ifx6x60: SPI protocol driver for Infineon 6x60 modem

Prototype driver for the IFX6x60 series of SPI attached modems by Jim
Stanley and Russ Gorby

Signed-off-by: Russ Gorby <richardx.r.gorby@intel.com>

[Some reworking and a major cleanup]

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 1538 insertions, 0 deletions

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index aff9dcd051c6..0b9cc17b380b 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -1632,4 +1632,10 @@ config SERIAL_ALTERA_UART_CONSOLE
         help
           Enable a Altera UART port to be the system console.
 
+config SERIAL_IFX6X60
+        tristate "SPI protocol driver for Infineon 6x60 modem (EXPERIMENTAL)"
+        depends on GPIOLIB && EXPERIMENTAL
+        help
+          Support for the IFX6x60 modem devices on Intel MID platforms.
+
 endmenu
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index c5705765454f..783638b10698 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -89,3 +89,4 @@ obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
 obj-$(CONFIG_SERIAL_MRST_MAX3110)       += mrst_max3110.o
 obj-$(CONFIG_SERIAL_MFD_HSU)    += mfd.o
 obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
+obj-$(CONFIG_SERIAL_IFX6X60)    += ifx6x60.o
diff --git a/drivers/serial/ifx6x60.c b/drivers/serial/ifx6x60.c
new file mode 100644
index 000000000000..b9b7e0601961
--- /dev/null
+++ b/drivers/serial/ifx6x60.c
@@ -0,0 +1,1402 @@
+/****************************************************************************
+ *
+ * Driver for the IFX 6x60 spi modem.
+ *
+ * Copyright (C) 2008 Option International
+ * Copyright (C) 2008 Filip Aben <f.aben@option.com>
+ *                    Denis Joseph Barrow <d.barow@option.com>
+ *                    Jan Dumon <j.dumon@option.com>
+ *
+ * Copyright (C) 2009, 2010 Intel Corp
+ * Russ Gorby <richardx.r.gorby@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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 Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA
+ *
+ * Driver modified by Intel from Option gtm501l_spi.c
+ *
+ * Notes
+ * o    The driver currently assumes a single device only. If you need to
+ *      change this then look for saved_ifx_dev and add a device lookup
+ * o    The driver is intended to be big-endian safe but has never been
+ *      tested that way (no suitable hardware). There are a couple of FIXME
+ *      notes by areas that may need addressing
+ * o    Some of the GPIO naming/setup assumptions may need revisiting if
+ *      you need to use this driver for another platform.
+ *
+ *****************************************************************************/
+#include <linux/module.h>
+#include <linux/termios.h>
+#include <linux/tty.h>
+#include <linux/device.h>
+#include <linux/spi/spi.h>
+#include <linux/tty.h>
+#include <linux/kfifo.h>
+#include <linux/tty_flip.h>
+#include <linux/timer.h>
+#include <linux/serial.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/rfkill.h>
+#include <linux/fs.h>
+#include <linux/ip.h>
+#include <linux/dmapool.h>
+#include <linux/gpio.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <linux/wait.h>
+#include <linux/tty.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/spi/ifx_modem.h>
+
+#include "ifx6x60.h"
+
+#define IFX_SPI_MORE_MASK               0x10
+#define IFX_SPI_MORE_BIT                12      /* bit position in u16 */
+#define IFX_SPI_CTS_BIT                 13      /* bit position in u16 */
+#define IFX_SPI_TTY_ID                  0
+#define IFX_SPI_TIMEOUT_SEC             2
+#define IFX_SPI_HEADER_0                (-1)
+#define IFX_SPI_HEADER_F                (-2)
+
+/* forward reference */
+static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev);
+
+/* local variables */
+static int spi_b16 = 1;                 /* 8 or 16 bit word length */
+static struct tty_driver *tty_drv;
+static struct ifx_spi_device *saved_ifx_dev;
+static struct lock_class_key ifx_spi_key;
+
+/* GPIO/GPE settings */
+
+/**
+ *      mrdy_set_high           -       set MRDY GPIO
+ *      @ifx: device we are controlling
+ *
+ */
+static inline void mrdy_set_high(struct ifx_spi_device *ifx)
+{
+        gpio_set_value(ifx->gpio.mrdy, 1);
+}
+
+/**
+ *      mrdy_set_low            -       clear MRDY GPIO
+ *      @ifx: device we are controlling
+ *
+ */
+static inline void mrdy_set_low(struct ifx_spi_device *ifx)
+{
+        gpio_set_value(ifx->gpio.mrdy, 0);
+}
+
+/**
+ *      ifx_spi_power_state_set
+ *      @ifx_dev: our SPI device
+ *      @val: bits to set
+ *
+ *      Set bit in power status and signal power system if status becomes non-0
+ */
+static void
+ifx_spi_power_state_set(struct ifx_spi_device *ifx_dev, unsigned char val)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&ifx_dev->power_lock, flags);
+
+        /*
+         * if power status is already non-0, just update, else
+         * tell power system
+         */
+        if (!ifx_dev->power_status)
+                pm_runtime_get(&ifx_dev->spi_dev->dev);
+        ifx_dev->power_status |= val;
+
+        spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
+}
+
+/**
+ *      ifx_spi_power_state_clear       -       clear power bit
+ *      @ifx_dev: our SPI device
+ *      @val: bits to clear
+ *
+ *      clear bit in power status and signal power system if status becomes 0
+ */
+static void
+ifx_spi_power_state_clear(struct ifx_spi_device *ifx_dev, unsigned char val)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&ifx_dev->power_lock, flags);
+
+        if (ifx_dev->power_status) {
+                ifx_dev->power_status &= ~val;
+                if (!ifx_dev->power_status)
+                        pm_runtime_put(&ifx_dev->spi_dev->dev);
+        }
+
+        spin_unlock_irqrestore(&ifx_dev->power_lock, flags);
+}
+
+/**
+ *      swap_buf
+ *      @buf: our buffer
+ *      @len : number of bytes (not words) in the buffer
+ *      @end: end of buffer
+ *
+ *      Swap the contents of a buffer into big endian format
+ */
+static inline void swap_buf(u16 *buf, int len, void *end)
+{
+        int n;
+
+        len = ((len + 1) >> 1);
+        if ((void *)&buf[len] > end) {
+                pr_err("swap_buf: swap exceeds boundary (%p > %p)!",
+                       &buf[len], end);
+                return;
+        }
+        for (n = 0; n < len; n++) {
+                *buf = cpu_to_be16(*buf);
+                buf++;
+        }
+}
+
+/**
+ *      mrdy_assert             -       assert MRDY line
+ *      @ifx_dev: our SPI device
+ *
+ *      Assert mrdy and set timer to wait for SRDY interrupt, if SRDY is low
+ *      now.
+ *
+ *      FIXME: Can SRDY even go high as we are running this code ?
+ */
+static void mrdy_assert(struct ifx_spi_device *ifx_dev)
+{
+        int val = gpio_get_value(ifx_dev->gpio.srdy);
+        if (!val) {
+                if (!test_and_set_bit(IFX_SPI_STATE_TIMER_PENDING,
+                                      &ifx_dev->flags)) {
+                        ifx_dev->spi_timer.expires =
+                                jiffies + IFX_SPI_TIMEOUT_SEC*HZ;
+                        add_timer(&ifx_dev->spi_timer);
+
+                }
+        }
+        ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_DATA_PENDING);
+        mrdy_set_high(ifx_dev);
+}
+
+/**
+ *      ifx_spi_hangup          -       hang up an IFX device
+ *      @ifx_dev: our SPI device
+ *
+ *      Hang up the tty attached to the IFX device if one is currently
+ *      open. If not take no action
+ */
+static void ifx_spi_ttyhangup(struct ifx_spi_device *ifx_dev)
+{
+        struct tty_port *pport = &ifx_dev->tty_port;
+        struct tty_struct *tty = tty_port_tty_get(pport);
+        if (tty) {
+                tty_hangup(tty);
+                tty_kref_put(tty);
+        }
+}
+
+/**
+ *      ifx_spi_timeout         -       SPI timeout
+ *      @arg: our SPI device
+ *
+ *      The SPI has timed out: hang up the tty. Users will then see a hangup
+ *      and error events.
+ */
+static void ifx_spi_timeout(unsigned long arg)
+{
+        struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *)arg;
+
+        dev_warn(&ifx_dev->spi_dev->dev, "*** SPI Timeout ***");
+        ifx_spi_ttyhangup(ifx_dev);
+        mrdy_set_low(ifx_dev);
+        clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
+}
+
+/* char/tty operations */
+
+/**
+ *      ifx_spi_tiocmget        -       get modem lines
+ *      @tty: our tty device
+ *      @filp: file handle issuing the request
+ *
+ *      Map the signal state into Linux modem flags and report the value
+ *      in Linux terms
+ */
+static int ifx_spi_tiocmget(struct tty_struct *tty, struct file *filp)
+{
+        unsigned int value;
+        struct ifx_spi_device *ifx_dev = tty->driver_data;
+
+        value =
+        (test_bit(IFX_SPI_RTS, &ifx_dev->signal_state) ? TIOCM_RTS : 0) |
+        (test_bit(IFX_SPI_DTR, &ifx_dev->signal_state) ? TIOCM_DTR : 0) |
+        (test_bit(IFX_SPI_CTS, &ifx_dev->signal_state) ? TIOCM_CTS : 0) |
+        (test_bit(IFX_SPI_DSR, &ifx_dev->signal_state) ? TIOCM_DSR : 0) |
+        (test_bit(IFX_SPI_DCD, &ifx_dev->signal_state) ? TIOCM_CAR : 0) |
+        (test_bit(IFX_SPI_RI, &ifx_dev->signal_state) ? TIOCM_RNG : 0);
+        return value;
+}
+
+/**
+ *      ifx_spi_tiocmset        -       set modem bits
+ *      @tty: the tty structure
+ *      @filp: file handle issuing the request
+ *      @set: bits to set
+ *      @clear: bits to clear
+ *
+ *      The IFX6x60 only supports DTR and RTS. Set them accordingly
+ *      and flag that an update to the modem is needed.
+ *
+ *      FIXME: do we need to kick the tranfers when we do this ?
+ */
+static int ifx_spi_tiocmset(struct tty_struct *tty, struct file *filp,
+                            unsigned int set, unsigned int clear)
+{
+        struct ifx_spi_device *ifx_dev = tty->driver_data;
+
+        if (set & TIOCM_RTS)
+                set_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
+        if (set & TIOCM_DTR)
+                set_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
+        if (clear & TIOCM_RTS)
+                clear_bit(IFX_SPI_RTS, &ifx_dev->signal_state);
+        if (clear & TIOCM_DTR)
+                clear_bit(IFX_SPI_DTR, &ifx_dev->signal_state);
+
+        set_bit(IFX_SPI_UPDATE, &ifx_dev->signal_state);
+        return 0;
+}
+
+/**
+ *      ifx_spi_open    -       called on tty open
+ *      @tty: our tty device
+ *      @filp: file handle being associated with the tty
+ *
+ *      Open the tty interface. We let the tty_port layer do all the work
+ *      for us.
+ *
+ *      FIXME: Remove single device assumption and saved_ifx_dev
+ */
+static int ifx_spi_open(struct tty_struct *tty, struct file *filp)
+{
+        return tty_port_open(&saved_ifx_dev->tty_port, tty, filp);
+}
+
+/**
+ *      ifx_spi_close   -       called when our tty closes
+ *      @tty: the tty being closed
+ *      @filp: the file handle being closed
+ *
+ *      Perform the close of the tty. We use the tty_port layer to do all
+ *      our hard work.
+ */
+static void ifx_spi_close(struct tty_struct *tty, struct file *filp)
+{
+        struct ifx_spi_device *ifx_dev = tty->driver_data;
+        tty_port_close(&ifx_dev->tty_port, tty, filp);
+        /* FIXME: should we do an ifx_spi_reset here ? */
+}
+
+/**
+ *      ifx_decode_spi_header   -       decode received header
+ *      @buffer: the received data
+ *      @length: decoded length
+ *      @more: decoded more flag
+ *      @received_cts: status of cts we received
+ *
+ *      Note how received_cts is handled -- if header is all F it is left
+ *      the same as it was, if header is all 0 it is set to 0 otherwise it is
+ *      taken from the incoming header.
+ *
+ *      FIXME: endianness
+ */
+static int ifx_spi_decode_spi_header(unsigned char *buffer, int *length,
+                        unsigned char *more, unsigned char *received_cts)
+{
+        u16 h1;
+        u16 h2;
+        u16 *in_buffer = (u16 *)buffer;
+
+        h1 = *in_buffer;
+        h2 = *(in_buffer+1);
+
+        if (h1 == 0 && h2 == 0) {
+                *received_cts = 0;
+                return IFX_SPI_HEADER_0;
+        } else if (h1 == 0xffff && h2 == 0xffff) {
+                /* spi_slave_cts remains as it was */
+                return IFX_SPI_HEADER_F;
+        }
+
+        *length = h1 & 0xfff;   /* upper bits of byte are flags */
+        *more = (buffer[1] >> IFX_SPI_MORE_BIT) & 1;
+        *received_cts = (buffer[3] >> IFX_SPI_CTS_BIT) & 1;
+        return 0;
+}
+
+/**
+ *      ifx_setup_spi_header    -       set header fields
+ *      @txbuffer: pointer to start of SPI buffer
+ *      @tx_count: bytes
+ *      @more: indicate if more to follow
+ *
+ *      Format up an SPI header for a transfer
+ *
+ *      FIXME: endianness?
+ */
+static void ifx_spi_setup_spi_header(unsigned char *txbuffer, int tx_count,
+                                        unsigned char more)
+{
+        *(u16 *)(txbuffer) = tx_count;
+        *(u16 *)(txbuffer+2) = IFX_SPI_PAYLOAD_SIZE;
+        txbuffer[1] |= (more << IFX_SPI_MORE_BIT) & IFX_SPI_MORE_MASK;
+}
+
+/**
+ *      ifx_spi_wakeup_serial   -       SPI space made
+ *      @port_data: our SPI device
+ *
+ *      We have emptied the FIFO enough that we want to get more data
+ *      queued into it. Poke the line discipline via tty_wakeup so that
+ *      it will feed us more bits
+ */
+static void ifx_spi_wakeup_serial(struct ifx_spi_device *ifx_dev)
+{
+        struct tty_struct *tty;
+
+        tty = tty_port_tty_get(&ifx_dev->tty_port);
+        if (!tty)
+                return;
+        tty_wakeup(tty);
+        tty_kref_put(tty);
+}
+
+/**
+ *      ifx_spi_prepare_tx_buffer       -       prepare transmit frame
+ *      @ifx_dev: our SPI device
+ *
+ *      The transmit buffr needs a header and various other bits of
+ *      information followed by as much data as we can pull from the FIFO
+ *      and transfer. This function formats up a suitable buffer in the
+ *      ifx_dev->tx_buffer
+ *
+ *      FIXME: performance - should we wake the tty when the queue is half
+ *                           empty ?
+ */
+static int ifx_spi_prepare_tx_buffer(struct ifx_spi_device *ifx_dev)
+{
+        int temp_count;
+        int queue_length;
+        int tx_count;
+        unsigned char *tx_buffer;
+
+        tx_buffer = ifx_dev->tx_buffer;
+        memset(tx_buffer, 0, IFX_SPI_TRANSFER_SIZE);
+
+        /* make room for required SPI header */
+        tx_buffer += IFX_SPI_HEADER_OVERHEAD;
+        tx_count = IFX_SPI_HEADER_OVERHEAD;
+
+        /* clear to signal no more data if this turns out to be the
+         * last buffer sent in a sequence */
+        ifx_dev->spi_more = 0;
+
+        /* if modem cts is set, just send empty buffer */
+        if (!ifx_dev->spi_slave_cts) {
+                /* see if there's tx data */
+                queue_length = kfifo_len(&ifx_dev->tx_fifo);
+                if (queue_length != 0) {
+                        /* data to mux -- see if there's room for it */
+                        temp_count = min(queue_length, IFX_SPI_PAYLOAD_SIZE);
+                        temp_count = kfifo_out_locked(&ifx_dev->tx_fifo,
+                                        tx_buffer, temp_count,
+                                        &ifx_dev->fifo_lock);
+
+                        /* update buffer pointer and data count in message */
+                        tx_buffer += temp_count;
+                        tx_count += temp_count;
+                        if (temp_count == queue_length)
+                                /* poke port to get more data */
+                                ifx_spi_wakeup_serial(ifx_dev);
+                        else /* more data in port, use next SPI message */
+                                ifx_dev->spi_more = 1;
+                }
+        }
+        /* have data and info for header -- set up SPI header in buffer */
+        /* spi header needs payload size, not entire buffer size */
+        ifx_spi_setup_spi_header(ifx_dev->tx_buffer,
+                                        tx_count-IFX_SPI_HEADER_OVERHEAD,
+                                        ifx_dev->spi_more);
+        /* swap actual data in the buffer */
+        swap_buf((u16 *)(ifx_dev->tx_buffer), tx_count,
+                &ifx_dev->tx_buffer[IFX_SPI_TRANSFER_SIZE]);
+        return tx_count;
+}
+
+/**
+ *      ifx_spi_write           -       line discipline write
+ *      @tty: our tty device
+ *      @buf: pointer to buffer to write (kernel space)
+ *      @count: size of buffer
+ *
+ *      Write the characters we have been given into the FIFO. If the device
+ *      is not active then activate it, when the SRDY line is asserted back
+ *      this will commence I/O
+ */
+static int ifx_spi_write(struct tty_struct *tty, const unsigned char *buf,
+                         int count)
+{
+        struct ifx_spi_device *ifx_dev = tty->driver_data;
+        unsigned char *tmp_buf = (unsigned char *)buf;
+        int tx_count = kfifo_in_locked(&ifx_dev->tx_fifo, tmp_buf, count,
+                                   &ifx_dev->fifo_lock);
+        mrdy_assert(ifx_dev);
+        return tx_count;
+}
+
+/**
+ *      ifx_spi_chars_in_buffer -       line discipline helper
+ *      @tty: our tty device
+ *
+ *      Report how much data we can accept before we drop bytes. As we use
+ *      a simple FIFO this is nice and easy.
+ */
+static int ifx_spi_write_room(struct tty_struct *tty)
+{
+        struct ifx_spi_device *ifx_dev = tty->driver_data;
+        return IFX_SPI_FIFO_SIZE - kfifo_len(&ifx_dev->tx_fifo);
+}
+
+/**
+ *      ifx_spi_chars_in_buffer -       line discipline helper
+ *      @tty: our tty device
+ *
+ *      Report how many characters we have buffered. In our case this is the
+ *      number of bytes sitting in our transmit FIFO.
+ */
+static int ifx_spi_chars_in_buffer(struct tty_struct *tty)
+{
+        struct ifx_spi_device *ifx_dev = tty->driver_data;
+        return kfifo_len(&ifx_dev->tx_fifo);
+}
+
+/**
+ *      ifx_port_hangup
+ *      @port: our tty port
+ *
+ *      tty port hang up. Called when tty_hangup processing is invoked either
+ *      by loss of carrier, or by software (eg vhangup). Serialized against
+ *      activate/shutdown by the tty layer.
+ */
+static void ifx_spi_hangup(struct tty_struct *tty)
+{
+        struct ifx_spi_device *ifx_dev = tty->driver_data;
+        tty_port_hangup(&ifx_dev->tty_port);
+}
+
+/**
+ *      ifx_port_activate
+ *      @port: our tty port
+ *
+ *      tty port activate method - called for first open. Serialized
+ *      with hangup and shutdown by the tty layer.
+ */
+static int ifx_port_activate(struct tty_port *port, struct tty_struct *tty)
+{
+        struct ifx_spi_device *ifx_dev =
+                container_of(port, struct ifx_spi_device, tty_port);
+
+        /* clear any old data; can't do this in 'close' */
+        kfifo_reset(&ifx_dev->tx_fifo);
+
+        /* put port data into this tty */
+        tty->driver_data = ifx_dev;
+
+        /* allows flip string push from int context */
+        tty->low_latency = 1;
+
+        return 0;
+}
+
+/**
+ *      ifx_port_shutdown
+ *      @port: our tty port
+ *
+ *      tty port shutdown method - called for last port close. Serialized
+ *      with hangup and activate by the tty layer.
+ */
+static void ifx_port_shutdown(struct tty_port *port)
+{
+        struct ifx_spi_device *ifx_dev =
+                container_of(port, struct ifx_spi_device, tty_port);
+
+        mrdy_set_low(ifx_dev);
+        clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
+        tasklet_kill(&ifx_dev->io_work_tasklet);
+}
+
+static const struct tty_port_operations ifx_tty_port_ops = {
+        .activate = ifx_port_activate,
+        .shutdown = ifx_port_shutdown,
+};
+
+static const struct tty_operations ifx_spi_serial_ops = {
+        .open = ifx_spi_open,
+        .close = ifx_spi_close,
+        .write = ifx_spi_write,
+        .hangup = ifx_spi_hangup,
+        .write_room = ifx_spi_write_room,
+        .chars_in_buffer = ifx_spi_chars_in_buffer,
+        .tiocmget = ifx_spi_tiocmget,
+        .tiocmset = ifx_spi_tiocmset,
+};
+
+/**
+ *      ifx_spi_insert_fip_string       -       queue received data
+ *      @ifx_ser: our SPI device
+ *      @chars: buffer we have received
+ *      @size: number of chars reeived
+ *
+ *      Queue bytes to the tty assuming the tty side is currently open. If
+ *      not the discard the data.
+ */
+static void ifx_spi_insert_flip_string(struct ifx_spi_device *ifx_dev,
+                                    unsigned char *chars, size_t size)
+{
+        struct tty_struct *tty = tty_port_tty_get(&ifx_dev->tty_port);
+        if (!tty)
+                return;
+        tty_insert_flip_string(tty, chars, size);
+        tty_flip_buffer_push(tty);
+        tty_kref_put(tty);
+}
+
+/**
+ *      ifx_spi_complete        -       SPI transfer completed
+ *      @ctx: our SPI device
+ *
+ *      An SPI transfer has completed. Process any received data and kick off
+ *      any further transmits we can commence.
+ */
+static void ifx_spi_complete(void *ctx)
+{
+        struct ifx_spi_device *ifx_dev = ctx;
+        struct tty_struct *tty;
+        struct tty_ldisc *ldisc = NULL;
+        int length;
+        int actual_length;
+        unsigned char more;
+        unsigned char cts;
+        int local_write_pending = 0;
+        int queue_length;
+        int srdy;
+        int decode_result;
+
+        mrdy_set_low(ifx_dev);
+
+        if (!ifx_dev->spi_msg.status) {
+                /* check header validity, get comm flags */
+                swap_buf((u16 *)ifx_dev->rx_buffer, IFX_SPI_HEADER_OVERHEAD,
+                        &ifx_dev->rx_buffer[IFX_SPI_HEADER_OVERHEAD]);
+                decode_result = ifx_spi_decode_spi_header(ifx_dev->rx_buffer,
+                                &length, &more, &cts);
+                if (decode_result == IFX_SPI_HEADER_0) {
+                        dev_dbg(&ifx_dev->spi_dev->dev,
+                                "ignore input: invalid header 0");
+                        ifx_dev->spi_slave_cts = 0;
+                        goto complete_exit;
+                } else if (decode_result == IFX_SPI_HEADER_F) {
+                        dev_dbg(&ifx_dev->spi_dev->dev,
+                                "ignore input: invalid header F");
+                        goto complete_exit;
+                }
+
+                ifx_dev->spi_slave_cts = cts;
+
+                actual_length = min((unsigned int)length,
+                                        ifx_dev->spi_msg.actual_length);
+                swap_buf((u16 *)(ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD),
+                         actual_length,
+                         &ifx_dev->rx_buffer[IFX_SPI_TRANSFER_SIZE]);
+                ifx_spi_insert_flip_string(
+                        ifx_dev,
+                        ifx_dev->rx_buffer + IFX_SPI_HEADER_OVERHEAD,
+                        (size_t)actual_length);
+        } else {
+                dev_dbg(&ifx_dev->spi_dev->dev, "SPI transfer error %d",
+                       ifx_dev->spi_msg.status);
+        }
+
+complete_exit:
+        if (ifx_dev->write_pending) {
+                ifx_dev->write_pending = 0;
+                local_write_pending = 1;
+        }
+
+        clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &(ifx_dev->flags));
+
+        queue_length = kfifo_len(&ifx_dev->tx_fifo);
+        srdy = gpio_get_value(ifx_dev->gpio.srdy);
+        if (!srdy)
+                ifx_spi_power_state_clear(ifx_dev, IFX_SPI_POWER_SRDY);
+
+        /* schedule output if there is more to do */
+        if (test_and_clear_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags))
+                tasklet_schedule(&ifx_dev->io_work_tasklet);
+        else {
+                if (more || ifx_dev->spi_more || queue_length > 0 ||
+                        local_write_pending) {
+                        if (ifx_dev->spi_slave_cts) {
+                                if (more)
+                                        mrdy_assert(ifx_dev);
+                        } else
+                                mrdy_assert(ifx_dev);
+                } else {
+                        /*
+                         * poke line discipline driver if any for more data
+                         * may or may not get more data to write
+                         * for now, say not busy
+                         */
+                        ifx_spi_power_state_clear(ifx_dev,
+                                                  IFX_SPI_POWER_DATA_PENDING);
+                        tty = tty_port_tty_get(&ifx_dev->tty_port);
+                        if (tty) {
+                                ldisc = tty_ldisc_ref(tty);
+                                if (ldisc) {
+                                        ldisc->ops->write_wakeup(tty);
+                                        tty_ldisc_deref(ldisc);
+                                }
+                                tty_kref_put(tty);
+                        }
+                }
+        }
+}
+
+/**
+ *      ifx_spio_io             -       I/O tasklet
+ *      @data: our SPI device
+ *
+ *      Queue data for transmission if possible and then kick off the
+ *      transfer.
+ */
+static void ifx_spi_io(unsigned long data)
+{
+        int retval;
+        struct ifx_spi_device *ifx_dev = (struct ifx_spi_device *) data;
+
+        if (!test_and_set_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags)) {
+                if (ifx_dev->gpio.unack_srdy_int_nb > 0)
+                        ifx_dev->gpio.unack_srdy_int_nb--;
+
+                ifx_spi_prepare_tx_buffer(ifx_dev);
+
+                spi_message_init(&ifx_dev->spi_msg);
+                INIT_LIST_HEAD(&ifx_dev->spi_msg.queue);
+
+                ifx_dev->spi_msg.context = ifx_dev;
+                ifx_dev->spi_msg.complete = ifx_spi_complete;
+
+                /* set up our spi transfer */
+                /* note len is BYTES, not transfers */
+                ifx_dev->spi_xfer.len = IFX_SPI_TRANSFER_SIZE;
+                ifx_dev->spi_xfer.cs_change = 0;
+                ifx_dev->spi_xfer.speed_hz = 12500000;
+                /* ifx_dev->spi_xfer.speed_hz = 390625; */
+                ifx_dev->spi_xfer.bits_per_word = spi_b16 ? 16 : 8;
+
+                ifx_dev->spi_xfer.tx_buf = ifx_dev->tx_buffer;
+                ifx_dev->spi_xfer.rx_buf = ifx_dev->rx_buffer;
+
+                /*
+                 * setup dma pointers
+                 */
+                if (ifx_dev->is_6160) {
+                        ifx_dev->spi_msg.is_dma_mapped = 1;
+                        ifx_dev->tx_dma = ifx_dev->tx_bus;
+                        ifx_dev->rx_dma = ifx_dev->rx_bus;
+                        ifx_dev->spi_xfer.tx_dma = ifx_dev->tx_dma;
+                        ifx_dev->spi_xfer.rx_dma = ifx_dev->rx_dma;
+                } else {
+                        ifx_dev->spi_msg.is_dma_mapped = 0;
+                        ifx_dev->tx_dma = (dma_addr_t)0;
+                        ifx_dev->rx_dma = (dma_addr_t)0;
+                        ifx_dev->spi_xfer.tx_dma = (dma_addr_t)0;
+                        ifx_dev->spi_xfer.rx_dma = (dma_addr_t)0;
+                }
+
+                spi_message_add_tail(&ifx_dev->spi_xfer, &ifx_dev->spi_msg);
+
+                /* Assert MRDY. This may have already been done by the write
+                 * routine.
+                 */
+                mrdy_assert(ifx_dev);
+
+                retval = spi_async(ifx_dev->spi_dev, &ifx_dev->spi_msg);
+                if (retval) {
+                        clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS,
+                                  &ifx_dev->flags);
+                        tasklet_schedule(&ifx_dev->io_work_tasklet);
+                        return;
+                }
+        } else
+                ifx_dev->write_pending = 1;
+}
+
+/**
+ *      ifx_spi_free_port       -       free up the tty side
+ *      @ifx_dev: IFX device going away
+ *
+ *      Unregister and free up a port when the device goes away
+ */
+static void ifx_spi_free_port(struct ifx_spi_device *ifx_dev)
+{
+        if (ifx_dev->tty_dev)
+                tty_unregister_device(tty_drv, ifx_dev->minor);
+        kfifo_free(&ifx_dev->tx_fifo);
+}
+
+/**
+ *      ifx_spi_create_port     -       create a new port
+ *      @ifx_dev: our spi device
+ *
+ *      Allocate and initialise the tty port that goes with this interface
+ *      and add it to the tty layer so that it can be opened.
+ */
+static int ifx_spi_create_port(struct ifx_spi_device *ifx_dev)
+{
+        int ret = 0;
+        struct tty_port *pport = &ifx_dev->tty_port;
+
+        spin_lock_init(&ifx_dev->fifo_lock);
+        lockdep_set_class_and_subclass(&ifx_dev->fifo_lock,
+                &ifx_spi_key, 0);
+
+        if (kfifo_alloc(&ifx_dev->tx_fifo, IFX_SPI_FIFO_SIZE, GFP_KERNEL)) {
+                ret = -ENOMEM;
+                goto error_ret;
+        }
+
+        pport->ops = &ifx_tty_port_ops;
+        tty_port_init(pport);
+        ifx_dev->minor = IFX_SPI_TTY_ID;
+        ifx_dev->tty_dev = tty_register_device(tty_drv, ifx_dev->minor,
+                                               &ifx_dev->spi_dev->dev);
+        if (IS_ERR(ifx_dev->tty_dev)) {
+                dev_dbg(&ifx_dev->spi_dev->dev,
+                        "%s: registering tty device failed", __func__);
+                ret = PTR_ERR(ifx_dev->tty_dev);
+                goto error_ret;
+        }
+        return 0;
+
+error_ret:
+        ifx_spi_free_port(ifx_dev);
+        return ret;
+}
+
+/**
+ *      ifx_spi_handle_srdy             -       handle SRDY
+ *      @ifx_dev: device asserting SRDY
+ *
+ *      Check our device state and see what we need to kick off when SRDY
+ *      is asserted. This usually means killing the timer and firing off the
+ *      I/O processing.
+ */
+static void ifx_spi_handle_srdy(struct ifx_spi_device *ifx_dev)
+{
+        if (test_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags)) {
+                del_timer_sync(&ifx_dev->spi_timer);
+                clear_bit(IFX_SPI_STATE_TIMER_PENDING, &ifx_dev->flags);
+        }
+
+        ifx_spi_power_state_set(ifx_dev, IFX_SPI_POWER_SRDY);
+
+        if (!test_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags))
+                tasklet_schedule(&ifx_dev->io_work_tasklet);
+        else
+                set_bit(IFX_SPI_STATE_IO_READY, &ifx_dev->flags);
+}
+
+/**
+ *      ifx_spi_srdy_interrupt  -       SRDY asserted
+ *      @irq: our IRQ number
+ *      @dev: our ifx device
+ *
+ *      The modem asserted SRDY. Handle the srdy event
+ */
+static irqreturn_t ifx_spi_srdy_interrupt(int irq, void *dev)
+{
+        struct ifx_spi_device *ifx_dev = dev;
+        ifx_dev->gpio.unack_srdy_int_nb++;
+        ifx_spi_handle_srdy(ifx_dev);
+        return IRQ_HANDLED;
+}
+
+/**
+ *      ifx_spi_reset_interrupt -       Modem has changed reset state
+ *      @irq: interrupt number
+ *      @dev: our device pointer
+ *
+ *      The modem has either entered or left reset state. Check the GPIO
+ *      line to see which.
+ *
+ *      FIXME: review locking on MR_INPROGRESS versus
+ *      parallel unsolicited reset/solicited reset
+ */
+static irqreturn_t ifx_spi_reset_interrupt(int irq, void *dev)
+{
+        struct ifx_spi_device *ifx_dev = dev;
+        int val = gpio_get_value(ifx_dev->gpio.reset_out);
+        int solreset = test_bit(MR_START, &ifx_dev->mdm_reset_state);
+
+        if (val == 0) {
+                /* entered reset */
+                set_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
+                if (!solreset) {
+                        /* unsolicited reset  */
+                        ifx_spi_ttyhangup(ifx_dev);
+                }
+        } else {
+                /* exited reset */
+                clear_bit(MR_INPROGRESS, &ifx_dev->mdm_reset_state);
+                if (solreset) {
+                        set_bit(MR_COMPLETE, &ifx_dev->mdm_reset_state);
+                        wake_up(&ifx_dev->mdm_reset_wait);
+                }
+        }
+        return IRQ_HANDLED;
+}
+
+/**
+ *      ifx_spi_free_device - free device
+ *      @ifx_dev: device to free
+ *
+ *      Free the IFX device
+ */
+static void ifx_spi_free_device(struct ifx_spi_device *ifx_dev)
+{
+        ifx_spi_free_port(ifx_dev);
+        dma_free_coherent(&ifx_dev->spi_dev->dev,
+                                IFX_SPI_TRANSFER_SIZE,
+                                ifx_dev->tx_buffer,
+                                ifx_dev->tx_bus);
+        dma_free_coherent(&ifx_dev->spi_dev->dev,
+                                IFX_SPI_TRANSFER_SIZE,
+                                ifx_dev->rx_buffer,
+                                ifx_dev->rx_bus);
+}
+
+/**
+ *      ifx_spi_reset   -       reset modem
+ *      @ifx_dev: modem to reset
+ *
+ *      Perform a reset on the modem
+ */
+static int ifx_spi_reset(struct ifx_spi_device *ifx_dev)
+{
+        int ret;
+        /*
+         * set up modem power, reset
+         *
+         * delays are required on some platforms for the modem
+         * to reset properly
+         */
+        set_bit(MR_START, &ifx_dev->mdm_reset_state);
+        gpio_set_value(ifx_dev->gpio.po, 0);
+        gpio_set_value(ifx_dev->gpio.reset, 0);
+        msleep(25);
+        gpio_set_value(ifx_dev->gpio.reset, 1);
+        msleep(1);
+        gpio_set_value(ifx_dev->gpio.po, 1);
+        msleep(1);
+        gpio_set_value(ifx_dev->gpio.po, 0);
+        ret = wait_event_timeout(ifx_dev->mdm_reset_wait,
+                                 test_bit(MR_COMPLETE,
+                                          &ifx_dev->mdm_reset_state),
+                                 IFX_RESET_TIMEOUT);
+        if (!ret)
+                dev_warn(&ifx_dev->spi_dev->dev, "Modem reset timeout: (state:%lx)",
+                         ifx_dev->mdm_reset_state);
+
+        ifx_dev->mdm_reset_state = 0;
+        return ret;
+}
+
+/**
+ *      ifx_spi_spi_probe       -       probe callback
+ *      @spi: our possible matching SPI device
+ *
+ *      Probe for a 6x60 modem on SPI bus. Perform any needed device and
+ *      GPIO setup.
+ *
+ *      FIXME:
+ *      -       Support for multiple devices
+ *      -       Split out MID specific GPIO handling eventually
+ */
+
+static int ifx_spi_spi_probe(struct spi_device *spi)
+{
+        int ret;
+        int srdy;
+        struct ifx_modem_platform_data *pl_data = NULL;
+        struct ifx_spi_device *ifx_dev;
+
+        if (saved_ifx_dev) {
+                dev_dbg(&spi->dev, "ignoring subsequent detection");
+                return -ENODEV;
+        }
+
+        /* initialize structure to hold our device variables */
+        ifx_dev = kzalloc(sizeof(struct ifx_spi_device), GFP_KERNEL);
+        if (!ifx_dev) {
+                dev_err(&spi->dev, "spi device allocation failed");
+                return -ENOMEM;
+        }
+        saved_ifx_dev = ifx_dev;
+        ifx_dev->spi_dev = spi;
+        clear_bit(IFX_SPI_STATE_IO_IN_PROGRESS, &ifx_dev->flags);
+        spin_lock_init(&ifx_dev->write_lock);
+        spin_lock_init(&ifx_dev->power_lock);
+        ifx_dev->power_status = 0;
+        init_timer(&ifx_dev->spi_timer);
+        ifx_dev->spi_timer.function = ifx_spi_timeout;
+        ifx_dev->spi_timer.data = (unsigned long)ifx_dev;
+        ifx_dev->is_6160 = pl_data->is_6160;
+
+        /* ensure SPI protocol flags are initialized to enable transfer */
+        ifx_dev->spi_more = 0;
+        ifx_dev->spi_slave_cts = 0;
+
+        /*initialize transfer and dma buffers */
+        ifx_dev->tx_buffer = dma_alloc_coherent(&ifx_dev->spi_dev->dev,
+                                IFX_SPI_TRANSFER_SIZE,
+                                &ifx_dev->tx_bus,
+                                GFP_KERNEL);
+        if (!ifx_dev->tx_buffer) {
+                dev_err(&spi->dev, "DMA-TX buffer allocation failed");
+                ret = -ENOMEM;
+                goto error_ret;
+        }
+        ifx_dev->rx_buffer = dma_alloc_coherent(&ifx_dev->spi_dev->dev,
+                                IFX_SPI_TRANSFER_SIZE,
+                                &ifx_dev->rx_bus,
+                                GFP_KERNEL);
+        if (!ifx_dev->rx_buffer) {
+                dev_err(&spi->dev, "DMA-RX buffer allocation failed");
+                ret = -ENOMEM;
+                goto error_ret;
+        }
+
+        /* initialize waitq for modem reset */
+        init_waitqueue_head(&ifx_dev->mdm_reset_wait);
+
+        spi_set_drvdata(spi, ifx_dev);
+        tasklet_init(&ifx_dev->io_work_tasklet, ifx_spi_io,
+                                                (unsigned long)ifx_dev);
+
+        set_bit(IFX_SPI_STATE_PRESENT, &ifx_dev->flags);
+
+        /* create our tty port */
+        ret = ifx_spi_create_port(ifx_dev);
+        if (ret != 0) {
+                dev_err(&spi->dev, "create default tty port failed");
+                goto error_ret;
+        }
+
+        pl_data = (struct ifx_modem_platform_data *)spi->dev.platform_data;
+        if (pl_data) {
+                ifx_dev->gpio.reset = pl_data->rst_pmu;
+                ifx_dev->gpio.po = pl_data->pwr_on;
+                ifx_dev->gpio.mrdy = pl_data->mrdy;
+                ifx_dev->gpio.srdy = pl_data->srdy;
+                ifx_dev->gpio.reset_out = pl_data->rst_out;
+        } else {
+                dev_err(&spi->dev, "missing platform data!");
+                ret = -ENODEV;
+                goto error_ret;
+        }
+
+        dev_info(&spi->dev, "gpios %d, %d, %d, %d, %d",
+                 ifx_dev->gpio.reset, ifx_dev->gpio.po, ifx_dev->gpio.mrdy,
+                 ifx_dev->gpio.srdy, ifx_dev->gpio.reset_out);
+
+        /* Configure gpios */
+        ret = gpio_request(ifx_dev->gpio.reset, "ifxModem");
+        if (ret < 0) {
+                dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET)",
+                        ifx_dev->gpio.reset);
+                goto error_ret;
+        }
+        ret += gpio_direction_output(ifx_dev->gpio.reset, 0);
+        ret += gpio_export(ifx_dev->gpio.reset, 1);
+        if (ret) {
+                dev_err(&spi->dev, "Unable to configure GPIO%d (RESET)",
+                        ifx_dev->gpio.reset);
+                ret = -EBUSY;
+                goto error_ret2;
+        }
+
+        ret = gpio_request(ifx_dev->gpio.po, "ifxModem");
+        ret += gpio_direction_output(ifx_dev->gpio.po, 0);
+        ret += gpio_export(ifx_dev->gpio.po, 1);
+        if (ret) {
+                dev_err(&spi->dev, "Unable to configure GPIO%d (ON)",
+                        ifx_dev->gpio.po);
+                ret = -EBUSY;
+                goto error_ret3;
+        }
+
+        ret = gpio_request(ifx_dev->gpio.mrdy, "ifxModem");
+        if (ret < 0) {
+                dev_err(&spi->dev, "Unable to allocate GPIO%d (MRDY)",
+                        ifx_dev->gpio.mrdy);
+                goto error_ret3;
+        }
+        ret += gpio_export(ifx_dev->gpio.mrdy, 1);
+        ret += gpio_direction_output(ifx_dev->gpio.mrdy, 0);
+        if (ret) {
+                dev_err(&spi->dev, "Unable to configure GPIO%d (MRDY)",
+                        ifx_dev->gpio.mrdy);
+                ret = -EBUSY;
+                goto error_ret4;
+        }
+
+        ret = gpio_request(ifx_dev->gpio.srdy, "ifxModem");
+        if (ret < 0) {
+                dev_err(&spi->dev, "Unable to allocate GPIO%d (SRDY)",
+                        ifx_dev->gpio.srdy);
+                ret = -EBUSY;
+                goto error_ret4;
+        }
+        ret += gpio_export(ifx_dev->gpio.srdy, 1);
+        ret += gpio_direction_input(ifx_dev->gpio.srdy);
+        if (ret) {
+                dev_err(&spi->dev, "Unable to configure GPIO%d (SRDY)",
+                        ifx_dev->gpio.srdy);
+                ret = -EBUSY;
+                goto error_ret5;
+        }
+
+        ret = gpio_request(ifx_dev->gpio.reset_out, "ifxModem");
+        if (ret < 0) {
+                dev_err(&spi->dev, "Unable to allocate GPIO%d (RESET_OUT)",
+                        ifx_dev->gpio.reset_out);
+                goto error_ret5;
+        }
+        ret += gpio_export(ifx_dev->gpio.reset_out, 1);
+        ret += gpio_direction_input(ifx_dev->gpio.reset_out);
+        if (ret) {
+                dev_err(&spi->dev, "Unable to configure GPIO%d (RESET_OUT)",
+                        ifx_dev->gpio.reset_out);
+                ret = -EBUSY;
+                goto error_ret6;
+        }
+
+        ret = request_irq(gpio_to_irq(ifx_dev->gpio.reset_out),
+                          ifx_spi_reset_interrupt,
+                          IRQF_TRIGGER_RISING|IRQF_TRIGGER_FALLING, DRVNAME,
+                (void *)ifx_dev);
+        if (ret) {
+                dev_err(&spi->dev, "Unable to get irq %x\n",
+                        gpio_to_irq(ifx_dev->gpio.reset_out));
+                goto error_ret6;
+        }
+
+        ret = ifx_spi_reset(ifx_dev);
+
+        ret = request_irq(gpio_to_irq(ifx_dev->gpio.srdy),
+                          ifx_spi_srdy_interrupt,
+                          IRQF_TRIGGER_RISING, DRVNAME,
+                          (void *)ifx_dev);
+        if (ret) {
+                dev_err(&spi->dev, "Unable to get irq %x",
+                        gpio_to_irq(ifx_dev->gpio.srdy));
+                goto error_ret6;
+        }
+
+        /* set pm runtime power state and register with power system */
+        pm_runtime_set_active(&spi->dev);
+        pm_runtime_enable(&spi->dev);
+
+        /* handle case that modem is already signaling SRDY */
+        /* no outgoing tty open at this point, this just satisfies the
+         * modem's read and should reset communication properly
+         */
+        srdy = gpio_get_value(ifx_dev->gpio.srdy);
+
+        if (srdy) {
+                mrdy_assert(ifx_dev);
+                ifx_spi_handle_srdy(ifx_dev);
+        } else
+                mrdy_set_low(ifx_dev);
+        return 0;
+
+error_ret6:
+        gpio_free(ifx_dev->gpio.srdy);
+error_ret5:
+        gpio_free(ifx_dev->gpio.mrdy);
+error_ret4:
+        gpio_free(ifx_dev->gpio.reset);
+error_ret3:
+        gpio_free(ifx_dev->gpio.po);
+error_ret2:
+        gpio_free(ifx_dev->gpio.reset_out);
+error_ret:
+        ifx_spi_free_device(ifx_dev);
+        saved_ifx_dev = NULL;
+        return ret;
+}
+
+/**
+ *      ifx_spi_spi_remove      -       SPI device was removed
+ *      @spi: SPI device
+ *
+ *      FIXME: We should be shutting the device down here not in
+ *      the module unload path.
+ */
+
+static int ifx_spi_spi_remove(struct spi_device *spi)
+{
+        struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
+        /* stop activity */
+        tasklet_kill(&ifx_dev->io_work_tasklet);
+        /* free irq */
+        free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), (void *)ifx_dev);
+        free_irq(gpio_to_irq(ifx_dev->gpio.srdy), (void *)ifx_dev);
+
+        gpio_free(ifx_dev->gpio.srdy);
+        gpio_free(ifx_dev->gpio.mrdy);
+        gpio_free(ifx_dev->gpio.reset);
+        gpio_free(ifx_dev->gpio.po);
+        gpio_free(ifx_dev->gpio.reset_out);
+
+        /* free allocations */
+        ifx_spi_free_device(ifx_dev);
+
+        saved_ifx_dev = NULL;
+        return 0;
+}
+
+/**
+ *      ifx_spi_spi_shutdown    -       called on SPI shutdown
+ *      @spi: SPI device
+ *
+ *      No action needs to be taken here
+ */
+
+static void ifx_spi_spi_shutdown(struct spi_device *spi)
+{
+}
+
+/*
+ * various suspends and resumes have nothing to do
+ * no hardware to save state for
+ */
+
+/**
+ *      ifx_spi_spi_suspend     -       suspend SPI on system suspend
+ *      @dev: device being suspended
+ *
+ *      Suspend the SPI side. No action needed on Intel MID platforms, may
+ *      need extending for other systems.
+ */
+static int ifx_spi_spi_suspend(struct spi_device *spi, pm_message_t msg)
+{
+        return 0;
+}
+
+/**
+ *      ifx_spi_spi_resume      -       resume SPI side on system resume
+ *      @dev: device being suspended
+ *
+ *      Suspend the SPI side. No action needed on Intel MID platforms, may
+ *      need extending for other systems.
+ */
+static int ifx_spi_spi_resume(struct spi_device *spi)
+{
+        return 0;
+}
+
+/**
+ *      ifx_spi_pm_suspend      -       suspend modem on system suspend
+ *      @dev: device being suspended
+ *
+ *      Suspend the modem. No action needed on Intel MID platforms, may
+ *      need extending for other systems.
+ */
+static int ifx_spi_pm_suspend(struct device *dev)
+{
+        return 0;
+}
+
+/**
+ *      ifx_spi_pm_resume       -       resume modem on system resume
+ *      @dev: device being suspended
+ *
+ *      Allow the modem to resume. No action needed.
+ *
+ *      FIXME: do we need to reset anything here ?
+ */
+static int ifx_spi_pm_resume(struct device *dev)
+{
+        return 0;
+}
+
+/**
+ *      ifx_spi_pm_runtime_resume       -       suspend modem
+ *      @dev: device being suspended
+ *
+ *      Allow the modem to resume. No action needed.
+ */
+static int ifx_spi_pm_runtime_resume(struct device *dev)
+{
+        return 0;
+}
+
+/**
+ *      ifx_spi_pm_runtime_suspend      -       suspend modem
+ *      @dev: device being suspended
+ *
+ *      Allow the modem to suspend and thus suspend to continue up the
+ *      device tree.
+ */
+static int ifx_spi_pm_runtime_suspend(struct device *dev)
+{
+        return 0;
+}
+
+/**
+ *      ifx_spi_pm_runtime_idle         -       check if modem idle
+ *      @dev: our device
+ *
+ *      Check conditions and queue runtime suspend if idle.
+ */
+static int ifx_spi_pm_runtime_idle(struct device *dev)
+{
+        struct spi_device *spi = to_spi_device(dev);
+        struct ifx_spi_device *ifx_dev = spi_get_drvdata(spi);
+
+        if (!ifx_dev->power_status)
+                pm_runtime_suspend(dev);
+
+        return 0;
+}
+
+static const struct dev_pm_ops ifx_spi_pm = {
+        .resume = ifx_spi_pm_resume,
+        .suspend = ifx_spi_pm_suspend,
+        .runtime_resume = ifx_spi_pm_runtime_resume,
+        .runtime_suspend = ifx_spi_pm_runtime_suspend,
+        .runtime_idle = ifx_spi_pm_runtime_idle
+};
+
+static const struct spi_device_id ifx_id_table[] = {
+        {"ifx6160", 0},
+        {"ifx6260", 0},
+        { }
+};
+MODULE_DEVICE_TABLE(spi, ifx_id_table);
+
+/* spi operations */
+static const struct spi_driver ifx_spi_driver_6160 = {
+        .driver = {
+                .name = "ifx6160",
+                .bus = &spi_bus_type,
+                .pm = &ifx_spi_pm,
+                .owner = THIS_MODULE},
+        .probe = ifx_spi_spi_probe,
+        .shutdown = ifx_spi_spi_shutdown,
+        .remove = __devexit_p(ifx_spi_spi_remove),
+        .suspend = ifx_spi_spi_suspend,
+        .resume = ifx_spi_spi_resume,
+        .id_table = ifx_id_table
+};
+
+/**
+ *      ifx_spi_exit    -       module exit
+ *
+ *      Unload the module.
+ */
+
+static void __exit ifx_spi_exit(void)
+{
+        /* unregister */
+        tty_unregister_driver(tty_drv);
+        spi_unregister_driver((void *)&ifx_spi_driver_6160);
+}
+
+/**
+ *      ifx_spi_init            -       module entry point
+ *
+ *      Initialise the SPI and tty interfaces for the IFX SPI driver
+ *      We need to initialize upper-edge spi driver after the tty
+ *      driver because otherwise the spi probe will race
+ */
+
+static int __init ifx_spi_init(void)
+{
+        int result;
+
+        tty_drv = alloc_tty_driver(1);
+        if (!tty_drv) {
+                pr_err("%s: alloc_tty_driver failed", DRVNAME);
+                return -ENOMEM;
+        }
+
+        tty_drv->magic = TTY_DRIVER_MAGIC;
+        tty_drv->owner = THIS_MODULE;
+        tty_drv->driver_name = DRVNAME;
+        tty_drv->name = TTYNAME;
+        tty_drv->minor_start = IFX_SPI_TTY_ID;
+        tty_drv->num = 1;
+        tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
+        tty_drv->subtype = SERIAL_TYPE_NORMAL;
+        tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
+        tty_drv->init_termios = tty_std_termios;
+
+        tty_set_operations(tty_drv, &ifx_spi_serial_ops);
+
+        result = tty_register_driver(tty_drv);
+        if (result) {
+                pr_err("%s: tty_register_driver failed(%d)",
+                        DRVNAME, result);
+                return result;
+        }
+
+        result = spi_register_driver((void *)&ifx_spi_driver_6160);
+        if (result) {
+                pr_err("%s: spi_register_driver failed(%d)",
+                        DRVNAME, result);
+                tty_unregister_driver(tty_drv);
+        }
+        return result;
+}
+
+module_init(ifx_spi_init);
+module_exit(ifx_spi_exit);
+
+MODULE_AUTHOR("Intel");
+MODULE_DESCRIPTION("IFX6x60 spi driver");
+MODULE_LICENSE("GPL");
+MODULE_INFO(Version, "0.1-IFX6x60");
diff --git a/drivers/serial/ifx6x60.h b/drivers/serial/ifx6x60.h
new file mode 100644
index 000000000000..deb7b8d977dc
--- /dev/null
+++ b/drivers/serial/ifx6x60.h
@@ -0,0 +1,129 @@
+/****************************************************************************
+ *
+ * Driver for the IFX spi modem.
+ *
+ * Copyright (C) 2009, 2010 Intel Corp
+ * Jim Stanley <jim.stanley@intel.com>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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 Street, Fifth Floor, Boston, MA  02110-1301,
+ * USA
+ *
+ *
+ *
+ *****************************************************************************/
+#ifndef _IFX6X60_H
+#define _IFX6X60_H
+
+#define DRVNAME                         "ifx6x60"
+#define TTYNAME                         "ttyIFX"
+
+/* #define IFX_THROTTLE_CODE */
+
+#define IFX_SPI_MAX_MINORS              1
+#define IFX_SPI_TRANSFER_SIZE           2048
+#define IFX_SPI_FIFO_SIZE               4096
+
+#define IFX_SPI_HEADER_OVERHEAD         4
+#define IFX_RESET_TIMEOUT               msecs_to_jiffies(50)
+
+/* device flags bitfield definitions */
+#define IFX_SPI_STATE_PRESENT           0
+#define IFX_SPI_STATE_IO_IN_PROGRESS    1
+#define IFX_SPI_STATE_IO_READY          2
+#define IFX_SPI_STATE_TIMER_PENDING     3
+
+/* flow control bitfields */
+#define IFX_SPI_DCD                     0
+#define IFX_SPI_CTS                     1
+#define IFX_SPI_DSR                     2
+#define IFX_SPI_RI                      3
+#define IFX_SPI_DTR                     4
+#define IFX_SPI_RTS                     5
+#define IFX_SPI_TX_FC                   6
+#define IFX_SPI_RX_FC                   7
+#define IFX_SPI_UPDATE                  8
+
+#define IFX_SPI_PAYLOAD_SIZE            (IFX_SPI_TRANSFER_SIZE - \
+                                                IFX_SPI_HEADER_OVERHEAD)
+
+#define IFX_SPI_IRQ_TYPE                DETECT_EDGE_RISING
+#define IFX_SPI_GPIO_TARGET             0
+#define IFX_SPI_GPIO0                   0x105
+
+#define IFX_SPI_STATUS_TIMEOUT          (2000*HZ)
+
+/* values for bits in power status byte */
+#define IFX_SPI_POWER_DATA_PENDING      1
+#define IFX_SPI_POWER_SRDY              2
+
+struct ifx_spi_device {
+        /* Our SPI device */
+        struct spi_device *spi_dev;
+
+        /* Port specific data */
+        struct kfifo tx_fifo;
+        spinlock_t fifo_lock;
+        unsigned long signal_state;
+
+        /* TTY Layer logic */
+        struct tty_port tty_port;
+        struct device *tty_dev;
+        int minor;
+
+        /* Low level I/O work */
+        struct tasklet_struct io_work_tasklet;
+        unsigned long flags;
+        dma_addr_t rx_dma;
+        dma_addr_t tx_dma;
+
+        int is_6160;                            /* Modem type */
+
+        spinlock_t write_lock;
+        int write_pending;
+        spinlock_t power_lock;
+        unsigned char power_status;
+
+        unsigned char *rx_buffer;
+        unsigned char *tx_buffer;
+        dma_addr_t rx_bus;
+        dma_addr_t tx_bus;
+        unsigned char spi_more;
+        unsigned char spi_slave_cts;
+
+        struct timer_list spi_timer;
+
+        struct spi_message spi_msg;
+        struct spi_transfer spi_xfer;
+
+        struct {
+                /* gpio lines */
+                unsigned short srdy;            /* slave-ready gpio */
+                unsigned short mrdy;            /* master-ready gpio */
+                unsigned short reset;           /* modem-reset gpio */
+                unsigned short po;              /* modem-on gpio */
+                unsigned short reset_out;       /* modem-in-reset gpio */
+                /* state/stats */
+                int unack_srdy_int_nb;
+        } gpio;
+
+        /* modem reset */
+        unsigned long mdm_reset_state;
+#define MR_START        0
+#define MR_INPROGRESS   1
+#define MR_COMPLETE     2
+        wait_queue_head_t mdm_reset_wait;
+};
+
+#endif /* _IFX6X60_H */