oti6858.c

linux 内核源代码

/*
 * Ours Technology Inc. OTi-6858 USB to serial adapter driver.
 *
 * Copyleft  (C) 2007 Kees Lemmens (adapted for kernel 2.6.20)
 * Copyright (C) 2006 Tomasz Michal Lukaszewski (FIXME: add e-mail)
 * Copyright (C) 2001-2004 Greg Kroah-Hartman ([e-mail])
 * Copyright (C) 2003 IBM Corp.
 *
 * Many thanks to the authors of pl2303 driver: all functions in this file
 * are heavily based on pl2303 code, buffering code is a 1-to-1 copy.
 *
 * Warning! You use this driver on your own risk! The only official
 * description of this device I have is datasheet from manufacturer,
 * and it doesn't contain almost any information needed to write a driver.
 * Almost all knowlegde used while writing this driver was gathered by:
 *  - analyzing traffic between device and the M$ Windows 2000 driver,
 *  - trying different bit combinations and checking pin states
 *    with a voltmeter,
 *  - receiving malformed frames and producing buffer overflows
 *    to learn how errors are reported,
 * So, THIS CODE CAN DESTROY OTi-6858 AND ANY OTHER DEVICES, THAT ARE
 * CONNECTED TO IT!
 *
 * 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.
 *
 * See Documentation/usb/usb-serial.txt for more information on using this driver
 *
 * TODO:
 *  - implement correct flushing for ioctls and oti6858_close()
 *  - check how errors (rx overflow, parity error, framing error) are reported
 *  - implement oti6858_break_ctl()
 *  - implement more ioctls
 *  - test/implement flow control
 *  - allow setting custom baud rates
 */

#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 <linux/usb.h>
#include <linux/usb/serial.h>
#include <asm/uaccess.h>
#include "oti6858.h"

#define OTI6858_DESCRIPTION \
	"Ours Technology Inc. OTi-6858 USB to serial adapter driver"
#define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
#define OTI6858_VERSION "0.1"

static struct usb_device_id id_table [] = {
	{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
	{ }
};

MODULE_DEVICE_TABLE(usb, id_table);

static struct usb_driver oti6858_driver = {
	.name =		"oti6858",
	.probe =	usb_serial_probe,
	.disconnect =	usb_serial_disconnect,
	.id_table =	id_table,
	.no_dynamic_id = 	1,
};

static int debug;


/* buffering code, copied from pl2303 driver */
#define PL2303_BUF_SIZE		1024
#define PL2303_TMP_BUF_SIZE	1024

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

/* requests */
#define	OTI6858_REQ_GET_STATUS		(USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
#define	OTI6858_REQ_T_GET_STATUS	0x01

#define	OTI6858_REQ_SET_LINE		(USB_DIR_OUT | USB_TYPE_VENDOR | 0x00)
#define	OTI6858_REQ_T_SET_LINE		0x00

#define	OTI6858_REQ_CHECK_TXBUFF	(USB_DIR_IN | USB_TYPE_VENDOR | 0x01)
#define	OTI6858_REQ_T_CHECK_TXBUFF	0x00

/* format of the control packet */
struct oti6858_control_pkt {
	u16	divisor;	/* baud rate = 96000000 / (16 * divisor), LE */
#define OTI6858_MAX_BAUD_RATE	3000000
	u8	frame_fmt;
#define FMT_STOP_BITS_MASK	0xc0
#define FMT_STOP_BITS_1		0x00
#define FMT_STOP_BITS_2		0x40	/* 1.5 stop bits if FMT_DATA_BITS_5 */
#define FMT_PARITY_MASK		0x38
#define FMT_PARITY_NONE		0x00
#define FMT_PARITY_ODD		0x08
#define FMT_PARITY_EVEN		0x18
#define FMT_PARITY_MARK		0x28
#define FMT_PARITY_SPACE	0x38
#define FMT_DATA_BITS_MASK	0x03
#define FMT_DATA_BITS_5		0x00
#define FMT_DATA_BITS_6		0x01
#define FMT_DATA_BITS_7		0x02
#define FMT_DATA_BITS_8		0x03
	u8	something;	/* always equals 0x43 */
	u8	control;	/* settings of flow control lines */
#define CONTROL_MASK		0x0c
#define CONTROL_DTR_HIGH	0x08
#define CONTROL_RTS_HIGH	0x04
	u8	tx_status;
#define	TX_BUFFER_EMPTIED	0x09
	u8	pin_state;
#define PIN_MASK		0x3f
#define PIN_RTS			0x20	/* output pin */
#define PIN_CTS			0x10	/* input pin, active low */
#define PIN_DSR			0x08	/* input pin, active low */
#define PIN_DTR			0x04	/* output pin */
#define PIN_RI			0x02	/* input pin, active low */
#define PIN_DCD			0x01	/* input pin, active low */
	u8	rx_bytes_avail;		/* number of bytes in rx buffer */;
};

#define OTI6858_CTRL_PKT_SIZE	sizeof(struct oti6858_control_pkt)
#define OTI6858_CTRL_EQUALS_PENDING(a, priv) \
	(    ((a)->divisor == (priv)->pending_setup.divisor) \
	  && ((a)->control == (priv)->pending_setup.control) \
	  && ((a)->frame_fmt == (priv)->pending_setup.frame_fmt) )

/* function prototypes */
static int oti6858_open(struct usb_serial_port *port, struct file *filp);
static void oti6858_close(struct usb_serial_port *port, struct file *filp);
static void oti6858_set_termios(struct usb_serial_port *port,
				struct ktermios *old);
static int oti6858_ioctl(struct usb_serial_port *port, struct file *file,
			unsigned int cmd, unsigned long arg);
static void oti6858_read_int_callback(struct urb *urb);
static void oti6858_read_bulk_callback(struct urb *urb);
static void oti6858_write_bulk_callback(struct urb *urb);
static int oti6858_write(struct usb_serial_port *port,
			const unsigned char *buf, int count);
static int oti6858_write_room(struct usb_serial_port *port);
static void oti6858_break_ctl(struct usb_serial_port *port, int break_state);
static int oti6858_chars_in_buffer(struct usb_serial_port *port);
static int oti6858_tiocmget(struct usb_serial_port *port, struct file *file);
static int oti6858_tiocmset(struct usb_serial_port *port, struct file *file,
				unsigned int set, unsigned int clear);
static int oti6858_startup(struct usb_serial *serial);
static void oti6858_shutdown(struct usb_serial *serial);

/* functions operating on buffers */
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);


/* device info */
static struct usb_serial_driver oti6858_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"oti6858",
	},
	.id_table =		id_table,
	.num_interrupt_in =	1,
	.num_bulk_in =		1,
	.num_bulk_out =		1,
	.num_ports =		1,
	.open =			oti6858_open,
	.close =		oti6858_close,
	.write =		oti6858_write,
	.ioctl =		oti6858_ioctl,
	.break_ctl =		oti6858_break_ctl,
	.set_termios =		oti6858_set_termios,
	.tiocmget =		oti6858_tiocmget,
	.tiocmset =		oti6858_tiocmset,
	.read_bulk_callback =	oti6858_read_bulk_callback,
	.read_int_callback =	oti6858_read_int_callback,
	.write_bulk_callback =	oti6858_write_bulk_callback,
	.write_room =		oti6858_write_room,
	.chars_in_buffer =	oti6858_chars_in_buffer,
	.attach =		oti6858_startup,
	.shutdown =		oti6858_shutdown,
};

struct oti6858_private {
	spinlock_t lock;

	struct pl2303_buf *buf;
	struct oti6858_control_pkt status;

	struct {
		u8 read_urb_in_use;
		u8 write_urb_in_use;
		u8 termios_initialized;
	} flags;
	struct delayed_work delayed_write_work;

	struct {
		u16 divisor;
		u8 frame_fmt;
		u8 control;
	} pending_setup;
	u8 transient;
	u8 setup_done;
	struct delayed_work delayed_setup_work;

	wait_queue_head_t intr_wait;
        struct usb_serial_port *port;   /* USB port with which associated */
};

#undef dbg
/* #define dbg(format, arg...) printk(KERN_INFO "%s: " format "\n", __FILE__, ## arg) */
#define dbg(format, arg...) printk(KERN_INFO "" format "\n", ## arg)

static void setup_line(struct work_struct *work)
{
	struct oti6858_private *priv = container_of(work, struct oti6858_private, delayed_setup_work.work);
	struct usb_serial_port *port = priv->port;
	struct oti6858_control_pkt *new_setup;
	unsigned long flags;
	int result;

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

	if ((new_setup = kmalloc(OTI6858_CTRL_PKT_SIZE, GFP_KERNEL)) == NULL) {
		dev_err(&port->dev, "%s(): out of memory!\n", __FUNCTION__);
		/* we will try again */
		schedule_delayed_work(&priv->delayed_setup_work, msecs_to_jiffies(2));
		return;
	}

	result = usb_control_msg(port->serial->dev,
				usb_rcvctrlpipe(port->serial->dev, 0),
				OTI6858_REQ_T_GET_STATUS,
				OTI6858_REQ_GET_STATUS,
				0, 0,
				new_setup, OTI6858_CTRL_PKT_SIZE,
				100);

	if (result != OTI6858_CTRL_PKT_SIZE) {
		dev_err(&port->dev, "%s(): error reading status\n", __FUNCTION__);
		kfree(new_setup);
		/* we will try again */
		schedule_delayed_work(&priv->delayed_setup_work, msecs_to_jiffies(2));
		return;
	}

	spin_lock_irqsave(&priv->lock, flags);
	if (!OTI6858_CTRL_EQUALS_PENDING(new_setup, priv)) {
		new_setup->divisor = priv->pending_setup.divisor;
		new_setup->control = priv->pending_setup.control;
		new_setup->frame_fmt = priv->pending_setup.frame_fmt;

		spin_unlock_irqrestore(&priv->lock, flags);
		result = usb_control_msg(port->serial->dev,
					usb_sndctrlpipe(port->serial->dev, 0),
					OTI6858_REQ_T_SET_LINE,
					OTI6858_REQ_SET_LINE,
					0, 0,
					new_setup, OTI6858_CTRL_PKT_SIZE,
					100);
	} else {
		spin_unlock_irqrestore(&priv->lock, flags);
		result = 0;
	}
	kfree(new_setup);

	spin_lock_irqsave(&priv->lock, flags);
	if (result != OTI6858_CTRL_PKT_SIZE)
		priv->transient = 0;
	priv->setup_done = 1;
	spin_unlock_irqrestore(&priv->lock, flags);

	dbg("%s(): submitting interrupt urb", __FUNCTION__);
	port->interrupt_in_urb->dev = port->serial->dev;
	result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
	if (result != 0) {
		dev_err(&port->dev, "%s(): usb_submit_urb() failed"
				" with error %d\n", __FUNCTION__, result);
	}
}

void send_data(struct work_struct *work)
{
	struct oti6858_private *priv = container_of(work, struct oti6858_private, delayed_write_work.work);
	struct usb_serial_port *port = priv->port;
	int count = 0, result;
	unsigned long flags;
	unsigned char allow;

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

	spin_lock_irqsave(&priv->lock, flags);
	if (priv->flags.write_urb_in_use) {
		spin_unlock_irqrestore(&priv->lock, flags);
		schedule_delayed_work(&priv->delayed_write_work, msecs_to_jiffies(2));
		return;
	}
	priv->flags.write_urb_in_use = 1;

	count = pl2303_buf_data_avail(priv->buf);
	spin_unlock_irqrestore(&priv->lock, flags);
	if (count > port->bulk_out_size)
		count = port->bulk_out_size;

	if (count != 0) {
		result = usb_control_msg(port->serial->dev,
				usb_rcvctrlpipe(port->serial->dev, 0),
				OTI6858_REQ_T_CHECK_TXBUFF,
				OTI6858_REQ_CHECK_TXBUFF,
				count, 0, &allow, 1, 100);
		if (result != 1 || allow != 0)
			count = 0;
	}

	if (count == 0) {
		priv->flags.write_urb_in_use = 0;

		dbg("%s(): submitting interrupt urb", __FUNCTION__);
		port->interrupt_in_urb->dev = port->serial->dev;
		result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
		if (result != 0) {
			dev_err(&port->dev, "%s(): usb_submit_urb() failed"
				" with error %d\n", __FUNCTION__, result);
		}
		return;
	}

	spin_lock_irqsave(&priv->lock, flags);
	pl2303_buf_get(priv->buf, port->write_urb->transfer_buffer, count);
	spin_unlock_irqrestore(&priv->lock, flags);

	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 != 0) {
		dev_err(&port->dev, "%s(): usb_submit_urb() failed"
			       " with error %d\n", __FUNCTION__, result);
		priv->flags.write_urb_in_use = 0;
	}

	usb_serial_port_softint(port);
}

static int oti6858_startup(struct usb_serial *serial)
{
        struct usb_serial_port *port = serial->port[0];
        struct oti6858_private *priv;
	int i;

	for (i = 0; i < serial->num_ports; ++i) {
		priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL);
		if (!priv)
			break;
		priv->buf = pl2303_buf_alloc(PL2303_BUF_SIZE);
		if (priv->buf == NULL) {
			kfree(priv);
			break;
		}

		spin_lock_init(&priv->lock);
		init_waitqueue_head(&priv->intr_wait);
//		INIT_WORK(&priv->setup_work, setup_line, serial->port[i]);
//		INIT_WORK(&priv->write_work, send_data, serial->port[i]);
		priv->port = port;
		INIT_DELAYED_WORK(&priv->delayed_setup_work, setup_line);
		INIT_DELAYED_WORK(&priv->delayed_write_work, send_data);

		usb_set_serial_port_data(serial->port[i], priv);
	}
	if (i == serial->num_ports)
		return 0;

	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 oti6858_write(struct usb_serial_port *port,
			const unsigned char *buf, int count)
{
	struct oti6858_private *priv = usb_get_serial_port_data(port);
	unsigned long flags;

	dbg("%s(port = %d, count = %d)", __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);

	return count;
}

static int oti6858_write_room(struct usb_serial_port *port)
{
	struct oti6858_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);

	return room;
}

static int oti6858_chars_in_buffer(struct usb_serial_port *port)
{
	struct oti6858_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);