ioc3_serial.c

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	/* Timeout is in ticks.  Let's figure out how many chars we
	 * can receive at the current baud rate in that interval
	 * and set the rx threshold to that amount.  There are 4 chars
	 * per ring entry, so we'll divide the number of chars that will
	 * arrive in timeout by 4.
	 * So .... timeout * baud / 10 / HZ / 4, with HZ = 100.
	 */
	threshold = timeout * port->ip_baud / 4000;
	if (threshold == 0)
		threshold = 1;	/* otherwise we'll intr all the time! */

	if ((unsigned)threshold > (unsigned)SSCR_RX_THRESHOLD)
		return 1;

	port->ip_sscr &= ~SSCR_RX_THRESHOLD;
	port->ip_sscr |= threshold;
	writel(port->ip_sscr, &port->ip_serial_regs->sscr);

	/* Now set the rx timeout to the given value
	 * again timeout * SRTR_HZ / HZ
	 */
	timeout = timeout * SRTR_HZ / 100;
	if (timeout > SRTR_CNT)
		timeout = SRTR_CNT;
	writel(timeout, &port->ip_serial_regs->srtr);
	return 0;
}

/**
 * config_port - config the hardware
 * @port: port to config
 * @baud: baud rate for the port
 * @byte_size: data size
 * @stop_bits: number of stop bits
 * @parenb: parity enable ?
 * @parodd: odd parity ?
 */
static inline int
config_port(struct ioc3_port *port,
	    int baud, int byte_size, int stop_bits, int parenb, int parodd)
{
	char lcr, sizebits;
	int spiniter = 0;

	DPRINT_CONFIG(("%s: line %d baud %d byte_size %d stop %d parenb %d "
			"parodd %d\n",
		       __FUNCTION__, ((struct uart_port *)port->ip_port)->line,
			baud, byte_size, stop_bits, parenb, parodd));

	if (set_baud(port, baud))
		return 1;

	switch (byte_size) {
	case 5:
		sizebits = UART_LCR_WLEN5;
		break;
	case 6:
		sizebits = UART_LCR_WLEN6;
		break;
	case 7:
		sizebits = UART_LCR_WLEN7;
		break;
	case 8:
		sizebits = UART_LCR_WLEN8;
		break;
	default:
		return 1;
	}

	/* Pause the DMA interface if necessary */
	if (port->ip_sscr & SSCR_DMA_EN) {
		writel(port->ip_sscr | SSCR_DMA_PAUSE,
		       &port->ip_serial_regs->sscr);
		while ((readl(&port->ip_serial_regs->sscr)
			& SSCR_PAUSE_STATE) == 0) {
			spiniter++;
			if (spiniter > MAXITER)
				return -1;
		}
	}

	/* Clear relevant fields in lcr */
	lcr = readb(&port->ip_uart_regs->iu_lcr);
	lcr &= ~(LCR_MASK_BITS_CHAR | UART_LCR_EPAR |
		 UART_LCR_PARITY | LCR_MASK_STOP_BITS);

	/* Set byte size in lcr */
	lcr |= sizebits;

	/* Set parity */
	if (parenb) {
		lcr |= UART_LCR_PARITY;
		if (!parodd)
			lcr |= UART_LCR_EPAR;
	}

	/* Set stop bits */
	if (stop_bits)
		lcr |= UART_LCR_STOP /* 2 stop bits */ ;

	writeb(lcr, &port->ip_uart_regs->iu_lcr);

	/* Re-enable the DMA interface if necessary */
	if (port->ip_sscr & SSCR_DMA_EN) {
		writel(port->ip_sscr, &port->ip_serial_regs->sscr);
	}
	port->ip_baud = baud;

	/* When we get within this number of ring entries of filling the
	 * entire ring on tx, place an EXPLICIT intr to generate a lowat
	 * notification when output has drained.
	 */
	port->ip_tx_lowat = (TX_LOWAT_CHARS(baud) + 3) / 4;
	if (port->ip_tx_lowat == 0)
		port->ip_tx_lowat = 1;

	set_rx_timeout(port, 2);
	return 0;
}

/**
 * do_write - Write bytes to the port.  Returns the number of bytes
 *			actually written. Called from transmit_chars
 * @port: port to use
 * @buf: the stuff to write
 * @len: how many bytes in 'buf'
 */
static inline int do_write(struct ioc3_port *port, char *buf, int len)
{
	int prod_ptr, cons_ptr, total = 0;
	struct ring *outring;
	struct ring_entry *entry;
	struct port_hooks *hooks = port->ip_hooks;

	BUG_ON(!(len >= 0));

	prod_ptr = port->ip_tx_prod;
	cons_ptr = readl(&port->ip_serial_regs->stcir) & PROD_CONS_MASK;
	outring = port->ip_outring;

	/* Maintain a 1-entry red-zone.  The ring buffer is full when
	 * (cons - prod) % ring_size is 1.  Rather than do this subtraction
	 * in the body of the loop, I'll do it now.
	 */
	cons_ptr = (cons_ptr - (int)sizeof(struct ring_entry)) & PROD_CONS_MASK;

	/* Stuff the bytes into the output */
	while ((prod_ptr != cons_ptr) && (len > 0)) {
		int xx;

		/* Get 4 bytes (one ring entry) at a time */
		entry = (struct ring_entry *)((caddr_t) outring + prod_ptr);

		/* Invalidate all entries */
		entry->ring_allsc = 0;

		/* Copy in some bytes */
		for (xx = 0; (xx < 4) && (len > 0); xx++) {
			entry->ring_data[xx] = *buf++;
			entry->ring_sc[xx] = TXCB_VALID;
			len--;
			total++;
		}

		/* If we are within some small threshold of filling up the
		 * entire ring buffer, we must place an EXPLICIT intr here
		 * to generate a lowat interrupt in case we subsequently
		 * really do fill up the ring and the caller goes to sleep.
		 * No need to place more than one though.
		 */
		if (!(port->ip_flags & LOWAT_WRITTEN) &&
		    ((cons_ptr - prod_ptr) & PROD_CONS_MASK)
		    <= port->ip_tx_lowat * (int)sizeof(struct ring_entry)) {
			port->ip_flags |= LOWAT_WRITTEN;
			entry->ring_sc[0] |= TXCB_INT_WHEN_DONE;
		}

		/* Go on to next entry */
		prod_ptr += sizeof(struct ring_entry);
		prod_ptr &= PROD_CONS_MASK;
	}

	/* If we sent something, start DMA if necessary */
	if (total > 0 && !(port->ip_sscr & SSCR_DMA_EN)) {
		port->ip_sscr |= SSCR_DMA_EN;
		writel(port->ip_sscr, &port->ip_serial_regs->sscr);
	}

	/* Store the new producer pointer.  If tx is disabled, we stuff the
	 * data into the ring buffer, but we don't actually start tx.
	 */
	if (!uart_tx_stopped(port->ip_port)) {
		writel(prod_ptr, &port->ip_serial_regs->stpir);

		/* If we are now transmitting, enable tx_mt interrupt so we
		 * can disable DMA if necessary when the tx finishes.
		 */
		if (total > 0)
			enable_intrs(port, hooks->intr_tx_mt);
	}
	port->ip_tx_prod = prod_ptr;

	return total;
}

/**
 * disable_intrs - disable interrupts
 * @port: port to enable
 * @mask: mask to use
 */
static inline void disable_intrs(struct ioc3_port *port, uint32_t mask)
{
	if (port->ip_card->ic_enable & mask) {
		ioc3_disable(port->ip_is, port->ip_idd, mask);
		port->ip_card->ic_enable &= ~mask;
	}
}

/**
 * set_notification - Modify event notification
 * @port: port to use
 * @mask: events mask
 * @set_on: set ?
 */
static int set_notification(struct ioc3_port *port, int mask, int set_on)
{
	struct port_hooks *hooks = port->ip_hooks;
	uint32_t intrbits, sscrbits;

	BUG_ON(!mask);

	intrbits = sscrbits = 0;

	if (mask & N_DATA_READY)
		intrbits |= (hooks->intr_rx_timer | hooks->intr_rx_high);
	if (mask & N_OUTPUT_LOWAT)
		intrbits |= hooks->intr_tx_explicit;
	if (mask & N_DDCD) {
		intrbits |= hooks->intr_delta_dcd;
		sscrbits |= SSCR_RX_RING_DCD;
	}
	if (mask & N_DCTS)
		intrbits |= hooks->intr_delta_cts;

	if (set_on) {
		enable_intrs(port, intrbits);
		port->ip_notify |= mask;
		port->ip_sscr |= sscrbits;
	} else {
		disable_intrs(port, intrbits);
		port->ip_notify &= ~mask;
		port->ip_sscr &= ~sscrbits;
	}

	/* We require DMA if either DATA_READY or DDCD notification is
	 * currently requested. If neither of these is requested and
	 * there is currently no tx in progress, DMA may be disabled.
	 */
	if (port->ip_notify & (N_DATA_READY | N_DDCD))
		port->ip_sscr |= SSCR_DMA_EN;
	else if (!(port->ip_card->ic_enable & hooks->intr_tx_mt))
		port->ip_sscr &= ~SSCR_DMA_EN;

	writel(port->ip_sscr, &port->ip_serial_regs->sscr);
	return 0;
}

/**
 * set_mcr - set the master control reg
 * @the_port: port to use
 * @mask1: mcr mask
 * @mask2: shadow mask
 */
static inline int set_mcr(struct uart_port *the_port,
			  int mask1, int mask2)
{
	struct ioc3_port *port = get_ioc3_port(the_port);
	uint32_t shadow;
	int spiniter = 0;
	char mcr;

	if (!port)
		return -1;

	/* Pause the DMA interface if necessary */
	if (port->ip_sscr & SSCR_DMA_EN) {
		writel(port->ip_sscr | SSCR_DMA_PAUSE,
		       &port->ip_serial_regs->sscr);
		while ((readl(&port->ip_serial_regs->sscr)
			& SSCR_PAUSE_STATE) == 0) {
			spiniter++;
			if (spiniter > MAXITER)
				return -1;
		}
	}
	shadow = readl(&port->ip_serial_regs->shadow);
	mcr = (shadow & 0xff000000) >> 24;

	/* Set new value */
	mcr |= mask1;
	shadow |= mask2;
	writeb(mcr, &port->ip_uart_regs->iu_mcr);
	writel(shadow, &port->ip_serial_regs->shadow);

	/* Re-enable the DMA interface if necessary */
	if (port->ip_sscr & SSCR_DMA_EN) {
		writel(port->ip_sscr, &port->ip_serial_regs->sscr);
	}
	return 0;
}

/**
 * ioc3_set_proto - set the protocol for the port
 * @port: port to use
 * @proto: protocol to use
 */
static int ioc3_set_proto(struct ioc3_port *port, int proto)
{
	struct port_hooks *hooks = port->ip_hooks;

	switch (proto) {
	default:
	case PROTO_RS232:
		/* Clear the appropriate GIO pin */
		DPRINT_CONFIG(("%s: rs232\n", __FUNCTION__));
		writel(0, (&port->ip_idd->vma->gppr[0]
					+ hooks->rs422_select_pin));
		break;

	case PROTO_RS422:
		/* Set the appropriate GIO pin */
		DPRINT_CONFIG(("%s: rs422\n", __FUNCTION__));
		writel(1, (&port->ip_idd->vma->gppr[0]
					+ hooks->rs422_select_pin));
		break;
	}
	return 0;
}

/**
 * transmit_chars - upper level write, called with the_port->lock
 * @the_port: port to write
 */
static void transmit_chars(struct uart_port *the_port)
{
	int xmit_count, tail, head;
	int result;
	char *start;
	struct tty_struct *tty;
	struct ioc3_port *port = get_ioc3_port(the_port);
	struct uart_info *info;

	if (!the_port)
		return;
	if (!port)
		return;

	info = the_port->info;
	tty = info->tty;

	if (uart_circ_empty(&info->xmit) || uart_tx_stopped(the_port)) {
		/* Nothing to do or hw stopped */
		set_notification(port, N_ALL_OUTPUT, 0);
		return;
	}

	head = info->xmit.head;
	tail = info->xmit.tail;
	start = (char *)&info->xmit.buf[tail];

	/* write out all the data or until the end of the buffer */
	xmit_count = (head < tail) ? (UART_XMIT_SIZE - tail) : (head - tail);
	if (xmit_count > 0) {
		result = do_write(port, start, xmit_count);
		if (result > 0) {
			/* booking */
			xmit_count -= result;
			the_port->icount.tx += result;
			/* advance the pointers */
			tail += result;
			tail &= UART_XMIT_SIZE - 1;
			info->xmit.tail = tail;
			start = (char *)&info->xmit.buf[tail];
		}
	}
	if (uart_circ_chars_pending(&info->xmit) < WAKEUP_CHARS)
		uart_write_wakeup(the_port);

	if (uart_circ_empty(&info->xmit)) {
		set_notification(port, N_OUTPUT_LOWAT, 0);
	} else {
		set_notification(port, N_OUTPUT_LOWAT, 1);
	}
}

/**
 * ioc3_change_speed - change the speed of the port
 * @the_port: port to change
 * @new_termios: new termios settings
 * @old_termios: old termios settings
 */
static void
ioc3_change_speed(struct uart_port *the_port,
		  struct ktermios *new_termios, struct ktermios *old_termios)
{
	struct ioc3_port *port = get_ioc3_port(the_port);
	unsigned int cflag;
	int baud;
	int new_parity = 0, new_parity_enable = 0, new_stop = 0, new_data = 8;
	struct uart_info *info = the_port->info;

	cflag = new_termios->c_cflag;

	switch (cflag & CSIZE) {
	case CS5:
		new_data = 5;
		break;
	case CS6:
		new_data = 6;
		break;
	case CS7:
		new_data = 7;
		break;
	case CS8:
		new_data = 8;
		break;
	default:
		/* cuz we always need a default ... */
		new_data = 5;
		break;
	}
	if (cflag & CSTOPB) {
		new_stop = 1;
	}
	if (cflag & PARENB) {
		new_parity_enable = 1;
		if (cflag & PARODD)
			new_parity = 1;
	}
	baud = uart_get_baud_rate(the_port, new_termios, old_termios,
				  MIN_BAUD_SUPPORTED, MAX_BAUD_SUPPORTED);
	DPRINT_CONFIG(("%s: returned baud %d for line %d\n", __FUNCTION__, baud,
				the_port->line));

	if (!the_port->fifosize)
		the_port->fifosize = FIFO_SIZE;
	uart_update_timeout(the_port, cflag, baud);

	the_port->ignore_status_mask = N_ALL_INPUT;

	info->tty->low_latency = 1;

	if (I_IGNPAR(info->tty))
		the_port->ignore_status_mask &= ~(N_PARITY_ERROR
						  | N_FRAMING_ERROR);
	if (I_IGNBRK(info->tty)) {
		the_port->ignore_status_mask &= ~N_BREAK;
		if (I_IGNPAR(info->tty))
			the_port->ignore_status_mask &= ~N_OVERRUN_ERROR;
	}
	if (!(cflag & CREAD)) {
		/* ignore everything */
		the_port->ignore_status_mask &= ~N_DATA_READY;
	}

	if (cflag & CRTSCTS) {
		/* enable hardware flow control */
		port->ip_sscr |= SSCR_HFC_EN;
	}
	else {
		/* disable hardware flow control */
		port->ip_sscr &= ~SSCR_HFC_EN;
	}
	writel(port->ip_sscr, &port->ip_serial_regs->sscr);

	/* Set the configuration and proper notification call */
	DPRINT_CONFIG(("%s : port 0x%p line %d cflag 0%o "
		       "config_port(baud %d data %d stop %d penable %d "
			" parity %d), notification 0x%x\n",
		       __FUNCTION__, (void *)port, the_port->line, cflag, baud,
		       new_data, new_stop, new_parity_enable, new_parity,
		       the_port->ignore_status_mask));

	if ((config_port(port, baud,	/* baud */
			 new_data,	/* byte size */
			 new_stop,	/* stop bits */
			 new_parity_enable,	/* set parity */
			 new_parity)) >= 0) {	/* parity 1==odd */
		set_notification(port, the_port->ignore_status_mask, 1);
	}
}

/**
 * ic3_startup_local - Start up the serial port - returns >= 0 if no errors
 * @the_port: Port to operate on
 */
static inline int ic3_startup_local(struct uart_port *the_port)
{
	struct ioc3_port *port;

	if (!the_port) {
		NOT_PROGRESS();
		return -1;
	}

	port = get_ioc3_port(the_port);
	if (!port) {
		NOT_PROGRESS();
		return -1;
	}

	local_open(port);

	/* set the protocol */
	ioc3_set_proto(port, IS_RS232(the_port->line) ? PROTO_RS232 :
							PROTO_RS422);
	return 0;
}

/*
 * ioc3_cb_output_lowat - called when the output low water mark is hit
 * @port: port to output
 */
static void ioc3_cb_output_lowat(struct ioc3_port *port)
{
	unsigned long pflags;

	/* the_port->lock is set on the call here */
	if (port->ip_port) {
		spin_lock_irqsave(&port->ip_port->lock, pflags);
		transmit_chars(port->ip_port);
		spin_unlock_irqrestore(&port->ip_port->lock, pflags);
	}
}

/*
 * ioc3_cb_post_ncs - called for some basic errors
 * @port: port to use
 * @ncs: event
 */
static void ioc3_cb_post_ncs(struct uart_port *the_port, int ncs)
{
	struct uart_icount *icount;

	icount = &the_port->icount;

	if (ncs & NCS_BREAK)
		icount->brk++;
	if (ncs & NCS_FRAMING)