diff options
| -rw-r--r-- | drivers/usb/serial/pl2303.c | 41 |
1 files changed, 25 insertions, 16 deletions
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index 394903b4ecb7..44f4b546adeb 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -339,6 +339,28 @@ static speed_t pl2303_get_supported_baud_rate(speed_t baud) return baud; } +static speed_t pl2303_encode_baud_rate_divisor(unsigned char buf[4], + speed_t baud) +{ + unsigned int tmp; + + /* + * Apparently the formula is: + * baudrate = 12M * 32 / (2^buf[1]) / buf[0] + */ + tmp = 12000000 * 32 / baud; + buf[3] = 0x80; + buf[2] = 0; + buf[1] = (tmp >= 256); + while (tmp >= 256) { + tmp >>= 2; + buf[1] <<= 1; + } + buf[0] = tmp; + + return baud; +} + static void pl2303_encode_baud_rate(struct tty_struct *tty, struct usb_serial_port *port, u8 buf[4]) @@ -362,23 +384,10 @@ static void pl2303_encode_baud_rate(struct tty_struct *tty, */ baud = pl2303_get_supported_baud_rate(baud); - if (baud <= 115200) { + if (baud <= 115200) put_unaligned_le32(baud, buf); - } else { - /* - * Apparently the formula for higher speeds is: - * baudrate = 12M * 32 / (2^buf[1]) / buf[0] - */ - unsigned tmp = 12000000 * 32 / baud; - buf[3] = 0x80; - buf[2] = 0; - buf[1] = (tmp >= 256); - while (tmp >= 256) { - tmp >>= 2; - buf[1] <<= 1; - } - buf[0] = tmp; - } + else + baud = pl2303_encode_baud_rate_divisor(buf, baud); /* Save resulting baud rate */ tty_encode_baud_rate(tty, baud, baud); |