imx.c

linux 内核源代码

error_out3:
	free_irq(sport->txirq, sport);
error_out2:
	free_irq(sport->rxirq, sport);
error_out1:
	return retval;
}

static void imx_shutdown(struct uart_port *port)
{
	struct imx_port *sport = (struct imx_port *)port;
	unsigned long temp;

	/*
	 * Stop our timer.
	 */
	del_timer_sync(&sport->timer);

	/*
	 * Free the interrupts
	 */
	free_irq(sport->rtsirq, sport);
	free_irq(sport->txirq, sport);
	free_irq(sport->rxirq, sport);

	/*
	 * Disable all interrupts, port and break condition.
	 */

	temp = readl(sport->port.membase + UCR1);
	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
	writel(temp, sport->port.membase + UCR1);
}

static void
imx_set_termios(struct uart_port *port, struct ktermios *termios,
		   struct ktermios *old)
{
	struct imx_port *sport = (struct imx_port *)port;
	unsigned long flags;
	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;

	/*
	 * If we don't support modem control lines, don't allow
	 * these to be set.
	 */
	if (0) {
		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
		termios->c_cflag |= CLOCAL;
	}

	/*
	 * We only support CS7 and CS8.
	 */
	while ((termios->c_cflag & CSIZE) != CS7 &&
	       (termios->c_cflag & CSIZE) != CS8) {
		termios->c_cflag &= ~CSIZE;
		termios->c_cflag |= old_csize;
		old_csize = CS8;
	}

	if ((termios->c_cflag & CSIZE) == CS8)
		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
	else
		ucr2 = UCR2_SRST | UCR2_IRTS;

	if (termios->c_cflag & CRTSCTS) {
		if( sport->have_rtscts ) {
			ucr2 &= ~UCR2_IRTS;
			ucr2 |= UCR2_CTSC;
		} else {
			termios->c_cflag &= ~CRTSCTS;
		}
	}

	if (termios->c_cflag & CSTOPB)
		ucr2 |= UCR2_STPB;
	if (termios->c_cflag & PARENB) {
		ucr2 |= UCR2_PREN;
		if (termios->c_cflag & PARODD)
			ucr2 |= UCR2_PROE;
	}

	/*
	 * Ask the core to calculate the divisor for us.
	 */
	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
	quot = uart_get_divisor(port, baud);

	spin_lock_irqsave(&sport->port.lock, flags);

	sport->port.read_status_mask = 0;
	if (termios->c_iflag & INPCK)
		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
	if (termios->c_iflag & (BRKINT | PARMRK))
		sport->port.read_status_mask |= URXD_BRK;

	/*
	 * Characters to ignore
	 */
	sport->port.ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
		sport->port.ignore_status_mask |= URXD_PRERR;
	if (termios->c_iflag & IGNBRK) {
		sport->port.ignore_status_mask |= URXD_BRK;
		/*
		 * If we're ignoring parity and break indicators,
		 * ignore overruns too (for real raw support).
		 */
		if (termios->c_iflag & IGNPAR)
			sport->port.ignore_status_mask |= URXD_OVRRUN;
	}

	del_timer_sync(&sport->timer);

	/*
	 * Update the per-port timeout.
	 */
	uart_update_timeout(port, termios->c_cflag, baud);

	/*
	 * disable interrupts and drain transmitter
	 */
	old_ucr1 = readl(sport->port.membase + UCR1);
	writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
			sport->port.membase + UCR1);

	while ( !(readl(sport->port.membase + USR2) & USR2_TXDC))
		barrier();

	/* then, disable everything */
	old_txrxen = readl(sport->port.membase + UCR2);
	writel(old_txrxen & ~( UCR2_TXEN | UCR2_RXEN),
			sport->port.membase + UCR2);
	old_txrxen &= (UCR2_TXEN | UCR2_RXEN);

	/* set the baud rate. We assume uartclk = 16 MHz
	 *
	 * baud * 16   UBIR - 1
	 * --------- = --------
	 *  uartclk    UBMR - 1
	 */
	writel((baud / 100) - 1, sport->port.membase + UBIR);
	writel(10000 - 1, sport->port.membase + UBMR);

	writel(old_ucr1, sport->port.membase + UCR1);

	/* set the parity, stop bits and data size */
	writel(ucr2 | old_txrxen, sport->port.membase + UCR2);

	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
		imx_enable_ms(&sport->port);

	spin_unlock_irqrestore(&sport->port.lock, flags);
}

static const char *imx_type(struct uart_port *port)
{
	struct imx_port *sport = (struct imx_port *)port;

	return sport->port.type == PORT_IMX ? "IMX" : NULL;
}

/*
 * Release the memory region(s) being used by 'port'.
 */
static void imx_release_port(struct uart_port *port)
{
	struct imx_port *sport = (struct imx_port *)port;

	release_mem_region(sport->port.mapbase, UART_PORT_SIZE);
}

/*
 * Request the memory region(s) being used by 'port'.
 */
static int imx_request_port(struct uart_port *port)
{
	struct imx_port *sport = (struct imx_port *)port;

	return request_mem_region(sport->port.mapbase, UART_PORT_SIZE,
			"imx-uart") != NULL ? 0 : -EBUSY;
}

/*
 * Configure/autoconfigure the port.
 */
static void imx_config_port(struct uart_port *port, int flags)
{
	struct imx_port *sport = (struct imx_port *)port;

	if (flags & UART_CONFIG_TYPE &&
	    imx_request_port(&sport->port) == 0)
		sport->port.type = PORT_IMX;
}

/*
 * Verify the new serial_struct (for TIOCSSERIAL).
 * The only change we allow are to the flags and type, and
 * even then only between PORT_IMX and PORT_UNKNOWN
 */
static int
imx_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	struct imx_port *sport = (struct imx_port *)port;
	int ret = 0;

	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
		ret = -EINVAL;
	if (sport->port.irq != ser->irq)
		ret = -EINVAL;
	if (ser->io_type != UPIO_MEM)
		ret = -EINVAL;
	if (sport->port.uartclk / 16 != ser->baud_base)
		ret = -EINVAL;
	if ((void *)sport->port.mapbase != ser->iomem_base)
		ret = -EINVAL;
	if (sport->port.iobase != ser->port)
		ret = -EINVAL;
	if (ser->hub6 != 0)
		ret = -EINVAL;
	return ret;
}

static struct uart_ops imx_pops = {
	.tx_empty	= imx_tx_empty,
	.set_mctrl	= imx_set_mctrl,
	.get_mctrl	= imx_get_mctrl,
	.stop_tx	= imx_stop_tx,
	.start_tx	= imx_start_tx,
	.stop_rx	= imx_stop_rx,
	.enable_ms	= imx_enable_ms,
	.break_ctl	= imx_break_ctl,
	.startup	= imx_startup,
	.shutdown	= imx_shutdown,
	.set_termios	= imx_set_termios,
	.type		= imx_type,
	.release_port	= imx_release_port,
	.request_port	= imx_request_port,
	.config_port	= imx_config_port,
	.verify_port	= imx_verify_port,
};

static struct imx_port imx_ports[] = {
	{
	.txirq  = UART1_MINT_TX,
	.rxirq  = UART1_MINT_RX,
	.rtsirq = UART1_MINT_RTS,
	.port	= {
		.type		= PORT_IMX,
		.iotype		= UPIO_MEM,
		.membase	= (void *)IMX_UART1_BASE,
		.mapbase	= IMX_UART1_BASE, /* FIXME */
		.irq		= UART1_MINT_RX,
		.uartclk	= 16000000,
		.fifosize	= 32,
		.flags		= UPF_BOOT_AUTOCONF,
		.ops		= &imx_pops,
		.line		= 0,
	},
	}, {
	.txirq  = UART2_MINT_TX,
	.rxirq  = UART2_MINT_RX,
	.rtsirq = UART2_MINT_RTS,
	.port	= {
		.type		= PORT_IMX,
		.iotype		= UPIO_MEM,
		.membase	= (void *)IMX_UART2_BASE,
		.mapbase	= IMX_UART2_BASE, /* FIXME */
		.irq		= UART2_MINT_RX,
		.uartclk	= 16000000,
		.fifosize	= 32,
		.flags		= UPF_BOOT_AUTOCONF,
		.ops		= &imx_pops,
		.line		= 1,
	},
	}
};

/*
 * Setup the IMX serial ports.
 * Note also that we support "console=ttySMXx" where "x" is either 0 or 1.
 * Which serial port this ends up being depends on the machine you're
 * running this kernel on.  I'm not convinced that this is a good idea,
 * but that's the way it traditionally works.
 *
 */
static void __init imx_init_ports(void)
{
	static int first = 1;
	int i;

	if (!first)
		return;
	first = 0;

	for (i = 0; i < ARRAY_SIZE(imx_ports); i++) {
		init_timer(&imx_ports[i].timer);
		imx_ports[i].timer.function = imx_timeout;
		imx_ports[i].timer.data     = (unsigned long)&imx_ports[i];
	}
}

#ifdef CONFIG_SERIAL_IMX_CONSOLE
static void imx_console_putchar(struct uart_port *port, int ch)
{
	struct imx_port *sport = (struct imx_port *)port;

	while (readl(sport->port.membase + UTS) & UTS_TXFULL)
		barrier();

	writel(ch, sport->port.membase + URTX0);
}

/*
 * Interrupts are disabled on entering
 */
static void
imx_console_write(struct console *co, const char *s, unsigned int count)
{
	struct imx_port *sport = &imx_ports[co->index];
	unsigned int old_ucr1, old_ucr2;

	/*
	 *	First, save UCR1/2 and then disable interrupts
	 */
	old_ucr1 = readl(sport->port.membase + UCR1);
	old_ucr2 = readl(sport->port.membase + UCR2);

	writel((old_ucr1 | UCR1_UARTCLKEN | UCR1_UARTEN) &
		~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
		sport->port.membase + UCR1);

	writel(old_ucr2 | UCR2_TXEN, sport->port.membase + UCR2);

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

	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore UCR1/2
	 */
	while (!(readl(sport->port.membase + USR2) & USR2_TXDC));

	writel(old_ucr1, sport->port.membase + UCR1);
	writel(old_ucr2, sport->port.membase + UCR2);
}

/*
 * If the port was already initialised (eg, by a boot loader),
 * try to determine the current setup.
 */
static void __init
imx_console_get_options(struct imx_port *sport, int *baud,
			   int *parity, int *bits)
{

	if ( readl(sport->port.membase + UCR1) | UCR1_UARTEN ) {
		/* ok, the port was enabled */
		unsigned int ucr2, ubir,ubmr, uartclk;
		unsigned int baud_raw;
		unsigned int ucfr_rfdiv;

		ucr2 = readl(sport->port.membase + UCR2);

		*parity = 'n';
		if (ucr2 & UCR2_PREN) {
			if (ucr2 & UCR2_PROE)
				*parity = 'o';
			else
				*parity = 'e';
		}

		if (ucr2 & UCR2_WS)
			*bits = 8;
		else
			*bits = 7;

		ubir = readl(sport->port.membase + UBIR) & 0xffff;
		ubmr = readl(sport->port.membase + UBMR) & 0xffff;

		ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
		if (ucfr_rfdiv == 6)
			ucfr_rfdiv = 7;
		else
			ucfr_rfdiv = 6 - ucfr_rfdiv;

		uartclk = imx_get_perclk1();
		uartclk /= ucfr_rfdiv;

		{	/*
			 * The next code provides exact computation of
			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
			 * without need of float support or long long division,
			 * which would be required to prevent 32bit arithmetic overflow
			 */
			unsigned int mul = ubir + 1;
			unsigned int div = 16 * (ubmr + 1);
			unsigned int rem = uartclk % div;

			baud_raw = (uartclk / div) * mul;
			baud_raw += (rem * mul + div / 2) / div;
			*baud = (baud_raw + 50) / 100 * 100;
		}

		if(*baud != baud_raw)
			printk(KERN_INFO "Serial: Console IMX rounded baud rate from %d to %d\n",
				baud_raw, *baud);
	}
}

static int __init
imx_console_setup(struct console *co, char *options)
{
	struct imx_port *sport;
	int baud = 9600;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	/*
	 * Check whether an invalid uart number has been specified, and
	 * if so, search for the first available port that does have
	 * console support.
	 */
	if (co->index == -1 || co->index >= ARRAY_SIZE(imx_ports))
		co->index = 0;
	sport = &imx_ports[co->index];

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);
	else
		imx_console_get_options(sport, &baud, &parity, &bits);

	imx_setup_ufcr(sport, 0);

	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
}

static struct uart_driver imx_reg;
static struct console imx_console = {
	.name		= "ttySMX",
	.write		= imx_console_write,
	.device		= uart_console_device,
	.setup		= imx_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &imx_reg,
};

static int __init imx_rs_console_init(void)
{
	imx_init_ports();
	register_console(&imx_console);
	return 0;
}
console_initcall(imx_rs_console_init);

#define IMX_CONSOLE	&imx_console
#else
#define IMX_CONSOLE	NULL
#endif

static struct uart_driver imx_reg = {
	.owner          = THIS_MODULE,
	.driver_name    = DRIVER_NAME,
	.dev_name       = "ttySMX",
	.major          = SERIAL_IMX_MAJOR,
	.minor          = MINOR_START,
	.nr             = ARRAY_SIZE(imx_ports),
	.cons           = IMX_CONSOLE,
};

static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
{
        struct imx_port *sport = platform_get_drvdata(dev);

        if (sport)
                uart_suspend_port(&imx_reg, &sport->port);

        return 0;
}

static int serial_imx_resume(struct platform_device *dev)
{
        struct imx_port *sport = platform_get_drvdata(dev);

        if (sport)
                uart_resume_port(&imx_reg, &sport->port);

        return 0;
}

static int serial_imx_probe(struct platform_device *dev)
{
	struct imxuart_platform_data *pdata;

	imx_ports[dev->id].port.dev = &dev->dev;

	pdata = (struct imxuart_platform_data *)dev->dev.platform_data;
	if(pdata && (pdata->flags & IMXUART_HAVE_RTSCTS))
		imx_ports[dev->id].have_rtscts = 1;

	uart_add_one_port(&imx_reg, &imx_ports[dev->id].port);
	platform_set_drvdata(dev, &imx_ports[dev->id]);
	return 0;
}

static int serial_imx_remove(struct platform_device *dev)
{
	struct imx_port *sport = platform_get_drvdata(dev);

	platform_set_drvdata(dev, NULL);

	if (sport)
		uart_remove_one_port(&imx_reg, &sport->port);

	return 0;
}

static struct platform_driver serial_imx_driver = {
        .probe          = serial_imx_probe,
        .remove         = serial_imx_remove,

	.suspend	= serial_imx_suspend,
	.resume		= serial_imx_resume,
	.driver		= {
	        .name	= "imx-uart",
	},
};

static int __init imx_serial_init(void)
{
	int ret;

	printk(KERN_INFO "Serial: IMX driver\n");

	imx_init_ports();

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

	ret = platform_driver_register(&serial_imx_driver);
	if (ret != 0)
		uart_unregister_driver(&imx_reg);

	return 0;
}

static void __exit imx_serial_exit(void)
{
	platform_driver_unregister(&serial_imx_driver);
	uart_unregister_driver(&imx_reg);
}

module_init(imx_serial_init);
module_exit(imx_serial_exit);

MODULE_AUTHOR("Sascha Hauer");
MODULE_DESCRIPTION("IMX generic serial port driver");
MODULE_LICENSE("GPL");