diff options
| -rw-r--r-- | drivers/usb/serial/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/usb/serial/Makefile | 1 | ||||
| -rw-r--r-- | drivers/usb/serial/usb-wwan.h | 67 | ||||
| -rw-r--r-- | drivers/usb/serial/usb_wwan.c | 665 |
4 files changed, 736 insertions, 0 deletions
diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig index 5f777c20f2e..e399efdb91e 100644 --- a/drivers/usb/serial/Kconfig +++ b/drivers/usb/serial/Kconfig @@ -576,6 +576,9 @@ config USB_SERIAL_XIRCOM To compile this driver as a module, choose M here: the module will be called keyspan_pda. +config USB_SERIAL_WWAN + tristate + config USB_SERIAL_OPTION tristate "USB driver for GSM and CDMA modems" help diff --git a/drivers/usb/serial/Makefile b/drivers/usb/serial/Makefile index 3203614e389..e54c728c016 100644 --- a/drivers/usb/serial/Makefile +++ b/drivers/usb/serial/Makefile @@ -52,6 +52,7 @@ obj-$(CONFIG_USB_SERIAL_SIEMENS_MPI) += siemens_mpi.o obj-$(CONFIG_USB_SERIAL_SIERRAWIRELESS) += sierra.o obj-$(CONFIG_USB_SERIAL_SPCP8X5) += spcp8x5.o obj-$(CONFIG_USB_SERIAL_SYMBOL) += symbolserial.o +obj-$(CONFIG_USB_SERIAL_WWAN) += usb_wwan.o obj-$(CONFIG_USB_SERIAL_TI) += ti_usb_3410_5052.o obj-$(CONFIG_USB_SERIAL_VISOR) += visor.o obj-$(CONFIG_USB_SERIAL_WHITEHEAT) += whiteheat.o diff --git a/drivers/usb/serial/usb-wwan.h b/drivers/usb/serial/usb-wwan.h new file mode 100644 index 00000000000..2be298a1305 --- /dev/null +++ b/drivers/usb/serial/usb-wwan.h @@ -0,0 +1,67 @@ +/* + * Definitions for USB serial mobile broadband cards + */ + +#ifndef __LINUX_USB_USB_WWAN +#define __LINUX_USB_USB_WWAN + +extern void usb_wwan_dtr_rts(struct usb_serial_port *port, int on); +extern int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port); +extern void usb_wwan_close(struct usb_serial_port *port); +extern int usb_wwan_startup(struct usb_serial *serial); +extern void usb_wwan_disconnect(struct usb_serial *serial); +extern void usb_wwan_release(struct usb_serial *serial); +extern int usb_wwan_write_room(struct tty_struct *tty); +extern void usb_wwan_set_termios(struct tty_struct *tty, + struct usb_serial_port *port, + struct ktermios *old); +extern int usb_wwan_tiocmget(struct tty_struct *tty, struct file *file); +extern int usb_wwan_tiocmset(struct tty_struct *tty, struct file *file, + unsigned int set, unsigned int clear); +extern int usb_wwan_send_setup(struct usb_serial_port *port); +extern int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port, + const unsigned char *buf, int count); +extern int usb_wwan_chars_in_buffer(struct tty_struct *tty); +#ifdef CONFIG_PM +extern int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message); +extern int usb_wwan_resume(struct usb_serial *serial); +#endif + +/* per port private data */ + +#define N_IN_URB 4 +#define N_OUT_URB 4 +#define IN_BUFLEN 4096 +#define OUT_BUFLEN 4096 + +struct usb_wwan_intf_private { + spinlock_t susp_lock; + unsigned int suspended:1; + int in_flight; + int (*send_setup) (struct usb_serial_port *port); + void *private; +}; + +struct usb_wwan_port_private { + /* Input endpoints and buffer for this port */ + struct urb *in_urbs[N_IN_URB]; + u8 *in_buffer[N_IN_URB]; + /* Output endpoints and buffer for this port */ + struct urb *out_urbs[N_OUT_URB]; + u8 *out_buffer[N_OUT_URB]; + unsigned long out_busy; /* Bit vector of URBs in use */ + int opened; + struct usb_anchor delayed; + + /* 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; + + unsigned long tx_start_time[N_OUT_URB]; +}; + +#endif /* __LINUX_USB_USB_WWAN */ diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c new file mode 100644 index 00000000000..0c70b4a621b --- /dev/null +++ b/drivers/usb/serial/usb_wwan.c @@ -0,0 +1,665 @@ +/* + USB Driver layer for GSM modems + + 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: see the git log. + + Work sponsored by: Sigos GmbH, Germany <info@sigos.de> + + This driver exists because the "normal" serial driver doesn't work too well + with GSM modems. Issues: + - data loss -- one single Receive URB is not nearly enough + - controlling the baud rate doesn't make sense +*/ + +#define DRIVER_VERSION "v0.7.2" +#define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>" +#define DRIVER_DESC "USB Driver for GSM modems" + +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/module.h> +#include <linux/bitops.h> +#include <linux/usb.h> +#include <linux/usb/serial.h> +#include "usb-wwan.h" + +static int debug; + +void usb_wwan_dtr_rts(struct usb_serial_port *port, int on) +{ + struct usb_serial *serial = port->serial; + struct usb_wwan_port_private *portdata; + + struct usb_wwan_intf_private *intfdata; + + dbg("%s", __func__); + + intfdata = port->serial->private; + + if (!intfdata->send_setup) + return; + + portdata = usb_get_serial_port_data(port); + mutex_lock(&serial->disc_mutex); + portdata->rts_state = on; + portdata->dtr_state = on; + if (serial->dev) + intfdata->send_setup(port); + mutex_unlock(&serial->disc_mutex); +} +EXPORT_SYMBOL(usb_wwan_dtr_rts); + +void usb_wwan_set_termios(struct tty_struct *tty, + struct usb_serial_port *port, + struct ktermios *old_termios) +{ + struct usb_wwan_intf_private *intfdata = port->serial->private; + + dbg("%s", __func__); + + /* Doesn't support option setting */ + tty_termios_copy_hw(tty->termios, old_termios); + + if (intfdata->send_setup) + intfdata->send_setup(port); +} +EXPORT_SYMBOL(usb_wwan_set_termios); + +int usb_wwan_tiocmget(struct tty_struct *tty, struct file *file) +{ + struct usb_serial_port *port = tty->driver_data; + unsigned int value; + struct usb_wwan_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; +} +EXPORT_SYMBOL(usb_wwan_tiocmget); + +int usb_wwan_tiocmset(struct tty_struct *tty, struct file *file, + unsigned int set, unsigned int clear) +{ + struct usb_serial_port *port = tty->driver_data; + struct usb_wwan_port_private *portdata; + struct usb_wwan_intf_private *intfdata; + + portdata = usb_get_serial_port_data(port); + intfdata = port->serial->private; + + if (!intfdata->send_setup) + return -EINVAL; + + /* FIXME: what locks portdata fields ? */ + 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 intfdata->send_setup(port); +} +EXPORT_SYMBOL(usb_wwan_tiocmset); + +/* Write */ +int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port, + const unsigned char *buf, int count) +{ + struct usb_wwan_port_private *portdata; + struct usb_wwan_intf_private *intfdata; + int i; + int left, todo; + struct urb *this_urb = NULL; /* spurious */ + int err; + unsigned long flags; + + portdata = usb_get_serial_port_data(port); + intfdata = port->serial->private; + + dbg("%s: write (%d chars)", __func__, count); + + i = 0; + left = count; + for (i = 0; left > 0 && i < N_OUT_URB; i++) { + todo = left; + if (todo > OUT_BUFLEN) + todo = OUT_BUFLEN; + + this_urb = portdata->out_urbs[i]; + if (test_and_set_bit(i, &portdata->out_busy)) { + if (time_before(jiffies, + portdata->tx_start_time[i] + 10 * HZ)) + continue; + usb_unlink_urb(this_urb); + continue; + } + dbg("%s: endpoint %d buf %d", __func__, + usb_pipeendpoint(this_urb->pipe), i); + + err = usb_autopm_get_interface_async(port->serial->interface); + if (err < 0) + break; + + /* send the data */ + memcpy(this_urb->transfer_buffer, buf, todo); + this_urb->transfer_buffer_length = todo; + + spin_lock_irqsave(&intfdata->susp_lock, flags); + if (intfdata->suspended) { + usb_anchor_urb(this_urb, &portdata->delayed); + spin_unlock_irqrestore(&intfdata->susp_lock, flags); + } else { + intfdata->in_flight++; + spin_unlock_irqrestore(&intfdata->susp_lock, flags); + err = usb_submit_urb(this_urb, GFP_ATOMIC); + if (err) { + dbg("usb_submit_urb %p (write bulk) failed " + "(%d)", this_urb, err); + clear_bit(i, &portdata->out_busy); + spin_lock_irqsave(&intfdata->susp_lock, flags); + intfdata->in_flight--; + spin_unlock_irqrestore(&intfdata->susp_lock, + flags); + continue; + } + } + + portdata->tx_start_time[i] = jiffies; + buf += todo; + left -= todo; + } + + count -= left; + dbg("%s: wrote (did %d)", __func__, count); + return count; +} +EXPORT_SYMBOL(usb_wwan_write); + +static void usb_wwan_indat_callback(struct urb *urb) +{ + int err; + int endpoint; + struct usb_serial_port *port; + struct tty_struct *tty; + unsigned char *data = urb->transfer_buffer; + int status = urb->status; + + dbg("%s: %p", __func__, urb); + + endpoint = usb_pipeendpoint(urb->pipe); + port = urb->context; + + if (status) { + dbg("%s: nonzero status: %d on endpoint %02x.", + __func__, status, endpoint); + } else { + tty = tty_port_tty_get(&port->port); + if (urb->actual_length) { + tty_insert_flip_string(tty, data, urb->actual_length); + tty_flip_buffer_push(tty); + } else + dbg("%s: empty read urb received", __func__); + tty_kref_put(tty); + + /* Resubmit urb so we continue receiving */ + if (status != -ESHUTDOWN) { + err = usb_submit_urb(urb, GFP_ATOMIC); + if (err && err != -EPERM) + printk(KERN_ERR "%s: resubmit read urb failed. " + "(%d)", __func__, err); + else + usb_mark_last_busy(port->serial->dev); + } + + } + return; +} + +static void usb_wwan_outdat_callback(struct urb *urb) +{ + struct usb_serial_port *port; + struct usb_wwan_port_private *portdata; + struct usb_wwan_intf_private *intfdata; + int i; + + dbg("%s", __func__); + + port = urb->context; + intfdata = port->serial->private; + + usb_serial_port_softint(port); + usb_autopm_put_interface_async(port->serial->interface); + portdata = usb_get_serial_port_data(port); + spin_lock(&intfdata->susp_lock); + intfdata->in_flight--; + spin_unlock(&intfdata->susp_lock); + + for (i = 0; i < N_OUT_URB; ++i) { + if (portdata->out_urbs[i] == urb) { + smp_mb__before_clear_bit(); + clear_bit(i, &portdata->out_busy); + break; + } + } +} + +int usb_wwan_write_room(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + struct usb_wwan_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 && !test_bit(i, &portdata->out_busy)) + data_len += OUT_BUFLEN; + } + + dbg("%s: %d", __func__, data_len); + return data_len; +} +EXPORT_SYMBOL(usb_wwan_write_room); + +int usb_wwan_chars_in_buffer(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + struct usb_wwan_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]; + /* FIXME: This locking is insufficient as this_urb may + go unused during the test */ + if (this_urb && test_bit(i, &portdata->out_busy)) + data_len += this_urb->transfer_buffer_length; + } + dbg("%s: %d", __func__, data_len); + return data_len; +} +EXPORT_SYMBOL(usb_wwan_chars_in_buffer); + +int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port) +{ + struct usb_wwan_port_private *portdata; + struct usb_wwan_intf_private *intfdata; + struct usb_serial *serial = port->serial; + int i, err; + struct urb *urb; + + portdata = usb_get_serial_port_data(port); + intfdata = serial->private; + + dbg("%s", __func__); + + /* Start reading from the IN endpoint */ + for (i = 0; i < N_IN_URB; i++) { + urb = portdata->in_urbs[i]; + if (!urb) + continue; + err = usb_submit_urb(urb, GFP_KERNEL); + if (err) { + dbg("%s: submit urb %d failed (%d) %d", + __func__, i, err, urb->transfer_buffer_length); + } + } + + if (intfdata->send_setup) + intfdata->send_setup(port); + + serial->interface->needs_remote_wakeup = 1; + spin_lock_irq(&intfdata->susp_lock); + portdata->opened = 1; + spin_unlock_irq(&intfdata->susp_lock); + usb_autopm_put_interface(serial->interface); + + return 0; +} +EXPORT_SYMBOL(usb_wwan_open); + +void usb_wwan_close(struct usb_serial_port *port) +{ + int i; + struct usb_serial *serial = port->serial; + struct usb_wwan_port_private *portdata; + struct usb_wwan_intf_private *intfdata = port->serial->private; + + dbg("%s", __func__); + portdata = usb_get_serial_port_data(port); + + if (serial->dev) { + /* Stop reading/writing urbs */ + spin_lock_irq(&intfdata->susp_lock); + portdata->opened = 0; + spin_unlock_irq(&intfdata->susp_lock); + + for (i = 0; i < N_IN_URB; i++) + usb_kill_urb(portdata->in_urbs[i]); + for (i = 0; i < N_OUT_URB; i++) + usb_kill_urb(portdata->out_urbs[i]); + usb_autopm_get_interface(serial->interface); + serial->interface->needs_remote_wakeup = 0; + } +} +EXPORT_SYMBOL(usb_wwan_close); + +/* Helper functions used by usb_wwan_setup_urbs */ +static struct urb *usb_wwan_setup_urb(struct usb_serial *serial, int endpoint, + int dir, void *ctx, char *buf, int len, + void (*callback) (struct urb *)) +{ + 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.", __func__, 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 usb_wwan_setup_urbs(struct usb_serial *serial) +{ + int i, j; + struct usb_serial_port *port; + struct usb_wwan_port_private *portdata; + + dbg("%s", __func__); + + for (i = 0; i < serial->num_ports; i++) { + port = serial->port[i]; + portdata = usb_get_serial_port_data(port); + + /* Do indat endpoints first */ + for (j = 0; j < N_IN_URB; ++j) { + portdata->in_urbs[j] = usb_wwan_setup_urb(serial, + port-> + bulk_in_endpointAddress, + USB_DIR_IN, + port, + portdata-> + in_buffer[j], + IN_BUFLEN, + usb_wwan_indat_callback); + } + + /* outdat endpoints */ + for (j = 0; j < N_OUT_URB; ++j) { + portdata->out_urbs[j] = usb_wwan_setup_urb(serial, + port-> + bulk_out_endpointAddress, + USB_DIR_OUT, + port, + portdata-> + out_buffer + [j], + OUT_BUFLEN, + usb_wwan_outdat_callback); + } + } +} + +int usb_wwan_startup(struct usb_serial *serial) +{ + int i, j, err; + struct usb_serial_port *port; + struct usb_wwan_port_private *portdata; + u8 *buffer; + + dbg("%s", __func__); + + /* Now setup per port private data */ + for (i = 0; i < serial->num_ports; i++) { + port = serial->port[i]; + portdata = kzalloc(sizeof(*portdata), GFP_KERNEL); + if (!portdata) { + dbg("%s: kmalloc for usb_wwan_port_private (%d) failed!.", + __func__, i); + return 1; + } + init_usb_anchor(&portdata->delayed); + + for (j = 0; j < N_IN_URB; j++) { + buffer = (u8 *) __get_free_page(GFP_KERNEL); + if (!buffer) + goto bail_out_error; + portdata->in_buffer[j] = buffer; + } + + for (j = 0; j < N_OUT_URB; j++) { + buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL); + if (!buffer) + goto bail_out_error2; + portdata->out_buffer[j] = buffer; + } + + 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", __func__, err); + } + usb_wwan_setup_urbs(serial); + return 0; + +bail_out_error2: + for (j = 0; j < N_OUT_URB; j++) + kfree(portdata->out_buffer[j]); +bail_out_error: + for (j = 0; j < N_IN_URB; j++) + if (portdata->in_buffer[j]) + free_page((unsigned long)portdata->in_buffer[j]); + kfree(portdata); + return 1; +} +EXPORT_SYMBOL(usb_wwan_startup); + +static void stop_read_write_urbs(struct usb_serial *serial) +{ + int i, j; + struct usb_serial_port *port; + struct usb_wwan_port_private *portdata; + + /* 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++) + usb_kill_urb(portdata->in_urbs[j]); + for (j = 0; j < N_OUT_URB; j++) + usb_kill_urb(portdata->out_urbs[j]); + } +} + +void usb_wwan_disconnect(struct usb_serial *serial) +{ + dbg("%s", __func__); + + stop_read_write_urbs(serial); +} +EXPORT_SYMBOL(usb_wwan_disconnect); + +void usb_wwan_release(struct usb_serial *serial) +{ + int i, j; + struct usb_serial_port *port; + struct usb_wwan_port_private *portdata; + + dbg("%s", __func__); + + /* 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++) { + usb_free_urb(portdata->in_urbs[j]); + free_page((unsigned long) + portdata->in_buffer[j]); + portdata->in_urbs[j] = NULL; + } + for (j = 0; j < N_OUT_URB; j++) { + usb_free_urb(portdata->out_urbs[j]); + kfree(portdata->out_buffer[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)); + } +} +EXPORT_SYMBOL(usb_wwan_release); + +#ifdef CONFIG_PM +int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message) +{ + struct usb_wwan_intf_private *intfdata = serial->private; + int b; + + dbg("%s entered", __func__); + + if (message.event & PM_EVENT_AUTO) { + spin_lock_irq(&intfdata->susp_lock); + b = intfdata->in_flight; + spin_unlock_irq(&intfdata->susp_lock); + + if (b) + return -EBUSY; + } + + spin_lock_irq(&intfdata->susp_lock); + intfdata->suspended = 1; + spin_unlock_irq(&intfdata->susp_lock); + stop_read_write_urbs(serial); + + return 0; +} +EXPORT_SYMBOL(usb_wwan_suspend); + +static void play_delayed(struct usb_serial_port *port) +{ + struct usb_wwan_intf_private *data; + struct usb_wwan_port_private *portdata; + struct urb *urb; + int err; + + portdata = usb_get_serial_port_data(port); + data = port->serial->private; + while ((urb = usb_get_from_anchor(&portdata->delayed))) { + err = usb_submit_urb(urb, GFP_ATOMIC); + if (!err) + data->in_flight++; + } +} + +int usb_wwan_resume(struct usb_serial *serial) +{ + int i, j; + struct usb_serial_port *port; + struct usb_wwan_intf_private *intfdata = serial->private; + struct usb_wwan_port_private *portdata; + struct urb *urb; + int err = 0; + + dbg("%s entered", __func__); + /* get the interrupt URBs resubmitted unconditionally */ + for (i = 0; i < serial->num_ports; i++) { + port = serial->port[i]; + if (!port->interrupt_in_urb) { + dbg("%s: No interrupt URB for port %d", __func__, i); + continue; + } + err = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO); + dbg("Submitted interrupt URB for port %d (result %d)", i, err); + if (err < 0) { + err("%s: Error %d for interrupt URB of port%d", + __func__, err, i); + goto err_out; + } + } + + for (i = 0; i < serial->num_ports; i++) { + /* walk all ports */ + port = serial->port[i]; + portdata = usb_get_serial_port_data(port); + + /* skip closed ports */ + spin_lock_irq(&intfdata->susp_lock); + if (!portdata->opened) { + spin_unlock_irq(&intfdata->susp_lock); + continue; + } + + for (j = 0; j < N_IN_URB; j++) { + urb = portdata->in_urbs[j]; + err = usb_submit_urb(urb, GFP_ATOMIC); + if (err < 0) { + err("%s: Error %d for bulk URB %d", + __func__, err, i); + spin_unlock_irq(&intfdata->susp_lock); + goto err_out; + } + } + play_delayed(port); + spin_unlock_irq(&intfdata->susp_lock); + } + spin_lock_irq(&intfdata->susp_lock); + intfdata->suspended = 0; + spin_unlock_irq(&intfdata->susp_lock); +err_out: + return err; +} +EXPORT_SYMBOL(usb_wwan_resume); +#endif + +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"); |