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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Serial driver for the amiga builtin port.
  *
  * This code was created by taking serial.c version 4.30 from kernel
  * release 2.3.22, replacing all hardware related stuff with the
  * corresponding amiga hardware actions, and removing all irrelevant
  * code. As a consequence, it uses many of the constants and names
  * associated with the registers and bits of 16550 compatible UARTS -
  * but only to keep track of status, etc in the state variables. It
  * was done this was to make it easier to keep the code in line with
  * (non hardware specific) changes to serial.c.
  *
  * The port is registered with the tty driver as minor device 64, and
  * therefore other ports should only use 65 upwards.
  *
  * Richard Lucock 28/12/99
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *  Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 
  *      1998, 1999  Theodore Ts'o
  *
  */
 
 /* Set of debugging defines */
 
 #undef SERIAL_DEBUG_INTR
 #undef SERIAL_DEBUG_OPEN
 #undef SERIAL_DEBUG_FLOW
 #undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
 
 /*
  * End of serial driver configuration section.
  */
 
 #include <linux/bitops.h>
 #include <linux/circ_buf.h>
 #include <linux/console.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/fcntl.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/kernel.h>
 #include <linux/major.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/ptrace.h>
 #include <linux/seq_file.h>
 #include <linux/serial.h>
 #include <linux/serial_reg.h>
 #include <linux/serial_core.h>
 #include <linux/sched.h>
 #include <linux/signal.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/timer.h>
 #include <linux/tty_flip.h>
 #include <linux/tty.h>
 #include <linux/types.h>
 #include <linux/uaccess.h>
 
 #include <asm/amigahw.h>
 #include <asm/amigaints.h>
 #include <asm/irq.h>
 #include <asm/setup.h>
 
 struct serial_state {
     struct tty_port     tport;
     struct circ_buf     xmit;
     struct async_icount icount;
 
     unsigned long       port;
     int         baud_base;
     int         custom_divisor;
     int         read_status_mask;
     int         ignore_status_mask;
     int         timeout;
     int         quot;
     int         IER;    /* Interrupt Enable Register */
     int         MCR;    /* Modem control register */
     int         x_char; /* xon/xoff character */
 };
 
 static struct tty_driver *serial_driver;
 
 /* number of characters left in xmit buffer before we ask for more */
 #define WAKEUP_CHARS 256
 
 #define XMIT_FIFO_SIZE 1
 
 static unsigned char current_ctl_bits;
 
 static void change_speed(struct tty_struct *tty, struct serial_state *info,
         struct ktermios *old);
 static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
 
 
 static struct serial_state serial_state;
 
 /* some serial hardware definitions */
 #define SDR_OVRUN   (1<<15)
 #define SDR_RBF     (1<<14)
 #define SDR_TBE     (1<<13)
 #define SDR_TSRE    (1<<12)
 
 #define SERPER_PARENB    (1<<15)
 
 #define AC_SETCLR   (1<<15)
 #define AC_UARTBRK  (1<<11)
 
 #define SER_DTR     (1<<7)
 #define SER_RTS     (1<<6)
 #define SER_DCD     (1<<5)
 #define SER_CTS     (1<<4)
 #define SER_DSR     (1<<3)
 
 static __inline__ void rtsdtr_ctrl(int bits)
 {
     ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
 }
 
 /*
  * ------------------------------------------------------------
  * rs_stop() and rs_start()
  *
  * This routines are called before setting or resetting tty->flow.stopped.
  * They enable or disable transmitter interrupts, as necessary.
  * ------------------------------------------------------------
  */
 static void rs_stop(struct tty_struct *tty)
 {
     struct serial_state *info = tty->driver_data;
     unsigned long flags;
 
     local_irq_save(flags);
     if (info->IER & UART_IER_THRI) {
         info->IER &= ~UART_IER_THRI;
         /* disable Tx interrupt and remove any pending interrupts */
         amiga_custom.intena = IF_TBE;
         mb();
         amiga_custom.intreq = IF_TBE;
         mb();
     }
     local_irq_restore(flags);
 }
 
 static void rs_start(struct tty_struct *tty)
 {
     struct serial_state *info = tty->driver_data;
     unsigned long flags;
 
     local_irq_save(flags);
     if (info->xmit.head != info->xmit.tail
         && info->xmit.buf
         && !(info->IER & UART_IER_THRI)) {
         info->IER |= UART_IER_THRI;
         amiga_custom.intena = IF_SETCLR | IF_TBE;
         mb();
         /* set a pending Tx Interrupt, transmitter should restart now */
         amiga_custom.intreq = IF_SETCLR | IF_TBE;
         mb();
     }
     local_irq_restore(flags);
 }
 
 /*
  * ----------------------------------------------------------------------
  *
  * Here start the interrupt handling routines.
  *
  * -----------------------------------------------------------------------
  */
 
 static void receive_chars(struct serial_state *info)
 {
         int status;
     int serdatr;
     unsigned char ch, flag;
     struct  async_icount *icount;
     int oe = 0;
 
     icount = &info->icount;
 
     status = UART_LSR_DR; /* We obviously have a character! */
     serdatr = amiga_custom.serdatr;
     mb();
     amiga_custom.intreq = IF_RBF;
     mb();
 
     if((serdatr & 0x1ff) == 0)
         status |= UART_LSR_BI;
     if(serdatr & SDR_OVRUN)
         status |= UART_LSR_OE;
 
     ch = serdatr & 0xff;
     icount->rx++;
 
 #ifdef SERIAL_DEBUG_INTR
     printk("DR%02x:%02x...", ch, status);
 #endif
     flag = TTY_NORMAL;
 
     /*
      * We don't handle parity or frame errors - but I have left
      * the code in, since I'm not sure that the errors can't be
      * detected.
      */
 
     if (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);
         icount->brk++;
       } else if (status & UART_LSR_PE)
         icount->parity++;
       else if (status & UART_LSR_FE)
         icount->frame++;
       if (status & UART_LSR_OE)
         icount->overrun++;
 
       /*
        * Now check to see if character should be
        * ignored, and mask off conditions which
        * should be ignored.
        */
       if (status & info->ignore_status_mask)
         goto out;
 
       status &= info->read_status_mask;
 
       if (status & (UART_LSR_BI)) {
 #ifdef SERIAL_DEBUG_INTR
         printk("handling break....");
 #endif
         flag = TTY_BREAK;
         if (info->tport.flags & ASYNC_SAK)
           do_SAK(info->tport.tty);
       } else if (status & UART_LSR_PE)
         flag = TTY_PARITY;
       else if (status & UART_LSR_FE)
         flag = TTY_FRAME;
       if (status & UART_LSR_OE) {
         /*
          * Overrun is special, since it's
          * reported immediately, and doesn't
          * affect the current character
          */
          oe = 1;
       }
     }
     tty_insert_flip_char(&info->tport, ch, flag);
     if (oe == 1)
         tty_insert_flip_char(&info->tport, 0, TTY_OVERRUN);
     tty_flip_buffer_push(&info->tport);
 out:
     return;
 }
 
 static void transmit_chars(struct serial_state *info)
 {
     amiga_custom.intreq = IF_TBE;
     mb();
     if (info->x_char) {
             amiga_custom.serdat = info->x_char | 0x100;
         mb();
         info->icount.tx++;
         info->x_char = 0;
         return;
     }
     if (info->xmit.head == info->xmit.tail
         || info->tport.tty->flow.stopped
         || info->tport.tty->hw_stopped) {
         info->IER &= ~UART_IER_THRI;
             amiga_custom.intena = IF_TBE;
         mb();
         return;
     }
 
     amiga_custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
     mb();
     info->xmit.tail = info->xmit.tail & (UART_XMIT_SIZE - 1);
     info->icount.tx++;
 
     if (CIRC_CNT(info->xmit.head,
              info->xmit.tail,
              UART_XMIT_SIZE) < WAKEUP_CHARS)
         tty_wakeup(info->tport.tty);
 
 #ifdef SERIAL_DEBUG_INTR
     printk("THRE...");
 #endif
     if (info->xmit.head == info->xmit.tail) {
             amiga_custom.intena = IF_TBE;
         mb();
         info->IER &= ~UART_IER_THRI;
     }
 }
 
 static void check_modem_status(struct serial_state *info)
 {
     struct tty_port *port = &info->tport;
     unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
     unsigned char dstatus;
     struct  async_icount *icount;
 
     /* Determine bits that have changed */
     dstatus = status ^ current_ctl_bits;
     current_ctl_bits = status;
 
     if (dstatus) {
         icount = &info->icount;
         /* update input line counters */
         if (dstatus & SER_DSR)
             icount->dsr++;
         if (dstatus & SER_DCD) {
             icount->dcd++;
         }
         if (dstatus & SER_CTS)
             icount->cts++;
         wake_up_interruptible(&port->delta_msr_wait);
     }
 
     if (tty_port_check_carrier(port) && (dstatus & SER_DCD)) {
 #if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
         printk("ttyS%d CD now %s...", info->line,
                (!(status & SER_DCD)) ? "on" : "off");
 #endif
         if (!(status & SER_DCD))
             wake_up_interruptible(&port->open_wait);
         else {
 #ifdef SERIAL_DEBUG_OPEN
             printk("doing serial hangup...");
 #endif
             if (port->tty)
                 tty_hangup(port->tty);
         }
     }
     if (tty_port_cts_enabled(port)) {
         if (port->tty->hw_stopped) {
             if (!(status & SER_CTS)) {
 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
                 printk("CTS tx start...");
 #endif
                 port->tty->hw_stopped = 0;
                 info->IER |= UART_IER_THRI;
                 amiga_custom.intena = IF_SETCLR | IF_TBE;
                 mb();
                 /* set a pending Tx Interrupt, transmitter should restart now */
                 amiga_custom.intreq = IF_SETCLR | IF_TBE;
                 mb();
                 tty_wakeup(port->tty);
                 return;
             }
         } else {
             if ((status & SER_CTS)) {
 #if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
                 printk("CTS tx stop...");
 #endif
                 port->tty->hw_stopped = 1;
                 info->IER &= ~UART_IER_THRI;
                 /* disable Tx interrupt and remove any pending interrupts */
                 amiga_custom.intena = IF_TBE;
                 mb();
                 amiga_custom.intreq = IF_TBE;
                 mb();
             }
         }
     }
 }
 
 static irqreturn_t ser_vbl_int( int irq, void *data)
 {
         /* vbl is just a periodic interrupt we tie into to update modem status */
     struct serial_state *info = data;
     /*
      * TBD - is it better to unregister from this interrupt or to
      * ignore it if MSI is clear ?
      */
     if(info->IER & UART_IER_MSI)
       check_modem_status(info);
     return IRQ_HANDLED;
 }
 
 static irqreturn_t ser_rx_int(int irq, void *dev_id)
 {
     struct serial_state *info = dev_id;
 
 #ifdef SERIAL_DEBUG_INTR
     printk("ser_rx_int...");
 #endif
 
     if (!info->tport.tty)
         return IRQ_NONE;
 
     receive_chars(info);
 #ifdef SERIAL_DEBUG_INTR
     printk("end.\n");
 #endif
     return IRQ_HANDLED;
 }
 
 static irqreturn_t ser_tx_int(int irq, void *dev_id)
 {
     struct serial_state *info = dev_id;
 
     if (amiga_custom.serdatr & SDR_TBE) {
 #ifdef SERIAL_DEBUG_INTR
       printk("ser_tx_int...");
 #endif
 
       if (!info->tport.tty)
         return IRQ_NONE;
 
       transmit_chars(info);
 #ifdef SERIAL_DEBUG_INTR
       printk("end.\n");
 #endif
     }
     return IRQ_HANDLED;
 }
 
 /*
  * -------------------------------------------------------------------
  * Here ends the serial interrupt routines.
  * -------------------------------------------------------------------
  */
 
 /*
  * ---------------------------------------------------------------
  * Low level utility subroutines for the serial driver:  routines to
  * figure out the appropriate timeout for an interrupt chain, routines
  * to initialize and startup a serial port, and routines to shutdown a
  * serial port.  Useful stuff like that.
  * ---------------------------------------------------------------
  */
 
 static int startup(struct tty_struct *tty, struct serial_state *info)
 {
     struct tty_port *port = &info->tport;
     unsigned long flags;
     int retval=0;
     unsigned long page;
 
     page = get_zeroed_page(GFP_KERNEL);
     if (!page)
         return -ENOMEM;
 
     local_irq_save(flags);
 
     if (tty_port_initialized(port)) {
         free_page(page);
         goto errout;
     }
 
     if (info->xmit.buf)
         free_page(page);
     else
         info->xmit.buf = (unsigned char *) page;
 
 #ifdef SERIAL_DEBUG_OPEN
     printk("starting up ttys%d ...", info->line);
 #endif
 
     /* Clear anything in the input buffer */
 
     amiga_custom.intreq = IF_RBF;
     mb();
 
     retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
     if (retval) {
         if (capable(CAP_SYS_ADMIN)) {
             set_bit(TTY_IO_ERROR, &tty->flags);
             retval = 0;
         }
         goto errout;
     }
 
     /* enable both Rx and Tx interrupts */
     amiga_custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
     mb();
     info->IER = UART_IER_MSI;
 
     /* remember current state of the DCD and CTS bits */
     current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
 
     info->MCR = 0;
     if (C_BAUD(tty))
       info->MCR = SER_DTR | SER_RTS;
     rtsdtr_ctrl(info->MCR);
 
     clear_bit(TTY_IO_ERROR, &tty->flags);
     info->xmit.head = info->xmit.tail = 0;
 
     /*
      * and set the speed of the serial port
      */
     change_speed(tty, info, NULL);
 
     tty_port_set_initialized(port, 1);
     local_irq_restore(flags);
     return 0;
 
 errout:
     local_irq_restore(flags);
     return retval;
 }
 
 /*
  * This routine will shutdown a serial port; interrupts are disabled, and
  * DTR is dropped if the hangup on close termio flag is on.
  */
 static void shutdown(struct tty_struct *tty, struct serial_state *info)
 {
     unsigned long   flags;
 
     if (!tty_port_initialized(&info->tport))
         return;
 
 #ifdef SERIAL_DEBUG_OPEN
     printk("Shutting down serial port %d ....\n", info->line);
 #endif
 
     local_irq_save(flags); /* Disable interrupts */
 
     /*
      * clear delta_msr_wait queue to avoid mem leaks: we may free the irq
      * here so the queue might never be waken up
      */
     wake_up_interruptible(&info->tport.delta_msr_wait);
 
     /*
      * Free the IRQ, if necessary
      */
     free_irq(IRQ_AMIGA_VERTB, info);
 
     free_page((unsigned long)info->xmit.buf);
     info->xmit.buf = NULL;
 
     info->IER = 0;
     amiga_custom.intena = IF_RBF | IF_TBE;
     mb();
 
     /* disable break condition */
     amiga_custom.adkcon = AC_UARTBRK;
     mb();
 
     if (C_HUPCL(tty))
         info->MCR &= ~(SER_DTR|SER_RTS);
     rtsdtr_ctrl(info->MCR);
 
     set_bit(TTY_IO_ERROR, &tty->flags);
 
     tty_port_set_initialized(&info->tport, 0);
     local_irq_restore(flags);
 }
 
 
 /*
  * This routine is called to set the UART divisor registers to match
  * the specified baud rate for a serial port.
  */
 static void change_speed(struct tty_struct *tty, struct serial_state *info,
              struct ktermios *old_termios)
 {
     struct tty_port *port = &info->tport;
     int quot = 0, baud_base, baud;
     unsigned cflag, cval = 0;
     int bits;
     unsigned long   flags;
 
     cflag = tty->termios.c_cflag;
 
     /* Byte size is always 8 bits plus parity bit if requested */
 
     cval = 3; bits = 10;
     if (cflag & CSTOPB) {
         cval |= 0x04;
         bits++;
     }
     if (cflag & PARENB) {
         cval |= UART_LCR_PARITY;
         bits++;
     }
     if (!(cflag & PARODD))
         cval |= UART_LCR_EPAR;
     if (cflag & CMSPAR)
         cval |= UART_LCR_SPAR;
 
     /* Determine divisor based on baud rate */
     baud = tty_get_baud_rate(tty);
     if (!baud)
         baud = 9600;    /* B0 transition handled in rs_set_termios */
     baud_base = info->baud_base;
     if (baud == 38400 && (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
         quot = info->custom_divisor;
     else {
         if (baud == 134)
             /* Special case since 134 is really 134.5 */
             quot = (2*baud_base / 269);
         else if (baud)
             quot = baud_base / baud;
     }
     /* If the quotient is zero refuse the change */
     if (!quot && old_termios) {
         /* FIXME: Will need updating for new tty in the end */
         tty->termios.c_cflag &= ~CBAUD;
         tty->termios.c_cflag |= (old_termios->c_cflag & CBAUD);
         baud = tty_get_baud_rate(tty);
         if (!baud)
             baud = 9600;
         if (baud == 38400 &&
             (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
             quot = info->custom_divisor;
         else {
             if (baud == 134)
                 /* Special case since 134 is really 134.5 */
                 quot = (2*baud_base / 269);
             else if (baud)
                 quot = baud_base / baud;
         }
     }
     /* As a last resort, if the quotient is zero, default to 9600 bps */
     if (!quot)
         quot = baud_base / 9600;
     info->quot = quot;
     info->timeout = (XMIT_FIFO_SIZE*HZ*bits*quot) / baud_base;
     info->timeout += HZ/50;     /* Add .02 seconds of slop */
 
     /* CTS flow control flag and modem status interrupts */
     info->IER &= ~UART_IER_MSI;
     if (port->flags & ASYNC_HARDPPS_CD)
         info->IER |= UART_IER_MSI;
     tty_port_set_cts_flow(port, cflag & CRTSCTS);
     if (cflag & CRTSCTS)
         info->IER |= UART_IER_MSI;
     tty_port_set_check_carrier(port, ~cflag & CLOCAL);
     if (~cflag & CLOCAL)
         info->IER |= UART_IER_MSI;
     /* TBD:
      * Does clearing IER_MSI imply that we should disable the VBL interrupt ?
      */
 
     /*
      * Set up parity check flag
      */
 
     info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
     if (I_INPCK(tty))
         info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
     if (I_BRKINT(tty) || I_PARMRK(tty))
         info->read_status_mask |= UART_LSR_BI;
 
     /*
      * Characters to ignore
      */
     info->ignore_status_mask = 0;
     if (I_IGNPAR(tty))
         info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
     if (I_IGNBRK(tty)) {
         info->ignore_status_mask |= UART_LSR_BI;
         /*
          * If we're ignore parity and break indicators, ignore 
          * overruns too.  (For real raw support).
          */
         if (I_IGNPAR(tty))
             info->ignore_status_mask |= UART_LSR_OE;
     }
     /*
      * !!! ignore all characters if CREAD is not set
      */
     if ((cflag & CREAD) == 0)
         info->ignore_status_mask |= UART_LSR_DR;
     local_irq_save(flags);
 
     {
       short serper;
 
     /* Set up the baud rate */
       serper = quot - 1;
 
     /* Enable or disable parity bit */
 
     if(cval & UART_LCR_PARITY)
       serper |= (SERPER_PARENB);
 
     amiga_custom.serper = serper;
     mb();
     }
 
     local_irq_restore(flags);
 }
 
 static int rs_put_char(struct tty_struct *tty, unsigned char ch)
 {
     struct serial_state *info;
     unsigned long flags;
 
     info = tty->driver_data;
 
     if (!info->xmit.buf)
         return 0;
 
     local_irq_save(flags);
     if (CIRC_SPACE(info->xmit.head,
                info->xmit.tail,
                UART_XMIT_SIZE) == 0) {
         local_irq_restore(flags);
         return 0;
     }
 
     info->xmit.buf[info->xmit.head++] = ch;
     info->xmit.head &= UART_XMIT_SIZE - 1;
     local_irq_restore(flags);
     return 1;
 }
 
 static void rs_flush_chars(struct tty_struct *tty)
 {
     struct serial_state *info = tty->driver_data;
     unsigned long flags;
 
     if (info->xmit.head == info->xmit.tail
         || tty->flow.stopped
         || tty->hw_stopped
         || !info->xmit.buf)
         return;
 
     local_irq_save(flags);
     info->IER |= UART_IER_THRI;
     amiga_custom.intena = IF_SETCLR | IF_TBE;
     mb();
     /* set a pending Tx Interrupt, transmitter should restart now */
     amiga_custom.intreq = IF_SETCLR | IF_TBE;
     mb();
     local_irq_restore(flags);
 }
 
 static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
 {
     int c, ret = 0;
     struct serial_state *info = tty->driver_data;
     unsigned long flags;
 
     if (!info->xmit.buf)
         return 0;
 
     local_irq_save(flags);
     while (1) {
         c = CIRC_SPACE_TO_END(info->xmit.head,
                       info->xmit.tail,
                       UART_XMIT_SIZE);
         if (count < c)
             c = count;
         if (c <= 0) {
             break;
         }
         memcpy(info->xmit.buf + info->xmit.head, buf, c);
         info->xmit.head = (info->xmit.head + c) & (UART_XMIT_SIZE - 1);
         buf += c;
         count -= c;
         ret += c;
     }
     local_irq_restore(flags);
 
     if (info->xmit.head != info->xmit.tail
         && !tty->flow.stopped
         && !tty->hw_stopped
         && !(info->IER & UART_IER_THRI)) {
         info->IER |= UART_IER_THRI;
         local_irq_disable();
         amiga_custom.intena = IF_SETCLR | IF_TBE;
         mb();
         /* set a pending Tx Interrupt, transmitter should restart now */
         amiga_custom.intreq = IF_SETCLR | IF_TBE;
         mb();
         local_irq_restore(flags);
     }
     return ret;
 }
 
 static unsigned int rs_write_room(struct tty_struct *tty)
 {
     struct serial_state *info = tty->driver_data;
 
     return CIRC_SPACE(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE);
 }
 
 static unsigned int rs_chars_in_buffer(struct tty_struct *tty)
 {
     struct serial_state *info = tty->driver_data;
 
     return CIRC_CNT(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE);
 }
 
 static void rs_flush_buffer(struct tty_struct *tty)
 {
     struct serial_state *info = tty->driver_data;
     unsigned long flags;
 
     local_irq_save(flags);
     info->xmit.head = info->xmit.tail = 0;
     local_irq_restore(flags);
     tty_wakeup(tty);
 }
 
 /*
  * This function is used to send a high-priority XON/XOFF character to
  * the device
  */
 static void rs_send_xchar(struct tty_struct *tty, char ch)
 {
     struct serial_state *info = tty->driver_data;
         unsigned long flags;
 
     info->x_char = ch;
     if (ch) {
         /* Make sure transmit interrupts are on */
 
             /* Check this ! */
             local_irq_save(flags);
         if(!(amiga_custom.intenar & IF_TBE)) {
             amiga_custom.intena = IF_SETCLR | IF_TBE;
             mb();
             /* set a pending Tx Interrupt, transmitter should restart now */
             amiga_custom.intreq = IF_SETCLR | IF_TBE;
             mb();
         }
         local_irq_restore(flags);
 
         info->IER |= UART_IER_THRI;
     }
 }
 
 /*
  * ------------------------------------------------------------
  * rs_throttle()
  * 
  * This routine is called by the upper-layer tty layer to signal that
  * incoming characters should be throttled.
  * ------------------------------------------------------------
  */
 static void rs_throttle(struct tty_struct * tty)
 {
     struct serial_state *info = tty->driver_data;
     unsigned long flags;
 #ifdef SERIAL_DEBUG_THROTTLE
     printk("throttle %s ....\n", tty_name(tty));
 #endif
 
     if (I_IXOFF(tty))
         rs_send_xchar(tty, STOP_CHAR(tty));
 
     if (C_CRTSCTS(tty))
         info->MCR &= ~SER_RTS;
 
     local_irq_save(flags);
     rtsdtr_ctrl(info->MCR);
     local_irq_restore(flags);
 }
 
 static void rs_unthrottle(struct tty_struct * tty)
 {
     struct serial_state *info = tty->driver_data;
     unsigned long flags;
 #ifdef SERIAL_DEBUG_THROTTLE
     printk("unthrottle %s ....\n", tty_name(tty));
 #endif
 
     if (I_IXOFF(tty)) {
         if (info->x_char)
             info->x_char = 0;
         else
             rs_send_xchar(tty, START_CHAR(tty));
     }
     if (C_CRTSCTS(tty))
         info->MCR |= SER_RTS;
     local_irq_save(flags);
     rtsdtr_ctrl(info->MCR);
     local_irq_restore(flags);
 }
 
 /*
  * ------------------------------------------------------------
  * rs_ioctl() and friends
  * ------------------------------------------------------------
  */
 
 static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
 {
     struct serial_state *state = tty->driver_data;
     unsigned int close_delay, closing_wait;
 
     tty_lock(tty);
     close_delay = jiffies_to_msecs(state->tport.close_delay) / 10;
     closing_wait = state->tport.closing_wait;
     if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
         closing_wait = jiffies_to_msecs(closing_wait) / 10;
 
     ss->line = tty->index;
     ss->port = state->port;
     ss->flags = state->tport.flags;
     ss->xmit_fifo_size = XMIT_FIFO_SIZE;
     ss->baud_base = state->baud_base;
     ss->close_delay = close_delay;
     ss->closing_wait = closing_wait;
     ss->custom_divisor = state->custom_divisor;
     tty_unlock(tty);
     return 0;
 }
 
 static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
 {
     struct serial_state *state = tty->driver_data;
     struct tty_port *port = &state->tport;
     bool change_spd;
     int             retval = 0;
     unsigned int close_delay, closing_wait;
 
     tty_lock(tty);
     change_spd = ((ss->flags ^ port->flags) & ASYNC_SPD_MASK) ||
         ss->custom_divisor != state->custom_divisor;
     if (ss->irq || ss->port != state->port ||
             ss->xmit_fifo_size != XMIT_FIFO_SIZE) {
         tty_unlock(tty);
         return -EINVAL;
     }
 
     close_delay = msecs_to_jiffies(ss->close_delay * 10);
     closing_wait = ss->closing_wait;
     if (closing_wait != ASYNC_CLOSING_WAIT_NONE)
         closing_wait = msecs_to_jiffies(closing_wait * 10);
 
     if (!capable(CAP_SYS_ADMIN)) {
         if ((ss->baud_base != state->baud_base) ||
             (close_delay != port->close_delay) ||
             (closing_wait != port->closing_wait) ||
             ((ss->flags & ~ASYNC_USR_MASK) !=
              (port->flags & ~ASYNC_USR_MASK))) {
             tty_unlock(tty);
             return -EPERM;
         }
         port->flags = ((port->flags & ~ASYNC_USR_MASK) |
                    (ss->flags & ASYNC_USR_MASK));
         state->custom_divisor = ss->custom_divisor;
         goto check_and_exit;
     }
 
     if (ss->baud_base < 9600) {
         tty_unlock(tty);
         return -EINVAL;
     }
 
     /*
      * OK, past this point, all the error checking has been done.
      * At this point, we start making changes.....
      */
 
     state->baud_base = ss->baud_base;
     port->flags = ((port->flags & ~ASYNC_FLAGS) |
             (ss->flags & ASYNC_FLAGS));
     state->custom_divisor = ss->custom_divisor;
     port->close_delay = close_delay;
     port->closing_wait = closing_wait;
 
 check_and_exit:
     if (tty_port_initialized(port)) {
         if (change_spd) {
             /* warn about deprecation unless clearing */
             if (ss->flags & ASYNC_SPD_MASK)
                 dev_warn_ratelimited(tty->dev, "use of SPD flags is deprecated\n");
             change_speed(tty, state, NULL);
         }
     } else
         retval = startup(tty, state);
     tty_unlock(tty);
     return retval;
 }
 
 /*
  * get_lsr_info - get line status register info
  *
  * Purpose: Let user call ioctl() to get info when the UART physically
  *      is emptied.  On bus types like RS485, the transmitter must
  *      release the bus after transmitting. This must be done when
  *      the transmit shift register is empty, not be done when the
  *      transmit holding register is empty.  This functionality
  *      allows an RS485 driver to be written in user space. 
  */
 static int get_lsr_info(struct serial_state *info, unsigned int __user *value)
 {
     unsigned char status;
     unsigned int result;
     unsigned long flags;
 
     local_irq_save(flags);
     status = amiga_custom.serdatr;
     mb();
     local_irq_restore(flags);
     result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
     if (copy_to_user(value, &result, sizeof(int)))
         return -EFAULT;
     return 0;
 }
 
 
 static int rs_tiocmget(struct tty_struct *tty)
 {
     struct serial_state *info = tty->driver_data;
     unsigned char control, status;
     unsigned long flags;
 
     if (tty_io_error(tty))
         return -EIO;
 
     control = info->MCR;
     local_irq_save(flags);
     status = ciab.pra;
     local_irq_restore(flags);
     return    ((control & SER_RTS) ? TIOCM_RTS : 0)
         | ((control & SER_DTR) ? TIOCM_DTR : 0)
         | (!(status  & SER_DCD) ? TIOCM_CAR : 0)
         | (!(status  & SER_DSR) ? TIOCM_DSR : 0)
         | (!(status  & SER_CTS) ? TIOCM_CTS : 0);
 }
 
 static int rs_tiocmset(struct tty_struct *tty, unsigned int set,
                         unsigned int clear)
 {
     struct serial_state *info = tty->driver_data;
     unsigned long flags;
 
     if (tty_io_error(tty))
         return -EIO;
 
     local_irq_save(flags);
     if (set & TIOCM_RTS)
         info->MCR |= SER_RTS;
     if (set & TIOCM_DTR)
         info->MCR |= SER_DTR;
     if (clear & TIOCM_RTS)
         info->MCR &= ~SER_RTS;
     if (clear & TIOCM_DTR)
         info->MCR &= ~SER_DTR;
     rtsdtr_ctrl(info->MCR);
     local_irq_restore(flags);
     return 0;
 }
 
 /*
  * rs_break() --- routine which turns the break handling on or off
  */
 static int rs_break(struct tty_struct *tty, int break_state)
 {
     unsigned long flags;
 
     local_irq_save(flags);
     if (break_state == -1)
       amiga_custom.adkcon = AC_SETCLR | AC_UARTBRK;
     else
       amiga_custom.adkcon = AC_UARTBRK;
     mb();
     local_irq_restore(flags);
     return 0;
 }
 
 /*
  * Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
  * Return: write counters to the user passed counter struct
  * NB: both 1->0 and 0->1 transitions are counted except for
  *     RI where only 0->1 is counted.
  */
 static int rs_get_icount(struct tty_struct *tty,
                 struct serial_icounter_struct *icount)
 {
     struct serial_state *info = tty->driver_data;
     struct async_icount cnow;
     unsigned long flags;
 
     local_irq_save(flags);
     cnow = info->icount;
     local_irq_restore(flags);
     icount->cts = cnow.cts;
     icount->dsr = cnow.dsr;
     icount->rng = cnow.rng;
     icount->dcd = cnow.dcd;
     icount->rx = cnow.rx;
     icount->tx = cnow.tx;
     icount->frame = cnow.frame;
     icount->overrun = cnow.overrun;
     icount->parity = cnow.parity;
     icount->brk = cnow.brk;
     icount->buf_overrun = cnow.buf_overrun;
 
     return 0;
 }
 
 static int rs_ioctl(struct tty_struct *tty,
             unsigned int cmd, unsigned long arg)
 {
     struct serial_state *info = tty->driver_data;
     struct async_icount cprev, cnow;    /* kernel counter temps */
     void __user *argp = (void __user *)arg;
     unsigned long flags;
     DEFINE_WAIT(wait);
     int ret;
 
     if ((cmd != TIOCSERCONFIG) &&
         (cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
         if (tty_io_error(tty))
             return -EIO;
     }
 
     switch (cmd) {
         case TIOCSERCONFIG:
             return 0;
 
         case TIOCSERGETLSR: /* Get line status register */
             return get_lsr_info(info, argp);
 
         /*
          * Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
          * - mask passed in arg for lines of interest
          *   (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
          * Caller should use TIOCGICOUNT to see which one it was
          */
         case TIOCMIWAIT:
             local_irq_save(flags);
             /* note the counters on entry */
             cprev = info->icount;
             local_irq_restore(flags);
             while (1) {
                 prepare_to_wait(&info->tport.delta_msr_wait,
                         &wait, TASK_INTERRUPTIBLE);
                 local_irq_save(flags);
                 cnow = info->icount; /* atomic copy */
                 local_irq_restore(flags);
                 if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
                     cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
                     ret = -EIO; /* no change => error */
                     break;
                 }
                 if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
                      ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
                      ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
                      ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
                     ret = 0;
                     break;
                 }
                 schedule();
                 /* see if a signal did it */
                 if (signal_pending(current)) {
                     ret = -ERESTARTSYS;
                     break;
                 }
                 cprev = cnow;
             }
             finish_wait(&info->tport.delta_msr_wait, &wait);
             return ret;
 
         default:
             return -ENOIOCTLCMD;
         }
     return 0;
 }
 
 static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
 {
     struct serial_state *info = tty->driver_data;
     unsigned long flags;
     unsigned int cflag = tty->termios.c_cflag;
 
     change_speed(tty, info, old_termios);
 
     /* Handle transition to B0 status */
     if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) {
         info->MCR &= ~(SER_DTR|SER_RTS);
         local_irq_save(flags);
         rtsdtr_ctrl(info->MCR);
         local_irq_restore(flags);
     }
 
     /* Handle transition away from B0 status */
     if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
         info->MCR |= SER_DTR;
         if (!C_CRTSCTS(tty) || !tty_throttled(tty))
             info->MCR |= SER_RTS;
         local_irq_save(flags);
         rtsdtr_ctrl(info->MCR);
         local_irq_restore(flags);
     }
 
     /* Handle turning off CRTSCTS */
     if ((old_termios->c_cflag & CRTSCTS) && !C_CRTSCTS(tty)) {
         tty->hw_stopped = 0;
         rs_start(tty);
     }
 
 #if 0
     /*
      * No need to wake up processes in open wait, since they
      * sample the CLOCAL flag once, and don't recheck it.
      * XXX  It's not clear whether the current behavior is correct
      * or not.  Hence, this may change.....
      */
     if (!(old_termios->c_cflag & CLOCAL) && C_CLOCAL(tty))
         wake_up_interruptible(&info->open_wait);
 #endif
 }
 
 /*
  * ------------------------------------------------------------
  * rs_close()
  * 
  * This routine is called when the serial port gets closed.  First, we
  * wait for the last remaining data to be sent.  Then, we unlink its
  * async structure from the interrupt chain if necessary, and we free
  * that IRQ if nothing is left in the chain.
  * ------------------------------------------------------------
  */
 static void rs_close(struct tty_struct *tty, struct file * filp)
 {
     struct serial_state *state = tty->driver_data;
     struct tty_port *port = &state->tport;
 
     if (tty_port_close_start(port, tty, filp) == 0)
         return;
 
     /*
      * At this point we stop accepting input.  To do this, we
      * disable the receive line status interrupts, and tell the
      * interrupt driver to stop checking the data ready bit in the
      * line status register.
      */
     state->read_status_mask &= ~UART_LSR_DR;
     if (tty_port_initialized(port)) {
             /* disable receive interrupts */
             amiga_custom.intena = IF_RBF;
         mb();
         /* clear any pending receive interrupt */
         amiga_custom.intreq = IF_RBF;
         mb();
 
         /*
          * Before we drop DTR, make sure the UART transmitter
          * has completely drained; this is especially
          * important if there is a transmit FIFO!
          */
         rs_wait_until_sent(tty, state->timeout);
     }
     shutdown(tty, state);
     rs_flush_buffer(tty);
         
     tty_ldisc_flush(tty);
     port->tty = NULL;
 
     tty_port_close_end(port, tty);
 }
 
 /*
  * rs_wait_until_sent() --- wait until the transmitter is empty
  */
 static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
 {
     struct serial_state *info = tty->driver_data;
     unsigned long orig_jiffies, char_time;
     int lsr;
 
     orig_jiffies = jiffies;
 
     /*
      * Set the check interval to be 1/5 of the estimated time to
      * send a single character, and make it at least 1.  The check
      * interval should also be less than the timeout.
      * 
      * Note: we have to use pretty tight timings here to satisfy
      * the NIST-PCTS.
      */
     char_time = (info->timeout - HZ/50) / XMIT_FIFO_SIZE;
     char_time = char_time / 5;
     if (char_time == 0)
         char_time = 1;
     if (timeout)
       char_time = min_t(unsigned long, char_time, timeout);
     /*
      * If the transmitter hasn't cleared in twice the approximate
      * amount of time to send the entire FIFO, it probably won't
      * ever clear.  This assumes the UART isn't doing flow
      * control, which is currently the case.  Hence, if it ever
      * takes longer than info->timeout, this is probably due to a
      * UART bug of some kind.  So, we clamp the timeout parameter at
      * 2*info->timeout.
      */
     if (!timeout || timeout > 2*info->timeout)
         timeout = 2*info->timeout;
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
     printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
     printk("jiff=%lu...", jiffies);
 #endif
     while(!((lsr = amiga_custom.serdatr) & SDR_TSRE)) {
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
         printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
 #endif
         msleep_interruptible(jiffies_to_msecs(char_time));
         if (signal_pending(current))
             break;
         if (timeout && time_after(jiffies, orig_jiffies + timeout))
             break;
     }
     __set_current_state(TASK_RUNNING);
 
 #ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
     printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
 #endif
 }
 
 /*
  * rs_hangup() --- called by tty_hangup() when a hangup is signaled.
  */
 static void rs_hangup(struct tty_struct *tty)
 {
     struct serial_state *info = tty->driver_data;
 
     rs_flush_buffer(tty);
     shutdown(tty, info);
     info->tport.count = 0;
     tty_port_set_active(&info->tport, 0);
     info->tport.tty = NULL;
     wake_up_interruptible(&info->tport.open_wait);
 }
 
 /*
  * This routine is called whenever a serial port is opened.  It
  * enables interrupts for a serial port, linking in its async structure into
  * the IRQ chain.   It also performs the serial-specific
  * initialization for the tty structure.
  */
 static int rs_open(struct tty_struct *tty, struct file * filp)
 {
     struct tty_port *port = tty->port;
     struct serial_state *info = container_of(port, struct serial_state,
             tport);
     int retval;
 
     port->count++;
     port->tty = tty;
     tty->driver_data = info;
 
     retval = startup(tty, info);
     if (retval) {
         return retval;
     }
 
     return tty_port_block_til_ready(port, tty, filp);
 }
 
 /*
  * /proc fs routines....
  */
 
 static inline void line_info(struct seq_file *m, int line,
         struct serial_state *state)
 {
     char    stat_buf[30], control, status;
     unsigned long flags;
 
     seq_printf(m, "%d: uart:amiga_builtin", line);
 
     local_irq_save(flags);
     status = ciab.pra;
     control = tty_port_initialized(&state->tport) ? state->MCR : status;
     local_irq_restore(flags);
 
     stat_buf[0] = 0;
     stat_buf[1] = 0;
     if(!(control & SER_RTS))
         strcat(stat_buf, "|RTS");
     if(!(status & SER_CTS))
         strcat(stat_buf, "|CTS");
     if(!(control & SER_DTR))
         strcat(stat_buf, "|DTR");
     if(!(status & SER_DSR))
         strcat(stat_buf, "|DSR");
     if(!(status & SER_DCD))
         strcat(stat_buf, "|CD");
 
     if (state->quot)
         seq_printf(m, " baud:%d", state->baud_base / state->quot);
 
     seq_printf(m, " tx:%d rx:%d", state->icount.tx, state->icount.rx);
 
     if (state->icount.frame)
         seq_printf(m, " fe:%d", state->icount.frame);
 
     if (state->icount.parity)
         seq_printf(m, " pe:%d", state->icount.parity);
 
     if (state->icount.brk)
         seq_printf(m, " brk:%d", state->icount.brk);
 
     if (state->icount.overrun)
         seq_printf(m, " oe:%d", state->icount.overrun);
 
     /*
      * Last thing is the RS-232 status lines
      */
     seq_printf(m, " %s\n", stat_buf+1);
 }
 
 static int rs_proc_show(struct seq_file *m, void *v)
 {
     seq_printf(m, "serinfo:1.0 driver:4.30\n");
     line_info(m, 0, &serial_state);
     return 0;
 }
 
 /*
  * ---------------------------------------------------------------------
  * rs_init() and friends
  *
  * rs_init() is called at boot-time to initialize the serial driver.
  * ---------------------------------------------------------------------
  */
 
 static const struct tty_operations serial_ops = {
     .open = rs_open,
     .close = rs_close,
     .write = rs_write,
     .put_char = rs_put_char,
     .flush_chars = rs_flush_chars,
     .write_room = rs_write_room,
     .chars_in_buffer = rs_chars_in_buffer,
     .flush_buffer = rs_flush_buffer,
     .ioctl = rs_ioctl,
     .throttle = rs_throttle,
     .unthrottle = rs_unthrottle,
     .set_termios = rs_set_termios,
     .stop = rs_stop,
     .start = rs_start,
     .hangup = rs_hangup,
     .break_ctl = rs_break,
     .send_xchar = rs_send_xchar,
     .wait_until_sent = rs_wait_until_sent,
     .tiocmget = rs_tiocmget,
     .tiocmset = rs_tiocmset,
     .get_icount = rs_get_icount,
     .set_serial = set_serial_info,
     .get_serial = get_serial_info,
     .proc_show = rs_proc_show,
 };
 
 static int amiga_carrier_raised(struct tty_port *port)
 {
     return !(ciab.pra & SER_DCD);
 }
 
 static void amiga_dtr_rts(struct tty_port *port, int raise)
 {
     struct serial_state *info = container_of(port, struct serial_state,
             tport);
     unsigned long flags;
 
     if (raise)
         info->MCR |= SER_DTR|SER_RTS;
     else
         info->MCR &= ~(SER_DTR|SER_RTS);
 
     local_irq_save(flags);
     rtsdtr_ctrl(info->MCR);
     local_irq_restore(flags);
 }
 
 static const struct tty_port_operations amiga_port_ops = {
     .carrier_raised = amiga_carrier_raised,
     .dtr_rts = amiga_dtr_rts,
 };
 
 /*
  * The serial driver boot-time initialization code!
  */
 static int __init amiga_serial_probe(struct platform_device *pdev)
 {
     struct serial_state *state = &serial_state;
     struct tty_driver *driver;
     unsigned long flags;
     int error;
 
     driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
     if (IS_ERR(driver))
         return PTR_ERR(driver);
 
     /* Initialize the tty_driver structure */
 
     driver->driver_name = "amiserial";
     driver->name = "ttyS";
     driver->major = TTY_MAJOR;
     driver->minor_start = 64;
     driver->type = TTY_DRIVER_TYPE_SERIAL;
     driver->subtype = SERIAL_TYPE_NORMAL;
     driver->init_termios = tty_std_termios;
     driver->init_termios.c_cflag =
         B9600 | CS8 | CREAD | HUPCL | CLOCAL;
     tty_set_operations(driver, &serial_ops);
 
     memset(state, 0, sizeof(*state));
     state->port = (int)&amiga_custom.serdatr; /* Just to give it a value */
     tty_port_init(&state->tport);
     state->tport.ops = &amiga_port_ops;
     tty_port_link_device(&state->tport, driver, 0);
 
     error = tty_register_driver(driver);
     if (error)
         goto fail_tty_driver_kref_put;
 
     printk(KERN_INFO "ttyS0 is the amiga builtin serial port\n");
 
     /* Hardware set up */
 
     state->baud_base = amiga_colorclock;
 
     /* set ISRs, and then disable the rx interrupts */
     error = request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
     if (error)
         goto fail_unregister;
 
     error = request_irq(IRQ_AMIGA_RBF, ser_rx_int, 0,
                 "serial RX", state);
     if (error)
         goto fail_free_irq;
 
     local_irq_save(flags);
 
     /* turn off Rx and Tx interrupts */
     amiga_custom.intena = IF_RBF | IF_TBE;
     mb();
 
     /* clear any pending interrupt */
     amiga_custom.intreq = IF_RBF | IF_TBE;
     mb();
 
     local_irq_restore(flags);
 
     /*
      * set the appropriate directions for the modem control flags,
      * and clear RTS and DTR
      */
     ciab.ddra |= (SER_DTR | SER_RTS);   /* outputs */
     ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR);  /* inputs */
 
     platform_set_drvdata(pdev, state);
 
     serial_driver = driver;
 
     return 0;
 
 fail_free_irq:
     free_irq(IRQ_AMIGA_TBE, state);
 fail_unregister:
     tty_unregister_driver(driver);
 fail_tty_driver_kref_put:
     tty_port_destroy(&state->tport);
     tty_driver_kref_put(driver);
     return error;
 }
 
 static int __exit amiga_serial_remove(struct platform_device *pdev)
 {
     struct serial_state *state = platform_get_drvdata(pdev);
 
     tty_unregister_driver(serial_driver);
     tty_driver_kref_put(serial_driver);
     tty_port_destroy(&state->tport);
 
     free_irq(IRQ_AMIGA_TBE, state);
     free_irq(IRQ_AMIGA_RBF, state);
 
     return 0;
 }
 
 static struct platform_driver amiga_serial_driver = {
     .remove = __exit_p(amiga_serial_remove),
     .driver   = {
         .name   = "amiga-serial",
     },
 };
 
 module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
 
 
 #if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
 
 /*
  * ------------------------------------------------------------
  * Serial console driver
  * ------------------------------------------------------------
  */
 
 static void amiga_serial_putc(char c)
 {
     amiga_custom.serdat = (unsigned char)c | 0x100;
     while (!(amiga_custom.serdatr & 0x2000))
         barrier();
 }
 
 /*
  *  Print a string to the serial port trying not to disturb
  *  any possible real use of the port...
  *
  *  The console must be locked when we get here.
  */
 static void serial_console_write(struct console *co, const char *s,
                 unsigned count)
 {
     unsigned short intena = amiga_custom.intenar;
 
     amiga_custom.intena = IF_TBE;
 
     while (count--) {
         if (*s == '\n')
             amiga_serial_putc('\r');
         amiga_serial_putc(*s++);
     }
 
     amiga_custom.intena = IF_SETCLR | (intena & IF_TBE);
 }
 
 static struct tty_driver *serial_console_device(struct console *c, int *index)
 {
     *index = 0;
     return serial_driver;
 }
 
 static struct console sercons = {
     .name =     "ttyS",
     .write =    serial_console_write,
     .device =   serial_console_device,
     .flags =    CON_PRINTBUFFER,
     .index =    -1,
 };
 
 /*
  *  Register console.
  */
 static int __init amiserial_console_init(void)
 {
     if (!MACH_IS_AMIGA)
         return -ENODEV;
 
     register_console(&sercons);
     return 0;
 }
 console_initcall(amiserial_console_init);
 
 #endif /* CONFIG_SERIAL_CONSOLE && !MODULE */
 
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:amiga-serial");

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