[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: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/cp2101.c b/drivers/usb/serial/cp2101.c
index 7e9bb63..4ace996 100644
--- a/drivers/usb/serial/cp2101.c
+++ b/drivers/usb/serial/cp2101.c
@@ -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_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 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 @@
.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 @@
#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;
- /*For get requests, the request number must be incremented*/
+ /* 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 */
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) {
+ /* Convert data into an array of integers */
+ for (i=0; i<length; i++)
+ data[i] = le32_to_cpu(buf[i]);
+
+ kfree(buf);
+
+ if (result != size) {
dev_err(&port->dev, "%s - Unable to send config request, "
- "request=0x%x result=%d\n",
- __FUNCTION__, request, result);
- return result;
+ "request=0x%x size=%d result=%d\n",
+ __FUNCTION__, request, size, result);
+ return -EPROTO;
}
- /*Assemble each byte read into an integer value*/
- value = 0;
- for (i=0; i<4 && i<result; i++)
- value |= (buf[i] << (i * 8));
-
- dbg( " %s - request=0x%x result=%d value=0x%x",
- __FUNCTION__, request, result, value);
-
- return value;
-}
-
-static int cp2101_set_config(struct usb_serial_port* port, u8 request, u16 value)
-{
- 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);
-
- 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;
- }
-
- dbg(" %s - request=0x%x value=0x%x result=%d",
- __FUNCTION__, request, value, result);
-
return 0;
}
+/*
+ * 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;
+ 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);
+ 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);
+ }
+
+ 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 @@
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 @@
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 @@
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 @@
}
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 @@
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 @@
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 @@
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 @@
"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 @@
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 @@
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 @@
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 @@
}
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 @@
/* 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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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;
}