I sent this to Jiri Kosina and linux-kernel a week ago and
haven't gotten any attention. Maybe linux-usb can tell me
if this driver is any good.
From: David Barksdale <dbarksdale@xxxxxxxxxxx>
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 byte-word-read
transfer modes to talk to an I2C sensor. The other
transfer modes have not been tested.
Signed-off-by: David Barksdale <dbarksdale@xxxxxxxxxxx>
---
drivers/hid/Kconfig | 6 +
drivers/hid/Makefile | 1 +
drivers/hid/hid-core.c | 3 +
drivers/hid/hid-cp2112.c | 504 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 514 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..b472a0d 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1568,6 +1568,9 @@ 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) },
+#if IS_ENABLED(CONFIG_HID_CP2112)
+ { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, 0xEA90) },
+#endif
{ 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..8737d18
--- /dev/null
+++ b/drivers/hid/hid-cp2112.c
@@ -0,0 +1,504 @@
+/*
+ hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
+ Copyright (c) 2013 Uplogix, Inc.
+ David Barksdale <dbarksdale@xxxxxxxxxxx>
+
+ 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.
+ */
+
+#include <linux/hid.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include "hid-ids.h"
+
+enum {
+ GET_VERSION_INFO = 0x05,
+ SMBUS_CONFIG = 0x06,
+ DATA_READ_REQUEST = 0x10,
+ DATA_WRITE_READ_REQUEST = 0x11,
+ DATA_READ_FORCE_SEND = 0x12,
+ DATA_READ_RESPONSE = 0x13,
+ DATA_WRITE_REQUEST = 0x14,
+ TRANSFER_STATUS_REQUEST = 0x15,
+ TRANSFER_STATUS_RESPONSE = 0x16,
+ 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__)) 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 */
+};
+
+static const int MAX_TIMEOUT = 100;
+
+static const struct hid_device_id cp2112_devices[] = {
+ { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, 0xEA90) },
+ { }
+};
+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(50));
+ 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;
+ uint8_t buf[2];
+ int ret;
+
+ buf[0] = TRANSFER_STATUS_REQUEST;
+ buf[1] = 0x01;
+ atomic_set(&dev->xfer_avail, 0);
+ ret = hdev->hid_output_raw_report(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] = DATA_READ_FORCE_SEND;
+ *(uint16_t *)&buf[1] = htons(size);
+ atomic_set(&dev->read_avail, 0);
+ ret = hdev->hid_output_raw_report(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_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];
+ size_t count;
+ size_t read_length = 0;
+ size_t write_length;
+ 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);
+ buf[1] = addr << 1;
+ switch (size) {
+ case I2C_SMBUS_BYTE:
+ if (I2C_SMBUS_READ == read_write) {
+ read_length = 1;
+ buf[0] = DATA_READ_REQUEST;
+ *(uint16_t *)&buf[2] = htons(read_length);
+ count = 4;
+ } else {
+ write_length = 1;
+ buf[0] = DATA_WRITE_REQUEST;
+ buf[2] = write_length;
+ buf[3] = data->byte;
+ count = 4;
+ }
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ if (I2C_SMBUS_READ == read_write) {
+ read_length = 1;
+ buf[0] = DATA_WRITE_READ_REQUEST;
+ *(uint16_t *)&buf[2] = htons(read_length);
+ buf[4] = 1;
+ buf[5] = command;
+ count = 6;
+ } else {
+ write_length = 2;
+ buf[0] = DATA_WRITE_REQUEST;
+ buf[2] = write_length;
+ buf[3] = command;
+ buf[4] = data->byte;
+ count = 5;
+ }
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ if (I2C_SMBUS_READ == read_write) {
+ read_length = 2;
+ buf[0] = DATA_WRITE_READ_REQUEST;
+ *(uint16_t *)&buf[2] = htons(read_length);
+ buf[4] = 1;
+ buf[5] = command;
+ count = 6;
+ } else {
+ write_length = 3;
+ buf[0] = DATA_WRITE_REQUEST;
+ buf[2] = write_length;
+ buf[3] = command;
+ *(uint16_t *)&buf[4] = htons(data->word);
+ count = 6;
+ }
+ break;
+ case I2C_SMBUS_PROC_CALL:
+ size = I2C_SMBUS_WORD_DATA;
+ read_write = I2C_SMBUS_READ;
+ read_length = 2;
+ write_length = 3;
+ buf[0] = DATA_WRITE_READ_REQUEST;
+ *(uint16_t *)&buf[2] = htons(read_length);
+ buf[4] = write_length;
+ buf[5] = command;
+ *(uint16_t *)&buf[6] = data->word;
+ count = 8;
+ break;
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ size = I2C_SMBUS_BLOCK_DATA;
+ /* fallthrough */
+ case I2C_SMBUS_BLOCK_DATA:
+ if (I2C_SMBUS_READ == read_write) {
+ buf[0] = DATA_WRITE_READ_REQUEST;
+ *(uint16_t *)&buf[2] = htons(I2C_SMBUS_BLOCK_MAX);
+ buf[4] = 1;
+ buf[5] = command;
+ count = 6;
+ } else {
+ write_length = data->block[0];
+ if (write_length > 61 - 2)
+ return -EINVAL;
+ buf[0] = DATA_WRITE_REQUEST;
+ buf[2] = write_length + 2;
+ buf[3] = command;
+ memcpy(&buf[4], data->block, write_length + 1);
+ count = 5 + write_length;
+ }
+ break;
+ case I2C_SMBUS_BLOCK_PROC_CALL:
+ size = I2C_SMBUS_BLOCK_DATA;
+ read_write = I2C_SMBUS_READ;
+ write_length = data->block[0];
+ if (write_length > 16 - 2)
+ return -EINVAL;
+ buf[0] = DATA_WRITE_READ_REQUEST;
+ *(uint16_t *)&buf[2] = htons(I2C_SMBUS_BLOCK_MAX);
+ buf[4] = write_length + 2;
+ buf[5] = command;
+ memcpy(&buf[6], data->block, write_length + 1);
+ count = 7 + write_length;
+ default:
+ hid_warn(hdev, "Unsupported transaction %d\n", size);
+ return -EOPNOTSUPP;
+ }
+ 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 = hdev->hid_output_raw_report(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 < MAX_TIMEOUT; ++timeout) {
+ ret = cp2112_xfer_status(dev);
+ if (-EBUSY == ret)
+ continue;
+ if (ret < 0)
+ goto power_normal;
+ break;
+ }
+ if (MAX_TIMEOUT <= timeout) {
+ hid_warn(hdev, "Transfer timed out, cancelling.\n");
+ buf[0] = CANCEL_TRANSFER;
+ buf[1] = 0x01;
+ ret = hdev->hid_output_raw_report(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 cp2122_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 = cp2122_functionality,
+};
+
+static int
+cp2112_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+ struct cp2112_device *dev;
+ uint8_t buf[64];
+ struct 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_DEFAULT);
+ if (ret) {
+ hid_err(hdev, "hw start failed\n");
+ return ret;
+ }
+ ret = hdev->hid_get_raw_report(hdev, GET_VERSION_INFO, buf, 3,
+ HID_FEATURE_REPORT);
+ if (ret != 3) {
+ hid_err(hdev, "error requesting version\n");
+ return ret;
+ }
+ hid_info(hdev, "Part Number: 0x%02X Device Version: 0x%02X\n",
+ buf[1], buf[2]);
+ ret = hdev->hid_get_raw_report(hdev, SMBUS_CONFIG, buf,
+ sizeof(*config) + 1, HID_FEATURE_REPORT);
+ if (ret != sizeof(*config) + 1) {
+ hid_err(hdev, "error requesting SMBus config\n");
+ return ret;
+ }
+ config = (struct smbus_config *)&buf[1];
+ config->retry_time = htons(1);
+ ret = hdev->hid_output_raw_report(hdev, buf,
+ sizeof(*config) + 1, HID_FEATURE_REPORT);
+ if (ret != sizeof(*config) + 1) {
+ hid_err(hdev, "error setting SMBus config\n");
+ return ret;
+ }
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev) {
+ hid_err(hdev, "out of memory\n");
+ return -ENOMEM;
+ }
+ 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;
+ 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");
+ kfree(dev);
+ hid_set_drvdata(hdev, NULL);
+ }
+ hid_dbg(hdev, "adapter registered\n");
+ return ret;
+}
+
+static void cp2112_remove(struct hid_device *hdev)
+{
+ struct cp2112_device *dev = hid_get_drvdata(hdev);
+
+ if (dev) {
+ i2c_del_adapter(&dev->adap);
+ wake_up_interruptible(&dev->wait);
+ kfree(dev);
+ hid_set_drvdata(hdev, NULL);
+ }
+ hid_hw_stop(hdev);
+}
+
+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 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 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,
+};
+
+static int __init cp2112_init(void)
+{
+ return hid_register_driver(&cp2112_driver);
+}
+
+static void __exit cp2112_exit(void)
+{
+ hid_unregister_driver(&cp2112_driver);
+}
+
+module_init(cp2112_init);
+module_exit(cp2112_exit);
+MODULE_DESCRIPTION("Silicon Labs HID USB to SMBus master bridge");
+MODULE_AUTHOR("David Barksdale <dbarksdale@xxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
+
--
tg: (584d88b..) upstream/hid-cp2112 (depends on: upstream/master)
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