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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
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
68 { }
69};
70MODULE_DEVICE_TABLE(usb, appledisplay_table);
71
72
73struct appledisplay {
74 struct usb_device *udev;
75 struct urb *urb;
76 struct backlight_device *bd;
77 u8 *urbdata;
78 u8 *msgdata;
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
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
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
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
216
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
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
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
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
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
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
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
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
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
306 pdata->bd->props.brightness = brightness;
307
308
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);
382
