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 <asm/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_SET_PWR_WAKEUP_DEV	BIT(0)
48 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET	BIT(1)
49 #define I2C_HID_QUIRK_BOGUS_IRQ			BIT(4)
50 #define I2C_HID_QUIRK_RESET_ON_RESUME		BIT(5)
51 #define I2C_HID_QUIRK_BAD_INPUT_SIZE		BIT(6)
52 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET	BIT(7)
53 
54 /* Command opcodes */
55 #define I2C_HID_OPCODE_RESET			0x01
56 #define I2C_HID_OPCODE_GET_REPORT		0x02
57 #define I2C_HID_OPCODE_SET_REPORT		0x03
58 #define I2C_HID_OPCODE_GET_IDLE			0x04
59 #define I2C_HID_OPCODE_SET_IDLE			0x05
60 #define I2C_HID_OPCODE_GET_PROTOCOL		0x06
61 #define I2C_HID_OPCODE_SET_PROTOCOL		0x07
62 #define I2C_HID_OPCODE_SET_POWER		0x08
63 
64 /* flags */
65 #define I2C_HID_STARTED		0
66 #define I2C_HID_RESET_PENDING	1
67 #define I2C_HID_READ_PENDING	2
68 
69 #define I2C_HID_PWR_ON		0x00
70 #define I2C_HID_PWR_SLEEP	0x01
71 
72 #define i2c_hid_dbg(ihid, ...) dev_dbg(&(ihid)->client->dev, __VA_ARGS__)
73 
74 struct i2c_hid_desc {
75 	__le16 wHIDDescLength;
76 	__le16 bcdVersion;
77 	__le16 wReportDescLength;
78 	__le16 wReportDescRegister;
79 	__le16 wInputRegister;
80 	__le16 wMaxInputLength;
81 	__le16 wOutputRegister;
82 	__le16 wMaxOutputLength;
83 	__le16 wCommandRegister;
84 	__le16 wDataRegister;
85 	__le16 wVendorID;
86 	__le16 wProductID;
87 	__le16 wVersionID;
88 	__le32 reserved;
89 } __packed;
90 
91 /* The main device structure */
92 struct i2c_hid {
93 	struct i2c_client	*client;	/* i2c client */
94 	struct hid_device	*hid;	/* pointer to corresponding HID dev */
95 	struct i2c_hid_desc hdesc;		/* the HID Descriptor */
96 	__le16			wHIDDescRegister; /* location of the i2c
97 						   * register of the HID
98 						   * descriptor. */
99 	unsigned int		bufsize;	/* i2c buffer size */
100 	u8			*inbuf;		/* Input buffer */
101 	u8			*rawbuf;	/* Raw Input buffer */
102 	u8			*cmdbuf;	/* Command buffer */
103 
104 	unsigned long		flags;		/* device flags */
105 	unsigned long		quirks;		/* Various quirks */
106 
107 	wait_queue_head_t	wait;		/* For waiting the interrupt */
108 
109 	struct mutex		reset_lock;
110 
111 	struct i2chid_ops	*ops;
112 	struct drm_panel_follower panel_follower;
113 	struct work_struct	panel_follower_prepare_work;
114 	bool			is_panel_follower;
115 	bool			prepare_work_finished;
116 };
117 
118 static const struct i2c_hid_quirks {
119 	__u16 idVendor;
120 	__u16 idProduct;
121 	__u32 quirks;
122 } i2c_hid_quirks[] = {
123 	{ USB_VENDOR_ID_WEIDA, HID_ANY_ID,
124 		I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
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 	/*
138 	 * Sending the wakeup after reset actually break ELAN touchscreen controller
139 	 */
140 	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
141 		 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
142 		 I2C_HID_QUIRK_BOGUS_IRQ },
143 	{ 0, 0 }
144 };
145 
146 /*
147  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
148  * @idVendor: the 16-bit vendor ID
149  * @idProduct: the 16-bit product ID
150  *
151  * Returns: a u32 quirks value.
152  */
153 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
154 {
155 	u32 quirks = 0;
156 	int n;
157 
158 	for (n = 0; i2c_hid_quirks[n].idVendor; n++)
159 		if (i2c_hid_quirks[n].idVendor == idVendor &&
160 		    (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
161 		     i2c_hid_quirks[n].idProduct == idProduct))
162 			quirks = i2c_hid_quirks[n].quirks;
163 
164 	return quirks;
165 }
166 
167 static int i2c_hid_xfer(struct i2c_hid *ihid,
168 			u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
169 {
170 	struct i2c_client *client = ihid->client;
171 	struct i2c_msg msgs[2] = { 0 };
172 	int n = 0;
173 	int ret;
174 
175 	if (send_len) {
176 		i2c_hid_dbg(ihid, "%s: cmd=%*ph\n",
177 			    __func__, send_len, send_buf);
178 
179 		msgs[n].addr = client->addr;
180 		msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE;
181 		msgs[n].len = send_len;
182 		msgs[n].buf = send_buf;
183 		n++;
184 	}
185 
186 	if (recv_len) {
187 		msgs[n].addr = client->addr;
188 		msgs[n].flags = (client->flags & I2C_M_TEN) |
189 				I2C_M_RD | I2C_M_DMA_SAFE;
190 		msgs[n].len = recv_len;
191 		msgs[n].buf = recv_buf;
192 		n++;
193 
194 		set_bit(I2C_HID_READ_PENDING, &ihid->flags);
195 	}
196 
197 	ret = i2c_transfer(client->adapter, msgs, n);
198 
199 	if (recv_len)
200 		clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
201 
202 	if (ret != n)
203 		return ret < 0 ? ret : -EIO;
204 
205 	return 0;
206 }
207 
208 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
209 				 void *buf, size_t len)
210 {
211 	*(__le16 *)ihid->cmdbuf = reg;
212 
213 	return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
214 }
215 
216 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
217 				     int report_type, int report_id)
218 {
219 	size_t length = 0;
220 
221 	if (report_id < 0x0F) {
222 		buf[length++] = report_type << 4 | report_id;
223 		buf[length++] = opcode;
224 	} else {
225 		buf[length++] = report_type << 4 | 0x0F;
226 		buf[length++] = opcode;
227 		buf[length++] = report_id;
228 	}
229 
230 	return length;
231 }
232 
233 static int i2c_hid_get_report(struct i2c_hid *ihid,
234 			      u8 report_type, u8 report_id,
235 			      u8 *recv_buf, size_t recv_len)
236 {
237 	size_t length = 0;
238 	size_t ret_count;
239 	int error;
240 
241 	i2c_hid_dbg(ihid, "%s\n", __func__);
242 
243 	/* Command register goes first */
244 	*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
245 	length += sizeof(__le16);
246 	/* Next is GET_REPORT command */
247 	length += i2c_hid_encode_command(ihid->cmdbuf + length,
248 					 I2C_HID_OPCODE_GET_REPORT,
249 					 report_type, report_id);
250 	/*
251 	 * Device will send report data through data register. Because
252 	 * command can be either 2 or 3 bytes destination for the data
253 	 * register may be not aligned.
254 	 */
255 	put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
256 			   ihid->cmdbuf + length);
257 	length += sizeof(__le16);
258 
259 	/*
260 	 * In addition to report data device will supply data length
261 	 * in the first 2 bytes of the response, so adjust .
262 	 */
263 	error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
264 			     ihid->rawbuf, recv_len + sizeof(__le16));
265 	if (error) {
266 		dev_err(&ihid->client->dev,
267 			"failed to set a report to device: %d\n", error);
268 		return error;
269 	}
270 
271 	/* The buffer is sufficiently aligned */
272 	ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
273 
274 	/* Check for empty report response */
275 	if (ret_count <= sizeof(__le16))
276 		return 0;
277 
278 	recv_len = min(recv_len, ret_count - sizeof(__le16));
279 	memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
280 
281 	if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
282 		dev_err(&ihid->client->dev,
283 			"device returned incorrect report (%d vs %d expected)\n",
284 			recv_buf[0], report_id);
285 		return -EINVAL;
286 	}
287 
288 	return recv_len;
289 }
290 
291 static size_t i2c_hid_format_report(u8 *buf, int report_id,
292 				    const u8 *data, size_t size)
293 {
294 	size_t length = sizeof(__le16); /* reserve space to store size */
295 
296 	if (report_id)
297 		buf[length++] = report_id;
298 
299 	memcpy(buf + length, data, size);
300 	length += size;
301 
302 	/* Store overall size in the beginning of the buffer */
303 	put_unaligned_le16(length, buf);
304 
305 	return length;
306 }
307 
308 /**
309  * i2c_hid_set_or_send_report: forward an incoming report to the device
310  * @ihid: the i2c hid device
311  * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
312  * @report_id: the report ID
313  * @buf: the actual data to transfer, without the report ID
314  * @data_len: size of buf
315  * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
316  */
317 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
318 				      u8 report_type, u8 report_id,
319 				      const u8 *buf, size_t data_len,
320 				      bool do_set)
321 {
322 	size_t length = 0;
323 	int error;
324 
325 	i2c_hid_dbg(ihid, "%s\n", __func__);
326 
327 	if (data_len > ihid->bufsize)
328 		return -EINVAL;
329 
330 	if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
331 		return -ENOSYS;
332 
333 	if (do_set) {
334 		/* Command register goes first */
335 		*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
336 		length += sizeof(__le16);
337 		/* Next is SET_REPORT command */
338 		length += i2c_hid_encode_command(ihid->cmdbuf + length,
339 						 I2C_HID_OPCODE_SET_REPORT,
340 						 report_type, report_id);
341 		/*
342 		 * Report data will go into the data register. Because
343 		 * command can be either 2 or 3 bytes destination for
344 		 * the data register may be not aligned.
345 		*/
346 		put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
347 				   ihid->cmdbuf + length);
348 		length += sizeof(__le16);
349 	} else {
350 		/*
351 		 * With simple "send report" all data goes into the output
352 		 * register.
353 		 */
354 		*(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
355 		length += sizeof(__le16);
356 	}
357 
358 	length += i2c_hid_format_report(ihid->cmdbuf + length,
359 					report_id, buf, data_len);
360 
361 	error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
362 	if (error) {
363 		dev_err(&ihid->client->dev,
364 			"failed to set a report to device: %d\n", error);
365 		return error;
366 	}
367 
368 	return data_len;
369 }
370 
371 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
372 {
373 	size_t length;
374 
375 	/* SET_POWER uses command register */
376 	*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
377 	length = sizeof(__le16);
378 
379 	/* Now the command itself */
380 	length += i2c_hid_encode_command(ihid->cmdbuf + length,
381 					 I2C_HID_OPCODE_SET_POWER,
382 					 0, power_state);
383 
384 	return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
385 }
386 
387 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
388 {
389 	int ret;
390 
391 	i2c_hid_dbg(ihid, "%s\n", __func__);
392 
393 	/*
394 	 * Some devices require to send a command to wakeup before power on.
395 	 * The call will get a return value (EREMOTEIO) but device will be
396 	 * triggered and activated. After that, it goes like a normal device.
397 	 */
398 	if (power_state == I2C_HID_PWR_ON &&
399 	    ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
400 		ret = i2c_hid_set_power_command(ihid, I2C_HID_PWR_ON);
401 
402 		/* Device was already activated */
403 		if (!ret)
404 			goto set_pwr_exit;
405 	}
406 
407 	ret = i2c_hid_set_power_command(ihid, power_state);
408 	if (ret)
409 		dev_err(&ihid->client->dev,
410 			"failed to change power setting.\n");
411 
412 set_pwr_exit:
413 
414 	/*
415 	 * The HID over I2C specification states that if a DEVICE needs time
416 	 * after the PWR_ON request, it should utilise CLOCK stretching.
417 	 * However, it has been observered that the Windows driver provides a
418 	 * 1ms sleep between the PWR_ON and RESET requests.
419 	 * According to Goodix Windows even waits 60 ms after (other?)
420 	 * PWR_ON requests. Testing has confirmed that several devices
421 	 * will not work properly without a delay after a PWR_ON request.
422 	 */
423 	if (!ret && power_state == I2C_HID_PWR_ON)
424 		msleep(60);
425 
426 	return ret;
427 }
428 
429 static int i2c_hid_execute_reset(struct i2c_hid *ihid)
430 {
431 	size_t length = 0;
432 	int ret;
433 
434 	i2c_hid_dbg(ihid, "resetting...\n");
435 
436 	/* Prepare reset command. Command register goes first. */
437 	*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
438 	length += sizeof(__le16);
439 	/* Next is RESET command itself */
440 	length += i2c_hid_encode_command(ihid->cmdbuf + length,
441 					 I2C_HID_OPCODE_RESET, 0, 0);
442 
443 	set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
444 
445 	ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
446 	if (ret) {
447 		dev_err(&ihid->client->dev, "failed to reset device.\n");
448 		goto out;
449 	}
450 
451 	if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
452 		msleep(100);
453 		goto out;
454 	}
455 
456 	i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
457 	if (!wait_event_timeout(ihid->wait,
458 				!test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
459 				msecs_to_jiffies(5000))) {
460 		ret = -ENODATA;
461 		goto out;
462 	}
463 	i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
464 
465 out:
466 	clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
467 	return ret;
468 }
469 
470 static int i2c_hid_hwreset(struct i2c_hid *ihid)
471 {
472 	int ret;
473 
474 	i2c_hid_dbg(ihid, "%s\n", __func__);
475 
476 	/*
477 	 * This prevents sending feature reports while the device is
478 	 * being reset. Otherwise we may lose the reset complete
479 	 * interrupt.
480 	 */
481 	mutex_lock(&ihid->reset_lock);
482 
483 	ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
484 	if (ret)
485 		goto out_unlock;
486 
487 	ret = i2c_hid_execute_reset(ihid);
488 	if (ret) {
489 		dev_err(&ihid->client->dev,
490 			"failed to reset device: %d\n", ret);
491 		i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
492 		goto out_unlock;
493 	}
494 
495 	/* At least some SIS devices need this after reset */
496 	if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
497 		ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
498 
499 out_unlock:
500 	mutex_unlock(&ihid->reset_lock);
501 	return ret;
502 }
503 
504 static void i2c_hid_get_input(struct i2c_hid *ihid)
505 {
506 	u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
507 	u16 ret_size;
508 	int ret;
509 
510 	if (size > ihid->bufsize)
511 		size = ihid->bufsize;
512 
513 	ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
514 	if (ret != size) {
515 		if (ret < 0)
516 			return;
517 
518 		dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
519 			__func__, ret, size);
520 		return;
521 	}
522 
523 	/* Receiving buffer is properly aligned */
524 	ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
525 	if (!ret_size) {
526 		/* host or device initiated RESET completed */
527 		if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
528 			wake_up(&ihid->wait);
529 		return;
530 	}
531 
532 	if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
533 		dev_warn_once(&ihid->client->dev,
534 			      "%s: IRQ triggered but there's no data\n",
535 			      __func__);
536 		return;
537 	}
538 
539 	if (ret_size > size || ret_size < sizeof(__le16)) {
540 		if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
541 			*(__le16 *)ihid->inbuf = cpu_to_le16(size);
542 			ret_size = size;
543 		} else {
544 			dev_err(&ihid->client->dev,
545 				"%s: incomplete report (%d/%d)\n",
546 				__func__, size, ret_size);
547 			return;
548 		}
549 	}
550 
551 	i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
552 
553 	if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
554 		if (ihid->hid->group != HID_GROUP_RMI)
555 			pm_wakeup_event(&ihid->client->dev, 0);
556 
557 		hid_input_report(ihid->hid, HID_INPUT_REPORT,
558 				ihid->inbuf + sizeof(__le16),
559 				ret_size - sizeof(__le16), 1);
560 	}
561 
562 	return;
563 }
564 
565 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
566 {
567 	struct i2c_hid *ihid = dev_id;
568 
569 	if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
570 		return IRQ_HANDLED;
571 
572 	i2c_hid_get_input(ihid);
573 
574 	return IRQ_HANDLED;
575 }
576 
577 static int i2c_hid_get_report_length(struct hid_report *report)
578 {
579 	return ((report->size - 1) >> 3) + 1 +
580 		report->device->report_enum[report->type].numbered + 2;
581 }
582 
583 /*
584  * Traverse the supplied list of reports and find the longest
585  */
586 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
587 		unsigned int *max)
588 {
589 	struct hid_report *report;
590 	unsigned int size;
591 
592 	/* We should not rely on wMaxInputLength, as some devices may set it to
593 	 * a wrong length. */
594 	list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
595 		size = i2c_hid_get_report_length(report);
596 		if (*max < size)
597 			*max = size;
598 	}
599 }
600 
601 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
602 {
603 	kfree(ihid->inbuf);
604 	kfree(ihid->rawbuf);
605 	kfree(ihid->cmdbuf);
606 	ihid->inbuf = NULL;
607 	ihid->rawbuf = NULL;
608 	ihid->cmdbuf = NULL;
609 	ihid->bufsize = 0;
610 }
611 
612 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
613 {
614 	/*
615 	 * The worst case is computed from the set_report command with a
616 	 * reportID > 15 and the maximum report length.
617 	 */
618 	int cmd_len = sizeof(__le16) +	/* command register */
619 		      sizeof(u8) +	/* encoded report type/ID */
620 		      sizeof(u8) +	/* opcode */
621 		      sizeof(u8) +	/* optional 3rd byte report ID */
622 		      sizeof(__le16) +	/* data register */
623 		      sizeof(__le16) +	/* report data size */
624 		      sizeof(u8) +	/* report ID if numbered report */
625 		      report_size;
626 
627 	ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
628 	ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
629 	ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
630 
631 	if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
632 		i2c_hid_free_buffers(ihid);
633 		return -ENOMEM;
634 	}
635 
636 	ihid->bufsize = report_size;
637 
638 	return 0;
639 }
640 
641 static int i2c_hid_get_raw_report(struct hid_device *hid,
642 				  u8 report_type, u8 report_id,
643 				  u8 *buf, size_t count)
644 {
645 	struct i2c_client *client = hid->driver_data;
646 	struct i2c_hid *ihid = i2c_get_clientdata(client);
647 	int ret_count;
648 
649 	if (report_type == HID_OUTPUT_REPORT)
650 		return -EINVAL;
651 
652 	/*
653 	 * In case of unnumbered reports the response from the device will
654 	 * not have the report ID that the upper layers expect, so we need
655 	 * to stash it the buffer ourselves and adjust the data size.
656 	 */
657 	if (!report_id) {
658 		buf[0] = 0;
659 		buf++;
660 		count--;
661 	}
662 
663 	ret_count = i2c_hid_get_report(ihid,
664 			report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
665 			report_id, buf, count);
666 
667 	if (ret_count > 0 && !report_id)
668 		ret_count++;
669 
670 	return ret_count;
671 }
672 
673 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
674 				     const u8 *buf, size_t count, bool do_set)
675 {
676 	struct i2c_client *client = hid->driver_data;
677 	struct i2c_hid *ihid = i2c_get_clientdata(client);
678 	int report_id = buf[0];
679 	int ret;
680 
681 	if (report_type == HID_INPUT_REPORT)
682 		return -EINVAL;
683 
684 	mutex_lock(&ihid->reset_lock);
685 
686 	/*
687 	 * Note that both numbered and unnumbered reports passed here
688 	 * are supposed to have report ID stored in the 1st byte of the
689 	 * buffer, so we strip it off unconditionally before passing payload
690 	 * to i2c_hid_set_or_send_report which takes care of encoding
691 	 * everything properly.
692 	 */
693 	ret = i2c_hid_set_or_send_report(ihid,
694 				report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
695 				report_id, buf + 1, count - 1, do_set);
696 
697 	if (ret >= 0)
698 		ret++; /* add report_id to the number of transferred bytes */
699 
700 	mutex_unlock(&ihid->reset_lock);
701 
702 	return ret;
703 }
704 
705 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
706 {
707 	return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
708 					 false);
709 }
710 
711 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
712 			       __u8 *buf, size_t len, unsigned char rtype,
713 			       int reqtype)
714 {
715 	switch (reqtype) {
716 	case HID_REQ_GET_REPORT:
717 		return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
718 	case HID_REQ_SET_REPORT:
719 		if (buf[0] != reportnum)
720 			return -EINVAL;
721 		return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
722 	default:
723 		return -EIO;
724 	}
725 }
726 
727 static int i2c_hid_parse(struct hid_device *hid)
728 {
729 	struct i2c_client *client = hid->driver_data;
730 	struct i2c_hid *ihid = i2c_get_clientdata(client);
731 	struct i2c_hid_desc *hdesc = &ihid->hdesc;
732 	unsigned int rsize;
733 	char *rdesc;
734 	int ret;
735 	int tries = 3;
736 	char *use_override;
737 
738 	i2c_hid_dbg(ihid, "entering %s\n", __func__);
739 
740 	rsize = le16_to_cpu(hdesc->wReportDescLength);
741 	if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
742 		dbg_hid("weird size of report descriptor (%u)\n", rsize);
743 		return -EINVAL;
744 	}
745 
746 	do {
747 		ret = i2c_hid_hwreset(ihid);
748 		if (ret)
749 			msleep(1000);
750 	} while (tries-- > 0 && ret);
751 
752 	if (ret)
753 		return ret;
754 
755 	use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
756 								&rsize);
757 
758 	if (use_override) {
759 		rdesc = use_override;
760 		i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
761 	} else {
762 		rdesc = kzalloc(rsize, GFP_KERNEL);
763 
764 		if (!rdesc) {
765 			dbg_hid("couldn't allocate rdesc memory\n");
766 			return -ENOMEM;
767 		}
768 
769 		i2c_hid_dbg(ihid, "asking HID report descriptor\n");
770 
771 		ret = i2c_hid_read_register(ihid,
772 					    ihid->hdesc.wReportDescRegister,
773 					    rdesc, rsize);
774 		if (ret) {
775 			hid_err(hid, "reading report descriptor failed\n");
776 			kfree(rdesc);
777 			return -EIO;
778 		}
779 	}
780 
781 	i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
782 
783 	ret = hid_parse_report(hid, rdesc, rsize);
784 	if (!use_override)
785 		kfree(rdesc);
786 
787 	if (ret) {
788 		dbg_hid("parsing report descriptor failed\n");
789 		return ret;
790 	}
791 
792 	return 0;
793 }
794 
795 static int i2c_hid_start(struct hid_device *hid)
796 {
797 	struct i2c_client *client = hid->driver_data;
798 	struct i2c_hid *ihid = i2c_get_clientdata(client);
799 	int ret;
800 	unsigned int bufsize = HID_MIN_BUFFER_SIZE;
801 
802 	i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
803 	i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
804 	i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
805 
806 	if (bufsize > ihid->bufsize) {
807 		disable_irq(client->irq);
808 		i2c_hid_free_buffers(ihid);
809 
810 		ret = i2c_hid_alloc_buffers(ihid, bufsize);
811 		enable_irq(client->irq);
812 
813 		if (ret)
814 			return ret;
815 	}
816 
817 	return 0;
818 }
819 
820 static void i2c_hid_stop(struct hid_device *hid)
821 {
822 	hid->claimed = 0;
823 }
824 
825 static int i2c_hid_open(struct hid_device *hid)
826 {
827 	struct i2c_client *client = hid->driver_data;
828 	struct i2c_hid *ihid = i2c_get_clientdata(client);
829 
830 	set_bit(I2C_HID_STARTED, &ihid->flags);
831 	return 0;
832 }
833 
834 static void i2c_hid_close(struct hid_device *hid)
835 {
836 	struct i2c_client *client = hid->driver_data;
837 	struct i2c_hid *ihid = i2c_get_clientdata(client);
838 
839 	clear_bit(I2C_HID_STARTED, &ihid->flags);
840 }
841 
842 static const struct hid_ll_driver i2c_hid_ll_driver = {
843 	.parse = i2c_hid_parse,
844 	.start = i2c_hid_start,
845 	.stop = i2c_hid_stop,
846 	.open = i2c_hid_open,
847 	.close = i2c_hid_close,
848 	.output_report = i2c_hid_output_report,
849 	.raw_request = i2c_hid_raw_request,
850 };
851 
852 static int i2c_hid_init_irq(struct i2c_client *client)
853 {
854 	struct i2c_hid *ihid = i2c_get_clientdata(client);
855 	unsigned long irqflags = 0;
856 	int ret;
857 
858 	i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq);
859 
860 	if (!irq_get_trigger_type(client->irq))
861 		irqflags = IRQF_TRIGGER_LOW;
862 
863 	ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
864 				   irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN,
865 				   client->name, ihid);
866 	if (ret < 0) {
867 		dev_warn(&client->dev,
868 			"Could not register for %s interrupt, irq = %d,"
869 			" ret = %d\n",
870 			client->name, client->irq, ret);
871 
872 		return ret;
873 	}
874 
875 	return 0;
876 }
877 
878 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
879 {
880 	struct i2c_client *client = ihid->client;
881 	struct i2c_hid_desc *hdesc = &ihid->hdesc;
882 	unsigned int dsize;
883 	int error;
884 
885 	/* i2c hid fetch using a fixed descriptor size (30 bytes) */
886 	if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
887 		i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
888 		ihid->hdesc =
889 			*i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
890 	} else {
891 		i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
892 		error = i2c_hid_read_register(ihid,
893 					      ihid->wHIDDescRegister,
894 					      &ihid->hdesc,
895 					      sizeof(ihid->hdesc));
896 		if (error) {
897 			dev_err(&ihid->client->dev,
898 				"failed to fetch HID descriptor: %d\n",
899 				error);
900 			return -ENODEV;
901 		}
902 	}
903 
904 	/* Validate the length of HID descriptor, the 4 first bytes:
905 	 * bytes 0-1 -> length
906 	 * bytes 2-3 -> bcdVersion (has to be 1.00) */
907 	/* check bcdVersion == 1.0 */
908 	if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
909 		dev_err(&ihid->client->dev,
910 			"unexpected HID descriptor bcdVersion (0x%04hx)\n",
911 			le16_to_cpu(hdesc->bcdVersion));
912 		return -ENODEV;
913 	}
914 
915 	/* Descriptor length should be 30 bytes as per the specification */
916 	dsize = le16_to_cpu(hdesc->wHIDDescLength);
917 	if (dsize != sizeof(struct i2c_hid_desc)) {
918 		dev_err(&ihid->client->dev,
919 			"weird size of HID descriptor (%u)\n", dsize);
920 		return -ENODEV;
921 	}
922 	i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
923 	return 0;
924 }
925 
926 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
927 {
928 	if (!ihid->ops->power_up)
929 		return 0;
930 
931 	return ihid->ops->power_up(ihid->ops);
932 }
933 
934 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
935 {
936 	if (!ihid->ops->power_down)
937 		return;
938 
939 	ihid->ops->power_down(ihid->ops);
940 }
941 
942 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
943 {
944 	if (!ihid->ops->shutdown_tail)
945 		return;
946 
947 	ihid->ops->shutdown_tail(ihid->ops);
948 }
949 
950 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)
951 {
952 	struct i2c_client *client = ihid->client;
953 	struct hid_device *hid = ihid->hid;
954 	int ret;
955 
956 	ret = hid_driver_suspend(hid, PMSG_SUSPEND);
957 	if (ret < 0)
958 		return ret;
959 
960 	/* Save some power */
961 	i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
962 
963 	disable_irq(client->irq);
964 
965 	if (force_poweroff || !device_may_wakeup(&client->dev))
966 		i2c_hid_core_power_down(ihid);
967 
968 	return 0;
969 }
970 
971 static int i2c_hid_core_resume(struct i2c_hid *ihid)
972 {
973 	struct i2c_client *client = ihid->client;
974 	struct hid_device *hid = ihid->hid;
975 	int ret;
976 
977 	if (!device_may_wakeup(&client->dev))
978 		i2c_hid_core_power_up(ihid);
979 
980 	enable_irq(client->irq);
981 
982 	/* Instead of resetting device, simply powers the device on. This
983 	 * solves "incomplete reports" on Raydium devices 2386:3118 and
984 	 * 2386:4B33 and fixes various SIS touchscreens no longer sending
985 	 * data after a suspend/resume.
986 	 *
987 	 * However some ALPS touchpads generate IRQ storm without reset, so
988 	 * let's still reset them here.
989 	 */
990 	if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
991 		ret = i2c_hid_hwreset(ihid);
992 	else
993 		ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
994 
995 	if (ret)
996 		return ret;
997 
998 	return hid_driver_reset_resume(hid);
999 }
1000 
1001 /*
1002  * Check that the device exists and parse the HID descriptor.
1003  */
1004 static int __i2c_hid_core_probe(struct i2c_hid *ihid)
1005 {
1006 	struct i2c_client *client = ihid->client;
1007 	struct hid_device *hid = ihid->hid;
1008 	int ret;
1009 
1010 	/* Make sure there is something at this address */
1011 	ret = i2c_smbus_read_byte(client);
1012 	if (ret < 0) {
1013 		i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
1014 		return -ENXIO;
1015 	}
1016 
1017 	ret = i2c_hid_fetch_hid_descriptor(ihid);
1018 	if (ret < 0) {
1019 		dev_err(&client->dev,
1020 			"Failed to fetch the HID Descriptor\n");
1021 		return ret;
1022 	}
1023 
1024 	hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1025 	hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1026 	hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1027 
1028 	hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
1029 						      hid->product);
1030 
1031 	snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1032 		 client->name, (u16)hid->vendor, (u16)hid->product);
1033 	strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1034 
1035 	ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1036 
1037 	return 0;
1038 }
1039 
1040 static int i2c_hid_core_register_hid(struct i2c_hid *ihid)
1041 {
1042 	struct i2c_client *client = ihid->client;
1043 	struct hid_device *hid = ihid->hid;
1044 	int ret;
1045 
1046 	enable_irq(client->irq);
1047 
1048 	ret = hid_add_device(hid);
1049 	if (ret) {
1050 		if (ret != -ENODEV)
1051 			hid_err(client, "can't add hid device: %d\n", ret);
1052 		disable_irq(client->irq);
1053 		return ret;
1054 	}
1055 
1056 	return 0;
1057 }
1058 
1059 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid)
1060 {
1061 	int ret;
1062 
1063 	ret = i2c_hid_core_power_up(ihid);
1064 	if (ret)
1065 		return ret;
1066 
1067 	ret = __i2c_hid_core_probe(ihid);
1068 	if (ret)
1069 		goto err_power_down;
1070 
1071 	ret = i2c_hid_core_register_hid(ihid);
1072 	if (ret)
1073 		goto err_power_down;
1074 
1075 	return 0;
1076 
1077 err_power_down:
1078 	i2c_hid_core_power_down(ihid);
1079 
1080 	return ret;
1081 }
1082 
1083 static void ihid_core_panel_prepare_work(struct work_struct *work)
1084 {
1085 	struct i2c_hid *ihid = container_of(work, struct i2c_hid,
1086 					    panel_follower_prepare_work);
1087 	struct hid_device *hid = ihid->hid;
1088 	int ret;
1089 
1090 	/*
1091 	 * hid->version is set on the first power up. If it's still zero then
1092 	 * this is the first power on so we should perform initial power up
1093 	 * steps.
1094 	 */
1095 	if (!hid->version)
1096 		ret = i2c_hid_core_probe_panel_follower(ihid);
1097 	else
1098 		ret = i2c_hid_core_resume(ihid);
1099 
1100 	if (ret)
1101 		dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret);
1102 	else
1103 		WRITE_ONCE(ihid->prepare_work_finished, true);
1104 
1105 	/*
1106 	 * The work APIs provide a number of memory ordering guarantees
1107 	 * including one that says that memory writes before schedule_work()
1108 	 * are always visible to the work function, but they don't appear to
1109 	 * guarantee that a write that happened in the work is visible after
1110 	 * cancel_work_sync(). We'll add a write memory barrier here to match
1111 	 * with i2c_hid_core_panel_unpreparing() to ensure that our write to
1112 	 * prepare_work_finished is visible there.
1113 	 */
1114 	smp_wmb();
1115 }
1116 
1117 static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower)
1118 {
1119 	struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1120 
1121 	/*
1122 	 * Powering on a touchscreen can be a slow process. Queue the work to
1123 	 * the system workqueue so we don't block the panel's power up.
1124 	 */
1125 	WRITE_ONCE(ihid->prepare_work_finished, false);
1126 	schedule_work(&ihid->panel_follower_prepare_work);
1127 
1128 	return 0;
1129 }
1130 
1131 static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower)
1132 {
1133 	struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1134 
1135 	cancel_work_sync(&ihid->panel_follower_prepare_work);
1136 
1137 	/* Match with ihid_core_panel_prepare_work() */
1138 	smp_rmb();
1139 	if (!READ_ONCE(ihid->prepare_work_finished))
1140 		return 0;
1141 
1142 	return i2c_hid_core_suspend(ihid, true);
1143 }
1144 
1145 static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = {
1146 	.panel_prepared = i2c_hid_core_panel_prepared,
1147 	.panel_unpreparing = i2c_hid_core_panel_unpreparing,
1148 };
1149 
1150 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid)
1151 {
1152 	struct device *dev = &ihid->client->dev;
1153 	int ret;
1154 
1155 	ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs;
1156 
1157 	/*
1158 	 * If we're not in control of our own power up/power down then we can't
1159 	 * do the logic to manage wakeups. Give a warning if a user thought
1160 	 * that was possible then force the capability off.
1161 	 */
1162 	if (device_can_wakeup(dev)) {
1163 		dev_warn(dev, "Can't wakeup if following panel\n");
1164 		device_set_wakeup_capable(dev, false);
1165 	}
1166 
1167 	ret = drm_panel_add_follower(dev, &ihid->panel_follower);
1168 	if (ret)
1169 		return ret;
1170 
1171 	return 0;
1172 }
1173 
1174 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
1175 		       u16 hid_descriptor_address, u32 quirks)
1176 {
1177 	int ret;
1178 	struct i2c_hid *ihid;
1179 	struct hid_device *hid;
1180 
1181 	dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1182 
1183 	if (!client->irq) {
1184 		dev_err(&client->dev,
1185 			"HID over i2c has not been provided an Int IRQ\n");
1186 		return -EINVAL;
1187 	}
1188 
1189 	if (client->irq < 0) {
1190 		if (client->irq != -EPROBE_DEFER)
1191 			dev_err(&client->dev,
1192 				"HID over i2c doesn't have a valid IRQ\n");
1193 		return client->irq;
1194 	}
1195 
1196 	ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
1197 	if (!ihid)
1198 		return -ENOMEM;
1199 
1200 	i2c_set_clientdata(client, ihid);
1201 
1202 	ihid->ops = ops;
1203 	ihid->client = client;
1204 	ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
1205 	ihid->is_panel_follower = drm_is_panel_follower(&client->dev);
1206 
1207 	init_waitqueue_head(&ihid->wait);
1208 	mutex_init(&ihid->reset_lock);
1209 	INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work);
1210 
1211 	/* we need to allocate the command buffer without knowing the maximum
1212 	 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1213 	 * real computation later. */
1214 	ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1215 	if (ret < 0)
1216 		return ret;
1217 	device_enable_async_suspend(&client->dev);
1218 
1219 	hid = hid_allocate_device();
1220 	if (IS_ERR(hid)) {
1221 		ret = PTR_ERR(hid);
1222 		goto err_free_buffers;
1223 	}
1224 
1225 	ihid->hid = hid;
1226 
1227 	hid->driver_data = client;
1228 	hid->ll_driver = &i2c_hid_ll_driver;
1229 	hid->dev.parent = &client->dev;
1230 	hid->bus = BUS_I2C;
1231 	hid->initial_quirks = quirks;
1232 
1233 	/* Power on and probe unless device is a panel follower. */
1234 	if (!ihid->is_panel_follower) {
1235 		ret = i2c_hid_core_power_up(ihid);
1236 		if (ret < 0)
1237 			goto err_destroy_device;
1238 
1239 		ret = __i2c_hid_core_probe(ihid);
1240 		if (ret < 0)
1241 			goto err_power_down;
1242 	}
1243 
1244 	ret = i2c_hid_init_irq(client);
1245 	if (ret < 0)
1246 		goto err_power_down;
1247 
1248 	/*
1249 	 * If we're a panel follower, we'll register when the panel turns on;
1250 	 * otherwise we do it right away.
1251 	 */
1252 	if (ihid->is_panel_follower)
1253 		ret = i2c_hid_core_register_panel_follower(ihid);
1254 	else
1255 		ret = i2c_hid_core_register_hid(ihid);
1256 	if (ret)
1257 		goto err_free_irq;
1258 
1259 	return 0;
1260 
1261 err_free_irq:
1262 	free_irq(client->irq, ihid);
1263 err_power_down:
1264 	if (!ihid->is_panel_follower)
1265 		i2c_hid_core_power_down(ihid);
1266 err_destroy_device:
1267 	hid_destroy_device(hid);
1268 err_free_buffers:
1269 	i2c_hid_free_buffers(ihid);
1270 
1271 	return ret;
1272 }
1273 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1274 
1275 void i2c_hid_core_remove(struct i2c_client *client)
1276 {
1277 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1278 	struct hid_device *hid;
1279 
1280 	/*
1281 	 * If we're a follower, the act of unfollowing will cause us to be
1282 	 * powered down. Otherwise we need to manually do it.
1283 	 */
1284 	if (ihid->is_panel_follower)
1285 		drm_panel_remove_follower(&ihid->panel_follower);
1286 	else
1287 		i2c_hid_core_suspend(ihid, true);
1288 
1289 	hid = ihid->hid;
1290 	hid_destroy_device(hid);
1291 
1292 	free_irq(client->irq, ihid);
1293 
1294 	if (ihid->bufsize)
1295 		i2c_hid_free_buffers(ihid);
1296 }
1297 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1298 
1299 void i2c_hid_core_shutdown(struct i2c_client *client)
1300 {
1301 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1302 
1303 	i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1304 	free_irq(client->irq, ihid);
1305 
1306 	i2c_hid_core_shutdown_tail(ihid);
1307 }
1308 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1309 
1310 static int i2c_hid_core_pm_suspend(struct device *dev)
1311 {
1312 	struct i2c_client *client = to_i2c_client(dev);
1313 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1314 
1315 	if (ihid->is_panel_follower)
1316 		return 0;
1317 
1318 	return i2c_hid_core_suspend(ihid, false);
1319 }
1320 
1321 static int i2c_hid_core_pm_resume(struct device *dev)
1322 {
1323 	struct i2c_client *client = to_i2c_client(dev);
1324 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1325 
1326 	if (ihid->is_panel_follower)
1327 		return 0;
1328 
1329 	return i2c_hid_core_resume(ihid);
1330 }
1331 
1332 const struct dev_pm_ops i2c_hid_core_pm = {
1333 	SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume)
1334 };
1335 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1336 
1337 MODULE_DESCRIPTION("HID over I2C core driver");
1338 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1339 MODULE_LICENSE("GPL");
1340