xref: /linux/drivers/hid/hid-cp2112.c (revision e3966940559d52aa1800a008dcfeec218dd31f88)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
4  * Copyright (c) 2013,2014 Uplogix, Inc.
5  * David Barksdale <dbarksdale@uplogix.com>
6  */
7 
8 /*
9  * The Silicon Labs CP2112 chip is a USB HID device which provides an
10  * SMBus controller for talking to slave devices and 8 GPIO pins. The
11  * host communicates with the CP2112 via raw HID reports.
12  *
13  * Data Sheet:
14  *   https://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
15  * Programming Interface Specification:
16  *   https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf
17  */
18 
19 #include <linux/bitops.h>
20 #include <linux/cleanup.h>
21 #include <linux/gpio/driver.h>
22 #include <linux/hid.h>
23 #include <linux/hidraw.h>
24 #include <linux/i2c.h>
25 #include <linux/module.h>
26 #include <linux/mutex.h>
27 #include <linux/nls.h>
28 #include <linux/string_choices.h>
29 #include <linux/usb/ch9.h>
30 #include "hid-ids.h"
31 
32 #define CP2112_REPORT_MAX_LENGTH		64
33 #define CP2112_GPIO_CONFIG_LENGTH		5
34 #define CP2112_GPIO_GET_LENGTH			2
35 #define CP2112_GPIO_SET_LENGTH			3
36 #define CP2112_GPIO_MAX_GPIO			8
37 #define CP2112_GPIO_ALL_GPIO_MASK		GENMASK(7, 0)
38 
39 enum {
40 	CP2112_GPIO_CONFIG		= 0x02,
41 	CP2112_GPIO_GET			= 0x03,
42 	CP2112_GPIO_SET			= 0x04,
43 	CP2112_GET_VERSION_INFO		= 0x05,
44 	CP2112_SMBUS_CONFIG		= 0x06,
45 	CP2112_DATA_READ_REQUEST	= 0x10,
46 	CP2112_DATA_WRITE_READ_REQUEST	= 0x11,
47 	CP2112_DATA_READ_FORCE_SEND	= 0x12,
48 	CP2112_DATA_READ_RESPONSE	= 0x13,
49 	CP2112_DATA_WRITE_REQUEST	= 0x14,
50 	CP2112_TRANSFER_STATUS_REQUEST	= 0x15,
51 	CP2112_TRANSFER_STATUS_RESPONSE	= 0x16,
52 	CP2112_CANCEL_TRANSFER		= 0x17,
53 	CP2112_LOCK_BYTE		= 0x20,
54 	CP2112_USB_CONFIG		= 0x21,
55 	CP2112_MANUFACTURER_STRING	= 0x22,
56 	CP2112_PRODUCT_STRING		= 0x23,
57 	CP2112_SERIAL_STRING		= 0x24,
58 };
59 
60 enum {
61 	STATUS0_IDLE		= 0x00,
62 	STATUS0_BUSY		= 0x01,
63 	STATUS0_COMPLETE	= 0x02,
64 	STATUS0_ERROR		= 0x03,
65 };
66 
67 enum {
68 	STATUS1_TIMEOUT_NACK		= 0x00,
69 	STATUS1_TIMEOUT_BUS		= 0x01,
70 	STATUS1_ARBITRATION_LOST	= 0x02,
71 	STATUS1_READ_INCOMPLETE		= 0x03,
72 	STATUS1_WRITE_INCOMPLETE	= 0x04,
73 	STATUS1_SUCCESS			= 0x05,
74 };
75 
76 struct cp2112_smbus_config_report {
77 	u8 report;		/* CP2112_SMBUS_CONFIG */
78 	__be32 clock_speed;	/* Hz */
79 	u8 device_address;	/* Stored in the upper 7 bits */
80 	u8 auto_send_read;	/* 1 = enabled, 0 = disabled */
81 	__be16 write_timeout;	/* ms, 0 = no timeout */
82 	__be16 read_timeout;	/* ms, 0 = no timeout */
83 	u8 scl_low_timeout;	/* 1 = enabled, 0 = disabled */
84 	__be16 retry_time;	/* # of retries, 0 = no limit */
85 } __packed;
86 
87 struct cp2112_usb_config_report {
88 	u8 report;	/* CP2112_USB_CONFIG */
89 	__le16 vid;	/* Vendor ID */
90 	__le16 pid;	/* Product ID */
91 	u8 max_power;	/* Power requested in 2mA units */
92 	u8 power_mode;	/* 0x00 = bus powered
93 			   0x01 = self powered & regulator off
94 			   0x02 = self powered & regulator on */
95 	u8 release_major;
96 	u8 release_minor;
97 	u8 mask;	/* What fields to program */
98 } __packed;
99 
100 struct cp2112_read_req_report {
101 	u8 report;	/* CP2112_DATA_READ_REQUEST */
102 	u8 slave_address;
103 	__be16 length;
104 } __packed;
105 
106 struct cp2112_write_read_req_report {
107 	u8 report;	/* CP2112_DATA_WRITE_READ_REQUEST */
108 	u8 slave_address;
109 	__be16 length;
110 	u8 target_address_length;
111 	u8 target_address[16];
112 } __packed;
113 
114 struct cp2112_write_req_report {
115 	u8 report;	/* CP2112_DATA_WRITE_REQUEST */
116 	u8 slave_address;
117 	u8 length;
118 	u8 data[61];
119 } __packed;
120 
121 struct cp2112_force_read_report {
122 	u8 report;	/* CP2112_DATA_READ_FORCE_SEND */
123 	__be16 length;
124 } __packed;
125 
126 struct cp2112_xfer_status_report {
127 	u8 report;	/* CP2112_TRANSFER_STATUS_RESPONSE */
128 	u8 status0;	/* STATUS0_* */
129 	u8 status1;	/* STATUS1_* */
130 	__be16 retries;
131 	__be16 length;
132 } __packed;
133 
134 struct cp2112_string_report {
135 	u8 dummy;		/* force .string to be aligned */
136 	struct_group_attr(contents, __packed,
137 		u8 report;		/* CP2112_*_STRING */
138 		u8 length;		/* length in bytes of everything after .report */
139 		u8 type;		/* USB_DT_STRING */
140 		wchar_t string[30];	/* UTF16_LITTLE_ENDIAN string */
141 	);
142 } __packed;
143 
144 /* Number of times to request transfer status before giving up waiting for a
145    transfer to complete. This may need to be changed if SMBUS clock, retries,
146    or read/write/scl_low timeout settings are changed. */
147 static const int XFER_STATUS_RETRIES = 10;
148 
149 /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or
150    CP2112_TRANSFER_STATUS_RESPONSE. */
151 static const int RESPONSE_TIMEOUT = 50;
152 
153 static const struct hid_device_id cp2112_devices[] = {
154 	{ HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
155 	{ }
156 };
157 MODULE_DEVICE_TABLE(hid, cp2112_devices);
158 
159 struct cp2112_device {
160 	struct i2c_adapter adap;
161 	struct hid_device *hdev;
162 	wait_queue_head_t wait;
163 	u8 read_data[61];
164 	u8 read_length;
165 	u8 hwversion;
166 	int xfer_status;
167 	atomic_t read_avail;
168 	atomic_t xfer_avail;
169 	struct gpio_chip gc;
170 	u8 *in_out_buffer;
171 	struct mutex lock;
172 
173 	bool gpio_poll;
174 	struct delayed_work gpio_poll_worker;
175 	unsigned long irq_mask;
176 	u8 gpio_prev_state;
177 };
178 
179 static int gpio_push_pull = CP2112_GPIO_ALL_GPIO_MASK;
180 module_param(gpio_push_pull, int, 0644);
181 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
182 
183 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
184 {
185 	struct cp2112_device *dev = gpiochip_get_data(chip);
186 	struct hid_device *hdev = dev->hdev;
187 	u8 *buf = dev->in_out_buffer;
188 	int ret;
189 
190 	guard(mutex)(&dev->lock);
191 
192 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
193 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
194 				 HID_REQ_GET_REPORT);
195 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
196 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
197 		if (ret >= 0)
198 			ret = -EIO;
199 		return ret;
200 	}
201 
202 	buf[1] &= ~BIT(offset);
203 	buf[2] = gpio_push_pull;
204 
205 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
206 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
207 				 HID_REQ_SET_REPORT);
208 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
209 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
210 		if (ret >= 0)
211 			ret = -EIO;
212 		return ret;
213 	}
214 
215 	return 0;
216 }
217 
218 static int cp2112_gpio_set_unlocked(struct cp2112_device *dev,
219 				    unsigned int offset, int value)
220 {
221 	struct hid_device *hdev = dev->hdev;
222 	u8 *buf = dev->in_out_buffer;
223 	int ret;
224 
225 	buf[0] = CP2112_GPIO_SET;
226 	buf[1] = value ? CP2112_GPIO_ALL_GPIO_MASK : 0;
227 	buf[2] = BIT(offset);
228 
229 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
230 				 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
231 				 HID_REQ_SET_REPORT);
232 	if (ret != CP2112_GPIO_SET_LENGTH) {
233 		hid_err(hdev, "error setting GPIO values: %d\n", ret);
234 		return ret < 0 ? ret : -EIO;
235 	}
236 
237 	return 0;
238 }
239 
240 static int cp2112_gpio_set(struct gpio_chip *chip, unsigned int offset,
241 			   int value)
242 {
243 	struct cp2112_device *dev = gpiochip_get_data(chip);
244 
245 	guard(mutex)(&dev->lock);
246 
247 	return cp2112_gpio_set_unlocked(dev, offset, value);
248 }
249 
250 static int cp2112_gpio_get_all(struct gpio_chip *chip)
251 {
252 	struct cp2112_device *dev = gpiochip_get_data(chip);
253 	struct hid_device *hdev = dev->hdev;
254 	u8 *buf = dev->in_out_buffer;
255 	int ret;
256 
257 	guard(mutex)(&dev->lock);
258 
259 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
260 				 CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
261 				 HID_REQ_GET_REPORT);
262 	if (ret != CP2112_GPIO_GET_LENGTH) {
263 		hid_err(hdev, "error requesting GPIO values: %d\n", ret);
264 		return ret < 0 ? ret : -EIO;
265 	}
266 
267 	return buf[1];
268 }
269 
270 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
271 {
272 	int ret;
273 
274 	ret = cp2112_gpio_get_all(chip);
275 	if (ret < 0)
276 		return ret;
277 
278 	return (ret >> offset) & 1;
279 }
280 
281 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
282 					unsigned offset, int value)
283 {
284 	struct cp2112_device *dev = gpiochip_get_data(chip);
285 	struct hid_device *hdev = dev->hdev;
286 	u8 *buf = dev->in_out_buffer;
287 	int ret;
288 
289 	guard(mutex)(&dev->lock);
290 
291 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
292 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
293 				 HID_REQ_GET_REPORT);
294 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
295 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
296 		return ret < 0 ? ret : -EIO;
297 	}
298 
299 	buf[1] |= 1 << offset;
300 	buf[2] = gpio_push_pull;
301 
302 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
303 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
304 				 HID_REQ_SET_REPORT);
305 	if (ret < 0) {
306 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
307 		return ret;
308 	}
309 
310 	/*
311 	 * Set gpio value when output direction is already set,
312 	 * as specified in AN495, Rev. 0.2, cpt. 4.4
313 	 */
314 	return cp2112_gpio_set_unlocked(dev, offset, value);
315 }
316 
317 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
318 			  u8 *data, size_t count, unsigned char report_type)
319 {
320 	u8 *buf;
321 	int ret;
322 
323 	buf = kmalloc(count, GFP_KERNEL);
324 	if (!buf)
325 		return -ENOMEM;
326 
327 	ret = hid_hw_raw_request(hdev, report_number, buf, count,
328 				       report_type, HID_REQ_GET_REPORT);
329 	memcpy(data, buf, count);
330 	kfree(buf);
331 	return ret;
332 }
333 
334 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
335 			     unsigned char report_type)
336 {
337 	u8 *buf;
338 	int ret;
339 
340 	buf = kmemdup(data, count, GFP_KERNEL);
341 	if (!buf)
342 		return -ENOMEM;
343 
344 	if (report_type == HID_OUTPUT_REPORT)
345 		ret = hid_hw_output_report(hdev, buf, count);
346 	else
347 		ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
348 				HID_REQ_SET_REPORT);
349 
350 	kfree(buf);
351 	return ret;
352 }
353 
354 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
355 {
356 	int ret = 0;
357 
358 	/* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
359 	 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
360 	 * come in cp2112_raw_event or timeout. There will only be one of these
361 	 * in flight at any one time. The timeout is extremely large and is a
362 	 * last resort if the CP2112 has died. If we do timeout we don't expect
363 	 * to receive the response which would cause data races, it's not like
364 	 * we can do anything about it anyway.
365 	 */
366 	ret = wait_event_interruptible_timeout(dev->wait,
367 		atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
368 	if (-ERESTARTSYS == ret)
369 		return ret;
370 	if (!ret)
371 		return -ETIMEDOUT;
372 
373 	atomic_set(avail, 0);
374 	return 0;
375 }
376 
377 static int cp2112_xfer_status(struct cp2112_device *dev)
378 {
379 	struct hid_device *hdev = dev->hdev;
380 	u8 buf[2];
381 	int ret;
382 
383 	buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
384 	buf[1] = 0x01;
385 	atomic_set(&dev->xfer_avail, 0);
386 
387 	ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
388 	if (ret < 0) {
389 		hid_warn(hdev, "Error requesting status: %d\n", ret);
390 		return ret;
391 	}
392 
393 	ret = cp2112_wait(dev, &dev->xfer_avail);
394 	if (ret)
395 		return ret;
396 
397 	return dev->xfer_status;
398 }
399 
400 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
401 {
402 	struct hid_device *hdev = dev->hdev;
403 	struct cp2112_force_read_report report;
404 	int ret;
405 
406 	if (size > sizeof(dev->read_data))
407 		size = sizeof(dev->read_data);
408 	report.report = CP2112_DATA_READ_FORCE_SEND;
409 	report.length = cpu_to_be16(size);
410 
411 	atomic_set(&dev->read_avail, 0);
412 
413 	ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
414 				HID_OUTPUT_REPORT);
415 	if (ret < 0) {
416 		hid_warn(hdev, "Error requesting data: %d\n", ret);
417 		return ret;
418 	}
419 
420 	ret = cp2112_wait(dev, &dev->read_avail);
421 	if (ret)
422 		return ret;
423 
424 	hid_dbg(hdev, "read %d of %zd bytes requested\n",
425 		dev->read_length, size);
426 
427 	if (size > dev->read_length)
428 		size = dev->read_length;
429 
430 	memcpy(data, dev->read_data, size);
431 	return dev->read_length;
432 }
433 
434 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
435 {
436 	struct cp2112_read_req_report *report = buf;
437 
438 	if (length < 1 || length > 512)
439 		return -EINVAL;
440 
441 	report->report = CP2112_DATA_READ_REQUEST;
442 	report->slave_address = slave_address << 1;
443 	report->length = cpu_to_be16(length);
444 	return sizeof(*report);
445 }
446 
447 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
448 				 u8 command, u8 *data, u8 data_length)
449 {
450 	struct cp2112_write_read_req_report *report = buf;
451 
452 	if (length < 1 || length > 512
453 	    || data_length > sizeof(report->target_address) - 1)
454 		return -EINVAL;
455 
456 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
457 	report->slave_address = slave_address << 1;
458 	report->length = cpu_to_be16(length);
459 	report->target_address_length = data_length + 1;
460 	report->target_address[0] = command;
461 	memcpy(&report->target_address[1], data, data_length);
462 	return data_length + 6;
463 }
464 
465 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
466 			    u8 data_length)
467 {
468 	struct cp2112_write_req_report *report = buf;
469 
470 	if (data_length > sizeof(report->data) - 1)
471 		return -EINVAL;
472 
473 	report->report = CP2112_DATA_WRITE_REQUEST;
474 	report->slave_address = slave_address << 1;
475 	report->length = data_length + 1;
476 	report->data[0] = command;
477 	memcpy(&report->data[1], data, data_length);
478 	return data_length + 4;
479 }
480 
481 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
482 				u8 data_length)
483 {
484 	struct cp2112_write_req_report *report = buf;
485 
486 	if (data_length > sizeof(report->data))
487 		return -EINVAL;
488 
489 	report->report = CP2112_DATA_WRITE_REQUEST;
490 	report->slave_address = slave_address << 1;
491 	report->length = data_length;
492 	memcpy(report->data, data, data_length);
493 	return data_length + 3;
494 }
495 
496 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
497 				     u8 *addr, int addr_length,
498 				     int read_length)
499 {
500 	struct cp2112_write_read_req_report *report = buf;
501 
502 	if (read_length < 1 || read_length > 512 ||
503 	    addr_length > sizeof(report->target_address))
504 		return -EINVAL;
505 
506 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
507 	report->slave_address = slave_address << 1;
508 	report->length = cpu_to_be16(read_length);
509 	report->target_address_length = addr_length;
510 	memcpy(report->target_address, addr, addr_length);
511 	return addr_length + 5;
512 }
513 
514 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
515 			   int num)
516 {
517 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
518 	struct hid_device *hdev = dev->hdev;
519 	u8 buf[64];
520 	ssize_t count;
521 	ssize_t read_length = 0;
522 	u8 *read_buf = NULL;
523 	unsigned int retries;
524 	int ret;
525 
526 	hid_dbg(hdev, "I2C %d messages\n", num);
527 
528 	if (num == 1) {
529 		hid_dbg(hdev, "I2C %s %#04x len %d\n",
530 			str_read_write(msgs->flags & I2C_M_RD), msgs->addr, msgs->len);
531 		if (msgs->flags & I2C_M_RD) {
532 			read_length = msgs->len;
533 			read_buf = msgs->buf;
534 			count = cp2112_read_req(buf, msgs->addr, msgs->len);
535 		} else {
536 			count = cp2112_i2c_write_req(buf, msgs->addr,
537 						     msgs->buf, msgs->len);
538 		}
539 		if (count < 0)
540 			return count;
541 	} else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */
542 		   num == 2 &&
543 		   msgs[0].addr == msgs[1].addr &&
544 		   !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
545 		hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
546 			msgs[0].addr, msgs[0].len, msgs[1].len);
547 		read_length = msgs[1].len;
548 		read_buf = msgs[1].buf;
549 		count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
550 				msgs[0].buf, msgs[0].len, msgs[1].len);
551 		if (count < 0)
552 			return count;
553 	} else {
554 		hid_err(hdev,
555 			"Multi-message I2C transactions not supported\n");
556 		return -EOPNOTSUPP;
557 	}
558 
559 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
560 	if (ret < 0) {
561 		hid_err(hdev, "power management error: %d\n", ret);
562 		return ret;
563 	}
564 
565 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
566 	if (ret < 0) {
567 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
568 		goto power_normal;
569 	}
570 
571 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
572 		ret = cp2112_xfer_status(dev);
573 		if (-EBUSY == ret)
574 			continue;
575 		if (ret < 0)
576 			goto power_normal;
577 		break;
578 	}
579 
580 	if (XFER_STATUS_RETRIES <= retries) {
581 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
582 		buf[0] = CP2112_CANCEL_TRANSFER;
583 		buf[1] = 0x01;
584 
585 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
586 		if (ret < 0)
587 			hid_warn(hdev, "Error cancelling transaction: %d\n",
588 				 ret);
589 
590 		ret = -ETIMEDOUT;
591 		goto power_normal;
592 	}
593 
594 	for (count = 0; count < read_length;) {
595 		ret = cp2112_read(dev, read_buf + count, read_length - count);
596 		if (ret < 0)
597 			goto power_normal;
598 		if (ret == 0) {
599 			hid_err(hdev, "read returned 0\n");
600 			ret = -EIO;
601 			goto power_normal;
602 		}
603 		count += ret;
604 		if (count > read_length) {
605 			/*
606 			 * The hardware returned too much data.
607 			 * This is mostly harmless because cp2112_read()
608 			 * has a limit check so didn't overrun our
609 			 * buffer.  Nevertheless, we return an error
610 			 * because something is seriously wrong and
611 			 * it shouldn't go unnoticed.
612 			 */
613 			hid_err(hdev, "long read: %d > %zd\n",
614 				ret, read_length - count + ret);
615 			ret = -EIO;
616 			goto power_normal;
617 		}
618 	}
619 
620 	/* return the number of transferred messages */
621 	ret = num;
622 
623 power_normal:
624 	hid_hw_power(hdev, PM_HINT_NORMAL);
625 	hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
626 	return ret;
627 }
628 
629 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
630 		       unsigned short flags, char read_write, u8 command,
631 		       int size, union i2c_smbus_data *data)
632 {
633 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
634 	struct hid_device *hdev = dev->hdev;
635 	u8 buf[64];
636 	__le16 word;
637 	ssize_t count;
638 	size_t read_length = 0;
639 	unsigned int retries;
640 	int ret;
641 
642 	hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
643 		str_write_read(read_write == I2C_SMBUS_WRITE),
644 		addr, flags, command, size);
645 
646 	switch (size) {
647 	case I2C_SMBUS_BYTE:
648 		read_length = 1;
649 
650 		if (I2C_SMBUS_READ == read_write)
651 			count = cp2112_read_req(buf, addr, read_length);
652 		else
653 			count = cp2112_write_req(buf, addr, command, NULL,
654 						 0);
655 		break;
656 	case I2C_SMBUS_BYTE_DATA:
657 		read_length = 1;
658 
659 		if (I2C_SMBUS_READ == read_write)
660 			count = cp2112_write_read_req(buf, addr, read_length,
661 						      command, NULL, 0);
662 		else
663 			count = cp2112_write_req(buf, addr, command,
664 						 &data->byte, 1);
665 		break;
666 	case I2C_SMBUS_WORD_DATA:
667 		read_length = 2;
668 		word = cpu_to_le16(data->word);
669 
670 		if (I2C_SMBUS_READ == read_write)
671 			count = cp2112_write_read_req(buf, addr, read_length,
672 						      command, NULL, 0);
673 		else
674 			count = cp2112_write_req(buf, addr, command,
675 						 (u8 *)&word, 2);
676 		break;
677 	case I2C_SMBUS_PROC_CALL:
678 		size = I2C_SMBUS_WORD_DATA;
679 		read_write = I2C_SMBUS_READ;
680 		read_length = 2;
681 		word = cpu_to_le16(data->word);
682 
683 		count = cp2112_write_read_req(buf, addr, read_length, command,
684 					      (u8 *)&word, 2);
685 		break;
686 	case I2C_SMBUS_I2C_BLOCK_DATA:
687 		if (read_write == I2C_SMBUS_READ) {
688 			read_length = data->block[0];
689 			count = cp2112_write_read_req(buf, addr, read_length,
690 						      command, NULL, 0);
691 		} else {
692 			/* Copy starts from data->block[1] so the length can
693 			 * be at max I2C_SMBUS_CLOCK_MAX + 1
694 			 */
695 
696 			if (data->block[0] > I2C_SMBUS_BLOCK_MAX + 1)
697 				count = -EINVAL;
698 			else
699 				count = cp2112_write_req(buf, addr, command,
700 						 data->block + 1,
701 						 data->block[0]);
702 		}
703 		break;
704 	case I2C_SMBUS_BLOCK_DATA:
705 		if (I2C_SMBUS_READ == read_write) {
706 			count = cp2112_write_read_req(buf, addr,
707 						      I2C_SMBUS_BLOCK_MAX,
708 						      command, NULL, 0);
709 		} else {
710 			/* data_length here is data->block[0] + 1
711 			 * so make sure that the data->block[0] is
712 			 * less than or equals I2C_SMBUS_BLOCK_MAX + 1
713 			*/
714 			if (data->block[0] > I2C_SMBUS_BLOCK_MAX + 1)
715 				count = -EINVAL;
716 			else
717 				count = cp2112_write_req(buf, addr, command,
718 						 data->block,
719 						 data->block[0] + 1);
720 		}
721 		break;
722 	case I2C_SMBUS_BLOCK_PROC_CALL:
723 		size = I2C_SMBUS_BLOCK_DATA;
724 		read_write = I2C_SMBUS_READ;
725 
726 		/* data_length is data->block[0] + 1, so
727 		 * so data->block[0] should be less than or
728 		 * equal to the I2C_SMBUS_BLOCK_MAX + 1
729 		*/
730 		if (data->block[0] > I2C_SMBUS_BLOCK_MAX + 1)
731 			count = -EINVAL;
732 		else
733 			count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
734 					      command, data->block,
735 					      data->block[0] + 1);
736 		break;
737 	default:
738 		hid_warn(hdev, "Unsupported transaction %d\n", size);
739 		return -EOPNOTSUPP;
740 	}
741 
742 	if (count < 0)
743 		return count;
744 
745 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
746 	if (ret < 0) {
747 		hid_err(hdev, "power management error: %d\n", ret);
748 		return ret;
749 	}
750 
751 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
752 	if (ret < 0) {
753 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
754 		goto power_normal;
755 	}
756 
757 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
758 		ret = cp2112_xfer_status(dev);
759 		if (-EBUSY == ret)
760 			continue;
761 		if (ret < 0)
762 			goto power_normal;
763 		break;
764 	}
765 
766 	if (XFER_STATUS_RETRIES <= retries) {
767 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
768 		buf[0] = CP2112_CANCEL_TRANSFER;
769 		buf[1] = 0x01;
770 
771 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
772 		if (ret < 0)
773 			hid_warn(hdev, "Error cancelling transaction: %d\n",
774 				 ret);
775 
776 		ret = -ETIMEDOUT;
777 		goto power_normal;
778 	}
779 
780 	if (I2C_SMBUS_WRITE == read_write) {
781 		ret = 0;
782 		goto power_normal;
783 	}
784 
785 	if (I2C_SMBUS_BLOCK_DATA == size)
786 		read_length = ret;
787 
788 	ret = cp2112_read(dev, buf, read_length);
789 	if (ret < 0)
790 		goto power_normal;
791 	if (ret != read_length) {
792 		hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
793 		ret = -EIO;
794 		goto power_normal;
795 	}
796 
797 	switch (size) {
798 	case I2C_SMBUS_BYTE:
799 	case I2C_SMBUS_BYTE_DATA:
800 		data->byte = buf[0];
801 		break;
802 	case I2C_SMBUS_WORD_DATA:
803 		data->word = le16_to_cpup((__le16 *)buf);
804 		break;
805 	case I2C_SMBUS_I2C_BLOCK_DATA:
806 		if (read_length > I2C_SMBUS_BLOCK_MAX) {
807 			ret = -EINVAL;
808 			goto power_normal;
809 		}
810 
811 		memcpy(data->block + 1, buf, read_length);
812 		break;
813 	case I2C_SMBUS_BLOCK_DATA:
814 		if (read_length > I2C_SMBUS_BLOCK_MAX) {
815 			ret = -EPROTO;
816 			goto power_normal;
817 		}
818 
819 		memcpy(data->block, buf, read_length);
820 		break;
821 	}
822 
823 	ret = 0;
824 power_normal:
825 	hid_hw_power(hdev, PM_HINT_NORMAL);
826 	hid_dbg(hdev, "transfer finished: %d\n", ret);
827 	return ret;
828 }
829 
830 static u32 cp2112_functionality(struct i2c_adapter *adap)
831 {
832 	return I2C_FUNC_I2C |
833 		I2C_FUNC_SMBUS_BYTE |
834 		I2C_FUNC_SMBUS_BYTE_DATA |
835 		I2C_FUNC_SMBUS_WORD_DATA |
836 		I2C_FUNC_SMBUS_BLOCK_DATA |
837 		I2C_FUNC_SMBUS_I2C_BLOCK |
838 		I2C_FUNC_SMBUS_PROC_CALL |
839 		I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
840 }
841 
842 static const struct i2c_algorithm smbus_algorithm = {
843 	.master_xfer	= cp2112_i2c_xfer,
844 	.smbus_xfer	= cp2112_xfer,
845 	.functionality	= cp2112_functionality,
846 };
847 
848 static int cp2112_get_usb_config(struct hid_device *hdev,
849 				 struct cp2112_usb_config_report *cfg)
850 {
851 	int ret;
852 
853 	ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
854 			     HID_FEATURE_REPORT);
855 	if (ret != sizeof(*cfg)) {
856 		hid_err(hdev, "error reading usb config: %d\n", ret);
857 		if (ret < 0)
858 			return ret;
859 		return -EIO;
860 	}
861 
862 	return 0;
863 }
864 
865 static int cp2112_set_usb_config(struct hid_device *hdev,
866 				 struct cp2112_usb_config_report *cfg)
867 {
868 	int ret;
869 
870 	if (WARN_ON(cfg->report != CP2112_USB_CONFIG))
871 		return -EINVAL;
872 
873 	ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
874 				HID_FEATURE_REPORT);
875 	if (ret != sizeof(*cfg)) {
876 		hid_err(hdev, "error writing usb config: %d\n", ret);
877 		if (ret < 0)
878 			return ret;
879 		return -EIO;
880 	}
881 
882 	return 0;
883 }
884 
885 static void chmod_sysfs_attrs(struct hid_device *hdev);
886 
887 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
888 static ssize_t name##_store(struct device *kdev, \
889 			    struct device_attribute *attr, const char *buf, \
890 			    size_t count) \
891 { \
892 	struct hid_device *hdev = to_hid_device(kdev); \
893 	struct cp2112_usb_config_report cfg; \
894 	int ret = cp2112_get_usb_config(hdev, &cfg); \
895 	if (ret) \
896 		return ret; \
897 	store; \
898 	ret = cp2112_set_usb_config(hdev, &cfg); \
899 	if (ret) \
900 		return ret; \
901 	chmod_sysfs_attrs(hdev); \
902 	return count; \
903 } \
904 static ssize_t name##_show(struct device *kdev, \
905 			   struct device_attribute *attr, char *buf) \
906 { \
907 	struct hid_device *hdev = to_hid_device(kdev); \
908 	struct cp2112_usb_config_report cfg; \
909 	int ret = cp2112_get_usb_config(hdev, &cfg); \
910 	if (ret) \
911 		return ret; \
912 	return sysfs_emit(buf, format, ##__VA_ARGS__); \
913 } \
914 static DEVICE_ATTR_RW(name);
915 
916 CP2112_CONFIG_ATTR(vendor_id, ({
917 	u16 vid;
918 
919 	if (sscanf(buf, "%hi", &vid) != 1)
920 		return -EINVAL;
921 
922 	cfg.vid = cpu_to_le16(vid);
923 	cfg.mask = 0x01;
924 }), "0x%04x\n", le16_to_cpu(cfg.vid));
925 
926 CP2112_CONFIG_ATTR(product_id, ({
927 	u16 pid;
928 
929 	if (sscanf(buf, "%hi", &pid) != 1)
930 		return -EINVAL;
931 
932 	cfg.pid = cpu_to_le16(pid);
933 	cfg.mask = 0x02;
934 }), "0x%04x\n", le16_to_cpu(cfg.pid));
935 
936 CP2112_CONFIG_ATTR(max_power, ({
937 	int mA;
938 
939 	if (sscanf(buf, "%i", &mA) != 1)
940 		return -EINVAL;
941 
942 	cfg.max_power = (mA + 1) / 2;
943 	cfg.mask = 0x04;
944 }), "%u mA\n", cfg.max_power * 2);
945 
946 CP2112_CONFIG_ATTR(power_mode, ({
947 	if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
948 		return -EINVAL;
949 
950 	cfg.mask = 0x08;
951 }), "%u\n", cfg.power_mode);
952 
953 CP2112_CONFIG_ATTR(release_version, ({
954 	if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
955 	    != 2)
956 		return -EINVAL;
957 
958 	cfg.mask = 0x10;
959 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
960 
961 #undef CP2112_CONFIG_ATTR
962 
963 static ssize_t pstr_store(struct device *kdev, struct device_attribute *kattr,
964 			  const char *buf, size_t count, int number)
965 {
966 	struct hid_device *hdev = to_hid_device(kdev);
967 	struct cp2112_string_report report;
968 	int ret;
969 
970 	memset(&report, 0, sizeof(report));
971 
972 	ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
973 			      report.string, ARRAY_SIZE(report.string));
974 	report.report = number;
975 	report.length = ret * sizeof(report.string[0]) + 2;
976 	report.type = USB_DT_STRING;
977 
978 	ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
979 				HID_FEATURE_REPORT);
980 	if (ret != report.length + 1) {
981 		hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
982 			ret);
983 		if (ret < 0)
984 			return ret;
985 		return -EIO;
986 	}
987 
988 	chmod_sysfs_attrs(hdev);
989 	return count;
990 }
991 
992 static ssize_t pstr_show(struct device *kdev, struct device_attribute *kattr,
993 			 char *buf, int number)
994 {
995 	struct hid_device *hdev = to_hid_device(kdev);
996 	struct cp2112_string_report report;
997 	u8 length;
998 	int ret;
999 
1000 	ret = cp2112_hid_get(hdev, number, (u8 *)&report.contents,
1001 			     sizeof(report.contents), HID_FEATURE_REPORT);
1002 	if (ret < 3) {
1003 		hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
1004 			ret);
1005 		if (ret < 0)
1006 			return ret;
1007 		return -EIO;
1008 	}
1009 
1010 	if (report.length < 2) {
1011 		hid_err(hdev, "invalid %s string length: %d\n",
1012 			kattr->attr.name, report.length);
1013 		return -EIO;
1014 	}
1015 
1016 	length = report.length > ret - 1 ? ret - 1 : report.length;
1017 	length = (length - 2) / sizeof(report.string[0]);
1018 	ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
1019 			      PAGE_SIZE - 1);
1020 	buf[ret++] = '\n';
1021 	return ret;
1022 }
1023 
1024 #define CP2112_PSTR_ATTR(name, _report) \
1025 static ssize_t name##_store(struct device *kdev, struct device_attribute *kattr, \
1026 			    const char *buf, size_t count) \
1027 { \
1028 	return pstr_store(kdev, kattr, buf, count, _report); \
1029 } \
1030 static ssize_t name##_show(struct device *kdev, struct device_attribute *kattr, char *buf) \
1031 { \
1032 	return pstr_show(kdev, kattr, buf, _report); \
1033 } \
1034 static DEVICE_ATTR_RW(name);
1035 
1036 CP2112_PSTR_ATTR(manufacturer,	CP2112_MANUFACTURER_STRING);
1037 CP2112_PSTR_ATTR(product,	CP2112_PRODUCT_STRING);
1038 CP2112_PSTR_ATTR(serial,	CP2112_SERIAL_STRING);
1039 
1040 #undef CP2112_PSTR_ATTR
1041 
1042 static const struct attribute_group cp2112_attr_group = {
1043 	.attrs = (struct attribute *[]){
1044 		&dev_attr_vendor_id.attr,
1045 		&dev_attr_product_id.attr,
1046 		&dev_attr_max_power.attr,
1047 		&dev_attr_power_mode.attr,
1048 		&dev_attr_release_version.attr,
1049 		&dev_attr_manufacturer.attr,
1050 		&dev_attr_product.attr,
1051 		&dev_attr_serial.attr,
1052 		NULL
1053 	}
1054 };
1055 
1056 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
1057  * PROM have already been programmed. We do not depend on this preventing
1058  * writing to these attributes since the CP2112 will simply ignore writes to
1059  * already-programmed fields. This is why there is no sense in fixing this
1060  * racy behaviour.
1061  */
1062 static void chmod_sysfs_attrs(struct hid_device *hdev)
1063 {
1064 	struct attribute **attr;
1065 	u8 buf[2];
1066 	int ret;
1067 
1068 	ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
1069 			     HID_FEATURE_REPORT);
1070 	if (ret != sizeof(buf)) {
1071 		hid_err(hdev, "error reading lock byte: %d\n", ret);
1072 		return;
1073 	}
1074 
1075 	for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
1076 		umode_t mode = (buf[1] & 1) ? 0644 : 0444;
1077 		ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
1078 		if (ret < 0)
1079 			hid_err(hdev, "error chmoding sysfs file %s\n",
1080 				(*attr)->name);
1081 		buf[1] >>= 1;
1082 	}
1083 }
1084 
1085 static void cp2112_gpio_irq_ack(struct irq_data *d)
1086 {
1087 }
1088 
1089 static void cp2112_gpio_irq_mask(struct irq_data *d)
1090 {
1091 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1092 	struct cp2112_device *dev = gpiochip_get_data(gc);
1093 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
1094 
1095 	__clear_bit(hwirq, &dev->irq_mask);
1096 	gpiochip_disable_irq(gc, hwirq);
1097 }
1098 
1099 static void cp2112_gpio_irq_unmask(struct irq_data *d)
1100 {
1101 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1102 	struct cp2112_device *dev = gpiochip_get_data(gc);
1103 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
1104 
1105 	gpiochip_enable_irq(gc, hwirq);
1106 	__set_bit(hwirq, &dev->irq_mask);
1107 }
1108 
1109 static void cp2112_gpio_poll_callback(struct work_struct *work)
1110 {
1111 	struct cp2112_device *dev = container_of(work, struct cp2112_device,
1112 						 gpio_poll_worker.work);
1113 	u8 gpio_mask;
1114 	u32 irq_type;
1115 	int irq, virq, ret;
1116 
1117 	ret = cp2112_gpio_get_all(&dev->gc);
1118 	if (ret == -ENODEV) /* the hardware has been disconnected */
1119 		return;
1120 	if (ret < 0)
1121 		goto exit;
1122 
1123 	gpio_mask = ret;
1124 	for_each_set_bit(virq, &dev->irq_mask, CP2112_GPIO_MAX_GPIO) {
1125 		irq = irq_find_mapping(dev->gc.irq.domain, virq);
1126 		if (!irq)
1127 			continue;
1128 
1129 		irq_type = irq_get_trigger_type(irq);
1130 		if (!irq_type)
1131 			continue;
1132 
1133 		if (gpio_mask & BIT(virq)) {
1134 			/* Level High */
1135 
1136 			if (irq_type & IRQ_TYPE_LEVEL_HIGH)
1137 				handle_nested_irq(irq);
1138 
1139 			if ((irq_type & IRQ_TYPE_EDGE_RISING) &&
1140 			    !(dev->gpio_prev_state & BIT(virq)))
1141 				handle_nested_irq(irq);
1142 		} else {
1143 			/* Level Low */
1144 
1145 			if (irq_type & IRQ_TYPE_LEVEL_LOW)
1146 				handle_nested_irq(irq);
1147 
1148 			if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&
1149 			    (dev->gpio_prev_state & BIT(virq)))
1150 				handle_nested_irq(irq);
1151 		}
1152 	}
1153 
1154 	dev->gpio_prev_state = gpio_mask;
1155 
1156 exit:
1157 	if (dev->gpio_poll)
1158 		schedule_delayed_work(&dev->gpio_poll_worker, 10);
1159 }
1160 
1161 
1162 static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
1163 {
1164 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1165 	struct cp2112_device *dev = gpiochip_get_data(gc);
1166 
1167 	if (!dev->gpio_poll) {
1168 		dev->gpio_poll = true;
1169 		schedule_delayed_work(&dev->gpio_poll_worker, 0);
1170 	}
1171 
1172 	cp2112_gpio_irq_unmask(d);
1173 	return 0;
1174 }
1175 
1176 static void cp2112_gpio_irq_shutdown(struct irq_data *d)
1177 {
1178 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1179 	struct cp2112_device *dev = gpiochip_get_data(gc);
1180 
1181 	cp2112_gpio_irq_mask(d);
1182 
1183 	if (!dev->irq_mask) {
1184 		dev->gpio_poll = false;
1185 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
1186 	}
1187 }
1188 
1189 static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
1190 {
1191 	return 0;
1192 }
1193 
1194 static const struct irq_chip cp2112_gpio_irqchip = {
1195 	.name = "cp2112-gpio",
1196 	.irq_startup = cp2112_gpio_irq_startup,
1197 	.irq_shutdown = cp2112_gpio_irq_shutdown,
1198 	.irq_ack = cp2112_gpio_irq_ack,
1199 	.irq_mask = cp2112_gpio_irq_mask,
1200 	.irq_unmask = cp2112_gpio_irq_unmask,
1201 	.irq_set_type = cp2112_gpio_irq_type,
1202 	.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,
1203 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
1204 };
1205 
1206 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1207 {
1208 	struct cp2112_device *dev;
1209 	u8 buf[3];
1210 	struct cp2112_smbus_config_report config;
1211 	struct gpio_irq_chip *girq;
1212 	int ret;
1213 
1214 	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
1215 	if (!dev)
1216 		return -ENOMEM;
1217 
1218 	dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
1219 					  GFP_KERNEL);
1220 	if (!dev->in_out_buffer)
1221 		return -ENOMEM;
1222 
1223 	ret = devm_mutex_init(&hdev->dev, &dev->lock);
1224 	if (ret) {
1225 		hid_err(hdev, "mutex init failed\n");
1226 		return ret;
1227 	}
1228 
1229 	ret = hid_parse(hdev);
1230 	if (ret) {
1231 		hid_err(hdev, "parse failed\n");
1232 		return ret;
1233 	}
1234 
1235 	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1236 	if (ret) {
1237 		hid_err(hdev, "hw start failed\n");
1238 		return ret;
1239 	}
1240 
1241 	ret = hid_hw_open(hdev);
1242 	if (ret) {
1243 		hid_err(hdev, "hw open failed\n");
1244 		goto err_hid_stop;
1245 	}
1246 
1247 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
1248 	if (ret < 0) {
1249 		hid_err(hdev, "power management error: %d\n", ret);
1250 		goto err_hid_close;
1251 	}
1252 
1253 	ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
1254 			     HID_FEATURE_REPORT);
1255 	if (ret != sizeof(buf)) {
1256 		hid_err(hdev, "error requesting version\n");
1257 		if (ret >= 0)
1258 			ret = -EIO;
1259 		goto err_power_normal;
1260 	}
1261 
1262 	hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
1263 		 buf[1], buf[2]);
1264 
1265 	ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
1266 			     sizeof(config), HID_FEATURE_REPORT);
1267 	if (ret != sizeof(config)) {
1268 		hid_err(hdev, "error requesting SMBus config\n");
1269 		if (ret >= 0)
1270 			ret = -EIO;
1271 		goto err_power_normal;
1272 	}
1273 
1274 	config.retry_time = cpu_to_be16(1);
1275 
1276 	ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1277 				HID_FEATURE_REPORT);
1278 	if (ret != sizeof(config)) {
1279 		hid_err(hdev, "error setting SMBus config\n");
1280 		if (ret >= 0)
1281 			ret = -EIO;
1282 		goto err_power_normal;
1283 	}
1284 
1285 	hid_set_drvdata(hdev, (void *)dev);
1286 	dev->hdev		= hdev;
1287 	dev->adap.owner		= THIS_MODULE;
1288 	dev->adap.class		= I2C_CLASS_HWMON;
1289 	dev->adap.algo		= &smbus_algorithm;
1290 	dev->adap.algo_data	= dev;
1291 	dev->adap.dev.parent	= &hdev->dev;
1292 	snprintf(dev->adap.name, sizeof(dev->adap.name),
1293 		 "CP2112 SMBus Bridge on hidraw%d",
1294 		 ((struct hidraw *)hdev->hidraw)->minor);
1295 	dev->hwversion = buf[2];
1296 	init_waitqueue_head(&dev->wait);
1297 
1298 	hid_device_io_start(hdev);
1299 	ret = i2c_add_adapter(&dev->adap);
1300 	hid_device_io_stop(hdev);
1301 
1302 	if (ret) {
1303 		hid_err(hdev, "error registering i2c adapter\n");
1304 		goto err_power_normal;
1305 	}
1306 
1307 	hid_dbg(hdev, "adapter registered\n");
1308 
1309 	dev->gc.label			= "cp2112_gpio";
1310 	dev->gc.direction_input		= cp2112_gpio_direction_input;
1311 	dev->gc.direction_output	= cp2112_gpio_direction_output;
1312 	dev->gc.set			= cp2112_gpio_set;
1313 	dev->gc.get			= cp2112_gpio_get;
1314 	dev->gc.base			= -1;
1315 	dev->gc.ngpio			= CP2112_GPIO_MAX_GPIO;
1316 	dev->gc.can_sleep		= 1;
1317 	dev->gc.parent			= &hdev->dev;
1318 
1319 	girq = &dev->gc.irq;
1320 	gpio_irq_chip_set_chip(girq, &cp2112_gpio_irqchip);
1321 	/* The event comes from the outside so no parent handler */
1322 	girq->parent_handler = NULL;
1323 	girq->num_parents = 0;
1324 	girq->parents = NULL;
1325 	girq->default_type = IRQ_TYPE_NONE;
1326 	girq->handler = handle_simple_irq;
1327 	girq->threaded = true;
1328 
1329 	INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
1330 
1331 	ret = gpiochip_add_data(&dev->gc, dev);
1332 	if (ret < 0) {
1333 		hid_err(hdev, "error registering gpio chip\n");
1334 		goto err_free_i2c;
1335 	}
1336 
1337 	ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1338 	if (ret < 0) {
1339 		hid_err(hdev, "error creating sysfs attrs\n");
1340 		goto err_gpiochip_remove;
1341 	}
1342 
1343 	chmod_sysfs_attrs(hdev);
1344 	hid_hw_power(hdev, PM_HINT_NORMAL);
1345 
1346 	return ret;
1347 
1348 err_gpiochip_remove:
1349 	gpiochip_remove(&dev->gc);
1350 err_free_i2c:
1351 	i2c_del_adapter(&dev->adap);
1352 err_power_normal:
1353 	hid_hw_power(hdev, PM_HINT_NORMAL);
1354 err_hid_close:
1355 	hid_hw_close(hdev);
1356 err_hid_stop:
1357 	hid_hw_stop(hdev);
1358 	return ret;
1359 }
1360 
1361 static void cp2112_remove(struct hid_device *hdev)
1362 {
1363 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1364 
1365 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1366 	i2c_del_adapter(&dev->adap);
1367 
1368 	if (dev->gpio_poll) {
1369 		dev->gpio_poll = false;
1370 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
1371 	}
1372 
1373 	gpiochip_remove(&dev->gc);
1374 	/* i2c_del_adapter has finished removing all i2c devices from our
1375 	 * adapter. Well behaved devices should no longer call our cp2112_xfer
1376 	 * and should have waited for any pending calls to finish. It has also
1377 	 * waited for device_unregister(&adap->dev) to complete. Therefore we
1378 	 * can safely free our struct cp2112_device.
1379 	 */
1380 	hid_hw_close(hdev);
1381 	hid_hw_stop(hdev);
1382 }
1383 
1384 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1385 			    u8 *data, int size)
1386 {
1387 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1388 	struct cp2112_xfer_status_report *xfer = (void *)data;
1389 
1390 	switch (data[0]) {
1391 	case CP2112_TRANSFER_STATUS_RESPONSE:
1392 		hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1393 			xfer->status0, xfer->status1,
1394 			be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1395 
1396 		switch (xfer->status0) {
1397 		case STATUS0_IDLE:
1398 			dev->xfer_status = -EAGAIN;
1399 			break;
1400 		case STATUS0_BUSY:
1401 			dev->xfer_status = -EBUSY;
1402 			break;
1403 		case STATUS0_COMPLETE:
1404 			dev->xfer_status = be16_to_cpu(xfer->length);
1405 			break;
1406 		case STATUS0_ERROR:
1407 			switch (xfer->status1) {
1408 			case STATUS1_TIMEOUT_NACK:
1409 			case STATUS1_TIMEOUT_BUS:
1410 				dev->xfer_status = -ETIMEDOUT;
1411 				break;
1412 			default:
1413 				dev->xfer_status = -EIO;
1414 				break;
1415 			}
1416 			break;
1417 		default:
1418 			dev->xfer_status = -EINVAL;
1419 			break;
1420 		}
1421 
1422 		atomic_set(&dev->xfer_avail, 1);
1423 		break;
1424 	case CP2112_DATA_READ_RESPONSE:
1425 		hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1426 
1427 		dev->read_length = data[2];
1428 		if (dev->read_length > sizeof(dev->read_data))
1429 			dev->read_length = sizeof(dev->read_data);
1430 
1431 		memcpy(dev->read_data, &data[3], dev->read_length);
1432 		atomic_set(&dev->read_avail, 1);
1433 		break;
1434 	default:
1435 		hid_err(hdev, "unknown report\n");
1436 
1437 		return 0;
1438 	}
1439 
1440 	wake_up_interruptible(&dev->wait);
1441 	return 1;
1442 }
1443 
1444 static struct hid_driver cp2112_driver = {
1445 	.name		= "cp2112",
1446 	.id_table	= cp2112_devices,
1447 	.probe		= cp2112_probe,
1448 	.remove		= cp2112_remove,
1449 	.raw_event	= cp2112_raw_event,
1450 };
1451 
1452 module_hid_driver(cp2112_driver);
1453 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1454 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1455 MODULE_LICENSE("GPL");
1456 
1457