Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 964 insertions, 0 deletions

diff --git a/drivers/tty/serial/sb1250-duart.c b/drivers/tty/serial/sb1250-duart.c
new file mode 100644
index 000000000..c5d2b6cdc
--- /dev/null
+++ b/drivers/tty/serial/sb1250-duart.c
@@ -0,0 +1,964 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *	Support for the asynchronous serial interface (DUART) included
+ *	in the BCM1250 and derived System-On-a-Chip (SOC) devices.
+ *
+ *	Copyright (c) 2007  Maciej W. Rozycki
+ *
+ *	Derived from drivers/char/sb1250_duart.c for which the following
+ *	copyright applies:
+ *
+ *	Copyright (c) 2000, 2001, 2002, 2003, 2004  Broadcom Corporation
+ *
+ *	References:
+ *
+ *	"BCM1250/BCM1125/BCM1125H User Manual", Broadcom Corporation
+ */
+
+#include <linux/compiler.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/major.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/spinlock.h>
+#include <linux/sysrq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/types.h>
+
+#include <linux/refcount.h>
+#include <linux/io.h>
+
+#include <asm/sibyte/sb1250.h>
+#include <asm/sibyte/sb1250_uart.h>
+#include <asm/sibyte/swarm.h>
+
+
+#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80)
+#include <asm/sibyte/bcm1480_regs.h>
+#include <asm/sibyte/bcm1480_int.h>
+
+#define SBD_CHANREGS(line)	A_BCM1480_DUART_CHANREG((line), 0)
+#define SBD_CTRLREGS(line)	A_BCM1480_DUART_CTRLREG((line), 0)
+#define SBD_INT(line)		(K_BCM1480_INT_UART_0 + (line))
+
+#define DUART_CHANREG_SPACING	BCM1480_DUART_CHANREG_SPACING
+
+#define R_DUART_IMRREG(line)	R_BCM1480_DUART_IMRREG(line)
+#define R_DUART_INCHREG(line)	R_BCM1480_DUART_INCHREG(line)
+#define R_DUART_ISRREG(line)	R_BCM1480_DUART_ISRREG(line)
+
+#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X)
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_int.h>
+
+#define SBD_CHANREGS(line)	A_DUART_CHANREG((line), 0)
+#define SBD_CTRLREGS(line)	A_DUART_CTRLREG(0)
+#define SBD_INT(line)		(K_INT_UART_0 + (line))
+
+#else
+#error invalid SB1250 UART configuration
+
+#endif
+
+
+MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>");
+MODULE_DESCRIPTION("BCM1xxx on-chip DUART serial driver");
+MODULE_LICENSE("GPL");
+
+
+#define DUART_MAX_CHIP 2
+#define DUART_MAX_SIDE 2
+
+/*
+ * Per-port state.
+ */
+struct sbd_port {
+	struct sbd_duart	*duart;
+	struct uart_port	port;
+	unsigned char __iomem	*memctrl;
+	int			tx_stopped;
+	int			initialised;
+};
+
+/*
+ * Per-DUART state for the shared register space.
+ */
+struct sbd_duart {
+	struct sbd_port		sport[2];
+	unsigned long		mapctrl;
+	refcount_t		map_guard;
+};
+
+#define to_sport(uport) container_of(uport, struct sbd_port, port)
+
+static struct sbd_duart sbd_duarts[DUART_MAX_CHIP];
+
+
+/*
+ * Reading and writing SB1250 DUART registers.
+ *
+ * There are three register spaces: two per-channel ones and
+ * a shared one.  We have to define accessors appropriately.
+ * All registers are 64-bit and all but the Baud Rate Clock
+ * registers only define 8 least significant bits.  There is
+ * also a workaround to take into account.  Raw accessors use
+ * the full register width, but cooked ones truncate it
+ * intentionally so that the rest of the driver does not care.
+ */
+static u64 __read_sbdchn(struct sbd_port *sport, int reg)
+{
+	void __iomem *csr = sport->port.membase + reg;
+
+	return __raw_readq(csr);
+}
+
+static u64 __read_sbdshr(struct sbd_port *sport, int reg)
+{
+	void __iomem *csr = sport->memctrl + reg;
+
+	return __raw_readq(csr);
+}
+
+static void __write_sbdchn(struct sbd_port *sport, int reg, u64 value)
+{
+	void __iomem *csr = sport->port.membase + reg;
+
+	__raw_writeq(value, csr);
+}
+
+static void __write_sbdshr(struct sbd_port *sport, int reg, u64 value)
+{
+	void __iomem *csr = sport->memctrl + reg;
+
+	__raw_writeq(value, csr);
+}
+
+/*
+ * In bug 1956, we get glitches that can mess up uart registers.  This
+ * "read-mode-reg after any register access" is an accepted workaround.
+ */
+static void __war_sbd1956(struct sbd_port *sport)
+{
+	__read_sbdchn(sport, R_DUART_MODE_REG_1);
+	__read_sbdchn(sport, R_DUART_MODE_REG_2);
+}
+
+static unsigned char read_sbdchn(struct sbd_port *sport, int reg)
+{
+	unsigned char retval;
+
+	retval = __read_sbdchn(sport, reg);
+	if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
+		__war_sbd1956(sport);
+	return retval;
+}
+
+static unsigned char read_sbdshr(struct sbd_port *sport, int reg)
+{
+	unsigned char retval;
+
+	retval = __read_sbdshr(sport, reg);
+	if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
+		__war_sbd1956(sport);
+	return retval;
+}
+
+static void write_sbdchn(struct sbd_port *sport, int reg, unsigned int value)
+{
+	__write_sbdchn(sport, reg, value);
+	if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
+		__war_sbd1956(sport);
+}
+
+static void write_sbdshr(struct sbd_port *sport, int reg, unsigned int value)
+{
+	__write_sbdshr(sport, reg, value);
+	if (IS_ENABLED(CONFIG_SB1_PASS_2_WORKAROUNDS))
+		__war_sbd1956(sport);
+}
+
+
+static int sbd_receive_ready(struct sbd_port *sport)
+{
+	return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_RX_RDY;
+}
+
+static int sbd_receive_drain(struct sbd_port *sport)
+{
+	int loops = 10000;
+
+	while (sbd_receive_ready(sport) && --loops)
+		read_sbdchn(sport, R_DUART_RX_HOLD);
+	return loops;
+}
+
+static int __maybe_unused sbd_transmit_ready(struct sbd_port *sport)
+{
+	return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_RDY;
+}
+
+static int __maybe_unused sbd_transmit_drain(struct sbd_port *sport)
+{
+	int loops = 10000;
+
+	while (!sbd_transmit_ready(sport) && --loops)
+		udelay(2);
+	return loops;
+}
+
+static int sbd_transmit_empty(struct sbd_port *sport)
+{
+	return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_EMT;
+}
+
+static int sbd_line_drain(struct sbd_port *sport)
+{
+	int loops = 10000;
+
+	while (!sbd_transmit_empty(sport) && --loops)
+		udelay(2);
+	return loops;
+}
+
+
+static unsigned int sbd_tx_empty(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	return sbd_transmit_empty(sport) ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int sbd_get_mctrl(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int mctrl, status;
+
+	status = read_sbdshr(sport, R_DUART_IN_PORT);
+	status >>= (uport->line) % 2;
+	mctrl = (!(status & M_DUART_IN_PIN0_VAL) ? TIOCM_CTS : 0) |
+		(!(status & M_DUART_IN_PIN4_VAL) ? TIOCM_CAR : 0) |
+		(!(status & M_DUART_RIN0_PIN) ? TIOCM_RNG : 0) |
+		(!(status & M_DUART_IN_PIN2_VAL) ? TIOCM_DSR : 0);
+	return mctrl;
+}
+
+static void sbd_set_mctrl(struct uart_port *uport, unsigned int mctrl)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int clr = 0, set = 0, mode2;
+
+	if (mctrl & TIOCM_DTR)
+		set |= M_DUART_SET_OPR2;
+	else
+		clr |= M_DUART_CLR_OPR2;
+	if (mctrl & TIOCM_RTS)
+		set |= M_DUART_SET_OPR0;
+	else
+		clr |= M_DUART_CLR_OPR0;
+	clr <<= (uport->line) % 2;
+	set <<= (uport->line) % 2;
+
+	mode2 = read_sbdchn(sport, R_DUART_MODE_REG_2);
+	mode2 &= ~M_DUART_CHAN_MODE;
+	if (mctrl & TIOCM_LOOP)
+		mode2 |= V_DUART_CHAN_MODE_LCL_LOOP;
+	else
+		mode2 |= V_DUART_CHAN_MODE_NORMAL;
+
+	write_sbdshr(sport, R_DUART_CLEAR_OPR, clr);
+	write_sbdshr(sport, R_DUART_SET_OPR, set);
+	write_sbdchn(sport, R_DUART_MODE_REG_2, mode2);
+}
+
+static void sbd_stop_tx(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
+	sport->tx_stopped = 1;
+};
+
+static void sbd_start_tx(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int mask;
+
+	/* Enable tx interrupts.  */
+	mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
+	mask |= M_DUART_IMR_TX;
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
+
+	/* Go!, go!, go!...  */
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
+	sport->tx_stopped = 0;
+};
+
+static void sbd_stop_rx(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
+};
+
+static void sbd_enable_ms(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	write_sbdchn(sport, R_DUART_AUXCTL_X,
+		     M_DUART_CIN_CHNG_ENA | M_DUART_CTS_CHNG_ENA);
+}
+
+static void sbd_break_ctl(struct uart_port *uport, int break_state)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	if (break_state == -1)
+		write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_START_BREAK);
+	else
+		write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_STOP_BREAK);
+}
+
+
+static void sbd_receive_chars(struct sbd_port *sport)
+{
+	struct uart_port *uport = &sport->port;
+	struct uart_icount *icount;
+	unsigned int status, ch, flag;
+	int count;
+
+	for (count = 16; count; count--) {
+		status = read_sbdchn(sport, R_DUART_STATUS);
+		if (!(status & M_DUART_RX_RDY))
+			break;
+
+		ch = read_sbdchn(sport, R_DUART_RX_HOLD);
+
+		flag = TTY_NORMAL;
+
+		icount = &uport->icount;
+		icount->rx++;
+
+		if (unlikely(status &
+			     (M_DUART_RCVD_BRK | M_DUART_FRM_ERR |
+			      M_DUART_PARITY_ERR | M_DUART_OVRUN_ERR))) {
+			if (status & M_DUART_RCVD_BRK) {
+				icount->brk++;
+				if (uart_handle_break(uport))
+					continue;
+			} else if (status & M_DUART_FRM_ERR)
+				icount->frame++;
+			else if (status & M_DUART_PARITY_ERR)
+				icount->parity++;
+			if (status & M_DUART_OVRUN_ERR)
+				icount->overrun++;
+
+			status &= uport->read_status_mask;
+			if (status & M_DUART_RCVD_BRK)
+				flag = TTY_BREAK;
+			else if (status & M_DUART_FRM_ERR)
+				flag = TTY_FRAME;
+			else if (status & M_DUART_PARITY_ERR)
+				flag = TTY_PARITY;
+		}
+
+		if (uart_handle_sysrq_char(uport, ch))
+			continue;
+
+		uart_insert_char(uport, status, M_DUART_OVRUN_ERR, ch, flag);
+	}
+
+	tty_flip_buffer_push(&uport->state->port);
+}
+
+static void sbd_transmit_chars(struct sbd_port *sport)
+{
+	struct uart_port *uport = &sport->port;
+	struct circ_buf *xmit = &sport->port.state->xmit;
+	unsigned int mask;
+	int stop_tx;
+
+	/* XON/XOFF chars.  */
+	if (sport->port.x_char) {
+		write_sbdchn(sport, R_DUART_TX_HOLD, sport->port.x_char);
+		sport->port.icount.tx++;
+		sport->port.x_char = 0;
+		return;
+	}
+
+	/* If nothing to do or stopped or hardware stopped.  */
+	stop_tx = (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port));
+
+	/* Send char.  */
+	if (!stop_tx) {
+		write_sbdchn(sport, R_DUART_TX_HOLD, xmit->buf[xmit->tail]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		sport->port.icount.tx++;
+
+		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+			uart_write_wakeup(&sport->port);
+	}
+
+	/* Are we are done?  */
+	if (stop_tx || uart_circ_empty(xmit)) {
+		/* Disable tx interrupts.  */
+		mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
+		mask &= ~M_DUART_IMR_TX;
+		write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
+	}
+}
+
+static void sbd_status_handle(struct sbd_port *sport)
+{
+	struct uart_port *uport = &sport->port;
+	unsigned int delta;
+
+	delta = read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
+	delta >>= (uport->line) % 2;
+
+	if (delta & (M_DUART_IN_PIN0_VAL << S_DUART_IN_PIN_CHNG))
+		uart_handle_cts_change(uport, !(delta & M_DUART_IN_PIN0_VAL));
+
+	if (delta & (M_DUART_IN_PIN2_VAL << S_DUART_IN_PIN_CHNG))
+		uport->icount.dsr++;
+
+	if (delta & ((M_DUART_IN_PIN2_VAL | M_DUART_IN_PIN0_VAL) <<
+		     S_DUART_IN_PIN_CHNG))
+		wake_up_interruptible(&uport->state->port.delta_msr_wait);
+}
+
+static irqreturn_t sbd_interrupt(int irq, void *dev_id)
+{
+	struct sbd_port *sport = dev_id;
+	struct uart_port *uport = &sport->port;
+	irqreturn_t status = IRQ_NONE;
+	unsigned int intstat;
+	int count;
+
+	for (count = 16; count; count--) {
+		intstat = read_sbdshr(sport,
+				      R_DUART_ISRREG((uport->line) % 2));
+		intstat &= read_sbdshr(sport,
+				       R_DUART_IMRREG((uport->line) % 2));
+		intstat &= M_DUART_ISR_ALL;
+		if (!intstat)
+			break;
+
+		if (intstat & M_DUART_ISR_RX)
+			sbd_receive_chars(sport);
+		if (intstat & M_DUART_ISR_IN)
+			sbd_status_handle(sport);
+		if (intstat & M_DUART_ISR_TX)
+			sbd_transmit_chars(sport);
+
+		status = IRQ_HANDLED;
+	}
+
+	return status;
+}
+
+
+static int sbd_startup(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int mode1;
+	int ret;
+
+	ret = request_irq(sport->port.irq, sbd_interrupt,
+			  IRQF_SHARED, "sb1250-duart", sport);
+	if (ret)
+		return ret;
+
+	/* Clear the receive FIFO.  */
+	sbd_receive_drain(sport);
+
+	/* Clear the interrupt registers.  */
+	write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT);
+	read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2));
+
+	/* Set rx/tx interrupt to FIFO available.  */
+	mode1 = read_sbdchn(sport, R_DUART_MODE_REG_1);
+	mode1 &= ~(M_DUART_RX_IRQ_SEL_RXFULL | M_DUART_TX_IRQ_SEL_TXEMPT);
+	write_sbdchn(sport, R_DUART_MODE_REG_1, mode1);
+
+	/* Disable tx, enable rx.  */
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_EN);
+	sport->tx_stopped = 1;
+
+	/* Enable interrupts.  */
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
+		     M_DUART_IMR_IN | M_DUART_IMR_RX);
+
+	return 0;
+}
+
+static void sbd_shutdown(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
+	sport->tx_stopped = 1;
+	free_irq(sport->port.irq, sport);
+}
+
+
+static void sbd_init_port(struct sbd_port *sport)
+{
+	struct uart_port *uport = &sport->port;
+
+	if (sport->initialised)
+		return;
+
+	/* There is no DUART reset feature, so just set some sane defaults.  */
+	write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_TX);
+	write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_RX);
+	write_sbdchn(sport, R_DUART_MODE_REG_1, V_DUART_BITS_PER_CHAR_8);
+	write_sbdchn(sport, R_DUART_MODE_REG_2, 0);
+	write_sbdchn(sport, R_DUART_FULL_CTL,
+		     V_DUART_INT_TIME(0) | V_DUART_SIG_FULL(15));
+	write_sbdchn(sport, R_DUART_OPCR_X, 0);
+	write_sbdchn(sport, R_DUART_AUXCTL_X, 0);
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0);
+
+	sport->initialised = 1;
+}
+
+static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios,
+			    const struct ktermios *old_termios)
+{
+	struct sbd_port *sport = to_sport(uport);
+	unsigned int mode1 = 0, mode2 = 0, aux = 0;
+	unsigned int mode1mask = 0, mode2mask = 0, auxmask = 0;
+	unsigned int oldmode1, oldmode2, oldaux;
+	unsigned int baud, brg;
+	unsigned int command;
+
+	mode1mask |= ~(M_DUART_PARITY_MODE | M_DUART_PARITY_TYPE_ODD |
+		       M_DUART_BITS_PER_CHAR);
+	mode2mask |= ~M_DUART_STOP_BIT_LEN_2;
+	auxmask |= ~M_DUART_CTS_CHNG_ENA;
+
+	/* Byte size.  */
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+	case CS6:
+		/* Unsupported, leave unchanged.  */
+		mode1mask |= M_DUART_PARITY_MODE;
+		break;
+	case CS7:
+		mode1 |= V_DUART_BITS_PER_CHAR_7;
+		break;
+	case CS8:
+	default:
+		mode1 |= V_DUART_BITS_PER_CHAR_8;
+		break;
+	}
+
+	/* Parity and stop bits.  */
+	if (termios->c_cflag & CSTOPB)
+		mode2 |= M_DUART_STOP_BIT_LEN_2;
+	else
+		mode2 |= M_DUART_STOP_BIT_LEN_1;
+	if (termios->c_cflag & PARENB)
+		mode1 |= V_DUART_PARITY_MODE_ADD;
+	else
+		mode1 |= V_DUART_PARITY_MODE_NONE;
+	if (termios->c_cflag & PARODD)
+		mode1 |= M_DUART_PARITY_TYPE_ODD;
+	else
+		mode1 |= M_DUART_PARITY_TYPE_EVEN;
+
+	baud = uart_get_baud_rate(uport, termios, old_termios, 1200, 5000000);
+	brg = V_DUART_BAUD_RATE(baud);
+	/* The actual lower bound is 1221bps, so compensate.  */
+	if (brg > M_DUART_CLK_COUNTER)
+		brg = M_DUART_CLK_COUNTER;
+
+	uart_update_timeout(uport, termios->c_cflag, baud);
+
+	uport->read_status_mask = M_DUART_OVRUN_ERR;
+	if (termios->c_iflag & INPCK)
+		uport->read_status_mask |= M_DUART_FRM_ERR |
+					   M_DUART_PARITY_ERR;
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+		uport->read_status_mask |= M_DUART_RCVD_BRK;
+
+	uport->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		uport->ignore_status_mask |= M_DUART_FRM_ERR |
+					     M_DUART_PARITY_ERR;
+	if (termios->c_iflag & IGNBRK) {
+		uport->ignore_status_mask |= M_DUART_RCVD_BRK;
+		if (termios->c_iflag & IGNPAR)
+			uport->ignore_status_mask |= M_DUART_OVRUN_ERR;
+	}
+
+	if (termios->c_cflag & CREAD)
+		command = M_DUART_RX_EN;
+	else
+		command = M_DUART_RX_DIS;
+
+	if (termios->c_cflag & CRTSCTS)
+		aux |= M_DUART_CTS_CHNG_ENA;
+	else
+		aux &= ~M_DUART_CTS_CHNG_ENA;
+
+	spin_lock(&uport->lock);
+
+	if (sport->tx_stopped)
+		command |= M_DUART_TX_DIS;
+	else
+		command |= M_DUART_TX_EN;
+
+	oldmode1 = read_sbdchn(sport, R_DUART_MODE_REG_1) & mode1mask;
+	oldmode2 = read_sbdchn(sport, R_DUART_MODE_REG_2) & mode2mask;
+	oldaux = read_sbdchn(sport, R_DUART_AUXCTL_X) & auxmask;
+
+	if (!sport->tx_stopped)
+		sbd_line_drain(sport);
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS);
+
+	write_sbdchn(sport, R_DUART_MODE_REG_1, mode1 | oldmode1);
+	write_sbdchn(sport, R_DUART_MODE_REG_2, mode2 | oldmode2);
+	write_sbdchn(sport, R_DUART_CLK_SEL, brg);
+	write_sbdchn(sport, R_DUART_AUXCTL_X, aux | oldaux);
+
+	write_sbdchn(sport, R_DUART_CMD, command);
+
+	spin_unlock(&uport->lock);
+}
+
+
+static const char *sbd_type(struct uart_port *uport)
+{
+	return "SB1250 DUART";
+}
+
+static void sbd_release_port(struct uart_port *uport)
+{
+	struct sbd_port *sport = to_sport(uport);
+	struct sbd_duart *duart = sport->duart;
+
+	iounmap(sport->memctrl);
+	sport->memctrl = NULL;
+	iounmap(uport->membase);
+	uport->membase = NULL;
+
+	if(refcount_dec_and_test(&duart->map_guard))
+		release_mem_region(duart->mapctrl, DUART_CHANREG_SPACING);
+	release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
+}
+
+static int sbd_map_port(struct uart_port *uport)
+{
+	const char *err = KERN_ERR "sbd: Cannot map MMIO\n";
+	struct sbd_port *sport = to_sport(uport);
+	struct sbd_duart *duart = sport->duart;
+
+	if (!uport->membase)
+		uport->membase = ioremap(uport->mapbase,
+						 DUART_CHANREG_SPACING);
+	if (!uport->membase) {
+		printk(err);
+		return -ENOMEM;
+	}
+
+	if (!sport->memctrl)
+		sport->memctrl = ioremap(duart->mapctrl,
+						 DUART_CHANREG_SPACING);
+	if (!sport->memctrl) {
+		printk(err);
+		iounmap(uport->membase);
+		uport->membase = NULL;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int sbd_request_port(struct uart_port *uport)
+{
+	const char *err = KERN_ERR "sbd: Unable to reserve MMIO resource\n";
+	struct sbd_duart *duart = to_sport(uport)->duart;
+	int ret = 0;
+
+	if (!request_mem_region(uport->mapbase, DUART_CHANREG_SPACING,
+				"sb1250-duart")) {
+		printk(err);
+		return -EBUSY;
+	}
+	refcount_inc(&duart->map_guard);
+	if (refcount_read(&duart->map_guard) == 1) {
+		if (!request_mem_region(duart->mapctrl, DUART_CHANREG_SPACING,
+					"sb1250-duart")) {
+			refcount_dec(&duart->map_guard);
+			printk(err);
+			ret = -EBUSY;
+		}
+	}
+	if (!ret) {
+		ret = sbd_map_port(uport);
+		if (ret) {
+			if (refcount_dec_and_test(&duart->map_guard))
+				release_mem_region(duart->mapctrl,
+						   DUART_CHANREG_SPACING);
+		}
+	}
+	if (ret) {
+		release_mem_region(uport->mapbase, DUART_CHANREG_SPACING);
+		return ret;
+	}
+	return 0;
+}
+
+static void sbd_config_port(struct uart_port *uport, int flags)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	if (flags & UART_CONFIG_TYPE) {
+		if (sbd_request_port(uport))
+			return;
+
+		uport->type = PORT_SB1250_DUART;
+
+		sbd_init_port(sport);
+	}
+}
+
+static int sbd_verify_port(struct uart_port *uport, struct serial_struct *ser)
+{
+	int ret = 0;
+
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_SB1250_DUART)
+		ret = -EINVAL;
+	if (ser->irq != uport->irq)
+		ret = -EINVAL;
+	if (ser->baud_base != uport->uartclk / 16)
+		ret = -EINVAL;
+	return ret;
+}
+
+
+static const struct uart_ops sbd_ops = {
+	.tx_empty	= sbd_tx_empty,
+	.set_mctrl	= sbd_set_mctrl,
+	.get_mctrl	= sbd_get_mctrl,
+	.stop_tx	= sbd_stop_tx,
+	.start_tx	= sbd_start_tx,
+	.stop_rx	= sbd_stop_rx,
+	.enable_ms	= sbd_enable_ms,
+	.break_ctl	= sbd_break_ctl,
+	.startup	= sbd_startup,
+	.shutdown	= sbd_shutdown,
+	.set_termios	= sbd_set_termios,
+	.type		= sbd_type,
+	.release_port	= sbd_release_port,
+	.request_port	= sbd_request_port,
+	.config_port	= sbd_config_port,
+	.verify_port	= sbd_verify_port,
+};
+
+/* Initialize SB1250 DUART port structures.  */
+static void __init sbd_probe_duarts(void)
+{
+	static int probed;
+	int chip, side;
+	int max_lines, line;
+
+	if (probed)
+		return;
+
+	/* Set the number of available units based on the SOC type.  */
+	switch (soc_type) {
+	case K_SYS_SOC_TYPE_BCM1x55:
+	case K_SYS_SOC_TYPE_BCM1x80:
+		max_lines = 4;
+		break;
+	default:
+		/* Assume at least two serial ports at the normal address.  */
+		max_lines = 2;
+		break;
+	}
+
+	probed = 1;
+
+	for (chip = 0, line = 0; chip < DUART_MAX_CHIP && line < max_lines;
+	     chip++) {
+		sbd_duarts[chip].mapctrl = SBD_CTRLREGS(line);
+
+		for (side = 0; side < DUART_MAX_SIDE && line < max_lines;
+		     side++, line++) {
+			struct sbd_port *sport = &sbd_duarts[chip].sport[side];
+			struct uart_port *uport = &sport->port;
+
+			sport->duart	= &sbd_duarts[chip];
+
+			uport->irq	= SBD_INT(line);
+			uport->uartclk	= 100000000 / 20 * 16;
+			uport->fifosize	= 16;
+			uport->iotype	= UPIO_MEM;
+			uport->flags	= UPF_BOOT_AUTOCONF;
+			uport->ops	= &sbd_ops;
+			uport->line	= line;
+			uport->mapbase	= SBD_CHANREGS(line);
+			uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SB1250_DUART_CONSOLE);
+		}
+	}
+}
+
+
+#ifdef CONFIG_SERIAL_SB1250_DUART_CONSOLE
+/*
+ * Serial console stuff.  Very basic, polling driver for doing serial
+ * console output.  The console_lock is held by the caller, so we
+ * shouldn't be interrupted for more console activity.
+ */
+static void sbd_console_putchar(struct uart_port *uport, unsigned char ch)
+{
+	struct sbd_port *sport = to_sport(uport);
+
+	sbd_transmit_drain(sport);
+	write_sbdchn(sport, R_DUART_TX_HOLD, ch);
+}
+
+static void sbd_console_write(struct console *co, const char *s,
+			      unsigned int count)
+{
+	int chip = co->index / DUART_MAX_SIDE;
+	int side = co->index % DUART_MAX_SIDE;
+	struct sbd_port *sport = &sbd_duarts[chip].sport[side];
+	struct uart_port *uport = &sport->port;
+	unsigned long flags;
+	unsigned int mask;
+
+	/* Disable transmit interrupts and enable the transmitter. */
+	spin_lock_irqsave(&uport->lock, flags);
+	mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2));
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2),
+		     mask & ~M_DUART_IMR_TX);
+	write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN);
+	spin_unlock_irqrestore(&uport->lock, flags);
+
+	uart_console_write(&sport->port, s, count, sbd_console_putchar);
+
+	/* Restore transmit interrupts and the transmitter enable. */
+	spin_lock_irqsave(&uport->lock, flags);
+	sbd_line_drain(sport);
+	if (sport->tx_stopped)
+		write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS);
+	write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask);
+	spin_unlock_irqrestore(&uport->lock, flags);
+}
+
+static int __init sbd_console_setup(struct console *co, char *options)
+{
+	int chip = co->index / DUART_MAX_SIDE;
+	int side = co->index % DUART_MAX_SIDE;
+	struct sbd_port *sport = &sbd_duarts[chip].sport[side];
+	struct uart_port *uport = &sport->port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	if (!sport->duart)
+		return -ENXIO;
+
+	ret = sbd_map_port(uport);
+	if (ret)
+		return ret;
+
+	sbd_init_port(sport);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	return uart_set_options(uport, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver sbd_reg;
+static struct console sbd_console = {
+	.name	= "duart",
+	.write	= sbd_console_write,
+	.device	= uart_console_device,
+	.setup	= sbd_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+	.data	= &sbd_reg
+};
+
+static int __init sbd_serial_console_init(void)
+{
+	sbd_probe_duarts();
+	register_console(&sbd_console);
+
+	return 0;
+}
+
+console_initcall(sbd_serial_console_init);
+
+#define SERIAL_SB1250_DUART_CONSOLE	&sbd_console
+#else
+#define SERIAL_SB1250_DUART_CONSOLE	NULL
+#endif /* CONFIG_SERIAL_SB1250_DUART_CONSOLE */
+
+
+static struct uart_driver sbd_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "sb1250_duart",
+	.dev_name	= "duart",
+	.major		= TTY_MAJOR,
+	.minor		= SB1250_DUART_MINOR_BASE,
+	.nr		= DUART_MAX_CHIP * DUART_MAX_SIDE,
+	.cons		= SERIAL_SB1250_DUART_CONSOLE,
+};
+
+/* Set up the driver and register it.  */
+static int __init sbd_init(void)
+{
+	int i, ret;
+
+	sbd_probe_duarts();
+
+	ret = uart_register_driver(&sbd_reg);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < DUART_MAX_CHIP * DUART_MAX_SIDE; i++) {
+		struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
+		struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
+		struct uart_port *uport = &sport->port;
+
+		if (sport->duart)
+			uart_add_one_port(&sbd_reg, uport);
+	}
+
+	return 0;
+}
+
+/* Unload the driver.  Unregister stuff, get ready to go away.  */
+static void __exit sbd_exit(void)
+{
+	int i;
+
+	for (i = DUART_MAX_CHIP * DUART_MAX_SIDE - 1; i >= 0; i--) {
+		struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE];
+		struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE];
+		struct uart_port *uport = &sport->port;
+
+		if (sport->duart)
+			uart_remove_one_port(&sbd_reg, uport);
+	}
+
+	uart_unregister_driver(&sbd_reg);
+}
+
+module_init(sbd_init);
+module_exit(sbd_exit);