xref: /openbmc/linux/drivers/usb/misc/appledisplay.c (revision 22246614)
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 
33 #define APPLE_VENDOR_ID		0x05AC
34 
35 #define USB_REQ_GET_REPORT	0x01
36 #define USB_REQ_SET_REPORT	0x09
37 
38 #define ACD_USB_TIMEOUT		250
39 
40 #define ACD_USB_EDID		0x0302
41 #define ACD_USB_BRIGHTNESS	0x0310
42 
43 #define ACD_BTN_NONE		0
44 #define ACD_BTN_BRIGHT_UP	3
45 #define ACD_BTN_BRIGHT_DOWN	4
46 
47 #define ACD_URB_BUFFER_LEN	2
48 #define ACD_MSG_BUFFER_LEN	2
49 
50 #define APPLEDISPLAY_DEVICE(prod)				\
51 	.match_flags = USB_DEVICE_ID_MATCH_DEVICE |		\
52 		       USB_DEVICE_ID_MATCH_INT_CLASS |		\
53 		       USB_DEVICE_ID_MATCH_INT_PROTOCOL,	\
54 	.idVendor = APPLE_VENDOR_ID,				\
55 	.idProduct = (prod),					\
56 	.bInterfaceClass = USB_CLASS_HID,			\
57 	.bInterfaceProtocol = 0x00
58 
59 /* table of devices that work with this driver */
60 static struct usb_device_id appledisplay_table [] = {
61 	{ APPLEDISPLAY_DEVICE(0x9218) },
62 	{ APPLEDISPLAY_DEVICE(0x9219) },
63 	{ APPLEDISPLAY_DEVICE(0x921d) },
64 
65 	/* Terminating entry */
66 	{ }
67 };
68 MODULE_DEVICE_TABLE(usb, appledisplay_table);
69 
70 /* Structure to hold all of our device specific stuff */
71 struct appledisplay {
72 	struct usb_device *udev;	/* usb device */
73 	struct urb *urb;		/* usb request block */
74 	struct backlight_device *bd;	/* backlight device */
75 	char *urbdata;			/* interrupt URB data buffer */
76 	char *msgdata;			/* control message data buffer */
77 
78 	struct delayed_work work;
79 	int button_pressed;
80 	spinlock_t lock;
81 };
82 
83 static atomic_t count_displays = ATOMIC_INIT(0);
84 static struct workqueue_struct *wq;
85 
86 static void appledisplay_complete(struct urb *urb)
87 {
88 	struct appledisplay *pdata = urb->context;
89 	unsigned long flags;
90 	int status = urb->status;
91 	int retval;
92 
93 	switch (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 shuttingdown with status: %d",
106 			__func__, status);
107 		return;
108 	default:
109 		dbg("%s - nonzero urb status received: %d",
110 			__func__, 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 
130 exit:
131 	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
132 	if (retval) {
133 		err("%s - usb_submit_urb failed with result %d",
134 			__func__, retval);
135 	}
136 }
137 
138 static int appledisplay_bl_update_status(struct backlight_device *bd)
139 {
140 	struct appledisplay *pdata = bl_get_data(bd);
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 
159 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
160 {
161 	struct appledisplay *pdata = bl_get_data(bd);
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 
180 static struct backlight_ops appledisplay_bl_data = {
181 	.get_brightness	= appledisplay_bl_get_brightness,
182 	.update_status	= appledisplay_bl_update_status,
183 };
184 
185 static 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 
200 static 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 
308 error:
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 
326 static 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 
344 static struct usb_driver appledisplay_driver = {
345 	.name		= "appledisplay",
346 	.probe		= appledisplay_probe,
347 	.disconnect	= appledisplay_disconnect,
348 	.id_table	= appledisplay_table,
349 };
350 
351 static 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 
362 static void __exit appledisplay_exit(void)
363 {
364 	flush_workqueue(wq);
365 	destroy_workqueue(wq);
366 	usb_deregister(&appledisplay_driver);
367 }
368 
369 MODULE_AUTHOR("Michael Hanselmann");
370 MODULE_DESCRIPTION("Apple Cinema Display driver");
371 MODULE_LICENSE("GPL");
372 
373 module_init(appledisplay_init);
374 module_exit(appledisplay_exit);
375