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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[deliverable/linux.git] / drivers / hid / hid-cp2112.c
1 /*
2 * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
3 * Copyright (c) 2013,2014 Uplogix, Inc.
4 * David Barksdale <dbarksdale@uplogix.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 */
15
16 /*
17 * The Silicon Labs CP2112 chip is a USB HID device which provides an
18 * SMBus controller for talking to slave devices and 8 GPIO pins. The
19 * host communicates with the CP2112 via raw HID reports.
20 *
21 * Data Sheet:
22 * http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
23 * Programming Interface Specification:
24 * http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf
25 */
26
27 #include <linux/gpio.h>
28 #include <linux/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
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 int xfer_status;
160 atomic_t read_avail;
161 atomic_t xfer_avail;
162 struct gpio_chip gc;
163 };
164
165 static int gpio_push_pull = 0xFF;
166 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
167 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
168
169 static 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
177 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
178 sizeof(buf), HID_FEATURE_REPORT,
179 HID_REQ_GET_REPORT);
180 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
188 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
189 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
190 if (ret < 0) {
191 hid_err(hdev, "error setting GPIO config: %d\n", ret);
192 return ret;
193 }
194
195 return 0;
196 }
197
198 static 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
210 ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf),
211 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
212 if (ret < 0)
213 hid_err(hdev, "error setting GPIO values: %d\n", ret);
214 }
215
216 static 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
224 ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, sizeof(buf),
225 HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
226 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
234 static 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
243 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
244 sizeof(buf), HID_FEATURE_REPORT,
245 HID_REQ_GET_REPORT);
246 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
254 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
255 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
256 if (ret < 0) {
257 hid_err(hdev, "error setting GPIO config: %d\n", ret);
258 return ret;
259 }
260
261 /*
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
267 return 0;
268 }
269
270 static 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
280 ret = hid_hw_raw_request(hdev, report_number, buf, count,
281 report_type, HID_REQ_GET_REPORT);
282 memcpy(data, buf, count);
283 kfree(buf);
284 return ret;
285 }
286
287 static 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
297 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
303 kfree(buf);
304 return ret;
305 }
306
307 static 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
330 static 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
353 static 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 if (size > sizeof(dev->read_data))
360 size = sizeof(dev->read_data);
361 report.report = CP2112_DATA_READ_FORCE_SEND;
362 report.length = cpu_to_be16(size);
363
364 atomic_set(&dev->read_avail, 0);
365
366 ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
367 HID_OUTPUT_REPORT);
368 if (ret < 0) {
369 hid_warn(hdev, "Error requesting data: %d\n", ret);
370 return ret;
371 }
372
373 ret = cp2112_wait(dev, &dev->read_avail);
374 if (ret)
375 return ret;
376
377 hid_dbg(hdev, "read %d of %zd bytes requested\n",
378 dev->read_length, size);
379
380 if (size > dev->read_length)
381 size = dev->read_length;
382
383 memcpy(data, dev->read_data, size);
384 return dev->read_length;
385 }
386
387 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
388 {
389 struct cp2112_read_req_report *report = buf;
390
391 if (length < 1 || length > 512)
392 return -EINVAL;
393
394 report->report = CP2112_DATA_READ_REQUEST;
395 report->slave_address = slave_address << 1;
396 report->length = cpu_to_be16(length);
397 return sizeof(*report);
398 }
399
400 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
401 u8 command, u8 *data, u8 data_length)
402 {
403 struct cp2112_write_read_req_report *report = buf;
404
405 if (length < 1 || length > 512
406 || data_length > sizeof(report->target_address) - 1)
407 return -EINVAL;
408
409 report->report = CP2112_DATA_WRITE_READ_REQUEST;
410 report->slave_address = slave_address << 1;
411 report->length = cpu_to_be16(length);
412 report->target_address_length = data_length + 1;
413 report->target_address[0] = command;
414 memcpy(&report->target_address[1], data, data_length);
415 return data_length + 6;
416 }
417
418 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
419 u8 data_length)
420 {
421 struct cp2112_write_req_report *report = buf;
422
423 if (data_length > sizeof(report->data) - 1)
424 return -EINVAL;
425
426 report->report = CP2112_DATA_WRITE_REQUEST;
427 report->slave_address = slave_address << 1;
428 report->length = data_length + 1;
429 report->data[0] = command;
430 memcpy(&report->data[1], data, data_length);
431 return data_length + 4;
432 }
433
434 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
435 u8 data_length)
436 {
437 struct cp2112_write_req_report *report = buf;
438
439 if (data_length > sizeof(report->data))
440 return -EINVAL;
441
442 report->report = CP2112_DATA_WRITE_REQUEST;
443 report->slave_address = slave_address << 1;
444 report->length = data_length;
445 memcpy(report->data, data, data_length);
446 return data_length + 3;
447 }
448
449 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
450 int num)
451 {
452 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
453 struct hid_device *hdev = dev->hdev;
454 u8 buf[64];
455 ssize_t count;
456 unsigned int retries;
457 int ret;
458
459 hid_dbg(hdev, "I2C %d messages\n", num);
460
461 if (num != 1) {
462 hid_err(hdev,
463 "Multi-message I2C transactions not supported\n");
464 return -EOPNOTSUPP;
465 }
466
467 if (msgs->flags & I2C_M_RD)
468 count = cp2112_read_req(buf, msgs->addr, msgs->len);
469 else
470 count = cp2112_i2c_write_req(buf, msgs->addr, msgs->buf,
471 msgs->len);
472
473 if (count < 0)
474 return count;
475
476 ret = hid_hw_power(hdev, PM_HINT_FULLON);
477 if (ret < 0) {
478 hid_err(hdev, "power management error: %d\n", ret);
479 return ret;
480 }
481
482 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
483 if (ret < 0) {
484 hid_warn(hdev, "Error starting transaction: %d\n", ret);
485 goto power_normal;
486 }
487
488 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
489 ret = cp2112_xfer_status(dev);
490 if (-EBUSY == ret)
491 continue;
492 if (ret < 0)
493 goto power_normal;
494 break;
495 }
496
497 if (XFER_STATUS_RETRIES <= retries) {
498 hid_warn(hdev, "Transfer timed out, cancelling.\n");
499 buf[0] = CP2112_CANCEL_TRANSFER;
500 buf[1] = 0x01;
501
502 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
503 if (ret < 0)
504 hid_warn(hdev, "Error cancelling transaction: %d\n",
505 ret);
506
507 ret = -ETIMEDOUT;
508 goto power_normal;
509 }
510
511 if (!(msgs->flags & I2C_M_RD))
512 goto finish;
513
514 ret = cp2112_read(dev, msgs->buf, msgs->len);
515 if (ret < 0)
516 goto power_normal;
517 if (ret != msgs->len) {
518 hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len);
519 ret = -EIO;
520 goto power_normal;
521 }
522
523 finish:
524 /* return the number of transferred messages */
525 ret = 1;
526
527 power_normal:
528 hid_hw_power(hdev, PM_HINT_NORMAL);
529 hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
530 return ret;
531 }
532
533 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
534 unsigned short flags, char read_write, u8 command,
535 int size, union i2c_smbus_data *data)
536 {
537 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
538 struct hid_device *hdev = dev->hdev;
539 u8 buf[64];
540 __be16 word;
541 ssize_t count;
542 size_t read_length = 0;
543 unsigned int retries;
544 int ret;
545
546 hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
547 read_write == I2C_SMBUS_WRITE ? "write" : "read",
548 addr, flags, command, size);
549
550 switch (size) {
551 case I2C_SMBUS_BYTE:
552 read_length = 1;
553
554 if (I2C_SMBUS_READ == read_write)
555 count = cp2112_read_req(buf, addr, read_length);
556 else
557 count = cp2112_write_req(buf, addr, data->byte, NULL,
558 0);
559 break;
560 case I2C_SMBUS_BYTE_DATA:
561 read_length = 1;
562
563 if (I2C_SMBUS_READ == read_write)
564 count = cp2112_write_read_req(buf, addr, read_length,
565 command, NULL, 0);
566 else
567 count = cp2112_write_req(buf, addr, command,
568 &data->byte, 1);
569 break;
570 case I2C_SMBUS_WORD_DATA:
571 read_length = 2;
572 word = cpu_to_be16(data->word);
573
574 if (I2C_SMBUS_READ == read_write)
575 count = cp2112_write_read_req(buf, addr, read_length,
576 command, NULL, 0);
577 else
578 count = cp2112_write_req(buf, addr, command,
579 (u8 *)&word, 2);
580 break;
581 case I2C_SMBUS_PROC_CALL:
582 size = I2C_SMBUS_WORD_DATA;
583 read_write = I2C_SMBUS_READ;
584 read_length = 2;
585 word = cpu_to_be16(data->word);
586
587 count = cp2112_write_read_req(buf, addr, read_length, command,
588 (u8 *)&word, 2);
589 break;
590 case I2C_SMBUS_I2C_BLOCK_DATA:
591 size = I2C_SMBUS_BLOCK_DATA;
592 /* fallthrough */
593 case I2C_SMBUS_BLOCK_DATA:
594 if (I2C_SMBUS_READ == read_write) {
595 count = cp2112_write_read_req(buf, addr,
596 I2C_SMBUS_BLOCK_MAX,
597 command, NULL, 0);
598 } else {
599 count = cp2112_write_req(buf, addr, command,
600 data->block,
601 data->block[0] + 1);
602 }
603 break;
604 case I2C_SMBUS_BLOCK_PROC_CALL:
605 size = I2C_SMBUS_BLOCK_DATA;
606 read_write = I2C_SMBUS_READ;
607
608 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
609 command, data->block,
610 data->block[0] + 1);
611 break;
612 default:
613 hid_warn(hdev, "Unsupported transaction %d\n", size);
614 return -EOPNOTSUPP;
615 }
616
617 if (count < 0)
618 return count;
619
620 ret = hid_hw_power(hdev, PM_HINT_FULLON);
621 if (ret < 0) {
622 hid_err(hdev, "power management error: %d\n", ret);
623 return ret;
624 }
625
626 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
627 if (ret < 0) {
628 hid_warn(hdev, "Error starting transaction: %d\n", ret);
629 goto power_normal;
630 }
631
632 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
633 ret = cp2112_xfer_status(dev);
634 if (-EBUSY == ret)
635 continue;
636 if (ret < 0)
637 goto power_normal;
638 break;
639 }
640
641 if (XFER_STATUS_RETRIES <= retries) {
642 hid_warn(hdev, "Transfer timed out, cancelling.\n");
643 buf[0] = CP2112_CANCEL_TRANSFER;
644 buf[1] = 0x01;
645
646 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
647 if (ret < 0)
648 hid_warn(hdev, "Error cancelling transaction: %d\n",
649 ret);
650
651 ret = -ETIMEDOUT;
652 goto power_normal;
653 }
654
655 if (I2C_SMBUS_WRITE == read_write) {
656 ret = 0;
657 goto power_normal;
658 }
659
660 if (I2C_SMBUS_BLOCK_DATA == size)
661 read_length = ret;
662
663 ret = cp2112_read(dev, buf, read_length);
664 if (ret < 0)
665 goto power_normal;
666 if (ret != read_length) {
667 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
668 ret = -EIO;
669 goto power_normal;
670 }
671
672 switch (size) {
673 case I2C_SMBUS_BYTE:
674 case I2C_SMBUS_BYTE_DATA:
675 data->byte = buf[0];
676 break;
677 case I2C_SMBUS_WORD_DATA:
678 data->word = be16_to_cpup((__be16 *)buf);
679 break;
680 case I2C_SMBUS_BLOCK_DATA:
681 if (read_length > I2C_SMBUS_BLOCK_MAX) {
682 ret = -EPROTO;
683 goto power_normal;
684 }
685
686 memcpy(data->block, buf, read_length);
687 break;
688 }
689
690 ret = 0;
691 power_normal:
692 hid_hw_power(hdev, PM_HINT_NORMAL);
693 hid_dbg(hdev, "transfer finished: %d\n", ret);
694 return ret;
695 }
696
697 static u32 cp2112_functionality(struct i2c_adapter *adap)
698 {
699 return I2C_FUNC_I2C |
700 I2C_FUNC_SMBUS_BYTE |
701 I2C_FUNC_SMBUS_BYTE_DATA |
702 I2C_FUNC_SMBUS_WORD_DATA |
703 I2C_FUNC_SMBUS_BLOCK_DATA |
704 I2C_FUNC_SMBUS_I2C_BLOCK |
705 I2C_FUNC_SMBUS_PROC_CALL |
706 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
707 }
708
709 static const struct i2c_algorithm smbus_algorithm = {
710 .master_xfer = cp2112_i2c_xfer,
711 .smbus_xfer = cp2112_xfer,
712 .functionality = cp2112_functionality,
713 };
714
715 static int cp2112_get_usb_config(struct hid_device *hdev,
716 struct cp2112_usb_config_report *cfg)
717 {
718 int ret;
719
720 ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
721 HID_FEATURE_REPORT);
722 if (ret != sizeof(*cfg)) {
723 hid_err(hdev, "error reading usb config: %d\n", ret);
724 if (ret < 0)
725 return ret;
726 return -EIO;
727 }
728
729 return 0;
730 }
731
732 static int cp2112_set_usb_config(struct hid_device *hdev,
733 struct cp2112_usb_config_report *cfg)
734 {
735 int ret;
736
737 BUG_ON(cfg->report != CP2112_USB_CONFIG);
738
739 ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
740 HID_FEATURE_REPORT);
741 if (ret != sizeof(*cfg)) {
742 hid_err(hdev, "error writing usb config: %d\n", ret);
743 if (ret < 0)
744 return ret;
745 return -EIO;
746 }
747
748 return 0;
749 }
750
751 static void chmod_sysfs_attrs(struct hid_device *hdev);
752
753 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
754 static ssize_t name##_store(struct device *kdev, \
755 struct device_attribute *attr, const char *buf, \
756 size_t count) \
757 { \
758 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
759 struct cp2112_usb_config_report cfg; \
760 int ret = cp2112_get_usb_config(hdev, &cfg); \
761 if (ret) \
762 return ret; \
763 store; \
764 ret = cp2112_set_usb_config(hdev, &cfg); \
765 if (ret) \
766 return ret; \
767 chmod_sysfs_attrs(hdev); \
768 return count; \
769 } \
770 static ssize_t name##_show(struct device *kdev, \
771 struct device_attribute *attr, char *buf) \
772 { \
773 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
774 struct cp2112_usb_config_report cfg; \
775 int ret = cp2112_get_usb_config(hdev, &cfg); \
776 if (ret) \
777 return ret; \
778 return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
779 } \
780 static DEVICE_ATTR_RW(name);
781
782 CP2112_CONFIG_ATTR(vendor_id, ({
783 u16 vid;
784
785 if (sscanf(buf, "%hi", &vid) != 1)
786 return -EINVAL;
787
788 cfg.vid = cpu_to_le16(vid);
789 cfg.mask = 0x01;
790 }), "0x%04x\n", le16_to_cpu(cfg.vid));
791
792 CP2112_CONFIG_ATTR(product_id, ({
793 u16 pid;
794
795 if (sscanf(buf, "%hi", &pid) != 1)
796 return -EINVAL;
797
798 cfg.pid = cpu_to_le16(pid);
799 cfg.mask = 0x02;
800 }), "0x%04x\n", le16_to_cpu(cfg.pid));
801
802 CP2112_CONFIG_ATTR(max_power, ({
803 int mA;
804
805 if (sscanf(buf, "%i", &mA) != 1)
806 return -EINVAL;
807
808 cfg.max_power = (mA + 1) / 2;
809 cfg.mask = 0x04;
810 }), "%u mA\n", cfg.max_power * 2);
811
812 CP2112_CONFIG_ATTR(power_mode, ({
813 if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
814 return -EINVAL;
815
816 cfg.mask = 0x08;
817 }), "%u\n", cfg.power_mode);
818
819 CP2112_CONFIG_ATTR(release_version, ({
820 if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
821 != 2)
822 return -EINVAL;
823
824 cfg.mask = 0x10;
825 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
826
827 #undef CP2112_CONFIG_ATTR
828
829 struct cp2112_pstring_attribute {
830 struct device_attribute attr;
831 unsigned char report;
832 };
833
834 static ssize_t pstr_store(struct device *kdev,
835 struct device_attribute *kattr, const char *buf,
836 size_t count)
837 {
838 struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
839 struct cp2112_pstring_attribute *attr =
840 container_of(kattr, struct cp2112_pstring_attribute, attr);
841 struct cp2112_string_report report;
842 int ret;
843
844 memset(&report, 0, sizeof(report));
845
846 ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
847 report.string, ARRAY_SIZE(report.string));
848 report.report = attr->report;
849 report.length = ret * sizeof(report.string[0]) + 2;
850 report.type = USB_DT_STRING;
851
852 ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
853 HID_FEATURE_REPORT);
854 if (ret != report.length + 1) {
855 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
856 ret);
857 if (ret < 0)
858 return ret;
859 return -EIO;
860 }
861
862 chmod_sysfs_attrs(hdev);
863 return count;
864 }
865
866 static ssize_t pstr_show(struct device *kdev,
867 struct device_attribute *kattr, char *buf)
868 {
869 struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
870 struct cp2112_pstring_attribute *attr =
871 container_of(kattr, struct cp2112_pstring_attribute, attr);
872 struct cp2112_string_report report;
873 u8 length;
874 int ret;
875
876 ret = cp2112_hid_get(hdev, attr->report, &report.report,
877 sizeof(report) - 1, HID_FEATURE_REPORT);
878 if (ret < 3) {
879 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
880 ret);
881 if (ret < 0)
882 return ret;
883 return -EIO;
884 }
885
886 if (report.length < 2) {
887 hid_err(hdev, "invalid %s string length: %d\n",
888 kattr->attr.name, report.length);
889 return -EIO;
890 }
891
892 length = report.length > ret - 1 ? ret - 1 : report.length;
893 length = (length - 2) / sizeof(report.string[0]);
894 ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
895 PAGE_SIZE - 1);
896 buf[ret++] = '\n';
897 return ret;
898 }
899
900 #define CP2112_PSTR_ATTR(name, _report) \
901 static struct cp2112_pstring_attribute dev_attr_##name = { \
902 .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
903 .report = _report, \
904 };
905
906 CP2112_PSTR_ATTR(manufacturer, CP2112_MANUFACTURER_STRING);
907 CP2112_PSTR_ATTR(product, CP2112_PRODUCT_STRING);
908 CP2112_PSTR_ATTR(serial, CP2112_SERIAL_STRING);
909
910 #undef CP2112_PSTR_ATTR
911
912 static const struct attribute_group cp2112_attr_group = {
913 .attrs = (struct attribute *[]){
914 &dev_attr_vendor_id.attr,
915 &dev_attr_product_id.attr,
916 &dev_attr_max_power.attr,
917 &dev_attr_power_mode.attr,
918 &dev_attr_release_version.attr,
919 &dev_attr_manufacturer.attr.attr,
920 &dev_attr_product.attr.attr,
921 &dev_attr_serial.attr.attr,
922 NULL
923 }
924 };
925
926 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
927 * PROM have already been programmed. We do not depend on this preventing
928 * writing to these attributes since the CP2112 will simply ignore writes to
929 * already-programmed fields. This is why there is no sense in fixing this
930 * racy behaviour.
931 */
932 static void chmod_sysfs_attrs(struct hid_device *hdev)
933 {
934 struct attribute **attr;
935 u8 buf[2];
936 int ret;
937
938 ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
939 HID_FEATURE_REPORT);
940 if (ret != sizeof(buf)) {
941 hid_err(hdev, "error reading lock byte: %d\n", ret);
942 return;
943 }
944
945 for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
946 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
947 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
948 if (ret < 0)
949 hid_err(hdev, "error chmoding sysfs file %s\n",
950 (*attr)->name);
951 buf[1] >>= 1;
952 }
953 }
954
955 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
956 {
957 struct cp2112_device *dev;
958 u8 buf[3];
959 struct cp2112_smbus_config_report config;
960 int ret;
961
962 ret = hid_parse(hdev);
963 if (ret) {
964 hid_err(hdev, "parse failed\n");
965 return ret;
966 }
967
968 ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
969 if (ret) {
970 hid_err(hdev, "hw start failed\n");
971 return ret;
972 }
973
974 ret = hid_hw_open(hdev);
975 if (ret) {
976 hid_err(hdev, "hw open failed\n");
977 goto err_hid_stop;
978 }
979
980 ret = hid_hw_power(hdev, PM_HINT_FULLON);
981 if (ret < 0) {
982 hid_err(hdev, "power management error: %d\n", ret);
983 goto err_hid_close;
984 }
985
986 ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
987 HID_FEATURE_REPORT);
988 if (ret != sizeof(buf)) {
989 hid_err(hdev, "error requesting version\n");
990 if (ret >= 0)
991 ret = -EIO;
992 goto err_power_normal;
993 }
994
995 hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
996 buf[1], buf[2]);
997
998 ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
999 sizeof(config), HID_FEATURE_REPORT);
1000 if (ret != sizeof(config)) {
1001 hid_err(hdev, "error requesting SMBus config\n");
1002 if (ret >= 0)
1003 ret = -EIO;
1004 goto err_power_normal;
1005 }
1006
1007 config.retry_time = cpu_to_be16(1);
1008
1009 ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1010 HID_FEATURE_REPORT);
1011 if (ret != sizeof(config)) {
1012 hid_err(hdev, "error setting SMBus config\n");
1013 if (ret >= 0)
1014 ret = -EIO;
1015 goto err_power_normal;
1016 }
1017
1018 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1019 if (!dev) {
1020 ret = -ENOMEM;
1021 goto err_power_normal;
1022 }
1023
1024 hid_set_drvdata(hdev, (void *)dev);
1025 dev->hdev = hdev;
1026 dev->adap.owner = THIS_MODULE;
1027 dev->adap.class = I2C_CLASS_HWMON;
1028 dev->adap.algo = &smbus_algorithm;
1029 dev->adap.algo_data = dev;
1030 dev->adap.dev.parent = &hdev->dev;
1031 snprintf(dev->adap.name, sizeof(dev->adap.name),
1032 "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
1033 init_waitqueue_head(&dev->wait);
1034
1035 hid_device_io_start(hdev);
1036 ret = i2c_add_adapter(&dev->adap);
1037 hid_device_io_stop(hdev);
1038
1039 if (ret) {
1040 hid_err(hdev, "error registering i2c adapter\n");
1041 goto err_free_dev;
1042 }
1043
1044 hid_dbg(hdev, "adapter registered\n");
1045
1046 dev->gc.label = "cp2112_gpio";
1047 dev->gc.direction_input = cp2112_gpio_direction_input;
1048 dev->gc.direction_output = cp2112_gpio_direction_output;
1049 dev->gc.set = cp2112_gpio_set;
1050 dev->gc.get = cp2112_gpio_get;
1051 dev->gc.base = -1;
1052 dev->gc.ngpio = 8;
1053 dev->gc.can_sleep = 1;
1054 dev->gc.dev = &hdev->dev;
1055
1056 ret = gpiochip_add(&dev->gc);
1057 if (ret < 0) {
1058 hid_err(hdev, "error registering gpio chip\n");
1059 goto err_free_i2c;
1060 }
1061
1062 ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1063 if (ret < 0) {
1064 hid_err(hdev, "error creating sysfs attrs\n");
1065 goto err_gpiochip_remove;
1066 }
1067
1068 chmod_sysfs_attrs(hdev);
1069 hid_hw_power(hdev, PM_HINT_NORMAL);
1070
1071 return ret;
1072
1073 err_gpiochip_remove:
1074 gpiochip_remove(&dev->gc);
1075 err_free_i2c:
1076 i2c_del_adapter(&dev->adap);
1077 err_free_dev:
1078 kfree(dev);
1079 err_power_normal:
1080 hid_hw_power(hdev, PM_HINT_NORMAL);
1081 err_hid_close:
1082 hid_hw_close(hdev);
1083 err_hid_stop:
1084 hid_hw_stop(hdev);
1085 return ret;
1086 }
1087
1088 static void cp2112_remove(struct hid_device *hdev)
1089 {
1090 struct cp2112_device *dev = hid_get_drvdata(hdev);
1091
1092 sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1093 gpiochip_remove(&dev->gc);
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
1106 static 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
1166 static 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
1174 module_hid_driver(cp2112_driver);
1175 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1176 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1177 MODULE_LICENSE("GPL");
1178
Linux kernel - Deliverables
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