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 */
61 static const struct usb_device_id appledisplay_table[] = {
62 { APPLEDISPLAY_DEVICE(0x9218) },
63 { APPLEDISPLAY_DEVICE(0x9219) },
64 { APPLEDISPLAY_DEVICE(0x921c) },
65 { APPLEDISPLAY_DEVICE(0x921d) },
66 { APPLEDISPLAY_DEVICE(0x9222) },
67 { APPLEDISPLAY_DEVICE(0x9226) },
68 { APPLEDISPLAY_DEVICE(0x9236) },
69
70 /* Terminating entry */
71 { }
72 };
73 MODULE_DEVICE_TABLE(usb, appledisplay_table);
74
75 /* Structure to hold all of our device specific stuff */
76 struct appledisplay {
77 struct usb_device *udev; /* usb device */
78 struct urb *urb; /* usb request block */
79 struct backlight_device *bd; /* backlight device */
80 u8 *urbdata; /* interrupt URB data buffer */
81 u8 *msgdata; /* control message data buffer */
82
83 struct delayed_work work;
84 int button_pressed;
85 spinlock_t lock;
86 struct mutex sysfslock; /* concurrent read and write */
87 };
88
89 static atomic_t count_displays = ATOMIC_INIT(0);
90 static struct workqueue_struct *wq;
91
appledisplay_complete(struct urb * urb)92 static void appledisplay_complete(struct urb *urb)
93 {
94 struct appledisplay *pdata = urb->context;
95 struct device *dev = &pdata->udev->dev;
96 unsigned long flags;
97 int status = urb->status;
98 int retval;
99
100 switch (status) {
101 case 0:
102 /* success */
103 break;
104 case -EOVERFLOW:
105 dev_err(dev,
106 "OVERFLOW with data length %d, actual length is %d\n",
107 ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
108 case -ECONNRESET:
109 case -ENOENT:
110 case -ESHUTDOWN:
111 /* This urb is terminated, clean up */
112 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
113 __func__, status);
114 return;
115 default:
116 dev_dbg(dev, "%s - nonzero urb status received: %d\n",
117 __func__, status);
118 goto exit;
119 }
120
121 spin_lock_irqsave(&pdata->lock, flags);
122
123 switch(pdata->urbdata[1]) {
124 case ACD_BTN_BRIGHT_UP:
125 case ACD_BTN_BRIGHT_DOWN:
126 pdata->button_pressed = 1;
127 queue_delayed_work(wq, &pdata->work, 0);
128 break;
129 case ACD_BTN_NONE:
130 default:
131 pdata->button_pressed = 0;
132 break;
133 }
134
135 spin_unlock_irqrestore(&pdata->lock, flags);
136
137 exit:
138 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
139 if (retval) {
140 dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
141 __func__, retval);
142 }
143 }
144
appledisplay_bl_update_status(struct backlight_device * bd)145 static int appledisplay_bl_update_status(struct backlight_device *bd)
146 {
147 struct appledisplay *pdata = bl_get_data(bd);
148 int retval;
149
150 mutex_lock(&pdata->sysfslock);
151 pdata->msgdata[0] = 0x10;
152 pdata->msgdata[1] = bd->props.brightness;
153
154 retval = usb_control_msg(
155 pdata->udev,
156 usb_sndctrlpipe(pdata->udev, 0),
157 USB_REQ_SET_REPORT,
158 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
159 ACD_USB_BRIGHTNESS,
160 0,
161 pdata->msgdata, 2,
162 ACD_USB_TIMEOUT);
163 mutex_unlock(&pdata->sysfslock);
164
165 if (retval < 0)
166 return retval;
167 else
168 return 0;
169 }
170
appledisplay_bl_get_brightness(struct backlight_device * bd)171 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
172 {
173 struct appledisplay *pdata = bl_get_data(bd);
174 int retval, brightness;
175
176 mutex_lock(&pdata->sysfslock);
177 retval = usb_control_msg(
178 pdata->udev,
179 usb_rcvctrlpipe(pdata->udev, 0),
180 USB_REQ_GET_REPORT,
181 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
182 ACD_USB_BRIGHTNESS,
183 0,
184 pdata->msgdata, 2,
185 ACD_USB_TIMEOUT);
186 if (retval < 2) {
187 if (retval >= 0)
188 retval = -EMSGSIZE;
189 } else {
190 brightness = pdata->msgdata[1];
191 }
192 mutex_unlock(&pdata->sysfslock);
193
194 if (retval < 0)
195 return retval;
196 else
197 return brightness;
198 }
199
200 static const struct backlight_ops appledisplay_bl_data = {
201 .get_brightness = appledisplay_bl_get_brightness,
202 .update_status = appledisplay_bl_update_status,
203 };
204
appledisplay_work(struct work_struct * work)205 static void appledisplay_work(struct work_struct *work)
206 {
207 struct appledisplay *pdata =
208 container_of(work, struct appledisplay, work.work);
209 int retval;
210
211 retval = appledisplay_bl_get_brightness(pdata->bd);
212 if (retval >= 0)
213 pdata->bd->props.brightness = retval;
214
215 /* Poll again in about 125ms if there's still a button pressed */
216 if (pdata->button_pressed)
217 schedule_delayed_work(&pdata->work, HZ / 8);
218 }
219
appledisplay_probe(struct usb_interface * iface,const struct usb_device_id * id)220 static int appledisplay_probe(struct usb_interface *iface,
221 const struct usb_device_id *id)
222 {
223 struct backlight_properties props;
224 struct appledisplay *pdata;
225 struct usb_device *udev = interface_to_usbdev(iface);
226 struct usb_host_interface *iface_desc;
227 struct usb_endpoint_descriptor *endpoint;
228 int int_in_endpointAddr = 0;
229 int i, retval = -ENOMEM, brightness;
230 char bl_name[20];
231
232 /* set up the endpoint information */
233 /* use only the first interrupt-in endpoint */
234 iface_desc = iface->cur_altsetting;
235 for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
236 endpoint = &iface_desc->endpoint[i].desc;
237 if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
238 /* we found an interrupt in endpoint */
239 int_in_endpointAddr = endpoint->bEndpointAddress;
240 break;
241 }
242 }
243 if (!int_in_endpointAddr) {
244 dev_err(&iface->dev, "Could not find int-in endpoint\n");
245 return -EIO;
246 }
247
248 /* allocate memory for our device state and initialize it */
249 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
250 if (!pdata) {
251 retval = -ENOMEM;
252 dev_err(&iface->dev, "Out of memory\n");
253 goto error;
254 }
255
256 pdata->udev = udev;
257
258 spin_lock_init(&pdata->lock);
259 INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
260 mutex_init(&pdata->sysfslock);
261
262 /* Allocate buffer for control messages */
263 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
264 if (!pdata->msgdata) {
265 retval = -ENOMEM;
266 dev_err(&iface->dev,
267 "Allocating buffer for control messages failed\n");
268 goto error;
269 }
270
271 /* Allocate interrupt URB */
272 pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
273 if (!pdata->urb) {
274 retval = -ENOMEM;
275 dev_err(&iface->dev, "Allocating URB failed\n");
276 goto error;
277 }
278
279 /* Allocate buffer for interrupt data */
280 pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
281 GFP_KERNEL, &pdata->urb->transfer_dma);
282 if (!pdata->urbdata) {
283 retval = -ENOMEM;
284 dev_err(&iface->dev, "Allocating URB buffer failed\n");
285 goto error;
286 }
287
288 /* Configure interrupt URB */
289 usb_fill_int_urb(pdata->urb, udev,
290 usb_rcvintpipe(udev, int_in_endpointAddr),
291 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
292 pdata, 1);
293 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
294 retval = -EIO;
295 dev_err(&iface->dev, "Submitting URB failed\n");
296 goto error;
297 }
298
299 /* Register backlight device */
300 snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
301 atomic_inc_return(&count_displays) - 1);
302 memset(&props, 0, sizeof(struct backlight_properties));
303 props.type = BACKLIGHT_RAW;
304 props.max_brightness = 0xff;
305 pdata->bd = backlight_device_register(bl_name, NULL, pdata,
306 &appledisplay_bl_data, &props);
307 if (IS_ERR(pdata->bd)) {
308 dev_err(&iface->dev, "Backlight registration failed\n");
309 retval = PTR_ERR(pdata->bd);
310 goto error;
311 }
312
313 /* Try to get brightness */
314 brightness = appledisplay_bl_get_brightness(pdata->bd);
315
316 if (brightness < 0) {
317 retval = brightness;
318 dev_err(&iface->dev,
319 "Error while getting initial brightness: %d\n", retval);
320 goto error;
321 }
322
323 /* Set brightness in backlight device */
324 pdata->bd->props.brightness = brightness;
325
326 /* save our data pointer in the interface device */
327 usb_set_intfdata(iface, pdata);
328
329 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
330
331 return 0;
332
333 error:
334 if (pdata) {
335 if (pdata->urb) {
336 usb_kill_urb(pdata->urb);
337 cancel_delayed_work_sync(&pdata->work);
338 if (pdata->urbdata)
339 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
340 pdata->urbdata, pdata->urb->transfer_dma);
341 usb_free_urb(pdata->urb);
342 }
343 if (!IS_ERR(pdata->bd))
344 backlight_device_unregister(pdata->bd);
345 kfree(pdata->msgdata);
346 }
347 usb_set_intfdata(iface, NULL);
348 kfree(pdata);
349 return retval;
350 }
351
appledisplay_disconnect(struct usb_interface * iface)352 static void appledisplay_disconnect(struct usb_interface *iface)
353 {
354 struct appledisplay *pdata = usb_get_intfdata(iface);
355
356 if (pdata) {
357 usb_kill_urb(pdata->urb);
358 cancel_delayed_work(&pdata->work);
359 backlight_device_unregister(pdata->bd);
360 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
361 pdata->urbdata, pdata->urb->transfer_dma);
362 usb_free_urb(pdata->urb);
363 kfree(pdata->msgdata);
364 kfree(pdata);
365 }
366
367 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
368 }
369
370 static struct usb_driver appledisplay_driver = {
371 .name = "appledisplay",
372 .probe = appledisplay_probe,
373 .disconnect = appledisplay_disconnect,
374 .id_table = appledisplay_table,
375 };
376
appledisplay_init(void)377 static int __init appledisplay_init(void)
378 {
379 wq = create_singlethread_workqueue("appledisplay");
380 if (!wq) {
381 printk(KERN_ERR "appledisplay: Could not create work queue\n");
382 return -ENOMEM;
383 }
384
385 return usb_register(&appledisplay_driver);
386 }
387
appledisplay_exit(void)388 static void __exit appledisplay_exit(void)
389 {
390 flush_workqueue(wq);
391 destroy_workqueue(wq);
392 usb_deregister(&appledisplay_driver);
393 }
394
395 MODULE_AUTHOR("Michael Hanselmann");
396 MODULE_DESCRIPTION("Apple Cinema Display driver");
397 MODULE_LICENSE("GPL");
398
399 module_init(appledisplay_init);
400 module_exit(appledisplay_exit);
401