/*

   *  linux/drivers/char/atmel_serial.c

   *

   *  Driver for Atmel AT91 / AT32 Serial ports

   *  Copyright (C) 2003 Rick Bronson
   *
   *  Based on drivers/char/serial_sa1100.c, by Deep Blue Solutions Ltd.
   *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   */

  #include <linux/module.h>
  #include <linux/tty.h>
  #include <linux/ioport.h>
  #include <linux/slab.h>
  #include <linux/init.h>
  #include <linux/serial.h>

  #include <linux/clk.h>

  #include <linux/console.h>
  #include <linux/sysrq.h>
  #include <linux/tty_flip.h>

  #include <linux/platform_device.h>

  #include <linux/atmel_pdc.h>

  
  #include <asm/io.h>

  #include <asm/mach/serial_at91.h>

  #include <asm/arch/board.h>

  #ifdef CONFIG_ARM

  #include <asm/arch/cpu.h>

  #include <asm/arch/gpio.h>

  #endif

  #include "atmel_serial.h"

  #if defined(CONFIG_SERIAL_ATMEL_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)

  #define SUPPORT_SYSRQ
  #endif
  
  #include <linux/serial_core.h>

  #ifdef CONFIG_SERIAL_ATMEL_TTYAT

  
  /* Use device name ttyAT, major 204 and minor 154-169.  This is necessary if we
   * should coexist with the 8250 driver, such as if we have an external 16C550
   * UART. */

  #define SERIAL_ATMEL_MAJOR	204

  #define MINOR_START		154

  #define ATMEL_DEVICENAME	"ttyAT"

  
  #else
  
  /* Use device name ttyS, major 4, minor 64-68.  This is the usual serial port
   * name, but it is legally reserved for the 8250 driver. */

  #define SERIAL_ATMEL_MAJOR	TTY_MAJOR

  #define MINOR_START		64

  #define ATMEL_DEVICENAME	"ttyS"

  
  #endif

  #define ATMEL_ISR_PASS_LIMIT	256

  #define UART_PUT_CR(port,v)	__raw_writel(v, (port)->membase + ATMEL_US_CR)
  #define UART_GET_MR(port)	__raw_readl((port)->membase + ATMEL_US_MR)
  #define UART_PUT_MR(port,v)	__raw_writel(v, (port)->membase + ATMEL_US_MR)
  #define UART_PUT_IER(port,v)	__raw_writel(v, (port)->membase + ATMEL_US_IER)
  #define UART_PUT_IDR(port,v)	__raw_writel(v, (port)->membase + ATMEL_US_IDR)
  #define UART_GET_IMR(port)	__raw_readl((port)->membase + ATMEL_US_IMR)
  #define UART_GET_CSR(port)	__raw_readl((port)->membase + ATMEL_US_CSR)
  #define UART_GET_CHAR(port)	__raw_readl((port)->membase + ATMEL_US_RHR)
  #define UART_PUT_CHAR(port,v)	__raw_writel(v, (port)->membase + ATMEL_US_THR)
  #define UART_GET_BRGR(port)	__raw_readl((port)->membase + ATMEL_US_BRGR)
  #define UART_PUT_BRGR(port,v)	__raw_writel(v, (port)->membase + ATMEL_US_BRGR)
  #define UART_PUT_RTOR(port,v)	__raw_writel(v, (port)->membase + ATMEL_US_RTOR)
  
  // #define UART_GET_CR(port)	__raw_readl((port)->membase + ATMEL_US_CR)		// is write-only

  
   /* PDC registers */

  #define UART_PUT_PTCR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_PTCR)
  #define UART_GET_PTSR(port)	__raw_readl((port)->membase + ATMEL_PDC_PTSR)
  
  #define UART_PUT_RPR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_RPR)
  #define UART_GET_RPR(port)	__raw_readl((port)->membase + ATMEL_PDC_RPR)
  #define UART_PUT_RCR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_RCR)
  #define UART_PUT_RNPR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_RNPR)
  #define UART_PUT_RNCR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_RNCR)
  
  #define UART_PUT_TPR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_TPR)
  #define UART_PUT_TCR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_TCR)
  //#define UART_PUT_TNPR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_TNPR)
  //#define UART_PUT_TNCR(port,v)	__raw_writel(v, (port)->membase + ATMEL_PDC_TNCR)

  static int (*atmel_open_hook)(struct uart_port *);
  static void (*atmel_close_hook)(struct uart_port *);

  /*
   * We wrap our port structure around the generic uart_port.
   */

  struct atmel_uart_port {

  	struct uart_port	uart;		/* uart */
  	struct clk		*clk;		/* uart clock */
  	unsigned short		suspended;	/* is port suspended? */

  	int			break_active;	/* break being received */

  };

  static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];

  #ifdef SUPPORT_SYSRQ

  static struct console atmel_console;

  #endif
  
  /*
   * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
   */

  static u_int atmel_tx_empty(struct uart_port *port)

  {

  	return (UART_GET_CSR(port) & ATMEL_US_TXEMPTY) ? TIOCSER_TEMT : 0;

  }
  
  /*
   * Set state of the modem control output lines
   */

  static void atmel_set_mctrl(struct uart_port *port, u_int mctrl)

  {
  	unsigned int control = 0;

  	unsigned int mode;

  #ifdef CONFIG_ARCH_AT91RM9200

  	if (cpu_is_at91rm9200()) {

  		/*
  		 * AT91RM9200 Errata #39: RTS0 is not internally connected to PA21.
  		 *  We need to drive the pin manually.
  		 */

  		if (port->mapbase == AT91RM9200_BASE_US0) {

  			if (mctrl & TIOCM_RTS)

  				at91_set_gpio_value(AT91_PIN_PA21, 0);

  			else

  				at91_set_gpio_value(AT91_PIN_PA21, 1);

  		}

  	}

  #endif

  
  	if (mctrl & TIOCM_RTS)

  		control |= ATMEL_US_RTSEN;

  	else

  		control |= ATMEL_US_RTSDIS;

  
  	if (mctrl & TIOCM_DTR)

  		control |= ATMEL_US_DTREN;

  	else

  		control |= ATMEL_US_DTRDIS;

  	UART_PUT_CR(port, control);
  
  	/* Local loopback mode? */

  	mode = UART_GET_MR(port) & ~ATMEL_US_CHMODE;

  	if (mctrl & TIOCM_LOOP)

  		mode |= ATMEL_US_CHMODE_LOC_LOOP;

  	else

  		mode |= ATMEL_US_CHMODE_NORMAL;

  	UART_PUT_MR(port, mode);

  }
  
  /*
   * Get state of the modem control input lines
   */

  static u_int atmel_get_mctrl(struct uart_port *port)

  {
  	unsigned int status, ret = 0;
  
  	status = UART_GET_CSR(port);
  
  	/*
  	 * The control signals are active low.
  	 */

  	if (!(status & ATMEL_US_DCD))

  		ret |= TIOCM_CD;

  	if (!(status & ATMEL_US_CTS))

  		ret |= TIOCM_CTS;

  	if (!(status & ATMEL_US_DSR))

  		ret |= TIOCM_DSR;

  	if (!(status & ATMEL_US_RI))

  		ret |= TIOCM_RI;
  
  	return ret;
  }
  
  /*
   * Stop transmitting.
   */

  static void atmel_stop_tx(struct uart_port *port)

  {

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  	UART_PUT_IDR(port, ATMEL_US_TXRDY);

  }
  
  /*
   * Start transmitting.
   */

  static void atmel_start_tx(struct uart_port *port)

  {

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  	UART_PUT_IER(port, ATMEL_US_TXRDY);

  }
  
  /*
   * Stop receiving - port is in process of being closed.
   */

  static void atmel_stop_rx(struct uart_port *port)

  {

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  	UART_PUT_IDR(port, ATMEL_US_RXRDY);

  }
  
  /*
   * Enable modem status interrupts
   */

  static void atmel_enable_ms(struct uart_port *port)

  {

  	UART_PUT_IER(port, ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC | ATMEL_US_CTSIC);

  }
  
  /*
   * Control the transmission of a break signal
   */

  static void atmel_break_ctl(struct uart_port *port, int break_state)

  {
  	if (break_state != 0)

  		UART_PUT_CR(port, ATMEL_US_STTBRK);	/* start break */

  	else

  		UART_PUT_CR(port, ATMEL_US_STPBRK);	/* stop break */

  }
  
  /*
   * Characters received (called from interrupt handler)
   */

  static void atmel_rx_chars(struct uart_port *port)

  {

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  	struct tty_struct *tty = port->info->tty;
  	unsigned int status, ch, flg;

  	status = UART_GET_CSR(port);

  	while (status & ATMEL_US_RXRDY) {

  		ch = UART_GET_CHAR(port);

  		port->icount.rx++;
  
  		flg = TTY_NORMAL;
  
  		/*
  		 * note that the error handling code is
  		 * out of the main execution path
  		 */

  		if (unlikely(status & (ATMEL_US_PARE | ATMEL_US_FRAME
  				       | ATMEL_US_OVRE | ATMEL_US_RXBRK)
  			     || atmel_port->break_active)) {

  			UART_PUT_CR(port, ATMEL_US_RSTSTA);	/* clear error */

  			if (status & ATMEL_US_RXBRK
  			    && !atmel_port->break_active) {

  				status &= ~(ATMEL_US_PARE | ATMEL_US_FRAME);	/* ignore side-effect */

  				port->icount.brk++;

  				atmel_port->break_active = 1;
  				UART_PUT_IER(port, ATMEL_US_RXBRK);

  				if (uart_handle_break(port))
  					goto ignore_char;

  			} else {
  				/*
  				 * This is either the end-of-break
  				 * condition or we've received at
  				 * least one character without RXBRK
  				 * being set. In both cases, the next
  				 * RXBRK will indicate start-of-break.
  				 */
  				UART_PUT_IDR(port, ATMEL_US_RXBRK);
  				status &= ~ATMEL_US_RXBRK;
  				atmel_port->break_active = 0;

  			}

  			if (status & ATMEL_US_PARE)

  				port->icount.parity++;

  			if (status & ATMEL_US_FRAME)

  				port->icount.frame++;

  			if (status & ATMEL_US_OVRE)

  				port->icount.overrun++;

  			status &= port->read_status_mask;

  			if (status & ATMEL_US_RXBRK)

  				flg = TTY_BREAK;

  			else if (status & ATMEL_US_PARE)

  				flg = TTY_PARITY;

  			else if (status & ATMEL_US_FRAME)

  				flg = TTY_FRAME;

  		}

  		if (uart_handle_sysrq_char(port, ch))

  			goto ignore_char;

  		uart_insert_char(port, status, ATMEL_US_OVRE, ch, flg);

  
  	ignore_char:

  		status = UART_GET_CSR(port);

  	}
  
  	tty_flip_buffer_push(tty);
  }
  
  /*
   * Transmit characters (called from interrupt handler)
   */

  static void atmel_tx_chars(struct uart_port *port)

  {
  	struct circ_buf *xmit = &port->info->xmit;
  
  	if (port->x_char) {
  		UART_PUT_CHAR(port, port->x_char);
  		port->icount.tx++;
  		port->x_char = 0;
  		return;
  	}
  	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {

  		atmel_stop_tx(port);

  		return;
  	}

  	while (UART_GET_CSR(port) & ATMEL_US_TXRDY) {

  		UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
  		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
  		port->icount.tx++;
  		if (uart_circ_empty(xmit))
  			break;
  	}
  
  	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
  		uart_write_wakeup(port);
  
  	if (uart_circ_empty(xmit))

  		atmel_stop_tx(port);

  }
  
  /*
   * Interrupt handler
   */

  static irqreturn_t atmel_interrupt(int irq, void *dev_id)

  {
  	struct uart_port *port = dev_id;

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  	unsigned int status, pending, pass_counter = 0;
  
  	status = UART_GET_CSR(port);

  	pending = status & UART_GET_IMR(port);
  	while (pending) {
  		/* Interrupt receive */

  		if (pending & ATMEL_US_RXRDY)

  			atmel_rx_chars(port);

  		else if (pending & ATMEL_US_RXBRK) {
  			/*
  			 * End of break detected. If it came along
  			 * with a character, atmel_rx_chars will
  			 * handle it.
  			 */
  			UART_PUT_CR(port, ATMEL_US_RSTSTA);
  			UART_PUT_IDR(port, ATMEL_US_RXBRK);
  			atmel_port->break_active = 0;
  		}

  
  		// TODO: All reads to CSR will clear these interrupts!

  		if (pending & ATMEL_US_RIIC) port->icount.rng++;
  		if (pending & ATMEL_US_DSRIC) port->icount.dsr++;
  		if (pending & ATMEL_US_DCDIC)
  			uart_handle_dcd_change(port, !(status & ATMEL_US_DCD));
  		if (pending & ATMEL_US_CTSIC)
  			uart_handle_cts_change(port, !(status & ATMEL_US_CTS));
  		if (pending & (ATMEL_US_RIIC | ATMEL_US_DSRIC | ATMEL_US_DCDIC | ATMEL_US_CTSIC))

  			wake_up_interruptible(&port->info->delta_msr_wait);
  
  		/* Interrupt transmit */

  		if (pending & ATMEL_US_TXRDY)
  			atmel_tx_chars(port);

  		if (pass_counter++ > ATMEL_ISR_PASS_LIMIT)

  			break;

  		status = UART_GET_CSR(port);
  		pending = status & UART_GET_IMR(port);

  	}
  	return IRQ_HANDLED;
  }
  
  /*
   * Perform initialization and enable port for reception
   */

  static int atmel_startup(struct uart_port *port)

  {

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  	int retval;
  
  	/*
  	 * Ensure that no interrupts are enabled otherwise when
  	 * request_irq() is called we could get stuck trying to
  	 * handle an unexpected interrupt
  	 */
  	UART_PUT_IDR(port, -1);
  
  	/*
  	 * Allocate the IRQ
  	 */

  	retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED, "atmel_serial", port);

  	if (retval) {

  		printk("atmel_serial: atmel_startup - Can't get irq
  ");

  		return retval;
  	}
  
  	/*
  	 * If there is a specific "open" function (to register
  	 * control line interrupts)
  	 */

  	if (atmel_open_hook) {
  		retval = atmel_open_hook(port);

  		if (retval) {
  			free_irq(port->irq, port);
  			return retval;
  		}
  	}

  	/*
  	 * Finally, enable the serial port
  	 */

  	UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
  	UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);		/* enable xmit & rcvr */

  	UART_PUT_IER(port, ATMEL_US_RXRDY);		/* enable receive only */

  	return 0;
  }
  
  /*
   * Disable the port
   */

  static void atmel_shutdown(struct uart_port *port)

  {

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

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

  	UART_PUT_CR(port, ATMEL_US_RSTSTA);

  	UART_PUT_IDR(port, -1);
  
  	/*
  	 * Free the interrupt
  	 */
  	free_irq(port->irq, port);
  
  	/*
  	 * If there is a specific "close" function (to unregister
  	 * control line interrupts)
  	 */

  	if (atmel_close_hook)
  		atmel_close_hook(port);

  }
  
  /*
   * Power / Clock management.
   */

  static void atmel_serial_pm(struct uart_port *port, unsigned int state, unsigned int oldstate)

  {

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  	switch (state) {
  		case 0:
  			/*
  			 * Enable the peripheral clock for this serial port.
  			 * This is called on uart_open() or a resume event.
  			 */

  			clk_enable(atmel_port->clk);

  			break;
  		case 3:
  			/*
  			 * Disable the peripheral clock for this serial port.
  			 * This is called on uart_close() or a suspend event.
  			 */

  			clk_disable(atmel_port->clk);

  			break;
  		default:

  			printk(KERN_ERR "atmel_serial: unknown pm %d
  ", state);

  	}
  }
  
  /*
   * Change the port parameters
   */

  static void atmel_set_termios(struct uart_port *port, struct ktermios * termios, struct ktermios * old)

  {
  	unsigned long flags;
  	unsigned int mode, imr, quot, baud;

  	/* Get current mode register */
  	mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL | ATMEL_US_NBSTOP | ATMEL_US_PAR);

  	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
  	quot = uart_get_divisor(port, baud);

  	if (quot > 65535) {		/* BRGR is 16-bit, so switch to slower clock */
  		quot /= 8;
  		mode |= ATMEL_US_USCLKS_MCK_DIV8;
  	}

  
  	/* byte size */
  	switch (termios->c_cflag & CSIZE) {
  	case CS5:

  		mode |= ATMEL_US_CHRL_5;

  		break;
  	case CS6:

  		mode |= ATMEL_US_CHRL_6;

  		break;
  	case CS7:

  		mode |= ATMEL_US_CHRL_7;

  		break;
  	default:

  		mode |= ATMEL_US_CHRL_8;

  		break;
  	}
  
  	/* stop bits */
  	if (termios->c_cflag & CSTOPB)

  		mode |= ATMEL_US_NBSTOP_2;

  
  	/* parity */
  	if (termios->c_cflag & PARENB) {
  		if (termios->c_cflag & CMSPAR) {			/* Mark or Space parity */
  			if (termios->c_cflag & PARODD)

  				mode |= ATMEL_US_PAR_MARK;

  			else

  				mode |= ATMEL_US_PAR_SPACE;

  		}
  		else if (termios->c_cflag & PARODD)

  			mode |= ATMEL_US_PAR_ODD;

  		else

  			mode |= ATMEL_US_PAR_EVEN;

  	}
  	else

  		mode |= ATMEL_US_PAR_NONE;

  
  	spin_lock_irqsave(&port->lock, flags);

  	port->read_status_mask = ATMEL_US_OVRE;

  	if (termios->c_iflag & INPCK)

  		port->read_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);

  	if (termios->c_iflag & (BRKINT | PARMRK))

  		port->read_status_mask |= ATMEL_US_RXBRK;

  
  	/*
  	 * Characters to ignore
  	 */
  	port->ignore_status_mask = 0;
  	if (termios->c_iflag & IGNPAR)

  		port->ignore_status_mask |= (ATMEL_US_FRAME | ATMEL_US_PARE);

  	if (termios->c_iflag & IGNBRK) {

  		port->ignore_status_mask |= ATMEL_US_RXBRK;

  		/*
  		 * If we're ignoring parity and break indicators,
  		 * ignore overruns too (for real raw support).
  		 */
  		if (termios->c_iflag & IGNPAR)

  			port->ignore_status_mask |= ATMEL_US_OVRE;

  	}
  
  	// TODO: Ignore all characters if CREAD is set.
  
  	/* update the per-port timeout */
  	uart_update_timeout(port, termios->c_cflag, baud);
  
  	/* disable interrupts and drain transmitter */
  	imr = UART_GET_IMR(port);	/* get interrupt mask */
  	UART_PUT_IDR(port, -1);		/* disable all interrupts */

  	while (!(UART_GET_CSR(port) & ATMEL_US_TXEMPTY)) { barrier(); }

  
  	/* disable receiver and transmitter */

  	UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS);

  
  	/* set the parity, stop bits and data size */
  	UART_PUT_MR(port, mode);
  
  	/* set the baud rate */
  	UART_PUT_BRGR(port, quot);

  	UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
  	UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);

  
  	/* restore interrupts */
  	UART_PUT_IER(port, imr);
  
  	/* CTS flow-control and modem-status interrupts */
  	if (UART_ENABLE_MS(port, termios->c_cflag))
  		port->ops->enable_ms(port);
  
  	spin_unlock_irqrestore(&port->lock, flags);
  }
  
  /*
   * Return string describing the specified port
   */

  static const char *atmel_type(struct uart_port *port)

  {

  	return (port->type == PORT_ATMEL) ? "ATMEL_SERIAL" : NULL;

  }
  
  /*
   * Release the memory region(s) being used by 'port'.
   */

  static void atmel_release_port(struct uart_port *port)

  {

  	struct platform_device *pdev = to_platform_device(port->dev);
  	int size = pdev->resource[0].end - pdev->resource[0].start + 1;
  
  	release_mem_region(port->mapbase, size);
  
  	if (port->flags & UPF_IOREMAP) {
  		iounmap(port->membase);
  		port->membase = NULL;
  	}

  }
  
  /*
   * Request the memory region(s) being used by 'port'.
   */

  static int atmel_request_port(struct uart_port *port)

  {

  	struct platform_device *pdev = to_platform_device(port->dev);
  	int size = pdev->resource[0].end - pdev->resource[0].start + 1;

  	if (!request_mem_region(port->mapbase, size, "atmel_serial"))

  		return -EBUSY;
  
  	if (port->flags & UPF_IOREMAP) {
  		port->membase = ioremap(port->mapbase, size);
  		if (port->membase == NULL) {
  			release_mem_region(port->mapbase, size);
  			return -ENOMEM;
  		}
  	}

  	return 0;

  }
  
  /*
   * Configure/autoconfigure the port.
   */

  static void atmel_config_port(struct uart_port *port, int flags)

  {
  	if (flags & UART_CONFIG_TYPE) {

  		port->type = PORT_ATMEL;

  		atmel_request_port(port);

  	}
  }
  
  /*
   * Verify the new serial_struct (for TIOCSSERIAL).
   */

  static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser)

  {
  	int ret = 0;

  	if (ser->type != PORT_UNKNOWN && ser->type != PORT_ATMEL)

  		ret = -EINVAL;
  	if (port->irq != ser->irq)
  		ret = -EINVAL;
  	if (ser->io_type != SERIAL_IO_MEM)
  		ret = -EINVAL;
  	if (port->uartclk / 16 != ser->baud_base)
  		ret = -EINVAL;
  	if ((void *)port->mapbase != ser->iomem_base)
  		ret = -EINVAL;
  	if (port->iobase != ser->port)
  		ret = -EINVAL;
  	if (ser->hub6 != 0)
  		ret = -EINVAL;
  	return ret;
  }

  static struct uart_ops atmel_pops = {
  	.tx_empty	= atmel_tx_empty,
  	.set_mctrl	= atmel_set_mctrl,
  	.get_mctrl	= atmel_get_mctrl,
  	.stop_tx	= atmel_stop_tx,
  	.start_tx	= atmel_start_tx,
  	.stop_rx	= atmel_stop_rx,
  	.enable_ms	= atmel_enable_ms,
  	.break_ctl	= atmel_break_ctl,
  	.startup	= atmel_startup,
  	.shutdown	= atmel_shutdown,
  	.set_termios	= atmel_set_termios,
  	.type		= atmel_type,
  	.release_port	= atmel_release_port,
  	.request_port	= atmel_request_port,
  	.config_port	= atmel_config_port,
  	.verify_port	= atmel_verify_port,
  	.pm		= atmel_serial_pm,

  };

  /*
   * Configure the port from the platform device resource info.
   */

  static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, struct platform_device *pdev)

  {

  	struct uart_port *port = &atmel_port->uart;

  	struct atmel_uart_data *data = pdev->dev.platform_data;

  
  	port->iotype	= UPIO_MEM;

  	port->flags	= UPF_BOOT_AUTOCONF;

  	port->ops	= &atmel_pops;

  	port->fifosize	= 1;

  	port->line	= pdev->id;
  	port->dev	= &pdev->dev;
  
  	port->mapbase	= pdev->resource[0].start;
  	port->irq	= pdev->resource[1].start;

  	if (data->regs)
  		/* Already mapped by setup code */
  		port->membase = data->regs;

  	else {
  		port->flags	|= UPF_IOREMAP;
  		port->membase	= NULL;
  	}

  	if (!atmel_port->clk) {		/* for console, the clock could already be configured */
  		atmel_port->clk = clk_get(&pdev->dev, "usart");
  		clk_enable(atmel_port->clk);
  		port->uartclk = clk_get_rate(atmel_port->clk);

  	}

  }

  /*
   * Register board-specific modem-control line handlers.
   */

  void __init atmel_register_uart_fns(struct atmel_port_fns *fns)

  {
  	if (fns->enable_ms)

  		atmel_pops.enable_ms = fns->enable_ms;

  	if (fns->get_mctrl)

  		atmel_pops.get_mctrl = fns->get_mctrl;

  	if (fns->set_mctrl)

  		atmel_pops.set_mctrl = fns->set_mctrl;

  	atmel_open_hook		= fns->open;
  	atmel_close_hook	= fns->close;

  	atmel_pops.pm		= fns->pm;
  	atmel_pops.set_wake	= fns->set_wake;

  }

  #ifdef CONFIG_SERIAL_ATMEL_CONSOLE

  static void atmel_console_putchar(struct uart_port *port, int ch)

  {

  	while (!(UART_GET_CSR(port) & ATMEL_US_TXRDY))

  		barrier();
  	UART_PUT_CHAR(port, ch);
  }

  
  /*
   * Interrupts are disabled on entering
   */

  static void atmel_console_write(struct console *co, const char *s, u_int count)

  {

  	struct uart_port *port = &atmel_ports[co->index].uart;

  	unsigned int status, imr;

  
  	/*
  	 *	First, save IMR and then disable interrupts
  	 */
  	imr = UART_GET_IMR(port);	/* get interrupt mask */

  	UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY);

  	uart_console_write(port, s, count, atmel_console_putchar);

  
  	/*
  	 *	Finally, wait for transmitter to become empty
  	 *	and restore IMR
  	 */
  	do {
  		status = UART_GET_CSR(port);

  	} while (!(status & ATMEL_US_TXRDY));

  	UART_PUT_IER(port, imr);	/* set interrupts back the way they were */
  }
  
  /*
   * If the port was already initialised (eg, by a boot loader), try to determine
   * the current setup.
   */

  static void __init atmel_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)

  {
  	unsigned int mr, quot;
  
  // TODO: CR is a write-only register
  //	unsigned int cr;
  //

  //	cr = UART_GET_CR(port) & (ATMEL_US_RXEN | ATMEL_US_TXEN);
  //	if (cr == (ATMEL_US_RXEN | ATMEL_US_TXEN)) {

  //		/* ok, the port was enabled */
  //	}

  	mr = UART_GET_MR(port) & ATMEL_US_CHRL;
  	if (mr == ATMEL_US_CHRL_8)

  		*bits = 8;
  	else
  		*bits = 7;

  	mr = UART_GET_MR(port) & ATMEL_US_PAR;
  	if (mr == ATMEL_US_PAR_EVEN)

  		*parity = 'e';

  	else if (mr == ATMEL_US_PAR_ODD)

  		*parity = 'o';

  	/*
  	 * The serial core only rounds down when matching this to a
  	 * supported baud rate. Make sure we don't end up slightly
  	 * lower than one of those, as it would make us fall through
  	 * to a much lower baud rate than we really want.
  	 */

  	quot = UART_GET_BRGR(port);

  	*baud = port->uartclk / (16 * (quot - 1));

  }

  static int __init atmel_console_setup(struct console *co, char *options)

  {

  	struct uart_port *port = &atmel_ports[co->index].uart;

  	int baud = 115200;
  	int bits = 8;
  	int parity = 'n';
  	int flow = 'n';

  	if (port->membase == 0)		/* Port not initialized yet - delay setup */
  		return -ENODEV;

  	UART_PUT_IDR(port, -1);				/* disable interrupts */

  	UART_PUT_CR(port, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
  	UART_PUT_CR(port, ATMEL_US_TXEN | ATMEL_US_RXEN);

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

  		atmel_console_get_options(port, &baud, &parity, &bits);

  
  	return uart_set_options(port, co, baud, parity, bits, flow);
  }

  static struct uart_driver atmel_uart;

  static struct console atmel_console = {
  	.name		= ATMEL_DEVICENAME,
  	.write		= atmel_console_write,

  	.device		= uart_console_device,

  	.setup		= atmel_console_setup,

  	.flags		= CON_PRINTBUFFER,
  	.index		= -1,

  	.data		= &atmel_uart,

  };

  #define ATMEL_CONSOLE_DEVICE	&atmel_console

  /*
   * Early console initialization (before VM subsystem initialized).
   */

  static int __init atmel_console_init(void)

  {

  	if (atmel_default_console_device) {

  		add_preferred_console(ATMEL_DEVICENAME, atmel_default_console_device->id, NULL);
  		atmel_init_port(&(atmel_ports[atmel_default_console_device->id]), atmel_default_console_device);
  		register_console(&atmel_console);

  	}

  	return 0;
  }

  console_initcall(atmel_console_init);

  /*
   * Late console initialization.
   */

  static int __init atmel_late_console_init(void)

  {

  	if (atmel_default_console_device && !(atmel_console.flags & CON_ENABLED))
  		register_console(&atmel_console);

  
  	return 0;
  }

  core_initcall(atmel_late_console_init);

  #else

  #define ATMEL_CONSOLE_DEVICE	NULL

  #endif

  static struct uart_driver atmel_uart = {

  	.owner			= THIS_MODULE,

  	.driver_name		= "atmel_serial",
  	.dev_name		= ATMEL_DEVICENAME,
  	.major			= SERIAL_ATMEL_MAJOR,

  	.minor			= MINOR_START,

  	.nr			= ATMEL_MAX_UART,

  	.cons			= ATMEL_CONSOLE_DEVICE,

  };

  #ifdef CONFIG_PM

  static int atmel_serial_suspend(struct platform_device *pdev, pm_message_t state)

  {

  	struct uart_port *port = platform_get_drvdata(pdev);

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  
  	if (device_may_wakeup(&pdev->dev) && !at91_suspend_entering_slow_clock())
  		enable_irq_wake(port->irq);
  	else {

  		uart_suspend_port(&atmel_uart, port);
  		atmel_port->suspended = 1;

  	}

  	return 0;
  }

  static int atmel_serial_resume(struct platform_device *pdev)

  {
  	struct uart_port *port = platform_get_drvdata(pdev);

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  	if (atmel_port->suspended) {
  		uart_resume_port(&atmel_uart, port);
  		atmel_port->suspended = 0;

  	}

  	else
  		disable_irq_wake(port->irq);

  
  	return 0;
  }

  #else

  #define atmel_serial_suspend NULL
  #define atmel_serial_resume NULL

  #endif

  static int __devinit atmel_serial_probe(struct platform_device *pdev)

  {

  	struct atmel_uart_port *port;

  	int ret;

  	port = &atmel_ports[pdev->id];
  	atmel_init_port(port, pdev);

  	ret = uart_add_one_port(&atmel_uart, &port->uart);

  	if (!ret) {
  		device_init_wakeup(&pdev->dev, 1);
  		platform_set_drvdata(pdev, port);
  	}
  
  	return ret;
  }

  static int __devexit atmel_serial_remove(struct platform_device *pdev)

  {
  	struct uart_port *port = platform_get_drvdata(pdev);

  	struct atmel_uart_port *atmel_port = (struct atmel_uart_port *) port;

  	int ret = 0;

  	clk_disable(atmel_port->clk);
  	clk_put(atmel_port->clk);

  
  	device_init_wakeup(&pdev->dev, 0);
  	platform_set_drvdata(pdev, NULL);
  
  	if (port) {

  		ret = uart_remove_one_port(&atmel_uart, port);

  		kfree(port);
  	}
  
  	return ret;
  }

  static struct platform_driver atmel_serial_driver = {
  	.probe		= atmel_serial_probe,
  	.remove		= __devexit_p(atmel_serial_remove),
  	.suspend	= atmel_serial_suspend,
  	.resume		= atmel_serial_resume,

  	.driver		= {

  		.name	= "atmel_usart",

  		.owner	= THIS_MODULE,
  	},
  };

  static int __init atmel_serial_init(void)

  {
  	int ret;

  	ret = uart_register_driver(&atmel_uart);

  	if (ret)
  		return ret;

  	ret = platform_driver_register(&atmel_serial_driver);

  	if (ret)

  		uart_unregister_driver(&atmel_uart);

  
  	return ret;
  }

  static void __exit atmel_serial_exit(void)

  {

  	platform_driver_unregister(&atmel_serial_driver);
  	uart_unregister_driver(&atmel_uart);

  }

  module_init(atmel_serial_init);
  module_exit(atmel_serial_exit);

  
  MODULE_AUTHOR("Rick Bronson");

  MODULE_DESCRIPTION("Atmel AT91 / AT32 serial port driver");

  MODULE_LICENSE("GPL");