--- /dev/null
+/*
+ * hid-cp2112.c - Silicon Labs HID USB to SMBus master bridge
+ * Copyright (c) 2013,2014 Uplogix, Inc.
+ * David Barksdale <dbarksdale@uplogix.com>
+ *
+ * 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 <linux/gpio.h>
+#include <linux/hid.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/nls.h>
+#include <linux/usb/ch9.h>
+#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 <dbarksdale@uplogix.com>");
+MODULE_LICENSE("GPL");
+
Code Review / kvmfornfv.git / blobdiff