sb1250-duart.c

linux 内核源代码

	/* Clear the interrupt registers.  */
	write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT);
	read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));

	/* Set rx/tx interrupt to FIFO available.  */
	mode1 = read_sbdchn(sport, R_DUART_MODE_REG_1);
	mode1 &= ~(M_DUART_RX_IRQ_SEL_RXFULL | M_DUART_TX_IRQ_SEL_TXEMPT);
	write_sbdchn(sport, R_DUART_MODE_REG_1, mode1);

	/* Disable tx, enable rx.  */
	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_EN);
	sport->tx_stopped = 1;

	/* Enable interrupts.  */
	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
		     M_DUART_IMR_IN | M_DUART_IMR_RX);

	return 0;
}

static void sbd_shutdown(struct uart_port *uport)
{
	struct sbd_port *sport = to_sport(uport);

	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
	sport->tx_stopped = 1;
	free_irq(sport->port.irq, sport);
}


static void sbd_init_port(struct sbd_port *sport)
{
	struct uart_port *uport = &sport->port;

	if (sport->initialised)
		return;

	/* There is no DUART reset feature, so just set some sane defaults.  */
	write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_TX);
	write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_RX);
	write_sbdchn(sport, R_DUART_MODE_REG_1, V_DUART_BITS_PER_CHAR_8);
	write_sbdchn(sport, R_DUART_MODE_REG_2, 0);
	write_sbdchn(sport, R_DUART_FULL_CTL,
		     V_DUART_INT_TIME(0) | V_DUART_SIG_FULL(15));
	write_sbdchn(sport, R_DUART_OPCR_X, 0);
	write_sbdchn(sport, R_DUART_AUXCTL_X, 0);
	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);

	sport->initialised = 1;
}

static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
			    struct ktermios *old_termios)
{
	struct sbd_port *sport = to_sport(uport);
	unsigned int mode1 = 0, mode2 = 0, aux = 0;
	unsigned int mode1mask = 0, mode2mask = 0, auxmask = 0;
	unsigned int oldmode1, oldmode2, oldaux;
	unsigned int baud, brg;
	unsigned int command;

	mode1mask |= ~(M_DUART_PARITY_MODE | M_DUART_PARITY_TYPE_ODD |
		       M_DUART_BITS_PER_CHAR);
	mode2mask |= ~M_DUART_STOP_BIT_LEN_2;
	auxmask |= ~M_DUART_CTS_CHNG_ENA;

	/* Byte size.  */
	switch (termios->c_cflag & CSIZE) {
	case CS5:
	case CS6:
		/* Unsupported, leave unchanged.  */
		mode1mask |= M_DUART_PARITY_MODE;
		break;
	case CS7:
		mode1 |= V_DUART_BITS_PER_CHAR_7;
		break;
	case CS8:
	default:
		mode1 |= V_DUART_BITS_PER_CHAR_8;
		break;
	}

	/* Parity and stop bits.  */
	if (termios->c_cflag & CSTOPB)
		mode2 |= M_DUART_STOP_BIT_LEN_2;
	else
		mode2 |= M_DUART_STOP_BIT_LEN_1;
	if (termios->c_cflag & PARENB)
		mode1 |= V_DUART_PARITY_MODE_ADD;
	else
		mode1 |= V_DUART_PARITY_MODE_NONE;
	if (termios->c_cflag & PARODD)
		mode1 |= M_DUART_PARITY_TYPE_ODD;
	else
		mode1 |= M_DUART_PARITY_TYPE_EVEN;

	baud = uart_get_baud_rate(uport, termios, old_termios, 1200, 5000000);
	brg = V_DUART_BAUD_RATE(baud);
	/* The actual lower bound is 1221bps, so compensate.  */
	if (brg > M_DUART_CLK_COUNTER)
		brg = M_DUART_CLK_COUNTER;

	uart_update_timeout(uport, termios->c_cflag, baud);

	uport->read_status_mask = M_DUART_OVRUN_ERR;
	if (termios->c_iflag & INPCK)
		uport->read_status_mask |= M_DUART_FRM_ERR |
					   M_DUART_PARITY_ERR;
	if (termios->c_iflag & (BRKINT | PARMRK))
		uport->read_status_mask |= M_DUART_RCVD_BRK;

	uport->ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
		uport->ignore_status_mask |= M_DUART_FRM_ERR |
					     M_DUART_PARITY_ERR;
	if (termios->c_iflag & IGNBRK) {
		uport->ignore_status_mask |= M_DUART_RCVD_BRK;
		if (termios->c_iflag & IGNPAR)
			uport->ignore_status_mask |= M_DUART_OVRUN_ERR;
	}

	if (termios->c_cflag & CREAD)
		command = M_DUART_RX_EN;
	else
		command = M_DUART_RX_DIS;

	if (termios->c_cflag & CRTSCTS)
		aux |= M_DUART_CTS_CHNG_ENA;
	else
		aux &= ~M_DUART_CTS_CHNG_ENA;

	spin_lock(&uport->lock);

	if (sport->tx_stopped)
		command |= M_DUART_TX_DIS;
	else
		command |= M_DUART_TX_EN;

	oldmode1 = read_sbdchn(sport, R_DUART_MODE_REG_1) & mode1mask;
	oldmode2 = read_sbdchn(sport, R_DUART_MODE_REG_2) & mode2mask;
	oldaux = read_sbdchn(sport, R_DUART_AUXCTL_X) & auxmask;

	if (!sport->tx_stopped)
		sbd_line_drain(sport);
	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);

	write_sbdchn(sport, R_DUART_MODE_REG_1, mode1 | oldmode1);
	write_sbdchn(sport, R_DUART_MODE_REG_2, mode2 | oldmode2);
	write_sbdchn(sport, R_DUART_CLK_SEL, brg);
	write_sbdchn(sport, R_DUART_AUXCTL_X, aux | oldaux);

	write_sbdchn(sport, R_DUART_CMD, command);

	spin_unlock(&uport->lock);
}


static const char *sbd_type(struct uart_port *uport)
{
	return "SB1250 DUART";
}

static void sbd_release_port(struct uart_port *uport)
{
	struct sbd_port *sport = to_sport(uport);
	struct sbd_duart *duart = sport->duart;
	int map_guard;

	iounmap(sport->memctrl);
	sport->memctrl = NULL;
	iounmap(uport->membase);
	uport->membase = NULL;

	map_guard = atomic_add_return(-1, &duart->map_guard);
	if (!map_guard)
		release_mem_region(duart->mapctrl, DUART_CHANREG_SPACING);
	release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
}

static int sbd_map_port(struct uart_port *uport)
{
	const char *err = KERN_ERR "sbd: Cannot map MMIO\n";
	struct sbd_port *sport = to_sport(uport);
	struct sbd_duart *duart = sport->duart;

	if (!uport->membase)
		uport->membase = ioremap_nocache(uport->mapbase,
						 DUART_CHANREG_SPACING);
	if (!uport->membase) {
		printk(err);
		return -ENOMEM;
	}

	if (!sport->memctrl)
		sport->memctrl = ioremap_nocache(duart->mapctrl,
						 DUART_CHANREG_SPACING);
	if (!sport->memctrl) {
		printk(err);
		iounmap(uport->membase);
		uport->membase = NULL;
		return -ENOMEM;
	}

	return 0;
}

static int sbd_request_port(struct uart_port *uport)
{
	const char *err = KERN_ERR "sbd: Unable to reserve MMIO resource\n";
	struct sbd_duart *duart = to_sport(uport)->duart;
	int map_guard;
	int ret = 0;

	if (!request_mem_region(uport->mapbase, DUART_CHANREG_SPACING,
				"sb1250-duart")) {
		printk(err);
		return -EBUSY;
	}
	map_guard = atomic_add_return(1, &duart->map_guard);
	if (map_guard == 1) {
		if (!request_mem_region(duart->mapctrl, DUART_CHANREG_SPACING,
					"sb1250-duart")) {
			atomic_add(-1, &duart->map_guard);
			printk(err);
			ret = -EBUSY;
		}
	}
	if (!ret) {
		ret = sbd_map_port(uport);
		if (ret) {
			map_guard = atomic_add_return(-1, &duart->map_guard);
			if (!map_guard)
				release_mem_region(duart->mapctrl,
						   DUART_CHANREG_SPACING);
		}
	}
	if (ret) {
		release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
		return ret;
	}
	return 0;
}

static void sbd_config_port(struct uart_port *uport, int flags)
{
	struct sbd_port *sport = to_sport(uport);

	if (flags & UART_CONFIG_TYPE) {
		if (sbd_request_port(uport))
			return;

		uport->type = PORT_SB1250_DUART;

		sbd_init_port(sport);
	}
}

static int sbd_verify_port(struct uart_port *uport, struct serial_struct *ser)
{
	int ret = 0;

	if (ser->type != PORT_UNKNOWN && ser->type != PORT_SB1250_DUART)
		ret = -EINVAL;
	if (ser->irq != uport->irq)
		ret = -EINVAL;
	if (ser->baud_base != uport->uartclk / 16)
		ret = -EINVAL;
	return ret;
}


static const struct uart_ops sbd_ops = {
	.tx_empty	= sbd_tx_empty,
	.set_mctrl	= sbd_set_mctrl,
	.get_mctrl	= sbd_get_mctrl,
	.stop_tx	= sbd_stop_tx,
	.start_tx	= sbd_start_tx,
	.stop_rx	= sbd_stop_rx,
	.enable_ms	= sbd_enable_ms,
	.break_ctl	= sbd_break_ctl,
	.startup	= sbd_startup,
	.shutdown	= sbd_shutdown,
	.set_termios	= sbd_set_termios,
	.type		= sbd_type,
	.release_port	= sbd_release_port,
	.request_port	= sbd_request_port,
	.config_port	= sbd_config_port,
	.verify_port	= sbd_verify_port,
};

/* Initialize SB1250 DUART port structures.  */
static void __init sbd_probe_duarts(void)
{
	static int probed;
	int chip, side;
	int max_lines, line;

	if (probed)
		return;

	/* Set the number of available units based on the SOC type.  */
	switch (soc_type) {
	case K_SYS_SOC_TYPE_BCM1x55:
	case K_SYS_SOC_TYPE_BCM1x80:
		max_lines = 4;
		break;
	default:
		/* Assume at least two serial ports at the normal address.  */
		max_lines = 2;
		break;
	}

	probed = 1;

	for (chip = 0, line = 0; chip < DUART_MAX_CHIP && line < max_lines;
	     chip++) {
		sbd_duarts[chip].mapctrl = SBD_CTRLREGS(line);

		for (side = 0; side < DUART_MAX_SIDE && line < max_lines;
		     side++, line++) {
			struct sbd_port *sport = &sbd_duarts[chip].sport[side];
			struct uart_port *uport = &sport->port;

			sport->duart	= &sbd_duarts[chip];

			uport->irq	= SBD_INT(line);
			uport->uartclk	= 100000000 / 20 * 16;
			uport->fifosize	= 16;
			uport->iotype	= UPIO_MEM;
			uport->flags	= UPF_BOOT_AUTOCONF;
			uport->ops	= &sbd_ops;
			uport->line	= line;
			uport->mapbase	= SBD_CHANREGS(line);
		}
	}
}


#ifdef CONFIG_SERIAL_SB1250_DUART_CONSOLE
/*
 * Serial console stuff.  Very basic, polling driver for doing serial
 * console output.  The console_sem is held by the caller, so we
 * shouldn't be interrupted for more console activity.
 */
static void sbd_console_putchar(struct uart_port *uport, int ch)
{
	struct sbd_port *sport = to_sport(uport);

	sbd_transmit_drain(sport);
	write_sbdchn(sport, R_DUART_TX_HOLD, ch);
}

static void sbd_console_write(struct console *co, const char *s,
			      unsigned int count)
{
	int chip = co->index / DUART_MAX_SIDE;
	int side = co->index % DUART_MAX_SIDE;
	struct sbd_port *sport = &sbd_duarts[chip].sport[side];
	struct uart_port *uport = &sport->port;
	unsigned long flags;
	unsigned int mask;

	/* Disable transmit interrupts and enable the transmitter. */
	spin_lock_irqsave(&uport->lock, flags);
	mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
		     mask & ~M_DUART_IMR_TX);
	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
	spin_unlock_irqrestore(&uport->lock, flags);

	uart_console_write(&sport->port, s, count, sbd_console_putchar);

	/* Restore transmit interrupts and the transmitter enable. */
	spin_lock_irqsave(&uport->lock, flags);
	sbd_line_drain(sport);
	if (sport->tx_stopped)
		write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
	spin_unlock_irqrestore(&uport->lock, flags);
}

static int __init sbd_console_setup(struct console *co, char *options)
{
	int chip = co->index / DUART_MAX_SIDE;
	int side = co->index % DUART_MAX_SIDE;
	struct sbd_port *sport = &sbd_duarts[chip].sport[side];
	struct uart_port *uport = &sport->port;
	int baud = 115200;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';
	int ret;

	if (!sport->duart)
		return -ENXIO;

	ret = sbd_map_port(uport);
	if (ret)
		return ret;

	sbd_init_port(sport);

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);
	return uart_set_options(uport, co, baud, parity, bits, flow);
}

static struct uart_driver sbd_reg;
static struct console sbd_console = {
	.name	= "duart",
	.write	= sbd_console_write,
	.device	= uart_console_device,
	.setup	= sbd_console_setup,
	.flags	= CON_PRINTBUFFER,
	.index	= -1,
	.data	= &sbd_reg
};

static int __init sbd_serial_console_init(void)
{
	sbd_probe_duarts();
	register_console(&sbd_console);

	return 0;
}

console_initcall(sbd_serial_console_init);

#define SERIAL_SB1250_DUART_CONSOLE	&sbd_console
#else
#define SERIAL_SB1250_DUART_CONSOLE	NULL
#endif /* CONFIG_SERIAL_SB1250_DUART_CONSOLE */


static struct uart_driver sbd_reg = {
	.owner		= THIS_MODULE,
	.driver_name	= "serial",
	.dev_name	= "duart",
	.major		= TTY_MAJOR,
	.minor		= SB1250_DUART_MINOR_BASE,
	.nr		= DUART_MAX_CHIP * DUART_MAX_SIDE,
	.cons		= SERIAL_SB1250_DUART_CONSOLE,
};

/* Set up the driver and register it.  */
static int __init sbd_init(void)
{
	int i, ret;

	sbd_probe_duarts();

	ret = uart_register_driver(&sbd_reg);
	if (ret)
		return ret;

	for (i = 0; i < DUART_MAX_CHIP * DUART_MAX_SIDE; i++) {
		struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
		struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
		struct uart_port *uport = &sport->port;

		if (sport->duart)
			uart_add_one_port(&sbd_reg, uport);
	}

	return 0;
}

/* Unload the driver.  Unregister stuff, get ready to go away.  */
static void __exit sbd_exit(void)
{
	int i;

	for (i = DUART_MAX_CHIP * DUART_MAX_SIDE - 1; i >= 0; i--) {
		struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
		struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
		struct uart_port *uport = &sport->port;

		if (sport->duart)
			uart_remove_one_port(&sbd_reg, uport);
	}

	uart_unregister_driver(&sbd_reg);
}

module_init(sbd_init);
module_exit(sbd_exit);