Commit 39a66b8d authored by Craig Shelley's avatar Craig Shelley Committed by Greg KH

[PATCH] USB: CP2101 Add support for flow control

Added support to get/set flow control line levels using TIOCMGET and
TIOCMSET.
Added support for RTSCTS hardware flow control.
cp2101_get_config and cp2101_set_config modified to support long request
strings, required for configuring flow control.

Signed-off-by: Craig Shelley craig@microtron.org.uk
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 719df469
......@@ -7,6 +7,14 @@
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* Support to set flow control line levels using TIOCMGET and TIOCMSET
* thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
* control thanks to Munir Nassar nassarmu@real-time.com
*
* Outstanding Issues:
* Buffers are not flushed when the port is opened.
* Multiple calls to write() may fail with "Resource temporarily unavailable"
*
*/
#include <linux/config.h>
......@@ -24,7 +32,7 @@
/*
* Version Information
*/
#define DRIVER_VERSION "v0.03"
#define DRIVER_VERSION "v0.04"
#define DRIVER_DESC "Silicon Labs CP2101/CP2102 RS232 serial adaptor driver"
/*
......@@ -35,6 +43,9 @@ static void cp2101_cleanup(struct usb_serial_port*);
static void cp2101_close(struct usb_serial_port*, struct file*);
static void cp2101_get_termios(struct usb_serial_port*);
static void cp2101_set_termios(struct usb_serial_port*, struct termios*);
static int cp2101_tiocmget (struct usb_serial_port *, struct file *);
static int cp2101_tiocmset (struct usb_serial_port *, struct file *,
unsigned int, unsigned int);
static void cp2101_break_ctl(struct usb_serial_port*, int);
static int cp2101_startup (struct usb_serial *);
static void cp2101_shutdown(struct usb_serial*);
......@@ -43,9 +54,10 @@ static void cp2101_shutdown(struct usb_serial*);
static int debug;
static struct usb_device_id id_table [] = {
{USB_DEVICE(0x10c4, 0xea60) }, /*Silicon labs factory default*/
{USB_DEVICE(0x10ab, 0x10c5) }, /*Siemens MC60 Cable*/
{ } /* Terminating Entry*/
{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
{ } /* Terminating Entry */
};
MODULE_DEVICE_TABLE (usb, id_table);
......@@ -70,32 +82,35 @@ static struct usb_serial_device_type cp2101_device = {
.close = cp2101_close,
.break_ctl = cp2101_break_ctl,
.set_termios = cp2101_set_termios,
.tiocmget = cp2101_tiocmget,
.tiocmset = cp2101_tiocmset,
.attach = cp2101_startup,
.shutdown = cp2101_shutdown,
};
/*Config request types*/
/* Config request types */
#define REQTYPE_HOST_TO_DEVICE 0x41
#define REQTYPE_DEVICE_TO_HOST 0xc1
/*Config SET requests. To GET, add 1 to the request number*/
#define CP2101_UART 0x00 /*Enable / Disable*/
#define CP2101_BAUDRATE 0x01 /*(BAUD_RATE_GEN_FREQ / baudrate)*/
#define CP2101_BITS 0x03 /*0x(0)(data bits)(parity)(stop bits)*/
#define CP2101_BREAK 0x05 /*On / Off*/
#define CP2101_DTRRTS 0x07 /*101 / 202 ???*/
#define CP2101_CONFIG_16 0x13 /*16 bytes of config data ???*/
#define CP2101_CONFIG_6 0x19 /*6 bytes of config data ???*/
/* Config SET requests. To GET, add 1 to the request number */
#define CP2101_UART 0x00 /* Enable / Disable */
#define CP2101_BAUDRATE 0x01 /* (BAUD_RATE_GEN_FREQ / baudrate) */
#define CP2101_BITS 0x03 /* 0x(0)(databits)(parity)(stopbits) */
#define CP2101_BREAK 0x05 /* On / Off */
#define CP2101_CONTROL 0x07 /* Flow control line states */
#define CP2101_MODEMCTL 0x13 /* Modem controls */
#define CP2101_CONFIG_6 0x19 /* 6 bytes of config data ??? */
/*CP2101_UART*/
/* CP2101_UART */
#define UART_ENABLE 0x0001
#define UART_DISABLE 0x0000
/*CP2101_BAUDRATE*/
/* CP2101_BAUDRATE */
#define BAUD_RATE_GEN_FREQ 0x384000
/*CP2101_BITS*/
/* CP2101_BITS */
#define BITS_DATA_MASK 0X0f00
#define BITS_DATA_5 0X0500
#define BITS_DATA_6 0X0600
#define BITS_DATA_7 0X0700
#define BITS_DATA_8 0X0800
......@@ -112,64 +127,137 @@ static struct usb_serial_device_type cp2101_device = {
#define BITS_STOP_1 0x0000
#define BITS_STOP_1_5 0x0001
#define BITS_STOP_2 0x0002
/* CP2101_BREAK */
#define BREAK_ON 0x0000
#define BREAK_OFF 0x0001
/* CP2101_CONTROL */
#define CONTROL_DTR 0x0001
#define CONTROL_RTS 0x0002
#define CONTROL_CTS 0x0010
#define CONTROL_DSR 0x0020
#define CONTROL_RING 0x0040
#define CONTROL_DCD 0x0080
#define CONTROL_WRITE_DTR 0x0100
#define CONTROL_WRITE_RTS 0x0200
static int cp2101_get_config(struct usb_serial_port* port, u8 request)
/*
* cp2101_get_config
* Reads from the CP2101 configuration registers
* 'size' is specified in bytes.
* 'data' is a pointer to a pre-allocated array of integers large
* enough to hold 'size' bytes (with 4 bytes to each integer)
*/
static int cp2101_get_config(struct usb_serial_port* port, u8 request,
unsigned int *data, int size)
{
struct usb_serial *serial = port->serial;
unsigned char buf[4];
unsigned int value;
int result, i;
u32 *buf;
int result, i, length;
/* Number of integers required to contain the array */
length = (((size - 1) | 3) + 1)/4;
buf = kmalloc (length * sizeof(u32), GFP_KERNEL);
memset(buf, 0, length * sizeof(u32));
if (!buf) {
dev_err(&port->dev, "%s - out of memory.\n", __FUNCTION__);
return -ENOMEM;
}
/*For get requests, the request number must be incremented*/
/* For get requests, the request number must be incremented */
request++;
/*Issue the request, attempting to read 4 bytes*/
/* Issue the request, attempting to read 'size' bytes */
result = usb_control_msg (serial->dev,usb_rcvctrlpipe (serial->dev, 0),
request, REQTYPE_DEVICE_TO_HOST, 0x0000,
0, buf, 4, 300);
0, buf, size, 300);
if (result < 0) {
dev_err(&port->dev, "%s - Unable to send config request, "
"request=0x%x result=%d\n",
__FUNCTION__, request, result);
return result;
}
/* Convert data into an array of integers */
for (i=0; i<length; i++)
data[i] = le32_to_cpu(buf[i]);
/*Assemble each byte read into an integer value*/
value = 0;
for (i=0; i<4 && i<result; i++)
value |= (buf[i] << (i * 8));
kfree(buf);
dbg( " %s - request=0x%x result=%d value=0x%x",
__FUNCTION__, request, result, value);
if (result != size) {
dev_err(&port->dev, "%s - Unable to send config request, "
"request=0x%x size=%d result=%d\n",
__FUNCTION__, request, size, result);
return -EPROTO;
}
return value;
return 0;
}
static int cp2101_set_config(struct usb_serial_port* port, u8 request, u16 value)
/*
* cp2101_set_config
* Writes to the CP2101 configuration registers
* Values less than 16 bits wide are sent directly
* 'size' is specified in bytes.
*/
static int cp2101_set_config(struct usb_serial_port* port, u8 request,
unsigned int *data, int size)
{
struct usb_serial *serial = port->serial;
int result;
result = usb_control_msg (serial->dev, usb_sndctrlpipe(serial->dev, 0),
request, REQTYPE_HOST_TO_DEVICE, value,
0, NULL, 0, 300);
u32 *buf;
int result, i, length;
if (result <0) {
dev_err(&port->dev, "%s - Unable to send config request, "
"request=0x%x value=0x%x result=%d\n",
__FUNCTION__, request, value, result);
return result;
/* Number of integers required to contain the array */
length = (((size - 1) | 3) + 1)/4;
buf = kmalloc(length * sizeof(u32), GFP_KERNEL);
if (!buf) {
dev_err(&port->dev, "%s - out of memory.\n",
__FUNCTION__);
return -ENOMEM;
}
/* Array of integers into bytes */
for (i = 0; i < length; i++)
buf[i] = cpu_to_le32(data[i]);
if (size > 2) {
result = usb_control_msg (serial->dev,
usb_sndctrlpipe(serial->dev, 0),
request, REQTYPE_HOST_TO_DEVICE, 0x0000,
0, buf, size, 300);
} else {
result = usb_control_msg (serial->dev,
usb_sndctrlpipe(serial->dev, 0),
request, REQTYPE_HOST_TO_DEVICE, data[0],
0, NULL, 0, 300);
}
dbg(" %s - request=0x%x value=0x%x result=%d",
__FUNCTION__, request, value, result);
kfree(buf);
if ((size > 2 && result != size) || result < 0) {
dev_err(&port->dev, "%s - Unable to send request, "
"request=0x%x size=%d result=%d\n",
__FUNCTION__, request, size, result);
return -EPROTO;
}
/* Single data value */
result = usb_control_msg (serial->dev,
usb_sndctrlpipe(serial->dev, 0),
request, REQTYPE_HOST_TO_DEVICE, data[0],
0, NULL, 0, 300);
return 0;
}
/*
* cp2101_set_config_single
* Convenience function for calling cp2101_set_config on single data values
* without requiring an integer pointer
*/
static inline int cp2101_set_config_single(struct usb_serial_port* port,
u8 request, unsigned int data)
{
return cp2101_set_config(port, request, &data, 2);
}
static int cp2101_open (struct usb_serial_port *port, struct file *filp)
{
struct usb_serial *serial = port->serial;
......@@ -177,7 +265,7 @@ static int cp2101_open (struct usb_serial_port *port, struct file *filp)
dbg("%s - port %d", __FUNCTION__, port->number);
if (cp2101_set_config(port, CP2101_UART, UART_ENABLE)) {
if (cp2101_set_config_single(port, CP2101_UART, UART_ENABLE)) {
dev_err(&port->dev, "%s - Unable to enable UART\n",
__FUNCTION__);
return -EPROTO;
......@@ -198,9 +286,12 @@ static int cp2101_open (struct usb_serial_port *port, struct file *filp)
return result;
}
/*Configure the termios structure*/
/* Configure the termios structure */
cp2101_get_termios(port);
/* Set the DTR and RTS pins low */
cp2101_tiocmset(port, NULL, TIOCM_DTR | TIOCM_RTS, 0);
return 0;
}
......@@ -228,16 +319,18 @@ static void cp2101_close (struct usb_serial_port *port, struct file * filp)
usb_kill_urb(port->write_urb);
usb_kill_urb(port->read_urb);
cp2101_set_config(port, CP2101_UART, UART_DISABLE);
cp2101_set_config_single(port, CP2101_UART, UART_DISABLE);
}
/* cp2101_get_termios*/
/* Reads the baud rate, data bits, parity and stop bits from the device*/
/* Corrects any unsupported values*/
/* Configures the termios structure to reflect the state of the device*/
/*
* cp2101_get_termios
* Reads the baud rate, data bits, parity, stop bits and flow control mode
* from the device, corrects any unsupported values, and configures the
* termios structure to reflect the state of the device
*/
static void cp2101_get_termios (struct usb_serial_port *port)
{
unsigned int cflag;
unsigned int cflag, modem_ctl[4];
int baud;
int bits;
......@@ -249,15 +342,16 @@ static void cp2101_get_termios (struct usb_serial_port *port)
}
cflag = port->tty->termios->c_cflag;
baud = cp2101_get_config(port, CP2101_BAUDRATE);
/*Convert to baudrate*/
cp2101_get_config(port, CP2101_BAUDRATE, &baud, 2);
/* Convert to baudrate */
if (baud)
baud = BAUD_RATE_GEN_FREQ / baud;
dbg("%s - baud rate = %d", __FUNCTION__, baud);
cflag &= ~CBAUD;
switch (baud) {
/* The baud rates which are commented out below
/*
* The baud rates which are commented out below
* appear to be supported by the device
* but are non-standard
*/
......@@ -284,14 +378,18 @@ static void cp2101_get_termios (struct usb_serial_port *port)
dbg("%s - Baud rate is not supported, "
"using 9600 baud", __FUNCTION__);
cflag |= B9600;
cp2101_set_config(port, CP2101_BAUDRATE,
cp2101_set_config_single(port, CP2101_BAUDRATE,
(BAUD_RATE_GEN_FREQ/9600));
break;
}
bits = cp2101_get_config(port, CP2101_BITS);
cp2101_get_config(port, CP2101_BITS, &bits, 2);
cflag &= ~CSIZE;
switch(bits & BITS_DATA_MASK) {
case BITS_DATA_5:
dbg("%s - data bits = 5", __FUNCTION__);
cflag |= CS5;
break;
case BITS_DATA_6:
dbg("%s - data bits = 6", __FUNCTION__);
cflag |= CS6;
......@@ -310,7 +408,7 @@ static void cp2101_get_termios (struct usb_serial_port *port)
cflag |= CS8;
bits &= ~BITS_DATA_MASK;
bits |= BITS_DATA_8;
cp2101_set_config(port, CP2101_BITS, bits);
cp2101_set_config(port, CP2101_BITS, &bits, 2);
break;
default:
dbg("%s - Unknown number of data bits, "
......@@ -318,7 +416,7 @@ static void cp2101_get_termios (struct usb_serial_port *port)
cflag |= CS8;
bits &= ~BITS_DATA_MASK;
bits |= BITS_DATA_8;
cp2101_set_config(port, CP2101_BITS, bits);
cp2101_set_config(port, CP2101_BITS, &bits, 2);
break;
}
......@@ -341,21 +439,21 @@ static void cp2101_get_termios (struct usb_serial_port *port)
"disabling parity)", __FUNCTION__);
cflag &= ~PARENB;
bits &= ~BITS_PARITY_MASK;
cp2101_set_config(port, CP2101_BITS, bits);
cp2101_set_config(port, CP2101_BITS, &bits, 2);
break;
case BITS_PARITY_SPACE:
dbg("%s - parity = SPACE (not supported, "
"disabling parity)", __FUNCTION__);
cflag &= ~PARENB;
bits &= ~BITS_PARITY_MASK;
cp2101_set_config(port, CP2101_BITS, bits);
cp2101_set_config(port, CP2101_BITS, &bits, 2);
break;
default:
dbg("%s - Unknown parity mode, "
"disabling parity", __FUNCTION__);
cflag &= ~PARENB;
bits &= ~BITS_PARITY_MASK;
cp2101_set_config(port, CP2101_BITS, bits);
cp2101_set_config(port, CP2101_BITS, &bits, 2);
break;
}
......@@ -366,9 +464,9 @@ static void cp2101_get_termios (struct usb_serial_port *port)
break;
case BITS_STOP_1_5:
dbg("%s - stop bits = 1.5 (not supported, "
"using 1 stop bit", __FUNCTION__);
"using 1 stop bit)", __FUNCTION__);
bits &= ~BITS_STOP_MASK;
cp2101_set_config(port, CP2101_BITS, bits);
cp2101_set_config(port, CP2101_BITS, &bits, 2);
break;
case BITS_STOP_2:
dbg("%s - stop bits = 2", __FUNCTION__);
......@@ -378,10 +476,19 @@ static void cp2101_get_termios (struct usb_serial_port *port)
dbg("%s - Unknown number of stop bits, "
"using 1 stop bit", __FUNCTION__);
bits &= ~BITS_STOP_MASK;
cp2101_set_config(port, CP2101_BITS, bits);
cp2101_set_config(port, CP2101_BITS, &bits, 2);
break;
}
cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);
if (modem_ctl[0] & 0x0008) {
dbg("%s - flow control = CRTSCTS", __FUNCTION__);
cflag |= CRTSCTS;
} else {
dbg("%s - flow control = NONE", __FUNCTION__);
cflag &= ~CRTSCTS;
}
port->tty->termios->c_cflag = cflag;
}
......@@ -389,8 +496,8 @@ static void cp2101_set_termios (struct usb_serial_port *port,
struct termios *old_termios)
{
unsigned int cflag, old_cflag=0;
int baud=0;
int bits;
int baud=0, bits;
unsigned int modem_ctl[4];
dbg("%s - port %d", __FUNCTION__, port->number);
......@@ -400,7 +507,7 @@ static void cp2101_set_termios (struct usb_serial_port *port,
}
cflag = port->tty->termios->c_cflag;
/* check that they really want us to change something */
/* Check that they really want us to change something */
if (old_termios) {
if ((cflag == old_termios->c_cflag) &&
(RELEVANT_IFLAG(port->tty->termios->c_iflag)
......@@ -415,7 +522,8 @@ static void cp2101_set_termios (struct usb_serial_port *port,
/* If the baud rate is to be updated*/
if ((cflag & CBAUD) != (old_cflag & CBAUD)) {
switch (cflag & CBAUD) {
/* The baud rates which are commented out below
/*
* The baud rates which are commented out below
* appear to be supported by the device
* but are non-standard
*/
......@@ -448,18 +556,22 @@ static void cp2101_set_termios (struct usb_serial_port *port,
if (baud) {
dbg("%s - Setting baud rate to %d baud", __FUNCTION__,
baud);
if (cp2101_set_config(port, CP2101_BAUDRATE,
if (cp2101_set_config_single(port, CP2101_BAUDRATE,
(BAUD_RATE_GEN_FREQ / baud)))
dev_err(&port->dev, "Baud rate requested not "
"supported by device\n");
}
}
/*If the number of data bits is to be updated*/
/* If the number of data bits is to be updated */
if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
bits = cp2101_get_config(port, CP2101_BITS);
cp2101_get_config(port, CP2101_BITS, &bits, 2);
bits &= ~BITS_DATA_MASK;
switch (cflag & CSIZE) {
case CS5:
bits |= BITS_DATA_5;
dbg("%s - data bits = 5", __FUNCTION__);
break;
case CS6:
bits |= BITS_DATA_6;
dbg("%s - data bits = 6", __FUNCTION__);
......@@ -483,13 +595,13 @@ static void cp2101_set_termios (struct usb_serial_port *port,
bits |= BITS_DATA_8;
break;
}
if (cp2101_set_config(port, CP2101_BITS, bits))
if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
dev_err(&port->dev, "Number of data bits requested "
"not supported by device\n");
}
if ((cflag & (PARENB|PARODD)) != (old_cflag & (PARENB|PARODD))) {
bits = cp2101_get_config(port, CP2101_BITS);
cp2101_get_config(port, CP2101_BITS, &bits, 2);
bits &= ~BITS_PARITY_MASK;
if (cflag & PARENB) {
if (cflag & PARODD) {
......@@ -500,13 +612,13 @@ static void cp2101_set_termios (struct usb_serial_port *port,
dbg("%s - parity = EVEN", __FUNCTION__);
}
}
if (cp2101_set_config(port, CP2101_BITS, bits))
if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
dev_err(&port->dev, "Parity mode not supported "
"by device\n");
}
if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
bits = cp2101_get_config(port, CP2101_BITS);
cp2101_get_config(port, CP2101_BITS, &bits, 2);
bits &= ~BITS_STOP_MASK;
if (cflag & CSTOPB) {
bits |= BITS_STOP_2;
......@@ -515,15 +627,90 @@ static void cp2101_set_termios (struct usb_serial_port *port,
bits |= BITS_STOP_1;
dbg("%s - stop bits = 1", __FUNCTION__);
}
if (cp2101_set_config(port, CP2101_BITS, bits))
if (cp2101_set_config(port, CP2101_BITS, &bits, 2))
dev_err(&port->dev, "Number of stop bits requested "
"not supported by device\n");
}
if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
cp2101_get_config(port, CP2101_MODEMCTL, modem_ctl, 16);
dbg("%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
__FUNCTION__, modem_ctl[0], modem_ctl[1],
modem_ctl[2], modem_ctl[3]);
if (cflag & CRTSCTS) {
modem_ctl[0] &= ~0x7B;
modem_ctl[0] |= 0x09;
modem_ctl[1] = 0x80;
dbg("%s - flow control = CRTSCTS", __FUNCTION__);
} else {
modem_ctl[0] &= ~0x7B;
modem_ctl[0] |= 0x01;
modem_ctl[1] |= 0x40;
dbg("%s - flow control = NONE", __FUNCTION__);
}
dbg("%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x",
__FUNCTION__, modem_ctl[0], modem_ctl[1],
modem_ctl[2], modem_ctl[3]);
cp2101_set_config(port, CP2101_MODEMCTL, modem_ctl, 16);
}
}
static int cp2101_tiocmset (struct usb_serial_port *port, struct file *file,
unsigned int set, unsigned int clear)
{
int control = 0;
dbg("%s - port %d", __FUNCTION__, port->number);
if (set & TIOCM_RTS) {
control |= CONTROL_RTS;
control |= CONTROL_WRITE_RTS;
}
if (set & TIOCM_DTR) {
control |= CONTROL_DTR;
control |= CONTROL_WRITE_DTR;
}
if (clear & TIOCM_RTS) {
control &= ~CONTROL_RTS;
control |= CONTROL_WRITE_RTS;
}
if (clear & TIOCM_DTR) {
control &= ~CONTROL_DTR;
control |= CONTROL_WRITE_DTR;
}
dbg("%s - control = 0x%.4x", __FUNCTION__, control);
return cp2101_set_config(port, CP2101_CONTROL, &control, 2);
}
static int cp2101_tiocmget (struct usb_serial_port *port, struct file *file)
{
int control, result;
dbg("%s - port %d", __FUNCTION__, port->number);
cp2101_get_config(port, CP2101_CONTROL, &control, 1);
result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
|((control & CONTROL_RING)? TIOCM_RI : 0)
|((control & CONTROL_DCD) ? TIOCM_CD : 0);
dbg("%s - control = 0x%.2x", __FUNCTION__, control);
return result;
}
static void cp2101_break_ctl (struct usb_serial_port *port, int break_state)
{
u16 state;
int state;
dbg("%s - port %d", __FUNCTION__, port->number);
if (break_state == 0)
......@@ -532,12 +719,12 @@ static void cp2101_break_ctl (struct usb_serial_port *port, int break_state)
state = BREAK_ON;
dbg("%s - turning break %s", __FUNCTION__,
state==BREAK_OFF ? "off" : "on");
cp2101_set_config(port, CP2101_BREAK, state);
cp2101_set_config(port, CP2101_BREAK, &state, 2);
}
static int cp2101_startup (struct usb_serial *serial)
{
/*CP2101 buffers behave strangely unless device is reset*/
/* CP2101 buffers behave strangely unless device is reset */
usb_reset_device(serial->dev);
return 0;
}
......@@ -548,7 +735,7 @@ static void cp2101_shutdown (struct usb_serial *serial)
dbg("%s", __FUNCTION__);
/* stop reads and writes on all ports */
/* Stop reads and writes on all ports */
for (i=0; i < serial->num_ports; ++i) {
cp2101_cleanup(serial->port[i]);
}
......@@ -560,16 +747,16 @@ static int __init cp2101_init (void)
retval = usb_serial_register(&cp2101_device);
if (retval)
return retval; /*Failed to register*/
return retval; /* Failed to register */
retval = usb_register(&cp2101_driver);
if (retval) {
/*Failed to register*/
/* Failed to register */
usb_serial_deregister(&cp2101_device);
return retval;
}
/*Success*/
/* Success */
info(DRIVER_DESC " " DRIVER_VERSION);
return 0;
}
......
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