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_runtime.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/acpi.h>
40 #include <linux/of.h>
41 #include <linux/regulator/consumer.h>
42 
43 #include <linux/platform_data/i2c-hid.h>
44 
45 #include "../hid-ids.h"
46 #include "i2c-hid.h"
47 
48 /* quirks to control the device */
49 #define I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV	BIT(0)
50 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET	BIT(1)
51 #define I2C_HID_QUIRK_NO_RUNTIME_PM		BIT(2)
52 #define I2C_HID_QUIRK_DELAY_AFTER_SLEEP		BIT(3)
53 #define I2C_HID_QUIRK_BOGUS_IRQ			BIT(4)
54 #define I2C_HID_QUIRK_RESET_ON_RESUME		BIT(5)
55 #define I2C_HID_QUIRK_BAD_INPUT_SIZE		BIT(6)
56 
57 
58 /* flags */
59 #define I2C_HID_STARTED		0
60 #define I2C_HID_RESET_PENDING	1
61 #define I2C_HID_READ_PENDING	2
62 
63 #define I2C_HID_PWR_ON		0x00
64 #define I2C_HID_PWR_SLEEP	0x01
65 
66 /* debug option */
67 static bool debug;
68 module_param(debug, bool, 0444);
69 MODULE_PARM_DESC(debug, "print a lot of debug information");
70 
71 #define i2c_hid_dbg(ihid, fmt, arg...)					  \
72 do {									  \
73 	if (debug)							  \
74 		dev_printk(KERN_DEBUG, &(ihid)->client->dev, fmt, ##arg); \
75 } while (0)
76 
77 struct i2c_hid_desc {
78 	__le16 wHIDDescLength;
79 	__le16 bcdVersion;
80 	__le16 wReportDescLength;
81 	__le16 wReportDescRegister;
82 	__le16 wInputRegister;
83 	__le16 wMaxInputLength;
84 	__le16 wOutputRegister;
85 	__le16 wMaxOutputLength;
86 	__le16 wCommandRegister;
87 	__le16 wDataRegister;
88 	__le16 wVendorID;
89 	__le16 wProductID;
90 	__le16 wVersionID;
91 	__le32 reserved;
92 } __packed;
93 
94 struct i2c_hid_cmd {
95 	unsigned int registerIndex;
96 	__u8 opcode;
97 	unsigned int length;
98 	bool wait;
99 };
100 
101 union command {
102 	u8 data[0];
103 	struct cmd {
104 		__le16 reg;
105 		__u8 reportTypeID;
106 		__u8 opcode;
107 	} __packed c;
108 };
109 
110 #define I2C_HID_CMD(opcode_) \
111 	.opcode = opcode_, .length = 4, \
112 	.registerIndex = offsetof(struct i2c_hid_desc, wCommandRegister)
113 
114 /* fetch HID descriptor */
115 static const struct i2c_hid_cmd hid_descr_cmd = { .length = 2 };
116 /* fetch report descriptors */
117 static const struct i2c_hid_cmd hid_report_descr_cmd = {
118 		.registerIndex = offsetof(struct i2c_hid_desc,
119 			wReportDescRegister),
120 		.opcode = 0x00,
121 		.length = 2 };
122 /* commands */
123 static const struct i2c_hid_cmd hid_reset_cmd =		{ I2C_HID_CMD(0x01),
124 							  .wait = true };
125 static const struct i2c_hid_cmd hid_get_report_cmd =	{ I2C_HID_CMD(0x02) };
126 static const struct i2c_hid_cmd hid_set_report_cmd =	{ I2C_HID_CMD(0x03) };
127 static const struct i2c_hid_cmd hid_set_power_cmd =	{ I2C_HID_CMD(0x08) };
128 static const struct i2c_hid_cmd hid_no_cmd =		{ .length = 0 };
129 
130 /*
131  * These definitions are not used here, but are defined by the spec.
132  * Keeping them here for documentation purposes.
133  *
134  * static const struct i2c_hid_cmd hid_get_idle_cmd = { I2C_HID_CMD(0x04) };
135  * static const struct i2c_hid_cmd hid_set_idle_cmd = { I2C_HID_CMD(0x05) };
136  * static const struct i2c_hid_cmd hid_get_protocol_cmd = { I2C_HID_CMD(0x06) };
137  * static const struct i2c_hid_cmd hid_set_protocol_cmd = { I2C_HID_CMD(0x07) };
138  */
139 
140 /* The main device structure */
141 struct i2c_hid {
142 	struct i2c_client	*client;	/* i2c client */
143 	struct hid_device	*hid;	/* pointer to corresponding HID dev */
144 	union {
145 		__u8 hdesc_buffer[sizeof(struct i2c_hid_desc)];
146 		struct i2c_hid_desc hdesc;	/* the HID Descriptor */
147 	};
148 	__le16			wHIDDescRegister; /* location of the i2c
149 						   * register of the HID
150 						   * descriptor. */
151 	unsigned int		bufsize;	/* i2c buffer size */
152 	u8			*inbuf;		/* Input buffer */
153 	u8			*rawbuf;	/* Raw Input buffer */
154 	u8			*cmdbuf;	/* Command buffer */
155 	u8			*argsbuf;	/* Command arguments buffer */
156 
157 	unsigned long		flags;		/* device flags */
158 	unsigned long		quirks;		/* Various quirks */
159 
160 	wait_queue_head_t	wait;		/* For waiting the interrupt */
161 
162 	struct i2c_hid_platform_data pdata;
163 
164 	bool			irq_wake_enabled;
165 	struct mutex		reset_lock;
166 
167 	unsigned long		sleep_delay;
168 };
169 
170 static const struct i2c_hid_quirks {
171 	__u16 idVendor;
172 	__u16 idProduct;
173 	__u32 quirks;
174 } i2c_hid_quirks[] = {
175 	{ USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8752,
176 		I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
177 	{ USB_VENDOR_ID_WEIDA, USB_DEVICE_ID_WEIDA_8755,
178 		I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV },
179 	{ I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288,
180 		I2C_HID_QUIRK_NO_IRQ_AFTER_RESET |
181 		I2C_HID_QUIRK_NO_RUNTIME_PM },
182 	{ I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_4B33,
183 		I2C_HID_QUIRK_DELAY_AFTER_SLEEP },
184 	{ USB_VENDOR_ID_LG, I2C_DEVICE_ID_LG_8001,
185 		I2C_HID_QUIRK_NO_RUNTIME_PM },
186 	{ USB_VENDOR_ID_ELAN, HID_ANY_ID,
187 		 I2C_HID_QUIRK_BOGUS_IRQ },
188 	{ USB_VENDOR_ID_ALPS_JP, HID_ANY_ID,
189 		 I2C_HID_QUIRK_RESET_ON_RESUME },
190 	{ I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393,
191 		 I2C_HID_QUIRK_RESET_ON_RESUME },
192 	{ USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
193 		I2C_HID_QUIRK_BAD_INPUT_SIZE },
194 	{ 0, 0 }
195 };
196 
197 /*
198  * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device
199  * @idVendor: the 16-bit vendor ID
200  * @idProduct: the 16-bit product ID
201  *
202  * Returns: a u32 quirks value.
203  */
i2c_hid_lookup_quirk(const u16 idVendor,const u16 idProduct)204 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct)
205 {
206 	u32 quirks = 0;
207 	int n;
208 
209 	for (n = 0; i2c_hid_quirks[n].idVendor; n++)
210 		if (i2c_hid_quirks[n].idVendor == idVendor &&
211 		    (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID ||
212 		     i2c_hid_quirks[n].idProduct == idProduct))
213 			quirks = i2c_hid_quirks[n].quirks;
214 
215 	return quirks;
216 }
217 
__i2c_hid_command(struct i2c_client * client,const struct i2c_hid_cmd * command,u8 reportID,u8 reportType,u8 * args,int args_len,unsigned char * buf_recv,int data_len)218 static int __i2c_hid_command(struct i2c_client *client,
219 		const struct i2c_hid_cmd *command, u8 reportID,
220 		u8 reportType, u8 *args, int args_len,
221 		unsigned char *buf_recv, int data_len)
222 {
223 	struct i2c_hid *ihid = i2c_get_clientdata(client);
224 	union command *cmd = (union command *)ihid->cmdbuf;
225 	int ret;
226 	struct i2c_msg msg[2];
227 	int msg_num = 1;
228 
229 	int length = command->length;
230 	bool wait = command->wait;
231 	unsigned int registerIndex = command->registerIndex;
232 
233 	/* special case for hid_descr_cmd */
234 	if (command == &hid_descr_cmd) {
235 		cmd->c.reg = ihid->wHIDDescRegister;
236 	} else {
237 		cmd->data[0] = ihid->hdesc_buffer[registerIndex];
238 		cmd->data[1] = ihid->hdesc_buffer[registerIndex + 1];
239 	}
240 
241 	if (length > 2) {
242 		cmd->c.opcode = command->opcode;
243 		cmd->c.reportTypeID = reportID | reportType << 4;
244 	}
245 
246 	memcpy(cmd->data + length, args, args_len);
247 	length += args_len;
248 
249 	i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", __func__, length, cmd->data);
250 
251 	msg[0].addr = client->addr;
252 	msg[0].flags = client->flags & I2C_M_TEN;
253 	msg[0].len = length;
254 	msg[0].buf = cmd->data;
255 	if (data_len > 0) {
256 		msg[1].addr = client->addr;
257 		msg[1].flags = client->flags & I2C_M_TEN;
258 		msg[1].flags |= I2C_M_RD;
259 		msg[1].len = data_len;
260 		msg[1].buf = buf_recv;
261 		msg_num = 2;
262 		set_bit(I2C_HID_READ_PENDING, &ihid->flags);
263 	}
264 
265 	if (wait)
266 		set_bit(I2C_HID_RESET_PENDING, &ihid->flags);
267 
268 	ret = i2c_transfer(client->adapter, msg, msg_num);
269 
270 	if (data_len > 0)
271 		clear_bit(I2C_HID_READ_PENDING, &ihid->flags);
272 
273 	if (ret != msg_num)
274 		return ret < 0 ? ret : -EIO;
275 
276 	ret = 0;
277 
278 	if (wait && (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET)) {
279 		msleep(100);
280 	} else if (wait) {
281 		i2c_hid_dbg(ihid, "%s: waiting...\n", __func__);
282 		if (!wait_event_timeout(ihid->wait,
283 				!test_bit(I2C_HID_RESET_PENDING, &ihid->flags),
284 				msecs_to_jiffies(5000)))
285 			ret = -ENODATA;
286 		i2c_hid_dbg(ihid, "%s: finished.\n", __func__);
287 	}
288 
289 	return ret;
290 }
291 
i2c_hid_command(struct i2c_client * client,const struct i2c_hid_cmd * command,unsigned char * buf_recv,int data_len)292 static int i2c_hid_command(struct i2c_client *client,
293 		const struct i2c_hid_cmd *command,
294 		unsigned char *buf_recv, int data_len)
295 {
296 	return __i2c_hid_command(client, command, 0, 0, NULL, 0,
297 				buf_recv, data_len);
298 }
299 
i2c_hid_get_report(struct i2c_client * client,u8 reportType,u8 reportID,unsigned char * buf_recv,int data_len)300 static int i2c_hid_get_report(struct i2c_client *client, u8 reportType,
301 		u8 reportID, unsigned char *buf_recv, int data_len)
302 {
303 	struct i2c_hid *ihid = i2c_get_clientdata(client);
304 	u8 args[3];
305 	int ret;
306 	int args_len = 0;
307 	u16 readRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
308 
309 	i2c_hid_dbg(ihid, "%s\n", __func__);
310 
311 	if (reportID >= 0x0F) {
312 		args[args_len++] = reportID;
313 		reportID = 0x0F;
314 	}
315 
316 	args[args_len++] = readRegister & 0xFF;
317 	args[args_len++] = readRegister >> 8;
318 
319 	ret = __i2c_hid_command(client, &hid_get_report_cmd, reportID,
320 		reportType, args, args_len, buf_recv, data_len);
321 	if (ret) {
322 		dev_err(&client->dev,
323 			"failed to retrieve report from device.\n");
324 		return ret;
325 	}
326 
327 	return 0;
328 }
329 
330 /**
331  * i2c_hid_set_or_send_report: forward an incoming report to the device
332  * @client: the i2c_client of the device
333  * @reportType: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT
334  * @reportID: the report ID
335  * @buf: the actual data to transfer, without the report ID
336  * @len: size of buf
337  * @use_data: true: use SET_REPORT HID command, false: send plain OUTPUT report
338  */
i2c_hid_set_or_send_report(struct i2c_client * client,u8 reportType,u8 reportID,unsigned char * buf,size_t data_len,bool use_data)339 static int i2c_hid_set_or_send_report(struct i2c_client *client, u8 reportType,
340 		u8 reportID, unsigned char *buf, size_t data_len, bool use_data)
341 {
342 	struct i2c_hid *ihid = i2c_get_clientdata(client);
343 	u8 *args = ihid->argsbuf;
344 	const struct i2c_hid_cmd *hidcmd;
345 	int ret;
346 	u16 dataRegister = le16_to_cpu(ihid->hdesc.wDataRegister);
347 	u16 outputRegister = le16_to_cpu(ihid->hdesc.wOutputRegister);
348 	u16 maxOutputLength = le16_to_cpu(ihid->hdesc.wMaxOutputLength);
349 	u16 size;
350 	int args_len;
351 	int index = 0;
352 
353 	i2c_hid_dbg(ihid, "%s\n", __func__);
354 
355 	if (data_len > ihid->bufsize)
356 		return -EINVAL;
357 
358 	size =		2			/* size */ +
359 			(reportID ? 1 : 0)	/* reportID */ +
360 			data_len		/* buf */;
361 	args_len =	(reportID >= 0x0F ? 1 : 0) /* optional third byte */ +
362 			2			/* dataRegister */ +
363 			size			/* args */;
364 
365 	if (!use_data && maxOutputLength == 0)
366 		return -ENOSYS;
367 
368 	if (reportID >= 0x0F) {
369 		args[index++] = reportID;
370 		reportID = 0x0F;
371 	}
372 
373 	/*
374 	 * use the data register for feature reports or if the device does not
375 	 * support the output register
376 	 */
377 	if (use_data) {
378 		args[index++] = dataRegister & 0xFF;
379 		args[index++] = dataRegister >> 8;
380 		hidcmd = &hid_set_report_cmd;
381 	} else {
382 		args[index++] = outputRegister & 0xFF;
383 		args[index++] = outputRegister >> 8;
384 		hidcmd = &hid_no_cmd;
385 	}
386 
387 	args[index++] = size & 0xFF;
388 	args[index++] = size >> 8;
389 
390 	if (reportID)
391 		args[index++] = reportID;
392 
393 	memcpy(&args[index], buf, data_len);
394 
395 	ret = __i2c_hid_command(client, hidcmd, reportID,
396 		reportType, args, args_len, NULL, 0);
397 	if (ret) {
398 		dev_err(&client->dev, "failed to set a report to device.\n");
399 		return ret;
400 	}
401 
402 	return data_len;
403 }
404 
i2c_hid_set_power(struct i2c_client * client,int power_state)405 static int i2c_hid_set_power(struct i2c_client *client, int power_state)
406 {
407 	struct i2c_hid *ihid = i2c_get_clientdata(client);
408 	int ret;
409 	unsigned long now, delay;
410 
411 	i2c_hid_dbg(ihid, "%s\n", __func__);
412 
413 	/*
414 	 * Some devices require to send a command to wakeup before power on.
415 	 * The call will get a return value (EREMOTEIO) but device will be
416 	 * triggered and activated. After that, it goes like a normal device.
417 	 */
418 	if (power_state == I2C_HID_PWR_ON &&
419 	    ihid->quirks & I2C_HID_QUIRK_SET_PWR_WAKEUP_DEV) {
420 		ret = i2c_hid_command(client, &hid_set_power_cmd, NULL, 0);
421 
422 		/* Device was already activated */
423 		if (!ret)
424 			goto set_pwr_exit;
425 	}
426 
427 	if (ihid->quirks & I2C_HID_QUIRK_DELAY_AFTER_SLEEP &&
428 	    power_state == I2C_HID_PWR_ON) {
429 		now = jiffies;
430 		if (time_after(ihid->sleep_delay, now)) {
431 			delay = jiffies_to_usecs(ihid->sleep_delay - now);
432 			usleep_range(delay, delay + 1);
433 		}
434 	}
435 
436 	ret = __i2c_hid_command(client, &hid_set_power_cmd, power_state,
437 		0, NULL, 0, NULL, 0);
438 
439 	if (ihid->quirks & I2C_HID_QUIRK_DELAY_AFTER_SLEEP &&
440 	    power_state == I2C_HID_PWR_SLEEP)
441 		ihid->sleep_delay = jiffies + msecs_to_jiffies(20);
442 
443 	if (ret)
444 		dev_err(&client->dev, "failed to change power setting.\n");
445 
446 set_pwr_exit:
447 
448 	/*
449 	 * The HID over I2C specification states that if a DEVICE needs time
450 	 * after the PWR_ON request, it should utilise CLOCK stretching.
451 	 * However, it has been observered that the Windows driver provides a
452 	 * 1ms sleep between the PWR_ON and RESET requests.
453 	 * According to Goodix Windows even waits 60 ms after (other?)
454 	 * PWR_ON requests. Testing has confirmed that several devices
455 	 * will not work properly without a delay after a PWR_ON request.
456 	 */
457 	if (!ret && power_state == I2C_HID_PWR_ON)
458 		msleep(60);
459 
460 	return ret;
461 }
462 
i2c_hid_hwreset(struct i2c_client * client)463 static int i2c_hid_hwreset(struct i2c_client *client)
464 {
465 	struct i2c_hid *ihid = i2c_get_clientdata(client);
466 	int ret;
467 
468 	i2c_hid_dbg(ihid, "%s\n", __func__);
469 
470 	/*
471 	 * This prevents sending feature reports while the device is
472 	 * being reset. Otherwise we may lose the reset complete
473 	 * interrupt.
474 	 */
475 	mutex_lock(&ihid->reset_lock);
476 
477 	ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
478 	if (ret)
479 		goto out_unlock;
480 
481 	i2c_hid_dbg(ihid, "resetting...\n");
482 
483 	ret = i2c_hid_command(client, &hid_reset_cmd, NULL, 0);
484 	if (ret) {
485 		dev_err(&client->dev, "failed to reset device.\n");
486 		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
487 	}
488 
489 out_unlock:
490 	mutex_unlock(&ihid->reset_lock);
491 	return ret;
492 }
493 
i2c_hid_get_input(struct i2c_hid * ihid)494 static void i2c_hid_get_input(struct i2c_hid *ihid)
495 {
496 	int ret;
497 	u32 ret_size;
498 	int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
499 
500 	if (size > ihid->bufsize)
501 		size = ihid->bufsize;
502 
503 	ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
504 	if (ret != size) {
505 		if (ret < 0)
506 			return;
507 
508 		dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n",
509 			__func__, ret, size);
510 		return;
511 	}
512 
513 	ret_size = ihid->inbuf[0] | ihid->inbuf[1] << 8;
514 
515 	if (!ret_size) {
516 		/* host or device initiated RESET completed */
517 		if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags))
518 			wake_up(&ihid->wait);
519 		return;
520 	}
521 
522 	if (ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ && ret_size == 0xffff) {
523 		dev_warn_once(&ihid->client->dev, "%s: IRQ triggered but "
524 			      "there's no data\n", __func__);
525 		return;
526 	}
527 
528 	if ((ret_size > size) || (ret_size < 2)) {
529 		if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) {
530 			ihid->inbuf[0] = size & 0xff;
531 			ihid->inbuf[1] = size >> 8;
532 			ret_size = size;
533 		} else {
534 			dev_err(&ihid->client->dev, "%s: incomplete report (%d/%d)\n",
535 				__func__, size, ret_size);
536 			return;
537 		}
538 	}
539 
540 	i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf);
541 
542 	if (test_bit(I2C_HID_STARTED, &ihid->flags))
543 		hid_input_report(ihid->hid, HID_INPUT_REPORT, ihid->inbuf + 2,
544 				ret_size - 2, 1);
545 
546 	return;
547 }
548 
i2c_hid_irq(int irq,void * dev_id)549 static irqreturn_t i2c_hid_irq(int irq, void *dev_id)
550 {
551 	struct i2c_hid *ihid = dev_id;
552 
553 	if (test_bit(I2C_HID_READ_PENDING, &ihid->flags))
554 		return IRQ_HANDLED;
555 
556 	i2c_hid_get_input(ihid);
557 
558 	return IRQ_HANDLED;
559 }
560 
i2c_hid_get_report_length(struct hid_report * report)561 static int i2c_hid_get_report_length(struct hid_report *report)
562 {
563 	return ((report->size - 1) >> 3) + 1 +
564 		report->device->report_enum[report->type].numbered + 2;
565 }
566 
567 /*
568  * Traverse the supplied list of reports and find the longest
569  */
i2c_hid_find_max_report(struct hid_device * hid,unsigned int type,unsigned int * max)570 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
571 		unsigned int *max)
572 {
573 	struct hid_report *report;
574 	unsigned int size;
575 
576 	/* We should not rely on wMaxInputLength, as some devices may set it to
577 	 * a wrong length. */
578 	list_for_each_entry(report, &hid->report_enum[type].report_list, list) {
579 		size = i2c_hid_get_report_length(report);
580 		if (*max < size)
581 			*max = size;
582 	}
583 }
584 
i2c_hid_free_buffers(struct i2c_hid * ihid)585 static void i2c_hid_free_buffers(struct i2c_hid *ihid)
586 {
587 	kfree(ihid->inbuf);
588 	kfree(ihid->rawbuf);
589 	kfree(ihid->argsbuf);
590 	kfree(ihid->cmdbuf);
591 	ihid->inbuf = NULL;
592 	ihid->rawbuf = NULL;
593 	ihid->cmdbuf = NULL;
594 	ihid->argsbuf = NULL;
595 	ihid->bufsize = 0;
596 }
597 
i2c_hid_alloc_buffers(struct i2c_hid * ihid,size_t report_size)598 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
599 {
600 	/* the worst case is computed from the set_report command with a
601 	 * reportID > 15 and the maximum report length */
602 	int args_len = sizeof(__u8) + /* ReportID */
603 		       sizeof(__u8) + /* optional ReportID byte */
604 		       sizeof(__u16) + /* data register */
605 		       sizeof(__u16) + /* size of the report */
606 		       report_size; /* report */
607 
608 	ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
609 	ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
610 	ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
611 	ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
612 
613 	if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
614 		i2c_hid_free_buffers(ihid);
615 		return -ENOMEM;
616 	}
617 
618 	ihid->bufsize = report_size;
619 
620 	return 0;
621 }
622 
i2c_hid_get_raw_report(struct hid_device * hid,unsigned char report_number,__u8 * buf,size_t count,unsigned char report_type)623 static int i2c_hid_get_raw_report(struct hid_device *hid,
624 		unsigned char report_number, __u8 *buf, size_t count,
625 		unsigned char report_type)
626 {
627 	struct i2c_client *client = hid->driver_data;
628 	struct i2c_hid *ihid = i2c_get_clientdata(client);
629 	size_t ret_count, ask_count;
630 	int ret;
631 
632 	if (report_type == HID_OUTPUT_REPORT)
633 		return -EINVAL;
634 
635 	/*
636 	 * In case of unnumbered reports the response from the device will
637 	 * not have the report ID that the upper layers expect, so we need
638 	 * to stash it the buffer ourselves and adjust the data size.
639 	 */
640 	if (!report_number) {
641 		buf[0] = 0;
642 		buf++;
643 		count--;
644 	}
645 
646 	/* +2 bytes to include the size of the reply in the query buffer */
647 	ask_count = min(count + 2, (size_t)ihid->bufsize);
648 
649 	ret = i2c_hid_get_report(client,
650 			report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
651 			report_number, ihid->rawbuf, ask_count);
652 
653 	if (ret < 0)
654 		return ret;
655 
656 	ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
657 
658 	if (ret_count <= 2)
659 		return 0;
660 
661 	ret_count = min(ret_count, ask_count);
662 
663 	/* The query buffer contains the size, dropping it in the reply */
664 	count = min(count, ret_count - 2);
665 	memcpy(buf, ihid->rawbuf + 2, count);
666 
667 	if (!report_number)
668 		count++;
669 
670 	return count;
671 }
672 
i2c_hid_output_raw_report(struct hid_device * hid,__u8 * buf,size_t count,unsigned char report_type,bool use_data)673 static int i2c_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
674 		size_t count, unsigned char report_type, bool use_data)
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(client,
694 				report_type == HID_FEATURE_REPORT ? 0x03 : 0x02,
695 				report_id, buf + 1, count - 1, use_data);
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 
i2c_hid_output_report(struct hid_device * hid,__u8 * buf,size_t count)705 static int i2c_hid_output_report(struct hid_device *hid, __u8 *buf,
706 		size_t count)
707 {
708 	return i2c_hid_output_raw_report(hid, buf, count, HID_OUTPUT_REPORT,
709 			false);
710 }
711 
i2c_hid_raw_request(struct hid_device * hid,unsigned char reportnum,__u8 * buf,size_t len,unsigned char rtype,int reqtype)712 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum,
713 			       __u8 *buf, size_t len, unsigned char rtype,
714 			       int reqtype)
715 {
716 	switch (reqtype) {
717 	case HID_REQ_GET_REPORT:
718 		return i2c_hid_get_raw_report(hid, reportnum, buf, len, rtype);
719 	case HID_REQ_SET_REPORT:
720 		if (buf[0] != reportnum)
721 			return -EINVAL;
722 		return i2c_hid_output_raw_report(hid, buf, len, rtype, true);
723 	default:
724 		return -EIO;
725 	}
726 }
727 
i2c_hid_parse(struct hid_device * hid)728 static int i2c_hid_parse(struct hid_device *hid)
729 {
730 	struct i2c_client *client = hid->driver_data;
731 	struct i2c_hid *ihid = i2c_get_clientdata(client);
732 	struct i2c_hid_desc *hdesc = &ihid->hdesc;
733 	unsigned int rsize;
734 	char *rdesc;
735 	int ret;
736 	int tries = 3;
737 	char *use_override;
738 
739 	i2c_hid_dbg(ihid, "entering %s\n", __func__);
740 
741 	rsize = le16_to_cpu(hdesc->wReportDescLength);
742 	if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) {
743 		dbg_hid("weird size of report descriptor (%u)\n", rsize);
744 		return -EINVAL;
745 	}
746 
747 	do {
748 		ret = i2c_hid_hwreset(client);
749 		if (ret)
750 			msleep(1000);
751 	} while (tries-- > 0 && ret);
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 
765 		if (!rdesc) {
766 			dbg_hid("couldn't allocate rdesc memory\n");
767 			return -ENOMEM;
768 		}
769 
770 		i2c_hid_dbg(ihid, "asking HID report descriptor\n");
771 
772 		ret = i2c_hid_command(client, &hid_report_descr_cmd,
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 
i2c_hid_start(struct hid_device * hid)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 
i2c_hid_stop(struct hid_device * hid)820 static void i2c_hid_stop(struct hid_device *hid)
821 {
822 	hid->claimed = 0;
823 }
824 
i2c_hid_open(struct hid_device * hid)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 	int ret = 0;
830 
831 	ret = pm_runtime_get_sync(&client->dev);
832 	if (ret < 0)
833 		return ret;
834 
835 	set_bit(I2C_HID_STARTED, &ihid->flags);
836 	return 0;
837 }
838 
i2c_hid_close(struct hid_device * hid)839 static void i2c_hid_close(struct hid_device *hid)
840 {
841 	struct i2c_client *client = hid->driver_data;
842 	struct i2c_hid *ihid = i2c_get_clientdata(client);
843 
844 	clear_bit(I2C_HID_STARTED, &ihid->flags);
845 
846 	/* Save some power */
847 	pm_runtime_put(&client->dev);
848 }
849 
i2c_hid_power(struct hid_device * hid,int lvl)850 static int i2c_hid_power(struct hid_device *hid, int lvl)
851 {
852 	struct i2c_client *client = hid->driver_data;
853 	struct i2c_hid *ihid = i2c_get_clientdata(client);
854 
855 	i2c_hid_dbg(ihid, "%s lvl:%d\n", __func__, lvl);
856 
857 	switch (lvl) {
858 	case PM_HINT_FULLON:
859 		pm_runtime_get_sync(&client->dev);
860 		break;
861 	case PM_HINT_NORMAL:
862 		pm_runtime_put(&client->dev);
863 		break;
864 	}
865 	return 0;
866 }
867 
868 struct hid_ll_driver i2c_hid_ll_driver = {
869 	.parse = i2c_hid_parse,
870 	.start = i2c_hid_start,
871 	.stop = i2c_hid_stop,
872 	.open = i2c_hid_open,
873 	.close = i2c_hid_close,
874 	.power = i2c_hid_power,
875 	.output_report = i2c_hid_output_report,
876 	.raw_request = i2c_hid_raw_request,
877 };
878 EXPORT_SYMBOL_GPL(i2c_hid_ll_driver);
879 
i2c_hid_init_irq(struct i2c_client * client)880 static int i2c_hid_init_irq(struct i2c_client *client)
881 {
882 	struct i2c_hid *ihid = i2c_get_clientdata(client);
883 	unsigned long irqflags = 0;
884 	int ret;
885 
886 	dev_dbg(&client->dev, "Requesting IRQ: %d\n", client->irq);
887 
888 	if (!irq_get_trigger_type(client->irq))
889 		irqflags = IRQF_TRIGGER_LOW;
890 
891 	ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
892 				   irqflags | IRQF_ONESHOT, client->name, ihid);
893 	if (ret < 0) {
894 		dev_warn(&client->dev,
895 			"Could not register for %s interrupt, irq = %d,"
896 			" ret = %d\n",
897 			client->name, client->irq, ret);
898 
899 		return ret;
900 	}
901 
902 	return 0;
903 }
904 
i2c_hid_fetch_hid_descriptor(struct i2c_hid * ihid)905 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid)
906 {
907 	struct i2c_client *client = ihid->client;
908 	struct i2c_hid_desc *hdesc = &ihid->hdesc;
909 	unsigned int dsize;
910 	int ret;
911 
912 	/* i2c hid fetch using a fixed descriptor size (30 bytes) */
913 	if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) {
914 		i2c_hid_dbg(ihid, "Using a HID descriptor override\n");
915 		ihid->hdesc =
916 			*i2c_hid_get_dmi_i2c_hid_desc_override(client->name);
917 	} else {
918 		i2c_hid_dbg(ihid, "Fetching the HID descriptor\n");
919 		ret = i2c_hid_command(client, &hid_descr_cmd,
920 				      ihid->hdesc_buffer,
921 				      sizeof(struct i2c_hid_desc));
922 		if (ret) {
923 			dev_err(&client->dev, "hid_descr_cmd failed\n");
924 			return -ENODEV;
925 		}
926 	}
927 
928 	/* Validate the length of HID descriptor, the 4 first bytes:
929 	 * bytes 0-1 -> length
930 	 * bytes 2-3 -> bcdVersion (has to be 1.00) */
931 	/* check bcdVersion == 1.0 */
932 	if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) {
933 		dev_err(&client->dev,
934 			"unexpected HID descriptor bcdVersion (0x%04hx)\n",
935 			le16_to_cpu(hdesc->bcdVersion));
936 		return -ENODEV;
937 	}
938 
939 	/* Descriptor length should be 30 bytes as per the specification */
940 	dsize = le16_to_cpu(hdesc->wHIDDescLength);
941 	if (dsize != sizeof(struct i2c_hid_desc)) {
942 		dev_err(&client->dev, "weird size of HID descriptor (%u)\n",
943 			dsize);
944 		return -ENODEV;
945 	}
946 	i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, ihid->hdesc_buffer);
947 	return 0;
948 }
949 
950 #ifdef CONFIG_ACPI
951 static const struct acpi_device_id i2c_hid_acpi_blacklist[] = {
952 	/*
953 	 * The CHPN0001 ACPI device, which is used to describe the Chipone
954 	 * ICN8505 controller, has a _CID of PNP0C50 but is not HID compatible.
955 	 */
956 	{"CHPN0001", 0 },
957 	{ },
958 };
959 
i2c_hid_acpi_pdata(struct i2c_client * client,struct i2c_hid_platform_data * pdata)960 static int i2c_hid_acpi_pdata(struct i2c_client *client,
961 		struct i2c_hid_platform_data *pdata)
962 {
963 	static guid_t i2c_hid_guid =
964 		GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
965 			  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
966 	union acpi_object *obj;
967 	struct acpi_device *adev;
968 	acpi_handle handle;
969 
970 	handle = ACPI_HANDLE(&client->dev);
971 	if (!handle || acpi_bus_get_device(handle, &adev)) {
972 		dev_err(&client->dev, "Error could not get ACPI device\n");
973 		return -ENODEV;
974 	}
975 
976 	if (acpi_match_device_ids(adev, i2c_hid_acpi_blacklist) == 0)
977 		return -ENODEV;
978 
979 	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL,
980 				      ACPI_TYPE_INTEGER);
981 	if (!obj) {
982 		dev_err(&client->dev, "Error _DSM call to get HID descriptor address failed\n");
983 		return -ENODEV;
984 	}
985 
986 	pdata->hid_descriptor_address = obj->integer.value;
987 	ACPI_FREE(obj);
988 
989 	return 0;
990 }
991 
i2c_hid_acpi_fix_up_power(struct device * dev)992 static void i2c_hid_acpi_fix_up_power(struct device *dev)
993 {
994 	struct acpi_device *adev;
995 
996 	adev = ACPI_COMPANION(dev);
997 	if (adev)
998 		acpi_device_fix_up_power(adev);
999 }
1000 
1001 static const struct acpi_device_id i2c_hid_acpi_match[] = {
1002 	{"ACPI0C50", 0 },
1003 	{"PNP0C50", 0 },
1004 	{ },
1005 };
1006 MODULE_DEVICE_TABLE(acpi, i2c_hid_acpi_match);
1007 #else
i2c_hid_acpi_pdata(struct i2c_client * client,struct i2c_hid_platform_data * pdata)1008 static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
1009 		struct i2c_hid_platform_data *pdata)
1010 {
1011 	return -ENODEV;
1012 }
1013 
i2c_hid_acpi_fix_up_power(struct device * dev)1014 static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {}
1015 #endif
1016 
1017 #ifdef CONFIG_OF
i2c_hid_of_probe(struct i2c_client * client,struct i2c_hid_platform_data * pdata)1018 static int i2c_hid_of_probe(struct i2c_client *client,
1019 		struct i2c_hid_platform_data *pdata)
1020 {
1021 	struct device *dev = &client->dev;
1022 	u32 val;
1023 	int ret;
1024 
1025 	ret = of_property_read_u32(dev->of_node, "hid-descr-addr", &val);
1026 	if (ret) {
1027 		dev_err(&client->dev, "HID register address not provided\n");
1028 		return -ENODEV;
1029 	}
1030 	if (val >> 16) {
1031 		dev_err(&client->dev, "Bad HID register address: 0x%08x\n",
1032 			val);
1033 		return -EINVAL;
1034 	}
1035 	pdata->hid_descriptor_address = val;
1036 
1037 	return 0;
1038 }
1039 
1040 static const struct of_device_id i2c_hid_of_match[] = {
1041 	{ .compatible = "hid-over-i2c" },
1042 	{},
1043 };
1044 MODULE_DEVICE_TABLE(of, i2c_hid_of_match);
1045 #else
i2c_hid_of_probe(struct i2c_client * client,struct i2c_hid_platform_data * pdata)1046 static inline int i2c_hid_of_probe(struct i2c_client *client,
1047 		struct i2c_hid_platform_data *pdata)
1048 {
1049 	return -ENODEV;
1050 }
1051 #endif
1052 
i2c_hid_fwnode_probe(struct i2c_client * client,struct i2c_hid_platform_data * pdata)1053 static void i2c_hid_fwnode_probe(struct i2c_client *client,
1054 				 struct i2c_hid_platform_data *pdata)
1055 {
1056 	u32 val;
1057 
1058 	if (!device_property_read_u32(&client->dev, "post-power-on-delay-ms",
1059 				      &val))
1060 		pdata->post_power_delay_ms = val;
1061 }
1062 
i2c_hid_probe(struct i2c_client * client,const struct i2c_device_id * dev_id)1063 static int i2c_hid_probe(struct i2c_client *client,
1064 			 const struct i2c_device_id *dev_id)
1065 {
1066 	int ret;
1067 	struct i2c_hid *ihid;
1068 	struct hid_device *hid;
1069 	__u16 hidRegister;
1070 	struct i2c_hid_platform_data *platform_data = client->dev.platform_data;
1071 
1072 	dbg_hid("HID probe called for i2c 0x%02x\n", client->addr);
1073 
1074 	if (!client->irq) {
1075 		dev_err(&client->dev,
1076 			"HID over i2c has not been provided an Int IRQ\n");
1077 		return -EINVAL;
1078 	}
1079 
1080 	if (client->irq < 0) {
1081 		if (client->irq != -EPROBE_DEFER)
1082 			dev_err(&client->dev,
1083 				"HID over i2c doesn't have a valid IRQ\n");
1084 		return client->irq;
1085 	}
1086 
1087 	ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL);
1088 	if (!ihid)
1089 		return -ENOMEM;
1090 
1091 	if (client->dev.of_node) {
1092 		ret = i2c_hid_of_probe(client, &ihid->pdata);
1093 		if (ret)
1094 			return ret;
1095 	} else if (!platform_data) {
1096 		ret = i2c_hid_acpi_pdata(client, &ihid->pdata);
1097 		if (ret)
1098 			return ret;
1099 	} else {
1100 		ihid->pdata = *platform_data;
1101 	}
1102 
1103 	/* Parse platform agnostic common properties from ACPI / device tree */
1104 	i2c_hid_fwnode_probe(client, &ihid->pdata);
1105 
1106 	ihid->pdata.supplies[0].supply = "vdd";
1107 	ihid->pdata.supplies[1].supply = "vddl";
1108 
1109 	ret = devm_regulator_bulk_get(&client->dev,
1110 				      ARRAY_SIZE(ihid->pdata.supplies),
1111 				      ihid->pdata.supplies);
1112 	if (ret)
1113 		return ret;
1114 
1115 	ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies),
1116 				    ihid->pdata.supplies);
1117 	if (ret < 0)
1118 		return ret;
1119 
1120 	if (ihid->pdata.post_power_delay_ms)
1121 		msleep(ihid->pdata.post_power_delay_ms);
1122 
1123 	i2c_set_clientdata(client, ihid);
1124 
1125 	ihid->client = client;
1126 
1127 	hidRegister = ihid->pdata.hid_descriptor_address;
1128 	ihid->wHIDDescRegister = cpu_to_le16(hidRegister);
1129 
1130 	init_waitqueue_head(&ihid->wait);
1131 	mutex_init(&ihid->reset_lock);
1132 
1133 	/* we need to allocate the command buffer without knowing the maximum
1134 	 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
1135 	 * real computation later. */
1136 	ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
1137 	if (ret < 0)
1138 		goto err_regulator;
1139 
1140 	i2c_hid_acpi_fix_up_power(&client->dev);
1141 
1142 	pm_runtime_get_noresume(&client->dev);
1143 	pm_runtime_set_active(&client->dev);
1144 	pm_runtime_enable(&client->dev);
1145 	device_enable_async_suspend(&client->dev);
1146 
1147 	/* Make sure there is something at this address */
1148 	ret = i2c_smbus_read_byte(client);
1149 	if (ret < 0) {
1150 		dev_dbg(&client->dev, "nothing at this address: %d\n", ret);
1151 		ret = -ENXIO;
1152 		goto err_pm;
1153 	}
1154 
1155 	ret = i2c_hid_fetch_hid_descriptor(ihid);
1156 	if (ret < 0)
1157 		goto err_pm;
1158 
1159 	ret = i2c_hid_init_irq(client);
1160 	if (ret < 0)
1161 		goto err_pm;
1162 
1163 	hid = hid_allocate_device();
1164 	if (IS_ERR(hid)) {
1165 		ret = PTR_ERR(hid);
1166 		goto err_irq;
1167 	}
1168 
1169 	ihid->hid = hid;
1170 
1171 	hid->driver_data = client;
1172 	hid->ll_driver = &i2c_hid_ll_driver;
1173 	hid->dev.parent = &client->dev;
1174 	hid->bus = BUS_I2C;
1175 	hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
1176 	hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
1177 	hid->product = le16_to_cpu(ihid->hdesc.wProductID);
1178 
1179 	snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
1180 		 client->name, (u16)hid->vendor, (u16)hid->product);
1181 	strlcpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
1182 
1183 	ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
1184 
1185 	ret = hid_add_device(hid);
1186 	if (ret) {
1187 		if (ret != -ENODEV)
1188 			hid_err(client, "can't add hid device: %d\n", ret);
1189 		goto err_mem_free;
1190 	}
1191 
1192 	if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM))
1193 		pm_runtime_put(&client->dev);
1194 
1195 	return 0;
1196 
1197 err_mem_free:
1198 	hid_destroy_device(hid);
1199 
1200 err_irq:
1201 	free_irq(client->irq, ihid);
1202 
1203 err_pm:
1204 	pm_runtime_put_noidle(&client->dev);
1205 	pm_runtime_disable(&client->dev);
1206 
1207 err_regulator:
1208 	regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies),
1209 			       ihid->pdata.supplies);
1210 	i2c_hid_free_buffers(ihid);
1211 	return ret;
1212 }
1213 
i2c_hid_remove(struct i2c_client * client)1214 static int i2c_hid_remove(struct i2c_client *client)
1215 {
1216 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1217 	struct hid_device *hid;
1218 
1219 	if (!(ihid->quirks & I2C_HID_QUIRK_NO_RUNTIME_PM))
1220 		pm_runtime_get_sync(&client->dev);
1221 	pm_runtime_disable(&client->dev);
1222 	pm_runtime_set_suspended(&client->dev);
1223 	pm_runtime_put_noidle(&client->dev);
1224 
1225 	hid = ihid->hid;
1226 	hid_destroy_device(hid);
1227 
1228 	free_irq(client->irq, ihid);
1229 
1230 	if (ihid->bufsize)
1231 		i2c_hid_free_buffers(ihid);
1232 
1233 	regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies),
1234 			       ihid->pdata.supplies);
1235 
1236 	return 0;
1237 }
1238 
i2c_hid_shutdown(struct i2c_client * client)1239 static void i2c_hid_shutdown(struct i2c_client *client)
1240 {
1241 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1242 
1243 	i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1244 	free_irq(client->irq, ihid);
1245 }
1246 
1247 #ifdef CONFIG_PM_SLEEP
i2c_hid_suspend(struct device * dev)1248 static int i2c_hid_suspend(struct device *dev)
1249 {
1250 	struct i2c_client *client = to_i2c_client(dev);
1251 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1252 	struct hid_device *hid = ihid->hid;
1253 	int ret;
1254 	int wake_status;
1255 
1256 	if (hid->driver && hid->driver->suspend) {
1257 		/*
1258 		 * Wake up the device so that IO issues in
1259 		 * HID driver's suspend code can succeed.
1260 		 */
1261 		ret = pm_runtime_resume(dev);
1262 		if (ret < 0)
1263 			return ret;
1264 
1265 		ret = hid->driver->suspend(hid, PMSG_SUSPEND);
1266 		if (ret < 0)
1267 			return ret;
1268 	}
1269 
1270 	if (!pm_runtime_suspended(dev)) {
1271 		/* Save some power */
1272 		i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1273 
1274 		disable_irq(client->irq);
1275 	}
1276 
1277 	if (device_may_wakeup(&client->dev)) {
1278 		wake_status = enable_irq_wake(client->irq);
1279 		if (!wake_status)
1280 			ihid->irq_wake_enabled = true;
1281 		else
1282 			hid_warn(hid, "Failed to enable irq wake: %d\n",
1283 				wake_status);
1284 	} else {
1285 		regulator_bulk_disable(ARRAY_SIZE(ihid->pdata.supplies),
1286 				       ihid->pdata.supplies);
1287 	}
1288 
1289 	return 0;
1290 }
1291 
i2c_hid_resume(struct device * dev)1292 static int i2c_hid_resume(struct device *dev)
1293 {
1294 	int ret;
1295 	struct i2c_client *client = to_i2c_client(dev);
1296 	struct i2c_hid *ihid = i2c_get_clientdata(client);
1297 	struct hid_device *hid = ihid->hid;
1298 	int wake_status;
1299 
1300 	if (!device_may_wakeup(&client->dev)) {
1301 		ret = regulator_bulk_enable(ARRAY_SIZE(ihid->pdata.supplies),
1302 					    ihid->pdata.supplies);
1303 		if (ret)
1304 			hid_warn(hid, "Failed to enable supplies: %d\n", ret);
1305 
1306 		if (ihid->pdata.post_power_delay_ms)
1307 			msleep(ihid->pdata.post_power_delay_ms);
1308 	} else if (ihid->irq_wake_enabled) {
1309 		wake_status = disable_irq_wake(client->irq);
1310 		if (!wake_status)
1311 			ihid->irq_wake_enabled = false;
1312 		else
1313 			hid_warn(hid, "Failed to disable irq wake: %d\n",
1314 				wake_status);
1315 	}
1316 
1317 	/* We'll resume to full power */
1318 	pm_runtime_disable(dev);
1319 	pm_runtime_set_active(dev);
1320 	pm_runtime_enable(dev);
1321 
1322 	enable_irq(client->irq);
1323 
1324 	/* Instead of resetting device, simply powers the device on. This
1325 	 * solves "incomplete reports" on Raydium devices 2386:3118 and
1326 	 * 2386:4B33 and fixes various SIS touchscreens no longer sending
1327 	 * data after a suspend/resume.
1328 	 *
1329 	 * However some ALPS touchpads generate IRQ storm without reset, so
1330 	 * let's still reset them here.
1331 	 */
1332 	if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
1333 		ret = i2c_hid_hwreset(client);
1334 	else
1335 		ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
1336 
1337 	if (ret)
1338 		return ret;
1339 
1340 	if (hid->driver && hid->driver->reset_resume) {
1341 		ret = hid->driver->reset_resume(hid);
1342 		return ret;
1343 	}
1344 
1345 	return 0;
1346 }
1347 #endif
1348 
1349 #ifdef CONFIG_PM
i2c_hid_runtime_suspend(struct device * dev)1350 static int i2c_hid_runtime_suspend(struct device *dev)
1351 {
1352 	struct i2c_client *client = to_i2c_client(dev);
1353 
1354 	i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
1355 	disable_irq(client->irq);
1356 	return 0;
1357 }
1358 
i2c_hid_runtime_resume(struct device * dev)1359 static int i2c_hid_runtime_resume(struct device *dev)
1360 {
1361 	struct i2c_client *client = to_i2c_client(dev);
1362 
1363 	enable_irq(client->irq);
1364 	i2c_hid_set_power(client, I2C_HID_PWR_ON);
1365 	return 0;
1366 }
1367 #endif
1368 
1369 static const struct dev_pm_ops i2c_hid_pm = {
1370 	SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_suspend, i2c_hid_resume)
1371 	SET_RUNTIME_PM_OPS(i2c_hid_runtime_suspend, i2c_hid_runtime_resume,
1372 			   NULL)
1373 };
1374 
1375 static const struct i2c_device_id i2c_hid_id_table[] = {
1376 	{ "hid", 0 },
1377 	{ "hid-over-i2c", 0 },
1378 	{ },
1379 };
1380 MODULE_DEVICE_TABLE(i2c, i2c_hid_id_table);
1381 
1382 
1383 static struct i2c_driver i2c_hid_driver = {
1384 	.driver = {
1385 		.name	= "i2c_hid",
1386 		.pm	= &i2c_hid_pm,
1387 		.acpi_match_table = ACPI_PTR(i2c_hid_acpi_match),
1388 		.of_match_table = of_match_ptr(i2c_hid_of_match),
1389 	},
1390 
1391 	.probe		= i2c_hid_probe,
1392 	.remove		= i2c_hid_remove,
1393 	.shutdown	= i2c_hid_shutdown,
1394 	.id_table	= i2c_hid_id_table,
1395 };
1396 
1397 module_i2c_driver(i2c_hid_driver);
1398 
1399 MODULE_DESCRIPTION("HID over I2C core driver");
1400 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
1401 MODULE_LICENSE("GPL");
1402