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_prepare_work;
116 bool is_panel_follower;
117 bool prepare_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 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
290 ihid->rawbuf, recv_len + sizeof(__le16));
291 if (error) {
292 dev_err(&ihid->client->dev,
293 "failed to get a report from device: %d\n", error);
294 return error;
295 }
296
297 /* The buffer is sufficiently aligned */
298 ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
299
300 /* Check for empty report response */
301 if (ret_count <= sizeof(__le16))
302 return 0;
303
304 recv_len = min(recv_len, ret_count - sizeof(__le16));
305 memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
306
307 if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
308 dev_err(&ihid->client->dev,
309 "device returned incorrect report (%d vs %d expected)\n",
310 recv_buf[0], report_id);
311 return -EINVAL;
312 }
313
314 return recv_len;
315 }
316
i2c_hid_format_report(u8 * buf,int report_id,const u8 * data,size_t size)317 static size_t i2c_hid_format_report(u8 *buf, int report_id,
318 const u8 *data, size_t size)
319 {
320 size_t length = sizeof(__le16); /* reserve space to store size */
321
322 if (report_id)
323 buf[length++] = report_id;
324
325 memcpy(buf + length, data, size);
326 length += size;
327
328 /* Store overall size in the beginning of the buffer */
329 put_unaligned_le16(length, buf);
330
331 return length;
332 }
333
334 /**
335 * i2c_hid_set_or_send_report: forward an incoming report to the device
336 * @ihid: the i2c hid device
337 * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
338 * @report_id: the report ID
339 * @buf: the actual data to transfer, without the report ID
340 * @data_len: size of buf
341 * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
342 */
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)343 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
344 u8 report_type, u8 report_id,
345 const u8 *buf, size_t data_len,
346 bool do_set)
347 {
348 size_t length = 0;
349 int error;
350
351 i2c_hid_dbg(ihid, "%s\n", __func__);
352
353 if (data_len > ihid->bufsize)
354 return -EINVAL;
355
356 if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
357 return -ENOSYS;
358
359 guard(mutex)(&ihid->cmd_lock);
360
361 if (do_set) {
362 /* Command register goes first */
363 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
364 length += sizeof(__le16);
365 /* Next is SET_REPORT command */
366 length += i2c_hid_encode_command(ihid->cmdbuf + length,
367 I2C_HID_OPCODE_SET_REPORT,
368 report_type, report_id);
369 /*
370 * Report data will go into the data register. Because
371 * command can be either 2 or 3 bytes destination for
372 * the data register may be not aligned.
373 */
374 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
375 ihid->cmdbuf + length);
376 length += sizeof(__le16);
377 } else {
378 /*
379 * With simple "send report" all data goes into the output
380 * register.
381 */
382 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
383 length += sizeof(__le16);
384 }
385
386 length += i2c_hid_format_report(ihid->cmdbuf + length,
387 report_id, buf, data_len);
388
389 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
390 if (error) {
391 dev_err(&ihid->client->dev,
392 "failed to set a report to device: %d\n", error);
393 return error;
394 }
395
396 return data_len;
397 }
398
i2c_hid_set_power_command(struct i2c_hid * ihid,int power_state)399 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
400 {
401 size_t length;
402
403 guard(mutex)(&ihid->cmd_lock);
404
405 /* SET_POWER uses command register */
406 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
407 length = sizeof(__le16);
408
409 /* Now the command itself */
410 length += i2c_hid_encode_command(ihid->cmdbuf + length,
411 I2C_HID_OPCODE_SET_POWER,
412 0, power_state);
413
414 return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
415 }
416
i2c_hid_set_power(struct i2c_hid * ihid,int power_state)417 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
418 {
419 int ret;
420
421 i2c_hid_dbg(ihid, "%s\n", __func__);
422
423 /*
424 * Some STM-based devices need 400µs after a rising clock edge to wake
425 * from deep sleep, in which case the first request will fail due to
426 * the address not being acknowledged. Try after a short sleep to see
427 * if the device came alive on the bus. Certain Weida Tech devices also
428 * need this.
429 */
430 ret = i2c_hid_set_power_command(ihid, power_state);
431 if (ret && power_state == I2C_HID_PWR_ON) {
432 usleep_range(400, 500);
433 ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
434 }
435
436 if (ret)
437 dev_err(&ihid->client->dev,
438 "failed to change power setting.\n");
439
440 /*
441 * The HID over I2C specification states that if a DEVICE needs time
442 * after the PWR_ON request, it should utilise CLOCK stretching.
443 * However, it has been observered that the Windows driver provides a
444 * 1ms sleep between the PWR_ON and RESET requests.
445 * According to Goodix Windows even waits 60 ms after (other?)
446 * PWR_ON requests. Testing has confirmed that several devices
447 * will not work properly without a delay after a PWR_ON request.
448 */
449 if (!ret && power_state == I2C_HID_PWR_ON)
450 msleep(60);
451
452 return ret;
453 }
454
i2c_hid_start_hwreset(struct i2c_hid * ihid)455 static int i2c_hid_start_hwreset(struct i2c_hid *ihid)
456 {
457 size_t length = 0;
458 int ret;
459
460 i2c_hid_dbg(ihid, "%s\n", __func__);
461
462 /*
463 * This prevents sending feature reports while the device is
464 * being reset. Otherwise we may lose the reset complete
465 * interrupt.
466 */
467 lockdep_assert_held(&ihid->reset_lock);
468
469 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
470 if (ret)
471 return ret;
472
473 scoped_guard(mutex, &ihid->cmd_lock) {
474 /* Prepare reset command. Command register goes first. */
475 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
476 length += sizeof(__le16);
477 /* Next is RESET command itself */
478 length += i2c_hid_encode_command(ihid->cmdbuf + length,
479 I2C_HID_OPCODE_RESET, 0, 0);
480
481 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
482
483 ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
484 if (ret) {
485 dev_err(&ihid->client->dev,
486 "failed to reset device: %d\n", ret);
487 break;
488 }
489
490 return 0;
491 }
492
493 /* Clean up if sending reset command failed */
494 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
495 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
496 return ret;
497 }
498
i2c_hid_finish_hwreset(struct i2c_hid * ihid)499 static int i2c_hid_finish_hwreset(struct i2c_hid *ihid)
500 {
501 int ret = 0;
502
503 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
504
505 if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
506 msleep(100);
507 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
508 } else if (!wait_event_timeout(ihid->wait,
509 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
510 msecs_to_jiffies(1000))) {
511 dev_warn(&ihid->client->dev, "device did not ack reset within 1000 ms\n");
512 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
513 }
514 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
515
516 /* At least some SIS devices need this after reset */
517 if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
518 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
519
520 return ret;
521 }
522
i2c_hid_get_input(struct i2c_hid * ihid)523 static void i2c_hid_get_input(struct i2c_hid *ihid)
524 {
525 u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
526 u16 ret_size;
527 int ret;
528
529 if (size > ihid->bufsize)
530 size = ihid->bufsize;
531
532 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
533 if (ret != size) {
534 if (ret < 0)
535 return;
536
537 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
538 __func__, ret, size);
539 return;
540 }
541
542 /* Receiving buffer is properly aligned */
543 ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
544 if (!ret_size) {
545 /* host or device initiated RESET completed */
546 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
547 wake_up(&ihid->wait);
548 return;
549 }
550
551 if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
552 dev_warn_once(&ihid->client->dev,
553 "%s: IRQ triggered but there's no data\n",
554 __func__);
555 return;
556 }
557
558 if (ret_size > size || ret_size < sizeof(__le16)) {
559 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
560 *(__le16 *)ihid->inbuf = cpu_to_le16(size);
561 ret_size = size;
562 } else {
563 dev_err(&ihid->client->dev,
564 "%s: incomplete report (%d/%d)\n",
565 __func__, size, ret_size);
566 return;
567 }
568 }
569
570 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
571
572 if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
573 if (ihid->hid->group != HID_GROUP_RMI)
574 pm_wakeup_event(&ihid->client->dev, 0);
575
576 hid_input_report(ihid->hid, HID_INPUT_REPORT,
577 ihid->inbuf + sizeof(__le16),
578 ret_size - sizeof(__le16), 1);
579 }
580
581 return;
582 }
583
i2c_hid_irq(int irq,void * dev_id)584 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
585 {
586 struct i2c_hid *ihid = dev_id;
587
588 i2c_hid_get_input(ihid);
589
590 return IRQ_HANDLED;
591 }
592
i2c_hid_get_report_length(struct hid_report * report)593 static int i2c_hid_get_report_length(struct hid_report *report)
594 {
595 return ((report->size - 1) >> 3) + 1 +
596 report->device->report_enum[report->type].numbered + 2;
597 }
598
599 /*
600 * Traverse the supplied list of reports and find the longest
601 */
i2c_hid_find_max_report(struct hid_device * hid,unsigned int type,unsigned int * max)602 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
603 unsigned int *max)
604 {
605 struct hid_report *report;
606 unsigned int size;
607
608 /* We should not rely on wMaxInputLength, as some devices may set it to
609 * a wrong length. */
610 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
611 size = i2c_hid_get_report_length(report);
612 if (*max < size)
613 *max = size;
614 }
615 }
616
i2c_hid_free_buffers(struct i2c_hid * ihid)617 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
618 {
619 kfree(ihid->inbuf);
620 kfree(ihid->rawbuf);
621 kfree(ihid->cmdbuf);
622 ihid->inbuf = NULL;
623 ihid->rawbuf = NULL;
624 ihid->cmdbuf = NULL;
625 ihid->bufsize = 0;
626 }
627
i2c_hid_alloc_buffers(struct i2c_hid * ihid,size_t report_size)628 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
629 {
630 /*
631 * The worst case is computed from the set_report command with a
632 * reportID > 15 and the maximum report length.
633 */
634 int cmd_len = sizeof(__le16) + /* command register */
635 sizeof(u8) + /* encoded report type/ID */
636 sizeof(u8) + /* opcode */
637 sizeof(u8) + /* optional 3rd byte report ID */
638 sizeof(__le16) + /* data register */
639 sizeof(__le16) + /* report data size */
640 sizeof(u8) + /* report ID if numbered report */
641 report_size;
642
643 ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
644 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
645 ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
646
647 if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
648 i2c_hid_free_buffers(ihid);
649 return -ENOMEM;
650 }
651
652 ihid->bufsize = report_size;
653
654 return 0;
655 }
656
i2c_hid_get_raw_report(struct hid_device * hid,u8 report_type,u8 report_id,u8 * buf,size_t count)657 static int i2c_hid_get_raw_report(struct hid_device *hid,
658 u8 report_type, u8 report_id,
659 u8 *buf, size_t count)
660 {
661 struct i2c_client *client = hid->driver_data;
662 struct i2c_hid *ihid = i2c_get_clientdata(client);
663 int ret_count;
664
665 if (report_type == HID_OUTPUT_REPORT)
666 return -EINVAL;
667
668 /*
669 * In case of unnumbered reports the response from the device will
670 * not have the report ID that the upper layers expect, so we need
671 * to stash it the buffer ourselves and adjust the data size.
672 */
673 if (!report_id) {
674 buf[0] = 0;
675 buf++;
676 count--;
677 }
678
679 ret_count = i2c_hid_get_report(ihid,
680 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
681 report_id, buf, count);
682
683 if (ret_count > 0 && !report_id)
684 ret_count++;
685
686 return ret_count;
687 }
688
i2c_hid_output_raw_report(struct hid_device * hid,u8 report_type,const u8 * buf,size_t count,bool do_set)689 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
690 const u8 *buf, size_t count, bool do_set)
691 {
692 struct i2c_client *client = hid->driver_data;
693 struct i2c_hid *ihid = i2c_get_clientdata(client);
694 int report_id = buf[0];
695 int ret;
696
697 if (report_type == HID_INPUT_REPORT)
698 return -EINVAL;
699
700 mutex_lock(&ihid->reset_lock);
701
702 /*
703 * Note that both numbered and unnumbered reports passed here
704 * are supposed to have report ID stored in the 1st byte of the
705 * buffer, so we strip it off unconditionally before passing payload
706 * to i2c_hid_set_or_send_report which takes care of encoding
707 * everything properly.
708 */
709 ret = i2c_hid_set_or_send_report(ihid,
710 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
711 report_id, buf + 1, count - 1, do_set);
712
713 if (ret >= 0)
714 ret++; /* add report_id to the number of transferred bytes */
715
716 mutex_unlock(&ihid->reset_lock);
717
718 return ret;
719 }
720
i2c_hid_output_report(struct hid_device * hid,u8 * buf,size_t count)721 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
722 {
723 return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
724 false);
725 }
726
i2c_hid_raw_request(struct hid_device * hid,unsigned char reportnum,__u8 * buf,size_t len,unsigned char rtype,int reqtype)727 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
728 __u8 *buf, size_t len, unsigned char rtype,
729 int reqtype)
730 {
731 switch (reqtype) {
732 case HID_REQ_GET_REPORT:
733 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
734 case HID_REQ_SET_REPORT:
735 if (buf[0] != reportnum)
736 return -EINVAL;
737 return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
738 default:
739 return -EIO;
740 }
741 }
742
i2c_hid_parse(struct hid_device * hid)743 static int i2c_hid_parse(struct hid_device *hid)
744 {
745 struct i2c_client *client = hid->driver_data;
746 struct i2c_hid *ihid = i2c_get_clientdata(client);
747 struct i2c_hid_desc *hdesc = &ihid->hdesc;
748 char *rdesc = NULL, *use_override = NULL;
749 unsigned int rsize;
750 int ret;
751 int tries = 3;
752
753 i2c_hid_dbg(ihid, "entering %s\n", __func__);
754
755 rsize = le16_to_cpu(hdesc->wReportDescLength);
756 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
757 dbg_hid("weird size of report descriptor (%u)\n", rsize);
758 return -EINVAL;
759 }
760
761 mutex_lock(&ihid->reset_lock);
762 do {
763 ret = i2c_hid_start_hwreset(ihid);
764 if (ret == 0)
765 ret = i2c_hid_finish_hwreset(ihid);
766 else
767 msleep(1000);
768 } while (tries-- > 0 && ret);
769 mutex_unlock(&ihid->reset_lock);
770
771 if (ret)
772 return ret;
773
774 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
775 &rsize);
776
777 if (use_override) {
778 rdesc = use_override;
779 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
780 } else {
781 rdesc = kzalloc(rsize, GFP_KERNEL);
782 if (!rdesc)
783 return -ENOMEM;
784
785 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
786
787 ret = i2c_hid_read_register(ihid,
788 ihid->hdesc.wReportDescRegister,
789 rdesc, rsize);
790 if (ret) {
791 hid_err(hid, "reading report descriptor failed\n");
792 goto out;
793 }
794 }
795
796 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
797
798 ret = hid_parse_report(hid, rdesc, rsize);
799 if (ret)
800 dbg_hid("parsing report descriptor failed\n");
801
802 out:
803 if (!use_override)
804 kfree(rdesc);
805
806 return ret;
807 }
808
i2c_hid_start(struct hid_device * hid)809 static int i2c_hid_start(struct hid_device *hid)
810 {
811 struct i2c_client *client = hid->driver_data;
812 struct i2c_hid *ihid = i2c_get_clientdata(client);
813 int ret;
814 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
815
816 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
817 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
818 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
819
820 if (bufsize > ihid->bufsize) {
821 disable_irq(client->irq);
822 i2c_hid_free_buffers(ihid);
823
824 ret = i2c_hid_alloc_buffers(ihid, bufsize);
825 enable_irq(client->irq);
826
827 if (ret)
828 return ret;
829 }
830
831 return 0;
832 }
833
i2c_hid_stop(struct hid_device * hid)834 static void i2c_hid_stop(struct hid_device *hid)
835 {
836 hid->claimed = 0;
837 }
838
i2c_hid_open(struct hid_device * hid)839 static int i2c_hid_open(struct hid_device *hid)
840 {
841 struct i2c_client *client = hid->driver_data;
842 struct i2c_hid *ihid = i2c_get_clientdata(client);
843
844 set_bit(I2C_HID_STARTED, &ihid->flags);
845 return 0;
846 }
847
i2c_hid_close(struct hid_device * hid)848 static void i2c_hid_close(struct hid_device *hid)
849 {
850 struct i2c_client *client = hid->driver_data;
851 struct i2c_hid *ihid = i2c_get_clientdata(client);
852
853 clear_bit(I2C_HID_STARTED, &ihid->flags);
854 }
855
856 static const struct hid_ll_driver i2c_hid_ll_driver = {
857 .parse = i2c_hid_parse,
858 .start = i2c_hid_start,
859 .stop = i2c_hid_stop,
860 .open = i2c_hid_open,
861 .close = i2c_hid_close,
862 .output_report = i2c_hid_output_report,
863 .raw_request = i2c_hid_raw_request,
864 };
865
i2c_hid_init_irq(struct i2c_client * client)866 static int i2c_hid_init_irq(struct i2c_client *client)
867 {
868 struct i2c_hid *ihid = i2c_get_clientdata(client);
869 unsigned long irqflags = 0;
870 int ret;
871
872 i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq);
873
874 if (!irq_get_trigger_type(client->irq))
875 irqflags = IRQF_TRIGGER_LOW;
876
877 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
878 irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN,
879 client->name, ihid);
880 if (ret < 0) {
881 dev_warn(&client->dev,
882 "Could not register for %s interrupt, irq = %d,"
883 " ret = %d\n",
884 client->name, client->irq, ret);
885
886 return ret;
887 }
888
889 return 0;
890 }
891
i2c_hid_fetch_hid_descriptor(struct i2c_hid * ihid)892 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
893 {
894 struct i2c_client *client = ihid->client;
895 struct i2c_hid_desc *hdesc = &ihid->hdesc;
896 unsigned int dsize;
897 int error;
898
899 /* i2c hid fetch using a fixed descriptor size (30 bytes) */
900 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
901 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
902 ihid->hdesc =
903 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
904 } else {
905 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
906 error = i2c_hid_read_register(ihid,
907 ihid->wHIDDescRegister,
908 &ihid->hdesc,
909 sizeof(ihid->hdesc));
910 if (error) {
911 dev_err(&ihid->client->dev,
912 "failed to fetch HID descriptor: %d\n",
913 error);
914 return -ENODEV;
915 }
916 }
917
918 /* Validate the length of HID descriptor, the 4 first bytes:
919 * bytes 0-1 -> length
920 * bytes 2-3 -> bcdVersion (has to be 1.00) */
921 /* check bcdVersion == 1.0 */
922 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
923 dev_err(&ihid->client->dev,
924 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
925 le16_to_cpu(hdesc->bcdVersion));
926 return -ENODEV;
927 }
928
929 /* Descriptor length should be 30 bytes as per the specification */
930 dsize = le16_to_cpu(hdesc->wHIDDescLength);
931 if (dsize != sizeof(struct i2c_hid_desc)) {
932 dev_err(&ihid->client->dev,
933 "weird size of HID descriptor (%u)\n", dsize);
934 return -ENODEV;
935 }
936 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
937 return 0;
938 }
939
i2c_hid_core_power_up(struct i2c_hid * ihid)940 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
941 {
942 if (!ihid->ops->power_up)
943 return 0;
944
945 return ihid->ops->power_up(ihid->ops);
946 }
947
i2c_hid_core_power_down(struct i2c_hid * ihid)948 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
949 {
950 if (!ihid->ops->power_down)
951 return;
952
953 ihid->ops->power_down(ihid->ops);
954 }
955
i2c_hid_core_shutdown_tail(struct i2c_hid * ihid)956 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
957 {
958 if (!ihid->ops->shutdown_tail)
959 return;
960
961 ihid->ops->shutdown_tail(ihid->ops);
962 }
963
i2c_hid_core_suspend(struct i2c_hid * ihid,bool force_poweroff)964 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)
965 {
966 struct i2c_client *client = ihid->client;
967 struct hid_device *hid = ihid->hid;
968 int ret;
969
970 ret = hid_driver_suspend(hid, PMSG_SUSPEND);
971 if (ret < 0)
972 return ret;
973
974 /* Save some power */
975 if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND))
976 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
977
978 disable_irq(client->irq);
979
980 if (force_poweroff || !device_may_wakeup(&client->dev))
981 i2c_hid_core_power_down(ihid);
982
983 return 0;
984 }
985
i2c_hid_core_resume(struct i2c_hid * ihid)986 static int i2c_hid_core_resume(struct i2c_hid *ihid)
987 {
988 struct i2c_client *client = ihid->client;
989 struct hid_device *hid = ihid->hid;
990 int ret;
991
992 if (!device_may_wakeup(&client->dev))
993 i2c_hid_core_power_up(ihid);
994
995 enable_irq(client->irq);
996
997 /* On Goodix 27c6:0d42 wait extra time before device wakeup.
998 * It's not clear why but if we send wakeup too early, the device will
999 * never trigger input interrupts.
1000 */
1001 if (ihid->quirks & I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME)
1002 msleep(1500);
1003
1004 /* Instead of resetting device, simply powers the device on. This
1005 * solves "incomplete reports" on Raydium devices 2386:3118 and
1006 * 2386:4B33 and fixes various SIS touchscreens no longer sending
1007 * data after a suspend/resume.
1008 *
1009 * However some ALPS touchpads generate IRQ storm without reset, so
1010 * let's still reset them here.
1011 */
1012 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) {
1013 mutex_lock(&ihid->reset_lock);
1014 ret = i2c_hid_start_hwreset(ihid);
1015 if (ret == 0)
1016 ret = i2c_hid_finish_hwreset(ihid);
1017 mutex_unlock(&ihid->reset_lock);
1018 } else {
1019 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1020 }
1021
1022 if (ret)
1023 return ret;
1024
1025 return hid_driver_reset_resume(hid);
1026 }
1027
1028 /*
1029 * Check that the device exists and parse the HID descriptor.
1030 */
__i2c_hid_core_probe(struct i2c_hid * ihid)1031 static int __i2c_hid_core_probe(struct i2c_hid *ihid)
1032 {
1033 struct i2c_client *client = ihid->client;
1034 struct hid_device *hid = ihid->hid;
1035 int ret;
1036
1037 ret = i2c_hid_probe_address(ihid);
1038 if (ret < 0) {
1039 i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
1040 return -ENXIO;
1041 }
1042
1043 ret = i2c_hid_fetch_hid_descriptor(ihid);
1044 if (ret < 0) {
1045 dev_err(&client->dev,
1046 "Failed to fetch the HID Descriptor\n");
1047 return ret;
1048 }
1049
1050 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1051 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1052 hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1053
1054 hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
1055 hid->product);
1056
1057 snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1058 client->name, (u16)hid->vendor, (u16)hid->product);
1059 strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1060
1061 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1062
1063 return 0;
1064 }
1065
i2c_hid_core_register_hid(struct i2c_hid * ihid)1066 static int i2c_hid_core_register_hid(struct i2c_hid *ihid)
1067 {
1068 struct i2c_client *client = ihid->client;
1069 struct hid_device *hid = ihid->hid;
1070 int ret;
1071
1072 enable_irq(client->irq);
1073
1074 ret = hid_add_device(hid);
1075 if (ret) {
1076 if (ret != -ENODEV)
1077 hid_err(client, "can't add hid device: %d\n", ret);
1078 disable_irq(client->irq);
1079 return ret;
1080 }
1081
1082 /* At least some QTEC devices need this after initialization */
1083 if (ihid->quirks & I2C_HID_QUIRK_RE_POWER_ON)
1084 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1085
1086 return ret;
1087 }
1088
i2c_hid_core_probe_panel_follower(struct i2c_hid * ihid)1089 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid)
1090 {
1091 int ret;
1092
1093 ret = i2c_hid_core_power_up(ihid);
1094 if (ret)
1095 return ret;
1096
1097 ret = __i2c_hid_core_probe(ihid);
1098 if (ret)
1099 goto err_power_down;
1100
1101 ret = i2c_hid_core_register_hid(ihid);
1102 if (ret)
1103 goto err_power_down;
1104
1105 return 0;
1106
1107 err_power_down:
1108 i2c_hid_core_power_down(ihid);
1109
1110 return ret;
1111 }
1112
ihid_core_panel_prepare_work(struct work_struct * work)1113 static void ihid_core_panel_prepare_work(struct work_struct *work)
1114 {
1115 struct i2c_hid *ihid = container_of(work, struct i2c_hid,
1116 panel_follower_prepare_work);
1117 struct hid_device *hid = ihid->hid;
1118 int ret;
1119
1120 /*
1121 * hid->version is set on the first power up. If it's still zero then
1122 * this is the first power on so we should perform initial power up
1123 * steps.
1124 */
1125 if (!hid->version)
1126 ret = i2c_hid_core_probe_panel_follower(ihid);
1127 else
1128 ret = i2c_hid_core_resume(ihid);
1129
1130 if (ret)
1131 dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret);
1132 else
1133 WRITE_ONCE(ihid->prepare_work_finished, true);
1134
1135 /*
1136 * The work APIs provide a number of memory ordering guarantees
1137 * including one that says that memory writes before schedule_work()
1138 * are always visible to the work function, but they don't appear to
1139 * guarantee that a write that happened in the work is visible after
1140 * cancel_work_sync(). We'll add a write memory barrier here to match
1141 * with i2c_hid_core_panel_unpreparing() to ensure that our write to
1142 * prepare_work_finished is visible there.
1143 */
1144 smp_wmb();
1145 }
1146
i2c_hid_core_panel_prepared(struct drm_panel_follower * follower)1147 static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower)
1148 {
1149 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1150
1151 /*
1152 * Powering on a touchscreen can be a slow process. Queue the work to
1153 * the system workqueue so we don't block the panel's power up.
1154 */
1155 WRITE_ONCE(ihid->prepare_work_finished, false);
1156 schedule_work(&ihid->panel_follower_prepare_work);
1157
1158 return 0;
1159 }
1160
i2c_hid_core_panel_unpreparing(struct drm_panel_follower * follower)1161 static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower)
1162 {
1163 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1164
1165 cancel_work_sync(&ihid->panel_follower_prepare_work);
1166
1167 /* Match with ihid_core_panel_prepare_work() */
1168 smp_rmb();
1169 if (!READ_ONCE(ihid->prepare_work_finished))
1170 return 0;
1171
1172 return i2c_hid_core_suspend(ihid, true);
1173 }
1174
1175 static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = {
1176 .panel_prepared = i2c_hid_core_panel_prepared,
1177 .panel_unpreparing = i2c_hid_core_panel_unpreparing,
1178 };
1179
i2c_hid_core_register_panel_follower(struct i2c_hid * ihid)1180 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid)
1181 {
1182 struct device *dev = &ihid->client->dev;
1183 int ret;
1184
1185 ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs;
1186
1187 /*
1188 * If we're not in control of our own power up/power down then we can't
1189 * do the logic to manage wakeups. Give a warning if a user thought
1190 * that was possible then force the capability off.
1191 */
1192 if (device_can_wakeup(dev)) {
1193 dev_warn(dev, "Can't wakeup if following panel\n");
1194 device_set_wakeup_capable(dev, false);
1195 }
1196
1197 ret = drm_panel_add_follower(dev, &ihid->panel_follower);
1198 if (ret)
1199 return ret;
1200
1201 return 0;
1202 }
1203
i2c_hid_core_probe(struct i2c_client * client,struct i2chid_ops * ops,u16 hid_descriptor_address,u32 quirks)1204 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
1205 u16 hid_descriptor_address, u32 quirks)
1206 {
1207 int ret;
1208 struct i2c_hid *ihid;
1209 struct hid_device *hid;
1210
1211 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1212
1213 if (!client->irq) {
1214 dev_err(&client->dev,
1215 "HID over i2c has not been provided an Int IRQ\n");
1216 return -EINVAL;
1217 }
1218
1219 if (client->irq < 0) {
1220 if (client->irq != -EPROBE_DEFER)
1221 dev_err(&client->dev,
1222 "HID over i2c doesn't have a valid IRQ\n");
1223 return client->irq;
1224 }
1225
1226 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
1227 if (!ihid)
1228 return -ENOMEM;
1229
1230 i2c_set_clientdata(client, ihid);
1231
1232 ihid->ops = ops;
1233 ihid->client = client;
1234 ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
1235 ihid->is_panel_follower = drm_is_panel_follower(&client->dev);
1236
1237 init_waitqueue_head(&ihid->wait);
1238 mutex_init(&ihid->cmd_lock);
1239 mutex_init(&ihid->reset_lock);
1240 INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work);
1241
1242 /* we need to allocate the command buffer without knowing the maximum
1243 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1244 * real computation later. */
1245 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1246 if (ret < 0)
1247 return ret;
1248 device_enable_async_suspend(&client->dev);
1249
1250 hid = hid_allocate_device();
1251 if (IS_ERR(hid)) {
1252 ret = PTR_ERR(hid);
1253 goto err_free_buffers;
1254 }
1255
1256 ihid->hid = hid;
1257
1258 hid->driver_data = client;
1259 hid->ll_driver = &i2c_hid_ll_driver;
1260 hid->dev.parent = &client->dev;
1261 hid->bus = BUS_I2C;
1262 hid->initial_quirks = quirks;
1263
1264 /* Power on and probe unless device is a panel follower. */
1265 if (!ihid->is_panel_follower) {
1266 ret = i2c_hid_core_power_up(ihid);
1267 if (ret < 0)
1268 goto err_destroy_device;
1269
1270 ret = __i2c_hid_core_probe(ihid);
1271 if (ret < 0)
1272 goto err_power_down;
1273 }
1274
1275 ret = i2c_hid_init_irq(client);
1276 if (ret < 0)
1277 goto err_power_down;
1278
1279 /*
1280 * If we're a panel follower, we'll register when the panel turns on;
1281 * otherwise we do it right away.
1282 */
1283 if (ihid->is_panel_follower)
1284 ret = i2c_hid_core_register_panel_follower(ihid);
1285 else
1286 ret = i2c_hid_core_register_hid(ihid);
1287 if (ret)
1288 goto err_free_irq;
1289
1290 return 0;
1291
1292 err_free_irq:
1293 free_irq(client->irq, ihid);
1294 err_power_down:
1295 if (!ihid->is_panel_follower)
1296 i2c_hid_core_power_down(ihid);
1297 err_destroy_device:
1298 hid_destroy_device(hid);
1299 err_free_buffers:
1300 i2c_hid_free_buffers(ihid);
1301
1302 return ret;
1303 }
1304 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1305
i2c_hid_core_remove(struct i2c_client * client)1306 void i2c_hid_core_remove(struct i2c_client *client)
1307 {
1308 struct i2c_hid *ihid = i2c_get_clientdata(client);
1309 struct hid_device *hid;
1310
1311 /*
1312 * If we're a follower, the act of unfollowing will cause us to be
1313 * powered down. Otherwise we need to manually do it.
1314 */
1315 if (ihid->is_panel_follower)
1316 drm_panel_remove_follower(&ihid->panel_follower);
1317 else
1318 i2c_hid_core_suspend(ihid, true);
1319
1320 hid = ihid->hid;
1321 hid_destroy_device(hid);
1322
1323 free_irq(client->irq, ihid);
1324
1325 if (ihid->bufsize)
1326 i2c_hid_free_buffers(ihid);
1327 }
1328 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1329
i2c_hid_core_shutdown(struct i2c_client * client)1330 void i2c_hid_core_shutdown(struct i2c_client *client)
1331 {
1332 struct i2c_hid *ihid = i2c_get_clientdata(client);
1333
1334 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1335 free_irq(client->irq, ihid);
1336
1337 i2c_hid_core_shutdown_tail(ihid);
1338 }
1339 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1340
i2c_hid_core_pm_suspend(struct device * dev)1341 static int i2c_hid_core_pm_suspend(struct device *dev)
1342 {
1343 struct i2c_client *client = to_i2c_client(dev);
1344 struct i2c_hid *ihid = i2c_get_clientdata(client);
1345
1346 if (ihid->is_panel_follower)
1347 return 0;
1348
1349 return i2c_hid_core_suspend(ihid, false);
1350 }
1351
i2c_hid_core_pm_resume(struct device * dev)1352 static int i2c_hid_core_pm_resume(struct device *dev)
1353 {
1354 struct i2c_client *client = to_i2c_client(dev);
1355 struct i2c_hid *ihid = i2c_get_clientdata(client);
1356
1357 if (ihid->is_panel_follower)
1358 return 0;
1359
1360 return i2c_hid_core_resume(ihid);
1361 }
1362
1363 const struct dev_pm_ops i2c_hid_core_pm = {
1364 SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume)
1365 };
1366 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1367
1368 MODULE_DESCRIPTION("HID over I2C core driver");
1369 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1370 MODULE_LICENSE("GPL");
1371