amba-pl010.c

linux 内核源代码

		lcr_h |= UART01x_LCRH_PEN;
		if (!(termios->c_cflag & PARODD))
			lcr_h |= UART01x_LCRH_EPS;
	}
	if (uap->port.fifosize > 1)
		lcr_h |= UART01x_LCRH_FEN;

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

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

	uap->port.read_status_mask = UART01x_RSR_OE;
	if (termios->c_iflag & INPCK)
		uap->port.read_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
	if (termios->c_iflag & (BRKINT | PARMRK))
		uap->port.read_status_mask |= UART01x_RSR_BE;

	/*
	 * Characters to ignore
	 */
	uap->port.ignore_status_mask = 0;
	if (termios->c_iflag & IGNPAR)
		uap->port.ignore_status_mask |= UART01x_RSR_FE | UART01x_RSR_PE;
	if (termios->c_iflag & IGNBRK) {
		uap->port.ignore_status_mask |= UART01x_RSR_BE;
		/*
		 * If we're ignoring parity and break indicators,
		 * ignore overruns too (for real raw support).
		 */
		if (termios->c_iflag & IGNPAR)
			uap->port.ignore_status_mask |= UART01x_RSR_OE;
	}

	/*
	 * Ignore all characters if CREAD is not set.
	 */
	if ((termios->c_cflag & CREAD) == 0)
		uap->port.ignore_status_mask |= UART_DUMMY_RSR_RX;

	/* first, disable everything */
	old_cr = readb(uap->port.membase + UART010_CR) & ~UART010_CR_MSIE;

	if (UART_ENABLE_MS(port, termios->c_cflag))
		old_cr |= UART010_CR_MSIE;

	writel(0, uap->port.membase + UART010_CR);

	/* Set baud rate */
	quot -= 1;
	writel((quot & 0xf00) >> 8, uap->port.membase + UART010_LCRM);
	writel(quot & 0xff, uap->port.membase + UART010_LCRL);

	/*
	 * ----------v----------v----------v----------v-----
	 * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L
	 * ----------^----------^----------^----------^-----
	 */
	writel(lcr_h, uap->port.membase + UART010_LCRH);
	writel(old_cr, uap->port.membase + UART010_CR);

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

static const char *pl010_type(struct uart_port *port)
{
	return port->type == PORT_AMBA ? "AMBA" : NULL;
}

/*
 * Release the memory region(s) being used by 'port'
 */
static void pl010_release_port(struct uart_port *port)
{
	release_mem_region(port->mapbase, UART_PORT_SIZE);
}

/*
 * Request the memory region(s) being used by 'port'
 */
static int pl010_request_port(struct uart_port *port)
{
	return request_mem_region(port->mapbase, UART_PORT_SIZE, "uart-pl010")
			!= NULL ? 0 : -EBUSY;
}

/*
 * Configure/autoconfigure the port.
 */
static void pl010_config_port(struct uart_port *port, int flags)
{
	if (flags & UART_CONFIG_TYPE) {
		port->type = PORT_AMBA;
		pl010_request_port(port);
	}
}

/*
 * verify the new serial_struct (for TIOCSSERIAL).
 */
static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	int ret = 0;
	if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
		ret = -EINVAL;
	if (ser->irq < 0 || ser->irq >= NR_IRQS)
		ret = -EINVAL;
	if (ser->baud_base < 9600)
		ret = -EINVAL;
	return ret;
}

static struct uart_ops amba_pl010_pops = {
	.tx_empty	= pl010_tx_empty,
	.set_mctrl	= pl010_set_mctrl,
	.get_mctrl	= pl010_get_mctrl,
	.stop_tx	= pl010_stop_tx,
	.start_tx	= pl010_start_tx,
	.stop_rx	= pl010_stop_rx,
	.enable_ms	= pl010_enable_ms,
	.break_ctl	= pl010_break_ctl,
	.startup	= pl010_startup,
	.shutdown	= pl010_shutdown,
	.set_termios	= pl010_set_termios,
	.type		= pl010_type,
	.release_port	= pl010_release_port,
	.request_port	= pl010_request_port,
	.config_port	= pl010_config_port,
	.verify_port	= pl010_verify_port,
};

static struct uart_amba_port *amba_ports[UART_NR];

#ifdef CONFIG_SERIAL_AMBA_PL010_CONSOLE

static void pl010_console_putchar(struct uart_port *port, int ch)
{
	struct uart_amba_port *uap = (struct uart_amba_port *)port;
	unsigned int status;

	do {
		status = readb(uap->port.membase + UART01x_FR);
		barrier();
	} while (!UART_TX_READY(status));
	writel(ch, uap->port.membase + UART01x_DR);
}

static void
pl010_console_write(struct console *co, const char *s, unsigned int count)
{
	struct uart_amba_port *uap = amba_ports[co->index];
	unsigned int status, old_cr;

	clk_enable(uap->clk);

	/*
	 *	First save the CR then disable the interrupts
	 */
	old_cr = readb(uap->port.membase + UART010_CR);
	writel(UART01x_CR_UARTEN, uap->port.membase + UART010_CR);

	uart_console_write(&uap->port, s, count, pl010_console_putchar);

	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore the TCR
	 */
	do {
		status = readb(uap->port.membase + UART01x_FR);
		barrier();
	} while (status & UART01x_FR_BUSY);
	writel(old_cr, uap->port.membase + UART010_CR);

	clk_disable(uap->clk);
}

static void __init
pl010_console_get_options(struct uart_amba_port *uap, int *baud,
			     int *parity, int *bits)
{
	if (readb(uap->port.membase + UART010_CR) & UART01x_CR_UARTEN) {
		unsigned int lcr_h, quot;
		lcr_h = readb(uap->port.membase + UART010_LCRH);

		*parity = 'n';
		if (lcr_h & UART01x_LCRH_PEN) {
			if (lcr_h & UART01x_LCRH_EPS)
				*parity = 'e';
			else
				*parity = 'o';
		}

		if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
			*bits = 7;
		else
			*bits = 8;

		quot = readb(uap->port.membase + UART010_LCRL) |
		       readb(uap->port.membase + UART010_LCRM) << 8;
		*baud = uap->port.uartclk / (16 * (quot + 1));
	}
}

static int __init pl010_console_setup(struct console *co, char *options)
{
	struct uart_amba_port *uap;
	int baud = 38400;
	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 >= UART_NR)
		co->index = 0;
	uap = amba_ports[co->index];
	if (!uap)
		return -ENODEV;

	uap->port.uartclk = clk_get_rate(uap->clk);

	if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);
	else
		pl010_console_get_options(uap, &baud, &parity, &bits);

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

static struct uart_driver amba_reg;
static struct console amba_console = {
	.name		= "ttyAM",
	.write		= pl010_console_write,
	.device		= uart_console_device,
	.setup		= pl010_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &amba_reg,
};

#define AMBA_CONSOLE	&amba_console
#else
#define AMBA_CONSOLE	NULL
#endif

static struct uart_driver amba_reg = {
	.owner			= THIS_MODULE,
	.driver_name		= "ttyAM",
	.dev_name		= "ttyAM",
	.major			= SERIAL_AMBA_MAJOR,
	.minor			= SERIAL_AMBA_MINOR,
	.nr			= UART_NR,
	.cons			= AMBA_CONSOLE,
};

static int pl010_probe(struct amba_device *dev, void *id)
{
	struct uart_amba_port *uap;
	void __iomem *base;
	int i, ret;

	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
		if (amba_ports[i] == NULL)
			break;

	if (i == ARRAY_SIZE(amba_ports)) {
		ret = -EBUSY;
		goto out;
	}

	uap = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL);
	if (!uap) {
		ret = -ENOMEM;
		goto out;
	}

	base = ioremap(dev->res.start, PAGE_SIZE);
	if (!base) {
		ret = -ENOMEM;
		goto free;
	}

	uap->clk = clk_get(&dev->dev, "UARTCLK");
	if (IS_ERR(uap->clk)) {
		ret = PTR_ERR(uap->clk);
		goto unmap;
	}

	uap->port.dev = &dev->dev;
	uap->port.mapbase = dev->res.start;
	uap->port.membase = base;
	uap->port.iotype = UPIO_MEM;
	uap->port.irq = dev->irq[0];
	uap->port.fifosize = 16;
	uap->port.ops = &amba_pl010_pops;
	uap->port.flags = UPF_BOOT_AUTOCONF;
	uap->port.line = i;
	uap->dev = dev;
	uap->data = dev->dev.platform_data;

	amba_ports[i] = uap;

	amba_set_drvdata(dev, uap);
	ret = uart_add_one_port(&amba_reg, &uap->port);
	if (ret) {
		amba_set_drvdata(dev, NULL);
		amba_ports[i] = NULL;
		clk_put(uap->clk);
 unmap:
		iounmap(base);
 free:
		kfree(uap);
	}
 out:
	return ret;
}

static int pl010_remove(struct amba_device *dev)
{
	struct uart_amba_port *uap = amba_get_drvdata(dev);
	int i;

	amba_set_drvdata(dev, NULL);

	uart_remove_one_port(&amba_reg, &uap->port);

	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
		if (amba_ports[i] == uap)
			amba_ports[i] = NULL;

	iounmap(uap->port.membase);
	clk_put(uap->clk);
	kfree(uap);
	return 0;
}

static int pl010_suspend(struct amba_device *dev, pm_message_t state)
{
	struct uart_amba_port *uap = amba_get_drvdata(dev);

	if (uap)
		uart_suspend_port(&amba_reg, &uap->port);

	return 0;
}

static int pl010_resume(struct amba_device *dev)
{
	struct uart_amba_port *uap = amba_get_drvdata(dev);

	if (uap)
		uart_resume_port(&amba_reg, &uap->port);

	return 0;
}

static struct amba_id pl010_ids[] __initdata = {
	{
		.id	= 0x00041010,
		.mask	= 0x000fffff,
	},
	{ 0, 0 },
};

static struct amba_driver pl010_driver = {
	.drv = {
		.name	= "uart-pl010",
	},
	.id_table	= pl010_ids,
	.probe		= pl010_probe,
	.remove		= pl010_remove,
	.suspend	= pl010_suspend,
	.resume		= pl010_resume,
};

static int __init pl010_init(void)
{
	int ret;

	printk(KERN_INFO "Serial: AMBA driver $Revision: 1.41 $\n");

	ret = uart_register_driver(&amba_reg);
	if (ret == 0) {
		ret = amba_driver_register(&pl010_driver);
		if (ret)
			uart_unregister_driver(&amba_reg);
	}
	return ret;
}

static void __exit pl010_exit(void)
{
	amba_driver_unregister(&pl010_driver);
	uart_unregister_driver(&amba_reg);
}

module_init(pl010_init);
module_exit(pl010_exit);

MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
MODULE_DESCRIPTION("ARM AMBA serial port driver $Revision: 1.41 $");
MODULE_LICENSE("GPL");