Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1161 insertions, 0 deletions

diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
new file mode 100644
index 000000000..7ace3aa49
--- /dev/null
+++ b/drivers/tty/serial/sunsab.c
@@ -0,0 +1,1161 @@
+// SPDX-License-Identifier: GPL-2.0
+/* sunsab.c: ASYNC Driver for the SIEMENS SAB82532 DUSCC.
+ *
+ * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
+ * Copyright (C) 2002, 2006  David S. Miller (davem@davemloft.net)
+ *
+ * Rewrote buffer handling to use CIRC(Circular Buffer) macros.
+ *   Maxim Krasnyanskiy <maxk@qualcomm.com>
+ *
+ * Fixed to use tty_get_baud_rate, and to allow for arbitrary baud
+ * rates to be programmed into the UART.  Also eliminated a lot of
+ * duplicated code in the console setup.
+ *   Theodore Ts'o <tytso@mit.edu>, 2001-Oct-12
+ *
+ * Ported to new 2.5.x UART layer.
+ *   David S. Miller <davem@davemloft.net>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/major.h>
+#include <linux/string.h>
+#include <linux/ptrace.h>
+#include <linux/ioport.h>
+#include <linux/circ_buf.h>
+#include <linux/serial.h>
+#include <linux/sysrq.h>
+#include <linux/console.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/of_device.h>
+
+#include <linux/io.h>
+#include <asm/irq.h>
+#include <asm/prom.h>
+#include <asm/setup.h>
+
+#include <linux/serial_core.h>
+#include <linux/sunserialcore.h>
+
+#include "sunsab.h"
+
+struct uart_sunsab_port {
+	struct uart_port		port;		/* Generic UART port	*/
+	union sab82532_async_regs	__iomem *regs;	/* Chip registers	*/
+	unsigned long			irqflags;	/* IRQ state flags	*/
+	int				dsr;		/* Current DSR state	*/
+	unsigned int			cec_timeout;	/* Chip poll timeout... */
+	unsigned int			tec_timeout;	/* likewise		*/
+	unsigned char			interrupt_mask0;/* ISR0 masking		*/
+	unsigned char			interrupt_mask1;/* ISR1 masking		*/
+	unsigned char			pvr_dtr_bit;	/* Which PVR bit is DTR */
+	unsigned char			pvr_dsr_bit;	/* Which PVR bit is DSR */
+	unsigned int			gis_shift;
+	int				type;		/* SAB82532 version	*/
+
+	/* Setting configuration bits while the transmitter is active
+	 * can cause garbage characters to get emitted by the chip.
+	 * Therefore, we cache such writes here and do the real register
+	 * write the next time the transmitter becomes idle.
+	 */
+	unsigned int			cached_ebrg;
+	unsigned char			cached_mode;
+	unsigned char			cached_pvr;
+	unsigned char			cached_dafo;
+};
+
+/*
+ * This assumes you have a 29.4912 MHz clock for your UART.
+ */
+#define SAB_BASE_BAUD ( 29491200 / 16 )
+
+static char *sab82532_version[16] = {
+	"V1.0", "V2.0", "V3.2", "V(0x03)",
+	"V(0x04)", "V(0x05)", "V(0x06)", "V(0x07)",
+	"V(0x08)", "V(0x09)", "V(0x0a)", "V(0x0b)",
+	"V(0x0c)", "V(0x0d)", "V(0x0e)", "V(0x0f)"
+};
+
+#define SAB82532_MAX_TEC_TIMEOUT 200000	/* 1 character time (at 50 baud) */
+#define SAB82532_MAX_CEC_TIMEOUT  50000	/* 2.5 TX CLKs (at 50 baud) */
+
+#define SAB82532_RECV_FIFO_SIZE	32      /* Standard async fifo sizes */
+#define SAB82532_XMIT_FIFO_SIZE	32
+
+static __inline__ void sunsab_tec_wait(struct uart_sunsab_port *up)
+{
+	int timeout = up->tec_timeout;
+
+	while ((readb(&up->regs->r.star) & SAB82532_STAR_TEC) && --timeout)
+		udelay(1);
+}
+
+static __inline__ void sunsab_cec_wait(struct uart_sunsab_port *up)
+{
+	int timeout = up->cec_timeout;
+
+	while ((readb(&up->regs->r.star) & SAB82532_STAR_CEC) && --timeout)
+		udelay(1);
+}
+
+static struct tty_port *
+receive_chars(struct uart_sunsab_port *up,
+	      union sab82532_irq_status *stat)
+{
+	struct tty_port *port = NULL;
+	unsigned char buf[32];
+	int saw_console_brk = 0;
+	int free_fifo = 0;
+	int count = 0;
+	int i;
+
+	if (up->port.state != NULL)		/* Unopened serial console */
+		port = &up->port.state->port;
+
+	/* Read number of BYTES (Character + Status) available. */
+	if (stat->sreg.isr0 & SAB82532_ISR0_RPF) {
+		count = SAB82532_RECV_FIFO_SIZE;
+		free_fifo++;
+	}
+
+	if (stat->sreg.isr0 & SAB82532_ISR0_TCD) {
+		count = readb(&up->regs->r.rbcl) & (SAB82532_RECV_FIFO_SIZE - 1);
+		free_fifo++;
+	}
+
+	/* Issue a FIFO read command in case we where idle. */
+	if (stat->sreg.isr0 & SAB82532_ISR0_TIME) {
+		sunsab_cec_wait(up);
+		writeb(SAB82532_CMDR_RFRD, &up->regs->w.cmdr);
+		return port;
+	}
+
+	if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
+		free_fifo++;
+
+	/* Read the FIFO. */
+	for (i = 0; i < count; i++)
+		buf[i] = readb(&up->regs->r.rfifo[i]);
+
+	/* Issue Receive Message Complete command. */
+	if (free_fifo) {
+		sunsab_cec_wait(up);
+		writeb(SAB82532_CMDR_RMC, &up->regs->w.cmdr);
+	}
+
+	/* Count may be zero for BRK, so we check for it here */
+	if ((stat->sreg.isr1 & SAB82532_ISR1_BRK) &&
+	    (up->port.line == up->port.cons->index))
+		saw_console_brk = 1;
+
+	if (count == 0) {
+		if (unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
+			stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
+					     SAB82532_ISR0_FERR);
+			up->port.icount.brk++;
+			uart_handle_break(&up->port);
+		}
+	}
+
+	for (i = 0; i < count; i++) {
+		unsigned char ch = buf[i], flag;
+
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+
+		if (unlikely(stat->sreg.isr0 & (SAB82532_ISR0_PERR |
+						SAB82532_ISR0_FERR |
+						SAB82532_ISR0_RFO)) ||
+		    unlikely(stat->sreg.isr1 & SAB82532_ISR1_BRK)) {
+			/*
+			 * For statistics only
+			 */
+			if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
+				stat->sreg.isr0 &= ~(SAB82532_ISR0_PERR |
+						     SAB82532_ISR0_FERR);
+				up->port.icount.brk++;
+				/*
+				 * We do the SysRQ and SAK checking
+				 * here because otherwise the break
+				 * may get masked by ignore_status_mask
+				 * or read_status_mask.
+				 */
+				if (uart_handle_break(&up->port))
+					continue;
+			} else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
+				up->port.icount.parity++;
+			else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
+				up->port.icount.frame++;
+			if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
+				up->port.icount.overrun++;
+
+			/*
+			 * Mask off conditions which should be ingored.
+			 */
+			stat->sreg.isr0 &= (up->port.read_status_mask & 0xff);
+			stat->sreg.isr1 &= ((up->port.read_status_mask >> 8) & 0xff);
+
+			if (stat->sreg.isr1 & SAB82532_ISR1_BRK) {
+				flag = TTY_BREAK;
+			} else if (stat->sreg.isr0 & SAB82532_ISR0_PERR)
+				flag = TTY_PARITY;
+			else if (stat->sreg.isr0 & SAB82532_ISR0_FERR)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(&up->port, ch) || !port)
+			continue;
+
+		if ((stat->sreg.isr0 & (up->port.ignore_status_mask & 0xff)) == 0 &&
+		    (stat->sreg.isr1 & ((up->port.ignore_status_mask >> 8) & 0xff)) == 0)
+			tty_insert_flip_char(port, ch, flag);
+		if (stat->sreg.isr0 & SAB82532_ISR0_RFO)
+			tty_insert_flip_char(port, 0, TTY_OVERRUN);
+	}
+
+	if (saw_console_brk)
+		sun_do_break();
+
+	return port;
+}
+
+static void sunsab_stop_tx(struct uart_port *);
+static void sunsab_tx_idle(struct uart_sunsab_port *);
+
+static void transmit_chars(struct uart_sunsab_port *up,
+			   union sab82532_irq_status *stat)
+{
+	struct circ_buf *xmit = &up->port.state->xmit;
+	int i;
+
+	if (stat->sreg.isr1 & SAB82532_ISR1_ALLS) {
+		up->interrupt_mask1 |= SAB82532_IMR1_ALLS;
+		writeb(up->interrupt_mask1, &up->regs->w.imr1);
+		set_bit(SAB82532_ALLS, &up->irqflags);
+	}
+
+#if 0 /* bde@nwlink.com says this check causes problems */
+	if (!(stat->sreg.isr1 & SAB82532_ISR1_XPR))
+		return;
+#endif
+
+	if (!(readb(&up->regs->r.star) & SAB82532_STAR_XFW))
+		return;
+
+	set_bit(SAB82532_XPR, &up->irqflags);
+	sunsab_tx_idle(up);
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
+		up->interrupt_mask1 |= SAB82532_IMR1_XPR;
+		writeb(up->interrupt_mask1, &up->regs->w.imr1);
+		return;
+	}
+
+	up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+	clear_bit(SAB82532_ALLS, &up->irqflags);
+
+	/* Stuff 32 bytes into Transmit FIFO. */
+	clear_bit(SAB82532_XPR, &up->irqflags);
+	for (i = 0; i < up->port.fifosize; i++) {
+		writeb(xmit->buf[xmit->tail],
+		       &up->regs->w.xfifo[i]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		up->port.icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	}
+
+	/* Issue a Transmit Frame command. */
+	sunsab_cec_wait(up);
+	writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	if (uart_circ_empty(xmit))
+		sunsab_stop_tx(&up->port);
+}
+
+static void check_status(struct uart_sunsab_port *up,
+			 union sab82532_irq_status *stat)
+{
+	if (stat->sreg.isr0 & SAB82532_ISR0_CDSC)
+		uart_handle_dcd_change(&up->port,
+				       !(readb(&up->regs->r.vstr) & SAB82532_VSTR_CD));
+
+	if (stat->sreg.isr1 & SAB82532_ISR1_CSC)
+		uart_handle_cts_change(&up->port,
+				       (readb(&up->regs->r.star) & SAB82532_STAR_CTS));
+
+	if ((readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ^ up->dsr) {
+		up->dsr = (readb(&up->regs->r.pvr) & up->pvr_dsr_bit) ? 0 : 1;
+		up->port.icount.dsr++;
+	}
+
+	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+}
+
+static irqreturn_t sunsab_interrupt(int irq, void *dev_id)
+{
+	struct uart_sunsab_port *up = dev_id;
+	struct tty_port *port = NULL;
+	union sab82532_irq_status status;
+	unsigned long flags;
+	unsigned char gis;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	status.stat = 0;
+	gis = readb(&up->regs->r.gis) >> up->gis_shift;
+	if (gis & 1)
+		status.sreg.isr0 = readb(&up->regs->r.isr0);
+	if (gis & 2)
+		status.sreg.isr1 = readb(&up->regs->r.isr1);
+
+	if (status.stat) {
+		if ((status.sreg.isr0 & (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
+					 SAB82532_ISR0_RFO | SAB82532_ISR0_RPF)) ||
+		    (status.sreg.isr1 & SAB82532_ISR1_BRK))
+			port = receive_chars(up, &status);
+		if ((status.sreg.isr0 & SAB82532_ISR0_CDSC) ||
+		    (status.sreg.isr1 & SAB82532_ISR1_CSC))
+			check_status(up, &status);
+		if (status.sreg.isr1 & (SAB82532_ISR1_ALLS | SAB82532_ISR1_XPR))
+			transmit_chars(up, &status);
+	}
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	if (port)
+		tty_flip_buffer_push(port);
+
+	return IRQ_HANDLED;
+}
+
+/* port->lock is not held.  */
+static unsigned int sunsab_tx_empty(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	int ret;
+
+	/* Do not need a lock for a state test like this.  */
+	if (test_bit(SAB82532_ALLS, &up->irqflags))
+		ret = TIOCSER_TEMT;
+	else
+		ret = 0;
+
+	return ret;
+}
+
+/* port->lock held by caller.  */
+static void sunsab_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+
+	if (mctrl & TIOCM_RTS) {
+		up->cached_mode &= ~SAB82532_MODE_FRTS;
+		up->cached_mode |= SAB82532_MODE_RTS;
+	} else {
+		up->cached_mode |= (SAB82532_MODE_FRTS |
+				    SAB82532_MODE_RTS);
+	}
+	if (mctrl & TIOCM_DTR) {
+		up->cached_pvr &= ~(up->pvr_dtr_bit);
+	} else {
+		up->cached_pvr |= up->pvr_dtr_bit;
+	}
+
+	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
+	if (test_bit(SAB82532_XPR, &up->irqflags))
+		sunsab_tx_idle(up);
+}
+
+/* port->lock is held by caller and interrupts are disabled.  */
+static unsigned int sunsab_get_mctrl(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned char val;
+	unsigned int result;
+
+	result = 0;
+
+	val = readb(&up->regs->r.pvr);
+	result |= (val & up->pvr_dsr_bit) ? 0 : TIOCM_DSR;
+
+	val = readb(&up->regs->r.vstr);
+	result |= (val & SAB82532_VSTR_CD) ? 0 : TIOCM_CAR;
+
+	val = readb(&up->regs->r.star);
+	result |= (val & SAB82532_STAR_CTS) ? TIOCM_CTS : 0;
+
+	return result;
+}
+
+/* port->lock held by caller.  */
+static void sunsab_stop_tx(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+
+	up->interrupt_mask1 |= SAB82532_IMR1_XPR;
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+}
+
+/* port->lock held by caller.  */
+static void sunsab_tx_idle(struct uart_sunsab_port *up)
+{
+	if (test_bit(SAB82532_REGS_PENDING, &up->irqflags)) {
+		u8 tmp;
+
+		clear_bit(SAB82532_REGS_PENDING, &up->irqflags);
+		writeb(up->cached_mode, &up->regs->rw.mode);
+		writeb(up->cached_pvr, &up->regs->rw.pvr);
+		writeb(up->cached_dafo, &up->regs->w.dafo);
+
+		writeb(up->cached_ebrg & 0xff, &up->regs->w.bgr);
+		tmp = readb(&up->regs->rw.ccr2);
+		tmp &= ~0xc0;
+		tmp |= (up->cached_ebrg >> 2) & 0xc0;
+		writeb(tmp, &up->regs->rw.ccr2);
+	}
+}
+
+/* port->lock held by caller.  */
+static void sunsab_start_tx(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	struct circ_buf *xmit = &up->port.state->xmit;
+	int i;
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+		return;
+
+	up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+	
+	if (!test_bit(SAB82532_XPR, &up->irqflags))
+		return;
+
+	clear_bit(SAB82532_ALLS, &up->irqflags);
+	clear_bit(SAB82532_XPR, &up->irqflags);
+
+	for (i = 0; i < up->port.fifosize; i++) {
+		writeb(xmit->buf[xmit->tail],
+		       &up->regs->w.xfifo[i]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		up->port.icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	}
+
+	/* Issue a Transmit Frame command.  */
+	sunsab_cec_wait(up);
+	writeb(SAB82532_CMDR_XF, &up->regs->w.cmdr);
+}
+
+/* port->lock is not held.  */
+static void sunsab_send_xchar(struct uart_port *port, char ch)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+
+	if (ch == __DISABLED_CHAR)
+		return;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	sunsab_tec_wait(up);
+	writeb(ch, &up->regs->w.tic);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+/* port->lock held by caller.  */
+static void sunsab_stop_rx(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+
+	up->interrupt_mask0 |= SAB82532_IMR0_TCD;
+	writeb(up->interrupt_mask1, &up->regs->w.imr0);
+}
+
+/* port->lock is not held.  */
+static void sunsab_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+	unsigned char val;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	val = up->cached_dafo;
+	if (break_state)
+		val |= SAB82532_DAFO_XBRK;
+	else
+		val &= ~SAB82532_DAFO_XBRK;
+	up->cached_dafo = val;
+
+	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
+	if (test_bit(SAB82532_XPR, &up->irqflags))
+		sunsab_tx_idle(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+/* port->lock is not held.  */
+static int sunsab_startup(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+	unsigned char tmp;
+	int err = request_irq(up->port.irq, sunsab_interrupt,
+			      IRQF_SHARED, "sab", up);
+	if (err)
+		return err;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 * Wait for any commands or immediate characters
+	 */
+	sunsab_cec_wait(up);
+	sunsab_tec_wait(up);
+
+	/*
+	 * Clear the FIFO buffers.
+	 */
+	writeb(SAB82532_CMDR_RRES, &up->regs->w.cmdr);
+	sunsab_cec_wait(up);
+	writeb(SAB82532_CMDR_XRES, &up->regs->w.cmdr);
+
+	/*
+	 * Clear the interrupt registers.
+	 */
+	(void) readb(&up->regs->r.isr0);
+	(void) readb(&up->regs->r.isr1);
+
+	/*
+	 * Now, initialize the UART 
+	 */
+	writeb(0, &up->regs->w.ccr0);				/* power-down */
+	writeb(SAB82532_CCR0_MCE | SAB82532_CCR0_SC_NRZ |
+	       SAB82532_CCR0_SM_ASYNC, &up->regs->w.ccr0);
+	writeb(SAB82532_CCR1_ODS | SAB82532_CCR1_BCR | 7, &up->regs->w.ccr1);
+	writeb(SAB82532_CCR2_BDF | SAB82532_CCR2_SSEL |
+	       SAB82532_CCR2_TOE, &up->regs->w.ccr2);
+	writeb(0, &up->regs->w.ccr3);
+	writeb(SAB82532_CCR4_MCK4 | SAB82532_CCR4_EBRG, &up->regs->w.ccr4);
+	up->cached_mode = (SAB82532_MODE_RTS | SAB82532_MODE_FCTS |
+			   SAB82532_MODE_RAC);
+	writeb(up->cached_mode, &up->regs->w.mode);
+	writeb(SAB82532_RFC_DPS|SAB82532_RFC_RFTH_32, &up->regs->w.rfc);
+	
+	tmp = readb(&up->regs->rw.ccr0);
+	tmp |= SAB82532_CCR0_PU;	/* power-up */
+	writeb(tmp, &up->regs->rw.ccr0);
+
+	/*
+	 * Finally, enable interrupts
+	 */
+	up->interrupt_mask0 = (SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
+			       SAB82532_IMR0_PLLA);
+	writeb(up->interrupt_mask0, &up->regs->w.imr0);
+	up->interrupt_mask1 = (SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
+			       SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
+			       SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
+			       SAB82532_IMR1_XPR);
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+	set_bit(SAB82532_ALLS, &up->irqflags);
+	set_bit(SAB82532_XPR, &up->irqflags);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return 0;
+}
+
+/* port->lock is not held.  */
+static void sunsab_shutdown(struct uart_port *port)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/* Disable Interrupts */
+	up->interrupt_mask0 = 0xff;
+	writeb(up->interrupt_mask0, &up->regs->w.imr0);
+	up->interrupt_mask1 = 0xff;
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+
+	/* Disable break condition */
+	up->cached_dafo = readb(&up->regs->rw.dafo);
+	up->cached_dafo &= ~SAB82532_DAFO_XBRK;
+	writeb(up->cached_dafo, &up->regs->rw.dafo);
+
+	/* Disable Receiver */	
+	up->cached_mode &= ~SAB82532_MODE_RAC;
+	writeb(up->cached_mode, &up->regs->rw.mode);
+
+	/*
+	 * XXX FIXME
+	 *
+	 * If the chip is powered down here the system hangs/crashes during
+	 * reboot or shutdown.  This needs to be investigated further,
+	 * similar behaviour occurs in 2.4 when the driver is configured
+	 * as a module only.  One hint may be that data is sometimes
+	 * transmitted at 9600 baud during shutdown (regardless of the
+	 * speed the chip was configured for when the port was open).
+	 */
+#if 0
+	/* Power Down */	
+	tmp = readb(&up->regs->rw.ccr0);
+	tmp &= ~SAB82532_CCR0_PU;
+	writeb(tmp, &up->regs->rw.ccr0);
+#endif
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	free_irq(up->port.irq, up);
+}
+
+/*
+ * This is used to figure out the divisor speeds.
+ *
+ * The formula is:    Baud = SAB_BASE_BAUD / ((N + 1) * (1 << M)),
+ *
+ * with               0 <= N < 64 and 0 <= M < 16
+ */
+
+static void calc_ebrg(int baud, int *n_ret, int *m_ret)
+{
+	int	n, m;
+
+	if (baud == 0) {
+		*n_ret = 0;
+		*m_ret = 0;
+		return;
+	}
+     
+	/*
+	 * We scale numbers by 10 so that we get better accuracy
+	 * without having to use floating point.  Here we increment m
+	 * until n is within the valid range.
+	 */
+	n = (SAB_BASE_BAUD * 10) / baud;
+	m = 0;
+	while (n >= 640) {
+		n = n / 2;
+		m++;
+	}
+	n = (n+5) / 10;
+	/*
+	 * We try very hard to avoid speeds with M == 0 since they may
+	 * not work correctly for XTAL frequences above 10 MHz.
+	 */
+	if ((m == 0) && ((n & 1) == 0)) {
+		n = n / 2;
+		m++;
+	}
+	*n_ret = n - 1;
+	*m_ret = m;
+}
+
+/* Internal routine, port->lock is held and local interrupts are disabled.  */
+static void sunsab_convert_to_sab(struct uart_sunsab_port *up, unsigned int cflag,
+				  unsigned int iflag, unsigned int baud,
+				  unsigned int quot)
+{
+	unsigned char dafo;
+	int n, m;
+
+	/* Byte size and parity */
+	switch (cflag & CSIZE) {
+	      case CS5: dafo = SAB82532_DAFO_CHL5; break;
+	      case CS6: dafo = SAB82532_DAFO_CHL6; break;
+	      case CS7: dafo = SAB82532_DAFO_CHL7; break;
+	      case CS8: dafo = SAB82532_DAFO_CHL8; break;
+	      /* Never happens, but GCC is too dumb to figure it out */
+	      default:  dafo = SAB82532_DAFO_CHL5; break;
+	}
+
+	if (cflag & CSTOPB)
+		dafo |= SAB82532_DAFO_STOP;
+
+	if (cflag & PARENB)
+		dafo |= SAB82532_DAFO_PARE;
+
+	if (cflag & PARODD) {
+		dafo |= SAB82532_DAFO_PAR_ODD;
+	} else {
+		dafo |= SAB82532_DAFO_PAR_EVEN;
+	}
+	up->cached_dafo = dafo;
+
+	calc_ebrg(baud, &n, &m);
+
+	up->cached_ebrg = n | (m << 6);
+
+	up->tec_timeout = (10 * 1000000) / baud;
+	up->cec_timeout = up->tec_timeout >> 2;
+
+	/* CTS flow control flags */
+	/* We encode read_status_mask and ignore_status_mask like so:
+	 *
+	 * ---------------------
+	 * | ... | ISR1 | ISR0 |
+	 * ---------------------
+	 *  ..    15   8 7    0
+	 */
+
+	up->port.read_status_mask = (SAB82532_ISR0_TCD | SAB82532_ISR0_TIME |
+				     SAB82532_ISR0_RFO | SAB82532_ISR0_RPF |
+				     SAB82532_ISR0_CDSC);
+	up->port.read_status_mask |= (SAB82532_ISR1_CSC |
+				      SAB82532_ISR1_ALLS |
+				      SAB82532_ISR1_XPR) << 8;
+	if (iflag & INPCK)
+		up->port.read_status_mask |= (SAB82532_ISR0_PERR |
+					      SAB82532_ISR0_FERR);
+	if (iflag & (IGNBRK | BRKINT | PARMRK))
+		up->port.read_status_mask |= (SAB82532_ISR1_BRK << 8);
+
+	/*
+	 * Characteres to ignore
+	 */
+	up->port.ignore_status_mask = 0;
+	if (iflag & IGNPAR)
+		up->port.ignore_status_mask |= (SAB82532_ISR0_PERR |
+						SAB82532_ISR0_FERR);
+	if (iflag & IGNBRK) {
+		up->port.ignore_status_mask |= (SAB82532_ISR1_BRK << 8);
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (iflag & IGNPAR)
+			up->port.ignore_status_mask |= SAB82532_ISR0_RFO;
+	}
+
+	/*
+	 * ignore all characters if CREAD is not set
+	 */
+	if ((cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= (SAB82532_ISR0_RPF |
+						SAB82532_ISR0_TCD);
+
+	uart_update_timeout(&up->port, cflag,
+			    (up->port.uartclk / (16 * quot)));
+
+	/* Now schedule a register update when the chip's
+	 * transmitter is idle.
+	 */
+	up->cached_mode |= SAB82532_MODE_RAC;
+	set_bit(SAB82532_REGS_PENDING, &up->irqflags);
+	if (test_bit(SAB82532_XPR, &up->irqflags))
+		sunsab_tx_idle(up);
+}
+
+/* port->lock is not held.  */
+static void sunsab_set_termios(struct uart_port *port, struct ktermios *termios,
+			       const struct ktermios *old)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+	unsigned long flags;
+	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
+	unsigned int quot = uart_get_divisor(port, baud);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *sunsab_type(struct uart_port *port)
+{
+	struct uart_sunsab_port *up = (void *)port;
+	static char buf[36];
+	
+	sprintf(buf, "SAB82532 %s", sab82532_version[up->type]);
+	return buf;
+}
+
+static void sunsab_release_port(struct uart_port *port)
+{
+}
+
+static int sunsab_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void sunsab_config_port(struct uart_port *port, int flags)
+{
+}
+
+static int sunsab_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	return -EINVAL;
+}
+
+static const struct uart_ops sunsab_pops = {
+	.tx_empty	= sunsab_tx_empty,
+	.set_mctrl	= sunsab_set_mctrl,
+	.get_mctrl	= sunsab_get_mctrl,
+	.stop_tx	= sunsab_stop_tx,
+	.start_tx	= sunsab_start_tx,
+	.send_xchar	= sunsab_send_xchar,
+	.stop_rx	= sunsab_stop_rx,
+	.break_ctl	= sunsab_break_ctl,
+	.startup	= sunsab_startup,
+	.shutdown	= sunsab_shutdown,
+	.set_termios	= sunsab_set_termios,
+	.type		= sunsab_type,
+	.release_port	= sunsab_release_port,
+	.request_port	= sunsab_request_port,
+	.config_port	= sunsab_config_port,
+	.verify_port	= sunsab_verify_port,
+};
+
+static struct uart_driver sunsab_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "sunsab",
+	.dev_name		= "ttyS",
+	.major			= TTY_MAJOR,
+};
+
+static struct uart_sunsab_port *sunsab_ports;
+
+#ifdef CONFIG_SERIAL_SUNSAB_CONSOLE
+
+static void sunsab_console_putchar(struct uart_port *port, unsigned char c)
+{
+	struct uart_sunsab_port *up =
+		container_of(port, struct uart_sunsab_port, port);
+
+	sunsab_tec_wait(up);
+	writeb(c, &up->regs->w.tic);
+}
+
+static void sunsab_console_write(struct console *con, const char *s, unsigned n)
+{
+	struct uart_sunsab_port *up = &sunsab_ports[con->index];
+	unsigned long flags;
+	int locked = 1;
+
+	if (up->port.sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
+	else
+		spin_lock_irqsave(&up->port.lock, flags);
+
+	uart_console_write(&up->port, s, n, sunsab_console_putchar);
+	sunsab_tec_wait(up);
+
+	if (locked)
+		spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int sunsab_console_setup(struct console *con, char *options)
+{
+	struct uart_sunsab_port *up = &sunsab_ports[con->index];
+	unsigned long flags;
+	unsigned int baud, quot;
+
+	/*
+	 * The console framework calls us for each and every port
+	 * registered. Defer the console setup until the requested
+	 * port has been properly discovered. A bit of a hack,
+	 * though...
+	 */
+	if (up->port.type != PORT_SUNSAB)
+		return -EINVAL;
+
+	printk("Console: ttyS%d (SAB82532)\n",
+	       (sunsab_reg.minor - 64) + con->index);
+
+	sunserial_console_termios(con, up->port.dev->of_node);
+
+	switch (con->cflag & CBAUD) {
+	case B150: baud = 150; break;
+	case B300: baud = 300; break;
+	case B600: baud = 600; break;
+	case B1200: baud = 1200; break;
+	case B2400: baud = 2400; break;
+	case B4800: baud = 4800; break;
+	default: case B9600: baud = 9600; break;
+	case B19200: baud = 19200; break;
+	case B38400: baud = 38400; break;
+	case B57600: baud = 57600; break;
+	case B115200: baud = 115200; break;
+	case B230400: baud = 230400; break;
+	case B460800: baud = 460800; break;
+	}
+
+	/*
+	 * Temporary fix.
+	 */
+	spin_lock_init(&up->port.lock);
+
+	/*
+	 * Initialize the hardware
+	 */
+	sunsab_startup(&up->port);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/*
+	 * Finally, enable interrupts
+	 */
+	up->interrupt_mask0 = SAB82532_IMR0_PERR | SAB82532_IMR0_FERR |
+				SAB82532_IMR0_PLLA | SAB82532_IMR0_CDSC;
+	writeb(up->interrupt_mask0, &up->regs->w.imr0);
+	up->interrupt_mask1 = SAB82532_IMR1_BRKT | SAB82532_IMR1_ALLS |
+				SAB82532_IMR1_XOFF | SAB82532_IMR1_TIN |
+				SAB82532_IMR1_CSC | SAB82532_IMR1_XON |
+				SAB82532_IMR1_XPR;
+	writeb(up->interrupt_mask1, &up->regs->w.imr1);
+
+	quot = uart_get_divisor(&up->port, baud);
+	sunsab_convert_to_sab(up, con->cflag, 0, baud, quot);
+	sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	
+	return 0;
+}
+
+static struct console sunsab_console = {
+	.name	=	"ttyS",
+	.write	=	sunsab_console_write,
+	.device	=	uart_console_device,
+	.setup	=	sunsab_console_setup,
+	.flags	=	CON_PRINTBUFFER,
+	.index	=	-1,
+	.data	=	&sunsab_reg,
+};
+
+static inline struct console *SUNSAB_CONSOLE(void)
+{
+	return &sunsab_console;
+}
+#else
+#define SUNSAB_CONSOLE()	(NULL)
+#define sunsab_console_init()	do { } while (0)
+#endif
+
+static int sunsab_init_one(struct uart_sunsab_port *up,
+				     struct platform_device *op,
+				     unsigned long offset,
+				     int line)
+{
+	up->port.line = line;
+	up->port.dev = &op->dev;
+
+	up->port.mapbase = op->resource[0].start + offset;
+	up->port.membase = of_ioremap(&op->resource[0], offset,
+				      sizeof(union sab82532_async_regs),
+				      "sab");
+	if (!up->port.membase)
+		return -ENOMEM;
+	up->regs = (union sab82532_async_regs __iomem *) up->port.membase;
+
+	up->port.irq = op->archdata.irqs[0];
+
+	up->port.fifosize = SAB82532_XMIT_FIFO_SIZE;
+	up->port.iotype = UPIO_MEM;
+	up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_SUNSAB_CONSOLE);
+
+	writeb(SAB82532_IPC_IC_ACT_LOW, &up->regs->w.ipc);
+
+	up->port.ops = &sunsab_pops;
+	up->port.type = PORT_SUNSAB;
+	up->port.uartclk = SAB_BASE_BAUD;
+
+	up->type = readb(&up->regs->r.vstr) & 0x0f;
+	writeb(~((1 << 1) | (1 << 2) | (1 << 4)), &up->regs->w.pcr);
+	writeb(0xff, &up->regs->w.pim);
+	if ((up->port.line & 0x1) == 0) {
+		up->pvr_dsr_bit = (1 << 0);
+		up->pvr_dtr_bit = (1 << 1);
+		up->gis_shift = 2;
+	} else {
+		up->pvr_dsr_bit = (1 << 3);
+		up->pvr_dtr_bit = (1 << 2);
+		up->gis_shift = 0;
+	}
+	up->cached_pvr = (1 << 1) | (1 << 2) | (1 << 4);
+	writeb(up->cached_pvr, &up->regs->w.pvr);
+	up->cached_mode = readb(&up->regs->rw.mode);
+	up->cached_mode |= SAB82532_MODE_FRTS;
+	writeb(up->cached_mode, &up->regs->rw.mode);
+	up->cached_mode |= SAB82532_MODE_RTS;
+	writeb(up->cached_mode, &up->regs->rw.mode);
+
+	up->tec_timeout = SAB82532_MAX_TEC_TIMEOUT;
+	up->cec_timeout = SAB82532_MAX_CEC_TIMEOUT;
+
+	return 0;
+}
+
+static int sab_probe(struct platform_device *op)
+{
+	static int inst;
+	struct uart_sunsab_port *up;
+	int err;
+
+	up = &sunsab_ports[inst * 2];
+
+	err = sunsab_init_one(&up[0], op,
+			      0,
+			      (inst * 2) + 0);
+	if (err)
+		goto out;
+
+	err = sunsab_init_one(&up[1], op,
+			      sizeof(union sab82532_async_regs),
+			      (inst * 2) + 1);
+	if (err)
+		goto out1;
+
+	sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
+				&sunsab_reg, up[0].port.line,
+				false);
+
+	sunserial_console_match(SUNSAB_CONSOLE(), op->dev.of_node,
+				&sunsab_reg, up[1].port.line,
+				false);
+
+	err = uart_add_one_port(&sunsab_reg, &up[0].port);
+	if (err)
+		goto out2;
+
+	err = uart_add_one_port(&sunsab_reg, &up[1].port);
+	if (err)
+		goto out3;
+
+	platform_set_drvdata(op, &up[0]);
+
+	inst++;
+
+	return 0;
+
+out3:
+	uart_remove_one_port(&sunsab_reg, &up[0].port);
+out2:
+	of_iounmap(&op->resource[0],
+		   up[1].port.membase,
+		   sizeof(union sab82532_async_regs));
+out1:
+	of_iounmap(&op->resource[0],
+		   up[0].port.membase,
+		   sizeof(union sab82532_async_regs));
+out:
+	return err;
+}
+
+static int sab_remove(struct platform_device *op)
+{
+	struct uart_sunsab_port *up = platform_get_drvdata(op);
+
+	uart_remove_one_port(&sunsab_reg, &up[1].port);
+	uart_remove_one_port(&sunsab_reg, &up[0].port);
+	of_iounmap(&op->resource[0],
+		   up[1].port.membase,
+		   sizeof(union sab82532_async_regs));
+	of_iounmap(&op->resource[0],
+		   up[0].port.membase,
+		   sizeof(union sab82532_async_regs));
+
+	return 0;
+}
+
+static const struct of_device_id sab_match[] = {
+	{
+		.name = "se",
+	},
+	{
+		.name = "serial",
+		.compatible = "sab82532",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, sab_match);
+
+static struct platform_driver sab_driver = {
+	.driver = {
+		.name = "sab",
+		.of_match_table = sab_match,
+	},
+	.probe		= sab_probe,
+	.remove		= sab_remove,
+};
+
+static int __init sunsab_init(void)
+{
+	struct device_node *dp;
+	int err;
+	int num_channels = 0;
+
+	for_each_node_by_name(dp, "se")
+		num_channels += 2;
+	for_each_node_by_name(dp, "serial") {
+		if (of_device_is_compatible(dp, "sab82532"))
+			num_channels += 2;
+	}
+
+	if (num_channels) {
+		sunsab_ports = kcalloc(num_channels,
+				       sizeof(struct uart_sunsab_port),
+				       GFP_KERNEL);
+		if (!sunsab_ports)
+			return -ENOMEM;
+
+		err = sunserial_register_minors(&sunsab_reg, num_channels);
+		if (err) {
+			kfree(sunsab_ports);
+			sunsab_ports = NULL;
+
+			return err;
+		}
+	}
+
+	err = platform_driver_register(&sab_driver);
+	if (err) {
+		kfree(sunsab_ports);
+		sunsab_ports = NULL;
+	}
+
+	return err;
+}
+
+static void __exit sunsab_exit(void)
+{
+	platform_driver_unregister(&sab_driver);
+	if (sunsab_reg.nr) {
+		sunserial_unregister_minors(&sunsab_reg, sunsab_reg.nr);
+	}
+
+	kfree(sunsab_ports);
+	sunsab_ports = NULL;
+}
+
+module_init(sunsab_init);
+module_exit(sunsab_exit);
+
+MODULE_AUTHOR("Eddie C. Dost and David S. Miller");
+MODULE_DESCRIPTION("Sun SAB82532 serial port driver");
+MODULE_LICENSE("GPL");