xref: /linux/drivers/hid/i2c-hid/i2c-hid-core.c (revision c9a50b90905a1dc79ca72d4a262da30d3572ca9e)
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 
55 /* Command opcodes */
56 #define I2C_HID_OPCODE_RESET			0x01
57 #define I2C_HID_OPCODE_GET_REPORT		0x02
58 #define I2C_HID_OPCODE_SET_REPORT		0x03
59 #define I2C_HID_OPCODE_GET_IDLE			0x04
60 #define I2C_HID_OPCODE_SET_IDLE			0x05
61 #define I2C_HID_OPCODE_GET_PROTOCOL		0x06
62 #define I2C_HID_OPCODE_SET_PROTOCOL		0x07
63 #define I2C_HID_OPCODE_SET_POWER		0x08
64 
65 /* flags */
66 #define I2C_HID_STARTED		0
67 #define I2C_HID_RESET_PENDING	1
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		cmd_lock;	/* protects cmdbuf and rawbuf */
110 	struct mutex		reset_lock;
111 
112 	struct i2chid_ops	*ops;
113 	struct drm_panel_follower panel_follower;
114 	struct work_struct	panel_follower_prepare_work;
115 	bool			is_panel_follower;
116 	bool			prepare_work_finished;
117 };
118 
119 static const struct i2c_hid_quirks {
120 	__u16 idVendor;
121 	__u16 idProduct;
122 	__u32 quirks;
123 } i2c_hid_quirks[] = {
124 	{ I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
125 		I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
126 	{ I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15,
127 		I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
128 	{ I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118,
129 		I2C_HID_QUIRK_NO_IRQ_AFTER_RESET },
130 	{ USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
131 		 I2C_HID_QUIRK_RESET_ON_RESUME },
132 	{ I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
133 		 I2C_HID_QUIRK_RESET_ON_RESUME },
134 	{ USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
135 		I2C_HID_QUIRK_BAD_INPUT_SIZE },
136 	{ I2C_VENDOR_ID_CIRQUE, I2C_PRODUCT_ID_CIRQUE_1063,
137 		I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND },
138 	/*
139 	 * Sending the wakeup after reset actually break ELAN touchscreen controller
140 	 */
141 	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
142 		 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET |
143 		 I2C_HID_QUIRK_BOGUS_IRQ },
144 	{ I2C_VENDOR_ID_GOODIX, I2C_DEVICE_ID_GOODIX_0D42,
145 		 I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME },
146 	{ 0, 0 }
147 };
148 
149 /*
150  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
151  * @idVendor: the 16-bit vendor ID
152  * @idProduct: the 16-bit product ID
153  *
154  * Returns: a u32 quirks value.
155  */
i2c_hid_lookup_quirk(const u16 idVendor,const u16 idProduct)156 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
157 {
158 	u32 quirks = 0;
159 	int n;
160 
161 	for (n = 0; i2c_hid_quirks[n].idVendor; n++)
162 		if (i2c_hid_quirks[n].idVendor == idVendor &&
163 		    (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
164 		     i2c_hid_quirks[n].idProduct == idProduct))
165 			quirks = i2c_hid_quirks[n].quirks;
166 
167 	return quirks;
168 }
169 
i2c_hid_probe_address(struct i2c_hid * ihid)170 static int i2c_hid_probe_address(struct i2c_hid *ihid)
171 {
172 	int ret;
173 
174 	/*
175 	 * Some STM-based devices need 400µs after a rising clock edge to wake
176 	 * from deep sleep, in which case the first read will fail. Try after a
177 	 * short sleep to see if the device came alive on the bus. Certain
178 	 * Weida Tech devices also need this.
179 	 */
180 	ret = i2c_smbus_read_byte(ihid->client);
181 	if (ret < 0) {
182 		usleep_range(400, 500);
183 		ret = i2c_smbus_read_byte(ihid->client);
184 	}
185 	return ret < 0 ? ret : 0;
186 }
187 
i2c_hid_xfer(struct i2c_hid * ihid,u8 * send_buf,int send_len,u8 * recv_buf,int recv_len)188 static int i2c_hid_xfer(struct i2c_hid *ihid,
189 			u8 *send_buf, int send_len, u8 *recv_buf, int recv_len)
190 {
191 	struct i2c_client *client = ihid->client;
192 	struct i2c_msg msgs[2] = { 0 };
193 	int n = 0;
194 	int ret;
195 
196 	if (send_len) {
197 		i2c_hid_dbg(ihid, "%s: cmd=%*ph\n",
198 			    __func__, send_len, send_buf);
199 
200 		msgs[n].addr = client->addr;
201 		msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE;
202 		msgs[n].len = send_len;
203 		msgs[n].buf = send_buf;
204 		n++;
205 	}
206 
207 	if (recv_len) {
208 		msgs[n].addr = client->addr;
209 		msgs[n].flags = (client->flags & I2C_M_TEN) |
210 				I2C_M_RD | I2C_M_DMA_SAFE;
211 		msgs[n].len = recv_len;
212 		msgs[n].buf = recv_buf;
213 		n++;
214 	}
215 
216 	ret = i2c_transfer(client->adapter, msgs, n);
217 
218 	if (ret != n)
219 		return ret < 0 ? ret : -EIO;
220 
221 	return 0;
222 }
223 
i2c_hid_read_register(struct i2c_hid * ihid,__le16 reg,void * buf,size_t len)224 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg,
225 				 void *buf, size_t len)
226 {
227 	guard(mutex)(&ihid->cmd_lock);
228 
229 	*(__le16 *)ihid->cmdbuf = reg;
230 
231 	return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len);
232 }
233 
i2c_hid_encode_command(u8 * buf,u8 opcode,int report_type,int report_id)234 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode,
235 				     int report_type, int report_id)
236 {
237 	size_t length = 0;
238 
239 	if (report_id < 0x0F) {
240 		buf[length++] = report_type << 4 | report_id;
241 		buf[length++] = opcode;
242 	} else {
243 		buf[length++] = report_type << 4 | 0x0F;
244 		buf[length++] = opcode;
245 		buf[length++] = report_id;
246 	}
247 
248 	return length;
249 }
250 
i2c_hid_get_report(struct i2c_hid * ihid,u8 report_type,u8 report_id,u8 * recv_buf,size_t recv_len)251 static int i2c_hid_get_report(struct i2c_hid *ihid,
252 			      u8 report_type, u8 report_id,
253 			      u8 *recv_buf, size_t recv_len)
254 {
255 	size_t length = 0;
256 	size_t ret_count;
257 	int error;
258 
259 	i2c_hid_dbg(ihid, "%s\n", __func__);
260 
261 	guard(mutex)(&ihid->cmd_lock);
262 
263 	/* Command register goes first */
264 	*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
265 	length += sizeof(__le16);
266 	/* Next is GET_REPORT command */
267 	length += i2c_hid_encode_command(ihid->cmdbuf + length,
268 					 I2C_HID_OPCODE_GET_REPORT,
269 					 report_type, report_id);
270 	/*
271 	 * Device will send report data through data register. Because
272 	 * command can be either 2 or 3 bytes destination for the data
273 	 * register may be not aligned.
274 	 */
275 	put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
276 			   ihid->cmdbuf + length);
277 	length += sizeof(__le16);
278 
279 	/*
280 	 * In addition to report data device will supply data length
281 	 * in the first 2 bytes of the response, so adjust .
282 	 */
283 	error = i2c_hid_xfer(ihid, ihid->cmdbuf, length,
284 			     ihid->rawbuf, recv_len + sizeof(__le16));
285 	if (error) {
286 		dev_err(&ihid->client->dev,
287 			"failed to set a report to device: %d\n", error);
288 		return error;
289 	}
290 
291 	/* The buffer is sufficiently aligned */
292 	ret_count = le16_to_cpup((__le16 *)ihid->rawbuf);
293 
294 	/* Check for empty report response */
295 	if (ret_count <= sizeof(__le16))
296 		return 0;
297 
298 	recv_len = min(recv_len, ret_count - sizeof(__le16));
299 	memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len);
300 
301 	if (report_id && recv_len != 0 && recv_buf[0] != report_id) {
302 		dev_err(&ihid->client->dev,
303 			"device returned incorrect report (%d vs %d expected)\n",
304 			recv_buf[0], report_id);
305 		return -EINVAL;
306 	}
307 
308 	return recv_len;
309 }
310 
i2c_hid_format_report(u8 * buf,int report_id,const u8 * data,size_t size)311 static size_t i2c_hid_format_report(u8 *buf, int report_id,
312 				    const u8 *data, size_t size)
313 {
314 	size_t length = sizeof(__le16); /* reserve space to store size */
315 
316 	if (report_id)
317 		buf[length++] = report_id;
318 
319 	memcpy(buf + length, data, size);
320 	length += size;
321 
322 	/* Store overall size in the beginning of the buffer */
323 	put_unaligned_le16(length, buf);
324 
325 	return length;
326 }
327 
328 /**
329  * i2c_hid_set_or_send_report: forward an incoming report to the device
330  * @ihid: the i2c hid device
331  * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
332  * @report_id: the report ID
333  * @buf: the actual data to transfer, without the report ID
334  * @data_len: size of buf
335  * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report
336  */
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)337 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid,
338 				      u8 report_type, u8 report_id,
339 				      const u8 *buf, size_t data_len,
340 				      bool do_set)
341 {
342 	size_t length = 0;
343 	int error;
344 
345 	i2c_hid_dbg(ihid, "%s\n", __func__);
346 
347 	if (data_len > ihid->bufsize)
348 		return -EINVAL;
349 
350 	if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0)
351 		return -ENOSYS;
352 
353 	guard(mutex)(&ihid->cmd_lock);
354 
355 	if (do_set) {
356 		/* Command register goes first */
357 		*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
358 		length += sizeof(__le16);
359 		/* Next is SET_REPORT command */
360 		length += i2c_hid_encode_command(ihid->cmdbuf + length,
361 						 I2C_HID_OPCODE_SET_REPORT,
362 						 report_type, report_id);
363 		/*
364 		 * Report data will go into the data register. Because
365 		 * command can be either 2 or 3 bytes destination for
366 		 * the data register may be not aligned.
367 		*/
368 		put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister),
369 				   ihid->cmdbuf + length);
370 		length += sizeof(__le16);
371 	} else {
372 		/*
373 		 * With simple "send report" all data goes into the output
374 		 * register.
375 		 */
376 		*(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister;
377 		length += sizeof(__le16);
378 	}
379 
380 	length += i2c_hid_format_report(ihid->cmdbuf + length,
381 					report_id, buf, data_len);
382 
383 	error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
384 	if (error) {
385 		dev_err(&ihid->client->dev,
386 			"failed to set a report to device: %d\n", error);
387 		return error;
388 	}
389 
390 	return data_len;
391 }
392 
i2c_hid_set_power_command(struct i2c_hid * ihid,int power_state)393 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state)
394 {
395 	size_t length;
396 
397 	guard(mutex)(&ihid->cmd_lock);
398 
399 	/* SET_POWER uses command register */
400 	*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
401 	length = sizeof(__le16);
402 
403 	/* Now the command itself */
404 	length += i2c_hid_encode_command(ihid->cmdbuf + length,
405 					 I2C_HID_OPCODE_SET_POWER,
406 					 0, power_state);
407 
408 	return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
409 }
410 
i2c_hid_set_power(struct i2c_hid * ihid,int power_state)411 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state)
412 {
413 	int ret;
414 
415 	i2c_hid_dbg(ihid, "%s\n", __func__);
416 
417 	ret = i2c_hid_set_power_command(ihid, power_state);
418 	if (ret)
419 		dev_err(&ihid->client->dev,
420 			"failed to change power setting.\n");
421 
422 	/*
423 	 * The HID over I2C specification states that if a DEVICE needs time
424 	 * after the PWR_ON request, it should utilise CLOCK stretching.
425 	 * However, it has been observered that the Windows driver provides a
426 	 * 1ms sleep between the PWR_ON and RESET requests.
427 	 * According to Goodix Windows even waits 60 ms after (other?)
428 	 * PWR_ON requests. Testing has confirmed that several devices
429 	 * will not work properly without a delay after a PWR_ON request.
430 	 */
431 	if (!ret && power_state == I2C_HID_PWR_ON)
432 		msleep(60);
433 
434 	return ret;
435 }
436 
i2c_hid_start_hwreset(struct i2c_hid * ihid)437 static int i2c_hid_start_hwreset(struct i2c_hid *ihid)
438 {
439 	size_t length = 0;
440 	int ret;
441 
442 	i2c_hid_dbg(ihid, "%s\n", __func__);
443 
444 	/*
445 	 * This prevents sending feature reports while the device is
446 	 * being reset. Otherwise we may lose the reset complete
447 	 * interrupt.
448 	 */
449 	lockdep_assert_held(&ihid->reset_lock);
450 
451 	ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
452 	if (ret)
453 		return ret;
454 
455 	scoped_guard(mutex, &ihid->cmd_lock) {
456 		/* Prepare reset command. Command register goes first. */
457 		*(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister;
458 		length += sizeof(__le16);
459 		/* Next is RESET command itself */
460 		length += i2c_hid_encode_command(ihid->cmdbuf + length,
461 						 I2C_HID_OPCODE_RESET, 0, 0);
462 
463 		set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
464 
465 		ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0);
466 		if (ret) {
467 			dev_err(&ihid->client->dev,
468 				"failed to reset device: %d\n", ret);
469 			break;
470 		}
471 
472 		return 0;
473 	}
474 
475 	/* Clean up if sending reset command failed */
476 	clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
477 	i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
478 	return ret;
479 }
480 
i2c_hid_finish_hwreset(struct i2c_hid * ihid)481 static int i2c_hid_finish_hwreset(struct i2c_hid *ihid)
482 {
483 	int ret = 0;
484 
485 	i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
486 
487 	if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) {
488 		msleep(100);
489 		clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
490 	} else if (!wait_event_timeout(ihid->wait,
491 				       !test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
492 				       msecs_to_jiffies(1000))) {
493 		dev_warn(&ihid->client->dev, "device did not ack reset within 1000 ms\n");
494 		clear_bit(I2C_HID_RESET_PENDING, &ihid->flags);
495 	}
496 	i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
497 
498 	/* At least some SIS devices need this after reset */
499 	if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
500 		ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
501 
502 	return ret;
503 }
504 
i2c_hid_get_input(struct i2c_hid * ihid)505 static void i2c_hid_get_input(struct i2c_hid *ihid)
506 {
507 	u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
508 	u16 ret_size;
509 	int ret;
510 
511 	if (size > ihid->bufsize)
512 		size = ihid->bufsize;
513 
514 	ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
515 	if (ret != size) {
516 		if (ret < 0)
517 			return;
518 
519 		dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
520 			__func__, ret, size);
521 		return;
522 	}
523 
524 	/* Receiving buffer is properly aligned */
525 	ret_size = le16_to_cpup((__le16 *)ihid->inbuf);
526 	if (!ret_size) {
527 		/* host or device initiated RESET completed */
528 		if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
529 			wake_up(&ihid->wait);
530 		return;
531 	}
532 
533 	if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) {
534 		dev_warn_once(&ihid->client->dev,
535 			      "%s: IRQ triggered but there's no data\n",
536 			      __func__);
537 		return;
538 	}
539 
540 	if (ret_size > size || ret_size < sizeof(__le16)) {
541 		if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
542 			*(__le16 *)ihid->inbuf = cpu_to_le16(size);
543 			ret_size = size;
544 		} else {
545 			dev_err(&ihid->client->dev,
546 				"%s: incomplete report (%d/%d)\n",
547 				__func__, size, ret_size);
548 			return;
549 		}
550 	}
551 
552 	i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
553 
554 	if (test_bit(I2C_HID_STARTED, &ihid->flags)) {
555 		if (ihid->hid->group != HID_GROUP_RMI)
556 			pm_wakeup_event(&ihid->client->dev, 0);
557 
558 		hid_input_report(ihid->hid, HID_INPUT_REPORT,
559 				ihid->inbuf + sizeof(__le16),
560 				ret_size - sizeof(__le16), 1);
561 	}
562 
563 	return;
564 }
565 
i2c_hid_irq(int irq,void * dev_id)566 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
567 {
568 	struct i2c_hid *ihid = dev_id;
569 
570 	i2c_hid_get_input(ihid);
571 
572 	return IRQ_HANDLED;
573 }
574 
i2c_hid_get_report_length(struct hid_report * report)575 static int i2c_hid_get_report_length(struct hid_report *report)
576 {
577 	return ((report->size - 1) >> 3) + 1 +
578 		report->device->report_enum[report->type].numbered + 2;
579 }
580 
581 /*
582  * Traverse the supplied list of reports and find the longest
583  */
i2c_hid_find_max_report(struct hid_device * hid,unsigned int type,unsigned int * max)584 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
585 		unsigned int *max)
586 {
587 	struct hid_report *report;
588 	unsigned int size;
589 
590 	/* We should not rely on wMaxInputLength, as some devices may set it to
591 	 * a wrong length. */
592 	list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
593 		size = i2c_hid_get_report_length(report);
594 		if (*max < size)
595 			*max = size;
596 	}
597 }
598 
i2c_hid_free_buffers(struct i2c_hid * ihid)599 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
600 {
601 	kfree(ihid->inbuf);
602 	kfree(ihid->rawbuf);
603 	kfree(ihid->cmdbuf);
604 	ihid->inbuf = NULL;
605 	ihid->rawbuf = NULL;
606 	ihid->cmdbuf = NULL;
607 	ihid->bufsize = 0;
608 }
609 
i2c_hid_alloc_buffers(struct i2c_hid * ihid,size_t report_size)610 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
611 {
612 	/*
613 	 * The worst case is computed from the set_report command with a
614 	 * reportID > 15 and the maximum report length.
615 	 */
616 	int cmd_len = sizeof(__le16) +	/* command register */
617 		      sizeof(u8) +	/* encoded report type/ID */
618 		      sizeof(u8) +	/* opcode */
619 		      sizeof(u8) +	/* optional 3rd byte report ID */
620 		      sizeof(__le16) +	/* data register */
621 		      sizeof(__le16) +	/* report data size */
622 		      sizeof(u8) +	/* report ID if numbered report */
623 		      report_size;
624 
625 	ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
626 	ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
627 	ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL);
628 
629 	if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) {
630 		i2c_hid_free_buffers(ihid);
631 		return -ENOMEM;
632 	}
633 
634 	ihid->bufsize = report_size;
635 
636 	return 0;
637 }
638 
i2c_hid_get_raw_report(struct hid_device * hid,u8 report_type,u8 report_id,u8 * buf,size_t count)639 static int i2c_hid_get_raw_report(struct hid_device *hid,
640 				  u8 report_type, u8 report_id,
641 				  u8 *buf, size_t count)
642 {
643 	struct i2c_client *client = hid->driver_data;
644 	struct i2c_hid *ihid = i2c_get_clientdata(client);
645 	int ret_count;
646 
647 	if (report_type == HID_OUTPUT_REPORT)
648 		return -EINVAL;
649 
650 	/*
651 	 * In case of unnumbered reports the response from the device will
652 	 * not have the report ID that the upper layers expect, so we need
653 	 * to stash it the buffer ourselves and adjust the data size.
654 	 */
655 	if (!report_id) {
656 		buf[0] = 0;
657 		buf++;
658 		count--;
659 	}
660 
661 	ret_count = i2c_hid_get_report(ihid,
662 			report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
663 			report_id, buf, count);
664 
665 	if (ret_count > 0 && !report_id)
666 		ret_count++;
667 
668 	return ret_count;
669 }
670 
i2c_hid_output_raw_report(struct hid_device * hid,u8 report_type,const u8 * buf,size_t count,bool do_set)671 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type,
672 				     const u8 *buf, size_t count, bool do_set)
673 {
674 	struct i2c_client *client = hid->driver_data;
675 	struct i2c_hid *ihid = i2c_get_clientdata(client);
676 	int report_id = buf[0];
677 	int ret;
678 
679 	if (report_type == HID_INPUT_REPORT)
680 		return -EINVAL;
681 
682 	mutex_lock(&ihid->reset_lock);
683 
684 	/*
685 	 * Note that both numbered and unnumbered reports passed here
686 	 * are supposed to have report ID stored in the 1st byte of the
687 	 * buffer, so we strip it off unconditionally before passing payload
688 	 * to i2c_hid_set_or_send_report which takes care of encoding
689 	 * everything properly.
690 	 */
691 	ret = i2c_hid_set_or_send_report(ihid,
692 				report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
693 				report_id, buf + 1, count - 1, do_set);
694 
695 	if (ret >= 0)
696 		ret++; /* add report_id to the number of transferred bytes */
697 
698 	mutex_unlock(&ihid->reset_lock);
699 
700 	return ret;
701 }
702 
i2c_hid_output_report(struct hid_device * hid,u8 * buf,size_t count)703 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count)
704 {
705 	return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count,
706 					 false);
707 }
708 
i2c_hid_raw_request(struct hid_device * hid,unsigned char reportnum,__u8 * buf,size_t len,unsigned char rtype,int reqtype)709 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
710 			       __u8 *buf, size_t len, unsigned char rtype,
711 			       int reqtype)
712 {
713 	switch (reqtype) {
714 	case HID_REQ_GET_REPORT:
715 		return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len);
716 	case HID_REQ_SET_REPORT:
717 		if (buf[0] != reportnum)
718 			return -EINVAL;
719 		return i2c_hid_output_raw_report(hid, rtype, buf, len, true);
720 	default:
721 		return -EIO;
722 	}
723 }
724 
i2c_hid_parse(struct hid_device * hid)725 static int i2c_hid_parse(struct hid_device *hid)
726 {
727 	struct i2c_client *client = hid->driver_data;
728 	struct i2c_hid *ihid = i2c_get_clientdata(client);
729 	struct i2c_hid_desc *hdesc = &ihid->hdesc;
730 	char *rdesc = NULL, *use_override = NULL;
731 	unsigned int rsize;
732 	int ret;
733 	int tries = 3;
734 
735 	i2c_hid_dbg(ihid, "entering %s\n", __func__);
736 
737 	rsize = le16_to_cpu(hdesc->wReportDescLength);
738 	if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
739 		dbg_hid("weird size of report descriptor (%u)\n", rsize);
740 		return -EINVAL;
741 	}
742 
743 	mutex_lock(&ihid->reset_lock);
744 	do {
745 		ret = i2c_hid_start_hwreset(ihid);
746 		if (ret == 0)
747 			ret = i2c_hid_finish_hwreset(ihid);
748 		else
749 			msleep(1000);
750 	} while (tries-- > 0 && ret);
751 	mutex_unlock(&ihid->reset_lock);
752 
753 	if (ret)
754 		return ret;
755 
756 	use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name,
757 								&rsize);
758 
759 	if (use_override) {
760 		rdesc = use_override;
761 		i2c_hid_dbg(ihid, "Using a HID report descriptor override\n");
762 	} else {
763 		rdesc = kzalloc(rsize, GFP_KERNEL);
764 		if (!rdesc)
765 			return -ENOMEM;
766 
767 		i2c_hid_dbg(ihid, "asking HID report descriptor\n");
768 
769 		ret = i2c_hid_read_register(ihid,
770 					    ihid->hdesc.wReportDescRegister,
771 					    rdesc, rsize);
772 		if (ret) {
773 			hid_err(hid, "reading report descriptor failed\n");
774 			goto out;
775 		}
776 	}
777 
778 	i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc);
779 
780 	ret = hid_parse_report(hid, rdesc, rsize);
781 	if (ret)
782 		dbg_hid("parsing report descriptor failed\n");
783 
784 out:
785 	if (!use_override)
786 		kfree(rdesc);
787 
788 	return ret;
789 }
790 
i2c_hid_start(struct hid_device * hid)791 static int i2c_hid_start(struct hid_device *hid)
792 {
793 	struct i2c_client *client = hid->driver_data;
794 	struct i2c_hid *ihid = i2c_get_clientdata(client);
795 	int ret;
796 	unsigned int bufsize = HID_MIN_BUFFER_SIZE;
797 
798 	i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize);
799 	i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize);
800 	i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize);
801 
802 	if (bufsize > ihid->bufsize) {
803 		disable_irq(client->irq);
804 		i2c_hid_free_buffers(ihid);
805 
806 		ret = i2c_hid_alloc_buffers(ihid, bufsize);
807 		enable_irq(client->irq);
808 
809 		if (ret)
810 			return ret;
811 	}
812 
813 	return 0;
814 }
815 
i2c_hid_stop(struct hid_device * hid)816 static void i2c_hid_stop(struct hid_device *hid)
817 {
818 	hid->claimed = 0;
819 }
820 
i2c_hid_open(struct hid_device * hid)821 static int i2c_hid_open(struct hid_device *hid)
822 {
823 	struct i2c_client *client = hid->driver_data;
824 	struct i2c_hid *ihid = i2c_get_clientdata(client);
825 
826 	set_bit(I2C_HID_STARTED, &ihid->flags);
827 	return 0;
828 }
829 
i2c_hid_close(struct hid_device * hid)830 static void i2c_hid_close(struct hid_device *hid)
831 {
832 	struct i2c_client *client = hid->driver_data;
833 	struct i2c_hid *ihid = i2c_get_clientdata(client);
834 
835 	clear_bit(I2C_HID_STARTED, &ihid->flags);
836 }
837 
838 static const struct hid_ll_driver i2c_hid_ll_driver = {
839 	.parse = i2c_hid_parse,
840 	.start = i2c_hid_start,
841 	.stop = i2c_hid_stop,
842 	.open = i2c_hid_open,
843 	.close = i2c_hid_close,
844 	.output_report = i2c_hid_output_report,
845 	.raw_request = i2c_hid_raw_request,
846 };
847 
i2c_hid_init_irq(struct i2c_client * client)848 static int i2c_hid_init_irq(struct i2c_client *client)
849 {
850 	struct i2c_hid *ihid = i2c_get_clientdata(client);
851 	unsigned long irqflags = 0;
852 	int ret;
853 
854 	i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq);
855 
856 	if (!irq_get_trigger_type(client->irq))
857 		irqflags = IRQF_TRIGGER_LOW;
858 
859 	ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
860 				   irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN,
861 				   client->name, ihid);
862 	if (ret < 0) {
863 		dev_warn(&client->dev,
864 			"Could not register for %s interrupt, irq = %d,"
865 			" ret = %d\n",
866 			client->name, client->irq, ret);
867 
868 		return ret;
869 	}
870 
871 	return 0;
872 }
873 
i2c_hid_fetch_hid_descriptor(struct i2c_hid * ihid)874 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
875 {
876 	struct i2c_client *client = ihid->client;
877 	struct i2c_hid_desc *hdesc = &ihid->hdesc;
878 	unsigned int dsize;
879 	int error;
880 
881 	/* i2c hid fetch using a fixed descriptor size (30 bytes) */
882 	if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
883 		i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
884 		ihid->hdesc =
885 			*i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
886 	} else {
887 		i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
888 		error = i2c_hid_read_register(ihid,
889 					      ihid->wHIDDescRegister,
890 					      &ihid->hdesc,
891 					      sizeof(ihid->hdesc));
892 		if (error) {
893 			dev_err(&ihid->client->dev,
894 				"failed to fetch HID descriptor: %d\n",
895 				error);
896 			return -ENODEV;
897 		}
898 	}
899 
900 	/* Validate the length of HID descriptor, the 4 first bytes:
901 	 * bytes 0-1 -> length
902 	 * bytes 2-3 -> bcdVersion (has to be 1.00) */
903 	/* check bcdVersion == 1.0 */
904 	if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
905 		dev_err(&ihid->client->dev,
906 			"unexpected HID descriptor bcdVersion (0x%04hx)\n",
907 			le16_to_cpu(hdesc->bcdVersion));
908 		return -ENODEV;
909 	}
910 
911 	/* Descriptor length should be 30 bytes as per the specification */
912 	dsize = le16_to_cpu(hdesc->wHIDDescLength);
913 	if (dsize != sizeof(struct i2c_hid_desc)) {
914 		dev_err(&ihid->client->dev,
915 			"weird size of HID descriptor (%u)\n", dsize);
916 		return -ENODEV;
917 	}
918 	i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc);
919 	return 0;
920 }
921 
i2c_hid_core_power_up(struct i2c_hid * ihid)922 static int i2c_hid_core_power_up(struct i2c_hid *ihid)
923 {
924 	if (!ihid->ops->power_up)
925 		return 0;
926 
927 	return ihid->ops->power_up(ihid->ops);
928 }
929 
i2c_hid_core_power_down(struct i2c_hid * ihid)930 static void i2c_hid_core_power_down(struct i2c_hid *ihid)
931 {
932 	if (!ihid->ops->power_down)
933 		return;
934 
935 	ihid->ops->power_down(ihid->ops);
936 }
937 
i2c_hid_core_shutdown_tail(struct i2c_hid * ihid)938 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
939 {
940 	if (!ihid->ops->shutdown_tail)
941 		return;
942 
943 	ihid->ops->shutdown_tail(ihid->ops);
944 }
945 
i2c_hid_core_suspend(struct i2c_hid * ihid,bool force_poweroff)946 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)
947 {
948 	struct i2c_client *client = ihid->client;
949 	struct hid_device *hid = ihid->hid;
950 	int ret;
951 
952 	ret = hid_driver_suspend(hid, PMSG_SUSPEND);
953 	if (ret < 0)
954 		return ret;
955 
956 	/* Save some power */
957 	if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND))
958 		i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
959 
960 	disable_irq(client->irq);
961 
962 	if (force_poweroff || !device_may_wakeup(&client->dev))
963 		i2c_hid_core_power_down(ihid);
964 
965 	return 0;
966 }
967 
i2c_hid_core_resume(struct i2c_hid * ihid)968 static int i2c_hid_core_resume(struct i2c_hid *ihid)
969 {
970 	struct i2c_client *client = ihid->client;
971 	struct hid_device *hid = ihid->hid;
972 	int ret;
973 
974 	if (!device_may_wakeup(&client->dev))
975 		i2c_hid_core_power_up(ihid);
976 
977 	enable_irq(client->irq);
978 
979 	/* Make sure the device is awake on the bus */
980 	ret = i2c_hid_probe_address(ihid);
981 	if (ret < 0) {
982 		dev_err(&client->dev, "nothing at address after resume: %d\n",
983 			ret);
984 		return -ENXIO;
985 	}
986 
987 	/* On Goodix 27c6:0d42 wait extra time before device wakeup.
988 	 * It's not clear why but if we send wakeup too early, the device will
989 	 * never trigger input interrupts.
990 	 */
991 	if (ihid->quirks & I2C_HID_QUIRK_DELAY_WAKEUP_AFTER_RESUME)
992 		msleep(1500);
993 
994 	/* Instead of resetting device, simply powers the device on. This
995 	 * solves "incomplete reports" on Raydium devices 2386:3118 and
996 	 * 2386:4B33 and fixes various SIS touchscreens no longer sending
997 	 * data after a suspend/resume.
998 	 *
999 	 * However some ALPS touchpads generate IRQ storm without reset, so
1000 	 * let's still reset them here.
1001 	 */
1002 	if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) {
1003 		mutex_lock(&ihid->reset_lock);
1004 		ret = i2c_hid_start_hwreset(ihid);
1005 		if (ret == 0)
1006 			ret = i2c_hid_finish_hwreset(ihid);
1007 		mutex_unlock(&ihid->reset_lock);
1008 	} else {
1009 		ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
1010 	}
1011 
1012 	if (ret)
1013 		return ret;
1014 
1015 	return hid_driver_reset_resume(hid);
1016 }
1017 
1018 /*
1019  * Check that the device exists and parse the HID descriptor.
1020  */
__i2c_hid_core_probe(struct i2c_hid * ihid)1021 static int __i2c_hid_core_probe(struct i2c_hid *ihid)
1022 {
1023 	struct i2c_client *client = ihid->client;
1024 	struct hid_device *hid = ihid->hid;
1025 	int ret;
1026 
1027 	ret = i2c_hid_probe_address(ihid);
1028 	if (ret < 0) {
1029 		i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
1030 		return -ENXIO;
1031 	}
1032 
1033 	ret = i2c_hid_fetch_hid_descriptor(ihid);
1034 	if (ret < 0) {
1035 		dev_err(&client->dev,
1036 			"Failed to fetch the HID Descriptor\n");
1037 		return ret;
1038 	}
1039 
1040 	hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1041 	hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1042 	hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1043 
1044 	hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
1045 						      hid->product);
1046 
1047 	snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1048 		 client->name, (u16)hid->vendor, (u16)hid->product);
1049 	strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1050 
1051 	ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1052 
1053 	return 0;
1054 }
1055 
i2c_hid_core_register_hid(struct i2c_hid * ihid)1056 static int i2c_hid_core_register_hid(struct i2c_hid *ihid)
1057 {
1058 	struct i2c_client *client = ihid->client;
1059 	struct hid_device *hid = ihid->hid;
1060 	int ret;
1061 
1062 	enable_irq(client->irq);
1063 
1064 	ret = hid_add_device(hid);
1065 	if (ret) {
1066 		if (ret != -ENODEV)
1067 			hid_err(client, "can't add hid device: %d\n", ret);
1068 		disable_irq(client->irq);
1069 		return ret;
1070 	}
1071 
1072 	return 0;
1073 }
1074 
i2c_hid_core_probe_panel_follower(struct i2c_hid * ihid)1075 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid)
1076 {
1077 	int ret;
1078 
1079 	ret = i2c_hid_core_power_up(ihid);
1080 	if (ret)
1081 		return ret;
1082 
1083 	ret = __i2c_hid_core_probe(ihid);
1084 	if (ret)
1085 		goto err_power_down;
1086 
1087 	ret = i2c_hid_core_register_hid(ihid);
1088 	if (ret)
1089 		goto err_power_down;
1090 
1091 	return 0;
1092 
1093 err_power_down:
1094 	i2c_hid_core_power_down(ihid);
1095 
1096 	return ret;
1097 }
1098 
ihid_core_panel_prepare_work(struct work_struct * work)1099 static void ihid_core_panel_prepare_work(struct work_struct *work)
1100 {
1101 	struct i2c_hid *ihid = container_of(work, struct i2c_hid,
1102 					    panel_follower_prepare_work);
1103 	struct hid_device *hid = ihid->hid;
1104 	int ret;
1105 
1106 	/*
1107 	 * hid->version is set on the first power up. If it's still zero then
1108 	 * this is the first power on so we should perform initial power up
1109 	 * steps.
1110 	 */
1111 	if (!hid->version)
1112 		ret = i2c_hid_core_probe_panel_follower(ihid);
1113 	else
1114 		ret = i2c_hid_core_resume(ihid);
1115 
1116 	if (ret)
1117 		dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret);
1118 	else
1119 		WRITE_ONCE(ihid->prepare_work_finished, true);
1120 
1121 	/*
1122 	 * The work APIs provide a number of memory ordering guarantees
1123 	 * including one that says that memory writes before schedule_work()
1124 	 * are always visible to the work function, but they don't appear to
1125 	 * guarantee that a write that happened in the work is visible after
1126 	 * cancel_work_sync(). We'll add a write memory barrier here to match
1127 	 * with i2c_hid_core_panel_unpreparing() to ensure that our write to
1128 	 * prepare_work_finished is visible there.
1129 	 */
1130 	smp_wmb();
1131 }
1132 
i2c_hid_core_panel_prepared(struct drm_panel_follower * follower)1133 static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower)
1134 {
1135 	struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1136 
1137 	/*
1138 	 * Powering on a touchscreen can be a slow process. Queue the work to
1139 	 * the system workqueue so we don't block the panel's power up.
1140 	 */
1141 	WRITE_ONCE(ihid->prepare_work_finished, false);
1142 	schedule_work(&ihid->panel_follower_prepare_work);
1143 
1144 	return 0;
1145 }
1146 
i2c_hid_core_panel_unpreparing(struct drm_panel_follower * follower)1147 static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower)
1148 {
1149 	struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
1150 
1151 	cancel_work_sync(&ihid->panel_follower_prepare_work);
1152 
1153 	/* Match with ihid_core_panel_prepare_work() */
1154 	smp_rmb();
1155 	if (!READ_ONCE(ihid->prepare_work_finished))
1156 		return 0;
1157 
1158 	return i2c_hid_core_suspend(ihid, true);
1159 }
1160 
1161 static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = {
1162 	.panel_prepared = i2c_hid_core_panel_prepared,
1163 	.panel_unpreparing = i2c_hid_core_panel_unpreparing,
1164 };
1165 
i2c_hid_core_register_panel_follower(struct i2c_hid * ihid)1166 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid)
1167 {
1168 	struct device *dev = &ihid->client->dev;
1169 	int ret;
1170 
1171 	ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs;
1172 
1173 	/*
1174 	 * If we're not in control of our own power up/power down then we can't
1175 	 * do the logic to manage wakeups. Give a warning if a user thought
1176 	 * that was possible then force the capability off.
1177 	 */
1178 	if (device_can_wakeup(dev)) {
1179 		dev_warn(dev, "Can't wakeup if following panel\n");
1180 		device_set_wakeup_capable(dev, false);
1181 	}
1182 
1183 	ret = drm_panel_add_follower(dev, &ihid->panel_follower);
1184 	if (ret)
1185 		return ret;
1186 
1187 	return 0;
1188 }
1189 
i2c_hid_core_probe(struct i2c_client * client,struct i2chid_ops * ops,u16 hid_descriptor_address,u32 quirks)1190 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
1191 		       u16 hid_descriptor_address, u32 quirks)
1192 {
1193 	int ret;
1194 	struct i2c_hid *ihid;
1195 	struct hid_device *hid;
1196 
1197 	dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1198 
1199 	if (!client->irq) {
1200 		dev_err(&client->dev,
1201 			"HID over i2c has not been provided an Int IRQ\n");
1202 		return -EINVAL;
1203 	}
1204 
1205 	if (client->irq < 0) {
1206 		if (client->irq != -EPROBE_DEFER)
1207 			dev_err(&client->dev,
1208 				"HID over i2c doesn't have a valid IRQ\n");
1209 		return client->irq;
1210 	}
1211 
1212 	ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
1213 	if (!ihid)
1214 		return -ENOMEM;
1215 
1216 	i2c_set_clientdata(client, ihid);
1217 
1218 	ihid->ops = ops;
1219 	ihid->client = client;
1220 	ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
1221 	ihid->is_panel_follower = drm_is_panel_follower(&client->dev);
1222 
1223 	init_waitqueue_head(&ihid->wait);
1224 	mutex_init(&ihid->cmd_lock);
1225 	mutex_init(&ihid->reset_lock);
1226 	INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work);
1227 
1228 	/* we need to allocate the command buffer without knowing the maximum
1229 	 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1230 	 * real computation later. */
1231 	ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1232 	if (ret < 0)
1233 		return ret;
1234 	device_enable_async_suspend(&client->dev);
1235 
1236 	hid = hid_allocate_device();
1237 	if (IS_ERR(hid)) {
1238 		ret = PTR_ERR(hid);
1239 		goto err_free_buffers;
1240 	}
1241 
1242 	ihid->hid = hid;
1243 
1244 	hid->driver_data = client;
1245 	hid->ll_driver = &i2c_hid_ll_driver;
1246 	hid->dev.parent = &client->dev;
1247 	hid->bus = BUS_I2C;
1248 	hid->initial_quirks = quirks;
1249 
1250 	/* Power on and probe unless device is a panel follower. */
1251 	if (!ihid->is_panel_follower) {
1252 		ret = i2c_hid_core_power_up(ihid);
1253 		if (ret < 0)
1254 			goto err_destroy_device;
1255 
1256 		ret = __i2c_hid_core_probe(ihid);
1257 		if (ret < 0)
1258 			goto err_power_down;
1259 	}
1260 
1261 	ret = i2c_hid_init_irq(client);
1262 	if (ret < 0)
1263 		goto err_power_down;
1264 
1265 	/*
1266 	 * If we're a panel follower, we'll register when the panel turns on;
1267 	 * otherwise we do it right away.
1268 	 */
1269 	if (ihid->is_panel_follower)
1270 		ret = i2c_hid_core_register_panel_follower(ihid);
1271 	else
1272 		ret = i2c_hid_core_register_hid(ihid);
1273 	if (ret)
1274 		goto err_free_irq;
1275 
1276 	return 0;
1277 
1278 err_free_irq:
1279 	free_irq(client->irq, ihid);
1280 err_power_down:
1281 	if (!ihid->is_panel_follower)
1282 		i2c_hid_core_power_down(ihid);
1283 err_destroy_device:
1284 	hid_destroy_device(hid);
1285 err_free_buffers:
1286 	i2c_hid_free_buffers(ihid);
1287 
1288 	return ret;
1289 }
1290 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
1291 
i2c_hid_core_remove(struct i2c_client * client)1292 void i2c_hid_core_remove(struct i2c_client *client)
1293 {
1294 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1295 	struct hid_device *hid;
1296 
1297 	/*
1298 	 * If we're a follower, the act of unfollowing will cause us to be
1299 	 * powered down. Otherwise we need to manually do it.
1300 	 */
1301 	if (ihid->is_panel_follower)
1302 		drm_panel_remove_follower(&ihid->panel_follower);
1303 	else
1304 		i2c_hid_core_suspend(ihid, true);
1305 
1306 	hid = ihid->hid;
1307 	hid_destroy_device(hid);
1308 
1309 	free_irq(client->irq, ihid);
1310 
1311 	if (ihid->bufsize)
1312 		i2c_hid_free_buffers(ihid);
1313 }
1314 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
1315 
i2c_hid_core_shutdown(struct i2c_client * client)1316 void i2c_hid_core_shutdown(struct i2c_client *client)
1317 {
1318 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1319 
1320 	i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
1321 	free_irq(client->irq, ihid);
1322 
1323 	i2c_hid_core_shutdown_tail(ihid);
1324 }
1325 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
1326 
i2c_hid_core_pm_suspend(struct device * dev)1327 static int i2c_hid_core_pm_suspend(struct device *dev)
1328 {
1329 	struct i2c_client *client = to_i2c_client(dev);
1330 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1331 
1332 	if (ihid->is_panel_follower)
1333 		return 0;
1334 
1335 	return i2c_hid_core_suspend(ihid, false);
1336 }
1337 
i2c_hid_core_pm_resume(struct device * dev)1338 static int i2c_hid_core_pm_resume(struct device *dev)
1339 {
1340 	struct i2c_client *client = to_i2c_client(dev);
1341 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1342 
1343 	if (ihid->is_panel_follower)
1344 		return 0;
1345 
1346 	return i2c_hid_core_resume(ihid);
1347 }
1348 
1349 const struct dev_pm_ops i2c_hid_core_pm = {
1350 	SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume)
1351 };
1352 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);
1353 
1354 MODULE_DESCRIPTION("HID over I2C core driver");
1355 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1356 MODULE_LICENSE("GPL");
1357