ifx6x60: SPI protocol driver for Infineon 6x60 modem
authorRuss Gorby <richardx.r.gorby@intel.com>
Tue, 26 Oct 2010 13:13:52 +0000 (14:13 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Thu, 11 Nov 2010 19:35:57 +0000 (11:35 -0800)
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>
drivers/serial/Kconfig
drivers/serial/Makefile
drivers/serial/ifx6x60.c [new file with mode: 0644]
drivers/serial/ifx6x60.h [new file with mode: 0644]
include/linux/spi/ifx_modem.h [new file with mode: 0644]

index aff9dcd051c65c6eac6adaea5b4088ebe6e74408..0b9cc17b380b13667a532d0023b928737c066b15 100644 (file)
@@ -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
index c5705765454f997c6865e5d4dfaa2ec8cefdc75d..783638b10698bf9d076779c29f6ec995db4a458b 100644 (file)
@@ -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 (file)
index 0000000..b9b7e06
--- /dev/null
@@ -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 (file)
index 0000000..deb7b8d
--- /dev/null
@@ -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 */
diff --git a/include/linux/spi/ifx_modem.h b/include/linux/spi/ifx_modem.h
new file mode 100644 (file)
index 0000000..a68f3b1
--- /dev/null
@@ -0,0 +1,14 @@
+#ifndef LINUX_IFX_MODEM_H
+#define LINUX_IFX_MODEM_H
+
+struct ifx_modem_platform_data {
+       unsigned short rst_out; /* modem reset out */
+       unsigned short pwr_on;  /* power on */
+       unsigned short rst_pmu; /* reset modem */
+       unsigned short tx_pwr;  /* modem power threshold */
+       unsigned short srdy;    /* SRDY */
+       unsigned short mrdy;    /* MRDY */
+       unsigned short is_6160; /* Modem type */
+};
+
+#endif