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/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>
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 struct usb_device_id appledisplay_table [] = {
62	{ APPLEDISPLAY_DEVICE(0x9218) },
63	{ APPLEDISPLAY_DEVICE(0x9219) },
64	{ APPLEDISPLAY_DEVICE(0x921d) },
65
66	/* Terminating entry */
67	{ }
68};
69MODULE_DEVICE_TABLE(usb, appledisplay_table);
70
71/* Structure to hold all of our device specific stuff */
72struct appledisplay {
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 */
78
79	struct delayed_work work;
80	int button_pressed;
81	spinlock_t lock;
82};
83
84static atomic_t count_displays = ATOMIC_INIT(0);
85static struct workqueue_struct *wq;
86
87static void appledisplay_complete(struct urb *urb)
88{
89	struct appledisplay *pdata = urb->context;
90	unsigned long flags;
91	int retval;
92
93	switch (urb->status) {
94	case 0:
95		/* success */
96		break;
97	case -EOVERFLOW:
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);
101	case -ECONNRESET:
102	case -ENOENT:
103	case -ESHUTDOWN:
104		/* This urb is terminated, clean up */
105		dbg("%s - urb shutting down with status: %d",
106			__FUNCTION__, urb->status);
107		return;
108	default:
109		dbg("%s - nonzero urb status received: %d",
110			__FUNCTION__, urb->status);
111		goto exit;
112	}
113
114	spin_lock_irqsave(&pdata->lock, flags);
115
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);
121		break;
122	case ACD_BTN_NONE:
123	default:
124		pdata->button_pressed = 0;
125		break;
126	}
127
128	spin_unlock_irqrestore(&pdata->lock, flags);
129
130exit:
131	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
132	if (retval) {
133		err("%s - usb_submit_urb failed with result %d",
134			__FUNCTION__, retval);
135	}
136}
137
138static int appledisplay_bl_update_status(struct backlight_device *bd)
139{
140	struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
141	int retval;
142
143	pdata->msgdata[0] = 0x10;
144	pdata->msgdata[1] = bd->props.brightness;
145
146	retval = usb_control_msg(
147		pdata->udev,
148		usb_sndctrlpipe(pdata->udev, 0),
149		USB_REQ_SET_REPORT,
150		USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
151		ACD_USB_BRIGHTNESS,
152		0,
153		pdata->msgdata, 2,
154		ACD_USB_TIMEOUT);
155
156	return retval;
157}
158
159static int appledisplay_bl_get_brightness(struct backlight_device *bd)
160{
161	struct appledisplay *pdata = class_get_devdata(&bd->class_dev);
162	int retval;
163
164	retval = usb_control_msg(
165		pdata->udev,
166		usb_rcvctrlpipe(pdata->udev, 0),
167		USB_REQ_GET_REPORT,
168		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
169		ACD_USB_BRIGHTNESS,
170		0,
171		pdata->msgdata, 2,
172		ACD_USB_TIMEOUT);
173
174	if (retval < 0)
175		return retval;
176	else
177		return pdata->msgdata[1];
178}
179
180static struct backlight_ops appledisplay_bl_data = {
181	.get_brightness	= appledisplay_bl_get_brightness,
182	.update_status	= appledisplay_bl_update_status,
183};
184
185static void appledisplay_work(struct work_struct *work)
186{
187	struct appledisplay *pdata =
188		container_of(work, struct appledisplay, work.work);
189	int retval;
190
191	retval = appledisplay_bl_get_brightness(pdata->bd);
192	if (retval >= 0)
193		pdata->bd->props.brightness = retval;
194
195	/* Poll again in about 125ms if there's still a button pressed */
196	if (pdata->button_pressed)
197		schedule_delayed_work(&pdata->work, HZ / 8);
198}
199
200static int appledisplay_probe(struct usb_interface *iface,
201	const struct usb_device_id *id)
202{
203	struct appledisplay *pdata;
204	struct usb_device *udev = interface_to_usbdev(iface);
205	struct usb_host_interface *iface_desc;
206	struct usb_endpoint_descriptor *endpoint;
207	int int_in_endpointAddr = 0;
208	int i, retval = -ENOMEM, brightness;
209	char bl_name[20];
210
211	/* set up the endpoint information */
212	/* use only the first interrupt-in endpoint */
213	iface_desc = iface->cur_altsetting;
214	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
215		endpoint = &iface_desc->endpoint[i].desc;
216		if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
217			/* we found an interrupt in endpoint */
218			int_in_endpointAddr = endpoint->bEndpointAddress;
219			break;
220		}
221	}
222	if (!int_in_endpointAddr) {
223		err("Could not find int-in endpoint");
224		return -EIO;
225	}
226
227	/* allocate memory for our device state and initialize it */
228	pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
229	if (!pdata) {
230		retval = -ENOMEM;
231		err("Out of memory");
232		goto error;
233	}
234
235	pdata->udev = udev;
236
237	spin_lock_init(&pdata->lock);
238	INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
239
240	/* Allocate buffer for control messages */
241	pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
242	if (!pdata->msgdata) {
243		retval = -ENOMEM;
244		err("appledisplay: Allocating buffer for control messages "
245			"failed");
246		goto error;
247	}
248
249	/* Allocate interrupt URB */
250	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
251	if (!pdata->urb) {
252		retval = -ENOMEM;
253		err("appledisplay: Allocating URB failed");
254		goto error;
255	}
256
257	/* Allocate buffer for interrupt data */
258	pdata->urbdata = usb_buffer_alloc(pdata->udev, ACD_URB_BUFFER_LEN,
259		GFP_KERNEL, &pdata->urb->transfer_dma);
260	if (!pdata->urbdata) {
261		retval = -ENOMEM;
262		err("appledisplay: Allocating URB buffer failed");
263		goto error;
264	}
265
266	/* Configure interrupt URB */
267	usb_fill_int_urb(pdata->urb, udev,
268		usb_rcvintpipe(udev, int_in_endpointAddr),
269		pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
270		pdata, 1);
271	if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
272		retval = -EIO;
273		err("appledisplay: Submitting URB failed");
274		goto error;
275	}
276
277	/* Register backlight device */
278	snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
279		atomic_inc_return(&count_displays) - 1);
280	pdata->bd = backlight_device_register(bl_name, NULL, pdata,
281						&appledisplay_bl_data);
282	if (IS_ERR(pdata->bd)) {
283		err("appledisplay: Backlight registration failed");
284		goto error;
285	}
286
287	pdata->bd->props.max_brightness = 0xff;
288
289	/* Try to get brightness */
290	brightness = appledisplay_bl_get_brightness(pdata->bd);
291
292	if (brightness < 0) {
293		retval = brightness;
294		err("appledisplay: Error while getting initial brightness: %d", retval);
295		goto error;
296	}
297
298	/* Set brightness in backlight device */
299	pdata->bd->props.brightness = brightness;
300
301	/* save our data pointer in the interface device */
302	usb_set_intfdata(iface, pdata);
303
304	printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
305
306	return 0;
307
308error:
309	if (pdata) {
310		if (pdata->urb) {
311			usb_kill_urb(pdata->urb);
312			if (pdata->urbdata)
313				usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
314					pdata->urbdata, pdata->urb->transfer_dma);
315			usb_free_urb(pdata->urb);
316		}
317		if (pdata->bd)
318			backlight_device_unregister(pdata->bd);
319		kfree(pdata->msgdata);
320	}
321	usb_set_intfdata(iface, NULL);
322	kfree(pdata);
323	return retval;
324}
325
326static void appledisplay_disconnect(struct usb_interface *iface)
327{
328	struct appledisplay *pdata = usb_get_intfdata(iface);
329
330	if (pdata) {
331		usb_kill_urb(pdata->urb);
332		cancel_delayed_work(&pdata->work);
333		backlight_device_unregister(pdata->bd);
334		usb_buffer_free(pdata->udev, ACD_URB_BUFFER_LEN,
335			pdata->urbdata, pdata->urb->transfer_dma);
336		usb_free_urb(pdata->urb);
337		kfree(pdata->msgdata);
338		kfree(pdata);
339	}
340
341	printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
342}
343
344static struct usb_driver appledisplay_driver = {
345	.name		= "appledisplay",
346	.probe		= appledisplay_probe,
347	.disconnect	= appledisplay_disconnect,
348	.id_table	= appledisplay_table,
349};
350
351static int __init appledisplay_init(void)
352{
353	wq = create_singlethread_workqueue("appledisplay");
354	if (!wq) {
355		err("Could not create work queue\n");
356		return -ENOMEM;
357	}
358
359	return usb_register(&appledisplay_driver);
360}
361
362static void __exit appledisplay_exit(void)
363{
364	flush_workqueue(wq);
365	destroy_workqueue(wq);
366	usb_deregister(&appledisplay_driver);
367}
368
369MODULE_AUTHOR("Michael Hanselmann");
370MODULE_DESCRIPTION("Apple Cinema Display driver");
371MODULE_LICENSE("GPL");
372
373module_init(appledisplay_init);
374module_exit(appledisplay_exit);
375