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kernel-fxtec-pro1x/drivers/hid/hid-cp2112.c
Eudean Sun 542134c037 HID: cp2112: Fix I2C_BLOCK_DATA transactions 
The existing driver erroneously treats I2C_BLOCK_DATA and BLOCK_DATA
commands the same.

For I2C_BLOCK_DATA reads, the length of the read is provided in
data->block[0], but the length itself should not be sent to the slave. In
contrast, for BLOCK_DATA reads no length is specified since the length
will be the first byte returned from the slave. When copying data back
to the data buffer, for an I2C_BLOCK_DATA read we have to take care not to
overwrite data->block[0] to avoid overwriting the length. A BLOCK_DATA
read doesn't have this concern since the first byte returned by the device
is the length and belongs in data->block[0].

For I2C_BLOCK_DATA writes, the length is also provided in data->block[0],
but the length itself is not sent to the slave (in contrast to BLOCK_DATA
writes where the length prefixes the data sent to the slave).

This was tested on physical hardware using i2cdump with the i and s flags
to test the behavior of I2C_BLOCK_DATA reads and BLOCK_DATA reads,
respectively. Writes were not tested but the I2C_BLOCK_DATA write change
is pretty simple to verify by inspection.

Signed-off-by: Eudean Sun <eudean@arista.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-11-21 21:39:45 +01:00

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/*
* 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:
* https://www.silabs.com/documents/public/application-notes/an495-cp2112-interface-specification.pdf
*/
#include <linux/gpio.h>
#include <linux/gpio/driver.h>
#include <linux/hid.h>
#include <linux/hidraw.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/nls.h>
#include <linux/usb/ch9.h>
#include "hid-ids.h"
#define CP2112_REPORT_MAX_LENGTH 64
#define CP2112_GPIO_CONFIG_LENGTH 5
#define CP2112_GPIO_GET_LENGTH 2
#define CP2112_GPIO_SET_LENGTH 3
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;
u8 hwversion;
int xfer_status;
atomic_t read_avail;
atomic_t xfer_avail;
struct gpio_chip gc;
u8 *in_out_buffer;
struct mutex lock;
struct gpio_desc *desc[8];
bool gpio_poll;
struct delayed_work gpio_poll_worker;
unsigned long irq_mask;
u8 gpio_prev_state;
};
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 = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 *buf = dev->in_out_buffer;
int ret;
mutex_lock(&dev->lock);
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
HID_REQ_GET_REPORT);
if (ret != CP2112_GPIO_CONFIG_LENGTH) {
hid_err(hdev, "error requesting GPIO config: %d\n", ret);
if (ret >= 0)
ret = -EIO;
goto exit;
}
buf[1] &= ~(1 << offset);
buf[2] = gpio_push_pull;
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
HID_REQ_SET_REPORT);
if (ret != CP2112_GPIO_CONFIG_LENGTH) {
hid_err(hdev, "error setting GPIO config: %d\n", ret);
if (ret >= 0)
ret = -EIO;
goto exit;
}
ret = 0;
exit:
mutex_unlock(&dev->lock);
return ret;
}
static void cp2112_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct cp2112_device *dev = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 *buf = dev->in_out_buffer;
int ret;
mutex_lock(&dev->lock);
buf[0] = CP2112_GPIO_SET;
buf[1] = value ? 0xff : 0;
buf[2] = 1 << offset;
ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
HID_REQ_SET_REPORT);
if (ret < 0)
hid_err(hdev, "error setting GPIO values: %d\n", ret);
mutex_unlock(&dev->lock);
}
static int cp2112_gpio_get_all(struct gpio_chip *chip)
{
struct cp2112_device *dev = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 *buf = dev->in_out_buffer;
int ret;
mutex_lock(&dev->lock);
ret = hid_hw_raw_request(hdev, CP2112_GPIO_GET, buf,
CP2112_GPIO_GET_LENGTH, HID_FEATURE_REPORT,
HID_REQ_GET_REPORT);
if (ret != CP2112_GPIO_GET_LENGTH) {
hid_err(hdev, "error requesting GPIO values: %d\n", ret);
ret = ret < 0 ? ret : -EIO;
goto exit;
}
ret = buf[1];
exit:
mutex_unlock(&dev->lock);
return ret;
}
static int cp2112_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
int ret;
ret = cp2112_gpio_get_all(chip);
if (ret < 0)
return ret;
return (ret >> offset) & 1;
}
static int cp2112_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
struct cp2112_device *dev = gpiochip_get_data(chip);
struct hid_device *hdev = dev->hdev;
u8 *buf = dev->in_out_buffer;
int ret;
mutex_lock(&dev->lock);
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
HID_REQ_GET_REPORT);
if (ret != CP2112_GPIO_CONFIG_LENGTH) {
hid_err(hdev, "error requesting GPIO config: %d\n", ret);
goto fail;
}
buf[1] |= 1 << offset;
buf[2] = gpio_push_pull;
ret = hid_hw_raw_request(hdev, CP2112_GPIO_CONFIG, buf,
CP2112_GPIO_CONFIG_LENGTH, HID_FEATURE_REPORT,
HID_REQ_SET_REPORT);
if (ret < 0) {
hid_err(hdev, "error setting GPIO config: %d\n", ret);
goto fail;
}
mutex_unlock(&dev->lock);
/*
* 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;
fail:
mutex_unlock(&dev->lock);
return ret < 0 ? ret : -EIO;
}
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;
if (size > sizeof(dev->read_data))
size = sizeof(dev->read_data);
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_write_read_req(void *buf, u8 slave_address,
u8 *addr, int addr_length,
int read_length)
{
struct cp2112_write_read_req_report *report = buf;
if (read_length < 1 || read_length > 512 ||
addr_length > sizeof(report->target_address))
return -EINVAL;
report->report = CP2112_DATA_WRITE_READ_REQUEST;
report->slave_address = slave_address << 1;
report->length = cpu_to_be16(read_length);
report->target_address_length = addr_length;
memcpy(report->target_address, addr, addr_length);
return addr_length + 5;
}
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;
ssize_t read_length = 0;
u8 *read_buf = NULL;
unsigned int retries;
int ret;
hid_dbg(hdev, "I2C %d messages\n", num);
if (num == 1) {
if (msgs->flags & I2C_M_RD) {
hid_dbg(hdev, "I2C read %#04x len %d\n",
msgs->addr, msgs->len);
read_length = msgs->len;
read_buf = msgs->buf;
count = cp2112_read_req(buf, msgs->addr, msgs->len);
} else {
hid_dbg(hdev, "I2C write %#04x len %d\n",
msgs->addr, msgs->len);
count = cp2112_i2c_write_req(buf, msgs->addr,
msgs->buf, msgs->len);
}
if (count < 0)
return count;
} else if (dev->hwversion > 1 && /* no repeated start in rev 1 */
num == 2 &&
msgs[0].addr == msgs[1].addr &&
!(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD)) {
hid_dbg(hdev, "I2C write-read %#04x wlen %d rlen %d\n",
msgs[0].addr, msgs[0].len, msgs[1].len);
read_length = msgs[1].len;
read_buf = msgs[1].buf;
count = cp2112_i2c_write_read_req(buf, msgs[0].addr,
msgs[0].buf, msgs[0].len, msgs[1].len);
if (count < 0)
return count;
} else {
hid_err(hdev,
"Multi-message I2C transactions not supported\n");
return -EOPNOTSUPP;
}
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;
}
for (count = 0; count < read_length;) {
ret = cp2112_read(dev, read_buf + count, read_length - count);
if (ret < 0)
goto power_normal;
if (ret == 0) {
hid_err(hdev, "read returned 0\n");
ret = -EIO;
goto power_normal;
}
count += ret;
if (count > read_length) {
/*
* The hardware returned too much data.
* This is mostly harmless because cp2112_read()
* has a limit check so didn't overrun our
* buffer. Nevertheless, we return an error
* because something is seriously wrong and
* it shouldn't go unnoticed.
*/
hid_err(hdev, "long read: %d > %zd\n",
ret, read_length - count + ret);
ret = -EIO;
goto power_normal;
}
}
/* return the number of transferred messages */
ret = num;
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];
__le16 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, command, 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_le16(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_le16(data->word);
count = cp2112_write_read_req(buf, addr, read_length, command,
(u8 *)&word, 2);
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
if (read_write == I2C_SMBUS_READ) {
read_length = data->block[0];
count = cp2112_write_read_req(buf, addr, read_length,
command, NULL, 0);
} else {
count = cp2112_write_req(buf, addr, command,
data->block + 1,
data->block[0]);
}
break;
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 = le16_to_cpup((__le16 *)buf);
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
memcpy(data->block + 1, buf, read_length);
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 = to_hid_device(kdev); \
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 = to_hid_device(kdev); \
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 = to_hid_device(kdev);
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 = to_hid_device(kdev);
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 void cp2112_gpio_irq_ack(struct irq_data *d)
{
}
static void cp2112_gpio_irq_mask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct cp2112_device *dev = gpiochip_get_data(gc);
__clear_bit(d->hwirq, &dev->irq_mask);
}
static void cp2112_gpio_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct cp2112_device *dev = gpiochip_get_data(gc);
__set_bit(d->hwirq, &dev->irq_mask);
}
static void cp2112_gpio_poll_callback(struct work_struct *work)
{
struct cp2112_device *dev = container_of(work, struct cp2112_device,
gpio_poll_worker.work);
struct irq_data *d;
u8 gpio_mask;
u8 virqs = (u8)dev->irq_mask;
u32 irq_type;
int irq, virq, ret;
ret = cp2112_gpio_get_all(&dev->gc);
if (ret == -ENODEV) /* the hardware has been disconnected */
return;
if (ret < 0)
goto exit;
gpio_mask = ret;
while (virqs) {
virq = ffs(virqs) - 1;
virqs &= ~BIT(virq);
if (!dev->gc.to_irq)
break;
irq = dev->gc.to_irq(&dev->gc, virq);
d = irq_get_irq_data(irq);
if (!d)
continue;
irq_type = irqd_get_trigger_type(d);
if (gpio_mask & BIT(virq)) {
/* Level High */
if (irq_type & IRQ_TYPE_LEVEL_HIGH)
handle_nested_irq(irq);
if ((irq_type & IRQ_TYPE_EDGE_RISING) &&
!(dev->gpio_prev_state & BIT(virq)))
handle_nested_irq(irq);
} else {
/* Level Low */
if (irq_type & IRQ_TYPE_LEVEL_LOW)
handle_nested_irq(irq);
if ((irq_type & IRQ_TYPE_EDGE_FALLING) &&
(dev->gpio_prev_state & BIT(virq)))
handle_nested_irq(irq);
}
}
dev->gpio_prev_state = gpio_mask;
exit:
if (dev->gpio_poll)
schedule_delayed_work(&dev->gpio_poll_worker, 10);
}
static unsigned int cp2112_gpio_irq_startup(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct cp2112_device *dev = gpiochip_get_data(gc);
INIT_DELAYED_WORK(&dev->gpio_poll_worker, cp2112_gpio_poll_callback);
cp2112_gpio_direction_input(gc, d->hwirq);
if (!dev->gpio_poll) {
dev->gpio_poll = true;
schedule_delayed_work(&dev->gpio_poll_worker, 0);
}
cp2112_gpio_irq_unmask(d);
return 0;
}
static void cp2112_gpio_irq_shutdown(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct cp2112_device *dev = gpiochip_get_data(gc);
cancel_delayed_work_sync(&dev->gpio_poll_worker);
}
static int cp2112_gpio_irq_type(struct irq_data *d, unsigned int type)
{
return 0;
}
static struct irq_chip cp2112_gpio_irqchip = {
.name = "cp2112-gpio",
.irq_startup = cp2112_gpio_irq_startup,
.irq_shutdown = cp2112_gpio_irq_shutdown,
.irq_ack = cp2112_gpio_irq_ack,
.irq_mask = cp2112_gpio_irq_mask,
.irq_unmask = cp2112_gpio_irq_unmask,
.irq_set_type = cp2112_gpio_irq_type,
};
static int __maybe_unused cp2112_allocate_irq(struct cp2112_device *dev,
int pin)
{
int ret;
if (dev->desc[pin])
return -EINVAL;
dev->desc[pin] = gpiochip_request_own_desc(&dev->gc, pin,
"HID/I2C:Event");
if (IS_ERR(dev->desc[pin])) {
dev_err(dev->gc.parent, "Failed to request GPIO\n");
return PTR_ERR(dev->desc[pin]);
}
ret = gpiochip_lock_as_irq(&dev->gc, pin);
if (ret) {
dev_err(dev->gc.parent, "Failed to lock GPIO as interrupt\n");
goto err_desc;
}
ret = gpiod_to_irq(dev->desc[pin]);
if (ret < 0) {
dev_err(dev->gc.parent, "Failed to translate GPIO to IRQ\n");
goto err_lock;
}
return ret;
err_lock:
gpiochip_unlock_as_irq(&dev->gc, pin);
err_desc:
gpiochip_free_own_desc(dev->desc[pin]);
dev->desc[pin] = NULL;
return ret;
}
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;
dev = devm_kzalloc(&hdev->dev, sizeof(*dev), GFP_KERNEL);
if (!dev)
return -ENOMEM;
dev->in_out_buffer = devm_kzalloc(&hdev->dev, CP2112_REPORT_MAX_LENGTH,
GFP_KERNEL);
if (!dev->in_out_buffer)
return -ENOMEM;
mutex_init(&dev->lock);
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;
}
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 hidraw%d",
((struct hidraw *)hdev->hidraw)->minor);
dev->hwversion = buf[2];
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_power_normal;
}
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.parent = &hdev->dev;
ret = gpiochip_add_data(&dev->gc, dev);
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);
ret = gpiochip_irqchip_add(&dev->gc, &cp2112_gpio_irqchip, 0,
handle_simple_irq, IRQ_TYPE_NONE);
if (ret) {
dev_err(dev->gc.parent, "failed to add IRQ chip\n");
goto err_sysfs_remove;
}
return ret;
err_sysfs_remove:
sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
err_gpiochip_remove:
gpiochip_remove(&dev->gc);
err_free_i2c:
i2c_del_adapter(&dev->adap);
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);
int i;
sysfs_remove_group(&hdev->dev.kobj, &cp2112_attr_group);
i2c_del_adapter(&dev->adap);
if (dev->gpio_poll) {
dev->gpio_poll = false;
cancel_delayed_work_sync(&dev->gpio_poll_worker);
}
for (i = 0; i < ARRAY_SIZE(dev->desc); i++) {
gpiochip_unlock_as_irq(&dev->gc, i);
gpiochip_free_own_desc(dev->desc[i]);
}
gpiochip_remove(&dev->gc);
/* 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);
}
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");
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