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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  *   http://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/gpio/consumer.h>
20 #include <linux/gpio/machine.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/nls.h>
27 #include <linux/usb/ch9.h>
28 #include "hid-ids.h"
29 
30 #define CP2112_REPORT_MAX_LENGTH		64
31 #define CP2112_GPIO_CONFIG_LENGTH		5
32 #define CP2112_GPIO_GET_LENGTH			2
33 #define CP2112_GPIO_SET_LENGTH			3
34 
35 enum {
36 	CP2112_GPIO_CONFIG		= 0x02,
37 	CP2112_GPIO_GET			= 0x03,
38 	CP2112_GPIO_SET			= 0x04,
39 	CP2112_GET_VERSION_INFO		= 0x05,
40 	CP2112_SMBUS_CONFIG		= 0x06,
41 	CP2112_DATA_READ_REQUEST	= 0x10,
42 	CP2112_DATA_WRITE_READ_REQUEST	= 0x11,
43 	CP2112_DATA_READ_FORCE_SEND	= 0x12,
44 	CP2112_DATA_READ_RESPONSE	= 0x13,
45 	CP2112_DATA_WRITE_REQUEST	= 0x14,
46 	CP2112_TRANSFER_STATUS_REQUEST	= 0x15,
47 	CP2112_TRANSFER_STATUS_RESPONSE	= 0x16,
48 	CP2112_CANCEL_TRANSFER		= 0x17,
49 	CP2112_LOCK_BYTE		= 0x20,
50 	CP2112_USB_CONFIG		= 0x21,
51 	CP2112_MANUFACTURER_STRING	= 0x22,
52 	CP2112_PRODUCT_STRING		= 0x23,
53 	CP2112_SERIAL_STRING		= 0x24,
54 };
55 
56 enum {
57 	STATUS0_IDLE		= 0x00,
58 	STATUS0_BUSY		= 0x01,
59 	STATUS0_COMPLETE	= 0x02,
60 	STATUS0_ERROR		= 0x03,
61 };
62 
63 enum {
64 	STATUS1_TIMEOUT_NACK		= 0x00,
65 	STATUS1_TIMEOUT_BUS		= 0x01,
66 	STATUS1_ARBITRATION_LOST	= 0x02,
67 	STATUS1_READ_INCOMPLETE		= 0x03,
68 	STATUS1_WRITE_INCOMPLETE	= 0x04,
69 	STATUS1_SUCCESS			= 0x05,
70 };
71 
72 struct cp2112_smbus_config_report {
73 	u8 report;		/* CP2112_SMBUS_CONFIG */
74 	__be32 clock_speed;	/* Hz */
75 	u8 device_address;	/* Stored in the upper 7 bits */
76 	u8 auto_send_read;	/* 1 = enabled, 0 = disabled */
77 	__be16 write_timeout;	/* ms, 0 = no timeout */
78 	__be16 read_timeout;	/* ms, 0 = no timeout */
79 	u8 scl_low_timeout;	/* 1 = enabled, 0 = disabled */
80 	__be16 retry_time;	/* # of retries, 0 = no limit */
81 } __packed;
82 
83 struct cp2112_usb_config_report {
84 	u8 report;	/* CP2112_USB_CONFIG */
85 	__le16 vid;	/* Vendor ID */
86 	__le16 pid;	/* Product ID */
87 	u8 max_power;	/* Power requested in 2mA units */
88 	u8 power_mode;	/* 0x00 = bus powered
89 			   0x01 = self powered & regulator off
90 			   0x02 = self powered & regulator on */
91 	u8 release_major;
92 	u8 release_minor;
93 	u8 mask;	/* What fields to program */
94 } __packed;
95 
96 struct cp2112_read_req_report {
97 	u8 report;	/* CP2112_DATA_READ_REQUEST */
98 	u8 slave_address;
99 	__be16 length;
100 } __packed;
101 
102 struct cp2112_write_read_req_report {
103 	u8 report;	/* CP2112_DATA_WRITE_READ_REQUEST */
104 	u8 slave_address;
105 	__be16 length;
106 	u8 target_address_length;
107 	u8 target_address[16];
108 } __packed;
109 
110 struct cp2112_write_req_report {
111 	u8 report;	/* CP2112_DATA_WRITE_REQUEST */
112 	u8 slave_address;
113 	u8 length;
114 	u8 data[61];
115 } __packed;
116 
117 struct cp2112_force_read_report {
118 	u8 report;	/* CP2112_DATA_READ_FORCE_SEND */
119 	__be16 length;
120 } __packed;
121 
122 struct cp2112_xfer_status_report {
123 	u8 report;	/* CP2112_TRANSFER_STATUS_RESPONSE */
124 	u8 status0;	/* STATUS0_* */
125 	u8 status1;	/* STATUS1_* */
126 	__be16 retries;
127 	__be16 length;
128 } __packed;
129 
130 struct cp2112_string_report {
131 	u8 dummy;		/* force .string to be aligned */
132 	u8 report;		/* CP2112_*_STRING */
133 	u8 length;		/* length in bytes of everyting after .report */
134 	u8 type;		/* USB_DT_STRING */
135 	wchar_t string[30];	/* UTF16_LITTLE_ENDIAN string */
136 } __packed;
137 
138 /* Number of times to request transfer status before giving up waiting for a
139    transfer to complete. This may need to be changed if SMBUS clock, retries,
140    or read/write/scl_low timeout settings are changed. */
141 static const int XFER_STATUS_RETRIES = 10;
142 
143 /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or
144    CP2112_TRANSFER_STATUS_RESPONSE. */
145 static const int RESPONSE_TIMEOUT = 50;
146 
147 static const struct hid_device_id cp2112_devices[] = {
148 	{ HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
149 	{ }
150 };
151 MODULE_DEVICE_TABLE(hid, cp2112_devices);
152 
153 struct cp2112_device {
154 	struct i2c_adapter adap;
155 	struct hid_device *hdev;
156 	wait_queue_head_t wait;
157 	u8 read_data[61];
158 	u8 read_length;
159 	u8 hwversion;
160 	int xfer_status;
161 	atomic_t read_avail;
162 	atomic_t xfer_avail;
163 	struct gpio_chip gc;
164 	u8 *in_out_buffer;
165 	struct mutex lock;
166 
167 	struct gpio_desc *desc[8];
168 	bool gpio_poll;
169 	struct delayed_work gpio_poll_worker;
170 	unsigned long irq_mask;
171 	u8 gpio_prev_state;
172 };
173 
174 static int gpio_push_pull = 0xFF;
175 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
176 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
177 
cp2112_gpio_direction_input(struct gpio_chip * chip,unsigned offset)178 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
179 {
180 	struct cp2112_device *dev = gpiochip_get_data(chip);
181 	struct hid_device *hdev = dev->hdev;
182 	u8 *buf = dev->in_out_buffer;
183 	int ret;
184 
185 	mutex_lock(&dev->lock);
186 
187 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
188 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
189 				 HID_REQ_GET_REPORT);
190 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
191 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
192 		if (ret >= 0)
193 			ret = -EIO;
194 		goto exit;
195 	}
196 
197 	buf[1] &= ~(1 << offset);
198 	buf[2] = gpio_push_pull;
199 
200 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
201 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
202 				 HID_REQ_SET_REPORT);
203 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
204 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
205 		if (ret >= 0)
206 			ret = -EIO;
207 		goto exit;
208 	}
209 
210 	ret = 0;
211 
212 exit:
213 	mutex_unlock(&dev->lock);
214 	return ret;
215 }
216 
cp2112_gpio_set(struct gpio_chip * chip,unsigned offset,int value)217 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
218 {
219 	struct cp2112_device *dev = gpiochip_get_data(chip);
220 	struct hid_device *hdev = dev->hdev;
221 	u8 *buf = dev->in_out_buffer;
222 	int ret;
223 
224 	mutex_lock(&dev->lock);
225 
226 	buf[0] = CP2112_GPIO_SET;
227 	buf[1] = value ? 0xff : 0;
228 	buf[2] = 1 << offset;
229 
230 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
231 				 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
232 				 HID_REQ_SET_REPORT);
233 	if (ret < 0)
234 		hid_err(hdev, "error setting GPIO values: %d\n", ret);
235 
236 	mutex_unlock(&dev->lock);
237 }
238 
cp2112_gpio_get_all(struct gpio_chip * chip)239 static int cp2112_gpio_get_all(struct gpio_chip *chip)
240 {
241 	struct cp2112_device *dev = gpiochip_get_data(chip);
242 	struct hid_device *hdev = dev->hdev;
243 	u8 *buf = dev->in_out_buffer;
244 	int ret;
245 
246 	mutex_lock(&dev->lock);
247 
248 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
249 				 CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
250 				 HID_REQ_GET_REPORT);
251 	if (ret != CP2112_GPIO_GET_LENGTH) {
252 		hid_err(hdev, "error requesting GPIO values: %d\n", ret);
253 		ret = ret < 0 ? ret : -EIO;
254 		goto exit;
255 	}
256 
257 	ret = buf[1];
258 
259 exit:
260 	mutex_unlock(&dev->lock);
261 
262 	return ret;
263 }
264 
cp2112_gpio_get(struct gpio_chip * chip,unsigned int offset)265 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
266 {
267 	int ret;
268 
269 	ret = cp2112_gpio_get_all(chip);
270 	if (ret < 0)
271 		return ret;
272 
273 	return (ret >> offset) & 1;
274 }
275 
cp2112_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)276 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
277 					unsigned offset, int value)
278 {
279 	struct cp2112_device *dev = gpiochip_get_data(chip);
280 	struct hid_device *hdev = dev->hdev;
281 	u8 *buf = dev->in_out_buffer;
282 	int ret;
283 
284 	mutex_lock(&dev->lock);
285 
286 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
287 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
288 				 HID_REQ_GET_REPORT);
289 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
290 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
291 		goto fail;
292 	}
293 
294 	buf[1] |= 1 << offset;
295 	buf[2] = gpio_push_pull;
296 
297 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
298 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
299 				 HID_REQ_SET_REPORT);
300 	if (ret < 0) {
301 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
302 		goto fail;
303 	}
304 
305 	mutex_unlock(&dev->lock);
306 
307 	/*
308 	 * Set gpio value when output direction is already set,
309 	 * as specified in AN495, Rev. 0.2, cpt. 4.4
310 	 */
311 	cp2112_gpio_set(chip, offset, value);
312 
313 	return 0;
314 
315 fail:
316 	mutex_unlock(&dev->lock);
317 	return ret < 0 ? ret : -EIO;
318 }
319 
cp2112_hid_get(struct hid_device * hdev,unsigned char report_number,u8 * data,size_t count,unsigned char report_type)320 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
321 			  u8 *data, size_t count, unsigned char report_type)
322 {
323 	u8 *buf;
324 	int ret;
325 
326 	buf = kmalloc(count, GFP_KERNEL);
327 	if (!buf)
328 		return -ENOMEM;
329 
330 	ret = hid_hw_raw_request(hdev, report_number, buf, count,
331 				       report_type, HID_REQ_GET_REPORT);
332 	memcpy(data, buf, count);
333 	kfree(buf);
334 	return ret;
335 }
336 
cp2112_hid_output(struct hid_device * hdev,u8 * data,size_t count,unsigned char report_type)337 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
338 			     unsigned char report_type)
339 {
340 	u8 *buf;
341 	int ret;
342 
343 	buf = kmemdup(data, count, GFP_KERNEL);
344 	if (!buf)
345 		return -ENOMEM;
346 
347 	if (report_type == HID_OUTPUT_REPORT)
348 		ret = hid_hw_output_report(hdev, buf, count);
349 	else
350 		ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
351 				HID_REQ_SET_REPORT);
352 
353 	kfree(buf);
354 	return ret;
355 }
356 
cp2112_wait(struct cp2112_device * dev,atomic_t * avail)357 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
358 {
359 	int ret = 0;
360 
361 	/* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
362 	 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
363 	 * come in cp2112_raw_event or timeout. There will only be one of these
364 	 * in flight at any one time. The timeout is extremely large and is a
365 	 * last resort if the CP2112 has died. If we do timeout we don't expect
366 	 * to receive the response which would cause data races, it's not like
367 	 * we can do anything about it anyway.
368 	 */
369 	ret = wait_event_interruptible_timeout(dev->wait,
370 		atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
371 	if (-ERESTARTSYS == ret)
372 		return ret;
373 	if (!ret)
374 		return -ETIMEDOUT;
375 
376 	atomic_set(avail, 0);
377 	return 0;
378 }
379 
cp2112_xfer_status(struct cp2112_device * dev)380 static int cp2112_xfer_status(struct cp2112_device *dev)
381 {
382 	struct hid_device *hdev = dev->hdev;
383 	u8 buf[2];
384 	int ret;
385 
386 	buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
387 	buf[1] = 0x01;
388 	atomic_set(&dev->xfer_avail, 0);
389 
390 	ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
391 	if (ret < 0) {
392 		hid_warn(hdev, "Error requesting status: %d\n", ret);
393 		return ret;
394 	}
395 
396 	ret = cp2112_wait(dev, &dev->xfer_avail);
397 	if (ret)
398 		return ret;
399 
400 	return dev->xfer_status;
401 }
402 
cp2112_read(struct cp2112_device * dev,u8 * data,size_t size)403 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
404 {
405 	struct hid_device *hdev = dev->hdev;
406 	struct cp2112_force_read_report report;
407 	int ret;
408 
409 	if (size > sizeof(dev->read_data))
410 		size = sizeof(dev->read_data);
411 	report.report = CP2112_DATA_READ_FORCE_SEND;
412 	report.length = cpu_to_be16(size);
413 
414 	atomic_set(&dev->read_avail, 0);
415 
416 	ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
417 				HID_OUTPUT_REPORT);
418 	if (ret < 0) {
419 		hid_warn(hdev, "Error requesting data: %d\n", ret);
420 		return ret;
421 	}
422 
423 	ret = cp2112_wait(dev, &dev->read_avail);
424 	if (ret)
425 		return ret;
426 
427 	hid_dbg(hdev, "read %d of %zd bytes requested\n",
428 		dev->read_length, size);
429 
430 	if (size > dev->read_length)
431 		size = dev->read_length;
432 
433 	memcpy(data, dev->read_data, size);
434 	return dev->read_length;
435 }
436 
cp2112_read_req(void * buf,u8 slave_address,u16 length)437 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
438 {
439 	struct cp2112_read_req_report *report = buf;
440 
441 	if (length < 1 || length > 512)
442 		return -EINVAL;
443 
444 	report->report = CP2112_DATA_READ_REQUEST;
445 	report->slave_address = slave_address << 1;
446 	report->length = cpu_to_be16(length);
447 	return sizeof(*report);
448 }
449 
cp2112_write_read_req(void * buf,u8 slave_address,u16 length,u8 command,u8 * data,u8 data_length)450 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
451 				 u8 command, u8 *data, u8 data_length)
452 {
453 	struct cp2112_write_read_req_report *report = buf;
454 
455 	if (length < 1 || length > 512
456 	    || data_length > sizeof(report->target_address) - 1)
457 		return -EINVAL;
458 
459 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
460 	report->slave_address = slave_address << 1;
461 	report->length = cpu_to_be16(length);
462 	report->target_address_length = data_length + 1;
463 	report->target_address[0] = command;
464 	memcpy(&report->target_address[1], data, data_length);
465 	return data_length + 6;
466 }
467 
cp2112_write_req(void * buf,u8 slave_address,u8 command,u8 * data,u8 data_length)468 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
469 			    u8 data_length)
470 {
471 	struct cp2112_write_req_report *report = buf;
472 
473 	if (data_length > sizeof(report->data) - 1)
474 		return -EINVAL;
475 
476 	report->report = CP2112_DATA_WRITE_REQUEST;
477 	report->slave_address = slave_address << 1;
478 	report->length = data_length + 1;
479 	report->data[0] = command;
480 	memcpy(&report->data[1], data, data_length);
481 	return data_length + 4;
482 }
483 
cp2112_i2c_write_req(void * buf,u8 slave_address,u8 * data,u8 data_length)484 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
485 				u8 data_length)
486 {
487 	struct cp2112_write_req_report *report = buf;
488 
489 	if (data_length > sizeof(report->data))
490 		return -EINVAL;
491 
492 	report->report = CP2112_DATA_WRITE_REQUEST;
493 	report->slave_address = slave_address << 1;
494 	report->length = data_length;
495 	memcpy(report->data, data, data_length);
496 	return data_length + 3;
497 }
498 
cp2112_i2c_write_read_req(void * buf,u8 slave_address,u8 * addr,int addr_length,int read_length)499 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
500 				     u8 *addr, int addr_length,
501 				     int read_length)
502 {
503 	struct cp2112_write_read_req_report *report = buf;
504 
505 	if (read_length < 1 || read_length > 512 ||
506 	    addr_length > sizeof(report->target_address))
507 		return -EINVAL;
508 
509 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
510 	report->slave_address = slave_address << 1;
511 	report->length = cpu_to_be16(read_length);
512 	report->target_address_length = addr_length;
513 	memcpy(report->target_address, addr, addr_length);
514 	return addr_length + 5;
515 }
516 
cp2112_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)517 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
518 			   int num)
519 {
520 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
521 	struct hid_device *hdev = dev->hdev;
522 	u8 buf[64];
523 	ssize_t count;
524 	ssize_t read_length = 0;
525 	u8 *read_buf = NULL;
526 	unsigned int retries;
527 	int ret;
528 
529 	hid_dbg(hdev, "I2C %d messages\n", num);
530 
531 	if (num == 1) {
532 		if (msgs->flags & I2C_M_RD) {
533 			hid_dbg(hdev, "I2C read %#04x len %d\n",
534 				msgs->addr, msgs->len);
535 			read_length = msgs->len;
536 			read_buf = msgs->buf;
537 			count = cp2112_read_req(buf, msgs->addr, msgs->len);
538 		} else {
539 			hid_dbg(hdev, "I2C write %#04x len %d\n",
540 				msgs->addr, msgs->len);
541 			count = cp2112_i2c_write_req(buf, msgs->addr,
542 						     msgs->buf, msgs->len);
543 		}
544 		if (count < 0)
545 			return count;
546 	} else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */
547 		   num == 2 &&
548 		   msgs[0].addr == msgs[1].addr &&
549 		   !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
550 		hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
551 			msgs[0].addr, msgs[0].len, msgs[1].len);
552 		read_length = msgs[1].len;
553 		read_buf = msgs[1].buf;
554 		count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
555 				msgs[0].buf, msgs[0].len, msgs[1].len);
556 		if (count < 0)
557 			return count;
558 	} else {
559 		hid_err(hdev,
560 			"Multi-message I2C transactions not supported\n");
561 		return -EOPNOTSUPP;
562 	}
563 
564 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
565 	if (ret < 0) {
566 		hid_err(hdev, "power management error: %d\n", ret);
567 		return ret;
568 	}
569 
570 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
571 	if (ret < 0) {
572 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
573 		goto power_normal;
574 	}
575 
576 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
577 		ret = cp2112_xfer_status(dev);
578 		if (-EBUSY == ret)
579 			continue;
580 		if (ret < 0)
581 			goto power_normal;
582 		break;
583 	}
584 
585 	if (XFER_STATUS_RETRIES <= retries) {
586 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
587 		buf[0] = CP2112_CANCEL_TRANSFER;
588 		buf[1] = 0x01;
589 
590 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
591 		if (ret < 0)
592 			hid_warn(hdev, "Error cancelling transaction: %d\n",
593 				 ret);
594 
595 		ret = -ETIMEDOUT;
596 		goto power_normal;
597 	}
598 
599 	for (count = 0; count < read_length;) {
600 		ret = cp2112_read(dev, read_buf + count, read_length - count);
601 		if (ret < 0)
602 			goto power_normal;
603 		if (ret == 0) {
604 			hid_err(hdev, "read returned 0\n");
605 			ret = -EIO;
606 			goto power_normal;
607 		}
608 		count += ret;
609 		if (count > read_length) {
610 			/*
611 			 * The hardware returned too much data.
612 			 * This is mostly harmless because cp2112_read()
613 			 * has a limit check so didn't overrun our
614 			 * buffer.  Nevertheless, we return an error
615 			 * because something is seriously wrong and
616 			 * it shouldn't go unnoticed.
617 			 */
618 			hid_err(hdev, "long read: %d > %zd\n",
619 				ret, read_length - count + ret);
620 			ret = -EIO;
621 			goto power_normal;
622 		}
623 	}
624 
625 	/* return the number of transferred messages */
626 	ret = num;
627 
628 power_normal:
629 	hid_hw_power(hdev, PM_HINT_NORMAL);
630 	hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
631 	return ret;
632 }
633 
cp2112_xfer(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)634 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
635 		       unsigned short flags, char read_write, u8 command,
636 		       int size, union i2c_smbus_data *data)
637 {
638 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
639 	struct hid_device *hdev = dev->hdev;
640 	u8 buf[64];
641 	__le16 word;
642 	ssize_t count;
643 	size_t read_length = 0;
644 	unsigned int retries;
645 	int ret;
646 
647 	hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
648 		read_write == I2C_SMBUS_WRITE ? "write" : "read",
649 		addr, flags, command, size);
650 
651 	switch (size) {
652 	case I2C_SMBUS_BYTE:
653 		read_length = 1;
654 
655 		if (I2C_SMBUS_READ == read_write)
656 			count = cp2112_read_req(buf, addr, read_length);
657 		else
658 			count = cp2112_write_req(buf, addr, command, NULL,
659 						 0);
660 		break;
661 	case I2C_SMBUS_BYTE_DATA:
662 		read_length = 1;
663 
664 		if (I2C_SMBUS_READ == read_write)
665 			count = cp2112_write_read_req(buf, addr, read_length,
666 						      command, NULL, 0);
667 		else
668 			count = cp2112_write_req(buf, addr, command,
669 						 &data->byte, 1);
670 		break;
671 	case I2C_SMBUS_WORD_DATA:
672 		read_length = 2;
673 		word = cpu_to_le16(data->word);
674 
675 		if (I2C_SMBUS_READ == read_write)
676 			count = cp2112_write_read_req(buf, addr, read_length,
677 						      command, NULL, 0);
678 		else
679 			count = cp2112_write_req(buf, addr, command,
680 						 (u8 *)&word, 2);
681 		break;
682 	case I2C_SMBUS_PROC_CALL:
683 		size = I2C_SMBUS_WORD_DATA;
684 		read_write = I2C_SMBUS_READ;
685 		read_length = 2;
686 		word = cpu_to_le16(data->word);
687 
688 		count = cp2112_write_read_req(buf, addr, read_length, command,
689 					      (u8 *)&word, 2);
690 		break;
691 	case I2C_SMBUS_I2C_BLOCK_DATA:
692 		if (read_write == I2C_SMBUS_READ) {
693 			read_length = data->block[0];
694 			count = cp2112_write_read_req(buf, addr, read_length,
695 						      command, NULL, 0);
696 		} else {
697 			count = cp2112_write_req(buf, addr, command,
698 						 data->block + 1,
699 						 data->block[0]);
700 		}
701 		break;
702 	case I2C_SMBUS_BLOCK_DATA:
703 		if (I2C_SMBUS_READ == read_write) {
704 			count = cp2112_write_read_req(buf, addr,
705 						      I2C_SMBUS_BLOCK_MAX,
706 						      command, NULL, 0);
707 		} else {
708 			count = cp2112_write_req(buf, addr, command,
709 						 data->block,
710 						 data->block[0] + 1);
711 		}
712 		break;
713 	case I2C_SMBUS_BLOCK_PROC_CALL:
714 		size = I2C_SMBUS_BLOCK_DATA;
715 		read_write = I2C_SMBUS_READ;
716 
717 		count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
718 					      command, data->block,
719 					      data->block[0] + 1);
720 		break;
721 	default:
722 		hid_warn(hdev, "Unsupported transaction %d\n", size);
723 		return -EOPNOTSUPP;
724 	}
725 
726 	if (count < 0)
727 		return count;
728 
729 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
730 	if (ret < 0) {
731 		hid_err(hdev, "power management error: %d\n", ret);
732 		return ret;
733 	}
734 
735 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
736 	if (ret < 0) {
737 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
738 		goto power_normal;
739 	}
740 
741 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
742 		ret = cp2112_xfer_status(dev);
743 		if (-EBUSY == ret)
744 			continue;
745 		if (ret < 0)
746 			goto power_normal;
747 		break;
748 	}
749 
750 	if (XFER_STATUS_RETRIES <= retries) {
751 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
752 		buf[0] = CP2112_CANCEL_TRANSFER;
753 		buf[1] = 0x01;
754 
755 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
756 		if (ret < 0)
757 			hid_warn(hdev, "Error cancelling transaction: %d\n",
758 				 ret);
759 
760 		ret = -ETIMEDOUT;
761 		goto power_normal;
762 	}
763 
764 	if (I2C_SMBUS_WRITE == read_write) {
765 		ret = 0;
766 		goto power_normal;
767 	}
768 
769 	if (I2C_SMBUS_BLOCK_DATA == size)
770 		read_length = ret;
771 
772 	ret = cp2112_read(dev, buf, read_length);
773 	if (ret < 0)
774 		goto power_normal;
775 	if (ret != read_length) {
776 		hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
777 		ret = -EIO;
778 		goto power_normal;
779 	}
780 
781 	switch (size) {
782 	case I2C_SMBUS_BYTE:
783 	case I2C_SMBUS_BYTE_DATA:
784 		data->byte = buf[0];
785 		break;
786 	case I2C_SMBUS_WORD_DATA:
787 		data->word = le16_to_cpup((__le16 *)buf);
788 		break;
789 	case I2C_SMBUS_I2C_BLOCK_DATA:
790 		memcpy(data->block + 1, buf, read_length);
791 		break;
792 	case I2C_SMBUS_BLOCK_DATA:
793 		if (read_length > I2C_SMBUS_BLOCK_MAX) {
794 			ret = -EPROTO;
795 			goto power_normal;
796 		}
797 
798 		memcpy(data->block, buf, read_length);
799 		break;
800 	}
801 
802 	ret = 0;
803 power_normal:
804 	hid_hw_power(hdev, PM_HINT_NORMAL);
805 	hid_dbg(hdev, "transfer finished: %d\n", ret);
806 	return ret;
807 }
808 
cp2112_functionality(struct i2c_adapter * adap)809 static u32 cp2112_functionality(struct i2c_adapter *adap)
810 {
811 	return I2C_FUNC_I2C |
812 		I2C_FUNC_SMBUS_BYTE |
813 		I2C_FUNC_SMBUS_BYTE_DATA |
814 		I2C_FUNC_SMBUS_WORD_DATA |
815 		I2C_FUNC_SMBUS_BLOCK_DATA |
816 		I2C_FUNC_SMBUS_I2C_BLOCK |
817 		I2C_FUNC_SMBUS_PROC_CALL |
818 		I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
819 }
820 
821 static const struct i2c_algorithm smbus_algorithm = {
822 	.master_xfer	= cp2112_i2c_xfer,
823 	.smbus_xfer	= cp2112_xfer,
824 	.functionality	= cp2112_functionality,
825 };
826 
cp2112_get_usb_config(struct hid_device * hdev,struct cp2112_usb_config_report * cfg)827 static int cp2112_get_usb_config(struct hid_device *hdev,
828 				 struct cp2112_usb_config_report *cfg)
829 {
830 	int ret;
831 
832 	ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
833 			     HID_FEATURE_REPORT);
834 	if (ret != sizeof(*cfg)) {
835 		hid_err(hdev, "error reading usb config: %d\n", ret);
836 		if (ret < 0)
837 			return ret;
838 		return -EIO;
839 	}
840 
841 	return 0;
842 }
843 
cp2112_set_usb_config(struct hid_device * hdev,struct cp2112_usb_config_report * cfg)844 static int cp2112_set_usb_config(struct hid_device *hdev,
845 				 struct cp2112_usb_config_report *cfg)
846 {
847 	int ret;
848 
849 	BUG_ON(cfg->report != CP2112_USB_CONFIG);
850 
851 	ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
852 				HID_FEATURE_REPORT);
853 	if (ret != sizeof(*cfg)) {
854 		hid_err(hdev, "error writing usb config: %d\n", ret);
855 		if (ret < 0)
856 			return ret;
857 		return -EIO;
858 	}
859 
860 	return 0;
861 }
862 
863 static void chmod_sysfs_attrs(struct hid_device *hdev);
864 
865 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
866 static ssize_t name##_store(struct device *kdev, \
867 			    struct device_attribute *attr, const char *buf, \
868 			    size_t count) \
869 { \
870 	struct hid_device *hdev = to_hid_device(kdev); \
871 	struct cp2112_usb_config_report cfg; \
872 	int ret = cp2112_get_usb_config(hdev, &cfg); \
873 	if (ret) \
874 		return ret; \
875 	store; \
876 	ret = cp2112_set_usb_config(hdev, &cfg); \
877 	if (ret) \
878 		return ret; \
879 	chmod_sysfs_attrs(hdev); \
880 	return count; \
881 } \
882 static ssize_t name##_show(struct device *kdev, \
883 			   struct device_attribute *attr, char *buf) \
884 { \
885 	struct hid_device *hdev = to_hid_device(kdev); \
886 	struct cp2112_usb_config_report cfg; \
887 	int ret = cp2112_get_usb_config(hdev, &cfg); \
888 	if (ret) \
889 		return ret; \
890 	return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
891 } \
892 static DEVICE_ATTR_RW(name);
893 
894 CP2112_CONFIG_ATTR(vendor_id, ({
895 	u16 vid;
896 
897 	if (sscanf(buf, "%hi", &vid) != 1)
898 		return -EINVAL;
899 
900 	cfg.vid = cpu_to_le16(vid);
901 	cfg.mask = 0x01;
902 }), "0x%04x\n", le16_to_cpu(cfg.vid));
903 
904 CP2112_CONFIG_ATTR(product_id, ({
905 	u16 pid;
906 
907 	if (sscanf(buf, "%hi", &pid) != 1)
908 		return -EINVAL;
909 
910 	cfg.pid = cpu_to_le16(pid);
911 	cfg.mask = 0x02;
912 }), "0x%04x\n", le16_to_cpu(cfg.pid));
913 
914 CP2112_CONFIG_ATTR(max_power, ({
915 	int mA;
916 
917 	if (sscanf(buf, "%i", &mA) != 1)
918 		return -EINVAL;
919 
920 	cfg.max_power = (mA + 1) / 2;
921 	cfg.mask = 0x04;
922 }), "%u mA\n", cfg.max_power * 2);
923 
924 CP2112_CONFIG_ATTR(power_mode, ({
925 	if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
926 		return -EINVAL;
927 
928 	cfg.mask = 0x08;
929 }), "%u\n", cfg.power_mode);
930 
931 CP2112_CONFIG_ATTR(release_version, ({
932 	if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
933 	    != 2)
934 		return -EINVAL;
935 
936 	cfg.mask = 0x10;
937 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
938 
939 #undef CP2112_CONFIG_ATTR
940 
941 struct cp2112_pstring_attribute {
942 	struct device_attribute attr;
943 	unsigned char report;
944 };
945 
pstr_store(struct device * kdev,struct device_attribute * kattr,const char * buf,size_t count)946 static ssize_t pstr_store(struct device *kdev,
947 			  struct device_attribute *kattr, const char *buf,
948 			  size_t count)
949 {
950 	struct hid_device *hdev = to_hid_device(kdev);
951 	struct cp2112_pstring_attribute *attr =
952 		container_of(kattr, struct cp2112_pstring_attribute, attr);
953 	struct cp2112_string_report report;
954 	int ret;
955 
956 	memset(&report, 0, sizeof(report));
957 
958 	ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
959 			      report.string, ARRAY_SIZE(report.string));
960 	report.report = attr->report;
961 	report.length = ret * sizeof(report.string[0]) + 2;
962 	report.type = USB_DT_STRING;
963 
964 	ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
965 				HID_FEATURE_REPORT);
966 	if (ret != report.length + 1) {
967 		hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
968 			ret);
969 		if (ret < 0)
970 			return ret;
971 		return -EIO;
972 	}
973 
974 	chmod_sysfs_attrs(hdev);
975 	return count;
976 }
977 
pstr_show(struct device * kdev,struct device_attribute * kattr,char * buf)978 static ssize_t pstr_show(struct device *kdev,
979 			 struct device_attribute *kattr, char *buf)
980 {
981 	struct hid_device *hdev = to_hid_device(kdev);
982 	struct cp2112_pstring_attribute *attr =
983 		container_of(kattr, struct cp2112_pstring_attribute, attr);
984 	struct cp2112_string_report report;
985 	u8 length;
986 	int ret;
987 
988 	ret = cp2112_hid_get(hdev, attr->report, &report.report,
989 			     sizeof(report) - 1, HID_FEATURE_REPORT);
990 	if (ret < 3) {
991 		hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
992 			ret);
993 		if (ret < 0)
994 			return ret;
995 		return -EIO;
996 	}
997 
998 	if (report.length < 2) {
999 		hid_err(hdev, "invalid %s string length: %d\n",
1000 			kattr->attr.name, report.length);
1001 		return -EIO;
1002 	}
1003 
1004 	length = report.length > ret - 1 ? ret - 1 : report.length;
1005 	length = (length - 2) / sizeof(report.string[0]);
1006 	ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
1007 			      PAGE_SIZE - 1);
1008 	buf[ret++] = '\n';
1009 	return ret;
1010 }
1011 
1012 #define CP2112_PSTR_ATTR(name, _report) \
1013 static struct cp2112_pstring_attribute dev_attr_##name = { \
1014 	.attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
1015 	.report = _report, \
1016 };
1017 
1018 CP2112_PSTR_ATTR(manufacturer,	CP2112_MANUFACTURER_STRING);
1019 CP2112_PSTR_ATTR(product,	CP2112_PRODUCT_STRING);
1020 CP2112_PSTR_ATTR(serial,	CP2112_SERIAL_STRING);
1021 
1022 #undef CP2112_PSTR_ATTR
1023 
1024 static const struct attribute_group cp2112_attr_group = {
1025 	.attrs = (struct attribute *[]){
1026 		&dev_attr_vendor_id.attr,
1027 		&dev_attr_product_id.attr,
1028 		&dev_attr_max_power.attr,
1029 		&dev_attr_power_mode.attr,
1030 		&dev_attr_release_version.attr,
1031 		&dev_attr_manufacturer.attr.attr,
1032 		&dev_attr_product.attr.attr,
1033 		&dev_attr_serial.attr.attr,
1034 		NULL
1035 	}
1036 };
1037 
1038 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
1039  * PROM have already been programmed. We do not depend on this preventing
1040  * writing to these attributes since the CP2112 will simply ignore writes to
1041  * already-programmed fields. This is why there is no sense in fixing this
1042  * racy behaviour.
1043  */
chmod_sysfs_attrs(struct hid_device * hdev)1044 static void chmod_sysfs_attrs(struct hid_device *hdev)
1045 {
1046 	struct attribute **attr;
1047 	u8 buf[2];
1048 	int ret;
1049 
1050 	ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
1051 			     HID_FEATURE_REPORT);
1052 	if (ret != sizeof(buf)) {
1053 		hid_err(hdev, "error reading lock byte: %d\n", ret);
1054 		return;
1055 	}
1056 
1057 	for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
1058 		umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
1059 		ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
1060 		if (ret < 0)
1061 			hid_err(hdev, "error chmoding sysfs file %s\n",
1062 				(*attr)->name);
1063 		buf[1] >>= 1;
1064 	}
1065 }
1066 
cp2112_gpio_irq_ack(struct irq_data * d)1067 static void cp2112_gpio_irq_ack(struct irq_data *d)
1068 {
1069 }
1070 
cp2112_gpio_irq_mask(struct irq_data * d)1071 static void cp2112_gpio_irq_mask(struct irq_data *d)
1072 {
1073 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1074 	struct cp2112_device *dev = gpiochip_get_data(gc);
1075 
1076 	__clear_bit(d->hwirq, &dev->irq_mask);
1077 }
1078 
cp2112_gpio_irq_unmask(struct irq_data * d)1079 static void cp2112_gpio_irq_unmask(struct irq_data *d)
1080 {
1081 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1082 	struct cp2112_device *dev = gpiochip_get_data(gc);
1083 
1084 	__set_bit(d->hwirq, &dev->irq_mask);
1085 }
1086 
cp2112_gpio_poll_callback(struct work_struct * work)1087 static void cp2112_gpio_poll_callback(struct work_struct *work)
1088 {
1089 	struct cp2112_device *dev = container_of(work, struct cp2112_device,
1090 						 gpio_poll_worker.work);
1091 	struct irq_data *d;
1092 	u8 gpio_mask;
1093 	u8 virqs = (u8)dev->irq_mask;
1094 	u32 irq_type;
1095 	int irq, virq, ret;
1096 
1097 	ret = cp2112_gpio_get_all(&dev->gc);
1098 	if (ret == -ENODEV) /* the hardware has been disconnected */
1099 		return;
1100 	if (ret < 0)
1101 		goto exit;
1102 
1103 	gpio_mask = ret;
1104 
1105 	while (virqs) {
1106 		virq = ffs(virqs) - 1;
1107 		virqs &= ~BIT(virq);
1108 
1109 		if (!dev->gc.to_irq)
1110 			break;
1111 
1112 		irq = dev->gc.to_irq(&dev->gc, virq);
1113 
1114 		d = irq_get_irq_data(irq);
1115 		if (!d)
1116 			continue;
1117 
1118 		irq_type = irqd_get_trigger_type(d);
1119 
1120 		if (gpio_mask & BIT(virq)) {
1121 			/* Level High */
1122 
1123 			if (irq_type & IRQ_TYPE_LEVEL_HIGH)
1124 				handle_nested_irq(irq);
1125 
1126 			if ((irq_type & IRQ_TYPE_EDGE_RISING) &&
1127 			    !(dev->gpio_prev_state & BIT(virq)))
1128 				handle_nested_irq(irq);
1129 		} else {
1130 			/* Level Low */
1131 
1132 			if (irq_type & IRQ_TYPE_LEVEL_LOW)
1133 				handle_nested_irq(irq);
1134 
1135 			if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&
1136 			    (dev->gpio_prev_state & BIT(virq)))
1137 				handle_nested_irq(irq);
1138 		}
1139 	}
1140 
1141 	dev->gpio_prev_state = gpio_mask;
1142 
1143 exit:
1144 	if (dev->gpio_poll)
1145 		schedule_delayed_work(&dev->gpio_poll_worker, 10);
1146 }
1147 
1148 
cp2112_gpio_irq_startup(struct irq_data * d)1149 static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
1150 {
1151 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1152 	struct cp2112_device *dev = gpiochip_get_data(gc);
1153 
1154 	INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
1155 
1156 	if (!dev->gpio_poll) {
1157 		dev->gpio_poll = true;
1158 		schedule_delayed_work(&dev->gpio_poll_worker, 0);
1159 	}
1160 
1161 	cp2112_gpio_irq_unmask(d);
1162 	return 0;
1163 }
1164 
cp2112_gpio_irq_shutdown(struct irq_data * d)1165 static void cp2112_gpio_irq_shutdown(struct irq_data *d)
1166 {
1167 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1168 	struct cp2112_device *dev = gpiochip_get_data(gc);
1169 
1170 	cancel_delayed_work_sync(&dev->gpio_poll_worker);
1171 }
1172 
cp2112_gpio_irq_type(struct irq_data * d,unsigned int type)1173 static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
1174 {
1175 	return 0;
1176 }
1177 
1178 static struct irq_chip cp2112_gpio_irqchip = {
1179 	.name = "cp2112-gpio",
1180 	.irq_startup = cp2112_gpio_irq_startup,
1181 	.irq_shutdown = cp2112_gpio_irq_shutdown,
1182 	.irq_ack = cp2112_gpio_irq_ack,
1183 	.irq_mask = cp2112_gpio_irq_mask,
1184 	.irq_unmask = cp2112_gpio_irq_unmask,
1185 	.irq_set_type = cp2112_gpio_irq_type,
1186 };
1187 
cp2112_allocate_irq(struct cp2112_device * dev,int pin)1188 static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
1189 					      int pin)
1190 {
1191 	int ret;
1192 
1193 	if (dev->desc[pin])
1194 		return -EINVAL;
1195 
1196 	dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin,
1197 						   "HID/I2C:Event",
1198 						   GPIO_ACTIVE_HIGH,
1199 						   GPIOD_IN);
1200 	if (IS_ERR(dev->desc[pin])) {
1201 		dev_err(dev->gc.parent, "Failed to request GPIO\n");
1202 		return PTR_ERR(dev->desc[pin]);
1203 	}
1204 
1205 	ret = cp2112_gpio_direction_input(&dev->gc, pin);
1206 	if (ret < 0) {
1207 		dev_err(dev->gc.parent, "Failed to set GPIO to input dir\n");
1208 		goto err_desc;
1209 	}
1210 
1211 	ret = gpiochip_lock_as_irq(&dev->gc, pin);
1212 	if (ret) {
1213 		dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n");
1214 		goto err_desc;
1215 	}
1216 
1217 	ret = gpiod_to_irq(dev->desc[pin]);
1218 	if (ret < 0) {
1219 		dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n");
1220 		goto err_lock;
1221 	}
1222 
1223 	return ret;
1224 
1225 err_lock:
1226 	gpiochip_unlock_as_irq(&dev->gc, pin);
1227 err_desc:
1228 	gpiochip_free_own_desc(dev->desc[pin]);
1229 	dev->desc[pin] = NULL;
1230 	return ret;
1231 }
1232 
cp2112_probe(struct hid_device * hdev,const struct hid_device_id * id)1233 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1234 {
1235 	struct cp2112_device *dev;
1236 	u8 buf[3];
1237 	struct cp2112_smbus_config_report config;
1238 	int ret;
1239 
1240 	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
1241 	if (!dev)
1242 		return -ENOMEM;
1243 
1244 	dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
1245 					  GFP_KERNEL);
1246 	if (!dev->in_out_buffer)
1247 		return -ENOMEM;
1248 
1249 	mutex_init(&dev->lock);
1250 
1251 	ret = hid_parse(hdev);
1252 	if (ret) {
1253 		hid_err(hdev, "parse failed\n");
1254 		return ret;
1255 	}
1256 
1257 	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1258 	if (ret) {
1259 		hid_err(hdev, "hw start failed\n");
1260 		return ret;
1261 	}
1262 
1263 	ret = hid_hw_open(hdev);
1264 	if (ret) {
1265 		hid_err(hdev, "hw open failed\n");
1266 		goto err_hid_stop;
1267 	}
1268 
1269 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
1270 	if (ret < 0) {
1271 		hid_err(hdev, "power management error: %d\n", ret);
1272 		goto err_hid_close;
1273 	}
1274 
1275 	ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
1276 			     HID_FEATURE_REPORT);
1277 	if (ret != sizeof(buf)) {
1278 		hid_err(hdev, "error requesting version\n");
1279 		if (ret >= 0)
1280 			ret = -EIO;
1281 		goto err_power_normal;
1282 	}
1283 
1284 	hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
1285 		 buf[1], buf[2]);
1286 
1287 	ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
1288 			     sizeof(config), HID_FEATURE_REPORT);
1289 	if (ret != sizeof(config)) {
1290 		hid_err(hdev, "error requesting SMBus config\n");
1291 		if (ret >= 0)
1292 			ret = -EIO;
1293 		goto err_power_normal;
1294 	}
1295 
1296 	config.retry_time = cpu_to_be16(1);
1297 
1298 	ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1299 				HID_FEATURE_REPORT);
1300 	if (ret != sizeof(config)) {
1301 		hid_err(hdev, "error setting SMBus config\n");
1302 		if (ret >= 0)
1303 			ret = -EIO;
1304 		goto err_power_normal;
1305 	}
1306 
1307 	hid_set_drvdata(hdev, (void *)dev);
1308 	dev->hdev		= hdev;
1309 	dev->adap.owner		= THIS_MODULE;
1310 	dev->adap.class		= I2C_CLASS_HWMON;
1311 	dev->adap.algo		= &smbus_algorithm;
1312 	dev->adap.algo_data	= dev;
1313 	dev->adap.dev.parent	= &hdev->dev;
1314 	snprintf(dev->adap.name, sizeof(dev->adap.name),
1315 		 "CP2112 SMBus Bridge on hidraw%d",
1316 		 ((struct hidraw *)hdev->hidraw)->minor);
1317 	dev->hwversion = buf[2];
1318 	init_waitqueue_head(&dev->wait);
1319 
1320 	hid_device_io_start(hdev);
1321 	ret = i2c_add_adapter(&dev->adap);
1322 	hid_device_io_stop(hdev);
1323 
1324 	if (ret) {
1325 		hid_err(hdev, "error registering i2c adapter\n");
1326 		goto err_power_normal;
1327 	}
1328 
1329 	hid_dbg(hdev, "adapter registered\n");
1330 
1331 	dev->gc.label			= "cp2112_gpio";
1332 	dev->gc.direction_input		= cp2112_gpio_direction_input;
1333 	dev->gc.direction_output	= cp2112_gpio_direction_output;
1334 	dev->gc.set			= cp2112_gpio_set;
1335 	dev->gc.get			= cp2112_gpio_get;
1336 	dev->gc.base			= -1;
1337 	dev->gc.ngpio			= 8;
1338 	dev->gc.can_sleep		= 1;
1339 	dev->gc.parent			= &hdev->dev;
1340 
1341 	ret = gpiochip_add_data(&dev->gc, dev);
1342 	if (ret < 0) {
1343 		hid_err(hdev, "error registering gpio chip\n");
1344 		goto err_free_i2c;
1345 	}
1346 
1347 	ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1348 	if (ret < 0) {
1349 		hid_err(hdev, "error creating sysfs attrs\n");
1350 		goto err_gpiochip_remove;
1351 	}
1352 
1353 	chmod_sysfs_attrs(hdev);
1354 	hid_hw_power(hdev, PM_HINT_NORMAL);
1355 
1356 	ret = gpiochip_irqchip_add(&dev->gc, &cp2112_gpio_irqchip, 0,
1357 				   handle_simple_irq, IRQ_TYPE_NONE);
1358 	if (ret) {
1359 		dev_err(dev->gc.parent, "failed to add IRQ chip\n");
1360 		goto err_sysfs_remove;
1361 	}
1362 
1363 	return ret;
1364 
1365 err_sysfs_remove:
1366 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1367 err_gpiochip_remove:
1368 	gpiochip_remove(&dev->gc);
1369 err_free_i2c:
1370 	i2c_del_adapter(&dev->adap);
1371 err_power_normal:
1372 	hid_hw_power(hdev, PM_HINT_NORMAL);
1373 err_hid_close:
1374 	hid_hw_close(hdev);
1375 err_hid_stop:
1376 	hid_hw_stop(hdev);
1377 	return ret;
1378 }
1379 
cp2112_remove(struct hid_device * hdev)1380 static void cp2112_remove(struct hid_device *hdev)
1381 {
1382 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1383 	int i;
1384 
1385 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1386 	i2c_del_adapter(&dev->adap);
1387 
1388 	if (dev->gpio_poll) {
1389 		dev->gpio_poll = false;
1390 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
1391 	}
1392 
1393 	for (i = 0; i < ARRAY_SIZE(dev->desc); i++) {
1394 		gpiochip_unlock_as_irq(&dev->gc, i);
1395 		gpiochip_free_own_desc(dev->desc[i]);
1396 	}
1397 
1398 	gpiochip_remove(&dev->gc);
1399 	/* i2c_del_adapter has finished removing all i2c devices from our
1400 	 * adapter. Well behaved devices should no longer call our cp2112_xfer
1401 	 * and should have waited for any pending calls to finish. It has also
1402 	 * waited for device_unregister(&adap->dev) to complete. Therefore we
1403 	 * can safely free our struct cp2112_device.
1404 	 */
1405 	hid_hw_close(hdev);
1406 	hid_hw_stop(hdev);
1407 }
1408 
cp2112_raw_event(struct hid_device * hdev,struct hid_report * report,u8 * data,int size)1409 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1410 			    u8 *data, int size)
1411 {
1412 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1413 	struct cp2112_xfer_status_report *xfer = (void *)data;
1414 
1415 	switch (data[0]) {
1416 	case CP2112_TRANSFER_STATUS_RESPONSE:
1417 		hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1418 			xfer->status0, xfer->status1,
1419 			be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1420 
1421 		switch (xfer->status0) {
1422 		case STATUS0_IDLE:
1423 			dev->xfer_status = -EAGAIN;
1424 			break;
1425 		case STATUS0_BUSY:
1426 			dev->xfer_status = -EBUSY;
1427 			break;
1428 		case STATUS0_COMPLETE:
1429 			dev->xfer_status = be16_to_cpu(xfer->length);
1430 			break;
1431 		case STATUS0_ERROR:
1432 			switch (xfer->status1) {
1433 			case STATUS1_TIMEOUT_NACK:
1434 			case STATUS1_TIMEOUT_BUS:
1435 				dev->xfer_status = -ETIMEDOUT;
1436 				break;
1437 			default:
1438 				dev->xfer_status = -EIO;
1439 				break;
1440 			}
1441 			break;
1442 		default:
1443 			dev->xfer_status = -EINVAL;
1444 			break;
1445 		}
1446 
1447 		atomic_set(&dev->xfer_avail, 1);
1448 		break;
1449 	case CP2112_DATA_READ_RESPONSE:
1450 		hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1451 
1452 		dev->read_length = data[2];
1453 		if (dev->read_length > sizeof(dev->read_data))
1454 			dev->read_length = sizeof(dev->read_data);
1455 
1456 		memcpy(dev->read_data, &data[3], dev->read_length);
1457 		atomic_set(&dev->read_avail, 1);
1458 		break;
1459 	default:
1460 		hid_err(hdev, "unknown report\n");
1461 
1462 		return 0;
1463 	}
1464 
1465 	wake_up_interruptible(&dev->wait);
1466 	return 1;
1467 }
1468 
1469 static struct hid_driver cp2112_driver = {
1470 	.name		= "cp2112",
1471 	.id_table	= cp2112_devices,
1472 	.probe		= cp2112_probe,
1473 	.remove		= cp2112_remove,
1474 	.raw_event	= cp2112_raw_event,
1475 };
1476 
1477 module_hid_driver(cp2112_driver);
1478 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1479 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1480 MODULE_LICENSE("GPL");
1481 
1482