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David Barksdalee932d812014-02-04 12:42:48 -06001/*
2 * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
3 * Copyright (c) 2013,2014 Uplogix, Inc.
4 * David Barksdale <dbarksdale@uplogix.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 */
15
16/*
17 * The Silicon Labs CP2112 chip is a USB HID device which provides an
18 * SMBus controller for talking to slave devices and 8 GPIO pins. The
19 * host communicates with the CP2112 via raw HID reports.
20 *
21 * Data Sheet:
22 * http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
23 * Programming Interface Specification:
24 * http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf
25 */
26
27#include <linux/gpio.h>
28#include <linux/hid.h>
29#include <linux/i2c.h>
30#include <linux/module.h>
31#include <linux/nls.h>
32#include <linux/usb/ch9.h>
33#include "hid-ids.h"
34
35enum {
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
56enum {
57 STATUS0_IDLE = 0x00,
58 STATUS0_BUSY = 0x01,
59 STATUS0_COMPLETE = 0x02,
60 STATUS0_ERROR = 0x03,
61};
62
63enum {
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
72struct 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
83struct 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
96struct cp2112_read_req_report {
97 u8 report; /* CP2112_DATA_READ_REQUEST */
98 u8 slave_address;
99 __be16 length;
100} __packed;
101
102struct 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
110struct 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
117struct cp2112_force_read_report {
118 u8 report; /* CP2112_DATA_READ_FORCE_SEND */
119 __be16 length;
120} __packed;
121
122struct 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
130struct 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. */
141static 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. */
145static const int RESPONSE_TIMEOUT = 50;
146
147static const struct hid_device_id cp2112_devices[] = {
148 { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
149 { }
150};
151MODULE_DEVICE_TABLE(hid, cp2112_devices);
152
153struct 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 int xfer_status;
160 atomic_t read_avail;
161 atomic_t xfer_avail;
162 struct gpio_chip gc;
163};
164
165static int gpio_push_pull = 0xFF;
166module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
167MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
168
169static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
170{
171 struct cp2112_device *dev = container_of(chip, struct cp2112_device,
172 gc);
173 struct hid_device *hdev = dev->hdev;
174 u8 buf[5];
175 int ret;
176
Jiri Kosina490051a2014-02-18 00:39:39 +0100177 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
178 sizeof(buf), HID_FEATURE_REPORT,
179 HID_REQ_GET_REPORT);
David Barksdalee932d812014-02-04 12:42:48 -0600180 if (ret != sizeof(buf)) {
181 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
182 return ret;
183 }
184
185 buf[1] &= ~(1 << offset);
186 buf[2] = gpio_push_pull;
187
Benjamin Tissoires293e4832014-03-08 22:52:40 -0500188 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
189 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
David Barksdalee932d812014-02-04 12:42:48 -0600190 if (ret < 0) {
191 hid_err(hdev, "error setting GPIO config: %d\n", ret);
192 return ret;
193 }
194
195 return 0;
196}
197
198static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
199{
200 struct cp2112_device *dev = container_of(chip, struct cp2112_device,
201 gc);
202 struct hid_device *hdev = dev->hdev;
203 u8 buf[3];
204 int ret;
205
206 buf[0] = CP2112_GPIO_SET;
207 buf[1] = value ? 0xff : 0;
208 buf[2] = 1 << offset;
209
Benjamin Tissoires293e4832014-03-08 22:52:40 -0500210 ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf),
211 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
David Barksdalee932d812014-02-04 12:42:48 -0600212 if (ret < 0)
213 hid_err(hdev, "error setting GPIO values: %d\n", ret);
214}
215
216static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset)
217{
218 struct cp2112_device *dev = container_of(chip, struct cp2112_device,
219 gc);
220 struct hid_device *hdev = dev->hdev;
221 u8 buf[2];
222 int ret;
223
Jiri Kosina490051a2014-02-18 00:39:39 +0100224 ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, sizeof(buf),
225 HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
David Barksdalee932d812014-02-04 12:42:48 -0600226 if (ret != sizeof(buf)) {
227 hid_err(hdev, "error requesting GPIO values: %d\n", ret);
228 return ret;
229 }
230
231 return (buf[1] >> offset) & 1;
232}
233
234static int cp2112_gpio_direction_output(struct gpio_chip *chip,
235 unsigned offset, int value)
236{
237 struct cp2112_device *dev = container_of(chip, struct cp2112_device,
238 gc);
239 struct hid_device *hdev = dev->hdev;
240 u8 buf[5];
241 int ret;
242
Jiri Kosina490051a2014-02-18 00:39:39 +0100243 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
244 sizeof(buf), HID_FEATURE_REPORT,
245 HID_REQ_GET_REPORT);
David Barksdalee932d812014-02-04 12:42:48 -0600246 if (ret != sizeof(buf)) {
247 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
248 return ret;
249 }
250
251 buf[1] |= 1 << offset;
252 buf[2] = gpio_push_pull;
253
Benjamin Tissoires293e4832014-03-08 22:52:40 -0500254 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
255 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
David Barksdalee932d812014-02-04 12:42:48 -0600256 if (ret < 0) {
257 hid_err(hdev, "error setting GPIO config: %d\n", ret);
258 return ret;
259 }
260
Antonio Borneobeb9d002014-06-29 14:13:48 +0800261 /*
262 * Set gpio value when output direction is already set,
263 * as specified in AN495, Rev. 0.2, cpt. 4.4
264 */
265 cp2112_gpio_set(chip, offset, value);
266
David Barksdalee932d812014-02-04 12:42:48 -0600267 return 0;
268}
269
270static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
271 u8 *data, size_t count, unsigned char report_type)
272{
273 u8 *buf;
274 int ret;
275
276 buf = kmalloc(count, GFP_KERNEL);
277 if (!buf)
278 return -ENOMEM;
279
Jiri Kosina490051a2014-02-18 00:39:39 +0100280 ret = hid_hw_raw_request(hdev, report_number, buf, count,
281 report_type, HID_REQ_GET_REPORT);
David Barksdalee932d812014-02-04 12:42:48 -0600282 memcpy(data, buf, count);
283 kfree(buf);
284 return ret;
285}
286
287static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
288 unsigned char report_type)
289{
290 u8 *buf;
291 int ret;
292
293 buf = kmemdup(data, count, GFP_KERNEL);
294 if (!buf)
295 return -ENOMEM;
296
Benjamin Tissoires866e4792014-03-08 22:52:41 -0500297 if (report_type == HID_OUTPUT_REPORT)
298 ret = hid_hw_output_report(hdev, buf, count);
299 else
300 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
301 HID_REQ_SET_REPORT);
302
David Barksdalee932d812014-02-04 12:42:48 -0600303 kfree(buf);
304 return ret;
305}
306
307static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
308{
309 int ret = 0;
310
311 /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
312 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
313 * come in cp2112_raw_event or timeout. There will only be one of these
314 * in flight at any one time. The timeout is extremely large and is a
315 * last resort if the CP2112 has died. If we do timeout we don't expect
316 * to receive the response which would cause data races, it's not like
317 * we can do anything about it anyway.
318 */
319 ret = wait_event_interruptible_timeout(dev->wait,
320 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
321 if (-ERESTARTSYS == ret)
322 return ret;
323 if (!ret)
324 return -ETIMEDOUT;
325
326 atomic_set(avail, 0);
327 return 0;
328}
329
330static int cp2112_xfer_status(struct cp2112_device *dev)
331{
332 struct hid_device *hdev = dev->hdev;
333 u8 buf[2];
334 int ret;
335
336 buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
337 buf[1] = 0x01;
338 atomic_set(&dev->xfer_avail, 0);
339
340 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
341 if (ret < 0) {
342 hid_warn(hdev, "Error requesting status: %d\n", ret);
343 return ret;
344 }
345
346 ret = cp2112_wait(dev, &dev->xfer_avail);
347 if (ret)
348 return ret;
349
350 return dev->xfer_status;
351}
352
353static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
354{
355 struct hid_device *hdev = dev->hdev;
356 struct cp2112_force_read_report report;
357 int ret;
358
359 report.report = CP2112_DATA_READ_FORCE_SEND;
360 report.length = cpu_to_be16(size);
361
362 atomic_set(&dev->read_avail, 0);
363
364 ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
365 HID_OUTPUT_REPORT);
366 if (ret < 0) {
367 hid_warn(hdev, "Error requesting data: %d\n", ret);
368 return ret;
369 }
370
371 ret = cp2112_wait(dev, &dev->read_avail);
372 if (ret)
373 return ret;
374
Jiri Kosina5a673fc2014-02-17 23:44:54 +0100375 hid_dbg(hdev, "read %d of %zd bytes requested\n",
David Barksdalee932d812014-02-04 12:42:48 -0600376 dev->read_length, size);
377
378 if (size > dev->read_length)
379 size = dev->read_length;
380
381 memcpy(data, dev->read_data, size);
382 return dev->read_length;
383}
384
385static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
386{
387 struct cp2112_read_req_report *report = buf;
388
389 if (length < 1 || length > 512)
390 return -EINVAL;
391
392 report->report = CP2112_DATA_READ_REQUEST;
393 report->slave_address = slave_address << 1;
394 report->length = cpu_to_be16(length);
395 return sizeof(*report);
396}
397
398static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
399 u8 command, u8 *data, u8 data_length)
400{
401 struct cp2112_write_read_req_report *report = buf;
402
403 if (length < 1 || length > 512
404 || data_length > sizeof(report->target_address) - 1)
405 return -EINVAL;
406
407 report->report = CP2112_DATA_WRITE_READ_REQUEST;
408 report->slave_address = slave_address << 1;
409 report->length = cpu_to_be16(length);
410 report->target_address_length = data_length + 1;
411 report->target_address[0] = command;
412 memcpy(&report->target_address[1], data, data_length);
413 return data_length + 6;
414}
415
416static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
417 u8 data_length)
418{
419 struct cp2112_write_req_report *report = buf;
420
421 if (data_length > sizeof(report->data) - 1)
422 return -EINVAL;
423
424 report->report = CP2112_DATA_WRITE_REQUEST;
425 report->slave_address = slave_address << 1;
426 report->length = data_length + 1;
427 report->data[0] = command;
428 memcpy(&report->data[1], data, data_length);
429 return data_length + 4;
430}
431
Antonio Borneob9029342014-07-08 07:25:39 +0800432static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
433 u8 data_length)
434{
435 struct cp2112_write_req_report *report = buf;
436
437 if (data_length > sizeof(report->data))
438 return -EINVAL;
439
440 report->report = CP2112_DATA_WRITE_REQUEST;
441 report->slave_address = slave_address << 1;
442 report->length = data_length;
443 memcpy(report->data, data, data_length);
444 return data_length + 3;
445}
446
447static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
448 int num)
449{
450 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
451 struct hid_device *hdev = dev->hdev;
452 u8 buf[64];
453 ssize_t count;
454 unsigned int retries;
455 int ret;
456
457 hid_dbg(hdev, "I2C %d messages\n", num);
458
459 if (num != 1) {
460 hid_err(hdev,
461 "Multi-message I2C transactions not supported\n");
462 return -EOPNOTSUPP;
463 }
464
465 if (msgs->flags & I2C_M_RD)
466 count = cp2112_read_req(buf, msgs->addr, msgs->len);
467 else
468 count = cp2112_i2c_write_req(buf, msgs->addr, msgs->buf,
469 msgs->len);
470
471 if (count < 0)
472 return count;
473
474 ret = hid_hw_power(hdev, PM_HINT_FULLON);
475 if (ret < 0) {
476 hid_err(hdev, "power management error: %d\n", ret);
477 return ret;
478 }
479
480 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
481 if (ret < 0) {
482 hid_warn(hdev, "Error starting transaction: %d\n", ret);
483 goto power_normal;
484 }
485
486 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
487 ret = cp2112_xfer_status(dev);
488 if (-EBUSY == ret)
489 continue;
490 if (ret < 0)
491 goto power_normal;
492 break;
493 }
494
495 if (XFER_STATUS_RETRIES <= retries) {
496 hid_warn(hdev, "Transfer timed out, cancelling.\n");
497 buf[0] = CP2112_CANCEL_TRANSFER;
498 buf[1] = 0x01;
499
500 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
501 if (ret < 0)
502 hid_warn(hdev, "Error cancelling transaction: %d\n",
503 ret);
504
505 ret = -ETIMEDOUT;
506 goto power_normal;
507 }
508
509 if (!(msgs->flags & I2C_M_RD))
510 goto finish;
511
512 ret = cp2112_read(dev, msgs->buf, msgs->len);
513 if (ret < 0)
514 goto power_normal;
515 if (ret != msgs->len) {
516 hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len);
517 ret = -EIO;
518 goto power_normal;
519 }
520
521finish:
522 /* return the number of transferred messages */
523 ret = 1;
524
525power_normal:
526 hid_hw_power(hdev, PM_HINT_NORMAL);
527 hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
528 return ret;
529}
530
David Barksdalee932d812014-02-04 12:42:48 -0600531static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
532 unsigned short flags, char read_write, u8 command,
533 int size, union i2c_smbus_data *data)
534{
535 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
536 struct hid_device *hdev = dev->hdev;
537 u8 buf[64];
538 __be16 word;
Jiri Kosina0438ee72014-02-18 09:43:53 +0100539 ssize_t count;
David Barksdalee932d812014-02-04 12:42:48 -0600540 size_t read_length = 0;
541 unsigned int retries;
542 int ret;
543
544 hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
545 read_write == I2C_SMBUS_WRITE ? "write" : "read",
546 addr, flags, command, size);
547
548 switch (size) {
549 case I2C_SMBUS_BYTE:
550 read_length = 1;
551
552 if (I2C_SMBUS_READ == read_write)
553 count = cp2112_read_req(buf, addr, read_length);
554 else
555 count = cp2112_write_req(buf, addr, data->byte, NULL,
556 0);
557 break;
558 case I2C_SMBUS_BYTE_DATA:
559 read_length = 1;
560
561 if (I2C_SMBUS_READ == read_write)
562 count = cp2112_write_read_req(buf, addr, read_length,
563 command, NULL, 0);
564 else
565 count = cp2112_write_req(buf, addr, command,
566 &data->byte, 1);
567 break;
568 case I2C_SMBUS_WORD_DATA:
569 read_length = 2;
570 word = cpu_to_be16(data->word);
571
572 if (I2C_SMBUS_READ == read_write)
573 count = cp2112_write_read_req(buf, addr, read_length,
574 command, NULL, 0);
575 else
576 count = cp2112_write_req(buf, addr, command,
577 (u8 *)&word, 2);
578 break;
579 case I2C_SMBUS_PROC_CALL:
580 size = I2C_SMBUS_WORD_DATA;
581 read_write = I2C_SMBUS_READ;
582 read_length = 2;
583 word = cpu_to_be16(data->word);
584
585 count = cp2112_write_read_req(buf, addr, read_length, command,
586 (u8 *)&word, 2);
587 break;
588 case I2C_SMBUS_I2C_BLOCK_DATA:
589 size = I2C_SMBUS_BLOCK_DATA;
590 /* fallthrough */
591 case I2C_SMBUS_BLOCK_DATA:
592 if (I2C_SMBUS_READ == read_write) {
593 count = cp2112_write_read_req(buf, addr,
594 I2C_SMBUS_BLOCK_MAX,
595 command, NULL, 0);
596 } else {
597 count = cp2112_write_req(buf, addr, command,
598 data->block,
599 data->block[0] + 1);
600 }
601 break;
602 case I2C_SMBUS_BLOCK_PROC_CALL:
603 size = I2C_SMBUS_BLOCK_DATA;
604 read_write = I2C_SMBUS_READ;
605
606 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
607 command, data->block,
608 data->block[0] + 1);
609 break;
610 default:
611 hid_warn(hdev, "Unsupported transaction %d\n", size);
612 return -EOPNOTSUPP;
613 }
614
615 if (count < 0)
616 return count;
617
618 ret = hid_hw_power(hdev, PM_HINT_FULLON);
619 if (ret < 0) {
620 hid_err(hdev, "power management error: %d\n", ret);
621 return ret;
622 }
623
624 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
625 if (ret < 0) {
626 hid_warn(hdev, "Error starting transaction: %d\n", ret);
627 goto power_normal;
628 }
629
630 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
631 ret = cp2112_xfer_status(dev);
632 if (-EBUSY == ret)
633 continue;
634 if (ret < 0)
635 goto power_normal;
636 break;
637 }
638
639 if (XFER_STATUS_RETRIES <= retries) {
640 hid_warn(hdev, "Transfer timed out, cancelling.\n");
641 buf[0] = CP2112_CANCEL_TRANSFER;
642 buf[1] = 0x01;
643
644 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
645 if (ret < 0)
646 hid_warn(hdev, "Error cancelling transaction: %d\n",
647 ret);
648
649 ret = -ETIMEDOUT;
650 goto power_normal;
651 }
652
653 if (I2C_SMBUS_WRITE == read_write) {
654 ret = 0;
655 goto power_normal;
656 }
657
658 if (I2C_SMBUS_BLOCK_DATA == size)
659 read_length = ret;
660
661 ret = cp2112_read(dev, buf, read_length);
662 if (ret < 0)
663 goto power_normal;
664 if (ret != read_length) {
Jiri Kosina5a673fc2014-02-17 23:44:54 +0100665 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
David Barksdalee932d812014-02-04 12:42:48 -0600666 ret = -EIO;
667 goto power_normal;
668 }
669
670 switch (size) {
671 case I2C_SMBUS_BYTE:
672 case I2C_SMBUS_BYTE_DATA:
673 data->byte = buf[0];
674 break;
675 case I2C_SMBUS_WORD_DATA:
676 data->word = be16_to_cpup((__be16 *)buf);
677 break;
678 case I2C_SMBUS_BLOCK_DATA:
679 if (read_length > I2C_SMBUS_BLOCK_MAX) {
680 ret = -EPROTO;
681 goto power_normal;
682 }
683
684 memcpy(data->block, buf, read_length);
685 break;
686 }
687
688 ret = 0;
689power_normal:
690 hid_hw_power(hdev, PM_HINT_NORMAL);
691 hid_dbg(hdev, "transfer finished: %d\n", ret);
692 return ret;
693}
694
695static u32 cp2112_functionality(struct i2c_adapter *adap)
696{
Antonio Borneob9029342014-07-08 07:25:39 +0800697 return I2C_FUNC_I2C |
698 I2C_FUNC_SMBUS_BYTE |
David Barksdalee932d812014-02-04 12:42:48 -0600699 I2C_FUNC_SMBUS_BYTE_DATA |
700 I2C_FUNC_SMBUS_WORD_DATA |
701 I2C_FUNC_SMBUS_BLOCK_DATA |
702 I2C_FUNC_SMBUS_I2C_BLOCK |
703 I2C_FUNC_SMBUS_PROC_CALL |
704 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
705}
706
707static const struct i2c_algorithm smbus_algorithm = {
Antonio Borneob9029342014-07-08 07:25:39 +0800708 .master_xfer = cp2112_i2c_xfer,
David Barksdalee932d812014-02-04 12:42:48 -0600709 .smbus_xfer = cp2112_xfer,
710 .functionality = cp2112_functionality,
711};
712
713static int cp2112_get_usb_config(struct hid_device *hdev,
714 struct cp2112_usb_config_report *cfg)
715{
716 int ret;
717
718 ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
719 HID_FEATURE_REPORT);
720 if (ret != sizeof(*cfg)) {
721 hid_err(hdev, "error reading usb config: %d\n", ret);
722 if (ret < 0)
723 return ret;
724 return -EIO;
725 }
726
727 return 0;
728}
729
730static int cp2112_set_usb_config(struct hid_device *hdev,
731 struct cp2112_usb_config_report *cfg)
732{
733 int ret;
734
735 BUG_ON(cfg->report != CP2112_USB_CONFIG);
736
737 ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
738 HID_FEATURE_REPORT);
739 if (ret != sizeof(*cfg)) {
740 hid_err(hdev, "error writing usb config: %d\n", ret);
741 if (ret < 0)
742 return ret;
743 return -EIO;
744 }
745
746 return 0;
747}
748
749static void chmod_sysfs_attrs(struct hid_device *hdev);
750
751#define CP2112_CONFIG_ATTR(name, store, format, ...) \
752static ssize_t name##_store(struct device *kdev, \
753 struct device_attribute *attr, const char *buf, \
754 size_t count) \
755{ \
756 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
757 struct cp2112_usb_config_report cfg; \
758 int ret = cp2112_get_usb_config(hdev, &cfg); \
759 if (ret) \
760 return ret; \
761 store; \
762 ret = cp2112_set_usb_config(hdev, &cfg); \
763 if (ret) \
764 return ret; \
765 chmod_sysfs_attrs(hdev); \
766 return count; \
767} \
768static ssize_t name##_show(struct device *kdev, \
769 struct device_attribute *attr, char *buf) \
770{ \
771 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
772 struct cp2112_usb_config_report cfg; \
773 int ret = cp2112_get_usb_config(hdev, &cfg); \
774 if (ret) \
775 return ret; \
776 return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
777} \
Jiri Kosinac3c041b2014-02-17 23:40:20 +0100778static DEVICE_ATTR_RW(name);
David Barksdalee932d812014-02-04 12:42:48 -0600779
780CP2112_CONFIG_ATTR(vendor_id, ({
781 u16 vid;
782
783 if (sscanf(buf, "%hi", &vid) != 1)
784 return -EINVAL;
785
786 cfg.vid = cpu_to_le16(vid);
787 cfg.mask = 0x01;
788}), "0x%04x\n", le16_to_cpu(cfg.vid));
789
790CP2112_CONFIG_ATTR(product_id, ({
791 u16 pid;
792
793 if (sscanf(buf, "%hi", &pid) != 1)
794 return -EINVAL;
795
796 cfg.pid = cpu_to_le16(pid);
797 cfg.mask = 0x02;
798}), "0x%04x\n", le16_to_cpu(cfg.pid));
799
800CP2112_CONFIG_ATTR(max_power, ({
801 int mA;
802
803 if (sscanf(buf, "%i", &mA) != 1)
804 return -EINVAL;
805
806 cfg.max_power = (mA + 1) / 2;
807 cfg.mask = 0x04;
808}), "%u mA\n", cfg.max_power * 2);
809
810CP2112_CONFIG_ATTR(power_mode, ({
811 if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
812 return -EINVAL;
813
814 cfg.mask = 0x08;
815}), "%u\n", cfg.power_mode);
816
817CP2112_CONFIG_ATTR(release_version, ({
818 if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
819 != 2)
820 return -EINVAL;
821
822 cfg.mask = 0x10;
823}), "%u.%u\n", cfg.release_major, cfg.release_minor);
824
825#undef CP2112_CONFIG_ATTR
826
827struct cp2112_pstring_attribute {
828 struct device_attribute attr;
829 unsigned char report;
830};
831
832static ssize_t pstr_store(struct device *kdev,
833 struct device_attribute *kattr, const char *buf,
834 size_t count)
835{
836 struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
837 struct cp2112_pstring_attribute *attr =
838 container_of(kattr, struct cp2112_pstring_attribute, attr);
839 struct cp2112_string_report report;
840 int ret;
841
842 memset(&report, 0, sizeof(report));
843
844 ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
845 report.string, ARRAY_SIZE(report.string));
846 report.report = attr->report;
847 report.length = ret * sizeof(report.string[0]) + 2;
848 report.type = USB_DT_STRING;
849
850 ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
851 HID_FEATURE_REPORT);
852 if (ret != report.length + 1) {
853 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
854 ret);
855 if (ret < 0)
856 return ret;
857 return -EIO;
858 }
859
860 chmod_sysfs_attrs(hdev);
861 return count;
862}
863
864static ssize_t pstr_show(struct device *kdev,
865 struct device_attribute *kattr, char *buf)
866{
867 struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
868 struct cp2112_pstring_attribute *attr =
869 container_of(kattr, struct cp2112_pstring_attribute, attr);
870 struct cp2112_string_report report;
871 u8 length;
872 int ret;
873
874 ret = cp2112_hid_get(hdev, attr->report, &report.report,
875 sizeof(report) - 1, HID_FEATURE_REPORT);
876 if (ret < 3) {
877 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
878 ret);
879 if (ret < 0)
880 return ret;
881 return -EIO;
882 }
883
884 if (report.length < 2) {
885 hid_err(hdev, "invalid %s string length: %d\n",
886 kattr->attr.name, report.length);
887 return -EIO;
888 }
889
890 length = report.length > ret - 1 ? ret - 1 : report.length;
891 length = (length - 2) / sizeof(report.string[0]);
892 ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
893 PAGE_SIZE - 1);
894 buf[ret++] = '\n';
895 return ret;
896}
897
898#define CP2112_PSTR_ATTR(name, _report) \
Jiri Kosinac3c041b2014-02-17 23:40:20 +0100899static struct cp2112_pstring_attribute dev_attr_##name = { \
David Barksdalee932d812014-02-04 12:42:48 -0600900 .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
901 .report = _report, \
902};
903
904CP2112_PSTR_ATTR(manufacturer, CP2112_MANUFACTURER_STRING);
905CP2112_PSTR_ATTR(product, CP2112_PRODUCT_STRING);
906CP2112_PSTR_ATTR(serial, CP2112_SERIAL_STRING);
907
908#undef CP2112_PSTR_ATTR
909
910static const struct attribute_group cp2112_attr_group = {
911 .attrs = (struct attribute *[]){
912 &dev_attr_vendor_id.attr,
913 &dev_attr_product_id.attr,
914 &dev_attr_max_power.attr,
915 &dev_attr_power_mode.attr,
916 &dev_attr_release_version.attr,
917 &dev_attr_manufacturer.attr.attr,
918 &dev_attr_product.attr.attr,
919 &dev_attr_serial.attr.attr,
920 NULL
921 }
922};
923
924/* Chmoding our sysfs attributes is simply a way to expose which fields in the
925 * PROM have already been programmed. We do not depend on this preventing
926 * writing to these attributes since the CP2112 will simply ignore writes to
927 * already-programmed fields. This is why there is no sense in fixing this
928 * racy behaviour.
929 */
930static void chmod_sysfs_attrs(struct hid_device *hdev)
931{
932 struct attribute **attr;
933 u8 buf[2];
934 int ret;
935
936 ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
937 HID_FEATURE_REPORT);
938 if (ret != sizeof(buf)) {
939 hid_err(hdev, "error reading lock byte: %d\n", ret);
940 return;
941 }
942
943 for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
944 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
945 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
946 if (ret < 0)
947 hid_err(hdev, "error chmoding sysfs file %s\n",
948 (*attr)->name);
949 buf[1] >>= 1;
950 }
951}
952
953static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
954{
955 struct cp2112_device *dev;
956 u8 buf[3];
957 struct cp2112_smbus_config_report config;
958 int ret;
959
960 ret = hid_parse(hdev);
961 if (ret) {
962 hid_err(hdev, "parse failed\n");
963 return ret;
964 }
965
966 ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
967 if (ret) {
968 hid_err(hdev, "hw start failed\n");
969 return ret;
970 }
971
972 ret = hid_hw_open(hdev);
973 if (ret) {
974 hid_err(hdev, "hw open failed\n");
975 goto err_hid_stop;
976 }
977
978 ret = hid_hw_power(hdev, PM_HINT_FULLON);
979 if (ret < 0) {
980 hid_err(hdev, "power management error: %d\n", ret);
981 goto err_hid_close;
982 }
983
984 ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
985 HID_FEATURE_REPORT);
986 if (ret != sizeof(buf)) {
987 hid_err(hdev, "error requesting version\n");
988 if (ret >= 0)
989 ret = -EIO;
990 goto err_power_normal;
991 }
992
993 hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
994 buf[1], buf[2]);
995
996 ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
997 sizeof(config), HID_FEATURE_REPORT);
998 if (ret != sizeof(config)) {
999 hid_err(hdev, "error requesting SMBus config\n");
1000 if (ret >= 0)
1001 ret = -EIO;
1002 goto err_power_normal;
1003 }
1004
1005 config.retry_time = cpu_to_be16(1);
1006
1007 ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1008 HID_FEATURE_REPORT);
1009 if (ret != sizeof(config)) {
1010 hid_err(hdev, "error setting SMBus config\n");
1011 if (ret >= 0)
1012 ret = -EIO;
1013 goto err_power_normal;
1014 }
1015
1016 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1017 if (!dev) {
1018 ret = -ENOMEM;
1019 goto err_power_normal;
1020 }
1021
1022 hid_set_drvdata(hdev, (void *)dev);
1023 dev->hdev = hdev;
1024 dev->adap.owner = THIS_MODULE;
1025 dev->adap.class = I2C_CLASS_HWMON;
1026 dev->adap.algo = &smbus_algorithm;
1027 dev->adap.algo_data = dev;
1028 dev->adap.dev.parent = &hdev->dev;
1029 snprintf(dev->adap.name, sizeof(dev->adap.name),
1030 "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
1031 init_waitqueue_head(&dev->wait);
1032
1033 hid_device_io_start(hdev);
1034 ret = i2c_add_adapter(&dev->adap);
1035 hid_device_io_stop(hdev);
1036
1037 if (ret) {
1038 hid_err(hdev, "error registering i2c adapter\n");
1039 goto err_free_dev;
1040 }
1041
1042 hid_dbg(hdev, "adapter registered\n");
1043
1044 dev->gc.label = "cp2112_gpio";
1045 dev->gc.direction_input = cp2112_gpio_direction_input;
1046 dev->gc.direction_output = cp2112_gpio_direction_output;
1047 dev->gc.set = cp2112_gpio_set;
1048 dev->gc.get = cp2112_gpio_get;
1049 dev->gc.base = -1;
1050 dev->gc.ngpio = 8;
1051 dev->gc.can_sleep = 1;
1052 dev->gc.dev = &hdev->dev;
1053
1054 ret = gpiochip_add(&dev->gc);
1055 if (ret < 0) {
1056 hid_err(hdev, "error registering gpio chip\n");
1057 goto err_free_i2c;
1058 }
1059
1060 ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1061 if (ret < 0) {
1062 hid_err(hdev, "error creating sysfs attrs\n");
1063 goto err_gpiochip_remove;
1064 }
1065
1066 chmod_sysfs_attrs(hdev);
1067 hid_hw_power(hdev, PM_HINT_NORMAL);
1068
1069 return ret;
1070
1071err_gpiochip_remove:
1072 if (gpiochip_remove(&dev->gc) < 0)
1073 hid_err(hdev, "error removing gpio chip\n");
1074err_free_i2c:
1075 i2c_del_adapter(&dev->adap);
1076err_free_dev:
1077 kfree(dev);
1078err_power_normal:
1079 hid_hw_power(hdev, PM_HINT_NORMAL);
1080err_hid_close:
1081 hid_hw_close(hdev);
1082err_hid_stop:
1083 hid_hw_stop(hdev);
1084 return ret;
1085}
1086
1087static void cp2112_remove(struct hid_device *hdev)
1088{
1089 struct cp2112_device *dev = hid_get_drvdata(hdev);
1090
1091 sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1092 if (gpiochip_remove(&dev->gc))
1093 hid_err(hdev, "unable to remove gpio chip\n");
1094 i2c_del_adapter(&dev->adap);
1095 /* i2c_del_adapter has finished removing all i2c devices from our
1096 * adapter. Well behaved devices should no longer call our cp2112_xfer
1097 * and should have waited for any pending calls to finish. It has also
1098 * waited for device_unregister(&adap->dev) to complete. Therefore we
1099 * can safely free our struct cp2112_device.
1100 */
1101 hid_hw_close(hdev);
1102 hid_hw_stop(hdev);
1103 kfree(dev);
1104}
1105
1106static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1107 u8 *data, int size)
1108{
1109 struct cp2112_device *dev = hid_get_drvdata(hdev);
1110 struct cp2112_xfer_status_report *xfer = (void *)data;
1111
1112 switch (data[0]) {
1113 case CP2112_TRANSFER_STATUS_RESPONSE:
1114 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1115 xfer->status0, xfer->status1,
1116 be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1117
1118 switch (xfer->status0) {
1119 case STATUS0_IDLE:
1120 dev->xfer_status = -EAGAIN;
1121 break;
1122 case STATUS0_BUSY:
1123 dev->xfer_status = -EBUSY;
1124 break;
1125 case STATUS0_COMPLETE:
1126 dev->xfer_status = be16_to_cpu(xfer->length);
1127 break;
1128 case STATUS0_ERROR:
1129 switch (xfer->status1) {
1130 case STATUS1_TIMEOUT_NACK:
1131 case STATUS1_TIMEOUT_BUS:
1132 dev->xfer_status = -ETIMEDOUT;
1133 break;
1134 default:
1135 dev->xfer_status = -EIO;
1136 break;
1137 }
1138 break;
1139 default:
1140 dev->xfer_status = -EINVAL;
1141 break;
1142 }
1143
1144 atomic_set(&dev->xfer_avail, 1);
1145 break;
1146 case CP2112_DATA_READ_RESPONSE:
1147 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1148
1149 dev->read_length = data[2];
1150 if (dev->read_length > sizeof(dev->read_data))
1151 dev->read_length = sizeof(dev->read_data);
1152
1153 memcpy(dev->read_data, &data[3], dev->read_length);
1154 atomic_set(&dev->read_avail, 1);
1155 break;
1156 default:
1157 hid_err(hdev, "unknown report\n");
1158
1159 return 0;
1160 }
1161
1162 wake_up_interruptible(&dev->wait);
1163 return 1;
1164}
1165
1166static struct hid_driver cp2112_driver = {
1167 .name = "cp2112",
1168 .id_table = cp2112_devices,
1169 .probe = cp2112_probe,
1170 .remove = cp2112_remove,
1171 .raw_event = cp2112_raw_event,
1172};
1173
1174module_hid_driver(cp2112_driver);
1175MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1176MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1177MODULE_LICENSE("GPL");
1178