diff options
| -rw-r--r-- | drivers/usb/serial/pl2303.c | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index 4cbe59c4ae7f..82055b07e02c 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -528,6 +528,12 @@ static void pl2303_set_termios(struct tty_struct *tty, int baud; int i; u8 control; + const int baud_sup[] = { 75, 150, 300, 600, 1200, 1800, 2400, 3600, + 4800, 7200, 9600, 14400, 19200, 28800, 38400, + 57600, 115200, 230400, 460800, 614400, + 921600, 1228800, 2457600, 3000000, 6000000 }; + int baud_floor, baud_ceil; + int k; dbg("%s - port %d", __func__, port->number); @@ -573,9 +579,39 @@ static void pl2303_set_termios(struct tty_struct *tty, dbg("%s - data bits = %d", __func__, buf[6]); } + /* For reference buf[0]:buf[3] baud rate value */ + /* NOTE: Only the values defined in baud_sup are supported ! + * => if unsupported values are set, the PL2303 seems to use + * 9600 baud (at least my PL2303X always does) + */ baud = tty_get_baud_rate(tty); - dbg("%s - baud = %d", __func__, baud); + dbg("%s - baud requested = %d", __func__, baud); if (baud) { + /* Set baudrate to nearest supported value */ + for (k=0; k<ARRAY_SIZE(baud_sup); k++) { + if (baud_sup[k] / baud) { + baud_ceil = baud_sup[k]; + if (k==0) { + baud = baud_ceil; + } else { + baud_floor = baud_sup[k-1]; + if ((baud_ceil % baud) + > (baud % baud_floor)) + baud = baud_floor; + else + baud = baud_ceil; + } + break; + } + } + if (baud > 1228800) { + /* type_0, type_1 only support up to 1228800 baud */ + if (priv->type != HX) + baud = 1228800; + else if (baud > 6000000) + baud = 6000000; + } + dbg("%s - baud set = %d", __func__, baud); buf[0] = baud & 0xff; buf[1] = (baud >> 8) & 0xff; buf[2] = (baud >> 16) & 0xff; @@ -648,7 +684,7 @@ static void pl2303_set_termios(struct tty_struct *tty, pl2303_vendor_write(0x0, 0x0, serial); } - /* FIXME: Need to read back resulting baud rate */ + /* Save resulting baud rate */ if (baud) tty_encode_baud_rate(tty, baud, baud); |