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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  *   https://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
15  * Programming Interface Specification:
16  *   https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf
17  */
18 
19 #include <linux/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 	struct irq_chip irq;
165 	u8 *in_out_buffer;
166 	struct mutex lock;
167 
168 	struct gpio_desc *desc[8];
169 	bool gpio_poll;
170 	struct delayed_work gpio_poll_worker;
171 	unsigned long irq_mask;
172 	u8 gpio_prev_state;
173 };
174 
175 static int gpio_push_pull = 0xFF;
176 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
177 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
178 
cp2112_gpio_direction_input(struct gpio_chip * chip,unsigned offset)179 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
180 {
181 	struct cp2112_device *dev = gpiochip_get_data(chip);
182 	struct hid_device *hdev = dev->hdev;
183 	u8 *buf = dev->in_out_buffer;
184 	int ret;
185 
186 	mutex_lock(&dev->lock);
187 
188 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
189 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
190 				 HID_REQ_GET_REPORT);
191 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
192 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
193 		if (ret >= 0)
194 			ret = -EIO;
195 		goto exit;
196 	}
197 
198 	buf[1] &= ~(1 << offset);
199 	buf[2] = gpio_push_pull;
200 
201 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
202 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
203 				 HID_REQ_SET_REPORT);
204 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
205 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
206 		if (ret >= 0)
207 			ret = -EIO;
208 		goto exit;
209 	}
210 
211 	ret = 0;
212 
213 exit:
214 	mutex_unlock(&dev->lock);
215 	return ret;
216 }
217 
cp2112_gpio_set(struct gpio_chip * chip,unsigned offset,int value)218 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
219 {
220 	struct cp2112_device *dev = gpiochip_get_data(chip);
221 	struct hid_device *hdev = dev->hdev;
222 	u8 *buf = dev->in_out_buffer;
223 	int ret;
224 
225 	mutex_lock(&dev->lock);
226 
227 	buf[0] = CP2112_GPIO_SET;
228 	buf[1] = value ? 0xff : 0;
229 	buf[2] = 1 << offset;
230 
231 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
232 				 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
233 				 HID_REQ_SET_REPORT);
234 	if (ret < 0)
235 		hid_err(hdev, "error setting GPIO values: %d\n", ret);
236 
237 	mutex_unlock(&dev->lock);
238 }
239 
cp2112_gpio_get_all(struct gpio_chip * chip)240 static int cp2112_gpio_get_all(struct gpio_chip *chip)
241 {
242 	struct cp2112_device *dev = gpiochip_get_data(chip);
243 	struct hid_device *hdev = dev->hdev;
244 	u8 *buf = dev->in_out_buffer;
245 	int ret;
246 
247 	mutex_lock(&dev->lock);
248 
249 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
250 				 CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
251 				 HID_REQ_GET_REPORT);
252 	if (ret != CP2112_GPIO_GET_LENGTH) {
253 		hid_err(hdev, "error requesting GPIO values: %d\n", ret);
254 		ret = ret < 0 ? ret : -EIO;
255 		goto exit;
256 	}
257 
258 	ret = buf[1];
259 
260 exit:
261 	mutex_unlock(&dev->lock);
262 
263 	return ret;
264 }
265 
cp2112_gpio_get(struct gpio_chip * chip,unsigned int offset)266 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
267 {
268 	int ret;
269 
270 	ret = cp2112_gpio_get_all(chip);
271 	if (ret < 0)
272 		return ret;
273 
274 	return (ret >> offset) & 1;
275 }
276 
cp2112_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)277 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
278 					unsigned offset, int value)
279 {
280 	struct cp2112_device *dev = gpiochip_get_data(chip);
281 	struct hid_device *hdev = dev->hdev;
282 	u8 *buf = dev->in_out_buffer;
283 	int ret;
284 
285 	mutex_lock(&dev->lock);
286 
287 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
288 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
289 				 HID_REQ_GET_REPORT);
290 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
291 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
292 		goto fail;
293 	}
294 
295 	buf[1] |= 1 << offset;
296 	buf[2] = gpio_push_pull;
297 
298 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
299 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
300 				 HID_REQ_SET_REPORT);
301 	if (ret < 0) {
302 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
303 		goto fail;
304 	}
305 
306 	mutex_unlock(&dev->lock);
307 
308 	/*
309 	 * Set gpio value when output direction is already set,
310 	 * as specified in AN495, Rev. 0.2, cpt. 4.4
311 	 */
312 	cp2112_gpio_set(chip, offset, value);
313 
314 	return 0;
315 
316 fail:
317 	mutex_unlock(&dev->lock);
318 	return ret < 0 ? ret : -EIO;
319 }
320 
cp2112_hid_get(struct hid_device * hdev,unsigned char report_number,u8 * data,size_t count,unsigned char report_type)321 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
322 			  u8 *data, size_t count, unsigned char report_type)
323 {
324 	u8 *buf;
325 	int ret;
326 
327 	buf = kmalloc(count, GFP_KERNEL);
328 	if (!buf)
329 		return -ENOMEM;
330 
331 	ret = hid_hw_raw_request(hdev, report_number, buf, count,
332 				       report_type, HID_REQ_GET_REPORT);
333 	memcpy(data, buf, count);
334 	kfree(buf);
335 	return ret;
336 }
337 
cp2112_hid_output(struct hid_device * hdev,u8 * data,size_t count,unsigned char report_type)338 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
339 			     unsigned char report_type)
340 {
341 	u8 *buf;
342 	int ret;
343 
344 	buf = kmemdup(data, count, GFP_KERNEL);
345 	if (!buf)
346 		return -ENOMEM;
347 
348 	if (report_type == HID_OUTPUT_REPORT)
349 		ret = hid_hw_output_report(hdev, buf, count);
350 	else
351 		ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
352 				HID_REQ_SET_REPORT);
353 
354 	kfree(buf);
355 	return ret;
356 }
357 
cp2112_wait(struct cp2112_device * dev,atomic_t * avail)358 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
359 {
360 	int ret = 0;
361 
362 	/* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
363 	 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
364 	 * come in cp2112_raw_event or timeout. There will only be one of these
365 	 * in flight at any one time. The timeout is extremely large and is a
366 	 * last resort if the CP2112 has died. If we do timeout we don't expect
367 	 * to receive the response which would cause data races, it's not like
368 	 * we can do anything about it anyway.
369 	 */
370 	ret = wait_event_interruptible_timeout(dev->wait,
371 		atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
372 	if (-ERESTARTSYS == ret)
373 		return ret;
374 	if (!ret)
375 		return -ETIMEDOUT;
376 
377 	atomic_set(avail, 0);
378 	return 0;
379 }
380 
cp2112_xfer_status(struct cp2112_device * dev)381 static int cp2112_xfer_status(struct cp2112_device *dev)
382 {
383 	struct hid_device *hdev = dev->hdev;
384 	u8 buf[2];
385 	int ret;
386 
387 	buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
388 	buf[1] = 0x01;
389 	atomic_set(&dev->xfer_avail, 0);
390 
391 	ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
392 	if (ret < 0) {
393 		hid_warn(hdev, "Error requesting status: %d\n", ret);
394 		return ret;
395 	}
396 
397 	ret = cp2112_wait(dev, &dev->xfer_avail);
398 	if (ret)
399 		return ret;
400 
401 	return dev->xfer_status;
402 }
403 
cp2112_read(struct cp2112_device * dev,u8 * data,size_t size)404 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
405 {
406 	struct hid_device *hdev = dev->hdev;
407 	struct cp2112_force_read_report report;
408 	int ret;
409 
410 	if (size > sizeof(dev->read_data))
411 		size = sizeof(dev->read_data);
412 	report.report = CP2112_DATA_READ_FORCE_SEND;
413 	report.length = cpu_to_be16(size);
414 
415 	atomic_set(&dev->read_avail, 0);
416 
417 	ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
418 				HID_OUTPUT_REPORT);
419 	if (ret < 0) {
420 		hid_warn(hdev, "Error requesting data: %d\n", ret);
421 		return ret;
422 	}
423 
424 	ret = cp2112_wait(dev, &dev->read_avail);
425 	if (ret)
426 		return ret;
427 
428 	hid_dbg(hdev, "read %d of %zd bytes requested\n",
429 		dev->read_length, size);
430 
431 	if (size > dev->read_length)
432 		size = dev->read_length;
433 
434 	memcpy(data, dev->read_data, size);
435 	return dev->read_length;
436 }
437 
cp2112_read_req(void * buf,u8 slave_address,u16 length)438 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
439 {
440 	struct cp2112_read_req_report *report = buf;
441 
442 	if (length < 1 || length > 512)
443 		return -EINVAL;
444 
445 	report->report = CP2112_DATA_READ_REQUEST;
446 	report->slave_address = slave_address << 1;
447 	report->length = cpu_to_be16(length);
448 	return sizeof(*report);
449 }
450 
cp2112_write_read_req(void * buf,u8 slave_address,u16 length,u8 command,u8 * data,u8 data_length)451 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
452 				 u8 command, u8 *data, u8 data_length)
453 {
454 	struct cp2112_write_read_req_report *report = buf;
455 
456 	if (length < 1 || length > 512
457 	    || data_length > sizeof(report->target_address) - 1)
458 		return -EINVAL;
459 
460 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
461 	report->slave_address = slave_address << 1;
462 	report->length = cpu_to_be16(length);
463 	report->target_address_length = data_length + 1;
464 	report->target_address[0] = command;
465 	memcpy(&report->target_address[1], data, data_length);
466 	return data_length + 6;
467 }
468 
cp2112_write_req(void * buf,u8 slave_address,u8 command,u8 * data,u8 data_length)469 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
470 			    u8 data_length)
471 {
472 	struct cp2112_write_req_report *report = buf;
473 
474 	if (data_length > sizeof(report->data) - 1)
475 		return -EINVAL;
476 
477 	report->report = CP2112_DATA_WRITE_REQUEST;
478 	report->slave_address = slave_address << 1;
479 	report->length = data_length + 1;
480 	report->data[0] = command;
481 	memcpy(&report->data[1], data, data_length);
482 	return data_length + 4;
483 }
484 
cp2112_i2c_write_req(void * buf,u8 slave_address,u8 * data,u8 data_length)485 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
486 				u8 data_length)
487 {
488 	struct cp2112_write_req_report *report = buf;
489 
490 	if (data_length > sizeof(report->data))
491 		return -EINVAL;
492 
493 	report->report = CP2112_DATA_WRITE_REQUEST;
494 	report->slave_address = slave_address << 1;
495 	report->length = data_length;
496 	memcpy(report->data, data, data_length);
497 	return data_length + 3;
498 }
499 
cp2112_i2c_write_read_req(void * buf,u8 slave_address,u8 * addr,int addr_length,int read_length)500 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
501 				     u8 *addr, int addr_length,
502 				     int read_length)
503 {
504 	struct cp2112_write_read_req_report *report = buf;
505 
506 	if (read_length < 1 || read_length > 512 ||
507 	    addr_length > sizeof(report->target_address))
508 		return -EINVAL;
509 
510 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
511 	report->slave_address = slave_address << 1;
512 	report->length = cpu_to_be16(read_length);
513 	report->target_address_length = addr_length;
514 	memcpy(report->target_address, addr, addr_length);
515 	return addr_length + 5;
516 }
517 
cp2112_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)518 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
519 			   int num)
520 {
521 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
522 	struct hid_device *hdev = dev->hdev;
523 	u8 buf[64];
524 	ssize_t count;
525 	ssize_t read_length = 0;
526 	u8 *read_buf = NULL;
527 	unsigned int retries;
528 	int ret;
529 
530 	hid_dbg(hdev, "I2C %d messages\n", num);
531 
532 	if (num == 1) {
533 		if (msgs->flags & I2C_M_RD) {
534 			hid_dbg(hdev, "I2C read %#04x len %d\n",
535 				msgs->addr, msgs->len);
536 			read_length = msgs->len;
537 			read_buf = msgs->buf;
538 			count = cp2112_read_req(buf, msgs->addr, msgs->len);
539 		} else {
540 			hid_dbg(hdev, "I2C write %#04x len %d\n",
541 				msgs->addr, msgs->len);
542 			count = cp2112_i2c_write_req(buf, msgs->addr,
543 						     msgs->buf, msgs->len);
544 		}
545 		if (count < 0)
546 			return count;
547 	} else if (dev->hwversion > 1 &&  /* no repeated start in rev 1 */
548 		   num == 2 &&
549 		   msgs[0].addr == msgs[1].addr &&
550 		   !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
551 		hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
552 			msgs[0].addr, msgs[0].len, msgs[1].len);
553 		read_length = msgs[1].len;
554 		read_buf = msgs[1].buf;
555 		count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
556 				msgs[0].buf, msgs[0].len, msgs[1].len);
557 		if (count < 0)
558 			return count;
559 	} else {
560 		hid_err(hdev,
561 			"Multi-message I2C transactions not supported\n");
562 		return -EOPNOTSUPP;
563 	}
564 
565 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
566 	if (ret < 0) {
567 		hid_err(hdev, "power management error: %d\n", ret);
568 		return ret;
569 	}
570 
571 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
572 	if (ret < 0) {
573 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
574 		goto power_normal;
575 	}
576 
577 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
578 		ret = cp2112_xfer_status(dev);
579 		if (-EBUSY == ret)
580 			continue;
581 		if (ret < 0)
582 			goto power_normal;
583 		break;
584 	}
585 
586 	if (XFER_STATUS_RETRIES <= retries) {
587 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
588 		buf[0] = CP2112_CANCEL_TRANSFER;
589 		buf[1] = 0x01;
590 
591 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
592 		if (ret < 0)
593 			hid_warn(hdev, "Error cancelling transaction: %d\n",
594 				 ret);
595 
596 		ret = -ETIMEDOUT;
597 		goto power_normal;
598 	}
599 
600 	for (count = 0; count < read_length;) {
601 		ret = cp2112_read(dev, read_buf + count, read_length - count);
602 		if (ret < 0)
603 			goto power_normal;
604 		if (ret == 0) {
605 			hid_err(hdev, "read returned 0\n");
606 			ret = -EIO;
607 			goto power_normal;
608 		}
609 		count += ret;
610 		if (count > read_length) {
611 			/*
612 			 * The hardware returned too much data.
613 			 * This is mostly harmless because cp2112_read()
614 			 * has a limit check so didn't overrun our
615 			 * buffer.  Nevertheless, we return an error
616 			 * because something is seriously wrong and
617 			 * it shouldn't go unnoticed.
618 			 */
619 			hid_err(hdev, "long read: %d > %zd\n",
620 				ret, read_length - count + ret);
621 			ret = -EIO;
622 			goto power_normal;
623 		}
624 	}
625 
626 	/* return the number of transferred messages */
627 	ret = num;
628 
629 power_normal:
630 	hid_hw_power(hdev, PM_HINT_NORMAL);
631 	hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
632 	return ret;
633 }
634 
cp2112_xfer(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)635 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
636 		       unsigned short flags, char read_write, u8 command,
637 		       int size, union i2c_smbus_data *data)
638 {
639 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
640 	struct hid_device *hdev = dev->hdev;
641 	u8 buf[64];
642 	__le16 word;
643 	ssize_t count;
644 	size_t read_length = 0;
645 	unsigned int retries;
646 	int ret;
647 
648 	hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
649 		read_write == I2C_SMBUS_WRITE ? "write" : "read",
650 		addr, flags, command, size);
651 
652 	switch (size) {
653 	case I2C_SMBUS_BYTE:
654 		read_length = 1;
655 
656 		if (I2C_SMBUS_READ == read_write)
657 			count = cp2112_read_req(buf, addr, read_length);
658 		else
659 			count = cp2112_write_req(buf, addr, command, NULL,
660 						 0);
661 		break;
662 	case I2C_SMBUS_BYTE_DATA:
663 		read_length = 1;
664 
665 		if (I2C_SMBUS_READ == read_write)
666 			count = cp2112_write_read_req(buf, addr, read_length,
667 						      command, NULL, 0);
668 		else
669 			count = cp2112_write_req(buf, addr, command,
670 						 &data->byte, 1);
671 		break;
672 	case I2C_SMBUS_WORD_DATA:
673 		read_length = 2;
674 		word = cpu_to_le16(data->word);
675 
676 		if (I2C_SMBUS_READ == read_write)
677 			count = cp2112_write_read_req(buf, addr, read_length,
678 						      command, NULL, 0);
679 		else
680 			count = cp2112_write_req(buf, addr, command,
681 						 (u8 *)&word, 2);
682 		break;
683 	case I2C_SMBUS_PROC_CALL:
684 		size = I2C_SMBUS_WORD_DATA;
685 		read_write = I2C_SMBUS_READ;
686 		read_length = 2;
687 		word = cpu_to_le16(data->word);
688 
689 		count = cp2112_write_read_req(buf, addr, read_length, command,
690 					      (u8 *)&word, 2);
691 		break;
692 	case I2C_SMBUS_I2C_BLOCK_DATA:
693 		if (read_write == I2C_SMBUS_READ) {
694 			read_length = data->block[0];
695 			count = cp2112_write_read_req(buf, addr, read_length,
696 						      command, NULL, 0);
697 		} else {
698 			count = cp2112_write_req(buf, addr, command,
699 						 data->block + 1,
700 						 data->block[0]);
701 		}
702 		break;
703 	case I2C_SMBUS_BLOCK_DATA:
704 		if (I2C_SMBUS_READ == read_write) {
705 			count = cp2112_write_read_req(buf, addr,
706 						      I2C_SMBUS_BLOCK_MAX,
707 						      command, NULL, 0);
708 		} else {
709 			count = cp2112_write_req(buf, addr, command,
710 						 data->block,
711 						 data->block[0] + 1);
712 		}
713 		break;
714 	case I2C_SMBUS_BLOCK_PROC_CALL:
715 		size = I2C_SMBUS_BLOCK_DATA;
716 		read_write = I2C_SMBUS_READ;
717 
718 		count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
719 					      command, data->block,
720 					      data->block[0] + 1);
721 		break;
722 	default:
723 		hid_warn(hdev, "Unsupported transaction %d\n", size);
724 		return -EOPNOTSUPP;
725 	}
726 
727 	if (count < 0)
728 		return count;
729 
730 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
731 	if (ret < 0) {
732 		hid_err(hdev, "power management error: %d\n", ret);
733 		return ret;
734 	}
735 
736 	ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
737 	if (ret < 0) {
738 		hid_warn(hdev, "Error starting transaction: %d\n", ret);
739 		goto power_normal;
740 	}
741 
742 	for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
743 		ret = cp2112_xfer_status(dev);
744 		if (-EBUSY == ret)
745 			continue;
746 		if (ret < 0)
747 			goto power_normal;
748 		break;
749 	}
750 
751 	if (XFER_STATUS_RETRIES <= retries) {
752 		hid_warn(hdev, "Transfer timed out, cancelling.\n");
753 		buf[0] = CP2112_CANCEL_TRANSFER;
754 		buf[1] = 0x01;
755 
756 		ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
757 		if (ret < 0)
758 			hid_warn(hdev, "Error cancelling transaction: %d\n",
759 				 ret);
760 
761 		ret = -ETIMEDOUT;
762 		goto power_normal;
763 	}
764 
765 	if (I2C_SMBUS_WRITE == read_write) {
766 		ret = 0;
767 		goto power_normal;
768 	}
769 
770 	if (I2C_SMBUS_BLOCK_DATA == size)
771 		read_length = ret;
772 
773 	ret = cp2112_read(dev, buf, read_length);
774 	if (ret < 0)
775 		goto power_normal;
776 	if (ret != read_length) {
777 		hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
778 		ret = -EIO;
779 		goto power_normal;
780 	}
781 
782 	switch (size) {
783 	case I2C_SMBUS_BYTE:
784 	case I2C_SMBUS_BYTE_DATA:
785 		data->byte = buf[0];
786 		break;
787 	case I2C_SMBUS_WORD_DATA:
788 		data->word = le16_to_cpup((__le16 *)buf);
789 		break;
790 	case I2C_SMBUS_I2C_BLOCK_DATA:
791 		if (read_length > I2C_SMBUS_BLOCK_MAX) {
792 			ret = -EINVAL;
793 			goto power_normal;
794 		}
795 
796 		memcpy(data->block + 1, buf, read_length);
797 		break;
798 	case I2C_SMBUS_BLOCK_DATA:
799 		if (read_length > I2C_SMBUS_BLOCK_MAX) {
800 			ret = -EPROTO;
801 			goto power_normal;
802 		}
803 
804 		memcpy(data->block, buf, read_length);
805 		break;
806 	}
807 
808 	ret = 0;
809 power_normal:
810 	hid_hw_power(hdev, PM_HINT_NORMAL);
811 	hid_dbg(hdev, "transfer finished: %d\n", ret);
812 	return ret;
813 }
814 
cp2112_functionality(struct i2c_adapter * adap)815 static u32 cp2112_functionality(struct i2c_adapter *adap)
816 {
817 	return I2C_FUNC_I2C |
818 		I2C_FUNC_SMBUS_BYTE |
819 		I2C_FUNC_SMBUS_BYTE_DATA |
820 		I2C_FUNC_SMBUS_WORD_DATA |
821 		I2C_FUNC_SMBUS_BLOCK_DATA |
822 		I2C_FUNC_SMBUS_I2C_BLOCK |
823 		I2C_FUNC_SMBUS_PROC_CALL |
824 		I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
825 }
826 
827 static const struct i2c_algorithm smbus_algorithm = {
828 	.master_xfer	= cp2112_i2c_xfer,
829 	.smbus_xfer	= cp2112_xfer,
830 	.functionality	= cp2112_functionality,
831 };
832 
cp2112_get_usb_config(struct hid_device * hdev,struct cp2112_usb_config_report * cfg)833 static int cp2112_get_usb_config(struct hid_device *hdev,
834 				 struct cp2112_usb_config_report *cfg)
835 {
836 	int ret;
837 
838 	ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
839 			     HID_FEATURE_REPORT);
840 	if (ret != sizeof(*cfg)) {
841 		hid_err(hdev, "error reading usb config: %d\n", ret);
842 		if (ret < 0)
843 			return ret;
844 		return -EIO;
845 	}
846 
847 	return 0;
848 }
849 
cp2112_set_usb_config(struct hid_device * hdev,struct cp2112_usb_config_report * cfg)850 static int cp2112_set_usb_config(struct hid_device *hdev,
851 				 struct cp2112_usb_config_report *cfg)
852 {
853 	int ret;
854 
855 	BUG_ON(cfg->report != CP2112_USB_CONFIG);
856 
857 	ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
858 				HID_FEATURE_REPORT);
859 	if (ret != sizeof(*cfg)) {
860 		hid_err(hdev, "error writing usb config: %d\n", ret);
861 		if (ret < 0)
862 			return ret;
863 		return -EIO;
864 	}
865 
866 	return 0;
867 }
868 
869 static void chmod_sysfs_attrs(struct hid_device *hdev);
870 
871 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
872 static ssize_t name##_store(struct device *kdev, \
873 			    struct device_attribute *attr, const char *buf, \
874 			    size_t count) \
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 	store; \
882 	ret = cp2112_set_usb_config(hdev, &cfg); \
883 	if (ret) \
884 		return ret; \
885 	chmod_sysfs_attrs(hdev); \
886 	return count; \
887 } \
888 static ssize_t name##_show(struct device *kdev, \
889 			   struct device_attribute *attr, char *buf) \
890 { \
891 	struct hid_device *hdev = to_hid_device(kdev); \
892 	struct cp2112_usb_config_report cfg; \
893 	int ret = cp2112_get_usb_config(hdev, &cfg); \
894 	if (ret) \
895 		return ret; \
896 	return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
897 } \
898 static DEVICE_ATTR_RW(name);
899 
900 CP2112_CONFIG_ATTR(vendor_id, ({
901 	u16 vid;
902 
903 	if (sscanf(buf, "%hi", &vid) != 1)
904 		return -EINVAL;
905 
906 	cfg.vid = cpu_to_le16(vid);
907 	cfg.mask = 0x01;
908 }), "0x%04x\n", le16_to_cpu(cfg.vid));
909 
910 CP2112_CONFIG_ATTR(product_id, ({
911 	u16 pid;
912 
913 	if (sscanf(buf, "%hi", &pid) != 1)
914 		return -EINVAL;
915 
916 	cfg.pid = cpu_to_le16(pid);
917 	cfg.mask = 0x02;
918 }), "0x%04x\n", le16_to_cpu(cfg.pid));
919 
920 CP2112_CONFIG_ATTR(max_power, ({
921 	int mA;
922 
923 	if (sscanf(buf, "%i", &mA) != 1)
924 		return -EINVAL;
925 
926 	cfg.max_power = (mA + 1) / 2;
927 	cfg.mask = 0x04;
928 }), "%u mA\n", cfg.max_power * 2);
929 
930 CP2112_CONFIG_ATTR(power_mode, ({
931 	if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
932 		return -EINVAL;
933 
934 	cfg.mask = 0x08;
935 }), "%u\n", cfg.power_mode);
936 
937 CP2112_CONFIG_ATTR(release_version, ({
938 	if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
939 	    != 2)
940 		return -EINVAL;
941 
942 	cfg.mask = 0x10;
943 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
944 
945 #undef CP2112_CONFIG_ATTR
946 
947 struct cp2112_pstring_attribute {
948 	struct device_attribute attr;
949 	unsigned char report;
950 };
951 
pstr_store(struct device * kdev,struct device_attribute * kattr,const char * buf,size_t count)952 static ssize_t pstr_store(struct device *kdev,
953 			  struct device_attribute *kattr, const char *buf,
954 			  size_t count)
955 {
956 	struct hid_device *hdev = to_hid_device(kdev);
957 	struct cp2112_pstring_attribute *attr =
958 		container_of(kattr, struct cp2112_pstring_attribute, attr);
959 	struct cp2112_string_report report;
960 	int ret;
961 
962 	memset(&report, 0, sizeof(report));
963 
964 	ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
965 			      report.string, ARRAY_SIZE(report.string));
966 	report.report = attr->report;
967 	report.length = ret * sizeof(report.string[0]) + 2;
968 	report.type = USB_DT_STRING;
969 
970 	ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
971 				HID_FEATURE_REPORT);
972 	if (ret != report.length + 1) {
973 		hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
974 			ret);
975 		if (ret < 0)
976 			return ret;
977 		return -EIO;
978 	}
979 
980 	chmod_sysfs_attrs(hdev);
981 	return count;
982 }
983 
pstr_show(struct device * kdev,struct device_attribute * kattr,char * buf)984 static ssize_t pstr_show(struct device *kdev,
985 			 struct device_attribute *kattr, char *buf)
986 {
987 	struct hid_device *hdev = to_hid_device(kdev);
988 	struct cp2112_pstring_attribute *attr =
989 		container_of(kattr, struct cp2112_pstring_attribute, attr);
990 	struct cp2112_string_report report;
991 	u8 length;
992 	int ret;
993 
994 	ret = cp2112_hid_get(hdev, attr->report, &report.report,
995 			     sizeof(report) - 1, HID_FEATURE_REPORT);
996 	if (ret < 3) {
997 		hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
998 			ret);
999 		if (ret < 0)
1000 			return ret;
1001 		return -EIO;
1002 	}
1003 
1004 	if (report.length < 2) {
1005 		hid_err(hdev, "invalid %s string length: %d\n",
1006 			kattr->attr.name, report.length);
1007 		return -EIO;
1008 	}
1009 
1010 	length = report.length > ret - 1 ? ret - 1 : report.length;
1011 	length = (length - 2) / sizeof(report.string[0]);
1012 	ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
1013 			      PAGE_SIZE - 1);
1014 	buf[ret++] = '\n';
1015 	return ret;
1016 }
1017 
1018 #define CP2112_PSTR_ATTR(name, _report) \
1019 static struct cp2112_pstring_attribute dev_attr_##name = { \
1020 	.attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
1021 	.report = _report, \
1022 };
1023 
1024 CP2112_PSTR_ATTR(manufacturer,	CP2112_MANUFACTURER_STRING);
1025 CP2112_PSTR_ATTR(product,	CP2112_PRODUCT_STRING);
1026 CP2112_PSTR_ATTR(serial,	CP2112_SERIAL_STRING);
1027 
1028 #undef CP2112_PSTR_ATTR
1029 
1030 static const struct attribute_group cp2112_attr_group = {
1031 	.attrs = (struct attribute *[]){
1032 		&dev_attr_vendor_id.attr,
1033 		&dev_attr_product_id.attr,
1034 		&dev_attr_max_power.attr,
1035 		&dev_attr_power_mode.attr,
1036 		&dev_attr_release_version.attr,
1037 		&dev_attr_manufacturer.attr.attr,
1038 		&dev_attr_product.attr.attr,
1039 		&dev_attr_serial.attr.attr,
1040 		NULL
1041 	}
1042 };
1043 
1044 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
1045  * PROM have already been programmed. We do not depend on this preventing
1046  * writing to these attributes since the CP2112 will simply ignore writes to
1047  * already-programmed fields. This is why there is no sense in fixing this
1048  * racy behaviour.
1049  */
chmod_sysfs_attrs(struct hid_device * hdev)1050 static void chmod_sysfs_attrs(struct hid_device *hdev)
1051 {
1052 	struct attribute **attr;
1053 	u8 buf[2];
1054 	int ret;
1055 
1056 	ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
1057 			     HID_FEATURE_REPORT);
1058 	if (ret != sizeof(buf)) {
1059 		hid_err(hdev, "error reading lock byte: %d\n", ret);
1060 		return;
1061 	}
1062 
1063 	for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
1064 		umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
1065 		ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
1066 		if (ret < 0)
1067 			hid_err(hdev, "error chmoding sysfs file %s\n",
1068 				(*attr)->name);
1069 		buf[1] >>= 1;
1070 	}
1071 }
1072 
cp2112_gpio_irq_ack(struct irq_data * d)1073 static void cp2112_gpio_irq_ack(struct irq_data *d)
1074 {
1075 }
1076 
cp2112_gpio_irq_mask(struct irq_data * d)1077 static void cp2112_gpio_irq_mask(struct irq_data *d)
1078 {
1079 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1080 	struct cp2112_device *dev = gpiochip_get_data(gc);
1081 
1082 	__clear_bit(d->hwirq, &dev->irq_mask);
1083 }
1084 
cp2112_gpio_irq_unmask(struct irq_data * d)1085 static void cp2112_gpio_irq_unmask(struct irq_data *d)
1086 {
1087 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1088 	struct cp2112_device *dev = gpiochip_get_data(gc);
1089 
1090 	__set_bit(d->hwirq, &dev->irq_mask);
1091 }
1092 
cp2112_gpio_poll_callback(struct work_struct * work)1093 static void cp2112_gpio_poll_callback(struct work_struct *work)
1094 {
1095 	struct cp2112_device *dev = container_of(work, struct cp2112_device,
1096 						 gpio_poll_worker.work);
1097 	struct irq_data *d;
1098 	u8 gpio_mask;
1099 	u8 virqs = (u8)dev->irq_mask;
1100 	u32 irq_type;
1101 	int irq, virq, ret;
1102 
1103 	ret = cp2112_gpio_get_all(&dev->gc);
1104 	if (ret == -ENODEV) /* the hardware has been disconnected */
1105 		return;
1106 	if (ret < 0)
1107 		goto exit;
1108 
1109 	gpio_mask = ret;
1110 
1111 	while (virqs) {
1112 		virq = ffs(virqs) - 1;
1113 		virqs &= ~BIT(virq);
1114 
1115 		if (!dev->gc.to_irq)
1116 			break;
1117 
1118 		irq = dev->gc.to_irq(&dev->gc, virq);
1119 
1120 		d = irq_get_irq_data(irq);
1121 		if (!d)
1122 			continue;
1123 
1124 		irq_type = irqd_get_trigger_type(d);
1125 
1126 		if (gpio_mask & BIT(virq)) {
1127 			/* Level High */
1128 
1129 			if (irq_type & IRQ_TYPE_LEVEL_HIGH)
1130 				handle_nested_irq(irq);
1131 
1132 			if ((irq_type & IRQ_TYPE_EDGE_RISING) &&
1133 			    !(dev->gpio_prev_state & BIT(virq)))
1134 				handle_nested_irq(irq);
1135 		} else {
1136 			/* Level Low */
1137 
1138 			if (irq_type & IRQ_TYPE_LEVEL_LOW)
1139 				handle_nested_irq(irq);
1140 
1141 			if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&
1142 			    (dev->gpio_prev_state & BIT(virq)))
1143 				handle_nested_irq(irq);
1144 		}
1145 	}
1146 
1147 	dev->gpio_prev_state = gpio_mask;
1148 
1149 exit:
1150 	if (dev->gpio_poll)
1151 		schedule_delayed_work(&dev->gpio_poll_worker, 10);
1152 }
1153 
1154 
cp2112_gpio_irq_startup(struct irq_data * d)1155 static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
1156 {
1157 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1158 	struct cp2112_device *dev = gpiochip_get_data(gc);
1159 
1160 	if (!dev->gpio_poll) {
1161 		dev->gpio_poll = true;
1162 		schedule_delayed_work(&dev->gpio_poll_worker, 0);
1163 	}
1164 
1165 	cp2112_gpio_irq_unmask(d);
1166 	return 0;
1167 }
1168 
cp2112_gpio_irq_shutdown(struct irq_data * d)1169 static void cp2112_gpio_irq_shutdown(struct irq_data *d)
1170 {
1171 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1172 	struct cp2112_device *dev = gpiochip_get_data(gc);
1173 
1174 	if (!dev->irq_mask) {
1175 		dev->gpio_poll = false;
1176 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
1177 	}
1178 }
1179 
cp2112_gpio_irq_type(struct irq_data * d,unsigned int type)1180 static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
1181 {
1182 	return 0;
1183 }
1184 
cp2112_allocate_irq(struct cp2112_device * dev,int pin)1185 static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
1186 					      int pin)
1187 {
1188 	int ret;
1189 
1190 	if (dev->desc[pin])
1191 		return -EINVAL;
1192 
1193 	dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin,
1194 						   "HID/I2C:Event",
1195 						   GPIO_ACTIVE_HIGH,
1196 						   GPIOD_IN);
1197 	if (IS_ERR(dev->desc[pin])) {
1198 		dev_err(dev->gc.parent, "Failed to request GPIO\n");
1199 		return PTR_ERR(dev->desc[pin]);
1200 	}
1201 
1202 	ret = cp2112_gpio_direction_input(&dev->gc, pin);
1203 	if (ret < 0) {
1204 		dev_err(dev->gc.parent, "Failed to set GPIO to input dir\n");
1205 		goto err_desc;
1206 	}
1207 
1208 	ret = gpiochip_lock_as_irq(&dev->gc, pin);
1209 	if (ret) {
1210 		dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n");
1211 		goto err_desc;
1212 	}
1213 
1214 	ret = gpiod_to_irq(dev->desc[pin]);
1215 	if (ret < 0) {
1216 		dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n");
1217 		goto err_lock;
1218 	}
1219 
1220 	return ret;
1221 
1222 err_lock:
1223 	gpiochip_unlock_as_irq(&dev->gc, pin);
1224 err_desc:
1225 	gpiochip_free_own_desc(dev->desc[pin]);
1226 	dev->desc[pin] = NULL;
1227 	return ret;
1228 }
1229 
cp2112_probe(struct hid_device * hdev,const struct hid_device_id * id)1230 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1231 {
1232 	struct cp2112_device *dev;
1233 	u8 buf[3];
1234 	struct cp2112_smbus_config_report config;
1235 	struct gpio_irq_chip *girq;
1236 	int ret;
1237 
1238 	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
1239 	if (!dev)
1240 		return -ENOMEM;
1241 
1242 	dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
1243 					  GFP_KERNEL);
1244 	if (!dev->in_out_buffer)
1245 		return -ENOMEM;
1246 
1247 	mutex_init(&dev->lock);
1248 
1249 	ret = hid_parse(hdev);
1250 	if (ret) {
1251 		hid_err(hdev, "parse failed\n");
1252 		return ret;
1253 	}
1254 
1255 	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1256 	if (ret) {
1257 		hid_err(hdev, "hw start failed\n");
1258 		return ret;
1259 	}
1260 
1261 	ret = hid_hw_open(hdev);
1262 	if (ret) {
1263 		hid_err(hdev, "hw open failed\n");
1264 		goto err_hid_stop;
1265 	}
1266 
1267 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
1268 	if (ret < 0) {
1269 		hid_err(hdev, "power management error: %d\n", ret);
1270 		goto err_hid_close;
1271 	}
1272 
1273 	ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
1274 			     HID_FEATURE_REPORT);
1275 	if (ret != sizeof(buf)) {
1276 		hid_err(hdev, "error requesting version\n");
1277 		if (ret >= 0)
1278 			ret = -EIO;
1279 		goto err_power_normal;
1280 	}
1281 
1282 	hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
1283 		 buf[1], buf[2]);
1284 
1285 	ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
1286 			     sizeof(config), HID_FEATURE_REPORT);
1287 	if (ret != sizeof(config)) {
1288 		hid_err(hdev, "error requesting SMBus config\n");
1289 		if (ret >= 0)
1290 			ret = -EIO;
1291 		goto err_power_normal;
1292 	}
1293 
1294 	config.retry_time = cpu_to_be16(1);
1295 
1296 	ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1297 				HID_FEATURE_REPORT);
1298 	if (ret != sizeof(config)) {
1299 		hid_err(hdev, "error setting SMBus config\n");
1300 		if (ret >= 0)
1301 			ret = -EIO;
1302 		goto err_power_normal;
1303 	}
1304 
1305 	hid_set_drvdata(hdev, (void *)dev);
1306 	dev->hdev		= hdev;
1307 	dev->adap.owner		= THIS_MODULE;
1308 	dev->adap.class		= I2C_CLASS_HWMON;
1309 	dev->adap.algo		= &smbus_algorithm;
1310 	dev->adap.algo_data	= dev;
1311 	dev->adap.dev.parent	= &hdev->dev;
1312 	snprintf(dev->adap.name, sizeof(dev->adap.name),
1313 		 "CP2112 SMBus Bridge on hidraw%d",
1314 		 ((struct hidraw *)hdev->hidraw)->minor);
1315 	dev->hwversion = buf[2];
1316 	init_waitqueue_head(&dev->wait);
1317 
1318 	hid_device_io_start(hdev);
1319 	ret = i2c_add_adapter(&dev->adap);
1320 	hid_device_io_stop(hdev);
1321 
1322 	if (ret) {
1323 		hid_err(hdev, "error registering i2c adapter\n");
1324 		goto err_power_normal;
1325 	}
1326 
1327 	hid_dbg(hdev, "adapter registered\n");
1328 
1329 	dev->gc.label			= "cp2112_gpio";
1330 	dev->gc.direction_input		= cp2112_gpio_direction_input;
1331 	dev->gc.direction_output	= cp2112_gpio_direction_output;
1332 	dev->gc.set			= cp2112_gpio_set;
1333 	dev->gc.get			= cp2112_gpio_get;
1334 	dev->gc.base			= -1;
1335 	dev->gc.ngpio			= 8;
1336 	dev->gc.can_sleep		= 1;
1337 	dev->gc.parent			= &hdev->dev;
1338 
1339 	dev->irq.name = "cp2112-gpio";
1340 	dev->irq.irq_startup = cp2112_gpio_irq_startup;
1341 	dev->irq.irq_shutdown = cp2112_gpio_irq_shutdown;
1342 	dev->irq.irq_ack = cp2112_gpio_irq_ack;
1343 	dev->irq.irq_mask = cp2112_gpio_irq_mask;
1344 	dev->irq.irq_unmask = cp2112_gpio_irq_unmask;
1345 	dev->irq.irq_set_type = cp2112_gpio_irq_type;
1346 	dev->irq.flags = IRQCHIP_MASK_ON_SUSPEND;
1347 
1348 	girq = &dev->gc.irq;
1349 	girq->chip = &dev->irq;
1350 	/* The event comes from the outside so no parent handler */
1351 	girq->parent_handler = NULL;
1352 	girq->num_parents = 0;
1353 	girq->parents = NULL;
1354 	girq->default_type = IRQ_TYPE_NONE;
1355 	girq->handler = handle_simple_irq;
1356 	girq->threaded = true;
1357 
1358 	INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
1359 
1360 	ret = gpiochip_add_data(&dev->gc, dev);
1361 	if (ret < 0) {
1362 		hid_err(hdev, "error registering gpio chip\n");
1363 		goto err_free_i2c;
1364 	}
1365 
1366 	ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1367 	if (ret < 0) {
1368 		hid_err(hdev, "error creating sysfs attrs\n");
1369 		goto err_gpiochip_remove;
1370 	}
1371 
1372 	chmod_sysfs_attrs(hdev);
1373 	hid_hw_power(hdev, PM_HINT_NORMAL);
1374 
1375 	return ret;
1376 
1377 err_gpiochip_remove:
1378 	gpiochip_remove(&dev->gc);
1379 err_free_i2c:
1380 	i2c_del_adapter(&dev->adap);
1381 err_power_normal:
1382 	hid_hw_power(hdev, PM_HINT_NORMAL);
1383 err_hid_close:
1384 	hid_hw_close(hdev);
1385 err_hid_stop:
1386 	hid_hw_stop(hdev);
1387 	return ret;
1388 }
1389 
cp2112_remove(struct hid_device * hdev)1390 static void cp2112_remove(struct hid_device *hdev)
1391 {
1392 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1393 	int i;
1394 
1395 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1396 	i2c_del_adapter(&dev->adap);
1397 
1398 	if (dev->gpio_poll) {
1399 		dev->gpio_poll = false;
1400 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
1401 	}
1402 
1403 	for (i = 0; i < ARRAY_SIZE(dev->desc); i++) {
1404 		gpiochip_unlock_as_irq(&dev->gc, i);
1405 		gpiochip_free_own_desc(dev->desc[i]);
1406 	}
1407 
1408 	gpiochip_remove(&dev->gc);
1409 	/* i2c_del_adapter has finished removing all i2c devices from our
1410 	 * adapter. Well behaved devices should no longer call our cp2112_xfer
1411 	 * and should have waited for any pending calls to finish. It has also
1412 	 * waited for device_unregister(&adap->dev) to complete. Therefore we
1413 	 * can safely free our struct cp2112_device.
1414 	 */
1415 	hid_hw_close(hdev);
1416 	hid_hw_stop(hdev);
1417 }
1418 
cp2112_raw_event(struct hid_device * hdev,struct hid_report * report,u8 * data,int size)1419 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1420 			    u8 *data, int size)
1421 {
1422 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1423 	struct cp2112_xfer_status_report *xfer = (void *)data;
1424 
1425 	switch (data[0]) {
1426 	case CP2112_TRANSFER_STATUS_RESPONSE:
1427 		hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1428 			xfer->status0, xfer->status1,
1429 			be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1430 
1431 		switch (xfer->status0) {
1432 		case STATUS0_IDLE:
1433 			dev->xfer_status = -EAGAIN;
1434 			break;
1435 		case STATUS0_BUSY:
1436 			dev->xfer_status = -EBUSY;
1437 			break;
1438 		case STATUS0_COMPLETE:
1439 			dev->xfer_status = be16_to_cpu(xfer->length);
1440 			break;
1441 		case STATUS0_ERROR:
1442 			switch (xfer->status1) {
1443 			case STATUS1_TIMEOUT_NACK:
1444 			case STATUS1_TIMEOUT_BUS:
1445 				dev->xfer_status = -ETIMEDOUT;
1446 				break;
1447 			default:
1448 				dev->xfer_status = -EIO;
1449 				break;
1450 			}
1451 			break;
1452 		default:
1453 			dev->xfer_status = -EINVAL;
1454 			break;
1455 		}
1456 
1457 		atomic_set(&dev->xfer_avail, 1);
1458 		break;
1459 	case CP2112_DATA_READ_RESPONSE:
1460 		hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1461 
1462 		dev->read_length = data[2];
1463 		if (dev->read_length > sizeof(dev->read_data))
1464 			dev->read_length = sizeof(dev->read_data);
1465 
1466 		memcpy(dev->read_data, &data[3], dev->read_length);
1467 		atomic_set(&dev->read_avail, 1);
1468 		break;
1469 	default:
1470 		hid_err(hdev, "unknown report\n");
1471 
1472 		return 0;
1473 	}
1474 
1475 	wake_up_interruptible(&dev->wait);
1476 	return 1;
1477 }
1478 
1479 static struct hid_driver cp2112_driver = {
1480 	.name		= "cp2112",
1481 	.id_table	= cp2112_devices,
1482 	.probe		= cp2112_probe,
1483 	.remove		= cp2112_remove,
1484 	.raw_event	= cp2112_raw_event,
1485 };
1486 
1487 module_hid_driver(cp2112_driver);
1488 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1489 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1490 MODULE_LICENSE("GPL");
1491 
1492