Linux下安装USB转串口驱动（PL2303）【转】

Linux下安装USB转串口驱动（PL2303）转自http://blog.csdn.net/yming0221/article/details/7194988

分类： 嵌入式ARM+Linux

主机:Gentoo Linux 11.2

内核版本：Linux 3.0.6

原创作品，转载请标明出处http://blog.csdn.net/yming0221/article/details/7194988

以前在Ubuntu下USB转串口驱动已经编译进内核，而编译的Gentoo内核没有编译进去，这里将内核中PL2303驱动 copy出来单独编译出pl2303.ko然后将其复制进/var/lib/(内核版本)/drivers/usb/serial/目录下

然后使用命令

depmod

modprobe pl2303

然后将usb转串口接口插入usb，使用命令查看dmesg | tail查看如下

查看内核中驱动，看到usbserial.ko驱动，下面单独编译pl2303.ko

从内核中拷贝的pl2303.h

/*
 * Prolific PL2303 USB to serial adaptor driver header file
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 */

#define BENQ_VENDOR_ID          0x04a5
#define BENQ_PRODUCT_ID_S81     0x4027

#define PL2303_VENDOR_ID    0x067b
#define PL2303_PRODUCT_ID   0x2303
#define PL2303_PRODUCT_ID_RSAQ2     0x04bb
#define PL2303_PRODUCT_ID_DCU11     0x1234
#define PL2303_PRODUCT_ID_PHAROS    0xaaa0
#define PL2303_PRODUCT_ID_RSAQ3     0xaaa2
#define PL2303_PRODUCT_ID_ALDIGA    0x0611
#define PL2303_PRODUCT_ID_MMX       0x0612
#define PL2303_PRODUCT_ID_GPRS      0x0609
#define PL2303_PRODUCT_ID_HCR331    0x331a
#define PL2303_PRODUCT_ID_MOTOROLA  0x0307

#define ATEN_VENDOR_ID      0x0557
#define ATEN_VENDOR_ID2     0x0547
#define ATEN_PRODUCT_ID     0x2008

#define IODATA_VENDOR_ID    0x04bb
#define IODATA_PRODUCT_ID   0x0a03
#define IODATA_PRODUCT_ID_RSAQ5 0x0a0e

#define ELCOM_VENDOR_ID     0x056e
#define ELCOM_PRODUCT_ID    0x5003
#define ELCOM_PRODUCT_ID_UCSGT  0x5004

#define ITEGNO_VENDOR_ID    0x0eba
#define ITEGNO_PRODUCT_ID   0x1080
#define ITEGNO_PRODUCT_ID_2080  0x2080

#define MA620_VENDOR_ID     0x0df7
#define MA620_PRODUCT_ID    0x0620

#define RATOC_VENDOR_ID     0x0584
#define RATOC_PRODUCT_ID    0xb000

#define TRIPP_VENDOR_ID     0x2478
#define TRIPP_PRODUCT_ID    0x2008

#define RADIOSHACK_VENDOR_ID    0x1453
#define RADIOSHACK_PRODUCT_ID   0x4026

#define DCU10_VENDOR_ID     0x0731
#define DCU10_PRODUCT_ID    0x0528

#define SITECOM_VENDOR_ID   0x6189
#define SITECOM_PRODUCT_ID  0x2068

/* Alcatel OT535/735 USB cable */
#define ALCATEL_VENDOR_ID   0x11f7
#define ALCATEL_PRODUCT_ID  0x02df

/* Samsung I330 phone cradle */
#define SAMSUNG_VENDOR_ID   0x04e8
#define SAMSUNG_PRODUCT_ID  0x8001

#define SIEMENS_VENDOR_ID   0x11f5
#define SIEMENS_PRODUCT_ID_SX1  0x0001
#define SIEMENS_PRODUCT_ID_X65  0x0003
#define SIEMENS_PRODUCT_ID_X75  0x0004
#define SIEMENS_PRODUCT_ID_EF81 0x0005

#define SYNTECH_VENDOR_ID   0x0745
#define SYNTECH_PRODUCT_ID  0x0001

/* Nokia CA-42 Cable */
#define NOKIA_CA42_VENDOR_ID    0x078b
#define NOKIA_CA42_PRODUCT_ID   0x1234

/* CA-42 CLONE Cable www.ca-42.com chipset: Prolific Technology Inc */
#define CA_42_CA42_VENDOR_ID    0x10b5
#define CA_42_CA42_PRODUCT_ID   0xac70

#define SAGEM_VENDOR_ID     0x079b
#define SAGEM_PRODUCT_ID    0x0027

/* Leadtek GPS 9531 (ID 0413:2101) */
#define LEADTEK_VENDOR_ID   0x0413
#define LEADTEK_9531_PRODUCT_ID 0x2101

/* USB GSM cable from Speed Dragon Multimedia, Ltd */
#define SPEEDDRAGON_VENDOR_ID   0x0e55
#define SPEEDDRAGON_PRODUCT_ID  0x110b

/* DATAPILOT Universal-2 Phone Cable */
#define DATAPILOT_U2_VENDOR_ID  0x0731
#define DATAPILOT_U2_PRODUCT_ID 0x2003

/* Belkin "F5U257" Serial Adapter */
#define BELKIN_VENDOR_ID    0x050d
#define BELKIN_PRODUCT_ID   0x0257

/* Alcor Micro Corp. USB 2.0 TO RS-232 */
#define ALCOR_VENDOR_ID     0x058F
#define ALCOR_PRODUCT_ID    0x9720

/* Willcom WS002IN Data Driver (by NetIndex Inc.) */
#define WS002IN_VENDOR_ID   0x11f6
#define WS002IN_PRODUCT_ID  0x2001

/* Corega CG-USBRS232R Serial Adapter */
#define COREGA_VENDOR_ID    0x07aa
#define COREGA_PRODUCT_ID   0x002a

/* Y.C. Cable U.S.A., Inc - USB to RS-232 */
#define YCCABLE_VENDOR_ID   0x05ad
#define YCCABLE_PRODUCT_ID  0x0fba

/* "Superial" USB - Serial */
#define SUPERIAL_VENDOR_ID  0x5372
#define SUPERIAL_PRODUCT_ID 0x2303

/* Hewlett-Packard LD220-HP POS Pole Display */
#define HP_VENDOR_ID        0x03f0
#define HP_LD220_PRODUCT_ID 0x3524

/* Cressi Edy (diving computer) PC interface */
#define CRESSI_VENDOR_ID    0x04b8
#define CRESSI_EDY_PRODUCT_ID   0x0521

/* Zeagle dive computer interface */
#define ZEAGLE_VENDOR_ID    0x04b8
#define ZEAGLE_N2ITION3_PRODUCT_ID  0x0522

/* Sony, USB data cable for CMD-Jxx mobile phones */
#define SONY_VENDOR_ID      0x054c
#define SONY_QN3USB_PRODUCT_ID  0x0437

/* Sanwa KB-USB2 multimeter cable (ID: 11ad:0001) */
#define SANWA_VENDOR_ID     0x11ad
#define SANWA_PRODUCT_ID    0x0001

/* ADLINK ND-6530 RS232,RS485 and RS422 adapter */
#define ADLINK_VENDOR_ID        0x0b63
#define ADLINK_ND6530_PRODUCT_ID    0x6530

/* WinChipHead USB->RS 232 adapter */
#define WINCHIPHEAD_VENDOR_ID       0x4348
#define WINCHIPHEAD_USBSER_PRODUCT_ID   0x5523

pl2303.c代码

/*
 * Prolific PL2303 USB to serial adaptor driver
 *
 * Copyright (C) 2001-2007 Greg Kroah-Hartman ([email protected])
 * Copyright (C) 2003 IBM Corp.
 *
 * Original driver for 2.2.x by anonymous
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License version
 *  2 as published by the Free Software Foundation.
 *
 * See Documentation/usb/usb-serial.txt for more information on using this
 * driver
 *
 */

#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include "pl2303.h"

/*
 * Version Information
 */
#define DRIVER_DESC "Prolific PL2303 USB to serial adaptor driver"

static int debug;

#define PL2303_CLOSING_WAIT (30*HZ)

static const struct usb_device_id id_table[] = {
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID) },
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ2) },
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_DCU11) },
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_RSAQ3) },
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_PHAROS) },
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_ALDIGA) },
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MMX) },
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_GPRS) },
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_HCR331) },
    { USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_MOTOROLA) },
    { USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
    { USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID_RSAQ5) },
    { USB_DEVICE(ATEN_VENDOR_ID, ATEN_PRODUCT_ID) },
    { USB_DEVICE(ATEN_VENDOR_ID2, ATEN_PRODUCT_ID) },
    { USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID) },
    { USB_DEVICE(ELCOM_VENDOR_ID, ELCOM_PRODUCT_ID_UCSGT) },
    { USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID) },
    { USB_DEVICE(ITEGNO_VENDOR_ID, ITEGNO_PRODUCT_ID_2080) },
    { USB_DEVICE(MA620_VENDOR_ID, MA620_PRODUCT_ID) },
    { USB_DEVICE(RATOC_VENDOR_ID, RATOC_PRODUCT_ID) },
    { USB_DEVICE(TRIPP_VENDOR_ID, TRIPP_PRODUCT_ID) },
    { USB_DEVICE(RADIOSHACK_VENDOR_ID, RADIOSHACK_PRODUCT_ID) },
    { USB_DEVICE(DCU10_VENDOR_ID, DCU10_PRODUCT_ID) },
    { USB_DEVICE(SITECOM_VENDOR_ID, SITECOM_PRODUCT_ID) },
    { USB_DEVICE(ALCATEL_VENDOR_ID, ALCATEL_PRODUCT_ID) },
    { USB_DEVICE(SAMSUNG_VENDOR_ID, SAMSUNG_PRODUCT_ID) },
    { USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_SX1) },
    { USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X65) },
    { USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_X75) },
    { USB_DEVICE(SIEMENS_VENDOR_ID, SIEMENS_PRODUCT_ID_EF81) },
    { USB_DEVICE(BENQ_VENDOR_ID, BENQ_PRODUCT_ID_S81) }, /* Benq/Siemens S81 */
    { USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
    { USB_DEVICE(NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID) },
    { USB_DEVICE(CA_42_CA42_VENDOR_ID, CA_42_CA42_PRODUCT_ID) },
    { USB_DEVICE(SAGEM_VENDOR_ID, SAGEM_PRODUCT_ID) },
    { USB_DEVICE(LEADTEK_VENDOR_ID, LEADTEK_9531_PRODUCT_ID) },
    { USB_DEVICE(SPEEDDRAGON_VENDOR_ID, SPEEDDRAGON_PRODUCT_ID) },
    { USB_DEVICE(DATAPILOT_U2_VENDOR_ID, DATAPILOT_U2_PRODUCT_ID) },
    { USB_DEVICE(BELKIN_VENDOR_ID, BELKIN_PRODUCT_ID) },
    { USB_DEVICE(ALCOR_VENDOR_ID, ALCOR_PRODUCT_ID) },
    { USB_DEVICE(WS002IN_VENDOR_ID, WS002IN_PRODUCT_ID) },
    { USB_DEVICE(COREGA_VENDOR_ID, COREGA_PRODUCT_ID) },
    { USB_DEVICE(YCCABLE_VENDOR_ID, YCCABLE_PRODUCT_ID) },
    { USB_DEVICE(SUPERIAL_VENDOR_ID, SUPERIAL_PRODUCT_ID) },
    { USB_DEVICE(HP_VENDOR_ID, HP_LD220_PRODUCT_ID) },
    { USB_DEVICE(CRESSI_VENDOR_ID, CRESSI_EDY_PRODUCT_ID) },
    { USB_DEVICE(ZEAGLE_VENDOR_ID, ZEAGLE_N2ITION3_PRODUCT_ID) },
    { 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 */
};

MODULE_DEVICE_TABLE(usb, id_table);

static struct usb_driver pl2303_driver = {
    .name =     "pl2303",
    .probe =    usb_serial_probe,
    .disconnect =   usb_serial_disconnect,
    .id_table = id_table,
    .suspend =      usb_serial_suspend,
    .resume =       usb_serial_resume,
    .no_dynamic_id =    1,
    .supports_autosuspend = 1,
};

#define SET_LINE_REQUEST_TYPE       0x21
#define SET_LINE_REQUEST        0x20

#define SET_CONTROL_REQUEST_TYPE    0x21
#define SET_CONTROL_REQUEST     0x22
#define CONTROL_DTR         0x01
#define CONTROL_RTS         0x02

#define BREAK_REQUEST_TYPE      0x21
#define BREAK_REQUEST           0x23
#define BREAK_ON            0xffff
#define BREAK_OFF           0x0000

#define GET_LINE_REQUEST_TYPE       0xa1
#define GET_LINE_REQUEST        0x21

#define VENDOR_WRITE_REQUEST_TYPE   0x40
#define VENDOR_WRITE_REQUEST        0x01

#define VENDOR_READ_REQUEST_TYPE    0xc0
#define VENDOR_READ_REQUEST     0x01

#define UART_STATE          0x08
#define UART_STATE_TRANSIENT_MASK   0x74
#define UART_DCD            0x01
#define UART_DSR            0x02
#define UART_BREAK_ERROR        0x04
#define UART_RING           0x08
#define UART_FRAME_ERROR        0x10
#define UART_PARITY_ERROR       0x20
#define UART_OVERRUN_ERROR      0x40
#define UART_CTS            0x80


enum pl2303_type {
    type_0,     /* don't know the difference between type 0 and */
    type_1,     /* type 1, until someone from prolific tells us... */
    HX,     /* HX version of the pl2303 chip */
};

struct pl2303_private {
    spinlock_t lock;
    wait_queue_head_t delta_msr_wait;
    u8 line_control;
    u8 line_status;
    enum pl2303_type type;
};

static int pl2303_vendor_read(__u16 value, __u16 index,
        struct usb_serial *serial, unsigned char *buf)
{
    int res = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
            VENDOR_READ_REQUEST, VENDOR_READ_REQUEST_TYPE,
            value, index, buf, 1, 100);
    dbg("0x%x:0x%x:0x%x:0x%x  %d - %x", VENDOR_READ_REQUEST_TYPE,
            VENDOR_READ_REQUEST, value, index, res, buf[0]);
    return res;
}

static int pl2303_vendor_write(__u16 value, __u16 index,
        struct usb_serial *serial)
{
    int res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
            VENDOR_WRITE_REQUEST, VENDOR_WRITE_REQUEST_TYPE,
            value, index, NULL, 0, 100);
    dbg("0x%x:0x%x:0x%x:0x%x  %d", VENDOR_WRITE_REQUEST_TYPE,
            VENDOR_WRITE_REQUEST, value, index, res);
    return res;
}

static int pl2303_startup(struct usb_serial *serial)
{
    struct pl2303_private *priv;
    enum pl2303_type type = type_0;
    unsigned char *buf;
    int i;

    buf = kmalloc(10, GFP_KERNEL);
    if (buf == NULL)
        return -ENOMEM;

    if (serial->dev->descriptor.bDeviceClass == 0x02)
        type = type_0;
    else if (serial->dev->descriptor.bMaxPacketSize0 == 0x40)
        type = HX;
    else if (serial->dev->descriptor.bDeviceClass == 0x00)
        type = type_1;
    else if (serial->dev->descriptor.bDeviceClass == 0xFF)
        type = type_1;
    dbg("device type: %d", type);

    for (i = 0; i < serial->num_ports; ++i) {
        priv = kzalloc(sizeof(struct pl2303_private), GFP_KERNEL);
        if (!priv)
            goto cleanup;
        spin_lock_init(&priv->lock);
        init_waitqueue_head(&priv->delta_msr_wait);
        priv->type = type;
        usb_set_serial_port_data(serial->port[i], priv);
    }

    pl2303_vendor_read(0x8484, 0, serial, buf);
    pl2303_vendor_write(0x0404, 0, serial);
    pl2303_vendor_read(0x8484, 0, serial, buf);
    pl2303_vendor_read(0x8383, 0, serial, buf);
    pl2303_vendor_read(0x8484, 0, serial, buf);
    pl2303_vendor_write(0x0404, 1, serial);
    pl2303_vendor_read(0x8484, 0, serial, buf);
    pl2303_vendor_read(0x8383, 0, serial, buf);
    pl2303_vendor_write(0, 1, serial);
    pl2303_vendor_write(1, 0, serial);
    if (type == HX)
        pl2303_vendor_write(2, 0x44, serial);
    else
        pl2303_vendor_write(2, 0x24, serial);

    kfree(buf);
    return 0;

cleanup:
    kfree(buf);
    for (--i; i >= 0; --i) {
        priv = usb_get_serial_port_data(serial->port[i]);
        kfree(priv);
        usb_set_serial_port_data(serial->port[i], NULL);
    }
    return -ENOMEM;
}

static int set_control_lines(struct usb_device *dev, u8 value)
{
    int retval;

    retval = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
                 SET_CONTROL_REQUEST, SET_CONTROL_REQUEST_TYPE,
                 value, 0, NULL, 0, 100);
    dbg("%s - value = %d, retval = %d", __func__, value, retval);
    return retval;
}

static void pl2303_set_termios(struct tty_struct *tty,
        struct usb_serial_port *port, struct ktermios *old_termios)
{
    struct usb_serial *serial = port->serial;
    struct pl2303_private *priv = usb_get_serial_port_data(port);
    unsigned long flags;
    unsigned int cflag;
    unsigned char *buf;
    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);

    /* The PL2303 is reported to lose bytes if you change
       serial settings even to the same values as before. Thus
       we actually need to filter in this specific case */

    if (!tty_termios_hw_change(tty->termios, old_termios))
        return;

    cflag = tty->termios->c_cflag;

    buf = kzalloc(7, GFP_KERNEL);
    if (!buf) {
        dev_err(&port->dev, "%s - out of memory.\n", __func__);
        /* Report back no change occurred */
        *tty->termios = *old_termios;
        return;
    }

    i = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
                GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
                0, 0, buf, 7, 100);
    dbg("0xa1:0x21:0:0  %d - %x %x %x %x %x %x %x", i,
        buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6]);

    if (cflag & CSIZE) {
        switch (cflag & CSIZE) {
        case CS5:
            buf[6] = 5;
            break;
        case CS6:
            buf[6] = 6;
            break;
        case CS7:
            buf[6] = 7;
            break;
        default:
        case CS8:
            buf[6] = 8;
            break;
        }
        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 requested = %d", __func__, baud);
    if (baud) {
        /* Set baudrate to nearest supported value */
        for (k=0; 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);
        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 */
    /* For reference buf[4]=1 is 1.5 stop bits */
    /* For reference buf[4]=2 is 2 stop bits */
    if (cflag & CSTOPB) {
        /* NOTE: Comply with "real" UARTs / RS232:
         *       use 1.5 instead of 2 stop bits with 5 data bits
         */
        if ((cflag & CSIZE) == CS5) {
            buf[4] = 1;
            dbg("%s - stop bits = 1.5", __func__);
        } else {
            buf[4] = 2;
            dbg("%s - stop bits = 2", __func__);
        }
    } else {
        buf[4] = 0;
        dbg("%s - stop bits = 1", __func__);
    }

    if (cflag & PARENB) {
        /* For reference buf[5]=0 is none parity */
        /* For reference buf[5]=1 is odd parity */
        /* For reference buf[5]=2 is even parity */
        /* For reference buf[5]=3 is mark parity */
        /* For reference buf[5]=4 is space parity */
        if (cflag & PARODD) {
            if (cflag & CMSPAR) {
                buf[5] = 3;
                dbg("%s - parity = mark", __func__);
            } else {
                buf[5] = 1;
                dbg("%s - parity = odd", __func__);
            }
        } else {
            if (cflag & CMSPAR) {
                buf[5] = 4;
                dbg("%s - parity = space", __func__);
            } else {
                buf[5] = 2;
                dbg("%s - parity = even", __func__);
            }
        }
    } else {
        buf[5] = 0;
        dbg("%s - parity = none", __func__);
    }

    i = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
                SET_LINE_REQUEST, SET_LINE_REQUEST_TYPE,
                0, 0, buf, 7, 100);
    dbg("0x21:0x20:0:0  %d", i);

    /* change control lines if we are switching to or from B0 */
    spin_lock_irqsave(&priv->lock, flags);
    control = priv->line_control;
    if ((cflag & CBAUD) == B0)
        priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
    else
        priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
    if (control != priv->line_control) {
        control = priv->line_control;
        spin_unlock_irqrestore(&priv->lock, flags);
        set_control_lines(serial->dev, control);
    } else {
        spin_unlock_irqrestore(&priv->lock, flags);
    }

    buf[0] = buf[1] = buf[2] = buf[3] = buf[4] = buf[5] = buf[6] = 0;

    i = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
                GET_LINE_REQUEST, GET_LINE_REQUEST_TYPE,
                0, 0, buf, 7, 100);
    dbg("0xa1:0x21:0:0  %d - %x %x %x %x %x %x %x", i,
         buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6]);

    if (cflag & CRTSCTS) {
        if (priv->type == HX)
            pl2303_vendor_write(0x0, 0x61, serial);
        else
            pl2303_vendor_write(0x0, 0x41, serial);
    } else {
        pl2303_vendor_write(0x0, 0x0, serial);
    }

    /* Save resulting baud rate */
    if (baud)
        tty_encode_baud_rate(tty, baud, baud);

    kfree(buf);
}

static void pl2303_dtr_rts(struct usb_serial_port *port, int on)
{
    struct pl2303_private *priv = usb_get_serial_port_data(port);
    unsigned long flags;
    u8 control;

    spin_lock_irqsave(&priv->lock, flags);
    /* Change DTR and RTS */
    if (on)
        priv->line_control |= (CONTROL_DTR | CONTROL_RTS);
    else
        priv->line_control &= ~(CONTROL_DTR | CONTROL_RTS);
    control = priv->line_control;
    spin_unlock_irqrestore(&priv->lock, flags);
    set_control_lines(port->serial->dev, control);
}

static void pl2303_close(struct usb_serial_port *port)
{
    dbg("%s - port %d", __func__, port->number);

    usb_serial_generic_close(port);
    usb_kill_urb(port->interrupt_in_urb);
}

static int pl2303_open(struct tty_struct *tty, struct usb_serial_port *port)
{
    struct ktermios tmp_termios;
    struct usb_serial *serial = port->serial;
    struct pl2303_private *priv = usb_get_serial_port_data(port);
    int result;

    dbg("%s -  port %d", __func__, port->number);

    if (priv->type != HX) {
        usb_clear_halt(serial->dev, port->write_urb->pipe);
        usb_clear_halt(serial->dev, port->read_urb->pipe);
    } else {
        /* reset upstream data pipes */
        pl2303_vendor_write(8, 0, serial);
        pl2303_vendor_write(9, 0, serial);
    }

    /* Setup termios */
    if (tty)
        pl2303_set_termios(tty, port, &tmp_termios);

    dbg("%s - submitting read urb", __func__);
    result = usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
    if (result) {
        pl2303_close(port);
        return -EPROTO;
    }

    dbg("%s - submitting interrupt urb", __func__);
    result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
    if (result) {
        dev_err(&port->dev, "%s - failed submitting interrupt urb,"
            " error %d\n", __func__, result);
        pl2303_close(port);
        return -EPROTO;
    }
    port->port.drain_delay = 256;
    return 0;
}

static int pl2303_tiocmset(struct tty_struct *tty,
               unsigned int set, unsigned int clear)
{
    struct usb_serial_port *port = tty->driver_data;
    struct pl2303_private *priv = usb_get_serial_port_data(port);
    unsigned long flags;
    u8 control;

    if (!usb_get_intfdata(port->serial->interface))
        return -ENODEV;

    spin_lock_irqsave(&priv->lock, flags);
    if (set & TIOCM_RTS)
        priv->line_control |= CONTROL_RTS;
    if (set & TIOCM_DTR)
        priv->line_control |= CONTROL_DTR;
    if (clear & TIOCM_RTS)
        priv->line_control &= ~CONTROL_RTS;
    if (clear & TIOCM_DTR)
        priv->line_control &= ~CONTROL_DTR;
    control = priv->line_control;
    spin_unlock_irqrestore(&priv->lock, flags);

    return set_control_lines(port->serial->dev, control);
}

static int pl2303_tiocmget(struct tty_struct *tty)
{
    struct usb_serial_port *port = tty->driver_data;
    struct pl2303_private *priv = usb_get_serial_port_data(port);
    unsigned long flags;
    unsigned int mcr;
    unsigned int status;
    unsigned int result;

    dbg("%s (%d)", __func__, port->number);

    if (!usb_get_intfdata(port->serial->interface))
        return -ENODEV;

    spin_lock_irqsave(&priv->lock, flags);
    mcr = priv->line_control;
    status = priv->line_status;
    spin_unlock_irqrestore(&priv->lock, flags);

    result = ((mcr & CONTROL_DTR)       ? TIOCM_DTR : 0)
          | ((mcr & CONTROL_RTS)    ? TIOCM_RTS : 0)
          | ((status & UART_CTS)    ? TIOCM_CTS : 0)
          | ((status & UART_DSR)    ? TIOCM_DSR : 0)
          | ((status & UART_RING)   ? TIOCM_RI  : 0)
          | ((status & UART_DCD)    ? TIOCM_CD  : 0);

    dbg("%s - result = %x", __func__, result);

    return result;
}

static int pl2303_carrier_raised(struct usb_serial_port *port)
{
    struct pl2303_private *priv = usb_get_serial_port_data(port);
    if (priv->line_status & UART_DCD)
        return 1;
    return 0;
}

static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
{
    struct pl2303_private *priv = usb_get_serial_port_data(port);
    unsigned long flags;
    unsigned int prevstatus;
    unsigned int status;
    unsigned int changed;

    spin_lock_irqsave(&priv->lock, flags);
    prevstatus = priv->line_status;
    spin_unlock_irqrestore(&priv->lock, flags);

    while (1) {
        interruptible_sleep_on(&priv->delta_msr_wait);
        /* see if a signal did it */
        if (signal_pending(current))
            return -ERESTARTSYS;

        spin_lock_irqsave(&priv->lock, flags);
        status = priv->line_status;
        spin_unlock_irqrestore(&priv->lock, flags);

        changed = prevstatus ^ status;

        if (((arg & TIOCM_RNG) && (changed & UART_RING)) ||
            ((arg & TIOCM_DSR) && (changed & UART_DSR)) ||
            ((arg & TIOCM_CD)  && (changed & UART_DCD)) ||
            ((arg & TIOCM_CTS) && (changed & UART_CTS))) {
            return 0;
        }
        prevstatus = status;
    }
    /* NOTREACHED */
    return 0;
}

static int pl2303_ioctl(struct tty_struct *tty,
            unsigned int cmd, unsigned long arg)
{
    struct serial_struct ser;
    struct usb_serial_port *port = tty->driver_data;
    dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);

    switch (cmd) {
    case TIOCGSERIAL:
        memset(&ser, 0, sizeof ser);
        ser.type = PORT_16654;
        ser.line = port->serial->minor;
        ser.port = port->number;
        ser.baud_base = 460800;

        if (copy_to_user((void __user *)arg, &ser, sizeof ser))
            return -EFAULT;

        return 0;

    case TIOCMIWAIT:
        dbg("%s (%d) TIOCMIWAIT", __func__,  port->number);
        return wait_modem_info(port, arg);
    default:
        dbg("%s not supported = 0x%04x", __func__, cmd);
        break;
    }
    return -ENOIOCTLCMD;
}

static void pl2303_break_ctl(struct tty_struct *tty, int break_state)
{
    struct usb_serial_port *port = tty->driver_data;
    struct usb_serial *serial = port->serial;
    u16 state;
    int result;

    dbg("%s - port %d", __func__, port->number);

    if (break_state == 0)
        state = BREAK_OFF;
    else
        state = BREAK_ON;
    dbg("%s - turning break %s", __func__,
            state == BREAK_OFF ? "off" : "on");

    result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
                 BREAK_REQUEST, BREAK_REQUEST_TYPE, state,
                 0, NULL, 0, 100);
    if (result)
        dbg("%s - error sending break = %d", __func__, result);
}

static void pl2303_release(struct usb_serial *serial)
{
    int i;
    struct pl2303_private *priv;

    dbg("%s", __func__);

    for (i = 0; i < serial->num_ports; ++i) {
        priv = usb_get_serial_port_data(serial->port[i]);
        kfree(priv);
    }
}

static void pl2303_update_line_status(struct usb_serial_port *port,
                      unsigned char *data,
                      unsigned int actual_length)
{

    struct pl2303_private *priv = usb_get_serial_port_data(port);
    struct tty_struct *tty;
    unsigned long flags;
    u8 status_idx = UART_STATE;
    u8 length = UART_STATE + 1;
    u8 prev_line_status;
    u16 idv, idp;

    idv = le16_to_cpu(port->serial->dev->descriptor.idVendor);
    idp = le16_to_cpu(port->serial->dev->descriptor.idProduct);


    if (idv == SIEMENS_VENDOR_ID) {
        if (idp == SIEMENS_PRODUCT_ID_X65 ||
            idp == SIEMENS_PRODUCT_ID_SX1 ||
            idp == SIEMENS_PRODUCT_ID_X75) {

            length = 1;
            status_idx = 0;
        }
    }

    if (actual_length < length)
        return;

    /* Save off the uart status for others to look at */
    spin_lock_irqsave(&priv->lock, flags);
    prev_line_status = priv->line_status;
    priv->line_status = data[status_idx];
    spin_unlock_irqrestore(&priv->lock, flags);
    if (priv->line_status & UART_BREAK_ERROR)
        usb_serial_handle_break(port);
    wake_up_interruptible(&priv->delta_msr_wait);

    tty = tty_port_tty_get(&port->port);
    if (!tty)
        return;
    if ((priv->line_status ^ prev_line_status) & UART_DCD)
        usb_serial_handle_dcd_change(port, tty,
                priv->line_status & UART_DCD);
    tty_kref_put(tty);
}

static void pl2303_read_int_callback(struct urb *urb)
{
    struct usb_serial_port *port =  urb->context;
    unsigned char *data = urb->transfer_buffer;
    unsigned int actual_length = urb->actual_length;
    int status = urb->status;
    int retval;

    dbg("%s (%d)", __func__, port->number);

    switch (status) {
    case 0:
        /* success */
        break;
    case -ECONNRESET:
    case -ENOENT:
    case -ESHUTDOWN:
        /* this urb is terminated, clean up */
        dbg("%s - urb shutting down with status: %d", __func__,
            status);
        return;
    default:
        dbg("%s - nonzero urb status received: %d", __func__,
            status);
        goto exit;
    }

    usb_serial_debug_data(debug, &port->dev, __func__,
                  urb->actual_length, urb->transfer_buffer);

    pl2303_update_line_status(port, data, actual_length);

exit:
    retval = usb_submit_urb(urb, GFP_ATOMIC);
    if (retval)
        dev_err(&urb->dev->dev,
            "%s - usb_submit_urb failed with result %d\n",
            __func__, retval);
}

static void pl2303_process_read_urb(struct urb *urb)
{
    struct usb_serial_port *port = urb->context;
    struct pl2303_private *priv = usb_get_serial_port_data(port);
    struct tty_struct *tty;
    unsigned char *data = urb->transfer_buffer;
    char tty_flag = TTY_NORMAL;
    unsigned long flags;
    u8 line_status;
    int i;

    /* update line status */
    spin_lock_irqsave(&priv->lock, flags);
    line_status = priv->line_status;
    priv->line_status &= ~UART_STATE_TRANSIENT_MASK;
    spin_unlock_irqrestore(&priv->lock, flags);
    wake_up_interruptible(&priv->delta_msr_wait);

    if (!urb->actual_length)
        return;

    tty = tty_port_tty_get(&port->port);
    if (!tty)
        return;

    /* break takes precedence over parity, */
    /* which takes precedence over framing errors */
    if (line_status & UART_BREAK_ERROR)
        tty_flag = TTY_BREAK;
    else if (line_status & UART_PARITY_ERROR)
        tty_flag = TTY_PARITY;
    else if (line_status & UART_FRAME_ERROR)
        tty_flag = TTY_FRAME;
    dbg("%s - tty_flag = %d", __func__, tty_flag);

    /* overrun is special, not associated with a char */
    if (line_status & UART_OVERRUN_ERROR)
        tty_insert_flip_char(tty, 0, TTY_OVERRUN);

    if (port->port.console && port->sysrq) {
        for (i = 0; i < urb->actual_length; ++i)
            if (!usb_serial_handle_sysrq_char(port, data[i]))
                tty_insert_flip_char(tty, data[i], tty_flag);
    } else {
        tty_insert_flip_string_fixed_flag(tty, data, tty_flag,
                            urb->actual_length);
    }

    tty_flip_buffer_push(tty);
    tty_kref_put(tty);
}

/* All of the device info needed for the PL2303 SIO serial converter */
static struct usb_serial_driver pl2303_device = {
    .driver = {
        .owner =    THIS_MODULE,
        .name =     "pl2303",
    },
    .id_table =     id_table,
    .usb_driver =       &pl2303_driver,
    .num_ports =        1,
    .bulk_in_size =     256,
    .bulk_out_size =    256,
    .open =         pl2303_open,
    .close =        pl2303_close,
    .dtr_rts =      pl2303_dtr_rts,
    .carrier_raised =   pl2303_carrier_raised,
    .ioctl =        pl2303_ioctl,
    .break_ctl =        pl2303_break_ctl,
    .set_termios =      pl2303_set_termios,
    .tiocmget =     pl2303_tiocmget,
    .tiocmset =     pl2303_tiocmset,
    .process_read_urb = pl2303_process_read_urb,
    .read_int_callback =    pl2303_read_int_callback,
    .attach =       pl2303_startup,
    .release =      pl2303_release,
};

static int __init pl2303_init(void)
{
    int retval;

    retval = usb_serial_register(&pl2303_device);
    if (retval)
        goto failed_usb_serial_register;
    retval = usb_register(&pl2303_driver);
    if (retval)
        goto failed_usb_register;
    printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");
    return 0;
failed_usb_register:
    usb_serial_deregister(&pl2303_device);
failed_usb_serial_register:
    return retval;
}

static void __exit pl2303_exit(void)
{
    usb_deregister(&pl2303_driver);
    usb_serial_deregister(&pl2303_device);
}

module_init(pl2303_init);
module_exit(pl2303_exit);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");

Makefile文件：

#KVER = /usr/src/linux
KVER = /lib/modules/`uname -r`/build
CURDIR = $(shell pwd)
# Kernel modules
obj-m := pl2303.o
build: kernel_modules
kernel_modules:
    $(MAKE) -C $(KVER) M=$(CURDIR) modules
clean:
    $(MAKE) -C $(KVER) M=$(CURDIR) clean