xref: /linux/drivers/hid/hid-mcp2221.c (revision 48976c0eba2ff3a3b893c35853bdf27369b16655)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * MCP2221A - Microchip USB to I2C Host Protocol Bridge
4  *
5  * Copyright (c) 2020, Rishi Gupta <gupt21@gmail.com>
6  *
7  * Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf
8  */
9 
10 #include <linux/module.h>
11 #include <linux/err.h>
12 #include <linux/mutex.h>
13 #include <linux/bitfield.h>
14 #include <linux/completion.h>
15 #include <linux/delay.h>
16 #include <linux/hid.h>
17 #include <linux/hidraw.h>
18 #include <linux/i2c.h>
19 #include <linux/gpio/driver.h>
20 #include <linux/iio/iio.h>
21 #include <linux/minmax.h>
22 #include "hid-ids.h"
23 
24 /* Commands codes in a raw output report */
25 enum {
26 	MCP2221_I2C_WR_DATA = 0x90,
27 	MCP2221_I2C_WR_NO_STOP = 0x94,
28 	MCP2221_I2C_RD_DATA = 0x91,
29 	MCP2221_I2C_RD_RPT_START = 0x93,
30 	MCP2221_I2C_GET_DATA = 0x40,
31 	MCP2221_I2C_PARAM_OR_STATUS	= 0x10,
32 	MCP2221_I2C_SET_SPEED = 0x20,
33 	MCP2221_I2C_CANCEL = 0x10,
34 	MCP2221_GPIO_SET = 0x50,
35 	MCP2221_GPIO_GET = 0x51,
36 	MCP2221_SET_SRAM_SETTINGS = 0x60,
37 	MCP2221_GET_SRAM_SETTINGS = 0x61,
38 	MCP2221_READ_FLASH_DATA = 0xb0,
39 };
40 
41 /* Response codes in a raw input report */
42 enum {
43 	MCP2221_SUCCESS = 0x00,
44 	MCP2221_I2C_ENG_BUSY = 0x01,
45 	MCP2221_I2C_START_TOUT = 0x12,
46 	MCP2221_I2C_STOP_TOUT = 0x62,
47 	MCP2221_I2C_WRADDRL_TOUT = 0x23,
48 	MCP2221_I2C_WRDATA_TOUT = 0x44,
49 	MCP2221_I2C_WRADDRL_NACK = 0x25,
50 	MCP2221_I2C_MASK_ADDR_NACK = 0x40,
51 	MCP2221_I2C_WRADDRL_SEND = 0x21,
52 	MCP2221_I2C_ADDR_NACK = 0x25,
53 	MCP2221_I2C_READ_PARTIAL = 0x54,
54 	MCP2221_I2C_READ_COMPL = 0x55,
55 	MCP2221_ALT_F_NOT_GPIOV = 0xEE,
56 	MCP2221_ALT_F_NOT_GPIOD = 0xEF,
57 };
58 
59 /* MCP SRAM read offsets cmd: MCP2221_GET_SRAM_SETTINGS */
60 enum {
61 	MCP2221_SRAM_RD_GP0 = 22,
62 	MCP2221_SRAM_RD_GP1 = 23,
63 	MCP2221_SRAM_RD_GP2 = 24,
64 	MCP2221_SRAM_RD_GP3 = 25,
65 };
66 
67 /* MCP SRAM write offsets cmd: MCP2221_SET_SRAM_SETTINGS */
68 enum {
69 	MCP2221_SRAM_WR_GP_ENA_ALTER = 7,
70 	MCP2221_SRAM_WR_GP0 = 8,
71 	MCP2221_SRAM_WR_GP1 = 9,
72 	MCP2221_SRAM_WR_GP2 = 10,
73 	MCP2221_SRAM_WR_GP3 = 11,
74 };
75 
76 #define MCP2221_SRAM_GP_DESIGN_MASK		0x07
77 #define MCP2221_SRAM_GP_DIRECTION_MASK		0x08
78 #define MCP2221_SRAM_GP_VALUE_MASK		0x10
79 
80 /* MCP GPIO direction encoding */
81 enum {
82 	MCP2221_DIR_OUT = 0x00,
83 	MCP2221_DIR_IN = 0x01,
84 };
85 
86 #define MCP_NGPIO	4
87 
88 /* MCP GPIO set command layout */
89 struct mcp_set_gpio {
90 	u8 cmd;
91 	u8 dummy;
92 	struct {
93 		u8 change_value;
94 		u8 value;
95 		u8 change_direction;
96 		u8 direction;
97 	} gpio[MCP_NGPIO];
98 } __packed;
99 
100 /* MCP GPIO get command layout */
101 struct mcp_get_gpio {
102 	u8 cmd;
103 	u8 dummy;
104 	struct {
105 		u8 value;
106 		u8 direction;
107 	} gpio[MCP_NGPIO];
108 } __packed;
109 
110 /*
111  * There is no way to distinguish responses. Therefore next command
112  * is sent only after response to previous has been received. Mutex
113  * lock is used for this purpose mainly.
114  */
115 struct mcp2221 {
116 	struct hid_device *hdev;
117 	struct i2c_adapter adapter;
118 	struct mutex lock;
119 	struct completion wait_in_report;
120 	struct delayed_work init_work;
121 	u8 *rxbuf;
122 	u8 txbuf[64];
123 	int rxbuf_idx;
124 	int status;
125 	u8 cur_i2c_clk_div;
126 	struct gpio_chip *gc;
127 	u8 gp_idx;
128 	u8 gpio_dir;
129 	u8 mode[4];
130 #if IS_REACHABLE(CONFIG_IIO)
131 	struct iio_chan_spec iio_channels[3];
132 	u16 adc_values[3];
133 	u8 adc_scale;
134 	u8 dac_value;
135 	u16 dac_scale;
136 #endif
137 };
138 
139 struct mcp2221_iio {
140 	struct mcp2221 *mcp;
141 };
142 
143 /*
144  * Default i2c bus clock frequency 400 kHz. Modify this if you
145  * want to set some other frequency (min 50 kHz - max 400 kHz).
146  */
147 static uint i2c_clk_freq = 400;
148 
149 /* Synchronously send output report to the device */
mcp_send_report(struct mcp2221 * mcp,u8 * out_report,size_t len)150 static int mcp_send_report(struct mcp2221 *mcp,
151 					u8 *out_report, size_t len)
152 {
153 	u8 *buf;
154 	int ret;
155 
156 	buf = kmemdup(out_report, len, GFP_KERNEL);
157 	if (!buf)
158 		return -ENOMEM;
159 
160 	/* mcp2221 uses interrupt endpoint for out reports */
161 	ret = hid_hw_output_report(mcp->hdev, buf, len);
162 	kfree(buf);
163 
164 	if (ret < 0)
165 		return ret;
166 	return 0;
167 }
168 
169 /*
170  * Send o/p report to the device and wait for i/p report to be
171  * received from the device. If the device does not respond,
172  * we timeout.
173  */
mcp_send_data_req_status(struct mcp2221 * mcp,u8 * out_report,int len)174 static int mcp_send_data_req_status(struct mcp2221 *mcp,
175 			u8 *out_report, int len)
176 {
177 	int ret;
178 	unsigned long t;
179 
180 	reinit_completion(&mcp->wait_in_report);
181 
182 	ret = mcp_send_report(mcp, out_report, len);
183 	if (ret)
184 		return ret;
185 
186 	t = wait_for_completion_timeout(&mcp->wait_in_report,
187 							msecs_to_jiffies(4000));
188 	if (!t)
189 		return -ETIMEDOUT;
190 
191 	return mcp->status;
192 }
193 
194 /* Check pass/fail for actual communication with i2c slave */
mcp_chk_last_cmd_status(struct mcp2221 * mcp)195 static int mcp_chk_last_cmd_status(struct mcp2221 *mcp)
196 {
197 	memset(mcp->txbuf, 0, 8);
198 	mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS;
199 
200 	return mcp_send_data_req_status(mcp, mcp->txbuf, 8);
201 }
202 
203 /* Cancels last command releasing i2c bus just in case occupied */
mcp_cancel_last_cmd(struct mcp2221 * mcp)204 static int mcp_cancel_last_cmd(struct mcp2221 *mcp)
205 {
206 	memset(mcp->txbuf, 0, 8);
207 	mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS;
208 	mcp->txbuf[2] = MCP2221_I2C_CANCEL;
209 
210 	return mcp_send_data_req_status(mcp, mcp->txbuf, 8);
211 }
212 
213 /* Check if the last command succeeded or failed and return the result.
214  * If the command did fail, cancel that command which will free the i2c bus.
215  */
mcp_chk_last_cmd_status_free_bus(struct mcp2221 * mcp)216 static int mcp_chk_last_cmd_status_free_bus(struct mcp2221 *mcp)
217 {
218 	int ret;
219 
220 	ret = mcp_chk_last_cmd_status(mcp);
221 	if (ret) {
222 		/* The last command was a failure.
223 		 * Send a cancel which will also free the bus.
224 		 */
225 		usleep_range(980, 1000);
226 		mcp_cancel_last_cmd(mcp);
227 	}
228 
229 	return ret;
230 }
231 
mcp_set_i2c_speed(struct mcp2221 * mcp)232 static int mcp_set_i2c_speed(struct mcp2221 *mcp)
233 {
234 	int ret;
235 
236 	memset(mcp->txbuf, 0, 8);
237 	mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS;
238 	mcp->txbuf[3] = MCP2221_I2C_SET_SPEED;
239 	mcp->txbuf[4] = mcp->cur_i2c_clk_div;
240 
241 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 8);
242 	if (ret) {
243 		/* Small delay is needed here */
244 		usleep_range(980, 1000);
245 		mcp_cancel_last_cmd(mcp);
246 	}
247 
248 	return 0;
249 }
250 
251 /*
252  * An output report can contain minimum 1 and maximum 60 user data
253  * bytes. If the number of data bytes is more then 60, we send it
254  * in chunks of 60 bytes. Last chunk may contain exactly 60 or less
255  * bytes. Total number of bytes is informed in very first report to
256  * mcp2221, from that point onwards it first collect all the data
257  * from host and then send to i2c slave device.
258  */
mcp_i2c_write(struct mcp2221 * mcp,struct i2c_msg * msg,int type,u8 last_status)259 static int mcp_i2c_write(struct mcp2221 *mcp,
260 				struct i2c_msg *msg, int type, u8 last_status)
261 {
262 	int ret, len, idx, sent;
263 
264 	idx = 0;
265 	sent  = 0;
266 	len = min(msg->len, 60);
267 
268 	do {
269 		mcp->txbuf[0] = type;
270 		mcp->txbuf[1] = msg->len & 0xff;
271 		mcp->txbuf[2] = msg->len >> 8;
272 		mcp->txbuf[3] = (u8)(msg->addr << 1);
273 
274 		memcpy(&mcp->txbuf[4], &msg->buf[idx], len);
275 
276 		ret = mcp_send_data_req_status(mcp, mcp->txbuf, len + 4);
277 		if (ret)
278 			return ret;
279 
280 		usleep_range(980, 1000);
281 
282 		if (last_status) {
283 			ret = mcp_chk_last_cmd_status_free_bus(mcp);
284 			if (ret)
285 				return ret;
286 		}
287 
288 		sent = sent + len;
289 		if (sent >= msg->len)
290 			break;
291 
292 		idx = idx + len;
293 		len = min(msg->len - sent, 60);
294 
295 		/*
296 		 * Testing shows delay is needed between successive writes
297 		 * otherwise next write fails on first-try from i2c core.
298 		 * This value is obtained through automated stress testing.
299 		 */
300 		usleep_range(980, 1000);
301 	} while (len > 0);
302 
303 	return ret;
304 }
305 
306 /*
307  * Device reads all data (0 - 65535 bytes) from i2c slave device and
308  * stores it in device itself. This data is read back from device to
309  * host in multiples of 60 bytes using input reports.
310  */
mcp_i2c_smbus_read(struct mcp2221 * mcp,struct i2c_msg * msg,int type,u16 smbus_addr,u8 smbus_len,u8 * smbus_buf)311 static int mcp_i2c_smbus_read(struct mcp2221 *mcp,
312 				struct i2c_msg *msg, int type, u16 smbus_addr,
313 				u8 smbus_len, u8 *smbus_buf)
314 {
315 	int ret;
316 	u16 total_len;
317 	int retries = 0;
318 
319 	mcp->txbuf[0] = type;
320 	if (msg) {
321 		mcp->txbuf[1] = msg->len & 0xff;
322 		mcp->txbuf[2] = msg->len >> 8;
323 		mcp->txbuf[3] = (u8)(msg->addr << 1);
324 		total_len = msg->len;
325 		mcp->rxbuf = msg->buf;
326 	} else {
327 		mcp->txbuf[1] = smbus_len;
328 		mcp->txbuf[2] = 0;
329 		mcp->txbuf[3] = (u8)(smbus_addr << 1);
330 		total_len = smbus_len;
331 		mcp->rxbuf = smbus_buf;
332 	}
333 
334 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 4);
335 	if (ret)
336 		return ret;
337 
338 	mcp->rxbuf_idx = 0;
339 
340 	do {
341 		/* Wait for the data to be read by the device */
342 		usleep_range(980, 1000);
343 
344 		memset(mcp->txbuf, 0, 4);
345 		mcp->txbuf[0] = MCP2221_I2C_GET_DATA;
346 
347 		ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
348 		if (ret) {
349 			if (retries < 5) {
350 				/* The data wasn't ready to read.
351 				 * Wait a bit longer and try again.
352 				 */
353 				usleep_range(90, 100);
354 				retries++;
355 			} else {
356 				usleep_range(980, 1000);
357 				mcp_cancel_last_cmd(mcp);
358 				return ret;
359 			}
360 		} else {
361 			retries = 0;
362 		}
363 	} while (mcp->rxbuf_idx < total_len);
364 
365 	usleep_range(980, 1000);
366 	ret = mcp_chk_last_cmd_status_free_bus(mcp);
367 
368 	return ret;
369 }
370 
mcp_i2c_xfer(struct i2c_adapter * adapter,struct i2c_msg msgs[],int num)371 static int mcp_i2c_xfer(struct i2c_adapter *adapter,
372 				struct i2c_msg msgs[], int num)
373 {
374 	int ret;
375 	struct mcp2221 *mcp = i2c_get_adapdata(adapter);
376 
377 	hid_hw_power(mcp->hdev, PM_HINT_FULLON);
378 
379 	mutex_lock(&mcp->lock);
380 
381 	if (num == 1) {
382 		if (msgs->flags & I2C_M_RD) {
383 			ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA,
384 							0, 0, NULL);
385 		} else {
386 			ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1);
387 		}
388 		if (ret)
389 			goto exit;
390 		ret = num;
391 	} else if (num == 2) {
392 		/* Ex transaction; send reg address and read its contents */
393 		if (msgs[0].addr == msgs[1].addr &&
394 			!(msgs[0].flags & I2C_M_RD) &&
395 			 (msgs[1].flags & I2C_M_RD)) {
396 
397 			ret = mcp_i2c_write(mcp, &msgs[0],
398 						MCP2221_I2C_WR_NO_STOP, 0);
399 			if (ret)
400 				goto exit;
401 
402 			ret = mcp_i2c_smbus_read(mcp, &msgs[1],
403 						MCP2221_I2C_RD_RPT_START,
404 						0, 0, NULL);
405 			if (ret)
406 				goto exit;
407 			ret = num;
408 		} else {
409 			dev_err(&adapter->dev,
410 				"unsupported multi-msg i2c transaction\n");
411 			ret = -EOPNOTSUPP;
412 		}
413 	} else {
414 		dev_err(&adapter->dev,
415 			"unsupported multi-msg i2c transaction\n");
416 		ret = -EOPNOTSUPP;
417 	}
418 
419 exit:
420 	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
421 	mutex_unlock(&mcp->lock);
422 	return ret;
423 }
424 
mcp_smbus_write(struct mcp2221 * mcp,u16 addr,u8 command,u8 * buf,u8 len,int type,u8 last_status)425 static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr,
426 				u8 command, u8 *buf, u8 len, int type,
427 				u8 last_status)
428 {
429 	int data_len, ret;
430 
431 	mcp->txbuf[0] = type;
432 	mcp->txbuf[1] = len + 1; /* 1 is due to command byte itself */
433 	mcp->txbuf[2] = 0;
434 	mcp->txbuf[3] = (u8)(addr << 1);
435 	mcp->txbuf[4] = command;
436 
437 	switch (len) {
438 	case 0:
439 		data_len = 5;
440 		break;
441 	case 1:
442 		mcp->txbuf[5] = buf[0];
443 		data_len = 6;
444 		break;
445 	case 2:
446 		mcp->txbuf[5] = buf[0];
447 		mcp->txbuf[6] = buf[1];
448 		data_len = 7;
449 		break;
450 	default:
451 		if (len > I2C_SMBUS_BLOCK_MAX)
452 			return -EINVAL;
453 
454 		memcpy(&mcp->txbuf[5], buf, len);
455 		data_len = len + 5;
456 	}
457 
458 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, data_len);
459 	if (ret)
460 		return ret;
461 
462 	if (last_status) {
463 		usleep_range(980, 1000);
464 
465 		ret = mcp_chk_last_cmd_status_free_bus(mcp);
466 	}
467 
468 	return ret;
469 }
470 
mcp_smbus_xfer(struct i2c_adapter * adapter,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)471 static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
472 				unsigned short flags, char read_write,
473 				u8 command, int size,
474 				union i2c_smbus_data *data)
475 {
476 	int ret;
477 	struct mcp2221 *mcp = i2c_get_adapdata(adapter);
478 
479 	hid_hw_power(mcp->hdev, PM_HINT_FULLON);
480 
481 	mutex_lock(&mcp->lock);
482 
483 	switch (size) {
484 
485 	case I2C_SMBUS_QUICK:
486 		if (read_write == I2C_SMBUS_READ)
487 			ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA,
488 						addr, 0, &data->byte);
489 		else
490 			ret = mcp_smbus_write(mcp, addr, command, NULL,
491 						0, MCP2221_I2C_WR_DATA, 1);
492 		break;
493 	case I2C_SMBUS_BYTE:
494 		if (read_write == I2C_SMBUS_READ)
495 			ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA,
496 						addr, 1, &data->byte);
497 		else
498 			ret = mcp_smbus_write(mcp, addr, command, NULL,
499 						0, MCP2221_I2C_WR_DATA, 1);
500 		break;
501 	case I2C_SMBUS_BYTE_DATA:
502 		if (read_write == I2C_SMBUS_READ) {
503 			ret = mcp_smbus_write(mcp, addr, command, NULL,
504 						0, MCP2221_I2C_WR_NO_STOP, 0);
505 			if (ret)
506 				goto exit;
507 
508 			ret = mcp_i2c_smbus_read(mcp, NULL,
509 						MCP2221_I2C_RD_RPT_START,
510 						addr, 1, &data->byte);
511 		} else {
512 			ret = mcp_smbus_write(mcp, addr, command, &data->byte,
513 						1, MCP2221_I2C_WR_DATA, 1);
514 		}
515 		break;
516 	case I2C_SMBUS_WORD_DATA:
517 		if (read_write == I2C_SMBUS_READ) {
518 			ret = mcp_smbus_write(mcp, addr, command, NULL,
519 						0, MCP2221_I2C_WR_NO_STOP, 0);
520 			if (ret)
521 				goto exit;
522 
523 			ret = mcp_i2c_smbus_read(mcp, NULL,
524 						MCP2221_I2C_RD_RPT_START,
525 						addr, 2, (u8 *)&data->word);
526 		} else {
527 			ret = mcp_smbus_write(mcp, addr, command,
528 						(u8 *)&data->word, 2,
529 						MCP2221_I2C_WR_DATA, 1);
530 		}
531 		break;
532 	case I2C_SMBUS_BLOCK_DATA:
533 		if (read_write == I2C_SMBUS_READ) {
534 			ret = mcp_smbus_write(mcp, addr, command, NULL,
535 						0, MCP2221_I2C_WR_NO_STOP, 1);
536 			if (ret)
537 				goto exit;
538 
539 			mcp->rxbuf_idx = 0;
540 			mcp->rxbuf = data->block;
541 			mcp->txbuf[0] = MCP2221_I2C_GET_DATA;
542 			ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
543 			if (ret)
544 				goto exit;
545 		} else {
546 			if (!data->block[0]) {
547 				ret = -EINVAL;
548 				goto exit;
549 			}
550 			ret = mcp_smbus_write(mcp, addr, command, data->block,
551 						data->block[0] + 1,
552 						MCP2221_I2C_WR_DATA, 1);
553 		}
554 		break;
555 	case I2C_SMBUS_I2C_BLOCK_DATA:
556 		if (read_write == I2C_SMBUS_READ) {
557 			ret = mcp_smbus_write(mcp, addr, command, NULL,
558 						0, MCP2221_I2C_WR_NO_STOP, 1);
559 			if (ret)
560 				goto exit;
561 
562 			mcp->rxbuf_idx = 0;
563 			mcp->rxbuf = data->block;
564 			mcp->txbuf[0] = MCP2221_I2C_GET_DATA;
565 			ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
566 			if (ret)
567 				goto exit;
568 		} else {
569 			if (!data->block[0]) {
570 				ret = -EINVAL;
571 				goto exit;
572 			}
573 			ret = mcp_smbus_write(mcp, addr, command,
574 						&data->block[1], data->block[0],
575 						MCP2221_I2C_WR_DATA, 1);
576 		}
577 		break;
578 	case I2C_SMBUS_PROC_CALL:
579 		ret = mcp_smbus_write(mcp, addr, command,
580 						(u8 *)&data->word,
581 						2, MCP2221_I2C_WR_NO_STOP, 0);
582 		if (ret)
583 			goto exit;
584 
585 		ret = mcp_i2c_smbus_read(mcp, NULL,
586 						MCP2221_I2C_RD_RPT_START,
587 						addr, 2, (u8 *)&data->word);
588 		break;
589 	case I2C_SMBUS_BLOCK_PROC_CALL:
590 		ret = mcp_smbus_write(mcp, addr, command, data->block,
591 						data->block[0] + 1,
592 						MCP2221_I2C_WR_NO_STOP, 0);
593 		if (ret)
594 			goto exit;
595 
596 		ret = mcp_i2c_smbus_read(mcp, NULL,
597 						MCP2221_I2C_RD_RPT_START,
598 						addr, I2C_SMBUS_BLOCK_MAX,
599 						data->block);
600 		break;
601 	default:
602 		dev_err(&mcp->adapter.dev,
603 			"unsupported smbus transaction size:%d\n", size);
604 		ret = -EOPNOTSUPP;
605 	}
606 
607 exit:
608 	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
609 	mutex_unlock(&mcp->lock);
610 	return ret;
611 }
612 
mcp_i2c_func(struct i2c_adapter * adapter)613 static u32 mcp_i2c_func(struct i2c_adapter *adapter)
614 {
615 	return I2C_FUNC_I2C |
616 			I2C_FUNC_SMBUS_READ_BLOCK_DATA |
617 			I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
618 			(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_PEC);
619 }
620 
621 static const struct i2c_algorithm mcp_i2c_algo = {
622 	.master_xfer = mcp_i2c_xfer,
623 	.smbus_xfer = mcp_smbus_xfer,
624 	.functionality = mcp_i2c_func,
625 };
626 
627 #if IS_REACHABLE(CONFIG_GPIOLIB)
mcp_gpio_read_sram(struct mcp2221 * mcp)628 static int mcp_gpio_read_sram(struct mcp2221 *mcp)
629 {
630 	int ret;
631 
632 	memset(mcp->txbuf, 0, 64);
633 	mcp->txbuf[0] = MCP2221_GET_SRAM_SETTINGS;
634 
635 	mutex_lock(&mcp->lock);
636 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 64);
637 	mutex_unlock(&mcp->lock);
638 
639 	return ret;
640 }
641 
642 /*
643  * If CONFIG_IIO is not enabled, check for the gpio pins
644  * if they are in gpio mode. For the ones which are not
645  * in gpio mode, set them into gpio mode.
646  */
mcp2221_check_gpio_pinfunc(struct mcp2221 * mcp)647 static int mcp2221_check_gpio_pinfunc(struct mcp2221 *mcp)
648 {
649 	int i;
650 	int needgpiofix = 0;
651 	int ret;
652 
653 	if (IS_ENABLED(CONFIG_IIO))
654 		return 0;
655 
656 	ret = mcp_gpio_read_sram(mcp);
657 	if (ret)
658 		return ret;
659 
660 	for (i = 0; i < MCP_NGPIO; i++) {
661 		if ((mcp->mode[i] & MCP2221_SRAM_GP_DESIGN_MASK) != 0x0) {
662 			dev_warn(&mcp->hdev->dev,
663 				 "GPIO %d not in gpio mode\n", i);
664 			needgpiofix = 1;
665 		}
666 	}
667 
668 	if (!needgpiofix)
669 		return 0;
670 
671 	/*
672 	 * Set all bytes to 0, so Bit 7 is not set. The chip
673 	 * only changes content of a register when bit 7 is set.
674 	 */
675 	memset(mcp->txbuf, 0, 64);
676 	mcp->txbuf[0] = MCP2221_SET_SRAM_SETTINGS;
677 
678 	/*
679 	 * Set bit 7 in MCP2221_SRAM_WR_GP_ENA_ALTER to enable
680 	 * loading of a new set of gpio settings to GP SRAM
681 	 */
682 	mcp->txbuf[MCP2221_SRAM_WR_GP_ENA_ALTER] = 0x80;
683 	for (i = 0; i < MCP_NGPIO; i++) {
684 		if ((mcp->mode[i] & MCP2221_SRAM_GP_DESIGN_MASK) == 0x0) {
685 			/* write current GPIO mode */
686 			mcp->txbuf[MCP2221_SRAM_WR_GP0 + i] = mcp->mode[i];
687 		} else {
688 			/* pin is not in gpio mode, set it to input mode */
689 			mcp->txbuf[MCP2221_SRAM_WR_GP0 + i] = 0x08;
690 			dev_warn(&mcp->hdev->dev,
691 				 "Set GPIO mode for gpio pin %d!\n", i);
692 		}
693 	}
694 
695 	mutex_lock(&mcp->lock);
696 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 64);
697 	mutex_unlock(&mcp->lock);
698 
699 	return ret;
700 }
701 
mcp_gpio_get(struct gpio_chip * gc,unsigned int offset)702 static int mcp_gpio_get(struct gpio_chip *gc,
703 				unsigned int offset)
704 {
705 	int ret;
706 	struct mcp2221 *mcp = gpiochip_get_data(gc);
707 
708 	mcp->txbuf[0] = MCP2221_GPIO_GET;
709 
710 	mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset]);
711 
712 	mutex_lock(&mcp->lock);
713 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
714 	mutex_unlock(&mcp->lock);
715 
716 	return ret;
717 }
718 
mcp_gpio_set(struct gpio_chip * gc,unsigned int offset,int value)719 static int mcp_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
720 {
721 	struct mcp2221 *mcp = gpiochip_get_data(gc);
722 	int ret;
723 
724 	memset(mcp->txbuf, 0, 18);
725 	mcp->txbuf[0] = MCP2221_GPIO_SET;
726 
727 	mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].value);
728 
729 	mcp->txbuf[mcp->gp_idx - 1] = 1;
730 	mcp->txbuf[mcp->gp_idx] = !!value;
731 
732 	mutex_lock(&mcp->lock);
733 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 18);
734 	mutex_unlock(&mcp->lock);
735 
736 	return ret;
737 }
738 
mcp_gpio_dir_set(struct mcp2221 * mcp,unsigned int offset,u8 val)739 static int mcp_gpio_dir_set(struct mcp2221 *mcp,
740 				unsigned int offset, u8 val)
741 {
742 	memset(mcp->txbuf, 0, 18);
743 	mcp->txbuf[0] = MCP2221_GPIO_SET;
744 
745 	mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].direction);
746 
747 	mcp->txbuf[mcp->gp_idx - 1] = 1;
748 	mcp->txbuf[mcp->gp_idx] = val;
749 
750 	return mcp_send_data_req_status(mcp, mcp->txbuf, 18);
751 }
752 
mcp_gpio_direction_input(struct gpio_chip * gc,unsigned int offset)753 static int mcp_gpio_direction_input(struct gpio_chip *gc,
754 				unsigned int offset)
755 {
756 	int ret;
757 	struct mcp2221 *mcp = gpiochip_get_data(gc);
758 
759 	mutex_lock(&mcp->lock);
760 	ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_IN);
761 	mutex_unlock(&mcp->lock);
762 
763 	return ret;
764 }
765 
mcp_gpio_direction_output(struct gpio_chip * gc,unsigned int offset,int value)766 static int mcp_gpio_direction_output(struct gpio_chip *gc,
767 				unsigned int offset, int value)
768 {
769 	int ret;
770 	struct mcp2221 *mcp = gpiochip_get_data(gc);
771 
772 	mutex_lock(&mcp->lock);
773 	ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_OUT);
774 	mutex_unlock(&mcp->lock);
775 
776 	/* Can't configure as output, bailout early */
777 	if (ret)
778 		return ret;
779 
780 	mcp_gpio_set(gc, offset, value);
781 
782 	return 0;
783 }
784 
mcp_gpio_get_direction(struct gpio_chip * gc,unsigned int offset)785 static int mcp_gpio_get_direction(struct gpio_chip *gc,
786 				unsigned int offset)
787 {
788 	int ret;
789 	struct mcp2221 *mcp = gpiochip_get_data(gc);
790 
791 	mcp->txbuf[0] = MCP2221_GPIO_GET;
792 
793 	mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset]);
794 
795 	mutex_lock(&mcp->lock);
796 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
797 	mutex_unlock(&mcp->lock);
798 
799 	if (ret)
800 		return ret;
801 
802 	if (mcp->gpio_dir == MCP2221_DIR_IN)
803 		return GPIO_LINE_DIRECTION_IN;
804 
805 	return GPIO_LINE_DIRECTION_OUT;
806 }
807 #endif
808 
809 /* Gives current state of i2c engine inside mcp2221 */
mcp_get_i2c_eng_state(struct mcp2221 * mcp,u8 * data,u8 idx)810 static int mcp_get_i2c_eng_state(struct mcp2221 *mcp,
811 				u8 *data, u8 idx)
812 {
813 	int ret;
814 
815 	switch (data[idx]) {
816 	case MCP2221_I2C_WRADDRL_NACK:
817 	case MCP2221_I2C_WRADDRL_SEND:
818 		ret = -ENXIO;
819 		break;
820 	case MCP2221_I2C_START_TOUT:
821 	case MCP2221_I2C_STOP_TOUT:
822 	case MCP2221_I2C_WRADDRL_TOUT:
823 	case MCP2221_I2C_WRDATA_TOUT:
824 		ret = -ETIMEDOUT;
825 		break;
826 	case MCP2221_I2C_ENG_BUSY:
827 		ret = -EAGAIN;
828 		break;
829 	case MCP2221_SUCCESS:
830 		ret = 0x00;
831 		break;
832 	default:
833 		ret = -EIO;
834 	}
835 
836 	return ret;
837 }
838 
839 /*
840  * MCP2221 uses interrupt endpoint for input reports. This function
841  * is called by HID layer when it receives i/p report from mcp2221,
842  * which is actually a response to the previously sent command.
843  *
844  * MCP2221A firmware specific return codes are parsed and 0 or
845  * appropriate negative error code is returned. Delayed response
846  * results in timeout error and stray reponses results in -EIO.
847  */
mcp2221_raw_event(struct hid_device * hdev,struct hid_report * report,u8 * data,int size)848 static int mcp2221_raw_event(struct hid_device *hdev,
849 				struct hid_report *report, u8 *data, int size)
850 {
851 	u8 *buf;
852 	struct mcp2221 *mcp = hid_get_drvdata(hdev);
853 
854 	switch (data[0]) {
855 
856 	case MCP2221_I2C_WR_DATA:
857 	case MCP2221_I2C_WR_NO_STOP:
858 	case MCP2221_I2C_RD_DATA:
859 	case MCP2221_I2C_RD_RPT_START:
860 		switch (data[1]) {
861 		case MCP2221_SUCCESS:
862 			mcp->status = 0;
863 			break;
864 		default:
865 			mcp->status = mcp_get_i2c_eng_state(mcp, data, 2);
866 		}
867 		complete(&mcp->wait_in_report);
868 		break;
869 
870 	case MCP2221_I2C_PARAM_OR_STATUS:
871 		switch (data[1]) {
872 		case MCP2221_SUCCESS:
873 			if ((mcp->txbuf[3] == MCP2221_I2C_SET_SPEED) &&
874 				(data[3] != MCP2221_I2C_SET_SPEED)) {
875 				mcp->status = -EAGAIN;
876 				break;
877 			}
878 			if (data[20] & MCP2221_I2C_MASK_ADDR_NACK) {
879 				mcp->status = -ENXIO;
880 				break;
881 			}
882 			mcp->status = mcp_get_i2c_eng_state(mcp, data, 8);
883 #if IS_REACHABLE(CONFIG_IIO)
884 			memcpy(&mcp->adc_values, &data[50], sizeof(mcp->adc_values));
885 #endif
886 			break;
887 		default:
888 			mcp->status = -EIO;
889 		}
890 		complete(&mcp->wait_in_report);
891 		break;
892 
893 	case MCP2221_I2C_GET_DATA:
894 		switch (data[1]) {
895 		case MCP2221_SUCCESS:
896 			if (data[2] == MCP2221_I2C_ADDR_NACK) {
897 				mcp->status = -ENXIO;
898 				break;
899 			}
900 			if (!mcp_get_i2c_eng_state(mcp, data, 2)
901 				&& (data[3] == 0)) {
902 				mcp->status = 0;
903 				break;
904 			}
905 			if (data[3] == 127) {
906 				mcp->status = -EIO;
907 				break;
908 			}
909 			if (data[2] == MCP2221_I2C_READ_COMPL ||
910 			    data[2] == MCP2221_I2C_READ_PARTIAL) {
911 				if (!mcp->rxbuf || mcp->rxbuf_idx < 0 || data[3] > 60) {
912 					mcp->status = -EINVAL;
913 					break;
914 				}
915 				buf = mcp->rxbuf;
916 				memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]);
917 				mcp->rxbuf_idx = mcp->rxbuf_idx + data[3];
918 				mcp->status = 0;
919 				break;
920 			}
921 			mcp->status = -EIO;
922 			break;
923 		default:
924 			mcp->status = -EIO;
925 		}
926 		complete(&mcp->wait_in_report);
927 		break;
928 
929 	case MCP2221_GPIO_GET:
930 		switch (data[1]) {
931 		case MCP2221_SUCCESS:
932 			if ((data[mcp->gp_idx] == MCP2221_ALT_F_NOT_GPIOV) ||
933 				(data[mcp->gp_idx + 1] == MCP2221_ALT_F_NOT_GPIOD)) {
934 				mcp->status = -ENOENT;
935 			} else {
936 				mcp->status = !!data[mcp->gp_idx];
937 				mcp->gpio_dir = data[mcp->gp_idx + 1];
938 			}
939 			break;
940 		default:
941 			mcp->status = -EAGAIN;
942 		}
943 		complete(&mcp->wait_in_report);
944 		break;
945 
946 	case MCP2221_GPIO_SET:
947 		switch (data[1]) {
948 		case MCP2221_SUCCESS:
949 			if ((data[mcp->gp_idx] == MCP2221_ALT_F_NOT_GPIOV) ||
950 				(data[mcp->gp_idx - 1] == MCP2221_ALT_F_NOT_GPIOV)) {
951 				mcp->status = -ENOENT;
952 			} else {
953 				mcp->status = 0;
954 			}
955 			break;
956 		default:
957 			mcp->status = -EAGAIN;
958 		}
959 		complete(&mcp->wait_in_report);
960 		break;
961 
962 	case MCP2221_SET_SRAM_SETTINGS:
963 		switch (data[1]) {
964 		case MCP2221_SUCCESS:
965 			mcp->status = 0;
966 			break;
967 		default:
968 			mcp->status = -EAGAIN;
969 		}
970 		complete(&mcp->wait_in_report);
971 		break;
972 
973 	case MCP2221_GET_SRAM_SETTINGS:
974 		switch (data[1]) {
975 		case MCP2221_SUCCESS:
976 			memcpy(&mcp->mode, &data[22], 4);
977 #if IS_REACHABLE(CONFIG_IIO)
978 			mcp->dac_value = data[6] & GENMASK(4, 0);
979 #endif
980 			mcp->status = 0;
981 			break;
982 		default:
983 			mcp->status = -EAGAIN;
984 		}
985 		complete(&mcp->wait_in_report);
986 		break;
987 
988 	case MCP2221_READ_FLASH_DATA:
989 		switch (data[1]) {
990 		case MCP2221_SUCCESS:
991 			mcp->status = 0;
992 
993 			/* Only handles CHIP SETTINGS subpage currently */
994 			if (mcp->txbuf[1] != 0) {
995 				mcp->status = -EIO;
996 				break;
997 			}
998 
999 #if IS_REACHABLE(CONFIG_IIO)
1000 			{
1001 				u8 tmp;
1002 				/* DAC scale value */
1003 				tmp = FIELD_GET(GENMASK(7, 6), data[6]);
1004 				if ((data[6] & BIT(5)) && tmp)
1005 					mcp->dac_scale = tmp + 4;
1006 				else
1007 					mcp->dac_scale = 5;
1008 
1009 				/* ADC scale value */
1010 				tmp = FIELD_GET(GENMASK(4, 3), data[7]);
1011 				if ((data[7] & BIT(2)) && tmp)
1012 					mcp->adc_scale = tmp - 1;
1013 				else
1014 					mcp->adc_scale = 0;
1015 			}
1016 #endif
1017 
1018 			break;
1019 		default:
1020 			mcp->status = -EAGAIN;
1021 		}
1022 		complete(&mcp->wait_in_report);
1023 		break;
1024 
1025 	default:
1026 		mcp->status = -EIO;
1027 		complete(&mcp->wait_in_report);
1028 	}
1029 
1030 	return 1;
1031 }
1032 
1033 /* Device resource managed function for HID unregistration */
mcp2221_hid_unregister(void * ptr)1034 static void mcp2221_hid_unregister(void *ptr)
1035 {
1036 	struct hid_device *hdev = ptr;
1037 
1038 	hid_hw_close(hdev);
1039 	hid_hw_stop(hdev);
1040 }
1041 
1042 /* This is needed to be sure hid_hw_stop() isn't called twice by the subsystem */
mcp2221_remove(struct hid_device * hdev)1043 static void mcp2221_remove(struct hid_device *hdev)
1044 {
1045 #if IS_REACHABLE(CONFIG_IIO)
1046 	struct mcp2221 *mcp = hid_get_drvdata(hdev);
1047 
1048 	cancel_delayed_work_sync(&mcp->init_work);
1049 #endif
1050 }
1051 
1052 #if IS_REACHABLE(CONFIG_IIO)
mcp2221_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * channel,int * val,int * val2,long mask)1053 static int mcp2221_read_raw(struct iio_dev *indio_dev,
1054 			    struct iio_chan_spec const *channel, int *val,
1055 			    int *val2, long mask)
1056 {
1057 	struct mcp2221_iio *priv = iio_priv(indio_dev);
1058 	struct mcp2221 *mcp = priv->mcp;
1059 	int ret;
1060 
1061 	if (mask == IIO_CHAN_INFO_SCALE) {
1062 		if (channel->output)
1063 			*val = 1 << mcp->dac_scale;
1064 		else
1065 			*val = 1 << mcp->adc_scale;
1066 
1067 		return IIO_VAL_INT;
1068 	}
1069 
1070 	mutex_lock(&mcp->lock);
1071 
1072 	if (channel->output) {
1073 		*val = mcp->dac_value;
1074 		ret = IIO_VAL_INT;
1075 	} else {
1076 		/* Read ADC values */
1077 		ret = mcp_chk_last_cmd_status(mcp);
1078 
1079 		if (!ret) {
1080 			*val = le16_to_cpu((__force __le16) mcp->adc_values[channel->address]);
1081 			if (*val >= BIT(10))
1082 				ret =  -EINVAL;
1083 			else
1084 				ret = IIO_VAL_INT;
1085 		}
1086 	}
1087 
1088 	mutex_unlock(&mcp->lock);
1089 
1090 	return ret;
1091 }
1092 
mcp2221_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)1093 static int mcp2221_write_raw(struct iio_dev *indio_dev,
1094 			     struct iio_chan_spec const *chan,
1095 			     int val, int val2, long mask)
1096 {
1097 	struct mcp2221_iio *priv = iio_priv(indio_dev);
1098 	struct mcp2221 *mcp = priv->mcp;
1099 	int ret;
1100 
1101 	if (val < 0 || val >= BIT(5))
1102 		return -EINVAL;
1103 
1104 	mutex_lock(&mcp->lock);
1105 
1106 	memset(mcp->txbuf, 0, 12);
1107 	mcp->txbuf[0] = MCP2221_SET_SRAM_SETTINGS;
1108 	mcp->txbuf[4] = BIT(7) | val;
1109 
1110 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 12);
1111 	if (!ret)
1112 		mcp->dac_value = val;
1113 
1114 	mutex_unlock(&mcp->lock);
1115 
1116 	return ret;
1117 }
1118 
1119 static const struct iio_info mcp2221_info = {
1120 	.read_raw = &mcp2221_read_raw,
1121 	.write_raw = &mcp2221_write_raw,
1122 };
1123 
mcp_iio_channels(struct mcp2221 * mcp)1124 static int mcp_iio_channels(struct mcp2221 *mcp)
1125 {
1126 	int idx, cnt = 0;
1127 	bool dac_created = false;
1128 
1129 	/* GP0 doesn't have ADC/DAC alternative function */
1130 	for (idx = 1; idx < MCP_NGPIO; idx++) {
1131 		struct iio_chan_spec *chan = &mcp->iio_channels[cnt];
1132 
1133 		switch (mcp->mode[idx]) {
1134 		case 2:
1135 			chan->address = idx - 1;
1136 			chan->channel = cnt++;
1137 			break;
1138 		case 3:
1139 			/* GP1 doesn't have DAC alternative function */
1140 			if (idx == 1 || dac_created)
1141 				continue;
1142 			/* DAC1 and DAC2 outputs are connected to the same DAC */
1143 			dac_created = true;
1144 			chan->output = 1;
1145 			cnt++;
1146 			break;
1147 		default:
1148 			continue;
1149 		}
1150 
1151 		chan->type = IIO_VOLTAGE;
1152 		chan->indexed = 1;
1153 		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
1154 		chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
1155 		chan->scan_index = -1;
1156 	}
1157 
1158 	return cnt;
1159 }
1160 
mcp_init_work(struct work_struct * work)1161 static void mcp_init_work(struct work_struct *work)
1162 {
1163 	struct iio_dev *indio_dev;
1164 	struct mcp2221 *mcp = container_of(work, struct mcp2221, init_work.work);
1165 	struct mcp2221_iio *data;
1166 	static int retries = 5;
1167 	int ret, num_channels;
1168 
1169 	hid_hw_power(mcp->hdev, PM_HINT_FULLON);
1170 	mutex_lock(&mcp->lock);
1171 
1172 	mcp->txbuf[0] = MCP2221_GET_SRAM_SETTINGS;
1173 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
1174 
1175 	if (ret == -EAGAIN)
1176 		goto reschedule_task;
1177 
1178 	num_channels = mcp_iio_channels(mcp);
1179 	if (!num_channels)
1180 		goto unlock;
1181 
1182 	mcp->txbuf[0] = MCP2221_READ_FLASH_DATA;
1183 	mcp->txbuf[1] = 0;
1184 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 2);
1185 
1186 	if (ret == -EAGAIN)
1187 		goto reschedule_task;
1188 
1189 	indio_dev = devm_iio_device_alloc(&mcp->hdev->dev, sizeof(*data));
1190 	if (!indio_dev)
1191 		goto unlock;
1192 
1193 	data = iio_priv(indio_dev);
1194 	data->mcp = mcp;
1195 
1196 	indio_dev->name = "mcp2221";
1197 	indio_dev->modes = INDIO_DIRECT_MODE;
1198 	indio_dev->info = &mcp2221_info;
1199 	indio_dev->channels = mcp->iio_channels;
1200 	indio_dev->num_channels = num_channels;
1201 
1202 	devm_iio_device_register(&mcp->hdev->dev, indio_dev);
1203 
1204 unlock:
1205 	mutex_unlock(&mcp->lock);
1206 	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
1207 
1208 	return;
1209 
1210 reschedule_task:
1211 	mutex_unlock(&mcp->lock);
1212 	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
1213 
1214 	if (!retries--)
1215 		return;
1216 
1217 	/* Device is not ready to read SRAM or FLASH data, try again */
1218 	schedule_delayed_work(&mcp->init_work, msecs_to_jiffies(100));
1219 }
1220 #endif
1221 
mcp2221_probe(struct hid_device * hdev,const struct hid_device_id * id)1222 static int mcp2221_probe(struct hid_device *hdev,
1223 					const struct hid_device_id *id)
1224 {
1225 	int ret;
1226 	struct mcp2221 *mcp;
1227 
1228 	mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL);
1229 	if (!mcp)
1230 		return -ENOMEM;
1231 
1232 	ret = hid_parse(hdev);
1233 	if (ret) {
1234 		hid_err(hdev, "can't parse reports\n");
1235 		return ret;
1236 	}
1237 
1238 	/*
1239 	 * This driver uses the .raw_event callback and therefore does not need any
1240 	 * HID_CONNECT_xxx flags.
1241 	 */
1242 	ret = hid_hw_start(hdev, 0);
1243 	if (ret) {
1244 		hid_err(hdev, "can't start hardware\n");
1245 		return ret;
1246 	}
1247 
1248 	hid_info(hdev, "USB HID v%x.%02x Device [%s] on %s\n", hdev->version >> 8,
1249 			hdev->version & 0xff, hdev->name, hdev->phys);
1250 
1251 	ret = hid_hw_open(hdev);
1252 	if (ret) {
1253 		hid_err(hdev, "can't open device\n");
1254 		hid_hw_stop(hdev);
1255 		return ret;
1256 	}
1257 
1258 	mutex_init(&mcp->lock);
1259 	init_completion(&mcp->wait_in_report);
1260 	hid_set_drvdata(hdev, mcp);
1261 	mcp->hdev = hdev;
1262 
1263 	ret = devm_add_action_or_reset(&hdev->dev, mcp2221_hid_unregister, hdev);
1264 	if (ret)
1265 		return ret;
1266 
1267 	hid_device_io_start(hdev);
1268 
1269 	/* Set I2C bus clock diviser */
1270 	if (i2c_clk_freq > 400)
1271 		i2c_clk_freq = 400;
1272 	if (i2c_clk_freq < 50)
1273 		i2c_clk_freq = 50;
1274 	mcp->cur_i2c_clk_div = (12000000 / (i2c_clk_freq * 1000)) - 3;
1275 	ret = mcp_set_i2c_speed(mcp);
1276 	if (ret) {
1277 		hid_err(hdev, "can't set i2c speed: %d\n", ret);
1278 		return ret;
1279 	}
1280 
1281 	mcp->adapter.owner = THIS_MODULE;
1282 	mcp->adapter.class = I2C_CLASS_HWMON;
1283 	mcp->adapter.algo = &mcp_i2c_algo;
1284 	mcp->adapter.retries = 1;
1285 	mcp->adapter.dev.parent = &hdev->dev;
1286 	ACPI_COMPANION_SET(&mcp->adapter.dev, ACPI_COMPANION(hdev->dev.parent));
1287 	snprintf(mcp->adapter.name, sizeof(mcp->adapter.name),
1288 			"MCP2221 usb-i2c bridge");
1289 
1290 	i2c_set_adapdata(&mcp->adapter, mcp);
1291 	ret = devm_i2c_add_adapter(&hdev->dev, &mcp->adapter);
1292 	if (ret) {
1293 		hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret);
1294 		return ret;
1295 	}
1296 
1297 #if IS_REACHABLE(CONFIG_GPIOLIB)
1298 	/* Setup GPIO chip */
1299 	mcp->gc = devm_kzalloc(&hdev->dev, sizeof(*mcp->gc), GFP_KERNEL);
1300 	if (!mcp->gc)
1301 		return -ENOMEM;
1302 
1303 	mcp->gc->label = "mcp2221_gpio";
1304 	mcp->gc->direction_input = mcp_gpio_direction_input;
1305 	mcp->gc->direction_output = mcp_gpio_direction_output;
1306 	mcp->gc->get_direction = mcp_gpio_get_direction;
1307 	mcp->gc->set = mcp_gpio_set;
1308 	mcp->gc->get = mcp_gpio_get;
1309 	mcp->gc->ngpio = MCP_NGPIO;
1310 	mcp->gc->base = -1;
1311 	mcp->gc->can_sleep = 1;
1312 	mcp->gc->parent = &hdev->dev;
1313 
1314 	ret = devm_gpiochip_add_data(&hdev->dev, mcp->gc, mcp);
1315 	if (ret)
1316 		return ret;
1317 
1318 	mcp2221_check_gpio_pinfunc(mcp);
1319 #endif
1320 
1321 #if IS_REACHABLE(CONFIG_IIO)
1322 	INIT_DELAYED_WORK(&mcp->init_work, mcp_init_work);
1323 	schedule_delayed_work(&mcp->init_work, msecs_to_jiffies(100));
1324 #endif
1325 
1326 	return 0;
1327 }
1328 
1329 static const struct hid_device_id mcp2221_devices[] = {
1330 	{ HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2221) },
1331 	{ }
1332 };
1333 MODULE_DEVICE_TABLE(hid, mcp2221_devices);
1334 
1335 static struct hid_driver mcp2221_driver = {
1336 	.name		= "mcp2221",
1337 	.id_table	= mcp2221_devices,
1338 	.probe		= mcp2221_probe,
1339 	.remove		= mcp2221_remove,
1340 	.raw_event	= mcp2221_raw_event,
1341 };
1342 
1343 /* Register with HID core */
1344 module_hid_driver(mcp2221_driver);
1345 
1346 MODULE_AUTHOR("Rishi Gupta <gupt21@gmail.com>");
1347 MODULE_DESCRIPTION("MCP2221 Microchip HID USB to I2C master bridge");
1348 MODULE_LICENSE("GPL v2");
1349