static atomic_t count_displays = ATOMIC_INIT(0);

static void appledisplay_complete(struct urb *urb)
{
	struct appledisplay *pdata = urb->context;
	struct device *dev = &pdata->udev->dev;
	unsigned long flags;
	int status = urb->status;
	int retval;

	switch (status) {
	case 0:
		/* success */
		break;
	case -EOVERFLOW:
		dev_err(dev,
			"OVERFLOW with data length %d, actual length is %d\n",
			ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* This urb is terminated, clean up */
		dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
			__func__, status);
		return;
	default:
		dev_dbg(dev, "%s - nonzero urb status received: %d\n",
			__func__, status);
		goto exit;
	}

	spin_lock_irqsave(&pdata->lock, flags);

	switch(pdata->urbdata[1]) {
	case ACD_BTN_BRIGHT_UP:
	case ACD_BTN_BRIGHT_DOWN:
		pdata->button_pressed = 1;
		schedule_delayed_work(&pdata->work, 0);
		break;
	case ACD_BTN_NONE:
	default:
		pdata->button_pressed = 0;
		break;
	}

	spin_unlock_irqrestore(&pdata->lock, flags);

exit:
	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
	if (retval) {
		dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
			__func__, retval);
	}
}

static int appledisplay_bl_update_status(struct backlight_device *bd)
{
	struct appledisplay *pdata = bl_get_data(bd);
	int retval;

	mutex_lock(&pdata->sysfslock);
	pdata->msgdata[0] = 0x10;
	pdata->msgdata[1] = bd->props.brightness;

	retval = usb_control_msg(
		pdata->udev,
		usb_sndctrlpipe(pdata->udev, 0),
		USB_REQ_SET_REPORT,
		USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
		ACD_USB_BRIGHTNESS,
		0,
		pdata->msgdata, 2,
		ACD_USB_TIMEOUT);
	mutex_unlock(&pdata->sysfslock);
	
	return retval;
}

static int appledisplay_bl_get_brightness(struct backlight_device *bd)
{
	struct appledisplay *pdata = bl_get_data(bd);
	int retval, brightness;

	mutex_lock(&pdata->sysfslock);
	retval = usb_control_msg(
		pdata->udev,
		usb_rcvctrlpipe(pdata->udev, 0),
		USB_REQ_GET_REPORT,
		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
		ACD_USB_BRIGHTNESS,
		0,
		pdata->msgdata, 2,
		ACD_USB_TIMEOUT);
	brightness = pdata->msgdata[1];
	mutex_unlock(&pdata->sysfslock);

	if (retval < 0)
		return retval;
	else
		return brightness;
}

static const struct backlight_ops appledisplay_bl_data = {
	.get_brightness	= appledisplay_bl_get_brightness,
	.update_status	= appledisplay_bl_update_status,
};

static void appledisplay_work(struct work_struct *work)
{
	struct appledisplay *pdata =
		container_of(work, struct appledisplay, work.work);
	int retval;

	retval = appledisplay_bl_get_brightness(pdata->bd);
	if (retval >= 0)
		pdata->bd->props.brightness = retval;

	/* Poll again in about 125ms if there's still a button pressed */
	if (pdata->button_pressed)
		schedule_delayed_work(&pdata->work, HZ / 8);
}

static int appledisplay_probe(struct usb_interface *iface,
	const struct usb_device_id *id)
{
	struct backlight_properties props;
	struct appledisplay *pdata;
	struct usb_device *udev = interface_to_usbdev(iface);
	struct usb_endpoint_descriptor *endpoint;
	int int_in_endpointAddr = 0;
	int retval, brightness;
	char bl_name[20];

	/* set up the endpoint information */
	/* use only the first interrupt-in endpoint */
	retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint);
	if (retval) {
		dev_err(&iface->dev, "Could not find int-in endpoint\n");
		return retval;
	}

	int_in_endpointAddr = endpoint->bEndpointAddress;

	/* allocate memory for our device state and initialize it */
	pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
	if (!pdata) {
		retval = -ENOMEM;
		goto error;
	}

	pdata->udev = udev;

	spin_lock_init(&pdata->lock);
	INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
	mutex_init(&pdata->sysfslock);

	/* Allocate buffer for control messages */
	pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
	if (!pdata->msgdata) {
		retval = -ENOMEM;
		goto error;
	}

	/* Allocate interrupt URB */
	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!pdata->urb) {
		retval = -ENOMEM;
		goto error;
	}

	/* Allocate buffer for interrupt data */
	pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
		GFP_KERNEL, &pdata->urb->transfer_dma);
	if (!pdata->urbdata) {
		retval = -ENOMEM;
		dev_err(&iface->dev, "Allocating URB buffer failed\n");
		goto error;
	}

	/* Configure interrupt URB */
	usb_fill_int_urb(pdata->urb, udev,
		usb_rcvintpipe(udev, int_in_endpointAddr),
		pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
		pdata, 1);
	if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
		retval = -EIO;
		dev_err(&iface->dev, "Submitting URB failed\n");
		goto error;
	}

	/* Register backlight device */
	snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
		atomic_inc_return(&count_displays) - 1);
	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = 0xff;
	pdata->bd = backlight_device_register(bl_name, NULL, pdata,
					      &appledisplay_bl_data, &props);
	if (IS_ERR(pdata->bd)) {
		dev_err(&iface->dev, "Backlight registration failed\n");
		retval = PTR_ERR(pdata->bd);
		goto error;
	}

	/* Try to get brightness */
	brightness = appledisplay_bl_get_brightness(pdata->bd);

	if (brightness < 0) {
		retval = brightness;
		dev_err(&iface->dev,
			"Error while getting initial brightness: %d\n", retval);
		goto error;
	}

	/* Set brightness in backlight device */
	pdata->bd->props.brightness = brightness;

	/* save our data pointer in the interface device */
	usb_set_intfdata(iface, pdata);

	printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");

	return 0;

error:
	if (pdata) {
		if (pdata->urb) {
			usb_kill_urb(pdata->urb);
			if (pdata->urbdata)
				usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
					pdata->urbdata, pdata->urb->transfer_dma);
			usb_free_urb(pdata->urb);
		}
		if (!IS_ERR(pdata->bd))
			backlight_device_unregister(pdata->bd);
		kfree(pdata->msgdata);
	}
	usb_set_intfdata(iface, NULL);
	kfree(pdata);
	return retval;
}

static void appledisplay_disconnect(struct usb_interface *iface)
{
	struct appledisplay *pdata = usb_get_intfdata(iface);

	if (pdata) {
		usb_kill_urb(pdata->urb);
		cancel_delayed_work_sync(&pdata->work);
		backlight_device_unregister(pdata->bd);
		usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
			pdata->urbdata, pdata->urb->transfer_dma);
		usb_free_urb(pdata->urb);
		kfree(pdata->msgdata);
		kfree(pdata);
	}

	printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
}

static struct usb_driver appledisplay_driver = {
	.name		= "appledisplay",
	.probe		= appledisplay_probe,
	.disconnect	= appledisplay_disconnect,
	.id_table	= appledisplay_table,
};

static int __init appledisplay_init(void)
{
	return usb_register(&appledisplay_driver);
}

static void __exit appledisplay_exit(void)
{
	usb_deregister(&appledisplay_driver);
}

MODULE_AUTHOR("Michael Hanselmann");
MODULE_DESCRIPTION("Apple Cinema Display driver");
MODULE_LICENSE("GPL");

module_init(appledisplay_init);
module_exit(appledisplay_exit);
Commit	Line	Data
5fd54ace	1	// SPDX-License-Identifier: GPL-2.0+
069e8a65	2	/*
	3	* Apple Cinema Display driver
	4	*
	5	* Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
	6	*
	7	* Thanks to Caskey L. Dickson for his work with acdctl.
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License as published by
	11	* the Free Software Foundation; either version 2 of the License, or
	12	* (at your option) any later version.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software
	21	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	22	*/
	23
069e8a65	24	#include <linux/kernel.h>
	25	#include <linux/errno.h>
	26	#include <linux/init.h>
	27	#include <linux/module.h>
5a0e3ad6	28	#include <linux/slab.h>
069e8a65	29	#include <linux/usb.h>
	30	#include <linux/backlight.h>
	31	#include <linux/timer.h>
	32	#include <linux/workqueue.h>
60063497	33	#include <linux/atomic.h>
069e8a65	34
	35	#define APPLE_VENDOR_ID 0x05AC
	36
	37	#define USB_REQ_GET_REPORT 0x01
	38	#define USB_REQ_SET_REPORT 0x09
	39
	40	#define ACD_USB_TIMEOUT 250
	41
	42	#define ACD_USB_EDID 0x0302
	43	#define ACD_USB_BRIGHTNESS 0x0310
	44
	45	#define ACD_BTN_NONE 0
	46	#define ACD_BTN_BRIGHT_UP 3
	47	#define ACD_BTN_BRIGHT_DOWN 4
	48
	49	#define ACD_URB_BUFFER_LEN 2
	50	#define ACD_MSG_BUFFER_LEN 2
	51
	52	#define APPLEDISPLAY_DEVICE(prod) \
	53	.match_flags = USB_DEVICE_ID_MATCH_DEVICE \| \
	54	USB_DEVICE_ID_MATCH_INT_CLASS \| \
	55	USB_DEVICE_ID_MATCH_INT_PROTOCOL, \
	56	.idVendor = APPLE_VENDOR_ID, \
	57	.idProduct = (prod), \
	58	.bInterfaceClass = USB_CLASS_HID, \
	59	.bInterfaceProtocol = 0x00
	60
	61	/* table of devices that work with this driver */
33b9e162	62	static const struct usb_device_id appledisplay_table[] = {
069e8a65	63	{ APPLEDISPLAY_DEVICE(0x9218) },
069e8a65	64	{ APPLEDISPLAY_DEVICE(0x9219) },
4b372072	65	{ APPLEDISPLAY_DEVICE(0x921c) },
069e8a65	66	{ APPLEDISPLAY_DEVICE(0x921d) },
e7d3b6e2	67	{ APPLEDISPLAY_DEVICE(0x9236) },
069e8a65	68
	69	/* Terminating entry */
	70	{ }
	71	};
	72	MODULE_DEVICE_TABLE(usb, appledisplay_table);
	73
	74	/* Structure to hold all of our device specific stuff */
	75	struct appledisplay {
	76	struct usb_device udev; / usb device */
	77	struct urb urb; / usb request block */
	78	struct backlight_device bd; / backlight device */
37e9066b	79	u8 urbdata; / interrupt URB data buffer */
37e9066b	80	u8 msgdata; / control message data buffer */
069e8a65	81
6d5aefb8	82	struct delayed_work work;
069e8a65	83	int button_pressed;
069e8a65	84	spinlock_t lock;
552e1f26	85	struct mutex sysfslock; /* concurrent read and write */
069e8a65	86	};
	87
	88	static atomic_t count_displays = ATOMIC_INIT(0);
069e8a65	89
7d12e780	90	static void appledisplay_complete(struct urb *urb)
069e8a65	91	{
069e8a65	92	struct appledisplay *pdata = urb->context;
0a3fd536	93	struct device *dev = &pdata->udev->dev;
069e8a65	94	unsigned long flags;
13f9782d	95	int status = urb->status;
069e8a65	96	int retval;
069e8a65	97
13f9782d	98	switch (status) {
069e8a65	99	case 0:
	100	/* success */
	101	break;
	102	case -EOVERFLOW:
0a3fd536 GKH	103	dev_err(dev,
0a3fd536 GKH	104	"OVERFLOW with data length %d, actual length is %d\n",
069e8a65	105	ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
	106	case -ECONNRESET:
	107	case -ENOENT:
	108	case -ESHUTDOWN:
	109	/* This urb is terminated, clean up */
0a3fd536	110	dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
441b62c1	111	__func__, status);
069e8a65	112	return;
069e8a65	113	default:
e2b86c1d	114	dev_dbg(dev, "%s - nonzero urb status received: %d\n",
441b62c1	115	__func__, status);
069e8a65	116	goto exit;
	117	}
	118
	119	spin_lock_irqsave(&pdata->lock, flags);
	120
	121	switch(pdata->urbdata[1]) {
	122	case ACD_BTN_BRIGHT_UP:
	123	case ACD_BTN_BRIGHT_DOWN:
	124	pdata->button_pressed = 1;
6a0bb434	125	schedule_delayed_work(&pdata->work, 0);
069e8a65	126	break;
	127	case ACD_BTN_NONE:
	128	default:
	129	pdata->button_pressed = 0;
	130	break;
	131	}
	132
	133	spin_unlock_irqrestore(&pdata->lock, flags);
	134
	135	exit:
	136	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
	137	if (retval) {
0a3fd536	138	dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
441b62c1	139	__func__, retval);
069e8a65	140	}
	141	}
	142
	143	static int appledisplay_bl_update_status(struct backlight_device *bd)
	144	{
655bfd7a	145	struct appledisplay *pdata = bl_get_data(bd);
069e8a65	146	int retval;
069e8a65	147
552e1f26	148	mutex_lock(&pdata->sysfslock);
069e8a65	149	pdata->msgdata[0] = 0x10;
599a52d1	150	pdata->msgdata[1] = bd->props.brightness;
069e8a65	151
	152	retval = usb_control_msg(
	153	pdata->udev,
	154	usb_sndctrlpipe(pdata->udev, 0),
	155	USB_REQ_SET_REPORT,
	156	USB_DIR_OUT \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE,
	157	ACD_USB_BRIGHTNESS,
	158	0,
	159	pdata->msgdata, 2,
	160	ACD_USB_TIMEOUT);
552e1f26 ON	161	mutex_unlock(&pdata->sysfslock);
552e1f26 ON	162
069e8a65	163	return retval;
	164	}
	165
	166	static int appledisplay_bl_get_brightness(struct backlight_device *bd)
	167	{
655bfd7a	168	struct appledisplay *pdata = bl_get_data(bd);
552e1f26	169	int retval, brightness;
069e8a65	170
552e1f26	171	mutex_lock(&pdata->sysfslock);
069e8a65	172	retval = usb_control_msg(
	173	pdata->udev,
	174	usb_rcvctrlpipe(pdata->udev, 0),
	175	USB_REQ_GET_REPORT,
	176	USB_DIR_IN \| USB_TYPE_CLASS \| USB_RECIP_INTERFACE,
	177	ACD_USB_BRIGHTNESS,
	178	0,
	179	pdata->msgdata, 2,
	180	ACD_USB_TIMEOUT);
552e1f26 ON	181	brightness = pdata->msgdata[1];
552e1f26 ON	182	mutex_unlock(&pdata->sysfslock);
069e8a65	183
	184	if (retval < 0)
	185	return retval;
	186	else
552e1f26	187	return brightness;
069e8a65	188	}
069e8a65	189
cedf8a78	190	static const struct backlight_ops appledisplay_bl_data = {
069e8a65	191	.get_brightness = appledisplay_bl_get_brightness,
069e8a65	192	.update_status = appledisplay_bl_update_status,
069e8a65	193	};
069e8a65	194
6d5aefb8	195	static void appledisplay_work(struct work_struct *work)
069e8a65	196	{
6d5aefb8 DH	197	struct appledisplay *pdata =
6d5aefb8 DH	198	container_of(work, struct appledisplay, work.work);
069e8a65	199	int retval;
069e8a65	200
069e8a65	201	retval = appledisplay_bl_get_brightness(pdata->bd);
069e8a65	202	if (retval >= 0)
599a52d1	203	pdata->bd->props.brightness = retval;
069e8a65	204
	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);
	208	}
	209
	210	static int appledisplay_probe(struct usb_interface *iface,
	211	const struct usb_device_id *id)
	212	{
a19a6ee6	213	struct backlight_properties props;
069e8a65	214	struct appledisplay *pdata;
069e8a65	215	struct usb_device *udev = interface_to_usbdev(iface);
069e8a65	216	struct usb_endpoint_descriptor *endpoint;
069e8a65	217	int int_in_endpointAddr = 0;
c77b8855	218	int retval, brightness;
069e8a65	219	char bl_name[20];
	220
	221	/* set up the endpoint information */
	222	/* use only the first interrupt-in endpoint */
c77b8855 JH	223	retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint);
c77b8855 JH	224	if (retval) {
fd3f1917	225	dev_err(&iface->dev, "Could not find int-in endpoint\n");
c77b8855	226	return retval;
069e8a65	227	}
069e8a65	228
c77b8855 JH	229	int_in_endpointAddr = endpoint->bEndpointAddress;
c77b8855 JH	230
069e8a65	231	/* allocate memory for our device state and initialize it */
	232	pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
	233	if (!pdata) {
	234	retval = -ENOMEM;
069e8a65	235	goto error;
	236	}
	237
	238	pdata->udev = udev;
	239
	240	spin_lock_init(&pdata->lock);
6d5aefb8	241	INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
552e1f26	242	mutex_init(&pdata->sysfslock);
069e8a65	243
	244	/* Allocate buffer for control messages */
	245	pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
	246	if (!pdata->msgdata) {
	247	retval = -ENOMEM;
069e8a65	248	goto error;
	249	}
	250
	251	/* Allocate interrupt URB */
	252	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
	253	if (!pdata->urb) {
	254	retval = -ENOMEM;
069e8a65	255	goto error;
	256	}
	257
	258	/* Allocate buffer for interrupt data */
997ea58e	259	pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
069e8a65	260	GFP_KERNEL, &pdata->urb->transfer_dma);
	261	if (!pdata->urbdata) {
	262	retval = -ENOMEM;
fd3f1917	263	dev_err(&iface->dev, "Allocating URB buffer failed\n");
069e8a65	264	goto error;
	265	}
	266
	267	/* Configure interrupt URB */
	268	usb_fill_int_urb(pdata->urb, udev,
	269	usb_rcvintpipe(udev, int_in_endpointAddr),
	270	pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
	271	pdata, 1);
	272	if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
	273	retval = -EIO;
fd3f1917	274	dev_err(&iface->dev, "Submitting URB failed\n");
069e8a65	275	goto error;
	276	}
	277
	278	/* Register backlight device */
	279	snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
	280	atomic_inc_return(&count_displays) - 1);
a19a6ee6	281	memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747	282	props.type = BACKLIGHT_RAW;
a19a6ee6	283	props.max_brightness = 0xff;
81450b73	284	pdata->bd = backlight_device_register(bl_name, NULL, pdata,
a19a6ee6	285	&appledisplay_bl_data, &props);
069e8a65	286	if (IS_ERR(pdata->bd)) {
fd3f1917	287	dev_err(&iface->dev, "Backlight registration failed\n");
cedf8a78	288	retval = PTR_ERR(pdata->bd);
069e8a65	289	goto error;
	290	}
	291
	292	/* Try to get brightness */
069e8a65	293	brightness = appledisplay_bl_get_brightness(pdata->bd);
069e8a65	294
	295	if (brightness < 0) {
	296	retval = brightness;
fd3f1917 GKH	297	dev_err(&iface->dev,
fd3f1917 GKH	298	"Error while getting initial brightness: %d\n", retval);
069e8a65	299	goto error;
	300	}
	301
	302	/* Set brightness in backlight device */
599a52d1	303	pdata->bd->props.brightness = brightness;
069e8a65	304
	305	/* save our data pointer in the interface device */
	306	usb_set_intfdata(iface, pdata);
	307
	308	printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
	309
	310	return 0;
	311
	312	error:
	313	if (pdata) {
	314	if (pdata->urb) {
	315	usb_kill_urb(pdata->urb);
	316	if (pdata->urbdata)
997ea58e	317	usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
069e8a65	318	pdata->urbdata, pdata->urb->transfer_dma);
	319	usb_free_urb(pdata->urb);
	320	}
c60b89aa	321	if (!IS_ERR(pdata->bd))
069e8a65	322	backlight_device_unregister(pdata->bd);
	323	kfree(pdata->msgdata);
	324	}
	325	usb_set_intfdata(iface, NULL);
	326	kfree(pdata);
	327	return retval;
	328	}
	329
	330	static void appledisplay_disconnect(struct usb_interface *iface)
	331	{
	332	struct appledisplay *pdata = usb_get_intfdata(iface);
	333
	334	if (pdata) {
	335	usb_kill_urb(pdata->urb);
6a0bb434	336	cancel_delayed_work_sync(&pdata->work);
069e8a65	337	backlight_device_unregister(pdata->bd);
997ea58e	338	usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
069e8a65	339	pdata->urbdata, pdata->urb->transfer_dma);
	340	usb_free_urb(pdata->urb);
	341	kfree(pdata->msgdata);
	342	kfree(pdata);
	343	}
	344
	345	printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
	346	}
	347
	348	static struct usb_driver appledisplay_driver = {
	349	.name = "appledisplay",
	350	.probe = appledisplay_probe,
	351	.disconnect = appledisplay_disconnect,
	352	.id_table = appledisplay_table,
	353	};
	354
	355	static int __init appledisplay_init(void)
	356	{
069e8a65	357	return usb_register(&appledisplay_driver);
	358	}
	359
	360	static void __exit appledisplay_exit(void)
	361	{
069e8a65	362	usb_deregister(&appledisplay_driver);
	363	}
	364
	365	MODULE_AUTHOR("Michael Hanselmann");
	366	MODULE_DESCRIPTION("Apple Cinema Display driver");
	367	MODULE_LICENSE("GPL");
	368
	369	module_init(appledisplay_init);
	370	module_exit(appledisplay_exit);