/*
   *  Based on drivers/serial/8250.c by Russell King.
   *
   *  Author:	Nicolas Pitre
   *  Created:	Feb 20, 2003
   *  Copyright:	(C) 2003 Monta Vista Software, Inc.
   *
   * 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.
   *
   * Note 1: This driver is made separate from the already too overloaded
   * 8250.c because it needs some kirks of its own and that'll make it
   * easier to add DMA support.
   *
   * Note 2: I'm too sick of device allocation policies for serial ports.
   * If someone else wants to request an "official" allocation of major/minor
   * for this driver please be my guest.  And don't forget that new hardware
   * to come from Intel might have more than 3 or 4 of those UARTs.  Let's
   * hope for a better port registration and dynamic device allocation scheme
   * with the serial core maintainer satisfaction to appear soon.
   */
  
  
  #if defined(CONFIG_SERIAL_PXA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  #define SUPPORT_SYSRQ
  #endif
  
  #include <linux/module.h>
  #include <linux/ioport.h>
  #include <linux/init.h>
  #include <linux/console.h>
  #include <linux/sysrq.h>
  #include <linux/serial_reg.h>
  #include <linux/circ_buf.h>
  #include <linux/delay.h>
  #include <linux/interrupt.h>
  #include <linux/of.h>
  #include <linux/platform_device.h>
  #include <linux/tty.h>
  #include <linux/tty_flip.h>
  #include <linux/serial_core.h>
  #include <linux/clk.h>
  #include <linux/io.h>
  #include <linux/slab.h>
  
  #define PXA_NAME_LEN		8
  
  struct uart_pxa_port {
  	struct uart_port        port;
  	unsigned char           ier;
  	unsigned char           lcr;
  	unsigned char           mcr;
  	unsigned int            lsr_break_flag;
  	struct clk		*clk;
  	char			name[PXA_NAME_LEN];
  };
  
  static inline unsigned int serial_in(struct uart_pxa_port *up, int offset)
  {
  	offset <<= 2;
  	return readl(up->port.membase + offset);
  }
  
  static inline void serial_out(struct uart_pxa_port *up, int offset, int value)
  {
  	offset <<= 2;
  	writel(value, up->port.membase + offset);
  }
  
  static void serial_pxa_enable_ms(struct uart_port *port)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  
  	up->ier |= UART_IER_MSI;
  	serial_out(up, UART_IER, up->ier);
  }
  
  static void serial_pxa_stop_tx(struct uart_port *port)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  
  	if (up->ier & UART_IER_THRI) {
  		up->ier &= ~UART_IER_THRI;
  		serial_out(up, UART_IER, up->ier);
  	}
  }
  
  static void serial_pxa_stop_rx(struct uart_port *port)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  
  	up->ier &= ~UART_IER_RLSI;
  	up->port.read_status_mask &= ~UART_LSR_DR;
  	serial_out(up, UART_IER, up->ier);
  }
  
  static inline void receive_chars(struct uart_pxa_port *up, int *status)
  {
  	unsigned int ch, flag;
  	int max_count = 256;
  
  	do {
  		/* work around Errata #20 according to
  		 * Intel(R) PXA27x Processor Family
  		 * Specification Update (May 2005)
  		 *
  		 * Step 2
  		 * Disable the Reciever Time Out Interrupt via IER[RTOEI]
  		 */
  		up->ier &= ~UART_IER_RTOIE;
  		serial_out(up, UART_IER, up->ier);
  
  		ch = serial_in(up, UART_RX);
  		flag = TTY_NORMAL;
  		up->port.icount.rx++;
  
  		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
  				       UART_LSR_FE | UART_LSR_OE))) {
  			/*
  			 * For statistics only
  			 */
  			if (*status & UART_LSR_BI) {
  				*status &= ~(UART_LSR_FE | UART_LSR_PE);
  				up->port.icount.brk++;
  				/*
  				 * We do the SysRQ and SAK checking
  				 * here because otherwise the break
  				 * may get masked by ignore_status_mask
  				 * or read_status_mask.
  				 */
  				if (uart_handle_break(&up->port))
  					goto ignore_char;
  			} else if (*status & UART_LSR_PE)
  				up->port.icount.parity++;
  			else if (*status & UART_LSR_FE)
  				up->port.icount.frame++;
  			if (*status & UART_LSR_OE)
  				up->port.icount.overrun++;
  
  			/*
  			 * Mask off conditions which should be ignored.
  			 */
  			*status &= up->port.read_status_mask;
  
  #ifdef CONFIG_SERIAL_PXA_CONSOLE
  			if (up->port.line == up->port.cons->index) {
  				/* Recover the break flag from console xmit */
  				*status |= up->lsr_break_flag;
  				up->lsr_break_flag = 0;
  			}
  #endif
  			if (*status & UART_LSR_BI) {
  				flag = TTY_BREAK;
  			} else if (*status & UART_LSR_PE)
  				flag = TTY_PARITY;
  			else if (*status & UART_LSR_FE)
  				flag = TTY_FRAME;
  		}
  
  		if (uart_handle_sysrq_char(&up->port, ch))
  			goto ignore_char;
  
  		uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
  
  	ignore_char:
  		*status = serial_in(up, UART_LSR);
  	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
  	tty_flip_buffer_push(&up->port.state->port);
  
  	/* work around Errata #20 according to
  	 * Intel(R) PXA27x Processor Family
  	 * Specification Update (May 2005)
  	 *
  	 * Step 6:
  	 * No more data in FIFO: Re-enable RTO interrupt via IER[RTOIE]
  	 */
  	up->ier |= UART_IER_RTOIE;
  	serial_out(up, UART_IER, up->ier);
  }
  
  static void transmit_chars(struct uart_pxa_port *up)
  {
  	struct circ_buf *xmit = &up->port.state->xmit;
  	int count;
  
  	if (up->port.x_char) {
  		serial_out(up, UART_TX, up->port.x_char);
  		up->port.icount.tx++;
  		up->port.x_char = 0;
  		return;
  	}
  	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
  		serial_pxa_stop_tx(&up->port);
  		return;
  	}
  
  	count = up->port.fifosize / 2;
  	do {
  		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
  		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
  		up->port.icount.tx++;
  		if (uart_circ_empty(xmit))
  			break;
  	} while (--count > 0);
  
  	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
  		uart_write_wakeup(&up->port);
  
  
  	if (uart_circ_empty(xmit))
  		serial_pxa_stop_tx(&up->port);
  }
  
  static void serial_pxa_start_tx(struct uart_port *port)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  
  	if (!(up->ier & UART_IER_THRI)) {
  		up->ier |= UART_IER_THRI;
  		serial_out(up, UART_IER, up->ier);
  	}
  }
  
  static inline void check_modem_status(struct uart_pxa_port *up)
  {
  	int status;
  
  	status = serial_in(up, UART_MSR);
  
  	if ((status & UART_MSR_ANY_DELTA) == 0)
  		return;
  
  	if (status & UART_MSR_TERI)
  		up->port.icount.rng++;
  	if (status & UART_MSR_DDSR)
  		up->port.icount.dsr++;
  	if (status & UART_MSR_DDCD)
  		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
  	if (status & UART_MSR_DCTS)
  		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
  
  	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
  }
  
  /*
   * This handles the interrupt from one port.
   */
  static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
  {
  	struct uart_pxa_port *up = dev_id;
  	unsigned int iir, lsr;
  
  	iir = serial_in(up, UART_IIR);
  	if (iir & UART_IIR_NO_INT)
  		return IRQ_NONE;
  	lsr = serial_in(up, UART_LSR);
  	if (lsr & UART_LSR_DR)
  		receive_chars(up, &lsr);
  	check_modem_status(up);
  	if (lsr & UART_LSR_THRE)
  		transmit_chars(up);
  	return IRQ_HANDLED;
  }
  
  static unsigned int serial_pxa_tx_empty(struct uart_port *port)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  	unsigned long flags;
  	unsigned int ret;
  
  	spin_lock_irqsave(&up->port.lock, flags);
  	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
  	spin_unlock_irqrestore(&up->port.lock, flags);
  
  	return ret;
  }
  
  static unsigned int serial_pxa_get_mctrl(struct uart_port *port)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  	unsigned char status;
  	unsigned int ret;
  
  	status = serial_in(up, UART_MSR);
  
  	ret = 0;
  	if (status & UART_MSR_DCD)
  		ret |= TIOCM_CAR;
  	if (status & UART_MSR_RI)
  		ret |= TIOCM_RNG;
  	if (status & UART_MSR_DSR)
  		ret |= TIOCM_DSR;
  	if (status & UART_MSR_CTS)
  		ret |= TIOCM_CTS;
  	return ret;
  }
  
  static void serial_pxa_set_mctrl(struct uart_port *port, unsigned int mctrl)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  	unsigned char mcr = 0;
  
  	if (mctrl & TIOCM_RTS)
  		mcr |= UART_MCR_RTS;
  	if (mctrl & TIOCM_DTR)
  		mcr |= UART_MCR_DTR;
  	if (mctrl & TIOCM_OUT1)
  		mcr |= UART_MCR_OUT1;
  	if (mctrl & TIOCM_OUT2)
  		mcr |= UART_MCR_OUT2;
  	if (mctrl & TIOCM_LOOP)
  		mcr |= UART_MCR_LOOP;
  
  	mcr |= up->mcr;
  
  	serial_out(up, UART_MCR, mcr);
  }
  
  static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  	unsigned long flags;
  
  	spin_lock_irqsave(&up->port.lock, flags);
  	if (break_state == -1)
  		up->lcr |= UART_LCR_SBC;
  	else
  		up->lcr &= ~UART_LCR_SBC;
  	serial_out(up, UART_LCR, up->lcr);
  	spin_unlock_irqrestore(&up->port.lock, flags);
  }
  
  static int serial_pxa_startup(struct uart_port *port)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  	unsigned long flags;
  	int retval;
  
  	if (port->line == 3) /* HWUART */
  		up->mcr |= UART_MCR_AFE;
  	else
  		up->mcr = 0;
  
  	up->port.uartclk = clk_get_rate(up->clk);
  
  	/*
  	 * Allocate the IRQ
  	 */
  	retval = request_irq(up->port.irq, serial_pxa_irq, 0, up->name, up);
  	if (retval)
  		return retval;
  
  	/*
  	 * Clear the FIFO buffers and disable them.
  	 * (they will be reenabled in set_termios())
  	 */
  	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
  	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
  			UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
  	serial_out(up, UART_FCR, 0);
  
  	/*
  	 * Clear the interrupt registers.
  	 */
  	(void) serial_in(up, UART_LSR);
  	(void) serial_in(up, UART_RX);
  	(void) serial_in(up, UART_IIR);
  	(void) serial_in(up, UART_MSR);
  
  	/*
  	 * Now, initialize the UART
  	 */
  	serial_out(up, UART_LCR, UART_LCR_WLEN8);
  
  	spin_lock_irqsave(&up->port.lock, flags);
  	up->port.mctrl |= TIOCM_OUT2;
  	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
  	spin_unlock_irqrestore(&up->port.lock, flags);
  
  	/*
  	 * Finally, enable interrupts.  Note: Modem status interrupts
  	 * are set via set_termios(), which will be occurring imminently
  	 * anyway, so we don't enable them here.
  	 */
  	up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE | UART_IER_UUE;
  	serial_out(up, UART_IER, up->ier);
  
  	/*
  	 * And clear the interrupt registers again for luck.
  	 */
  	(void) serial_in(up, UART_LSR);
  	(void) serial_in(up, UART_RX);
  	(void) serial_in(up, UART_IIR);
  	(void) serial_in(up, UART_MSR);
  
  	return 0;
  }
  
  static void serial_pxa_shutdown(struct uart_port *port)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  	unsigned long flags;
  
  	free_irq(up->port.irq, up);
  
  	/*
  	 * Disable interrupts from this port
  	 */
  	up->ier = 0;
  	serial_out(up, UART_IER, 0);
  
  	spin_lock_irqsave(&up->port.lock, flags);
  	up->port.mctrl &= ~TIOCM_OUT2;
  	serial_pxa_set_mctrl(&up->port, up->port.mctrl);
  	spin_unlock_irqrestore(&up->port.lock, flags);
  
  	/*
  	 * Disable break condition and FIFOs
  	 */
  	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
  	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
  				  UART_FCR_CLEAR_RCVR |
  				  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;
  	unsigned int dll;
  
  	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 |= UART_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 & (IGNBRK | 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);
  
  	if (termios->c_cflag & CRTSCTS)
  		up->mcr |= UART_MCR_AFE;
  	else
  		up->mcr &= ~UART_MCR_AFE;
  
  	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);	/* set DLAB */
  	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
  
  	/*
  	 * work around Errata #75 according to Intel(R) PXA27x Processor Family
  	 * Specification Update (Nov 2005)
  	 */
  	dll = serial_in(up, UART_DLL);
  	WARN_ON(dll != (quot & 0xff));
  
  	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_prepare_enable(up->clk);
  	else
  		clk_disable_unprepare(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;
  	unsigned long flags;
  	int locked = 1;
  
  	clk_enable(up->clk);
  	local_irq_save(flags);
  	if (up->port.sysrq)
  		locked = 0;
  	else if (oops_in_progress)
  		locked = spin_trylock(&up->port.lock);
  	else
  		spin_lock(&up->port.lock);
  
  	/*
  	 *	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);
  
  	if (locked)
  		spin_unlock(&up->port.lock);
  	local_irq_restore(flags);
  	clk_disable(up->clk);
  
  }
  
  #ifdef CONFIG_CONSOLE_POLL
  /*
   * Console polling routines for writing and reading from the uart while
   * in an interrupt or debug context.
   */
  
  static int serial_pxa_get_poll_char(struct uart_port *port)
  {
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  	unsigned char lsr = serial_in(up, UART_LSR);
  
  	while (!(lsr & UART_LSR_DR))
  		lsr = serial_in(up, UART_LSR);
  
  	return serial_in(up, UART_RX);
  }
  
  
  static void serial_pxa_put_poll_char(struct uart_port *port,
  			 unsigned char c)
  {
  	unsigned int ier;
  	struct uart_pxa_port *up = (struct uart_pxa_port *)port;
  
  	/*
  	 *	First save the IER then disable the interrupts
  	 */
  	ier = serial_in(up, UART_IER);
  	serial_out(up, UART_IER, UART_IER_UUE);
  
  	wait_for_xmitr(up);
  	/*
  	 *	Send the character out.
  	 *	If a LF, also do CR...
  	 */
  	serial_out(up, UART_TX, c);
  	if (c == 10) {
  		wait_for_xmitr(up);
  		serial_out(up, UART_TX, 13);
  	}
  
  	/*
  	 *	Finally, wait for transmitter to become empty
  	 *	and restore the IER
  	 */
  	wait_for_xmitr(up);
  	serial_out(up, UART_IER, ier);
  }
  
  #endif /* CONFIG_CONSOLE_POLL */
  
  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
  
  static 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,
  #ifdef CONFIG_CONSOLE_POLL
  	.poll_get_char = serial_pxa_get_poll_char,
  	.poll_put_char = serial_pxa_put_poll_char,
  #endif
  };
  
  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,
  };
  
  #ifdef CONFIG_PM
  static int serial_pxa_suspend(struct device *dev)
  {
          struct uart_pxa_port *sport = dev_get_drvdata(dev);
  
          if (sport)
                  uart_suspend_port(&serial_pxa_reg, &sport->port);
  
          return 0;
  }
  
  static int serial_pxa_resume(struct device *dev)
  {
          struct uart_pxa_port *sport = dev_get_drvdata(dev);
  
          if (sport)
                  uart_resume_port(&serial_pxa_reg, &sport->port);
  
          return 0;
  }
  
  static const struct dev_pm_ops serial_pxa_pm_ops = {
  	.suspend	= serial_pxa_suspend,
  	.resume		= serial_pxa_resume,
  };
  #endif
  
  static struct of_device_id serial_pxa_dt_ids[] = {
  	{ .compatible = "mrvl,pxa-uart", },
  	{ .compatible = "mrvl,mmp-uart", },
  	{}
  };
  MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids);
  
  static int serial_pxa_probe_dt(struct platform_device *pdev,
  			       struct uart_pxa_port *sport)
  {
  	struct device_node *np = pdev->dev.of_node;
  	int ret;
  
  	if (!np)
  		return 1;
  
  	ret = of_alias_get_id(np, "serial");
  	if (ret < 0) {
  		dev_err(&pdev->dev, "failed to get alias id, errno %d
  ", ret);
  		return ret;
  	}
  	sport->port.line = ret;
  	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, NULL);
  	if (IS_ERR(sport->clk)) {
  		ret = PTR_ERR(sport->clk);
  		goto err_free;
  	}
  
  	ret = clk_prepare(sport->clk);
  	if (ret) {
  		clk_put(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.dev = &dev->dev;
  	sport->port.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
  	sport->port.uartclk = clk_get_rate(sport->clk);
  
  	ret = serial_pxa_probe_dt(dev, sport);
  	if (ret > 0)
  		sport->port.line = dev->id;
  	else if (ret < 0)
  		goto err_clk;
  	snprintf(sport->name, PXA_NAME_LEN - 1, "UART%d", sport->port.line + 1);
  
  	sport->port.membase = ioremap(mmres->start, resource_size(mmres));
  	if (!sport->port.membase) {
  		ret = -ENOMEM;
  		goto err_clk;
  	}
  
  	serial_pxa_ports[sport->port.line] = sport;
  
  	uart_add_one_port(&serial_pxa_reg, &sport->port);
  	platform_set_drvdata(dev, sport);
  
  	return 0;
  
   err_clk:
  	clk_unprepare(sport->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);
  
  	uart_remove_one_port(&serial_pxa_reg, &sport->port);
  
  	clk_unprepare(sport->clk);
  	clk_put(sport->clk);
  	kfree(sport);
  
  	return 0;
  }
  
  static struct platform_driver serial_pxa_driver = {
          .probe          = serial_pxa_probe,
          .remove         = serial_pxa_remove,
  
  	.driver		= {
  	        .name	= "pxa2xx-uart",
  #ifdef CONFIG_PM
  		.pm	= &serial_pxa_pm_ops,
  #endif
  		.of_match_table = serial_pxa_dt_ids,
  	},
  };
  
  static 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;
  }
  
  static 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");
  MODULE_ALIAS("platform:pxa2xx-uart");