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.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;
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");
169 static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
171 struct cp2112_device *dev = container_of(chip, struct cp2112_device,
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 = container_of(chip, struct cp2112_device,
202 struct hid_device *hdev = dev->hdev;
206 buf[0] = CP2112_GPIO_SET;
207 buf[1] = value ? 0xff : 0;
208 buf[2] = 1 << offset;
210 ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf),
211 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
213 hid_err(hdev, "error setting GPIO values: %d\n", ret);
216 static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset)
218 struct cp2112_device *dev = container_of(chip, struct cp2112_device,
220 struct hid_device *hdev = dev->hdev;
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);
231 return (buf[1] >> offset) & 1;
234 static int cp2112_gpio_direction_output(struct gpio_chip *chip,
235 unsigned offset, int value)
237 struct cp2112_device *dev = container_of(chip, struct cp2112_device,
239 struct hid_device *hdev = dev->hdev;
243 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
244 sizeof(buf), HID_FEATURE_REPORT,
246 if (ret != sizeof(buf)) {
247 hid_err(hdev, "error requesting GPIO config: %d\n", ret);
251 buf[1] |= 1 << offset;
252 buf[2] = gpio_push_pull;
254 ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf),
255 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
257 hid_err(hdev, "error setting GPIO config: %d\n", ret);
262 * Set gpio value when output direction is already set,
263 * as specified in AN495, Rev. 0.2, cpt. 4.4
265 cp2112_gpio_set(chip, offset, value);
270 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,
271 u8 *data, size_t count, unsigned char report_type)
276 buf = kmalloc(count, GFP_KERNEL);
280 ret = hid_hw_raw_request(hdev, report_number, buf, count,
281 report_type, HID_REQ_GET_REPORT);
282 memcpy(data, buf, count);
287 static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count,
288 unsigned char report_type)
293 buf = kmemdup(data, count, GFP_KERNEL);
297 if (report_type == HID_OUTPUT_REPORT)
298 ret = hid_hw_output_report(hdev, buf, count);
300 ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type,
307 static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail)
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.
319 ret = wait_event_interruptible_timeout(dev->wait,
320 atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT));
321 if (-ERESTARTSYS == ret)
326 atomic_set(avail, 0);
330 static int cp2112_xfer_status(struct cp2112_device *dev)
332 struct hid_device *hdev = dev->hdev;
336 buf[0] = CP2112_TRANSFER_STATUS_REQUEST;
338 atomic_set(&dev->xfer_avail, 0);
340 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
342 hid_warn(hdev, "Error requesting status: %d\n", ret);
346 ret = cp2112_wait(dev, &dev->xfer_avail);
350 return dev->xfer_status;
353 static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size)
355 struct hid_device *hdev = dev->hdev;
356 struct cp2112_force_read_report report;
359 report.report = CP2112_DATA_READ_FORCE_SEND;
360 report.length = cpu_to_be16(size);
362 atomic_set(&dev->read_avail, 0);
364 ret = cp2112_hid_output(hdev, &report.report, sizeof(report),
367 hid_warn(hdev, "Error requesting data: %d\n", ret);
371 ret = cp2112_wait(dev, &dev->read_avail);
375 hid_dbg(hdev, "read %d of %zd bytes requested\n",
376 dev->read_length, size);
378 if (size > dev->read_length)
379 size = dev->read_length;
381 memcpy(data, dev->read_data, size);
382 return dev->read_length;
385 static int cp2112_read_req(void *buf, u8 slave_address, u16 length)
387 struct cp2112_read_req_report *report = buf;
389 if (length < 1 || length > 512)
392 report->report = CP2112_DATA_READ_REQUEST;
393 report->slave_address = slave_address << 1;
394 report->length = cpu_to_be16(length);
395 return sizeof(*report);
398 static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length,
399 u8 command, u8 *data, u8 data_length)
401 struct cp2112_write_read_req_report *report = buf;
403 if (length < 1 || length > 512
404 || data_length > sizeof(report->target_address) - 1)
407 report->report = CP2112_DATA_WRITE_READ_REQUEST;
408 report->slave_address = slave_address << 1;
409 report->length = cpu_to_be16(length);
410 report->target_address_length = data_length + 1;
411 report->target_address[0] = command;
412 memcpy(&report->target_address[1], data, data_length);
413 return data_length + 6;
416 static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data,
419 struct cp2112_write_req_report *report = buf;
421 if (data_length > sizeof(report->data) - 1)
424 report->report = CP2112_DATA_WRITE_REQUEST;
425 report->slave_address = slave_address << 1;
426 report->length = data_length + 1;
427 report->data[0] = command;
428 memcpy(&report->data[1], data, data_length);
429 return data_length + 4;
432 static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data,
435 struct cp2112_write_req_report *report = buf;
437 if (data_length > sizeof(report->data))
440 report->report = CP2112_DATA_WRITE_REQUEST;
441 report->slave_address = slave_address << 1;
442 report->length = data_length;
443 memcpy(report->data, data, data_length);
444 return data_length + 3;
447 static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
450 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
451 struct hid_device *hdev = dev->hdev;
454 unsigned int retries;
457 hid_dbg(hdev, "I2C %d messages\n", num);
461 "Multi-message I2C transactions not supported\n");
465 if (msgs->flags & I2C_M_RD)
466 count = cp2112_read_req(buf, msgs->addr, msgs->len);
468 count = cp2112_i2c_write_req(buf, msgs->addr, msgs->buf,
474 ret = hid_hw_power(hdev, PM_HINT_FULLON);
476 hid_err(hdev, "power management error: %d\n", ret);
480 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
482 hid_warn(hdev, "Error starting transaction: %d\n", ret);
486 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
487 ret = cp2112_xfer_status(dev);
495 if (XFER_STATUS_RETRIES <= retries) {
496 hid_warn(hdev, "Transfer timed out, cancelling.\n");
497 buf[0] = CP2112_CANCEL_TRANSFER;
500 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
502 hid_warn(hdev, "Error cancelling transaction: %d\n",
509 if (!(msgs->flags & I2C_M_RD))
512 ret = cp2112_read(dev, msgs->buf, msgs->len);
515 if (ret != msgs->len) {
516 hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len);
522 /* return the number of transferred messages */
526 hid_hw_power(hdev, PM_HINT_NORMAL);
527 hid_dbg(hdev, "I2C transfer finished: %d\n", ret);
531 static int cp2112_xfer(struct i2c_adapter *adap, u16 addr,
532 unsigned short flags, char read_write, u8 command,
533 int size, union i2c_smbus_data *data)
535 struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data;
536 struct hid_device *hdev = dev->hdev;
540 size_t read_length = 0;
541 unsigned int retries;
544 hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n",
545 read_write == I2C_SMBUS_WRITE ? "write" : "read",
546 addr, flags, command, size);
552 if (I2C_SMBUS_READ == read_write)
553 count = cp2112_read_req(buf, addr, read_length);
555 count = cp2112_write_req(buf, addr, data->byte, NULL,
558 case I2C_SMBUS_BYTE_DATA:
561 if (I2C_SMBUS_READ == read_write)
562 count = cp2112_write_read_req(buf, addr, read_length,
565 count = cp2112_write_req(buf, addr, command,
568 case I2C_SMBUS_WORD_DATA:
570 word = cpu_to_be16(data->word);
572 if (I2C_SMBUS_READ == read_write)
573 count = cp2112_write_read_req(buf, addr, read_length,
576 count = cp2112_write_req(buf, addr, command,
579 case I2C_SMBUS_PROC_CALL:
580 size = I2C_SMBUS_WORD_DATA;
581 read_write = I2C_SMBUS_READ;
583 word = cpu_to_be16(data->word);
585 count = cp2112_write_read_req(buf, addr, read_length, command,
588 case I2C_SMBUS_I2C_BLOCK_DATA:
589 size = I2C_SMBUS_BLOCK_DATA;
591 case I2C_SMBUS_BLOCK_DATA:
592 if (I2C_SMBUS_READ == read_write) {
593 count = cp2112_write_read_req(buf, addr,
597 count = cp2112_write_req(buf, addr, command,
602 case I2C_SMBUS_BLOCK_PROC_CALL:
603 size = I2C_SMBUS_BLOCK_DATA;
604 read_write = I2C_SMBUS_READ;
606 count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX,
607 command, data->block,
611 hid_warn(hdev, "Unsupported transaction %d\n", size);
618 ret = hid_hw_power(hdev, PM_HINT_FULLON);
620 hid_err(hdev, "power management error: %d\n", ret);
624 ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT);
626 hid_warn(hdev, "Error starting transaction: %d\n", ret);
630 for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) {
631 ret = cp2112_xfer_status(dev);
639 if (XFER_STATUS_RETRIES <= retries) {
640 hid_warn(hdev, "Transfer timed out, cancelling.\n");
641 buf[0] = CP2112_CANCEL_TRANSFER;
644 ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT);
646 hid_warn(hdev, "Error cancelling transaction: %d\n",
653 if (I2C_SMBUS_WRITE == read_write) {
658 if (I2C_SMBUS_BLOCK_DATA == size)
661 ret = cp2112_read(dev, buf, read_length);
664 if (ret != read_length) {
665 hid_warn(hdev, "short read: %d < %zd\n", ret, read_length);
672 case I2C_SMBUS_BYTE_DATA:
675 case I2C_SMBUS_WORD_DATA:
676 data->word = be16_to_cpup((__be16 *)buf);
678 case I2C_SMBUS_BLOCK_DATA:
679 if (read_length > I2C_SMBUS_BLOCK_MAX) {
684 memcpy(data->block, buf, read_length);
690 hid_hw_power(hdev, PM_HINT_NORMAL);
691 hid_dbg(hdev, "transfer finished: %d\n", ret);
695 static u32 cp2112_functionality(struct i2c_adapter *adap)
697 return I2C_FUNC_I2C |
698 I2C_FUNC_SMBUS_BYTE |
699 I2C_FUNC_SMBUS_BYTE_DATA |
700 I2C_FUNC_SMBUS_WORD_DATA |
701 I2C_FUNC_SMBUS_BLOCK_DATA |
702 I2C_FUNC_SMBUS_I2C_BLOCK |
703 I2C_FUNC_SMBUS_PROC_CALL |
704 I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
707 static const struct i2c_algorithm smbus_algorithm = {
708 .master_xfer = cp2112_i2c_xfer,
709 .smbus_xfer = cp2112_xfer,
710 .functionality = cp2112_functionality,
713 static int cp2112_get_usb_config(struct hid_device *hdev,
714 struct cp2112_usb_config_report *cfg)
718 ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg),
720 if (ret != sizeof(*cfg)) {
721 hid_err(hdev, "error reading usb config: %d\n", ret);
730 static int cp2112_set_usb_config(struct hid_device *hdev,
731 struct cp2112_usb_config_report *cfg)
735 BUG_ON(cfg->report != CP2112_USB_CONFIG);
737 ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg),
739 if (ret != sizeof(*cfg)) {
740 hid_err(hdev, "error writing usb config: %d\n", ret);
749 static void chmod_sysfs_attrs(struct hid_device *hdev);
751 #define CP2112_CONFIG_ATTR(name, store, format, ...) \
752 static ssize_t name##_store(struct device *kdev, \
753 struct device_attribute *attr, const char *buf, \
756 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
757 struct cp2112_usb_config_report cfg; \
758 int ret = cp2112_get_usb_config(hdev, &cfg); \
762 ret = cp2112_set_usb_config(hdev, &cfg); \
765 chmod_sysfs_attrs(hdev); \
768 static ssize_t name##_show(struct device *kdev, \
769 struct device_attribute *attr, char *buf) \
771 struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \
772 struct cp2112_usb_config_report cfg; \
773 int ret = cp2112_get_usb_config(hdev, &cfg); \
776 return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \
778 static DEVICE_ATTR_RW(name);
780 CP2112_CONFIG_ATTR(vendor_id, ({
783 if (sscanf(buf, "%hi", &vid) != 1)
786 cfg.vid = cpu_to_le16(vid);
788 }), "0x%04x\n", le16_to_cpu(cfg.vid));
790 CP2112_CONFIG_ATTR(product_id, ({
793 if (sscanf(buf, "%hi", &pid) != 1)
796 cfg.pid = cpu_to_le16(pid);
798 }), "0x%04x\n", le16_to_cpu(cfg.pid));
800 CP2112_CONFIG_ATTR(max_power, ({
803 if (sscanf(buf, "%i", &mA) != 1)
806 cfg.max_power = (mA + 1) / 2;
808 }), "%u mA\n", cfg.max_power * 2);
810 CP2112_CONFIG_ATTR(power_mode, ({
811 if (sscanf(buf, "%hhi", &cfg.power_mode) != 1)
815 }), "%u\n", cfg.power_mode);
817 CP2112_CONFIG_ATTR(release_version, ({
818 if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor)
823 }), "%u.%u\n", cfg.release_major, cfg.release_minor);
825 #undef CP2112_CONFIG_ATTR
827 struct cp2112_pstring_attribute {
828 struct device_attribute attr;
829 unsigned char report;
832 static ssize_t pstr_store(struct device *kdev,
833 struct device_attribute *kattr, const char *buf,
836 struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
837 struct cp2112_pstring_attribute *attr =
838 container_of(kattr, struct cp2112_pstring_attribute, attr);
839 struct cp2112_string_report report;
842 memset(&report, 0, sizeof(report));
844 ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN,
845 report.string, ARRAY_SIZE(report.string));
846 report.report = attr->report;
847 report.length = ret * sizeof(report.string[0]) + 2;
848 report.type = USB_DT_STRING;
850 ret = cp2112_hid_output(hdev, &report.report, report.length + 1,
852 if (ret != report.length + 1) {
853 hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name,
860 chmod_sysfs_attrs(hdev);
864 static ssize_t pstr_show(struct device *kdev,
865 struct device_attribute *kattr, char *buf)
867 struct hid_device *hdev = container_of(kdev, struct hid_device, dev);
868 struct cp2112_pstring_attribute *attr =
869 container_of(kattr, struct cp2112_pstring_attribute, attr);
870 struct cp2112_string_report report;
874 ret = cp2112_hid_get(hdev, attr->report, &report.report,
875 sizeof(report) - 1, HID_FEATURE_REPORT);
877 hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name,
884 if (report.length < 2) {
885 hid_err(hdev, "invalid %s string length: %d\n",
886 kattr->attr.name, report.length);
890 length = report.length > ret - 1 ? ret - 1 : report.length;
891 length = (length - 2) / sizeof(report.string[0]);
892 ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf,
898 #define CP2112_PSTR_ATTR(name, _report) \
899 static struct cp2112_pstring_attribute dev_attr_##name = { \
900 .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \
904 CP2112_PSTR_ATTR(manufacturer, CP2112_MANUFACTURER_STRING);
905 CP2112_PSTR_ATTR(product, CP2112_PRODUCT_STRING);
906 CP2112_PSTR_ATTR(serial, CP2112_SERIAL_STRING);
908 #undef CP2112_PSTR_ATTR
910 static const struct attribute_group cp2112_attr_group = {
911 .attrs = (struct attribute *[]){
912 &dev_attr_vendor_id.attr,
913 &dev_attr_product_id.attr,
914 &dev_attr_max_power.attr,
915 &dev_attr_power_mode.attr,
916 &dev_attr_release_version.attr,
917 &dev_attr_manufacturer.attr.attr,
918 &dev_attr_product.attr.attr,
919 &dev_attr_serial.attr.attr,
924 /* Chmoding our sysfs attributes is simply a way to expose which fields in the
925 * PROM have already been programmed. We do not depend on this preventing
926 * writing to these attributes since the CP2112 will simply ignore writes to
927 * already-programmed fields. This is why there is no sense in fixing this
930 static void chmod_sysfs_attrs(struct hid_device *hdev)
932 struct attribute **attr;
936 ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf),
938 if (ret != sizeof(buf)) {
939 hid_err(hdev, "error reading lock byte: %d\n", ret);
943 for (attr = cp2112_attr_group.attrs; *attr; ++attr) {
944 umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO;
945 ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode);
947 hid_err(hdev, "error chmoding sysfs file %s\n",
953 static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
955 struct cp2112_device *dev;
957 struct cp2112_smbus_config_report config;
960 ret = hid_parse(hdev);
962 hid_err(hdev, "parse failed\n");
966 ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW);
968 hid_err(hdev, "hw start failed\n");
972 ret = hid_hw_open(hdev);
974 hid_err(hdev, "hw open failed\n");
978 ret = hid_hw_power(hdev, PM_HINT_FULLON);
980 hid_err(hdev, "power management error: %d\n", ret);
984 ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf),
986 if (ret != sizeof(buf)) {
987 hid_err(hdev, "error requesting version\n");
990 goto err_power_normal;
993 hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
996 ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config,
997 sizeof(config), HID_FEATURE_REPORT);
998 if (ret != sizeof(config)) {
999 hid_err(hdev, "error requesting SMBus config\n");
1002 goto err_power_normal;
1005 config.retry_time = cpu_to_be16(1);
1007 ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config),
1008 HID_FEATURE_REPORT);
1009 if (ret != sizeof(config)) {
1010 hid_err(hdev, "error setting SMBus config\n");
1013 goto err_power_normal;
1016 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1019 goto err_power_normal;
1022 hid_set_drvdata(hdev, (void *)dev);
1024 dev->adap.owner = THIS_MODULE;
1025 dev->adap.class = I2C_CLASS_HWMON;
1026 dev->adap.algo = &smbus_algorithm;
1027 dev->adap.algo_data = dev;
1028 dev->adap.dev.parent = &hdev->dev;
1029 snprintf(dev->adap.name, sizeof(dev->adap.name),
1030 "CP2112 SMBus Bridge on hiddev%d", hdev->minor);
1031 init_waitqueue_head(&dev->wait);
1033 hid_device_io_start(hdev);
1034 ret = i2c_add_adapter(&dev->adap);
1035 hid_device_io_stop(hdev);
1038 hid_err(hdev, "error registering i2c adapter\n");
1042 hid_dbg(hdev, "adapter registered\n");
1044 dev->gc.label = "cp2112_gpio";
1045 dev->gc.direction_input = cp2112_gpio_direction_input;
1046 dev->gc.direction_output = cp2112_gpio_direction_output;
1047 dev->gc.set = cp2112_gpio_set;
1048 dev->gc.get = cp2112_gpio_get;
1051 dev->gc.can_sleep = 1;
1052 dev->gc.dev = &hdev->dev;
1054 ret = gpiochip_add(&dev->gc);
1056 hid_err(hdev, "error registering gpio chip\n");
1060 ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group);
1062 hid_err(hdev, "error creating sysfs attrs\n");
1063 goto err_gpiochip_remove;
1066 chmod_sysfs_attrs(hdev);
1067 hid_hw_power(hdev, PM_HINT_NORMAL);
1071 err_gpiochip_remove:
1072 gpiochip_remove(&dev->gc);
1074 i2c_del_adapter(&dev->adap);
1078 hid_hw_power(hdev, PM_HINT_NORMAL);
1086 static void cp2112_remove(struct hid_device *hdev)
1088 struct cp2112_device *dev = hid_get_drvdata(hdev);
1090 sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
1091 gpiochip_remove(&dev->gc);
1092 i2c_del_adapter(&dev->adap);
1093 /* i2c_del_adapter has finished removing all i2c devices from our
1094 * adapter. Well behaved devices should no longer call our cp2112_xfer
1095 * and should have waited for any pending calls to finish. It has also
1096 * waited for device_unregister(&adap->dev) to complete. Therefore we
1097 * can safely free our struct cp2112_device.
1104 static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report,
1107 struct cp2112_device *dev = hid_get_drvdata(hdev);
1108 struct cp2112_xfer_status_report *xfer = (void *)data;
1111 case CP2112_TRANSFER_STATUS_RESPONSE:
1112 hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n",
1113 xfer->status0, xfer->status1,
1114 be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length));
1116 switch (xfer->status0) {
1118 dev->xfer_status = -EAGAIN;
1121 dev->xfer_status = -EBUSY;
1123 case STATUS0_COMPLETE:
1124 dev->xfer_status = be16_to_cpu(xfer->length);
1127 switch (xfer->status1) {
1128 case STATUS1_TIMEOUT_NACK:
1129 case STATUS1_TIMEOUT_BUS:
1130 dev->xfer_status = -ETIMEDOUT;
1133 dev->xfer_status = -EIO;
1138 dev->xfer_status = -EINVAL;
1142 atomic_set(&dev->xfer_avail, 1);
1144 case CP2112_DATA_READ_RESPONSE:
1145 hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]);
1147 dev->read_length = data[2];
1148 if (dev->read_length > sizeof(dev->read_data))
1149 dev->read_length = sizeof(dev->read_data);
1151 memcpy(dev->read_data, &data[3], dev->read_length);
1152 atomic_set(&dev->read_avail, 1);
1155 hid_err(hdev, "unknown report\n");
1160 wake_up_interruptible(&dev->wait);
1164 static struct hid_driver cp2112_driver = {
1166 .id_table = cp2112_devices,
1167 .probe = cp2112_probe,
1168 .remove = cp2112_remove,
1169 .raw_event = cp2112_raw_event,
1172 module_hid_driver(cp2112_driver);
1173 MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
1174 MODULE_AUTHOR("David Barksdale <dbarksdale@uplogix.com>");
1175 MODULE_LICENSE("GPL");