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path: root/drivers/usb/serial/pl2303.c
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Diffstat (limited to 'drivers/usb/serial/pl2303.c')
-rw-r--r--drivers/usb/serial/pl2303.c27
1 files changed, 23 insertions, 4 deletions
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 30461fc..1d33260 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -91,6 +91,7 @@ static const struct usb_device_id id_table[] = {
{ USB_DEVICE(SONY_VENDOR_ID, SONY_QN3USB_PRODUCT_ID) },
{ USB_DEVICE(SANWA_VENDOR_ID, SANWA_PRODUCT_ID) },
{ USB_DEVICE(ADLINK_VENDOR_ID, ADLINK_ND6530_PRODUCT_ID) },
+ { USB_DEVICE(WINCHIPHEAD_VENDOR_ID, WINCHIPHEAD_USBSER_PRODUCT_ID) },
{ } /* Terminating entry */
};
@@ -342,10 +343,28 @@ static void pl2303_set_termios(struct tty_struct *tty,
baud = 6000000;
}
dbg("%s - baud set = %d", __func__, baud);
- buf[0] = baud & 0xff;
- buf[1] = (baud >> 8) & 0xff;
- buf[2] = (baud >> 16) & 0xff;
- buf[3] = (baud >> 24) & 0xff;
+ if (baud <= 115200) {
+ buf[0] = baud & 0xff;
+ buf[1] = (baud >> 8) & 0xff;
+ buf[2] = (baud >> 16) & 0xff;
+ buf[3] = (baud >> 24) & 0xff;
+ } else {
+ /* apparently the formula for higher speeds is:
+ * baudrate = 12M * 32 / (2^buf[1]) / buf[0]
+ */
+ unsigned tmp = 12*1000*1000*32 / baud;
+ buf[3] = 0x80;
+ buf[2] = 0;
+ buf[1] = (tmp >= 256);
+ while (tmp >= 256) {
+ tmp >>= 2;
+ buf[1] <<= 1;
+ }
+ if (tmp > 256) {
+ tmp %= 256;
+ }
+ buf[0] = tmp;
+ }
}
/* For reference buf[4]=0 is 1 stop bits */