- 根目录:
- drivers
- usb
- serial
- generic.c
/*
* USB Serial Converter Generic functions
*
* Copyright (C) 2010 Johan Hovold (jhovold@gmail.com)
* Copyright (C) 1999 - 2002 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 version
* 2 as published by the Free Software Foundation.
*
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/sysrq.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/uaccess.h>
#include <linux/kfifo.h>
#include <linux/serial.h>
static int debug;
#ifdef CONFIG_USB_SERIAL_GENERIC
static int generic_probe(struct usb_interface *interface,
const struct usb_device_id *id);
static __u16 vendor = 0x05f9;
static __u16 product = 0xffff;
module_param(vendor, ushort, 0);
MODULE_PARM_DESC(vendor, "User specified USB idVendor");
module_param(product, ushort, 0);
MODULE_PARM_DESC(product, "User specified USB idProduct");
static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
/* we want to look at all devices, as the vendor/product id can change
* depending on the command line argument */
static const struct usb_device_id generic_serial_ids[] = {
{.driver_info = 42},
{}
};
static struct usb_driver generic_driver = {
.name = "usbserial_generic",
.probe = generic_probe,
.disconnect = usb_serial_disconnect,
.id_table = generic_serial_ids,
.no_dynamic_id = 1,
};
/* All of the device info needed for the Generic Serial Converter */
struct usb_serial_driver usb_serial_generic_device = {
.driver = {
.owner = THIS_MODULE,
.name = "generic",
},
.id_table = generic_device_ids,
.usb_driver = &generic_driver,
.num_ports = 1,
.disconnect = usb_serial_generic_disconnect,
.release = usb_serial_generic_release,
.throttle = usb_serial_generic_throttle,
.unthrottle = usb_serial_generic_unthrottle,
.resume = usb_serial_generic_resume,
};
static int generic_probe(struct usb_interface *interface,
const struct usb_device_id *id)
{
const struct usb_device_id *id_pattern;
id_pattern = usb_match_id(interface, generic_device_ids);
if (id_pattern != NULL)
return usb_serial_probe(interface, id);
return -ENODEV;
}
#endif
int usb_serial_generic_register(int _debug)
{
int retval = 0;
debug = _debug;
#ifdef CONFIG_USB_SERIAL_GENERIC
generic_device_ids[0].idVendor = vendor;
generic_device_ids[0].idProduct = product;
generic_device_ids[0].match_flags =
USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
/* register our generic driver with ourselves */
retval = usb_serial_register(&usb_serial_generic_device);
if (retval)
goto exit;
retval = usb_register(&generic_driver);
if (retval)
usb_serial_deregister(&usb_serial_generic_device);
exit:
#endif
return retval;
}
void usb_serial_generic_deregister(void)
{
#ifdef CONFIG_USB_SERIAL_GENERIC
/* remove our generic driver */
usb_deregister(&generic_driver);
usb_serial_deregister(&usb_serial_generic_device);
#endif
}
int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
{
int result = 0;
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
/* clear the throttle flags */
spin_lock_irqsave(&port->lock, flags);
port->throttled = 0;
port->throttle_req = 0;
spin_unlock_irqrestore(&port->lock, flags);
/* if we have a bulk endpoint, start reading from it */
if (port->bulk_in_size)
result = usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
return result;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_open);
static void generic_cleanup(struct usb_serial_port *port)
{
struct usb_serial *serial = port->serial;
unsigned long flags;
int i;
dbg("%s - port %d", __func__, port->number);
if (serial->dev) {
/* shutdown any bulk transfers that might be going on */
if (port->bulk_out_size) {
usb_kill_urb(port->write_urb);
for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
usb_kill_urb(port->write_urbs[i]);
spin_lock_irqsave(&port->lock, flags);
kfifo_reset_out(&port->write_fifo);
spin_unlock_irqrestore(&port->lock, flags);
}
if (port->bulk_in_size)
usb_kill_urb(port->read_urb);
}
}
void usb_serial_generic_close(struct usb_serial_port *port)
{
dbg("%s - port %d", __func__, port->number);
generic_cleanup(port);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_close);
int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
void *dest, size_t size)
{
return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);
}
/**
* usb_serial_generic_write_start - kick off an URB write
* @port: Pointer to the &struct usb_serial_port data
*
* Returns zero on success, or a negative errno value
*/
static int usb_serial_generic_write_start(struct usb_serial_port *port)
{
struct urb *urb;
int count, result;
unsigned long flags;
int i;
if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
return 0;
retry:
spin_lock_irqsave(&port->lock, flags);
if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
spin_unlock_irqrestore(&port->lock, flags);
return 0;
}
i = (int)find_first_bit(&port->write_urbs_free,
ARRAY_SIZE(port->write_urbs));
spin_unlock_irqrestore(&port->lock, flags);
urb = port->write_urbs[i];
count = port->serial->type->prepare_write_buffer(port,
urb->transfer_buffer,
port->bulk_out_size);
urb->transfer_buffer_length = count;
usb_serial_debug_data(debug, &port->dev, __func__, count,
urb->transfer_buffer);
spin_lock_irqsave(&port->lock, flags);
port->tx_bytes += count;
spin_unlock_irqrestore(&port->lock, flags);
clear_bit(i, &port->write_urbs_free);
result = usb_submit_urb(urb, GFP_ATOMIC);
if (result) {
dev_err(&port->dev, "%s - error submitting urb: %d\n",
__func__, result);
set_bit(i, &port->write_urbs_free);
spin_lock_irqsave(&port->lock, flags);
port->tx_bytes -= count;
spin_unlock_irqrestore(&port->lock, flags);
clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
return result;
}
/* Try sending off another urb, unless in irq context (in which case
* there will be no free urb). */
if (!in_irq())
goto retry;
clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
return 0;
}
/**
* usb_serial_generic_write - generic write function for serial USB devices
* @tty: Pointer to &struct tty_struct for the device
* @port: Pointer to the &usb_serial_port structure for the device
* @buf: Pointer to the data to write
* @count: Number of bytes to write
*
* Returns the number of characters actually written, which may be anything
* from zero to @count. If an error occurs, it returns the negative errno
* value.
*/
int usb_serial_generic_write(struct tty_struct *tty,
struct usb_serial_port *port, const unsigned char *buf, int count)
{
int result;
dbg("%s - port %d", __func__, port->number);
/* only do something if we have a bulk out endpoint */
if (!port->bulk_out_size)
return -ENODEV;
if (!count)
return 0;
count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
result = usb_serial_generic_write_start(port);
if (result)
return result;
return count;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_write);
int usb_serial_generic_write_room(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
unsigned long flags;
int room;
dbg("%s - port %d", __func__, port->number);
if (!port->bulk_out_size)
return 0;
spin_lock_irqsave(&port->lock, flags);
room = kfifo_avail(&port->write_fifo);
spin_unlock_irqrestore(&port->lock, flags);
dbg("%s - returns %d", __func__, room);
return room;
}
int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
unsigned long flags;
int chars;
dbg("%s - port %d", __func__, port->number);
if (!port->bulk_out_size)
return 0;
spin_lock_irqsave(&port->lock, flags);
chars = kfifo_len(&port->write_fifo) + port->tx_bytes;
spin_unlock_irqrestore(&port->lock, flags);
dbg("%s - returns %d", __func__, chars);
return chars;
}
int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
gfp_t mem_flags)
{
int result;
result = usb_submit_urb(port->read_urb, mem_flags);
if (result && result != -EPERM) {
dev_err(&port->dev, "%s - error submitting urb: %d\n",
__func__, result);
}
return result;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb);
void usb_serial_generic_process_read_urb(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
struct tty_struct *tty;
char *ch = (char *)urb->transfer_buffer;
int i;
if (!urb->actual_length)
return;
tty = tty_port_tty_get(&port->port);
if (!tty)
return;
/* The per character mucking around with sysrq path it too slow for
stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
where the USB serial is not a console anyway */
if (!port->port.console || !port->sysrq)
tty_insert_flip_string(tty, ch, urb->actual_length);
else {
for (i = 0; i < urb->actual_length; i++, ch++) {
if (!usb_serial_handle_sysrq_char(port, *ch))
tty_insert_flip_char(tty, *ch, TTY_NORMAL);
}
}
tty_flip_buffer_push(tty);
tty_kref_put(tty);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
void usb_serial_generic_read_bulk_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
unsigned char *data = urb->transfer_buffer;
int status = urb->status;
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
if (unlikely(status != 0)) {
dbg("%s - nonzero read bulk status received: %d",
__func__, status);
return;
}
usb_serial_debug_data(debug, &port->dev, __func__,
urb->actual_length, data);
port->serial->type->process_read_urb(urb);
/* Throttle the device if requested by tty */
spin_lock_irqsave(&port->lock, flags);
port->throttled = port->throttle_req;
if (!port->throttled) {
spin_unlock_irqrestore(&port->lock, flags);
usb_serial_generic_submit_read_urb(port, GFP_ATOMIC);
} else
spin_unlock_irqrestore(&port->lock, flags);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
void usb_serial_generic_write_bulk_callback(struct urb *urb)
{
unsigned long flags;
struct usb_serial_port *port = urb->context;
int status = urb->status;
int i;
dbg("%s - port %d", __func__, port->number);
for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
if (port->write_urbs[i] == urb)
break;
spin_lock_irqsave(&port->lock, flags);
port->tx_bytes -= urb->transfer_buffer_length;
set_bit(i, &port->write_urbs_free);
spin_unlock_irqrestore(&port->lock, flags);
if (status) {
dbg("%s - non-zero urb status: %d", __func__, status);
spin_lock_irqsave(&port->lock, flags);
kfifo_reset_out(&port->write_fifo);
spin_unlock_irqrestore(&port->lock, flags);
} else {
usb_serial_generic_write_start(port);
}
usb_serial_port_softint(port);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
void usb_serial_generic_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
/* Set the throttle request flag. It will be picked up
* by usb_serial_generic_read_bulk_callback(). */
spin_lock_irqsave(&port->lock, flags);
port->throttle_req = 1;
spin_unlock_irqrestore(&port->lock, flags);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
void usb_serial_generic_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
int was_throttled;
dbg("%s - port %d", __func__, port->number);
/* Clear the throttle flags */
spin_lock_irq(&port->lock);
was_throttled = port->throttled;
port->throttled = port->throttle_req = 0;
spin_unlock_irq(&port->lock);
if (was_throttled)
usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
#ifdef CONFIG_MAGIC_SYSRQ
int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
{
if (port->sysrq && port->port.console) {
if (ch && time_before(jiffies, port->sysrq)) {
handle_sysrq(ch);
port->sysrq = 0;
return 1;
}
port->sysrq = 0;
}
return 0;
}
#else
int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
{
return 0;
}
#endif
EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
int usb_serial_handle_break(struct usb_serial_port *port)
{
if (!port->sysrq) {
port->sysrq = jiffies + HZ*5;
return 1;
}
port->sysrq = 0;
return 0;
}
EXPORT_SYMBOL_GPL(usb_serial_handle_break);
/**
* usb_serial_handle_dcd_change - handle a change of carrier detect state
* @port: usb_serial_port structure for the open port
* @tty: tty_struct structure for the port
* @status: new carrier detect status, nonzero if active
*/
void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
struct tty_struct *tty, unsigned int status)
{
struct tty_port *port = &usb_port->port;
dbg("%s - port %d, status %d", __func__, usb_port->number, status);
if (status)
wake_up_interruptible(&port->open_wait);
else if (tty && !C_CLOCAL(tty))
tty_hangup(tty);
}
EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
int usb_serial_generic_resume(struct usb_serial *serial)
{
struct usb_serial_port *port;
int i, c = 0, r;
for (i = 0; i < serial->num_ports; i++) {
port = serial->port[i];
if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
continue;
if (port->read_urb) {
r = usb_submit_urb(port->read_urb, GFP_NOIO);
if (r < 0)
c++;
}
if (port->bulk_out_size) {
r = usb_serial_generic_write_start(port);
if (r < 0)
c++;
}
}
return c ? -EIO : 0;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
void usb_serial_generic_disconnect(struct usb_serial *serial)
{
int i;
dbg("%s", __func__);
/* stop reads and writes on all ports */
for (i = 0; i < serial->num_ports; ++i)
generic_cleanup(serial->port[i]);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_disconnect);
void usb_serial_generic_release(struct usb_serial *serial)
{
dbg("%s", __func__);
}