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, 919 insertions, 0 deletions

diff --git a/drivers/tty/serial/mrst_max3110.c b/drivers/tty/serial/mrst_max3110.c
new file mode 100644
index 000000000000..b62857bf2fdb
--- /dev/null
+++ b/drivers/tty/serial/mrst_max3110.c
@@ -0,0 +1,919 @@
+/*
+ *  mrst_max3110.c - spi uart protocol driver for Maxim 3110
+ *
+ * Copyright (c) 2008-2010, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/*
+ * Note:
+ * 1. From Max3110 spec, the Rx FIFO has 8 words, while the Tx FIFO only has
+ *    1 word. If SPI master controller doesn't support sclk frequency change,
+ *    then the char need be sent out one by one with some delay
+ *
+ * 2. Currently only RX availabe interrrupt is used, no need for waiting TXE
+ *    interrupt for a low speed UART device
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+
+#include <linux/kthread.h>
+#include <linux/spi/spi.h>
+
+#include "mrst_max3110.h"
+
+#define PR_FMT	"mrst_max3110: "
+
+#define UART_TX_NEEDED 1
+#define CON_TX_NEEDED  2
+#define BIT_IRQ_PENDING    3
+
+struct uart_max3110 {
+	struct uart_port port;
+	struct spi_device *spi;
+	char name[24];
+
+	wait_queue_head_t wq;
+	struct task_struct *main_thread;
+	struct task_struct *read_thread;
+	struct mutex thread_mutex;;
+
+	u32 baud;
+	u16 cur_conf;
+	u8 clock;
+	u8 parity, word_7bits;
+	u16 irq;
+
+	unsigned long uart_flags;
+
+	/* console related */
+	struct circ_buf con_xmit;
+};
+
+/* global data structure, may need be removed */
+static struct uart_max3110 *pmax;
+
+static void receive_chars(struct uart_max3110 *max,
+				unsigned char *str, int len);
+static int max3110_read_multi(struct uart_max3110 *max, u8 *buf);
+static void max3110_con_receive(struct uart_max3110 *max);
+
+static int max3110_write_then_read(struct uart_max3110 *max,
+		const void *txbuf, void *rxbuf, unsigned len, int always_fast)
+{
+	struct spi_device *spi = max->spi;
+	struct spi_message	message;
+	struct spi_transfer	x;
+	int ret;
+
+	spi_message_init(&message);
+	memset(&x, 0, sizeof x);
+	x.len = len;
+	x.tx_buf = txbuf;
+	x.rx_buf = rxbuf;
+	spi_message_add_tail(&x, &message);
+
+	if (always_fast)
+		x.speed_hz = spi->max_speed_hz;
+	else if (max->baud)
+		x.speed_hz = max->baud;
+
+	/* Do the i/o */
+	ret = spi_sync(spi, &message);
+	return ret;
+}
+
+/* Write a 16b word to the device */
+static int max3110_out(struct uart_max3110 *max, const u16 out)
+{
+	void *buf;
+	u16 *obuf, *ibuf;
+	u8  ch;
+	int ret;
+
+	buf = kzalloc(8, GFP_KERNEL | GFP_DMA);
+	if (!buf)
+		return -ENOMEM;
+
+	obuf = buf;
+	ibuf = buf + 4;
+	*obuf = out;
+	ret = max3110_write_then_read(max, obuf, ibuf, 2, 1);
+	if (ret) {
+		pr_warning(PR_FMT "%s(): get err msg %d when sending 0x%x\n",
+				__func__, ret, out);
+		goto exit;
+	}
+
+	/* If some valid data is read back */
+	if (*ibuf & MAX3110_READ_DATA_AVAILABLE) {
+		ch = *ibuf & 0xff;
+		receive_chars(max, &ch, 1);
+	}
+
+exit:
+	kfree(buf);
+	return ret;
+}
+
+/*
+ * This is usually used to read data from SPIC RX FIFO, which doesn't
+ * need any delay like flushing character out.
+ *
+ * Return how many valide bytes are read back
+ */
+static int max3110_read_multi(struct uart_max3110 *max, u8 *rxbuf)
+{
+	void *buf;
+	u16 *obuf, *ibuf;
+	u8 *pbuf, valid_str[M3110_RX_FIFO_DEPTH];
+	int i, j, blen;
+
+	blen = M3110_RX_FIFO_DEPTH * sizeof(u16);
+	buf = kzalloc(blen * 2, GFP_KERNEL | GFP_DMA);
+	if (!buf) {
+		pr_warning(PR_FMT "%s(): fail to alloc dma buffer\n", __func__);
+		return 0;
+	}
+
+	/* tx/rx always have the same length */
+	obuf = buf;
+	ibuf = buf + blen;
+
+	if (max3110_write_then_read(max, obuf, ibuf, blen, 1)) {
+		kfree(buf);
+		return 0;
+	}
+
+	/* If caller doesn't provide a buffer, then handle received char */
+	pbuf = rxbuf ? rxbuf : valid_str;
+
+	for (i = 0, j = 0; i < M3110_RX_FIFO_DEPTH; i++) {
+		if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
+			pbuf[j++] = ibuf[i] & 0xff;
+	}
+
+	if (j && (pbuf == valid_str))
+		receive_chars(max, valid_str, j);
+
+	kfree(buf);
+	return j;
+}
+
+static void serial_m3110_con_putchar(struct uart_port *port, int ch)
+{
+	struct uart_max3110 *max =
+		container_of(port, struct uart_max3110, port);
+	struct circ_buf *xmit = &max->con_xmit;
+
+	if (uart_circ_chars_free(xmit)) {
+		xmit->buf[xmit->head] = (char)ch;
+		xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1);
+	}
+}
+
+/*
+ * 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_m3110_con_write(struct console *co,
+				const char *s, unsigned int count)
+{
+	if (!pmax)
+		return;
+
+	uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar);
+
+	if (!test_and_set_bit(CON_TX_NEEDED, &pmax->uart_flags))
+		wake_up_process(pmax->main_thread);
+}
+
+static int __init
+serial_m3110_con_setup(struct console *co, char *options)
+{
+	struct uart_max3110 *max = pmax;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	pr_info(PR_FMT "setting up console\n");
+
+	if (co->index == -1)
+		co->index = 0;
+
+	if (!max) {
+		pr_err(PR_FMT "pmax is NULL, return");
+		return -ENODEV;
+	}
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(&max->port, co, baud, parity, bits, flow);
+}
+
+static struct tty_driver *serial_m3110_con_device(struct console *co,
+							int *index)
+{
+	struct uart_driver *p = co->data;
+	*index = co->index;
+	return p->tty_driver;
+}
+
+static struct uart_driver serial_m3110_reg;
+static struct console serial_m3110_console = {
+	.name		= "ttyS",
+	.write		= serial_m3110_con_write,
+	.device		= serial_m3110_con_device,
+	.setup		= serial_m3110_con_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &serial_m3110_reg,
+};
+
+static unsigned int serial_m3110_tx_empty(struct uart_port *port)
+{
+	return 1;
+}
+
+static void serial_m3110_stop_tx(struct uart_port *port)
+{
+	return;
+}
+
+/* stop_rx will be called in spin_lock env */
+static void serial_m3110_stop_rx(struct uart_port *port)
+{
+	return;
+}
+
+#define WORDS_PER_XFER	128
+static void send_circ_buf(struct uart_max3110 *max,
+				struct circ_buf *xmit)
+{
+	void *buf;
+	u16 *obuf, *ibuf;
+	u8 valid_str[WORDS_PER_XFER];
+	int i, j, len, blen, dma_size, left, ret = 0;
+
+
+	dma_size = WORDS_PER_XFER * sizeof(u16) * 2;
+	buf = kzalloc(dma_size, GFP_KERNEL | GFP_DMA);
+	if (!buf)
+		return;
+	obuf = buf;
+	ibuf = buf + dma_size/2;
+
+	while (!uart_circ_empty(xmit)) {
+		left = uart_circ_chars_pending(xmit);
+		while (left) {
+			len = min(left, WORDS_PER_XFER);
+			blen = len * sizeof(u16);
+			memset(ibuf, 0, blen);
+
+			for (i = 0; i < len; i++) {
+				obuf[i] = (u8)xmit->buf[xmit->tail] | WD_TAG;
+				xmit->tail = (xmit->tail + 1) &
+						(UART_XMIT_SIZE - 1);
+			}
+
+			/* Fail to send msg to console is not very critical */
+			ret = max3110_write_then_read(max, obuf, ibuf, blen, 0);
+			if (ret)
+				pr_warning(PR_FMT "%s(): get err msg %d\n",
+						__func__, ret);
+
+			for (i = 0, j = 0; i < len; i++) {
+				if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
+					valid_str[j++] = ibuf[i] & 0xff;
+			}
+
+			if (j)
+				receive_chars(max, valid_str, j);
+
+			max->port.icount.tx += len;
+			left -= len;
+		}
+	}
+
+	kfree(buf);
+}
+
+static void transmit_char(struct uart_max3110 *max)
+{
+	struct uart_port *port = &max->port;
+	struct circ_buf *xmit = &port->state->xmit;
+
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
+		return;
+
+	send_circ_buf(max, xmit);
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		serial_m3110_stop_tx(port);
+}
+
+/*
+ * This will be called by uart_write() and tty_write, can't
+ * go to sleep
+ */
+static void serial_m3110_start_tx(struct uart_port *port)
+{
+	struct uart_max3110 *max =
+		container_of(port, struct uart_max3110, port);
+
+	if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
+		wake_up_process(max->main_thread);
+}
+
+static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)
+{
+	struct uart_port *port = &max->port;
+	struct tty_struct *tty;
+	int usable;
+
+	/* If uart is not opened, just return */
+	if (!port->state)
+		return;
+
+	tty = port->state->port.tty;
+	if (!tty)
+		return;
+
+	while (len) {
+		usable = tty_buffer_request_room(tty, len);
+		if (usable) {
+			tty_insert_flip_string(tty, str, usable);
+			str += usable;
+			port->icount.rx += usable;
+		}
+		len -= usable;
+	}
+	tty_flip_buffer_push(tty);
+}
+
+/*
+ * This routine will be used in read_thread or RX IRQ handling,
+ * it will first do one round buffer read(8 words), if there is some
+ * valid RX data, will try to read 5 more rounds till all data
+ * is read out.
+ *
+ * Use stack space as data buffer to save some system load, and chose
+ * 504 Btyes as a threadhold to do a bulk push to upper tty layer when
+ * receiving bulk data, a much bigger buffer may cause stack overflow
+ */
+static void max3110_con_receive(struct uart_max3110 *max)
+{
+	int loop = 1, num, total = 0;
+	u8 recv_buf[512], *pbuf;
+
+	pbuf = recv_buf;
+	do {
+		num = max3110_read_multi(max, pbuf);
+
+		if (num) {
+			loop = 5;
+			pbuf += num;
+			total += num;
+
+			if (total >= 504) {
+				receive_chars(max, recv_buf, total);
+				pbuf = recv_buf;
+				total = 0;
+			}
+		}
+	} while (--loop);
+
+	if (total)
+		receive_chars(max, recv_buf, total);
+}
+
+static int max3110_main_thread(void *_max)
+{
+	struct uart_max3110 *max = _max;
+	wait_queue_head_t *wq = &max->wq;
+	int ret = 0;
+	struct circ_buf *xmit = &max->con_xmit;
+
+	init_waitqueue_head(wq);
+	pr_info(PR_FMT "start main thread\n");
+
+	do {
+		wait_event_interruptible(*wq, max->uart_flags || kthread_should_stop());
+
+		mutex_lock(&max->thread_mutex);
+
+		if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
+			max3110_con_receive(max);
+
+		/* first handle console output */
+		if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
+			send_circ_buf(max, xmit);
+
+		/* handle uart output */
+		if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
+			transmit_char(max);
+
+		mutex_unlock(&max->thread_mutex);
+
+	} while (!kthread_should_stop());
+
+	return ret;
+}
+
+static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
+{
+	struct uart_max3110 *max = dev_id;
+
+	/* max3110's irq is a falling edge, not level triggered,
+	 * so no need to disable the irq */
+	if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
+		wake_up_process(max->main_thread);
+
+	return IRQ_HANDLED;
+}
+
+/* if don't use RX IRQ, then need a thread to polling read */
+static int max3110_read_thread(void *_max)
+{
+	struct uart_max3110 *max = _max;
+
+	pr_info(PR_FMT "start read thread\n");
+	do {
+		/*
+		 * If can't acquire the mutex, it means the main thread
+		 * is running which will also perform the rx job
+		 */
+		if (mutex_trylock(&max->thread_mutex)) {
+			max3110_con_receive(max);
+			mutex_unlock(&max->thread_mutex);
+		}
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(HZ / 20);
+	} while (!kthread_should_stop());
+
+	return 0;
+}
+
+static int serial_m3110_startup(struct uart_port *port)
+{
+	struct uart_max3110 *max =
+		container_of(port, struct uart_max3110, port);
+	u16 config = 0;
+	int ret = 0;
+
+	if (port->line != 0) {
+		pr_err(PR_FMT "uart port startup failed\n");
+		return -1;
+	}
+
+	/* Disable all IRQ and config it to 115200, 8n1 */
+	config = WC_TAG | WC_FIFO_ENABLE
+			| WC_1_STOPBITS
+			| WC_8BIT_WORD
+			| WC_BAUD_DR2;
+
+	/* as we use thread to handle tx/rx, need set low latency */
+	port->state->port.tty->low_latency = 1;
+
+	if (max->irq) {
+		max->read_thread = NULL;
+		ret = request_irq(max->irq, serial_m3110_irq,
+				IRQ_TYPE_EDGE_FALLING, "max3110", max);
+		if (ret) {
+			max->irq = 0;
+			pr_err(PR_FMT "unable to allocate IRQ, polling\n");
+		}  else {
+			/* Enable RX IRQ only */
+			config |= WC_RXA_IRQ_ENABLE;
+		}
+	}
+
+	if (max->irq == 0) {
+		/* If IRQ is disabled, start a read thread for input data */
+		max->read_thread =
+			kthread_run(max3110_read_thread, max, "max3110_read");
+		if (IS_ERR(max->read_thread)) {
+			ret = PTR_ERR(max->read_thread);
+			max->read_thread = NULL;
+			pr_err(PR_FMT "Can't create read thread!\n");
+			return ret;
+		}
+	}
+
+	ret = max3110_out(max, config);
+	if (ret) {
+		if (max->irq)
+			free_irq(max->irq, max);
+		if (max->read_thread)
+			kthread_stop(max->read_thread);
+		max->read_thread = NULL;
+		return ret;
+	}
+
+	max->cur_conf = config;
+	return 0;
+}
+
+static void serial_m3110_shutdown(struct uart_port *port)
+{
+	struct uart_max3110 *max =
+		container_of(port, struct uart_max3110, port);
+	u16 config;
+
+	if (max->read_thread) {
+		kthread_stop(max->read_thread);
+		max->read_thread = NULL;
+	}
+
+	if (max->irq)
+		free_irq(max->irq, max);
+
+	/* Disable interrupts from this port */
+	config = WC_TAG | WC_SW_SHDI;
+	max3110_out(max, config);
+}
+
+static void serial_m3110_release_port(struct uart_port *port)
+{
+}
+
+static int serial_m3110_request_port(struct uart_port *port)
+{
+	return 0;
+}
+
+static void serial_m3110_config_port(struct uart_port *port, int flags)
+{
+	port->type = PORT_MAX3100;
+}
+
+static int
+serial_m3110_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_m3110_type(struct uart_port *port)
+{
+	struct uart_max3110 *max =
+		container_of(port, struct uart_max3110, port);
+	return max->name;
+}
+
+static void
+serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
+		       struct ktermios *old)
+{
+	struct uart_max3110 *max =
+		container_of(port, struct uart_max3110, port);
+	unsigned char cval;
+	unsigned int baud, parity = 0;
+	int clk_div = -1;
+	u16 new_conf = max->cur_conf;
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS7:
+		cval = UART_LCR_WLEN7;
+		new_conf |= WC_7BIT_WORD;
+		break;
+	default:
+		/* We only support CS7 & CS8 */
+		termios->c_cflag &= ~CSIZE;
+		termios->c_cflag |= CS8;
+	case CS8:
+		cval = UART_LCR_WLEN8;
+		new_conf |= WC_8BIT_WORD;
+		break;
+	}
+
+	baud = uart_get_baud_rate(port, termios, old, 0, 230400);
+
+	/* First calc the div for 1.8MHZ clock case */
+	switch (baud) {
+	case 300:
+		clk_div = WC_BAUD_DR384;
+		break;
+	case 600:
+		clk_div = WC_BAUD_DR192;
+		break;
+	case 1200:
+		clk_div = WC_BAUD_DR96;
+		break;
+	case 2400:
+		clk_div = WC_BAUD_DR48;
+		break;
+	case 4800:
+		clk_div = WC_BAUD_DR24;
+		break;
+	case 9600:
+		clk_div = WC_BAUD_DR12;
+		break;
+	case 19200:
+		clk_div = WC_BAUD_DR6;
+		break;
+	case 38400:
+		clk_div = WC_BAUD_DR3;
+		break;
+	case 57600:
+		clk_div = WC_BAUD_DR2;
+		break;
+	case 115200:
+		clk_div = WC_BAUD_DR1;
+		break;
+	case 230400:
+		if (max->clock & MAX3110_HIGH_CLK)
+			break;
+	default:
+		/* Pick the previous baud rate */
+		baud = max->baud;
+		clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
+		tty_termios_encode_baud_rate(termios, baud, baud);
+	}
+
+	if (max->clock & MAX3110_HIGH_CLK) {
+		clk_div += 1;
+		/* High clk version max3110 doesn't support B300 */
+		if (baud == 300) {
+			baud = 600;
+			clk_div = WC_BAUD_DR384;
+		}
+		if (baud == 230400)
+			clk_div = WC_BAUD_DR1;
+		tty_termios_encode_baud_rate(termios, baud, baud);
+	}
+
+	new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
+
+	if (unlikely(termios->c_cflag & CMSPAR))
+		termios->c_cflag &= ~CMSPAR;
+
+	if (termios->c_cflag & CSTOPB)
+		new_conf |= WC_2_STOPBITS;
+	else
+		new_conf &= ~WC_2_STOPBITS;
+
+	if (termios->c_cflag & PARENB) {
+		new_conf |= WC_PARITY_ENABLE;
+		parity |= UART_LCR_PARITY;
+	} else
+		new_conf &= ~WC_PARITY_ENABLE;
+
+	if (!(termios->c_cflag & PARODD))
+		parity |= UART_LCR_EPAR;
+	max->parity = parity;
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	new_conf |= WC_TAG;
+	if (new_conf != max->cur_conf) {
+		if (!max3110_out(max, new_conf)) {
+			max->cur_conf = new_conf;
+			max->baud = baud;
+		}
+	}
+}
+
+/* Don't handle hw handshaking */
+static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
+}
+
+static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static void serial_m3110_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static void serial_m3110_pm(struct uart_port *port, unsigned int state,
+			unsigned int oldstate)
+{
+}
+
+static void serial_m3110_enable_ms(struct uart_port *port)
+{
+}
+
+struct uart_ops serial_m3110_ops = {
+	.tx_empty	= serial_m3110_tx_empty,
+	.set_mctrl	= serial_m3110_set_mctrl,
+	.get_mctrl	= serial_m3110_get_mctrl,
+	.stop_tx	= serial_m3110_stop_tx,
+	.start_tx	= serial_m3110_start_tx,
+	.stop_rx	= serial_m3110_stop_rx,
+	.enable_ms	= serial_m3110_enable_ms,
+	.break_ctl	= serial_m3110_break_ctl,
+	.startup	= serial_m3110_startup,
+	.shutdown	= serial_m3110_shutdown,
+	.set_termios	= serial_m3110_set_termios,
+	.pm		= serial_m3110_pm,
+	.type		= serial_m3110_type,
+	.release_port	= serial_m3110_release_port,
+	.request_port	= serial_m3110_request_port,
+	.config_port	= serial_m3110_config_port,
+	.verify_port	= serial_m3110_verify_port,
+};
+
+static struct uart_driver serial_m3110_reg = {
+	.owner		= THIS_MODULE,
+	.driver_name	= "MRST serial",
+	.dev_name	= "ttyS",
+	.major		= TTY_MAJOR,
+	.minor		= 64,
+	.nr		= 1,
+	.cons		= &serial_m3110_console,
+};
+
+#ifdef CONFIG_PM
+static int serial_m3110_suspend(struct spi_device *spi, pm_message_t state)
+{
+	struct uart_max3110 *max = spi_get_drvdata(spi);
+
+	disable_irq(max->irq);
+	uart_suspend_port(&serial_m3110_reg, &max->port);
+	max3110_out(max, max->cur_conf | WC_SW_SHDI);
+	return 0;
+}
+
+static int serial_m3110_resume(struct spi_device *spi)
+{
+	struct uart_max3110 *max = spi_get_drvdata(spi);
+
+	max3110_out(max, max->cur_conf);
+	uart_resume_port(&serial_m3110_reg, &max->port);
+	enable_irq(max->irq);
+	return 0;
+}
+#else
+#define serial_m3110_suspend	NULL
+#define serial_m3110_resume	NULL
+#endif
+
+static int __devinit serial_m3110_probe(struct spi_device *spi)
+{
+	struct uart_max3110 *max;
+	void *buffer;
+	u16 res;
+	int ret = 0;
+
+	max = kzalloc(sizeof(*max), GFP_KERNEL);
+	if (!max)
+		return -ENOMEM;
+
+	/* Set spi info */
+	spi->bits_per_word = 16;
+	max->clock = MAX3110_HIGH_CLK;
+
+	spi_setup(spi);
+
+	max->port.type = PORT_MAX3100;
+	max->port.fifosize = 2;		/* Only have 16b buffer */
+	max->port.ops = &serial_m3110_ops;
+	max->port.line = 0;
+	max->port.dev = &spi->dev;
+	max->port.uartclk = 115200;
+
+	max->spi = spi;
+	strcpy(max->name, spi->modalias);
+	max->irq = (u16)spi->irq;
+
+	mutex_init(&max->thread_mutex);
+
+	max->word_7bits = 0;
+	max->parity = 0;
+	max->baud = 0;
+
+	max->cur_conf = 0;
+	max->uart_flags = 0;
+
+	/* Check if reading configuration register returns something sane */
+
+	res = RC_TAG;
+	ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
+	if (ret < 0 || res == 0 || res == 0xffff) {
+		printk(KERN_ERR "MAX3111 deemed not present (conf reg %04x)",
+									res);
+		ret = -ENODEV;
+		goto err_get_page;
+	}
+
+	buffer = (void *)__get_free_page(GFP_KERNEL);
+	if (!buffer) {
+		ret = -ENOMEM;
+		goto err_get_page;
+	}
+	max->con_xmit.buf = buffer;
+	max->con_xmit.head = 0;
+	max->con_xmit.tail = 0;
+
+	max->main_thread = kthread_run(max3110_main_thread,
+					max, "max3110_main");
+	if (IS_ERR(max->main_thread)) {
+		ret = PTR_ERR(max->main_thread);
+		goto err_kthread;
+	}
+
+	spi_set_drvdata(spi, max);
+	pmax = max;
+
+	/* Give membase a psudo value to pass serial_core's check */
+	max->port.membase = (void *)0xff110000;
+	uart_add_one_port(&serial_m3110_reg, &max->port);
+
+	return 0;
+
+err_kthread:
+	free_page((unsigned long)buffer);
+err_get_page:
+	kfree(max);
+	return ret;
+}
+
+static int __devexit serial_m3110_remove(struct spi_device *dev)
+{
+	struct uart_max3110 *max = spi_get_drvdata(dev);
+
+	if (!max)
+		return 0;
+
+	uart_remove_one_port(&serial_m3110_reg, &max->port);
+
+	free_page((unsigned long)max->con_xmit.buf);
+
+	if (max->main_thread)
+		kthread_stop(max->main_thread);
+
+	kfree(max);
+	return 0;
+}
+
+static struct spi_driver uart_max3110_driver = {
+	.driver = {
+			.name	= "spi_max3111",
+			.bus	= &spi_bus_type,
+			.owner	= THIS_MODULE,
+	},
+	.probe		= serial_m3110_probe,
+	.remove		= __devexit_p(serial_m3110_remove),
+	.suspend	= serial_m3110_suspend,
+	.resume		= serial_m3110_resume,
+};
+
+static int __init serial_m3110_init(void)
+{
+	int ret = 0;
+
+	ret = uart_register_driver(&serial_m3110_reg);
+	if (ret)
+		return ret;
+
+	ret = spi_register_driver(&uart_max3110_driver);
+	if (ret)
+		uart_unregister_driver(&serial_m3110_reg);
+
+	return ret;
+}
+
+static void __exit serial_m3110_exit(void)
+{
+	spi_unregister_driver(&uart_max3110_driver);
+	uart_unregister_driver(&serial_m3110_reg);
+}
+
+module_init(serial_m3110_init);
+module_exit(serial_m3110_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("max3110-uart");