Commit b2d6d98f authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
Browse files

USB: pl2303: clean up baud-rate handling 



Clean up baud-rate handling somewhat.

Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 15e7cead

drivers/usb/serial/pl2303.c

+41 −49
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <linux/uaccess.h>

#include <linux/usb.h>

#include <linux/usb/serial.h>

#include <asm/unaligned.h>

#include "pl2303.h"



/*
@@ -275,51 +276,43 @@ static void pl2303_encode_baudrate(struct tty_struct *tty, 
	struct usb_serial *serial = port->serial;

	struct pl2303_serial_private *spriv = usb_get_serial_data(serial);

	int baud;

	int baud_floor, baud_ceil;

	int k;

	int i;



	/* NOTE: Only the values defined in baud_sup are supported !

	/*

	 * 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);

	dev_dbg(&port->dev, "baud requested = %d\n", baud);

	if (baud) {

	if (!baud)

		return;



	/* 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;

				}

	for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {

		if (baud_sup[i] > baud)

			break;

	}

		}

		if (baud > 1228800) {



	if (i == ARRAY_SIZE(baud_sup))

		baud = baud_sup[i - 1];

	else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))

		baud = baud_sup[i - 1];

	else

		baud = baud_sup[i];



	/* type_0, type_1 only support up to 1228800 baud */

	if (spriv->type != HX)

				baud = 1228800;

			else if (baud > 6000000)

				baud = 6000000;

		}

		dev_dbg(&port->dev, "baud set = %d\n", baud);

		baud = max_t(int, baud, 1228800);



	if (baud <= 115200) {

			buf[0] = baud & 0xff;

			buf[1] = (baud >> 8) & 0xff;

			buf[2] = (baud >> 16) & 0xff;

			buf[3] = (baud >> 24) & 0xff;

		put_unaligned_le32(baud, buf);

	} else {

			/* apparently the formula for higher speeds is:

		/*

		 * Apparently the formula for higher speeds is:

		 * baudrate = 12M * 32 / (2^buf[1]) / buf[0]

		 */

			unsigned tmp = 12*1000*1000*32 / baud;

		unsigned tmp = 12000000 * 32 / baud;

		buf[3] = 0x80;

		buf[2] = 0;

		buf[1] = (tmp >= 256);
@@ -329,11 +322,10 @@ static void pl2303_encode_baudrate(struct tty_struct *tty, 
		}

		buf[0] = tmp;

	}

	}



	/* Save resulting baud rate */

	if (baud)

	tty_encode_baud_rate(tty, baud, baud);

	dev_dbg(&port->dev, "baud set = %d\n", baud);

}



static void pl2303_set_termios(struct tty_struct *tty,