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mm: remove more IS_ERR_VALUE abuses
[linux/fpc-iii.git] / drivers / hid / hid-cp2112.c
blob086d8a50715789d2237d19a59d8e24f407d35e23
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/driver.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 u8 hwversion;
160 int xfer_status;
161 atomic_t read_avail;
162 atomic_t xfer_avail;
163 struct gpio_chip gc;
164 };
165
166 static int gpio_push_pull = 0xFF;
167 module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR);
168 MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask");
169
170 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
171 {
172 struct cp2112_device *dev = gpiochip_get_data(chip);
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 = gpiochip_get_data(chip);
201 struct hid_device *hdev = dev->hdev;
202 u8 buf[3];
203 int ret;
204
205 buf[0] = CP2112_GPIO_SET;
206 buf[1] = value ? 0xff : 0;
207 buf[2] = 1 << offset;
208
209 ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf),
210 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
211 if (ret < 0)
212 hid_err(hdev, "error setting GPIO values: %d\n", ret);
213 }
214
215 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset)
216 {
217 struct cp2112_device *dev = gpiochip_get_data(chip);
218 struct hid_device *hdev = dev->hdev;
219 u8 buf[2];
220 int ret;
221
222 ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, sizeof(buf),
223 HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
224 if (ret != sizeof(buf)) {
225 hid_err(hdev, "error requesting GPIO values: %d\n", ret);
226 return ret;
227 }
228
229 return (buf[1] >> offset) & 1;
230 }
231
232 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
233 unsigned offset, int value)
234 {
235 struct cp2112_device *dev = gpiochip_get_data(chip);
236 struct hid_device *hdev = dev->hdev;
237 u8 buf[5];
238 int ret;
239
240 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
241 sizeof(buf), HID_FEATURE_REPORT,
242 HID_REQ_GET_REPORT);
243 if (ret != sizeof(buf)) {
244 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
245 return ret;
246 }
247
248 buf[1] |= 1 << offset;
249 buf[2] = gpio_push_pull;
250
251 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
252 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
253 if (ret < 0) {
254 hid_err(hdev, "error setting GPIO config: %d\n", ret);
255 return ret;
256 }
257
258 /*
259 * Set gpio value when output direction is already set,
260 * as specified in AN495, Rev. 0.2, cpt. 4.4
261 */
262 cp2112_gpio_set(chip, offset, value);
263
264 return 0;
265 }
266
267 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
268 u8 *data, size_t count, unsigned char report_type)
269 {
270 u8 *buf;
271 int ret;
272
273 buf = kmalloc(count, GFP_KERNEL);
274 if (!buf)
275 return -ENOMEM;
276
277 ret = hid_hw_raw_request(hdev, report_number, buf, count,
278 report_type, HID_REQ_GET_REPORT);
279 memcpy(data, buf, count);
280 kfree(buf);
281 return ret;
282 }
283
284 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
285 unsigned char report_type)
286 {
287 u8 *buf;
288 int ret;
289
290 buf = kmemdup(data, count, GFP_KERNEL);
291 if (!buf)
292 return -ENOMEM;
293
294 if (report_type == HID_OUTPUT_REPORT)
295 ret = hid_hw_output_report(hdev, buf, count);
296 else
297 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
298 HID_REQ_SET_REPORT);
299
300 kfree(buf);
301 return ret;
302 }
303
304 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
305 {
306 int ret = 0;
307
308 /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a
309 * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to
310 * come in cp2112_raw_event or timeout. There will only be one of these
311 * in flight at any one time. The timeout is extremely large and is a
312 * last resort if the CP2112 has died. If we do timeout we don't expect
313 * to receive the response which would cause data races, it's not like
314 * we can do anything about it anyway.
315 */
316 ret = wait_event_interruptible_timeout(dev->wait,
317 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
318 if (-ERESTARTSYS == ret)
319 return ret;
320 if (!ret)
321 return -ETIMEDOUT;
322
323 atomic_set(avail, 0);
324 return 0;
325 }
326
327 static int cp2112_xfer_status(struct cp2112_device *dev)
328 {
329 struct hid_device *hdev = dev->hdev;
330 u8 buf[2];
331 int ret;
332
333 buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
334 buf[1] = 0x01;
335 atomic_set(&dev->xfer_avail, 0);
336
337 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
338 if (ret < 0) {
339 hid_warn(hdev, "Error requesting status: %d\n", ret);
340 return ret;
341 }
342
343 ret = cp2112_wait(dev, &dev->xfer_avail);
344 if (ret)
345 return ret;
346
347 return dev->xfer_status;
348 }
349
350 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
351 {
352 struct hid_device *hdev = dev->hdev;
353 struct cp2112_force_read_report report;
354 int ret;
355
356 if (size > sizeof(dev->read_data))
357 size = sizeof(dev->read_data);
358 report.report = CP2112_DATA_READ_FORCE_SEND;
359 report.length = cpu_to_be16(size);
360
361 atomic_set(&dev->read_avail, 0);
362
363 ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
364 HID_OUTPUT_REPORT);
365 if (ret < 0) {
366 hid_warn(hdev, "Error requesting data: %d\n", ret);
367 return ret;
368 }
369
370 ret = cp2112_wait(dev, &dev->read_avail);
371 if (ret)
372 return ret;
373
374 hid_dbg(hdev, "read %d of %zd bytes requested\n",
375 dev->read_length, size);
376
377 if (size > dev->read_length)
378 size = dev->read_length;
379
380 memcpy(data, dev->read_data, size);
381 return dev->read_length;
382 }
383
384 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
385 {
386 struct cp2112_read_req_report *report = buf;
387
388 if (length < 1 || length > 512)
389 return -EINVAL;
390
391 report->report = CP2112_DATA_READ_REQUEST;
392 report->slave_address = slave_address << 1;
393 report->length = cpu_to_be16(length);
394 return sizeof(*report);
395 }
396
397 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
398 u8 command, u8 *data, u8 data_length)
399 {
400 struct cp2112_write_read_req_report *report = buf;
401
402 if (length < 1 || length > 512
403 || data_length > sizeof(report->target_address) - 1)
404 return -EINVAL;
405
406 report->report = CP2112_DATA_WRITE_READ_REQUEST;
407 report->slave_address = slave_address << 1;
408 report->length = cpu_to_be16(length);
409 report->target_address_length = data_length + 1;
410 report->target_address[0] = command;
411 memcpy(&report->target_address[1], data, data_length);
412 return data_length + 6;
413 }
414
415 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
416 u8 data_length)
417 {
418 struct cp2112_write_req_report *report = buf;
419
420 if (data_length > sizeof(report->data) - 1)
421 return -EINVAL;
422
423 report->report = CP2112_DATA_WRITE_REQUEST;
424 report->slave_address = slave_address << 1;
425 report->length = data_length + 1;
426 report->data[0] = command;
427 memcpy(&report->data[1], data, data_length);
428 return data_length + 4;
429 }
430
431 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
432 u8 data_length)
433 {
434 struct cp2112_write_req_report *report = buf;
435
436 if (data_length > sizeof(report->data))
437 return -EINVAL;
438
439 report->report = CP2112_DATA_WRITE_REQUEST;
440 report->slave_address = slave_address << 1;
441 report->length = data_length;
442 memcpy(report->data, data, data_length);
443 return data_length + 3;
444 }
445
446 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
447 u8 *addr, int addr_length,
448 int read_length)
449 {
450 struct cp2112_write_read_req_report *report = buf;
451
452 if (read_length < 1 || read_length > 512 ||
453 addr_length > sizeof(report->target_address))
454 return -EINVAL;
455
456 report->report = CP2112_DATA_WRITE_READ_REQUEST;
457 report->slave_address = slave_address << 1;
458 report->length = cpu_to_be16(read_length);
459 report->target_address_length = addr_length;
460 memcpy(report->target_address, addr, addr_length);
461 return addr_length + 5;
462 }
463
464 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
465 int num)
466 {
467 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
468 struct hid_device *hdev = dev->hdev;
469 u8 buf[64];
470 ssize_t count;
471 ssize_t read_length = 0;
472 u8 *read_buf = NULL;
473 unsigned int retries;
474 int ret;
475
476 hid_dbg(hdev, "I2C %d messages\n", num);
477
478 if (num == 1) {
479 if (msgs->flags & I2C_M_RD) {
480 hid_dbg(hdev, "I2C read %#04x len %d\n",
481 msgs->addr, msgs->len);
482 read_length = msgs->len;
483 read_buf = msgs->buf;
484 count = cp2112_read_req(buf, msgs->addr, msgs->len);
485 } else {
486 hid_dbg(hdev, "I2C write %#04x len %d\n",
487 msgs->addr, msgs->len);
488 count = cp2112_i2c_write_req(buf, msgs->addr,
489 msgs->buf, msgs->len);
490 }
491 if (count < 0)
492 return count;
493 } else if (dev->hwversion > 1 && /* no repeated start in rev 1 */
494 num == 2 &&
495 msgs[0].addr == msgs[1].addr &&
496 !(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
497 hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
498 msgs[0].addr, msgs[0].len, msgs[1].len);
499 read_length = msgs[1].len;
500 read_buf = msgs[1].buf;
501 count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
502 msgs[0].buf, msgs[0].len, msgs[1].len);
503 if (count < 0)
504 return count;
505 } else {
506 hid_err(hdev,
507 "Multi-message I2C transactions not supported\n");
508 return -EOPNOTSUPP;
509 }
510
511 ret = hid_hw_power(hdev, PM_HINT_FULLON);
512 if (ret < 0) {
513 hid_err(hdev, "power management error: %d\n", ret);
514 return ret;
515 }
516
517 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
518 if (ret < 0) {
519 hid_warn(hdev, "Error starting transaction: %d\n", ret);
520 goto power_normal;
521 }
522
523 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
524 ret = cp2112_xfer_status(dev);
525 if (-EBUSY == ret)
526 continue;
527 if (ret < 0)
528 goto power_normal;
529 break;
530 }
531
532 if (XFER_STATUS_RETRIES <= retries) {
533 hid_warn(hdev, "Transfer timed out, cancelling.\n");
534 buf[0] = CP2112_CANCEL_TRANSFER;
535 buf[1] = 0x01;
536
537 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
538 if (ret < 0)
539 hid_warn(hdev, "Error cancelling transaction: %d\n",
540 ret);
541
542 ret = -ETIMEDOUT;
543 goto power_normal;
544 }
545
546 for (count = 0; count < read_length;) {
547 ret = cp2112_read(dev, read_buf + count, read_length - count);
548 if (ret < 0)
549 goto power_normal;
550 if (ret == 0) {
551 hid_err(hdev, "read returned 0\n");
552 ret = -EIO;
553 goto power_normal;
554 }
555 count += ret;
556 if (count > read_length) {
557 /*
558 * The hardware returned too much data.
559 * This is mostly harmless because cp2112_read()
560 * has a limit check so didn't overrun our
561 * buffer. Nevertheless, we return an error
562 * because something is seriously wrong and
563 * it shouldn't go unnoticed.
564 */
565 hid_err(hdev, "long read: %d > %zd\n",
566 ret, read_length - count + ret);
567 ret = -EIO;
568 goto power_normal;
569 }
570 }
571
572 /* return the number of transferred messages */
573 ret = num;
574
575 power_normal:
576 hid_hw_power(hdev, PM_HINT_NORMAL);
577 hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
578 return ret;
579 }
580
581 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
582 unsigned short flags, char read_write, u8 command,
583 int size, union i2c_smbus_data *data)
584 {
585 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
586 struct hid_device *hdev = dev->hdev;
587 u8 buf[64];
588 __le16 word;
589 ssize_t count;
590 size_t read_length = 0;
591 unsigned int retries;
592 int ret;
593
594 hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
595 read_write == I2C_SMBUS_WRITE ? "write" : "read",
596 addr, flags, command, size);
597
598 switch (size) {
599 case I2C_SMBUS_BYTE:
600 read_length = 1;
601
602 if (I2C_SMBUS_READ == read_write)
603 count = cp2112_read_req(buf, addr, read_length);
604 else
605 count = cp2112_write_req(buf, addr, command, NULL,
606 0);
607 break;
608 case I2C_SMBUS_BYTE_DATA:
609 read_length = 1;
610
611 if (I2C_SMBUS_READ == read_write)
612 count = cp2112_write_read_req(buf, addr, read_length,
613 command, NULL, 0);
614 else
615 count = cp2112_write_req(buf, addr, command,
616 &data->byte, 1);
617 break;
618 case I2C_SMBUS_WORD_DATA:
619 read_length = 2;
620 word = cpu_to_le16(data->word);
621
622 if (I2C_SMBUS_READ == read_write)
623 count = cp2112_write_read_req(buf, addr, read_length,
624 command, NULL, 0);
625 else
626 count = cp2112_write_req(buf, addr, command,
627 (u8 *)&word, 2);
628 break;
629 case I2C_SMBUS_PROC_CALL:
630 size = I2C_SMBUS_WORD_DATA;
631 read_write = I2C_SMBUS_READ;
632 read_length = 2;
633 word = cpu_to_le16(data->word);
634
635 count = cp2112_write_read_req(buf, addr, read_length, command,
636 (u8 *)&word, 2);
637 break;
638 case I2C_SMBUS_I2C_BLOCK_DATA:
639 size = I2C_SMBUS_BLOCK_DATA;
640 /* fallthrough */
641 case I2C_SMBUS_BLOCK_DATA:
642 if (I2C_SMBUS_READ == read_write) {
643 count = cp2112_write_read_req(buf, addr,
644 I2C_SMBUS_BLOCK_MAX,
645 command, NULL, 0);
646 } else {
647 count = cp2112_write_req(buf, addr, command,
648 data->block,
649 data->block[0] + 1);
650 }
651 break;
652 case I2C_SMBUS_BLOCK_PROC_CALL:
653 size = I2C_SMBUS_BLOCK_DATA;
654 read_write = I2C_SMBUS_READ;
655
656 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
657 command, data->block,
658 data->block[0] + 1);
659 break;
660 default:
661 hid_warn(hdev, "Unsupported transaction %d\n", size);
662 return -EOPNOTSUPP;
663 }
664
665 if (count < 0)
666 return count;
667
668 ret = hid_hw_power(hdev, PM_HINT_FULLON);
669 if (ret < 0) {
670 hid_err(hdev, "power management error: %d\n", ret);
671 return ret;
672 }
673
674 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
675 if (ret < 0) {
676 hid_warn(hdev, "Error starting transaction: %d\n", ret);
677 goto power_normal;
678 }
679
680 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
681 ret = cp2112_xfer_status(dev);
682 if (-EBUSY == ret)
683 continue;
684 if (ret < 0)
685 goto power_normal;
686 break;
687 }
688
689 if (XFER_STATUS_RETRIES <= retries) {
690 hid_warn(hdev, "Transfer timed out, cancelling.\n");
691 buf[0] = CP2112_CANCEL_TRANSFER;
692 buf[1] = 0x01;
693
694 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
695 if (ret < 0)
696 hid_warn(hdev, "Error cancelling transaction: %d\n",
697 ret);
698
699 ret = -ETIMEDOUT;
700 goto power_normal;
701 }
702
703 if (I2C_SMBUS_WRITE == read_write) {
704 ret = 0;
705 goto power_normal;
706 }
707
708 if (I2C_SMBUS_BLOCK_DATA == size)
709 read_length = ret;
710
711 ret = cp2112_read(dev, buf, read_length);
712 if (ret < 0)
713 goto power_normal;
714 if (ret != read_length) {
715 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
716 ret = -EIO;
717 goto power_normal;
718 }
719
720 switch (size) {
721 case I2C_SMBUS_BYTE:
722 case I2C_SMBUS_BYTE_DATA:
723 data->byte = buf[0];
724 break;
725 case I2C_SMBUS_WORD_DATA:
726 data->word = le16_to_cpup((__le16 *)buf);
727 break;
728 case I2C_SMBUS_BLOCK_DATA:
729 if (read_length > I2C_SMBUS_BLOCK_MAX) {
730 ret = -EPROTO;
731 goto power_normal;
732 }
733
734 memcpy(data->block, buf, read_length);
735 break;
736 }
737
738 ret = 0;
739 power_normal:
740 hid_hw_power(hdev, PM_HINT_NORMAL);
741 hid_dbg(hdev, "transfer finished: %d\n", ret);
742 return ret;
743 }
744
745 static u32 cp2112_functionality(struct i2c_adapter *adap)
746 {
747 return I2C_FUNC_I2C |
748 I2C_FUNC_SMBUS_BYTE |
749 I2C_FUNC_SMBUS_BYTE_DATA |
750 I2C_FUNC_SMBUS_WORD_DATA |
751 I2C_FUNC_SMBUS_BLOCK_DATA |
752 I2C_FUNC_SMBUS_I2C_BLOCK |
753 I2C_FUNC_SMBUS_PROC_CALL |
754 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
755 }
756
757 static const struct i2c_algorithm smbus_algorithm = {
758 .master_xfer = cp2112_i2c_xfer,
759 .smbus_xfer = cp2112_xfer,
760 .functionality = cp2112_functionality,
761 };
762
763 static int cp2112_get_usb_config(struct hid_device *hdev,
764 struct cp2112_usb_config_report *cfg)
765 {
766 int ret;
767
768 ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
769 HID_FEATURE_REPORT);
770 if (ret != sizeof(*cfg)) {
771 hid_err(hdev, "error reading usb config: %d\n", ret);
772 if (ret < 0)
773 return ret;
774 return -EIO;
775 }
776
777 return 0;
778 }
779
780 static int cp2112_set_usb_config(struct hid_device *hdev,
781 struct cp2112_usb_config_report *cfg)
782 {
783 int ret;
784
785 BUG_ON(cfg->report != CP2112_USB_CONFIG);
786
787 ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
788 HID_FEATURE_REPORT);
789 if (ret != sizeof(*cfg)) {
790 hid_err(hdev, "error writing usb config: %d\n", ret);
791 if (ret < 0)
792 return ret;
793 return -EIO;
794 }
795
796 return 0;
797 }
798
799 static void chmod_sysfs_attrs(struct hid_device *hdev);
800
801 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
802 static ssize_t name##_store(struct device *kdev, \
803 struct device_attribute *attr, const char *buf, \
804 size_t count) \
805 { \
806 struct hid_device *hdev = to_hid_device(kdev); \
807 struct cp2112_usb_config_report cfg; \
808 int ret = cp2112_get_usb_config(hdev, &cfg); \
809 if (ret) \
810 return ret; \
811 store; \
812 ret = cp2112_set_usb_config(hdev, &cfg); \
813 if (ret) \
814 return ret; \
815 chmod_sysfs_attrs(hdev); \
816 return count; \
817 } \
818 static ssize_t name##_show(struct device *kdev, \
819 struct device_attribute *attr, char *buf) \
820 { \
821 struct hid_device *hdev = to_hid_device(kdev); \
822 struct cp2112_usb_config_report cfg; \
823 int ret = cp2112_get_usb_config(hdev, &cfg); \
824 if (ret) \
825 return ret; \
826 return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
827 } \
828 static DEVICE_ATTR_RW(name);
829
830 CP2112_CONFIG_ATTR(vendor_id, ({
831 u16 vid;
832
833 if (sscanf(buf, "%hi", &vid) != 1)
834 return -EINVAL;
835
836 cfg.vid = cpu_to_le16(vid);
837 cfg.mask = 0x01;
838 }), "0x%04x\n", le16_to_cpu(cfg.vid));
839
840 CP2112_CONFIG_ATTR(product_id, ({
841 u16 pid;
842
843 if (sscanf(buf, "%hi", &pid) != 1)
844 return -EINVAL;
845
846 cfg.pid = cpu_to_le16(pid);
847 cfg.mask = 0x02;
848 }), "0x%04x\n", le16_to_cpu(cfg.pid));
849
850 CP2112_CONFIG_ATTR(max_power, ({
851 int mA;
852
853 if (sscanf(buf, "%i", &mA) != 1)
854 return -EINVAL;
855
856 cfg.max_power = (mA + 1) / 2;
857 cfg.mask = 0x04;
858 }), "%u mA\n", cfg.max_power * 2);
859
860 CP2112_CONFIG_ATTR(power_mode, ({
861 if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
862 return -EINVAL;
863
864 cfg.mask = 0x08;
865 }), "%u\n", cfg.power_mode);
866
867 CP2112_CONFIG_ATTR(release_version, ({
868 if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
869 != 2)
870 return -EINVAL;
871
872 cfg.mask = 0x10;
873 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
874
875 #undef CP2112_CONFIG_ATTR
876
877 struct cp2112_pstring_attribute {
878 struct device_attribute attr;
879 unsigned char report;
880 };
881
882 static ssize_t pstr_store(struct device *kdev,
883 struct device_attribute *kattr, const char *buf,
884 size_t count)
885 {
886 struct hid_device *hdev = to_hid_device(kdev);
887 struct cp2112_pstring_attribute *attr =
888 container_of(kattr, struct cp2112_pstring_attribute, attr);
889 struct cp2112_string_report report;
890 int ret;
891
892 memset(&report, 0, sizeof(report));
893
894 ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
895 report.string, ARRAY_SIZE(report.string));
896 report.report = attr->report;
897 report.length = ret * sizeof(report.string[0]) + 2;
898 report.type = USB_DT_STRING;
899
900 ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
901 HID_FEATURE_REPORT);
902 if (ret != report.length + 1) {
903 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
904 ret);
905 if (ret < 0)
906 return ret;
907 return -EIO;
908 }
909
910 chmod_sysfs_attrs(hdev);
911 return count;
912 }
913
914 static ssize_t pstr_show(struct device *kdev,
915 struct device_attribute *kattr, char *buf)
916 {
917 struct hid_device *hdev = to_hid_device(kdev);
918 struct cp2112_pstring_attribute *attr =
919 container_of(kattr, struct cp2112_pstring_attribute, attr);
920 struct cp2112_string_report report;
921 u8 length;
922 int ret;
923
924 ret = cp2112_hid_get(hdev, attr->report, &report.report,
925 sizeof(report) - 1, HID_FEATURE_REPORT);
926 if (ret < 3) {
927 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
928 ret);
929 if (ret < 0)
930 return ret;
931 return -EIO;
932 }
933
934 if (report.length < 2) {
935 hid_err(hdev, "invalid %s string length: %d\n",
936 kattr->attr.name, report.length);
937 return -EIO;
938 }
939
940 length = report.length > ret - 1 ? ret - 1 : report.length;
941 length = (length - 2) / sizeof(report.string[0]);
942 ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
943 PAGE_SIZE - 1);
944 buf[ret++] = '\n';
945 return ret;
946 }
947
948 #define CP2112_PSTR_ATTR(name, _report) \
949 static struct cp2112_pstring_attribute dev_attr_##name = { \
950 .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
951 .report = _report, \
952 };
953
954 CP2112_PSTR_ATTR(manufacturer, CP2112_MANUFACTURER_STRING);
955 CP2112_PSTR_ATTR(product, CP2112_PRODUCT_STRING);
956 CP2112_PSTR_ATTR(serial, CP2112_SERIAL_STRING);
957
958 #undef CP2112_PSTR_ATTR
959
960 static const struct attribute_group cp2112_attr_group = {
961 .attrs = (struct attribute *[]){
962 &dev_attr_vendor_id.attr,
963 &dev_attr_product_id.attr,
964 &dev_attr_max_power.attr,
965 &dev_attr_power_mode.attr,
966 &dev_attr_release_version.attr,
967 &dev_attr_manufacturer.attr.attr,
968 &dev_attr_product.attr.attr,
969 &dev_attr_serial.attr.attr,
970 NULL
971 }
972 };
973
974 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
975 * PROM have already been programmed. We do not depend on this preventing
976 * writing to these attributes since the CP2112 will simply ignore writes to
977 * already-programmed fields. This is why there is no sense in fixing this
978 * racy behaviour.
979 */
980 static void chmod_sysfs_attrs(struct hid_device *hdev)
981 {
982 struct attribute **attr;
983 u8 buf[2];
984 int ret;
985
986 ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
987 HID_FEATURE_REPORT);
988 if (ret != sizeof(buf)) {
989 hid_err(hdev, "error reading lock byte: %d\n", ret);
990 return;
991 }
992
993 for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
994 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
995 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
996 if (ret < 0)
997 hid_err(hdev, "error chmoding sysfs file %s\n",
998 (*attr)->name);
999 buf[1] >>= 1;
1000 }
1001 }
1002
1003 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1004 {
1005 struct cp2112_device *dev;
1006 u8 buf[3];
1007 struct cp2112_smbus_config_report config;
1008 int ret;
1009
1010 ret = hid_parse(hdev);
1011 if (ret) {
1012 hid_err(hdev, "parse failed\n");
1013 return ret;
1014 }
1015
1016 ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1017 if (ret) {
1018 hid_err(hdev, "hw start failed\n");
1019 return ret;
1020 }
1021
1022 ret = hid_hw_open(hdev);
1023 if (ret) {
1024 hid_err(hdev, "hw open failed\n");
1025 goto err_hid_stop;
1026 }
1027
1028 ret = hid_hw_power(hdev, PM_HINT_FULLON);
1029 if (ret < 0) {
1030 hid_err(hdev, "power management error: %d\n", ret);
1031 goto err_hid_close;
1032 }
1033
1034 ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
1035 HID_FEATURE_REPORT);
1036 if (ret != sizeof(buf)) {
1037 hid_err(hdev, "error requesting version\n");
1038 if (ret >= 0)
1039 ret = -EIO;
1040 goto err_power_normal;
1041 }
1042
1043 hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
1044 buf[1], buf[2]);
1045
1046 ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
1047 sizeof(config), HID_FEATURE_REPORT);
1048 if (ret != sizeof(config)) {
1049 hid_err(hdev, "error requesting SMBus config\n");
1050 if (ret >= 0)
1051 ret = -EIO;
1052 goto err_power_normal;
1053 }
1054
1055 config.retry_time = cpu_to_be16(1);
1056
1057 ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1058 HID_FEATURE_REPORT);
1059 if (ret != sizeof(config)) {
1060 hid_err(hdev, "error setting SMBus config\n");
1061 if (ret >= 0)
1062 ret = -EIO;
1063 goto err_power_normal;
1064 }
1065
1066 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1067 if (!dev) {
1068 ret = -ENOMEM;
1069 goto err_power_normal;
1070 }
1071
1072 hid_set_drvdata(hdev, (void *)dev);
1073 dev->hdev = hdev;
1074 dev->adap.owner = THIS_MODULE;
1075 dev->adap.class = I2C_CLASS_HWMON;
1076 dev->adap.algo = &smbus_algorithm;
1077 dev->adap.algo_data = dev;
1078 dev->adap.dev.parent = &hdev->dev;
1079 snprintf(dev->adap.name, sizeof(dev->adap.name),
1080 "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
1081 dev->hwversion = buf[2];
1082 init_waitqueue_head(&dev->wait);
1083
1084 hid_device_io_start(hdev);
1085 ret = i2c_add_adapter(&dev->adap);
1086 hid_device_io_stop(hdev);
1087
1088 if (ret) {
1089 hid_err(hdev, "error registering i2c adapter\n");
1090 goto err_free_dev;
1091 }
1092
1093 hid_dbg(hdev, "adapter registered\n");
1094
1095 dev->gc.label = "cp2112_gpio";
1096 dev->gc.direction_input = cp2112_gpio_direction_input;
1097 dev->gc.direction_output = cp2112_gpio_direction_output;
1098 dev->gc.set = cp2112_gpio_set;
1099 dev->gc.get = cp2112_gpio_get;
1100 dev->gc.base = -1;
1101 dev->gc.ngpio = 8;
1102 dev->gc.can_sleep = 1;
1103 dev->gc.parent = &hdev->dev;
1104
1105 ret = gpiochip_add_data(&dev->gc, dev);
1106 if (ret < 0) {
1107 hid_err(hdev, "error registering gpio chip\n");
1108 goto err_free_i2c;
1109 }
1110
1111 ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1112 if (ret < 0) {
1113 hid_err(hdev, "error creating sysfs attrs\n");
1114 goto err_gpiochip_remove;
1115 }
1116
1117 chmod_sysfs_attrs(hdev);
1118 hid_hw_power(hdev, PM_HINT_NORMAL);
1119
1120 return ret;
1121
1122 err_gpiochip_remove:
1123 gpiochip_remove(&dev->gc);
1124 err_free_i2c:
1125 i2c_del_adapter(&dev->adap);
1126 err_free_dev:
1127 kfree(dev);
1128 err_power_normal:
1129 hid_hw_power(hdev, PM_HINT_NORMAL);
1130 err_hid_close:
1131 hid_hw_close(hdev);
1132 err_hid_stop:
1133 hid_hw_stop(hdev);
1134 return ret;
1135 }
1136
1137 static void cp2112_remove(struct hid_device *hdev)
1138 {
1139 struct cp2112_device *dev = hid_get_drvdata(hdev);
1140
1141 sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1142 gpiochip_remove(&dev->gc);
1143 i2c_del_adapter(&dev->adap);
1144 /* i2c_del_adapter has finished removing all i2c devices from our
1145 * adapter. Well behaved devices should no longer call our cp2112_xfer
1146 * and should have waited for any pending calls to finish. It has also
1147 * waited for device_unregister(&adap->dev) to complete. Therefore we
1148 * can safely free our struct cp2112_device.
1149 */
1150 hid_hw_close(hdev);
1151 hid_hw_stop(hdev);
1152 kfree(dev);
1153 }
1154
1155 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1156 u8 *data, int size)
1157 {
1158 struct cp2112_device *dev = hid_get_drvdata(hdev);
1159 struct cp2112_xfer_status_report *xfer = (void *)data;
1160
1161 switch (data[0]) {
1162 case CP2112_TRANSFER_STATUS_RESPONSE:
1163 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1164 xfer->status0, xfer->status1,
1165 be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1166
1167 switch (xfer->status0) {
1168 case STATUS0_IDLE:
1169 dev->xfer_status = -EAGAIN;
1170 break;
1171 case STATUS0_BUSY:
1172 dev->xfer_status = -EBUSY;
1173 break;
1174 case STATUS0_COMPLETE:
1175 dev->xfer_status = be16_to_cpu(xfer->length);
1176 break;
1177 case STATUS0_ERROR:
1178 switch (xfer->status1) {
1179 case STATUS1_TIMEOUT_NACK:
1180 case STATUS1_TIMEOUT_BUS:
1181 dev->xfer_status = -ETIMEDOUT;
1182 break;
1183 default:
1184 dev->xfer_status = -EIO;
1185 break;
1186 }
1187 break;
1188 default:
1189 dev->xfer_status = -EINVAL;
1190 break;
1191 }
1192
1193 atomic_set(&dev->xfer_avail, 1);
1194 break;
1195 case CP2112_DATA_READ_RESPONSE:
1196 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1197
1198 dev->read_length = data[2];
1199 if (dev->read_length > sizeof(dev->read_data))
1200 dev->read_length = sizeof(dev->read_data);
1201
1202 memcpy(dev->read_data, &data[3], dev->read_length);
1203 atomic_set(&dev->read_avail, 1);
1204 break;
1205 default:
1206 hid_err(hdev, "unknown report\n");
1207
1208 return 0;
1209 }
1210
1211 wake_up_interruptible(&dev->wait);
1212 return 1;
1213 }
1214
1215 static struct hid_driver cp2112_driver = {
1216 .name = "cp2112",
1217 .id_table = cp2112_devices,
1218 .probe = cp2112_probe,
1219 .remove = cp2112_remove,
1220 .raw_event = cp2112_raw_event,
1221 };
1222
1223 module_hid_driver(cp2112_driver);
1224 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1225 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1226 MODULE_LICENSE("GPL");
1227
Linux with added FPC-III support