Linux kernel mirror (for testing)
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linux
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Apple Cinema Display driver
4 *
5 * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
6 *
7 * Thanks to Caskey L. Dickson for his work with acdctl.
8 */
9
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/hid.h>
16#include <linux/usb.h>
17#include <linux/backlight.h>
18#include <linux/timer.h>
19#include <linux/workqueue.h>
20#include <linux/atomic.h>
21
22#define APPLE_VENDOR_ID 0x05AC
23
24#define ACD_USB_TIMEOUT 250
25
26#define ACD_USB_EDID 0x0302
27#define ACD_USB_BRIGHTNESS 0x0310
28
29#define ACD_BTN_NONE 0
30#define ACD_BTN_BRIGHT_UP 3
31#define ACD_BTN_BRIGHT_DOWN 4
32
33#define ACD_URB_BUFFER_LEN 2
34#define ACD_MSG_BUFFER_LEN 2
35
36#define APPLEDISPLAY_DEVICE(prod) \
37 .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
38 USB_DEVICE_ID_MATCH_INT_CLASS | \
39 USB_DEVICE_ID_MATCH_INT_PROTOCOL, \
40 .idVendor = APPLE_VENDOR_ID, \
41 .idProduct = (prod), \
42 .bInterfaceClass = USB_CLASS_HID, \
43 .bInterfaceProtocol = 0x00
44
45/* table of devices that work with this driver */
46static const struct usb_device_id appledisplay_table[] = {
47 { APPLEDISPLAY_DEVICE(0x9218) },
48 { APPLEDISPLAY_DEVICE(0x9219) },
49 { APPLEDISPLAY_DEVICE(0x921c) },
50 { APPLEDISPLAY_DEVICE(0x921d) },
51 { APPLEDISPLAY_DEVICE(0x9222) },
52 { APPLEDISPLAY_DEVICE(0x9226) },
53 { APPLEDISPLAY_DEVICE(0x9236) },
54
55 /* Terminating entry */
56 { }
57};
58MODULE_DEVICE_TABLE(usb, appledisplay_table);
59
60/* Structure to hold all of our device specific stuff */
61struct appledisplay {
62 struct usb_device *udev; /* usb device */
63 struct urb *urb; /* usb request block */
64 struct backlight_device *bd; /* backlight device */
65 u8 *urbdata; /* interrupt URB data buffer */
66 u8 *msgdata; /* control message data buffer */
67
68 struct delayed_work work;
69 int button_pressed;
70 struct mutex sysfslock; /* concurrent read and write */
71};
72
73static atomic_t count_displays = ATOMIC_INIT(0);
74
75static void appledisplay_complete(struct urb *urb)
76{
77 struct appledisplay *pdata = urb->context;
78 struct device *dev = &pdata->udev->dev;
79 int status = urb->status;
80 int retval;
81
82 switch (status) {
83 case 0:
84 /* success */
85 break;
86 case -EOVERFLOW:
87 dev_err(dev,
88 "OVERFLOW with data length %d, actual length is %d\n",
89 ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
90 fallthrough;
91 case -ECONNRESET:
92 case -ENOENT:
93 case -ESHUTDOWN:
94 /* This urb is terminated, clean up */
95 dev_dbg(dev, "%s - urb shuttingdown with status: %d\n",
96 __func__, status);
97 return;
98 default:
99 dev_dbg(dev, "%s - nonzero urb status received: %d\n",
100 __func__, status);
101 goto exit;
102 }
103
104 switch(pdata->urbdata[1]) {
105 case ACD_BTN_BRIGHT_UP:
106 case ACD_BTN_BRIGHT_DOWN:
107 pdata->button_pressed = 1;
108 /*
109 * there is a window during which no device
110 * is registered
111 */
112 if (pdata->bd )
113 schedule_delayed_work(&pdata->work, 0);
114 break;
115 case ACD_BTN_NONE:
116 default:
117 pdata->button_pressed = 0;
118 break;
119 }
120
121exit:
122 retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
123 if (retval) {
124 dev_err(dev, "%s - usb_submit_urb failed with result %d\n",
125 __func__, retval);
126 }
127}
128
129static int appledisplay_bl_update_status(struct backlight_device *bd)
130{
131 struct appledisplay *pdata = bl_get_data(bd);
132 int retval;
133
134 mutex_lock(&pdata->sysfslock);
135 pdata->msgdata[0] = 0x10;
136 pdata->msgdata[1] = bd->props.brightness;
137
138 retval = usb_control_msg(
139 pdata->udev,
140 usb_sndctrlpipe(pdata->udev, 0),
141 HID_REQ_SET_REPORT,
142 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
143 ACD_USB_BRIGHTNESS,
144 0,
145 pdata->msgdata, 2,
146 ACD_USB_TIMEOUT);
147 mutex_unlock(&pdata->sysfslock);
148
149 if (retval < 0)
150 return retval;
151 else
152 return 0;
153}
154
155static int appledisplay_bl_get_brightness(struct backlight_device *bd)
156{
157 struct appledisplay *pdata = bl_get_data(bd);
158 int retval, brightness;
159
160 mutex_lock(&pdata->sysfslock);
161 retval = usb_control_msg(
162 pdata->udev,
163 usb_rcvctrlpipe(pdata->udev, 0),
164 HID_REQ_GET_REPORT,
165 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
166 ACD_USB_BRIGHTNESS,
167 0,
168 pdata->msgdata, 2,
169 ACD_USB_TIMEOUT);
170 if (retval < 2) {
171 if (retval >= 0)
172 retval = -EMSGSIZE;
173 } else {
174 brightness = pdata->msgdata[1];
175 }
176 mutex_unlock(&pdata->sysfslock);
177
178 if (retval < 0)
179 return retval;
180 else
181 return brightness;
182}
183
184static const struct backlight_ops appledisplay_bl_data = {
185 .get_brightness = appledisplay_bl_get_brightness,
186 .update_status = appledisplay_bl_update_status,
187};
188
189static void appledisplay_work(struct work_struct *work)
190{
191 struct appledisplay *pdata =
192 container_of(work, struct appledisplay, work.work);
193 int retval;
194
195 retval = appledisplay_bl_get_brightness(pdata->bd);
196 if (retval >= 0)
197 pdata->bd->props.brightness = retval;
198
199 /* Poll again in about 125ms if there's still a button pressed */
200 if (pdata->button_pressed)
201 schedule_delayed_work(&pdata->work, HZ / 8);
202}
203
204static int appledisplay_probe(struct usb_interface *iface,
205 const struct usb_device_id *id)
206{
207 struct backlight_properties props;
208 struct backlight_device *backlight;
209 struct appledisplay *pdata;
210 struct usb_device *udev = interface_to_usbdev(iface);
211 struct usb_endpoint_descriptor *endpoint;
212 int int_in_endpointAddr = 0;
213 int retval, brightness;
214 char bl_name[20];
215
216 /* set up the endpoint information */
217 /* use only the first interrupt-in endpoint */
218 retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint);
219 if (retval) {
220 dev_err(&iface->dev, "Could not find int-in endpoint\n");
221 return retval;
222 }
223
224 int_in_endpointAddr = endpoint->bEndpointAddress;
225
226 /* allocate memory for our device state and initialize it */
227 pdata = kzalloc_obj(struct appledisplay);
228 if (!pdata) {
229 retval = -ENOMEM;
230 goto error;
231 }
232
233 pdata->udev = udev;
234
235 INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
236 mutex_init(&pdata->sysfslock);
237
238 /* Allocate buffer for control messages */
239 pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
240 if (!pdata->msgdata) {
241 retval = -ENOMEM;
242 goto error;
243 }
244
245 /* Allocate interrupt URB */
246 pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
247 if (!pdata->urb) {
248 retval = -ENOMEM;
249 goto error;
250 }
251
252 /* Allocate buffer for interrupt data */
253 pdata->urbdata = usb_alloc_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
254 GFP_KERNEL, &pdata->urb->transfer_dma);
255 if (!pdata->urbdata) {
256 retval = -ENOMEM;
257 dev_err(&iface->dev, "Allocating URB buffer failed\n");
258 goto error;
259 }
260
261 /* Configure interrupt URB */
262 usb_fill_int_urb(pdata->urb, udev,
263 usb_rcvintpipe(udev, int_in_endpointAddr),
264 pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
265 pdata, 1);
266 pdata->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
267 if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
268 retval = -EIO;
269 dev_err(&iface->dev, "Submitting URB failed\n");
270 goto error;
271 }
272
273 /* Register backlight device */
274 snprintf(bl_name, sizeof(bl_name), "appledisplay%d",
275 atomic_inc_return(&count_displays) - 1);
276 memset(&props, 0, sizeof(struct backlight_properties));
277 props.type = BACKLIGHT_RAW;
278 props.max_brightness = 0xff;
279 backlight = backlight_device_register(bl_name, NULL, pdata,
280 &appledisplay_bl_data, &props);
281 if (IS_ERR(backlight)) {
282 dev_err(&iface->dev, "Backlight registration failed\n");
283 retval = PTR_ERR(backlight);
284 goto error;
285 }
286 pdata->bd = backlight;
287
288 /* Try to get brightness */
289 brightness = appledisplay_bl_get_brightness(pdata->bd);
290
291 if (brightness < 0) {
292 retval = brightness;
293 dev_err(&iface->dev,
294 "Error while getting initial brightness: %d\n", 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 cancel_delayed_work_sync(&pdata->work);
313 usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
314 pdata->urbdata, pdata->urb->transfer_dma);
315 usb_free_urb(pdata->urb);
316 }
317 if (!IS_ERR(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_sync(&pdata->work);
333 backlight_device_unregister(pdata->bd);
334 usb_free_coherent(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};
350module_usb_driver(appledisplay_driver);
351
352MODULE_AUTHOR("Michael Hanselmann");
353MODULE_DESCRIPTION("Apple Cinema Display driver");
354MODULE_LICENSE("GPL");