/* * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge * Copyright (c) 2013,2014 Uplogix, Inc. * David Barksdale * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ /* * The Silicon Labs CP2112 chip is a USB HID device which provides an * SMBus controller for talking to slave devices and 8 GPIO pins. The * host communicates with the CP2112 via raw HID reports. * * Data Sheet: * http://www.silabs.com/Support%20Documents/TechnicalDocs/CP2112.pdf * Programming Interface Specification: * http://www.silabs.com/Support%20Documents/TechnicalDocs/AN495.pdf */ #include #include #include #include #include #include #include "hid-ids.h" enum { CP2112_GPIO_CONFIG = 0x02, CP2112_GPIO_GET = 0x03, CP2112_GPIO_SET = 0x04, CP2112_GET_VERSION_INFO = 0x05, CP2112_SMBUS_CONFIG = 0x06, CP2112_DATA_READ_REQUEST = 0x10, CP2112_DATA_WRITE_READ_REQUEST = 0x11, CP2112_DATA_READ_FORCE_SEND = 0x12, CP2112_DATA_READ_RESPONSE = 0x13, CP2112_DATA_WRITE_REQUEST = 0x14, CP2112_TRANSFER_STATUS_REQUEST = 0x15, CP2112_TRANSFER_STATUS_RESPONSE = 0x16, CP2112_CANCEL_TRANSFER = 0x17, CP2112_LOCK_BYTE = 0x20, CP2112_USB_CONFIG = 0x21, CP2112_MANUFACTURER_STRING = 0x22, CP2112_PRODUCT_STRING = 0x23, CP2112_SERIAL_STRING = 0x24, }; enum { STATUS0_IDLE = 0x00, STATUS0_BUSY = 0x01, STATUS0_COMPLETE = 0x02, STATUS0_ERROR = 0x03, }; enum { STATUS1_TIMEOUT_NACK = 0x00, STATUS1_TIMEOUT_BUS = 0x01, STATUS1_ARBITRATION_LOST = 0x02, STATUS1_READ_INCOMPLETE = 0x03, STATUS1_WRITE_INCOMPLETE = 0x04, STATUS1_SUCCESS = 0x05, }; struct cp2112_smbus_config_report { u8 report; /* CP2112_SMBUS_CONFIG */ __be32 clock_speed; /* Hz */ u8 device_address; /* Stored in the upper 7 bits */ u8 auto_send_read; /* 1 = enabled, 0 = disabled */ __be16 write_timeout; /* ms, 0 = no timeout */ __be16 read_timeout; /* ms, 0 = no timeout */ u8 scl_low_timeout; /* 1 = enabled, 0 = disabled */ __be16 retry_time; /* # of retries, 0 = no limit */ } __packed; struct cp2112_usb_config_report { u8 report; /* CP2112_USB_CONFIG */ __le16 vid; /* Vendor ID */ __le16 pid; /* Product ID */ u8 max_power; /* Power requested in 2mA units */ u8 power_mode; /* 0x00 = bus powered 0x01 = self powered & regulator off 0x02 = self powered & regulator on */ u8 release_major; u8 release_minor; u8 mask; /* What fields to program */ } __packed; struct cp2112_read_req_report { u8 report; /* CP2112_DATA_READ_REQUEST */ u8 slave_address; __be16 length; } __packed; struct cp2112_write_read_req_report { u8 report; /* CP2112_DATA_WRITE_READ_REQUEST */ u8 slave_address; __be16 length; u8 target_address_length; u8 target_address[16]; } __packed; struct cp2112_write_req_report { u8 report; /* CP2112_DATA_WRITE_REQUEST */ u8 slave_address; u8 length; u8 data[61]; } __packed; struct cp2112_force_read_report { u8 report; /* CP2112_DATA_READ_FORCE_SEND */ __be16 length; } __packed; struct cp2112_xfer_status_report { u8 report; /* CP2112_TRANSFER_STATUS_RESPONSE */ u8 status0; /* STATUS0_* */ u8 status1; /* STATUS1_* */ __be16 retries; __be16 length; } __packed; struct cp2112_string_report { u8 dummy; /* force .string to be aligned */ u8 report; /* CP2112_*_STRING */ u8 length; /* length in bytes of everyting after .report */ u8 type; /* USB_DT_STRING */ wchar_t string[30]; /* UTF16_LITTLE_ENDIAN string */ } __packed; /* Number of times to request transfer status before giving up waiting for a transfer to complete. This may need to be changed if SMBUS clock, retries, or read/write/scl_low timeout settings are changed. */ static const int XFER_STATUS_RETRIES = 10; /* Time in ms to wait for a CP2112_DATA_READ_RESPONSE or CP2112_TRANSFER_STATUS_RESPONSE. */ static const int RESPONSE_TIMEOUT = 50; static const struct hid_device_id cp2112_devices[] = { { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) }, { } }; MODULE_DEVICE_TABLE(hid, cp2112_devices); struct cp2112_device { struct i2c_adapter adap; struct hid_device *hdev; wait_queue_head_t wait; u8 read_data[61]; u8 read_length; int xfer_status; atomic_t read_avail; atomic_t xfer_avail; struct gpio_chip gc; }; static int gpio_push_pull = 0xFF; module_param(gpio_push_pull, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(gpio_push_pull, "GPIO push-pull configuration bitmask"); static int cp2112_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { struct cp2112_device *dev = container_of(chip, struct cp2112_device, gc); struct hid_device *hdev = dev->hdev; u8 buf[5]; int ret; ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf), HID_FEATURE_REPORT, HID_REQ_GET_REPORT); if (ret != sizeof(buf)) { hid_err(hdev, "error requesting GPIO config: %d\n", ret); return ret; } buf[1] &= ~(1 << offset); buf[2] = gpio_push_pull; ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf), HID_FEATURE_REPORT, HID_REQ_SET_REPORT); if (ret < 0) { hid_err(hdev, "error setting GPIO config: %d\n", ret); return ret; } return 0; } static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value) { struct cp2112_device *dev = container_of(chip, struct cp2112_device, gc); struct hid_device *hdev = dev->hdev; u8 buf[3]; int ret; buf[0] = CP2112_GPIO_SET; buf[1] = value ? 0xff : 0; buf[2] = 1 << offset; ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf, sizeof(buf), HID_FEATURE_REPORT, HID_REQ_SET_REPORT); if (ret < 0) hid_err(hdev, "error setting GPIO values: %d\n", ret); } static int cp2112_gpio_get(struct gpio_chip *chip, unsigned offset) { struct cp2112_device *dev = container_of(chip, struct cp2112_device, gc); struct hid_device *hdev = dev->hdev; u8 buf[2]; int ret; ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf, sizeof(buf), HID_FEATURE_REPORT, HID_REQ_GET_REPORT); if (ret != sizeof(buf)) { hid_err(hdev, "error requesting GPIO values: %d\n", ret); return ret; } return (buf[1] >> offset) & 1; } static int cp2112_gpio_direction_output(struct gpio_chip *chip, unsigned offset, int value) { struct cp2112_device *dev = container_of(chip, struct cp2112_device, gc); struct hid_device *hdev = dev->hdev; u8 buf[5]; int ret; ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf), HID_FEATURE_REPORT, HID_REQ_GET_REPORT); if (ret != sizeof(buf)) { hid_err(hdev, "error requesting GPIO config: %d\n", ret); return ret; } buf[1] |= 1 << offset; buf[2] = gpio_push_pull; ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf, sizeof(buf), HID_FEATURE_REPORT, HID_REQ_SET_REPORT); if (ret < 0) { hid_err(hdev, "error setting GPIO config: %d\n", ret); return ret; } /* * Set gpio value when output direction is already set, * as specified in AN495, Rev. 0.2, cpt. 4.4 */ cp2112_gpio_set(chip, offset, value); return 0; } static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number, u8 *data, size_t count, unsigned char report_type) { u8 *buf; int ret; buf = kmalloc(count, GFP_KERNEL); if (!buf) return -ENOMEM; ret = hid_hw_raw_request(hdev, report_number, buf, count, report_type, HID_REQ_GET_REPORT); memcpy(data, buf, count); kfree(buf); return ret; } static int cp2112_hid_output(struct hid_device *hdev, u8 *data, size_t count, unsigned char report_type) { u8 *buf; int ret; buf = kmemdup(data, count, GFP_KERNEL); if (!buf) return -ENOMEM; if (report_type == HID_OUTPUT_REPORT) ret = hid_hw_output_report(hdev, buf, count); else ret = hid_hw_raw_request(hdev, buf[0], buf, count, report_type, HID_REQ_SET_REPORT); kfree(buf); return ret; } static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail) { int ret = 0; /* We have sent either a CP2112_TRANSFER_STATUS_REQUEST or a * CP2112_DATA_READ_FORCE_SEND and we are waiting for the response to * come in cp2112_raw_event or timeout. There will only be one of these * in flight at any one time. The timeout is extremely large and is a * last resort if the CP2112 has died. If we do timeout we don't expect * to receive the response which would cause data races, it's not like * we can do anything about it anyway. */ ret = wait_event_interruptible_timeout(dev->wait, atomic_read(avail), msecs_to_jiffies(RESPONSE_TIMEOUT)); if (-ERESTARTSYS == ret) return ret; if (!ret) return -ETIMEDOUT; atomic_set(avail, 0); return 0; } static int cp2112_xfer_status(struct cp2112_device *dev) { struct hid_device *hdev = dev->hdev; u8 buf[2]; int ret; buf[0] = CP2112_TRANSFER_STATUS_REQUEST; buf[1] = 0x01; atomic_set(&dev->xfer_avail, 0); ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); if (ret < 0) { hid_warn(hdev, "Error requesting status: %d\n", ret); return ret; } ret = cp2112_wait(dev, &dev->xfer_avail); if (ret) return ret; return dev->xfer_status; } static int cp2112_read(struct cp2112_device *dev, u8 *data, size_t size) { struct hid_device *hdev = dev->hdev; struct cp2112_force_read_report report; int ret; report.report = CP2112_DATA_READ_FORCE_SEND; report.length = cpu_to_be16(size); atomic_set(&dev->read_avail, 0); ret = cp2112_hid_output(hdev, &report.report, sizeof(report), HID_OUTPUT_REPORT); if (ret < 0) { hid_warn(hdev, "Error requesting data: %d\n", ret); return ret; } ret = cp2112_wait(dev, &dev->read_avail); if (ret) return ret; hid_dbg(hdev, "read %d of %zd bytes requested\n", dev->read_length, size); if (size > dev->read_length) size = dev->read_length; memcpy(data, dev->read_data, size); return dev->read_length; } static int cp2112_read_req(void *buf, u8 slave_address, u16 length) { struct cp2112_read_req_report *report = buf; if (length < 1 || length > 512) return -EINVAL; report->report = CP2112_DATA_READ_REQUEST; report->slave_address = slave_address << 1; report->length = cpu_to_be16(length); return sizeof(*report); } static int cp2112_write_read_req(void *buf, u8 slave_address, u16 length, u8 command, u8 *data, u8 data_length) { struct cp2112_write_read_req_report *report = buf; if (length < 1 || length > 512 || data_length > sizeof(report->target_address) - 1) return -EINVAL; report->report = CP2112_DATA_WRITE_READ_REQUEST; report->slave_address = slave_address << 1; report->length = cpu_to_be16(length); report->target_address_length = data_length + 1; report->target_address[0] = command; memcpy(&report->target_address[1], data, data_length); return data_length + 6; } static int cp2112_write_req(void *buf, u8 slave_address, u8 command, u8 *data, u8 data_length) { struct cp2112_write_req_report *report = buf; if (data_length > sizeof(report->data) - 1) return -EINVAL; report->report = CP2112_DATA_WRITE_REQUEST; report->slave_address = slave_address << 1; report->length = data_length + 1; report->data[0] = command; memcpy(&report->data[1], data, data_length); return data_length + 4; } static int cp2112_i2c_write_req(void *buf, u8 slave_address, u8 *data, u8 data_length) { struct cp2112_write_req_report *report = buf; if (data_length > sizeof(report->data)) return -EINVAL; report->report = CP2112_DATA_WRITE_REQUEST; report->slave_address = slave_address << 1; report->length = data_length; memcpy(report->data, data, data_length); return data_length + 3; } static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data; struct hid_device *hdev = dev->hdev; u8 buf[64]; ssize_t count; unsigned int retries; int ret; hid_dbg(hdev, "I2C %d messages\n", num); if (num != 1) { hid_err(hdev, "Multi-message I2C transactions not supported\n"); return -EOPNOTSUPP; } if (msgs->flags & I2C_M_RD) count = cp2112_read_req(buf, msgs->addr, msgs->len); else count = cp2112_i2c_write_req(buf, msgs->addr, msgs->buf, msgs->len); if (count < 0) return count; ret = hid_hw_power(hdev, PM_HINT_FULLON); if (ret < 0) { hid_err(hdev, "power management error: %d\n", ret); return ret; } ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT); if (ret < 0) { hid_warn(hdev, "Error starting transaction: %d\n", ret); goto power_normal; } for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) { ret = cp2112_xfer_status(dev); if (-EBUSY == ret) continue; if (ret < 0) goto power_normal; break; } if (XFER_STATUS_RETRIES <= retries) { hid_warn(hdev, "Transfer timed out, cancelling.\n"); buf[0] = CP2112_CANCEL_TRANSFER; buf[1] = 0x01; ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); if (ret < 0) hid_warn(hdev, "Error cancelling transaction: %d\n", ret); ret = -ETIMEDOUT; goto power_normal; } if (!(msgs->flags & I2C_M_RD)) goto finish; ret = cp2112_read(dev, msgs->buf, msgs->len); if (ret < 0) goto power_normal; if (ret != msgs->len) { hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len); ret = -EIO; goto power_normal; } finish: /* return the number of transferred messages */ ret = 1; power_normal: hid_hw_power(hdev, PM_HINT_NORMAL); hid_dbg(hdev, "I2C transfer finished: %d\n", ret); return ret; } static int cp2112_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data *data) { struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data; struct hid_device *hdev = dev->hdev; u8 buf[64]; __be16 word; ssize_t count; size_t read_length = 0; unsigned int retries; int ret; hid_dbg(hdev, "%s addr 0x%x flags 0x%x cmd 0x%x size %d\n", read_write == I2C_SMBUS_WRITE ? "write" : "read", addr, flags, command, size); switch (size) { case I2C_SMBUS_BYTE: read_length = 1; if (I2C_SMBUS_READ == read_write) count = cp2112_read_req(buf, addr, read_length); else count = cp2112_write_req(buf, addr, data->byte, NULL, 0); break; case I2C_SMBUS_BYTE_DATA: read_length = 1; if (I2C_SMBUS_READ == read_write) count = cp2112_write_read_req(buf, addr, read_length, command, NULL, 0); else count = cp2112_write_req(buf, addr, command, &data->byte, 1); break; case I2C_SMBUS_WORD_DATA: read_length = 2; word = cpu_to_be16(data->word); if (I2C_SMBUS_READ == read_write) count = cp2112_write_read_req(buf, addr, read_length, command, NULL, 0); else count = cp2112_write_req(buf, addr, command, (u8 *)&word, 2); break; case I2C_SMBUS_PROC_CALL: size = I2C_SMBUS_WORD_DATA; read_write = I2C_SMBUS_READ; read_length = 2; word = cpu_to_be16(data->word); count = cp2112_write_read_req(buf, addr, read_length, command, (u8 *)&word, 2); break; case I2C_SMBUS_I2C_BLOCK_DATA: size = I2C_SMBUS_BLOCK_DATA; /* fallthrough */ case I2C_SMBUS_BLOCK_DATA: if (I2C_SMBUS_READ == read_write) { count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX, command, NULL, 0); } else { count = cp2112_write_req(buf, addr, command, data->block, data->block[0] + 1); } break; case I2C_SMBUS_BLOCK_PROC_CALL: size = I2C_SMBUS_BLOCK_DATA; read_write = I2C_SMBUS_READ; count = cp2112_write_read_req(buf, addr, I2C_SMBUS_BLOCK_MAX, command, data->block, data->block[0] + 1); break; default: hid_warn(hdev, "Unsupported transaction %d\n", size); return -EOPNOTSUPP; } if (count < 0) return count; ret = hid_hw_power(hdev, PM_HINT_FULLON); if (ret < 0) { hid_err(hdev, "power management error: %d\n", ret); return ret; } ret = cp2112_hid_output(hdev, buf, count, HID_OUTPUT_REPORT); if (ret < 0) { hid_warn(hdev, "Error starting transaction: %d\n", ret); goto power_normal; } for (retries = 0; retries < XFER_STATUS_RETRIES; ++retries) { ret = cp2112_xfer_status(dev); if (-EBUSY == ret) continue; if (ret < 0) goto power_normal; break; } if (XFER_STATUS_RETRIES <= retries) { hid_warn(hdev, "Transfer timed out, cancelling.\n"); buf[0] = CP2112_CANCEL_TRANSFER; buf[1] = 0x01; ret = cp2112_hid_output(hdev, buf, 2, HID_OUTPUT_REPORT); if (ret < 0) hid_warn(hdev, "Error cancelling transaction: %d\n", ret); ret = -ETIMEDOUT; goto power_normal; } if (I2C_SMBUS_WRITE == read_write) { ret = 0; goto power_normal; } if (I2C_SMBUS_BLOCK_DATA == size) read_length = ret; ret = cp2112_read(dev, buf, read_length); if (ret < 0) goto power_normal; if (ret != read_length) { hid_warn(hdev, "short read: %d < %zd\n", ret, read_length); ret = -EIO; goto power_normal; } switch (size) { case I2C_SMBUS_BYTE: case I2C_SMBUS_BYTE_DATA: data->byte = buf[0]; break; case I2C_SMBUS_WORD_DATA: data->word = be16_to_cpup((__be16 *)buf); break; case I2C_SMBUS_BLOCK_DATA: if (read_length > I2C_SMBUS_BLOCK_MAX) { ret = -EPROTO; goto power_normal; } memcpy(data->block, buf, read_length); break; } ret = 0; power_normal: hid_hw_power(hdev, PM_HINT_NORMAL); hid_dbg(hdev, "transfer finished: %d\n", ret); return ret; } static u32 cp2112_functionality(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_I2C_BLOCK | I2C_FUNC_SMBUS_PROC_CALL | I2C_FUNC_SMBUS_BLOCK_PROC_CALL; } static const struct i2c_algorithm smbus_algorithm = { .master_xfer = cp2112_i2c_xfer, .smbus_xfer = cp2112_xfer, .functionality = cp2112_functionality, }; static int cp2112_get_usb_config(struct hid_device *hdev, struct cp2112_usb_config_report *cfg) { int ret; ret = cp2112_hid_get(hdev, CP2112_USB_CONFIG, (u8 *)cfg, sizeof(*cfg), HID_FEATURE_REPORT); if (ret != sizeof(*cfg)) { hid_err(hdev, "error reading usb config: %d\n", ret); if (ret < 0) return ret; return -EIO; } return 0; } static int cp2112_set_usb_config(struct hid_device *hdev, struct cp2112_usb_config_report *cfg) { int ret; BUG_ON(cfg->report != CP2112_USB_CONFIG); ret = cp2112_hid_output(hdev, (u8 *)cfg, sizeof(*cfg), HID_FEATURE_REPORT); if (ret != sizeof(*cfg)) { hid_err(hdev, "error writing usb config: %d\n", ret); if (ret < 0) return ret; return -EIO; } return 0; } static void chmod_sysfs_attrs(struct hid_device *hdev); #define CP2112_CONFIG_ATTR(name, store, format, ...) \ static ssize_t name##_store(struct device *kdev, \ struct device_attribute *attr, const char *buf, \ size_t count) \ { \ struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \ struct cp2112_usb_config_report cfg; \ int ret = cp2112_get_usb_config(hdev, &cfg); \ if (ret) \ return ret; \ store; \ ret = cp2112_set_usb_config(hdev, &cfg); \ if (ret) \ return ret; \ chmod_sysfs_attrs(hdev); \ return count; \ } \ static ssize_t name##_show(struct device *kdev, \ struct device_attribute *attr, char *buf) \ { \ struct hid_device *hdev = container_of(kdev, struct hid_device, dev); \ struct cp2112_usb_config_report cfg; \ int ret = cp2112_get_usb_config(hdev, &cfg); \ if (ret) \ return ret; \ return scnprintf(buf, PAGE_SIZE, format, ##__VA_ARGS__); \ } \ static DEVICE_ATTR_RW(name); CP2112_CONFIG_ATTR(vendor_id, ({ u16 vid; if (sscanf(buf, "%hi", &vid) != 1) return -EINVAL; cfg.vid = cpu_to_le16(vid); cfg.mask = 0x01; }), "0x%04x\n", le16_to_cpu(cfg.vid)); CP2112_CONFIG_ATTR(product_id, ({ u16 pid; if (sscanf(buf, "%hi", &pid) != 1) return -EINVAL; cfg.pid = cpu_to_le16(pid); cfg.mask = 0x02; }), "0x%04x\n", le16_to_cpu(cfg.pid)); CP2112_CONFIG_ATTR(max_power, ({ int mA; if (sscanf(buf, "%i", &mA) != 1) return -EINVAL; cfg.max_power = (mA + 1) / 2; cfg.mask = 0x04; }), "%u mA\n", cfg.max_power * 2); CP2112_CONFIG_ATTR(power_mode, ({ if (sscanf(buf, "%hhi", &cfg.power_mode) != 1) return -EINVAL; cfg.mask = 0x08; }), "%u\n", cfg.power_mode); CP2112_CONFIG_ATTR(release_version, ({ if (sscanf(buf, "%hhi.%hhi", &cfg.release_major, &cfg.release_minor) != 2) return -EINVAL; cfg.mask = 0x10; }), "%u.%u\n", cfg.release_major, cfg.release_minor); #undef CP2112_CONFIG_ATTR struct cp2112_pstring_attribute { struct device_attribute attr; unsigned char report; }; static ssize_t pstr_store(struct device *kdev, struct device_attribute *kattr, const char *buf, size_t count) { struct hid_device *hdev = container_of(kdev, struct hid_device, dev); struct cp2112_pstring_attribute *attr = container_of(kattr, struct cp2112_pstring_attribute, attr); struct cp2112_string_report report; int ret; memset(&report, 0, sizeof(report)); ret = utf8s_to_utf16s(buf, count, UTF16_LITTLE_ENDIAN, report.string, ARRAY_SIZE(report.string)); report.report = attr->report; report.length = ret * sizeof(report.string[0]) + 2; report.type = USB_DT_STRING; ret = cp2112_hid_output(hdev, &report.report, report.length + 1, HID_FEATURE_REPORT); if (ret != report.length + 1) { hid_err(hdev, "error writing %s string: %d\n", kattr->attr.name, ret); if (ret < 0) return ret; return -EIO; } chmod_sysfs_attrs(hdev); return count; } static ssize_t pstr_show(struct device *kdev, struct device_attribute *kattr, char *buf) { struct hid_device *hdev = container_of(kdev, struct hid_device, dev); struct cp2112_pstring_attribute *attr = container_of(kattr, struct cp2112_pstring_attribute, attr); struct cp2112_string_report report; u8 length; int ret; ret = cp2112_hid_get(hdev, attr->report, &report.report, sizeof(report) - 1, HID_FEATURE_REPORT); if (ret < 3) { hid_err(hdev, "error reading %s string: %d\n", kattr->attr.name, ret); if (ret < 0) return ret; return -EIO; } if (report.length < 2) { hid_err(hdev, "invalid %s string length: %d\n", kattr->attr.name, report.length); return -EIO; } length = report.length > ret - 1 ? ret - 1 : report.length; length = (length - 2) / sizeof(report.string[0]); ret = utf16s_to_utf8s(report.string, length, UTF16_LITTLE_ENDIAN, buf, PAGE_SIZE - 1); buf[ret++] = '\n'; return ret; } #define CP2112_PSTR_ATTR(name, _report) \ static struct cp2112_pstring_attribute dev_attr_##name = { \ .attr = __ATTR(name, (S_IWUSR | S_IRUGO), pstr_show, pstr_store), \ .report = _report, \ }; CP2112_PSTR_ATTR(manufacturer, CP2112_MANUFACTURER_STRING); CP2112_PSTR_ATTR(product, CP2112_PRODUCT_STRING); CP2112_PSTR_ATTR(serial, CP2112_SERIAL_STRING); #undef CP2112_PSTR_ATTR static const struct attribute_group cp2112_attr_group = { .attrs = (struct attribute *[]){ &dev_attr_vendor_id.attr, &dev_attr_product_id.attr, &dev_attr_max_power.attr, &dev_attr_power_mode.attr, &dev_attr_release_version.attr, &dev_attr_manufacturer.attr.attr, &dev_attr_product.attr.attr, &dev_attr_serial.attr.attr, NULL } }; /* Chmoding our sysfs attributes is simply a way to expose which fields in the * PROM have already been programmed. We do not depend on this preventing * writing to these attributes since the CP2112 will simply ignore writes to * already-programmed fields. This is why there is no sense in fixing this * racy behaviour. */ static void chmod_sysfs_attrs(struct hid_device *hdev) { struct attribute **attr; u8 buf[2]; int ret; ret = cp2112_hid_get(hdev, CP2112_LOCK_BYTE, buf, sizeof(buf), HID_FEATURE_REPORT); if (ret != sizeof(buf)) { hid_err(hdev, "error reading lock byte: %d\n", ret); return; } for (attr = cp2112_attr_group.attrs; *attr; ++attr) { umode_t mode = (buf[1] & 1) ? S_IWUSR | S_IRUGO : S_IRUGO; ret = sysfs_chmod_file(&hdev->dev.kobj, *attr, mode); if (ret < 0) hid_err(hdev, "error chmoding sysfs file %s\n", (*attr)->name); buf[1] >>= 1; } } static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id) { struct cp2112_device *dev; u8 buf[3]; struct cp2112_smbus_config_report config; int ret; ret = hid_parse(hdev); if (ret) { hid_err(hdev, "parse failed\n"); return ret; } ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); if (ret) { hid_err(hdev, "hw start failed\n"); return ret; } ret = hid_hw_open(hdev); if (ret) { hid_err(hdev, "hw open failed\n"); goto err_hid_stop; } ret = hid_hw_power(hdev, PM_HINT_FULLON); if (ret < 0) { hid_err(hdev, "power management error: %d\n", ret); goto err_hid_close; } ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, sizeof(buf), HID_FEATURE_REPORT); if (ret != sizeof(buf)) { hid_err(hdev, "error requesting version\n"); if (ret >= 0) ret = -EIO; goto err_power_normal; } hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n", buf[1], buf[2]); ret = cp2112_hid_get(hdev, CP2112_SMBUS_CONFIG, (u8 *)&config, sizeof(config), HID_FEATURE_REPORT); if (ret != sizeof(config)) { hid_err(hdev, "error requesting SMBus config\n"); if (ret >= 0) ret = -EIO; goto err_power_normal; } config.retry_time = cpu_to_be16(1); ret = cp2112_hid_output(hdev, (u8 *)&config, sizeof(config), HID_FEATURE_REPORT); if (ret != sizeof(config)) { hid_err(hdev, "error setting SMBus config\n"); if (ret >= 0) ret = -EIO; goto err_power_normal; } dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) { ret = -ENOMEM; goto err_power_normal; } hid_set_drvdata(hdev, (void *)dev); dev->hdev = hdev; dev->adap.owner = THIS_MODULE; dev->adap.class = I2C_CLASS_HWMON; dev->adap.algo = &smbus_algorithm; dev->adap.algo_data = dev; dev->adap.dev.parent = &hdev->dev; snprintf(dev->adap.name, sizeof(dev->adap.name), "CP2112 SMBus Bridge on hiddev%d", hdev->minor); init_waitqueue_head(&dev->wait); hid_device_io_start(hdev); ret = i2c_add_adapter(&dev->adap); hid_device_io_stop(hdev); if (ret) { hid_err(hdev, "error registering i2c adapter\n"); goto err_free_dev; } hid_dbg(hdev, "adapter registered\n"); dev->gc.label = "cp2112_gpio"; dev->gc.direction_input = cp2112_gpio_direction_input; dev->gc.direction_output = cp2112_gpio_direction_output; dev->gc.set = cp2112_gpio_set; dev->gc.get = cp2112_gpio_get; dev->gc.base = -1; dev->gc.ngpio = 8; dev->gc.can_sleep = 1; dev->gc.dev = &hdev->dev; ret = gpiochip_add(&dev->gc); if (ret < 0) { hid_err(hdev, "error registering gpio chip\n"); goto err_free_i2c; } ret = sysfs_create_group(&hdev->dev.kobj, &cp2112_attr_group); if (ret < 0) { hid_err(hdev, "error creating sysfs attrs\n"); goto err_gpiochip_remove; } chmod_sysfs_attrs(hdev); hid_hw_power(hdev, PM_HINT_NORMAL); return ret; err_gpiochip_remove: gpiochip_remove(&dev->gc); err_free_i2c: i2c_del_adapter(&dev->adap); err_free_dev: kfree(dev); err_power_normal: hid_hw_power(hdev, PM_HINT_NORMAL); err_hid_close: hid_hw_close(hdev); err_hid_stop: hid_hw_stop(hdev); return ret; } static void cp2112_remove(struct hid_device *hdev) { struct cp2112_device *dev = hid_get_drvdata(hdev); sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group); gpiochip_remove(&dev->gc); i2c_del_adapter(&dev->adap); /* i2c_del_adapter has finished removing all i2c devices from our * adapter. Well behaved devices should no longer call our cp2112_xfer * and should have waited for any pending calls to finish. It has also * waited for device_unregister(&adap->dev) to complete. Therefore we * can safely free our struct cp2112_device. */ hid_hw_close(hdev); hid_hw_stop(hdev); kfree(dev); } static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report, u8 *data, int size) { struct cp2112_device *dev = hid_get_drvdata(hdev); struct cp2112_xfer_status_report *xfer = (void *)data; switch (data[0]) { case CP2112_TRANSFER_STATUS_RESPONSE: hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n", xfer->status0, xfer->status1, be16_to_cpu(xfer->retries), be16_to_cpu(xfer->length)); switch (xfer->status0) { case STATUS0_IDLE: dev->xfer_status = -EAGAIN; break; case STATUS0_BUSY: dev->xfer_status = -EBUSY; break; case STATUS0_COMPLETE: dev->xfer_status = be16_to_cpu(xfer->length); break; case STATUS0_ERROR: switch (xfer->status1) { case STATUS1_TIMEOUT_NACK: case STATUS1_TIMEOUT_BUS: dev->xfer_status = -ETIMEDOUT; break; default: dev->xfer_status = -EIO; break; } break; default: dev->xfer_status = -EINVAL; break; } atomic_set(&dev->xfer_avail, 1); break; case CP2112_DATA_READ_RESPONSE: hid_dbg(hdev, "read response: %02x %02x\n", data[1], data[2]); dev->read_length = data[2]; if (dev->read_length > sizeof(dev->read_data)) dev->read_length = sizeof(dev->read_data); memcpy(dev->read_data, &data[3], dev->read_length); atomic_set(&dev->read_avail, 1); break; default: hid_err(hdev, "unknown report\n"); return 0; } wake_up_interruptible(&dev->wait); return 1; } static struct hid_driver cp2112_driver = { .name = "cp2112", .id_table = cp2112_devices, .probe = cp2112_probe, .remove = cp2112_remove, .raw_event = cp2112_raw_event, }; module_hid_driver(cp2112_driver); MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge"); MODULE_AUTHOR("David Barksdale "); MODULE_LICENSE("GPL");