Logo Search packages:      
Sourcecode: linux version File versions  Download package

vme_scc.c

/*
 * drivers/char/vme_scc.c: MVME147, MVME162, BVME6000 SCC serial ports
 * implementation.
 * Copyright 1999 Richard Hirst <richard@sleepie.demon.co.uk>
 *
 * Based on atari_SCC.c which was
 *   Copyright 1994-95 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
 *   Partially based on PC-Linux serial.c by Linus Torvalds and Theodore Ts'o
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 *
 */

#include <linux/module.h>
#include <linux/kdev_t.h>
#include <asm/io.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/mm.h>
#include <linux/serial.h>
#include <linux/fcntl.h>
#include <linux/major.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/miscdevice.h>
#include <linux/console.h>
#include <linux/init.h>
#include <asm/setup.h>
#include <asm/bootinfo.h>

#ifdef CONFIG_MVME147_SCC
#include <asm/mvme147hw.h>
#endif
#ifdef CONFIG_MVME162_SCC
#include <asm/mvme16xhw.h>
#endif
#ifdef CONFIG_BVME6000_SCC
#include <asm/bvme6000hw.h>
#endif

#include <linux/generic_serial.h>
#include "scc.h"


#define CHANNEL_A 0
#define CHANNEL_B 1

#define SCC_MINOR_BASE  64

/* Shadows for all SCC write registers */
static unsigned char scc_shadow[2][16];

/* Location to access for SCC register access delay */
static volatile unsigned char *scc_del = NULL;

/* To keep track of STATUS_REG state for detection of Ext/Status int source */
static unsigned char scc_last_status_reg[2];

/***************************** Prototypes *****************************/

/* Function prototypes */
static void scc_disable_tx_interrupts(void * ptr);
static void scc_enable_tx_interrupts(void * ptr);
static void scc_disable_rx_interrupts(void * ptr);
static void scc_enable_rx_interrupts(void * ptr);
static int  scc_get_CD(void * ptr);
static void scc_shutdown_port(void * ptr);
static int scc_set_real_termios(void  *ptr);
static void scc_hungup(void  *ptr);
static void scc_close(void  *ptr);
static int scc_chars_in_buffer(void * ptr);
static int scc_open(struct tty_struct * tty, struct file * filp);
static int scc_ioctl(struct tty_struct * tty, struct file * filp,
                     unsigned int cmd, unsigned long arg);
static void scc_throttle(struct tty_struct *tty);
static void scc_unthrottle(struct tty_struct *tty);
static irqreturn_t scc_tx_int(int irq, void *data);
static irqreturn_t scc_rx_int(int irq, void *data);
static irqreturn_t scc_stat_int(int irq, void *data);
static irqreturn_t scc_spcond_int(int irq, void *data);
static void scc_setsignals(struct scc_port *port, int dtr, int rts);
static void scc_break_ctl(struct tty_struct *tty, int break_state);

static struct tty_driver *scc_driver;

struct scc_port scc_ports[2];

int scc_initialized = 0;

/*---------------------------------------------------------------------------
 * Interface from generic_serial.c back here
 *--------------------------------------------------------------------------*/

static struct real_driver scc_real_driver = {
        scc_disable_tx_interrupts,
        scc_enable_tx_interrupts,
        scc_disable_rx_interrupts,
        scc_enable_rx_interrupts,
        scc_get_CD,
        scc_shutdown_port,
        scc_set_real_termios,
        scc_chars_in_buffer,
        scc_close,
        scc_hungup,
        NULL
};


static const struct tty_operations scc_ops = {
      .open = scc_open,
      .close = gs_close,
      .write = gs_write,
      .put_char = gs_put_char,
      .flush_chars = gs_flush_chars,
      .write_room = gs_write_room,
      .chars_in_buffer = gs_chars_in_buffer,
      .flush_buffer = gs_flush_buffer,
      .ioctl = scc_ioctl,
      .throttle = scc_throttle,
      .unthrottle = scc_unthrottle,
      .set_termios = gs_set_termios,
      .stop = gs_stop,
      .start = gs_start,
      .hangup = gs_hangup,
      .break_ctl = scc_break_ctl,
};

/*----------------------------------------------------------------------------
 * vme_scc_init() and support functions
 *---------------------------------------------------------------------------*/

static int scc_init_drivers(void)
{
      int error;

      scc_driver = alloc_tty_driver(2);
      if (!scc_driver)
            return -ENOMEM;
      scc_driver->owner = THIS_MODULE;
      scc_driver->driver_name = "scc";
      scc_driver->name = "ttyS";
      scc_driver->major = TTY_MAJOR;
      scc_driver->minor_start = SCC_MINOR_BASE;
      scc_driver->type = TTY_DRIVER_TYPE_SERIAL;
      scc_driver->subtype = SERIAL_TYPE_NORMAL;
      scc_driver->init_termios = tty_std_termios;
      scc_driver->init_termios.c_cflag =
        B9600 | CS8 | CREAD | HUPCL | CLOCAL;
      scc_driver->init_termios.c_ispeed = 9600;
      scc_driver->init_termios.c_ospeed = 9600;
      scc_driver->flags = TTY_DRIVER_REAL_RAW;
      tty_set_operations(scc_driver, &scc_ops);

      if ((error = tty_register_driver(scc_driver))) {
            printk(KERN_ERR "scc: Couldn't register scc driver, error = %d\n",
                   error);
            put_tty_driver(scc_driver);
            return 1;
      }

      return 0;
}


/* ports[] array is indexed by line no (i.e. [0] for ttyS0, [1] for ttyS1).
 */

static void scc_init_portstructs(void)
{
      struct scc_port *port;
      int i;

      for (i = 0; i < 2; i++) {
            port = scc_ports + i;
            port->gs.magic = SCC_MAGIC;
            port->gs.close_delay = HZ/2;
            port->gs.closing_wait = 30 * HZ;
            port->gs.rd = &scc_real_driver;
#ifdef NEW_WRITE_LOCKING
            port->gs.port_write_mutex = MUTEX;
#endif
            init_waitqueue_head(&port->gs.open_wait);
            init_waitqueue_head(&port->gs.close_wait);
      }
}


#ifdef CONFIG_MVME147_SCC
static int mvme147_scc_init(void)
{
      struct scc_port *port;

      printk(KERN_INFO "SCC: MVME147 Serial Driver\n");
      /* Init channel A */
      port = &scc_ports[0];
      port->channel = CHANNEL_A;
      port->ctrlp = (volatile unsigned char *)M147_SCC_A_ADDR;
      port->datap = port->ctrlp + 1;
      port->port_a = &scc_ports[0];
      port->port_b = &scc_ports[1];
      request_irq(MVME147_IRQ_SCCA_TX, scc_tx_int, IRQF_DISABLED,
                        "SCC-A TX", port);
      request_irq(MVME147_IRQ_SCCA_STAT, scc_stat_int, IRQF_DISABLED,
                        "SCC-A status", port);
      request_irq(MVME147_IRQ_SCCA_RX, scc_rx_int, IRQF_DISABLED,
                        "SCC-A RX", port);
      request_irq(MVME147_IRQ_SCCA_SPCOND, scc_spcond_int, IRQF_DISABLED,
                        "SCC-A special cond", port);
      {
            SCC_ACCESS_INIT(port);

            /* disable interrupts for this channel */
            SCCwrite(INT_AND_DMA_REG, 0);
            /* Set the interrupt vector */
            SCCwrite(INT_VECTOR_REG, MVME147_IRQ_SCC_BASE);
            /* Interrupt parameters: vector includes status, status low */
            SCCwrite(MASTER_INT_CTRL, MIC_VEC_INCL_STAT);
            SCCmod(MASTER_INT_CTRL, 0xff, MIC_MASTER_INT_ENAB);
      }

      /* Init channel B */
      port = &scc_ports[1];
      port->channel = CHANNEL_B;
      port->ctrlp = (volatile unsigned char *)M147_SCC_B_ADDR;
      port->datap = port->ctrlp + 1;
      port->port_a = &scc_ports[0];
      port->port_b = &scc_ports[1];
      request_irq(MVME147_IRQ_SCCB_TX, scc_tx_int, IRQF_DISABLED,
                        "SCC-B TX", port);
      request_irq(MVME147_IRQ_SCCB_STAT, scc_stat_int, IRQF_DISABLED,
                        "SCC-B status", port);
      request_irq(MVME147_IRQ_SCCB_RX, scc_rx_int, IRQF_DISABLED,
                        "SCC-B RX", port);
      request_irq(MVME147_IRQ_SCCB_SPCOND, scc_spcond_int, IRQF_DISABLED,
                        "SCC-B special cond", port);
      {
            SCC_ACCESS_INIT(port);

            /* disable interrupts for this channel */
            SCCwrite(INT_AND_DMA_REG, 0);
      }

        /* Ensure interrupts are enabled in the PCC chip */
        m147_pcc->serial_cntrl=PCC_LEVEL_SERIAL|PCC_INT_ENAB;

      /* Initialise the tty driver structures and register */
      scc_init_portstructs();
      scc_init_drivers();

      return 0;
}
#endif


#ifdef CONFIG_MVME162_SCC
static int mvme162_scc_init(void)
{
      struct scc_port *port;

      if (!(mvme16x_config & MVME16x_CONFIG_GOT_SCCA))
            return (-ENODEV);

      printk(KERN_INFO "SCC: MVME162 Serial Driver\n");
      /* Init channel A */
      port = &scc_ports[0];
      port->channel = CHANNEL_A;
      port->ctrlp = (volatile unsigned char *)MVME_SCC_A_ADDR;
      port->datap = port->ctrlp + 2;
      port->port_a = &scc_ports[0];
      port->port_b = &scc_ports[1];
      request_irq(MVME162_IRQ_SCCA_TX, scc_tx_int, IRQF_DISABLED,
                        "SCC-A TX", port);
      request_irq(MVME162_IRQ_SCCA_STAT, scc_stat_int, IRQF_DISABLED,
                        "SCC-A status", port);
      request_irq(MVME162_IRQ_SCCA_RX, scc_rx_int, IRQF_DISABLED,
                        "SCC-A RX", port);
      request_irq(MVME162_IRQ_SCCA_SPCOND, scc_spcond_int, IRQF_DISABLED,
                        "SCC-A special cond", port);
      {
            SCC_ACCESS_INIT(port);

            /* disable interrupts for this channel */
            SCCwrite(INT_AND_DMA_REG, 0);
            /* Set the interrupt vector */
            SCCwrite(INT_VECTOR_REG, MVME162_IRQ_SCC_BASE);
            /* Interrupt parameters: vector includes status, status low */
            SCCwrite(MASTER_INT_CTRL, MIC_VEC_INCL_STAT);
            SCCmod(MASTER_INT_CTRL, 0xff, MIC_MASTER_INT_ENAB);
      }

      /* Init channel B */
      port = &scc_ports[1];
      port->channel = CHANNEL_B;
      port->ctrlp = (volatile unsigned char *)MVME_SCC_B_ADDR;
      port->datap = port->ctrlp + 2;
      port->port_a = &scc_ports[0];
      port->port_b = &scc_ports[1];
      request_irq(MVME162_IRQ_SCCB_TX, scc_tx_int, IRQF_DISABLED,
                        "SCC-B TX", port);
      request_irq(MVME162_IRQ_SCCB_STAT, scc_stat_int, IRQF_DISABLED,
                        "SCC-B status", port);
      request_irq(MVME162_IRQ_SCCB_RX, scc_rx_int, IRQF_DISABLED,
                        "SCC-B RX", port);
      request_irq(MVME162_IRQ_SCCB_SPCOND, scc_spcond_int, IRQF_DISABLED,
                        "SCC-B special cond", port);

      {
            SCC_ACCESS_INIT(port);  /* Either channel will do */

            /* disable interrupts for this channel */
            SCCwrite(INT_AND_DMA_REG, 0);
      }

        /* Ensure interrupts are enabled in the MC2 chip */
        *(volatile char *)0xfff4201d = 0x14;

      /* Initialise the tty driver structures and register */
      scc_init_portstructs();
      scc_init_drivers();

      return 0;
}
#endif


#ifdef CONFIG_BVME6000_SCC
static int bvme6000_scc_init(void)
{
      struct scc_port *port;

      printk(KERN_INFO "SCC: BVME6000 Serial Driver\n");
      /* Init channel A */
      port = &scc_ports[0];
      port->channel = CHANNEL_A;
      port->ctrlp = (volatile unsigned char *)BVME_SCC_A_ADDR;
      port->datap = port->ctrlp + 4;
      port->port_a = &scc_ports[0];
      port->port_b = &scc_ports[1];
      request_irq(BVME_IRQ_SCCA_TX, scc_tx_int, IRQF_DISABLED,
                        "SCC-A TX", port);
      request_irq(BVME_IRQ_SCCA_STAT, scc_stat_int, IRQF_DISABLED,
                        "SCC-A status", port);
      request_irq(BVME_IRQ_SCCA_RX, scc_rx_int, IRQF_DISABLED,
                        "SCC-A RX", port);
      request_irq(BVME_IRQ_SCCA_SPCOND, scc_spcond_int, IRQF_DISABLED,
                        "SCC-A special cond", port);
      {
            SCC_ACCESS_INIT(port);

            /* disable interrupts for this channel */
            SCCwrite(INT_AND_DMA_REG, 0);
            /* Set the interrupt vector */
            SCCwrite(INT_VECTOR_REG, BVME_IRQ_SCC_BASE);
            /* Interrupt parameters: vector includes status, status low */
            SCCwrite(MASTER_INT_CTRL, MIC_VEC_INCL_STAT);
            SCCmod(MASTER_INT_CTRL, 0xff, MIC_MASTER_INT_ENAB);
      }

      /* Init channel B */
      port = &scc_ports[1];
      port->channel = CHANNEL_B;
      port->ctrlp = (volatile unsigned char *)BVME_SCC_B_ADDR;
      port->datap = port->ctrlp + 4;
      port->port_a = &scc_ports[0];
      port->port_b = &scc_ports[1];
      request_irq(BVME_IRQ_SCCB_TX, scc_tx_int, IRQF_DISABLED,
                        "SCC-B TX", port);
      request_irq(BVME_IRQ_SCCB_STAT, scc_stat_int, IRQF_DISABLED,
                        "SCC-B status", port);
      request_irq(BVME_IRQ_SCCB_RX, scc_rx_int, IRQF_DISABLED,
                        "SCC-B RX", port);
      request_irq(BVME_IRQ_SCCB_SPCOND, scc_spcond_int, IRQF_DISABLED,
                        "SCC-B special cond", port);

      {
            SCC_ACCESS_INIT(port);  /* Either channel will do */

            /* disable interrupts for this channel */
            SCCwrite(INT_AND_DMA_REG, 0);
      }

      /* Initialise the tty driver structures and register */
      scc_init_portstructs();
      scc_init_drivers();

      return 0;
}
#endif


static int vme_scc_init(void)
{
      int res = -ENODEV;

#ifdef CONFIG_MVME147_SCC
      if (MACH_IS_MVME147)
            res = mvme147_scc_init();
#endif
#ifdef CONFIG_MVME162_SCC
      if (MACH_IS_MVME16x)
            res = mvme162_scc_init();
#endif
#ifdef CONFIG_BVME6000_SCC
      if (MACH_IS_BVME6000)
            res = bvme6000_scc_init();
#endif
      return res;
}

module_init(vme_scc_init);


/*---------------------------------------------------------------------------
 * Interrupt handlers
 *--------------------------------------------------------------------------*/

static irqreturn_t scc_rx_int(int irq, void *data)
{
      unsigned char     ch;
      struct scc_port *port = data;
      struct tty_struct *tty = port->gs.tty;
      SCC_ACCESS_INIT(port);

      ch = SCCread_NB(RX_DATA_REG);
      if (!tty) {
            printk(KERN_WARNING "scc_rx_int with NULL tty!\n");
            SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
            return IRQ_HANDLED;
      }
      tty_insert_flip_char(tty, ch, 0);

      /* Check if another character is already ready; in that case, the
       * spcond_int() function must be used, because this character may have an
       * error condition that isn't signalled by the interrupt vector used!
       */
      if (SCCread(INT_PENDING_REG) &
          (port->channel == CHANNEL_A ? IPR_A_RX : IPR_B_RX)) {
            scc_spcond_int (irq, data);
            return IRQ_HANDLED;
      }

      SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);

      tty_flip_buffer_push(tty);
      return IRQ_HANDLED;
}


static irqreturn_t scc_spcond_int(int irq, void *data)
{
      struct scc_port *port = data;
      struct tty_struct *tty = port->gs.tty;
      unsigned char     stat, ch, err;
      int         int_pending_mask = port->channel == CHANNEL_A ?
                                     IPR_A_RX : IPR_B_RX;
      SCC_ACCESS_INIT(port);
      
      if (!tty) {
            printk(KERN_WARNING "scc_spcond_int with NULL tty!\n");
            SCCwrite(COMMAND_REG, CR_ERROR_RESET);
            SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
            return IRQ_HANDLED;
      }
      do {
            stat = SCCread(SPCOND_STATUS_REG);
            ch = SCCread_NB(RX_DATA_REG);

            if (stat & SCSR_RX_OVERRUN)
                  err = TTY_OVERRUN;
            else if (stat & SCSR_PARITY_ERR)
                  err = TTY_PARITY;
            else if (stat & SCSR_CRC_FRAME_ERR)
                  err = TTY_FRAME;
            else
                  err = 0;

            tty_insert_flip_char(tty, ch, err);

            /* ++TeSche: *All* errors have to be cleared manually,
             * else the condition persists for the next chars
             */
            if (err)
              SCCwrite(COMMAND_REG, CR_ERROR_RESET);

      } while(SCCread(INT_PENDING_REG) & int_pending_mask);

      SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);

      tty_flip_buffer_push(tty);
      return IRQ_HANDLED;
}


static irqreturn_t scc_tx_int(int irq, void *data)
{
      struct scc_port *port = data;
      SCC_ACCESS_INIT(port);

      if (!port->gs.tty) {
            printk(KERN_WARNING "scc_tx_int with NULL tty!\n");
            SCCmod (INT_AND_DMA_REG, ~IDR_TX_INT_ENAB, 0);
            SCCwrite(COMMAND_REG, CR_TX_PENDING_RESET);
            SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
            return IRQ_HANDLED;
      }
      while ((SCCread_NB(STATUS_REG) & SR_TX_BUF_EMPTY)) {
            if (port->x_char) {
                  SCCwrite(TX_DATA_REG, port->x_char);
                  port->x_char = 0;
            }
            else if ((port->gs.xmit_cnt <= 0) || port->gs.tty->stopped ||
                        port->gs.tty->hw_stopped)
                  break;
            else {
                  SCCwrite(TX_DATA_REG, port->gs.xmit_buf[port->gs.xmit_tail++]);
                  port->gs.xmit_tail = port->gs.xmit_tail & (SERIAL_XMIT_SIZE-1);
                  if (--port->gs.xmit_cnt <= 0)
                        break;
            }
      }
      if ((port->gs.xmit_cnt <= 0) || port->gs.tty->stopped ||
                  port->gs.tty->hw_stopped) {
            /* disable tx interrupts */
            SCCmod (INT_AND_DMA_REG, ~IDR_TX_INT_ENAB, 0);
            SCCwrite(COMMAND_REG, CR_TX_PENDING_RESET);   /* disable tx_int on next tx underrun? */
            port->gs.flags &= ~GS_TX_INTEN;
      }
      if (port->gs.tty && port->gs.xmit_cnt <= port->gs.wakeup_chars)
            tty_wakeup(port->gs.tty);

      SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
      return IRQ_HANDLED;
}


static irqreturn_t scc_stat_int(int irq, void *data)
{
      struct scc_port *port = data;
      unsigned channel = port->channel;
      unsigned char     last_sr, sr, changed;
      SCC_ACCESS_INIT(port);

      last_sr = scc_last_status_reg[channel];
      sr = scc_last_status_reg[channel] = SCCread_NB(STATUS_REG);
      changed = last_sr ^ sr;

      if (changed & SR_DCD) {
            port->c_dcd = !!(sr & SR_DCD);
            if (!(port->gs.flags & ASYNC_CHECK_CD))
                  ;     /* Don't report DCD changes */
            else if (port->c_dcd) {
                  wake_up_interruptible(&port->gs.open_wait);
            }
            else {
                  if (port->gs.tty)
                        tty_hangup (port->gs.tty);
            }
      }
      SCCwrite(COMMAND_REG, CR_EXTSTAT_RESET);
      SCCwrite_NB(COMMAND_REG, CR_HIGHEST_IUS_RESET);
      return IRQ_HANDLED;
}


/*---------------------------------------------------------------------------
 * generic_serial.c callback funtions
 *--------------------------------------------------------------------------*/

static void scc_disable_tx_interrupts(void *ptr)
{
      struct scc_port *port = ptr;
      unsigned long     flags;
      SCC_ACCESS_INIT(port);

      local_irq_save(flags);
      SCCmod(INT_AND_DMA_REG, ~IDR_TX_INT_ENAB, 0);
      port->gs.flags &= ~GS_TX_INTEN;
      local_irq_restore(flags);
}


static void scc_enable_tx_interrupts(void *ptr)
{
      struct scc_port *port = ptr;
      unsigned long     flags;
      SCC_ACCESS_INIT(port);

      local_irq_save(flags);
      SCCmod(INT_AND_DMA_REG, 0xff, IDR_TX_INT_ENAB);
      /* restart the transmitter */
      scc_tx_int (0, port);
      local_irq_restore(flags);
}


static void scc_disable_rx_interrupts(void *ptr)
{
      struct scc_port *port = ptr;
      unsigned long     flags;
      SCC_ACCESS_INIT(port);

      local_irq_save(flags);
      SCCmod(INT_AND_DMA_REG,
          ~(IDR_RX_INT_MASK|IDR_PARERR_AS_SPCOND|IDR_EXTSTAT_INT_ENAB), 0);
      local_irq_restore(flags);
}


static void scc_enable_rx_interrupts(void *ptr)
{
      struct scc_port *port = ptr;
      unsigned long     flags;
      SCC_ACCESS_INIT(port);

      local_irq_save(flags);
      SCCmod(INT_AND_DMA_REG, 0xff,
            IDR_EXTSTAT_INT_ENAB|IDR_PARERR_AS_SPCOND|IDR_RX_INT_ALL);
      local_irq_restore(flags);
}


static int scc_get_CD(void *ptr)
{
      struct scc_port *port = ptr;
      unsigned channel = port->channel;

      return !!(scc_last_status_reg[channel] & SR_DCD);
}


static void scc_shutdown_port(void *ptr)
{
      struct scc_port *port = ptr;

      port->gs.flags &= ~ GS_ACTIVE;
      if (port->gs.tty && port->gs.tty->termios->c_cflag & HUPCL) {
            scc_setsignals (port, 0, 0);
      }
}


static int scc_set_real_termios (void *ptr)
{
      /* the SCC has char sizes 5,7,6,8 in that order! */
      static int chsize_map[4] = { 0, 2, 1, 3 };
      unsigned cflag, baud, chsize, channel, brgval = 0;
      unsigned long flags;
      struct scc_port *port = ptr;
      SCC_ACCESS_INIT(port);

      if (!port->gs.tty || !port->gs.tty->termios) return 0;

      channel = port->channel;

      if (channel == CHANNEL_A)
            return 0;         /* Settings controlled by boot PROM */

      cflag  = port->gs.tty->termios->c_cflag;
      baud = port->gs.baud;
      chsize = (cflag & CSIZE) >> 4;

      if (baud == 0) {
            /* speed == 0 -> drop DTR */
            local_irq_save(flags);
            SCCmod(TX_CTRL_REG, ~TCR_DTR, 0);
            local_irq_restore(flags);
            return 0;
      }
      else if ((MACH_IS_MVME16x && (baud < 50 || baud > 38400)) ||
             (MACH_IS_MVME147 && (baud < 50 || baud > 19200)) ||
             (MACH_IS_BVME6000 &&(baud < 50 || baud > 76800))) {
            printk(KERN_NOTICE "SCC: Bad speed requested, %d\n", baud);
            return 0;
      }

      if (cflag & CLOCAL)
            port->gs.flags &= ~ASYNC_CHECK_CD;
      else
            port->gs.flags |= ASYNC_CHECK_CD;

#ifdef CONFIG_MVME147_SCC
      if (MACH_IS_MVME147)
            brgval = (M147_SCC_PCLK + baud/2) / (16 * 2 * baud) - 2;
#endif
#ifdef CONFIG_MVME162_SCC
      if (MACH_IS_MVME16x)
            brgval = (MVME_SCC_PCLK + baud/2) / (16 * 2 * baud) - 2;
#endif
#ifdef CONFIG_BVME6000_SCC
      if (MACH_IS_BVME6000)
            brgval = (BVME_SCC_RTxC + baud/2) / (16 * 2 * baud) - 2;
#endif
      /* Now we have all parameters and can go to set them: */
      local_irq_save(flags);

      /* receiver's character size and auto-enables */
      SCCmod(RX_CTRL_REG, ~(RCR_CHSIZE_MASK|RCR_AUTO_ENAB_MODE),
                  (chsize_map[chsize] << 6) |
                  ((cflag & CRTSCTS) ? RCR_AUTO_ENAB_MODE : 0));
      /* parity and stop bits (both, Tx and Rx), clock mode never changes */
      SCCmod (AUX1_CTRL_REG,
            ~(A1CR_PARITY_MASK | A1CR_MODE_MASK),
            ((cflag & PARENB
              ? (cflag & PARODD ? A1CR_PARITY_ODD : A1CR_PARITY_EVEN)
              : A1CR_PARITY_NONE)
             | (cflag & CSTOPB ? A1CR_MODE_ASYNC_2 : A1CR_MODE_ASYNC_1)));
      /* sender's character size, set DTR for valid baud rate */
      SCCmod(TX_CTRL_REG, ~TCR_CHSIZE_MASK, chsize_map[chsize] << 5 | TCR_DTR);
      /* clock sources never change */
      /* disable BRG before changing the value */
      SCCmod(DPLL_CTRL_REG, ~DCR_BRG_ENAB, 0);
      /* BRG value */
      SCCwrite(TIMER_LOW_REG, brgval & 0xff);
      SCCwrite(TIMER_HIGH_REG, (brgval >> 8) & 0xff);
      /* BRG enable, and clock source never changes */
      SCCmod(DPLL_CTRL_REG, 0xff, DCR_BRG_ENAB);

      local_irq_restore(flags);

      return 0;
}


static int scc_chars_in_buffer (void *ptr)
{
      struct scc_port *port = ptr;
      SCC_ACCESS_INIT(port);

      return (SCCread (SPCOND_STATUS_REG) & SCSR_ALL_SENT) ? 0  : 1;
}


/* Comment taken from sx.c (2.4.0):
   I haven't the foggiest why the decrement use count has to happen
   here. The whole linux serial drivers stuff needs to be redesigned.
   My guess is that this is a hack to minimize the impact of a bug
   elsewhere. Thinking about it some more. (try it sometime) Try
   running minicom on a serial port that is driven by a modularized
   driver. Have the modem hangup. Then remove the driver module. Then
   exit minicom.  I expect an "oops".  -- REW */

static void scc_hungup(void *ptr)
{
      scc_disable_tx_interrupts(ptr);
      scc_disable_rx_interrupts(ptr);
}


static void scc_close(void *ptr)
{
      scc_disable_tx_interrupts(ptr);
      scc_disable_rx_interrupts(ptr);
}


/*---------------------------------------------------------------------------
 * Internal support functions
 *--------------------------------------------------------------------------*/

static void scc_setsignals(struct scc_port *port, int dtr, int rts)
{
      unsigned long flags;
      unsigned char t;
      SCC_ACCESS_INIT(port);

      local_irq_save(flags);
      t = SCCread(TX_CTRL_REG);
      if (dtr >= 0) t = dtr? (t | TCR_DTR): (t & ~TCR_DTR);
      if (rts >= 0) t = rts? (t | TCR_RTS): (t & ~TCR_RTS);
      SCCwrite(TX_CTRL_REG, t);
      local_irq_restore(flags);
}


static void scc_send_xchar(struct tty_struct *tty, char ch)
{
      struct scc_port *port = (struct scc_port *)tty->driver_data;

      port->x_char = ch;
      if (ch)
            scc_enable_tx_interrupts(port);
}


/*---------------------------------------------------------------------------
 * Driver entrypoints referenced from above
 *--------------------------------------------------------------------------*/

static int scc_open (struct tty_struct * tty, struct file * filp)
{
      int line = tty->index;
      int retval;
      struct scc_port *port = &scc_ports[line];
      int i, channel = port->channel;
      unsigned long     flags;
      SCC_ACCESS_INIT(port);
#if defined(CONFIG_MVME162_SCC) || defined(CONFIG_MVME147_SCC)
      static const struct {
            unsigned reg, val;
      } mvme_init_tab[] = {
            /* Values for MVME162 and MVME147 */
            /* no parity, 1 stop bit, async, 1:16 */
            { AUX1_CTRL_REG, A1CR_PARITY_NONE|A1CR_MODE_ASYNC_1|A1CR_CLKMODE_x16 },
            /* parity error is special cond, ints disabled, no DMA */
            { INT_AND_DMA_REG, IDR_PARERR_AS_SPCOND | IDR_RX_INT_DISAB },
            /* Rx 8 bits/char, no auto enable, Rx off */
            { RX_CTRL_REG, RCR_CHSIZE_8 },
            /* DTR off, Tx 8 bits/char, RTS off, Tx off */
            { TX_CTRL_REG, TCR_CHSIZE_8 },
            /* special features off */
            { AUX2_CTRL_REG, 0 },
            { CLK_CTRL_REG, CCR_RXCLK_BRG | CCR_TXCLK_BRG },
            { DPLL_CTRL_REG, DCR_BRG_ENAB | DCR_BRG_USE_PCLK },
            /* Start Rx */
            { RX_CTRL_REG, RCR_RX_ENAB | RCR_CHSIZE_8 },
            /* Start Tx */
            { TX_CTRL_REG, TCR_TX_ENAB | TCR_RTS | TCR_DTR | TCR_CHSIZE_8 },
            /* Ext/Stat ints: DCD only */
            { INT_CTRL_REG, ICR_ENAB_DCD_INT },
            /* Reset Ext/Stat ints */
            { COMMAND_REG, CR_EXTSTAT_RESET },
            /* ...again */
            { COMMAND_REG, CR_EXTSTAT_RESET },
      };
#endif
#if defined(CONFIG_BVME6000_SCC)
      static const struct {
            unsigned reg, val;
      } bvme_init_tab[] = {
            /* Values for BVME6000 */
            /* no parity, 1 stop bit, async, 1:16 */
            { AUX1_CTRL_REG, A1CR_PARITY_NONE|A1CR_MODE_ASYNC_1|A1CR_CLKMODE_x16 },
            /* parity error is special cond, ints disabled, no DMA */
            { INT_AND_DMA_REG, IDR_PARERR_AS_SPCOND | IDR_RX_INT_DISAB },
            /* Rx 8 bits/char, no auto enable, Rx off */
            { RX_CTRL_REG, RCR_CHSIZE_8 },
            /* DTR off, Tx 8 bits/char, RTS off, Tx off */
            { TX_CTRL_REG, TCR_CHSIZE_8 },
            /* special features off */
            { AUX2_CTRL_REG, 0 },
            { CLK_CTRL_REG, CCR_RTxC_XTAL | CCR_RXCLK_BRG | CCR_TXCLK_BRG },
            { DPLL_CTRL_REG, DCR_BRG_ENAB },
            /* Start Rx */
            { RX_CTRL_REG, RCR_RX_ENAB | RCR_CHSIZE_8 },
            /* Start Tx */
            { TX_CTRL_REG, TCR_TX_ENAB | TCR_RTS | TCR_DTR | TCR_CHSIZE_8 },
            /* Ext/Stat ints: DCD only */
            { INT_CTRL_REG, ICR_ENAB_DCD_INT },
            /* Reset Ext/Stat ints */
            { COMMAND_REG, CR_EXTSTAT_RESET },
            /* ...again */
            { COMMAND_REG, CR_EXTSTAT_RESET },
      };
#endif
      if (!(port->gs.flags & ASYNC_INITIALIZED)) {
            local_irq_save(flags);
#if defined(CONFIG_MVME147_SCC) || defined(CONFIG_MVME162_SCC)
            if (MACH_IS_MVME147 || MACH_IS_MVME16x) {
                  for (i = 0; i < ARRAY_SIZE(mvme_init_tab); ++i)
                        SCCwrite(mvme_init_tab[i].reg, mvme_init_tab[i].val);
            }
#endif
#if defined(CONFIG_BVME6000_SCC)
            if (MACH_IS_BVME6000) {
                  for (i = 0; i < ARRAY_SIZE(bvme_init_tab); ++i)
                        SCCwrite(bvme_init_tab[i].reg, bvme_init_tab[i].val);
            }
#endif

            /* remember status register for detection of DCD and CTS changes */
            scc_last_status_reg[channel] = SCCread(STATUS_REG);

            port->c_dcd = 0;  /* Prevent initial 1->0 interrupt */
            scc_setsignals (port, 1,1);
            local_irq_restore(flags);
      }

      tty->driver_data = port;
      port->gs.tty = tty;
      port->gs.count++;
      retval = gs_init_port(&port->gs);
      if (retval) {
            port->gs.count--;
            return retval;
      }
      port->gs.flags |= GS_ACTIVE;
      retval = gs_block_til_ready(port, filp);

      if (retval) {
            port->gs.count--;
            return retval;
      }

      port->c_dcd = scc_get_CD (port);

      scc_enable_rx_interrupts(port);

      return 0;
}


static void scc_throttle (struct tty_struct * tty)
{
      struct scc_port *port = (struct scc_port *)tty->driver_data;
      unsigned long     flags;
      SCC_ACCESS_INIT(port);

      if (tty->termios->c_cflag & CRTSCTS) {
            local_irq_save(flags);
            SCCmod(TX_CTRL_REG, ~TCR_RTS, 0);
            local_irq_restore(flags);
      }
      if (I_IXOFF(tty))
            scc_send_xchar(tty, STOP_CHAR(tty));
}


static void scc_unthrottle (struct tty_struct * tty)
{
      struct scc_port *port = (struct scc_port *)tty->driver_data;
      unsigned long     flags;
      SCC_ACCESS_INIT(port);

      if (tty->termios->c_cflag & CRTSCTS) {
            local_irq_save(flags);
            SCCmod(TX_CTRL_REG, 0xff, TCR_RTS);
            local_irq_restore(flags);
      }
      if (I_IXOFF(tty))
            scc_send_xchar(tty, START_CHAR(tty));
}


static int scc_ioctl(struct tty_struct *tty, struct file *file,
                 unsigned int cmd, unsigned long arg)
{
      return -ENOIOCTLCMD;
}


static void scc_break_ctl(struct tty_struct *tty, int break_state)
{
      struct scc_port *port = (struct scc_port *)tty->driver_data;
      unsigned long     flags;
      SCC_ACCESS_INIT(port);

      local_irq_save(flags);
      SCCmod(TX_CTRL_REG, ~TCR_SEND_BREAK, 
                  break_state ? TCR_SEND_BREAK : 0);
      local_irq_restore(flags);
}


/*---------------------------------------------------------------------------
 * Serial console stuff...
 *--------------------------------------------------------------------------*/

#define scc_delay() do { __asm__ __volatile__ (" nop; nop"); } while (0)

static void scc_ch_write (char ch)
{
      volatile char *p = NULL;
      
#ifdef CONFIG_MVME147_SCC
      if (MACH_IS_MVME147)
            p = (volatile char *)M147_SCC_A_ADDR;
#endif
#ifdef CONFIG_MVME162_SCC
      if (MACH_IS_MVME16x)
            p = (volatile char *)MVME_SCC_A_ADDR;
#endif
#ifdef CONFIG_BVME6000_SCC
      if (MACH_IS_BVME6000)
            p = (volatile char *)BVME_SCC_A_ADDR;
#endif

      do {
            scc_delay();
      }
      while (!(*p & 4));
      scc_delay();
      *p = 8;
      scc_delay();
      *p = ch;
}

/* The console must be locked when we get here. */

static void scc_console_write (struct console *co, const char *str, unsigned count)
{
      unsigned long     flags;

      local_irq_save(flags);

      while (count--)
      {
            if (*str == '\n')
                  scc_ch_write ('\r');
            scc_ch_write (*str++);
      }
      local_irq_restore(flags);
}

static struct tty_driver *scc_console_device(struct console *c, int *index)
{
      *index = c->index;
      return scc_driver;
}

static struct console sercons = {
      .name       = "ttyS",
      .write            = scc_console_write,
      .device           = scc_console_device,
      .flags            = CON_PRINTBUFFER,
      .index            = -1,
};


static int __init vme_scc_console_init(void)
{
      if (vme_brdtype == VME_TYPE_MVME147 ||
                  vme_brdtype == VME_TYPE_MVME162 ||
                  vme_brdtype == VME_TYPE_MVME172 ||
                  vme_brdtype == VME_TYPE_BVME4000 ||
                  vme_brdtype == VME_TYPE_BVME6000)
            register_console(&sercons);
      return 0;
}
console_initcall(vme_scc_console_init);

Generated by  Doxygen 1.6.0   Back to index