/****************************************************************************
*
* 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 <russ.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/dma-mapping.h>
#include <linux/module.h>
#include <linux/termios.h>
#include <linux/tty.h>
#include <linux/device.h>
#include <linux/spi/spi.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/pm.h>
#include <linux/pm_runtime.h>
#include <linux/spi/ifx_modem.h>
#include <linux/delay.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_MODE SPI_MODE_1
#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_bpw = 16; /* 8, 16 or 32 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)
{
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
* @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,
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 = ifx_dev->spi_dev->max_speed_hz;
/* ifx_dev->spi_xfer.speed_hz = 390625; */
ifx_dev->spi_xfer.bits_per_word = spi_bpw;
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->use_dma) {
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;
}
tty_port_init(pport);
pport->ops = &ifx_tty_port_ops;
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;
struct ifx_spi_device *ifx_dev;
if (saved_ifx_dev) {
dev_dbg(&spi->dev, "ignoring subsequent detection");
return -ENODEV;
}
pl_data = (struct ifx_modem_platform_data *)spi->dev.platform_data;
if (!pl_data) {
dev_err(&spi->dev, "missing platform data!");
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->modem = pl_data->modem_type;
ifx_dev->use_dma = pl_data->use_dma;
ifx_dev->max_hz = pl_data->max_hz;
/* initialize spi mode, etc */
spi->max_speed_hz = ifx_dev->max_hz;
spi->mode = IFX_SPI_MODE | (SPI_LOOP & spi->mode);
spi->bits_per_word = spi_bpw;
ret = spi_setup(spi);
if (ret) {
dev_err(&spi->dev, "SPI setup wasn't successful %d", ret);
return -ENODEV;
}
/* 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.parent,
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.parent,
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;
}
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;
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_ret7;
}
/* 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_ret7:
free_irq(gpio_to_irq(ifx_dev->gpio.reset_out), (void *)ifx_dev);
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 struct spi_driver ifx_spi_driver = {
.driver = {
.name = DRVNAME,
.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);
}
/**
* 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->driver_name = DRVNAME;
tty_drv->name = TTYNAME;
tty_drv->minor_start = IFX_SPI_TTY_ID;
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);
put_tty_driver(tty_drv);
return result;
}
result = spi_register_driver((void *)&ifx_spi_driver);
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");
