tty: move drivers/serial/ to drivers/tty/serial/

The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 1513 insertions, 0 deletions

diff --git a/drivers/tty/serial/mfd.c b/drivers/tty/serial/mfd.c
new file mode 100644
index 000000000000..d40010a22ecd
--- /dev/null
+++ b/drivers/tty/serial/mfd.c
@@ -0,0 +1,1513 @@
+/*
+ * mfd.c: driver for High Speed UART device of Intel Medfield platform
+ *
+ * Refer pxa.c, 8250.c and some other drivers in drivers/serial/
+ *
+ * (C) Copyright 2010 Intel Corporation
+ *
+ * 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; version 2
+ * of the License.
+ */
+
+/* Notes:
+ * 1. DMA channel allocation: 0/1 channel are assigned to port 0,
+ *    2/3 chan to port 1, 4/5 chan to port 3. Even number chans
+ *    are used for RX, odd chans for TX
+ *
+ * 2. In A0 stepping, UART will not support TX half empty flag
+ *
+ * 3. The RI/DSR/DCD/DTR are not pinned out, DCD & DSR are always
+ *    asserted, only when the HW is reset the DDCD and DDSR will
+ *    be triggered
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/slab.h>
+#include <linux/serial_reg.h>
+#include <linux/circ_buf.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial_mfd.h>
+#include <linux/dma-mapping.h>
+#include <linux/pci.h>
+#include <linux/io.h>
+#include <linux/debugfs.h>
+
+#define  MFD_HSU_A0_STEPPING	1
+
+#define HSU_DMA_BUF_SIZE	2048
+
+#define chan_readl(chan, offset)	readl(chan->reg + offset)
+#define chan_writel(chan, offset, val)	writel(val, chan->reg + offset)
+
+#define mfd_readl(obj, offset)		readl(obj->reg + offset)
+#define mfd_writel(obj, offset, val)	writel(val, obj->reg + offset)
+
+#define HSU_DMA_TIMEOUT_CHECK_FREQ	(HZ/10)
+
+struct hsu_dma_buffer {
+	u8		*buf;
+	dma_addr_t	dma_addr;
+	u32		dma_size;
+	u32		ofs;
+};
+
+struct hsu_dma_chan {
+	u32	id;
+	enum dma_data_direction	dirt;
+	struct uart_hsu_port	*uport;
+	void __iomem		*reg;
+	struct timer_list	rx_timer; /* only needed by RX channel */
+};
+
+struct uart_hsu_port {
+	struct uart_port        port;
+	unsigned char           ier;
+	unsigned char           lcr;
+	unsigned char           mcr;
+	unsigned int            lsr_break_flag;
+	char			name[12];
+	int			index;
+	struct device		*dev;
+
+	struct hsu_dma_chan	*txc;
+	struct hsu_dma_chan	*rxc;
+	struct hsu_dma_buffer	txbuf;
+	struct hsu_dma_buffer	rxbuf;
+	int			use_dma;	/* flag for DMA/PIO */
+	int			running;
+	int			dma_tx_on;
+};
+
+/* Top level data structure of HSU */
+struct hsu_port {
+	void __iomem	*reg;
+	unsigned long	paddr;
+	unsigned long	iolen;
+	u32		irq;
+
+	struct uart_hsu_port	port[3];
+	struct hsu_dma_chan	chans[10];
+
+	struct dentry *debugfs;
+};
+
+static inline unsigned int serial_in(struct uart_hsu_port *up, int offset)
+{
+	unsigned int val;
+
+	if (offset > UART_MSR) {
+		offset <<= 2;
+		val = readl(up->port.membase + offset);
+	} else
+		val = (unsigned int)readb(up->port.membase + offset);
+
+	return val;
+}
+
+static inline void serial_out(struct uart_hsu_port *up, int offset, int value)
+{
+	if (offset > UART_MSR) {
+		offset <<= 2;
+		writel(value, up->port.membase + offset);
+	} else {
+		unsigned char val = value & 0xff;
+		writeb(val, up->port.membase + offset);
+	}
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+#define HSU_REGS_BUFSIZE	1024
+
+static int hsu_show_regs_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+static ssize_t port_show_regs(struct file *file, char __user *user_buf,
+				size_t count, loff_t *ppos)
+{
+	struct uart_hsu_port *up = file->private_data;
+	char *buf;
+	u32 len = 0;
+	ssize_t ret;
+
+	buf = kzalloc(HSU_REGS_BUFSIZE, GFP_KERNEL);
+	if (!buf)
+		return 0;
+
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"MFD HSU port[%d] regs:\n", up->index);
+
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"=================================\n");
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"IER: \t\t0x%08x\n", serial_in(up, UART_IER));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"IIR: \t\t0x%08x\n", serial_in(up, UART_IIR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"LCR: \t\t0x%08x\n", serial_in(up, UART_LCR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"MCR: \t\t0x%08x\n", serial_in(up, UART_MCR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"LSR: \t\t0x%08x\n", serial_in(up, UART_LSR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"MSR: \t\t0x%08x\n", serial_in(up, UART_MSR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"FOR: \t\t0x%08x\n", serial_in(up, UART_FOR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"PS: \t\t0x%08x\n", serial_in(up, UART_PS));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"MUL: \t\t0x%08x\n", serial_in(up, UART_MUL));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"DIV: \t\t0x%08x\n", serial_in(up, UART_DIV));
+
+	if (len > HSU_REGS_BUFSIZE)
+		len = HSU_REGS_BUFSIZE;
+
+	ret =  simple_read_from_buffer(user_buf, count, ppos, buf, len);
+	kfree(buf);
+	return ret;
+}
+
+static ssize_t dma_show_regs(struct file *file, char __user *user_buf,
+				size_t count, loff_t *ppos)
+{
+	struct hsu_dma_chan *chan = file->private_data;
+	char *buf;
+	u32 len = 0;
+	ssize_t ret;
+
+	buf = kzalloc(HSU_REGS_BUFSIZE, GFP_KERNEL);
+	if (!buf)
+		return 0;
+
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"MFD HSU DMA channel [%d] regs:\n", chan->id);
+
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"=================================\n");
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"CR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_CR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"DCR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_DCR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"BSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_BSR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"MOTSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_MOTSR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D0SAR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D0TSR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D1SAR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D1TSR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D2SAR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D2TSR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"D0SAR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D3SAR));
+	len += snprintf(buf + len, HSU_REGS_BUFSIZE - len,
+			"D0TSR: \t\t0x%08x\n", chan_readl(chan, HSU_CH_D3TSR));
+
+	if (len > HSU_REGS_BUFSIZE)
+		len = HSU_REGS_BUFSIZE;
+
+	ret =  simple_read_from_buffer(user_buf, count, ppos, buf, len);
+	kfree(buf);
+	return ret;
+}
+
+static const struct file_operations port_regs_ops = {
+	.owner		= THIS_MODULE,
+	.open		= hsu_show_regs_open,
+	.read		= port_show_regs,
+	.llseek		= default_llseek,
+};
+
+static const struct file_operations dma_regs_ops = {
+	.owner		= THIS_MODULE,
+	.open		= hsu_show_regs_open,
+	.read		= dma_show_regs,
+	.llseek		= default_llseek,
+};
+
+static int hsu_debugfs_init(struct hsu_port *hsu)
+{
+	int i;
+	char name[32];
+
+	hsu->debugfs = debugfs_create_dir("hsu", NULL);
+	if (!hsu->debugfs)
+		return -ENOMEM;
+
+	for (i = 0; i < 3; i++) {
+		snprintf(name, sizeof(name), "port_%d_regs", i);
+		debugfs_create_file(name, S_IFREG | S_IRUGO,
+			hsu->debugfs, (void *)(&hsu->port[i]), &port_regs_ops);
+	}
+
+	for (i = 0; i < 6; i++) {
+		snprintf(name, sizeof(name), "dma_chan_%d_regs", i);
+		debugfs_create_file(name, S_IFREG | S_IRUGO,
+			hsu->debugfs, (void *)&hsu->chans[i], &dma_regs_ops);
+	}
+
+	return 0;
+}
+
+static void hsu_debugfs_remove(struct hsu_port *hsu)
+{
+	if (hsu->debugfs)
+		debugfs_remove_recursive(hsu->debugfs);
+}
+
+#else
+static inline int hsu_debugfs_init(struct hsu_port *hsu)
+{
+	return 0;
+}
+
+static inline void hsu_debugfs_remove(struct hsu_port *hsu)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
+static void serial_hsu_enable_ms(struct uart_port *port)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+
+	up->ier |= UART_IER_MSI;
+	serial_out(up, UART_IER, up->ier);
+}
+
+void hsu_dma_tx(struct uart_hsu_port *up)
+{
+	struct circ_buf *xmit = &up->port.state->xmit;
+	struct hsu_dma_buffer *dbuf = &up->txbuf;
+	int count;
+
+	/* test_and_set_bit may be better, but anyway it's in lock protected mode */
+	if (up->dma_tx_on)
+		return;
+
+	/* Update the circ buf info */
+	xmit->tail += dbuf->ofs;
+	xmit->tail &= UART_XMIT_SIZE - 1;
+
+	up->port.icount.tx += dbuf->ofs;
+	dbuf->ofs = 0;
+
+	/* Disable the channel */
+	chan_writel(up->txc, HSU_CH_CR, 0x0);
+
+	if (!uart_circ_empty(xmit) && !uart_tx_stopped(&up->port)) {
+		dma_sync_single_for_device(up->port.dev,
+					   dbuf->dma_addr,
+					   dbuf->dma_size,
+					   DMA_TO_DEVICE);
+
+		count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+		dbuf->ofs = count;
+
+		/* Reprogram the channel */
+		chan_writel(up->txc, HSU_CH_D0SAR, dbuf->dma_addr + xmit->tail);
+		chan_writel(up->txc, HSU_CH_D0TSR, count);
+
+		/* Reenable the channel */
+		chan_writel(up->txc, HSU_CH_DCR, 0x1
+						 | (0x1 << 8)
+						 | (0x1 << 16)
+						 | (0x1 << 24));
+		up->dma_tx_on = 1;
+		chan_writel(up->txc, HSU_CH_CR, 0x1);
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+}
+
+/* The buffer is already cache coherent */
+void hsu_dma_start_rx_chan(struct hsu_dma_chan *rxc, struct hsu_dma_buffer *dbuf)
+{
+	dbuf->ofs = 0;
+
+	chan_writel(rxc, HSU_CH_BSR, 32);
+	chan_writel(rxc, HSU_CH_MOTSR, 4);
+
+	chan_writel(rxc, HSU_CH_D0SAR, dbuf->dma_addr);
+	chan_writel(rxc, HSU_CH_D0TSR, dbuf->dma_size);
+	chan_writel(rxc, HSU_CH_DCR, 0x1 | (0x1 << 8)
+					 | (0x1 << 16)
+					 | (0x1 << 24)	/* timeout bit, see HSU Errata 1 */
+					 );
+	chan_writel(rxc, HSU_CH_CR, 0x3);
+
+	mod_timer(&rxc->rx_timer, jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ);
+}
+
+/* Protected by spin_lock_irqsave(port->lock) */
+static void serial_hsu_start_tx(struct uart_port *port)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+
+	if (up->use_dma) {
+		hsu_dma_tx(up);
+	} else if (!(up->ier & UART_IER_THRI)) {
+		up->ier |= UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+static void serial_hsu_stop_tx(struct uart_port *port)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	struct hsu_dma_chan *txc = up->txc;
+
+	if (up->use_dma)
+		chan_writel(txc, HSU_CH_CR, 0x0);
+	else if (up->ier & UART_IER_THRI) {
+		up->ier &= ~UART_IER_THRI;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+/* This is always called in spinlock protected mode, so
+ * modify timeout timer is safe here */
+void hsu_dma_rx(struct uart_hsu_port *up, u32 int_sts)
+{
+	struct hsu_dma_buffer *dbuf = &up->rxbuf;
+	struct hsu_dma_chan *chan = up->rxc;
+	struct uart_port *port = &up->port;
+	struct tty_struct *tty = port->state->port.tty;
+	int count;
+
+	if (!tty)
+		return;
+
+	/*
+	 * First need to know how many is already transferred,
+	 * then check if its a timeout DMA irq, and return
+	 * the trail bytes out, push them up and reenable the
+	 * channel
+	 */
+
+	/* Timeout IRQ, need wait some time, see Errata 2 */
+	if (int_sts & 0xf00)
+		udelay(2);
+
+	/* Stop the channel */
+	chan_writel(chan, HSU_CH_CR, 0x0);
+
+	count = chan_readl(chan, HSU_CH_D0SAR) - dbuf->dma_addr;
+	if (!count) {
+		/* Restart the channel before we leave */
+		chan_writel(chan, HSU_CH_CR, 0x3);
+		return;
+	}
+	del_timer(&chan->rx_timer);
+
+	dma_sync_single_for_cpu(port->dev, dbuf->dma_addr,
+			dbuf->dma_size, DMA_FROM_DEVICE);
+
+	/*
+	 * Head will only wrap around when we recycle
+	 * the DMA buffer, and when that happens, we
+	 * explicitly set tail to 0. So head will
+	 * always be greater than tail.
+	 */
+	tty_insert_flip_string(tty, dbuf->buf, count);
+	port->icount.rx += count;
+
+	dma_sync_single_for_device(up->port.dev, dbuf->dma_addr,
+			dbuf->dma_size, DMA_FROM_DEVICE);
+
+	/* Reprogram the channel */
+	chan_writel(chan, HSU_CH_D0SAR, dbuf->dma_addr);
+	chan_writel(chan, HSU_CH_D0TSR, dbuf->dma_size);
+	chan_writel(chan, HSU_CH_DCR, 0x1
+					 | (0x1 << 8)
+					 | (0x1 << 16)
+					 | (0x1 << 24)	/* timeout bit, see HSU Errata 1 */
+					 );
+	tty_flip_buffer_push(tty);
+
+	chan_writel(chan, HSU_CH_CR, 0x3);
+	chan->rx_timer.expires = jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ;
+	add_timer(&chan->rx_timer);
+
+}
+
+static void serial_hsu_stop_rx(struct uart_port *port)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	struct hsu_dma_chan *chan = up->rxc;
+
+	if (up->use_dma)
+		chan_writel(chan, HSU_CH_CR, 0x2);
+	else {
+		up->ier &= ~UART_IER_RLSI;
+		up->port.read_status_mask &= ~UART_LSR_DR;
+		serial_out(up, UART_IER, up->ier);
+	}
+}
+
+static inline void receive_chars(struct uart_hsu_port *up, int *status)
+{
+	struct tty_struct *tty = up->port.state->port.tty;
+	unsigned int ch, flag;
+	unsigned int max_count = 256;
+
+	if (!tty)
+		return;
+
+	do {
+		ch = serial_in(up, UART_RX);
+		flag = TTY_NORMAL;
+		up->port.icount.rx++;
+
+		if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
+				       UART_LSR_FE | UART_LSR_OE))) {
+
+			dev_warn(up->dev, "We really rush into ERR/BI case"
+				"status = 0x%02x", *status);
+			/* For statistics only */
+			if (*status & UART_LSR_BI) {
+				*status &= ~(UART_LSR_FE | UART_LSR_PE);
+				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))
+					goto ignore_char;
+			} else if (*status & UART_LSR_PE)
+				up->port.icount.parity++;
+			else if (*status & UART_LSR_FE)
+				up->port.icount.frame++;
+			if (*status & UART_LSR_OE)
+				up->port.icount.overrun++;
+
+			/* Mask off conditions which should be ignored. */
+			*status &= up->port.read_status_mask;
+
+#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE
+			if (up->port.cons &&
+				up->port.cons->index == up->port.line) {
+				/* Recover the break flag from console xmit */
+				*status |= up->lsr_break_flag;
+				up->lsr_break_flag = 0;
+			}
+#endif
+			if (*status & UART_LSR_BI) {
+				flag = TTY_BREAK;
+			} else if (*status & UART_LSR_PE)
+				flag = TTY_PARITY;
+			else if (*status & UART_LSR_FE)
+				flag = TTY_FRAME;
+		}
+
+		if (uart_handle_sysrq_char(&up->port, ch))
+			goto ignore_char;
+
+		uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
+	ignore_char:
+		*status = serial_in(up, UART_LSR);
+	} while ((*status & UART_LSR_DR) && max_count--);
+	tty_flip_buffer_push(tty);
+}
+
+static void transmit_chars(struct uart_hsu_port *up)
+{
+	struct circ_buf *xmit = &up->port.state->xmit;
+	int count;
+
+	if (up->port.x_char) {
+		serial_out(up, UART_TX, up->port.x_char);
+		up->port.icount.tx++;
+		up->port.x_char = 0;
+		return;
+	}
+	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
+		serial_hsu_stop_tx(&up->port);
+		return;
+	}
+
+#ifndef MFD_HSU_A0_STEPPING
+	count = up->port.fifosize / 2;
+#else
+	/*
+	 * A0 only supports fully empty IRQ, and the first char written
+	 * into it won't clear the EMPT bit, so we may need be cautious
+	 * by useing a shorter buffer
+	 */
+	count = up->port.fifosize - 4;
+#endif
+	do {
+		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+
+		up->port.icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	} while (--count > 0);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(&up->port);
+
+	if (uart_circ_empty(xmit))
+		serial_hsu_stop_tx(&up->port);
+}
+
+static inline void check_modem_status(struct uart_hsu_port *up)
+{
+	int status;
+
+	status = serial_in(up, UART_MSR);
+
+	if ((status & UART_MSR_ANY_DELTA) == 0)
+		return;
+
+	if (status & UART_MSR_TERI)
+		up->port.icount.rng++;
+	if (status & UART_MSR_DDSR)
+		up->port.icount.dsr++;
+	/* We may only get DDCD when HW init and reset */
+	if (status & UART_MSR_DDCD)
+		uart_handle_dcd_change(&up->port, status & UART_MSR_DCD);
+	/* Will start/stop_tx accordingly */
+	if (status & UART_MSR_DCTS)
+		uart_handle_cts_change(&up->port, status & UART_MSR_CTS);
+
+	wake_up_interruptible(&up->port.state->port.delta_msr_wait);
+}
+
+/*
+ * This handles the interrupt from one port.
+ */
+static irqreturn_t port_irq(int irq, void *dev_id)
+{
+	struct uart_hsu_port *up = dev_id;
+	unsigned int iir, lsr;
+	unsigned long flags;
+
+	if (unlikely(!up->running))
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (up->use_dma) {
+		lsr = serial_in(up, UART_LSR);
+		if (unlikely(lsr & (UART_LSR_BI | UART_LSR_PE |
+				       UART_LSR_FE | UART_LSR_OE)))
+			dev_warn(up->dev,
+				"Got lsr irq while using DMA, lsr = 0x%2x\n",
+				lsr);
+		check_modem_status(up);
+		spin_unlock_irqrestore(&up->port.lock, flags);
+		return IRQ_HANDLED;
+	}
+
+	iir = serial_in(up, UART_IIR);
+	if (iir & UART_IIR_NO_INT) {
+		spin_unlock_irqrestore(&up->port.lock, flags);
+		return IRQ_NONE;
+	}
+
+	lsr = serial_in(up, UART_LSR);
+	if (lsr & UART_LSR_DR)
+		receive_chars(up, &lsr);
+	check_modem_status(up);
+
+	/* lsr will be renewed during the receive_chars */
+	if (lsr & UART_LSR_THRE)
+		transmit_chars(up);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	return IRQ_HANDLED;
+}
+
+static inline void dma_chan_irq(struct hsu_dma_chan *chan)
+{
+	struct uart_hsu_port *up = chan->uport;
+	unsigned long flags;
+	u32 int_sts;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	if (!up->use_dma || !up->running)
+		goto exit;
+
+	/*
+	 * No matter what situation, need read clear the IRQ status
+	 * There is a bug, see Errata 5, HSD 2900918
+	 */
+	int_sts = chan_readl(chan, HSU_CH_SR);
+
+	/* Rx channel */
+	if (chan->dirt == DMA_FROM_DEVICE)
+		hsu_dma_rx(up, int_sts);
+
+	/* Tx channel */
+	if (chan->dirt == DMA_TO_DEVICE) {
+		chan_writel(chan, HSU_CH_CR, 0x0);
+		up->dma_tx_on = 0;
+		hsu_dma_tx(up);
+	}
+
+exit:
+	spin_unlock_irqrestore(&up->port.lock, flags);
+	return;
+}
+
+static irqreturn_t dma_irq(int irq, void *dev_id)
+{
+	struct hsu_port *hsu = dev_id;
+	u32 int_sts, i;
+
+	int_sts = mfd_readl(hsu, HSU_GBL_DMAISR);
+
+	/* Currently we only have 6 channels may be used */
+	for (i = 0; i < 6; i++) {
+		if (int_sts & 0x1)
+			dma_chan_irq(&hsu->chans[i]);
+		int_sts >>= 1;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int serial_hsu_tx_empty(struct uart_port *port)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	unsigned long flags;
+	unsigned int ret;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	return ret;
+}
+
+static unsigned int serial_hsu_get_mctrl(struct uart_port *port)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	unsigned char status;
+	unsigned int ret;
+
+	status = serial_in(up, UART_MSR);
+
+	ret = 0;
+	if (status & UART_MSR_DCD)
+		ret |= TIOCM_CAR;
+	if (status & UART_MSR_RI)
+		ret |= TIOCM_RNG;
+	if (status & UART_MSR_DSR)
+		ret |= TIOCM_DSR;
+	if (status & UART_MSR_CTS)
+		ret |= TIOCM_CTS;
+	return ret;
+}
+
+static void serial_hsu_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	unsigned char mcr = 0;
+
+	if (mctrl & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (mctrl & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (mctrl & TIOCM_OUT1)
+		mcr |= UART_MCR_OUT1;
+	if (mctrl & TIOCM_OUT2)
+		mcr |= UART_MCR_OUT2;
+	if (mctrl & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	mcr |= up->mcr;
+
+	serial_out(up, UART_MCR, mcr);
+}
+
+static void serial_hsu_break_ctl(struct uart_port *port, int break_state)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	if (break_state == -1)
+		up->lcr |= UART_LCR_SBC;
+	else
+		up->lcr &= ~UART_LCR_SBC;
+	serial_out(up, UART_LCR, up->lcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+/*
+ * What special to do:
+ * 1. chose the 64B fifo mode
+ * 2. make sure not to select half empty mode for A0 stepping
+ * 3. start dma or pio depends on configuration
+ * 4. we only allocate dma memory when needed
+ */
+static int serial_hsu_startup(struct uart_port *port)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	unsigned long flags;
+
+	/*
+	 * Clear the FIFO buffers and disable them.
+	 * (they will be reenabled in set_termios())
+	 */
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+			UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+	serial_out(up, UART_FCR, 0);
+
+	/* Clear the interrupt registers. */
+	(void) serial_in(up, UART_LSR);
+	(void) serial_in(up, UART_RX);
+	(void) serial_in(up, UART_IIR);
+	(void) serial_in(up, UART_MSR);
+
+	/* Now, initialize the UART, default is 8n1 */
+	serial_out(up, UART_LCR, UART_LCR_WLEN8);
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	up->port.mctrl |= TIOCM_OUT2;
+	serial_hsu_set_mctrl(&up->port, up->port.mctrl);
+
+	/*
+	 * Finally, enable interrupts.  Note: Modem status interrupts
+	 * are set via set_termios(), which will be occurring imminently
+	 * anyway, so we don't enable them here.
+	 */
+	if (!up->use_dma)
+		up->ier = UART_IER_RLSI | UART_IER_RDI | UART_IER_RTOIE;
+	else
+		up->ier = 0;
+	serial_out(up, UART_IER, up->ier);
+
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	/* DMA init */
+	if (up->use_dma) {
+		struct hsu_dma_buffer *dbuf;
+		struct circ_buf *xmit = &port->state->xmit;
+
+		up->dma_tx_on = 0;
+
+		/* First allocate the RX buffer */
+		dbuf = &up->rxbuf;
+		dbuf->buf = kzalloc(HSU_DMA_BUF_SIZE, GFP_KERNEL);
+		if (!dbuf->buf) {
+			up->use_dma = 0;
+			goto exit;
+		}
+		dbuf->dma_addr = dma_map_single(port->dev,
+						dbuf->buf,
+						HSU_DMA_BUF_SIZE,
+						DMA_FROM_DEVICE);
+		dbuf->dma_size = HSU_DMA_BUF_SIZE;
+
+		/* Start the RX channel right now */
+		hsu_dma_start_rx_chan(up->rxc, dbuf);
+
+		/* Next init the TX DMA */
+		dbuf = &up->txbuf;
+		dbuf->buf = xmit->buf;
+		dbuf->dma_addr = dma_map_single(port->dev,
+					       dbuf->buf,
+					       UART_XMIT_SIZE,
+					       DMA_TO_DEVICE);
+		dbuf->dma_size = UART_XMIT_SIZE;
+
+		/* This should not be changed all around */
+		chan_writel(up->txc, HSU_CH_BSR, 32);
+		chan_writel(up->txc, HSU_CH_MOTSR, 4);
+		dbuf->ofs = 0;
+	}
+
+exit:
+	 /* And clear the interrupt registers again for luck. */
+	(void) serial_in(up, UART_LSR);
+	(void) serial_in(up, UART_RX);
+	(void) serial_in(up, UART_IIR);
+	(void) serial_in(up, UART_MSR);
+
+	up->running = 1;
+	return 0;
+}
+
+static void serial_hsu_shutdown(struct uart_port *port)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	unsigned long flags;
+
+	del_timer_sync(&up->rxc->rx_timer);
+
+	/* Disable interrupts from this port */
+	up->ier = 0;
+	serial_out(up, UART_IER, 0);
+	up->running = 0;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+	up->port.mctrl &= ~TIOCM_OUT2;
+	serial_hsu_set_mctrl(&up->port, up->port.mctrl);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+
+	/* Disable break condition and FIFOs */
+	serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
+	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
+				  UART_FCR_CLEAR_RCVR |
+				  UART_FCR_CLEAR_XMIT);
+	serial_out(up, UART_FCR, 0);
+}
+
+static void
+serial_hsu_set_termios(struct uart_port *port, struct ktermios *termios,
+		       struct ktermios *old)
+{
+	struct uart_hsu_port *up =
+			container_of(port, struct uart_hsu_port, port);
+	struct tty_struct *tty = port->state->port.tty;
+	unsigned char cval, fcr = 0;
+	unsigned long flags;
+	unsigned int baud, quot;
+	u32 ps, mul;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		cval = UART_LCR_WLEN5;
+		break;
+	case CS6:
+		cval = UART_LCR_WLEN6;
+		break;
+	case CS7:
+		cval = UART_LCR_WLEN7;
+		break;
+	default:
+	case CS8:
+		cval = UART_LCR_WLEN8;
+		break;
+	}
+
+	/* CMSPAR isn't supported by this driver */
+	if (tty)
+		tty->termios->c_cflag &= ~CMSPAR;
+
+	if (termios->c_cflag & CSTOPB)
+		cval |= UART_LCR_STOP;
+	if (termios->c_cflag & PARENB)
+		cval |= UART_LCR_PARITY;
+	if (!(termios->c_cflag & PARODD))
+		cval |= UART_LCR_EPAR;
+
+	/*
+	 * The base clk is 50Mhz, and the baud rate come from:
+	 *	baud = 50M * MUL / (DIV * PS * DLAB)
+	 *
+	 * For those basic low baud rate we can get the direct
+	 * scalar from 2746800, like 115200 = 2746800/24. For those
+	 * higher baud rate, we handle them case by case, mainly by
+	 * adjusting the MUL/PS registers, and DIV register is kept
+	 * as default value 0x3d09 to make things simple
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
+
+	quot = 1;
+	ps = 0x10;
+	mul = 0x3600;
+	switch (baud) {
+	case 3500000:
+		mul = 0x3345;
+		ps = 0xC;
+		break;
+	case 1843200:
+		mul = 0x2400;
+		break;
+	case 3000000:
+	case 2500000:
+	case 2000000:
+	case 1500000:
+	case 1000000:
+	case 500000:
+		/* mul/ps/quot = 0x9C4/0x10/0x1 will make a 500000 bps */
+		mul = baud / 500000 * 0x9C4;
+		break;
+	default:
+		/* Use uart_get_divisor to get quot for other baud rates */
+		quot = 0;
+	}
+
+	if (!quot)
+		quot = uart_get_divisor(port, baud);
+
+	if ((up->port.uartclk / quot) < (2400 * 16))
+		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_1B;
+	else if ((up->port.uartclk / quot) < (230400 * 16))
+		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_16B;
+	else
+		fcr = UART_FCR_ENABLE_FIFO | UART_FCR_HSU_64_32B;
+
+	fcr |= UART_FCR_HSU_64B_FIFO;
+#ifdef MFD_HSU_A0_STEPPING
+	/* A0 doesn't support half empty IRQ */
+	fcr |= UART_FCR_FULL_EMPT_TXI;
+#endif
+
+	/*
+	 * Ok, we're now changing the port state.  Do it with
+	 * interrupts disabled.
+	 */
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	/* Update the per-port timeout */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
+	if (termios->c_iflag & INPCK)
+		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
+	if (termios->c_iflag & (BRKINT | PARMRK))
+		up->port.read_status_mask |= UART_LSR_BI;
+
+	/* Characters to ignore */
+	up->port.ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
+	if (termios->c_iflag & IGNBRK) {
+		up->port.ignore_status_mask |= UART_LSR_BI;
+		/*
+		 * If we're ignoring parity and break indicators,
+		 * ignore overruns too (for real raw support).
+		 */
+		if (termios->c_iflag & IGNPAR)
+			up->port.ignore_status_mask |= UART_LSR_OE;
+	}
+
+	/* Ignore all characters if CREAD is not set */
+	if ((termios->c_cflag & CREAD) == 0)
+		up->port.ignore_status_mask |= UART_LSR_DR;
+
+	/*
+	 * CTS flow control flag and modem status interrupts, disable
+	 * MSI by default
+	 */
+	up->ier &= ~UART_IER_MSI;
+	if (UART_ENABLE_MS(&up->port, termios->c_cflag))
+		up->ier |= UART_IER_MSI;
+
+	serial_out(up, UART_IER, up->ier);
+
+	if (termios->c_cflag & CRTSCTS)
+		up->mcr |= UART_MCR_AFE | UART_MCR_RTS;
+	else
+		up->mcr &= ~UART_MCR_AFE;
+
+	serial_out(up, UART_LCR, cval | UART_LCR_DLAB);	/* set DLAB */
+	serial_out(up, UART_DLL, quot & 0xff);		/* LS of divisor */
+	serial_out(up, UART_DLM, quot >> 8);		/* MS of divisor */
+	serial_out(up, UART_LCR, cval);			/* reset DLAB */
+	serial_out(up, UART_MUL, mul);			/* set MUL */
+	serial_out(up, UART_PS, ps);			/* set PS */
+	up->lcr = cval;					/* Save LCR */
+	serial_hsu_set_mctrl(&up->port, up->port.mctrl);
+	serial_out(up, UART_FCR, fcr);
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static void
+serial_hsu_pm(struct uart_port *port, unsigned int state,
+	      unsigned int oldstate)
+{
+}
+
+static void serial_hsu_release_port(struct uart_port *port)
+{
+}
+
+static int serial_hsu_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void serial_hsu_config_port(struct uart_port *port, int flags)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	up->port.type = PORT_MFD;
+}
+
+static int
+serial_hsu_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	/* We don't want the core code to modify any port params */
+	return -EINVAL;
+}
+
+static const char *
+serial_hsu_type(struct uart_port *port)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+	return up->name;
+}
+
+/* Mainly for uart console use */
+static struct uart_hsu_port *serial_hsu_ports[3];
+static struct uart_driver serial_hsu_reg;
+
+#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE
+
+#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
+
+/* Wait for transmitter & holding register to empty */
+static inline void wait_for_xmitr(struct uart_hsu_port *up)
+{
+	unsigned int status, tmout = 1000;
+
+	/* Wait up to 1ms for the character to be sent. */
+	do {
+		status = serial_in(up, UART_LSR);
+
+		if (status & UART_LSR_BI)
+			up->lsr_break_flag = UART_LSR_BI;
+
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	} while (!(status & BOTH_EMPTY));
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->port.flags & UPF_CONS_FLOW) {
+		tmout = 1000000;
+		while (--tmout &&
+		       ((serial_in(up, UART_MSR) & UART_MSR_CTS) == 0))
+			udelay(1);
+	}
+}
+
+static void serial_hsu_console_putchar(struct uart_port *port, int ch)
+{
+	struct uart_hsu_port *up =
+		container_of(port, struct uart_hsu_port, port);
+
+	wait_for_xmitr(up);
+	serial_out(up, UART_TX, ch);
+}
+
+/*
+ * Print a string to the serial port trying not to disturb
+ * any possible real use of the port...
+ *
+ *	The console_lock must be held when we get here.
+ */
+static void
+serial_hsu_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct uart_hsu_port *up = serial_hsu_ports[co->index];
+	unsigned long flags;
+	unsigned int ier;
+	int locked = 1;
+
+	local_irq_save(flags);
+	if (up->port.sysrq)
+		locked = 0;
+	else if (oops_in_progress) {
+		locked = spin_trylock(&up->port.lock);
+	} else
+		spin_lock(&up->port.lock);
+
+	/* First save the IER then disable the interrupts */
+	ier = serial_in(up, UART_IER);
+	serial_out(up, UART_IER, 0);
+
+	uart_console_write(&up->port, s, count, serial_hsu_console_putchar);
+
+	/*
+	 * Finally, wait for transmitter to become empty
+	 * and restore the IER
+	 */
+	wait_for_xmitr(up);
+	serial_out(up, UART_IER, ier);
+
+	if (locked)
+		spin_unlock(&up->port.lock);
+	local_irq_restore(flags);
+}
+
+static struct console serial_hsu_console;
+
+static int __init
+serial_hsu_console_setup(struct console *co, char *options)
+{
+	struct uart_hsu_port *up;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	if (co->index == -1 || co->index >= serial_hsu_reg.nr)
+		co->index = 0;
+	up = serial_hsu_ports[co->index];
+	if (!up)
+		return -ENODEV;
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	ret = uart_set_options(&up->port, co, baud, parity, bits, flow);
+
+	return ret;
+}
+
+static struct console serial_hsu_console = {
+	.name		= "ttyMFD",
+	.write		= serial_hsu_console_write,
+	.device		= uart_console_device,
+	.setup		= serial_hsu_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= 2,
+	.data		= &serial_hsu_reg,
+};
+#endif
+
+struct uart_ops serial_hsu_pops = {
+	.tx_empty	= serial_hsu_tx_empty,
+	.set_mctrl	= serial_hsu_set_mctrl,
+	.get_mctrl	= serial_hsu_get_mctrl,
+	.stop_tx	= serial_hsu_stop_tx,
+	.start_tx	= serial_hsu_start_tx,
+	.stop_rx	= serial_hsu_stop_rx,
+	.enable_ms	= serial_hsu_enable_ms,
+	.break_ctl	= serial_hsu_break_ctl,
+	.startup	= serial_hsu_startup,
+	.shutdown	= serial_hsu_shutdown,
+	.set_termios	= serial_hsu_set_termios,
+	.pm		= serial_hsu_pm,
+	.type		= serial_hsu_type,
+	.release_port	= serial_hsu_release_port,
+	.request_port	= serial_hsu_request_port,
+	.config_port	= serial_hsu_config_port,
+	.verify_port	= serial_hsu_verify_port,
+};
+
+static struct uart_driver serial_hsu_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "MFD serial",
+	.dev_name	= "ttyMFD",
+	.major		= TTY_MAJOR,
+	.minor		= 128,
+	.nr		= 3,
+};
+
+#ifdef CONFIG_PM
+static int serial_hsu_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	void *priv = pci_get_drvdata(pdev);
+	struct uart_hsu_port *up;
+
+	/* Make sure this is not the internal dma controller */
+	if (priv && (pdev->device != 0x081E)) {
+		up = priv;
+		uart_suspend_port(&serial_hsu_reg, &up->port);
+	}
+
+	pci_save_state(pdev);
+	pci_set_power_state(pdev, pci_choose_state(pdev, state));
+        return 0;
+}
+
+static int serial_hsu_resume(struct pci_dev *pdev)
+{
+	void *priv = pci_get_drvdata(pdev);
+	struct uart_hsu_port *up;
+	int ret;
+
+	pci_set_power_state(pdev, PCI_D0);
+	pci_restore_state(pdev);
+
+	ret = pci_enable_device(pdev);
+	if (ret)
+		dev_warn(&pdev->dev,
+			"HSU: can't re-enable device, try to continue\n");
+
+	if (priv && (pdev->device != 0x081E)) {
+		up = priv;
+		uart_resume_port(&serial_hsu_reg, &up->port);
+	}
+	return 0;
+}
+#else
+#define serial_hsu_suspend	NULL
+#define serial_hsu_resume	NULL
+#endif
+
+/* temp global pointer before we settle down on using one or four PCI dev */
+static struct hsu_port *phsu;
+
+static int serial_hsu_probe(struct pci_dev *pdev,
+				const struct pci_device_id *ent)
+{
+	struct uart_hsu_port *uport;
+	int index, ret;
+
+	printk(KERN_INFO "HSU: found PCI Serial controller(ID: %04x:%04x)\n",
+		pdev->vendor, pdev->device);
+
+	switch (pdev->device) {
+	case 0x081B:
+		index = 0;
+		break;
+	case 0x081C:
+		index = 1;
+		break;
+	case 0x081D:
+		index = 2;
+		break;
+	case 0x081E:
+		/* internal DMA controller */
+		index = 3;
+		break;
+	default:
+		dev_err(&pdev->dev, "HSU: out of index!");
+		return -ENODEV;
+	}
+
+	ret = pci_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	if (index == 3) {
+		/* DMA controller */
+		ret = request_irq(pdev->irq, dma_irq, 0, "hsu_dma", phsu);
+		if (ret) {
+			dev_err(&pdev->dev, "can not get IRQ\n");
+			goto err_disable;
+		}
+		pci_set_drvdata(pdev, phsu);
+	} else {
+		/* UART port 0~2 */
+		uport = &phsu->port[index];
+		uport->port.irq = pdev->irq;
+		uport->port.dev = &pdev->dev;
+		uport->dev = &pdev->dev;
+
+		ret = request_irq(pdev->irq, port_irq, 0, uport->name, uport);
+		if (ret) {
+			dev_err(&pdev->dev, "can not get IRQ\n");
+			goto err_disable;
+		}
+		uart_add_one_port(&serial_hsu_reg, &uport->port);
+
+#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE
+		if (index == 2) {
+			register_console(&serial_hsu_console);
+			uport->port.cons = &serial_hsu_console;
+		}
+#endif
+		pci_set_drvdata(pdev, uport);
+	}
+
+	return 0;
+
+err_disable:
+	pci_disable_device(pdev);
+	return ret;
+}
+
+static void hsu_dma_rx_timeout(unsigned long data)
+{
+	struct hsu_dma_chan *chan = (void *)data;
+	struct uart_hsu_port *up = chan->uport;
+	struct hsu_dma_buffer *dbuf = &up->rxbuf;
+	int count = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&up->port.lock, flags);
+
+	count = chan_readl(chan, HSU_CH_D0SAR) - dbuf->dma_addr;
+
+	if (!count) {
+		mod_timer(&chan->rx_timer, jiffies + HSU_DMA_TIMEOUT_CHECK_FREQ);
+		goto exit;
+	}
+
+	hsu_dma_rx(up, 0);
+exit:
+	spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static void hsu_global_init(void)
+{
+	struct hsu_port *hsu;
+	struct uart_hsu_port *uport;
+	struct hsu_dma_chan *dchan;
+	int i, ret;
+
+	hsu = kzalloc(sizeof(struct hsu_port), GFP_KERNEL);
+	if (!hsu)
+		return;
+
+	/* Get basic io resource and map it */
+	hsu->paddr = 0xffa28000;
+	hsu->iolen = 0x1000;
+
+	if (!(request_mem_region(hsu->paddr, hsu->iolen, "HSU global")))
+		pr_warning("HSU: error in request mem region\n");
+
+	hsu->reg = ioremap_nocache((unsigned long)hsu->paddr, hsu->iolen);
+	if (!hsu->reg) {
+		pr_err("HSU: error in ioremap\n");
+		ret = -ENOMEM;
+		goto err_free_region;
+	}
+
+	/* Initialise the 3 UART ports */
+	uport = hsu->port;
+	for (i = 0; i < 3; i++) {
+		uport->port.type = PORT_MFD;
+		uport->port.iotype = UPIO_MEM;
+		uport->port.mapbase = (resource_size_t)hsu->paddr
+					+ HSU_PORT_REG_OFFSET
+					+ i * HSU_PORT_REG_LENGTH;
+		uport->port.membase = hsu->reg + HSU_PORT_REG_OFFSET
+					+ i * HSU_PORT_REG_LENGTH;
+
+		sprintf(uport->name, "hsu_port%d", i);
+		uport->port.fifosize = 64;
+		uport->port.ops = &serial_hsu_pops;
+		uport->port.line = i;
+		uport->port.flags = UPF_IOREMAP;
+		/* set the scalable maxim support rate to 2746800 bps */
+		uport->port.uartclk = 115200 * 24 * 16;
+
+		uport->running = 0;
+		uport->txc = &hsu->chans[i * 2];
+		uport->rxc = &hsu->chans[i * 2 + 1];
+
+		serial_hsu_ports[i] = uport;
+		uport->index = i;
+		uport++;
+	}
+
+	/* Initialise 6 dma channels */
+	dchan = hsu->chans;
+	for (i = 0; i < 6; i++) {
+		dchan->id = i;
+		dchan->dirt = (i & 0x1) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+		dchan->uport = &hsu->port[i/2];
+		dchan->reg = hsu->reg + HSU_DMA_CHANS_REG_OFFSET +
+				i * HSU_DMA_CHANS_REG_LENGTH;
+
+		/* Work around for RX */
+		if (dchan->dirt == DMA_FROM_DEVICE) {
+			init_timer(&dchan->rx_timer);
+			dchan->rx_timer.function = hsu_dma_rx_timeout;
+			dchan->rx_timer.data = (unsigned long)dchan;
+		}
+		dchan++;
+	}
+
+	phsu = hsu;
+	hsu_debugfs_init(hsu);
+	return;
+
+err_free_region:
+	release_mem_region(hsu->paddr, hsu->iolen);
+	kfree(hsu);
+	return;
+}
+
+static void serial_hsu_remove(struct pci_dev *pdev)
+{
+	void *priv = pci_get_drvdata(pdev);
+	struct uart_hsu_port *up;
+
+	if (!priv)
+		return;
+
+	/* For port 0/1/2, priv is the address of uart_hsu_port */
+	if (pdev->device != 0x081E) {
+		up = priv;
+		uart_remove_one_port(&serial_hsu_reg, &up->port);
+	}
+
+	pci_set_drvdata(pdev, NULL);
+	free_irq(pdev->irq, priv);
+	pci_disable_device(pdev);
+}
+
+/* First 3 are UART ports, and the 4th is the DMA */
+static const struct pci_device_id pci_ids[] __devinitdata = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081B) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081C) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081D) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x081E) },
+	{},
+};
+
+static struct pci_driver hsu_pci_driver = {
+	.name =		"HSU serial",
+	.id_table =	pci_ids,
+	.probe =	serial_hsu_probe,
+	.remove =	__devexit_p(serial_hsu_remove),
+	.suspend =	serial_hsu_suspend,
+	.resume	=	serial_hsu_resume,
+};
+
+static int __init hsu_pci_init(void)
+{
+	int ret;
+
+	hsu_global_init();
+
+	ret = uart_register_driver(&serial_hsu_reg);
+	if (ret)
+		return ret;
+
+	return pci_register_driver(&hsu_pci_driver);
+}
+
+static void __exit hsu_pci_exit(void)
+{
+	pci_unregister_driver(&hsu_pci_driver);
+	uart_unregister_driver(&serial_hsu_reg);
+
+	hsu_debugfs_remove(phsu);
+
+	kfree(phsu);
+}
+
+module_init(hsu_pci_init);
+module_exit(hsu_pci_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:medfield-hsu");