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 { I2C_VENDOR_ID_BLTP, I2C_PRODUCT_ID_BLTP7853,
153 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
154 { 0, 0 }
155 };
156
157 /*
158 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
159 * @idVendor: the 16-bit vendor ID
160 * @idProduct: the 16-bit product ID
161 *
162 * Returns: a u32 quirks value.
163 */
i2c_hid_lookup_quirk(const u16 idVendor,const u16 idProduct)164 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
165 {
166 u32 quirks = 0;
167 int n;
168
169 for (n = 0; i2c_hid_quirks[n].idVendor; n++)
170 if (i2c_hid_quirks[n].idVendor == idVendor &&
171 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
172 i2c_hid_quirks[n].idProduct == idProduct))
173 quirks = i2c_hid_quirks[n].quirks;
174
175 return quirks;
176 }
177
i2c_hid_probe_address(struct i2c_hid * ihid)178 static int i2c_hid_probe_address(struct i2c_hid *ihid)
179 {
180 int ret;
181
182 /*
183 * Some STM-based devices need 400µs after a rising clock edge to wake
184 * from deep sleep, in which case the first read will fail. Try after a
185 * short sleep to see if the device came alive on the bus. Certain
186 * Weida Tech devices also need this.
187 */
188 ret = i2c_smbus_read_byte(ihid->client);
189 if (ret < 0) {
190 usleep_range(400, 500);
191 ret = i2c_smbus_read_byte(ihid->client);
192 }
193 return ret < 0 ? ret : 0;
194 }
195
i2c_hid_xfer(struct i2c_hid * ihid,u8 * send_buf,int send_len,u8 * recv_buf,int recv_len)196 static int i2c_hid_xfer(struct i2c_hid *ihid,
197 u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
198 {
199 struct i2c_client *client = ihid->client;
200 struct i2c_msg msgs[2] = { 0 };
201 int n = 0;
202 int ret;
203
204 if (send_len) {
205 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n",
206 __func__, send_len, send_buf);
207
208 msgs[n].addr = client->addr;
209 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE;
210 msgs[n].len = send_len;
211 msgs[n].buf = send_buf;
212 n++;
213 }
214
215 if (recv_len) {
216 msgs[n].addr = client->addr;
217 msgs[n].flags = (client->flags & I2C_M_TEN) |
218 I2C_M_RD | I2C_M_DMA_SAFE;
219 msgs[n].len = recv_len;
220 msgs[n].buf = recv_buf;
221 n++;
222 }
223
224 ret = i2c_transfer(client->adapter, msgs, n);
225
226 if (ret != n)
227 return ret < 0 ? ret : -EIO;
228
229 return 0;
230 }
231
i2c_hid_read_register(struct i2c_hid * ihid,__le16 reg,void * buf,size_t len)232 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
233 void *buf, size_t len)
234 {
235 guard(mutex)(&ihid->cmd_lock);
236
237 *(__le16 *)ihid->cmdbuf = reg;
238
239 return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
240 }
241
i2c_hid_encode_command(u8 * buf,u8 opcode,int report_type,int report_id)242 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
243 int report_type, int report_id)
244 {
245 size_t length = 0;
246
247 if (report_id < 0x0F) {
248 buf[length++] = report_type << 4 | report_id;
249 buf[length++] = opcode;
250 } else {
251 buf[length++] = report_type << 4 | 0x0F;
252 buf[length++] = opcode;
253 buf[length++] = report_id;
254 }
255
256 return length;
257 }
258
i2c_hid_get_report(struct i2c_hid * ihid,u8 report_type,u8 report_id,u8 * recv_buf,size_t recv_len)259 static int i2c_hid_get_report(struct i2c_hid *ihid,
260 u8 report_type, u8 report_id,
261 u8 *recv_buf, size_t recv_len)
262 {
263 size_t length = 0;
264 size_t ret_count;
265 int error;
266
267 i2c_hid_dbg(ihid, "%s\n", __func__);
268
269 guard(mutex)(&ihid->cmd_lock);
270
271 /* Command register goes first */
272 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
273 length += sizeof(__le16);
274 /* Next is GET_REPORT command */
275 length += i2c_hid_encode_command(ihid->cmdbuf + length,
276 I2C_HID_OPCODE_GET_REPORT,
277 report_type, report_id);
278 /*
279 * Device will send report data through data register. Because
280 * command can be either 2 or 3 bytes destination for the data
281 * register may be not aligned.
282 */
283 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
284 ihid->cmdbuf + length);
285 length += sizeof(__le16);
286
287 /*
288 * In addition to report data device will supply data length
289 * in the first 2 bytes of the response, so adjust .
290 */
291 recv_len = min(recv_len, ihid->bufsize - sizeof(__le16));
292 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
293 ihid->rawbuf, recv_len + sizeof(__le16));
294 if (error) {
295 dev_err(&ihid->client->dev,
296 "failed to get a report from device: %d\n", error);
297 return error;
298 }
299
300 /* The buffer is sufficiently aligned */
301 ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
302
303 /* Check for empty report response */
304 if (ret_count <= sizeof(__le16))
305 return 0;
306
307 recv_len = min(recv_len, ret_count - sizeof(__le16));
308 memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
309
310 if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
311 dev_err(&ihid->client->dev,
312 "device returned incorrect report (%d vs %d expected)\n",
313 recv_buf[0], report_id);
314 return -EINVAL;
315 }
316
317 return recv_len;
318 }
319
i2c_hid_format_report(u8 * buf,int report_id,const u8 * data,size_t size)320 static size_t i2c_hid_format_report(u8 *buf, int report_id,
321 const u8 *data, size_t size)
322 {
323 size_t length = sizeof(__le16); /* reserve space to store size */
324
325 if (report_id)
326 buf[length++] = report_id;
327
328 memcpy(buf + length, data, size);
329 length += size;
330
331 /* Store overall size in the beginning of the buffer */
332 put_unaligned_le16(length, buf);
333
334 return length;
335 }
336
337 /**
338 * i2c_hid_set_or_send_report: forward an incoming report to the device
339 * @ihid: the i2c hid device
340 * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
341 * @report_id: the report ID
342 * @buf: the actual data to transfer, without the report ID
343 * @data_len: size of buf
344 * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
345 */
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)346 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
347 u8 report_type, u8 report_id,
348 const u8 *buf, size_t data_len,
349 bool do_set)
350 {
351 size_t length = 0;
352 int error;
353
354 i2c_hid_dbg(ihid, "%s\n", __func__);
355
356 if (data_len > ihid->bufsize)
357 return -EINVAL;
358
359 if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
360 return -ENOSYS;
361
362 guard(mutex)(&ihid->cmd_lock);
363
364 if (do_set) {
365 /* Command register goes first */
366 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
367 length += sizeof(__le16);
368 /* Next is SET_REPORT command */
369 length += i2c_hid_encode_command(ihid->cmdbuf + length,
370 I2C_HID_OPCODE_SET_REPORT,
371 report_type, report_id);
372 /*
373 * Report data will go into the data register. Because
374 * command can be either 2 or 3 bytes destination for
375 * the data register may be not aligned.
376 */
377 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
378 ihid->cmdbuf + length);
379 length += sizeof(__le16);
380 } else {
381 /*
382 * With simple "send report" all data goes into the output
383 * register.
384 */
385 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
386 length += sizeof(__le16);
387 }
388
389 length += i2c_hid_format_report(ihid->cmdbuf + length,
390 report_id, buf, data_len);
391
392 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
393 if (error) {
394 dev_err(&ihid->client->dev,
395 "failed to set a report to device: %d\n", error);
396 return error;
397 }
398
399 return data_len;
400 }
401
i2c_hid_set_power_command(struct i2c_hid * ihid,int power_state)402 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
403 {
404 size_t length;
405
406 guard(mutex)(&ihid->cmd_lock);
407
408 /* SET_POWER uses command register */
409 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
410 length = sizeof(__le16);
411
412 /* Now the command itself */
413 length += i2c_hid_encode_command(ihid->cmdbuf + length,
414 I2C_HID_OPCODE_SET_POWER,
415 0, power_state);
416
417 return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
418 }
419
i2c_hid_set_power(struct i2c_hid * ihid,int power_state)420 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
421 {
422 int ret;
423
424 i2c_hid_dbg(ihid, "%s\n", __func__);
425
426 /*
427 * Some STM-based devices need 400µs after a rising clock edge to wake
428 * from deep sleep, in which case the first request will fail due to
429 * the address not being acknowledged. Try after a short sleep to see
430 * if the device came alive on the bus. Certain Weida Tech devices also
431 * need this.
432 */
433 ret = i2c_hid_set_power_command(ihid, power_state);
434 if (ret && power_state == I2C_HID_PWR_ON) {
435 usleep_range(400, 500);
436 ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
437 }
438
439 if (ret)
440 dev_err(&ihid->client->dev,
441 "failed to change power setting.\n");
442
443 /*
444 * The HID over I2C specification states that if a DEVICE needs time
445 * after the PWR_ON request, it should utilise CLOCK stretching.
446 * However, it has been observered that the Windows driver provides a
447 * 1ms sleep between the PWR_ON and RESET requests.
448 * According to Goodix Windows even waits 60 ms after (other?)
449 * PWR_ON requests. Testing has confirmed that several devices
450 * will not work properly without a delay after a PWR_ON request.
451 */
452 if (!ret && power_state == I2C_HID_PWR_ON)
453 msleep(60);
454
455 return ret;
456 }
457
i2c_hid_start_hwreset(struct i2c_hid * ihid)458 static int i2c_hid_start_hwreset(struct i2c_hid *ihid)
459 {
460 size_t length = 0;
461 int ret;
462
463 i2c_hid_dbg(ihid, "%s\n", __func__);
464
465 /*
466 * This prevents sending feature reports while the device is
467 * being reset. Otherwise we may lose the reset complete
468 * interrupt.
469 */
470 lockdep_assert_held(&ihid->reset_lock);
471
472 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
473 if (ret)
474 return ret;
475
476 scoped_guard(mutex, &ihid->cmd_lock) {
477 /* Prepare reset command. Command register goes first. */
478 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
479 length += sizeof(__le16);
480 /* Next is RESET command itself */
481 length += i2c_hid_encode_command(ihid->cmdbuf + length,
482 I2C_HID_OPCODE_RESET, 0, 0);
483
484 set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
485
486 ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
487 if (ret) {
488 dev_err(&ihid->client->dev,
489 "failed to reset device: %d\n", ret);
490 break;
491 }
492
493 return 0;
494 }
495
496 /* Clean up if sending reset command failed */
497 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
498 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
499 return ret;
500 }
501
i2c_hid_finish_hwreset(struct i2c_hid * ihid)502 static int i2c_hid_finish_hwreset(struct i2c_hid *ihid)
503 {
504 int ret = 0;
505
506 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
507
508 if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
509 msleep(100);
510 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
511 } else if (!wait_event_timeout(ihid->wait,
512 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
513 msecs_to_jiffies(1000))) {
514 dev_warn(&ihid->client->dev, "device did not ack reset within 1000 ms\n");
515 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
516 }
517 i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
518
519 /* At least some SIS devices need this after reset */
520 if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
521 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
522
523 return ret;
524 }
525
i2c_hid_get_input(struct i2c_hid * ihid)526 static void i2c_hid_get_input(struct i2c_hid *ihid)
527 {
528 u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
529 u16 ret_size;
530 int ret;
531
532 if (size > ihid->bufsize)
533 size = ihid->bufsize;
534
535 ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
536 if (ret != size) {
537 if (ret < 0)
538 return;
539
540 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
541 __func__, ret, size);
542 return;
543 }
544
545 /* Receiving buffer is properly aligned */
546 ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
547 if (!ret_size) {
548 /* host or device initiated RESET completed */
549 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
550 wake_up(&ihid->wait);
551 return;
552 }
553
554 if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
555 dev_warn_once(&ihid->client->dev,
556 "%s: IRQ triggered but there's no data\n",
557 __func__);
558 return;
559 }
560
561 if (ret_size > size || ret_size < sizeof(__le16)) {
562 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
563 *(__le16 *)ihid->inbuf = cpu_to_le16(size);
564 ret_size = size;
565 } else {
566 dev_err(&ihid->client->dev,
567 "%s: incomplete report (%d/%d)\n",
568 __func__, size, ret_size);
569 return;
570 }
571 }
572
573 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
574
575 if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
576 if (ihid->hid->group != HID_GROUP_RMI)
577 pm_wakeup_event(&ihid->client->dev, 0);
578
579 hid_safe_input_report(ihid->hid, HID_INPUT_REPORT,
580 ihid->inbuf + sizeof(__le16),
581 ihid->bufsize - sizeof(__le16),
582 ret_size - sizeof(__le16), 1);
583 }
584
585 return;
586 }
587
i2c_hid_irq(int irq,void * dev_id)588 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
589 {
590 struct i2c_hid *ihid = dev_id;
591
592 i2c_hid_get_input(ihid);
593
594 return IRQ_HANDLED;
595 }
596
i2c_hid_get_report_length(struct hid_report * report)597 static int i2c_hid_get_report_length(struct hid_report *report)
598 {
599 return ((report->size - 1) >> 3) + 1 +
600 report->device->report_enum[report->type].numbered + 2;
601 }
602
603 /*
604 * Traverse the supplied list of reports and find the longest
605 */
i2c_hid_find_max_report(struct hid_device * hid,unsigned int type,unsigned int * max)606 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
607 unsigned int *max)
608 {
609 struct hid_report *report;
610 unsigned int size;
611
612 /* We should not rely on wMaxInputLength, as some devices may set it to
613 * a wrong length. */
614 list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
615 size = i2c_hid_get_report_length(report);
616 if (*max < size)
617 *max = size;
618 }
619 }
620
i2c_hid_free_buffers(struct i2c_hid * ihid)621 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
622 {
623 kfree(ihid->inbuf);
624 kfree(ihid->rawbuf);
625 kfree(ihid->cmdbuf);
626 ihid->inbuf = NULL;
627 ihid->rawbuf = NULL;
628 ihid->cmdbuf = NULL;
629 ihid->bufsize = 0;
630 }
631
i2c_hid_alloc_buffers(struct i2c_hid * ihid,size_t report_size)632 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
633 {
634 /*
635 * The worst case is computed from the set_report command with a
636 * reportID > 15 and the maximum report length.
637 */
638 int cmd_len = sizeof(__le16) + /* command register */
639 sizeof(u8) + /* encoded report type/ID */
640 sizeof(u8) + /* opcode */
641 sizeof(u8) + /* optional 3rd byte report ID */
642 sizeof(__le16) + /* data register */
643 sizeof(__le16) + /* report data size */
644 sizeof(u8) + /* report ID if numbered report */
645 report_size;
646
647 ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
648 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
649 ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
650
651 if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
652 i2c_hid_free_buffers(ihid);
653 return -ENOMEM;
654 }
655
656 ihid->bufsize = report_size;
657
658 return 0;
659 }
660
i2c_hid_get_raw_report(struct hid_device * hid,u8 report_type,u8 report_id,u8 * buf,size_t count)661 static int i2c_hid_get_raw_report(struct hid_device *hid,
662 u8 report_type, u8 report_id,
663 u8 *buf, size_t count)
664 {
665 struct i2c_client *client = hid->driver_data;
666 struct i2c_hid *ihid = i2c_get_clientdata(client);
667 int ret_count;
668
669 if (report_type == HID_OUTPUT_REPORT)
670 return -EINVAL;
671
672 /*
673 * In case of unnumbered reports the response from the device will
674 * not have the report ID that the upper layers expect, so we need
675 * to stash it the buffer ourselves and adjust the data size.
676 */
677 if (!report_id) {
678 buf[0] = 0;
679 buf++;
680 count--;
681 }
682
683 ret_count = i2c_hid_get_report(ihid,
684 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
685 report_id, buf, count);
686
687 if (ret_count > 0 && !report_id)
688 ret_count++;
689
690 return ret_count;
691 }
692
i2c_hid_output_raw_report(struct hid_device * hid,u8 report_type,const u8 * buf,size_t count,bool do_set)693 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
694 const u8 *buf, size_t count, bool do_set)
695 {
696 struct i2c_client *client = hid->driver_data;
697 struct i2c_hid *ihid = i2c_get_clientdata(client);
698 int report_id = buf[0];
699 int ret;
700
701 if (report_type == HID_INPUT_REPORT)
702 return -EINVAL;
703
704 mutex_lock(&ihid->reset_lock);
705
706 /*
707 * Note that both numbered and unnumbered reports passed here
708 * are supposed to have report ID stored in the 1st byte of the
709 * buffer, so we strip it off unconditionally before passing payload
710 * to i2c_hid_set_or_send_report which takes care of encoding
711 * everything properly.
712 */
713 ret = i2c_hid_set_or_send_report(ihid,
714 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
715 report_id, buf + 1, count - 1, do_set);
716
717 if (ret >= 0)
718 ret++; /* add report_id to the number of transferred bytes */
719
720 mutex_unlock(&ihid->reset_lock);
721
722 return ret;
723 }
724
i2c_hid_output_report(struct hid_device * hid,u8 * buf,size_t count)725 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
726 {
727 return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
728 false);
729 }
730
i2c_hid_raw_request(struct hid_device * hid,unsigned char reportnum,__u8 * buf,size_t len,unsigned char rtype,int reqtype)731 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
732 __u8 *buf, size_t len, unsigned char rtype,
733 int reqtype)
734 {
735 switch (reqtype) {
736 case HID_REQ_GET_REPORT:
737 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
738 case HID_REQ_SET_REPORT:
739 if (buf[0] != reportnum)
740 return -EINVAL;
741 return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
742 default:
743 return -EIO;
744 }
745 }
746
i2c_hid_parse(struct hid_device * hid)747 static int i2c_hid_parse(struct hid_device *hid)
748 {
749 struct i2c_client *client = hid->driver_data;
750 struct i2c_hid *ihid = i2c_get_clientdata(client);
751 struct i2c_hid_desc *hdesc = &ihid->hdesc;
752 char *rdesc = NULL, *use_override = NULL;
753 unsigned int rsize;
754 int ret;
755 int tries = 3;
756
757 i2c_hid_dbg(ihid, "entering %s\n", __func__);
758
759 rsize = le16_to_cpu(hdesc->wReportDescLength);
760 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
761 dbg_hid("weird size of report descriptor (%u)\n", rsize);
762 return -EINVAL;
763 }
764
765 mutex_lock(&ihid->reset_lock);
766 do {
767 ret = i2c_hid_start_hwreset(ihid);
768 if (ret == 0)
769 ret = i2c_hid_finish_hwreset(ihid);
770 else
771 msleep(1000);
772 } while (tries-- > 0 && ret);
773 mutex_unlock(&ihid->reset_lock);
774
775 if (ret)
776 return ret;
777
778 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
779 &rsize);
780
781 if (use_override) {
782 rdesc = use_override;
783 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
784 } else {
785 rdesc = kzalloc(rsize, GFP_KERNEL);
786 if (!rdesc)
787 return -ENOMEM;
788
789 i2c_hid_dbg(ihid, "asking HID report descriptor\n");
790
791 ret = i2c_hid_read_register(ihid,
792 ihid->hdesc.wReportDescRegister,
793 rdesc, rsize);
794 if (ret) {
795 hid_err(hid, "reading report descriptor failed\n");
796 goto out;
797 }
798 }
799
800 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
801
802 ret = hid_parse_report(hid, rdesc, rsize);
803 if (ret)
804 dbg_hid("parsing report descriptor failed\n");
805
806 out:
807 if (!use_override)
808 kfree(rdesc);
809
810 return ret;
811 }
812
i2c_hid_start(struct hid_device * hid)813 static int i2c_hid_start(struct hid_device *hid)
814 {
815 struct i2c_client *client = hid->driver_data;
816 struct i2c_hid *ihid = i2c_get_clientdata(client);
817 int ret;
818 unsigned int bufsize = HID_MIN_BUFFER_SIZE;
819
820 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
821 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
822 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
823
824 if (bufsize > ihid->bufsize) {
825 disable_irq(client->irq);
826 i2c_hid_free_buffers(ihid);
827
828 ret = i2c_hid_alloc_buffers(ihid, bufsize);
829 enable_irq(client->irq);
830
831 if (ret)
832 return ret;
833 }
834
835 return 0;
836 }
837
i2c_hid_stop(struct hid_device * hid)838 static void i2c_hid_stop(struct hid_device *hid)
839 {
840 hid->claimed = 0;
841 }
842
i2c_hid_open(struct hid_device * hid)843 static int i2c_hid_open(struct hid_device *hid)
844 {
845 struct i2c_client *client = hid->driver_data;
846 struct i2c_hid *ihid = i2c_get_clientdata(client);
847
848 set_bit(I2C_HID_STARTED, &ihid->flags);
849 return 0;
850 }
851
i2c_hid_close(struct hid_device * hid)852 static void i2c_hid_close(struct hid_device *hid)
853 {
854 struct i2c_client *client = hid->driver_data;
855 struct i2c_hid *ihid = i2c_get_clientdata(client);
856
857 clear_bit(I2C_HID_STARTED, &ihid->flags);
858 }
859
860 static const struct hid_ll_driver i2c_hid_ll_driver = {
861 .parse = i2c_hid_parse,
862 .start = i2c_hid_start,
863 .stop = i2c_hid_stop,
864 .open = i2c_hid_open,
865 .close = i2c_hid_close,
866 .output_report = i2c_hid_output_report,
867 .raw_request = i2c_hid_raw_request,
868 };
869
i2c_hid_init_irq(struct i2c_client * client)870 static int i2c_hid_init_irq(struct i2c_client *client)
871 {
872 struct i2c_hid *ihid = i2c_get_clientdata(client);
873 unsigned long irqflags = 0;
874 int ret;
875
876 i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq);
877
878 if (!irq_get_trigger_type(client->irq))
879 irqflags = IRQF_TRIGGER_LOW;
880
881 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
882 irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN,
883 client->name, ihid);
884 if (ret < 0) {
885 dev_warn(&client->dev,
886 "Could not register for %s interrupt, irq = %d,"
887 " ret = %d\n",
888 client->name, client->irq, ret);
889
890 return ret;
891 }
892
893 return 0;
894 }
895
i2c_hid_fetch_hid_descriptor(struct i2c_hid * ihid)896 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
897 {
898 struct i2c_client *client = ihid->client;
899 struct i2c_hid_desc *hdesc = &ihid->hdesc;
900 unsigned int dsize;
901 int error;
902
903 /* i2c hid fetch using a fixed descriptor size (30 bytes) */
904 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
905 i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
906 ihid->hdesc =
907 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
908 } else {
909 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
910 error = i2c_hid_read_register(ihid,
911 ihid->wHIDDescRegister,
912 &ihid->hdesc,
913 sizeof(ihid->hdesc));
914 if (error) {
915 dev_err(&ihid->client->dev,
916 "failed to fetch HID descriptor: %d\n",
917 error);
918 return -ENODEV;
919 }
920 }
921
922 /* Validate the length of HID descriptor, the 4 first bytes:
923 * bytes 0-1 -> length
924 * bytes 2-3 -> bcdVersion (has to be 1.00) */
925 /* check bcdVersion == 1.0 */
926 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
927 dev_err(&ihid->client->dev,
928 "unexpected HID descriptor bcdVersion (0x%04hx)\n",
929 le16_to_cpu(hdesc->bcdVersion));
930 return -ENODEV;
931 }
932
933 /* Descriptor length should be 30 bytes as per the specification */
934 dsize = le16_to_cpu(hdesc->wHIDDescLength);
935 if (dsize != sizeof(struct i2c_hid_desc)) {
936 dev_err(&ihid->client->dev,
937 "weird size of HID descriptor (%u)\n", dsize);
938 return -ENODEV;
939 }
940 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
941 return 0;
942 }
943
i2c_hid_core_power_up(struct i2c_hid * ihid)944 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
945 {
946 if (!ihid->ops->power_up)
947 return 0;
948
949 return ihid->ops->power_up(ihid->ops);
950 }
951
i2c_hid_core_power_down(struct i2c_hid * ihid)952 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
953 {
954 if (!ihid->ops->power_down)
955 return;
956
957 ihid->ops->power_down(ihid->ops);
958 }
959
i2c_hid_core_shutdown_tail(struct i2c_hid * ihid)960 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
961 {
962 if (!ihid->ops->shutdown_tail)
963 return;
964
965 ihid->ops->shutdown_tail(ihid->ops);
966 }
967
i2c_hid_core_restore_sequence(struct i2c_hid * ihid)968 static void i2c_hid_core_restore_sequence(struct i2c_hid *ihid)
969 {
970 if (!ihid->ops->restore_sequence)
971 return;
972
973 ihid->ops->restore_sequence(ihid->ops);
974 }
975
i2c_hid_core_suspend(struct i2c_hid * ihid,bool force_poweroff)976 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)
977 {
978 struct i2c_client *client = ihid->client;
979 struct hid_device *hid = ihid->hid;
980 int ret;
981
982 ret = hid_driver_suspend(hid, PMSG_SUSPEND);
983 if (ret < 0)
984 return ret;
985
986 /* Save some power */
987 if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND))
988 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
989
990 disable_irq(client->irq);
991
992 if (force_poweroff || !device_may_wakeup(&client->dev))
993 i2c_hid_core_power_down(ihid);
994
995 return 0;
996 }
997
i2c_hid_core_resume(struct i2c_hid * ihid)998 static int i2c_hid_core_resume(struct i2c_hid *ihid)
999 {
1000 struct i2c_client *client = ihid->client;
1001 struct hid_device *hid = ihid->hid;
1002 int ret;
1003
1004 if (!device_may_wakeup(&client->dev))
1005 i2c_hid_core_power_up(ihid);
1006
1007 enable_irq(client->irq);
1008
1009 /* On Goodix 27c6:0d42 wait extra time before device wakeup.
1010 * It's not clear why but if we send wakeup too early, the device will
1011 * never trigger input interrupts.
1012 */
1013 if (ihid->quirks & I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME)
1014 msleep(1500);
1015
1016 /* Instead of resetting device, simply powers the device on. This
1017 * solves "incomplete reports" on Raydium devices 2386:3118 and
1018 * 2386:4B33 and fixes various SIS touchscreens no longer sending
1019 * data after a suspend/resume.
1020 *
1021 * However some ALPS touchpads generate IRQ storm without reset, so
1022 * let's still reset them here.
1023 */
1024 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) {
1025 mutex_lock(&ihid->reset_lock);
1026 ret = i2c_hid_start_hwreset(ihid);
1027 if (ret == 0)
1028 ret = i2c_hid_finish_hwreset(ihid);
1029 mutex_unlock(&ihid->reset_lock);
1030 } else {
1031 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1032 }
1033
1034 if (ret)
1035 return ret;
1036
1037 return hid_driver_reset_resume(hid);
1038 }
1039
1040 /*
1041 * Check that the device exists and parse the HID descriptor.
1042 */
__i2c_hid_core_probe(struct i2c_hid * ihid)1043 static int __i2c_hid_core_probe(struct i2c_hid *ihid)
1044 {
1045 struct i2c_client *client = ihid->client;
1046 struct hid_device *hid = ihid->hid;
1047 int ret;
1048
1049 ret = i2c_hid_probe_address(ihid);
1050 if (ret < 0) {
1051 i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
1052 return -ENXIO;
1053 }
1054
1055 ret = i2c_hid_fetch_hid_descriptor(ihid);
1056 if (ret < 0) {
1057 dev_err(&client->dev,
1058 "Failed to fetch the HID Descriptor\n");
1059 return ret;
1060 }
1061
1062 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1063 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1064 hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1065
1066 hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
1067 hid->product);
1068
1069 snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1070 client->name, (u16)hid->vendor, (u16)hid->product);
1071 strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1072
1073 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1074
1075 return 0;
1076 }
1077
i2c_hid_core_register_hid(struct i2c_hid * ihid)1078 static int i2c_hid_core_register_hid(struct i2c_hid *ihid)
1079 {
1080 struct i2c_client *client = ihid->client;
1081 struct hid_device *hid = ihid->hid;
1082 int ret;
1083
1084 enable_irq(client->irq);
1085
1086 ret = hid_add_device(hid);
1087 if (ret) {
1088 if (ret != -ENODEV)
1089 hid_err(client, "can't add hid device: %d\n", ret);
1090 disable_irq(client->irq);
1091 return ret;
1092 }
1093
1094 /* At least some QTEC devices need this after initialization */
1095 if (ihid->quirks & I2C_HID_QUIRK_RE_POWER_ON)
1096 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1097
1098 return ret;
1099 }
1100
i2c_hid_core_probe_panel_follower(struct i2c_hid * ihid)1101 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid)
1102 {
1103 int ret;
1104
1105 ret = i2c_hid_core_power_up(ihid);
1106 if (ret)
1107 return ret;
1108
1109 ret = __i2c_hid_core_probe(ihid);
1110 if (ret)
1111 goto err_power_down;
1112
1113 ret = i2c_hid_core_register_hid(ihid);
1114 if (ret)
1115 goto err_power_down;
1116
1117 return 0;
1118
1119 err_power_down:
1120 i2c_hid_core_power_down(ihid);
1121
1122 return ret;
1123 }
1124
ihid_core_panel_follower_work(struct work_struct * work)1125 static void ihid_core_panel_follower_work(struct work_struct *work)
1126 {
1127 struct i2c_hid *ihid = container_of(work, struct i2c_hid,
1128 panel_follower_work);
1129 struct hid_device *hid = ihid->hid;
1130 int ret;
1131
1132 /*
1133 * hid->version is set on the first power up. If it's still zero then
1134 * this is the first power on so we should perform initial power up
1135 * steps.
1136 */
1137 if (!hid->version)
1138 ret = i2c_hid_core_probe_panel_follower(ihid);
1139 else
1140 ret = i2c_hid_core_resume(ihid);
1141
1142 if (ret)
1143 dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret);
1144 else
1145 WRITE_ONCE(ihid->panel_follower_work_finished, true);
1146
1147 /*
1148 * The work APIs provide a number of memory ordering guarantees
1149 * including one that says that memory writes before schedule_work()
1150 * are always visible to the work function, but they don't appear to
1151 * guarantee that a write that happened in the work is visible after
1152 * cancel_work_sync(). We'll add a write memory barrier here to match
1153 * with i2c_hid_core_panel_unpreparing() to ensure that our write to
1154 * panel_follower_work_finished is visible there.
1155 */
1156 smp_wmb();
1157 }
1158
i2c_hid_core_panel_follower_resume(struct drm_panel_follower * follower)1159 static int i2c_hid_core_panel_follower_resume(struct drm_panel_follower *follower)
1160 {
1161 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1162
1163 /*
1164 * Powering on a touchscreen can be a slow process. Queue the work to
1165 * the system workqueue so we don't block the panel's power up.
1166 */
1167 WRITE_ONCE(ihid->panel_follower_work_finished, false);
1168 schedule_work(&ihid->panel_follower_work);
1169
1170 return 0;
1171 }
1172
i2c_hid_core_panel_follower_suspend(struct drm_panel_follower * follower)1173 static int i2c_hid_core_panel_follower_suspend(struct drm_panel_follower *follower)
1174 {
1175 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1176
1177 cancel_work_sync(&ihid->panel_follower_work);
1178
1179 /* Match with ihid_core_panel_follower_work() */
1180 smp_rmb();
1181 if (!READ_ONCE(ihid->panel_follower_work_finished))
1182 return 0;
1183
1184 return i2c_hid_core_suspend(ihid, true);
1185 }
1186
1187 static const struct drm_panel_follower_funcs
1188 i2c_hid_core_panel_follower_prepare_funcs = {
1189 .panel_prepared = i2c_hid_core_panel_follower_resume,
1190 .panel_unpreparing = i2c_hid_core_panel_follower_suspend,
1191 };
1192
1193 static const struct drm_panel_follower_funcs
1194 i2c_hid_core_panel_follower_enable_funcs = {
1195 .panel_enabled = i2c_hid_core_panel_follower_resume,
1196 .panel_disabling = i2c_hid_core_panel_follower_suspend,
1197 };
1198
i2c_hid_core_register_panel_follower(struct i2c_hid * ihid)1199 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid)
1200 {
1201 struct device *dev = &ihid->client->dev;
1202 int ret;
1203
1204 if (ihid->hid->initial_quirks & HID_QUIRK_POWER_ON_AFTER_BACKLIGHT)
1205 ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_enable_funcs;
1206 else
1207 ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_prepare_funcs;
1208
1209 /*
1210 * If we're not in control of our own power up/power down then we can't
1211 * do the logic to manage wakeups. Give a warning if a user thought
1212 * that was possible then force the capability off.
1213 */
1214 if (device_can_wakeup(dev)) {
1215 dev_warn(dev, "Can't wakeup if following panel\n");
1216 device_set_wakeup_capable(dev, false);
1217 }
1218
1219 ret = drm_panel_add_follower(dev, &ihid->panel_follower);
1220 if (ret)
1221 return ret;
1222
1223 return 0;
1224 }
1225
i2c_hid_core_probe(struct i2c_client * client,struct i2chid_ops * ops,u16 hid_descriptor_address,u32 quirks)1226 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
1227 u16 hid_descriptor_address, u32 quirks)
1228 {
1229 int ret;
1230 struct i2c_hid *ihid;
1231 struct hid_device *hid;
1232
1233 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1234
1235 if (!client->irq) {
1236 dev_err(&client->dev,
1237 "HID over i2c has not been provided an Int IRQ\n");
1238 return -EINVAL;
1239 }
1240
1241 if (client->irq < 0) {
1242 if (client->irq != -EPROBE_DEFER)
1243 dev_err(&client->dev,
1244 "HID over i2c doesn't have a valid IRQ\n");
1245 return client->irq;
1246 }
1247
1248 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
1249 if (!ihid)
1250 return -ENOMEM;
1251
1252 i2c_set_clientdata(client, ihid);
1253
1254 ihid->ops = ops;
1255 ihid->client = client;
1256 ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
1257 ihid->is_panel_follower = drm_is_panel_follower(&client->dev);
1258
1259 init_waitqueue_head(&ihid->wait);
1260 mutex_init(&ihid->cmd_lock);
1261 mutex_init(&ihid->reset_lock);
1262 INIT_WORK(&ihid->panel_follower_work, ihid_core_panel_follower_work);
1263
1264 /* we need to allocate the command buffer without knowing the maximum
1265 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1266 * real computation later. */
1267 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1268 if (ret < 0)
1269 return ret;
1270 device_enable_async_suspend(&client->dev);
1271
1272 hid = hid_allocate_device();
1273 if (IS_ERR(hid)) {
1274 ret = PTR_ERR(hid);
1275 goto err_free_buffers;
1276 }
1277
1278 ihid->hid = hid;
1279
1280 hid->driver_data = client;
1281 hid->ll_driver = &i2c_hid_ll_driver;
1282 hid->dev.parent = &client->dev;
1283 hid->bus = BUS_I2C;
1284 hid->initial_quirks = quirks;
1285
1286 /* Power on and probe unless device is a panel follower. */
1287 if (!ihid->is_panel_follower) {
1288 ret = i2c_hid_core_power_up(ihid);
1289 if (ret < 0)
1290 goto err_destroy_device;
1291
1292 ret = __i2c_hid_core_probe(ihid);
1293 if (ret < 0)
1294 goto err_power_down;
1295 }
1296
1297 ret = i2c_hid_init_irq(client);
1298 if (ret < 0)
1299 goto err_power_down;
1300
1301 /*
1302 * If we're a panel follower, we'll register when the panel turns on;
1303 * otherwise we do it right away.
1304 */
1305 if (ihid->is_panel_follower)
1306 ret = i2c_hid_core_register_panel_follower(ihid);
1307 else
1308 ret = i2c_hid_core_register_hid(ihid);
1309 if (ret)
1310 goto err_free_irq;
1311
1312 return 0;
1313
1314 err_free_irq:
1315 free_irq(client->irq, ihid);
1316 err_power_down:
1317 if (!ihid->is_panel_follower)
1318 i2c_hid_core_power_down(ihid);
1319 err_destroy_device:
1320 hid_destroy_device(hid);
1321 err_free_buffers:
1322 i2c_hid_free_buffers(ihid);
1323
1324 return ret;
1325 }
1326 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1327
i2c_hid_core_remove(struct i2c_client * client)1328 void i2c_hid_core_remove(struct i2c_client *client)
1329 {
1330 struct i2c_hid *ihid = i2c_get_clientdata(client);
1331 struct hid_device *hid;
1332
1333 /*
1334 * If we're a follower, the act of unfollowing will cause us to be
1335 * powered down. Otherwise we need to manually do it.
1336 */
1337 if (ihid->is_panel_follower)
1338 drm_panel_remove_follower(&ihid->panel_follower);
1339 else
1340 i2c_hid_core_suspend(ihid, true);
1341
1342 hid = ihid->hid;
1343 hid_destroy_device(hid);
1344
1345 free_irq(client->irq, ihid);
1346
1347 if (ihid->bufsize)
1348 i2c_hid_free_buffers(ihid);
1349 }
1350 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1351
i2c_hid_core_shutdown(struct i2c_client * client)1352 void i2c_hid_core_shutdown(struct i2c_client *client)
1353 {
1354 struct i2c_hid *ihid = i2c_get_clientdata(client);
1355
1356 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1357 free_irq(client->irq, ihid);
1358
1359 i2c_hid_core_shutdown_tail(ihid);
1360 }
1361 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1362
i2c_hid_core_pm_suspend(struct device * dev)1363 static int i2c_hid_core_pm_suspend(struct device *dev)
1364 {
1365 struct i2c_client *client = to_i2c_client(dev);
1366 struct i2c_hid *ihid = i2c_get_clientdata(client);
1367
1368 if (ihid->is_panel_follower)
1369 return 0;
1370
1371 return i2c_hid_core_suspend(ihid, false);
1372 }
1373
i2c_hid_core_pm_resume(struct device * dev)1374 static int i2c_hid_core_pm_resume(struct device *dev)
1375 {
1376 struct i2c_client *client = to_i2c_client(dev);
1377 struct i2c_hid *ihid = i2c_get_clientdata(client);
1378
1379 if (ihid->is_panel_follower)
1380 return 0;
1381
1382 return i2c_hid_core_resume(ihid);
1383 }
1384
i2c_hid_core_pm_restore(struct device * dev)1385 static int i2c_hid_core_pm_restore(struct device *dev)
1386 {
1387 struct i2c_client *client = to_i2c_client(dev);
1388 struct i2c_hid *ihid = i2c_get_clientdata(client);
1389
1390 if (ihid->is_panel_follower)
1391 return 0;
1392
1393 i2c_hid_core_restore_sequence(ihid);
1394
1395 return i2c_hid_core_resume(ihid);
1396 }
1397
1398 const struct dev_pm_ops i2c_hid_core_pm = {
1399 .suspend = pm_sleep_ptr(i2c_hid_core_pm_suspend),
1400 .resume = pm_sleep_ptr(i2c_hid_core_pm_resume),
1401 .freeze = pm_sleep_ptr(i2c_hid_core_pm_suspend),
1402 .thaw = pm_sleep_ptr(i2c_hid_core_pm_resume),
1403 .poweroff = pm_sleep_ptr(i2c_hid_core_pm_suspend),
1404 .restore = pm_sleep_ptr(i2c_hid_core_pm_restore),
1405 };
1406 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1407
1408 MODULE_DESCRIPTION("HID over I2C core driver");
1409 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1410 MODULE_LICENSE("GPL");
1411