diff options
| author | Johan Hovold | 2013-12-29 19:23:13 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2014-01-03 12:31:48 -0800 |
| commit | c82c6d45a2fc882fedfde517ba86690b2d5ed555 (patch) | |
| tree | 4e5192dca62e8c971300bcc380db6d83b67d2815 /drivers/usb | |
| parent | 871996ede12306cd1d75ed8135bed6f1fcbcd0e6 (diff) | |
USB: pl2303: refactor baud-rate divisor handling
Refactor baud-rate divisor handling.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
| -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); |