xref: /openbmc/linux/drivers/hid/hid-cp2112.c (revision e2847849)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
4  * Copyright (c) 2013,2014 Uplogix, Inc.
5  * David Barksdale <dbarksdale@uplogix.com>
6  */
7 
8 /*
9  * The Silicon Labs CP2112 chip is a USB HID device which provides an
10  * SMBus controller for talking to slave devices and 8 GPIO pins. The
11  * host communicates with the CP2112 via raw HID reports.
12  *
13  * Data Sheet:
14  *   https://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
15  * Programming Interface Specification:
16  *   https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf
17  */
18 
19 #include <linux/bitops.h>
20 #include <linux/gpio/driver.h>
21 #include <linux/hid.h>
22 #include <linux/hidraw.h>
23 #include <linux/i2c.h>
24 #include <linux/module.h>
25 #include <linux/nls.h>
26 #include <linux/string_choices.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 #define CP2112_GPIO_MAX_GPIO			8
35 #define CP2112_GPIO_ALL_GPIO_MASK		GENMASK(7, 0)
36 
37 enum {
38 	CP2112_GPIO_CONFIG		= 0x02,
39 	CP2112_GPIO_GET			= 0x03,
40 	CP2112_GPIO_SET			= 0x04,
41 	CP2112_GET_VERSION_INFO		= 0x05,
42 	CP2112_SMBUS_CONFIG		= 0x06,
43 	CP2112_DATA_READ_REQUEST	= 0x10,
44 	CP2112_DATA_WRITE_READ_REQUEST	= 0x11,
45 	CP2112_DATA_READ_FORCE_SEND	= 0x12,
46 	CP2112_DATA_READ_RESPONSE	= 0x13,
47 	CP2112_DATA_WRITE_REQUEST	= 0x14,
48 	CP2112_TRANSFER_STATUS_REQUEST	= 0x15,
49 	CP2112_TRANSFER_STATUS_RESPONSE	= 0x16,
50 	CP2112_CANCEL_TRANSFER		= 0x17,
51 	CP2112_LOCK_BYTE		= 0x20,
52 	CP2112_USB_CONFIG		= 0x21,
53 	CP2112_MANUFACTURER_STRING	= 0x22,
54 	CP2112_PRODUCT_STRING		= 0x23,
55 	CP2112_SERIAL_STRING		= 0x24,
56 };
57 
58 enum {
59 	STATUS0_IDLE		= 0x00,
60 	STATUS0_BUSY		= 0x01,
61 	STATUS0_COMPLETE	= 0x02,
62 	STATUS0_ERROR		= 0x03,
63 };
64 
65 enum {
66 	STATUS1_TIMEOUT_NACK		= 0x00,
67 	STATUS1_TIMEOUT_BUS		= 0x01,
68 	STATUS1_ARBITRATION_LOST	= 0x02,
69 	STATUS1_READ_INCOMPLETE		= 0x03,
70 	STATUS1_WRITE_INCOMPLETE	= 0x04,
71 	STATUS1_SUCCESS			= 0x05,
72 };
73 
74 struct cp2112_smbus_config_report {
75 	u8 report;		/* CP2112_SMBUS_CONFIG */
76 	__be32 clock_speed;	/* Hz */
77 	u8 device_address;	/* Stored in the upper 7 bits */
78 	u8 auto_send_read;	/* 1 = enabled, 0 = disabled */
79 	__be16 write_timeout;	/* ms, 0 = no timeout */
80 	__be16 read_timeout;	/* ms, 0 = no timeout */
81 	u8 scl_low_timeout;	/* 1 = enabled, 0 = disabled */
82 	__be16 retry_time;	/* # of retries, 0 = no limit */
83 } __packed;
84 
85 struct cp2112_usb_config_report {
86 	u8 report;	/* CP2112_USB_CONFIG */
87 	__le16 vid;	/* Vendor ID */
88 	__le16 pid;	/* Product ID */
89 	u8 max_power;	/* Power requested in 2mA units */
90 	u8 power_mode;	/* 0x00 = bus powered
91 			   0x01 = self powered & regulator off
92 			   0x02 = self powered & regulator on */
93 	u8 release_major;
94 	u8 release_minor;
95 	u8 mask;	/* What fields to program */
96 } __packed;
97 
98 struct cp2112_read_req_report {
99 	u8 report;	/* CP2112_DATA_READ_REQUEST */
100 	u8 slave_address;
101 	__be16 length;
102 } __packed;
103 
104 struct cp2112_write_read_req_report {
105 	u8 report;	/* CP2112_DATA_WRITE_READ_REQUEST */
106 	u8 slave_address;
107 	__be16 length;
108 	u8 target_address_length;
109 	u8 target_address[16];
110 } __packed;
111 
112 struct cp2112_write_req_report {
113 	u8 report;	/* CP2112_DATA_WRITE_REQUEST */
114 	u8 slave_address;
115 	u8 length;
116 	u8 data[61];
117 } __packed;
118 
119 struct cp2112_force_read_report {
120 	u8 report;	/* CP2112_DATA_READ_FORCE_SEND */
121 	__be16 length;
122 } __packed;
123 
124 struct cp2112_xfer_status_report {
125 	u8 report;	/* CP2112_TRANSFER_STATUS_RESPONSE */
126 	u8 status0;	/* STATUS0_* */
127 	u8 status1;	/* STATUS1_* */
128 	__be16 retries;
129 	__be16 length;
130 } __packed;
131 
132 struct cp2112_string_report {
133 	u8 dummy;		/* force .string to be aligned */
134 	struct_group_attr(contents, __packed,
135 		u8 report;		/* CP2112_*_STRING */
136 		u8 length;		/* length in bytes of everything after .report */
137 		u8 type;		/* USB_DT_STRING */
138 		wchar_t string[30];	/* UTF16_LITTLE_ENDIAN string */
139 	);
140 } __packed;
141 
142 /* Number of times to request transfer status before giving up waiting for a
143    transfer to complete. This may need to be changed if SMBUS clock, retries,
144    or read/write/scl_low timeout settings are changed. */
145 static const int XFER_STATUS_RETRIES = 10;
146 
147 /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or
148    CP2112_TRANSFER_STATUS_RESPONSE. */
149 static const int RESPONSE_TIMEOUT = 50;
150 
151 static const struct hid_device_id cp2112_devices[] = {
152 	{ HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
153 	{ }
154 };
155 MODULE_DEVICE_TABLE(hid, cp2112_devices);
156 
157 struct cp2112_device {
158 	struct i2c_adapter adap;
159 	struct hid_device *hdev;
160 	wait_queue_head_t wait;
161 	u8 read_data[61];
162 	u8 read_length;
163 	u8 hwversion;
164 	int xfer_status;
165 	atomic_t read_avail;
166 	atomic_t xfer_avail;
167 	struct gpio_chip gc;
168 	u8 *in_out_buffer;
169 	struct mutex lock;
170 
171 	bool gpio_poll;
172 	struct delayed_work gpio_poll_worker;
173 	unsigned long irq_mask;
174 	u8 gpio_prev_state;
175 };
176 
177 static int gpio_push_pull = CP2112_GPIO_ALL_GPIO_MASK;
178 module_param(gpio_push_pull, int, 0644);
179 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
180 
cp2112_gpio_direction_input(struct gpio_chip * chip,unsigned offset)181 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
182 {
183 	struct cp2112_device *dev = gpiochip_get_data(chip);
184 	struct hid_device *hdev = dev->hdev;
185 	u8 *buf = dev->in_out_buffer;
186 	int ret;
187 
188 	mutex_lock(&dev->lock);
189 
190 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
191 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
192 				 HID_REQ_GET_REPORT);
193 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
194 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
195 		if (ret >= 0)
196 			ret = -EIO;
197 		goto exit;
198 	}
199 
200 	buf[1] &= ~BIT(offset);
201 	buf[2] = gpio_push_pull;
202 
203 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
204 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
205 				 HID_REQ_SET_REPORT);
206 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
207 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
208 		if (ret >= 0)
209 			ret = -EIO;
210 		goto exit;
211 	}
212 
213 	ret = 0;
214 
215 exit:
216 	mutex_unlock(&dev->lock);
217 	return ret;
218 }
219 
cp2112_gpio_set(struct gpio_chip * chip,unsigned offset,int value)220 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
221 {
222 	struct cp2112_device *dev = gpiochip_get_data(chip);
223 	struct hid_device *hdev = dev->hdev;
224 	u8 *buf = dev->in_out_buffer;
225 	int ret;
226 
227 	mutex_lock(&dev->lock);
228 
229 	buf[0] = CP2112_GPIO_SET;
230 	buf[1] = value ? CP2112_GPIO_ALL_GPIO_MASK : 0;
231 	buf[2] = BIT(offset);
232 
233 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
234 				 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
235 				 HID_REQ_SET_REPORT);
236 	if (ret < 0)
237 		hid_err(hdev, "error setting GPIO values: %d\n", ret);
238 
239 	mutex_unlock(&dev->lock);
240 }
241 
cp2112_gpio_get_all(struct gpio_chip * chip)242 static int cp2112_gpio_get_all(struct gpio_chip *chip)
243 {
244 	struct cp2112_device *dev = gpiochip_get_data(chip);
245 	struct hid_device *hdev = dev->hdev;
246 	u8 *buf = dev->in_out_buffer;
247 	int ret;
248 
249 	mutex_lock(&dev->lock);
250 
251 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
252 				 CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
253 				 HID_REQ_GET_REPORT);
254 	if (ret != CP2112_GPIO_GET_LENGTH) {
255 		hid_err(hdev, "error requesting GPIO values: %d\n", ret);
256 		ret = ret < 0 ? ret : -EIO;
257 		goto exit;
258 	}
259 
260 	ret = buf[1];
261 
262 exit:
263 	mutex_unlock(&dev->lock);
264 
265 	return ret;
266 }
267 
cp2112_gpio_get(struct gpio_chip * chip,unsigned int offset)268 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
269 {
270 	int ret;
271 
272 	ret = cp2112_gpio_get_all(chip);
273 	if (ret < 0)
274 		return ret;
275 
276 	return (ret >> offset) & 1;
277 }
278 
cp2112_gpio_direction_output(struct gpio_chip * chip,unsigned offset,int value)279 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
280 					unsigned offset, int value)
281 {
282 	struct cp2112_device *dev = gpiochip_get_data(chip);
283 	struct hid_device *hdev = dev->hdev;
284 	u8 *buf = dev->in_out_buffer;
285 	int ret;
286 
287 	mutex_lock(&dev->lock);
288 
289 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
290 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
291 				 HID_REQ_GET_REPORT);
292 	if (ret != CP2112_GPIO_CONFIG_LENGTH) {
293 		hid_err(hdev, "error requesting GPIO config: %d\n", ret);
294 		goto fail;
295 	}
296 
297 	buf[1] |= 1 << offset;
298 	buf[2] = gpio_push_pull;
299 
300 	ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
301 				 CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
302 				 HID_REQ_SET_REPORT);
303 	if (ret < 0) {
304 		hid_err(hdev, "error setting GPIO config: %d\n", ret);
305 		goto fail;
306 	}
307 
308 	mutex_unlock(&dev->lock);
309 
310 	/*
311 	 * Set gpio value when output direction is already set,
312 	 * as specified in AN495, Rev. 0.2, cpt. 4.4
313 	 */
314 	cp2112_gpio_set(chip, offset, value);
315 
316 	return 0;
317 
318 fail:
319 	mutex_unlock(&dev->lock);
320 	return ret < 0 ? ret : -EIO;
321 }
322 
cp2112_hid_get(struct hid_device * hdev,unsigned char report_number,u8 * data,size_t count,unsigned char report_type)323 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
324 			  u8 *data, size_t count, unsigned char report_type)
325 {
326 	u8 *buf;
327 	int ret;
328 
329 	buf = kmalloc(count, GFP_KERNEL);
330 	if (!buf)
331 		return -ENOMEM;
332 
333 	ret = hid_hw_raw_request(hdev, report_number, buf, count,
334 				       report_type, HID_REQ_GET_REPORT);
335 	memcpy(data, buf, count);
336 	kfree(buf);
337 	return ret;
338 }
339 
cp2112_hid_output(struct hid_device * hdev,u8 * data,size_t count,unsigned char report_type)340 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
341 			     unsigned char report_type)
342 {
343 	u8 *buf;
344 	int ret;
345 
346 	buf = kmemdup(data, count, GFP_KERNEL);
347 	if (!buf)
348 		return -ENOMEM;
349 
350 	if (report_type == HID_OUTPUT_REPORT)
351 		ret = hid_hw_output_report(hdev, buf, count);
352 	else
353 		ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
354 				HID_REQ_SET_REPORT);
355 
356 	kfree(buf);
357 	return ret;
358 }
359 
cp2112_wait(struct cp2112_device * dev,atomic_t * avail)360 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
361 {
362 	int ret = 0;
363 
364 	/* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
365 	 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
366 	 * come in cp2112_raw_event or timeout. There will only be one of these
367 	 * in flight at any one time. The timeout is extremely large and is a
368 	 * last resort if the CP2112 has died. If we do timeout we don't expect
369 	 * to receive the response which would cause data races, it's not like
370 	 * we can do anything about it anyway.
371 	 */
372 	ret = wait_event_interruptible_timeout(dev->wait,
373 		atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
374 	if (-ERESTARTSYS == ret)
375 		return ret;
376 	if (!ret)
377 		return -ETIMEDOUT;
378 
379 	atomic_set(avail, 0);
380 	return 0;
381 }
382 
cp2112_xfer_status(struct cp2112_device * dev)383 static int cp2112_xfer_status(struct cp2112_device *dev)
384 {
385 	struct hid_device *hdev = dev->hdev;
386 	u8 buf[2];
387 	int ret;
388 
389 	buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
390 	buf[1] = 0x01;
391 	atomic_set(&dev->xfer_avail, 0);
392 
393 	ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
394 	if (ret < 0) {
395 		hid_warn(hdev, "Error requesting status: %d\n", ret);
396 		return ret;
397 	}
398 
399 	ret = cp2112_wait(dev, &dev->xfer_avail);
400 	if (ret)
401 		return ret;
402 
403 	return dev->xfer_status;
404 }
405 
cp2112_read(struct cp2112_device * dev,u8 * data,size_t size)406 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
407 {
408 	struct hid_device *hdev = dev->hdev;
409 	struct cp2112_force_read_report report;
410 	int ret;
411 
412 	if (size > sizeof(dev->read_data))
413 		size = sizeof(dev->read_data);
414 	report.report = CP2112_DATA_READ_FORCE_SEND;
415 	report.length = cpu_to_be16(size);
416 
417 	atomic_set(&dev->read_avail, 0);
418 
419 	ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
420 				HID_OUTPUT_REPORT);
421 	if (ret < 0) {
422 		hid_warn(hdev, "Error requesting data: %d\n", ret);
423 		return ret;
424 	}
425 
426 	ret = cp2112_wait(dev, &dev->read_avail);
427 	if (ret)
428 		return ret;
429 
430 	hid_dbg(hdev, "read %d of %zd bytes requested\n",
431 		dev->read_length, size);
432 
433 	if (size > dev->read_length)
434 		size = dev->read_length;
435 
436 	memcpy(data, dev->read_data, size);
437 	return dev->read_length;
438 }
439 
cp2112_read_req(void * buf,u8 slave_address,u16 length)440 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
441 {
442 	struct cp2112_read_req_report *report = buf;
443 
444 	if (length < 1 || length > 512)
445 		return -EINVAL;
446 
447 	report->report = CP2112_DATA_READ_REQUEST;
448 	report->slave_address = slave_address << 1;
449 	report->length = cpu_to_be16(length);
450 	return sizeof(*report);
451 }
452 
cp2112_write_read_req(void * buf,u8 slave_address,u16 length,u8 command,u8 * data,u8 data_length)453 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
454 				 u8 command, u8 *data, u8 data_length)
455 {
456 	struct cp2112_write_read_req_report *report = buf;
457 
458 	if (length < 1 || length > 512
459 	    || data_length > sizeof(report->target_address) - 1)
460 		return -EINVAL;
461 
462 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
463 	report->slave_address = slave_address << 1;
464 	report->length = cpu_to_be16(length);
465 	report->target_address_length = data_length + 1;
466 	report->target_address[0] = command;
467 	memcpy(&report->target_address[1], data, data_length);
468 	return data_length + 6;
469 }
470 
cp2112_write_req(void * buf,u8 slave_address,u8 command,u8 * data,u8 data_length)471 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
472 			    u8 data_length)
473 {
474 	struct cp2112_write_req_report *report = buf;
475 
476 	if (data_length > sizeof(report->data) - 1)
477 		return -EINVAL;
478 
479 	report->report = CP2112_DATA_WRITE_REQUEST;
480 	report->slave_address = slave_address << 1;
481 	report->length = data_length + 1;
482 	report->data[0] = command;
483 	memcpy(&report->data[1], data, data_length);
484 	return data_length + 4;
485 }
486 
cp2112_i2c_write_req(void * buf,u8 slave_address,u8 * data,u8 data_length)487 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
488 				u8 data_length)
489 {
490 	struct cp2112_write_req_report *report = buf;
491 
492 	if (data_length > sizeof(report->data))
493 		return -EINVAL;
494 
495 	report->report = CP2112_DATA_WRITE_REQUEST;
496 	report->slave_address = slave_address << 1;
497 	report->length = data_length;
498 	memcpy(report->data, data, data_length);
499 	return data_length + 3;
500 }
501 
cp2112_i2c_write_read_req(void * buf,u8 slave_address,u8 * addr,int addr_length,int read_length)502 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
503 				     u8 *addr, int addr_length,
504 				     int read_length)
505 {
506 	struct cp2112_write_read_req_report *report = buf;
507 
508 	if (read_length < 1 || read_length > 512 ||
509 	    addr_length > sizeof(report->target_address))
510 		return -EINVAL;
511 
512 	report->report = CP2112_DATA_WRITE_READ_REQUEST;
513 	report->slave_address = slave_address << 1;
514 	report->length = cpu_to_be16(read_length);
515 	report->target_address_length = addr_length;
516 	memcpy(report->target_address, addr, addr_length);
517 	return addr_length + 5;
518 }
519 
cp2112_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)520 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
521 			   int num)
522 {
523 	struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
524 	struct hid_device *hdev = dev->hdev;
525 	u8 buf[64];
526 	ssize_t count;
527 	ssize_t read_length = 0;
528 	u8 *read_buf = NULL;
529 	unsigned int retries;
530 	int ret;
531 
532 	hid_dbg(hdev, "I2C %d messages\n", num);
533 
534 	if (num == 1) {
535 		hid_dbg(hdev, "I2C %s %#04x len %d\n",
536 			str_read_write(msgs->flags & I2C_M_RD), msgs->addr, msgs->len);
537 		if (msgs->flags & I2C_M_RD) {
538 			read_length = msgs->len;
539 			read_buf = msgs->buf;
540 			count = cp2112_read_req(buf, msgs->addr, msgs->len);
541 		} else {
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 		str_write_read(read_write == I2C_SMBUS_WRITE),
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 sysfs_emit(buf, 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 
pstr_store(struct device * kdev,struct device_attribute * kattr,const char * buf,size_t count,int number)947 static ssize_t pstr_store(struct device *kdev, struct device_attribute *kattr,
948 			  const char *buf, size_t count, int number)
949 {
950 	struct hid_device *hdev = to_hid_device(kdev);
951 	struct cp2112_string_report report;
952 	int ret;
953 
954 	memset(&report, 0, sizeof(report));
955 
956 	ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
957 			      report.string, ARRAY_SIZE(report.string));
958 	report.report = number;
959 	report.length = ret * sizeof(report.string[0]) + 2;
960 	report.type = USB_DT_STRING;
961 
962 	ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
963 				HID_FEATURE_REPORT);
964 	if (ret != report.length + 1) {
965 		hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
966 			ret);
967 		if (ret < 0)
968 			return ret;
969 		return -EIO;
970 	}
971 
972 	chmod_sysfs_attrs(hdev);
973 	return count;
974 }
975 
pstr_show(struct device * kdev,struct device_attribute * kattr,char * buf,int number)976 static ssize_t pstr_show(struct device *kdev, struct device_attribute *kattr,
977 			 char *buf, int number)
978 {
979 	struct hid_device *hdev = to_hid_device(kdev);
980 	struct cp2112_string_report report;
981 	u8 length;
982 	int ret;
983 
984 	ret = cp2112_hid_get(hdev, number, (u8 *)&report.contents,
985 			     sizeof(report.contents), HID_FEATURE_REPORT);
986 	if (ret < 3) {
987 		hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
988 			ret);
989 		if (ret < 0)
990 			return ret;
991 		return -EIO;
992 	}
993 
994 	if (report.length < 2) {
995 		hid_err(hdev, "invalid %s string length: %d\n",
996 			kattr->attr.name, report.length);
997 		return -EIO;
998 	}
999 
1000 	length = report.length > ret - 1 ? ret - 1 : report.length;
1001 	length = (length - 2) / sizeof(report.string[0]);
1002 	ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
1003 			      PAGE_SIZE - 1);
1004 	buf[ret++] = '\n';
1005 	return ret;
1006 }
1007 
1008 #define CP2112_PSTR_ATTR(name, _report) \
1009 static ssize_t name##_store(struct device *kdev, struct device_attribute *kattr, \
1010 			    const char *buf, size_t count) \
1011 { \
1012 	return pstr_store(kdev, kattr, buf, count, _report); \
1013 } \
1014 static ssize_t name##_show(struct device *kdev, struct device_attribute *kattr, char *buf) \
1015 { \
1016 	return pstr_show(kdev, kattr, buf, _report); \
1017 } \
1018 static DEVICE_ATTR_RW(name);
1019 
1020 CP2112_PSTR_ATTR(manufacturer,	CP2112_MANUFACTURER_STRING);
1021 CP2112_PSTR_ATTR(product,	CP2112_PRODUCT_STRING);
1022 CP2112_PSTR_ATTR(serial,	CP2112_SERIAL_STRING);
1023 
1024 #undef CP2112_PSTR_ATTR
1025 
1026 static const struct attribute_group cp2112_attr_group = {
1027 	.attrs = (struct attribute *[]){
1028 		&dev_attr_vendor_id.attr,
1029 		&dev_attr_product_id.attr,
1030 		&dev_attr_max_power.attr,
1031 		&dev_attr_power_mode.attr,
1032 		&dev_attr_release_version.attr,
1033 		&dev_attr_manufacturer.attr,
1034 		&dev_attr_product.attr,
1035 		&dev_attr_serial.attr,
1036 		NULL
1037 	}
1038 };
1039 
1040 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
1041  * PROM have already been programmed. We do not depend on this preventing
1042  * writing to these attributes since the CP2112 will simply ignore writes to
1043  * already-programmed fields. This is why there is no sense in fixing this
1044  * racy behaviour.
1045  */
chmod_sysfs_attrs(struct hid_device * hdev)1046 static void chmod_sysfs_attrs(struct hid_device *hdev)
1047 {
1048 	struct attribute **attr;
1049 	u8 buf[2];
1050 	int ret;
1051 
1052 	ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
1053 			     HID_FEATURE_REPORT);
1054 	if (ret != sizeof(buf)) {
1055 		hid_err(hdev, "error reading lock byte: %d\n", ret);
1056 		return;
1057 	}
1058 
1059 	for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
1060 		umode_t mode = (buf[1] & 1) ? 0644 : 0444;
1061 		ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
1062 		if (ret < 0)
1063 			hid_err(hdev, "error chmoding sysfs file %s\n",
1064 				(*attr)->name);
1065 		buf[1] >>= 1;
1066 	}
1067 }
1068 
cp2112_gpio_irq_ack(struct irq_data * d)1069 static void cp2112_gpio_irq_ack(struct irq_data *d)
1070 {
1071 }
1072 
cp2112_gpio_irq_mask(struct irq_data * d)1073 static void cp2112_gpio_irq_mask(struct irq_data *d)
1074 {
1075 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1076 	struct cp2112_device *dev = gpiochip_get_data(gc);
1077 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
1078 
1079 	__clear_bit(hwirq, &dev->irq_mask);
1080 	gpiochip_disable_irq(gc, hwirq);
1081 }
1082 
cp2112_gpio_irq_unmask(struct irq_data * d)1083 static void cp2112_gpio_irq_unmask(struct irq_data *d)
1084 {
1085 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1086 	struct cp2112_device *dev = gpiochip_get_data(gc);
1087 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
1088 
1089 	gpiochip_enable_irq(gc, hwirq);
1090 	__set_bit(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 	u32 irq_type;
1100 	int irq, virq, ret;
1101 
1102 	ret = cp2112_gpio_get_all(&dev->gc);
1103 	if (ret == -ENODEV) /* the hardware has been disconnected */
1104 		return;
1105 	if (ret < 0)
1106 		goto exit;
1107 
1108 	gpio_mask = ret;
1109 	for_each_set_bit(virq, &dev->irq_mask, CP2112_GPIO_MAX_GPIO) {
1110 		irq = irq_find_mapping(dev->gc.irq.domain, virq);
1111 		if (!irq)
1112 			continue;
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 	if (!dev->gpio_poll) {
1155 		dev->gpio_poll = true;
1156 		schedule_delayed_work(&dev->gpio_poll_worker, 0);
1157 	}
1158 
1159 	cp2112_gpio_irq_unmask(d);
1160 	return 0;
1161 }
1162 
cp2112_gpio_irq_shutdown(struct irq_data * d)1163 static void cp2112_gpio_irq_shutdown(struct irq_data *d)
1164 {
1165 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
1166 	struct cp2112_device *dev = gpiochip_get_data(gc);
1167 
1168 	cp2112_gpio_irq_mask(d);
1169 
1170 	if (!dev->irq_mask) {
1171 		dev->gpio_poll = false;
1172 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
1173 	}
1174 }
1175 
cp2112_gpio_irq_type(struct irq_data * d,unsigned int type)1176 static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
1177 {
1178 	return 0;
1179 }
1180 
1181 static const struct irq_chip cp2112_gpio_irqchip = {
1182 	.name = "cp2112-gpio",
1183 	.irq_startup = cp2112_gpio_irq_startup,
1184 	.irq_shutdown = cp2112_gpio_irq_shutdown,
1185 	.irq_ack = cp2112_gpio_irq_ack,
1186 	.irq_mask = cp2112_gpio_irq_mask,
1187 	.irq_unmask = cp2112_gpio_irq_unmask,
1188 	.irq_set_type = cp2112_gpio_irq_type,
1189 	.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,
1190 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
1191 };
1192 
cp2112_probe(struct hid_device * hdev,const struct hid_device_id * id)1193 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1194 {
1195 	struct cp2112_device *dev;
1196 	u8 buf[3];
1197 	struct cp2112_smbus_config_report config;
1198 	struct gpio_irq_chip *girq;
1199 	int ret;
1200 
1201 	dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
1202 	if (!dev)
1203 		return -ENOMEM;
1204 
1205 	dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
1206 					  GFP_KERNEL);
1207 	if (!dev->in_out_buffer)
1208 		return -ENOMEM;
1209 
1210 	mutex_init(&dev->lock);
1211 
1212 	ret = hid_parse(hdev);
1213 	if (ret) {
1214 		hid_err(hdev, "parse failed\n");
1215 		return ret;
1216 	}
1217 
1218 	ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1219 	if (ret) {
1220 		hid_err(hdev, "hw start failed\n");
1221 		return ret;
1222 	}
1223 
1224 	ret = hid_hw_open(hdev);
1225 	if (ret) {
1226 		hid_err(hdev, "hw open failed\n");
1227 		goto err_hid_stop;
1228 	}
1229 
1230 	ret = hid_hw_power(hdev, PM_HINT_FULLON);
1231 	if (ret < 0) {
1232 		hid_err(hdev, "power management error: %d\n", ret);
1233 		goto err_hid_close;
1234 	}
1235 
1236 	ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
1237 			     HID_FEATURE_REPORT);
1238 	if (ret != sizeof(buf)) {
1239 		hid_err(hdev, "error requesting version\n");
1240 		if (ret >= 0)
1241 			ret = -EIO;
1242 		goto err_power_normal;
1243 	}
1244 
1245 	hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
1246 		 buf[1], buf[2]);
1247 
1248 	ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
1249 			     sizeof(config), HID_FEATURE_REPORT);
1250 	if (ret != sizeof(config)) {
1251 		hid_err(hdev, "error requesting SMBus config\n");
1252 		if (ret >= 0)
1253 			ret = -EIO;
1254 		goto err_power_normal;
1255 	}
1256 
1257 	config.retry_time = cpu_to_be16(1);
1258 
1259 	ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1260 				HID_FEATURE_REPORT);
1261 	if (ret != sizeof(config)) {
1262 		hid_err(hdev, "error setting SMBus config\n");
1263 		if (ret >= 0)
1264 			ret = -EIO;
1265 		goto err_power_normal;
1266 	}
1267 
1268 	hid_set_drvdata(hdev, (void *)dev);
1269 	dev->hdev		= hdev;
1270 	dev->adap.owner		= THIS_MODULE;
1271 	dev->adap.class		= I2C_CLASS_HWMON;
1272 	dev->adap.algo		= &smbus_algorithm;
1273 	dev->adap.algo_data	= dev;
1274 	dev->adap.dev.parent	= &hdev->dev;
1275 	snprintf(dev->adap.name, sizeof(dev->adap.name),
1276 		 "CP2112 SMBus Bridge on hidraw%d",
1277 		 ((struct hidraw *)hdev->hidraw)->minor);
1278 	dev->hwversion = buf[2];
1279 	init_waitqueue_head(&dev->wait);
1280 
1281 	hid_device_io_start(hdev);
1282 	ret = i2c_add_adapter(&dev->adap);
1283 	hid_device_io_stop(hdev);
1284 
1285 	if (ret) {
1286 		hid_err(hdev, "error registering i2c adapter\n");
1287 		goto err_power_normal;
1288 	}
1289 
1290 	hid_dbg(hdev, "adapter registered\n");
1291 
1292 	dev->gc.label			= "cp2112_gpio";
1293 	dev->gc.direction_input		= cp2112_gpio_direction_input;
1294 	dev->gc.direction_output	= cp2112_gpio_direction_output;
1295 	dev->gc.set			= cp2112_gpio_set;
1296 	dev->gc.get			= cp2112_gpio_get;
1297 	dev->gc.base			= -1;
1298 	dev->gc.ngpio			= CP2112_GPIO_MAX_GPIO;
1299 	dev->gc.can_sleep		= 1;
1300 	dev->gc.parent			= &hdev->dev;
1301 
1302 	girq = &dev->gc.irq;
1303 	gpio_irq_chip_set_chip(girq, &cp2112_gpio_irqchip);
1304 	/* The event comes from the outside so no parent handler */
1305 	girq->parent_handler = NULL;
1306 	girq->num_parents = 0;
1307 	girq->parents = NULL;
1308 	girq->default_type = IRQ_TYPE_NONE;
1309 	girq->handler = handle_simple_irq;
1310 	girq->threaded = true;
1311 
1312 	INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
1313 
1314 	ret = gpiochip_add_data(&dev->gc, dev);
1315 	if (ret < 0) {
1316 		hid_err(hdev, "error registering gpio chip\n");
1317 		goto err_free_i2c;
1318 	}
1319 
1320 	ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1321 	if (ret < 0) {
1322 		hid_err(hdev, "error creating sysfs attrs\n");
1323 		goto err_gpiochip_remove;
1324 	}
1325 
1326 	chmod_sysfs_attrs(hdev);
1327 	hid_hw_power(hdev, PM_HINT_NORMAL);
1328 
1329 	return ret;
1330 
1331 err_gpiochip_remove:
1332 	gpiochip_remove(&dev->gc);
1333 err_free_i2c:
1334 	i2c_del_adapter(&dev->adap);
1335 err_power_normal:
1336 	hid_hw_power(hdev, PM_HINT_NORMAL);
1337 err_hid_close:
1338 	hid_hw_close(hdev);
1339 err_hid_stop:
1340 	hid_hw_stop(hdev);
1341 	return ret;
1342 }
1343 
cp2112_remove(struct hid_device * hdev)1344 static void cp2112_remove(struct hid_device *hdev)
1345 {
1346 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1347 
1348 	sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1349 	i2c_del_adapter(&dev->adap);
1350 
1351 	if (dev->gpio_poll) {
1352 		dev->gpio_poll = false;
1353 		cancel_delayed_work_sync(&dev->gpio_poll_worker);
1354 	}
1355 
1356 	gpiochip_remove(&dev->gc);
1357 	/* i2c_del_adapter has finished removing all i2c devices from our
1358 	 * adapter. Well behaved devices should no longer call our cp2112_xfer
1359 	 * and should have waited for any pending calls to finish. It has also
1360 	 * waited for device_unregister(&adap->dev) to complete. Therefore we
1361 	 * can safely free our struct cp2112_device.
1362 	 */
1363 	hid_hw_close(hdev);
1364 	hid_hw_stop(hdev);
1365 }
1366 
cp2112_raw_event(struct hid_device * hdev,struct hid_report * report,u8 * data,int size)1367 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1368 			    u8 *data, int size)
1369 {
1370 	struct cp2112_device *dev = hid_get_drvdata(hdev);
1371 	struct cp2112_xfer_status_report *xfer = (void *)data;
1372 
1373 	switch (data[0]) {
1374 	case CP2112_TRANSFER_STATUS_RESPONSE:
1375 		hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1376 			xfer->status0, xfer->status1,
1377 			be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1378 
1379 		switch (xfer->status0) {
1380 		case STATUS0_IDLE:
1381 			dev->xfer_status = -EAGAIN;
1382 			break;
1383 		case STATUS0_BUSY:
1384 			dev->xfer_status = -EBUSY;
1385 			break;
1386 		case STATUS0_COMPLETE:
1387 			dev->xfer_status = be16_to_cpu(xfer->length);
1388 			break;
1389 		case STATUS0_ERROR:
1390 			switch (xfer->status1) {
1391 			case STATUS1_TIMEOUT_NACK:
1392 			case STATUS1_TIMEOUT_BUS:
1393 				dev->xfer_status = -ETIMEDOUT;
1394 				break;
1395 			default:
1396 				dev->xfer_status = -EIO;
1397 				break;
1398 			}
1399 			break;
1400 		default:
1401 			dev->xfer_status = -EINVAL;
1402 			break;
1403 		}
1404 
1405 		atomic_set(&dev->xfer_avail, 1);
1406 		break;
1407 	case CP2112_DATA_READ_RESPONSE:
1408 		hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1409 
1410 		dev->read_length = data[2];
1411 		if (dev->read_length > sizeof(dev->read_data))
1412 			dev->read_length = sizeof(dev->read_data);
1413 
1414 		memcpy(dev->read_data, &data[3], dev->read_length);
1415 		atomic_set(&dev->read_avail, 1);
1416 		break;
1417 	default:
1418 		hid_err(hdev, "unknown report\n");
1419 
1420 		return 0;
1421 	}
1422 
1423 	wake_up_interruptible(&dev->wait);
1424 	return 1;
1425 }
1426 
1427 static struct hid_driver cp2112_driver = {
1428 	.name		= "cp2112",
1429 	.id_table	= cp2112_devices,
1430 	.probe		= cp2112_probe,
1431 	.remove		= cp2112_remove,
1432 	.raw_event	= cp2112_raw_event,
1433 };
1434 
1435 module_hid_driver(cp2112_driver);
1436 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1437 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1438 MODULE_LICENSE("GPL");
1439 
1440