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Commit 7af75af2 authored by Vadim Tsozik's avatar Vadim Tsozik Committed by Greg Kroah-Hartman
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USB: serial: mct_u232: added _ioctl, _msr_to_icount and _get_icount functions 



Added mct_u232_ioctl (implements TIOCMIWAIT command),
mct_u232_get_icount (implements TIOCGICOUNT command) and
mct_u232_msr_to_icount functions. MCT U232 P9 is one of a few usb to
serail adapters which converts USB +/-5v voltage levels to COM +/-15
voltages. So it can also power COM interfaced devices. This makes it
very usable for legacy COM interfaced data-acquisition hardware. I
tested new implementation with AWARE Electronics RM-60 radiation meter,
which sends pulse via RNG COM line whenever new particle is registered.

Signed-off-by: default avatarVadim Tsozik <tsozik@yahoo.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 0fe6f1d1

drivers/usb/serial/mct_u232.c

+105 −2
Original line number Diff line number Diff line
@@ -78,6 +78,8 @@ 
#include <asm/unaligned.h>

#include <linux/usb.h>

#include <linux/usb/serial.h>

#include <linux/serial.h>

#include <linux/ioctl.h>

#include "mct_u232.h"



/*
@@ -104,6 +106,10 @@ static void mct_u232_break_ctl(struct tty_struct *tty, int break_state); 
static int  mct_u232_tiocmget(struct tty_struct *tty, struct file *file);

static int  mct_u232_tiocmset(struct tty_struct *tty, struct file *file,

			unsigned int set, unsigned int clear);

static int  mct_u232_ioctl(struct tty_struct *tty, struct file *file,

			unsigned int cmd, unsigned long arg);

static int  mct_u232_get_icount(struct tty_struct *tty,

			struct serial_icounter_struct *icount);

static void mct_u232_throttle(struct tty_struct *tty);

static void mct_u232_unthrottle(struct tty_struct *tty);
@@ -150,9 +156,10 @@ static struct usb_serial_driver mct_u232_device = { 
	.tiocmset =	     mct_u232_tiocmset,

	.attach =	     mct_u232_startup,

	.release =	     mct_u232_release,

	.ioctl =             mct_u232_ioctl,

	.get_icount =        mct_u232_get_icount,

};





struct mct_u232_private {

	spinlock_t lock;

	unsigned int	     control_state; /* Modem Line Setting (TIOCM) */
@@ -160,6 +167,9 @@ struct mct_u232_private { 
	unsigned char	     last_lsr;      /* Line Status Register */

	unsigned char	     last_msr;      /* Modem Status Register */

	unsigned int	     rx_flags;      /* Throttling flags */

	struct async_icount  icount;

	wait_queue_head_t    msr_wait;	/* for handling sleeping while waiting

						for msr change to happen */

};



#define THROTTLED		0x01
@@ -386,6 +396,20 @@ static int mct_u232_get_modem_stat(struct usb_serial *serial, 
	return rc;

} /* mct_u232_get_modem_stat */



static void mct_u232_msr_to_icount(struct async_icount *icount,

						unsigned char msr)

{

	/* Translate Control Line states */

	if (msr & MCT_U232_MSR_DDSR)

		icount->dsr++;

	if (msr & MCT_U232_MSR_DCTS)

		icount->cts++;

	if (msr & MCT_U232_MSR_DRI)

		icount->rng++;

	if (msr & MCT_U232_MSR_DCD)

		icount->dcd++;

} /* mct_u232_msr_to_icount */



static void mct_u232_msr_to_state(unsigned int *control_state,

						unsigned char msr)

{
@@ -422,6 +446,7 @@ static int mct_u232_startup(struct usb_serial *serial) 
	if (!priv)

		return -ENOMEM;

	spin_lock_init(&priv->lock);

	init_waitqueue_head(&priv->msr_wait);

	usb_set_serial_port_data(serial->port[0], priv);



	init_waitqueue_head(&serial->port[0]->write_wait);
@@ -621,6 +646,8 @@ static void mct_u232_read_int_callback(struct urb *urb) 
	/* Record Control Line states */

	mct_u232_msr_to_state(&priv->control_state, priv->last_msr);



	mct_u232_msr_to_icount(&priv->icount, priv->last_msr);



#if 0

	/* Not yet handled. See belkin_sa.c for further information */

	/* Now to report any errors */
@@ -647,6 +674,7 @@ static void mct_u232_read_int_callback(struct urb *urb) 
		tty_kref_put(tty);

	}

#endif

	wake_up_interruptible(&priv->msr_wait);

	spin_unlock_irqrestore(&priv->lock, flags);

exit:

	retval = usb_submit_urb(urb, GFP_ATOMIC);
@@ -826,7 +854,6 @@ static void mct_u232_throttle(struct tty_struct *tty) 
	}

}





static void mct_u232_unthrottle(struct tty_struct *tty)

{

	struct usb_serial_port *port = tty->driver_data;
@@ -847,6 +874,82 @@ static void mct_u232_unthrottle(struct tty_struct *tty) 
	}

}



static int  mct_u232_ioctl(struct tty_struct *tty, struct file *file,

			unsigned int cmd, unsigned long arg)

{

	DEFINE_WAIT(wait);

	struct usb_serial_port *port = tty->driver_data;

	struct mct_u232_private *mct_u232_port = usb_get_serial_port_data(port);

	struct async_icount cnow, cprev;

	unsigned long flags;



	dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);



	switch (cmd) {



	case TIOCMIWAIT:



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



		spin_lock_irqsave(&mct_u232_port->lock, flags);

		cprev = mct_u232_port->icount;

		spin_unlock_irqrestore(&mct_u232_port->lock, flags);

		for ( ; ; ) {

			prepare_to_wait(&mct_u232_port->msr_wait,

					&wait, TASK_INTERRUPTIBLE);

			schedule();

			finish_wait(&mct_u232_port->msr_wait, &wait);

			/* see if a signal did it */

			if (signal_pending(current))

				return -ERESTARTSYS;

			spin_lock_irqsave(&mct_u232_port->lock, flags);

			cnow = mct_u232_port->icount;

			spin_unlock_irqrestore(&mct_u232_port->lock, flags);

			if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&

			    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)

				return -EIO; /* no change => error */

			if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||

			    ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||

			    ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||

			    ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) {

				return 0;

			}

			cprev = cnow;

		}



	}

	return -ENOIOCTLCMD;

}



static int  mct_u232_get_icount(struct tty_struct *tty,

			struct serial_icounter_struct *icount)

{

	struct usb_serial_port *port = tty->driver_data;

	struct mct_u232_private *mct_u232_port = usb_get_serial_port_data(port);

	struct async_icount *ic = &mct_u232_port->icount;

	unsigned long flags;



	spin_lock_irqsave(&mct_u232_port->lock, flags);



	icount->cts = ic->cts;

	icount->dsr = ic->dsr;

	icount->rng = ic->rng;

	icount->dcd = ic->dcd;

	icount->rx = ic->rx;

	icount->tx = ic->tx;

	icount->frame = ic->frame;

	icount->overrun = ic->overrun;

	icount->parity = ic->parity;

	icount->brk = ic->brk;

	icount->buf_overrun = ic->buf_overrun;



	spin_unlock_irqrestore(&mct_u232_port->lock, flags);



	dbg("%s (%d) TIOCGICOUNT RX=%d, TX=%d",

		__func__,  port->number, icount->rx, icount->tx);

	return 0;

}



static int __init mct_u232_init(void)

{

	int retval;