drivers: serial: jsm: Add the Classic board implementation

This commit adds the Digi Classic board implementation to the
staging/jsm driver.

The code here is taken from the staging/dgnc driver and modified to
match the serial/jsm state. This work is mostly based on the changes
that has been done to the code handling the Digi Neo cards with the
inspiration coming from the diff between staging/dgnc and serial/jsm
as well as the LKML history for the jsm_neo.c

The code compiles now and has no sparse and checkpatch errors or
warnings.

Signed-off-by: Konrad Zapalowicz <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/jsm/Makefile

···
 
 obj-$(CONFIG_SERIAL_JSM) += jsm.o
 
-jsm-objs :=    jsm_driver.o jsm_neo.o jsm_tty.o
+jsm-objs :=    jsm_driver.o jsm_neo.o jsm_tty.o jsm_cls.o
 

drivers/tty/serial/jsm/jsm.h

···
 #define CH_LOOPBACK 0x2000		/* Channel is in lookback mode	*/
 #define CH_BAUD0	0x08000		/* Used for checking B0 transitions */
 
-/* Our Read/Error/Write queue sizes */
+/* Our Read/Error queue sizes */
 #define RQUEUEMASK	0x1FFF		/* 8 K - 1 */
 #define EQUEUEMASK	0x1FFF		/* 8 K - 1 */
 #define RQUEUESIZE	(RQUEUEMASK + 1)
···
  */
 extern struct	uart_driver jsm_uart_driver;
 extern struct	board_ops jsm_neo_ops;
+extern struct	board_ops jsm_cls_ops;
 extern int	jsm_debug;
 
 /*************************************************************************

drivers/tty/serial/jsm/jsm_cls.c

···
+/*
+ * Copyright 2003 Digi International (www.digi.com)
+ *	Scott H Kilau <Scott_Kilau at digi dot com>
+ *
+ * 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, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
+ * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE.  See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ *	NOTE TO LINUX KERNEL HACKERS:  DO NOT REFORMAT THIS CODE!
+ *
+ *	This is shared code between Digi's CVS archive and the
+ *	Linux Kernel sources.
+ *	Changing the source just for reformatting needlessly breaks
+ *	our CVS diff history.
+ *
+ *	Send any bug fixes/changes to:  Eng.Linux at digi dot com.
+ *	Thank you.
+ *
+ */
+
+#include <linux/delay.h>	/* For udelay */
+#include <linux/io.h>		/* For read[bwl]/write[bwl] */
+#include <linux/serial.h>	/* For struct async_serial */
+#include <linux/serial_reg.h>	/* For the various UART offsets */
+#include <linux/pci.h>
+#include <linux/tty.h>
+
+#include "jsm.h"	/* Driver main header file */
+
+static struct {
+	unsigned int rate;
+	unsigned int cflag;
+} baud_rates[] = {
+	{ 921600, B921600 },
+	{ 460800, B460800 },
+	{ 230400, B230400 },
+	{ 115200, B115200 },
+	{  57600, B57600  },
+	{  38400, B38400  },
+	{  19200, B19200  },
+	{   9600, B9600   },
+	{   4800, B4800   },
+	{   2400, B2400   },
+	{   1200, B1200   },
+	{    600, B600    },
+	{    300, B300    },
+	{    200, B200    },
+	{    150, B150    },
+	{    134, B134    },
+	{    110, B110    },
+	{     75, B75     },
+	{     50, B50     },
+};
+
+static void cls_set_cts_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on CTS flow control, turn off IXON flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_CTSDSR);
+	isr_fcr &= ~(UART_EXAR654_EFR_IXON);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/*
+	 * Enable interrupts for CTS flow, turn off interrupts for
+	 * received XOFF chars
+	 */
+	ier |= (UART_EXAR654_IER_CTSDSR);
+	ier &= ~(UART_EXAR654_IER_XOFF);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+
+	ch->ch_t_tlevel = 16;
+}
+
+static void cls_set_ixon_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on IXON flow control, turn off CTS flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXON);
+	isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Now set our current start/stop chars while in enhanced mode */
+	writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
+	writeb(0, &ch->ch_cls_uart->lsr);
+	writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
+	writeb(0, &ch->ch_cls_uart->spr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/*
+	 * Disable interrupts for CTS flow, turn on interrupts for
+	 * received XOFF chars
+	 */
+	ier &= ~(UART_EXAR654_IER_CTSDSR);
+	ier |= (UART_EXAR654_IER_XOFF);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+}
+
+static void cls_set_no_output_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn off IXON flow control, turn off CTS flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB);
+	isr_fcr &= ~(UART_EXAR654_EFR_CTSDSR | UART_EXAR654_EFR_IXON);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/*
+	 * Disable interrupts for CTS flow, turn off interrupts for
+	 * received XOFF chars
+	 */
+	ier &= ~(UART_EXAR654_IER_CTSDSR);
+	ier &= ~(UART_EXAR654_IER_XOFF);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+
+	ch->ch_r_watermark = 0;
+	ch->ch_t_tlevel = 16;
+	ch->ch_r_tlevel = 16;
+}
+
+static void cls_set_rts_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on RTS flow control, turn off IXOFF flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_RTSDTR);
+	isr_fcr &= ~(UART_EXAR654_EFR_IXOFF);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/* Enable interrupts for RTS flow */
+	ier |= (UART_EXAR654_IER_RTSDTR);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_56 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+
+	ch->ch_r_watermark = 4;
+	ch->ch_r_tlevel = 8;
+}
+
+static void cls_set_ixoff_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on IXOFF flow control, turn off RTS flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB | UART_EXAR654_EFR_IXOFF);
+	isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Now set our current start/stop chars while in enhanced mode */
+	writeb(ch->ch_startc, &ch->ch_cls_uart->mcr);
+	writeb(0, &ch->ch_cls_uart->lsr);
+	writeb(ch->ch_stopc, &ch->ch_cls_uart->msr);
+	writeb(0, &ch->ch_cls_uart->spr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/* Disable interrupts for RTS flow */
+	ier &= ~(UART_EXAR654_IER_RTSDTR);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+}
+
+static void cls_set_no_input_flow_control(struct jsm_channel *ch)
+{
+	u8 lcrb = readb(&ch->ch_cls_uart->lcr);
+	u8 ier = readb(&ch->ch_cls_uart->ier);
+	u8 isr_fcr = 0;
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn off IXOFF flow control, turn off RTS flow control */
+	isr_fcr |= (UART_EXAR654_EFR_ECB);
+	isr_fcr &= ~(UART_EXAR654_EFR_RTSDTR | UART_EXAR654_EFR_IXOFF);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/* Disable interrupts for RTS flow */
+	ier &= ~(UART_EXAR654_IER_RTSDTR);
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	/* Set the usual FIFO values */
+	writeb((UART_FCR_ENABLE_FIFO), &ch->ch_cls_uart->isr_fcr);
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_16654_FCR_RXTRIGGER_16 |
+		UART_16654_FCR_TXTRIGGER_16 | UART_FCR_CLEAR_RCVR),
+		&ch->ch_cls_uart->isr_fcr);
+
+	ch->ch_t_tlevel = 16;
+	ch->ch_r_tlevel = 16;
+}
+
+/*
+ * cls_clear_break.
+ * Determines whether its time to shut off break condition.
+ *
+ * No locks are assumed to be held when calling this function.
+ * channel lock is held and released in this function.
+ */
+static void cls_clear_break(struct jsm_channel *ch, int force)
+{
+	unsigned long lock_flags;
+
+	spin_lock_irqsave(&ch->ch_lock, lock_flags);
+
+	/* Turn break off, and unset some variables */
+	if (ch->ch_flags & CH_BREAK_SENDING) {
+		u8 temp = readb(&ch->ch_cls_uart->lcr);
+
+		writeb((temp & ~UART_LCR_SBC), &ch->ch_cls_uart->lcr);
+
+		ch->ch_flags &= ~(CH_BREAK_SENDING);
+		jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
+			"clear break Finishing UART_LCR_SBC! finished: %lx\n",
+			jiffies);
+	}
+	spin_unlock_irqrestore(&ch->ch_lock, lock_flags);
+}
+
+static void cls_disable_receiver(struct jsm_channel *ch)
+{
+	u8 tmp = readb(&ch->ch_cls_uart->ier);
+
+	tmp &= ~(UART_IER_RDI);
+	writeb(tmp, &ch->ch_cls_uart->ier);
+}
+
+static void cls_enable_receiver(struct jsm_channel *ch)
+{
+	u8 tmp = readb(&ch->ch_cls_uart->ier);
+
+	tmp |= (UART_IER_RDI);
+	writeb(tmp, &ch->ch_cls_uart->ier);
+}
+
+/* Make the UART raise any of the output signals we want up */
+static void cls_assert_modem_signals(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	writeb(ch->ch_mostat, &ch->ch_cls_uart->mcr);
+}
+
+static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch)
+{
+	int qleft = 0;
+	u8 linestatus = 0;
+	u8 error_mask = 0;
+	u16 head;
+	u16 tail;
+	unsigned long flags;
+
+	if (!ch)
+		return;
+
+	spin_lock_irqsave(&ch->ch_lock, flags);
+
+	/* cache head and tail of queue */
+	head = ch->ch_r_head & RQUEUEMASK;
+	tail = ch->ch_r_tail & RQUEUEMASK;
+
+	/* Get our cached LSR */
+	linestatus = ch->ch_cached_lsr;
+	ch->ch_cached_lsr = 0;
+
+	/* Store how much space we have left in the queue */
+	qleft = tail - head - 1;
+	if (qleft < 0)
+		qleft += RQUEUEMASK + 1;
+
+	/*
+	 * Create a mask to determine whether we should
+	 * insert the character (if any) into our queue.
+	 */
+	if (ch->ch_c_iflag & IGNBRK)
+		error_mask |= UART_LSR_BI;
+
+	while (1) {
+		/*
+		 * Grab the linestatus register, we need to
+		 * check to see if there is any data to read
+		 */
+		linestatus = readb(&ch->ch_cls_uart->lsr);
+
+		/* Break out if there is no data to fetch */
+		if (!(linestatus & UART_LSR_DR))
+			break;
+
+		/*
+		 * Discard character if we are ignoring the error mask
+		 * which in this case is the break signal.
+		 */
+		if (linestatus & error_mask)  {
+			u8 discard;
+
+			linestatus = 0;
+			discard = readb(&ch->ch_cls_uart->txrx);
+			continue;
+		}
+
+		/*
+		 * If our queue is full, we have no choice but to drop some
+		 * data. The assumption is that HWFLOW or SWFLOW should have
+		 * stopped things way way before we got to this point.
+		 *
+		 * I decided that I wanted to ditch the oldest data first,
+		 * I hope thats okay with everyone? Yes? Good.
+		 */
+		while (qleft < 1) {
+			tail = (tail + 1) & RQUEUEMASK;
+			ch->ch_r_tail = tail;
+			ch->ch_err_overrun++;
+			qleft++;
+		}
+
+		ch->ch_equeue[head] = linestatus & (UART_LSR_BI | UART_LSR_PE
+								 | UART_LSR_FE);
+		ch->ch_rqueue[head] = readb(&ch->ch_cls_uart->txrx);
+
+		qleft--;
+
+		if (ch->ch_equeue[head] & UART_LSR_PE)
+			ch->ch_err_parity++;
+		if (ch->ch_equeue[head] & UART_LSR_BI)
+			ch->ch_err_break++;
+		if (ch->ch_equeue[head] & UART_LSR_FE)
+			ch->ch_err_frame++;
+
+		/* Add to, and flip head if needed */
+		head = (head + 1) & RQUEUEMASK;
+		ch->ch_rxcount++;
+	}
+
+	/*
+	 * Write new final heads to channel structure.
+	 */
+	ch->ch_r_head = head & RQUEUEMASK;
+	ch->ch_e_head = head & EQUEUEMASK;
+
+	spin_unlock_irqrestore(&ch->ch_lock, flags);
+}
+
+static void cls_copy_data_from_queue_to_uart(struct jsm_channel *ch)
+{
+	u16 tail;
+	int n;
+	int qlen;
+	u32 len_written = 0;
+	struct circ_buf *circ;
+
+	if (!ch)
+		return;
+
+	circ = &ch->uart_port.state->xmit;
+
+	/* No data to write to the UART */
+	if (uart_circ_empty(circ))
+		return;
+
+	/* If port is "stopped", don't send any data to the UART */
+	if ((ch->ch_flags & CH_STOP) || (ch->ch_flags & CH_BREAK_SENDING))
+		return;
+
+	/* We have to do it this way, because of the EXAR TXFIFO count bug. */
+	if (!(ch->ch_flags & (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM)))
+		return;
+
+	n = 32;
+
+	/* cache tail of queue */
+	tail = circ->tail & (UART_XMIT_SIZE - 1);
+	qlen = uart_circ_chars_pending(circ);
+
+	/* Find minimum of the FIFO space, versus queue length */
+	n = min(n, qlen);
+
+	while (n > 0) {
+		writeb(circ->buf[tail], &ch->ch_cls_uart->txrx);
+		tail = (tail + 1) & (UART_XMIT_SIZE - 1);
+		n--;
+		ch->ch_txcount++;
+		len_written++;
+	}
+
+	/* Update the final tail */
+	circ->tail = tail & (UART_XMIT_SIZE - 1);
+
+	if (len_written > ch->ch_t_tlevel)
+		ch->ch_flags &= ~(CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+
+	if (uart_circ_empty(circ))
+		uart_write_wakeup(&ch->uart_port);
+}
+
+static void cls_parse_modem(struct jsm_channel *ch, u8 signals)
+{
+	u8 msignals = signals;
+
+	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
+		"neo_parse_modem: port: %d msignals: %x\n",
+		ch->ch_portnum, msignals);
+
+	/*
+	 * Scrub off lower bits.
+	 * They signify delta's, which I don't care about
+	 * Keep DDCD and DDSR though
+	 */
+	msignals &= 0xf8;
+
+	if (msignals & UART_MSR_DDCD)
+		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_DCD);
+	if (msignals & UART_MSR_DDSR)
+		uart_handle_dcd_change(&ch->uart_port, msignals & UART_MSR_CTS);
+
+	if (msignals & UART_MSR_DCD)
+		ch->ch_mistat |= UART_MSR_DCD;
+	else
+		ch->ch_mistat &= ~UART_MSR_DCD;
+
+	if (msignals & UART_MSR_DSR)
+		ch->ch_mistat |= UART_MSR_DSR;
+	else
+		ch->ch_mistat &= ~UART_MSR_DSR;
+
+	if (msignals & UART_MSR_RI)
+		ch->ch_mistat |= UART_MSR_RI;
+	else
+		ch->ch_mistat &= ~UART_MSR_RI;
+
+	if (msignals & UART_MSR_CTS)
+		ch->ch_mistat |= UART_MSR_CTS;
+	else
+		ch->ch_mistat &= ~UART_MSR_CTS;
+
+	jsm_dbg(MSIGS, &ch->ch_bd->pci_dev,
+		"Port: %d DTR: %d RTS: %d CTS: %d DSR: %d " "RI: %d CD: %d\n",
+		ch->ch_portnum,
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_DTR),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MCR_RTS),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_CTS),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DSR),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_RI),
+		!!((ch->ch_mistat | ch->ch_mostat) & UART_MSR_DCD));
+}
+
+/* Parse the ISR register for the specific port */
+static inline void cls_parse_isr(struct jsm_board *brd, uint port)
+{
+	struct jsm_channel *ch;
+	u8 isr = 0;
+	unsigned long flags;
+
+	/*
+	 * No need to verify board pointer, it was already
+	 * verified in the interrupt routine.
+	 */
+
+	if (port > brd->nasync)
+		return;
+
+	ch = brd->channels[port];
+	if (!ch)
+		return;
+
+	/* Here we try to figure out what caused the interrupt to happen */
+	while (1) {
+		isr = readb(&ch->ch_cls_uart->isr_fcr);
+
+		/* Bail if no pending interrupt on port */
+		if (isr & UART_IIR_NO_INT)
+			break;
+
+		/* Receive Interrupt pending */
+		if (isr & (UART_IIR_RDI | UART_IIR_RDI_TIMEOUT)) {
+			/* Read data from uart -> queue */
+			cls_copy_data_from_uart_to_queue(ch);
+			jsm_check_queue_flow_control(ch);
+		}
+
+		/* Transmit Hold register empty pending */
+		if (isr & UART_IIR_THRI) {
+			/* Transfer data (if any) from Write Queue -> UART. */
+			spin_lock_irqsave(&ch->ch_lock, flags);
+			ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+			spin_unlock_irqrestore(&ch->ch_lock, flags);
+			cls_copy_data_from_queue_to_uart(ch);
+		}
+
+		/*
+		 * CTS/RTS change of state:
+		 * Don't need to do anything, the cls_parse_modem
+		 * below will grab the updated modem signals.
+		 */
+
+		/* Parse any modem signal changes */
+		cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
+	}
+}
+
+/* Channel lock MUST be held before calling this function! */
+static void cls_flush_uart_write(struct jsm_channel *ch)
+{
+	u8 tmp = 0;
+	u8 i = 0;
+
+	if (!ch)
+		return;
+
+	writeb((UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_XMIT),
+						&ch->ch_cls_uart->isr_fcr);
+
+	for (i = 0; i < 10; i++) {
+		/* Check to see if the UART feels it completely flushed FIFO */
+		tmp = readb(&ch->ch_cls_uart->isr_fcr);
+		if (tmp & UART_FCR_CLEAR_XMIT) {
+			jsm_dbg(IOCTL, &ch->ch_bd->pci_dev,
+				"Still flushing TX UART... i: %d\n", i);
+			udelay(10);
+		} else
+			break;
+	}
+
+	ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+}
+
+/* Channel lock MUST be held before calling this function! */
+static void cls_flush_uart_read(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	/*
+	 * For complete POSIX compatibility, we should be purging the
+	 * read FIFO in the UART here.
+	 *
+	 * However, clearing the read FIFO (UART_FCR_CLEAR_RCVR) also
+	 * incorrectly flushes write data as well as just basically trashing the
+	 * FIFO.
+	 *
+	 * Presumably, this is a bug in this UART.
+	 */
+
+	udelay(10);
+}
+
+static void cls_send_start_character(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	if (ch->ch_startc != __DISABLED_CHAR) {
+		ch->ch_xon_sends++;
+		writeb(ch->ch_startc, &ch->ch_cls_uart->txrx);
+	}
+}
+
+static void cls_send_stop_character(struct jsm_channel *ch)
+{
+	if (!ch)
+		return;
+
+	if (ch->ch_stopc != __DISABLED_CHAR) {
+		ch->ch_xoff_sends++;
+		writeb(ch->ch_stopc, &ch->ch_cls_uart->txrx);
+	}
+}
+
+/*
+ * cls_param()
+ * Send any/all changes to the line to the UART.
+ */
+static void cls_param(struct jsm_channel *ch)
+{
+	u8 lcr = 0;
+	u8 uart_lcr = 0;
+	u8 ier = 0;
+	u32 baud = 9600;
+	int quot = 0;
+	struct jsm_board *bd;
+	int i;
+	unsigned int cflag;
+
+	bd = ch->ch_bd;
+	if (!bd)
+		return;
+
+	/*
+	 * If baud rate is zero, flush queues, and set mval to drop DTR.
+	 */
+	if ((ch->ch_c_cflag & (CBAUD)) == 0) {
+		ch->ch_r_head = 0;
+		ch->ch_r_tail = 0;
+		ch->ch_e_head = 0;
+		ch->ch_e_tail = 0;
+
+		cls_flush_uart_write(ch);
+		cls_flush_uart_read(ch);
+
+		/* The baudrate is B0 so all modem lines are to be dropped. */
+		ch->ch_flags |= (CH_BAUD0);
+		ch->ch_mostat &= ~(UART_MCR_RTS | UART_MCR_DTR);
+		cls_assert_modem_signals(ch);
+		return;
+	}
+
+	cflag = C_BAUD(ch->uart_port.state->port.tty);
+	baud = 9600;
+	for (i = 0; i < ARRAY_SIZE(baud_rates); i++) {
+		if (baud_rates[i].cflag == cflag) {
+			baud = baud_rates[i].rate;
+			break;
+		}
+	}
+
+	if (ch->ch_flags & CH_BAUD0)
+		ch->ch_flags &= ~(CH_BAUD0);
+
+	if (ch->ch_c_cflag & PARENB)
+		lcr |= UART_LCR_PARITY;
+
+	if (!(ch->ch_c_cflag & PARODD))
+		lcr |= UART_LCR_EPAR;
+
+	/*
+	 * Not all platforms support mark/space parity,
+	 * so this will hide behind an ifdef.
+	 */
+#ifdef CMSPAR
+	if (ch->ch_c_cflag & CMSPAR)
+		lcr |= UART_LCR_SPAR;
+#endif
+
+	if (ch->ch_c_cflag & CSTOPB)
+		lcr |= UART_LCR_STOP;
+
+	switch (ch->ch_c_cflag & CSIZE) {
+	case CS5:
+		lcr |= UART_LCR_WLEN5;
+		break;
+	case CS6:
+		lcr |= UART_LCR_WLEN6;
+		break;
+	case CS7:
+		lcr |= UART_LCR_WLEN7;
+		break;
+	case CS8:
+	default:
+		lcr |= UART_LCR_WLEN8;
+		break;
+	}
+
+	ier = readb(&ch->ch_cls_uart->ier);
+	uart_lcr = readb(&ch->ch_cls_uart->lcr);
+
+	if (baud == 0)
+		baud = 9600;
+
+	quot = ch->ch_bd->bd_dividend / baud;
+
+	if (quot != 0) {
+		writeb(UART_LCR_DLAB, &ch->ch_cls_uart->lcr);
+		writeb((quot & 0xff), &ch->ch_cls_uart->txrx);
+		writeb((quot >> 8), &ch->ch_cls_uart->ier);
+		writeb(lcr, &ch->ch_cls_uart->lcr);
+	}
+
+	if (uart_lcr != lcr)
+		writeb(lcr, &ch->ch_cls_uart->lcr);
+
+	if (ch->ch_c_cflag & CREAD)
+		ier |= (UART_IER_RDI | UART_IER_RLSI);
+
+	ier |= (UART_IER_THRI | UART_IER_MSI);
+
+	writeb(ier, &ch->ch_cls_uart->ier);
+
+	if (ch->ch_c_cflag & CRTSCTS)
+		cls_set_cts_flow_control(ch);
+	else if (ch->ch_c_iflag & IXON) {
+		/*
+		 * If start/stop is set to disable,
+		 * then we should disable flow control.
+		 */
+		if ((ch->ch_startc == __DISABLED_CHAR) ||
+			(ch->ch_stopc == __DISABLED_CHAR))
+			cls_set_no_output_flow_control(ch);
+		else
+			cls_set_ixon_flow_control(ch);
+	} else
+		cls_set_no_output_flow_control(ch);
+
+	if (ch->ch_c_cflag & CRTSCTS)
+		cls_set_rts_flow_control(ch);
+	else if (ch->ch_c_iflag & IXOFF) {
+		/*
+		 * If start/stop is set to disable,
+		 * then we should disable flow control.
+		 */
+		if ((ch->ch_startc == __DISABLED_CHAR) ||
+			(ch->ch_stopc == __DISABLED_CHAR))
+			cls_set_no_input_flow_control(ch);
+		else
+			cls_set_ixoff_flow_control(ch);
+	} else
+		cls_set_no_input_flow_control(ch);
+
+	cls_assert_modem_signals(ch);
+
+	/* get current status of the modem signals now */
+	cls_parse_modem(ch, readb(&ch->ch_cls_uart->msr));
+}
+
+/*
+ * cls_intr()
+ *
+ * Classic specific interrupt handler.
+ */
+static irqreturn_t cls_intr(int irq, void *voidbrd)
+{
+	struct jsm_board *brd = voidbrd;
+	unsigned long lock_flags;
+	unsigned char uart_poll;
+	uint i = 0;
+
+	/* Lock out the slow poller from running on this board. */
+	spin_lock_irqsave(&brd->bd_intr_lock, lock_flags);
+
+	/*
+	 * Check the board's global interrupt offset to see if we
+	 * acctually do have an interrupt pending on us.
+	 */
+	uart_poll = readb(brd->re_map_membase + UART_CLASSIC_POLL_ADDR_OFFSET);
+
+	jsm_dbg(INTR, &brd->pci_dev, "%s:%d uart_poll: %x\n",
+		__FILE__, __LINE__, uart_poll);
+
+	if (!uart_poll) {
+		jsm_dbg(INTR, &brd->pci_dev,
+			"Kernel interrupted to me, but no pending interrupts...\n");
+		spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
+		return IRQ_NONE;
+	}
+
+	/* At this point, we have at least SOMETHING to service, dig further. */
+
+	/* Parse each port to find out what caused the interrupt */
+	for (i = 0; i < brd->nasync; i++)
+		cls_parse_isr(brd, i);
+
+	spin_unlock_irqrestore(&brd->bd_intr_lock, lock_flags);
+
+	return IRQ_HANDLED;
+}
+
+/* Inits UART */
+static void cls_uart_init(struct jsm_channel *ch)
+{
+	unsigned char lcrb = readb(&ch->ch_cls_uart->lcr);
+	unsigned char isr_fcr = 0;
+
+	writeb(0, &ch->ch_cls_uart->ier);
+
+	/*
+	 * The Enhanced Register Set may only be accessed when
+	 * the Line Control Register is set to 0xBFh.
+	 */
+	writeb(UART_EXAR654_ENHANCED_REGISTER_SET, &ch->ch_cls_uart->lcr);
+
+	isr_fcr = readb(&ch->ch_cls_uart->isr_fcr);
+
+	/* Turn on Enhanced/Extended controls */
+	isr_fcr |= (UART_EXAR654_EFR_ECB);
+
+	writeb(isr_fcr, &ch->ch_cls_uart->isr_fcr);
+
+	/* Write old LCR value back out, which turns enhanced access off */
+	writeb(lcrb, &ch->ch_cls_uart->lcr);
+
+	/* Clear out UART and FIFO */
+	readb(&ch->ch_cls_uart->txrx);
+
+	writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT),
+						 &ch->ch_cls_uart->isr_fcr);
+	udelay(10);
+
+	ch->ch_flags |= (CH_FIFO_ENABLED | CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+
+	readb(&ch->ch_cls_uart->lsr);
+	readb(&ch->ch_cls_uart->msr);
+}
+
+/*
+ * Turns off UART.
+ */
+static void cls_uart_off(struct jsm_channel *ch)
+{
+	/* Stop all interrupts from accurring. */
+	writeb(0, &ch->ch_cls_uart->ier);
+}
+
+/*
+ * cls_get_uarts_bytes_left.
+ * Returns 0 is nothing left in the FIFO, returns 1 otherwise.
+ *
+ * The channel lock MUST be held by the calling function.
+ */
+static u32 cls_get_uart_bytes_left(struct jsm_channel *ch)
+{
+	u8 left = 0;
+	u8 lsr = readb(&ch->ch_cls_uart->lsr);
+
+	/* Determine whether the Transmitter is empty or not */
+	if (!(lsr & UART_LSR_TEMT))
+		left = 1;
+	else {
+		ch->ch_flags |= (CH_TX_FIFO_EMPTY | CH_TX_FIFO_LWM);
+		left = 0;
+	}
+
+	return left;
+}
+
+/*
+ * cls_send_break.
+ * Starts sending a break thru the UART.
+ *
+ * The channel lock MUST be held by the calling function.
+ */
+static void cls_send_break(struct jsm_channel *ch)
+{
+	/* Tell the UART to start sending the break */
+	if (!(ch->ch_flags & CH_BREAK_SENDING)) {
+		u8 temp = readb(&ch->ch_cls_uart->lcr);
+
+		writeb((temp | UART_LCR_SBC), &ch->ch_cls_uart->lcr);
+		ch->ch_flags |= (CH_BREAK_SENDING);
+	}
+}
+
+/*
+ * cls_send_immediate_char.
+ * Sends a specific character as soon as possible to the UART,
+ * jumping over any bytes that might be in the write queue.
+ *
+ * The channel lock MUST be held by the calling function.
+ */
+static void cls_send_immediate_char(struct jsm_channel *ch, unsigned char c)
+{
+	writeb(c, &ch->ch_cls_uart->txrx);
+}
+
+struct board_ops jsm_cls_ops = {
+	.intr =				cls_intr,
+	.uart_init =			cls_uart_init,
+	.uart_off =			cls_uart_off,
+	.param =			cls_param,
+	.assert_modem_signals =		cls_assert_modem_signals,
+	.flush_uart_write =		cls_flush_uart_write,
+	.flush_uart_read =		cls_flush_uart_read,
+	.disable_receiver =		cls_disable_receiver,
+	.enable_receiver =		cls_enable_receiver,
+	.send_break =			cls_send_break,
+	.clear_break =			cls_clear_break,
+	.send_start_character =		cls_send_start_character,
+	.send_stop_character =		cls_send_stop_character,
+	.copy_data_from_queue_to_uart = cls_copy_data_from_queue_to_uart,
+	.get_uart_bytes_left =		cls_get_uart_bytes_left,
+	.send_immediate_char =		cls_send_immediate_char
+};
+