mpc52xx_uart.c

linux 内核源代码

static struct console mpc52xx_console = {
	.name	= "ttyPSC",
	.write	= mpc52xx_console_write,
	.device	= uart_console_device,
	.setup	= mpc52xx_console_setup,
	.flags	= CON_PRINTBUFFER,
	.index	= -1,	/* Specified on the cmdline (e.g. console=ttyPSC0 ) */
	.data	= &mpc52xx_uart_driver,
};


static int __init
mpc52xx_console_init(void)
{
#if defined(CONFIG_PPC_MERGE)
	mpc52xx_uart_of_enumerate();
#endif
	register_console(&mpc52xx_console);
	return 0;
}

console_initcall(mpc52xx_console_init);

#define MPC52xx_PSC_CONSOLE &mpc52xx_console
#else
#define MPC52xx_PSC_CONSOLE NULL
#endif


/* ======================================================================== */
/* UART Driver                                                              */
/* ======================================================================== */

static struct uart_driver mpc52xx_uart_driver = {
	.owner		= THIS_MODULE,
	.driver_name	= "mpc52xx_psc_uart",
	.dev_name	= "ttyPSC",
	.major		= SERIAL_PSC_MAJOR,
	.minor		= SERIAL_PSC_MINOR,
	.nr		= MPC52xx_PSC_MAXNUM,
	.cons		= MPC52xx_PSC_CONSOLE,
};


#if !defined(CONFIG_PPC_MERGE)
/* ======================================================================== */
/* Platform Driver                                                          */
/* ======================================================================== */

static int __devinit
mpc52xx_uart_probe(struct platform_device *dev)
{
	struct resource *res = dev->resource;

	struct uart_port *port = NULL;
	int i, idx, ret;

	/* Check validity & presence */
	idx = dev->id;
	if (idx < 0 || idx >= MPC52xx_PSC_MAXNUM)
		return -EINVAL;

	if (!mpc52xx_match_psc_function(idx,"uart"))
		return -ENODEV;

	/* Init the port structure */
	port = &mpc52xx_uart_ports[idx];

	spin_lock_init(&port->lock);
	port->uartclk	= __res.bi_ipbfreq / 2; /* Look at CTLR doc */
	port->fifosize	= 512;
	port->iotype	= UPIO_MEM;
	port->flags	= UPF_BOOT_AUTOCONF |
			  ( uart_console(port) ? 0 : UPF_IOREMAP );
	port->line	= idx;
	port->ops	= &mpc52xx_uart_ops;
	port->dev	= &dev->dev;

	/* Search for IRQ and mapbase */
	for (i=0 ; i<dev->num_resources ; i++, res++) {
		if (res->flags & IORESOURCE_MEM)
			port->mapbase = res->start;
		else if (res->flags & IORESOURCE_IRQ)
			port->irq = res->start;
	}
	if (!port->irq || !port->mapbase)
		return -EINVAL;

	/* Add the port to the uart sub-system */
	ret = uart_add_one_port(&mpc52xx_uart_driver, port);
	if (!ret)
		platform_set_drvdata(dev, (void*)port);

	return ret;
}

static int
mpc52xx_uart_remove(struct platform_device *dev)
{
	struct uart_port *port = (struct uart_port *) platform_get_drvdata(dev);

	platform_set_drvdata(dev, NULL);

	if (port)
		uart_remove_one_port(&mpc52xx_uart_driver, port);

	return 0;
}

#ifdef CONFIG_PM
static int
mpc52xx_uart_suspend(struct platform_device *dev, pm_message_t state)
{
	struct uart_port *port = (struct uart_port *) platform_get_drvdata(dev);

	if (port)
		uart_suspend_port(&mpc52xx_uart_driver, port);

	return 0;
}

static int
mpc52xx_uart_resume(struct platform_device *dev)
{
	struct uart_port *port = (struct uart_port *) platform_get_drvdata(dev);

	if (port)
		uart_resume_port(&mpc52xx_uart_driver, port);

	return 0;
}
#endif


static struct platform_driver mpc52xx_uart_platform_driver = {
	.probe		= mpc52xx_uart_probe,
	.remove		= mpc52xx_uart_remove,
#ifdef CONFIG_PM
	.suspend	= mpc52xx_uart_suspend,
	.resume		= mpc52xx_uart_resume,
#endif
	.driver		= {
		.name	= "mpc52xx-psc",
	},
};
#endif /* !defined(CONFIG_PPC_MERGE) */


#if defined(CONFIG_PPC_MERGE)
/* ======================================================================== */
/* OF Platform Driver                                                       */
/* ======================================================================== */

static int __devinit
mpc52xx_uart_of_probe(struct of_device *op, const struct of_device_id *match)
{
	int idx = -1;
	unsigned int ipb_freq;
	struct uart_port *port = NULL;
	struct resource res;
	int ret;

	dev_dbg(&op->dev, "mpc52xx_uart_probe(op=%p, match=%p)\n", op, match);

	/* Check validity & presence */
	for (idx = 0; idx < MPC52xx_PSC_MAXNUM; idx++)
		if (mpc52xx_uart_nodes[idx] == op->node)
			break;
	if (idx >= MPC52xx_PSC_MAXNUM)
		return -EINVAL;
	pr_debug("Found %s assigned to ttyPSC%x\n",
	         mpc52xx_uart_nodes[idx]->full_name, idx);

	/* Search for bus-frequency property in this node or a parent */
	if ((ipb_freq = mpc52xx_find_ipb_freq(op->node)) == 0) {
		dev_dbg(&op->dev, "Could not find IPB bus frequency!\n");
		return -EINVAL;
	}

	/* Init the port structure */
	port = &mpc52xx_uart_ports[idx];

	spin_lock_init(&port->lock);
	port->uartclk	= ipb_freq / 2;
	port->fifosize	= 512;
	port->iotype	= UPIO_MEM;
	port->flags	= UPF_BOOT_AUTOCONF |
			  ( uart_console(port) ? 0 : UPF_IOREMAP );
	port->line	= idx;
	port->ops	= &mpc52xx_uart_ops;
	port->dev	= &op->dev;

	/* Search for IRQ and mapbase */
	if ((ret = of_address_to_resource(op->node, 0, &res)) != 0)
		return ret;

	port->mapbase = res.start;
	port->irq = irq_of_parse_and_map(op->node, 0);

	dev_dbg(&op->dev, "mpc52xx-psc uart at %p, irq=%x, freq=%i\n",
	        (void*)port->mapbase, port->irq, port->uartclk);

	if ((port->irq==NO_IRQ) || !port->mapbase) {
		printk(KERN_ERR "Could not allocate resources for PSC\n");
		return -EINVAL;
	}

	/* Add the port to the uart sub-system */
	ret = uart_add_one_port(&mpc52xx_uart_driver, port);
	if (!ret)
		dev_set_drvdata(&op->dev, (void*)port);

	return ret;
}

static int
mpc52xx_uart_of_remove(struct of_device *op)
{
	struct uart_port *port = dev_get_drvdata(&op->dev);
	dev_set_drvdata(&op->dev, NULL);

	if (port) {
		uart_remove_one_port(&mpc52xx_uart_driver, port);
		irq_dispose_mapping(port->irq);
	}

	return 0;
}

#ifdef CONFIG_PM
static int
mpc52xx_uart_of_suspend(struct of_device *op, pm_message_t state)
{
	struct uart_port *port = (struct uart_port *) dev_get_drvdata(&op->dev);

	if (port)
		uart_suspend_port(&mpc52xx_uart_driver, port);

	return 0;
}

static int
mpc52xx_uart_of_resume(struct of_device *op)
{
	struct uart_port *port = (struct uart_port *) dev_get_drvdata(&op->dev);

	if (port)
		uart_resume_port(&mpc52xx_uart_driver, port);

	return 0;
}
#endif

static void
mpc52xx_uart_of_assign(struct device_node *np, int idx)
{
	int free_idx = -1;
	int i;

	/* Find the first free node */
	for (i = 0; i < MPC52xx_PSC_MAXNUM; i++) {
		if (mpc52xx_uart_nodes[i] == NULL) {
			free_idx = i;
			break;
		}
	}

	if ((idx < 0) || (idx >= MPC52xx_PSC_MAXNUM))
		idx = free_idx;

	if (idx < 0)
		return; /* No free slot; abort */

	/* If the slot is already occupied, then swap slots */
	if (mpc52xx_uart_nodes[idx] && (free_idx != -1))
		mpc52xx_uart_nodes[free_idx] = mpc52xx_uart_nodes[idx];
	mpc52xx_uart_nodes[idx] = np;
}

static void
mpc52xx_uart_of_enumerate(void)
{
	static int enum_done = 0;
	struct device_node *np;
	const unsigned int *devno;
	int i;

	if (enum_done)
		return;

	for_each_node_by_type(np, "serial") {
		if (!of_match_node(mpc52xx_uart_of_match, np))
			continue;

		/* Is a particular device number requested? */
		devno = of_get_property(np, "port-number", NULL);
		mpc52xx_uart_of_assign(of_node_get(np), devno ? *devno : -1);
	}

	enum_done = 1;

	for (i = 0; i < MPC52xx_PSC_MAXNUM; i++) {
		if (mpc52xx_uart_nodes[i])
			pr_debug("%s assigned to ttyPSC%x\n",
			         mpc52xx_uart_nodes[i]->full_name, i);
	}
}

MODULE_DEVICE_TABLE(of, mpc52xx_uart_of_match);

static struct of_platform_driver mpc52xx_uart_of_driver = {
	.owner		= THIS_MODULE,
	.name		= "mpc52xx-psc-uart",
	.match_table	= mpc52xx_uart_of_match,
	.probe		= mpc52xx_uart_of_probe,
	.remove		= mpc52xx_uart_of_remove,
#ifdef CONFIG_PM
	.suspend	= mpc52xx_uart_of_suspend,
	.resume		= mpc52xx_uart_of_resume,
#endif
	.driver		= {
		.name	= "mpc52xx-psc-uart",
	},
};
#endif /* defined(CONFIG_PPC_MERGE) */


/* ======================================================================== */
/* Module                                                                   */
/* ======================================================================== */

static int __init
mpc52xx_uart_init(void)
{
	int ret;

	printk(KERN_INFO "Serial: MPC52xx PSC UART driver\n");

	if ((ret = uart_register_driver(&mpc52xx_uart_driver)) != 0) {
		printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
		       __FILE__, ret);
		return ret;
	}

#if defined(CONFIG_PPC_MERGE)
	mpc52xx_uart_of_enumerate();

	ret = of_register_platform_driver(&mpc52xx_uart_of_driver);
	if (ret) {
		printk(KERN_ERR "%s: of_register_platform_driver failed (%i)\n",
		       __FILE__, ret);
		uart_unregister_driver(&mpc52xx_uart_driver);
		return ret;
	}
#else
	ret = platform_driver_register(&mpc52xx_uart_platform_driver);
	if (ret) {
		printk(KERN_ERR "%s: platform_driver_register failed (%i)\n",
		       __FILE__, ret);
		uart_unregister_driver(&mpc52xx_uart_driver);
		return ret;
	}
#endif

	return 0;
}

static void __exit
mpc52xx_uart_exit(void)
{
#if defined(CONFIG_PPC_MERGE)
	of_unregister_platform_driver(&mpc52xx_uart_of_driver);
#else
	platform_driver_unregister(&mpc52xx_uart_platform_driver);
#endif
	uart_unregister_driver(&mpc52xx_uart_driver);
}


module_init(mpc52xx_uart_init);
module_exit(mpc52xx_uart_exit);

MODULE_AUTHOR("Sylvain Munaut <[e-mail]>");
MODULE_DESCRIPTION("Freescale MPC52xx PSC UART");
MODULE_LICENSE("GPL");