zs.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 2,301 行 · 第 1/4 页

#ifndef CONFIG_SERIAL_CONSOLE
			/*
			 * We're called early and memory managment isn't up, yet.
			 * Thus check_region would fail.
			 */
			if (!request_region((unsigned long)
					 zs_channels[n_channels].control,
					 ZS_CHAN_IO_SIZE, "SCC"))
				panic("SCC I/O region is not free");
#endif
			zs_soft[n_channels].zs_channel = &zs_channels[n_channels];
			zs_soft[n_channels].irq = zs_parms->irq;

			/* 
			 *  Identification of channel A. Location of channel A
                         *  inside chip depends on mapping of internal address
			 *  the chip decodes channels by.
			 *  CHANNEL_A_NR returns either 0 (in case of 
			 *  DECstations) or 1 (in case of Baget).
			 */
			if (CHANNEL_A_NR == channel)
				zs_soft[n_channels].zs_chan_a = 
				    &zs_channels[n_channels+1-2*CHANNEL_A_NR];
			else
				zs_soft[n_channels].zs_chan_a = 
				    &zs_channels[n_channels];

			*pp = &zs_soft[n_channels];
			pp = &zs_soft[n_channels].zs_next;
			n_channels++;
		}
	}

	*pp = 0;
	zs_channels_found = n_channels;

	for (n = 0; n < zs_channels_found; n++) {
		for (i = 0; i < 16; i++) {
			zs_soft[n].zs_channel->curregs[i] = zs_init_regs[i];
		}
	}

/*	save_and_cli(flags);
	for (n = 0; n < zs_channels_found; n++) {
		if (((int)zs_channels[n].control & 0xf) == 1) {
			write_zsreg(zs_soft[n].zs_chan_a, R9, FHWRES);
			mdelay(10);
			write_zsreg(zs_soft[n].zs_chan_a, R9, 0);
		}
		load_zsregs(zs_soft[n].zs_channel, zs_soft[n].zs_channel->curregs);
	} 
	restore_flags(flags); */
}

static struct tty_operations serial_ops = {
	.open = rs_open,
	.close = rs_close,
	.write = rs_write,
	.flush_chars = rs_flush_chars,
	.write_room = rs_write_room,
	.chars_in_buffer = rs_chars_in_buffer,
	.flush_buffer = rs_flush_buffer,
	.ioctl = rs_ioctl,
	.throttle = rs_throttle,
	.unthrottle = rs_unthrottle,
	.set_termios = rs_set_termios,
	.stop = rs_stop,
	.start = rs_start,
	.hangup = rs_hangup,
	.break_ctl = rs_break,
	.wait_until_sent = rs_wait_until_sent,
	.tiocmget = rs_tiocmget,
	.tiocmset = rs_tiocmset,
};

/* zs_init inits the driver */
int __init zs_init(void)
{
	int channel, i;
	unsigned long flags;
	struct dec_serial *info;

	if(!BUS_PRESENT)
		return -ENODEV;

	/* Setup base handler, and timer table. */
	init_bh(SERIAL_BH, do_serial_bh);

	/* Find out how many Z8530 SCCs we have */
	if (zs_chain == 0)
		probe_sccs();

	serial_driver = alloc_tty_driver(zs_channels_found);
	if (!serial_driver)
		return -ENOMEM;

	show_serial_version();

	/* Initialize the tty_driver structure */
	/* Not all of this is exactly right for us. */

	serial_driver->owner = THIS_MODULE;
	serial_driver->devfs_name = "tts/";
	serial_driver->name = "ttyS";
	serial_driver->major = TTY_MAJOR;
	serial_driver->minor_start = 64;
	serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
	serial_driver->subtype = SERIAL_TYPE_NORMAL;
	serial_driver->init_termios = tty_std_termios;
	serial_driver->init_termios.c_cflag =
		B9600 | CS8 | CREAD | HUPCL | CLOCAL;
	serial_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
	tty_set_operations(serial_driver, &serial_ops);

	if (tty_register_driver(serial_driver))
		panic("Couldn't register serial driver\n");

	save_flags(flags); cli();

	for (channel = 0; channel < zs_channels_found; ++channel) {
		if (zs_soft[channel].hook &&
		    zs_soft[channel].hook->init_channel)
			(*zs_soft[channel].hook->init_channel)
				(&zs_soft[channel]);

		zs_soft[channel].clk_divisor = 16;
		zs_soft[channel].zs_baud = get_zsbaud(&zs_soft[channel]);

		if (request_irq(zs_parms->irq, rs_interrupt, SA_SHIRQ,
				"SCC", &zs_soft[channel]))
			printk(KERN_ERR "decserial: can't get irq %d\n",
			       zs_parms->irq);
	}

	for (info = zs_chain, i = 0; info; info = info->zs_next, i++)
	{
		if (info->hook && info->hook->init_info) {
			(*info->hook->init_info)(info);
			continue;
		}
		info->magic = SERIAL_MAGIC;
		info->port = (int) info->zs_channel->control;
		info->line = i;
		info->tty = 0;
		info->custom_divisor = 16;
		info->close_delay = 50;
		info->closing_wait = 3000;
		info->x_char = 0;
		info->event = 0;
		info->count = 0;
		info->blocked_open = 0;
		info->tqueue.routine = do_softint;
		info->tqueue.data = info;
		init_waitqueue_head(&info->open_wait);
		init_waitqueue_head(&info->close_wait);
		printk("ttyS%d at 0x%08x (irq = %d)", info->line,
		       info->port, info->irq);
		printk(" is a Z85C30 SCC\n");
		tty_register_device(serial_driver, info->line, NULL);
	}

	restore_flags(flags);

	return 0;
}

/*
 * register_serial and unregister_serial allows for serial ports to be
 * configured at run-time, to support PCMCIA modems.
 */
/* PowerMac: Unused at this time, just here to make things link. */
int register_serial(struct serial_struct *req)
{
	return -1;
}

void unregister_serial(int line)
{
	return;
}

/*
 * polling I/O routines
 */
static int
zs_poll_tx_char(struct dec_serial *info, unsigned char ch)
{
	struct dec_zschannel *chan = info->zs_channel;
	int    ret;

	if(chan) {
		int loops = 10000;
//		int nine = read_zsreg(chan, R9);

		RECOVERY_DELAY;
//        	write_zsreg(chan, R9, nine & ~MIE);
               	wbflush();
		RECOVERY_DELAY;

        	while (!(*(chan->control) & Tx_BUF_EMP) && --loops)
	        	RECOVERY_DELAY;

                if (loops) {
                        ret = 0;
        	        *(chan->data) = ch;
                	wbflush();
			RECOVERY_DELAY;
                } else
                        ret = -EAGAIN;

//        	write_zsreg(chan, R9, nine);
               	wbflush();
		RECOVERY_DELAY;

                return ret;
        }

	return -ENODEV;
}

static int
zs_poll_rx_char(struct dec_serial *info)
{
        struct dec_zschannel *chan = info->zs_channel;
        int    ret;

	if(chan) {
                int loops = 10000;

                while((read_zsreg(chan, 0) & Rx_CH_AV) == 0)
		        loops--;

                if (loops)
                        ret = read_zsdata(chan);
                else
                        ret = -EAGAIN;

                return ret;
        } else
                return -ENODEV;
}

unsigned int register_zs_hook(unsigned int channel, struct zs_hook *hook)
{
	struct dec_serial *info = &zs_soft[channel];

	if (info->hook) {
		printk("%s: line %d has already a hook registered\n",
		       __FUNCTION__, channel);

		return 0;
	} else {
		info->hook = hook;

		if (zs_chain == 0)
			probe_sccs();

		if (!(info->flags & ZILOG_INITIALIZED))
			zs_startup(info);

		hook->poll_rx_char = zs_poll_rx_char;
		hook->poll_tx_char = zs_poll_tx_char;

		return 1;
	}
}

unsigned int unregister_zs_hook(unsigned int channel)
{
	struct dec_serial *info = &zs_soft[channel];

        if (info->hook) {
                info->hook = NULL;
                return 1;
        } else {
                printk("%s: trying to unregister hook on line %d,"
                       " but none is registered\n", __FUNCTION__, channel);
                return 0;
        }
}

/*
 * ------------------------------------------------------------
 * Serial console driver
 * ------------------------------------------------------------
 */
#ifdef CONFIG_SERIAL_CONSOLE


/*
 *	Print a string to the serial port trying not to disturb
 *	any possible real use of the port...
 */
static void serial_console_write(struct console *co, const char *s,
				 unsigned count)
{
	struct dec_serial *info;
	int i;

	info = zs_soft + co->index;

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

static struct tty_driver *serial_console_device(struct console *c, int *index)
{
	*index = c->index;
	return serial_driver;
}

/*
 *	Setup initial baud/bits/parity. We do two things here:
 *	- construct a cflag setting for the first rs_open()
 *	- initialize the serial port
 *	Return non-zero if we didn't find a serial port.
 */
static int __init serial_console_setup(struct console *co, char *options)
{
	struct dec_serial *info;
	int	baud = 9600;
	int	bits = 8;
	int	parity = 'n';
	int	cflag = CREAD | HUPCL | CLOCAL;
	char	*s;
	unsigned long flags;

	if(!BUS_PRESENT)
		return -ENODEV;

	info = zs_soft + co->index;

	if (zs_chain == 0)
		probe_sccs();

	info->is_cons = 1;

	if (options) {
		baud = simple_strtoul(options, NULL, 10);
		s = options;
		while(*s >= '0' && *s <= '9')
			s++;
		if (*s)
			parity = *s++;
		if (*s)
			bits   = *s - '0';
	}

	/*
	 *	Now construct a cflag setting.
	 */
	switch(baud) {
	case 1200:
		cflag |= B1200;
		break;
	case 2400:
		cflag |= B2400;
		break;
	case 4800:
		cflag |= B4800;
		break;
	case 19200:
		cflag |= B19200;
		break;
	case 38400:
		cflag |= B38400;
		break;
	case 57600:
		cflag |= B57600;
		break;
	case 115200:
		cflag |= B115200;
		break;
	case 9600:
	default:
		cflag |= B9600;
		break;
	}
	switch(bits) {
	case 7:
		cflag |= CS7;
		break;
	default:
	case 8:
		cflag |= CS8;
		break;
	}
	switch(parity) {
	case 'o': case 'O':
		cflag |= PARODD;
		break;
	case 'e': case 'E':
		cflag |= PARENB;
		break;
	}
	co->cflag = cflag;
#if 1 
	save_and_cli(flags);

	/*
	 * Turn on RTS and DTR.
	 */
	zs_rtsdtr(info, RTS | DTR, 1);

	/*
	 * Finally, enable sequencing
	 */
	info->zs_channel->curregs[3] |= (RxENABLE | Rx8);
	info->zs_channel->curregs[5] |= (TxENAB | Tx8);
	info->zs_channel->curregs[9] |= (VIS);
	write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
	write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
	write_zsreg(info->zs_channel, 9, info->zs_channel->curregs[9]);

	/*
	 * Clear the interrupt registers.
	 */
	write_zsreg(info->zs_channel, 0, ERR_RES);
	write_zsreg(info->zs_channel, 0, RES_H_IUS);

	/*
	 * Set the speed of the serial port
	 */
	change_speed(info);

	/* Save the current value of RR0 */
	info->read_reg_zero = read_zsreg(info->zs_channel, 0);

	zs_soft[co->index].clk_divisor = 16;
	zs_soft[co->index].zs_baud = get_zsbaud(&zs_soft[co->index]);

	restore_flags(flags);
#endif
	return 0;
}

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

/*
 *	Register console.
 */
void __init zs_serial_console_init(void)
{
	register_console(&sercons);
}
#endif /* ifdef CONFIG_SERIAL_CONSOLE */

#ifdef CONFIG_KGDB
struct dec_zschannel *zs_kgdbchan;
static unsigned char scc_inittab[] = {
	9,  0x80,	/* reset A side (CHRA) */
	13, 0,		/* set baud rate divisor */
	12, 1,
	14, 1,		/* baud rate gen enable, src=rtxc (BRENABL) */
	11, 0x50,	/* clocks = br gen (RCBR | TCBR) */
	5,  0x6a,	/* tx 8 bits, assert RTS (Tx8 | TxENAB | RTS) */
	4,  0x44,	/* x16 clock, 1 stop (SB1 | X16CLK)*/
	3,  0xc1,	/* rx enable, 8 bits (RxENABLE | Rx8)*/
};

/* These are for receiving and sending characters under the kgdb
 * source level kernel debugger.
 */
void putDebugChar(char kgdb_char)
{
	struct dec_zschannel *chan = zs_kgdbchan;
	while ((read_zsreg(chan, 0) & Tx_BUF_EMP) == 0)
		RECOVERY_DELAY;
	write_zsdata(chan, kgdb_char);
}
char getDebugChar(void)
{
	struct dec_zschannel *chan = zs_kgdbchan;
	while((read_zsreg(chan, 0) & Rx_CH_AV) == 0)
		eieio(); /*barrier();*/
	return read_zsdata(chan);
}
void kgdb_interruptible(int yes)
{
	struct dec_zschannel *chan = zs_kgdbchan;
	int one, nine;
	nine = read_zsreg(chan, 9);
	if (yes == 1) {
		one = EXT_INT_ENAB|INT_ALL_Rx;
		nine |= MIE;
		printk("turning serial ints on\n");
	} else {
		one = RxINT_DISAB;
		nine &= ~MIE;
		printk("turning serial ints off\n");
	}
	write_zsreg(chan, 1, one);
	write_zsreg(chan, 9, nine);
}

static int kgdbhook_init_channel(struct dec_serial* info) 
{
	return 0;
}

static void kgdbhook_init_info(struct dec_serial* info)
{
}

static void kgdbhook_rx_char(struct dec_serial* info, 
			     unsigned char ch, unsigned char stat)
{
	if (ch == 0x03 || ch == '$')
		breakpoint();
	if (stat & (Rx_OVR|FRM_ERR|PAR_ERR))
		write_zsreg(info->zs_channel, 0, ERR_RES);
}

/* This sets up the serial port we're using, and turns on
 * interrupts for that channel, so kgdb is usable once we're done.
 */
static inline void kgdb_chaninit(struct dec_zschannel *ms, int intson, int bps)
{
	int brg;
	int i, x;
	volatile char *sccc = ms->control;
	brg = BPS_TO_BRG(bps, zs_parms->clock/16);
	printk("setting bps on kgdb line to %d [brg=%x]\n", bps, brg);
	for (i = 20000; i != 0; --i) {
		x = *sccc; eieio();
	}
	for (i = 0; i < sizeof(scc_inittab); ++i) {
		write_zsreg(ms, scc_inittab[i], scc_inittab[i+1]);
		i++;
	}
}
/* This is called at boot time to prime the kgdb serial debugging
 * serial line.  The 'tty_num' argument is 0 for /dev/ttya and 1
 * for /dev/ttyb which is determined in setup_arch() from the
 * boot command line flags.
 */
struct zs_hook zs_kgdbhook = {
	init_channel : kgdbhook_init_channel,
	init_info    : kgdbhook_init_info,
	cflags       : B38400|CS8|CLOCAL,
	rx_char      : kgdbhook_rx_char,
}

void __init zs_kgdb_hook(int tty_num)
{
	/* Find out how many Z8530 SCCs we have */
	if (zs_chain == 0)
		probe_sccs();
	zs_soft[tty_num].zs_channel = &zs_channels[tty_num];
	zs_kgdbchan = zs_soft[tty_num].zs_channel;
	zs_soft[tty_num].change_needed = 0;
	zs_soft[tty_num].clk_divisor = 16;
	zs_soft[tty_num].zs_baud = 38400;
 	zs_soft[tty_num].hook = &zs_kgdbhook; /* This runs kgdb */
	/* Turn on transmitter/receiver at 8-bits/char */
        kgdb_chaninit(zs_soft[tty_num].zs_channel, 1, 38400);
	printk("KGDB: on channel %d initialized\n", tty_num);
	set_debug_traps(); /* init stub */
}
#endif /* ifdef CONFIG_KGDB */