This patch adds support for the Silicon Labs CP2112 "Single-Chip HID USB to SMBus Master Bridge."
I wrote this to support a USB temperature and humidity sensor I've been working on. It's been tested by using SMBus byte-read, byte-data-read/write, and word-data-read transfer modes to talk to an I2C sensor. The other transfer modes have not been tested. Signed-off-by: David Barksdale <dbarksd...@uplogix.com> -- Changes since v1: * Prefix symbols to avoid name collision. * Define CP2112 device ID. * Missing break. * Use module_hid_driver(). * Fix cp2122 typo. * Fix probe and remove functions. * Remove #if in hid_have_special_driver[]. * Improve symbolic constants for timeouts. * Wrap DMA functions to kmalloc buffers. * Added a short description of the device. * Add request formatting functions for readability. * Whitespace changes. * Fix endianess of word transfers. However this version doesn't work. Adding the hid_hw_open/hid_hw_close calls to cp2112_probe() as suggested by David Herrmann seems to have stopped events being delivered to cp2112_raw_event(). Why is that? --- drivers/hid/Kconfig | 6 + drivers/hid/Makefile | 1 + drivers/hid/hid-core.c | 1 + drivers/hid/hid-cp2112.c | 559 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/hid/hid-ids.h | 1 + 5 files changed, 568 insertions(+) diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig index 14ef6ab..1833948 100644 --- a/drivers/hid/Kconfig +++ b/drivers/hid/Kconfig @@ -175,6 +175,12 @@ config HID_PRODIKEYS multimedia keyboard, but will lack support for the musical keyboard and some additional multimedia keys. +config HID_CP2112 + tristate "Silicon Labs CP2112 HID USB-to-SMBus Bridge support" + depends on USB_HID + ---help--- + Support for Silicon Labs CP2112 HID USB to SMBus Master Bridge. + config HID_CYPRESS tristate "Cypress mouse and barcode readers" if EXPERT depends on HID diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile index 6f68728..a88a5c4 100644 --- a/drivers/hid/Makefile +++ b/drivers/hid/Makefile @@ -41,6 +41,7 @@ obj-$(CONFIG_HID_AUREAL) += hid-aureal.o obj-$(CONFIG_HID_BELKIN) += hid-belkin.o obj-$(CONFIG_HID_CHERRY) += hid-cherry.o obj-$(CONFIG_HID_CHICONY) += hid-chicony.o +obj-$(CONFIG_HID_CP2112) += hid-cp2112.o obj-$(CONFIG_HID_CYPRESS) += hid-cypress.o obj-$(CONFIG_HID_DRAGONRISE) += hid-dr.o obj-$(CONFIG_HID_EMS_FF) += hid-emsff.o diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 36668d1..69e5f39 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -1568,6 +1568,7 @@ static const struct hid_device_id hid_have_special_driver[] = { { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS2) }, { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_AK1D) }, { HID_USB_DEVICE(USB_VENDOR_ID_CREATIVELABS, USB_DEVICE_ID_PRODIKEYS_PCMIDI) }, + { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) }, { HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS, USB_DEVICE_ID_CYPRESS_BARCODE_1) }, { HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS, USB_DEVICE_ID_CYPRESS_BARCODE_2) }, { HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS, USB_DEVICE_ID_CYPRESS_BARCODE_3) }, diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c new file mode 100644 index 0000000..5c6d294 --- /dev/null +++ b/drivers/hid/hid-cp2112.c @@ -0,0 +1,559 @@ +/* + hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge + Copyright (c) 2013 Uplogix, Inc. + David Barksdale <dbarksd...@uplogix.com> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that 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. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +/* + The Silicon Labs CP2112 chip is a USB HID device which provides an + SMBus controller for talking to slave devices. The host communicates + with the CP2112 via raw HID reports. + */ + +#include <linux/hid.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include "hid-ids.h" + +enum { + 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, +}; + +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, +}; + +/* All values are in big-endian */ +struct __attribute__ ((__packed__)) cp2112_smbus_config { + uint32_t clock_speed; /* Hz */ + uint8_t device_address; /* Stored in the upper 7 bits */ + uint8_t auto_send_read; /* 1 = enabled, 0 = disabled */ + uint16_t write_timeout; /* ms, 0 = no timeout */ + uint16_t read_timeout; /* ms, 0 = no timeout */ + uint8_t scl_low_timeout; /* 1 = enabled, 0 = disabled */ + uint16_t retry_time; /* # of retries, 0 = no limit */ +}; + +/* Number of times to request transfer status before giving up waiting for a + transfer to complete. */ +static const int XFER_TIMEOUT = 100; + +/* 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; + uint8_t read_data[61]; + uint8_t read_length; + int xfer_status; + atomic_t read_avail; + atomic_t xfer_avail; +}; + +static int cp2112_wait(struct cp2112_device *dev, atomic_t *avail) +{ + int ret = 0; + + 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_hid_get(struct hid_device *hdev, unsigned char report_number, + uint8_t *data, size_t count, + unsigned char report_type) +{ + uint8_t *buf; + int ret; + + buf = kmalloc(count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + ret = hdev->hid_get_raw_report(hdev, report_number, buf, count, + report_type); + memcpy(data, buf, count); + kfree(buf); + return ret; +} + +static int cp2112_hid_output(struct hid_device *hdev, uint8_t *data, + size_t count, unsigned char report_type) +{ + uint8_t *buf; + int ret; + + buf = kmemdup(data, count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + ret = hdev->hid_output_raw_report(hdev, buf, count, report_type); + kfree(buf); + return ret; +} + +static int cp2112_xfer_status(struct cp2112_device *dev) +{ + struct hid_device *hdev = dev->hdev; + uint8_t 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, uint8_t *data, size_t size) +{ + struct hid_device *hdev = dev->hdev; + uint8_t buf[3]; + int ret; + + buf[0] = CP2112_DATA_READ_FORCE_SEND; + *(uint16_t *)&buf[1] = htons(size); + atomic_set(&dev->read_avail, 0); + ret = cp2112_hid_output(hdev, buf, 3, 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 %d 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(uint8_t *buf, uint8_t slave_address, uint16_t length) +{ + if (length < 1 || length > 512) + return -EINVAL; + buf[0] = CP2112_DATA_READ_REQUEST; + buf[1] = slave_address << 1; + *(uint16_t *)&buf[2] = htons(length); + return 4; +} + +static int cp2112_write_read_req(uint8_t *buf, uint8_t slave_address, + uint16_t length, uint8_t command, + uint8_t *data, uint8_t data_length) +{ + if (length < 1 || length > 512 || data_length > 15) + return -EINVAL; + buf[0] = CP2112_DATA_WRITE_READ_REQUEST; + buf[1] = slave_address << 1; + *(uint16_t *)&buf[2] = htons(length); + buf[4] = data_length + 1; + buf[5] = command; + memcpy(&buf[6], data, data_length); + return data_length + 6; +} + +static int cp2112_write_req(uint8_t *buf, uint8_t slave_address, + uint8_t command, uint8_t *data, uint8_t data_length) +{ + if (data_length > 60) + return -EINVAL; + buf[0] = CP2112_DATA_WRITE_REQUEST; + buf[1] = slave_address << 1; + buf[2] = data_length + 1; + buf[3] = command; + memcpy(&buf[4], data, data_length); + return data_length + 4; +} + +static int cp2112_xfer(struct i2c_adapter *adap, uint16_t addr, + unsigned short flags, char read_write, uint8_t command, + int size, union i2c_smbus_data *data) +{ + struct cp2112_device *dev = (struct cp2112_device *)adap->algo_data; + struct hid_device *hdev = dev->hdev; + uint8_t buf[64]; + uint16_t word; + size_t count; + size_t read_length = 0; + size_t timeout; + 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 = htons(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, + (uint8_t *)&word, 2); + break; + case I2C_SMBUS_PROC_CALL: + size = I2C_SMBUS_WORD_DATA; + read_write = I2C_SMBUS_READ; + read_length = 2; + word = htons(data->word); + count = cp2112_write_read_req(buf, addr, read_length, command, + (uint8_t *)&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_open(hdev); + if (ret) { + hid_err(hdev, "hw open failed\n"); + return ret; + } + ret = hid_hw_power(hdev, PM_HINT_FULLON); + if (ret < 0) { + hid_err(hdev, "power management error: %d\n", ret); + goto hid_close; + } + 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 (timeout = 0; timeout < XFER_TIMEOUT; ++timeout) { + ret = cp2112_xfer_status(dev); + if (-EBUSY == ret) + continue; + if (ret < 0) + goto power_normal; + break; + } + if (XFER_TIMEOUT <= timeout) { + 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 < %d\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 = ntohs(*(uint16_t *)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_close: + hid_hw_close(hdev); + hid_dbg(hdev, "transfer finished: %d\n", ret); + return ret; +} + +static uint32_t cp2112_functionality(struct i2c_adapter *adap) +{ + return 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 = { + .smbus_xfer = cp2112_xfer, + .functionality = cp2112_functionality, +}; + +static int cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id) +{ + struct cp2112_device *dev; + uint8_t buf[64]; + struct cp2112_smbus_config *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 hid_stop; + } + ret = hid_hw_power(hdev, PM_HINT_FULLON); + if (ret < 0) { + hid_err(hdev, "power management error: %d\n", ret); + goto hid_close; + } + ret = cp2112_hid_get(hdev, CP2112_GET_VERSION_INFO, buf, 3, + HID_FEATURE_REPORT); + if (ret != 3) { + hid_err(hdev, "error requesting version\n"); + if (ret >= 0) + ret = -EIO; + goto 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, buf, + sizeof(*config) + 1, HID_FEATURE_REPORT); + if (ret != sizeof(*config) + 1) { + hid_err(hdev, "error requesting SMBus config\n"); + if (ret >= 0) + ret = -EIO; + goto power_normal; + } + config = (struct cp2112_smbus_config *)&buf[1]; + config->retry_time = htons(1); + ret = cp2112_hid_output(hdev, buf, sizeof(*config) + 1, + HID_FEATURE_REPORT); + if (ret != sizeof(*config) + 1) { + hid_err(hdev, "error setting SMBus config\n"); + if (ret >= 0) + ret = -EIO; + goto power_normal; + } + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) { + hid_err(hdev, "out of memory\n"); + ret = -ENOMEM; + goto power_normal; + } + dev->hdev = hdev; + hid_set_drvdata(hdev, (void *)dev); + 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); + hid_hw_power(hdev, PM_HINT_NORMAL); + hid_hw_close(hdev); + if (ret) { + hid_err(hdev, "error registering i2c adapter\n"); + kfree(dev); + goto hid_stop; + } + hid_dbg(hdev, "adapter registered\n"); + return ret; +power_normal: + hid_hw_power(hdev, PM_HINT_NORMAL); +hid_close: + hid_hw_close(hdev); +hid_stop: + hid_hw_stop(hdev); + return ret; +} + +static void cp2112_remove(struct hid_device *hdev) +{ + struct cp2112_device *dev = hid_get_drvdata(hdev); + + hid_hw_stop(hdev); + i2c_del_adapter(&dev->adap); + kfree(dev); +} + +static int cp2112_raw_event(struct hid_device *hdev, struct hid_report *report, + uint8_t *data, int size) +{ + struct cp2112_device *dev = hid_get_drvdata(hdev); + + switch (data[0]) { + case CP2112_TRANSFER_STATUS_RESPONSE: + hid_dbg(hdev, "xfer status: %02x %02x %04x %04x\n", + data[1], data[2], htons(*(uint16_t *)&data[3]), + htons(*(uint16_t *)&data[5])); + switch (data[1]) { + case STATUS0_IDLE: + dev->xfer_status = -EAGAIN; + break; + case STATUS0_BUSY: + dev->xfer_status = -EBUSY; + break; + case STATUS0_COMPLETE: + dev->xfer_status = ntohs(*(uint16_t *)&data[5]); + break; + case STATUS0_ERROR: + switch (data[2]) { + case STATUS1_TIMEOUT_NACK: + case STATUS1_TIMEOUT_BUS: + dev->xfer_status = -ETIMEDOUT; + break; + default: + dev->xfer_status = -EIO; + } + 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 <dbarksd...@uplogix.com>"); +MODULE_LICENSE("GPL"); + diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h index ffe4c7a..3a9dd5d 100644 --- a/drivers/hid/hid-ids.h +++ b/drivers/hid/hid-ids.h @@ -240,6 +240,7 @@ #define USB_VENDOR_ID_CYGNAL 0x10c4 #define USB_DEVICE_ID_CYGNAL_RADIO_SI470X 0x818a +#define USB_DEVICE_ID_CYGNAL_CP2112 0xEA90 #define USB_VENDOR_ID_CYPRESS 0x04b4 #define USB_DEVICE_ID_CYPRESS_MOUSE 0x0001 -- tg: (584d88b..) upstream/hid-cp2112 (depends on: upstream/master) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/