pxa.c

来自「linux 内核源代码」· C语言 代码 · 共 865 行 · 第 1/2 页

				  UART_FCR_CLEAR_XMIT);
	serial_out(up, UART_FCR, 0);
}

static void
serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
		       struct ktermios *old)
{
	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
	unsigned char cval, fcr = 0;
	unsigned long flags;
	unsigned int baud, quot;

	switch (termios->c_cflag & CSIZE) {
	case CS5:
		cval = UART_LCR_WLEN5;
		break;
	case CS6:
		cval = UART_LCR_WLEN6;
		break;
	case CS7:
		cval = UART_LCR_WLEN7;
		break;
	default:
	case CS8:
		cval = UART_LCR_WLEN8;
		break;
	}

	if (termios->c_cflag & CSTOPB)
		cval |= UART_LCR_STOP;
	if (termios->c_cflag & PARENB)
		cval |= UART_LCR_PARITY;
	if (!(termios->c_cflag & PARODD))
		cval |= UART_LCR_EPAR;

	/*
	 * 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);

	if ((up->port.uartclk / quot) < (2400 * 16))
		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR1;
	else if ((up->port.uartclk / quot) < (230400 * 16))
		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR8;
	else
		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_PXAR32;

	/*
	 * Ok, we're now changing the port state.  Do it with
	 * interrupts disabled.
	 */
	spin_lock_irqsave(&up->port.lock, flags);

	/*
	 * Ensure the port will be enabled.
	 * This is required especially for serial console.
	 */
	up->ier |= IER_UUE;

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

	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
	if (termios->c_iflag & INPCK)
		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
	if (termios->c_iflag & (BRKINT | PARMRK))
		up->port.read_status_mask |= UART_LSR_BI;

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

	/*
	 * ignore all characters if CREAD is not set
	 */
	if ((termios->c_cflag & CREAD) == 0)
		up->port.ignore_status_mask |= UART_LSR_DR;

	/*
	 * CTS flow control flag and modem status interrupts
	 */
	up->ier &= ~UART_IER_MSI;
	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
		up->ier |= UART_IER_MSI;

	serial_out(up, UART_IER, up->ier);

	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
	serial_out(up, UART_LCR, cval);		/* reset DLAB */
	up->lcr = cval;					/* Save LCR */
	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
	serial_out(up, UART_FCR, fcr);
	spin_unlock_irqrestore(&up->port.lock, flags);
}

static void
serial_pxa_pm(struct uart_port *port, unsigned int state,
	      unsigned int oldstate)
{
	struct uart_pxa_port *up = (struct uart_pxa_port *)port;

	if (!state)
		clk_enable(up->clk);
	else
		clk_disable(up->clk);
}

static void serial_pxa_release_port(struct uart_port *port)
{
}

static int serial_pxa_request_port(struct uart_port *port)
{
	return 0;
}

static void serial_pxa_config_port(struct uart_port *port, int flags)
{
	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
	up->port.type = PORT_PXA;
}

static int
serial_pxa_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	/* we don't want the core code to modify any port params */
	return -EINVAL;
}

static const char *
serial_pxa_type(struct uart_port *port)
{
	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
	return up->name;
}

static struct uart_pxa_port *serial_pxa_ports[4];
static struct uart_driver serial_pxa_reg;

#ifdef CONFIG_SERIAL_PXA_CONSOLE

#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)

/*
 *	Wait for transmitter & holding register to empty
 */
static inline void wait_for_xmitr(struct uart_pxa_port *up)
{
	unsigned int status, tmout = 10000;

	/* Wait up to 10ms for the character(s) to be sent. */
	do {
		status = serial_in(up, UART_LSR);

		if (status & UART_LSR_BI)
			up->lsr_break_flag = UART_LSR_BI;

		if (--tmout == 0)
			break;
		udelay(1);
	} while ((status & BOTH_EMPTY) != BOTH_EMPTY);

	/* Wait up to 1s for flow control if necessary */
	if (up->port.flags & UPF_CONS_FLOW) {
		tmout = 1000000;
		while (--tmout &&
		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
			udelay(1);
	}
}

static void serial_pxa_console_putchar(struct uart_port *port, int ch)
{
	struct uart_pxa_port *up = (struct uart_pxa_port *)port;

	wait_for_xmitr(up);
	serial_out(up, UART_TX, ch);
}

/*
 * Print a string to the serial port trying not to disturb
 * any possible real use of the port...
 *
 *	The console_lock must be held when we get here.
 */
static void
serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
{
	struct uart_pxa_port *up = serial_pxa_ports[co->index];
	unsigned int ier;

	clk_enable(up->clk);

	/*
	 *	First save the IER then disable the interrupts
	 */
	ier = serial_in(up, UART_IER);
	serial_out(up, UART_IER, UART_IER_UUE);

	uart_console_write(&up->port, s, count, serial_pxa_console_putchar);

	/*
	 *	Finally, wait for transmitter to become empty
	 *	and restore the IER
	 */
	wait_for_xmitr(up);
	serial_out(up, UART_IER, ier);

	clk_disable(up->clk);
}

static int __init
serial_pxa_console_setup(struct console *co, char *options)
{
	struct uart_pxa_port *up;
	int baud = 9600;
	int bits = 8;
	int parity = 'n';
	int flow = 'n';

	if (co->index == -1 || co->index >= serial_pxa_reg.nr)
		co->index = 0;
	up = serial_pxa_ports[co->index];
	if (!up)
		return -ENODEV;

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

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

static struct console serial_pxa_console = {
	.name		= "ttyS",
	.write		= serial_pxa_console_write,
	.device		= uart_console_device,
	.setup		= serial_pxa_console_setup,
	.flags		= CON_PRINTBUFFER,
	.index		= -1,
	.data		= &serial_pxa_reg,
};

#define PXA_CONSOLE	&serial_pxa_console
#else
#define PXA_CONSOLE	NULL
#endif

struct uart_ops serial_pxa_pops = {
	.tx_empty	= serial_pxa_tx_empty,
	.set_mctrl	= serial_pxa_set_mctrl,
	.get_mctrl	= serial_pxa_get_mctrl,
	.stop_tx	= serial_pxa_stop_tx,
	.start_tx	= serial_pxa_start_tx,
	.stop_rx	= serial_pxa_stop_rx,
	.enable_ms	= serial_pxa_enable_ms,
	.break_ctl	= serial_pxa_break_ctl,
	.startup	= serial_pxa_startup,
	.shutdown	= serial_pxa_shutdown,
	.set_termios	= serial_pxa_set_termios,
	.pm		= serial_pxa_pm,
	.type		= serial_pxa_type,
	.release_port	= serial_pxa_release_port,
	.request_port	= serial_pxa_request_port,
	.config_port	= serial_pxa_config_port,
	.verify_port	= serial_pxa_verify_port,
};

static struct uart_driver serial_pxa_reg = {
	.owner		= THIS_MODULE,
	.driver_name	= "PXA serial",
	.dev_name	= "ttyS",
	.major		= TTY_MAJOR,
	.minor		= 64,
	.nr		= 4,
	.cons		= PXA_CONSOLE,
};

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

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

        return 0;
}

static int serial_pxa_resume(struct platform_device *dev)
{
        struct uart_pxa_port *sport = platform_get_drvdata(dev);

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

        return 0;
}

static int serial_pxa_probe(struct platform_device *dev)
{
	struct uart_pxa_port *sport;
	struct resource *mmres, *irqres;
	int ret;

	mmres = platform_get_resource(dev, IORESOURCE_MEM, 0);
	irqres = platform_get_resource(dev, IORESOURCE_IRQ, 0);
	if (!mmres || !irqres)
		return -ENODEV;

	sport = kzalloc(sizeof(struct uart_pxa_port), GFP_KERNEL);
	if (!sport)
		return -ENOMEM;

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

	sport->port.type = PORT_PXA;
	sport->port.iotype = UPIO_MEM;
	sport->port.mapbase = mmres->start;
	sport->port.irq = irqres->start;
	sport->port.fifosize = 64;
	sport->port.ops = &serial_pxa_pops;
	sport->port.line = dev->id;
	sport->port.dev = &dev->dev;
	sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
	sport->port.uartclk = clk_get_rate(sport->clk);

	/*
	 * Is it worth keeping this?
	 */
	if (mmres->start == __PREG(FFUART))
		sport->name = "FFUART";
	else if (mmres->start == __PREG(BTUART))
		sport->name = "BTUART";
	else if (mmres->start == __PREG(STUART))
		sport->name = "STUART";
	else if (mmres->start == __PREG(HWUART))
		sport->name = "HWUART";
	else
		sport->name = "???";

	sport->port.membase = ioremap(mmres->start, mmres->end - mmres->start + 1);
	if (!sport->port.membase) {
		ret = -ENOMEM;
		goto err_clk;
	}

	serial_pxa_ports[dev->id] = sport;

	uart_add_one_port(&serial_pxa_reg, &sport->port);
	platform_set_drvdata(dev, sport);

	return 0;

 err_clk:
	clk_put(sport->clk);
 err_free:
	kfree(sport);
	return ret;
}

static int serial_pxa_remove(struct platform_device *dev)
{
	struct uart_pxa_port *sport = platform_get_drvdata(dev);

	platform_set_drvdata(dev, NULL);

	uart_remove_one_port(&serial_pxa_reg, &sport->port);
	clk_put(sport->clk);
	kfree(sport);

	return 0;
}

static struct platform_driver serial_pxa_driver = {
        .probe          = serial_pxa_probe,
        .remove         = serial_pxa_remove,

	.suspend	= serial_pxa_suspend,
	.resume		= serial_pxa_resume,
	.driver		= {
	        .name	= "pxa2xx-uart",
	},
};

int __init serial_pxa_init(void)
{
	int ret;

	ret = uart_register_driver(&serial_pxa_reg);
	if (ret != 0)
		return ret;

	ret = platform_driver_register(&serial_pxa_driver);
	if (ret != 0)
		uart_unregister_driver(&serial_pxa_reg);

	return ret;
}

void __exit serial_pxa_exit(void)
{
	platform_driver_unregister(&serial_pxa_driver);
	uart_unregister_driver(&serial_pxa_reg);
}

module_init(serial_pxa_init);
module_exit(serial_pxa_exit);

MODULE_LICENSE("GPL");