xref: /linux/drivers/hid/hid-cp2112.c (revision 7b47c66cfa203288c43851260edeeb0fae56f692)
1 /*
2  * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
3  * Copyright (c) 2013,2014 Uplogix, Inc.
4  * David Barksdale <dbarksdale@uplogix.com>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  */
15 
16 /*
17  * The Silicon Labs CP2112 chip is a USB HID device which provides an
18  * SMBus controller for talking to slave devices and 8 GPIO pins. The
19  * host communicates with the CP2112 via raw HID reports.
20  *
21  * Data Sheet:
22  *   http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
23  * Programming Interface Specification:
24  *   https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf
25  */
26 
27 #include <linux/gpio.h>
28 #include <linux/gpio/driver.h>
29 #include <linux/hid.h>
30 #include <linux/hidraw.h>
31 #include <linux/i2c.h>
32 #include <linux/module.h>
33 #include <linux/nls.h>
34 #include <linux/usb/ch9.h>
35 #include "hid-ids.h"
36 
37 #define CP2112_REPORT_MAX_LENGTH		64
38 #define CP2112_GPIO_CONFIG_LENGTH		5
39 #define CP2112_GPIO_GET_LENGTH			2
40 #define CP2112_GPIO_SET_LENGTH			3
41 
42 enum {
43 	CP2112_GPIO_CONFIG		= 0x02,
44 	CP2112_GPIO_GET			= 0x03,
45 	CP2112_GPIO_SET			= 0x04,
46 	CP2112_GET_VERSION_INFO		= 0x05,
47 	CP2112_SMBUS_CONFIG		= 0x06,
48 	CP2112_DATA_READ_REQUEST	= 0x10,
49 	CP2112_DATA_WRITE_READ_REQUEST	= 0x11,
50 	CP2112_DATA_READ_FORCE_SEND	= 0x12,
51 	CP2112_DATA_READ_RESPONSE	= 0x13,
52 	CP2112_DATA_WRITE_REQUEST	= 0x14,
53 	CP2112_TRANSFER_STATUS_REQUEST	= 0x15,
54 	CP2112_TRANSFER_STATUS_RESPONSE	= 0x16,
55 	CP2112_CANCEL_TRANSFER		= 0x17,
56 	CP2112_LOCK_BYTE		= 0x20,
57 	CP2112_USB_CONFIG		= 0x21,
58 	CP2112_MANUFACTURER_STRING	= 0x22,
59 	CP2112_PRODUCT_STRING		= 0x23,
60 	CP2112_SERIAL_STRING		= 0x24,
61 };
62 
63 enum {
64 	STATUS0_IDLE		= 0x00,
65 	STATUS0_BUSY		= 0x01,
66 	STATUS0_COMPLETE	= 0x02,
67 	STATUS0_ERROR		= 0x03,
68 };
69 
70 enum {
71 	STATUS1_TIMEOUT_NACK		= 0x00,
72 	STATUS1_TIMEOUT_BUS		= 0x01,
73 	STATUS1_ARBITRATION_LOST	= 0x02,
74 	STATUS1_READ_INCOMPLETE		= 0x03,
75 	STATUS1_WRITE_INCOMPLETE	= 0x04,
76 	STATUS1_SUCCESS			= 0x05,
77 };
78 
79 struct cp2112_smbus_config_report {
80 	u8 report;		/* CP2112_SMBUS_CONFIG */
81 	__be32 clock_speed;	/* Hz */
82 	u8 device_address;	/* Stored in the upper 7 bits */
83 	u8 auto_send_read;	/* 1 = enabled, 0 = disabled */
84 	__be16 write_timeout;	/* ms, 0 = no timeout */
85 	__be16 read_timeout;	/* ms, 0 = no timeout */
86 	u8 scl_low_timeout;	/* 1 = enabled, 0 = disabled */
87 	__be16 retry_time;	/* # of retries, 0 = no limit */
88 } __packed;
89 
90 struct cp2112_usb_config_report {
91 	u8 report;	/* CP2112_USB_CONFIG */
92 	__le16 vid;	/* Vendor ID */
93 	__le16 pid;	/* Product ID */
94 	u8 max_power;	/* Power requested in 2mA units */
95 	u8 power_mode;	/* 0x00 = bus powered
96 			   0x01 = self powered & regulator off
97 			   0x02 = self powered & regulator on */
98 	u8 release_major;
99 	u8 release_minor;
100 	u8 mask;	/* What fields to program */
101 } __packed;
102 
103 struct cp2112_read_req_report {
104 	u8 report;	/* CP2112_DATA_READ_REQUEST */
105 	u8 slave_address;
106 	__be16 length;
107 } __packed;
108 
109 struct cp2112_write_read_req_report {
110 	u8 report;	/* CP2112_DATA_WRITE_READ_REQUEST */
111 	u8 slave_address;
112 	__be16 length;
113 	u8 target_address_length;
114 	u8 target_address[16];
115 } __packed;
116 
117 struct cp2112_write_req_report {
118 	u8 report;	/* CP2112_DATA_WRITE_REQUEST */
119 	u8 slave_address;
120 	u8 length;
121 	u8 data[61];
122 } __packed;
123 
124 struct cp2112_force_read_report {
125 	u8 report;	/* CP2112_DATA_READ_FORCE_SEND */
126 	__be16 length;
127 } __packed;
128 
129 struct cp2112_xfer_status_report {
130 	u8 report;	/* CP2112_TRANSFER_STATUS_RESPONSE */
131 	u8 status0;	/* STATUS0_* */
132 	u8 status1;	/* STATUS1_* */
133 	__be16 retries;
134 	__be16 length;
135 } __packed;
136 
137 struct cp2112_string_report {
138 	u8 dummy;		/* force .string to be aligned */
139 	u8 report;		/* CP2112_*_STRING */
140 	u8 length;		/* length in bytes of everyting after .report */
141 	u8 type;		/* USB_DT_STRING */
142 	wchar_t string[30];	/* UTF16_LITTLE_ENDIAN string */
143 } __packed;
144 
145 /* Number of times to request transfer status before giving up waiting for a
146    transfer to complete. This may need to be changed if SMBUS clock, retries,
147    or read/write/scl_low timeout settings are changed. */
148 static const int XFER_STATUS_RETRIES = 10;
149 
150 /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or
151    CP2112_TRANSFER_STATUS_RESPONSE. */
152 static const int RESPONSE_TIMEOUT = 50;
153 
154 static const struct hid_device_id cp2112_devices[] = {
155 	{ HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
156 	{ }
157 };
158 MODULE_DEVICE_TABLE(hid, cp2112_devices);
159 
160 struct cp2112_device {
161 	struct i2c_adapter adap;
162 	struct hid_device *hdev;
163 	wait_queue_head_t wait;
164 	u8 read_data[61];
165 	u8 read_length;
166 	u8 hwversion;
167 	int xfer_status;
168 	atomic_t read_avail;
169 	atomic_t xfer_avail;
170 	struct gpio_chip gc;
171 	u8 *in_out_buffer;
172 	struct mutex lock;
173 
174 	struct gpio_desc *desc[8];
175 	bool gpio_poll;
176 	struct delayed_work gpio_poll_worker;
177 	unsigned long irq_mask;
178 	u8 gpio_prev_state;
179 };
180 
181 static int gpio_push_pull = 0xFF;
182 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
183 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
184 
185 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
186 {
187 	struct cp2112_device *dev = gpiochip_get_data(chip);
188 	struct hid_device *hdev = dev->hdev;
189 	u8 *buf = dev->in_out_buffer;
190 	int ret;
191 
192 	mutex_lock(&dev->lock);
193 
194 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
195 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
196 				 HID_REQ_GET_REPORT);
197 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
198 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
199 		if (ret >= 0)
200 			ret = -EIO;
201 		goto exit;
202 	}
203 
204 	buf[1] &= ~(1 << offset);
205 	buf[2] = gpio_push_pull;
206 
207 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
208 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
209 				 HID_REQ_SET_REPORT);
210 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
211 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
212 		if (ret >= 0)
213 			ret = -EIO;
214 		goto exit;
215 	}
216 
217 	ret = 0;
218 
219 exit:
220 	mutex_unlock(&dev->lock);
221 	return ret;
222 }
223 
224 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
225 {
226 	struct cp2112_device *dev = gpiochip_get_data(chip);
227 	struct hid_device *hdev = dev->hdev;
228 	u8 *buf = dev->in_out_buffer;
229 	int ret;
230 
231 	mutex_lock(&dev->lock);
232 
233 	buf[0] = CP2112_GPIO_SET;
234 	buf[1] = value ? 0xff : 0;
235 	buf[2] = 1 << offset;
236 
237 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
238 				 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
239 				 HID_REQ_SET_REPORT);
240 	if (ret < 0)
241 		hid_err(hdev, "error setting GPIO values: %d\n", ret);
242 
243 	mutex_unlock(&dev->lock);
244 }
245 
246 static int cp2112_gpio_get_all(struct gpio_chip *chip)
247 {
248 	struct cp2112_device *dev = gpiochip_get_data(chip);
249 	struct hid_device *hdev = dev->hdev;
250 	u8 *buf = dev->in_out_buffer;
251 	int ret;
252 
253 	mutex_lock(&dev->lock);
254 
255 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
256 				 CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
257 				 HID_REQ_GET_REPORT);
258 	if (ret != CP2112_GPIO_GET_LENGTH) {
259 		hid_err(hdev, "error requesting GPIO values: %d\n", ret);
260 		ret = ret < 0 ? ret : -EIO;
261 		goto exit;
262 	}
263 
264 	ret = buf[1];
265 
266 exit:
267 	mutex_unlock(&dev->lock);
268 
269 	return ret;
270 }
271 
272 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
273 {
274 	int ret;
275 
276 	ret = cp2112_gpio_get_all(chip);
277 	if (ret < 0)
278 		return ret;
279 
280 	return (ret >> offset) & 1;
281 }
282 
283 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
284 					unsigned offset, int value)
285 {
286 	struct cp2112_device *dev = gpiochip_get_data(chip);
287 	struct hid_device *hdev = dev->hdev;
288 	u8 *buf = dev->in_out_buffer;
289 	int ret;
290 
291 	mutex_lock(&dev->lock);
292 
293 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
294 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
295 				 HID_REQ_GET_REPORT);
296 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
297 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
298 		goto fail;
299 	}
300 
301 	buf[1] |= 1 << offset;
302 	buf[2] = gpio_push_pull;
303 
304 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
305 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
306 				 HID_REQ_SET_REPORT);
307 	if (ret < 0) {
308 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
309 		goto fail;
310 	}
311 
312 	mutex_unlock(&dev->lock);
313 
314 	/*
315 	 * Set gpio value when output direction is already set,
316 	 * as specified in AN495, Rev. 0.2, cpt. 4.4
317 	 */
318 	cp2112_gpio_set(chip, offset, value);
319 
320 	return 0;
321 
322 fail:
323 	mutex_unlock(&dev->lock);
324 	return ret < 0 ? ret : -EIO;
325 }
326 
327 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
328 			  u8 *data, size_t count, unsigned char report_type)
329 {
330 	u8 *buf;
331 	int ret;
332 
333 	buf = kmalloc(count, GFP_KERNEL);
334 	if (!buf)
335 		return -ENOMEM;
336 
337 	ret = hid_hw_raw_request(hdev, report_number, buf, count,
338 				       report_type, HID_REQ_GET_REPORT);
339 	memcpy(data, buf, count);
340 	kfree(buf);
341 	return ret;
342 }
343 
344 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
345 			     unsigned char report_type)
346 {
347 	u8 *buf;
348 	int ret;
349 
350 	buf = kmemdup(data, count, GFP_KERNEL);
351 	if (!buf)
352 		return -ENOMEM;
353 
354 	if (report_type == HID_OUTPUT_REPORT)
355 		ret = hid_hw_output_report(hdev, buf, count);
356 	else
357 		ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
358 				HID_REQ_SET_REPORT);
359 
360 	kfree(buf);
361 	return ret;
362 }
363 
364 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
365 {
366 	int ret = 0;
367 
368 	/* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
369 	 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
370 	 * come in cp2112_raw_event or timeout. There will only be one of these
371 	 * in flight at any one time. The timeout is extremely large and is a
372 	 * last resort if the CP2112 has died. If we do timeout we don't expect
373 	 * to receive the response which would cause data races, it's not like
374 	 * we can do anything about it anyway.
375 	 */
376 	ret = wait_event_interruptible_timeout(dev->wait,
377 		atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
378 	if (-ERESTARTSYS == ret)
379 		return ret;
380 	if (!ret)
381 		return -ETIMEDOUT;
382 
383 	atomic_set(avail, 0);
384 	return 0;
385 }
386 
387 static int cp2112_xfer_status(struct cp2112_device *dev)
388 {
389 	struct hid_device *hdev = dev->hdev;
390 	u8 buf[2];
391 	int ret;
392 
393 	buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
394 	buf[1] = 0x01;
395 	atomic_set(&dev->xfer_avail, 0);
396 
397 	ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
398 	if (ret < 0) {
399 		hid_warn(hdev, "Error requesting status: %d\n", ret);
400 		return ret;
401 	}
402 
403 	ret = cp2112_wait(dev, &dev->xfer_avail);
404 	if (ret)
405 		return ret;
406 
407 	return dev->xfer_status;
408 }
409 
410 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
411 {
412 	struct hid_device *hdev = dev->hdev;
413 	struct cp2112_force_read_report report;
414 	int ret;
415 
416 	if (size > sizeof(dev->read_data))
417 		size = sizeof(dev->read_data);
418 	report.report = CP2112_DATA_READ_FORCE_SEND;
419 	report.length = cpu_to_be16(size);
420 
421 	atomic_set(&dev->read_avail, 0);
422 
423 	ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
424 				HID_OUTPUT_REPORT);
425 	if (ret < 0) {
426 		hid_warn(hdev, "Error requesting data: %d\n", ret);
427 		return ret;
428 	}
429 
430 	ret = cp2112_wait(dev, &dev->read_avail);
431 	if (ret)
432 		return ret;
433 
434 	hid_dbg(hdev, "read %d of %zd bytes requested\n",
435 		dev->read_length, size);
436 
437 	if (size > dev->read_length)
438 		size = dev->read_length;
439 
440 	memcpy(data, dev->read_data, size);
441 	return dev->read_length;
442 }
443 
444 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
445 {
446 	struct cp2112_read_req_report *report = buf;
447 
448 	if (length < 1 || length > 512)
449 		return -EINVAL;
450 
451 	report->report = CP2112_DATA_READ_REQUEST;
452 	report->slave_address = slave_address << 1;
453 	report->length = cpu_to_be16(length);
454 	return sizeof(*report);
455 }
456 
457 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
458 				 u8 command, u8 *data, u8 data_length)
459 {
460 	struct cp2112_write_read_req_report *report = buf;
461 
462 	if (length < 1 || length > 512
463 	    || data_length > sizeof(report->target_address) - 1)
464 		return -EINVAL;
465 
466 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
467 	report->slave_address = slave_address << 1;
468 	report->length = cpu_to_be16(length);
469 	report->target_address_length = data_length + 1;
470 	report->target_address[0] = command;
471 	memcpy(&report->target_address[1], data, data_length);
472 	return data_length + 6;
473 }
474 
475 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
476 			    u8 data_length)
477 {
478 	struct cp2112_write_req_report *report = buf;
479 
480 	if (data_length > sizeof(report->data) - 1)
481 		return -EINVAL;
482 
483 	report->report = CP2112_DATA_WRITE_REQUEST;
484 	report->slave_address = slave_address << 1;
485 	report->length = data_length + 1;
486 	report->data[0] = command;
487 	memcpy(&report->data[1], data, data_length);
488 	return data_length + 4;
489 }
490 
491 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
492 				u8 data_length)
493 {
494 	struct cp2112_write_req_report *report = buf;
495 
496 	if (data_length > sizeof(report->data))
497 		return -EINVAL;
498 
499 	report->report = CP2112_DATA_WRITE_REQUEST;
500 	report->slave_address = slave_address << 1;
501 	report->length = data_length;
502 	memcpy(report->data, data, data_length);
503 	return data_length + 3;
504 }
505 
506 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
507 				     u8 *addr, int addr_length,
508 				     int read_length)
509 {
510 	struct cp2112_write_read_req_report *report = buf;
511 
512 	if (read_length < 1 || read_length > 512 ||
513 	    addr_length > sizeof(report->target_address))
514 		return -EINVAL;
515 
516 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
517 	report->slave_address = slave_address << 1;
518 	report->length = cpu_to_be16(read_length);
519 	report->target_address_length = addr_length;
520 	memcpy(report->target_address, addr, addr_length);
521 	return addr_length + 5;
522 }
523 
524 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
525 			   int num)
526 {
527 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
528 	struct hid_device *hdev = dev->hdev;
529 	u8 buf[64];
530 	ssize_t count;
531 	ssize_t read_length = 0;
532 	u8 *read_buf = NULL;
533 	unsigned int retries;
534 	int ret;
535 
536 	hid_dbg(hdev, "I2C %d messages\n", num);
537 
538 	if (num == 1) {
539 		if (msgs->flags & I2C_M_RD) {
540 			hid_dbg(hdev, "I2C read %#04x len %d\n",
541 				msgs->addr, msgs->len);
542 			read_length = msgs->len;
543 			read_buf = msgs->buf;
544 			count = cp2112_read_req(buf, msgs->addr, msgs->len);
545 		} else {
546 			hid_dbg(hdev, "I2C write %#04x len %d\n",
547 				msgs->addr, msgs->len);
548 			count = cp2112_i2c_write_req(buf, msgs->addr,
549 						     msgs->buf, msgs->len);
550 		}
551 		if (count < 0)
552 			return count;
553 	} else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */
554 		   num == 2 &&
555 		   msgs[0].addr == msgs[1].addr &&
556 		   !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
557 		hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
558 			msgs[0].addr, msgs[0].len, msgs[1].len);
559 		read_length = msgs[1].len;
560 		read_buf = msgs[1].buf;
561 		count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
562 				msgs[0].buf, msgs[0].len, msgs[1].len);
563 		if (count < 0)
564 			return count;
565 	} else {
566 		hid_err(hdev,
567 			"Multi-message I2C transactions not supported\n");
568 		return -EOPNOTSUPP;
569 	}
570 
571 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
572 	if (ret < 0) {
573 		hid_err(hdev, "power management error: %d\n", ret);
574 		return ret;
575 	}
576 
577 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
578 	if (ret < 0) {
579 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
580 		goto power_normal;
581 	}
582 
583 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
584 		ret = cp2112_xfer_status(dev);
585 		if (-EBUSY == ret)
586 			continue;
587 		if (ret < 0)
588 			goto power_normal;
589 		break;
590 	}
591 
592 	if (XFER_STATUS_RETRIES <= retries) {
593 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
594 		buf[0] = CP2112_CANCEL_TRANSFER;
595 		buf[1] = 0x01;
596 
597 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
598 		if (ret < 0)
599 			hid_warn(hdev, "Error cancelling transaction: %d\n",
600 				 ret);
601 
602 		ret = -ETIMEDOUT;
603 		goto power_normal;
604 	}
605 
606 	for (count = 0; count < read_length;) {
607 		ret = cp2112_read(dev, read_buf + count, read_length - count);
608 		if (ret < 0)
609 			goto power_normal;
610 		if (ret == 0) {
611 			hid_err(hdev, "read returned 0\n");
612 			ret = -EIO;
613 			goto power_normal;
614 		}
615 		count += ret;
616 		if (count > read_length) {
617 			/*
618 			 * The hardware returned too much data.
619 			 * This is mostly harmless because cp2112_read()
620 			 * has a limit check so didn't overrun our
621 			 * buffer.  Nevertheless, we return an error
622 			 * because something is seriously wrong and
623 			 * it shouldn't go unnoticed.
624 			 */
625 			hid_err(hdev, "long read: %d > %zd\n",
626 				ret, read_length - count + ret);
627 			ret = -EIO;
628 			goto power_normal;
629 		}
630 	}
631 
632 	/* return the number of transferred messages */
633 	ret = num;
634 
635 power_normal:
636 	hid_hw_power(hdev, PM_HINT_NORMAL);
637 	hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
638 	return ret;
639 }
640 
641 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
642 		       unsigned short flags, char read_write, u8 command,
643 		       int size, union i2c_smbus_data *data)
644 {
645 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
646 	struct hid_device *hdev = dev->hdev;
647 	u8 buf[64];
648 	__le16 word;
649 	ssize_t count;
650 	size_t read_length = 0;
651 	unsigned int retries;
652 	int ret;
653 
654 	hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
655 		read_write == I2C_SMBUS_WRITE ? "write" : "read",
656 		addr, flags, command, size);
657 
658 	switch (size) {
659 	case I2C_SMBUS_BYTE:
660 		read_length = 1;
661 
662 		if (I2C_SMBUS_READ == read_write)
663 			count = cp2112_read_req(buf, addr, read_length);
664 		else
665 			count = cp2112_write_req(buf, addr, command, NULL,
666 						 0);
667 		break;
668 	case I2C_SMBUS_BYTE_DATA:
669 		read_length = 1;
670 
671 		if (I2C_SMBUS_READ == read_write)
672 			count = cp2112_write_read_req(buf, addr, read_length,
673 						      command, NULL, 0);
674 		else
675 			count = cp2112_write_req(buf, addr, command,
676 						 &data->byte, 1);
677 		break;
678 	case I2C_SMBUS_WORD_DATA:
679 		read_length = 2;
680 		word = cpu_to_le16(data->word);
681 
682 		if (I2C_SMBUS_READ == read_write)
683 			count = cp2112_write_read_req(buf, addr, read_length,
684 						      command, NULL, 0);
685 		else
686 			count = cp2112_write_req(buf, addr, command,
687 						 (u8 *)&word, 2);
688 		break;
689 	case I2C_SMBUS_PROC_CALL:
690 		size = I2C_SMBUS_WORD_DATA;
691 		read_write = I2C_SMBUS_READ;
692 		read_length = 2;
693 		word = cpu_to_le16(data->word);
694 
695 		count = cp2112_write_read_req(buf, addr, read_length, command,
696 					      (u8 *)&word, 2);
697 		break;
698 	case I2C_SMBUS_I2C_BLOCK_DATA:
699 		size = I2C_SMBUS_BLOCK_DATA;
700 		/* fallthrough */
701 	case I2C_SMBUS_BLOCK_DATA:
702 		if (I2C_SMBUS_READ == read_write) {
703 			count = cp2112_write_read_req(buf, addr,
704 						      I2C_SMBUS_BLOCK_MAX,
705 						      command, NULL, 0);
706 		} else {
707 			count = cp2112_write_req(buf, addr, command,
708 						 data->block,
709 						 data->block[0] + 1);
710 		}
711 		break;
712 	case I2C_SMBUS_BLOCK_PROC_CALL:
713 		size = I2C_SMBUS_BLOCK_DATA;
714 		read_write = I2C_SMBUS_READ;
715 
716 		count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
717 					      command, data->block,
718 					      data->block[0] + 1);
719 		break;
720 	default:
721 		hid_warn(hdev, "Unsupported transaction %d\n", size);
722 		return -EOPNOTSUPP;
723 	}
724 
725 	if (count < 0)
726 		return count;
727 
728 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
729 	if (ret < 0) {
730 		hid_err(hdev, "power management error: %d\n", ret);
731 		return ret;
732 	}
733 
734 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
735 	if (ret < 0) {
736 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
737 		goto power_normal;
738 	}
739 
740 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
741 		ret = cp2112_xfer_status(dev);
742 		if (-EBUSY == ret)
743 			continue;
744 		if (ret < 0)
745 			goto power_normal;
746 		break;
747 	}
748 
749 	if (XFER_STATUS_RETRIES <= retries) {
750 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
751 		buf[0] = CP2112_CANCEL_TRANSFER;
752 		buf[1] = 0x01;
753 
754 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
755 		if (ret < 0)
756 			hid_warn(hdev, "Error cancelling transaction: %d\n",
757 				 ret);
758 
759 		ret = -ETIMEDOUT;
760 		goto power_normal;
761 	}
762 
763 	if (I2C_SMBUS_WRITE == read_write) {
764 		ret = 0;
765 		goto power_normal;
766 	}
767 
768 	if (I2C_SMBUS_BLOCK_DATA == size)
769 		read_length = ret;
770 
771 	ret = cp2112_read(dev, buf, read_length);
772 	if (ret < 0)
773 		goto power_normal;
774 	if (ret != read_length) {
775 		hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
776 		ret = -EIO;
777 		goto power_normal;
778 	}
779 
780 	switch (size) {
781 	case I2C_SMBUS_BYTE:
782 	case I2C_SMBUS_BYTE_DATA:
783 		data->byte = buf[0];
784 		break;
785 	case I2C_SMBUS_WORD_DATA:
786 		data->word = le16_to_cpup((__le16 *)buf);
787 		break;
788 	case I2C_SMBUS_BLOCK_DATA:
789 		if (read_length > I2C_SMBUS_BLOCK_MAX) {
790 			ret = -EPROTO;
791 			goto power_normal;
792 		}
793 
794 		memcpy(data->block, buf, read_length);
795 		break;
796 	}
797 
798 	ret = 0;
799 power_normal:
800 	hid_hw_power(hdev, PM_HINT_NORMAL);
801 	hid_dbg(hdev, "transfer finished: %d\n", ret);
802 	return ret;
803 }
804 
805 static u32 cp2112_functionality(struct i2c_adapter *adap)
806 {
807 	return I2C_FUNC_I2C |
808 		I2C_FUNC_SMBUS_BYTE |
809 		I2C_FUNC_SMBUS_BYTE_DATA |
810 		I2C_FUNC_SMBUS_WORD_DATA |
811 		I2C_FUNC_SMBUS_BLOCK_DATA |
812 		I2C_FUNC_SMBUS_I2C_BLOCK |
813 		I2C_FUNC_SMBUS_PROC_CALL |
814 		I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
815 }
816 
817 static const struct i2c_algorithm smbus_algorithm = {
818 	.master_xfer	= cp2112_i2c_xfer,
819 	.smbus_xfer	= cp2112_xfer,
820 	.functionality	= cp2112_functionality,
821 };
822 
823 static int cp2112_get_usb_config(struct hid_device *hdev,
824 				 struct cp2112_usb_config_report *cfg)
825 {
826 	int ret;
827 
828 	ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
829 			     HID_FEATURE_REPORT);
830 	if (ret != sizeof(*cfg)) {
831 		hid_err(hdev, "error reading usb config: %d\n", ret);
832 		if (ret < 0)
833 			return ret;
834 		return -EIO;
835 	}
836 
837 	return 0;
838 }
839 
840 static int cp2112_set_usb_config(struct hid_device *hdev,
841 				 struct cp2112_usb_config_report *cfg)
842 {
843 	int ret;
844 
845 	BUG_ON(cfg->report != CP2112_USB_CONFIG);
846 
847 	ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
848 				HID_FEATURE_REPORT);
849 	if (ret != sizeof(*cfg)) {
850 		hid_err(hdev, "error writing usb config: %d\n", ret);
851 		if (ret < 0)
852 			return ret;
853 		return -EIO;
854 	}
855 
856 	return 0;
857 }
858 
859 static void chmod_sysfs_attrs(struct hid_device *hdev);
860 
861 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
862 static ssize_t name##_store(struct device *kdev, \
863 			    struct device_attribute *attr, const char *buf, \
864 			    size_t count) \
865 { \
866 	struct hid_device *hdev = to_hid_device(kdev); \
867 	struct cp2112_usb_config_report cfg; \
868 	int ret = cp2112_get_usb_config(hdev, &cfg); \
869 	if (ret) \
870 		return ret; \
871 	store; \
872 	ret = cp2112_set_usb_config(hdev, &cfg); \
873 	if (ret) \
874 		return ret; \
875 	chmod_sysfs_attrs(hdev); \
876 	return count; \
877 } \
878 static ssize_t name##_show(struct device *kdev, \
879 			   struct device_attribute *attr, char *buf) \
880 { \
881 	struct hid_device *hdev = to_hid_device(kdev); \
882 	struct cp2112_usb_config_report cfg; \
883 	int ret = cp2112_get_usb_config(hdev, &cfg); \
884 	if (ret) \
885 		return ret; \
886 	return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
887 } \
888 static DEVICE_ATTR_RW(name);
889 
890 CP2112_CONFIG_ATTR(vendor_id, ({
891 	u16 vid;
892 
893 	if (sscanf(buf, "%hi", &vid) != 1)
894 		return -EINVAL;
895 
896 	cfg.vid = cpu_to_le16(vid);
897 	cfg.mask = 0x01;
898 }), "0x%04x\n", le16_to_cpu(cfg.vid));
899 
900 CP2112_CONFIG_ATTR(product_id, ({
901 	u16 pid;
902 
903 	if (sscanf(buf, "%hi", &pid) != 1)
904 		return -EINVAL;
905 
906 	cfg.pid = cpu_to_le16(pid);
907 	cfg.mask = 0x02;
908 }), "0x%04x\n", le16_to_cpu(cfg.pid));
909 
910 CP2112_CONFIG_ATTR(max_power, ({
911 	int mA;
912 
913 	if (sscanf(buf, "%i", &mA) != 1)
914 		return -EINVAL;
915 
916 	cfg.max_power = (mA + 1) / 2;
917 	cfg.mask = 0x04;
918 }), "%u mA\n", cfg.max_power * 2);
919 
920 CP2112_CONFIG_ATTR(power_mode, ({
921 	if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
922 		return -EINVAL;
923 
924 	cfg.mask = 0x08;
925 }), "%u\n", cfg.power_mode);
926 
927 CP2112_CONFIG_ATTR(release_version, ({
928 	if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
929 	    != 2)
930 		return -EINVAL;
931 
932 	cfg.mask = 0x10;
933 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
934 
935 #undef CP2112_CONFIG_ATTR
936 
937 struct cp2112_pstring_attribute {
938 	struct device_attribute attr;
939 	unsigned char report;
940 };
941 
942 static ssize_t pstr_store(struct device *kdev,
943 			  struct device_attribute *kattr, const char *buf,
944 			  size_t count)
945 {
946 	struct hid_device *hdev = to_hid_device(kdev);
947 	struct cp2112_pstring_attribute *attr =
948 		container_of(kattr, struct cp2112_pstring_attribute, attr);
949 	struct cp2112_string_report report;
950 	int ret;
951 
952 	memset(&report, 0, sizeof(report));
953 
954 	ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
955 			      report.string, ARRAY_SIZE(report.string));
956 	report.report = attr->report;
957 	report.length = ret * sizeof(report.string[0]) + 2;
958 	report.type = USB_DT_STRING;
959 
960 	ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
961 				HID_FEATURE_REPORT);
962 	if (ret != report.length + 1) {
963 		hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
964 			ret);
965 		if (ret < 0)
966 			return ret;
967 		return -EIO;
968 	}
969 
970 	chmod_sysfs_attrs(hdev);
971 	return count;
972 }
973 
974 static ssize_t pstr_show(struct device *kdev,
975 			 struct device_attribute *kattr, char *buf)
976 {
977 	struct hid_device *hdev = to_hid_device(kdev);
978 	struct cp2112_pstring_attribute *attr =
979 		container_of(kattr, struct cp2112_pstring_attribute, attr);
980 	struct cp2112_string_report report;
981 	u8 length;
982 	int ret;
983 
984 	ret = cp2112_hid_get(hdev, attr->report, &report.report,
985 			     sizeof(report) - 1, HID_FEATURE_REPORT);
986 	if (ret < 3) {
987 		hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
988 			ret);
989 		if (ret < 0)
990 			return ret;
991 		return -EIO;
992 	}
993 
994 	if (report.length < 2) {
995 		hid_err(hdev, "invalid %s string length: %d\n",
996 			kattr->attr.name, report.length);
997 		return -EIO;
998 	}
999 
1000 	length = report.length > ret - 1 ? ret - 1 : report.length;
1001 	length = (length - 2) / sizeof(report.string[0]);
1002 	ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
1003 			      PAGE_SIZE - 1);
1004 	buf[ret++] = '\n';
1005 	return ret;
1006 }
1007 
1008 #define CP2112_PSTR_ATTR(name, _report) \
1009 static struct cp2112_pstring_attribute dev_attr_##name = { \
1010 	.attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
1011 	.report = _report, \
1012 };
1013 
1014 CP2112_PSTR_ATTR(manufacturer,	CP2112_MANUFACTURER_STRING);
1015 CP2112_PSTR_ATTR(product,	CP2112_PRODUCT_STRING);
1016 CP2112_PSTR_ATTR(serial,	CP2112_SERIAL_STRING);
1017 
1018 #undef CP2112_PSTR_ATTR
1019 
1020 static const struct attribute_group cp2112_attr_group = {
1021 	.attrs = (struct attribute *[]){
1022 		&dev_attr_vendor_id.attr,
1023 		&dev_attr_product_id.attr,
1024 		&dev_attr_max_power.attr,
1025 		&dev_attr_power_mode.attr,
1026 		&dev_attr_release_version.attr,
1027 		&dev_attr_manufacturer.attr.attr,
1028 		&dev_attr_product.attr.attr,
1029 		&dev_attr_serial.attr.attr,
1030 		NULL
1031 	}
1032 };
1033 
1034 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
1035  * PROM have already been programmed. We do not depend on this preventing
1036  * writing to these attributes since the CP2112 will simply ignore writes to
1037  * already-programmed fields. This is why there is no sense in fixing this
1038  * racy behaviour.
1039  */
1040 static void chmod_sysfs_attrs(struct hid_device *hdev)
1041 {
1042 	struct attribute **attr;
1043 	u8 buf[2];
1044 	int ret;
1045 
1046 	ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
1047 			     HID_FEATURE_REPORT);
1048 	if (ret != sizeof(buf)) {
1049 		hid_err(hdev, "error reading lock byte: %d\n", ret);
1050 		return;
1051 	}
1052 
1053 	for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
1054 		umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
1055 		ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
1056 		if (ret < 0)
1057 			hid_err(hdev, "error chmoding sysfs file %s\n",
1058 				(*attr)->name);
1059 		buf[1] >>= 1;
1060 	}
1061 }
1062 
1063 static void cp2112_gpio_irq_ack(struct irq_data *d)
1064 {
1065 }
1066 
1067 static void cp2112_gpio_irq_mask(struct irq_data *d)
1068 {
1069 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1070 	struct cp2112_device *dev = gpiochip_get_data(gc);
1071 
1072 	__clear_bit(d->hwirq, &dev->irq_mask);
1073 }
1074 
1075 static void cp2112_gpio_irq_unmask(struct irq_data *d)
1076 {
1077 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1078 	struct cp2112_device *dev = gpiochip_get_data(gc);
1079 
1080 	__set_bit(d->hwirq, &dev->irq_mask);
1081 }
1082 
1083 static void cp2112_gpio_poll_callback(struct work_struct *work)
1084 {
1085 	struct cp2112_device *dev = container_of(work, struct cp2112_device,
1086 						 gpio_poll_worker.work);
1087 	struct irq_data *d;
1088 	u8 gpio_mask;
1089 	u8 virqs = (u8)dev->irq_mask;
1090 	u32 irq_type;
1091 	int irq, virq, ret;
1092 
1093 	ret = cp2112_gpio_get_all(&dev->gc);
1094 	if (ret == -ENODEV) /* the hardware has been disconnected */
1095 		return;
1096 	if (ret < 0)
1097 		goto exit;
1098 
1099 	gpio_mask = ret;
1100 
1101 	while (virqs) {
1102 		virq = ffs(virqs) - 1;
1103 		virqs &= ~BIT(virq);
1104 
1105 		if (!dev->gc.to_irq)
1106 			break;
1107 
1108 		irq = dev->gc.to_irq(&dev->gc, virq);
1109 
1110 		d = irq_get_irq_data(irq);
1111 		if (!d)
1112 			continue;
1113 
1114 		irq_type = irqd_get_trigger_type(d);
1115 
1116 		if (gpio_mask & BIT(virq)) {
1117 			/* Level High */
1118 
1119 			if (irq_type & IRQ_TYPE_LEVEL_HIGH)
1120 				handle_nested_irq(irq);
1121 
1122 			if ((irq_type & IRQ_TYPE_EDGE_RISING) &&
1123 			    !(dev->gpio_prev_state & BIT(virq)))
1124 				handle_nested_irq(irq);
1125 		} else {
1126 			/* Level Low */
1127 
1128 			if (irq_type & IRQ_TYPE_LEVEL_LOW)
1129 				handle_nested_irq(irq);
1130 
1131 			if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&
1132 			    (dev->gpio_prev_state & BIT(virq)))
1133 				handle_nested_irq(irq);
1134 		}
1135 	}
1136 
1137 	dev->gpio_prev_state = gpio_mask;
1138 
1139 exit:
1140 	if (dev->gpio_poll)
1141 		schedule_delayed_work(&dev->gpio_poll_worker, 10);
1142 }
1143 
1144 
1145 static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
1146 {
1147 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1148 	struct cp2112_device *dev = gpiochip_get_data(gc);
1149 
1150 	INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
1151 
1152 	cp2112_gpio_direction_input(gc, d->hwirq);
1153 
1154 	if (!dev->gpio_poll) {
1155 		dev->gpio_poll = true;
1156 		schedule_delayed_work(&dev->gpio_poll_worker, 0);
1157 	}
1158 
1159 	cp2112_gpio_irq_unmask(d);
1160 	return 0;
1161 }
1162 
1163 static void cp2112_gpio_irq_shutdown(struct irq_data *d)
1164 {
1165 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1166 	struct cp2112_device *dev = gpiochip_get_data(gc);
1167 
1168 	cancel_delayed_work_sync(&dev->gpio_poll_worker);
1169 }
1170 
1171 static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
1172 {
1173 	return 0;
1174 }
1175 
1176 static struct irq_chip cp2112_gpio_irqchip = {
1177 	.name = "cp2112-gpio",
1178 	.irq_startup = cp2112_gpio_irq_startup,
1179 	.irq_shutdown = cp2112_gpio_irq_shutdown,
1180 	.irq_ack = cp2112_gpio_irq_ack,
1181 	.irq_mask = cp2112_gpio_irq_mask,
1182 	.irq_unmask = cp2112_gpio_irq_unmask,
1183 	.irq_set_type = cp2112_gpio_irq_type,
1184 };
1185 
1186 static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
1187 					      int pin)
1188 {
1189 	int ret;
1190 
1191 	if (dev->desc[pin])
1192 		return -EINVAL;
1193 
1194 	dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin,
1195 						   "HID/I2C:Event");
1196 	if (IS_ERR(dev->desc[pin])) {
1197 		dev_err(dev->gc.parent, "Failed to request GPIO\n");
1198 		return PTR_ERR(dev->desc[pin]);
1199 	}
1200 
1201 	ret = gpiochip_lock_as_irq(&dev->gc, pin);
1202 	if (ret) {
1203 		dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n");
1204 		goto err_desc;
1205 	}
1206 
1207 	ret = gpiod_to_irq(dev->desc[pin]);
1208 	if (ret < 0) {
1209 		dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n");
1210 		goto err_lock;
1211 	}
1212 
1213 	return ret;
1214 
1215 err_lock:
1216 	gpiochip_unlock_as_irq(&dev->gc, pin);
1217 err_desc:
1218 	gpiochip_free_own_desc(dev->desc[pin]);
1219 	dev->desc[pin] = NULL;
1220 	return ret;
1221 }
1222 
1223 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1224 {
1225 	struct cp2112_device *dev;
1226 	u8 buf[3];
1227 	struct cp2112_smbus_config_report config;
1228 	int ret;
1229 
1230 	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
1231 	if (!dev)
1232 		return -ENOMEM;
1233 
1234 	dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
1235 					  GFP_KERNEL);
1236 	if (!dev->in_out_buffer)
1237 		return -ENOMEM;
1238 
1239 	mutex_init(&dev->lock);
1240 
1241 	ret = hid_parse(hdev);
1242 	if (ret) {
1243 		hid_err(hdev, "parse failed\n");
1244 		return ret;
1245 	}
1246 
1247 	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1248 	if (ret) {
1249 		hid_err(hdev, "hw start failed\n");
1250 		return ret;
1251 	}
1252 
1253 	ret = hid_hw_open(hdev);
1254 	if (ret) {
1255 		hid_err(hdev, "hw open failed\n");
1256 		goto err_hid_stop;
1257 	}
1258 
1259 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
1260 	if (ret < 0) {
1261 		hid_err(hdev, "power management error: %d\n", ret);
1262 		goto err_hid_close;
1263 	}
1264 
1265 	ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
1266 			     HID_FEATURE_REPORT);
1267 	if (ret != sizeof(buf)) {
1268 		hid_err(hdev, "error requesting version\n");
1269 		if (ret >= 0)
1270 			ret = -EIO;
1271 		goto err_power_normal;
1272 	}
1273 
1274 	hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
1275 		 buf[1], buf[2]);
1276 
1277 	ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
1278 			     sizeof(config), HID_FEATURE_REPORT);
1279 	if (ret != sizeof(config)) {
1280 		hid_err(hdev, "error requesting SMBus config\n");
1281 		if (ret >= 0)
1282 			ret = -EIO;
1283 		goto err_power_normal;
1284 	}
1285 
1286 	config.retry_time = cpu_to_be16(1);
1287 
1288 	ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1289 				HID_FEATURE_REPORT);
1290 	if (ret != sizeof(config)) {
1291 		hid_err(hdev, "error setting SMBus config\n");
1292 		if (ret >= 0)
1293 			ret = -EIO;
1294 		goto err_power_normal;
1295 	}
1296 
1297 	hid_set_drvdata(hdev, (void *)dev);
1298 	dev->hdev		= hdev;
1299 	dev->adap.owner		= THIS_MODULE;
1300 	dev->adap.class		= I2C_CLASS_HWMON;
1301 	dev->adap.algo		= &smbus_algorithm;
1302 	dev->adap.algo_data	= dev;
1303 	dev->adap.dev.parent	= &hdev->dev;
1304 	snprintf(dev->adap.name, sizeof(dev->adap.name),
1305 		 "CP2112 SMBus Bridge on hidraw%d",
1306 		 ((struct hidraw *)hdev->hidraw)->minor);
1307 	dev->hwversion = buf[2];
1308 	init_waitqueue_head(&dev->wait);
1309 
1310 	hid_device_io_start(hdev);
1311 	ret = i2c_add_adapter(&dev->adap);
1312 	hid_device_io_stop(hdev);
1313 
1314 	if (ret) {
1315 		hid_err(hdev, "error registering i2c adapter\n");
1316 		goto err_power_normal;
1317 	}
1318 
1319 	hid_dbg(hdev, "adapter registered\n");
1320 
1321 	dev->gc.label			= "cp2112_gpio";
1322 	dev->gc.direction_input		= cp2112_gpio_direction_input;
1323 	dev->gc.direction_output	= cp2112_gpio_direction_output;
1324 	dev->gc.set			= cp2112_gpio_set;
1325 	dev->gc.get			= cp2112_gpio_get;
1326 	dev->gc.base			= -1;
1327 	dev->gc.ngpio			= 8;
1328 	dev->gc.can_sleep		= 1;
1329 	dev->gc.parent			= &hdev->dev;
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 	ret = gpiochip_irqchip_add(&dev->gc, &cp2112_gpio_irqchip, 0,
1347 				   handle_simple_irq, IRQ_TYPE_NONE);
1348 	if (ret) {
1349 		dev_err(dev->gc.parent, "failed to add IRQ chip\n");
1350 		goto err_sysfs_remove;
1351 	}
1352 
1353 	return ret;
1354 
1355 err_sysfs_remove:
1356 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1357 err_gpiochip_remove:
1358 	gpiochip_remove(&dev->gc);
1359 err_free_i2c:
1360 	i2c_del_adapter(&dev->adap);
1361 err_power_normal:
1362 	hid_hw_power(hdev, PM_HINT_NORMAL);
1363 err_hid_close:
1364 	hid_hw_close(hdev);
1365 err_hid_stop:
1366 	hid_hw_stop(hdev);
1367 	return ret;
1368 }
1369 
1370 static void cp2112_remove(struct hid_device *hdev)
1371 {
1372 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1373 	int i;
1374 
1375 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1376 	i2c_del_adapter(&dev->adap);
1377 
1378 	if (dev->gpio_poll) {
1379 		dev->gpio_poll = false;
1380 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
1381 	}
1382 
1383 	for (i = 0; i < ARRAY_SIZE(dev->desc); i++) {
1384 		gpiochip_unlock_as_irq(&dev->gc, i);
1385 		gpiochip_free_own_desc(dev->desc[i]);
1386 	}
1387 
1388 	gpiochip_remove(&dev->gc);
1389 	/* i2c_del_adapter has finished removing all i2c devices from our
1390 	 * adapter. Well behaved devices should no longer call our cp2112_xfer
1391 	 * and should have waited for any pending calls to finish. It has also
1392 	 * waited for device_unregister(&adap->dev) to complete. Therefore we
1393 	 * can safely free our struct cp2112_device.
1394 	 */
1395 	hid_hw_close(hdev);
1396 	hid_hw_stop(hdev);
1397 }
1398 
1399 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1400 			    u8 *data, int size)
1401 {
1402 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1403 	struct cp2112_xfer_status_report *xfer = (void *)data;
1404 
1405 	switch (data[0]) {
1406 	case CP2112_TRANSFER_STATUS_RESPONSE:
1407 		hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1408 			xfer->status0, xfer->status1,
1409 			be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1410 
1411 		switch (xfer->status0) {
1412 		case STATUS0_IDLE:
1413 			dev->xfer_status = -EAGAIN;
1414 			break;
1415 		case STATUS0_BUSY:
1416 			dev->xfer_status = -EBUSY;
1417 			break;
1418 		case STATUS0_COMPLETE:
1419 			dev->xfer_status = be16_to_cpu(xfer->length);
1420 			break;
1421 		case STATUS0_ERROR:
1422 			switch (xfer->status1) {
1423 			case STATUS1_TIMEOUT_NACK:
1424 			case STATUS1_TIMEOUT_BUS:
1425 				dev->xfer_status = -ETIMEDOUT;
1426 				break;
1427 			default:
1428 				dev->xfer_status = -EIO;
1429 				break;
1430 			}
1431 			break;
1432 		default:
1433 			dev->xfer_status = -EINVAL;
1434 			break;
1435 		}
1436 
1437 		atomic_set(&dev->xfer_avail, 1);
1438 		break;
1439 	case CP2112_DATA_READ_RESPONSE:
1440 		hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1441 
1442 		dev->read_length = data[2];
1443 		if (dev->read_length > sizeof(dev->read_data))
1444 			dev->read_length = sizeof(dev->read_data);
1445 
1446 		memcpy(dev->read_data, &data[3], dev->read_length);
1447 		atomic_set(&dev->read_avail, 1);
1448 		break;
1449 	default:
1450 		hid_err(hdev, "unknown report\n");
1451 
1452 		return 0;
1453 	}
1454 
1455 	wake_up_interruptible(&dev->wait);
1456 	return 1;
1457 }
1458 
1459 static struct hid_driver cp2112_driver = {
1460 	.name		= "cp2112",
1461 	.id_table	= cp2112_devices,
1462 	.probe		= cp2112_probe,
1463 	.remove		= cp2112_remove,
1464 	.raw_event	= cp2112_raw_event,
1465 };
1466 
1467 module_hid_driver(cp2112_driver);
1468 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1469 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1470 MODULE_LICENSE("GPL");
1471 
1472