pc300_tty.c

linux-2.6.15.6

/*
 * pc300_tty.c	Cyclades-PC300(tm) TTY Driver.
 *
 * Author:	Regina Kodato <[e-mail]>
 *
 * 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/pci.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(void *data);
static void cpc_tty_tx_work(void *data);
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, (void *)cpc_tty);
	INIT_WORK(&cpc_tty->tty_rx_work, cpc_tty_rx_work, (void *)port);
	
	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);