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41 results

imx.c

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    Xinyu Chen authored and Greg Kroah-Hartman committed
    The console feature's write routing is unsafe on SMP with
    the startup/shutdown call.
    
    There could be several consumers of the console
    * the kernel printk
    * the init process using /dev/kmsg to call printk to show log
    * shell, which open /dev/console and write with sys_write()
    
    The shell goes into the normal uart open/write routing,
    but the other two go into the console operations.
    The open routing calls imx serial startup, which will write USR1/2
    register without any lock and critical with imx_console_write call.
    
    Add a spin_lock for startup/shutdown/console_write routing.
    
    This patch is a port from Freescale's Android kernel.
    
    Signed-off-by: default avatarXinyu Chen <xinyu.chen@freescale.com>
    Tested-by: default avatarDirk Behme <dirk.behme@de.bosch.com>
    CC: Sascha Hauer <s.hauer@pengutronix.de>
    Acked-by: default avatarShawn Guo <shawn.guo@linaro.org>
    Cc: stable <stable@vger.kernel.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    9ec1882d
    History
    Code owners
    Assign users and groups as approvers for specific file changes. Learn more.
    imx.c 41.37 KiB
    /*
     *  Driver for Motorola IMX serial ports
     *
     *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
     *
     *  Author: Sascha Hauer <sascha@saschahauer.de>
     *  Copyright (C) 2004 Pengutronix
     *
     *  Copyright (C) 2009 emlix GmbH
     *  Author: Fabian Godehardt (added IrDA support for iMX)
     *
     * 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
     *
     * [29-Mar-2005] Mike Lee
     * Added hardware handshake
     */
    
    #if defined(CONFIG_SERIAL_IMX_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/platform_device.h>
    #include <linux/tty.h>
    #include <linux/tty_flip.h>
    #include <linux/serial_core.h>
    #include <linux/serial.h>
    #include <linux/clk.h>
    #include <linux/delay.h>
    #include <linux/rational.h>
    #include <linux/slab.h>
    #include <linux/of.h>
    #include <linux/of_device.h>
    #include <linux/pinctrl/consumer.h>
    
    #include <asm/io.h>
    #include <asm/irq.h>
    #include <mach/imx-uart.h>
    
    /* Register definitions */
    #define URXD0 0x0  /* Receiver Register */
    #define URTX0 0x40 /* Transmitter Register */
    #define UCR1  0x80 /* Control Register 1 */
    #define UCR2  0x84 /* Control Register 2 */
    #define UCR3  0x88 /* Control Register 3 */
    #define UCR4  0x8c /* Control Register 4 */
    #define UFCR  0x90 /* FIFO Control Register */
    #define USR1  0x94 /* Status Register 1 */
    #define USR2  0x98 /* Status Register 2 */
    #define UESC  0x9c /* Escape Character Register */
    #define UTIM  0xa0 /* Escape Timer Register */
    #define UBIR  0xa4 /* BRM Incremental Register */
    #define UBMR  0xa8 /* BRM Modulator Register */
    #define UBRC  0xac /* Baud Rate Count Register */
    #define IMX21_ONEMS 0xb0 /* One Millisecond register */
    #define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
    #define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
    
    /* UART Control Register Bit Fields.*/
    #define  URXD_CHARRDY    (1<<15)
    #define  URXD_ERR        (1<<14)
    #define  URXD_OVRRUN     (1<<13)
    #define  URXD_FRMERR     (1<<12)
    #define  URXD_BRK        (1<<11)
    #define  URXD_PRERR      (1<<10)
    #define  UCR1_ADEN       (1<<15) /* Auto detect interrupt */
    #define  UCR1_ADBR       (1<<14) /* Auto detect baud rate */
    #define  UCR1_TRDYEN     (1<<13) /* Transmitter ready interrupt enable */
    #define  UCR1_IDEN       (1<<12) /* Idle condition interrupt */
    #define  UCR1_RRDYEN     (1<<9)	 /* Recv ready interrupt enable */
    #define  UCR1_RDMAEN     (1<<8)	 /* Recv ready DMA enable */
    #define  UCR1_IREN       (1<<7)	 /* Infrared interface enable */
    #define  UCR1_TXMPTYEN   (1<<6)	 /* Transimitter empty interrupt enable */
    #define  UCR1_RTSDEN     (1<<5)	 /* RTS delta interrupt enable */
    #define  UCR1_SNDBRK     (1<<4)	 /* Send break */
    #define  UCR1_TDMAEN     (1<<3)	 /* Transmitter ready DMA enable */
    #define  IMX1_UCR1_UARTCLKEN  (1<<2)  /* UART clock enabled, i.mx1 only */
    #define  UCR1_DOZE       (1<<1)	 /* Doze */
    #define  UCR1_UARTEN     (1<<0)	 /* UART enabled */
    #define  UCR2_ESCI     	 (1<<15) /* Escape seq interrupt enable */
    #define  UCR2_IRTS  	 (1<<14) /* Ignore RTS pin */
    #define  UCR2_CTSC  	 (1<<13) /* CTS pin control */
    #define  UCR2_CTS        (1<<12) /* Clear to send */
    #define  UCR2_ESCEN      (1<<11) /* Escape enable */
    #define  UCR2_PREN       (1<<8)  /* Parity enable */
    #define  UCR2_PROE       (1<<7)  /* Parity odd/even */
    #define  UCR2_STPB       (1<<6)	 /* Stop */
    #define  UCR2_WS         (1<<5)	 /* Word size */
    #define  UCR2_RTSEN      (1<<4)	 /* Request to send interrupt enable */
    #define  UCR2_ATEN       (1<<3)  /* Aging Timer Enable */
    #define  UCR2_TXEN       (1<<2)	 /* Transmitter enabled */
    #define  UCR2_RXEN       (1<<1)	 /* Receiver enabled */
    #define  UCR2_SRST 	 (1<<0)	 /* SW reset */
    #define  UCR3_DTREN 	 (1<<13) /* DTR interrupt enable */
    #define  UCR3_PARERREN   (1<<12) /* Parity enable */
    #define  UCR3_FRAERREN   (1<<11) /* Frame error interrupt enable */
    #define  UCR3_DSR        (1<<10) /* Data set ready */
    #define  UCR3_DCD        (1<<9)  /* Data carrier detect */
    #define  UCR3_RI         (1<<8)  /* Ring indicator */
    #define  UCR3_TIMEOUTEN  (1<<7)  /* Timeout interrupt enable */
    #define  UCR3_RXDSEN	 (1<<6)  /* Receive status interrupt enable */
    #define  UCR3_AIRINTEN   (1<<5)  /* Async IR wake interrupt enable */
    #define  UCR3_AWAKEN	 (1<<4)  /* Async wake interrupt enable */
    #define  IMX21_UCR3_RXDMUXSEL	 (1<<2)  /* RXD Muxed Input Select */
    #define  UCR3_INVT  	 (1<<1)  /* Inverted Infrared transmission */
    #define  UCR3_BPEN  	 (1<<0)  /* Preset registers enable */
    #define  UCR4_CTSTL_SHF  10      /* CTS trigger level shift */
    #define  UCR4_CTSTL_MASK 0x3F    /* CTS trigger is 6 bits wide */
    #define  UCR4_INVR  	 (1<<9)  /* Inverted infrared reception */
    #define  UCR4_ENIRI 	 (1<<8)  /* Serial infrared interrupt enable */
    #define  UCR4_WKEN  	 (1<<7)  /* Wake interrupt enable */
    #define  UCR4_REF16 	 (1<<6)  /* Ref freq 16 MHz */
    #define  UCR4_IRSC  	 (1<<5)  /* IR special case */
    #define  UCR4_TCEN  	 (1<<3)  /* Transmit complete interrupt enable */
    #define  UCR4_BKEN  	 (1<<2)  /* Break condition interrupt enable */
    #define  UCR4_OREN  	 (1<<1)  /* Receiver overrun interrupt enable */
    #define  UCR4_DREN  	 (1<<0)  /* Recv data ready interrupt enable */
    #define  UFCR_RXTL_SHF   0       /* Receiver trigger level shift */
    #define  UFCR_RFDIV      (7<<7)  /* Reference freq divider mask */
    #define  UFCR_RFDIV_REG(x)	(((x) < 7 ? 6 - (x) : 6) << 7)
    #define  UFCR_TXTL_SHF   10      /* Transmitter trigger level shift */
    #define  USR1_PARITYERR  (1<<15) /* Parity error interrupt flag */
    #define  USR1_RTSS  	 (1<<14) /* RTS pin status */
    #define  USR1_TRDY  	 (1<<13) /* Transmitter ready interrupt/dma flag */
    #define  USR1_RTSD  	 (1<<12) /* RTS delta */
    #define  USR1_ESCF  	 (1<<11) /* Escape seq interrupt flag */
    #define  USR1_FRAMERR    (1<<10) /* Frame error interrupt flag */
    #define  USR1_RRDY       (1<<9)	 /* Receiver ready interrupt/dma flag */
    #define  USR1_TIMEOUT    (1<<7)	 /* Receive timeout interrupt status */
    #define  USR1_RXDS  	 (1<<6)	 /* Receiver idle interrupt flag */
    #define  USR1_AIRINT	 (1<<5)	 /* Async IR wake interrupt flag */
    #define  USR1_AWAKE 	 (1<<4)	 /* Aysnc wake interrupt flag */
    #define  USR2_ADET  	 (1<<15) /* Auto baud rate detect complete */
    #define  USR2_TXFE  	 (1<<14) /* Transmit buffer FIFO empty */
    #define  USR2_DTRF  	 (1<<13) /* DTR edge interrupt flag */
    #define  USR2_IDLE  	 (1<<12) /* Idle condition */
    #define  USR2_IRINT 	 (1<<8)	 /* Serial infrared interrupt flag */
    #define  USR2_WAKE  	 (1<<7)	 /* Wake */
    #define  USR2_RTSF  	 (1<<4)	 /* RTS edge interrupt flag */
    #define  USR2_TXDC  	 (1<<3)	 /* Transmitter complete */
    #define  USR2_BRCD  	 (1<<2)	 /* Break condition */
    #define  USR2_ORE        (1<<1)	 /* Overrun error */
    #define  USR2_RDR        (1<<0)	 /* Recv data ready */
    #define  UTS_FRCPERR	 (1<<13) /* Force parity error */
    #define  UTS_LOOP        (1<<12) /* Loop tx and rx */
    #define  UTS_TXEMPTY	 (1<<6)	 /* TxFIFO empty */
    #define  UTS_RXEMPTY	 (1<<5)	 /* RxFIFO empty */
    #define  UTS_TXFULL 	 (1<<4)	 /* TxFIFO full */
    #define  UTS_RXFULL 	 (1<<3)	 /* RxFIFO full */
    #define  UTS_SOFTRST	 (1<<0)	 /* Software reset */
    
    /* We've been assigned a range on the "Low-density serial ports" major */
    #define SERIAL_IMX_MAJOR        207
    #define MINOR_START	        16
    #define DEV_NAME		"ttymxc"
    
    /*
     * This determines how often we check the modem status signals
     * for any change.  They generally aren't connected to an IRQ
     * so we have to poll them.  We also check immediately before
     * filling the TX fifo incase CTS has been dropped.
     */
    #define MCTRL_TIMEOUT	(250*HZ/1000)
    
    #define DRIVER_NAME "IMX-uart"
    
    #define UART_NR 8
    
    /* i.mx21 type uart runs on all i.mx except i.mx1 */
    enum imx_uart_type {
    	IMX1_UART,
    	IMX21_UART,
    };
    
    /* device type dependent stuff */
    struct imx_uart_data {
    	unsigned uts_reg;
    	enum imx_uart_type devtype;
    };
    
    struct imx_port {
    	struct uart_port	port;
    	struct timer_list	timer;
    	unsigned int		old_status;
    	int			txirq,rxirq,rtsirq;
    	unsigned int		have_rtscts:1;
    	unsigned int		use_irda:1;
    	unsigned int		irda_inv_rx:1;
    	unsigned int		irda_inv_tx:1;
    	unsigned short		trcv_delay; /* transceiver delay */
    	struct clk		*clk_ipg;
    	struct clk		*clk_per;
    	struct imx_uart_data	*devdata;
    };
    
    struct imx_port_ucrs {
    	unsigned int	ucr1;
    	unsigned int	ucr2;
    	unsigned int	ucr3;
    };
    
    #ifdef CONFIG_IRDA
    #define USE_IRDA(sport)	((sport)->use_irda)
    #else
    #define USE_IRDA(sport)	(0)
    #endif
    
    static struct imx_uart_data imx_uart_devdata[] = {
    	[IMX1_UART] = {
    		.uts_reg = IMX1_UTS,
    		.devtype = IMX1_UART,
    	},
    	[IMX21_UART] = {
    		.uts_reg = IMX21_UTS,
    		.devtype = IMX21_UART,
    	},
    };
    
    static struct platform_device_id imx_uart_devtype[] = {
    	{
    		.name = "imx1-uart",
    		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
    	}, {
    		.name = "imx21-uart",
    		.driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
    	}, {
    		/* sentinel */
    	}
    };
    MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
    
    static struct of_device_id imx_uart_dt_ids[] = {
    	{ .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
    	{ .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
    	{ /* sentinel */ }
    };
    MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
    
    static inline unsigned uts_reg(struct imx_port *sport)
    {
    	return sport->devdata->uts_reg;
    }
    
    static inline int is_imx1_uart(struct imx_port *sport)
    {
    	return sport->devdata->devtype == IMX1_UART;
    }
    
    static inline int is_imx21_uart(struct imx_port *sport)
    {
    	return sport->devdata->devtype == IMX21_UART;
    }
    
    /*
     * Save and restore functions for UCR1, UCR2 and UCR3 registers
     */
    static void imx_port_ucrs_save(struct uart_port *port,
    			       struct imx_port_ucrs *ucr)
    {
    	/* save control registers */
    	ucr->ucr1 = readl(port->membase + UCR1);
    	ucr->ucr2 = readl(port->membase + UCR2);
    	ucr->ucr3 = readl(port->membase + UCR3);
    }
    
    static void imx_port_ucrs_restore(struct uart_port *port,
    				  struct imx_port_ucrs *ucr)
    {
    	/* restore control registers */
    	writel(ucr->ucr1, port->membase + UCR1);
    	writel(ucr->ucr2, port->membase + UCR2);
    	writel(ucr->ucr3, port->membase + UCR3);
    }
    
    /*
     * Handle any change of modem status signal since we were last called.
     */
    static void imx_mctrl_check(struct imx_port *sport)
    {
    	unsigned int status, changed;
    
    	status = sport->port.ops->get_mctrl(&sport->port);
    	changed = status ^ sport->old_status;
    
    	if (changed == 0)
    		return;
    
    	sport->old_status = status;
    
    	if (changed & TIOCM_RI)
    		sport->port.icount.rng++;
    	if (changed & TIOCM_DSR)
    		sport->port.icount.dsr++;
    	if (changed & TIOCM_CAR)
    		uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
    	if (changed & TIOCM_CTS)
    		uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
    
    	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
    }
    
    /*
     * This is our per-port timeout handler, for checking the
     * modem status signals.
     */
    static void imx_timeout(unsigned long data)
    {
    	struct imx_port *sport = (struct imx_port *)data;
    	unsigned long flags;
    
    	if (sport->port.state) {
    		spin_lock_irqsave(&sport->port.lock, flags);
    		imx_mctrl_check(sport);
    		spin_unlock_irqrestore(&sport->port.lock, flags);
    
    		mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
    	}
    }
    
    /*
     * interrupts disabled on entry
     */
    static void imx_stop_tx(struct uart_port *port)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	unsigned long temp;
    
    	if (USE_IRDA(sport)) {
    		/* half duplex - wait for end of transmission */
    		int n = 256;
    		while ((--n > 0) &&
    		      !(readl(sport->port.membase + USR2) & USR2_TXDC)) {
    			udelay(5);
    			barrier();
    		}
    		/*
    		 * irda transceiver - wait a bit more to avoid
    		 * cutoff, hardware dependent
    		 */
    		udelay(sport->trcv_delay);
    
    		/*
    		 * half duplex - reactivate receive mode,
    		 * flush receive pipe echo crap
    		 */
    		if (readl(sport->port.membase + USR2) & USR2_TXDC) {
    			temp = readl(sport->port.membase + UCR1);
    			temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN);
    			writel(temp, sport->port.membase + UCR1);
    
    			temp = readl(sport->port.membase + UCR4);
    			temp &= ~(UCR4_TCEN);
    			writel(temp, sport->port.membase + UCR4);
    
    			while (readl(sport->port.membase + URXD0) &
    			       URXD_CHARRDY)
    				barrier();
    
    			temp = readl(sport->port.membase + UCR1);
    			temp |= UCR1_RRDYEN;
    			writel(temp, sport->port.membase + UCR1);
    
    			temp = readl(sport->port.membase + UCR4);
    			temp |= UCR4_DREN;
    			writel(temp, sport->port.membase + UCR4);
    		}
    		return;
    	}
    
    	temp = readl(sport->port.membase + UCR1);
    	writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1);
    }
    
    /*
     * interrupts disabled on entry
     */
    static void imx_stop_rx(struct uart_port *port)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	unsigned long temp;
    
    	temp = readl(sport->port.membase + UCR2);
    	writel(temp &~ UCR2_RXEN, sport->port.membase + UCR2);
    }
    
    /*
     * Set the modem control timer to fire immediately.
     */
    static void imx_enable_ms(struct uart_port *port)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    
    	mod_timer(&sport->timer, jiffies);
    }
    
    static inline void imx_transmit_buffer(struct imx_port *sport)
    {
    	struct circ_buf *xmit = &sport->port.state->xmit;
    
    	while (!uart_circ_empty(xmit) &&
    			!(readl(sport->port.membase + uts_reg(sport))
    				& UTS_TXFULL)) {
    		/* send xmit->buf[xmit->tail]
    		 * out the port here */
    		writel(xmit->buf[xmit->tail], sport->port.membase + URTX0);
    		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
    		sport->port.icount.tx++;
    	}
    
    	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
    		uart_write_wakeup(&sport->port);
    
    	if (uart_circ_empty(xmit))
    		imx_stop_tx(&sport->port);
    }
    
    /*
     * interrupts disabled on entry
     */
    static void imx_start_tx(struct uart_port *port)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	unsigned long temp;
    
    	if (USE_IRDA(sport)) {
    		/* half duplex in IrDA mode; have to disable receive mode */
    		temp = readl(sport->port.membase + UCR4);
    		temp &= ~(UCR4_DREN);
    		writel(temp, sport->port.membase + UCR4);
    
    		temp = readl(sport->port.membase + UCR1);
    		temp &= ~(UCR1_RRDYEN);
    		writel(temp, sport->port.membase + UCR1);
    	}
    
    	temp = readl(sport->port.membase + UCR1);
    	writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1);
    
    	if (USE_IRDA(sport)) {
    		temp = readl(sport->port.membase + UCR1);
    		temp |= UCR1_TRDYEN;
    		writel(temp, sport->port.membase + UCR1);
    
    		temp = readl(sport->port.membase + UCR4);
    		temp |= UCR4_TCEN;
    		writel(temp, sport->port.membase + UCR4);
    	}
    
    	if (readl(sport->port.membase + uts_reg(sport)) & UTS_TXEMPTY)
    		imx_transmit_buffer(sport);
    }
    
    static irqreturn_t imx_rtsint(int irq, void *dev_id)
    {
    	struct imx_port *sport = dev_id;
    	unsigned int val;
    	unsigned long flags;
    
    	spin_lock_irqsave(&sport->port.lock, flags);
    
    	writel(USR1_RTSD, sport->port.membase + USR1);
    	val = readl(sport->port.membase + USR1) & USR1_RTSS;
    	uart_handle_cts_change(&sport->port, !!val);
    	wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
    
    	spin_unlock_irqrestore(&sport->port.lock, flags);
    	return IRQ_HANDLED;
    }
    
    static irqreturn_t imx_txint(int irq, void *dev_id)
    {
    	struct imx_port *sport = dev_id;
    	struct circ_buf *xmit = &sport->port.state->xmit;
    	unsigned long flags;
    
    	spin_lock_irqsave(&sport->port.lock,flags);
    	if (sport->port.x_char)
    	{
    		/* Send next char */
    		writel(sport->port.x_char, sport->port.membase + URTX0);
    		goto out;
    	}
    
    	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
    		imx_stop_tx(&sport->port);
    		goto out;
    	}
    
    	imx_transmit_buffer(sport);
    
    	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
    		uart_write_wakeup(&sport->port);
    
    out:
    	spin_unlock_irqrestore(&sport->port.lock,flags);
    	return IRQ_HANDLED;
    }
    
    static irqreturn_t imx_rxint(int irq, void *dev_id)
    {
    	struct imx_port *sport = dev_id;
    	unsigned int rx,flg,ignored = 0;
    	struct tty_struct *tty = sport->port.state->port.tty;
    	unsigned long flags, temp;
    
    	spin_lock_irqsave(&sport->port.lock,flags);
    
    	while (readl(sport->port.membase + USR2) & USR2_RDR) {
    		flg = TTY_NORMAL;
    		sport->port.icount.rx++;
    
    		rx = readl(sport->port.membase + URXD0);
    
    		temp = readl(sport->port.membase + USR2);
    		if (temp & USR2_BRCD) {
    			writel(USR2_BRCD, sport->port.membase + USR2);
    			if (uart_handle_break(&sport->port))
    				continue;
    		}
    
    		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
    			continue;
    
    		if (unlikely(rx & URXD_ERR)) {
    			if (rx & URXD_BRK)
    				sport->port.icount.brk++;
    			else if (rx & URXD_PRERR)
    				sport->port.icount.parity++;
    			else if (rx & URXD_FRMERR)
    				sport->port.icount.frame++;
    			if (rx & URXD_OVRRUN)
    				sport->port.icount.overrun++;
    
    			if (rx & sport->port.ignore_status_mask) {
    				if (++ignored > 100)
    					goto out;
    				continue;
    			}
    
    			rx &= sport->port.read_status_mask;
    
    			if (rx & URXD_BRK)
    				flg = TTY_BREAK;
    			else if (rx & URXD_PRERR)
    				flg = TTY_PARITY;
    			else if (rx & URXD_FRMERR)
    				flg = TTY_FRAME;
    			if (rx & URXD_OVRRUN)
    				flg = TTY_OVERRUN;
    
    #ifdef SUPPORT_SYSRQ
    			sport->port.sysrq = 0;
    #endif
    		}
    
    		tty_insert_flip_char(tty, rx, flg);
    	}
    
    out:
    	spin_unlock_irqrestore(&sport->port.lock,flags);
    	tty_flip_buffer_push(tty);
    	return IRQ_HANDLED;
    }
    
    static irqreturn_t imx_int(int irq, void *dev_id)
    {
    	struct imx_port *sport = dev_id;
    	unsigned int sts;
    
    	sts = readl(sport->port.membase + USR1);
    
    	if (sts & USR1_RRDY)
    		imx_rxint(irq, dev_id);
    
    	if (sts & USR1_TRDY &&
    			readl(sport->port.membase + UCR1) & UCR1_TXMPTYEN)
    		imx_txint(irq, dev_id);
    
    	if (sts & USR1_RTSD)
    		imx_rtsint(irq, dev_id);
    
    	if (sts & USR1_AWAKE)
    		writel(USR1_AWAKE, sport->port.membase + USR1);
    
    	return IRQ_HANDLED;
    }
    
    /*
     * Return TIOCSER_TEMT when transmitter is not busy.
     */
    static unsigned int imx_tx_empty(struct uart_port *port)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    
    	return (readl(sport->port.membase + USR2) & USR2_TXDC) ?  TIOCSER_TEMT : 0;
    }
    
    /*
     * We have a modem side uart, so the meanings of RTS and CTS are inverted.
     */
    static unsigned int imx_get_mctrl(struct uart_port *port)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	unsigned int tmp = TIOCM_DSR | TIOCM_CAR;
    
    	if (readl(sport->port.membase + USR1) & USR1_RTSS)
    		tmp |= TIOCM_CTS;
    
    	if (readl(sport->port.membase + UCR2) & UCR2_CTS)
    		tmp |= TIOCM_RTS;
    
    	return tmp;
    }
    
    static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	unsigned long temp;
    
    	temp = readl(sport->port.membase + UCR2) & ~UCR2_CTS;
    
    	if (mctrl & TIOCM_RTS)
    		temp |= UCR2_CTS;
    
    	writel(temp, sport->port.membase + UCR2);
    }
    
    /*
     * Interrupts always disabled.
     */
    static void imx_break_ctl(struct uart_port *port, int break_state)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	unsigned long flags, temp;
    
    	spin_lock_irqsave(&sport->port.lock, flags);
    
    	temp = readl(sport->port.membase + UCR1) & ~UCR1_SNDBRK;
    
    	if ( break_state != 0 )
    		temp |= UCR1_SNDBRK;
    
    	writel(temp, sport->port.membase + UCR1);
    
    	spin_unlock_irqrestore(&sport->port.lock, flags);
    }
    
    #define TXTL 2 /* reset default */
    #define RXTL 1 /* reset default */
    
    static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
    {
    	unsigned int val;
    	unsigned int ufcr_rfdiv;
    
    	/* set receiver / transmitter trigger level.
    	 * RFDIV is set such way to satisfy requested uartclk value
    	 */
    	val = TXTL << 10 | RXTL;
    	ufcr_rfdiv = (clk_get_rate(sport->clk_per) + sport->port.uartclk / 2)
    			/ sport->port.uartclk;
    
    	if(!ufcr_rfdiv)
    		ufcr_rfdiv = 1;
    
    	val |= UFCR_RFDIV_REG(ufcr_rfdiv);
    
    	writel(val, sport->port.membase + UFCR);
    
    	return 0;
    }
    
    /* half the RX buffer size */
    #define CTSTL 16
    
    static int imx_startup(struct uart_port *port)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	int retval;
    	unsigned long flags, temp;
    
    	imx_setup_ufcr(sport, 0);
    
    	/* disable the DREN bit (Data Ready interrupt enable) before
    	 * requesting IRQs
    	 */
    	temp = readl(sport->port.membase + UCR4);
    
    	if (USE_IRDA(sport))
    		temp |= UCR4_IRSC;
    
    	/* set the trigger level for CTS */
    	temp &= ~(UCR4_CTSTL_MASK<<  UCR4_CTSTL_SHF);
    	temp |= CTSTL<<  UCR4_CTSTL_SHF;
    
    	writel(temp & ~UCR4_DREN, sport->port.membase + UCR4);
    
    	if (USE_IRDA(sport)) {
    		/* reset fifo's and state machines */
    		int i = 100;
    		temp = readl(sport->port.membase + UCR2);
    		temp &= ~UCR2_SRST;
    		writel(temp, sport->port.membase + UCR2);
    		while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) &&
    		    (--i > 0)) {
    			udelay(1);
    		}
    	}
    
    	/*
    	 * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
    	 * chips only have one interrupt.
    	 */
    	if (sport->txirq > 0) {
    		retval = request_irq(sport->rxirq, imx_rxint, 0,
    				DRIVER_NAME, sport);
    		if (retval)
    			goto error_out1;
    
    		retval = request_irq(sport->txirq, imx_txint, 0,
    				DRIVER_NAME, sport);
    		if (retval)
    			goto error_out2;
    
    		/* do not use RTS IRQ on IrDA */
    		if (!USE_IRDA(sport)) {
    			retval = request_irq(sport->rtsirq, imx_rtsint, 0,
    					DRIVER_NAME, sport);
    			if (retval)
    				goto error_out3;
    		}
    	} else {
    		retval = request_irq(sport->port.irq, imx_int, 0,
    				DRIVER_NAME, sport);
    		if (retval) {
    			free_irq(sport->port.irq, sport);
    			goto error_out1;
    		}
    	}
    
    	spin_lock_irqsave(&sport->port.lock, flags);
    	/*
    	 * Finally, clear and enable interrupts
    	 */
    	writel(USR1_RTSD, sport->port.membase + USR1);
    
    	temp = readl(sport->port.membase + UCR1);
    	temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN;
    
    	if (USE_IRDA(sport)) {
    		temp |= UCR1_IREN;
    		temp &= ~(UCR1_RTSDEN);
    	}
    
    	writel(temp, sport->port.membase + UCR1);
    
    	temp = readl(sport->port.membase + UCR2);
    	temp |= (UCR2_RXEN | UCR2_TXEN);
    	writel(temp, sport->port.membase + UCR2);
    
    	if (USE_IRDA(sport)) {
    		/* clear RX-FIFO */
    		int i = 64;
    		while ((--i > 0) &&
    			(readl(sport->port.membase + URXD0) & URXD_CHARRDY)) {
    			barrier();
    		}
    	}
    
    	if (is_imx21_uart(sport)) {
    		temp = readl(sport->port.membase + UCR3);
    		temp |= IMX21_UCR3_RXDMUXSEL;
    		writel(temp, sport->port.membase + UCR3);
    	}
    
    	if (USE_IRDA(sport)) {
    		temp = readl(sport->port.membase + UCR4);
    		if (sport->irda_inv_rx)
    			temp |= UCR4_INVR;
    		else
    			temp &= ~(UCR4_INVR);
    		writel(temp | UCR4_DREN, sport->port.membase + UCR4);
    
    		temp = readl(sport->port.membase + UCR3);
    		if (sport->irda_inv_tx)
    			temp |= UCR3_INVT;
    		else
    			temp &= ~(UCR3_INVT);
    		writel(temp, sport->port.membase + UCR3);
    	}
    
    	/*
    	 * Enable modem status interrupts
    	 */
    	imx_enable_ms(&sport->port);
    	spin_unlock_irqrestore(&sport->port.lock,flags);
    
    	if (USE_IRDA(sport)) {
    		struct imxuart_platform_data *pdata;
    		pdata = sport->port.dev->platform_data;
    		sport->irda_inv_rx = pdata->irda_inv_rx;
    		sport->irda_inv_tx = pdata->irda_inv_tx;
    		sport->trcv_delay = pdata->transceiver_delay;
    		if (pdata->irda_enable)
    			pdata->irda_enable(1);
    	}
    
    	return 0;
    
    error_out3:
    	if (sport->txirq)
    		free_irq(sport->txirq, sport);
    error_out2:
    	if (sport->rxirq)
    		free_irq(sport->rxirq, sport);
    error_out1:
    	return retval;
    }
    
    static void imx_shutdown(struct uart_port *port)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	unsigned long temp;
    	unsigned long flags;
    
    	spin_lock_irqsave(&sport->port.lock, flags);
    	temp = readl(sport->port.membase + UCR2);
    	temp &= ~(UCR2_TXEN);
    	writel(temp, sport->port.membase + UCR2);
    	spin_unlock_irqrestore(&sport->port.lock, flags);
    
    	if (USE_IRDA(sport)) {
    		struct imxuart_platform_data *pdata;
    		pdata = sport->port.dev->platform_data;
    		if (pdata->irda_enable)
    			pdata->irda_enable(0);
    	}
    
    	/*
    	 * Stop our timer.
    	 */
    	del_timer_sync(&sport->timer);
    
    	/*
    	 * Free the interrupts
    	 */
    	if (sport->txirq > 0) {
    		if (!USE_IRDA(sport))
    			free_irq(sport->rtsirq, sport);
    		free_irq(sport->txirq, sport);
    		free_irq(sport->rxirq, sport);
    	} else
    		free_irq(sport->port.irq, sport);
    
    	/*
    	 * Disable all interrupts, port and break condition.
    	 */
    
    	spin_lock_irqsave(&sport->port.lock, flags);
    	temp = readl(sport->port.membase + UCR1);
    	temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN);
    	if (USE_IRDA(sport))
    		temp &= ~(UCR1_IREN);
    
    	writel(temp, sport->port.membase + UCR1);
    	spin_unlock_irqrestore(&sport->port.lock, flags);
    }
    
    static void
    imx_set_termios(struct uart_port *port, struct ktermios *termios,
    		   struct ktermios *old)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	unsigned long flags;
    	unsigned int ucr2, old_ucr1, old_txrxen, baud, quot;
    	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
    	unsigned int div, ufcr;
    	unsigned long num, denom;
    	uint64_t tdiv64;
    
    	/*
    	 * If we don't support modem control lines, don't allow
    	 * these to be set.
    	 */
    	if (0) {
    		termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
    		termios->c_cflag |= CLOCAL;
    	}
    
    	/*
    	 * We only support CS7 and CS8.
    	 */
    	while ((termios->c_cflag & CSIZE) != CS7 &&
    	       (termios->c_cflag & CSIZE) != CS8) {
    		termios->c_cflag &= ~CSIZE;
    		termios->c_cflag |= old_csize;
    		old_csize = CS8;
    	}
    
    	if ((termios->c_cflag & CSIZE) == CS8)
    		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
    	else
    		ucr2 = UCR2_SRST | UCR2_IRTS;
    
    	if (termios->c_cflag & CRTSCTS) {
    		if( sport->have_rtscts ) {
    			ucr2 &= ~UCR2_IRTS;
    			ucr2 |= UCR2_CTSC;
    		} else {
    			termios->c_cflag &= ~CRTSCTS;
    		}
    	}
    
    	if (termios->c_cflag & CSTOPB)
    		ucr2 |= UCR2_STPB;
    	if (termios->c_cflag & PARENB) {
    		ucr2 |= UCR2_PREN;
    		if (termios->c_cflag & PARODD)
    			ucr2 |= UCR2_PROE;
    	}
    
    	del_timer_sync(&sport->timer);
    
    	/*
    	 * Ask the core to calculate the divisor for us.
    	 */
    	baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
    	quot = uart_get_divisor(port, baud);
    
    	spin_lock_irqsave(&sport->port.lock, flags);
    
    	sport->port.read_status_mask = 0;
    	if (termios->c_iflag & INPCK)
    		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
    	if (termios->c_iflag & (BRKINT | PARMRK))
    		sport->port.read_status_mask |= URXD_BRK;
    
    	/*
    	 * Characters to ignore
    	 */
    	sport->port.ignore_status_mask = 0;
    	if (termios->c_iflag & IGNPAR)
    		sport->port.ignore_status_mask |= URXD_PRERR;
    	if (termios->c_iflag & IGNBRK) {
    		sport->port.ignore_status_mask |= URXD_BRK;
    		/*
    		 * If we're ignoring parity and break indicators,
    		 * ignore overruns too (for real raw support).
    		 */
    		if (termios->c_iflag & IGNPAR)
    			sport->port.ignore_status_mask |= URXD_OVRRUN;
    	}
    
    	/*
    	 * Update the per-port timeout.
    	 */
    	uart_update_timeout(port, termios->c_cflag, baud);
    
    	/*
    	 * disable interrupts and drain transmitter
    	 */
    	old_ucr1 = readl(sport->port.membase + UCR1);
    	writel(old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
    			sport->port.membase + UCR1);
    
    	while ( !(readl(sport->port.membase + USR2) & USR2_TXDC))
    		barrier();
    
    	/* then, disable everything */
    	old_txrxen = readl(sport->port.membase + UCR2);
    	writel(old_txrxen & ~( UCR2_TXEN | UCR2_RXEN),
    			sport->port.membase + UCR2);
    	old_txrxen &= (UCR2_TXEN | UCR2_RXEN);
    
    	if (USE_IRDA(sport)) {
    		/*
    		 * use maximum available submodule frequency to
    		 * avoid missing short pulses due to low sampling rate
    		 */
    		div = 1;
    	} else {
    		div = sport->port.uartclk / (baud * 16);
    		if (div > 7)
    			div = 7;
    		if (!div)
    			div = 1;
    	}
    
    	rational_best_approximation(16 * div * baud, sport->port.uartclk,
    		1 << 16, 1 << 16, &num, &denom);
    
    	tdiv64 = sport->port.uartclk;
    	tdiv64 *= num;
    	do_div(tdiv64, denom * 16 * div);
    	tty_termios_encode_baud_rate(termios,
    				(speed_t)tdiv64, (speed_t)tdiv64);
    
    	num -= 1;
    	denom -= 1;
    
    	ufcr = readl(sport->port.membase + UFCR);
    	ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
    	writel(ufcr, sport->port.membase + UFCR);
    
    	writel(num, sport->port.membase + UBIR);
    	writel(denom, sport->port.membase + UBMR);
    
    	if (is_imx21_uart(sport))
    		writel(sport->port.uartclk / div / 1000,
    				sport->port.membase + IMX21_ONEMS);
    
    	writel(old_ucr1, sport->port.membase + UCR1);
    
    	/* set the parity, stop bits and data size */
    	writel(ucr2 | old_txrxen, sport->port.membase + UCR2);
    
    	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
    		imx_enable_ms(&sport->port);
    
    	spin_unlock_irqrestore(&sport->port.lock, flags);
    }
    
    static const char *imx_type(struct uart_port *port)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    
    	return sport->port.type == PORT_IMX ? "IMX" : NULL;
    }
    
    /*
     * Release the memory region(s) being used by 'port'.
     */
    static void imx_release_port(struct uart_port *port)
    {
    	struct platform_device *pdev = to_platform_device(port->dev);
    	struct resource *mmres;
    
    	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    	release_mem_region(mmres->start, resource_size(mmres));
    }
    
    /*
     * Request the memory region(s) being used by 'port'.
     */
    static int imx_request_port(struct uart_port *port)
    {
    	struct platform_device *pdev = to_platform_device(port->dev);
    	struct resource *mmres;
    	void *ret;
    
    	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    	if (!mmres)
    		return -ENODEV;
    
    	ret = request_mem_region(mmres->start, resource_size(mmres), "imx-uart");
    
    	return  ret ? 0 : -EBUSY;
    }
    
    /*
     * Configure/autoconfigure the port.
     */
    static void imx_config_port(struct uart_port *port, int flags)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    
    	if (flags & UART_CONFIG_TYPE &&
    	    imx_request_port(&sport->port) == 0)
    		sport->port.type = PORT_IMX;
    }
    
    /*
     * Verify the new serial_struct (for TIOCSSERIAL).
     * The only change we allow are to the flags and type, and
     * even then only between PORT_IMX and PORT_UNKNOWN
     */
    static int
    imx_verify_port(struct uart_port *port, struct serial_struct *ser)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    	int ret = 0;
    
    	if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
    		ret = -EINVAL;
    	if (sport->port.irq != ser->irq)
    		ret = -EINVAL;
    	if (ser->io_type != UPIO_MEM)
    		ret = -EINVAL;
    	if (sport->port.uartclk / 16 != ser->baud_base)
    		ret = -EINVAL;
    	if ((void *)sport->port.mapbase != ser->iomem_base)
    		ret = -EINVAL;
    	if (sport->port.iobase != ser->port)
    		ret = -EINVAL;
    	if (ser->hub6 != 0)
    		ret = -EINVAL;
    	return ret;
    }
    
    #if defined(CONFIG_CONSOLE_POLL)
    static int imx_poll_get_char(struct uart_port *port)
    {
    	struct imx_port_ucrs old_ucr;
    	unsigned int status;
    	unsigned char c;
    
    	/* save control registers */
    	imx_port_ucrs_save(port, &old_ucr);
    
    	/* disable interrupts */
    	writel(UCR1_UARTEN, port->membase + UCR1);
    	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
    	       port->membase + UCR2);
    	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
    	       port->membase + UCR3);
    
    	/* poll */
    	do {
    		status = readl(port->membase + USR2);
    	} while (~status & USR2_RDR);
    
    	/* read */
    	c = readl(port->membase + URXD0);
    
    	/* restore control registers */
    	imx_port_ucrs_restore(port, &old_ucr);
    
    	return c;
    }
    
    static void imx_poll_put_char(struct uart_port *port, unsigned char c)
    {
    	struct imx_port_ucrs old_ucr;
    	unsigned int status;
    
    	/* save control registers */
    	imx_port_ucrs_save(port, &old_ucr);
    
    	/* disable interrupts */
    	writel(UCR1_UARTEN, port->membase + UCR1);
    	writel(old_ucr.ucr2 & ~(UCR2_ATEN | UCR2_RTSEN | UCR2_ESCI),
    	       port->membase + UCR2);
    	writel(old_ucr.ucr3 & ~(UCR3_DCD | UCR3_RI | UCR3_DTREN),
    	       port->membase + UCR3);
    
    	/* drain */
    	do {
    		status = readl(port->membase + USR1);
    	} while (~status & USR1_TRDY);
    
    	/* write */
    	writel(c, port->membase + URTX0);
    
    	/* flush */
    	do {
    		status = readl(port->membase + USR2);
    	} while (~status & USR2_TXDC);
    
    	/* restore control registers */
    	imx_port_ucrs_restore(port, &old_ucr);
    }
    #endif
    
    static struct uart_ops imx_pops = {
    	.tx_empty	= imx_tx_empty,
    	.set_mctrl	= imx_set_mctrl,
    	.get_mctrl	= imx_get_mctrl,
    	.stop_tx	= imx_stop_tx,
    	.start_tx	= imx_start_tx,
    	.stop_rx	= imx_stop_rx,
    	.enable_ms	= imx_enable_ms,
    	.break_ctl	= imx_break_ctl,
    	.startup	= imx_startup,
    	.shutdown	= imx_shutdown,
    	.set_termios	= imx_set_termios,
    	.type		= imx_type,
    	.release_port	= imx_release_port,
    	.request_port	= imx_request_port,
    	.config_port	= imx_config_port,
    	.verify_port	= imx_verify_port,
    #if defined(CONFIG_CONSOLE_POLL)
    	.poll_get_char  = imx_poll_get_char,
    	.poll_put_char  = imx_poll_put_char,
    #endif
    };
    
    static struct imx_port *imx_ports[UART_NR];
    
    #ifdef CONFIG_SERIAL_IMX_CONSOLE
    static void imx_console_putchar(struct uart_port *port, int ch)
    {
    	struct imx_port *sport = (struct imx_port *)port;
    
    	while (readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)
    		barrier();
    
    	writel(ch, sport->port.membase + URTX0);
    }
    
    /*
     * Interrupts are disabled on entering
     */
    static void
    imx_console_write(struct console *co, const char *s, unsigned int count)
    {
    	struct imx_port *sport = imx_ports[co->index];
    	struct imx_port_ucrs old_ucr;
    	unsigned int ucr1;
    	unsigned long flags;
    
    	spin_lock_irqsave(&sport->port.lock, flags);
    
    	/*
    	 *	First, save UCR1/2/3 and then disable interrupts
    	 */
    	imx_port_ucrs_save(&sport->port, &old_ucr);
    	ucr1 = old_ucr.ucr1;
    
    	if (is_imx1_uart(sport))
    		ucr1 |= IMX1_UCR1_UARTCLKEN;
    	ucr1 |= UCR1_UARTEN;
    	ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
    
    	writel(ucr1, sport->port.membase + UCR1);
    
    	writel(old_ucr.ucr2 | UCR2_TXEN, sport->port.membase + UCR2);
    
    	uart_console_write(&sport->port, s, count, imx_console_putchar);
    
    	/*
    	 *	Finally, wait for transmitter to become empty
    	 *	and restore UCR1/2/3
    	 */
    	while (!(readl(sport->port.membase + USR2) & USR2_TXDC));
    
    	imx_port_ucrs_restore(&sport->port, &old_ucr);
    
    	spin_unlock_irqrestore(&sport->port.lock, flags);
    }
    
    /*
     * If the port was already initialised (eg, by a boot loader),
     * try to determine the current setup.
     */
    static void __init
    imx_console_get_options(struct imx_port *sport, int *baud,
    			   int *parity, int *bits)
    {
    
    	if (readl(sport->port.membase + UCR1) & UCR1_UARTEN) {
    		/* ok, the port was enabled */
    		unsigned int ucr2, ubir,ubmr, uartclk;
    		unsigned int baud_raw;
    		unsigned int ucfr_rfdiv;
    
    		ucr2 = readl(sport->port.membase + UCR2);
    
    		*parity = 'n';
    		if (ucr2 & UCR2_PREN) {
    			if (ucr2 & UCR2_PROE)
    				*parity = 'o';
    			else
    				*parity = 'e';
    		}
    
    		if (ucr2 & UCR2_WS)
    			*bits = 8;
    		else
    			*bits = 7;
    
    		ubir = readl(sport->port.membase + UBIR) & 0xffff;
    		ubmr = readl(sport->port.membase + UBMR) & 0xffff;
    
    		ucfr_rfdiv = (readl(sport->port.membase + UFCR) & UFCR_RFDIV) >> 7;
    		if (ucfr_rfdiv == 6)
    			ucfr_rfdiv = 7;
    		else
    			ucfr_rfdiv = 6 - ucfr_rfdiv;
    
    		uartclk = clk_get_rate(sport->clk_per);
    		uartclk /= ucfr_rfdiv;
    
    		{	/*
    			 * The next code provides exact computation of
    			 *   baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
    			 * without need of float support or long long division,
    			 * which would be required to prevent 32bit arithmetic overflow
    			 */
    			unsigned int mul = ubir + 1;
    			unsigned int div = 16 * (ubmr + 1);
    			unsigned int rem = uartclk % div;
    
    			baud_raw = (uartclk / div) * mul;
    			baud_raw += (rem * mul + div / 2) / div;
    			*baud = (baud_raw + 50) / 100 * 100;
    		}
    
    		if(*baud != baud_raw)
    			printk(KERN_INFO "Serial: Console IMX rounded baud rate from %d to %d\n",
    				baud_raw, *baud);
    	}
    }
    
    static int __init
    imx_console_setup(struct console *co, char *options)
    {
    	struct imx_port *sport;
    	int baud = 9600;
    	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 == -1 || co->index >= ARRAY_SIZE(imx_ports))
    		co->index = 0;
    	sport = imx_ports[co->index];
    	if(sport == NULL)
    		return -ENODEV;
    
    	if (options)
    		uart_parse_options(options, &baud, &parity, &bits, &flow);
    	else
    		imx_console_get_options(sport, &baud, &parity, &bits);
    
    	imx_setup_ufcr(sport, 0);
    
    	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
    }
    
    static struct uart_driver imx_reg;
    static struct console imx_console = {
    	.name		= DEV_NAME,
    	.write		= imx_console_write,
    	.device		= uart_console_device,
    	.setup		= imx_console_setup,
    	.flags		= CON_PRINTBUFFER,
    	.index		= -1,
    	.data		= &imx_reg,
    };
    
    #define IMX_CONSOLE	&imx_console
    #else
    #define IMX_CONSOLE	NULL
    #endif
    
    static struct uart_driver imx_reg = {
    	.owner          = THIS_MODULE,
    	.driver_name    = DRIVER_NAME,
    	.dev_name       = DEV_NAME,
    	.major          = SERIAL_IMX_MAJOR,
    	.minor          = MINOR_START,
    	.nr             = ARRAY_SIZE(imx_ports),
    	.cons           = IMX_CONSOLE,
    };
    
    static int serial_imx_suspend(struct platform_device *dev, pm_message_t state)
    {
    	struct imx_port *sport = platform_get_drvdata(dev);
    	unsigned int val;
    
    	/* enable wakeup from i.MX UART */
    	val = readl(sport->port.membase + UCR3);
    	val |= UCR3_AWAKEN;
    	writel(val, sport->port.membase + UCR3);
    
    	if (sport)
    		uart_suspend_port(&imx_reg, &sport->port);
    
    	return 0;
    }
    
    static int serial_imx_resume(struct platform_device *dev)
    {
    	struct imx_port *sport = platform_get_drvdata(dev);
    	unsigned int val;
    
    	/* disable wakeup from i.MX UART */
    	val = readl(sport->port.membase + UCR3);
    	val &= ~UCR3_AWAKEN;
    	writel(val, sport->port.membase + UCR3);
    
    	if (sport)
    		uart_resume_port(&imx_reg, &sport->port);
    
    	return 0;
    }
    
    #ifdef CONFIG_OF
    /*
     * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
     * could successfully get all information from dt or a negative errno.
     */
    static int serial_imx_probe_dt(struct imx_port *sport,
    		struct platform_device *pdev)
    {
    	struct device_node *np = pdev->dev.of_node;
    	const struct of_device_id *of_id =
    			of_match_device(imx_uart_dt_ids, &pdev->dev);
    	int ret;
    
    	if (!np)
    		/* no device tree device */
    		return 1;
    
    	ret = of_alias_get_id(np, "serial");
    	if (ret < 0) {
    		dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
    		return ret;
    	}
    	sport->port.line = ret;
    
    	if (of_get_property(np, "fsl,uart-has-rtscts", NULL))
    		sport->have_rtscts = 1;
    
    	if (of_get_property(np, "fsl,irda-mode", NULL))
    		sport->use_irda = 1;
    
    	sport->devdata = of_id->data;
    
    	return 0;
    }
    #else
    static inline int serial_imx_probe_dt(struct imx_port *sport,
    		struct platform_device *pdev)
    {
    	return 1;
    }
    #endif
    
    static void serial_imx_probe_pdata(struct imx_port *sport,
    		struct platform_device *pdev)
    {
    	struct imxuart_platform_data *pdata = pdev->dev.platform_data;
    
    	sport->port.line = pdev->id;
    	sport->devdata = (struct imx_uart_data	*) pdev->id_entry->driver_data;
    
    	if (!pdata)
    		return;
    
    	if (pdata->flags & IMXUART_HAVE_RTSCTS)
    		sport->have_rtscts = 1;
    
    	if (pdata->flags & IMXUART_IRDA)
    		sport->use_irda = 1;
    }
    
    static int serial_imx_probe(struct platform_device *pdev)
    {
    	struct imx_port *sport;
    	struct imxuart_platform_data *pdata;
    	void __iomem *base;
    	int ret = 0;
    	struct resource *res;
    	struct pinctrl *pinctrl;
    
    	sport = kzalloc(sizeof(*sport), GFP_KERNEL);
    	if (!sport)
    		return -ENOMEM;
    
    	ret = serial_imx_probe_dt(sport, pdev);
    	if (ret > 0)
    		serial_imx_probe_pdata(sport, pdev);
    	else if (ret < 0)
    		goto free;
    
    	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    	if (!res) {
    		ret = -ENODEV;
    		goto free;
    	}
    
    	base = ioremap(res->start, PAGE_SIZE);
    	if (!base) {
    		ret = -ENOMEM;
    		goto free;
    	}
    
    	sport->port.dev = &pdev->dev;
    	sport->port.mapbase = res->start;
    	sport->port.membase = base;
    	sport->port.type = PORT_IMX,
    	sport->port.iotype = UPIO_MEM;
    	sport->port.irq = platform_get_irq(pdev, 0);
    	sport->rxirq = platform_get_irq(pdev, 0);
    	sport->txirq = platform_get_irq(pdev, 1);
    	sport->rtsirq = platform_get_irq(pdev, 2);
    	sport->port.fifosize = 32;
    	sport->port.ops = &imx_pops;
    	sport->port.flags = UPF_BOOT_AUTOCONF;
    	init_timer(&sport->timer);
    	sport->timer.function = imx_timeout;
    	sport->timer.data     = (unsigned long)sport;
    
    	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
    	if (IS_ERR(pinctrl)) {
    		ret = PTR_ERR(pinctrl);
    		goto unmap;
    	}
    
    	sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
    	if (IS_ERR(sport->clk_ipg)) {
    		ret = PTR_ERR(sport->clk_ipg);
    		goto unmap;
    	}
    
    	sport->clk_per = devm_clk_get(&pdev->dev, "per");
    	if (IS_ERR(sport->clk_per)) {
    		ret = PTR_ERR(sport->clk_per);
    		goto unmap;
    	}
    
    	clk_prepare_enable(sport->clk_per);
    	clk_prepare_enable(sport->clk_ipg);
    
    	sport->port.uartclk = clk_get_rate(sport->clk_per);
    
    	imx_ports[sport->port.line] = sport;
    
    	pdata = pdev->dev.platform_data;
    	if (pdata && pdata->init) {
    		ret = pdata->init(pdev);
    		if (ret)
    			goto clkput;
    	}
    
    	ret = uart_add_one_port(&imx_reg, &sport->port);
    	if (ret)
    		goto deinit;
    	platform_set_drvdata(pdev, &sport->port);
    
    	return 0;
    deinit:
    	if (pdata && pdata->exit)
    		pdata->exit(pdev);
    clkput:
    	clk_disable_unprepare(sport->clk_per);
    	clk_disable_unprepare(sport->clk_ipg);
    unmap:
    	iounmap(sport->port.membase);
    free:
    	kfree(sport);
    
    	return ret;
    }
    
    static int serial_imx_remove(struct platform_device *pdev)
    {
    	struct imxuart_platform_data *pdata;
    	struct imx_port *sport = platform_get_drvdata(pdev);
    
    	pdata = pdev->dev.platform_data;
    
    	platform_set_drvdata(pdev, NULL);
    
    	uart_remove_one_port(&imx_reg, &sport->port);
    
    	clk_disable_unprepare(sport->clk_per);
    	clk_disable_unprepare(sport->clk_ipg);
    
    	if (pdata && pdata->exit)
    		pdata->exit(pdev);
    
    	iounmap(sport->port.membase);
    	kfree(sport);
    
    	return 0;
    }
    
    static struct platform_driver serial_imx_driver = {
    	.probe		= serial_imx_probe,
    	.remove		= serial_imx_remove,
    
    	.suspend	= serial_imx_suspend,
    	.resume		= serial_imx_resume,
    	.id_table	= imx_uart_devtype,
    	.driver		= {
    		.name	= "imx-uart",
    		.owner	= THIS_MODULE,
    		.of_match_table = imx_uart_dt_ids,
    	},
    };
    
    static int __init imx_serial_init(void)
    {
    	int ret;
    
    	printk(KERN_INFO "Serial: IMX driver\n");
    
    	ret = uart_register_driver(&imx_reg);
    	if (ret)
    		return ret;
    
    	ret = platform_driver_register(&serial_imx_driver);
    	if (ret != 0)
    		uart_unregister_driver(&imx_reg);
    
    	return ret;
    }
    
    static void __exit imx_serial_exit(void)
    {
    	platform_driver_unregister(&serial_imx_driver);
    	uart_unregister_driver(&imx_reg);
    }
    
    module_init(imx_serial_init);
    module_exit(imx_serial_exit);
    
    MODULE_AUTHOR("Sascha Hauer");
    MODULE_DESCRIPTION("IMX generic serial port driver");
    MODULE_LICENSE("GPL");
    MODULE_ALIAS("platform:imx-uart");