kernel-fxtec-pro1x/drivers/usb/serial/whiteheat.c
Alan Cox 00a0d0d65b tty: remove filp from the USB tty ioctls
We don't use it so we can trim it from here as we try and stamp the file
object dependencies out of the serial code.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 11:59:14 -08:00

1565 lines
44 KiB
C

/*
* USB ConnectTech WhiteHEAT driver
*
* Copyright (C) 2002
* Connect Tech Inc.
*
* Copyright (C) 1999 - 2001
* Greg Kroah-Hartman (greg@kroah.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* See Documentation/usb/usb-serial.txt for more information on using this
* driver
*
* (10/09/2002) Stuart MacDonald (stuartm@connecttech.com)
* Upgrade to full working driver
*
* (05/30/2001) gkh
* switched from using spinlock to a semaphore, which fixes lots of
* problems.
*
* (04/08/2001) gb
* Identify version on module load.
*
* 2001_Mar_19 gkh
* Fixed MOD_INC and MOD_DEC logic, the ability to open a port more
* than once, and the got the proper usb_device_id table entries so
* the driver works again.
*
* (11/01/2000) Adam J. Richter
* usb_device_id table support
*
* (10/05/2000) gkh
* Fixed bug with urb->dev not being set properly, now that the usb
* core needs it.
*
* (10/03/2000) smd
* firmware is improved to guard against crap sent to device
* firmware now replies CMD_FAILURE on bad things
* read_callback fix you provided for private info struct
* command_finished now indicates success or fail
* setup_port struct now packed to avoid gcc padding
* firmware uses 1 based port numbering, driver now handles that
*
* (09/11/2000) gkh
* Removed DEBUG #ifdefs with call to usb_serial_debug_data
*
* (07/19/2000) gkh
* Added module_init and module_exit functions to handle the fact that this
* driver is a loadable module now.
* Fixed bug with port->minor that was found by Al Borchers
*
* (07/04/2000) gkh
* Added support for port settings. Baud rate can now be changed. Line
* signals are not transferred to and from the tty layer yet, but things
* seem to be working well now.
*
* (05/04/2000) gkh
* First cut at open and close commands. Data can flow through the ports at
* default speeds now.
*
* (03/26/2000) gkh
* Split driver up into device specific pieces.
*
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <asm/termbits.h>
#include <linux/usb.h>
#include <linux/serial_reg.h>
#include <linux/serial.h>
#include <linux/usb/serial.h>
#include <linux/firmware.h>
#include <linux/ihex.h>
#include "whiteheat.h" /* WhiteHEAT specific commands */
static int debug;
#ifndef CMSPAR
#define CMSPAR 0
#endif
/*
* Version Information
*/
#define DRIVER_VERSION "v2.0"
#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Stuart MacDonald <stuartm@connecttech.com>"
#define DRIVER_DESC "USB ConnectTech WhiteHEAT driver"
#define CONNECT_TECH_VENDOR_ID 0x0710
#define CONNECT_TECH_FAKE_WHITE_HEAT_ID 0x0001
#define CONNECT_TECH_WHITE_HEAT_ID 0x8001
/*
ID tables for whiteheat are unusual, because we want to different
things for different versions of the device. Eventually, this
will be doable from a single table. But, for now, we define two
separate ID tables, and then a third table that combines them
just for the purpose of exporting the autoloading information.
*/
static const struct usb_device_id id_table_std[] = {
{ USB_DEVICE(CONNECT_TECH_VENDOR_ID, CONNECT_TECH_WHITE_HEAT_ID) },
{ } /* Terminating entry */
};
static const struct usb_device_id id_table_prerenumeration[] = {
{ USB_DEVICE(CONNECT_TECH_VENDOR_ID, CONNECT_TECH_FAKE_WHITE_HEAT_ID) },
{ } /* Terminating entry */
};
static const struct usb_device_id id_table_combined[] = {
{ USB_DEVICE(CONNECT_TECH_VENDOR_ID, CONNECT_TECH_WHITE_HEAT_ID) },
{ USB_DEVICE(CONNECT_TECH_VENDOR_ID, CONNECT_TECH_FAKE_WHITE_HEAT_ID) },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, id_table_combined);
static struct usb_driver whiteheat_driver = {
.name = "whiteheat",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.id_table = id_table_combined,
.no_dynamic_id = 1,
};
/* function prototypes for the Connect Tech WhiteHEAT prerenumeration device */
static int whiteheat_firmware_download(struct usb_serial *serial,
const struct usb_device_id *id);
static int whiteheat_firmware_attach(struct usb_serial *serial);
/* function prototypes for the Connect Tech WhiteHEAT serial converter */
static int whiteheat_attach(struct usb_serial *serial);
static void whiteheat_release(struct usb_serial *serial);
static int whiteheat_open(struct tty_struct *tty,
struct usb_serial_port *port);
static void whiteheat_close(struct usb_serial_port *port);
static int whiteheat_write(struct tty_struct *tty,
struct usb_serial_port *port,
const unsigned char *buf, int count);
static int whiteheat_write_room(struct tty_struct *tty);
static int whiteheat_ioctl(struct tty_struct *tty,
unsigned int cmd, unsigned long arg);
static void whiteheat_set_termios(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old);
static int whiteheat_tiocmget(struct tty_struct *tty);
static int whiteheat_tiocmset(struct tty_struct *tty,
unsigned int set, unsigned int clear);
static void whiteheat_break_ctl(struct tty_struct *tty, int break_state);
static int whiteheat_chars_in_buffer(struct tty_struct *tty);
static void whiteheat_throttle(struct tty_struct *tty);
static void whiteheat_unthrottle(struct tty_struct *tty);
static void whiteheat_read_callback(struct urb *urb);
static void whiteheat_write_callback(struct urb *urb);
static struct usb_serial_driver whiteheat_fake_device = {
.driver = {
.owner = THIS_MODULE,
.name = "whiteheatnofirm",
},
.description = "Connect Tech - WhiteHEAT - (prerenumeration)",
.usb_driver = &whiteheat_driver,
.id_table = id_table_prerenumeration,
.num_ports = 1,
.probe = whiteheat_firmware_download,
.attach = whiteheat_firmware_attach,
};
static struct usb_serial_driver whiteheat_device = {
.driver = {
.owner = THIS_MODULE,
.name = "whiteheat",
},
.description = "Connect Tech - WhiteHEAT",
.usb_driver = &whiteheat_driver,
.id_table = id_table_std,
.num_ports = 4,
.attach = whiteheat_attach,
.release = whiteheat_release,
.open = whiteheat_open,
.close = whiteheat_close,
.write = whiteheat_write,
.write_room = whiteheat_write_room,
.ioctl = whiteheat_ioctl,
.set_termios = whiteheat_set_termios,
.break_ctl = whiteheat_break_ctl,
.tiocmget = whiteheat_tiocmget,
.tiocmset = whiteheat_tiocmset,
.chars_in_buffer = whiteheat_chars_in_buffer,
.throttle = whiteheat_throttle,
.unthrottle = whiteheat_unthrottle,
.read_bulk_callback = whiteheat_read_callback,
.write_bulk_callback = whiteheat_write_callback,
};
struct whiteheat_command_private {
struct mutex mutex;
__u8 port_running;
__u8 command_finished;
wait_queue_head_t wait_command; /* for handling sleeping whilst
waiting for a command to
finish */
__u8 result_buffer[64];
};
#define THROTTLED 0x01
#define ACTUALLY_THROTTLED 0x02
static int urb_pool_size = 8;
struct whiteheat_urb_wrap {
struct list_head list;
struct urb *urb;
};
struct whiteheat_private {
spinlock_t lock;
__u8 flags;
__u8 mcr; /* FIXME: no locking on mcr */
struct list_head rx_urbs_free;
struct list_head rx_urbs_submitted;
struct list_head rx_urb_q;
struct work_struct rx_work;
struct usb_serial_port *port;
struct list_head tx_urbs_free;
struct list_head tx_urbs_submitted;
struct mutex deathwarrant;
};
/* local function prototypes */
static int start_command_port(struct usb_serial *serial);
static void stop_command_port(struct usb_serial *serial);
static void command_port_write_callback(struct urb *urb);
static void command_port_read_callback(struct urb *urb);
static int start_port_read(struct usb_serial_port *port);
static struct whiteheat_urb_wrap *urb_to_wrap(struct urb *urb,
struct list_head *head);
static struct list_head *list_first(struct list_head *head);
static void rx_data_softint(struct work_struct *work);
static int firm_send_command(struct usb_serial_port *port, __u8 command,
__u8 *data, __u8 datasize);
static int firm_open(struct usb_serial_port *port);
static int firm_close(struct usb_serial_port *port);
static void firm_setup_port(struct tty_struct *tty);
static int firm_set_rts(struct usb_serial_port *port, __u8 onoff);
static int firm_set_dtr(struct usb_serial_port *port, __u8 onoff);
static int firm_set_break(struct usb_serial_port *port, __u8 onoff);
static int firm_purge(struct usb_serial_port *port, __u8 rxtx);
static int firm_get_dtr_rts(struct usb_serial_port *port);
static int firm_report_tx_done(struct usb_serial_port *port);
#define COMMAND_PORT 4
#define COMMAND_TIMEOUT (2*HZ) /* 2 second timeout for a command */
#define COMMAND_TIMEOUT_MS 2000
#define CLOSING_DELAY (30 * HZ)
/*****************************************************************************
* Connect Tech's White Heat prerenumeration driver functions
*****************************************************************************/
/* steps to download the firmware to the WhiteHEAT device:
- hold the reset (by writing to the reset bit of the CPUCS register)
- download the VEND_AX.HEX file to the chip using VENDOR_REQUEST-ANCHOR_LOAD
- release the reset (by writing to the CPUCS register)
- download the WH.HEX file for all addresses greater than 0x1b3f using
VENDOR_REQUEST-ANCHOR_EXTERNAL_RAM_LOAD
- hold the reset
- download the WH.HEX file for all addresses less than 0x1b40 using
VENDOR_REQUEST_ANCHOR_LOAD
- release the reset
- device renumerated itself and comes up as new device id with all
firmware download completed.
*/
static int whiteheat_firmware_download(struct usb_serial *serial,
const struct usb_device_id *id)
{
int response, ret = -ENOENT;
const struct firmware *loader_fw = NULL, *firmware_fw = NULL;
const struct ihex_binrec *record;
dbg("%s", __func__);
if (request_ihex_firmware(&firmware_fw, "whiteheat.fw",
&serial->dev->dev)) {
dev_err(&serial->dev->dev,
"%s - request \"whiteheat.fw\" failed\n", __func__);
goto out;
}
if (request_ihex_firmware(&loader_fw, "whiteheat_loader.fw",
&serial->dev->dev)) {
dev_err(&serial->dev->dev,
"%s - request \"whiteheat_loader.fw\" failed\n",
__func__);
goto out;
}
ret = 0;
response = ezusb_set_reset (serial, 1);
record = (const struct ihex_binrec *)loader_fw->data;
while (record) {
response = ezusb_writememory (serial, be32_to_cpu(record->addr),
(unsigned char *)record->data,
be16_to_cpu(record->len), 0xa0);
if (response < 0) {
dev_err(&serial->dev->dev, "%s - ezusb_writememory "
"failed for loader (%d %04X %p %d)\n",
__func__, response, be32_to_cpu(record->addr),
record->data, be16_to_cpu(record->len));
break;
}
record = ihex_next_binrec(record);
}
response = ezusb_set_reset(serial, 0);
record = (const struct ihex_binrec *)firmware_fw->data;
while (record && be32_to_cpu(record->addr) < 0x1b40)
record = ihex_next_binrec(record);
while (record) {
response = ezusb_writememory (serial, be32_to_cpu(record->addr),
(unsigned char *)record->data,
be16_to_cpu(record->len), 0xa3);
if (response < 0) {
dev_err(&serial->dev->dev, "%s - ezusb_writememory "
"failed for first firmware step "
"(%d %04X %p %d)\n", __func__, response,
be32_to_cpu(record->addr), record->data,
be16_to_cpu(record->len));
break;
}
++record;
}
response = ezusb_set_reset(serial, 1);
record = (const struct ihex_binrec *)firmware_fw->data;
while (record && be32_to_cpu(record->addr) < 0x1b40) {
response = ezusb_writememory (serial, be32_to_cpu(record->addr),
(unsigned char *)record->data,
be16_to_cpu(record->len), 0xa0);
if (response < 0) {
dev_err(&serial->dev->dev, "%s - ezusb_writememory "
"failed for second firmware step "
"(%d %04X %p %d)\n", __func__, response,
be32_to_cpu(record->addr), record->data,
be16_to_cpu(record->len));
break;
}
++record;
}
ret = 0;
response = ezusb_set_reset (serial, 0);
out:
release_firmware(loader_fw);
release_firmware(firmware_fw);
return ret;
}
static int whiteheat_firmware_attach(struct usb_serial *serial)
{
/* We want this device to fail to have a driver assigned to it */
return 1;
}
/*****************************************************************************
* Connect Tech's White Heat serial driver functions
*****************************************************************************/
static int whiteheat_attach(struct usb_serial *serial)
{
struct usb_serial_port *command_port;
struct whiteheat_command_private *command_info;
struct usb_serial_port *port;
struct whiteheat_private *info;
struct whiteheat_hw_info *hw_info;
int pipe;
int ret;
int alen;
__u8 *command;
__u8 *result;
int i;
int j;
struct urb *urb;
int buf_size;
struct whiteheat_urb_wrap *wrap;
struct list_head *tmp;
command_port = serial->port[COMMAND_PORT];
pipe = usb_sndbulkpipe(serial->dev,
command_port->bulk_out_endpointAddress);
command = kmalloc(2, GFP_KERNEL);
if (!command)
goto no_command_buffer;
command[0] = WHITEHEAT_GET_HW_INFO;
command[1] = 0;
result = kmalloc(sizeof(*hw_info) + 1, GFP_KERNEL);
if (!result)
goto no_result_buffer;
/*
* When the module is reloaded the firmware is still there and
* the endpoints are still in the usb core unchanged. This is the
* unlinking bug in disguise. Same for the call below.
*/
usb_clear_halt(serial->dev, pipe);
ret = usb_bulk_msg(serial->dev, pipe, command, 2,
&alen, COMMAND_TIMEOUT_MS);
if (ret) {
dev_err(&serial->dev->dev, "%s: Couldn't send command [%d]\n",
serial->type->description, ret);
goto no_firmware;
} else if (alen != 2) {
dev_err(&serial->dev->dev, "%s: Send command incomplete [%d]\n",
serial->type->description, alen);
goto no_firmware;
}
pipe = usb_rcvbulkpipe(serial->dev,
command_port->bulk_in_endpointAddress);
/* See the comment on the usb_clear_halt() above */
usb_clear_halt(serial->dev, pipe);
ret = usb_bulk_msg(serial->dev, pipe, result,
sizeof(*hw_info) + 1, &alen, COMMAND_TIMEOUT_MS);
if (ret) {
dev_err(&serial->dev->dev, "%s: Couldn't get results [%d]\n",
serial->type->description, ret);
goto no_firmware;
} else if (alen != sizeof(*hw_info) + 1) {
dev_err(&serial->dev->dev, "%s: Get results incomplete [%d]\n",
serial->type->description, alen);
goto no_firmware;
} else if (result[0] != command[0]) {
dev_err(&serial->dev->dev, "%s: Command failed [%d]\n",
serial->type->description, result[0]);
goto no_firmware;
}
hw_info = (struct whiteheat_hw_info *)&result[1];
dev_info(&serial->dev->dev, "%s: Driver %s: Firmware v%d.%02d\n",
serial->type->description, DRIVER_VERSION,
hw_info->sw_major_rev, hw_info->sw_minor_rev);
for (i = 0; i < serial->num_ports; i++) {
port = serial->port[i];
info = kmalloc(sizeof(struct whiteheat_private), GFP_KERNEL);
if (info == NULL) {
dev_err(&port->dev,
"%s: Out of memory for port structures\n",
serial->type->description);
goto no_private;
}
spin_lock_init(&info->lock);
mutex_init(&info->deathwarrant);
info->flags = 0;
info->mcr = 0;
INIT_WORK(&info->rx_work, rx_data_softint);
info->port = port;
INIT_LIST_HEAD(&info->rx_urbs_free);
INIT_LIST_HEAD(&info->rx_urbs_submitted);
INIT_LIST_HEAD(&info->rx_urb_q);
INIT_LIST_HEAD(&info->tx_urbs_free);
INIT_LIST_HEAD(&info->tx_urbs_submitted);
for (j = 0; j < urb_pool_size; j++) {
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb) {
dev_err(&port->dev, "No free urbs available\n");
goto no_rx_urb;
}
buf_size = port->read_urb->transfer_buffer_length;
urb->transfer_buffer = kmalloc(buf_size, GFP_KERNEL);
if (!urb->transfer_buffer) {
dev_err(&port->dev,
"Couldn't allocate urb buffer\n");
goto no_rx_buf;
}
wrap = kmalloc(sizeof(*wrap), GFP_KERNEL);
if (!wrap) {
dev_err(&port->dev,
"Couldn't allocate urb wrapper\n");
goto no_rx_wrap;
}
usb_fill_bulk_urb(urb, serial->dev,
usb_rcvbulkpipe(serial->dev,
port->bulk_in_endpointAddress),
urb->transfer_buffer, buf_size,
whiteheat_read_callback, port);
wrap->urb = urb;
list_add(&wrap->list, &info->rx_urbs_free);
urb = usb_alloc_urb(0, GFP_KERNEL);
if (!urb) {
dev_err(&port->dev, "No free urbs available\n");
goto no_tx_urb;
}
buf_size = port->write_urb->transfer_buffer_length;
urb->transfer_buffer = kmalloc(buf_size, GFP_KERNEL);
if (!urb->transfer_buffer) {
dev_err(&port->dev,
"Couldn't allocate urb buffer\n");
goto no_tx_buf;
}
wrap = kmalloc(sizeof(*wrap), GFP_KERNEL);
if (!wrap) {
dev_err(&port->dev,
"Couldn't allocate urb wrapper\n");
goto no_tx_wrap;
}
usb_fill_bulk_urb(urb, serial->dev,
usb_sndbulkpipe(serial->dev,
port->bulk_out_endpointAddress),
urb->transfer_buffer, buf_size,
whiteheat_write_callback, port);
wrap->urb = urb;
list_add(&wrap->list, &info->tx_urbs_free);
}
usb_set_serial_port_data(port, info);
}
command_info = kmalloc(sizeof(struct whiteheat_command_private),
GFP_KERNEL);
if (command_info == NULL) {
dev_err(&serial->dev->dev,
"%s: Out of memory for port structures\n",
serial->type->description);
goto no_command_private;
}
mutex_init(&command_info->mutex);
command_info->port_running = 0;
init_waitqueue_head(&command_info->wait_command);
usb_set_serial_port_data(command_port, command_info);
command_port->write_urb->complete = command_port_write_callback;
command_port->read_urb->complete = command_port_read_callback;
kfree(result);
kfree(command);
return 0;
no_firmware:
/* Firmware likely not running */
dev_err(&serial->dev->dev,
"%s: Unable to retrieve firmware version, try replugging\n",
serial->type->description);
dev_err(&serial->dev->dev,
"%s: If the firmware is not running (status led not blinking)\n",
serial->type->description);
dev_err(&serial->dev->dev,
"%s: please contact support@connecttech.com\n",
serial->type->description);
kfree(result);
return -ENODEV;
no_command_private:
for (i = serial->num_ports - 1; i >= 0; i--) {
port = serial->port[i];
info = usb_get_serial_port_data(port);
for (j = urb_pool_size - 1; j >= 0; j--) {
tmp = list_first(&info->tx_urbs_free);
list_del(tmp);
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
kfree(wrap);
no_tx_wrap:
kfree(urb->transfer_buffer);
no_tx_buf:
usb_free_urb(urb);
no_tx_urb:
tmp = list_first(&info->rx_urbs_free);
list_del(tmp);
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
kfree(wrap);
no_rx_wrap:
kfree(urb->transfer_buffer);
no_rx_buf:
usb_free_urb(urb);
no_rx_urb:
;
}
kfree(info);
no_private:
;
}
kfree(result);
no_result_buffer:
kfree(command);
no_command_buffer:
return -ENOMEM;
}
static void whiteheat_release(struct usb_serial *serial)
{
struct usb_serial_port *command_port;
struct usb_serial_port *port;
struct whiteheat_private *info;
struct whiteheat_urb_wrap *wrap;
struct urb *urb;
struct list_head *tmp;
struct list_head *tmp2;
int i;
dbg("%s", __func__);
/* free up our private data for our command port */
command_port = serial->port[COMMAND_PORT];
kfree(usb_get_serial_port_data(command_port));
for (i = 0; i < serial->num_ports; i++) {
port = serial->port[i];
info = usb_get_serial_port_data(port);
list_for_each_safe(tmp, tmp2, &info->rx_urbs_free) {
list_del(tmp);
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
kfree(wrap);
kfree(urb->transfer_buffer);
usb_free_urb(urb);
}
list_for_each_safe(tmp, tmp2, &info->tx_urbs_free) {
list_del(tmp);
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
kfree(wrap);
kfree(urb->transfer_buffer);
usb_free_urb(urb);
}
kfree(info);
}
}
static int whiteheat_open(struct tty_struct *tty, struct usb_serial_port *port)
{
int retval = 0;
dbg("%s - port %d", __func__, port->number);
retval = start_command_port(port->serial);
if (retval)
goto exit;
if (tty)
tty->low_latency = 1;
/* send an open port command */
retval = firm_open(port);
if (retval) {
stop_command_port(port->serial);
goto exit;
}
retval = firm_purge(port, WHITEHEAT_PURGE_RX | WHITEHEAT_PURGE_TX);
if (retval) {
firm_close(port);
stop_command_port(port->serial);
goto exit;
}
if (tty)
firm_setup_port(tty);
/* Work around HCD bugs */
usb_clear_halt(port->serial->dev, port->read_urb->pipe);
usb_clear_halt(port->serial->dev, port->write_urb->pipe);
/* Start reading from the device */
retval = start_port_read(port);
if (retval) {
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",
__func__, retval);
firm_close(port);
stop_command_port(port->serial);
goto exit;
}
exit:
dbg("%s - exit, retval = %d", __func__, retval);
return retval;
}
static void whiteheat_close(struct usb_serial_port *port)
{
struct whiteheat_private *info = usb_get_serial_port_data(port);
struct whiteheat_urb_wrap *wrap;
struct urb *urb;
struct list_head *tmp;
struct list_head *tmp2;
dbg("%s - port %d", __func__, port->number);
firm_report_tx_done(port);
firm_close(port);
/* shutdown our bulk reads and writes */
mutex_lock(&info->deathwarrant);
spin_lock_irq(&info->lock);
list_for_each_safe(tmp, tmp2, &info->rx_urbs_submitted) {
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
list_del(tmp);
spin_unlock_irq(&info->lock);
usb_kill_urb(urb);
spin_lock_irq(&info->lock);
list_add(tmp, &info->rx_urbs_free);
}
list_for_each_safe(tmp, tmp2, &info->rx_urb_q)
list_move(tmp, &info->rx_urbs_free);
list_for_each_safe(tmp, tmp2, &info->tx_urbs_submitted) {
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
list_del(tmp);
spin_unlock_irq(&info->lock);
usb_kill_urb(urb);
spin_lock_irq(&info->lock);
list_add(tmp, &info->tx_urbs_free);
}
spin_unlock_irq(&info->lock);
mutex_unlock(&info->deathwarrant);
stop_command_port(port->serial);
}
static int whiteheat_write(struct tty_struct *tty,
struct usb_serial_port *port, const unsigned char *buf, int count)
{
struct usb_serial *serial = port->serial;
struct whiteheat_private *info = usb_get_serial_port_data(port);
struct whiteheat_urb_wrap *wrap;
struct urb *urb;
int result;
int bytes;
int sent = 0;
unsigned long flags;
struct list_head *tmp;
dbg("%s - port %d", __func__, port->number);
if (count == 0) {
dbg("%s - write request of 0 bytes", __func__);
return (0);
}
while (count) {
spin_lock_irqsave(&info->lock, flags);
if (list_empty(&info->tx_urbs_free)) {
spin_unlock_irqrestore(&info->lock, flags);
break;
}
tmp = list_first(&info->tx_urbs_free);
list_del(tmp);
spin_unlock_irqrestore(&info->lock, flags);
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
bytes = (count > port->bulk_out_size) ?
port->bulk_out_size : count;
memcpy(urb->transfer_buffer, buf + sent, bytes);
usb_serial_debug_data(debug, &port->dev,
__func__, bytes, urb->transfer_buffer);
urb->dev = serial->dev;
urb->transfer_buffer_length = bytes;
result = usb_submit_urb(urb, GFP_ATOMIC);
if (result) {
dev_err(&port->dev,
"%s - failed submitting write urb, error %d\n",
__func__, result);
sent = result;
spin_lock_irqsave(&info->lock, flags);
list_add(tmp, &info->tx_urbs_free);
spin_unlock_irqrestore(&info->lock, flags);
break;
} else {
sent += bytes;
count -= bytes;
spin_lock_irqsave(&info->lock, flags);
list_add(tmp, &info->tx_urbs_submitted);
spin_unlock_irqrestore(&info->lock, flags);
}
}
return sent;
}
static int whiteheat_write_room(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct whiteheat_private *info = usb_get_serial_port_data(port);
struct list_head *tmp;
int room = 0;
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&info->lock, flags);
list_for_each(tmp, &info->tx_urbs_free)
room++;
spin_unlock_irqrestore(&info->lock, flags);
room *= port->bulk_out_size;
dbg("%s - returns %d", __func__, room);
return (room);
}
static int whiteheat_tiocmget(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct whiteheat_private *info = usb_get_serial_port_data(port);
unsigned int modem_signals = 0;
dbg("%s - port %d", __func__, port->number);
firm_get_dtr_rts(port);
if (info->mcr & UART_MCR_DTR)
modem_signals |= TIOCM_DTR;
if (info->mcr & UART_MCR_RTS)
modem_signals |= TIOCM_RTS;
return modem_signals;
}
static int whiteheat_tiocmset(struct tty_struct *tty,
unsigned int set, unsigned int clear)
{
struct usb_serial_port *port = tty->driver_data;
struct whiteheat_private *info = usb_get_serial_port_data(port);
dbg("%s - port %d", __func__, port->number);
if (set & TIOCM_RTS)
info->mcr |= UART_MCR_RTS;
if (set & TIOCM_DTR)
info->mcr |= UART_MCR_DTR;
if (clear & TIOCM_RTS)
info->mcr &= ~UART_MCR_RTS;
if (clear & TIOCM_DTR)
info->mcr &= ~UART_MCR_DTR;
firm_set_dtr(port, info->mcr & UART_MCR_DTR);
firm_set_rts(port, info->mcr & UART_MCR_RTS);
return 0;
}
static int whiteheat_ioctl(struct tty_struct *tty,
unsigned int cmd, unsigned long arg)
{
struct usb_serial_port *port = tty->driver_data;
struct serial_struct serstruct;
void __user *user_arg = (void __user *)arg;
dbg("%s - port %d, cmd 0x%.4x", __func__, port->number, cmd);
switch (cmd) {
case TIOCGSERIAL:
memset(&serstruct, 0, sizeof(serstruct));
serstruct.type = PORT_16654;
serstruct.line = port->serial->minor;
serstruct.port = port->number;
serstruct.flags = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
serstruct.xmit_fifo_size = port->bulk_out_size;
serstruct.custom_divisor = 0;
serstruct.baud_base = 460800;
serstruct.close_delay = CLOSING_DELAY;
serstruct.closing_wait = CLOSING_DELAY;
if (copy_to_user(user_arg, &serstruct, sizeof(serstruct)))
return -EFAULT;
break;
default:
break;
}
return -ENOIOCTLCMD;
}
static void whiteheat_set_termios(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios)
{
firm_setup_port(tty);
}
static void whiteheat_break_ctl(struct tty_struct *tty, int break_state)
{
struct usb_serial_port *port = tty->driver_data;
firm_set_break(port, break_state);
}
static int whiteheat_chars_in_buffer(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct whiteheat_private *info = usb_get_serial_port_data(port);
struct list_head *tmp;
struct whiteheat_urb_wrap *wrap;
int chars = 0;
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&info->lock, flags);
list_for_each(tmp, &info->tx_urbs_submitted) {
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
chars += wrap->urb->transfer_buffer_length;
}
spin_unlock_irqrestore(&info->lock, flags);
dbg("%s - returns %d", __func__, chars);
return chars;
}
static void whiteheat_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct whiteheat_private *info = usb_get_serial_port_data(port);
dbg("%s - port %d", __func__, port->number);
spin_lock_irq(&info->lock);
info->flags |= THROTTLED;
spin_unlock_irq(&info->lock);
}
static void whiteheat_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct whiteheat_private *info = usb_get_serial_port_data(port);
int actually_throttled;
dbg("%s - port %d", __func__, port->number);
spin_lock_irq(&info->lock);
actually_throttled = info->flags & ACTUALLY_THROTTLED;
info->flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
spin_unlock_irq(&info->lock);
if (actually_throttled)
rx_data_softint(&info->rx_work);
}
/*****************************************************************************
* Connect Tech's White Heat callback routines
*****************************************************************************/
static void command_port_write_callback(struct urb *urb)
{
int status = urb->status;
dbg("%s", __func__);
if (status) {
dbg("nonzero urb status: %d", status);
return;
}
}
static void command_port_read_callback(struct urb *urb)
{
struct usb_serial_port *command_port = urb->context;
struct whiteheat_command_private *command_info;
int status = urb->status;
unsigned char *data = urb->transfer_buffer;
int result;
dbg("%s", __func__);
command_info = usb_get_serial_port_data(command_port);
if (!command_info) {
dbg("%s - command_info is NULL, exiting.", __func__);
return;
}
if (status) {
dbg("%s - nonzero urb status: %d", __func__, status);
if (status != -ENOENT)
command_info->command_finished = WHITEHEAT_CMD_FAILURE;
wake_up(&command_info->wait_command);
return;
}
usb_serial_debug_data(debug, &command_port->dev,
__func__, urb->actual_length, data);
if (data[0] == WHITEHEAT_CMD_COMPLETE) {
command_info->command_finished = WHITEHEAT_CMD_COMPLETE;
wake_up(&command_info->wait_command);
} else if (data[0] == WHITEHEAT_CMD_FAILURE) {
command_info->command_finished = WHITEHEAT_CMD_FAILURE;
wake_up(&command_info->wait_command);
} else if (data[0] == WHITEHEAT_EVENT) {
/* These are unsolicited reports from the firmware, hence no
waiting command to wakeup */
dbg("%s - event received", __func__);
} else if (data[0] == WHITEHEAT_GET_DTR_RTS) {
memcpy(command_info->result_buffer, &data[1],
urb->actual_length - 1);
command_info->command_finished = WHITEHEAT_CMD_COMPLETE;
wake_up(&command_info->wait_command);
} else
dbg("%s - bad reply from firmware", __func__);
/* Continue trying to always read */
command_port->read_urb->dev = command_port->serial->dev;
result = usb_submit_urb(command_port->read_urb, GFP_ATOMIC);
if (result)
dbg("%s - failed resubmitting read urb, error %d",
__func__, result);
}
static void whiteheat_read_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
struct whiteheat_urb_wrap *wrap;
unsigned char *data = urb->transfer_buffer;
struct whiteheat_private *info = usb_get_serial_port_data(port);
int status = urb->status;
dbg("%s - port %d", __func__, port->number);
spin_lock(&info->lock);
wrap = urb_to_wrap(urb, &info->rx_urbs_submitted);
if (!wrap) {
spin_unlock(&info->lock);
dev_err(&port->dev, "%s - Not my urb!\n", __func__);
return;
}
list_del(&wrap->list);
spin_unlock(&info->lock);
if (status) {
dbg("%s - nonzero read bulk status received: %d",
__func__, status);
spin_lock(&info->lock);
list_add(&wrap->list, &info->rx_urbs_free);
spin_unlock(&info->lock);
return;
}
usb_serial_debug_data(debug, &port->dev,
__func__, urb->actual_length, data);
spin_lock(&info->lock);
list_add_tail(&wrap->list, &info->rx_urb_q);
if (info->flags & THROTTLED) {
info->flags |= ACTUALLY_THROTTLED;
spin_unlock(&info->lock);
return;
}
spin_unlock(&info->lock);
schedule_work(&info->rx_work);
}
static void whiteheat_write_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
struct whiteheat_private *info = usb_get_serial_port_data(port);
struct whiteheat_urb_wrap *wrap;
int status = urb->status;
dbg("%s - port %d", __func__, port->number);
spin_lock(&info->lock);
wrap = urb_to_wrap(urb, &info->tx_urbs_submitted);
if (!wrap) {
spin_unlock(&info->lock);
dev_err(&port->dev, "%s - Not my urb!\n", __func__);
return;
}
list_move(&wrap->list, &info->tx_urbs_free);
spin_unlock(&info->lock);
if (status) {
dbg("%s - nonzero write bulk status received: %d",
__func__, status);
return;
}
usb_serial_port_softint(port);
}
/*****************************************************************************
* Connect Tech's White Heat firmware interface
*****************************************************************************/
static int firm_send_command(struct usb_serial_port *port, __u8 command,
__u8 *data, __u8 datasize)
{
struct usb_serial_port *command_port;
struct whiteheat_command_private *command_info;
struct whiteheat_private *info;
__u8 *transfer_buffer;
int retval = 0;
int t;
dbg("%s - command %d", __func__, command);
command_port = port->serial->port[COMMAND_PORT];
command_info = usb_get_serial_port_data(command_port);
mutex_lock(&command_info->mutex);
command_info->command_finished = false;
transfer_buffer = (__u8 *)command_port->write_urb->transfer_buffer;
transfer_buffer[0] = command;
memcpy(&transfer_buffer[1], data, datasize);
command_port->write_urb->transfer_buffer_length = datasize + 1;
command_port->write_urb->dev = port->serial->dev;
retval = usb_submit_urb(command_port->write_urb, GFP_NOIO);
if (retval) {
dbg("%s - submit urb failed", __func__);
goto exit;
}
/* wait for the command to complete */
t = wait_event_timeout(command_info->wait_command,
(bool)command_info->command_finished, COMMAND_TIMEOUT);
if (!t)
usb_kill_urb(command_port->write_urb);
if (command_info->command_finished == false) {
dbg("%s - command timed out.", __func__);
retval = -ETIMEDOUT;
goto exit;
}
if (command_info->command_finished == WHITEHEAT_CMD_FAILURE) {
dbg("%s - command failed.", __func__);
retval = -EIO;
goto exit;
}
if (command_info->command_finished == WHITEHEAT_CMD_COMPLETE) {
dbg("%s - command completed.", __func__);
switch (command) {
case WHITEHEAT_GET_DTR_RTS:
info = usb_get_serial_port_data(port);
memcpy(&info->mcr, command_info->result_buffer,
sizeof(struct whiteheat_dr_info));
break;
}
}
exit:
mutex_unlock(&command_info->mutex);
return retval;
}
static int firm_open(struct usb_serial_port *port)
{
struct whiteheat_simple open_command;
open_command.port = port->number - port->serial->minor + 1;
return firm_send_command(port, WHITEHEAT_OPEN,
(__u8 *)&open_command, sizeof(open_command));
}
static int firm_close(struct usb_serial_port *port)
{
struct whiteheat_simple close_command;
close_command.port = port->number - port->serial->minor + 1;
return firm_send_command(port, WHITEHEAT_CLOSE,
(__u8 *)&close_command, sizeof(close_command));
}
static void firm_setup_port(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct whiteheat_port_settings port_settings;
unsigned int cflag = tty->termios->c_cflag;
port_settings.port = port->number + 1;
/* get the byte size */
switch (cflag & CSIZE) {
case CS5: port_settings.bits = 5; break;
case CS6: port_settings.bits = 6; break;
case CS7: port_settings.bits = 7; break;
default:
case CS8: port_settings.bits = 8; break;
}
dbg("%s - data bits = %d", __func__, port_settings.bits);
/* determine the parity */
if (cflag & PARENB)
if (cflag & CMSPAR)
if (cflag & PARODD)
port_settings.parity = WHITEHEAT_PAR_MARK;
else
port_settings.parity = WHITEHEAT_PAR_SPACE;
else
if (cflag & PARODD)
port_settings.parity = WHITEHEAT_PAR_ODD;
else
port_settings.parity = WHITEHEAT_PAR_EVEN;
else
port_settings.parity = WHITEHEAT_PAR_NONE;
dbg("%s - parity = %c", __func__, port_settings.parity);
/* figure out the stop bits requested */
if (cflag & CSTOPB)
port_settings.stop = 2;
else
port_settings.stop = 1;
dbg("%s - stop bits = %d", __func__, port_settings.stop);
/* figure out the flow control settings */
if (cflag & CRTSCTS)
port_settings.hflow = (WHITEHEAT_HFLOW_CTS |
WHITEHEAT_HFLOW_RTS);
else
port_settings.hflow = WHITEHEAT_HFLOW_NONE;
dbg("%s - hardware flow control = %s %s %s %s", __func__,
(port_settings.hflow & WHITEHEAT_HFLOW_CTS) ? "CTS" : "",
(port_settings.hflow & WHITEHEAT_HFLOW_RTS) ? "RTS" : "",
(port_settings.hflow & WHITEHEAT_HFLOW_DSR) ? "DSR" : "",
(port_settings.hflow & WHITEHEAT_HFLOW_DTR) ? "DTR" : "");
/* determine software flow control */
if (I_IXOFF(tty))
port_settings.sflow = WHITEHEAT_SFLOW_RXTX;
else
port_settings.sflow = WHITEHEAT_SFLOW_NONE;
dbg("%s - software flow control = %c", __func__, port_settings.sflow);
port_settings.xon = START_CHAR(tty);
port_settings.xoff = STOP_CHAR(tty);
dbg("%s - XON = %2x, XOFF = %2x",
__func__, port_settings.xon, port_settings.xoff);
/* get the baud rate wanted */
port_settings.baud = tty_get_baud_rate(tty);
dbg("%s - baud rate = %d", __func__, port_settings.baud);
/* fixme: should set validated settings */
tty_encode_baud_rate(tty, port_settings.baud, port_settings.baud);
/* handle any settings that aren't specified in the tty structure */
port_settings.lloop = 0;
/* now send the message to the device */
firm_send_command(port, WHITEHEAT_SETUP_PORT,
(__u8 *)&port_settings, sizeof(port_settings));
}
static int firm_set_rts(struct usb_serial_port *port, __u8 onoff)
{
struct whiteheat_set_rdb rts_command;
rts_command.port = port->number - port->serial->minor + 1;
rts_command.state = onoff;
return firm_send_command(port, WHITEHEAT_SET_RTS,
(__u8 *)&rts_command, sizeof(rts_command));
}
static int firm_set_dtr(struct usb_serial_port *port, __u8 onoff)
{
struct whiteheat_set_rdb dtr_command;
dtr_command.port = port->number - port->serial->minor + 1;
dtr_command.state = onoff;
return firm_send_command(port, WHITEHEAT_SET_DTR,
(__u8 *)&dtr_command, sizeof(dtr_command));
}
static int firm_set_break(struct usb_serial_port *port, __u8 onoff)
{
struct whiteheat_set_rdb break_command;
break_command.port = port->number - port->serial->minor + 1;
break_command.state = onoff;
return firm_send_command(port, WHITEHEAT_SET_BREAK,
(__u8 *)&break_command, sizeof(break_command));
}
static int firm_purge(struct usb_serial_port *port, __u8 rxtx)
{
struct whiteheat_purge purge_command;
purge_command.port = port->number - port->serial->minor + 1;
purge_command.what = rxtx;
return firm_send_command(port, WHITEHEAT_PURGE,
(__u8 *)&purge_command, sizeof(purge_command));
}
static int firm_get_dtr_rts(struct usb_serial_port *port)
{
struct whiteheat_simple get_dr_command;
get_dr_command.port = port->number - port->serial->minor + 1;
return firm_send_command(port, WHITEHEAT_GET_DTR_RTS,
(__u8 *)&get_dr_command, sizeof(get_dr_command));
}
static int firm_report_tx_done(struct usb_serial_port *port)
{
struct whiteheat_simple close_command;
close_command.port = port->number - port->serial->minor + 1;
return firm_send_command(port, WHITEHEAT_REPORT_TX_DONE,
(__u8 *)&close_command, sizeof(close_command));
}
/*****************************************************************************
* Connect Tech's White Heat utility functions
*****************************************************************************/
static int start_command_port(struct usb_serial *serial)
{
struct usb_serial_port *command_port;
struct whiteheat_command_private *command_info;
int retval = 0;
command_port = serial->port[COMMAND_PORT];
command_info = usb_get_serial_port_data(command_port);
mutex_lock(&command_info->mutex);
if (!command_info->port_running) {
/* Work around HCD bugs */
usb_clear_halt(serial->dev, command_port->read_urb->pipe);
command_port->read_urb->dev = serial->dev;
retval = usb_submit_urb(command_port->read_urb, GFP_KERNEL);
if (retval) {
dev_err(&serial->dev->dev,
"%s - failed submitting read urb, error %d\n",
__func__, retval);
goto exit;
}
}
command_info->port_running++;
exit:
mutex_unlock(&command_info->mutex);
return retval;
}
static void stop_command_port(struct usb_serial *serial)
{
struct usb_serial_port *command_port;
struct whiteheat_command_private *command_info;
command_port = serial->port[COMMAND_PORT];
command_info = usb_get_serial_port_data(command_port);
mutex_lock(&command_info->mutex);
command_info->port_running--;
if (!command_info->port_running)
usb_kill_urb(command_port->read_urb);
mutex_unlock(&command_info->mutex);
}
static int start_port_read(struct usb_serial_port *port)
{
struct whiteheat_private *info = usb_get_serial_port_data(port);
struct whiteheat_urb_wrap *wrap;
struct urb *urb;
int retval = 0;
unsigned long flags;
struct list_head *tmp;
struct list_head *tmp2;
spin_lock_irqsave(&info->lock, flags);
list_for_each_safe(tmp, tmp2, &info->rx_urbs_free) {
list_del(tmp);
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
urb->dev = port->serial->dev;
spin_unlock_irqrestore(&info->lock, flags);
retval = usb_submit_urb(urb, GFP_KERNEL);
if (retval) {
spin_lock_irqsave(&info->lock, flags);
list_add(tmp, &info->rx_urbs_free);
list_for_each_safe(tmp, tmp2, &info->rx_urbs_submitted) {
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
list_del(tmp);
spin_unlock_irqrestore(&info->lock, flags);
usb_kill_urb(urb);
spin_lock_irqsave(&info->lock, flags);
list_add(tmp, &info->rx_urbs_free);
}
break;
}
spin_lock_irqsave(&info->lock, flags);
list_add(tmp, &info->rx_urbs_submitted);
}
spin_unlock_irqrestore(&info->lock, flags);
return retval;
}
static struct whiteheat_urb_wrap *urb_to_wrap(struct urb *urb,
struct list_head *head)
{
struct whiteheat_urb_wrap *wrap;
struct list_head *tmp;
list_for_each(tmp, head) {
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
if (wrap->urb == urb)
return wrap;
}
return NULL;
}
static struct list_head *list_first(struct list_head *head)
{
return head->next;
}
static void rx_data_softint(struct work_struct *work)
{
struct whiteheat_private *info =
container_of(work, struct whiteheat_private, rx_work);
struct usb_serial_port *port = info->port;
struct tty_struct *tty = tty_port_tty_get(&port->port);
struct whiteheat_urb_wrap *wrap;
struct urb *urb;
unsigned long flags;
struct list_head *tmp;
struct list_head *tmp2;
int result;
int sent = 0;
spin_lock_irqsave(&info->lock, flags);
if (info->flags & THROTTLED) {
spin_unlock_irqrestore(&info->lock, flags);
goto out;
}
list_for_each_safe(tmp, tmp2, &info->rx_urb_q) {
list_del(tmp);
spin_unlock_irqrestore(&info->lock, flags);
wrap = list_entry(tmp, struct whiteheat_urb_wrap, list);
urb = wrap->urb;
if (tty && urb->actual_length)
sent += tty_insert_flip_string(tty,
urb->transfer_buffer, urb->actual_length);
urb->dev = port->serial->dev;
result = usb_submit_urb(urb, GFP_ATOMIC);
if (result) {
dev_err(&port->dev,
"%s - failed resubmitting read urb, error %d\n",
__func__, result);
spin_lock_irqsave(&info->lock, flags);
list_add(tmp, &info->rx_urbs_free);
continue;
}
spin_lock_irqsave(&info->lock, flags);
list_add(tmp, &info->rx_urbs_submitted);
}
spin_unlock_irqrestore(&info->lock, flags);
if (sent)
tty_flip_buffer_push(tty);
out:
tty_kref_put(tty);
}
/*****************************************************************************
* Connect Tech's White Heat module functions
*****************************************************************************/
static int __init whiteheat_init(void)
{
int retval;
retval = usb_serial_register(&whiteheat_fake_device);
if (retval)
goto failed_fake_register;
retval = usb_serial_register(&whiteheat_device);
if (retval)
goto failed_device_register;
retval = usb_register(&whiteheat_driver);
if (retval)
goto failed_usb_register;
printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
DRIVER_DESC "\n");
return 0;
failed_usb_register:
usb_serial_deregister(&whiteheat_device);
failed_device_register:
usb_serial_deregister(&whiteheat_fake_device);
failed_fake_register:
return retval;
}
static void __exit whiteheat_exit(void)
{
usb_deregister(&whiteheat_driver);
usb_serial_deregister(&whiteheat_fake_device);
usb_serial_deregister(&whiteheat_device);
}
module_init(whiteheat_init);
module_exit(whiteheat_exit);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
MODULE_FIRMWARE("whiteheat.fw");
MODULE_FIRMWARE("whiteheat_loader.fw");
module_param(urb_pool_size, int, 0);
MODULE_PARM_DESC(urb_pool_size, "Number of urbs to use for buffering");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");