--- /dev/null
+/*
+ * 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 2009 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. there should be 2 types of register access method, one for
+ *    UART ports, the other for the general purpose registers
+ *
+ * 2. It used to have a Irda port, but was defeatured recently
+ *
+ * 3. Based on the info from HSU MAS, 0/1 channel are assigned to
+ *    port0, 2/3 chan to port 1, 4/5 chan to port 3. Even number
+ *    chan will be read, odd chan for write
+ *
+ * 4. HUS supports both the 64B and 16B FIFO version, but this driver
+ *    will only use 64B version
+ *
+ * 5. In A0 stepping, UART will not support TX half empty flag, thus
+ *    need add a #ifdef judgement
+ *
+ * 6. One more bug for A0, the loopback mode won't support AFC
+ *    auto-flow control
+ *
+ * 7. HSU has some special FCR control bits, we add it to serial_reg.h
+ *
+ * 8. 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/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)
+
+struct hsu_dma_buffer {
+       u8              *buf;
+       dma_addr_t      dma_addr;
+       u32             dma_size;
+       u32             ofs;
+};
+
+struct hsu_dma_chan {
+       u32     id;
+       u32     dirt;   /* to or from device */
+       struct uart_hsu_port    *uport;
+       void __iomem    *reg;
+};
+
+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 {
+       struct pci_device       *pdev;
+
+       void __iomem    *reg;
+       unsigned long   paddr;
+       unsigned long   iolen;
+       u32             irq;
+
+       struct uart_hsu_port    port[3];
+       struct hsu_dma_chan     chans[10];
+
+#ifdef CONFIG_DEBUG_FS
+       struct dentry *debugfs;
+#endif
+};
+
+static inline void hexdump(char *str, u8 *addr, int cnt)
+{
+       int i;
+
+       for (i = 0; i < cnt; i += 8) {
+               printk("0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x",
+                       addr[i], addr[i+1], addr[i+2], addr[i+3],
+                       addr[i+4], addr[i+5], addr[i+6], addr[i+7]);
+               printk("\n");
+       }
+}
+
+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));
+
+       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));
+
+       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,
+};
+
+static const struct file_operations dma_regs_ops = {
+       .owner          = THIS_MODULE,
+       .open           = hsu_show_regs_open,
+       .read           = dma_show_regs,
+};
+
+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));
+
+               WARN(chan_readl(up->txc, HSU_CH_CR) & 0x1,
+                       "TX channel has already be started!!\n");
+               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)
+{
+       /* Need start RX dma channel here */
+       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);
+}
+
+/* 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, better to use 2 descriptors at the same time
+        */
+
+       /* 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);
+
+       /* We can use 2 ways to calc the actual transfer len */
+       count = chan_readl(chan, HSU_CH_D0SAR) - dbuf->dma_addr;
+
+       if (!count)
+               return;
+
+       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 */
+                                        );
+       chan_writel(chan, HSU_CH_CR, 0x3);
+
+       tty_flip_buffer_push(tty);
+}
+
+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);
+       }
+}
+
+/*
+ * if there is error flag, should we just reset the FIFO or keeps
+ * working on it
+ */
+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;
+       int i = 0; /* for debug use */
+
+       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; */
+       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);
+               i++;
+
+               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;
+
+       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);
+               return IRQ_HANDLED;
+       }
+
+       spin_lock_irqsave(&up->port.lock, flags);
+       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);
+
+       /* 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) {
+               /* dma for irq should be done */
+               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 */
+       /* When use DMA, TX/RX's FIFO and IRQ should be disabled */
+       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;
+
+       /* 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 mul = 0x3600;
+       u32 ps = 0x10;
+
+       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;
+
+       /*
+        * For those basic low baud rate we can get the direct
+        * scalar from 2746800, like 115200 = 2746800/24, for those
+        * higher baud rate, we have to handle them case by case,
+        * but DIV reg is never touched as its default value 0x3d09
+        */
+       baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
+       quot = uart_get_divisor(port, baud);
+
+       switch (baud) {
+       case 3500000:
+               mul = 0x3345;
+               ps = 0xC;
+               quot = 1;
+               break;
+       case 2500000:
+               mul = 0x2710;
+               ps = 0x10;
+               quot = 1;
+               break;
+       case 18432000:
+               mul = 0x2400;
+               ps = 0x10;
+               quot = 1;
+               break;
+       case 1500000:
+               mul = 0x1D4C;
+               ps = 0xc;
+               quot = 1;
+               break;
+       default:
+               ;
+       }
+
+       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)
+{
+#if 0
+       struct uart_hsu_port *up =
+               container_of(port, struct uart_hsu_port, port);
+       up->port.type = PORT_MFD;
+#endif
+}
+
+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)
+{
+       struct uart_hsu_port *up;
+
+       up = pci_get_drvdata(pdev);
+       if (!up)
+               return 0;
+
+       uart_suspend_port(&serial_hsu_reg, &up->port);
+
+        return 0;
+}
+
+static int serial_hsu_resume(struct pci_dev *pdev)
+{
+       struct uart_hsu_port *up;
+
+       up = pci_get_drvdata(pdev);
+       if (!up)
+               return 0;
+       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_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;
+               /* make the 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;
+               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)
+{
+       struct hsu_port *hsu;
+       int i;
+
+       hsu = pci_get_drvdata(pdev);
+       if (!hsu)
+               return;
+
+       for (i = 0; i < 3; i++)
+               uart_remove_one_port(&serial_hsu_reg, &hsu->port[i].port);
+
+       pci_set_drvdata(pdev, NULL);
+       free_irq(hsu->irq, hsu);
+       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");