pl2303.c

底层驱动开发

/*
 * Prolific PL2303 USB to serial adaptor driver
 *
 * Copyright (C) 2001-2004 Greg Kroah-Hartman ([e-mail])
 * 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 as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 * See Documentation/usb/usb-serial.txt for more information on using this driver
 *
 * 2002_Mar_26 gkh
 *	allowed driver to work properly if there is no tty assigned to a port
 *	(this happens for serial console devices.)
 *
 * 2001_Oct_06 gkh
 *	Added RTS and DTR line control.  Thanks to [e-mail] for parts of it.
 *
 * 2001_Sep_19 gkh
 *	Added break support.
 *
 * 2001_Aug_30 gkh
 *	fixed oops in write_bulk_callback.
 *
 * 2001_Aug_28 gkh
 *	reworked buffer logic to be like other usb-serial drivers.  Hopefully
 *	removing some reported problems.
 *
 * 2001_Jun_06 gkh
 *	finished porting to 2.4 format.
 * 
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include "usb-serial.h"
#include "pl2303.h"

/*
 * Version Information
 */
#define DRIVER_VERSION "v0.12"
#define DRIVER_DESC "Prolific PL2303 USB to serial adaptor driver"

static int debug;

#define PL2303_CLOSING_WAIT	(30*HZ)

#define PL2303_BUF_SIZE		1024
#define PL2303_TMP_BUF_SIZE	1024

static DECLARE_MUTEX(pl2303_tmp_buf_sem);

struct pl2303_buf {
	unsigned int	buf_size;
	char		*buf_buf;
	char		*buf_get;
	char		*buf_put;
};

static 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_RSAQ3) },
	{ USB_DEVICE(PL2303_VENDOR_ID, PL2303_PRODUCT_ID_PHAROS) },
	{ USB_DEVICE(IODATA_VENDOR_ID, IODATA_PRODUCT_ID) },
	{ 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(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_X65) },
	{ USB_DEVICE(SYNTECH_VENDOR_ID, SYNTECH_PRODUCT_ID) },
	{ USB_DEVICE( NOKIA_CA42_VENDOR_ID, NOKIA_CA42_PRODUCT_ID ) },
	{ }					/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, id_table);

static struct usb_driver pl2303_driver = {
	.owner =	THIS_MODULE,
	.name =		"pl2303",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	id_table,
};

#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

/* function prototypes for a PL2303 serial converter */
static int pl2303_open (struct usb_serial_port *port, struct file *filp);
static void pl2303_close (struct usb_serial_port *port, struct file *filp);
static void pl2303_set_termios (struct usb_serial_port *port,
				struct termios *old);
static int pl2303_ioctl (struct usb_serial_port *port, struct file *file,
			 unsigned int cmd, unsigned long arg);
static void pl2303_read_int_callback (struct urb *urb, struct pt_regs *regs);
static void pl2303_read_bulk_callback (struct urb *urb, struct pt_regs *regs);
static void pl2303_write_bulk_callback (struct urb *urb, struct pt_regs *regs);
static int pl2303_write (struct usb_serial_port *port,
			 const unsigned char *buf, int count);
static void pl2303_send (struct usb_serial_port *port);
static int pl2303_write_room(struct usb_serial_port *port);
static int pl2303_chars_in_buffer(struct usb_serial_port *port);
static void pl2303_break_ctl(struct usb_serial_port *port,int break_state);
static int pl2303_tiocmget (struct usb_serial_port *port, struct file *file);
static int pl2303_tiocmset (struct usb_serial_port *port, struct file *file,
			    unsigned int set, unsigned int clear);
static int pl2303_startup (struct usb_serial *serial);
static void pl2303_shutdown (struct usb_serial *serial);
static struct pl2303_buf *pl2303_buf_alloc(unsigned int size);
static void pl2303_buf_free(struct pl2303_buf *pb);
static void pl2303_buf_clear(struct pl2303_buf *pb);
static unsigned int pl2303_buf_data_avail(struct pl2303_buf *pb);
static unsigned int pl2303_buf_space_avail(struct pl2303_buf *pb);
static unsigned int pl2303_buf_put(struct pl2303_buf *pb, const char *buf,
	unsigned int count);
static unsigned int pl2303_buf_get(struct pl2303_buf *pb, char *buf,
	unsigned int count);


/* All of the device info needed for the PL2303 SIO serial converter */
static struct usb_serial_device_type pl2303_device = {
	.owner =		THIS_MODULE,
	.name =			"PL-2303",
	.id_table =		id_table,
	.num_interrupt_in =	NUM_DONT_CARE,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			pl2303_open,
	.close =		pl2303_close,
	.write =		pl2303_write,
	.ioctl =		pl2303_ioctl,
	.break_ctl =		pl2303_break_ctl,
	.set_termios =		pl2303_set_termios,
	.tiocmget =		pl2303_tiocmget,
	.tiocmset =		pl2303_tiocmset,
	.read_bulk_callback =	pl2303_read_bulk_callback,
	.read_int_callback =	pl2303_read_int_callback,
	.write_bulk_callback =	pl2303_write_bulk_callback,
	.write_room =		pl2303_write_room,
	.chars_in_buffer =	pl2303_chars_in_buffer,
	.attach =		pl2303_startup,
	.shutdown =		pl2303_shutdown,
};

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;
	struct pl2303_buf *buf;
	int write_urb_in_use;
	wait_queue_head_t delta_msr_wait;
	u8 line_control;
	u8 line_status;
	u8 termios_initialized;
	enum pl2303_type type;
};


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

	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 = kmalloc (sizeof (struct pl2303_private), GFP_KERNEL);
		if (!priv)
			goto cleanup;
		memset (priv, 0x00, sizeof (struct pl2303_private));
		spin_lock_init(&priv->lock);
		priv->buf = pl2303_buf_alloc(PL2303_BUF_SIZE);
		if (priv->buf == NULL) {
			kfree(priv);
			goto cleanup;
		}
		init_waitqueue_head(&priv->delta_msr_wait);
		priv->type = type;
		usb_set_serial_port_data(serial->port[i], priv);
	}
	return 0;

cleanup:
	for (--i; i>=0; --i) {
		priv = usb_get_serial_port_data(serial->port[i]);
		pl2303_buf_free(priv->buf);
		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", __FUNCTION__, value, retval);
	return retval;
}

static int pl2303_write (struct usb_serial_port *port,  const unsigned char *buf, int count)
{
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	dbg("%s - port %d, %d bytes", __FUNCTION__, port->number, count);

	if (!count)
		return count;

	spin_lock_irqsave(&priv->lock, flags);
	count = pl2303_buf_put(priv->buf, buf, count);
	spin_unlock_irqrestore(&priv->lock, flags);

	pl2303_send(port);

	return count;
}

static void pl2303_send(struct usb_serial_port *port)
{
	int count, result;
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

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

	spin_lock_irqsave(&priv->lock, flags);

	if (priv->write_urb_in_use) {
		spin_unlock_irqrestore(&priv->lock, flags);
		return;
	}

	count = pl2303_buf_get(priv->buf, port->write_urb->transfer_buffer,
		port->bulk_out_size);

	if (count == 0) {
		spin_unlock_irqrestore(&priv->lock, flags);
		return;
	}

	priv->write_urb_in_use = 1;

	spin_unlock_irqrestore(&priv->lock, flags);

	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, port->write_urb->transfer_buffer);

	port->write_urb->transfer_buffer_length = count;
	port->write_urb->dev = port->serial->dev;
	result = usb_submit_urb (port->write_urb, GFP_ATOMIC);
	if (result) {
		dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
		priv->write_urb_in_use = 0;
		// TODO: reschedule pl2303_send
	}

	schedule_work(&port->work);
}

static int pl2303_write_room(struct usb_serial_port *port)
{
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	int room = 0;
	unsigned long flags;

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

	spin_lock_irqsave(&priv->lock, flags);
	room = pl2303_buf_space_avail(priv->buf);
	spin_unlock_irqrestore(&priv->lock, flags);

	dbg("%s - returns %d", __FUNCTION__, room);
	return room;
}

static int pl2303_chars_in_buffer(struct usb_serial_port *port)
{
	struct pl2303_private *priv = usb_get_serial_port_data(port);
	int chars = 0;
	unsigned long flags;

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

	spin_lock_irqsave(&priv->lock, flags);
	chars = pl2303_buf_data_avail(priv->buf);
	spin_unlock_irqrestore(&priv->lock, flags);

	dbg("%s - returns %d", __FUNCTION__, chars);
	return chars;
}

static void pl2303_set_termios (struct usb_serial_port *port, struct termios *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;

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

	if ((!port->tty) || (!port->tty->termios)) {
		dbg("%s - no tty structures", __FUNCTION__);
		return;
	}

	spin_lock_irqsave(&priv->lock, flags);
	if (!priv->termios_initialized) {
		*(port->tty->termios) = tty_std_termios;
		port->tty->termios->c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
		priv->termios_initialized = 1;
	}
	spin_unlock_irqrestore(&priv->lock, flags);

	cflag = port->tty->termios->c_cflag;
	/* check that they really want us to change something */
	if (old_termios) {
		if ((cflag == old_termios->c_cflag) &&
		    (RELEVANT_IFLAG(port->tty->termios->c_iflag) == RELEVANT_IFLAG(old_termios->c_iflag))) {
		    dbg("%s - nothing to change...", __FUNCTION__);
		    return;
		}
	}

	buf = kmalloc (7, GFP_KERNEL);
	if (!buf) {
		dev_err(&port->dev, "%s - out of memory.\n", __FUNCTION__);
		return;
	}
	memset (buf, 0x00, 0x07);