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10#include <linux/kernel.h>
11#include <linux/errno.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/slab.h>
15#include <linux/usb.h>
16#include <linux/backlight.h>
17#include <linux/timer.h>
18#include <linux/workqueue.h>
19#include <linux/atomic.h>
20
21#define APPLE_VENDOR_ID 0x05AC
22
23#define USB_REQ_GET_REPORT 0x01
24#define USB_REQ_SET_REPORT 0x09
25
26#define ACD_USB_TIMEOUT 250
27
28#define ACD_USB_EDID 0x0302
29#define ACD_USB_BRIGHTNESS 0x0310
30
31#define ACD_BTN_NONE 0
32#define ACD_BTN_BRIGHT_UP 3
33#define ACD_BTN_BRIGHT_DOWN 4
34
35#define ACD_URB_BUFFER_LEN 2
36#define ACD_MSG_BUFFER_LEN 2
37
38#define APPLEDISPLAY_DEVICE(prod) \
39 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
40 USB_DEVICE_ID_MATCH_INT_CLASS | \
41 USB_DEVICE_ID_MATCH_INT_PROTOCOL, \
42 .idVendor = APPLE_VENDOR_ID, \
43 .idProduct = (prod), \
44 .bInterfaceClass = USB_CLASS_HID, \
45 .bInterfaceProtocol = 0x00
46
47
48static const struct usb_device_id appledisplay_table[] = {
49 { APPLEDISPLAY_DEVICE(0x9218) },
50 { APPLEDISPLAY_DEVICE(0x9219) },
51 { APPLEDISPLAY_DEVICE(0x921c) },
52 { APPLEDISPLAY_DEVICE(0x921d) },
53 { APPLEDISPLAY_DEVICE(0x9222) },
54 { APPLEDISPLAY_DEVICE(0x9226) },
55 { APPLEDISPLAY_DEVICE(0x9236) },
56
57
58 { }
59};
60MODULE_DEVICE_TABLE(usb, appledisplay_table);
61
62
63struct appledisplay {
64 struct usb_device *udev;
65 struct urb *urb;
66 struct backlight_device *bd;
67 u8 *urbdata;
68 u8 *msgdata;
69
70 struct delayed_work work;
71 int button_pressed;
72 struct mutex sysfslock;
73};
74
75static atomic_t count_displays = ATOMIC_INIT(0);
76
77static void appledisplay_complete(struct urb *urb)
78{
79 struct appledisplay *pdata = urb->context;
80 struct device *dev = &pdata->udev->dev;
81 int status = urb->status;
82 int retval;
83
84 switch (status) {
85 case 0:
86
87 break;
88 case -EOVERFLOW:
89 dev_err(dev,
90 "OVERFLOW with data length %d, actual length is %d\n",
91 ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
92 fallthrough;
93 case -ECONNRESET:
94 case -ENOENT:
95 case -ESHUTDOWN:
96
97 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
98 __func__, status);
99 return;
100 default:
101 dev_dbg(dev, "%s - nonzero urb status received: %d\n",
102 __func__, status);
103 goto exit;
104 }
105
106 switch(pdata->urbdata[1]) {
107 case ACD_BTN_BRIGHT_UP:
108 case ACD_BTN_BRIGHT_DOWN:
109 pdata->button_pressed = 1;
110 schedule_delayed_work(&pdata->work, 0);
111 break;
112 case ACD_BTN_NONE:
113 default:
114 pdata->button_pressed = 0;
115 break;
116 }
117
118exit:
119 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
120 if (retval) {
121 dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
122 __func__, retval);
123 }
124}
125
126static int appledisplay_bl_update_status(struct backlight_device *bd)
127{
128 struct appledisplay *pdata = bl_get_data(bd);
129 int retval;
130
131 mutex_lock(&pdata->sysfslock);
132 pdata->msgdata[0] = 0x10;
133 pdata->msgdata[1] = bd->props.brightness;
134
135 retval = usb_control_msg(
136 pdata->udev,
137 usb_sndctrlpipe(pdata->udev, 0),
138 USB_REQ_SET_REPORT,
139 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
140 ACD_USB_BRIGHTNESS,
141 0,
142 pdata->msgdata, 2,
143 ACD_USB_TIMEOUT);
144 mutex_unlock(&pdata->sysfslock);
145
146 if (retval < 0)
147 return retval;
148 else
149 return 0;
150}
151
152static int appledisplay_bl_get_brightness(struct backlight_device *bd)
153{
154 struct appledisplay *pdata = bl_get_data(bd);
155 int retval, brightness;
156
157 mutex_lock(&pdata->sysfslock);
158 retval = usb_control_msg(
159 pdata->udev,
160 usb_rcvctrlpipe(pdata->udev, 0),
161 USB_REQ_GET_REPORT,
162 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
163 ACD_USB_BRIGHTNESS,
164 0,
165 pdata->msgdata, 2,
166 ACD_USB_TIMEOUT);
167 if (retval < 2) {
168 if (retval >= 0)
169 retval = -EMSGSIZE;
170 } else {
171 brightness = pdata->msgdata[1];
172 }
173 mutex_unlock(&pdata->sysfslock);
174
175 if (retval < 0)
176 return retval;
177 else
178 return brightness;
179}
180
181static const struct backlight_ops appledisplay_bl_data = {
182 .get_brightness = appledisplay_bl_get_brightness,
183 .update_status = appledisplay_bl_update_status,
184};
185
186static void appledisplay_work(struct work_struct *work)
187{
188 struct appledisplay *pdata =
189 container_of(work, struct appledisplay, work.work);
190 int retval;
191
192 retval = appledisplay_bl_get_brightness(pdata->bd);
193 if (retval >= 0)
194 pdata->bd->props.brightness = retval;
195
196
197 if (pdata->button_pressed)
198 schedule_delayed_work(&pdata->work, HZ / 8);
199}
200
201static int appledisplay_probe(struct usb_interface *iface,
202 const struct usb_device_id *id)
203{
204 struct backlight_properties props;
205 struct appledisplay *pdata;
206 struct usb_device *udev = interface_to_usbdev(iface);
207 struct usb_endpoint_descriptor *endpoint;
208 int int_in_endpointAddr = 0;
209 int retval, brightness;
210 char bl_name[20];
211
212
213
214 retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint);
215 if (retval) {
216 dev_err(&iface->dev, "Could not find int-in endpoint\n");
217 return retval;
218 }
219
220 int_in_endpointAddr = endpoint->bEndpointAddress;
221
222
223 pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
224 if (!pdata) {
225 retval = -ENOMEM;
226 goto error;
227 }
228
229 pdata->udev = udev;
230
231 INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
232 mutex_init(&pdata->sysfslock);
233
234
235 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
236 if (!pdata->msgdata) {
237 retval = -ENOMEM;
238 goto error;
239 }
240
241
242 pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
243 if (!pdata->urb) {
244 retval = -ENOMEM;
245 goto error;
246 }
247
248
249 pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
250 GFP_KERNEL, &pdata->urb->transfer_dma);
251 if (!pdata->urbdata) {
252 retval = -ENOMEM;
253 dev_err(&iface->dev, "Allocating URB buffer failed\n");
254 goto error;
255 }
256
257
258 usb_fill_int_urb(pdata->urb, udev,
259 usb_rcvintpipe(udev, int_in_endpointAddr),
260 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
261 pdata, 1);
262 pdata->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
263 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
264 retval = -EIO;
265 dev_err(&iface->dev, "Submitting URB failed\n");
266 goto error;
267 }
268
269
270 snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
271 atomic_inc_return(&count_displays) - 1);
272 memset(&props, 0, sizeof(struct backlight_properties));
273 props.type = BACKLIGHT_RAW;
274 props.max_brightness = 0xff;
275 pdata->bd = backlight_device_register(bl_name, NULL, pdata,
276 &appledisplay_bl_data, &props);
277 if (IS_ERR(pdata->bd)) {
278 dev_err(&iface->dev, "Backlight registration failed\n");
279 retval = PTR_ERR(pdata->bd);
280 goto error;
281 }
282
283
284 brightness = appledisplay_bl_get_brightness(pdata->bd);
285
286 if (brightness < 0) {
287 retval = brightness;
288 dev_err(&iface->dev,
289 "Error while getting initial brightness: %d\n", retval);
290 goto error;
291 }
292
293
294 pdata->bd->props.brightness = brightness;
295
296
297 usb_set_intfdata(iface, pdata);
298
299 printk(KERN_INFO "appledisplay: Apple Cinema Display connected\n");
300
301 return 0;
302
303error:
304 if (pdata) {
305 if (pdata->urb) {
306 usb_kill_urb(pdata->urb);
307 cancel_delayed_work_sync(&pdata->work);
308 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
309 pdata->urbdata, pdata->urb->transfer_dma);
310 usb_free_urb(pdata->urb);
311 }
312 if (!IS_ERR(pdata->bd))
313 backlight_device_unregister(pdata->bd);
314 kfree(pdata->msgdata);
315 }
316 usb_set_intfdata(iface, NULL);
317 kfree(pdata);
318 return retval;
319}
320
321static void appledisplay_disconnect(struct usb_interface *iface)
322{
323 struct appledisplay *pdata = usb_get_intfdata(iface);
324
325 if (pdata) {
326 usb_kill_urb(pdata->urb);
327 cancel_delayed_work_sync(&pdata->work);
328 backlight_device_unregister(pdata->bd);
329 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
330 pdata->urbdata, pdata->urb->transfer_dma);
331 usb_free_urb(pdata->urb);
332 kfree(pdata->msgdata);
333 kfree(pdata);
334 }
335
336 printk(KERN_INFO "appledisplay: Apple Cinema Display disconnected\n");
337}
338
339static struct usb_driver appledisplay_driver = {
340 .name = "appledisplay",
341 .probe = appledisplay_probe,
342 .disconnect = appledisplay_disconnect,
343 .id_table = appledisplay_table,
344};
345module_usb_driver(appledisplay_driver);
346
347MODULE_AUTHOR("Michael Hanselmann");
348MODULE_DESCRIPTION("Apple Cinema Display driver");
349MODULE_LICENSE("GPL");
350
