xref: /linux/drivers/hid/hid-mcp2221.c (revision b80a75cf6999fb79971b41eaec7af2bb4b514714)
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 				return ret;
357 			}
358 		} else {
359 			retries = 0;
360 		}
361 	} while (mcp->rxbuf_idx < total_len);
362 
363 	usleep_range(980, 1000);
364 	ret = mcp_chk_last_cmd_status_free_bus(mcp);
365 
366 	return ret;
367 }
368 
mcp_i2c_xfer(struct i2c_adapter * adapter,struct i2c_msg msgs[],int num)369 static int mcp_i2c_xfer(struct i2c_adapter *adapter,
370 				struct i2c_msg msgs[], int num)
371 {
372 	int ret;
373 	struct mcp2221 *mcp = i2c_get_adapdata(adapter);
374 
375 	hid_hw_power(mcp->hdev, PM_HINT_FULLON);
376 
377 	mutex_lock(&mcp->lock);
378 
379 	if (num == 1) {
380 		if (msgs->flags & I2C_M_RD) {
381 			ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA,
382 							0, 0, NULL);
383 		} else {
384 			ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1);
385 		}
386 		if (ret)
387 			goto exit;
388 		ret = num;
389 	} else if (num == 2) {
390 		/* Ex transaction; send reg address and read its contents */
391 		if (msgs[0].addr == msgs[1].addr &&
392 			!(msgs[0].flags & I2C_M_RD) &&
393 			 (msgs[1].flags & I2C_M_RD)) {
394 
395 			ret = mcp_i2c_write(mcp, &msgs[0],
396 						MCP2221_I2C_WR_NO_STOP, 0);
397 			if (ret)
398 				goto exit;
399 
400 			ret = mcp_i2c_smbus_read(mcp, &msgs[1],
401 						MCP2221_I2C_RD_RPT_START,
402 						0, 0, NULL);
403 			if (ret)
404 				goto exit;
405 			ret = num;
406 		} else {
407 			dev_err(&adapter->dev,
408 				"unsupported multi-msg i2c transaction\n");
409 			ret = -EOPNOTSUPP;
410 		}
411 	} else {
412 		dev_err(&adapter->dev,
413 			"unsupported multi-msg i2c transaction\n");
414 		ret = -EOPNOTSUPP;
415 	}
416 
417 exit:
418 	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
419 	mutex_unlock(&mcp->lock);
420 	return ret;
421 }
422 
mcp_smbus_write(struct mcp2221 * mcp,u16 addr,u8 command,u8 * buf,u8 len,int type,u8 last_status)423 static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr,
424 				u8 command, u8 *buf, u8 len, int type,
425 				u8 last_status)
426 {
427 	int data_len, ret;
428 
429 	mcp->txbuf[0] = type;
430 	mcp->txbuf[1] = len + 1; /* 1 is due to command byte itself */
431 	mcp->txbuf[2] = 0;
432 	mcp->txbuf[3] = (u8)(addr << 1);
433 	mcp->txbuf[4] = command;
434 
435 	switch (len) {
436 	case 0:
437 		data_len = 5;
438 		break;
439 	case 1:
440 		mcp->txbuf[5] = buf[0];
441 		data_len = 6;
442 		break;
443 	case 2:
444 		mcp->txbuf[5] = buf[0];
445 		mcp->txbuf[6] = buf[1];
446 		data_len = 7;
447 		break;
448 	default:
449 		if (len > I2C_SMBUS_BLOCK_MAX)
450 			return -EINVAL;
451 
452 		memcpy(&mcp->txbuf[5], buf, len);
453 		data_len = len + 5;
454 	}
455 
456 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, data_len);
457 	if (ret)
458 		return ret;
459 
460 	if (last_status) {
461 		usleep_range(980, 1000);
462 
463 		ret = mcp_chk_last_cmd_status_free_bus(mcp);
464 	}
465 
466 	return ret;
467 }
468 
mcp_smbus_xfer(struct i2c_adapter * adapter,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)469 static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
470 				unsigned short flags, char read_write,
471 				u8 command, int size,
472 				union i2c_smbus_data *data)
473 {
474 	int ret;
475 	struct mcp2221 *mcp = i2c_get_adapdata(adapter);
476 
477 	hid_hw_power(mcp->hdev, PM_HINT_FULLON);
478 
479 	mutex_lock(&mcp->lock);
480 
481 	switch (size) {
482 
483 	case I2C_SMBUS_QUICK:
484 		if (read_write == I2C_SMBUS_READ)
485 			ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA,
486 						addr, 0, &data->byte);
487 		else
488 			ret = mcp_smbus_write(mcp, addr, command, NULL,
489 						0, MCP2221_I2C_WR_DATA, 1);
490 		break;
491 	case I2C_SMBUS_BYTE:
492 		if (read_write == I2C_SMBUS_READ)
493 			ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA,
494 						addr, 1, &data->byte);
495 		else
496 			ret = mcp_smbus_write(mcp, addr, command, NULL,
497 						0, MCP2221_I2C_WR_DATA, 1);
498 		break;
499 	case I2C_SMBUS_BYTE_DATA:
500 		if (read_write == I2C_SMBUS_READ) {
501 			ret = mcp_smbus_write(mcp, addr, command, NULL,
502 						0, MCP2221_I2C_WR_NO_STOP, 0);
503 			if (ret)
504 				goto exit;
505 
506 			ret = mcp_i2c_smbus_read(mcp, NULL,
507 						MCP2221_I2C_RD_RPT_START,
508 						addr, 1, &data->byte);
509 		} else {
510 			ret = mcp_smbus_write(mcp, addr, command, &data->byte,
511 						1, MCP2221_I2C_WR_DATA, 1);
512 		}
513 		break;
514 	case I2C_SMBUS_WORD_DATA:
515 		if (read_write == I2C_SMBUS_READ) {
516 			ret = mcp_smbus_write(mcp, addr, command, NULL,
517 						0, MCP2221_I2C_WR_NO_STOP, 0);
518 			if (ret)
519 				goto exit;
520 
521 			ret = mcp_i2c_smbus_read(mcp, NULL,
522 						MCP2221_I2C_RD_RPT_START,
523 						addr, 2, (u8 *)&data->word);
524 		} else {
525 			ret = mcp_smbus_write(mcp, addr, command,
526 						(u8 *)&data->word, 2,
527 						MCP2221_I2C_WR_DATA, 1);
528 		}
529 		break;
530 	case I2C_SMBUS_BLOCK_DATA:
531 		if (read_write == I2C_SMBUS_READ) {
532 			ret = mcp_smbus_write(mcp, addr, command, NULL,
533 						0, MCP2221_I2C_WR_NO_STOP, 1);
534 			if (ret)
535 				goto exit;
536 
537 			mcp->rxbuf_idx = 0;
538 			mcp->rxbuf = data->block;
539 			mcp->txbuf[0] = MCP2221_I2C_GET_DATA;
540 			ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
541 			if (ret)
542 				goto exit;
543 		} else {
544 			if (!data->block[0]) {
545 				ret = -EINVAL;
546 				goto exit;
547 			}
548 			ret = mcp_smbus_write(mcp, addr, command, data->block,
549 						data->block[0] + 1,
550 						MCP2221_I2C_WR_DATA, 1);
551 		}
552 		break;
553 	case I2C_SMBUS_I2C_BLOCK_DATA:
554 		if (read_write == I2C_SMBUS_READ) {
555 			ret = mcp_smbus_write(mcp, addr, command, NULL,
556 						0, MCP2221_I2C_WR_NO_STOP, 1);
557 			if (ret)
558 				goto exit;
559 
560 			mcp->rxbuf_idx = 0;
561 			mcp->rxbuf = data->block;
562 			mcp->txbuf[0] = MCP2221_I2C_GET_DATA;
563 			ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
564 			if (ret)
565 				goto exit;
566 		} else {
567 			if (!data->block[0]) {
568 				ret = -EINVAL;
569 				goto exit;
570 			}
571 			ret = mcp_smbus_write(mcp, addr, command,
572 						&data->block[1], data->block[0],
573 						MCP2221_I2C_WR_DATA, 1);
574 		}
575 		break;
576 	case I2C_SMBUS_PROC_CALL:
577 		ret = mcp_smbus_write(mcp, addr, command,
578 						(u8 *)&data->word,
579 						2, MCP2221_I2C_WR_NO_STOP, 0);
580 		if (ret)
581 			goto exit;
582 
583 		ret = mcp_i2c_smbus_read(mcp, NULL,
584 						MCP2221_I2C_RD_RPT_START,
585 						addr, 2, (u8 *)&data->word);
586 		break;
587 	case I2C_SMBUS_BLOCK_PROC_CALL:
588 		ret = mcp_smbus_write(mcp, addr, command, data->block,
589 						data->block[0] + 1,
590 						MCP2221_I2C_WR_NO_STOP, 0);
591 		if (ret)
592 			goto exit;
593 
594 		ret = mcp_i2c_smbus_read(mcp, NULL,
595 						MCP2221_I2C_RD_RPT_START,
596 						addr, I2C_SMBUS_BLOCK_MAX,
597 						data->block);
598 		break;
599 	default:
600 		dev_err(&mcp->adapter.dev,
601 			"unsupported smbus transaction size:%d\n", size);
602 		ret = -EOPNOTSUPP;
603 	}
604 
605 exit:
606 	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
607 	mutex_unlock(&mcp->lock);
608 	return ret;
609 }
610 
mcp_i2c_func(struct i2c_adapter * adapter)611 static u32 mcp_i2c_func(struct i2c_adapter *adapter)
612 {
613 	return I2C_FUNC_I2C |
614 			I2C_FUNC_SMBUS_READ_BLOCK_DATA |
615 			I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
616 			(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_PEC);
617 }
618 
619 static const struct i2c_algorithm mcp_i2c_algo = {
620 	.master_xfer = mcp_i2c_xfer,
621 	.smbus_xfer = mcp_smbus_xfer,
622 	.functionality = mcp_i2c_func,
623 };
624 
625 #if IS_REACHABLE(CONFIG_GPIOLIB)
mcp_gpio_read_sram(struct mcp2221 * mcp)626 static int mcp_gpio_read_sram(struct mcp2221 *mcp)
627 {
628 	int ret;
629 
630 	memset(mcp->txbuf, 0, 64);
631 	mcp->txbuf[0] = MCP2221_GET_SRAM_SETTINGS;
632 
633 	mutex_lock(&mcp->lock);
634 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 64);
635 	mutex_unlock(&mcp->lock);
636 
637 	return ret;
638 }
639 
640 /*
641  * If CONFIG_IIO is not enabled, check for the gpio pins
642  * if they are in gpio mode. For the ones which are not
643  * in gpio mode, set them into gpio mode.
644  */
mcp2221_check_gpio_pinfunc(struct mcp2221 * mcp)645 static int mcp2221_check_gpio_pinfunc(struct mcp2221 *mcp)
646 {
647 	int i;
648 	int needgpiofix = 0;
649 	int ret;
650 
651 	if (IS_ENABLED(CONFIG_IIO))
652 		return 0;
653 
654 	ret = mcp_gpio_read_sram(mcp);
655 	if (ret)
656 		return ret;
657 
658 	for (i = 0; i < MCP_NGPIO; i++) {
659 		if ((mcp->mode[i] & MCP2221_SRAM_GP_DESIGN_MASK) != 0x0) {
660 			dev_warn(&mcp->hdev->dev,
661 				 "GPIO %d not in gpio mode\n", i);
662 			needgpiofix = 1;
663 		}
664 	}
665 
666 	if (!needgpiofix)
667 		return 0;
668 
669 	/*
670 	 * Set all bytes to 0, so Bit 7 is not set. The chip
671 	 * only changes content of a register when bit 7 is set.
672 	 */
673 	memset(mcp->txbuf, 0, 64);
674 	mcp->txbuf[0] = MCP2221_SET_SRAM_SETTINGS;
675 
676 	/*
677 	 * Set bit 7 in MCP2221_SRAM_WR_GP_ENA_ALTER to enable
678 	 * loading of a new set of gpio settings to GP SRAM
679 	 */
680 	mcp->txbuf[MCP2221_SRAM_WR_GP_ENA_ALTER] = 0x80;
681 	for (i = 0; i < MCP_NGPIO; i++) {
682 		if ((mcp->mode[i] & MCP2221_SRAM_GP_DESIGN_MASK) == 0x0) {
683 			/* write current GPIO mode */
684 			mcp->txbuf[MCP2221_SRAM_WR_GP0 + i] = mcp->mode[i];
685 		} else {
686 			/* pin is not in gpio mode, set it to input mode */
687 			mcp->txbuf[MCP2221_SRAM_WR_GP0 + i] = 0x08;
688 			dev_warn(&mcp->hdev->dev,
689 				 "Set GPIO mode for gpio pin %d!\n", i);
690 		}
691 	}
692 
693 	mutex_lock(&mcp->lock);
694 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 64);
695 	mutex_unlock(&mcp->lock);
696 
697 	return ret;
698 }
699 
mcp_gpio_get(struct gpio_chip * gc,unsigned int offset)700 static int mcp_gpio_get(struct gpio_chip *gc,
701 				unsigned int offset)
702 {
703 	int ret;
704 	struct mcp2221 *mcp = gpiochip_get_data(gc);
705 
706 	mcp->txbuf[0] = MCP2221_GPIO_GET;
707 
708 	mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset]);
709 
710 	mutex_lock(&mcp->lock);
711 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
712 	mutex_unlock(&mcp->lock);
713 
714 	return ret;
715 }
716 
mcp_gpio_set(struct gpio_chip * gc,unsigned int offset,int value)717 static int mcp_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
718 {
719 	struct mcp2221 *mcp = gpiochip_get_data(gc);
720 	int ret;
721 
722 	memset(mcp->txbuf, 0, 18);
723 	mcp->txbuf[0] = MCP2221_GPIO_SET;
724 
725 	mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].value);
726 
727 	mcp->txbuf[mcp->gp_idx - 1] = 1;
728 	mcp->txbuf[mcp->gp_idx] = !!value;
729 
730 	mutex_lock(&mcp->lock);
731 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 18);
732 	mutex_unlock(&mcp->lock);
733 
734 	return ret;
735 }
736 
mcp_gpio_dir_set(struct mcp2221 * mcp,unsigned int offset,u8 val)737 static int mcp_gpio_dir_set(struct mcp2221 *mcp,
738 				unsigned int offset, u8 val)
739 {
740 	memset(mcp->txbuf, 0, 18);
741 	mcp->txbuf[0] = MCP2221_GPIO_SET;
742 
743 	mcp->gp_idx = offsetof(struct mcp_set_gpio, gpio[offset].direction);
744 
745 	mcp->txbuf[mcp->gp_idx - 1] = 1;
746 	mcp->txbuf[mcp->gp_idx] = val;
747 
748 	return mcp_send_data_req_status(mcp, mcp->txbuf, 18);
749 }
750 
mcp_gpio_direction_input(struct gpio_chip * gc,unsigned int offset)751 static int mcp_gpio_direction_input(struct gpio_chip *gc,
752 				unsigned int offset)
753 {
754 	int ret;
755 	struct mcp2221 *mcp = gpiochip_get_data(gc);
756 
757 	mutex_lock(&mcp->lock);
758 	ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_IN);
759 	mutex_unlock(&mcp->lock);
760 
761 	return ret;
762 }
763 
mcp_gpio_direction_output(struct gpio_chip * gc,unsigned int offset,int value)764 static int mcp_gpio_direction_output(struct gpio_chip *gc,
765 				unsigned int offset, int value)
766 {
767 	int ret;
768 	struct mcp2221 *mcp = gpiochip_get_data(gc);
769 
770 	mutex_lock(&mcp->lock);
771 	ret = mcp_gpio_dir_set(mcp, offset, MCP2221_DIR_OUT);
772 	mutex_unlock(&mcp->lock);
773 
774 	/* Can't configure as output, bailout early */
775 	if (ret)
776 		return ret;
777 
778 	mcp_gpio_set(gc, offset, value);
779 
780 	return 0;
781 }
782 
mcp_gpio_get_direction(struct gpio_chip * gc,unsigned int offset)783 static int mcp_gpio_get_direction(struct gpio_chip *gc,
784 				unsigned int offset)
785 {
786 	int ret;
787 	struct mcp2221 *mcp = gpiochip_get_data(gc);
788 
789 	mcp->txbuf[0] = MCP2221_GPIO_GET;
790 
791 	mcp->gp_idx = offsetof(struct mcp_get_gpio, gpio[offset]);
792 
793 	mutex_lock(&mcp->lock);
794 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
795 	mutex_unlock(&mcp->lock);
796 
797 	if (ret)
798 		return ret;
799 
800 	if (mcp->gpio_dir == MCP2221_DIR_IN)
801 		return GPIO_LINE_DIRECTION_IN;
802 
803 	return GPIO_LINE_DIRECTION_OUT;
804 }
805 #endif
806 
807 /* Gives current state of i2c engine inside mcp2221 */
mcp_get_i2c_eng_state(struct mcp2221 * mcp,u8 * data,u8 idx)808 static int mcp_get_i2c_eng_state(struct mcp2221 *mcp,
809 				u8 *data, u8 idx)
810 {
811 	int ret;
812 
813 	switch (data[idx]) {
814 	case MCP2221_I2C_WRADDRL_NACK:
815 	case MCP2221_I2C_WRADDRL_SEND:
816 		ret = -ENXIO;
817 		break;
818 	case MCP2221_I2C_START_TOUT:
819 	case MCP2221_I2C_STOP_TOUT:
820 	case MCP2221_I2C_WRADDRL_TOUT:
821 	case MCP2221_I2C_WRDATA_TOUT:
822 		ret = -ETIMEDOUT;
823 		break;
824 	case MCP2221_I2C_ENG_BUSY:
825 		ret = -EAGAIN;
826 		break;
827 	case MCP2221_SUCCESS:
828 		ret = 0x00;
829 		break;
830 	default:
831 		ret = -EIO;
832 	}
833 
834 	return ret;
835 }
836 
837 /*
838  * MCP2221 uses interrupt endpoint for input reports. This function
839  * is called by HID layer when it receives i/p report from mcp2221,
840  * which is actually a response to the previously sent command.
841  *
842  * MCP2221A firmware specific return codes are parsed and 0 or
843  * appropriate negative error code is returned. Delayed response
844  * results in timeout error and stray reponses results in -EIO.
845  */
mcp2221_raw_event(struct hid_device * hdev,struct hid_report * report,u8 * data,int size)846 static int mcp2221_raw_event(struct hid_device *hdev,
847 				struct hid_report *report, u8 *data, int size)
848 {
849 	u8 *buf;
850 	struct mcp2221 *mcp = hid_get_drvdata(hdev);
851 
852 	switch (data[0]) {
853 
854 	case MCP2221_I2C_WR_DATA:
855 	case MCP2221_I2C_WR_NO_STOP:
856 	case MCP2221_I2C_RD_DATA:
857 	case MCP2221_I2C_RD_RPT_START:
858 		switch (data[1]) {
859 		case MCP2221_SUCCESS:
860 			mcp->status = 0;
861 			break;
862 		default:
863 			mcp->status = mcp_get_i2c_eng_state(mcp, data, 2);
864 		}
865 		complete(&mcp->wait_in_report);
866 		break;
867 
868 	case MCP2221_I2C_PARAM_OR_STATUS:
869 		switch (data[1]) {
870 		case MCP2221_SUCCESS:
871 			if ((mcp->txbuf[3] == MCP2221_I2C_SET_SPEED) &&
872 				(data[3] != MCP2221_I2C_SET_SPEED)) {
873 				mcp->status = -EAGAIN;
874 				break;
875 			}
876 			if (data[20] & MCP2221_I2C_MASK_ADDR_NACK) {
877 				mcp->status = -ENXIO;
878 				break;
879 			}
880 			mcp->status = mcp_get_i2c_eng_state(mcp, data, 8);
881 #if IS_REACHABLE(CONFIG_IIO)
882 			memcpy(&mcp->adc_values, &data[50], sizeof(mcp->adc_values));
883 #endif
884 			break;
885 		default:
886 			mcp->status = -EIO;
887 		}
888 		complete(&mcp->wait_in_report);
889 		break;
890 
891 	case MCP2221_I2C_GET_DATA:
892 		switch (data[1]) {
893 		case MCP2221_SUCCESS:
894 			if (data[2] == MCP2221_I2C_ADDR_NACK) {
895 				mcp->status = -ENXIO;
896 				break;
897 			}
898 			if (!mcp_get_i2c_eng_state(mcp, data, 2)
899 				&& (data[3] == 0)) {
900 				mcp->status = 0;
901 				break;
902 			}
903 			if (data[3] == 127) {
904 				mcp->status = -EIO;
905 				break;
906 			}
907 			if (data[2] == MCP2221_I2C_READ_COMPL ||
908 			    data[2] == MCP2221_I2C_READ_PARTIAL) {
909 				buf = mcp->rxbuf;
910 				memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]);
911 				mcp->rxbuf_idx = mcp->rxbuf_idx + data[3];
912 				mcp->status = 0;
913 				break;
914 			}
915 			mcp->status = -EIO;
916 			break;
917 		default:
918 			mcp->status = -EIO;
919 		}
920 		complete(&mcp->wait_in_report);
921 		break;
922 
923 	case MCP2221_GPIO_GET:
924 		switch (data[1]) {
925 		case MCP2221_SUCCESS:
926 			if ((data[mcp->gp_idx] == MCP2221_ALT_F_NOT_GPIOV) ||
927 				(data[mcp->gp_idx + 1] == MCP2221_ALT_F_NOT_GPIOD)) {
928 				mcp->status = -ENOENT;
929 			} else {
930 				mcp->status = !!data[mcp->gp_idx];
931 				mcp->gpio_dir = data[mcp->gp_idx + 1];
932 			}
933 			break;
934 		default:
935 			mcp->status = -EAGAIN;
936 		}
937 		complete(&mcp->wait_in_report);
938 		break;
939 
940 	case MCP2221_GPIO_SET:
941 		switch (data[1]) {
942 		case MCP2221_SUCCESS:
943 			if ((data[mcp->gp_idx] == MCP2221_ALT_F_NOT_GPIOV) ||
944 				(data[mcp->gp_idx - 1] == MCP2221_ALT_F_NOT_GPIOV)) {
945 				mcp->status = -ENOENT;
946 			} else {
947 				mcp->status = 0;
948 			}
949 			break;
950 		default:
951 			mcp->status = -EAGAIN;
952 		}
953 		complete(&mcp->wait_in_report);
954 		break;
955 
956 	case MCP2221_SET_SRAM_SETTINGS:
957 		switch (data[1]) {
958 		case MCP2221_SUCCESS:
959 			mcp->status = 0;
960 			break;
961 		default:
962 			mcp->status = -EAGAIN;
963 		}
964 		complete(&mcp->wait_in_report);
965 		break;
966 
967 	case MCP2221_GET_SRAM_SETTINGS:
968 		switch (data[1]) {
969 		case MCP2221_SUCCESS:
970 			memcpy(&mcp->mode, &data[22], 4);
971 #if IS_REACHABLE(CONFIG_IIO)
972 			mcp->dac_value = data[6] & GENMASK(4, 0);
973 #endif
974 			mcp->status = 0;
975 			break;
976 		default:
977 			mcp->status = -EAGAIN;
978 		}
979 		complete(&mcp->wait_in_report);
980 		break;
981 
982 	case MCP2221_READ_FLASH_DATA:
983 		switch (data[1]) {
984 		case MCP2221_SUCCESS:
985 			mcp->status = 0;
986 
987 			/* Only handles CHIP SETTINGS subpage currently */
988 			if (mcp->txbuf[1] != 0) {
989 				mcp->status = -EIO;
990 				break;
991 			}
992 
993 #if IS_REACHABLE(CONFIG_IIO)
994 			{
995 				u8 tmp;
996 				/* DAC scale value */
997 				tmp = FIELD_GET(GENMASK(7, 6), data[6]);
998 				if ((data[6] & BIT(5)) && tmp)
999 					mcp->dac_scale = tmp + 4;
1000 				else
1001 					mcp->dac_scale = 5;
1002 
1003 				/* ADC scale value */
1004 				tmp = FIELD_GET(GENMASK(4, 3), data[7]);
1005 				if ((data[7] & BIT(2)) && tmp)
1006 					mcp->adc_scale = tmp - 1;
1007 				else
1008 					mcp->adc_scale = 0;
1009 			}
1010 #endif
1011 
1012 			break;
1013 		default:
1014 			mcp->status = -EAGAIN;
1015 		}
1016 		complete(&mcp->wait_in_report);
1017 		break;
1018 
1019 	default:
1020 		mcp->status = -EIO;
1021 		complete(&mcp->wait_in_report);
1022 	}
1023 
1024 	return 1;
1025 }
1026 
1027 /* Device resource managed function for HID unregistration */
mcp2221_hid_unregister(void * ptr)1028 static void mcp2221_hid_unregister(void *ptr)
1029 {
1030 	struct hid_device *hdev = ptr;
1031 
1032 	hid_hw_close(hdev);
1033 	hid_hw_stop(hdev);
1034 }
1035 
1036 /* This is needed to be sure hid_hw_stop() isn't called twice by the subsystem */
mcp2221_remove(struct hid_device * hdev)1037 static void mcp2221_remove(struct hid_device *hdev)
1038 {
1039 #if IS_REACHABLE(CONFIG_IIO)
1040 	struct mcp2221 *mcp = hid_get_drvdata(hdev);
1041 
1042 	cancel_delayed_work_sync(&mcp->init_work);
1043 #endif
1044 }
1045 
1046 #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)1047 static int mcp2221_read_raw(struct iio_dev *indio_dev,
1048 			    struct iio_chan_spec const *channel, int *val,
1049 			    int *val2, long mask)
1050 {
1051 	struct mcp2221_iio *priv = iio_priv(indio_dev);
1052 	struct mcp2221 *mcp = priv->mcp;
1053 	int ret;
1054 
1055 	if (mask == IIO_CHAN_INFO_SCALE) {
1056 		if (channel->output)
1057 			*val = 1 << mcp->dac_scale;
1058 		else
1059 			*val = 1 << mcp->adc_scale;
1060 
1061 		return IIO_VAL_INT;
1062 	}
1063 
1064 	mutex_lock(&mcp->lock);
1065 
1066 	if (channel->output) {
1067 		*val = mcp->dac_value;
1068 		ret = IIO_VAL_INT;
1069 	} else {
1070 		/* Read ADC values */
1071 		ret = mcp_chk_last_cmd_status(mcp);
1072 
1073 		if (!ret) {
1074 			*val = le16_to_cpu((__force __le16) mcp->adc_values[channel->address]);
1075 			if (*val >= BIT(10))
1076 				ret =  -EINVAL;
1077 			else
1078 				ret = IIO_VAL_INT;
1079 		}
1080 	}
1081 
1082 	mutex_unlock(&mcp->lock);
1083 
1084 	return ret;
1085 }
1086 
mcp2221_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)1087 static int mcp2221_write_raw(struct iio_dev *indio_dev,
1088 			     struct iio_chan_spec const *chan,
1089 			     int val, int val2, long mask)
1090 {
1091 	struct mcp2221_iio *priv = iio_priv(indio_dev);
1092 	struct mcp2221 *mcp = priv->mcp;
1093 	int ret;
1094 
1095 	if (val < 0 || val >= BIT(5))
1096 		return -EINVAL;
1097 
1098 	mutex_lock(&mcp->lock);
1099 
1100 	memset(mcp->txbuf, 0, 12);
1101 	mcp->txbuf[0] = MCP2221_SET_SRAM_SETTINGS;
1102 	mcp->txbuf[4] = BIT(7) | val;
1103 
1104 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 12);
1105 	if (!ret)
1106 		mcp->dac_value = val;
1107 
1108 	mutex_unlock(&mcp->lock);
1109 
1110 	return ret;
1111 }
1112 
1113 static const struct iio_info mcp2221_info = {
1114 	.read_raw = &mcp2221_read_raw,
1115 	.write_raw = &mcp2221_write_raw,
1116 };
1117 
mcp_iio_channels(struct mcp2221 * mcp)1118 static int mcp_iio_channels(struct mcp2221 *mcp)
1119 {
1120 	int idx, cnt = 0;
1121 	bool dac_created = false;
1122 
1123 	/* GP0 doesn't have ADC/DAC alternative function */
1124 	for (idx = 1; idx < MCP_NGPIO; idx++) {
1125 		struct iio_chan_spec *chan = &mcp->iio_channels[cnt];
1126 
1127 		switch (mcp->mode[idx]) {
1128 		case 2:
1129 			chan->address = idx - 1;
1130 			chan->channel = cnt++;
1131 			break;
1132 		case 3:
1133 			/* GP1 doesn't have DAC alternative function */
1134 			if (idx == 1 || dac_created)
1135 				continue;
1136 			/* DAC1 and DAC2 outputs are connected to the same DAC */
1137 			dac_created = true;
1138 			chan->output = 1;
1139 			cnt++;
1140 			break;
1141 		default:
1142 			continue;
1143 		}
1144 
1145 		chan->type = IIO_VOLTAGE;
1146 		chan->indexed = 1;
1147 		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
1148 		chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
1149 		chan->scan_index = -1;
1150 	}
1151 
1152 	return cnt;
1153 }
1154 
mcp_init_work(struct work_struct * work)1155 static void mcp_init_work(struct work_struct *work)
1156 {
1157 	struct iio_dev *indio_dev;
1158 	struct mcp2221 *mcp = container_of(work, struct mcp2221, init_work.work);
1159 	struct mcp2221_iio *data;
1160 	static int retries = 5;
1161 	int ret, num_channels;
1162 
1163 	hid_hw_power(mcp->hdev, PM_HINT_FULLON);
1164 	mutex_lock(&mcp->lock);
1165 
1166 	mcp->txbuf[0] = MCP2221_GET_SRAM_SETTINGS;
1167 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
1168 
1169 	if (ret == -EAGAIN)
1170 		goto reschedule_task;
1171 
1172 	num_channels = mcp_iio_channels(mcp);
1173 	if (!num_channels)
1174 		goto unlock;
1175 
1176 	mcp->txbuf[0] = MCP2221_READ_FLASH_DATA;
1177 	mcp->txbuf[1] = 0;
1178 	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 2);
1179 
1180 	if (ret == -EAGAIN)
1181 		goto reschedule_task;
1182 
1183 	indio_dev = devm_iio_device_alloc(&mcp->hdev->dev, sizeof(*data));
1184 	if (!indio_dev)
1185 		goto unlock;
1186 
1187 	data = iio_priv(indio_dev);
1188 	data->mcp = mcp;
1189 
1190 	indio_dev->name = "mcp2221";
1191 	indio_dev->modes = INDIO_DIRECT_MODE;
1192 	indio_dev->info = &mcp2221_info;
1193 	indio_dev->channels = mcp->iio_channels;
1194 	indio_dev->num_channels = num_channels;
1195 
1196 	devm_iio_device_register(&mcp->hdev->dev, indio_dev);
1197 
1198 unlock:
1199 	mutex_unlock(&mcp->lock);
1200 	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
1201 
1202 	return;
1203 
1204 reschedule_task:
1205 	mutex_unlock(&mcp->lock);
1206 	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
1207 
1208 	if (!retries--)
1209 		return;
1210 
1211 	/* Device is not ready to read SRAM or FLASH data, try again */
1212 	schedule_delayed_work(&mcp->init_work, msecs_to_jiffies(100));
1213 }
1214 #endif
1215 
mcp2221_probe(struct hid_device * hdev,const struct hid_device_id * id)1216 static int mcp2221_probe(struct hid_device *hdev,
1217 					const struct hid_device_id *id)
1218 {
1219 	int ret;
1220 	struct mcp2221 *mcp;
1221 
1222 	mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL);
1223 	if (!mcp)
1224 		return -ENOMEM;
1225 
1226 	ret = hid_parse(hdev);
1227 	if (ret) {
1228 		hid_err(hdev, "can't parse reports\n");
1229 		return ret;
1230 	}
1231 
1232 	/*
1233 	 * This driver uses the .raw_event callback and therefore does not need any
1234 	 * HID_CONNECT_xxx flags.
1235 	 */
1236 	ret = hid_hw_start(hdev, 0);
1237 	if (ret) {
1238 		hid_err(hdev, "can't start hardware\n");
1239 		return ret;
1240 	}
1241 
1242 	hid_info(hdev, "USB HID v%x.%02x Device [%s] on %s\n", hdev->version >> 8,
1243 			hdev->version & 0xff, hdev->name, hdev->phys);
1244 
1245 	ret = hid_hw_open(hdev);
1246 	if (ret) {
1247 		hid_err(hdev, "can't open device\n");
1248 		hid_hw_stop(hdev);
1249 		return ret;
1250 	}
1251 
1252 	mutex_init(&mcp->lock);
1253 	init_completion(&mcp->wait_in_report);
1254 	hid_set_drvdata(hdev, mcp);
1255 	mcp->hdev = hdev;
1256 
1257 	ret = devm_add_action_or_reset(&hdev->dev, mcp2221_hid_unregister, hdev);
1258 	if (ret)
1259 		return ret;
1260 
1261 	hid_device_io_start(hdev);
1262 
1263 	/* Set I2C bus clock diviser */
1264 	if (i2c_clk_freq > 400)
1265 		i2c_clk_freq = 400;
1266 	if (i2c_clk_freq < 50)
1267 		i2c_clk_freq = 50;
1268 	mcp->cur_i2c_clk_div = (12000000 / (i2c_clk_freq * 1000)) - 3;
1269 	ret = mcp_set_i2c_speed(mcp);
1270 	if (ret) {
1271 		hid_err(hdev, "can't set i2c speed: %d\n", ret);
1272 		return ret;
1273 	}
1274 
1275 	mcp->adapter.owner = THIS_MODULE;
1276 	mcp->adapter.class = I2C_CLASS_HWMON;
1277 	mcp->adapter.algo = &mcp_i2c_algo;
1278 	mcp->adapter.retries = 1;
1279 	mcp->adapter.dev.parent = &hdev->dev;
1280 	ACPI_COMPANION_SET(&mcp->adapter.dev, ACPI_COMPANION(hdev->dev.parent));
1281 	snprintf(mcp->adapter.name, sizeof(mcp->adapter.name),
1282 			"MCP2221 usb-i2c bridge");
1283 
1284 	i2c_set_adapdata(&mcp->adapter, mcp);
1285 	ret = devm_i2c_add_adapter(&hdev->dev, &mcp->adapter);
1286 	if (ret) {
1287 		hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret);
1288 		return ret;
1289 	}
1290 
1291 #if IS_REACHABLE(CONFIG_GPIOLIB)
1292 	/* Setup GPIO chip */
1293 	mcp->gc = devm_kzalloc(&hdev->dev, sizeof(*mcp->gc), GFP_KERNEL);
1294 	if (!mcp->gc)
1295 		return -ENOMEM;
1296 
1297 	mcp->gc->label = "mcp2221_gpio";
1298 	mcp->gc->direction_input = mcp_gpio_direction_input;
1299 	mcp->gc->direction_output = mcp_gpio_direction_output;
1300 	mcp->gc->get_direction = mcp_gpio_get_direction;
1301 	mcp->gc->set_rv = mcp_gpio_set;
1302 	mcp->gc->get = mcp_gpio_get;
1303 	mcp->gc->ngpio = MCP_NGPIO;
1304 	mcp->gc->base = -1;
1305 	mcp->gc->can_sleep = 1;
1306 	mcp->gc->parent = &hdev->dev;
1307 
1308 	ret = devm_gpiochip_add_data(&hdev->dev, mcp->gc, mcp);
1309 	if (ret)
1310 		return ret;
1311 
1312 	mcp2221_check_gpio_pinfunc(mcp);
1313 #endif
1314 
1315 #if IS_REACHABLE(CONFIG_IIO)
1316 	INIT_DELAYED_WORK(&mcp->init_work, mcp_init_work);
1317 	schedule_delayed_work(&mcp->init_work, msecs_to_jiffies(100));
1318 #endif
1319 
1320 	return 0;
1321 }
1322 
1323 static const struct hid_device_id mcp2221_devices[] = {
1324 	{ HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2221) },
1325 	{ }
1326 };
1327 MODULE_DEVICE_TABLE(hid, mcp2221_devices);
1328 
1329 static struct hid_driver mcp2221_driver = {
1330 	.name		= "mcp2221",
1331 	.id_table	= mcp2221_devices,
1332 	.probe		= mcp2221_probe,
1333 	.remove		= mcp2221_remove,
1334 	.raw_event	= mcp2221_raw_event,
1335 };
1336 
1337 /* Register with HID core */
1338 module_hid_driver(mcp2221_driver);
1339 
1340 MODULE_AUTHOR("Rishi Gupta <gupt21@gmail.com>");
1341 MODULE_DESCRIPTION("MCP2221 Microchip HID USB to I2C master bridge");
1342 MODULE_LICENSE("GPL v2");
1343