1 /*
2 * HID over I2C protocol implementation
3 *
4 * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
5 * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
6 * Copyright (c) 2012 Red Hat, Inc
7 *
8 * This code is partly based on "USB HID support for Linux":
9 *
10 * Copyright (c) 1999 Andreas Gal
11 * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
12 * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
13 * Copyright (c) 2007-2008 Oliver Neukum
14 * Copyright (c) 2006-2010 Jiri Kosina
15 *
16 * This file is subject to the terms and conditions of the GNU General Public
17 * License. See the file COPYING in the main directory of this archive for
18 * more details.
19 */
20
21 #include <linux/module.h>
22 #include <linux/i2c.h>
23 #include <linux/interrupt.h>
24 #include <linux/input.h>
25 #include <linux/irq.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
28 #include <linux/pm.h>
29 #include <linux/pm_wakeirq.h>
30 #include <linux/device.h>
31 #include <linux/wait.h>
32 #include <linux/err.h>
33 #include <linux/string.h>
34 #include <linux/list.h>
35 #include <linux/jiffies.h>
36 #include <linux/kernel.h>
37 #include <linux/hid.h>
38 #include <linux/mutex.h>
39 #include <linux/unaligned.h>
40
41 #include <drm/drm_panel.h>
42
43 #include "../hid-ids.h"
44 #include "i2c-hid.h"
45
46 /* quirks to control the device */
47 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(0)
48 #define I2C_HID_QUIRK_BOGUS_IRQ BIT(1)
49 #define I2C_HID_QUIRK_RESET_ON_RESUME BIT(2)
50 #define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(3)
51 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET BIT(4)
52 #define I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND BIT(5)
53 #define I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME BIT(6)
54 #define I2C_HID_QUIRK_RE_POWER_ON BIT(7)
55
56 /* Command opcodes */
57 #define I2C_HID_OPCODE_RESET 0x01
58 #define I2C_HID_OPCODE_GET_REPORT 0x02
59 #define I2C_HID_OPCODE_SET_REPORT 0x03
60 #define I2C_HID_OPCODE_GET_IDLE 0x04
61 #define I2C_HID_OPCODE_SET_IDLE 0x05
62 #define I2C_HID_OPCODE_GET_PROTOCOL 0x06
63 #define I2C_HID_OPCODE_SET_PROTOCOL 0x07
64 #define I2C_HID_OPCODE_SET_POWER 0x08
65
66 /* flags */
67 #define I2C_HID_STARTED 0
68 #define I2C_HID_RESET_PENDING 1
69
70 #define I2C_HID_PWR_ON 0x00
71 #define I2C_HID_PWR_SLEEP 0x01
72
73 #define i2c_hid_dbg(ihid, ...) dev_dbg(&(ihid)->client->dev, __VA_ARGS__)
74
75 struct i2c_hid_desc {
76 __le16 wHIDDescLength;
77 __le16 bcdVersion;
78 __le16 wReportDescLength;
79 __le16 wReportDescRegister;
80 __le16 wInputRegister;
81 __le16 wMaxInputLength;
82 __le16 wOutputRegister;
83 __le16 wMaxOutputLength;
84 __le16 wCommandRegister;
85 __le16 wDataRegister;
86 __le16 wVendorID;
87 __le16 wProductID;
88 __le16 wVersionID;
89 __le32 reserved;
90 } __packed;
91
92 /* The main device structure */
93 struct i2c_hid {
94 struct i2c_client *client; /* i2c client */
95 struct hid_device *hid; /* pointer to corresponding HID dev */
96 struct i2c_hid_desc hdesc; /* the HID Descriptor */
97 __le16 wHIDDescRegister; /* location of the i2c
98 * register of the HID
99 * descriptor. */
100 unsigned int bufsize; /* i2c buffer size */
101 u8 *inbuf; /* Input buffer */
102 u8 *rawbuf; /* Raw Input buffer */
103 u8 *cmdbuf; /* Command buffer */
104
105 unsigned long flags; /* device flags */
106 unsigned long quirks; /* Various quirks */
107
108 wait_queue_head_t wait; /* For waiting the interrupt */
109
110 struct mutex cmd_lock; /* protects cmdbuf and rawbuf */
111 struct mutex reset_lock;
112
113 struct i2chid_ops *ops;
114 struct drm_panel_follower panel_follower;
115 struct work_struct panel_follower_work;
116 bool is_panel_follower;
117 bool panel_follower_work_finished;
118 };
119
120 static const struct i2c_hid_quirks {
121 __u16 idVendor;
122 __u16 idProduct;
123 __u32 quirks;
124 } i2c_hid_quirks[] = {
125 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
126 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
127 { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
128 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
129 { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
130 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
131 { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
132 I2C_HID_QUIRK_RESET_ON_RESUME },
133 { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
134 I2C_HID_QUIRK_RESET_ON_RESUME },
135 { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
136 I2C_HID_QUIRK_BAD_INPUT_SIZE },
137 { I2C_VENDOR_ID_CIRQUE, I2C_PRODUCT_ID_CIRQUE_1063,
138 I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND },
139 /*
140 * Without additional power on command, at least some QTEC devices send garbage
141 */
142 { I2C_VENDOR_ID_QTEC, HID_ANY_ID,
143 I2C_HID_QUIRK_RE_POWER_ON },
144 /*
145 * Sending the wakeup after reset actually break ELAN touchscreen controller
146 */
147 { USB_VENDOR_ID_ELAN, HID_ANY_ID,
148 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
149 I2C_HID_QUIRK_BOGUS_IRQ },
150 { I2C_VENDOR_ID_GOODIX, I2C_DEVICE_ID_GOODIX_0D42,
151 I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME },
152 { 0, 0 }
153 };
154
155 /*
156 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
157 * @idVendor: the 16-bit vendor ID
158 * @idProduct: the 16-bit product ID
159 *
160 * Returns: a u32 quirks value.
161 */
i2c_hid_lookup_quirk(const u16 idVendor,const u16 idProduct)162 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
163 {
164 u32 quirks = 0;
165 int n;
166
167 for (n = 0; i2c_hid_quirks[n].idVendor; n++)
168 if (i2c_hid_quirks[n].idVendor == idVendor &&
169 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
170 i2c_hid_quirks[n].idProduct == idProduct))
171 quirks = i2c_hid_quirks[n].quirks;
172
173 return quirks;
174 }
175
i2c_hid_probe_address(struct i2c_hid * ihid)176 static int i2c_hid_probe_address(struct i2c_hid *ihid)
177 {
178 int ret;
179
180 /*
181 * Some STM-based devices need 400µs after a rising clock edge to wake
182 * from deep sleep, in which case the first read will fail. Try after a
183 * short sleep to see if the device came alive on the bus. Certain
184 * Weida Tech devices also need this.
185 */
186 ret = i2c_smbus_read_byte(ihid->client);
187 if (ret < 0) {
188 usleep_range(400, 500);
189 ret = i2c_smbus_read_byte(ihid->client);
190 }
191 return ret < 0 ? ret : 0;
192 }
193
i2c_hid_xfer(struct i2c_hid * ihid,u8 * send_buf,int send_len,u8 * recv_buf,int recv_len)194 static int i2c_hid_xfer(struct i2c_hid *ihid,
195 u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
196 {
197 struct i2c_client *client = ihid->client;
198 struct i2c_msg msgs[2] = { 0 };
199 int n = 0;
200 int ret;
201
202 if (send_len) {
203 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n",
204 __func__, send_len, send_buf);
205
206 msgs[n].addr = client->addr;
207 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE;
208 msgs[n].len = send_len;
209 msgs[n].buf = send_buf;
210 n++;
211 }
212
213 if (recv_len) {
214 msgs[n].addr = client->addr;
215 msgs[n].flags = (client->flags & I2C_M_TEN) |
216 I2C_M_RD | I2C_M_DMA_SAFE;
217 msgs[n].len = recv_len;
218 msgs[n].buf = recv_buf;
219 n++;
220 }
221
222 ret = i2c_transfer(client->adapter, msgs, n);
223
224 if (ret != n)
225 return ret < 0 ? ret : -EIO;
226
227 return 0;
228 }
229
i2c_hid_read_register(struct i2c_hid * ihid,__le16 reg,void * buf,size_t len)230 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
231 void *buf, size_t len)
232 {
233 guard(mutex)(&ihid->cmd_lock);
234
235 *(__le16 *)ihid->cmdbuf = reg;
236
237 return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
238 }
239
i2c_hid_encode_command(u8 * buf,u8 opcode,int report_type,int report_id)240 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
241 int report_type, int report_id)
242 {
243 size_t length = 0;
244
245 if (report_id < 0x0F) {
246 buf[length++] = report_type << 4 | report_id;
247 buf[length++] = opcode;
248 } else {
249 buf[length++] = report_type << 4 | 0x0F;
250 buf[length++] = opcode;
251 buf[length++] = report_id;
252 }
253
254 return length;
255 }
256
i2c_hid_get_report(struct i2c_hid * ihid,u8 report_type,u8 report_id,u8 * recv_buf,size_t recv_len)257 static int i2c_hid_get_report(struct i2c_hid *ihid,
258 u8 report_type, u8 report_id,
259 u8 *recv_buf, size_t recv_len)
260 {
261 size_t length = 0;
262 size_t ret_count;
263 int error;
264
265 i2c_hid_dbg(ihid, "%s\n", __func__);
266
267 guard(mutex)(&ihid->cmd_lock);
268
269 /* Command register goes first */
270 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
271 length += sizeof(__le16);
272 /* Next is GET_REPORT command */
273 length += i2c_hid_encode_command(ihid->cmdbuf + length,
274 I2C_HID_OPCODE_GET_REPORT,
275 report_type, report_id);
276 /*
277 * Device will send report data through data register. Because
278 * command can be either 2 or 3 bytes destination for the data
279 * register may be not aligned.
280 */
281 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
282 ihid->cmdbuf + length);
283 length += sizeof(__le16);
284
285 /*
286 * In addition to report data device will supply data length
287 * in the first 2 bytes of the response, so adjust .
288 */
289 recv_len = min(recv_len, ihid->bufsize - sizeof(__le16));
290 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
291 ihid->rawbuf, recv_len + sizeof(__le16));
292 if (error) {
293 dev_err(&ihid->client->dev,
294 "failed to get a report from device: %d\n", error);
295 return error;
296 }
297
298 /* The buffer is sufficiently aligned */
299 ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
300
301 /* Check for empty report response */
302 if (ret_count <= sizeof(__le16))
303 return 0;
304
305 recv_len = min(recv_len, ret_count - sizeof(__le16));
306 memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
307
308 if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
309 dev_err(&ihid->client->dev,
310 "device returned incorrect report (%d vs %d expected)\n",
311 recv_buf[0], report_id);
312 return -EINVAL;
313 }
314
315 return recv_len;
316 }
317
i2c_hid_format_report(u8 * buf,int report_id,const u8 * data,size_t size)318 static size_t i2c_hid_format_report(u8 *buf, int report_id,
319 const u8 *data, size_t size)
320 {
321 size_t length = sizeof(__le16); /* reserve space to store size */
322
323 if (report_id)
324 buf[length++] = report_id;
325
326 memcpy(buf + length, data, size);
327 length += size;
328
329 /* Store overall size in the beginning of the buffer */
330 put_unaligned_le16(length, buf);
331
332 return length;
333 }
334
335 /**
336 * i2c_hid_set_or_send_report: forward an incoming report to the device
337 * @ihid: the i2c hid device
338 * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
339 * @report_id: the report ID
340 * @buf: the actual data to transfer, without the report ID
341 * @data_len: size of buf
342 * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
343 */
i2c_hid_set_or_send_report(struct i2c_hid * ihid,u8 report_type,u8 report_id,const u8 * buf,size_t data_len,bool do_set)344 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
345 u8 report_type, u8 report_id,
346 const u8 *buf, size_t data_len,
347 bool do_set)
348 {
349 size_t length = 0;
350 int error;
351
352 i2c_hid_dbg(ihid, "%s\n", __func__);
353
354 if (data_len > ihid->bufsize)
355 return -EINVAL;
356
357 if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
358 return -ENOSYS;
359
360 guard(mutex)(&ihid->cmd_lock);
361
362 if (do_set) {
363 /* Command register goes first */
364 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
365 length += sizeof(__le16);
366 /* Next is SET_REPORT command */
367 length += i2c_hid_encode_command(ihid->cmdbuf + length,
368 I2C_HID_OPCODE_SET_REPORT,
369 report_type, report_id);
370 /*
371 * Report data will go into the data register. Because
372 * command can be either 2 or 3 bytes destination for
373 * the data register may be not aligned.
374 */
375 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
376 ihid->cmdbuf + length);
377 length += sizeof(__le16);
378 } else {
379 /*
380 * With simple "send report" all data goes into the output
381 * register.
382 */
383 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
384 length += sizeof(__le16);
385 }
386
387 length += i2c_hid_format_report(ihid->cmdbuf + length,
388 report_id, buf, data_len);
389
390 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
391 if (error) {
392 dev_err(&ihid->client->dev,
393 "failed to set a report to device: %d\n", error);
394 return error;
395 }
396
397 return data_len;
398 }
399
i2c_hid_set_power_command(struct i2c_hid * ihid,int power_state)400 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
401 {
402 size_t length;
403
404 guard(mutex)(&ihid->cmd_lock);
405
406 /* SET_POWER uses command register */
407 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
408 length = sizeof(__le16);
409
410 /* Now the command itself */
411 length += i2c_hid_encode_command(ihid->cmdbuf + length,
412 I2C_HID_OPCODE_SET_POWER,
413 0, power_state);
414
415 return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
416 }
417
i2c_hid_set_power(struct i2c_hid * ihid,int power_state)418 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
419 {
420 int ret;
421
422 i2c_hid_dbg(ihid, "%s\n", __func__);
423
424 /*
425 * Some STM-based devices need 400µs after a rising clock edge to wake
426 * from deep sleep, in which case the first request will fail due to
427 * the address not being acknowledged. Try after a short sleep to see
428 * if the device came alive on the bus. Certain Weida Tech devices also
429 * need this.
430 */
431 ret = i2c_hid_set_power_command(ihid, power_state);
432 if (ret && power_state == I2C_HID_PWR_ON) {
433 usleep_range(400, 500);
434 ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
435 }
436
437 if (ret)
438 dev_err(&ihid->client->dev,
439 "failed to change power setting.\n");
440
441 /*
442 * The HID over I2C specification states that if a DEVICE needs time
443 * after the PWR_ON request, it should utilise CLOCK stretching.
444 * However, it has been observered that the Windows driver provides a
445 * 1ms sleep between the PWR_ON and RESET requests.
446 * According to Goodix Windows even waits 60 ms after (other?)
447 * PWR_ON requests. Testing has confirmed that several devices
448 * will not work properly without a delay after a PWR_ON request.
449 */
450 if (!ret && power_state == I2C_HID_PWR_ON)
451 msleep(60);
452
453 return ret;
454 }
455
i2c_hid_start_hwreset(struct i2c_hid * ihid)456 static int i2c_hid_start_hwreset(struct i2c_hid *ihid)
457 {
458 size_t length = 0;
459 int ret;
460
461 i2c_hid_dbg(ihid, "%s\n", __func__);
462
463 /*
464 * This prevents sending feature reports while the device is
465 * being reset. Otherwise we may lose the reset complete
466 * interrupt.
467 */
468 lockdep_assert_held(&ihid->reset_lock);
469
470 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
471 if (ret)
472 return ret;
473
474 scoped_guard(mutex, &ihid->cmd_lock) {
475 /* Prepare reset command. Command register goes first. */
476 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
477 length += sizeof(__le16);
478 /* Next is RESET command itself */
479 length += i2c_hid_encode_command(ihid->cmdbuf + length,
480 I2C_HID_OPCODE_RESET, 0, 0);
481
482 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
483
484 ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
485 if (ret) {
486 dev_err(&ihid->client->dev,
487 "failed to reset device: %d\n", ret);
488 break;
489 }
490
491 return 0;
492 }
493
494 /* Clean up if sending reset command failed */
495 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
496 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
497 return ret;
498 }
499
i2c_hid_finish_hwreset(struct i2c_hid * ihid)500 static int i2c_hid_finish_hwreset(struct i2c_hid *ihid)
501 {
502 int ret = 0;
503
504 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
505
506 if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
507 msleep(100);
508 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
509 } else if (!wait_event_timeout(ihid->wait,
510 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
511 msecs_to_jiffies(1000))) {
512 dev_warn(&ihid->client->dev, "device did not ack reset within 1000 ms\n");
513 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
514 }
515 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
516
517 /* At least some SIS devices need this after reset */
518 if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
519 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
520
521 return ret;
522 }
523
i2c_hid_get_input(struct i2c_hid * ihid)524 static void i2c_hid_get_input(struct i2c_hid *ihid)
525 {
526 u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
527 u16 ret_size;
528 int ret;
529
530 if (size > ihid->bufsize)
531 size = ihid->bufsize;
532
533 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
534 if (ret != size) {
535 if (ret < 0)
536 return;
537
538 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
539 __func__, ret, size);
540 return;
541 }
542
543 /* Receiving buffer is properly aligned */
544 ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
545 if (!ret_size) {
546 /* host or device initiated RESET completed */
547 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
548 wake_up(&ihid->wait);
549 return;
550 }
551
552 if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
553 dev_warn_once(&ihid->client->dev,
554 "%s: IRQ triggered but there's no data\n",
555 __func__);
556 return;
557 }
558
559 if (ret_size > size || ret_size < sizeof(__le16)) {
560 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
561 *(__le16 *)ihid->inbuf = cpu_to_le16(size);
562 ret_size = size;
563 } else {
564 dev_err(&ihid->client->dev,
565 "%s: incomplete report (%d/%d)\n",
566 __func__, size, ret_size);
567 return;
568 }
569 }
570
571 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
572
573 if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
574 if (ihid->hid->group != HID_GROUP_RMI)
575 pm_wakeup_event(&ihid->client->dev, 0);
576
577 hid_input_report(ihid->hid, HID_INPUT_REPORT,
578 ihid->inbuf + sizeof(__le16),
579 ret_size - sizeof(__le16), 1);
580 }
581
582 return;
583 }
584
i2c_hid_irq(int irq,void * dev_id)585 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
586 {
587 struct i2c_hid *ihid = dev_id;
588
589 i2c_hid_get_input(ihid);
590
591 return IRQ_HANDLED;
592 }
593
i2c_hid_get_report_length(struct hid_report * report)594 static int i2c_hid_get_report_length(struct hid_report *report)
595 {
596 return ((report->size - 1) >> 3) + 1 +
597 report->device->report_enum[report->type].numbered + 2;
598 }
599
600 /*
601 * Traverse the supplied list of reports and find the longest
602 */
i2c_hid_find_max_report(struct hid_device * hid,unsigned int type,unsigned int * max)603 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
604 unsigned int *max)
605 {
606 struct hid_report *report;
607 unsigned int size;
608
609 /* We should not rely on wMaxInputLength, as some devices may set it to
610 * a wrong length. */
611 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
612 size = i2c_hid_get_report_length(report);
613 if (*max < size)
614 *max = size;
615 }
616 }
617
i2c_hid_free_buffers(struct i2c_hid * ihid)618 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
619 {
620 kfree(ihid->inbuf);
621 kfree(ihid->rawbuf);
622 kfree(ihid->cmdbuf);
623 ihid->inbuf = NULL;
624 ihid->rawbuf = NULL;
625 ihid->cmdbuf = NULL;
626 ihid->bufsize = 0;
627 }
628
i2c_hid_alloc_buffers(struct i2c_hid * ihid,size_t report_size)629 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
630 {
631 /*
632 * The worst case is computed from the set_report command with a
633 * reportID > 15 and the maximum report length.
634 */
635 int cmd_len = sizeof(__le16) + /* command register */
636 sizeof(u8) + /* encoded report type/ID */
637 sizeof(u8) + /* opcode */
638 sizeof(u8) + /* optional 3rd byte report ID */
639 sizeof(__le16) + /* data register */
640 sizeof(__le16) + /* report data size */
641 sizeof(u8) + /* report ID if numbered report */
642 report_size;
643
644 ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
645 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
646 ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
647
648 if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
649 i2c_hid_free_buffers(ihid);
650 return -ENOMEM;
651 }
652
653 ihid->bufsize = report_size;
654
655 return 0;
656 }
657
i2c_hid_get_raw_report(struct hid_device * hid,u8 report_type,u8 report_id,u8 * buf,size_t count)658 static int i2c_hid_get_raw_report(struct hid_device *hid,
659 u8 report_type, u8 report_id,
660 u8 *buf, size_t count)
661 {
662 struct i2c_client *client = hid->driver_data;
663 struct i2c_hid *ihid = i2c_get_clientdata(client);
664 int ret_count;
665
666 if (report_type == HID_OUTPUT_REPORT)
667 return -EINVAL;
668
669 /*
670 * In case of unnumbered reports the response from the device will
671 * not have the report ID that the upper layers expect, so we need
672 * to stash it the buffer ourselves and adjust the data size.
673 */
674 if (!report_id) {
675 buf[0] = 0;
676 buf++;
677 count--;
678 }
679
680 ret_count = i2c_hid_get_report(ihid,
681 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
682 report_id, buf, count);
683
684 if (ret_count > 0 && !report_id)
685 ret_count++;
686
687 return ret_count;
688 }
689
i2c_hid_output_raw_report(struct hid_device * hid,u8 report_type,const u8 * buf,size_t count,bool do_set)690 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
691 const u8 *buf, size_t count, bool do_set)
692 {
693 struct i2c_client *client = hid->driver_data;
694 struct i2c_hid *ihid = i2c_get_clientdata(client);
695 int report_id = buf[0];
696 int ret;
697
698 if (report_type == HID_INPUT_REPORT)
699 return -EINVAL;
700
701 mutex_lock(&ihid->reset_lock);
702
703 /*
704 * Note that both numbered and unnumbered reports passed here
705 * are supposed to have report ID stored in the 1st byte of the
706 * buffer, so we strip it off unconditionally before passing payload
707 * to i2c_hid_set_or_send_report which takes care of encoding
708 * everything properly.
709 */
710 ret = i2c_hid_set_or_send_report(ihid,
711 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
712 report_id, buf + 1, count - 1, do_set);
713
714 if (ret >= 0)
715 ret++; /* add report_id to the number of transferred bytes */
716
717 mutex_unlock(&ihid->reset_lock);
718
719 return ret;
720 }
721
i2c_hid_output_report(struct hid_device * hid,u8 * buf,size_t count)722 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
723 {
724 return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
725 false);
726 }
727
i2c_hid_raw_request(struct hid_device * hid,unsigned char reportnum,__u8 * buf,size_t len,unsigned char rtype,int reqtype)728 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
729 __u8 *buf, size_t len, unsigned char rtype,
730 int reqtype)
731 {
732 switch (reqtype) {
733 case HID_REQ_GET_REPORT:
734 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
735 case HID_REQ_SET_REPORT:
736 if (buf[0] != reportnum)
737 return -EINVAL;
738 return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
739 default:
740 return -EIO;
741 }
742 }
743
i2c_hid_parse(struct hid_device * hid)744 static int i2c_hid_parse(struct hid_device *hid)
745 {
746 struct i2c_client *client = hid->driver_data;
747 struct i2c_hid *ihid = i2c_get_clientdata(client);
748 struct i2c_hid_desc *hdesc = &ihid->hdesc;
749 char *rdesc = NULL, *use_override = NULL;
750 unsigned int rsize;
751 int ret;
752 int tries = 3;
753
754 i2c_hid_dbg(ihid, "entering %s\n", __func__);
755
756 rsize = le16_to_cpu(hdesc->wReportDescLength);
757 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
758 dbg_hid("weird size of report descriptor (%u)\n", rsize);
759 return -EINVAL;
760 }
761
762 mutex_lock(&ihid->reset_lock);
763 do {
764 ret = i2c_hid_start_hwreset(ihid);
765 if (ret == 0)
766 ret = i2c_hid_finish_hwreset(ihid);
767 else
768 msleep(1000);
769 } while (tries-- > 0 && ret);
770 mutex_unlock(&ihid->reset_lock);
771
772 if (ret)
773 return ret;
774
775 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
776 &rsize);
777
778 if (use_override) {
779 rdesc = use_override;
780 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
781 } else {
782 rdesc = kzalloc(rsize, GFP_KERNEL);
783 if (!rdesc)
784 return -ENOMEM;
785
786 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
787
788 ret = i2c_hid_read_register(ihid,
789 ihid->hdesc.wReportDescRegister,
790 rdesc, rsize);
791 if (ret) {
792 hid_err(hid, "reading report descriptor failed\n");
793 goto out;
794 }
795 }
796
797 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
798
799 ret = hid_parse_report(hid, rdesc, rsize);
800 if (ret)
801 dbg_hid("parsing report descriptor failed\n");
802
803 out:
804 if (!use_override)
805 kfree(rdesc);
806
807 return ret;
808 }
809
i2c_hid_start(struct hid_device * hid)810 static int i2c_hid_start(struct hid_device *hid)
811 {
812 struct i2c_client *client = hid->driver_data;
813 struct i2c_hid *ihid = i2c_get_clientdata(client);
814 int ret;
815 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
816
817 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
818 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
819 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
820
821 if (bufsize > ihid->bufsize) {
822 disable_irq(client->irq);
823 i2c_hid_free_buffers(ihid);
824
825 ret = i2c_hid_alloc_buffers(ihid, bufsize);
826 enable_irq(client->irq);
827
828 if (ret)
829 return ret;
830 }
831
832 return 0;
833 }
834
i2c_hid_stop(struct hid_device * hid)835 static void i2c_hid_stop(struct hid_device *hid)
836 {
837 hid->claimed = 0;
838 }
839
i2c_hid_open(struct hid_device * hid)840 static int i2c_hid_open(struct hid_device *hid)
841 {
842 struct i2c_client *client = hid->driver_data;
843 struct i2c_hid *ihid = i2c_get_clientdata(client);
844
845 set_bit(I2C_HID_STARTED, &ihid->flags);
846 return 0;
847 }
848
i2c_hid_close(struct hid_device * hid)849 static void i2c_hid_close(struct hid_device *hid)
850 {
851 struct i2c_client *client = hid->driver_data;
852 struct i2c_hid *ihid = i2c_get_clientdata(client);
853
854 clear_bit(I2C_HID_STARTED, &ihid->flags);
855 }
856
857 static const struct hid_ll_driver i2c_hid_ll_driver = {
858 .parse = i2c_hid_parse,
859 .start = i2c_hid_start,
860 .stop = i2c_hid_stop,
861 .open = i2c_hid_open,
862 .close = i2c_hid_close,
863 .output_report = i2c_hid_output_report,
864 .raw_request = i2c_hid_raw_request,
865 };
866
i2c_hid_init_irq(struct i2c_client * client)867 static int i2c_hid_init_irq(struct i2c_client *client)
868 {
869 struct i2c_hid *ihid = i2c_get_clientdata(client);
870 unsigned long irqflags = 0;
871 int ret;
872
873 i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq);
874
875 if (!irq_get_trigger_type(client->irq))
876 irqflags = IRQF_TRIGGER_LOW;
877
878 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
879 irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN,
880 client->name, ihid);
881 if (ret < 0) {
882 dev_warn(&client->dev,
883 "Could not register for %s interrupt, irq = %d,"
884 " ret = %d\n",
885 client->name, client->irq, ret);
886
887 return ret;
888 }
889
890 return 0;
891 }
892
i2c_hid_fetch_hid_descriptor(struct i2c_hid * ihid)893 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
894 {
895 struct i2c_client *client = ihid->client;
896 struct i2c_hid_desc *hdesc = &ihid->hdesc;
897 unsigned int dsize;
898 int error;
899
900 /* i2c hid fetch using a fixed descriptor size (30 bytes) */
901 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
902 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
903 ihid->hdesc =
904 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
905 } else {
906 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
907 error = i2c_hid_read_register(ihid,
908 ihid->wHIDDescRegister,
909 &ihid->hdesc,
910 sizeof(ihid->hdesc));
911 if (error) {
912 dev_err(&ihid->client->dev,
913 "failed to fetch HID descriptor: %d\n",
914 error);
915 return -ENODEV;
916 }
917 }
918
919 /* Validate the length of HID descriptor, the 4 first bytes:
920 * bytes 0-1 -> length
921 * bytes 2-3 -> bcdVersion (has to be 1.00) */
922 /* check bcdVersion == 1.0 */
923 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
924 dev_err(&ihid->client->dev,
925 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
926 le16_to_cpu(hdesc->bcdVersion));
927 return -ENODEV;
928 }
929
930 /* Descriptor length should be 30 bytes as per the specification */
931 dsize = le16_to_cpu(hdesc->wHIDDescLength);
932 if (dsize != sizeof(struct i2c_hid_desc)) {
933 dev_err(&ihid->client->dev,
934 "weird size of HID descriptor (%u)\n", dsize);
935 return -ENODEV;
936 }
937 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
938 return 0;
939 }
940
i2c_hid_core_power_up(struct i2c_hid * ihid)941 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
942 {
943 if (!ihid->ops->power_up)
944 return 0;
945
946 return ihid->ops->power_up(ihid->ops);
947 }
948
i2c_hid_core_power_down(struct i2c_hid * ihid)949 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
950 {
951 if (!ihid->ops->power_down)
952 return;
953
954 ihid->ops->power_down(ihid->ops);
955 }
956
i2c_hid_core_shutdown_tail(struct i2c_hid * ihid)957 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
958 {
959 if (!ihid->ops->shutdown_tail)
960 return;
961
962 ihid->ops->shutdown_tail(ihid->ops);
963 }
964
i2c_hid_core_restore_sequence(struct i2c_hid * ihid)965 static void i2c_hid_core_restore_sequence(struct i2c_hid *ihid)
966 {
967 if (!ihid->ops->restore_sequence)
968 return;
969
970 ihid->ops->restore_sequence(ihid->ops);
971 }
972
i2c_hid_core_suspend(struct i2c_hid * ihid,bool force_poweroff)973 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)
974 {
975 struct i2c_client *client = ihid->client;
976 struct hid_device *hid = ihid->hid;
977 int ret;
978
979 ret = hid_driver_suspend(hid, PMSG_SUSPEND);
980 if (ret < 0)
981 return ret;
982
983 /* Save some power */
984 if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND))
985 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
986
987 disable_irq(client->irq);
988
989 if (force_poweroff || !device_may_wakeup(&client->dev))
990 i2c_hid_core_power_down(ihid);
991
992 return 0;
993 }
994
i2c_hid_core_resume(struct i2c_hid * ihid)995 static int i2c_hid_core_resume(struct i2c_hid *ihid)
996 {
997 struct i2c_client *client = ihid->client;
998 struct hid_device *hid = ihid->hid;
999 int ret;
1000
1001 if (!device_may_wakeup(&client->dev))
1002 i2c_hid_core_power_up(ihid);
1003
1004 enable_irq(client->irq);
1005
1006 /* On Goodix 27c6:0d42 wait extra time before device wakeup.
1007 * It's not clear why but if we send wakeup too early, the device will
1008 * never trigger input interrupts.
1009 */
1010 if (ihid->quirks & I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME)
1011 msleep(1500);
1012
1013 /* Instead of resetting device, simply powers the device on. This
1014 * solves "incomplete reports" on Raydium devices 2386:3118 and
1015 * 2386:4B33 and fixes various SIS touchscreens no longer sending
1016 * data after a suspend/resume.
1017 *
1018 * However some ALPS touchpads generate IRQ storm without reset, so
1019 * let's still reset them here.
1020 */
1021 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) {
1022 mutex_lock(&ihid->reset_lock);
1023 ret = i2c_hid_start_hwreset(ihid);
1024 if (ret == 0)
1025 ret = i2c_hid_finish_hwreset(ihid);
1026 mutex_unlock(&ihid->reset_lock);
1027 } else {
1028 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1029 }
1030
1031 if (ret)
1032 return ret;
1033
1034 return hid_driver_reset_resume(hid);
1035 }
1036
1037 /*
1038 * Check that the device exists and parse the HID descriptor.
1039 */
__i2c_hid_core_probe(struct i2c_hid * ihid)1040 static int __i2c_hid_core_probe(struct i2c_hid *ihid)
1041 {
1042 struct i2c_client *client = ihid->client;
1043 struct hid_device *hid = ihid->hid;
1044 int ret;
1045
1046 ret = i2c_hid_probe_address(ihid);
1047 if (ret < 0) {
1048 i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
1049 return -ENXIO;
1050 }
1051
1052 ret = i2c_hid_fetch_hid_descriptor(ihid);
1053 if (ret < 0) {
1054 dev_err(&client->dev,
1055 "Failed to fetch the HID Descriptor\n");
1056 return ret;
1057 }
1058
1059 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1060 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1061 hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1062
1063 hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
1064 hid->product);
1065
1066 snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1067 client->name, (u16)hid->vendor, (u16)hid->product);
1068 strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1069
1070 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1071
1072 return 0;
1073 }
1074
i2c_hid_core_register_hid(struct i2c_hid * ihid)1075 static int i2c_hid_core_register_hid(struct i2c_hid *ihid)
1076 {
1077 struct i2c_client *client = ihid->client;
1078 struct hid_device *hid = ihid->hid;
1079 int ret;
1080
1081 enable_irq(client->irq);
1082
1083 ret = hid_add_device(hid);
1084 if (ret) {
1085 if (ret != -ENODEV)
1086 hid_err(client, "can't add hid device: %d\n", ret);
1087 disable_irq(client->irq);
1088 return ret;
1089 }
1090
1091 /* At least some QTEC devices need this after initialization */
1092 if (ihid->quirks & I2C_HID_QUIRK_RE_POWER_ON)
1093 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1094
1095 return ret;
1096 }
1097
i2c_hid_core_probe_panel_follower(struct i2c_hid * ihid)1098 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid)
1099 {
1100 int ret;
1101
1102 ret = i2c_hid_core_power_up(ihid);
1103 if (ret)
1104 return ret;
1105
1106 ret = __i2c_hid_core_probe(ihid);
1107 if (ret)
1108 goto err_power_down;
1109
1110 ret = i2c_hid_core_register_hid(ihid);
1111 if (ret)
1112 goto err_power_down;
1113
1114 return 0;
1115
1116 err_power_down:
1117 i2c_hid_core_power_down(ihid);
1118
1119 return ret;
1120 }
1121
ihid_core_panel_follower_work(struct work_struct * work)1122 static void ihid_core_panel_follower_work(struct work_struct *work)
1123 {
1124 struct i2c_hid *ihid = container_of(work, struct i2c_hid,
1125 panel_follower_work);
1126 struct hid_device *hid = ihid->hid;
1127 int ret;
1128
1129 /*
1130 * hid->version is set on the first power up. If it's still zero then
1131 * this is the first power on so we should perform initial power up
1132 * steps.
1133 */
1134 if (!hid->version)
1135 ret = i2c_hid_core_probe_panel_follower(ihid);
1136 else
1137 ret = i2c_hid_core_resume(ihid);
1138
1139 if (ret)
1140 dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret);
1141 else
1142 WRITE_ONCE(ihid->panel_follower_work_finished, true);
1143
1144 /*
1145 * The work APIs provide a number of memory ordering guarantees
1146 * including one that says that memory writes before schedule_work()
1147 * are always visible to the work function, but they don't appear to
1148 * guarantee that a write that happened in the work is visible after
1149 * cancel_work_sync(). We'll add a write memory barrier here to match
1150 * with i2c_hid_core_panel_unpreparing() to ensure that our write to
1151 * panel_follower_work_finished is visible there.
1152 */
1153 smp_wmb();
1154 }
1155
i2c_hid_core_panel_follower_resume(struct drm_panel_follower * follower)1156 static int i2c_hid_core_panel_follower_resume(struct drm_panel_follower *follower)
1157 {
1158 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1159
1160 /*
1161 * Powering on a touchscreen can be a slow process. Queue the work to
1162 * the system workqueue so we don't block the panel's power up.
1163 */
1164 WRITE_ONCE(ihid->panel_follower_work_finished, false);
1165 schedule_work(&ihid->panel_follower_work);
1166
1167 return 0;
1168 }
1169
i2c_hid_core_panel_follower_suspend(struct drm_panel_follower * follower)1170 static int i2c_hid_core_panel_follower_suspend(struct drm_panel_follower *follower)
1171 {
1172 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1173
1174 cancel_work_sync(&ihid->panel_follower_work);
1175
1176 /* Match with ihid_core_panel_follower_work() */
1177 smp_rmb();
1178 if (!READ_ONCE(ihid->panel_follower_work_finished))
1179 return 0;
1180
1181 return i2c_hid_core_suspend(ihid, true);
1182 }
1183
1184 static const struct drm_panel_follower_funcs
1185 i2c_hid_core_panel_follower_prepare_funcs = {
1186 .panel_prepared = i2c_hid_core_panel_follower_resume,
1187 .panel_unpreparing = i2c_hid_core_panel_follower_suspend,
1188 };
1189
1190 static const struct drm_panel_follower_funcs
1191 i2c_hid_core_panel_follower_enable_funcs = {
1192 .panel_enabled = i2c_hid_core_panel_follower_resume,
1193 .panel_disabling = i2c_hid_core_panel_follower_suspend,
1194 };
1195
i2c_hid_core_register_panel_follower(struct i2c_hid * ihid)1196 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid)
1197 {
1198 struct device *dev = &ihid->client->dev;
1199 int ret;
1200
1201 if (ihid->hid->initial_quirks & HID_QUIRK_POWER_ON_AFTER_BACKLIGHT)
1202 ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_enable_funcs;
1203 else
1204 ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_prepare_funcs;
1205
1206 /*
1207 * If we're not in control of our own power up/power down then we can't
1208 * do the logic to manage wakeups. Give a warning if a user thought
1209 * that was possible then force the capability off.
1210 */
1211 if (device_can_wakeup(dev)) {
1212 dev_warn(dev, "Can't wakeup if following panel\n");
1213 device_set_wakeup_capable(dev, false);
1214 }
1215
1216 ret = drm_panel_add_follower(dev, &ihid->panel_follower);
1217 if (ret)
1218 return ret;
1219
1220 return 0;
1221 }
1222
i2c_hid_core_probe(struct i2c_client * client,struct i2chid_ops * ops,u16 hid_descriptor_address,u32 quirks)1223 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
1224 u16 hid_descriptor_address, u32 quirks)
1225 {
1226 int ret;
1227 struct i2c_hid *ihid;
1228 struct hid_device *hid;
1229
1230 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1231
1232 if (!client->irq) {
1233 dev_err(&client->dev,
1234 "HID over i2c has not been provided an Int IRQ\n");
1235 return -EINVAL;
1236 }
1237
1238 if (client->irq < 0) {
1239 if (client->irq != -EPROBE_DEFER)
1240 dev_err(&client->dev,
1241 "HID over i2c doesn't have a valid IRQ\n");
1242 return client->irq;
1243 }
1244
1245 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
1246 if (!ihid)
1247 return -ENOMEM;
1248
1249 i2c_set_clientdata(client, ihid);
1250
1251 ihid->ops = ops;
1252 ihid->client = client;
1253 ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
1254 ihid->is_panel_follower = drm_is_panel_follower(&client->dev);
1255
1256 init_waitqueue_head(&ihid->wait);
1257 mutex_init(&ihid->cmd_lock);
1258 mutex_init(&ihid->reset_lock);
1259 INIT_WORK(&ihid->panel_follower_work, ihid_core_panel_follower_work);
1260
1261 /* we need to allocate the command buffer without knowing the maximum
1262 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1263 * real computation later. */
1264 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1265 if (ret < 0)
1266 return ret;
1267 device_enable_async_suspend(&client->dev);
1268
1269 hid = hid_allocate_device();
1270 if (IS_ERR(hid)) {
1271 ret = PTR_ERR(hid);
1272 goto err_free_buffers;
1273 }
1274
1275 ihid->hid = hid;
1276
1277 hid->driver_data = client;
1278 hid->ll_driver = &i2c_hid_ll_driver;
1279 hid->dev.parent = &client->dev;
1280 hid->bus = BUS_I2C;
1281 hid->initial_quirks = quirks;
1282
1283 /* Power on and probe unless device is a panel follower. */
1284 if (!ihid->is_panel_follower) {
1285 ret = i2c_hid_core_power_up(ihid);
1286 if (ret < 0)
1287 goto err_destroy_device;
1288
1289 ret = __i2c_hid_core_probe(ihid);
1290 if (ret < 0)
1291 goto err_power_down;
1292 }
1293
1294 ret = i2c_hid_init_irq(client);
1295 if (ret < 0)
1296 goto err_power_down;
1297
1298 /*
1299 * If we're a panel follower, we'll register when the panel turns on;
1300 * otherwise we do it right away.
1301 */
1302 if (ihid->is_panel_follower)
1303 ret = i2c_hid_core_register_panel_follower(ihid);
1304 else
1305 ret = i2c_hid_core_register_hid(ihid);
1306 if (ret)
1307 goto err_free_irq;
1308
1309 return 0;
1310
1311 err_free_irq:
1312 free_irq(client->irq, ihid);
1313 err_power_down:
1314 if (!ihid->is_panel_follower)
1315 i2c_hid_core_power_down(ihid);
1316 err_destroy_device:
1317 hid_destroy_device(hid);
1318 err_free_buffers:
1319 i2c_hid_free_buffers(ihid);
1320
1321 return ret;
1322 }
1323 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1324
i2c_hid_core_remove(struct i2c_client * client)1325 void i2c_hid_core_remove(struct i2c_client *client)
1326 {
1327 struct i2c_hid *ihid = i2c_get_clientdata(client);
1328 struct hid_device *hid;
1329
1330 /*
1331 * If we're a follower, the act of unfollowing will cause us to be
1332 * powered down. Otherwise we need to manually do it.
1333 */
1334 if (ihid->is_panel_follower)
1335 drm_panel_remove_follower(&ihid->panel_follower);
1336 else
1337 i2c_hid_core_suspend(ihid, true);
1338
1339 hid = ihid->hid;
1340 hid_destroy_device(hid);
1341
1342 free_irq(client->irq, ihid);
1343
1344 if (ihid->bufsize)
1345 i2c_hid_free_buffers(ihid);
1346 }
1347 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1348
i2c_hid_core_shutdown(struct i2c_client * client)1349 void i2c_hid_core_shutdown(struct i2c_client *client)
1350 {
1351 struct i2c_hid *ihid = i2c_get_clientdata(client);
1352
1353 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1354 free_irq(client->irq, ihid);
1355
1356 i2c_hid_core_shutdown_tail(ihid);
1357 }
1358 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1359
i2c_hid_core_pm_suspend(struct device * dev)1360 static int i2c_hid_core_pm_suspend(struct device *dev)
1361 {
1362 struct i2c_client *client = to_i2c_client(dev);
1363 struct i2c_hid *ihid = i2c_get_clientdata(client);
1364
1365 if (ihid->is_panel_follower)
1366 return 0;
1367
1368 return i2c_hid_core_suspend(ihid, false);
1369 }
1370
i2c_hid_core_pm_resume(struct device * dev)1371 static int i2c_hid_core_pm_resume(struct device *dev)
1372 {
1373 struct i2c_client *client = to_i2c_client(dev);
1374 struct i2c_hid *ihid = i2c_get_clientdata(client);
1375
1376 if (ihid->is_panel_follower)
1377 return 0;
1378
1379 return i2c_hid_core_resume(ihid);
1380 }
1381
i2c_hid_core_pm_restore(struct device * dev)1382 static int i2c_hid_core_pm_restore(struct device *dev)
1383 {
1384 struct i2c_client *client = to_i2c_client(dev);
1385 struct i2c_hid *ihid = i2c_get_clientdata(client);
1386
1387 if (ihid->is_panel_follower)
1388 return 0;
1389
1390 i2c_hid_core_restore_sequence(ihid);
1391
1392 return i2c_hid_core_resume(ihid);
1393 }
1394
1395 const struct dev_pm_ops i2c_hid_core_pm = {
1396 .suspend = pm_sleep_ptr(i2c_hid_core_pm_suspend),
1397 .resume = pm_sleep_ptr(i2c_hid_core_pm_resume),
1398 .freeze = pm_sleep_ptr(i2c_hid_core_pm_suspend),
1399 .thaw = pm_sleep_ptr(i2c_hid_core_pm_resume),
1400 .poweroff = pm_sleep_ptr(i2c_hid_core_pm_suspend),
1401 .restore = pm_sleep_ptr(i2c_hid_core_pm_restore),
1402 };
1403 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1404
1405 MODULE_DESCRIPTION("HID over I2C core driver");
1406 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1407 MODULE_LICENSE("GPL");
1408