elsa_ser.c

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/* $Id: elsa_ser.c,v 2.10 2000/11/19 17:02:47 kai Exp $
 *
 * stuff for the serial modem on ELSA cards
 *
 * This file is (c) under GNU PUBLIC LICENSE
 *
 */
#include <linux/config.h>
#include <linux/serial.h>
#include <linux/serial_reg.h>

#define MAX_MODEM_BUF	256
#define WAKEUP_CHARS	(MAX_MODEM_BUF/2)
#define RS_ISR_PASS_LIMIT 256
#define BASE_BAUD ( 1843200 / 16 )

#ifndef MIN
#define MIN(a,b)	((a) < (b) ? (a) : (b))
#endif

//#define SERIAL_DEBUG_OPEN 1
//#define SERIAL_DEBUG_INTR 1
//#define SERIAL_DEBUG_FLOW 1
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_INTR
#undef SERIAL_DEBUG_FLOW
#undef SERIAL_DEBUG_REG
//#define SERIAL_DEBUG_REG 1

#ifdef SERIAL_DEBUG_REG
static u_char deb[32];
const char *ModemIn[] = {"RBR","IER","IIR","LCR","MCR","LSR","MSR","SCR"};
const char *ModemOut[] = {"THR","IER","FCR","LCR","MCR","LSR","MSR","SCR"};
#endif

static char *MInit_1 = "AT&F&C1E0&D2\r\0";
static char *MInit_2 = "ATL2M1S64=13\r\0";
static char *MInit_3 = "AT+FCLASS=0\r\0";
static char *MInit_4 = "ATV1S2=128X1\r\0";
static char *MInit_5 = "AT\\V8\\N3\r\0";
static char *MInit_6 = "ATL0M0&G0%E1\r\0";
static char *MInit_7 = "AT%L1%M0%C3\r\0";

static char *MInit_speed28800 = "AT%G0%B28800\r\0";

static char *MInit_dialout = "ATs7=60 x1 d\r\0";
static char *MInit_dialin = "ATs7=60 x1 a\r\0";


static inline unsigned int serial_in(struct IsdnCardState *cs, int offset)
{
#ifdef SERIAL_DEBUG_REG
	u_int val = inb(cs->hw.elsa.base + 8 + offset);
	debugl1(cs,"in   %s %02x",ModemIn[offset], val);
	return(val);
#else
	return inb(cs->hw.elsa.base + 8 + offset);
#endif
}

static inline unsigned int serial_inp(struct IsdnCardState *cs, int offset)
{
#ifdef SERIAL_DEBUG_REG
#ifdef CONFIG_SERIAL_NOPAUSE_IO
	u_int val = inb(cs->hw.elsa.base + 8 + offset);
	debugl1(cs,"inp  %s %02x",ModemIn[offset], val);
#else
	u_int val = inb_p(cs->hw.elsa.base + 8 + offset);
	debugl1(cs,"inP  %s %02x",ModemIn[offset], val);
#endif
	return(val);
#else
#ifdef CONFIG_SERIAL_NOPAUSE_IO
	return inb(cs->hw.elsa.base + 8 + offset);
#else
	return inb_p(cs->hw.elsa.base + 8 + offset);
#endif
#endif
}

static inline void serial_out(struct IsdnCardState *cs, int offset, int value)
{
#ifdef SERIAL_DEBUG_REG
	debugl1(cs,"out  %s %02x",ModemOut[offset], value);
#endif
	outb(value, cs->hw.elsa.base + 8 + offset);
}

static inline void serial_outp(struct IsdnCardState *cs, int offset,
			       int value)
{
#ifdef SERIAL_DEBUG_REG
#ifdef CONFIG_SERIAL_NOPAUSE_IO
	debugl1(cs,"outp %s %02x",ModemOut[offset], value);
#else
	debugl1(cs,"outP %s %02x",ModemOut[offset], value);
#endif
#endif
#ifdef CONFIG_SERIAL_NOPAUSE_IO
	outb(value, cs->hw.elsa.base + 8 + offset);
#else
    	outb_p(value, cs->hw.elsa.base + 8 + offset);
#endif
}

/*
 * 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 IsdnCardState *cs, int baud)
{
	int	quot = 0, baud_base;
	unsigned cval, fcr = 0;
	int	bits;
	unsigned long	flags;


	/* byte size and parity */
	cval = 0x03; bits = 10;
	/* Determine divisor based on baud rate */
	baud_base = BASE_BAUD;
	quot = baud_base / baud;
	/* If the quotient is ever zero, default to 9600 bps */
	if (!quot)
		quot = baud_base / 9600;

	/* Set up FIFO's */
	if ((baud_base / quot) < 2400)
		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
	else
		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_8;
	serial_outp(cs, UART_FCR, fcr);
	/* CTS flow control flag and modem status interrupts */
	cs->hw.elsa.IER &= ~UART_IER_MSI;
	cs->hw.elsa.IER |= UART_IER_MSI;
	serial_outp(cs, UART_IER, cs->hw.elsa.IER);

	debugl1(cs,"modem quot=0x%x", quot);
	save_flags(flags);
	cli();
	serial_outp(cs, UART_LCR, cval | UART_LCR_DLAB);/* set DLAB */
	serial_outp(cs, UART_DLL, quot & 0xff);		/* LS of divisor */
	serial_outp(cs, UART_DLM, quot >> 8);		/* MS of divisor */
	serial_outp(cs, UART_LCR, cval);		/* reset DLAB */
	serial_inp(cs, UART_RX);
	restore_flags(flags);
}

static int mstartup(struct IsdnCardState *cs)
{
	unsigned long flags;
	int	retval=0;


	save_flags(flags); cli();

	/*
	 * Clear the FIFO buffers and disable them
	 * (they will be reenabled in change_speed())
	 */
	serial_outp(cs, UART_FCR, (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT));

	/*
	 * At this point there's no way the LSR could still be 0xFF;
	 * if it is, then bail out, because there's likely no UART
	 * here.
	 */
	if (serial_inp(cs, UART_LSR) == 0xff) {
		retval = -ENODEV;
		goto errout;
	}
	
	/*
	 * Clear the interrupt registers.
	 */
	(void) serial_inp(cs, UART_RX);
	(void) serial_inp(cs, UART_IIR);
	(void) serial_inp(cs, UART_MSR);

	/*
	 * Now, initialize the UART 
	 */
	serial_outp(cs, UART_LCR, UART_LCR_WLEN8);	/* reset DLAB */

	cs->hw.elsa.MCR = 0;
	cs->hw.elsa.MCR = UART_MCR_DTR | UART_MCR_RTS | UART_MCR_OUT2;
	serial_outp(cs, UART_MCR, cs->hw.elsa.MCR);
	
	/*
	 * Finally, enable interrupts
	 */
	cs->hw.elsa.IER = UART_IER_MSI | UART_IER_RLSI | UART_IER_RDI;
	serial_outp(cs, UART_IER, cs->hw.elsa.IER);	/* enable interrupts */
	
	/*
	 * And clear the interrupt registers again for luck.
	 */
	(void)serial_inp(cs, UART_LSR);
	(void)serial_inp(cs, UART_RX);
	(void)serial_inp(cs, UART_IIR);
	(void)serial_inp(cs, UART_MSR);

	cs->hw.elsa.transcnt = cs->hw.elsa.transp = 0;
	cs->hw.elsa.rcvcnt = cs->hw.elsa.rcvp =0;

	/*
	 * and set the speed of the serial port
	 */
	change_speed(cs, BASE_BAUD);
	cs->hw.elsa.MFlag = 1;
errout:
	restore_flags(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 mshutdown(struct IsdnCardState *cs)
{
	unsigned long	flags;


#ifdef SERIAL_DEBUG_OPEN
	printk(KERN_DEBUG"Shutting down serial ....");
#endif
	
	save_flags(flags); cli(); /* 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
	 */

	cs->hw.elsa.IER = 0;
	serial_outp(cs, UART_IER, 0x00);	/* disable all intrs */
	cs->hw.elsa.MCR &= ~UART_MCR_OUT2;
	
	/* disable break condition */
	serial_outp(cs, UART_LCR, serial_inp(cs, UART_LCR) & ~UART_LCR_SBC);
	
	cs->hw.elsa.MCR &= ~(UART_MCR_DTR|UART_MCR_RTS);
	serial_outp(cs, UART_MCR, cs->hw.elsa.MCR);

	/* disable FIFO's */	
	serial_outp(cs, UART_FCR, (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT));
	serial_inp(cs, UART_RX);    /* read data port to reset things */
	
	restore_flags(flags);
#ifdef SERIAL_DEBUG_OPEN
	printk(" done\n");
#endif
}

inline int
write_modem(struct BCState *bcs) {
	int ret=0;
	struct IsdnCardState *cs = bcs->cs;
	int count, len, fp, buflen;
	long flags;
	
	if (!bcs->tx_skb)
		return 0;
	if (bcs->tx_skb->len <= 0)
		return 0;
	save_flags(flags);
	cli();
	buflen = MAX_MODEM_BUF - cs->hw.elsa.transcnt;
	len = MIN(buflen, bcs->tx_skb->len);		
	fp = cs->hw.elsa.transcnt + cs->hw.elsa.transp;
	fp &= (MAX_MODEM_BUF -1);
	count = MIN(len, MAX_MODEM_BUF - fp);
	if (count < len) {
		memcpy(cs->hw.elsa.transbuf + fp, bcs->tx_skb->data, count);
		skb_pull(bcs->tx_skb, count);
		cs->hw.elsa.transcnt += count;
		ret = count;
		count = len - count;
		fp = 0;
	}
	memcpy((cs->hw.elsa.transbuf + fp), bcs->tx_skb->data, count);
	skb_pull(bcs->tx_skb, count);
	cs->hw.elsa.transcnt += count;
	ret += count;
	
	if (cs->hw.elsa.transcnt && 
	    !(cs->hw.elsa.IER & UART_IER_THRI)) {
			cs->hw.elsa.IER |= UART_IER_THRI;
		serial_outp(cs, UART_IER, cs->hw.elsa.IER);
	}
	restore_flags(flags);
	return(ret);
}

inline void
modem_fill(struct BCState *bcs) {
		
	if (bcs->tx_skb) {
		if (bcs->tx_skb->len) {
			write_modem(bcs);
			return;
		} else {
			if (bcs->st->lli.l1writewakeup &&
				(PACKET_NOACK != bcs->tx_skb->pkt_type))
					bcs->st->lli.l1writewakeup(bcs->st,
						bcs->hw.hscx.count);
			dev_kfree_skb_any(bcs->tx_skb);
			bcs->tx_skb = NULL;
		}
	}
	if ((bcs->tx_skb = skb_dequeue(&bcs->squeue))) {
		bcs->hw.hscx.count = 0;
		test_and_set_bit(BC_FLG_BUSY, &bcs->Flag);
		write_modem(bcs);
	} else {
		test_and_clear_bit(BC_FLG_BUSY, &bcs->Flag);
		hscx_sched_event(bcs, B_XMTBUFREADY);
	}
}

static inline void receive_chars(struct IsdnCardState *cs,
				 int *status)
{
	unsigned char ch;
	struct sk_buff *skb;

	do {
		ch = serial_in(cs, UART_RX);
		if (cs->hw.elsa.rcvcnt >= MAX_MODEM_BUF)
			break;
		cs->hw.elsa.rcvbuf[cs->hw.elsa.rcvcnt++] = ch;
#ifdef SERIAL_DEBUG_INTR
		printk("DR%02x:%02x...", ch, *status);
#endif
		if (*status & (UART_LSR_BI | UART_LSR_PE |
			       UART_LSR_FE | UART_LSR_OE)) {
					
#ifdef SERIAL_DEBUG_INTR
			printk("handling exept....");
#endif
		}
		*status = serial_inp(cs, UART_LSR);
	} while (*status & UART_LSR_DR);
	if (cs->hw.elsa.MFlag == 2) {
		if (!(skb = dev_alloc_skb(cs->hw.elsa.rcvcnt)))