xref: /openbmc/linux/drivers/hid/hid-cp2112.c (revision 4f6cce39)
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  *   http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf
25  */
26 
27 #include <linux/gpio.h>
28 #include <linux/gpio/driver.h>
29 #include <linux/hid.h>
30 #include <linux/i2c.h>
31 #include <linux/module.h>
32 #include <linux/nls.h>
33 #include <linux/usb/ch9.h>
34 #include "hid-ids.h"
35 
36 #define CP2112_REPORT_MAX_LENGTH		64
37 #define CP2112_GPIO_CONFIG_LENGTH		5
38 #define CP2112_GPIO_GET_LENGTH			2
39 #define CP2112_GPIO_SET_LENGTH			3
40 
41 enum {
42 	CP2112_GPIO_CONFIG		= 0x02,
43 	CP2112_GPIO_GET			= 0x03,
44 	CP2112_GPIO_SET			= 0x04,
45 	CP2112_GET_VERSION_INFO		= 0x05,
46 	CP2112_SMBUS_CONFIG		= 0x06,
47 	CP2112_DATA_READ_REQUEST	= 0x10,
48 	CP2112_DATA_WRITE_READ_REQUEST	= 0x11,
49 	CP2112_DATA_READ_FORCE_SEND	= 0x12,
50 	CP2112_DATA_READ_RESPONSE	= 0x13,
51 	CP2112_DATA_WRITE_REQUEST	= 0x14,
52 	CP2112_TRANSFER_STATUS_REQUEST	= 0x15,
53 	CP2112_TRANSFER_STATUS_RESPONSE	= 0x16,
54 	CP2112_CANCEL_TRANSFER		= 0x17,
55 	CP2112_LOCK_BYTE		= 0x20,
56 	CP2112_USB_CONFIG		= 0x21,
57 	CP2112_MANUFACTURER_STRING	= 0x22,
58 	CP2112_PRODUCT_STRING		= 0x23,
59 	CP2112_SERIAL_STRING		= 0x24,
60 };
61 
62 enum {
63 	STATUS0_IDLE		= 0x00,
64 	STATUS0_BUSY		= 0x01,
65 	STATUS0_COMPLETE	= 0x02,
66 	STATUS0_ERROR		= 0x03,
67 };
68 
69 enum {
70 	STATUS1_TIMEOUT_NACK		= 0x00,
71 	STATUS1_TIMEOUT_BUS		= 0x01,
72 	STATUS1_ARBITRATION_LOST	= 0x02,
73 	STATUS1_READ_INCOMPLETE		= 0x03,
74 	STATUS1_WRITE_INCOMPLETE	= 0x04,
75 	STATUS1_SUCCESS			= 0x05,
76 };
77 
78 struct cp2112_smbus_config_report {
79 	u8 report;		/* CP2112_SMBUS_CONFIG */
80 	__be32 clock_speed;	/* Hz */
81 	u8 device_address;	/* Stored in the upper 7 bits */
82 	u8 auto_send_read;	/* 1 = enabled, 0 = disabled */
83 	__be16 write_timeout;	/* ms, 0 = no timeout */
84 	__be16 read_timeout;	/* ms, 0 = no timeout */
85 	u8 scl_low_timeout;	/* 1 = enabled, 0 = disabled */
86 	__be16 retry_time;	/* # of retries, 0 = no limit */
87 } __packed;
88 
89 struct cp2112_usb_config_report {
90 	u8 report;	/* CP2112_USB_CONFIG */
91 	__le16 vid;	/* Vendor ID */
92 	__le16 pid;	/* Product ID */
93 	u8 max_power;	/* Power requested in 2mA units */
94 	u8 power_mode;	/* 0x00 = bus powered
95 			   0x01 = self powered & regulator off
96 			   0x02 = self powered & regulator on */
97 	u8 release_major;
98 	u8 release_minor;
99 	u8 mask;	/* What fields to program */
100 } __packed;
101 
102 struct cp2112_read_req_report {
103 	u8 report;	/* CP2112_DATA_READ_REQUEST */
104 	u8 slave_address;
105 	__be16 length;
106 } __packed;
107 
108 struct cp2112_write_read_req_report {
109 	u8 report;	/* CP2112_DATA_WRITE_READ_REQUEST */
110 	u8 slave_address;
111 	__be16 length;
112 	u8 target_address_length;
113 	u8 target_address[16];
114 } __packed;
115 
116 struct cp2112_write_req_report {
117 	u8 report;	/* CP2112_DATA_WRITE_REQUEST */
118 	u8 slave_address;
119 	u8 length;
120 	u8 data[61];
121 } __packed;
122 
123 struct cp2112_force_read_report {
124 	u8 report;	/* CP2112_DATA_READ_FORCE_SEND */
125 	__be16 length;
126 } __packed;
127 
128 struct cp2112_xfer_status_report {
129 	u8 report;	/* CP2112_TRANSFER_STATUS_RESPONSE */
130 	u8 status0;	/* STATUS0_* */
131 	u8 status1;	/* STATUS1_* */
132 	__be16 retries;
133 	__be16 length;
134 } __packed;
135 
136 struct cp2112_string_report {
137 	u8 dummy;		/* force .string to be aligned */
138 	u8 report;		/* CP2112_*_STRING */
139 	u8 length;		/* length in bytes of everyting after .report */
140 	u8 type;		/* USB_DT_STRING */
141 	wchar_t string[30];	/* UTF16_LITTLE_ENDIAN string */
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 	struct gpio_desc *desc[8];
174 	bool gpio_poll;
175 	struct delayed_work gpio_poll_worker;
176 	unsigned long irq_mask;
177 	u8 gpio_prev_state;
178 };
179 
180 static int gpio_push_pull = 0xFF;
181 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
182 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
183 
184 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
185 {
186 	struct cp2112_device *dev = gpiochip_get_data(chip);
187 	struct hid_device *hdev = dev->hdev;
188 	u8 *buf = dev->in_out_buffer;
189 	int ret;
190 
191 	mutex_lock(&dev->lock);
192 
193 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
194 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
195 				 HID_REQ_GET_REPORT);
196 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
197 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
198 		goto exit;
199 	}
200 
201 	buf[1] &= ~(1 << offset);
202 	buf[2] = gpio_push_pull;
203 
204 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
205 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
206 				 HID_REQ_SET_REPORT);
207 	if (ret < 0) {
208 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
209 		goto exit;
210 	}
211 
212 	ret = 0;
213 
214 exit:
215 	mutex_unlock(&dev->lock);
216 	return ret < 0 ? ret : -EIO;
217 }
218 
219 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
220 {
221 	struct cp2112_device *dev = gpiochip_get_data(chip);
222 	struct hid_device *hdev = dev->hdev;
223 	u8 *buf = dev->in_out_buffer;
224 	int ret;
225 
226 	mutex_lock(&dev->lock);
227 
228 	buf[0] = CP2112_GPIO_SET;
229 	buf[1] = value ? 0xff : 0;
230 	buf[2] = 1 << offset;
231 
232 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
233 				 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
234 				 HID_REQ_SET_REPORT);
235 	if (ret < 0)
236 		hid_err(hdev, "error setting GPIO values: %d\n", ret);
237 
238 	mutex_unlock(&dev->lock);
239 }
240 
241 static int cp2112_gpio_get_all(struct gpio_chip *chip)
242 {
243 	struct cp2112_device *dev = gpiochip_get_data(chip);
244 	struct hid_device *hdev = dev->hdev;
245 	u8 *buf = dev->in_out_buffer;
246 	int ret;
247 
248 	mutex_lock(&dev->lock);
249 
250 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
251 				 CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
252 				 HID_REQ_GET_REPORT);
253 	if (ret != CP2112_GPIO_GET_LENGTH) {
254 		hid_err(hdev, "error requesting GPIO values: %d\n", ret);
255 		ret = ret < 0 ? ret : -EIO;
256 		goto exit;
257 	}
258 
259 	ret = buf[1];
260 
261 exit:
262 	mutex_unlock(&dev->lock);
263 
264 	return ret;
265 }
266 
267 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
268 {
269 	int ret;
270 
271 	ret = cp2112_gpio_get_all(chip);
272 	if (ret < 0)
273 		return ret;
274 
275 	return (ret >> offset) & 1;
276 }
277 
278 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
279 					unsigned offset, int value)
280 {
281 	struct cp2112_device *dev = gpiochip_get_data(chip);
282 	struct hid_device *hdev = dev->hdev;
283 	u8 *buf = dev->in_out_buffer;
284 	int ret;
285 
286 	mutex_lock(&dev->lock);
287 
288 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
289 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
290 				 HID_REQ_GET_REPORT);
291 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
292 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
293 		goto fail;
294 	}
295 
296 	buf[1] |= 1 << offset;
297 	buf[2] = gpio_push_pull;
298 
299 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
300 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
301 				 HID_REQ_SET_REPORT);
302 	if (ret < 0) {
303 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
304 		goto fail;
305 	}
306 
307 	mutex_unlock(&dev->lock);
308 
309 	/*
310 	 * Set gpio value when output direction is already set,
311 	 * as specified in AN495, Rev. 0.2, cpt. 4.4
312 	 */
313 	cp2112_gpio_set(chip, offset, value);
314 
315 	return 0;
316 
317 fail:
318 	mutex_unlock(&dev->lock);
319 	return ret < 0 ? ret : -EIO;
320 }
321 
322 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
323 			  u8 *data, size_t count, unsigned char report_type)
324 {
325 	u8 *buf;
326 	int ret;
327 
328 	buf = kmalloc(count, GFP_KERNEL);
329 	if (!buf)
330 		return -ENOMEM;
331 
332 	ret = hid_hw_raw_request(hdev, report_number, buf, count,
333 				       report_type, HID_REQ_GET_REPORT);
334 	memcpy(data, buf, count);
335 	kfree(buf);
336 	return ret;
337 }
338 
339 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
340 			     unsigned char report_type)
341 {
342 	u8 *buf;
343 	int ret;
344 
345 	buf = kmemdup(data, count, GFP_KERNEL);
346 	if (!buf)
347 		return -ENOMEM;
348 
349 	if (report_type == HID_OUTPUT_REPORT)
350 		ret = hid_hw_output_report(hdev, buf, count);
351 	else
352 		ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
353 				HID_REQ_SET_REPORT);
354 
355 	kfree(buf);
356 	return ret;
357 }
358 
359 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
360 {
361 	int ret = 0;
362 
363 	/* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
364 	 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
365 	 * come in cp2112_raw_event or timeout. There will only be one of these
366 	 * in flight at any one time. The timeout is extremely large and is a
367 	 * last resort if the CP2112 has died. If we do timeout we don't expect
368 	 * to receive the response which would cause data races, it's not like
369 	 * we can do anything about it anyway.
370 	 */
371 	ret = wait_event_interruptible_timeout(dev->wait,
372 		atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
373 	if (-ERESTARTSYS == ret)
374 		return ret;
375 	if (!ret)
376 		return -ETIMEDOUT;
377 
378 	atomic_set(avail, 0);
379 	return 0;
380 }
381 
382 static int cp2112_xfer_status(struct cp2112_device *dev)
383 {
384 	struct hid_device *hdev = dev->hdev;
385 	u8 buf[2];
386 	int ret;
387 
388 	buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
389 	buf[1] = 0x01;
390 	atomic_set(&dev->xfer_avail, 0);
391 
392 	ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
393 	if (ret < 0) {
394 		hid_warn(hdev, "Error requesting status: %d\n", ret);
395 		return ret;
396 	}
397 
398 	ret = cp2112_wait(dev, &dev->xfer_avail);
399 	if (ret)
400 		return ret;
401 
402 	return dev->xfer_status;
403 }
404 
405 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
406 {
407 	struct hid_device *hdev = dev->hdev;
408 	struct cp2112_force_read_report report;
409 	int ret;
410 
411 	if (size > sizeof(dev->read_data))
412 		size = sizeof(dev->read_data);
413 	report.report = CP2112_DATA_READ_FORCE_SEND;
414 	report.length = cpu_to_be16(size);
415 
416 	atomic_set(&dev->read_avail, 0);
417 
418 	ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
419 				HID_OUTPUT_REPORT);
420 	if (ret < 0) {
421 		hid_warn(hdev, "Error requesting data: %d\n", ret);
422 		return ret;
423 	}
424 
425 	ret = cp2112_wait(dev, &dev->read_avail);
426 	if (ret)
427 		return ret;
428 
429 	hid_dbg(hdev, "read %d of %zd bytes requested\n",
430 		dev->read_length, size);
431 
432 	if (size > dev->read_length)
433 		size = dev->read_length;
434 
435 	memcpy(data, dev->read_data, size);
436 	return dev->read_length;
437 }
438 
439 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
440 {
441 	struct cp2112_read_req_report *report = buf;
442 
443 	if (length < 1 || length > 512)
444 		return -EINVAL;
445 
446 	report->report = CP2112_DATA_READ_REQUEST;
447 	report->slave_address = slave_address << 1;
448 	report->length = cpu_to_be16(length);
449 	return sizeof(*report);
450 }
451 
452 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
453 				 u8 command, u8 *data, u8 data_length)
454 {
455 	struct cp2112_write_read_req_report *report = buf;
456 
457 	if (length < 1 || length > 512
458 	    || data_length > sizeof(report->target_address) - 1)
459 		return -EINVAL;
460 
461 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
462 	report->slave_address = slave_address << 1;
463 	report->length = cpu_to_be16(length);
464 	report->target_address_length = data_length + 1;
465 	report->target_address[0] = command;
466 	memcpy(&report->target_address[1], data, data_length);
467 	return data_length + 6;
468 }
469 
470 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
471 			    u8 data_length)
472 {
473 	struct cp2112_write_req_report *report = buf;
474 
475 	if (data_length > sizeof(report->data) - 1)
476 		return -EINVAL;
477 
478 	report->report = CP2112_DATA_WRITE_REQUEST;
479 	report->slave_address = slave_address << 1;
480 	report->length = data_length + 1;
481 	report->data[0] = command;
482 	memcpy(&report->data[1], data, data_length);
483 	return data_length + 4;
484 }
485 
486 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
487 				u8 data_length)
488 {
489 	struct cp2112_write_req_report *report = buf;
490 
491 	if (data_length > sizeof(report->data))
492 		return -EINVAL;
493 
494 	report->report = CP2112_DATA_WRITE_REQUEST;
495 	report->slave_address = slave_address << 1;
496 	report->length = data_length;
497 	memcpy(report->data, data, data_length);
498 	return data_length + 3;
499 }
500 
501 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
502 				     u8 *addr, int addr_length,
503 				     int read_length)
504 {
505 	struct cp2112_write_read_req_report *report = buf;
506 
507 	if (read_length < 1 || read_length > 512 ||
508 	    addr_length > sizeof(report->target_address))
509 		return -EINVAL;
510 
511 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
512 	report->slave_address = slave_address << 1;
513 	report->length = cpu_to_be16(read_length);
514 	report->target_address_length = addr_length;
515 	memcpy(report->target_address, addr, addr_length);
516 	return addr_length + 5;
517 }
518 
519 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
520 			   int num)
521 {
522 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
523 	struct hid_device *hdev = dev->hdev;
524 	u8 buf[64];
525 	ssize_t count;
526 	ssize_t read_length = 0;
527 	u8 *read_buf = NULL;
528 	unsigned int retries;
529 	int ret;
530 
531 	hid_dbg(hdev, "I2C %d messages\n", num);
532 
533 	if (num == 1) {
534 		if (msgs->flags & I2C_M_RD) {
535 			hid_dbg(hdev, "I2C read %#04x len %d\n",
536 				msgs->addr, msgs->len);
537 			read_length = msgs->len;
538 			read_buf = msgs->buf;
539 			count = cp2112_read_req(buf, msgs->addr, msgs->len);
540 		} else {
541 			hid_dbg(hdev, "I2C write %#04x len %d\n",
542 				msgs->addr, msgs->len);
543 			count = cp2112_i2c_write_req(buf, msgs->addr,
544 						     msgs->buf, msgs->len);
545 		}
546 		if (count < 0)
547 			return count;
548 	} else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */
549 		   num == 2 &&
550 		   msgs[0].addr == msgs[1].addr &&
551 		   !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
552 		hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
553 			msgs[0].addr, msgs[0].len, msgs[1].len);
554 		read_length = msgs[1].len;
555 		read_buf = msgs[1].buf;
556 		count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
557 				msgs[0].buf, msgs[0].len, msgs[1].len);
558 		if (count < 0)
559 			return count;
560 	} else {
561 		hid_err(hdev,
562 			"Multi-message I2C transactions not supported\n");
563 		return -EOPNOTSUPP;
564 	}
565 
566 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
567 	if (ret < 0) {
568 		hid_err(hdev, "power management error: %d\n", ret);
569 		return ret;
570 	}
571 
572 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
573 	if (ret < 0) {
574 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
575 		goto power_normal;
576 	}
577 
578 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
579 		ret = cp2112_xfer_status(dev);
580 		if (-EBUSY == ret)
581 			continue;
582 		if (ret < 0)
583 			goto power_normal;
584 		break;
585 	}
586 
587 	if (XFER_STATUS_RETRIES <= retries) {
588 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
589 		buf[0] = CP2112_CANCEL_TRANSFER;
590 		buf[1] = 0x01;
591 
592 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
593 		if (ret < 0)
594 			hid_warn(hdev, "Error cancelling transaction: %d\n",
595 				 ret);
596 
597 		ret = -ETIMEDOUT;
598 		goto power_normal;
599 	}
600 
601 	for (count = 0; count < read_length;) {
602 		ret = cp2112_read(dev, read_buf + count, read_length - count);
603 		if (ret < 0)
604 			goto power_normal;
605 		if (ret == 0) {
606 			hid_err(hdev, "read returned 0\n");
607 			ret = -EIO;
608 			goto power_normal;
609 		}
610 		count += ret;
611 		if (count > read_length) {
612 			/*
613 			 * The hardware returned too much data.
614 			 * This is mostly harmless because cp2112_read()
615 			 * has a limit check so didn't overrun our
616 			 * buffer.  Nevertheless, we return an error
617 			 * because something is seriously wrong and
618 			 * it shouldn't go unnoticed.
619 			 */
620 			hid_err(hdev, "long read: %d > %zd\n",
621 				ret, read_length - count + ret);
622 			ret = -EIO;
623 			goto power_normal;
624 		}
625 	}
626 
627 	/* return the number of transferred messages */
628 	ret = num;
629 
630 power_normal:
631 	hid_hw_power(hdev, PM_HINT_NORMAL);
632 	hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
633 	return ret;
634 }
635 
636 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
637 		       unsigned short flags, char read_write, u8 command,
638 		       int size, union i2c_smbus_data *data)
639 {
640 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
641 	struct hid_device *hdev = dev->hdev;
642 	u8 buf[64];
643 	__le16 word;
644 	ssize_t count;
645 	size_t read_length = 0;
646 	unsigned int retries;
647 	int ret;
648 
649 	hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
650 		read_write == I2C_SMBUS_WRITE ? "write" : "read",
651 		addr, flags, command, size);
652 
653 	switch (size) {
654 	case I2C_SMBUS_BYTE:
655 		read_length = 1;
656 
657 		if (I2C_SMBUS_READ == read_write)
658 			count = cp2112_read_req(buf, addr, read_length);
659 		else
660 			count = cp2112_write_req(buf, addr, command, NULL,
661 						 0);
662 		break;
663 	case I2C_SMBUS_BYTE_DATA:
664 		read_length = 1;
665 
666 		if (I2C_SMBUS_READ == read_write)
667 			count = cp2112_write_read_req(buf, addr, read_length,
668 						      command, NULL, 0);
669 		else
670 			count = cp2112_write_req(buf, addr, command,
671 						 &data->byte, 1);
672 		break;
673 	case I2C_SMBUS_WORD_DATA:
674 		read_length = 2;
675 		word = cpu_to_le16(data->word);
676 
677 		if (I2C_SMBUS_READ == read_write)
678 			count = cp2112_write_read_req(buf, addr, read_length,
679 						      command, NULL, 0);
680 		else
681 			count = cp2112_write_req(buf, addr, command,
682 						 (u8 *)&word, 2);
683 		break;
684 	case I2C_SMBUS_PROC_CALL:
685 		size = I2C_SMBUS_WORD_DATA;
686 		read_write = I2C_SMBUS_READ;
687 		read_length = 2;
688 		word = cpu_to_le16(data->word);
689 
690 		count = cp2112_write_read_req(buf, addr, read_length, command,
691 					      (u8 *)&word, 2);
692 		break;
693 	case I2C_SMBUS_I2C_BLOCK_DATA:
694 		size = I2C_SMBUS_BLOCK_DATA;
695 		/* fallthrough */
696 	case I2C_SMBUS_BLOCK_DATA:
697 		if (I2C_SMBUS_READ == read_write) {
698 			count = cp2112_write_read_req(buf, addr,
699 						      I2C_SMBUS_BLOCK_MAX,
700 						      command, NULL, 0);
701 		} else {
702 			count = cp2112_write_req(buf, addr, command,
703 						 data->block,
704 						 data->block[0] + 1);
705 		}
706 		break;
707 	case I2C_SMBUS_BLOCK_PROC_CALL:
708 		size = I2C_SMBUS_BLOCK_DATA;
709 		read_write = I2C_SMBUS_READ;
710 
711 		count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
712 					      command, data->block,
713 					      data->block[0] + 1);
714 		break;
715 	default:
716 		hid_warn(hdev, "Unsupported transaction %d\n", size);
717 		return -EOPNOTSUPP;
718 	}
719 
720 	if (count < 0)
721 		return count;
722 
723 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
724 	if (ret < 0) {
725 		hid_err(hdev, "power management error: %d\n", ret);
726 		return ret;
727 	}
728 
729 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
730 	if (ret < 0) {
731 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
732 		goto power_normal;
733 	}
734 
735 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
736 		ret = cp2112_xfer_status(dev);
737 		if (-EBUSY == ret)
738 			continue;
739 		if (ret < 0)
740 			goto power_normal;
741 		break;
742 	}
743 
744 	if (XFER_STATUS_RETRIES <= retries) {
745 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
746 		buf[0] = CP2112_CANCEL_TRANSFER;
747 		buf[1] = 0x01;
748 
749 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
750 		if (ret < 0)
751 			hid_warn(hdev, "Error cancelling transaction: %d\n",
752 				 ret);
753 
754 		ret = -ETIMEDOUT;
755 		goto power_normal;
756 	}
757 
758 	if (I2C_SMBUS_WRITE == read_write) {
759 		ret = 0;
760 		goto power_normal;
761 	}
762 
763 	if (I2C_SMBUS_BLOCK_DATA == size)
764 		read_length = ret;
765 
766 	ret = cp2112_read(dev, buf, read_length);
767 	if (ret < 0)
768 		goto power_normal;
769 	if (ret != read_length) {
770 		hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
771 		ret = -EIO;
772 		goto power_normal;
773 	}
774 
775 	switch (size) {
776 	case I2C_SMBUS_BYTE:
777 	case I2C_SMBUS_BYTE_DATA:
778 		data->byte = buf[0];
779 		break;
780 	case I2C_SMBUS_WORD_DATA:
781 		data->word = le16_to_cpup((__le16 *)buf);
782 		break;
783 	case I2C_SMBUS_BLOCK_DATA:
784 		if (read_length > I2C_SMBUS_BLOCK_MAX) {
785 			ret = -EPROTO;
786 			goto power_normal;
787 		}
788 
789 		memcpy(data->block, buf, read_length);
790 		break;
791 	}
792 
793 	ret = 0;
794 power_normal:
795 	hid_hw_power(hdev, PM_HINT_NORMAL);
796 	hid_dbg(hdev, "transfer finished: %d\n", ret);
797 	return ret;
798 }
799 
800 static u32 cp2112_functionality(struct i2c_adapter *adap)
801 {
802 	return I2C_FUNC_I2C |
803 		I2C_FUNC_SMBUS_BYTE |
804 		I2C_FUNC_SMBUS_BYTE_DATA |
805 		I2C_FUNC_SMBUS_WORD_DATA |
806 		I2C_FUNC_SMBUS_BLOCK_DATA |
807 		I2C_FUNC_SMBUS_I2C_BLOCK |
808 		I2C_FUNC_SMBUS_PROC_CALL |
809 		I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
810 }
811 
812 static const struct i2c_algorithm smbus_algorithm = {
813 	.master_xfer	= cp2112_i2c_xfer,
814 	.smbus_xfer	= cp2112_xfer,
815 	.functionality	= cp2112_functionality,
816 };
817 
818 static int cp2112_get_usb_config(struct hid_device *hdev,
819 				 struct cp2112_usb_config_report *cfg)
820 {
821 	int ret;
822 
823 	ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
824 			     HID_FEATURE_REPORT);
825 	if (ret != sizeof(*cfg)) {
826 		hid_err(hdev, "error reading usb config: %d\n", ret);
827 		if (ret < 0)
828 			return ret;
829 		return -EIO;
830 	}
831 
832 	return 0;
833 }
834 
835 static int cp2112_set_usb_config(struct hid_device *hdev,
836 				 struct cp2112_usb_config_report *cfg)
837 {
838 	int ret;
839 
840 	BUG_ON(cfg->report != CP2112_USB_CONFIG);
841 
842 	ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
843 				HID_FEATURE_REPORT);
844 	if (ret != sizeof(*cfg)) {
845 		hid_err(hdev, "error writing usb config: %d\n", ret);
846 		if (ret < 0)
847 			return ret;
848 		return -EIO;
849 	}
850 
851 	return 0;
852 }
853 
854 static void chmod_sysfs_attrs(struct hid_device *hdev);
855 
856 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
857 static ssize_t name##_store(struct device *kdev, \
858 			    struct device_attribute *attr, const char *buf, \
859 			    size_t count) \
860 { \
861 	struct hid_device *hdev = to_hid_device(kdev); \
862 	struct cp2112_usb_config_report cfg; \
863 	int ret = cp2112_get_usb_config(hdev, &cfg); \
864 	if (ret) \
865 		return ret; \
866 	store; \
867 	ret = cp2112_set_usb_config(hdev, &cfg); \
868 	if (ret) \
869 		return ret; \
870 	chmod_sysfs_attrs(hdev); \
871 	return count; \
872 } \
873 static ssize_t name##_show(struct device *kdev, \
874 			   struct device_attribute *attr, char *buf) \
875 { \
876 	struct hid_device *hdev = to_hid_device(kdev); \
877 	struct cp2112_usb_config_report cfg; \
878 	int ret = cp2112_get_usb_config(hdev, &cfg); \
879 	if (ret) \
880 		return ret; \
881 	return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
882 } \
883 static DEVICE_ATTR_RW(name);
884 
885 CP2112_CONFIG_ATTR(vendor_id, ({
886 	u16 vid;
887 
888 	if (sscanf(buf, "%hi", &vid) != 1)
889 		return -EINVAL;
890 
891 	cfg.vid = cpu_to_le16(vid);
892 	cfg.mask = 0x01;
893 }), "0x%04x\n", le16_to_cpu(cfg.vid));
894 
895 CP2112_CONFIG_ATTR(product_id, ({
896 	u16 pid;
897 
898 	if (sscanf(buf, "%hi", &pid) != 1)
899 		return -EINVAL;
900 
901 	cfg.pid = cpu_to_le16(pid);
902 	cfg.mask = 0x02;
903 }), "0x%04x\n", le16_to_cpu(cfg.pid));
904 
905 CP2112_CONFIG_ATTR(max_power, ({
906 	int mA;
907 
908 	if (sscanf(buf, "%i", &mA) != 1)
909 		return -EINVAL;
910 
911 	cfg.max_power = (mA + 1) / 2;
912 	cfg.mask = 0x04;
913 }), "%u mA\n", cfg.max_power * 2);
914 
915 CP2112_CONFIG_ATTR(power_mode, ({
916 	if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
917 		return -EINVAL;
918 
919 	cfg.mask = 0x08;
920 }), "%u\n", cfg.power_mode);
921 
922 CP2112_CONFIG_ATTR(release_version, ({
923 	if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
924 	    != 2)
925 		return -EINVAL;
926 
927 	cfg.mask = 0x10;
928 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
929 
930 #undef CP2112_CONFIG_ATTR
931 
932 struct cp2112_pstring_attribute {
933 	struct device_attribute attr;
934 	unsigned char report;
935 };
936 
937 static ssize_t pstr_store(struct device *kdev,
938 			  struct device_attribute *kattr, const char *buf,
939 			  size_t count)
940 {
941 	struct hid_device *hdev = to_hid_device(kdev);
942 	struct cp2112_pstring_attribute *attr =
943 		container_of(kattr, struct cp2112_pstring_attribute, attr);
944 	struct cp2112_string_report report;
945 	int ret;
946 
947 	memset(&report, 0, sizeof(report));
948 
949 	ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
950 			      report.string, ARRAY_SIZE(report.string));
951 	report.report = attr->report;
952 	report.length = ret * sizeof(report.string[0]) + 2;
953 	report.type = USB_DT_STRING;
954 
955 	ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
956 				HID_FEATURE_REPORT);
957 	if (ret != report.length + 1) {
958 		hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
959 			ret);
960 		if (ret < 0)
961 			return ret;
962 		return -EIO;
963 	}
964 
965 	chmod_sysfs_attrs(hdev);
966 	return count;
967 }
968 
969 static ssize_t pstr_show(struct device *kdev,
970 			 struct device_attribute *kattr, char *buf)
971 {
972 	struct hid_device *hdev = to_hid_device(kdev);
973 	struct cp2112_pstring_attribute *attr =
974 		container_of(kattr, struct cp2112_pstring_attribute, attr);
975 	struct cp2112_string_report report;
976 	u8 length;
977 	int ret;
978 
979 	ret = cp2112_hid_get(hdev, attr->report, &report.report,
980 			     sizeof(report) - 1, HID_FEATURE_REPORT);
981 	if (ret < 3) {
982 		hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
983 			ret);
984 		if (ret < 0)
985 			return ret;
986 		return -EIO;
987 	}
988 
989 	if (report.length < 2) {
990 		hid_err(hdev, "invalid %s string length: %d\n",
991 			kattr->attr.name, report.length);
992 		return -EIO;
993 	}
994 
995 	length = report.length > ret - 1 ? ret - 1 : report.length;
996 	length = (length - 2) / sizeof(report.string[0]);
997 	ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
998 			      PAGE_SIZE - 1);
999 	buf[ret++] = '\n';
1000 	return ret;
1001 }
1002 
1003 #define CP2112_PSTR_ATTR(name, _report) \
1004 static struct cp2112_pstring_attribute dev_attr_##name = { \
1005 	.attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
1006 	.report = _report, \
1007 };
1008 
1009 CP2112_PSTR_ATTR(manufacturer,	CP2112_MANUFACTURER_STRING);
1010 CP2112_PSTR_ATTR(product,	CP2112_PRODUCT_STRING);
1011 CP2112_PSTR_ATTR(serial,	CP2112_SERIAL_STRING);
1012 
1013 #undef CP2112_PSTR_ATTR
1014 
1015 static const struct attribute_group cp2112_attr_group = {
1016 	.attrs = (struct attribute *[]){
1017 		&dev_attr_vendor_id.attr,
1018 		&dev_attr_product_id.attr,
1019 		&dev_attr_max_power.attr,
1020 		&dev_attr_power_mode.attr,
1021 		&dev_attr_release_version.attr,
1022 		&dev_attr_manufacturer.attr.attr,
1023 		&dev_attr_product.attr.attr,
1024 		&dev_attr_serial.attr.attr,
1025 		NULL
1026 	}
1027 };
1028 
1029 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
1030  * PROM have already been programmed. We do not depend on this preventing
1031  * writing to these attributes since the CP2112 will simply ignore writes to
1032  * already-programmed fields. This is why there is no sense in fixing this
1033  * racy behaviour.
1034  */
1035 static void chmod_sysfs_attrs(struct hid_device *hdev)
1036 {
1037 	struct attribute **attr;
1038 	u8 buf[2];
1039 	int ret;
1040 
1041 	ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
1042 			     HID_FEATURE_REPORT);
1043 	if (ret != sizeof(buf)) {
1044 		hid_err(hdev, "error reading lock byte: %d\n", ret);
1045 		return;
1046 	}
1047 
1048 	for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
1049 		umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
1050 		ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
1051 		if (ret < 0)
1052 			hid_err(hdev, "error chmoding sysfs file %s\n",
1053 				(*attr)->name);
1054 		buf[1] >>= 1;
1055 	}
1056 }
1057 
1058 static void cp2112_gpio_irq_ack(struct irq_data *d)
1059 {
1060 }
1061 
1062 static void cp2112_gpio_irq_mask(struct irq_data *d)
1063 {
1064 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1065 	struct cp2112_device *dev = gpiochip_get_data(gc);
1066 
1067 	__clear_bit(d->hwirq, &dev->irq_mask);
1068 }
1069 
1070 static void cp2112_gpio_irq_unmask(struct irq_data *d)
1071 {
1072 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1073 	struct cp2112_device *dev = gpiochip_get_data(gc);
1074 
1075 	__set_bit(d->hwirq, &dev->irq_mask);
1076 }
1077 
1078 static void cp2112_gpio_poll_callback(struct work_struct *work)
1079 {
1080 	struct cp2112_device *dev = container_of(work, struct cp2112_device,
1081 						 gpio_poll_worker.work);
1082 	struct irq_data *d;
1083 	u8 gpio_mask;
1084 	u8 virqs = (u8)dev->irq_mask;
1085 	u32 irq_type;
1086 	int irq, virq, ret;
1087 
1088 	ret = cp2112_gpio_get_all(&dev->gc);
1089 	if (ret == -ENODEV) /* the hardware has been disconnected */
1090 		return;
1091 	if (ret < 0)
1092 		goto exit;
1093 
1094 	gpio_mask = ret;
1095 
1096 	while (virqs) {
1097 		virq = ffs(virqs) - 1;
1098 		virqs &= ~BIT(virq);
1099 
1100 		if (!dev->gc.to_irq)
1101 			break;
1102 
1103 		irq = dev->gc.to_irq(&dev->gc, virq);
1104 
1105 		d = irq_get_irq_data(irq);
1106 		if (!d)
1107 			continue;
1108 
1109 		irq_type = irqd_get_trigger_type(d);
1110 
1111 		if (gpio_mask & BIT(virq)) {
1112 			/* Level High */
1113 
1114 			if (irq_type & IRQ_TYPE_LEVEL_HIGH)
1115 				handle_nested_irq(irq);
1116 
1117 			if ((irq_type & IRQ_TYPE_EDGE_RISING) &&
1118 			    !(dev->gpio_prev_state & BIT(virq)))
1119 				handle_nested_irq(irq);
1120 		} else {
1121 			/* Level Low */
1122 
1123 			if (irq_type & IRQ_TYPE_LEVEL_LOW)
1124 				handle_nested_irq(irq);
1125 
1126 			if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&
1127 			    (dev->gpio_prev_state & BIT(virq)))
1128 				handle_nested_irq(irq);
1129 		}
1130 	}
1131 
1132 	dev->gpio_prev_state = gpio_mask;
1133 
1134 exit:
1135 	if (dev->gpio_poll)
1136 		schedule_delayed_work(&dev->gpio_poll_worker, 10);
1137 }
1138 
1139 
1140 static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
1141 {
1142 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1143 	struct cp2112_device *dev = gpiochip_get_data(gc);
1144 
1145 	INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
1146 
1147 	cp2112_gpio_direction_input(gc, d->hwirq);
1148 
1149 	if (!dev->gpio_poll) {
1150 		dev->gpio_poll = true;
1151 		schedule_delayed_work(&dev->gpio_poll_worker, 0);
1152 	}
1153 
1154 	cp2112_gpio_irq_unmask(d);
1155 	return 0;
1156 }
1157 
1158 static void cp2112_gpio_irq_shutdown(struct irq_data *d)
1159 {
1160 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1161 	struct cp2112_device *dev = gpiochip_get_data(gc);
1162 
1163 	cancel_delayed_work_sync(&dev->gpio_poll_worker);
1164 }
1165 
1166 static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
1167 {
1168 	return 0;
1169 }
1170 
1171 static struct irq_chip cp2112_gpio_irqchip = {
1172 	.name = "cp2112-gpio",
1173 	.irq_startup = cp2112_gpio_irq_startup,
1174 	.irq_shutdown = cp2112_gpio_irq_shutdown,
1175 	.irq_ack = cp2112_gpio_irq_ack,
1176 	.irq_mask = cp2112_gpio_irq_mask,
1177 	.irq_unmask = cp2112_gpio_irq_unmask,
1178 	.irq_set_type = cp2112_gpio_irq_type,
1179 };
1180 
1181 static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
1182 					      int pin)
1183 {
1184 	int ret;
1185 
1186 	if (dev->desc[pin])
1187 		return -EINVAL;
1188 
1189 	dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin,
1190 						   "HID/I2C:Event");
1191 	if (IS_ERR(dev->desc[pin])) {
1192 		dev_err(dev->gc.parent, "Failed to request GPIO\n");
1193 		return PTR_ERR(dev->desc[pin]);
1194 	}
1195 
1196 	ret = gpiochip_lock_as_irq(&dev->gc, pin);
1197 	if (ret) {
1198 		dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n");
1199 		goto err_desc;
1200 	}
1201 
1202 	ret = gpiod_to_irq(dev->desc[pin]);
1203 	if (ret < 0) {
1204 		dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n");
1205 		goto err_lock;
1206 	}
1207 
1208 	return ret;
1209 
1210 err_lock:
1211 	gpiochip_unlock_as_irq(&dev->gc, pin);
1212 err_desc:
1213 	gpiochip_free_own_desc(dev->desc[pin]);
1214 	dev->desc[pin] = NULL;
1215 	return ret;
1216 }
1217 
1218 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1219 {
1220 	struct cp2112_device *dev;
1221 	u8 buf[3];
1222 	struct cp2112_smbus_config_report config;
1223 	int ret;
1224 
1225 	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
1226 	if (!dev)
1227 		return -ENOMEM;
1228 
1229 	dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
1230 					  GFP_KERNEL);
1231 	if (!dev->in_out_buffer)
1232 		return -ENOMEM;
1233 
1234 	mutex_init(&dev->lock);
1235 
1236 	ret = hid_parse(hdev);
1237 	if (ret) {
1238 		hid_err(hdev, "parse failed\n");
1239 		return ret;
1240 	}
1241 
1242 	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1243 	if (ret) {
1244 		hid_err(hdev, "hw start failed\n");
1245 		return ret;
1246 	}
1247 
1248 	ret = hid_hw_open(hdev);
1249 	if (ret) {
1250 		hid_err(hdev, "hw open failed\n");
1251 		goto err_hid_stop;
1252 	}
1253 
1254 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
1255 	if (ret < 0) {
1256 		hid_err(hdev, "power management error: %d\n", ret);
1257 		goto err_hid_close;
1258 	}
1259 
1260 	ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
1261 			     HID_FEATURE_REPORT);
1262 	if (ret != sizeof(buf)) {
1263 		hid_err(hdev, "error requesting version\n");
1264 		if (ret >= 0)
1265 			ret = -EIO;
1266 		goto err_power_normal;
1267 	}
1268 
1269 	hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
1270 		 buf[1], buf[2]);
1271 
1272 	ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
1273 			     sizeof(config), HID_FEATURE_REPORT);
1274 	if (ret != sizeof(config)) {
1275 		hid_err(hdev, "error requesting SMBus config\n");
1276 		if (ret >= 0)
1277 			ret = -EIO;
1278 		goto err_power_normal;
1279 	}
1280 
1281 	config.retry_time = cpu_to_be16(1);
1282 
1283 	ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1284 				HID_FEATURE_REPORT);
1285 	if (ret != sizeof(config)) {
1286 		hid_err(hdev, "error setting SMBus config\n");
1287 		if (ret >= 0)
1288 			ret = -EIO;
1289 		goto err_power_normal;
1290 	}
1291 
1292 	hid_set_drvdata(hdev, (void *)dev);
1293 	dev->hdev		= hdev;
1294 	dev->adap.owner		= THIS_MODULE;
1295 	dev->adap.class		= I2C_CLASS_HWMON;
1296 	dev->adap.algo		= &smbus_algorithm;
1297 	dev->adap.algo_data	= dev;
1298 	dev->adap.dev.parent	= &hdev->dev;
1299 	snprintf(dev->adap.name, sizeof(dev->adap.name),
1300 		 "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
1301 	dev->hwversion = buf[2];
1302 	init_waitqueue_head(&dev->wait);
1303 
1304 	hid_device_io_start(hdev);
1305 	ret = i2c_add_adapter(&dev->adap);
1306 	hid_device_io_stop(hdev);
1307 
1308 	if (ret) {
1309 		hid_err(hdev, "error registering i2c adapter\n");
1310 		goto err_power_normal;
1311 	}
1312 
1313 	hid_dbg(hdev, "adapter registered\n");
1314 
1315 	dev->gc.label			= "cp2112_gpio";
1316 	dev->gc.direction_input		= cp2112_gpio_direction_input;
1317 	dev->gc.direction_output	= cp2112_gpio_direction_output;
1318 	dev->gc.set			= cp2112_gpio_set;
1319 	dev->gc.get			= cp2112_gpio_get;
1320 	dev->gc.base			= -1;
1321 	dev->gc.ngpio			= 8;
1322 	dev->gc.can_sleep		= 1;
1323 	dev->gc.parent			= &hdev->dev;
1324 
1325 	ret = gpiochip_add_data(&dev->gc, dev);
1326 	if (ret < 0) {
1327 		hid_err(hdev, "error registering gpio chip\n");
1328 		goto err_free_i2c;
1329 	}
1330 
1331 	ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1332 	if (ret < 0) {
1333 		hid_err(hdev, "error creating sysfs attrs\n");
1334 		goto err_gpiochip_remove;
1335 	}
1336 
1337 	chmod_sysfs_attrs(hdev);
1338 	hid_hw_power(hdev, PM_HINT_NORMAL);
1339 
1340 	ret = gpiochip_irqchip_add(&dev->gc, &cp2112_gpio_irqchip, 0,
1341 				   handle_simple_irq, IRQ_TYPE_NONE);
1342 	if (ret) {
1343 		dev_err(dev->gc.parent, "failed to add IRQ chip\n");
1344 		goto err_sysfs_remove;
1345 	}
1346 
1347 	return ret;
1348 
1349 err_sysfs_remove:
1350 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1351 err_gpiochip_remove:
1352 	gpiochip_remove(&dev->gc);
1353 err_free_i2c:
1354 	i2c_del_adapter(&dev->adap);
1355 err_power_normal:
1356 	hid_hw_power(hdev, PM_HINT_NORMAL);
1357 err_hid_close:
1358 	hid_hw_close(hdev);
1359 err_hid_stop:
1360 	hid_hw_stop(hdev);
1361 	return ret;
1362 }
1363 
1364 static void cp2112_remove(struct hid_device *hdev)
1365 {
1366 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1367 	int i;
1368 
1369 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1370 	i2c_del_adapter(&dev->adap);
1371 
1372 	if (dev->gpio_poll) {
1373 		dev->gpio_poll = false;
1374 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
1375 	}
1376 
1377 	for (i = 0; i < ARRAY_SIZE(dev->desc); i++) {
1378 		gpiochip_unlock_as_irq(&dev->gc, i);
1379 		gpiochip_free_own_desc(dev->desc[i]);
1380 	}
1381 
1382 	gpiochip_remove(&dev->gc);
1383 	/* i2c_del_adapter has finished removing all i2c devices from our
1384 	 * adapter. Well behaved devices should no longer call our cp2112_xfer
1385 	 * and should have waited for any pending calls to finish. It has also
1386 	 * waited for device_unregister(&adap->dev) to complete. Therefore we
1387 	 * can safely free our struct cp2112_device.
1388 	 */
1389 	hid_hw_close(hdev);
1390 	hid_hw_stop(hdev);
1391 }
1392 
1393 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1394 			    u8 *data, int size)
1395 {
1396 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1397 	struct cp2112_xfer_status_report *xfer = (void *)data;
1398 
1399 	switch (data[0]) {
1400 	case CP2112_TRANSFER_STATUS_RESPONSE:
1401 		hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1402 			xfer->status0, xfer->status1,
1403 			be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1404 
1405 		switch (xfer->status0) {
1406 		case STATUS0_IDLE:
1407 			dev->xfer_status = -EAGAIN;
1408 			break;
1409 		case STATUS0_BUSY:
1410 			dev->xfer_status = -EBUSY;
1411 			break;
1412 		case STATUS0_COMPLETE:
1413 			dev->xfer_status = be16_to_cpu(xfer->length);
1414 			break;
1415 		case STATUS0_ERROR:
1416 			switch (xfer->status1) {
1417 			case STATUS1_TIMEOUT_NACK:
1418 			case STATUS1_TIMEOUT_BUS:
1419 				dev->xfer_status = -ETIMEDOUT;
1420 				break;
1421 			default:
1422 				dev->xfer_status = -EIO;
1423 				break;
1424 			}
1425 			break;
1426 		default:
1427 			dev->xfer_status = -EINVAL;
1428 			break;
1429 		}
1430 
1431 		atomic_set(&dev->xfer_avail, 1);
1432 		break;
1433 	case CP2112_DATA_READ_RESPONSE:
1434 		hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1435 
1436 		dev->read_length = data[2];
1437 		if (dev->read_length > sizeof(dev->read_data))
1438 			dev->read_length = sizeof(dev->read_data);
1439 
1440 		memcpy(dev->read_data, &data[3], dev->read_length);
1441 		atomic_set(&dev->read_avail, 1);
1442 		break;
1443 	default:
1444 		hid_err(hdev, "unknown report\n");
1445 
1446 		return 0;
1447 	}
1448 
1449 	wake_up_interruptible(&dev->wait);
1450 	return 1;
1451 }
1452 
1453 static struct hid_driver cp2112_driver = {
1454 	.name		= "cp2112",
1455 	.id_table	= cp2112_devices,
1456 	.probe		= cp2112_probe,
1457 	.remove		= cp2112_remove,
1458 	.raw_event	= cp2112_raw_event,
1459 };
1460 
1461 module_hid_driver(cp2112_driver);
1462 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1463 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1464 MODULE_LICENSE("GPL");
1465 
1466