static int mct_u232_set_baud_rate(struct usb_serial *serial, int value)
{
__le32 divisor;
int rc;
unsigned char zero_byte = 0;
divisor = cpu_to_le32(mct_u232_calculate_baud_rate(serial, value));
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
MCT_U232_SET_BAUD_RATE_REQUEST,
MCT_U232_SET_REQUEST_TYPE,
0, 0, &divisor, MCT_U232_SET_BAUD_RATE_SIZE,
WDR_TIMEOUT);
if (rc < 0)
err("Set BAUD RATE %d failed (error = %d)", value, rc);
dbg("set_baud_rate: value: 0x%x, divisor: 0x%x", value, divisor);
/* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
always sends two extra USB 'device request' messages after the
'baud rate change' message. The actual functionality of the
request codes in these messages is not fully understood but these
particular codes are never seen in any operation besides a baud
rate change. Both of these messages send a single byte of data
whose value is always zero. The second of these two extra messages
is required in order for data to be properly written to an RS-232
device which does not assert the 'CTS' signal. */
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
MCT_U232_SET_UNKNOWN1_REQUEST,
MCT_U232_SET_REQUEST_TYPE,
0, 0, &zero_byte, MCT_U232_SET_UNKNOWN1_SIZE,
WDR_TIMEOUT);
if (rc < 0)
err("Sending USB device request code %d failed (error = %d)",
MCT_U232_SET_UNKNOWN1_REQUEST, rc);
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
MCT_U232_SET_UNKNOWN2_REQUEST,
MCT_U232_SET_REQUEST_TYPE,
0, 0, &zero_byte, MCT_U232_SET_UNKNOWN2_SIZE,
WDR_TIMEOUT);
if (rc < 0)
err("Sending USB device request code %d failed (error = %d)",
MCT_U232_SET_UNKNOWN2_REQUEST, rc);
return rc;
} /* mct_u232_set_baud_rate */
static int mct_u232_set_baud_rate(struct tty_struct *tty,
struct usb_serial *serial, struct usb_serial_port *port, speed_t value)
{
unsigned int divisor;
int rc;
unsigned char *buf;
unsigned char cts_enable_byte = 0;
speed_t speed;
buf = kmalloc(MCT_U232_MAX_SIZE, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
divisor = mct_u232_calculate_baud_rate(serial, value, &speed);
put_unaligned_le32(cpu_to_le32(divisor), buf);
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
MCT_U232_SET_BAUD_RATE_REQUEST,
MCT_U232_SET_REQUEST_TYPE,
0, 0, buf, MCT_U232_SET_BAUD_RATE_SIZE,
WDR_TIMEOUT);
if (rc < 0) /*FIXME: What value speed results */
dev_err(&port->dev, "Set BAUD RATE %d failed (error = %d)\n",
value, rc);
else
tty_encode_baud_rate(tty, speed, speed);
dbg("set_baud_rate: value: 0x%x, divisor: 0x%x", value, divisor);
/* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
always sends two extra USB 'device request' messages after the
'baud rate change' message. The actual functionality of the
request codes in these messages is not fully understood but these
particular codes are never seen in any operation besides a baud
rate change. Both of these messages send a single byte of data.
In the first message, the value of this byte is always zero.
The second message has been determined experimentally to control
whether data will be transmitted to a device which is not asserting
the 'CTS' signal. If the second message's data byte is zero, data
will be transmitted even if 'CTS' is not asserted (i.e. no hardware
flow control). if the second message's data byte is nonzero (a
value of 1 is used by this driver), data will not be transmitted to
a device which is not asserting 'CTS'.
*/
buf[0] = 0;
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
MCT_U232_SET_UNKNOWN1_REQUEST,
MCT_U232_SET_REQUEST_TYPE,
0, 0, buf, MCT_U232_SET_UNKNOWN1_SIZE,
WDR_TIMEOUT);
if (rc < 0)
dev_err(&port->dev, "Sending USB device request code %d "
"failed (error = %d)\n", MCT_U232_SET_UNKNOWN1_REQUEST,
rc);
if (port && C_CRTSCTS(tty))
cts_enable_byte = 1;
dbg("set_baud_rate: send second control message, data = %02X",
cts_enable_byte);
buf[0] = cts_enable_byte;
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
MCT_U232_SET_CTS_REQUEST,
MCT_U232_SET_REQUEST_TYPE,
0, 0, buf, MCT_U232_SET_CTS_SIZE,
WDR_TIMEOUT);
if (rc < 0)
dev_err(&port->dev, "Sending USB device request code %d "
"failed (error = %d)\n", MCT_U232_SET_CTS_REQUEST, rc);
kfree(buf);
return rc;
} /* mct_u232_set_baud_rate */
static int mct_u232_set_baud_rate(struct usb_serial *serial, struct usb_serial_port *port,
speed_t value)
{
__le32 divisor;
int rc;
unsigned char zero_byte = 0;
unsigned char cts_enable_byte = 0;
divisor = cpu_to_le32(mct_u232_calculate_baud_rate(serial, value));
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
MCT_U232_SET_BAUD_RATE_REQUEST,
MCT_U232_SET_REQUEST_TYPE,
0, 0, &divisor, MCT_U232_SET_BAUD_RATE_SIZE,
WDR_TIMEOUT);
if (rc < 0)
err("Set BAUD RATE %d failed (error = %d)", value, rc);
dbg("set_baud_rate: value: 0x%x, divisor: 0x%x", value, divisor);
/* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
always sends two extra USB 'device request' messages after the
'baud rate change' message. The actual functionality of the
request codes in these messages is not fully understood but these
particular codes are never seen in any operation besides a baud
rate change. Both of these messages send a single byte of data.
In the first message, the value of this byte is always zero.
The second message has been determined experimentally to control
whether data will be transmitted to a device which is not asserting
the 'CTS' signal. If the second message's data byte is zero, data
will be transmitted even if 'CTS' is not asserted (i.e. no hardware
flow control). if the second message's data byte is nonzero (a value
of 1 is used by this driver), data will not be transmitted to a device
which is not asserting 'CTS'.
*/
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
MCT_U232_SET_UNKNOWN1_REQUEST,
MCT_U232_SET_REQUEST_TYPE,
0, 0, &zero_byte, MCT_U232_SET_UNKNOWN1_SIZE,
WDR_TIMEOUT);
if (rc < 0)
err("Sending USB device request code %d failed (error = %d)",
MCT_U232_SET_UNKNOWN1_REQUEST, rc);
if (port && C_CRTSCTS(port->tty)) {
cts_enable_byte = 1;
}
dbg("set_baud_rate: send second control message, data = %02X", cts_enable_byte);
rc = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
MCT_U232_SET_CTS_REQUEST,
MCT_U232_SET_REQUEST_TYPE,
0, 0, &cts_enable_byte, MCT_U232_SET_CTS_SIZE,
WDR_TIMEOUT);
if (rc < 0)
err("Sending USB device request code %d failed (error = %d)",
MCT_U232_SET_CTS_REQUEST, rc);
return rc;
} /* mct_u232_set_baud_rate */
