linux/drivers/usb/serial/generic.c

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/*
* USB Serial Converter Generic functions
*
* Copyright (C) 2010 - 2013 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>
#ifdef CONFIG_USB_SERIAL_GENERIC
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. */
/* 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,
.num_ports = 1,
.throttle = usb_serial_generic_throttle,
.unthrottle = usb_serial_generic_unthrottle,
.resume = usb_serial_generic_resume,
};
static struct usb_serial_driver * const serial_drivers[] = {
&usb_serial_generic_device, NULL
};
#endif
int usb_serial_generic_register(void)
{
int retval = 0;
#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_drivers(serial_drivers,
"usbserial_generic", generic_device_ids);
#endif
return retval;
}
void usb_serial_generic_deregister(void)
{
#ifdef CONFIG_USB_SERIAL_GENERIC
/* remove our generic driver */
USB: serial: rework usb_serial_register/deregister_drivers() This reworks the usb_serial_register_drivers() and usb_serial_deregister_drivers() to not need a pointer to a struct usb_driver anymore. The usb_driver structure is now created dynamically and registered and unregistered as needed. This saves lines of code in each usb-serial driver. All in-kernel users of these functions were also fixed up at this time. The pl2303 driver was tested that everything worked properly. Thanks for the idea to do this from Alan Stern. Cc: Adhir Ramjiawan <adhirramjiawan0@gmail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Al Borchers <alborchers@steinerpoint.com> Cc: Aleksey Babahin <tamerlan311@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrew Worsley <amworsley@gmail.com> Cc: Bart Hartgers <bart.hartgers@gmail.com> Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Dan Carpenter <error27@gmail.com> Cc: Dan Williams <dcbw@redhat.com> Cc: Donald Lee <donald@asix.com.tw> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Gary Brubaker <xavyer@ix.netcom.com> Cc: Jesper Juhl <jj@chaosbits.net> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Johan Hovold <jhovold@gmail.com> Cc: Julia Lawall <julia@diku.dk> Cc: Kautuk Consul <consul.kautuk@gmail.com> Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Cc: Lonnie Mendez <dignome@gmail.com> Cc: Matthias Bruestle and Harald Welte <support@reiner-sct.com> Cc: Matthias Urlichs <smurf@smurf.noris.de> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Michal Sroczynski <msroczyn@gmail.com> Cc: "Michał Wróbel" <michal.wrobel@flytronic.pl> Cc: Oliver Neukum <oliver@neukum.name> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Berger <pberger@brimson.com> Cc: Preston Fick <preston.fick@silabs.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Rigbert Hamisch <rigbert@gmx.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Simon Arlott <simon@fire.lp0.eu> Cc: Support Department <support@connecttech.com> Cc: Thomas Tuttle <ttuttle@chromium.org> Cc: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de> Cc: Wang YanQing <Udknight@gmail.com> Cc: William Greathouse <wgreathouse@smva.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-08 22:46:14 +00:00
usb_serial_deregister_drivers(serial_drivers);
#endif
}
int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
{
int result = 0;
unsigned long flags;
/* 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_urbs(port, GFP_KERNEL);
return result;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_open);
void usb_serial_generic_close(struct usb_serial_port *port)
{
unsigned long flags;
int i;
if (port->bulk_out_size) {
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) {
for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
usb_kill_urb(port->read_urbs[i]);
}
}
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(&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_console(port, "%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;
/* 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;
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);
dev_dbg(&port->dev, "%s - returns %d\n", __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;
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);
dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
return chars;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_chars_in_buffer);
void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout)
{
struct usb_serial_port *port = tty->driver_data;
unsigned int bps;
unsigned long period;
unsigned long expire;
bps = tty_get_baud_rate(tty);
if (!bps)
bps = 9600; /* B0 */
/*
* Use a poll-period of roughly the time it takes to send one
* character or at least one jiffy.
*/
period = max_t(unsigned long, (10 * HZ / bps), 1);
period = min_t(unsigned long, period, timeout);
dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",
__func__, jiffies_to_msecs(timeout),
jiffies_to_msecs(period));
expire = jiffies + timeout;
while (!port->serial->type->tx_empty(port)) {
schedule_timeout_interruptible(period);
if (signal_pending(current))
break;
if (time_after(jiffies, expire))
break;
}
}
EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent);
static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
int index, gfp_t mem_flags)
{
int res;
if (!test_and_clear_bit(index, &port->read_urbs_free))
return 0;
dev_dbg(&port->dev, "%s - urb %d\n", __func__, index);
res = usb_submit_urb(port->read_urbs[index], mem_flags);
if (res) {
if (res != -EPERM) {
dev_err(&port->dev,
"%s - usb_submit_urb failed: %d\n",
__func__, res);
}
set_bit(index, &port->read_urbs_free);
return res;
}
return 0;
}
int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
gfp_t mem_flags)
{
int res;
int i;
for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
res = usb_serial_generic_submit_read_urb(port, i, mem_flags);
if (res)
goto err;
}
return 0;
err:
for (; i >= 0; --i)
usb_kill_urb(port->read_urbs[i]);
return res;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs);
void usb_serial_generic_process_read_urb(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
char *ch = (char *)urb->transfer_buffer;
int i;
if (!urb->actual_length)
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(&port->port, 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(&port->port, *ch, TTY_NORMAL);
}
}
tty_flip_buffer_push(&port->port);
}
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;
unsigned long flags;
int i;
for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
if (urb == port->read_urbs[i])
break;
}
set_bit(i, &port->read_urbs_free);
dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
urb->actual_length);
if (urb->status) {
dev_dbg(&port->dev, "%s - non-zero urb status: %d\n",
__func__, urb->status);
return;
}
usb_serial_debug_data(&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, i, 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;
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) {
dev_dbg(&port->dev, "%s - non-zero urb status: %d\n",
__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;
/* 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;
/* 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_urbs(port, GFP_KERNEL);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
static bool usb_serial_generic_msr_changed(struct tty_struct *tty,
unsigned long arg, struct async_icount *cprev)
{
struct usb_serial_port *port = tty->driver_data;
struct async_icount cnow;
unsigned long flags;
bool ret;
/*
* Use tty-port initialised flag to detect all hangups including the
* one generated at USB-device disconnect.
*
* FIXME: Remove hupping check once tty_port_hangup calls shutdown
* (which clears the initialised flag) before wake up.
*/
if (test_bit(TTY_HUPPING, &tty->flags))
return true;
if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
return true;
spin_lock_irqsave(&port->lock, flags);
cnow = port->icount; /* atomic copy*/
spin_unlock_irqrestore(&port->lock, flags);
ret = ((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
((arg & TIOCM_CD) && (cnow.dcd != cprev->dcd)) ||
((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
*cprev = cnow;
return ret;
}
int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg)
{
struct usb_serial_port *port = tty->driver_data;
struct async_icount cnow;
unsigned long flags;
int ret;
spin_lock_irqsave(&port->lock, flags);
cnow = port->icount; /* atomic copy */
spin_unlock_irqrestore(&port->lock, flags);
ret = wait_event_interruptible(port->port.delta_msr_wait,
usb_serial_generic_msr_changed(tty, arg, &cnow));
if (!ret) {
if (test_bit(TTY_HUPPING, &tty->flags))
ret = -EIO;
if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
ret = -EIO;
}
return ret;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait);
int usb_serial_generic_get_icount(struct tty_struct *tty,
struct serial_icounter_struct *icount)
{
struct usb_serial_port *port = tty->driver_data;
struct async_icount cnow;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
cnow = port->icount; /* atomic copy */
spin_unlock_irqrestore(&port->lock, flags);
icount->cts = cnow.cts;
icount->dsr = cnow.dsr;
icount->rng = cnow.rng;
icount->dcd = cnow.dcd;
icount->tx = cnow.tx;
icount->rx = cnow.rx;
icount->frame = cnow.frame;
icount->parity = cnow.parity;
icount->overrun = cnow.overrun;
icount->brk = cnow.brk;
icount->buf_overrun = cnow.buf_overrun;
return 0;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount);
#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;
dev_dbg(&usb_port->dev, "%s - status %d\n", __func__, 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->bulk_in_size) {
r = usb_serial_generic_submit_read_urbs(port,
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);