diff options
author | Matthias Urlichs <smurf@smurf.noris.de> | 2005-05-24 00:00:48 (GMT) |
---|---|---|
committer | Greg KH <gregkh@suse.de> | 2005-06-03 07:04:29 (GMT) |
commit | 58cfe9113e485f7e04bd0eac4fc4251b330af501 (patch) | |
tree | f414ba56f95dddd5b90bdef86f1872849e801f9a /drivers | |
parent | 4871d3be13ea2b33edc9ba6fbcc30fc047087be7 (diff) | |
download | linux-58cfe9113e485f7e04bd0eac4fc4251b330af501.tar.xz |
[PATCH] USB: add Option Card driver
This patch adds a new driver for "Option" cards. This is a GSM data card,
controlled by three "serial ports" which are connected via an OHCI adapter,
all located on an oversized PC-Card. It's sold by several GSM service
providers.
Traditionally, this card has been accessed via the standard serial driver
and appropriate vendor= and product= options. However, testing has
revealed several problems with this approach, including hung data transfers
and lost data blocks when receiving.
Therefore, I've written a separate driver.
Signed-off-by: Matthias Urlichs <smurf@smurf.noris.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/usb/serial/Kconfig | 11 | ||||
-rw-r--r-- | drivers/usb/serial/Makefile | 1 | ||||
-rw-r--r-- | drivers/usb/serial/option.c | 729 |
3 files changed, 741 insertions, 0 deletions
diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig index bc798ed..9438909 100644 --- a/drivers/usb/serial/Kconfig +++ b/drivers/usb/serial/Kconfig @@ -455,6 +455,17 @@ config USB_SERIAL_XIRCOM To compile this driver as a module, choose M here: the module will be called keyspan_pda. +config USB_SERIAL_OPTION + tristate "USB Option PCMCIA serial driver" + depends on USB_SERIAL && USB_OHCI_HCD && PCCARD + help + Say Y here if you want to use an Option card. This is a + GSM card, controlled by three serial ports which are connected + via an OHCI adapter located on a PC card. + + To compile this driver as a module, choose M here: the + module will be called option. + config USB_SERIAL_OMNINET tristate "USB ZyXEL omni.net LCD Plus Driver (EXPERIMENTAL)" depends on USB_SERIAL && EXPERIMENTAL diff --git a/drivers/usb/serial/Makefile b/drivers/usb/serial/Makefile index d56ff6d..6c7cdcc 100644 --- a/drivers/usb/serial/Makefile +++ b/drivers/usb/serial/Makefile @@ -32,6 +32,7 @@ obj-$(CONFIG_USB_SERIAL_KLSI) += kl5kusb105.o obj-$(CONFIG_USB_SERIAL_KOBIL_SCT) += kobil_sct.o obj-$(CONFIG_USB_SERIAL_MCT_U232) += mct_u232.o obj-$(CONFIG_USB_SERIAL_OMNINET) += omninet.o +obj-$(CONFIG_USB_SERIAL_OPTION) += option.o obj-$(CONFIG_USB_SERIAL_PL2303) += pl2303.o obj-$(CONFIG_USB_SERIAL_SAFE) += safe_serial.o obj-$(CONFIG_USB_SERIAL_TI) += ti_usb_3410_5052.o diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c new file mode 100644 index 0000000..b722175 --- /dev/null +++ b/drivers/usb/serial/option.c @@ -0,0 +1,729 @@ +/* + Option Card (PCMCIA to) USB to Serial Driver + + Copyright (C) 2005 Matthias Urlichs <smurf@smurf.noris.de> + + This driver is free software; you can redistribute it and/or modify + it under the terms of Version 2 of the GNU General Public License as + published by the Free Software Foundation. + + Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org> + + History: + + 2005-05-19 v0.1 Initial version, based on incomplete docs + and analysis of misbehavior of the standard driver + 2005-05-20 v0.2 Extended the input buffer to avoid losing + random 64-byte chunks of data + 2005-05-21 v0.3 implemented chars_in_buffer() + turned on low_latency + simplified the code somewhat +*/ +#define DRIVER_VERSION "v0.3" +#define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>" +#define DRIVER_DESC "Option Card (PC-Card to) USB to Serial Driver" + +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/errno.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/module.h> +#include <linux/usb.h> +#include "usb-serial.h" + +/* Function prototypes */ +static int option_open (struct usb_serial_port *port, struct file *filp); +static void option_close (struct usb_serial_port *port, struct file *filp); +static int option_startup (struct usb_serial *serial); +static void option_shutdown (struct usb_serial *serial); +static void option_rx_throttle (struct usb_serial_port *port); +static void option_rx_unthrottle (struct usb_serial_port *port); +static int option_write_room (struct usb_serial_port *port); + +static void option_instat_callback(struct urb *urb, struct pt_regs *regs); + + +static int option_write (struct usb_serial_port *port, + const unsigned char *buf, int count); + +static int option_chars_in_buffer (struct usb_serial_port *port); +static int option_ioctl (struct usb_serial_port *port, struct file *file, + unsigned int cmd, unsigned long arg); +static void option_set_termios (struct usb_serial_port *port, + struct termios *old); +static void option_break_ctl (struct usb_serial_port *port, int break_state); +static int option_tiocmget (struct usb_serial_port *port, struct file *file); +static int option_tiocmset (struct usb_serial_port *port, struct file *file, + unsigned int set, unsigned int clear); +static int option_send_setup (struct usb_serial_port *port); + +/* Vendor and product IDs */ +#define OPTION_VENDOR_ID 0x0AF0 + +#define OPTION_PRODUCT_OLD 0x5000 +#define OPTION_PRODUCT_WLAN 0x6000 + +static struct usb_device_id option_ids[] = { + { USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_OLD) }, + { USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_WLAN) }, + { } /* Terminating entry */ +}; + +MODULE_DEVICE_TABLE(usb, option_ids); + +static struct usb_driver option_driver = { + .owner = THIS_MODULE, + .name = "option", + .probe = usb_serial_probe, + .disconnect = usb_serial_disconnect, + .id_table = option_ids, +}; + +/* The card has three separate interfaces, wich the serial driver + * recognizes separately, thus num_port=1. + */ +static struct usb_serial_device_type option_3port_device = { + .owner = THIS_MODULE, + .name = "Option 3-port card", + .short_name = "option", + .id_table = option_ids, + .num_interrupt_in = NUM_DONT_CARE, + .num_bulk_in = NUM_DONT_CARE, + .num_bulk_out = NUM_DONT_CARE, + .num_ports = 1, /* 3 */ + .open = option_open, + .close = option_close, + .write = option_write, + .write_room = option_write_room, + .chars_in_buffer = option_chars_in_buffer, + .throttle = option_rx_throttle, + .unthrottle = option_rx_unthrottle, + .ioctl = option_ioctl, + .set_termios = option_set_termios, + .break_ctl = option_break_ctl, + .tiocmget = option_tiocmget, + .tiocmset = option_tiocmset, + .attach = option_startup, + .shutdown = option_shutdown, + .read_int_callback = option_instat_callback, +}; + +static int debug; + +/* per port private data */ + +#define N_IN_URB 4 +#define N_OUT_URB 1 +#define IN_BUFLEN 1024 +#define OUT_BUFLEN 1024 + +struct option_port_private { + /* Input endpoints and buffer for this port */ + struct urb *in_urbs[N_IN_URB]; + char in_buffer[N_IN_URB][IN_BUFLEN]; + /* Output endpoints and buffer for this port */ + struct urb *out_urbs[N_OUT_URB]; + char out_buffer[N_OUT_URB][OUT_BUFLEN]; + + /* Settings for the port */ + int rts_state; /* Handshaking pins (outputs) */ + int dtr_state; + int cts_state; /* Handshaking pins (inputs) */ + int dsr_state; + int dcd_state; + int ri_state; + // int break_on; + + unsigned long tx_start_time[N_OUT_URB]; +}; + + +/* Functions used by new usb-serial code. */ +static int __init +option_init (void) +{ + int retval; + retval = usb_serial_register(&option_3port_device); + if (retval) + goto failed_3port_device_register; + retval = usb_register(&option_driver); + if (retval) + goto failed_driver_register; + + info(DRIVER_DESC ": " DRIVER_VERSION); + + return 0; + +failed_driver_register: + usb_serial_deregister (&option_3port_device); +failed_3port_device_register: + return retval; +} + +static void __exit +option_exit (void) +{ + usb_deregister (&option_driver); + usb_serial_deregister (&option_3port_device); +} + +module_init(option_init); +module_exit(option_exit); + +static void +option_rx_throttle (struct usb_serial_port *port) +{ + dbg("%s", __FUNCTION__); +} + + +static void +option_rx_unthrottle (struct usb_serial_port *port) +{ + dbg("%s", __FUNCTION__); +} + + +static void +option_break_ctl (struct usb_serial_port *port, int break_state) +{ + /* Unfortunately, I don't know how to send a break */ + dbg("%s", __FUNCTION__); +} + + +static void +option_set_termios (struct usb_serial_port *port, + struct termios *old_termios) +{ + dbg("%s", __FUNCTION__); + + option_send_setup(port); +} + +static int +option_tiocmget(struct usb_serial_port *port, struct file *file) +{ + unsigned int value; + struct option_port_private *portdata; + + portdata = usb_get_serial_port_data(port); + + value = ((portdata->rts_state) ? TIOCM_RTS : 0) | + ((portdata->dtr_state) ? TIOCM_DTR : 0) | + ((portdata->cts_state) ? TIOCM_CTS : 0) | + ((portdata->dsr_state) ? TIOCM_DSR : 0) | + ((portdata->dcd_state) ? TIOCM_CAR : 0) | + ((portdata->ri_state) ? TIOCM_RNG : 0); + + return value; +} + +static int +option_tiocmset (struct usb_serial_port *port, struct file *file, + unsigned int set, unsigned int clear) +{ + struct option_port_private *portdata; + + portdata = usb_get_serial_port_data(port); + + if (set & TIOCM_RTS) + portdata->rts_state = 1; + if (set & TIOCM_DTR) + portdata->dtr_state = 1; + + if (clear & TIOCM_RTS) + portdata->rts_state = 0; + if (clear & TIOCM_DTR) + portdata->dtr_state = 0; + return option_send_setup(port); +} + +static int +option_ioctl (struct usb_serial_port *port, struct file *file, + unsigned int cmd, unsigned long arg) +{ + return -ENOIOCTLCMD; +} + +/* Write */ +static int +option_write(struct usb_serial_port *port, + const unsigned char *buf, int count) +{ + struct option_port_private *portdata; + int i; + int left, todo; + struct urb *this_urb = NULL; /* spurious */ + int err; + + portdata = usb_get_serial_port_data(port); + + dbg("%s: write (%d chars)", __FUNCTION__, count); + +#if 0 + spin_lock(&port->lock); + if (port->write_urb_busy) { + spin_unlock(&port->lock); + dbg("%s: already writing", __FUNCTION__); + return 0; + } + port->write_urb_busy = 1; + spin_unlock(&port->lock); +#endif + + i = 0; + left = count; + while (left>0) { + todo = left; + if (todo > OUT_BUFLEN) + todo = OUT_BUFLEN; + + for (;i < N_OUT_URB; i++) { + /* Check we have a valid urb/endpoint before we use it... */ + this_urb = portdata->out_urbs[i]; + if (this_urb->status != -EINPROGRESS) + break; + if (this_urb->transfer_flags & URB_ASYNC_UNLINK) + continue; + if (time_before(jiffies, portdata->tx_start_time[i] + 10 * HZ)) + continue; + this_urb->transfer_flags |= URB_ASYNC_UNLINK; + usb_unlink_urb(this_urb); + } + + if (i == N_OUT_URB) { + /* no bulk out free! */ + dbg("%s: no output urb -- left %d", __FUNCTION__,count-left); +#if 0 + port->write_urb_busy = 0; +#endif + return count-left; + } + + dbg("%s: endpoint %d buf %d", __FUNCTION__, usb_pipeendpoint(this_urb->pipe), i); + + memcpy (this_urb->transfer_buffer, buf, todo); + + /* send the data out the bulk port */ + this_urb->transfer_buffer_length = todo; + + this_urb->transfer_flags &= ~URB_ASYNC_UNLINK; + this_urb->dev = port->serial->dev; + err = usb_submit_urb(this_urb, GFP_ATOMIC); + if (err) { + dbg("usb_submit_urb %p (write bulk) failed (%d,, has %d)", this_urb, err, this_urb->status); + continue; + } + portdata->tx_start_time[i] = jiffies; + buf += todo; + left -= todo; + } + + count -= left; +#if 0 + port->write_urb_busy = 0; +#endif + dbg("%s: wrote (did %d)", __FUNCTION__, count); + return count; +} + +static void +option_indat_callback (struct urb *urb, struct pt_regs *regs) +{ + int i, err; + int endpoint; + struct usb_serial_port *port; + struct tty_struct *tty; + unsigned char *data = urb->transfer_buffer; + + dbg("%s: %p", __FUNCTION__, urb); + + endpoint = usb_pipeendpoint(urb->pipe); + port = (struct usb_serial_port *) urb->context; + + if (urb->status) { + dbg("%s: nonzero status: %d on endpoint %02x.", + __FUNCTION__, urb->status, endpoint); + } else { + tty = port->tty; + if (urb->actual_length) { + for (i = 0; i < urb->actual_length ; ++i) { + if (tty->flip.count >= TTY_FLIPBUF_SIZE) + tty_flip_buffer_push(tty); + tty_insert_flip_char(tty, data[i], 0); + } + tty_flip_buffer_push(tty); + } else { + dbg("%s: empty read urb received", __FUNCTION__); + } + + /* Resubmit urb so we continue receiving */ + if (port->open_count && urb->status != -ESHUTDOWN) { + err = usb_submit_urb(urb, GFP_ATOMIC); + if (err) + printk(KERN_ERR "%s: resubmit read urb failed. (%d)", __FUNCTION__, err); + } + } + return; +} + +static void +option_outdat_callback (struct urb *urb, struct pt_regs *regs) +{ + struct usb_serial_port *port; + + dbg("%s", __FUNCTION__); + + port = (struct usb_serial_port *) urb->context; + + if (port->open_count) + schedule_work(&port->work); +} + +static void +option_instat_callback (struct urb *urb, struct pt_regs *regs) +{ + int err; + struct usb_serial_port *port = (struct usb_serial_port *) urb->context; + struct option_port_private *portdata = usb_get_serial_port_data(port); + struct usb_serial *serial = port->serial; + + dbg("%s", __FUNCTION__); + dbg("%s: urb %p port %p has data %p", __FUNCTION__,urb,port,portdata); + + if (urb->status == 0) { + struct usb_ctrlrequest *req_pkt = + (struct usb_ctrlrequest *)urb->transfer_buffer; + + if (!req_pkt) { + dbg("%s: NULL req_pkt\n", __FUNCTION__); + return; + } + if ((req_pkt->bRequestType == 0xA1) && (req_pkt->bRequest == 0x20)) { + int old_dcd_state; + unsigned char signals = *((unsigned char *) + urb->transfer_buffer + sizeof(struct usb_ctrlrequest)); + + dbg("%s: signal x%x", __FUNCTION__, signals); + + old_dcd_state = portdata->dcd_state; + portdata->cts_state = 1; + portdata->dcd_state = ((signals & 0x01) ? 1 : 0); + portdata->dsr_state = ((signals & 0x02) ? 1 : 0); + portdata->ri_state = ((signals & 0x08) ? 1 : 0); + + if (port->tty && !C_CLOCAL(port->tty) + && old_dcd_state && !portdata->dcd_state) { + tty_hangup(port->tty); + } + } else + dbg("%s: type %x req %x", __FUNCTION__, req_pkt->bRequestType,req_pkt->bRequest); + } else + dbg("%s: error %d", __FUNCTION__, urb->status); + + /* Resubmit urb so we continue receiving IRQ data */ + if (urb->status != -ESHUTDOWN) { + urb->dev = serial->dev; + err = usb_submit_urb(urb, GFP_ATOMIC); + if (err) + dbg("%s: resubmit intr urb failed. (%d)", __FUNCTION__, err); + } +} + + +static int +option_write_room (struct usb_serial_port *port) +{ + struct option_port_private *portdata; + int i; + int data_len = 0; + struct urb *this_urb; + + portdata = usb_get_serial_port_data(port); + + for (i=0; i < N_OUT_URB; i++) + this_urb = portdata->out_urbs[i]; + if (this_urb && this_urb->status != -EINPROGRESS) + data_len += OUT_BUFLEN; + + dbg("%s: %d", __FUNCTION__, data_len); + return data_len; +} + + +static int +option_chars_in_buffer (struct usb_serial_port *port) +{ + struct option_port_private *portdata; + int i; + int data_len = 0; + struct urb *this_urb; + + portdata = usb_get_serial_port_data(port); + + for (i=0; i < N_OUT_URB; i++) + this_urb = portdata->out_urbs[i]; + if (this_urb && this_urb->status == -EINPROGRESS) + data_len += this_urb->transfer_buffer_length; + + dbg("%s: %d", __FUNCTION__, data_len); + return data_len; +} + + +static int +option_open (struct usb_serial_port *port, struct file *filp) +{ + struct option_port_private *portdata; + struct usb_serial *serial = port->serial; + int i, err; + struct urb *urb; + + portdata = usb_get_serial_port_data(port); + + dbg("%s", __FUNCTION__); + + /* Set some sane defaults */ + portdata->rts_state = 1; + portdata->dtr_state = 1; + + /* Reset low level data toggle and start reading from endpoints */ + for (i = 0; i < N_IN_URB; i++) { + urb = portdata->in_urbs[i]; + if (! urb) + continue; + if (urb->dev != serial->dev) { + dbg("%s: dev %p != %p", __FUNCTION__, urb->dev, serial->dev); + continue; + } + + /* make sure endpoint data toggle is synchronized with the device */ + + usb_clear_halt(urb->dev, urb->pipe); + + err = usb_submit_urb(urb, GFP_KERNEL); + if (err) { + dbg("%s: submit urb %d failed (%d) %d", __FUNCTION__, i, err, + urb->transfer_buffer_length); + } + } + + /* Reset low level data toggle on out endpoints */ + for (i = 0; i < N_OUT_URB; i++) { + urb = portdata->out_urbs[i]; + if (! urb) + continue; + urb->dev = serial->dev; + /* usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe), usb_pipeout(urb->pipe), 0); */ + } + + port->tty->low_latency = 1; + + option_send_setup(port); + + return (0); +} + +static inline void +stop_urb(struct urb *urb) +{ + if (urb && urb->status == -EINPROGRESS) { + urb->transfer_flags &= ~URB_ASYNC_UNLINK; + usb_kill_urb(urb); + } +} + +static void +option_close(struct usb_serial_port *port, struct file *filp) +{ + int i; + struct usb_serial *serial = port->serial; + struct option_port_private *portdata; + + dbg("%s", __FUNCTION__); + portdata = usb_get_serial_port_data(port); + + portdata->rts_state = 0; + portdata->dtr_state = 0; + + if (serial->dev) { + option_send_setup(port); + + /* Stop reading/writing urbs */ + for (i = 0; i < N_IN_URB; i++) + stop_urb(portdata->in_urbs[i]); + for (i = 0; i < N_OUT_URB; i++) + stop_urb(portdata->out_urbs[i]); + } + port->tty = NULL; +} + + +/* Helper functions used by option_setup_urbs */ +static struct urb * +option_setup_urb (struct usb_serial *serial, int endpoint, + int dir, void *ctx, char *buf, int len, + void (*callback)(struct urb *, struct pt_regs *regs)) +{ + struct urb *urb; + + if (endpoint == -1) + return NULL; /* endpoint not needed */ + + urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */ + if (urb == NULL) { + dbg("%s: alloc for endpoint %d failed.", __FUNCTION__, endpoint); + return NULL; + } + + /* Fill URB using supplied data. */ + usb_fill_bulk_urb(urb, serial->dev, + usb_sndbulkpipe(serial->dev, endpoint) | dir, + buf, len, callback, ctx); + + return urb; +} + +/* Setup urbs */ +static void +option_setup_urbs(struct usb_serial *serial) +{ + int j; + struct usb_serial_port *port; + struct option_port_private *portdata; + + dbg("%s", __FUNCTION__); + + port = serial->port[0]; + portdata = usb_get_serial_port_data(port); + + /* Do indat endpoints first */ + for (j = 0; j <= N_IN_URB; ++j) { + portdata->in_urbs[j] = option_setup_urb (serial, + port->bulk_in_endpointAddress, USB_DIR_IN, port, + portdata->in_buffer[j], IN_BUFLEN, option_indat_callback); + } + + /* outdat endpoints */ + for (j = 0; j <= N_OUT_URB; ++j) { + portdata->out_urbs[j] = option_setup_urb (serial, + port->bulk_out_endpointAddress, USB_DIR_OUT, port, + portdata->out_buffer[j], OUT_BUFLEN, option_outdat_callback); + } +} + + +static int +option_send_setup(struct usb_serial_port *port) +{ + struct usb_serial *serial = port->serial; + struct option_port_private *portdata; + + dbg("%s", __FUNCTION__); + + portdata = usb_get_serial_port_data(port); + + if (port->tty) { + int val = 0; + if (portdata->dtr_state) + val |= 0x01; + if (portdata->rts_state) + val |= 0x02; + + return usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0), + 0x22,0x21,val,0,NULL,0,USB_CTRL_SET_TIMEOUT); + } + + return 0; +} + + +static int +option_startup (struct usb_serial *serial) +{ + int i, err; + struct usb_serial_port *port; + struct option_port_private *portdata; + + dbg("%s", __FUNCTION__); + + /* Now setup per port private data */ + for (i = 0; i < serial->num_ports; i++) { + port = serial->port[i]; + portdata = kmalloc(sizeof(struct option_port_private), GFP_KERNEL); + if (!portdata) { + dbg("%s: kmalloc for option_port_private (%d) failed!.", __FUNCTION__, i); + return (1); + } + memset(portdata, 0, sizeof(struct option_port_private)); + + usb_set_serial_port_data(port, portdata); + + if (! port->interrupt_in_urb) + continue; + err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); + if (err) + dbg("%s: submit irq_in urb failed %d", __FUNCTION__, err); + } + + option_setup_urbs(serial); + + return (0); +} + +static void +option_shutdown (struct usb_serial *serial) +{ + int i, j; + struct usb_serial_port *port; + struct option_port_private *portdata; + + dbg("%s", __FUNCTION__); + + /* Stop reading/writing urbs */ + for (i = 0; i < serial->num_ports; ++i) { + port = serial->port[i]; + portdata = usb_get_serial_port_data(port); + for (j = 0; j < N_IN_URB; j++) + stop_urb(portdata->in_urbs[j]); + for (j = 0; j < N_OUT_URB; j++) + stop_urb(portdata->out_urbs[j]); + } + + /* Now free them */ + for (i = 0; i < serial->num_ports; ++i) { + port = serial->port[i]; + portdata = usb_get_serial_port_data(port); + + for (j = 0; j < N_IN_URB; j++) { + if (portdata->in_urbs[j]) { + usb_free_urb(portdata->in_urbs[j]); + portdata->in_urbs[j] = NULL; + } + } + for (j = 0; j < N_OUT_URB; j++) { + if (portdata->out_urbs[j]) { + usb_free_urb(portdata->out_urbs[j]); + portdata->out_urbs[j] = NULL; + } + } + } + + /* Now free per port private data */ + for (i = 0; i < serial->num_ports; i++) { + port = serial->port[i]; + kfree(usb_get_serial_port_data(port)); + } +} + +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_VERSION(DRIVER_VERSION); +MODULE_LICENSE("GPL"); + +module_param(debug, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(debug, "Debug messages"); + |