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pc300_tty.c

/*
 * pc300_tty.c    Cyclades-PC300(tm) TTY Driver.
 *
 * Author:  Regina Kodato <reginak@cyclades.com>
 *
 * Copyright:     (c) 1999-2002 Cyclades Corp.
 *
 *    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.
 *   
 *  $Log: pc300_tty.c,v $
 *  Revision 3.7  2002/03/07 14:17:09  henrique
 *  License data fixed
 *
 *  Revision 3.6  2001/12/10 12:29:42  regina
 *  Fix the MLPPP bug
 *
 *  Revision 3.5  2001/10/31 11:20:05  regina
 *  automatic pppd starts
 *
 *  Revision 3.4  2001/08/06 12:01:51  regina
 *  problem in DSR_DE bit
 *
 *  Revision 3.3  2001/07/26 22:58:41  regina
 *  update EDA value
 *
 *  Revision 3.2  2001/07/12 13:11:20  regina
 *  bug fix - DCD-OFF in pc300 tty driver
 *
 *    DMA transmission bug fix
 *  
 *  Revision 3.1  2001/06/22 13:13:02  regina
 *  MLPPP implementation
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/if.h>
#include <linux/skbuff.h>
/* TTY includes */
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>

#include <asm/io.h>
#include <asm/uaccess.h>

#include "pc300.h"

/* defines and macros */
/* TTY Global definitions */
#define     CPC_TTY_NPORTS    8     /* maximum number of the sync tty connections */
#define     CPC_TTY_MAJOR     CYCLADES_MAJOR    
#define CPC_TTY_MINOR_START   240   /* minor of the first PC300 interface */

#define CPC_TTY_MAX_MTU 2000  

/* tty interface state */
#define     CPC_TTY_ST_IDLE   0
#define CPC_TTY_ST_INIT 1     /* configured with MLPPP and up */
#define CPC_TTY_ST_OPEN 2     /* opened by application */

#define     CPC_TTY_LOCK(card,flags)\
      do {\
            spin_lock_irqsave(&card->card_lock, flags);     \
      } while (0)

#define CPC_TTY_UNLOCK(card,flags)  \
      do {\
            spin_unlock_irqrestore(&card->card_lock, flags);      \
      } while (0)

//#define   CPC_TTY_DBG(format,a...)      printk(format,##a)
#define     CPC_TTY_DBG(format,a...)

/* data structures */
typedef struct _st_cpc_rx_buf {
      struct _st_cpc_rx_buf   *next;
      int         size;
      unsigned char     data[1];
} st_cpc_rx_buf;

struct st_cpc_rx_list {
      st_cpc_rx_buf     *first;
      st_cpc_rx_buf     *last;
};

typedef     struct _st_cpc_tty_area {
      int         state;            /* state of the TTY interface */
      int         num_open;   
      unsigned int      tty_minor;  /* minor this interface */
      volatile struct st_cpc_rx_list buf_rx;    /* ptr. to reception buffer */
      unsigned char*    buf_tx;           /* ptr. to transmission buffer */
      pc300dev_t* pc300dev;   /* ptr. to info struct in PC300 driver */
      unsigned char     name[20];   /* interf. name + "-tty" */
      struct tty_struct *tty;       
      struct work_struct tty_tx_work; /* tx work - tx interrupt */
      struct work_struct tty_rx_work; /* rx work - rx interrupt */
      } st_cpc_tty_area;

/* TTY data structures */
static struct tty_driver serial_drv;

/* local variables */
static st_cpc_tty_area  cpc_tty_area[CPC_TTY_NPORTS];

static int cpc_tty_cnt = 0;   /* number of intrfaces configured with MLPPP */
static int cpc_tty_unreg_flag = 0;

/* TTY functions prototype */
static int cpc_tty_open(struct tty_struct *tty, struct file *flip);
static void cpc_tty_close(struct tty_struct *tty, struct file *flip);
static int cpc_tty_write(struct tty_struct *tty, const unsigned char *buf, int count);
static int cpc_tty_write_room(struct tty_struct *tty);
static int cpc_tty_chars_in_buffer(struct tty_struct *tty);
static void cpc_tty_flush_buffer(struct tty_struct *tty);
static void cpc_tty_hangup(struct tty_struct *tty);
static void cpc_tty_rx_work(struct work_struct *work);
static void cpc_tty_tx_work(struct work_struct *work);
static int cpc_tty_send_to_card(pc300dev_t *dev,void *buf, int len);
static void cpc_tty_trace(pc300dev_t *dev, char* buf, int len, char rxtx);
static void cpc_tty_signal_off(pc300dev_t *pc300dev, unsigned char);
static void cpc_tty_signal_on(pc300dev_t *pc300dev, unsigned char);

static int pc300_tiocmset(struct tty_struct *, struct file *,
                    unsigned int, unsigned int);
static int pc300_tiocmget(struct tty_struct *, struct file *);

/* functions called by PC300 driver */
void cpc_tty_init(pc300dev_t *dev);
void cpc_tty_unregister_service(pc300dev_t *pc300dev);
void cpc_tty_receive(pc300dev_t *pc300dev);
void cpc_tty_trigger_poll(pc300dev_t *pc300dev);
void cpc_tty_reset_var(void);

/*
 * PC300 TTY clear "signal"
 */
static void cpc_tty_signal_off(pc300dev_t *pc300dev, unsigned char signal)
{
      pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan; 
      pc300_t *card = (pc300_t *) pc300chan->card; 
      int ch = pc300chan->channel; 
      unsigned long flags; 

      CPC_TTY_DBG("%s-tty: Clear signal %x\n",
            pc300dev->dev->name, signal);
      CPC_TTY_LOCK(card, flags); 
      cpc_writeb(card->hw.scabase + M_REG(CTL,ch), 
            cpc_readb(card->hw.scabase+M_REG(CTL,ch))& signal);
      CPC_TTY_UNLOCK(card,flags); 
}

/*
 * PC300 TTY set "signal" to ON
 */
static void cpc_tty_signal_on(pc300dev_t *pc300dev, unsigned char signal)
{
      pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan; 
      pc300_t *card = (pc300_t *) pc300chan->card; 
      int ch = pc300chan->channel; 
      unsigned long flags; 

      CPC_TTY_DBG("%s-tty: Set signal %x\n",
            pc300dev->dev->name, signal);
      CPC_TTY_LOCK(card, flags); 
      cpc_writeb(card->hw.scabase + M_REG(CTL,ch), 
            cpc_readb(card->hw.scabase+M_REG(CTL,ch))& ~signal);
      CPC_TTY_UNLOCK(card,flags); 
}

/*
 * PC300 TTY initialization routine
 *
 * This routine is called by the PC300 driver during board configuration 
 * (ioctl=SIOCSP300CONF). At this point the adapter is completely
 * initialized.
 * o verify kernel version (only 2.4.x)
 * o register TTY driver
 * o init cpc_tty_area struct
 */
void cpc_tty_init(pc300dev_t *pc300dev)
{
      unsigned long port;
      int aux;
      st_cpc_tty_area * cpc_tty;

      /* hdlcX - X=interface number */
      port = pc300dev->dev->name[4] - '0';
      if (port >= CPC_TTY_NPORTS) {
            printk("%s-tty: invalid interface selected (0-%i): %li",
                  pc300dev->dev->name,
                  CPC_TTY_NPORTS-1,port);
            return;
      }

      if (cpc_tty_cnt == 0) { /* first TTY connection -> register driver */
            CPC_TTY_DBG("%s-tty: driver init, major:%i, minor range:%i=%i\n",
                  pc300dev->dev->name,
                  CPC_TTY_MAJOR, CPC_TTY_MINOR_START,
                  CPC_TTY_MINOR_START+CPC_TTY_NPORTS);
            /* initialize tty driver struct */
            memset(&serial_drv,0,sizeof(struct tty_driver));
            serial_drv.magic = TTY_DRIVER_MAGIC;
            serial_drv.owner = THIS_MODULE;
            serial_drv.driver_name = "pc300_tty";
            serial_drv.name = "ttyCP";
            serial_drv.major = CPC_TTY_MAJOR;
            serial_drv.minor_start = CPC_TTY_MINOR_START;
            serial_drv.num = CPC_TTY_NPORTS;
            serial_drv.type = TTY_DRIVER_TYPE_SERIAL;
            serial_drv.subtype = SERIAL_TYPE_NORMAL;

            serial_drv.init_termios = tty_std_termios;
            serial_drv.init_termios.c_cflag = B9600|CS8|CREAD|HUPCL|CLOCAL;
            serial_drv.flags = TTY_DRIVER_REAL_RAW;

            /* interface routines from the upper tty layer to the tty driver */
            serial_drv.open = cpc_tty_open;
            serial_drv.close = cpc_tty_close;
            serial_drv.write = cpc_tty_write; 
            serial_drv.write_room = cpc_tty_write_room; 
            serial_drv.chars_in_buffer = cpc_tty_chars_in_buffer; 
            serial_drv.tiocmset = pc300_tiocmset;
            serial_drv.tiocmget = pc300_tiocmget;
            serial_drv.flush_buffer = cpc_tty_flush_buffer; 
            serial_drv.hangup = cpc_tty_hangup;

            /* register the TTY driver */
            if (tty_register_driver(&serial_drv)) { 
                  printk("%s-tty: Failed to register serial driver! ",
                        pc300dev->dev->name);
                  return;
            } 

            memset((void *)cpc_tty_area, 0,
                                                sizeof(st_cpc_tty_area) * CPC_TTY_NPORTS);
      }

      cpc_tty = &cpc_tty_area[port];
      
      if (cpc_tty->state != CPC_TTY_ST_IDLE) {
            CPC_TTY_DBG("%s-tty: TTY port %i, already in use.\n",
                        pc300dev->dev->name, port);
            return;
      }

      cpc_tty_cnt++;
      cpc_tty->state = CPC_TTY_ST_INIT; 
      cpc_tty->num_open= 0;
      cpc_tty->tty_minor = port + CPC_TTY_MINOR_START;
      cpc_tty->pc300dev = pc300dev; 

      INIT_WORK(&cpc_tty->tty_tx_work, cpc_tty_tx_work);
      INIT_WORK(&cpc_tty->tty_rx_work, cpc_tty_rx_work);
      
      cpc_tty->buf_rx.first = cpc_tty->buf_rx.last = NULL;

      pc300dev->cpc_tty = (void *)cpc_tty; 
      
      aux = strlen(pc300dev->dev->name);
      memcpy(cpc_tty->name, pc300dev->dev->name, aux);
      memcpy(&cpc_tty->name[aux], "-tty", 5);
      
      cpc_open(pc300dev->dev);
      cpc_tty_signal_off(pc300dev, CTL_DTR);

      CPC_TTY_DBG("%s: Initializing TTY Sync Driver, tty major#%d minor#%i\n",
                  cpc_tty->name,CPC_TTY_MAJOR,cpc_tty->tty_minor); 
      return; 
} 

/*
 * PC300 TTY OPEN routine
 *
 * This routine is called by the tty driver to open the interface 
 * o verify minor
 * o allocate buffer to Rx and Tx
 */
static int cpc_tty_open(struct tty_struct *tty, struct file *flip)
{
      int port ;
      st_cpc_tty_area *cpc_tty;

      if (!tty) { 
            return -ENODEV;
      } 

      port = tty->index;

      if ((port < 0) || (port >= CPC_TTY_NPORTS)){ 
            CPC_TTY_DBG("pc300_tty: open invalid port %d\n", port);
            return -ENODEV;
      } 

      cpc_tty = &cpc_tty_area[port];
      
      if (cpc_tty->state == CPC_TTY_ST_IDLE){
            CPC_TTY_DBG("%s: open - invalid interface, port=%d\n",
                              cpc_tty->name, tty->index);
            return -ENODEV;
      }

      if (cpc_tty->num_open == 0) { /* first open of this tty */
            if (!cpc_tty_area[port].buf_tx){
                  cpc_tty_area[port].buf_tx = kmalloc(CPC_TTY_MAX_MTU,GFP_KERNEL);
                  if (cpc_tty_area[port].buf_tx == 0){
                        CPC_TTY_DBG("%s: error in memory allocation\n",cpc_tty->name);
                        return -ENOMEM;
                  }
            } 

            if (cpc_tty_area[port].buf_rx.first) {
                  unsigned char * aux;
                  while (cpc_tty_area[port].buf_rx.first) {
                        aux = (unsigned char *)cpc_tty_area[port].buf_rx.first;
                        cpc_tty_area[port].buf_rx.first = cpc_tty_area[port].buf_rx.first->next;
                        kfree(aux);
                  }
                  cpc_tty_area[port].buf_rx.first = NULL;
                  cpc_tty_area[port].buf_rx.last = NULL;
            }

            cpc_tty_area[port].state = CPC_TTY_ST_OPEN;
            cpc_tty_area[port].tty = tty;
            tty->driver_data = &cpc_tty_area[port];

            cpc_tty_signal_on(cpc_tty->pc300dev, CTL_DTR);
      } 

      cpc_tty->num_open++;

      CPC_TTY_DBG("%s: opening TTY driver\n", cpc_tty->name);
      
      /* avisar driver PC300 */ 
      return 0; 
}

/*
 * PC300 TTY CLOSE routine
 *
 * This routine is called by the tty driver to close the interface 
 * o call close channel in PC300 driver (cpc_closech)
 * o free Rx and Tx buffers
 */

static void cpc_tty_close(struct tty_struct *tty, struct file *flip)
{
      st_cpc_tty_area    *cpc_tty;
      unsigned long flags;
      int res;

      if (!tty || !tty->driver_data ) {
            CPC_TTY_DBG("hdlx-tty: no TTY in close \n");
            return;
      }

      cpc_tty = (st_cpc_tty_area *) tty->driver_data;

      if ((cpc_tty->tty != tty)|| (cpc_tty->state != CPC_TTY_ST_OPEN)) {
            CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
            return;
      }
      
      if (!cpc_tty->num_open) {
            CPC_TTY_DBG("%s: TTY is closed\n",cpc_tty->name);
            return;
      }

      if (--cpc_tty->num_open > 0) {
            CPC_TTY_DBG("%s: TTY closed\n",cpc_tty->name);
            return;
      }

      cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);

      CPC_TTY_LOCK(cpc_tty->pc300dev->chan->card, flags);  /* lock irq */ 
      cpc_tty->tty = NULL;
      cpc_tty->state = CPC_TTY_ST_INIT;
      CPC_TTY_UNLOCK(cpc_tty->pc300dev->chan->card, flags); /* unlock irq */ 
      
      if (cpc_tty->buf_rx.first) {
            unsigned char * aux;
            while (cpc_tty->buf_rx.first) {
                  aux = (unsigned char *)cpc_tty->buf_rx.first;
                  cpc_tty->buf_rx.first = cpc_tty->buf_rx.first->next;
                  kfree(aux);
            }
            cpc_tty->buf_rx.first = NULL;
            cpc_tty->buf_rx.last = NULL;
      }
      
      kfree(cpc_tty->buf_tx);
      cpc_tty->buf_tx = NULL;

      CPC_TTY_DBG("%s: TTY closed\n",cpc_tty->name);
      
      if (!serial_drv.refcount && cpc_tty_unreg_flag) {
            cpc_tty_unreg_flag = 0;
            CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
            if ((res=tty_unregister_driver(&serial_drv))) { 
                  CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n",
                                          cpc_tty->name,res);
            }
      }
      return; 
} 

/*
 * PC300 TTY WRITE routine
 *
 * This routine is called by the tty driver to write a series of characters
 * to the tty device. The characters may come from user or kernel space.
 * o verify the DCD signal
 * o send characters to board and start the transmission
 */
static int cpc_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
      st_cpc_tty_area    *cpc_tty; 
      pc300ch_t *pc300chan; 
      pc300_t *card; 
      int ch; 
      unsigned long flags; 
      struct net_device_stats *stats; 

      if (!tty || !tty->driver_data ) { 
            CPC_TTY_DBG("hdlcX-tty: no TTY in write\n");
            return -ENODEV;
      } 

      cpc_tty = (st_cpc_tty_area *) tty->driver_data; 

      if ((cpc_tty->tty != tty) ||  (cpc_tty->state != CPC_TTY_ST_OPEN)) { 
            CPC_TTY_DBG("%s: TTY is not opened\n", cpc_tty->name);
            return -ENODEV; 
      }

      if (count > CPC_TTY_MAX_MTU) { 
            CPC_TTY_DBG("%s: count is invalid\n",cpc_tty->name);
            return -EINVAL;        /* frame too big */ 
      }

      CPC_TTY_DBG("%s: cpc_tty_write data len=%i\n",cpc_tty->name,count);
      
      pc300chan = (pc300ch_t *)((pc300dev_t*)cpc_tty->pc300dev)->chan; 
      stats = hdlc_stats(((pc300dev_t*)cpc_tty->pc300dev)->dev);
      card = (pc300_t *) pc300chan->card;
      ch = pc300chan->channel; 

      /* verify DCD signal*/ 
      if (cpc_readb(card->hw.scabase + M_REG(ST3,ch)) & ST3_DCD) { 
            /* DCD is OFF */ 
            CPC_TTY_DBG("%s : DCD is OFF\n", cpc_tty->name);
            stats->tx_errors++;
            stats->tx_carrier_errors++;
            CPC_TTY_LOCK(card, flags); 
            cpc_writeb(card->hw.scabase + M_REG(CMD, ch), CMD_TX_BUF_CLR); 
            
            if (card->hw.type == PC300_TE) { 
                  cpc_writeb(card->hw.falcbase + card->hw.cpld_reg2, 
                        cpc_readb(card->hw.falcbase + card->hw.cpld_reg2) & 
                        ~(CPLD_REG2_FALC_LED1 << (2 *ch))); 
            }

            CPC_TTY_UNLOCK(card, flags); 

            return -EINVAL; 
      }

      if (cpc_tty_send_to_card(cpc_tty->pc300dev, (void*)buf, count)) { 
         /* failed to send */
         CPC_TTY_DBG("%s: trasmition error\n", cpc_tty->name);
         return 0;
      }
      return count; 
} 

/*
 * PC300 TTY Write Room routine
 * 
 * This routine returns the numbers of characteres the tty driver will accept
 * for queuing to be written. 
 * o return MTU
 */
static int cpc_tty_write_room(struct tty_struct *tty)
{
      st_cpc_tty_area    *cpc_tty; 

      if (!tty || !tty->driver_data ) { 
            CPC_TTY_DBG("hdlcX-tty: no TTY to write room\n");
            return -ENODEV;
      }

      cpc_tty = (st_cpc_tty_area *) tty->driver_data; 

      if ((cpc_tty->tty != tty) ||  (cpc_tty->state != CPC_TTY_ST_OPEN)) { 
            CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
            return -ENODEV; 
      }
      
      CPC_TTY_DBG("%s: write room\n",cpc_tty->name);
      
      return CPC_TTY_MAX_MTU;
} 

/*
 * PC300 TTY chars in buffer routine
 * 
 * This routine returns the chars number in the transmission buffer 
 * o returns 0
 */
static int cpc_tty_chars_in_buffer(struct tty_struct *tty)
{
      st_cpc_tty_area    *cpc_tty; 

      if (!tty || !tty->driver_data ) {
            CPC_TTY_DBG("hdlcX-tty: no TTY to chars in buffer\n");
            return -ENODEV; 
      }

      cpc_tty = (st_cpc_tty_area *) tty->driver_data; 

      if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) { 
            CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
            return -ENODEV; 
      }
   
      return(0); 
} 

static int pc300_tiocmset(struct tty_struct *tty, struct file *file,
                    unsigned int set, unsigned int clear)
{
      st_cpc_tty_area    *cpc_tty; 

      CPC_TTY_DBG("%s: set:%x clear:%x\n", __FUNCTION__, set, clear);

      if (!tty || !tty->driver_data ) {
            CPC_TTY_DBG("hdlcX-tty: no TTY to chars in buffer\n");      
            return -ENODEV; 
      }

      cpc_tty = (st_cpc_tty_area *) tty->driver_data; 

      if (set & TIOCM_RTS)
            cpc_tty_signal_on(cpc_tty->pc300dev, CTL_RTS);
      if (set & TIOCM_DTR)
            cpc_tty_signal_on(cpc_tty->pc300dev, CTL_DTR);

      if (clear & TIOCM_RTS)
            cpc_tty_signal_off(cpc_tty->pc300dev, CTL_RTS);
      if (clear & TIOCM_DTR)
            cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);

      return 0;
}

static int pc300_tiocmget(struct tty_struct *tty, struct file *file)
{
      unsigned int result;
      unsigned char status;
      unsigned long flags;
      st_cpc_tty_area  *cpc_tty = (st_cpc_tty_area *) tty->driver_data;
      pc300dev_t *pc300dev = cpc_tty->pc300dev;
      pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan;
      pc300_t *card = (pc300_t *) pc300chan->card;
      int ch = pc300chan->channel;

      cpc_tty = (st_cpc_tty_area *) tty->driver_data;

      CPC_TTY_DBG("%s-tty: tiocmget\n",
            ((struct net_device*)(pc300dev->hdlc))->name);

      CPC_TTY_LOCK(card, flags);
      status = cpc_readb(card->hw.scabase+M_REG(CTL,ch));
      CPC_TTY_UNLOCK(card,flags);

      result = ((status & CTL_DTR) ? TIOCM_DTR : 0) |
             ((status & CTL_RTS) ? TIOCM_RTS : 0);

      return result;
}

/*
 * PC300 TTY Flush Buffer routine
 *
 * This routine resets the transmission buffer 
 */
static void cpc_tty_flush_buffer(struct tty_struct *tty)
{ 
      st_cpc_tty_area    *cpc_tty; 
      
      if (!tty || !tty->driver_data ) {
            CPC_TTY_DBG("hdlcX-tty: no TTY to flush buffer\n");   
            return; 
      }

      cpc_tty = (st_cpc_tty_area *) tty->driver_data; 

      if ((cpc_tty->tty != tty) ||  (cpc_tty->state != CPC_TTY_ST_OPEN)) { 
            CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
            return; 
      }

      CPC_TTY_DBG("%s: call wake_up_interruptible\n",cpc_tty->name);

      tty_wakeup(tty);  
      return; 
} 

/*
 * PC300 TTY Hangup routine
 *
 * This routine is called by the tty driver to hangup the interface 
 * o clear DTR signal
 */

static void cpc_tty_hangup(struct tty_struct *tty)
{ 
      st_cpc_tty_area    *cpc_tty; 
      int res;

      if (!tty || !tty->driver_data ) {
            CPC_TTY_DBG("hdlcX-tty: no TTY to hangup\n");   
            return ; 
      }

      cpc_tty = (st_cpc_tty_area *) tty->driver_data; 

      if ((cpc_tty->tty != tty) || (cpc_tty->state != CPC_TTY_ST_OPEN)) {
            CPC_TTY_DBG("%s: TTY is not opened\n",cpc_tty->name);
            return ;
      }
      if (!serial_drv.refcount && cpc_tty_unreg_flag) {
            cpc_tty_unreg_flag = 0;
            CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
            if ((res=tty_unregister_driver(&serial_drv))) { 
                  CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n",
                                          cpc_tty->name,res);
            }
      }
      cpc_tty_signal_off(cpc_tty->pc300dev, CTL_DTR);
}

/*
 * PC300 TTY RX work routine
 * This routine treats RX work
 * o verify read buffer
 * o call the line disc. read
 * o free memory
 */
static void cpc_tty_rx_work(struct work_struct *work)
{
      st_cpc_tty_area *cpc_tty;
      unsigned long port;
      int i, j;
      volatile st_cpc_rx_buf *buf;
      char flags=0,flg_rx=1; 
      struct tty_ldisc *ld;

      if (cpc_tty_cnt == 0) return;
      
      for (i=0; (i < 4) && flg_rx ; i++) {
            flg_rx = 0;

            cpc_tty = container_of(work, st_cpc_tty_area, tty_rx_work);
            port = cpc_tty - cpc_tty_area;

            for (j=0; j < CPC_TTY_NPORTS; j++) {
                  cpc_tty = &cpc_tty_area[port];
            
                  if ((buf=cpc_tty->buf_rx.first) != 0) {
                        if (cpc_tty->tty) {
                              ld = tty_ldisc_ref(cpc_tty->tty);
                              if (ld) {
                                    if (ld->receive_buf) {
                                          CPC_TTY_DBG("%s: call line disc. receive_buf\n",cpc_tty->name);
                                          ld->receive_buf(cpc_tty->tty, (char *)(buf->data), &flags, buf->size);
                                    }
                                    tty_ldisc_deref(ld);
                              }
                        }     
                        cpc_tty->buf_rx.first = cpc_tty->buf_rx.first->next;
                        kfree((void *)buf);
                        buf = cpc_tty->buf_rx.first;
                        flg_rx = 1;
                  }
                  if (++port == CPC_TTY_NPORTS) port = 0;
            }
      }
} 

/*
 * PC300 TTY RX work routine
 *
 * This routine treats RX interrupt. 
 * o read all frames in card
 * o verify the frame size
 * o read the frame in rx buffer
 */
static void cpc_tty_rx_disc_frame(pc300ch_t *pc300chan)
{
      volatile pcsca_bd_t __iomem * ptdescr; 
      volatile unsigned char status; 
      pc300_t *card = (pc300_t *)pc300chan->card; 
      int ch = pc300chan->channel; 

      /* dma buf read */ 
      ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + 
                        RX_BD_ADDR(ch, pc300chan->rx_first_bd)); 
      while (pc300chan->rx_first_bd != pc300chan->rx_last_bd) { 
            status = cpc_readb(&ptdescr->status); 
            cpc_writeb(&ptdescr->status, 0); 
            cpc_writeb(&ptdescr->len, 0); 
            pc300chan->rx_first_bd = (pc300chan->rx_first_bd + 1) & 
                              (N_DMA_RX_BUF - 1); 
            if (status & DST_EOM) { 
                  break; /* end of message */
            }
            ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + cpc_readl(&ptdescr->next)); 
      }
}

void cpc_tty_receive(pc300dev_t *pc300dev)
{
      st_cpc_tty_area *cpc_tty; 
      pc300ch_t *pc300chan = (pc300ch_t *)pc300dev->chan; 
      pc300_t *card = (pc300_t *)pc300chan->card; 
      int ch = pc300chan->channel; 
      volatile pcsca_bd_t  __iomem * ptdescr; 
      struct net_device_stats *stats = hdlc_stats(pc300dev->dev);
      int rx_len, rx_aux; 
      volatile unsigned char status; 
      unsigned short first_bd = pc300chan->rx_first_bd;
      st_cpc_rx_buf *new = NULL;
      unsigned char dsr_rx;

      if (pc300dev->cpc_tty == NULL) { 
            return; 
      }

      dsr_rx = cpc_readb(card->hw.scabase + DSR_RX(ch));

      cpc_tty = (st_cpc_tty_area *)pc300dev->cpc_tty; 

      while (1) { 
            rx_len = 0;
            ptdescr = (pcsca_bd_t  __iomem *)(card->hw.rambase + RX_BD_ADDR(ch, first_bd));
            while ((status = cpc_readb(&ptdescr->status)) & DST_OSB) {
                  rx_len += cpc_readw(&ptdescr->len);
                  first_bd = (first_bd + 1) & (N_DMA_RX_BUF - 1);
                  if (status & DST_EOM) {
                        break;
                  }
                  ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase+cpc_readl(&ptdescr->next));
            }
                  
            if (!rx_len) { 
                  if (dsr_rx & DSR_BOF) {
                        /* update EDA */ 
                        cpc_writel(card->hw.scabase + DRX_REG(EDAL, ch), 
                                    RX_BD_ADDR(ch, pc300chan->rx_last_bd)); 
                  }
                  kfree(new);
                  return; 
            }
            
            if (rx_len > CPC_TTY_MAX_MTU) { 
                  /* Free RX descriptors */ 
                  CPC_TTY_DBG("%s: frame size is invalid.\n",cpc_tty->name);
                  stats->rx_errors++; 
                  stats->rx_frame_errors++; 
                  cpc_tty_rx_disc_frame(pc300chan);
                  continue;
            } 
            
            new = kmalloc(rx_len + sizeof(st_cpc_rx_buf), GFP_ATOMIC);
            if (new == 0) {
                  cpc_tty_rx_disc_frame(pc300chan);
                  continue;
            }
            
            /* dma buf read */ 
            ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + 
                        RX_BD_ADDR(ch, pc300chan->rx_first_bd)); 

            rx_len = 0; /* counter frame size */
            
            while ((status = cpc_readb(&ptdescr->status)) & DST_OSB) {
                  rx_aux = cpc_readw(&ptdescr->len);
                  if ((status & (DST_OVR | DST_CRC | DST_RBIT |  DST_SHRT | DST_ABT))
                        || (rx_aux > BD_DEF_LEN)) {
                        CPC_TTY_DBG("%s: reception error\n", cpc_tty->name);
                        stats->rx_errors++; 
                        if (status & DST_OVR) { 
                              stats->rx_fifo_errors++; 
                        }
                        if (status & DST_CRC) { 
                              stats->rx_crc_errors++; 
                        }
                        if ((status & (DST_RBIT | DST_SHRT | DST_ABT)) ||
                              (rx_aux > BD_DEF_LEN))  { 
                              stats->rx_frame_errors++; 
                        } 
                        /* discard remainig descriptors used by the bad frame */ 
                        CPC_TTY_DBG("%s: reception error - discard descriptors",
                                    cpc_tty->name);
                        cpc_tty_rx_disc_frame(pc300chan);
                        rx_len = 0;
                        kfree(new);
                        new = NULL;
                        break; /* read next frame - while(1) */
                  }

                  if (cpc_tty->state != CPC_TTY_ST_OPEN) {
                        /* Free RX descriptors */ 
                        cpc_tty_rx_disc_frame(pc300chan);
                        stats->rx_dropped++; 
                        rx_len = 0; 
                        kfree(new);
                        new = NULL;
                        break; /* read next frame - while(1) */
                  }

                  /* read the segment of the frame */
                  if (rx_aux != 0) {
                        memcpy_fromio((new->data + rx_len), 
                              (void __iomem *)(card->hw.rambase + 
                               cpc_readl(&ptdescr->ptbuf)), rx_aux);
                        rx_len += rx_aux; 
                  }
                  cpc_writeb(&ptdescr->status,0); 
                  cpc_writeb(&ptdescr->len, 0); 
                  pc300chan->rx_first_bd = (pc300chan->rx_first_bd + 1) & 
                              (N_DMA_RX_BUF -1); 
                  if (status & DST_EOM)break;
                  
                  ptdescr = (pcsca_bd_t __iomem *) (card->hw.rambase + 
                              cpc_readl(&ptdescr->next)); 
            }
            /* update pointer */ 
            pc300chan->rx_last_bd = (pc300chan->rx_first_bd - 1) & 
                              (N_DMA_RX_BUF - 1) ; 
            if (!(dsr_rx & DSR_BOF)) {
                  /* update EDA */ 
                  cpc_writel(card->hw.scabase + DRX_REG(EDAL, ch), 
                              RX_BD_ADDR(ch, pc300chan->rx_last_bd)); 
            }
            if (rx_len != 0) { 
                  stats->rx_bytes += rx_len; 
            
                  if (pc300dev->trace_on) { 
                        cpc_tty_trace(pc300dev, new->data,rx_len, 'R'); 
                  } 
                  new->size = rx_len;
                  new->next = NULL;
                  if (cpc_tty->buf_rx.first == 0) {
                        cpc_tty->buf_rx.first = new;
                        cpc_tty->buf_rx.last = new;
                  } else {
                        cpc_tty->buf_rx.last->next = new;
                        cpc_tty->buf_rx.last = new;
                  }
                  schedule_work(&(cpc_tty->tty_rx_work));
                  stats->rx_packets++;
            }
      } 
} 

/*
 * PC300 TTY TX work routine
 * 
 * This routine treats TX interrupt. 
 * o if need call line discipline wakeup
 * o call wake_up_interruptible
 */
static void cpc_tty_tx_work(struct work_struct *work)
{
      st_cpc_tty_area *cpc_tty =
            container_of(work, st_cpc_tty_area, tty_tx_work);
      struct tty_struct *tty; 

      CPC_TTY_DBG("%s: cpc_tty_tx_work init\n",cpc_tty->name);
      
      if ((tty = cpc_tty->tty) == 0) { 
            CPC_TTY_DBG("%s: the interface is not opened\n",cpc_tty->name);
            return; 
      }
      tty_wakeup(tty);
}

/*
 * PC300 TTY send to card routine
 * 
 * This routine send data to card. 
 * o clear descriptors
 * o write data to DMA buffers
 * o start the transmission
 */
static int cpc_tty_send_to_card(pc300dev_t *dev,void* buf, int len)
{
      pc300ch_t *chan = (pc300ch_t *)dev->chan; 
      pc300_t *card = (pc300_t *)chan->card; 
      int ch = chan->channel; 
      struct net_device_stats *stats = hdlc_stats(dev->dev);
      unsigned long flags; 
      volatile pcsca_bd_t __iomem *ptdescr; 
      int i, nchar;
      int tosend = len;
      int nbuf = ((len - 1)/BD_DEF_LEN) + 1;
      unsigned char *pdata=buf;

      CPC_TTY_DBG("%s:cpc_tty_send_to_cars len=%i", 
                  (st_cpc_tty_area *)dev->cpc_tty->name,len);     

      if (nbuf >= card->chan[ch].nfree_tx_bd) {
            return 1;
      }
      
      /* write buffer to DMA buffers */ 
      CPC_TTY_DBG("%s: call dma_buf_write\n",
                  (st_cpc_tty_area *)dev->cpc_tty->name);   
      for (i = 0 ; i < nbuf ; i++) {
            ptdescr = (pcsca_bd_t __iomem *)(card->hw.rambase + 
                  TX_BD_ADDR(ch, card->chan[ch].tx_next_bd));
            nchar = (BD_DEF_LEN > tosend) ? tosend : BD_DEF_LEN;
            if (cpc_readb(&ptdescr->status) & DST_OSB) {
                  memcpy_toio((void __iomem *)(card->hw.rambase + 
                        cpc_readl(&ptdescr->ptbuf)), 
                        &pdata[len - tosend], 
                        nchar);
                  card->chan[ch].nfree_tx_bd--;
                  if ((i + 1) == nbuf) {
                        /* This must be the last BD to be used */
                        cpc_writeb(&ptdescr->status, DST_EOM);
                  } else {
                        cpc_writeb(&ptdescr->status, 0);
                  }
                  cpc_writew(&ptdescr->len, nchar);
            } else {
                  CPC_TTY_DBG("%s: error in dma_buf_write\n",
                              (st_cpc_tty_area *)dev->cpc_tty->name);   
                  stats->tx_dropped++;
                  return 1; 
            }
            tosend -= nchar;
            card->chan[ch].tx_next_bd = 
                  (card->chan[ch].tx_next_bd + 1) & (N_DMA_TX_BUF - 1);
      }

      if (dev->trace_on) { 
            cpc_tty_trace(dev, buf, len,'T'); 
      }

      /* start transmission */ 
      CPC_TTY_DBG("%s: start transmission\n",
            (st_cpc_tty_area *)dev->cpc_tty->name);   
      
      CPC_TTY_LOCK(card, flags); 
      cpc_writeb(card->hw.scabase + DTX_REG(EDAL, ch), 
                  TX_BD_ADDR(ch, chan->tx_next_bd)); 
      cpc_writeb(card->hw.scabase + M_REG(CMD, ch), CMD_TX_ENA); 
      cpc_writeb(card->hw.scabase + DSR_TX(ch), DSR_DE); 

      if (card->hw.type == PC300_TE) { 
            cpc_writeb(card->hw.falcbase + card->hw.cpld_reg2, 
                  cpc_readb(card->hw.falcbase + card->hw.cpld_reg2) |
                  (CPLD_REG2_FALC_LED1 << (2 * ch))); 
      }
      CPC_TTY_UNLOCK(card, flags); 
      return 0; 
} 

/*
 *    PC300 TTY trace routine
 *
 *  This routine send trace of connection to application. 
 *  o clear descriptors
 *  o write data to DMA buffers
 *  o start the transmission
 */

static void cpc_tty_trace(pc300dev_t *dev, char* buf, int len, char rxtx)
{
      struct sk_buff *skb; 

      if ((skb = dev_alloc_skb(10 + len)) == NULL) { 
            /* out of memory */ 
            CPC_TTY_DBG("%s: tty_trace - out of memory\n", dev->dev->name);
            return; 
      }

      skb_put (skb, 10 + len); 
      skb->dev = dev->dev; 
      skb->protocol = htons(ETH_P_CUST); 
      skb_reset_mac_header(skb);
      skb->pkt_type = PACKET_HOST; 
      skb->len = 10 + len; 

      skb_copy_to_linear_data(skb, dev->dev->name, 5);
      skb->data[5] = '['; 
      skb->data[6] = rxtx; 
      skb->data[7] = ']'; 
      skb->data[8] = ':'; 
      skb->data[9] = ' '; 
      skb_copy_to_linear_data_offset(skb, 10, buf, len);
      netif_rx(skb); 
}     

/*
 *    PC300 TTY unregister service routine
 *
 *    This routine unregister one interface. 
 */
void cpc_tty_unregister_service(pc300dev_t *pc300dev)
{
      st_cpc_tty_area *cpc_tty; 
      ulong flags;
      int res;

      if ((cpc_tty= (st_cpc_tty_area *) pc300dev->cpc_tty) == 0) { 
            CPC_TTY_DBG("%s: interface is not TTY\n", pc300dev->dev->name);
            return; 
      }
      CPC_TTY_DBG("%s: cpc_tty_unregister_service", cpc_tty->name);

      if (cpc_tty->pc300dev != pc300dev) { 
            CPC_TTY_DBG("%s: invalid tty ptr=%s\n", 
            pc300dev->dev->name, cpc_tty->name);
            return; 
      }

      if (--cpc_tty_cnt == 0) { 
            if (serial_drv.refcount) {
                  CPC_TTY_DBG("%s: unregister is not possible, refcount=%d",
                                          cpc_tty->name, serial_drv.refcount);
                  cpc_tty_cnt++;
                  cpc_tty_unreg_flag = 1;
                  return;
            } else { 
                  CPC_TTY_DBG("%s: unregister the tty driver\n", cpc_tty->name);
                  if ((res=tty_unregister_driver(&serial_drv))) { 
                        CPC_TTY_DBG("%s: ERROR ->unregister the tty driver error=%d\n",
                                                cpc_tty->name,res);
                  }
            }
      }
      CPC_TTY_LOCK(pc300dev->chan->card,flags);
      cpc_tty->tty = NULL; 
      CPC_TTY_UNLOCK(pc300dev->chan->card, flags);
      cpc_tty->tty_minor = 0; 
      cpc_tty->state = CPC_TTY_ST_IDLE; 
} 

/*
 * PC300 TTY trigger poll routine
 * This routine is called by pc300driver to treats Tx interrupt. 
 */
void cpc_tty_trigger_poll(pc300dev_t *pc300dev)
{
      st_cpc_tty_area *cpc_tty = (st_cpc_tty_area *)pc300dev->cpc_tty; 
      if (!cpc_tty) {
            return;
      }
      schedule_work(&(cpc_tty->tty_tx_work)); 
} 

/*
 * PC300 TTY reset var routine
 * This routine is called by pc300driver to init the TTY area. 
 */

void cpc_tty_reset_var(void)
{
      int i ; 

      CPC_TTY_DBG("hdlcX-tty: reset variables\n");
      /* reset  the tty_driver structure - serial_drv */ 
      memset(&serial_drv, 0, sizeof(struct tty_driver));
      for (i=0; i < CPC_TTY_NPORTS; i++){
            memset(&cpc_tty_area[i],0, sizeof(st_cpc_tty_area)); 
      }
}

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