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USB: pl2303: add helper function for direct baud-rate encoding

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Add helper function for direct baud-rate encoding.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2013-12-29 19:23:14 +01:00 committed by Greg Kroah-Hartman
parent c82c6d45a2
commit 20b4c78719
1 changed files with 15 additions and 7 deletions
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22
drivers/usb/serial/pl2303.c
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@ -339,6 +339,18 @@ static speed_t pl2303_get_supported_baud_rate(speed_t baud)
return baud;
}
/*
* NOTE: If unsupported baud rates are set directly, the PL2303 seems to
* use 9600 baud.
*/
static speed_t pl2303_encode_baud_rate_direct(unsigned char buf[4],
speed_t baud)
{
put_unaligned_le32(baud, buf);
return baud;
}
static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4],
speed_t baud)
{
@ -376,16 +388,12 @@ static void pl2303_encode_baud_rate(struct tty_struct *tty,
if (spriv->type->max_baud_rate)
baud = min_t(speed_t, baud, spriv->type->max_baud_rate);
/*
* Set baud rate to nearest supported value.
*
* NOTE: If unsupported values are set directly, the PL2303 seems to
* use 9600 baud.
*/
/* Set baud rate to nearest supported value. */
baud = pl2303_get_supported_baud_rate(baud);
if (baud <= 115200)
put_unaligned_le32(baud, buf);
baud = pl2303_encode_baud_rate_direct(buf, baud);
else
baud = pl2303_encode_baud_rate_divisor(buf, baud);