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>
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.
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
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.
22 * http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf
23 * Programming Interface Specification:
24 * http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf
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>
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,
59 STATUS0_COMPLETE = 0x02,
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,
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 */
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 */
93 u8 mask; /* What fields to program */
96 struct cp2112_read_req_report {
97 u8 report; /* CP2112_DATA_READ_REQUEST */
102 struct cp2112_write_read_req_report {
103 u8 report; /* CP2112_DATA_WRITE_READ_REQUEST */
106 u8 target_address_length;
107 u8 target_address[16];
110 struct cp2112_write_req_report {
111 u8 report; /* CP2112_DATA_WRITE_REQUEST */
117 struct cp2112_force_read_report {
118 u8 report; /* CP2112_DATA_READ_FORCE_SEND */
122 struct cp2112_xfer_status_report {
123 u8 report; /* CP2112_TRANSFER_STATUS_RESPONSE */
124 u8 status0; /* STATUS0_* */
125 u8 status1; /* STATUS1_* */
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 */
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;
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;
147 static const struct hid_device_id cp2112_devices[] = {
148 { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
151 MODULE_DEVICE_TABLE(hid, cp2112_devices);
153 struct cp2112_device {
154 struct i2c_adapter adap;
155 struct hid_device *hdev;
156 wait_queue_head_t wait;
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");
170 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
172 struct cp2112_device *dev = gpiochip_get_data(chip);
173 struct hid_device *hdev = dev->hdev;
177 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
178 sizeof(buf), HID_FEATURE_REPORT,
180 if (ret != sizeof(buf)) {
181 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
185 buf[1] &= ~(1 << offset);
186 buf[2] = gpio_push_pull;
188 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
189 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
191 hid_err(hdev, "error setting GPIO config: %d\n", ret);
198 static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
200 struct cp2112_device *dev = gpiochip_get_data(chip);
201 struct hid_device *hdev = dev->hdev;
205 buf[0] = CP2112_GPIO_SET;
206 buf[1] = value ? 0xff : 0;
207 buf[2] = 1 << offset;
209 ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf),
210 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
212 hid_err(hdev, "error setting GPIO values: %d\n", ret);
215 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset)
217 struct cp2112_device *dev = gpiochip_get_data(chip);
218 struct hid_device *hdev = dev->hdev;
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);
229 return (buf[1] >> offset) & 1;
232 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
233 unsigned offset, int value)
235 struct cp2112_device *dev = gpiochip_get_data(chip);
236 struct hid_device *hdev = dev->hdev;
240 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
241 sizeof(buf), HID_FEATURE_REPORT,
243 if (ret != sizeof(buf)) {
244 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
248 buf[1] |= 1 << offset;
249 buf[2] = gpio_push_pull;
251 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
252 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
254 hid_err(hdev, "error setting GPIO config: %d\n", ret);
259 * Set gpio value when output direction is already set,
260 * as specified in AN495, Rev. 0.2, cpt. 4.4
262 cp2112_gpio_set(chip, offset, value);
267 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
268 u8 *data, size_t count, unsigned char report_type)
273 buf = kmalloc(count, GFP_KERNEL);
277 ret = hid_hw_raw_request(hdev, report_number, buf, count,
278 report_type, HID_REQ_GET_REPORT);
279 memcpy(data, buf, count);
284 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
285 unsigned char report_type)
290 buf = kmemdup(data, count, GFP_KERNEL);
294 if (report_type == HID_OUTPUT_REPORT)
295 ret = hid_hw_output_report(hdev, buf, count);
297 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
304 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
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.
316 ret = wait_event_interruptible_timeout(dev->wait,
317 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
318 if (-ERESTARTSYS == ret)
323 atomic_set(avail, 0);
327 static int cp2112_xfer_status(struct cp2112_device *dev)
329 struct hid_device *hdev = dev->hdev;
333 buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
335 atomic_set(&dev->xfer_avail, 0);
337 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
339 hid_warn(hdev, "Error requesting status: %d\n", ret);
343 ret = cp2112_wait(dev, &dev->xfer_avail);
347 return dev->xfer_status;
350 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
352 struct hid_device *hdev = dev->hdev;
353 struct cp2112_force_read_report report;
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);
361 atomic_set(&dev->read_avail, 0);
363 ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
366 hid_warn(hdev, "Error requesting data: %d\n", ret);
370 ret = cp2112_wait(dev, &dev->read_avail);
374 hid_dbg(hdev, "read %d of %zd bytes requested\n",
375 dev->read_length, size);
377 if (size > dev->read_length)
378 size = dev->read_length;
380 memcpy(data, dev->read_data, size);
381 return dev->read_length;
384 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
386 struct cp2112_read_req_report *report = buf;
388 if (length < 1 || length > 512)
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);
397 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
398 u8 command, u8 *data, u8 data_length)
400 struct cp2112_write_read_req_report *report = buf;
402 if (length < 1 || length > 512
403 || data_length > sizeof(report->target_address) - 1)
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;
415 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
418 struct cp2112_write_req_report *report = buf;
420 if (data_length > sizeof(report->data) - 1)
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;
431 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
434 struct cp2112_write_req_report *report = buf;
436 if (data_length > sizeof(report->data))
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;
446 static int cp2112_i2c_write_read_req(void *buf, u8 slave_address,
447 u8 *addr, int addr_length,
450 struct cp2112_write_read_req_report *report = buf;
452 if (read_length < 1 || read_length > 512 ||
453 addr_length > sizeof(report->target_address))
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;
464 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
467 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
468 struct hid_device *hdev = dev->hdev;
471 ssize_t read_length = 0;
473 unsigned int retries;
476 hid_dbg(hdev, "I2C %d messages\n", num);
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);
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);
493 } else if (dev->hwversion > 1 && /* no repeated start in rev 1 */
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);
507 "Multi-message I2C transactions not supported\n");
511 ret = hid_hw_power(hdev, PM_HINT_FULLON);
513 hid_err(hdev, "power management error: %d\n", ret);
517 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
519 hid_warn(hdev, "Error starting transaction: %d\n", ret);
523 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
524 ret = cp2112_xfer_status(dev);
532 if (XFER_STATUS_RETRIES <= retries) {
533 hid_warn(hdev, "Transfer timed out, cancelling.\n");
534 buf[0] = CP2112_CANCEL_TRANSFER;
537 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
539 hid_warn(hdev, "Error cancelling transaction: %d\n",
546 for (count = 0; count < read_length;) {
547 ret = cp2112_read(dev, read_buf + count, read_length - count);
551 hid_err(hdev, "read returned 0\n");
556 if (count > read_length) {
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.
565 hid_err(hdev, "long read: %d > %zd\n",
566 ret, read_length - count + ret);
572 /* return the number of transferred messages */
576 hid_hw_power(hdev, PM_HINT_NORMAL);
577 hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
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)
585 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
586 struct hid_device *hdev = dev->hdev;
590 size_t read_length = 0;
591 unsigned int retries;
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);
602 if (I2C_SMBUS_READ == read_write)
603 count = cp2112_read_req(buf, addr, read_length);
605 count = cp2112_write_req(buf, addr, command, NULL,
608 case I2C_SMBUS_BYTE_DATA:
611 if (I2C_SMBUS_READ == read_write)
612 count = cp2112_write_read_req(buf, addr, read_length,
615 count = cp2112_write_req(buf, addr, command,
618 case I2C_SMBUS_WORD_DATA:
620 word = cpu_to_le16(data->word);
622 if (I2C_SMBUS_READ == read_write)
623 count = cp2112_write_read_req(buf, addr, read_length,
626 count = cp2112_write_req(buf, addr, command,
629 case I2C_SMBUS_PROC_CALL:
630 size = I2C_SMBUS_WORD_DATA;
631 read_write = I2C_SMBUS_READ;
633 word = cpu_to_le16(data->word);
635 count = cp2112_write_read_req(buf, addr, read_length, command,
638 case I2C_SMBUS_I2C_BLOCK_DATA:
639 size = I2C_SMBUS_BLOCK_DATA;
641 case I2C_SMBUS_BLOCK_DATA:
642 if (I2C_SMBUS_READ == read_write) {
643 count = cp2112_write_read_req(buf, addr,
647 count = cp2112_write_req(buf, addr, command,
652 case I2C_SMBUS_BLOCK_PROC_CALL:
653 size = I2C_SMBUS_BLOCK_DATA;
654 read_write = I2C_SMBUS_READ;
656 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
657 command, data->block,
661 hid_warn(hdev, "Unsupported transaction %d\n", size);
668 ret = hid_hw_power(hdev, PM_HINT_FULLON);
670 hid_err(hdev, "power management error: %d\n", ret);
674 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
676 hid_warn(hdev, "Error starting transaction: %d\n", ret);
680 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
681 ret = cp2112_xfer_status(dev);
689 if (XFER_STATUS_RETRIES <= retries) {
690 hid_warn(hdev, "Transfer timed out, cancelling.\n");
691 buf[0] = CP2112_CANCEL_TRANSFER;
694 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
696 hid_warn(hdev, "Error cancelling transaction: %d\n",
703 if (I2C_SMBUS_WRITE == read_write) {
708 if (I2C_SMBUS_BLOCK_DATA == size)
711 ret = cp2112_read(dev, buf, read_length);
714 if (ret != read_length) {
715 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
722 case I2C_SMBUS_BYTE_DATA:
725 case I2C_SMBUS_WORD_DATA:
726 data->word = le16_to_cpup((__le16 *)buf);
728 case I2C_SMBUS_BLOCK_DATA:
729 if (read_length > I2C_SMBUS_BLOCK_MAX) {
734 memcpy(data->block, buf, read_length);
740 hid_hw_power(hdev, PM_HINT_NORMAL);
741 hid_dbg(hdev, "transfer finished: %d\n", ret);
745 static u32 cp2112_functionality(struct i2c_adapter *adap)
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;
757 static const struct i2c_algorithm smbus_algorithm = {
758 .master_xfer = cp2112_i2c_xfer,
759 .smbus_xfer = cp2112_xfer,
760 .functionality = cp2112_functionality,
763 static int cp2112_get_usb_config(struct hid_device *hdev,
764 struct cp2112_usb_config_report *cfg)
768 ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
770 if (ret != sizeof(*cfg)) {
771 hid_err(hdev, "error reading usb config: %d\n", ret);
780 static int cp2112_set_usb_config(struct hid_device *hdev,
781 struct cp2112_usb_config_report *cfg)
785 BUG_ON(cfg->report != CP2112_USB_CONFIG);
787 ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
789 if (ret != sizeof(*cfg)) {
790 hid_err(hdev, "error writing usb config: %d\n", ret);
799 static void chmod_sysfs_attrs(struct hid_device *hdev);
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, \
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); \
812 ret = cp2112_set_usb_config(hdev, &cfg); \
815 chmod_sysfs_attrs(hdev); \
818 static ssize_t name##_show(struct device *kdev, \
819 struct device_attribute *attr, char *buf) \
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); \
826 return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
828 static DEVICE_ATTR_RW(name);
830 CP2112_CONFIG_ATTR(vendor_id, ({
833 if (sscanf(buf, "%hi", &vid) != 1)
836 cfg.vid = cpu_to_le16(vid);
838 }), "0x%04x\n", le16_to_cpu(cfg.vid));
840 CP2112_CONFIG_ATTR(product_id, ({
843 if (sscanf(buf, "%hi", &pid) != 1)
846 cfg.pid = cpu_to_le16(pid);
848 }), "0x%04x\n", le16_to_cpu(cfg.pid));
850 CP2112_CONFIG_ATTR(max_power, ({
853 if (sscanf(buf, "%i", &mA) != 1)
856 cfg.max_power = (mA + 1) / 2;
858 }), "%u mA\n", cfg.max_power * 2);
860 CP2112_CONFIG_ATTR(power_mode, ({
861 if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
865 }), "%u\n", cfg.power_mode);
867 CP2112_CONFIG_ATTR(release_version, ({
868 if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
873 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
875 #undef CP2112_CONFIG_ATTR
877 struct cp2112_pstring_attribute {
878 struct device_attribute attr;
879 unsigned char report;
882 static ssize_t pstr_store(struct device *kdev,
883 struct device_attribute *kattr, const char *buf,
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;
892 memset(&report, 0, sizeof(report));
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;
900 ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
902 if (ret != report.length + 1) {
903 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
910 chmod_sysfs_attrs(hdev);
914 static ssize_t pstr_show(struct device *kdev,
915 struct device_attribute *kattr, char *buf)
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;
924 ret = cp2112_hid_get(hdev, attr->report, &report.report,
925 sizeof(report) - 1, HID_FEATURE_REPORT);
927 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
934 if (report.length < 2) {
935 hid_err(hdev, "invalid %s string length: %d\n",
936 kattr->attr.name, report.length);
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,
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), \
954 CP2112_PSTR_ATTR(manufacturer, CP2112_MANUFACTURER_STRING);
955 CP2112_PSTR_ATTR(product, CP2112_PRODUCT_STRING);
956 CP2112_PSTR_ATTR(serial, CP2112_SERIAL_STRING);
958 #undef CP2112_PSTR_ATTR
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,
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
980 static void chmod_sysfs_attrs(struct hid_device *hdev)
982 struct attribute **attr;
986 ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
988 if (ret != sizeof(buf)) {
989 hid_err(hdev, "error reading lock byte: %d\n", ret);
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);
997 hid_err(hdev, "error chmoding sysfs file %s\n",
1003 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
1005 struct cp2112_device *dev;
1007 struct cp2112_smbus_config_report config;
1010 ret = hid_parse(hdev);
1012 hid_err(hdev, "parse failed\n");
1016 ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
1018 hid_err(hdev, "hw start failed\n");
1022 ret = hid_hw_open(hdev);
1024 hid_err(hdev, "hw open failed\n");
1028 ret = hid_hw_power(hdev, PM_HINT_FULLON);
1030 hid_err(hdev, "power management error: %d\n", ret);
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");
1040 goto err_power_normal;
1043 hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
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");
1052 goto err_power_normal;
1055 config.retry_time = cpu_to_be16(1);
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");
1063 goto err_power_normal;
1066 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1069 goto err_power_normal;
1072 hid_set_drvdata(hdev, (void *)dev);
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);
1084 hid_device_io_start(hdev);
1085 ret = i2c_add_adapter(&dev->adap);
1086 hid_device_io_stop(hdev);
1089 hid_err(hdev, "error registering i2c adapter\n");
1093 hid_dbg(hdev, "adapter registered\n");
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;
1102 dev->gc.can_sleep = 1;
1103 dev->gc.parent = &hdev->dev;
1105 ret = gpiochip_add_data(&dev->gc, dev);
1107 hid_err(hdev, "error registering gpio chip\n");
1111 ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1113 hid_err(hdev, "error creating sysfs attrs\n");
1114 goto err_gpiochip_remove;
1117 chmod_sysfs_attrs(hdev);
1118 hid_hw_power(hdev, PM_HINT_NORMAL);
1122 err_gpiochip_remove:
1123 gpiochip_remove(&dev->gc);
1125 i2c_del_adapter(&dev->adap);
1129 hid_hw_power(hdev, PM_HINT_NORMAL);
1137 static void cp2112_remove(struct hid_device *hdev)
1139 struct cp2112_device *dev = hid_get_drvdata(hdev);
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.
1155 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1158 struct cp2112_device *dev = hid_get_drvdata(hdev);
1159 struct cp2112_xfer_status_report *xfer = (void *)data;
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));
1167 switch (xfer->status0) {
1169 dev->xfer_status = -EAGAIN;
1172 dev->xfer_status = -EBUSY;
1174 case STATUS0_COMPLETE:
1175 dev->xfer_status = be16_to_cpu(xfer->length);
1178 switch (xfer->status1) {
1179 case STATUS1_TIMEOUT_NACK:
1180 case STATUS1_TIMEOUT_BUS:
1181 dev->xfer_status = -ETIMEDOUT;
1184 dev->xfer_status = -EIO;
1189 dev->xfer_status = -EINVAL;
1193 atomic_set(&dev->xfer_avail, 1);
1195 case CP2112_DATA_READ_RESPONSE:
1196 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1198 dev->read_length = data[2];
1199 if (dev->read_length > sizeof(dev->read_data))
1200 dev->read_length = sizeof(dev->read_data);
1202 memcpy(dev->read_data, &data[3], dev->read_length);
1203 atomic_set(&dev->read_avail, 1);
1206 hid_err(hdev, "unknown report\n");
1211 wake_up_interruptible(&dev->wait);
1215 static struct hid_driver cp2112_driver = {
1217 .id_table = cp2112_devices,
1218 .probe = cp2112_probe,
1219 .remove = cp2112_remove,
1220 .raw_event = cp2112_raw_event,
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");