serial_tx3912.c

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{
	struct rs_port *port;
	int retval, line;

	func_enter();

	if (!rs_initialized) {
		return -EIO;
	}

	line = MINOR(tty->device) - tty->driver.minor_start;
	rs_dprintk (TX3912_UART_DEBUG_OPEN, "%d: opening line %d. tty=%p ctty=%p)\n", 
	            (int) current->pid, line, tty, current->tty);

	if ((line < 0) || (line >= TX3912_UART_NPORTS))
		return -ENODEV;

	/* Pre-initialized already */
	port = & rs_ports[line];

	rs_dprintk (TX3912_UART_DEBUG_OPEN, "port = %p\n", port);

	tty->driver_data = port;
	port->gs.tty = tty;
	port->gs.count++;

	rs_dprintk (TX3912_UART_DEBUG_OPEN, "starting port\n");

	/*
	 * Start up serial port
	 */
	retval = gs_init_port(&port->gs);
	rs_dprintk (TX3912_UART_DEBUG_OPEN, "done gs_init\n");
	if (retval) {
		port->gs.count--;
		return retval;
	}

	port->gs.flags |= GS_ACTIVE;

	rs_dprintk (TX3912_UART_DEBUG_OPEN, "before inc_use_count (count=%d.\n", 
	            port->gs.count);
	if (port->gs.count == 1) {
		MOD_INC_USE_COUNT;
	}
	rs_dprintk (TX3912_UART_DEBUG_OPEN, "after inc_use_count\n");

	/* Jim: Initialize port hardware here */

	/* Enable high-priority interrupts for UARTA */
	IntEnable6 |= INT6_UARTARXINT; 
	rs_enable_rx_interrupts(&rs_ports[0]); 

	retval = gs_block_til_ready(&port->gs, filp);
	rs_dprintk (TX3912_UART_DEBUG_OPEN, "Block til ready returned %d. Count=%d\n", 
	            retval, port->gs.count);

	if (retval) {
		MOD_DEC_USE_COUNT;
		port->gs.count--;
		return retval;
	}
	/* tty->low_latency = 1; */

	if ((port->gs.count == 1) && (port->gs.flags & ASYNC_SPLIT_TERMIOS)) {
		if (tty->driver.subtype == SERIAL_TYPE_NORMAL)
			*tty->termios = port->gs.normal_termios;
		else 
			*tty->termios = port->gs.callout_termios;
		rs_set_real_termios (port);
	}

	port->gs.session = current->session;
	port->gs.pgrp = current->pgrp;
	func_exit();

	/* Jim */
/*	cli(); */

	return 0;

}



static void rs_close (void *ptr)
{
	func_enter ();

	/* Anything to do here? */

	MOD_DEC_USE_COUNT;
	func_exit ();
}


/* I haven't the foggiest why the decrement use count has to happen
   here. The whole linux serial drivers stuff needs to be redesigned.
   My guess is that this is a hack to minimize the impact of a bug
   elsewhere. Thinking about it some more. (try it sometime) Try
   running minicom on a serial port that is driven by a modularized
   driver. Have the modem hangup. Then remove the driver module. Then
   exit minicom.  I expect an "oops".  -- REW */
static void rs_hungup (void *ptr)
{
	func_enter ();
	MOD_DEC_USE_COUNT;
	func_exit ();
}

static int rs_ioctl (struct tty_struct * tty, struct file * filp, 
                     unsigned int cmd, unsigned long arg)
{
	int rc;
	struct rs_port *port = tty->driver_data;
	int ival;

	rc = 0;
	switch (cmd) {
	case TIOCGSOFTCAR:
		rc = put_user(((tty->termios->c_cflag & CLOCAL) ? 1 : 0),
		              (unsigned int *) arg);
		break;
	case TIOCSSOFTCAR:
		if ((rc = verify_area(VERIFY_READ, (void *) arg,
		                      sizeof(int))) == 0) {
			get_user(ival, (unsigned int *) arg);
			tty->termios->c_cflag =
				(tty->termios->c_cflag & ~CLOCAL) |
				(ival ? CLOCAL : 0);
		}
		break;
	case TIOCGSERIAL:
		if ((rc = verify_area(VERIFY_WRITE, (void *) arg,
		                      sizeof(struct serial_struct))) == 0)
			rc = gs_getserial(&port->gs, (struct serial_struct *) arg);
		break;
	case TIOCSSERIAL:
		if ((rc = verify_area(VERIFY_READ, (void *) arg,
		                      sizeof(struct serial_struct))) == 0)
			rc = gs_setserial(&port->gs, (struct serial_struct *) arg);
		break;
	default:
		rc = -ENOIOCTLCMD;
		break;
	}

	/* func_exit(); */
	return rc;
}


/*
 * This function is used to send a high-priority XON/XOFF character to
 * the device
 */
static void rs_send_xchar(struct tty_struct * tty, char ch)
{
	struct rs_port *port = (struct rs_port *)tty->driver_data;
	func_enter ();
	
	port->x_char = ch;
	if (ch) {
		/* Make sure transmit interrupts are on */
		rs_enable_tx_interrupts(tty);
	}

	func_exit();
}


/*
 * ------------------------------------------------------------
 * rs_throttle()
 * 
 * This routine is called by the upper-layer tty layer to signal that
 * incoming characters should be throttled.
 * ------------------------------------------------------------
 */
static void rs_throttle(struct tty_struct * tty)
{
#ifdef TX3912_UART_DEBUG_THROTTLE
	char	buf[64];
	
	printk("throttle %s: %d....\n", tty_name(tty, buf),
	       tty->ldisc.chars_in_buffer(tty));
#endif

	func_enter ();
	
	if (I_IXOFF(tty))
		rs_send_xchar(tty, STOP_CHAR(tty));

	func_exit ();
}

static void rs_unthrottle(struct tty_struct * tty)
{
	struct rs_port *port = (struct rs_port *)tty->driver_data;
#ifdef TX3912_UART_DEBUG_THROTTLE
	char	buf[64];
	
	printk("unthrottle %s: %d....\n", tty_name(tty, buf),
	       tty->ldisc.chars_in_buffer(tty));
#endif

	func_enter();
	
	if (I_IXOFF(tty)) {
		if (port->x_char)
			port->x_char = 0;
		else
			rs_send_xchar(tty, START_CHAR(tty));
	}

	func_exit();
}





/* ********************************************************************** *
 *                    Here are the initialization routines.               *
 * ********************************************************************** */

void * ckmalloc (int size)
{
        void *p;

        p = kmalloc(size, GFP_KERNEL);
        if (p) 
                memset(p, 0, size);
        return p;
}



static int rs_init_portstructs(void)
{
	struct rs_port *port;
	int i;

	/* Debugging */
	func_enter();

	rs_ports          = ckmalloc(TX3912_UART_NPORTS * sizeof (struct rs_port));
	if (!rs_ports)
		return -ENOMEM;

	rs_termios        = ckmalloc(TX3912_UART_NPORTS * sizeof (struct termios *));
	if (!rs_termios) {
		kfree (rs_ports);
		return -ENOMEM;
	}

	rs_termios_locked = ckmalloc(TX3912_UART_NPORTS * sizeof (struct termios *));
	if (!rs_termios_locked) {
		kfree (rs_ports);
		kfree (rs_termios);
		return -ENOMEM;
	}

	/* Adjust the values in the "driver" */
	rs_driver.termios = rs_termios;
	rs_driver.termios_locked = rs_termios_locked;

	port = rs_ports;
	for (i=0; i < TX3912_UART_NPORTS;i++) {
		rs_dprintk (TX3912_UART_DEBUG_INIT, "initing port %d\n", i);
		port->gs.callout_termios = tty_std_termios;
		port->gs.normal_termios	= tty_std_termios;
		port->gs.magic = SERIAL_MAGIC;
		port->gs.close_delay = HZ/2;
		port->gs.closing_wait = 30 * HZ;
		port->gs.rd = &rs_real_driver;
#ifdef NEW_WRITE_LOCKING
		port->gs.port_write_sem = MUTEX;
#endif
#ifdef DECLARE_WAITQUEUE
		init_waitqueue_head(&port->gs.open_wait);
		init_waitqueue_head(&port->gs.close_wait);
#endif
		port->base = (i == 0) ? TX3912_UARTA_BASE : TX3912_UARTB_BASE;
		port->intshift = (i == 0) ? UARTA_SHIFT : UARTB_SHIFT;
		rs_dprintk (TX3912_UART_DEBUG_INIT, "base 0x%08lx intshift %d\n",
			    port->base, port->intshift);
		port++;
	}

	func_exit();
	return 0;
}

static int rs_init_drivers(void)
{
	int error;

	func_enter();

	memset(&rs_driver, 0, sizeof(rs_driver));
	rs_driver.magic = TTY_DRIVER_MAGIC;
	rs_driver.driver_name = "serial";
	rs_driver.name = "ttyS";
	rs_driver.major = TTY_MAJOR;
	rs_driver.minor_start = 64;
	rs_driver.num = TX3912_UART_NPORTS;
	rs_driver.type = TTY_DRIVER_TYPE_SERIAL;
	rs_driver.subtype = SERIAL_TYPE_NORMAL;
	rs_driver.init_termios = tty_std_termios;
	rs_driver.init_termios.c_cflag =
		B115200 | CS8 | CREAD | HUPCL | CLOCAL;
	rs_driver.refcount = &rs_refcount;
	rs_driver.table = rs_table;
	rs_driver.termios = rs_termios;
	rs_driver.termios_locked = rs_termios_locked;

	rs_driver.open	= rs_open;
	rs_driver.close = gs_close;
	rs_driver.write = gs_write;
	rs_driver.put_char = gs_put_char; 
	rs_driver.flush_chars = gs_flush_chars;
	rs_driver.write_room = gs_write_room;
	rs_driver.chars_in_buffer = gs_chars_in_buffer;
	rs_driver.flush_buffer = gs_flush_buffer;
	rs_driver.ioctl = rs_ioctl;
	rs_driver.throttle = rs_throttle;
	rs_driver.unthrottle = rs_unthrottle;
	rs_driver.set_termios = gs_set_termios;
	rs_driver.stop = gs_stop;
	rs_driver.start = gs_start;
	rs_driver.hangup = gs_hangup;

	rs_callout_driver = rs_driver;
	rs_callout_driver.name = "cua";
	rs_callout_driver.major = TTYAUX_MAJOR;
	rs_callout_driver.subtype = SERIAL_TYPE_CALLOUT;

	if ((error = tty_register_driver(&rs_driver))) {
		printk(KERN_ERR "Couldn't register serial driver, error = %d\n",
		       error);
		return 1;
	}
	if ((error = tty_register_driver(&rs_callout_driver))) {
		tty_unregister_driver(&rs_driver);
		printk(KERN_ERR "Couldn't register callout driver, error = %d\n",
		       error);
		return 1;
	}

	func_exit();
	return 0;
}


void __init tx3912_rs_init(void)
{
	int rc;


	func_enter();
	rs_dprintk (TX3912_UART_DEBUG_INIT, "Initing serial module... (rs_debug=%d)\n", rs_debug);

	rc = rs_init_portstructs ();
	rs_init_drivers ();
	if (request_irq(2, rs_tx_interrupt_uarta, SA_SHIRQ | SA_INTERRUPT,
			"serial", &rs_ports[0])) {
		printk(KERN_ERR "rs: Cannot allocate irq for UARTA.\n");
		rc = 0;
	}
	if (request_irq(3, rs_rx_interrupt_uarta, SA_SHIRQ | SA_INTERRUPT,
			"serial", &rs_ports[0])) {
		printk(KERN_ERR "rs: Cannot allocate irq for UARTA.\n");
		rc = 0;
	}

	IntEnable6 |= INT6_UARTARXINT; 
	rs_enable_rx_interrupts(&rs_ports[0]); 

#ifndef CONFIG_SERIAL_TX3912_CONSOLE
{
	unsigned int scratch = 0;

	/* Setup master clock for UART */
	scratch = inl(TX3912_CLK_CTRL_BASE);
	scratch &= ~TX3912_CLK_CTRL_SIBMCLKDIV_MASK;
	scratch |= ((0x2 << TX3912_CLK_CTRL_SIBMCLKDIV_SHIFT) &
				TX3912_CLK_CTRL_SIBMCLKDIV_MASK)
			| TX3912_CLK_CTRL_SIBMCLKDIR
			| TX3912_CLK_CTRL_ENSIBMCLK
			| TX3912_CLK_CTRL_CSERSEL;
	outl(scratch, TX3912_CLK_CTRL_BASE);

	/* Configure UARTA clock */
	scratch = inl(TX3912_CLK_CTRL_BASE);
	scratch |= ((0x3 << TX3912_CLK_CTRL_CSERDIV_SHIFT) &
				TX3912_CLK_CTRL_CSERDIV_MASK)
			| TX3912_CLK_CTRL_ENCSERCLK
			| TX3912_CLK_CTRL_ENUARTACLK;
	outl(scratch, TX3912_CLK_CTRL_BASE);
		
	/* Setup UARTA for 115200,8N1 */
	outl(0, TX3912_UARTA_BASE + TX3912_UART_CTRL1);
	outl(TX3912_UART_CTRL2_B115200, TX3912_UARTA_BASE + TX3912_UART_CTRL2);
	outl(0, TX3912_UARTA_BASE + TX3912_UART_DMA_CTRL1);
	outl(0, TX3912_UARTA_BASE + TX3912_UART_DMA_CTRL2);

	/* Enable UARTA */
	outl(TX3912_UART_CTRL1_ENUART, TX3912_UARTA_BASE + TX3912_UART_CTRL1);
	while (~inl(TX3912_UARTA_BASE + TX3912_UART_CTRL1) &
		TX3912_UART_CTRL1_UARTON);
}
#endif

	/* Note: I didn't do anything to enable the second UART */
	if (rc >= 0) 
		rs_initialized++;

	func_exit();
}

/*
 * Begin serial console routines
 */
#ifdef CONFIG_SERIAL_TX3912_CONSOLE

void serial_outc(unsigned char c)
{
	int i;
	unsigned long int2;
	#define BUSY_WAIT 10000

	/*
	 * Turn UARTA interrupts off
	 */
	int2 = IntEnable2;
	IntEnable2 &=
		~(INT2_UARTATXINT | INT2_UARTATXOVERRUN | INT2_UARTAEMPTY);

	/*
	 * The UART_TX_EMPTY bit in UartA_Ctrl1 seems
	 * not to be very reliable :-(
	 *
	 * Wait for the Tx register to become empty
	 */
	for (i = 0; !(IntStatus2 & INT2_UARTATXINT) && (i < BUSY_WAIT); i++);

	IntClear2 = INT2_UARTATXINT | INT2_UARTATXOVERRUN | INT2_UARTAEMPTY;
	UartA_Data = c;
	for (i = 0; !(IntStatus2 & INT2_UARTATXINT) && (i < BUSY_WAIT); i++);
	IntClear2 = INT2_UARTATXINT | INT2_UARTATXOVERRUN | INT2_UARTAEMPTY;

	IntEnable2 = int2;
}

static int serial_console_wait_key(struct console *co)
{
	unsigned int int2, res;

	int2 = IntEnable2;
	IntEnable2 = 0;

	while (!(UartA_Ctrl1 & UART_RX_HOLD_FULL));
	res = UartA_Data;
	udelay(10);
	
	IntEnable2 = int2;
	return res;
}

static void serial_console_write(struct console *co, const char *s,
		unsigned count)
{
    	unsigned int i;

	for (i = 0; i < count; i++) {
		if (*s == '\n')
			serial_outc('\r');
		serial_outc(*s++);
    	}
}

static kdev_t serial_console_device(struct console *c)
{
	return MKDEV(TTY_MAJOR, 64 + c->index);
}

static __init int serial_console_setup(struct console *co, char *options)
{
	unsigned int scratch = 0;

	/* Setup master clock for UART */
	scratch = inl(TX3912_CLK_CTRL_BASE);
	scratch &= ~TX3912_CLK_CTRL_SIBMCLKDIV_MASK;
	scratch |= ((0x2 << TX3912_CLK_CTRL_SIBMCLKDIV_SHIFT) &
				TX3912_CLK_CTRL_SIBMCLKDIV_MASK)
			| TX3912_CLK_CTRL_SIBMCLKDIR
			| TX3912_CLK_CTRL_ENSIBMCLK
			| TX3912_CLK_CTRL_CSERSEL;
	outl(scratch, TX3912_CLK_CTRL_BASE);

	/* Configure UARTA clock */
	scratch = inl(TX3912_CLK_CTRL_BASE);
	scratch |= ((0x3 << TX3912_CLK_CTRL_CSERDIV_SHIFT) &
				TX3912_CLK_CTRL_CSERDIV_MASK)
			| TX3912_CLK_CTRL_ENCSERCLK
			| TX3912_CLK_CTRL_ENUARTACLK;
	outl(scratch, TX3912_CLK_CTRL_BASE);
		
	/* Setup UARTA for 115200,8N1 */
	outl(0, TX3912_UARTA_BASE + TX3912_UART_CTRL1);
	outl(TX3912_UART_CTRL2_B115200, TX3912_UARTA_BASE + TX3912_UART_CTRL2);
	outl(0, TX3912_UARTA_BASE + TX3912_UART_DMA_CTRL1);
	outl(0, TX3912_UARTA_BASE + TX3912_UART_DMA_CTRL2);

	/* Enable UARTA */
	outl(TX3912_UART_CTRL1_ENUART, TX3912_UARTA_BASE + TX3912_UART_CTRL1);
	while (~inl(TX3912_UARTA_BASE + TX3912_UART_CTRL1) &
		TX3912_UART_CTRL1_UARTON);

	return 0;
}

static struct console sercons = {
	name:     "ttyS",
	write:    serial_console_write,
	device:   serial_console_device,
	wait_key: serial_console_wait_key,
	setup:    serial_console_setup,
	flags:    CON_PRINTBUFFER,
	index:    -1
};

void __init tx3912_console_init(void)
{
	register_console(&sercons);
}

#endif