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cdc-acm.c
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cdc-acm.c
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// SPDX-License-Identifier: GPL-2.0+
/*
* cdc-acm.c
*
* Copyright (c) 1999 Armin Fuerst <fuerst@in.tum.de>
* Copyright (c) 1999 Pavel Machek <pavel@ucw.cz>
* Copyright (c) 1999 Johannes Erdfelt <johannes@erdfelt.com>
* Copyright (c) 2000 Vojtech Pavlik <vojtech@suse.cz>
* Copyright (c) 2004 Oliver Neukum <oliver@neukum.name>
* Copyright (c) 2005 David Kubicek <dave@awk.cz>
* Copyright (c) 2011 Johan Hovold <jhovold@gmail.com>
*
* USB Abstract Control Model driver for USB modems and ISDN adapters
*
* Sponsored by SuSE
*/
#undef DEBUG
#undef VERBOSE_DEBUG
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/log2.h>
#include <linux/tty.h>
#include <linux/serial.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/tty_ldisc.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <asm/byteorder.h>
#include <linux/unaligned.h>
#include <linux/idr.h>
#include <linux/list.h>
#include "cdc-acm.h"
#define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek, Johan Hovold"
#define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
static struct usb_driver acm_driver;
static struct tty_driver *acm_tty_driver;
static DEFINE_IDR(acm_minors);
static DEFINE_MUTEX(acm_minors_lock);
static void acm_tty_set_termios(struct tty_struct *tty,
const struct ktermios *termios_old);
/*
* acm_minors accessors
*/
/*
* Look up an ACM structure by minor. If found and not disconnected, increment
* its refcount and return it with its mutex held.
*/
static struct acm *acm_get_by_minor(unsigned int minor)
{
struct acm *acm;
mutex_lock(&acm_minors_lock);
acm = idr_find(&acm_minors, minor);
if (acm) {
mutex_lock(&acm->mutex);
if (acm->disconnected) {
mutex_unlock(&acm->mutex);
acm = NULL;
} else {
tty_port_get(&acm->port);
mutex_unlock(&acm->mutex);
}
}
mutex_unlock(&acm_minors_lock);
return acm;
}
/*
* Try to find an available minor number and if found, associate it with 'acm'.
*/
static int acm_alloc_minor(struct acm *acm)
{
int minor;
mutex_lock(&acm_minors_lock);
minor = idr_alloc(&acm_minors, acm, 0, ACM_TTY_MINORS, GFP_KERNEL);
mutex_unlock(&acm_minors_lock);
return minor;
}
/* Release the minor number associated with 'acm'. */
static void acm_release_minor(struct acm *acm)
{
mutex_lock(&acm_minors_lock);
idr_remove(&acm_minors, acm->minor);
mutex_unlock(&acm_minors_lock);
}
/*
* Functions for ACM control messages.
*/
static int acm_ctrl_msg(struct acm *acm, int request, int value,
void *buf, int len)
{
int retval;
retval = usb_autopm_get_interface(acm->control);
if (retval)
return retval;
retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
request, USB_RT_ACM, value,
acm->control->altsetting[0].desc.bInterfaceNumber,
buf, len, USB_CTRL_SET_TIMEOUT);
dev_dbg(&acm->control->dev,
"%s - rq 0x%02x, val %#x, len %#x, result %d\n",
__func__, request, value, len, retval);
usb_autopm_put_interface(acm->control);
return retval < 0 ? retval : 0;
}
/* devices aren't required to support these requests.
* the cdc acm descriptor tells whether they do...
*/
static inline int acm_set_control(struct acm *acm, int control)
{
if (acm->quirks & QUIRK_CONTROL_LINE_STATE)
return -EOPNOTSUPP;
return acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE,
control, NULL, 0);
}
#define acm_set_line(acm, line) \
acm_ctrl_msg(acm, USB_CDC_REQ_SET_LINE_CODING, 0, line, sizeof *(line))
#define acm_send_break(acm, ms) \
acm_ctrl_msg(acm, USB_CDC_REQ_SEND_BREAK, ms, NULL, 0)
static void acm_poison_urbs(struct acm *acm)
{
int i;
usb_poison_urb(acm->ctrlurb);
for (i = 0; i < ACM_NW; i++)
usb_poison_urb(acm->wb[i].urb);
for (i = 0; i < acm->rx_buflimit; i++)
usb_poison_urb(acm->read_urbs[i]);
}
static void acm_unpoison_urbs(struct acm *acm)
{
int i;
for (i = 0; i < acm->rx_buflimit; i++)
usb_unpoison_urb(acm->read_urbs[i]);
for (i = 0; i < ACM_NW; i++)
usb_unpoison_urb(acm->wb[i].urb);
usb_unpoison_urb(acm->ctrlurb);
}
/*
* Write buffer management.
* All of these assume proper locks taken by the caller.
*/
static int acm_wb_alloc(struct acm *acm)
{
int i, wbn;
struct acm_wb *wb;
wbn = 0;
i = 0;
for (;;) {
wb = &acm->wb[wbn];
if (!wb->use) {
wb->use = true;
wb->len = 0;
return wbn;
}
wbn = (wbn + 1) % ACM_NW;
if (++i >= ACM_NW)
return -1;
}
}
static int acm_wb_is_avail(struct acm *acm)
{
int i, n;
unsigned long flags;
n = ACM_NW;
spin_lock_irqsave(&acm->write_lock, flags);
for (i = 0; i < ACM_NW; i++)
if(acm->wb[i].use)
n--;
spin_unlock_irqrestore(&acm->write_lock, flags);
return n;
}
/*
* Finish write. Caller must hold acm->write_lock
*/
static void acm_write_done(struct acm *acm, struct acm_wb *wb)
{
wb->use = false;
acm->transmitting--;
usb_autopm_put_interface_async(acm->control);
}
/*
* Poke write.
*
* the caller is responsible for locking
*/
static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
{
int rc;
acm->transmitting++;
wb->urb->transfer_buffer = wb->buf;
wb->urb->transfer_dma = wb->dmah;
wb->urb->transfer_buffer_length = wb->len;
wb->urb->dev = acm->dev;
rc = usb_submit_urb(wb->urb, GFP_ATOMIC);
if (rc < 0) {
if (rc != -EPERM)
dev_err(&acm->data->dev,
"%s - usb_submit_urb(write bulk) failed: %d\n",
__func__, rc);
acm_write_done(acm, wb);
}
return rc;
}
/*
* attributes exported through sysfs
*/
static ssize_t bmCapabilities_show
(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_interface *intf = to_usb_interface(dev);
struct acm *acm = usb_get_intfdata(intf);
return sprintf(buf, "%d", acm->ctrl_caps);
}
static DEVICE_ATTR_RO(bmCapabilities);
static ssize_t wCountryCodes_show
(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_interface *intf = to_usb_interface(dev);
struct acm *acm = usb_get_intfdata(intf);
memcpy(buf, acm->country_codes, acm->country_code_size);
return acm->country_code_size;
}
static DEVICE_ATTR_RO(wCountryCodes);
static ssize_t iCountryCodeRelDate_show
(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_interface *intf = to_usb_interface(dev);
struct acm *acm = usb_get_intfdata(intf);
return sprintf(buf, "%d", acm->country_rel_date);
}
static DEVICE_ATTR_RO(iCountryCodeRelDate);
/*
* Interrupt handlers for various ACM device responses
*/
static void acm_process_notification(struct acm *acm, unsigned char *buf)
{
int newctrl;
int difference;
unsigned long flags;
struct usb_cdc_notification *dr = (struct usb_cdc_notification *)buf;
unsigned char *data = buf + sizeof(struct usb_cdc_notification);
switch (dr->bNotificationType) {
case USB_CDC_NOTIFY_NETWORK_CONNECTION:
dev_dbg(&acm->control->dev,
"%s - network connection: %d\n", __func__, dr->wValue);
break;
case USB_CDC_NOTIFY_SERIAL_STATE:
if (le16_to_cpu(dr->wLength) != 2) {
dev_dbg(&acm->control->dev,
"%s - malformed serial state\n", __func__);
break;
}
newctrl = get_unaligned_le16(data);
dev_dbg(&acm->control->dev,
"%s - serial state: 0x%x\n", __func__, newctrl);
if (!acm->clocal && (acm->ctrlin & ~newctrl & USB_CDC_SERIAL_STATE_DCD)) {
dev_dbg(&acm->control->dev,
"%s - calling hangup\n", __func__);
tty_port_tty_hangup(&acm->port, false);
}
difference = acm->ctrlin ^ newctrl;
if ((difference & USB_CDC_SERIAL_STATE_DCD) && acm->port.tty) {
struct tty_ldisc *ld = tty_ldisc_ref(acm->port.tty);
if (ld) {
if (ld->ops->dcd_change)
ld->ops->dcd_change(acm->port.tty, newctrl & USB_CDC_SERIAL_STATE_DCD);
tty_ldisc_deref(ld);
}
}
spin_lock_irqsave(&acm->read_lock, flags);
acm->ctrlin = newctrl;
acm->oldcount = acm->iocount;
if (difference & USB_CDC_SERIAL_STATE_DSR)
acm->iocount.dsr++;
if (difference & USB_CDC_SERIAL_STATE_DCD)
acm->iocount.dcd++;
if (newctrl & USB_CDC_SERIAL_STATE_BREAK) {
acm->iocount.brk++;
tty_insert_flip_char(&acm->port, 0, TTY_BREAK);
}
if (newctrl & USB_CDC_SERIAL_STATE_RING_SIGNAL)
acm->iocount.rng++;
if (newctrl & USB_CDC_SERIAL_STATE_FRAMING)
acm->iocount.frame++;
if (newctrl & USB_CDC_SERIAL_STATE_PARITY)
acm->iocount.parity++;
if (newctrl & USB_CDC_SERIAL_STATE_OVERRUN)
acm->iocount.overrun++;
spin_unlock_irqrestore(&acm->read_lock, flags);
if (newctrl & USB_CDC_SERIAL_STATE_BREAK)
tty_flip_buffer_push(&acm->port);
if (difference)
wake_up_all(&acm->wioctl);
break;
default:
dev_dbg(&acm->control->dev,
"%s - unknown notification %d received: index %d len %d\n",
__func__,
dr->bNotificationType, dr->wIndex, dr->wLength);
}
}
/* control interface reports status changes with "interrupt" transfers */
static void acm_ctrl_irq(struct urb *urb)
{
struct acm *acm = urb->context;
struct usb_cdc_notification *dr = urb->transfer_buffer;
unsigned int current_size = urb->actual_length;
unsigned int expected_size, copy_size, alloc_size;
int retval;
int status = urb->status;
switch (status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dev_dbg(&acm->control->dev,
"%s - urb shutting down with status: %d\n",
__func__, status);
return;
default:
dev_dbg(&acm->control->dev,
"%s - nonzero urb status received: %d\n",
__func__, status);
goto exit;
}
usb_mark_last_busy(acm->dev);
if (acm->nb_index)
dr = (struct usb_cdc_notification *)acm->notification_buffer;
/* size = notification-header + (optional) data */
expected_size = sizeof(struct usb_cdc_notification) +
le16_to_cpu(dr->wLength);
if (current_size < expected_size) {
/* notification is transmitted fragmented, reassemble */
if (acm->nb_size < expected_size) {
u8 *new_buffer;
alloc_size = roundup_pow_of_two(expected_size);
/* Final freeing is done on disconnect. */
new_buffer = krealloc(acm->notification_buffer,
alloc_size, GFP_ATOMIC);
if (!new_buffer) {
acm->nb_index = 0;
goto exit;
}
acm->notification_buffer = new_buffer;
acm->nb_size = alloc_size;
dr = (struct usb_cdc_notification *)acm->notification_buffer;
}
copy_size = min(current_size,
expected_size - acm->nb_index);
memcpy(&acm->notification_buffer[acm->nb_index],
urb->transfer_buffer, copy_size);
acm->nb_index += copy_size;
current_size = acm->nb_index;
}
if (current_size >= expected_size) {
/* notification complete */
acm_process_notification(acm, (unsigned char *)dr);
acm->nb_index = 0;
}
exit:
retval = usb_submit_urb(urb, GFP_ATOMIC);
if (retval && retval != -EPERM && retval != -ENODEV)
dev_err(&acm->control->dev,
"%s - usb_submit_urb failed: %d\n", __func__, retval);
else
dev_vdbg(&acm->control->dev,
"control resubmission terminated %d\n", retval);
}
static int acm_submit_read_urb(struct acm *acm, int index, gfp_t mem_flags)
{
int res;
if (!test_and_clear_bit(index, &acm->read_urbs_free))
return 0;
res = usb_submit_urb(acm->read_urbs[index], mem_flags);
if (res) {
if (res != -EPERM && res != -ENODEV) {
dev_err(&acm->data->dev,
"urb %d failed submission with %d\n",
index, res);
} else {
dev_vdbg(&acm->data->dev, "intended failure %d\n", res);
}
set_bit(index, &acm->read_urbs_free);
return res;
} else {
dev_vdbg(&acm->data->dev, "submitted urb %d\n", index);
}
return 0;
}
static int acm_submit_read_urbs(struct acm *acm, gfp_t mem_flags)
{
int res;
int i;
for (i = 0; i < acm->rx_buflimit; ++i) {
res = acm_submit_read_urb(acm, i, mem_flags);
if (res)
return res;
}
return 0;
}
static void acm_process_read_urb(struct acm *acm, struct urb *urb)
{
unsigned long flags;
if (!urb->actual_length)
return;
spin_lock_irqsave(&acm->read_lock, flags);
tty_insert_flip_string(&acm->port, urb->transfer_buffer,
urb->actual_length);
spin_unlock_irqrestore(&acm->read_lock, flags);
tty_flip_buffer_push(&acm->port);
}
static void acm_read_bulk_callback(struct urb *urb)
{
struct acm_rb *rb = urb->context;
struct acm *acm = rb->instance;
int status = urb->status;
bool stopped = false;
bool stalled = false;
bool cooldown = false;
dev_vdbg(&acm->data->dev, "got urb %d, len %d, status %d\n",
rb->index, urb->actual_length, status);
switch (status) {
case 0:
usb_mark_last_busy(acm->dev);
acm_process_read_urb(acm, urb);
break;
case -EPIPE:
set_bit(EVENT_RX_STALL, &acm->flags);
stalled = true;
break;
case -ENOENT:
case -ECONNRESET:
case -ESHUTDOWN:
dev_dbg(&acm->data->dev,
"%s - urb shutting down with status: %d\n",
__func__, status);
stopped = true;
break;
case -EOVERFLOW:
case -EPROTO:
dev_dbg(&acm->data->dev,
"%s - cooling babbling device\n", __func__);
usb_mark_last_busy(acm->dev);
set_bit(rb->index, &acm->urbs_in_error_delay);
set_bit(ACM_ERROR_DELAY, &acm->flags);
cooldown = true;
break;
default:
dev_dbg(&acm->data->dev,
"%s - nonzero urb status received: %d\n",
__func__, status);
break;
}
/*
* Make sure URB processing is done before marking as free to avoid
* racing with unthrottle() on another CPU. Matches the barriers
* implied by the test_and_clear_bit() in acm_submit_read_urb().
*/
smp_mb__before_atomic();
set_bit(rb->index, &acm->read_urbs_free);
/*
* Make sure URB is marked as free before checking the throttled flag
* to avoid racing with unthrottle() on another CPU. Matches the
* smp_mb() in unthrottle().
*/
smp_mb__after_atomic();
if (stopped || stalled || cooldown) {
if (stalled)
schedule_delayed_work(&acm->dwork, 0);
else if (cooldown)
schedule_delayed_work(&acm->dwork, HZ / 2);
return;
}
if (test_bit(ACM_THROTTLED, &acm->flags))
return;
acm_submit_read_urb(acm, rb->index, GFP_ATOMIC);
}
/* data interface wrote those outgoing bytes */
static void acm_write_bulk(struct urb *urb)
{
struct acm_wb *wb = urb->context;
struct acm *acm = wb->instance;
unsigned long flags;
int status = urb->status;
if (status || (urb->actual_length != urb->transfer_buffer_length))
dev_vdbg(&acm->data->dev, "wrote len %d/%d, status %d\n",
urb->actual_length,
urb->transfer_buffer_length,
status);
spin_lock_irqsave(&acm->write_lock, flags);
acm_write_done(acm, wb);
spin_unlock_irqrestore(&acm->write_lock, flags);
set_bit(EVENT_TTY_WAKEUP, &acm->flags);
schedule_delayed_work(&acm->dwork, 0);
}
static void acm_softint(struct work_struct *work)
{
int i;
struct acm *acm = container_of(work, struct acm, dwork.work);
if (test_bit(EVENT_RX_STALL, &acm->flags)) {
smp_mb(); /* against acm_suspend() */
if (!acm->susp_count) {
for (i = 0; i < acm->rx_buflimit; i++)
usb_kill_urb(acm->read_urbs[i]);
usb_clear_halt(acm->dev, acm->in);
acm_submit_read_urbs(acm, GFP_KERNEL);
clear_bit(EVENT_RX_STALL, &acm->flags);
}
}
if (test_and_clear_bit(ACM_ERROR_DELAY, &acm->flags)) {
for (i = 0; i < acm->rx_buflimit; i++)
if (test_and_clear_bit(i, &acm->urbs_in_error_delay))
acm_submit_read_urb(acm, i, GFP_KERNEL);
}
if (test_and_clear_bit(EVENT_TTY_WAKEUP, &acm->flags))
tty_port_tty_wakeup(&acm->port);
}
/*
* TTY handlers
*/
static int acm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
{
struct acm *acm;
int retval;
acm = acm_get_by_minor(tty->index);
if (!acm)
return -ENODEV;
retval = tty_standard_install(driver, tty);
if (retval)
goto error_init_termios;
/*
* Suppress initial echoing for some devices which might send data
* immediately after acm driver has been installed.
*/
if (acm->quirks & DISABLE_ECHO)
tty->termios.c_lflag &= ~ECHO;
tty->driver_data = acm;
return 0;
error_init_termios:
tty_port_put(&acm->port);
return retval;
}
static int acm_tty_open(struct tty_struct *tty, struct file *filp)
{
struct acm *acm = tty->driver_data;
return tty_port_open(&acm->port, tty, filp);
}
static void acm_port_dtr_rts(struct tty_port *port, bool active)
{
struct acm *acm = container_of(port, struct acm, port);
int val;
int res;
if (active)
val = USB_CDC_CTRL_DTR | USB_CDC_CTRL_RTS;
else
val = 0;
/* FIXME: add missing ctrlout locking throughout driver */
acm->ctrlout = val;
res = acm_set_control(acm, val);
if (res && (acm->ctrl_caps & USB_CDC_CAP_LINE))
/* This is broken in too many devices to spam the logs */
dev_dbg(&acm->control->dev, "failed to set dtr/rts\n");
}
static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
{
struct acm *acm = container_of(port, struct acm, port);
int retval = -ENODEV;
int i;
mutex_lock(&acm->mutex);
if (acm->disconnected)
goto disconnected;
retval = usb_autopm_get_interface(acm->control);
if (retval)
goto error_get_interface;
set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
acm->control->needs_remote_wakeup = 1;
acm->ctrlurb->dev = acm->dev;
retval = usb_submit_urb(acm->ctrlurb, GFP_KERNEL);
if (retval) {
dev_err(&acm->control->dev,
"%s - usb_submit_urb(ctrl irq) failed\n", __func__);
goto error_submit_urb;
}
acm_tty_set_termios(tty, NULL);
/*
* Unthrottle device in case the TTY was closed while throttled.
*/
clear_bit(ACM_THROTTLED, &acm->flags);
retval = acm_submit_read_urbs(acm, GFP_KERNEL);
if (retval)
goto error_submit_read_urbs;
usb_autopm_put_interface(acm->control);
mutex_unlock(&acm->mutex);
return 0;
error_submit_read_urbs:
for (i = 0; i < acm->rx_buflimit; i++)
usb_kill_urb(acm->read_urbs[i]);
usb_kill_urb(acm->ctrlurb);
error_submit_urb:
usb_autopm_put_interface(acm->control);
error_get_interface:
disconnected:
mutex_unlock(&acm->mutex);
return usb_translate_errors(retval);
}
static void acm_port_destruct(struct tty_port *port)
{
struct acm *acm = container_of(port, struct acm, port);
if (acm->minor != ACM_MINOR_INVALID)
acm_release_minor(acm);
usb_put_intf(acm->control);
kfree(acm->country_codes);
kfree(acm);
}
static void acm_port_shutdown(struct tty_port *port)
{
struct acm *acm = container_of(port, struct acm, port);
struct urb *urb;
struct acm_wb *wb;
/*
* Need to grab write_lock to prevent race with resume, but no need to
* hold it due to the tty-port initialised flag.
*/
acm_poison_urbs(acm);
spin_lock_irq(&acm->write_lock);
spin_unlock_irq(&acm->write_lock);
usb_autopm_get_interface_no_resume(acm->control);
acm->control->needs_remote_wakeup = 0;
usb_autopm_put_interface(acm->control);
for (;;) {
urb = usb_get_from_anchor(&acm->delayed);
if (!urb)
break;
wb = urb->context;
wb->use = false;
usb_autopm_put_interface_async(acm->control);
}
acm_unpoison_urbs(acm);
}
static void acm_tty_cleanup(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
tty_port_put(&acm->port);
}
static void acm_tty_hangup(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
tty_port_hangup(&acm->port);
}
static void acm_tty_close(struct tty_struct *tty, struct file *filp)
{
struct acm *acm = tty->driver_data;
tty_port_close(&acm->port, tty, filp);
}
static ssize_t acm_tty_write(struct tty_struct *tty, const u8 *buf,
size_t count)
{
struct acm *acm = tty->driver_data;
int stat;
unsigned long flags;
int wbn;
struct acm_wb *wb;
if (!count)
return 0;
dev_vdbg(&acm->data->dev, "%zu bytes from tty layer\n", count);
spin_lock_irqsave(&acm->write_lock, flags);
wbn = acm_wb_alloc(acm);
if (wbn < 0) {
spin_unlock_irqrestore(&acm->write_lock, flags);
return 0;
}
wb = &acm->wb[wbn];
if (!acm->dev) {
wb->use = false;
spin_unlock_irqrestore(&acm->write_lock, flags);
return -ENODEV;
}
count = (count > acm->writesize) ? acm->writesize : count;
dev_vdbg(&acm->data->dev, "writing %zu bytes\n", count);
memcpy(wb->buf, buf, count);
wb->len = count;
stat = usb_autopm_get_interface_async(acm->control);
if (stat) {
wb->use = false;
spin_unlock_irqrestore(&acm->write_lock, flags);
return stat;
}
if (acm->susp_count) {
usb_anchor_urb(wb->urb, &acm->delayed);
spin_unlock_irqrestore(&acm->write_lock, flags);
return count;
}
stat = acm_start_wb(acm, wb);
spin_unlock_irqrestore(&acm->write_lock, flags);
if (stat < 0)
return stat;
return count;
}
static unsigned int acm_tty_write_room(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
/*
* Do not let the line discipline to know that we have a reserve,
* or it might get too enthusiastic.
*/
return acm_wb_is_avail(acm) ? acm->writesize : 0;
}
static void acm_tty_flush_buffer(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
unsigned long flags;
int i;
spin_lock_irqsave(&acm->write_lock, flags);
for (i = 0; i < ACM_NW; i++)
if (acm->wb[i].use)
usb_unlink_urb(acm->wb[i].urb);
spin_unlock_irqrestore(&acm->write_lock, flags);
}
static unsigned int acm_tty_chars_in_buffer(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
/*
* if the device was unplugged then any remaining characters fell out
* of the connector ;)
*/
if (acm->disconnected)
return 0;
/*
* This is inaccurate (overcounts), but it works.
*/
return (ACM_NW - acm_wb_is_avail(acm)) * acm->writesize;
}
static void acm_tty_throttle(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
set_bit(ACM_THROTTLED, &acm->flags);
}
static void acm_tty_unthrottle(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
clear_bit(ACM_THROTTLED, &acm->flags);
/* Matches the smp_mb__after_atomic() in acm_read_bulk_callback(). */
smp_mb();
acm_submit_read_urbs(acm, GFP_KERNEL);
}
static int acm_tty_break_ctl(struct tty_struct *tty, int state)
{
struct acm *acm = tty->driver_data;
int retval;
if (!(acm->ctrl_caps & USB_CDC_CAP_BRK))
return -EOPNOTSUPP;
retval = acm_send_break(acm, state ? 0xffff : 0);
if (retval < 0)
dev_dbg(&acm->control->dev,
"%s - send break failed\n", __func__);
return retval;
}
static int acm_tty_tiocmget(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
return (acm->ctrlout & USB_CDC_CTRL_DTR ? TIOCM_DTR : 0) |
(acm->ctrlout & USB_CDC_CTRL_RTS ? TIOCM_RTS : 0) |
(acm->ctrlin & USB_CDC_SERIAL_STATE_DSR ? TIOCM_DSR : 0) |
(acm->ctrlin & USB_CDC_SERIAL_STATE_RING_SIGNAL ? TIOCM_RI : 0) |
(acm->ctrlin & USB_CDC_SERIAL_STATE_DCD ? TIOCM_CD : 0) |
TIOCM_CTS;
}
static int acm_tty_tiocmset(struct tty_struct *tty,
unsigned int set, unsigned int clear)
{
struct acm *acm = tty->driver_data;
unsigned int newctrl;
newctrl = acm->ctrlout;
set = (set & TIOCM_DTR ? USB_CDC_CTRL_DTR : 0) |
(set & TIOCM_RTS ? USB_CDC_CTRL_RTS : 0);
clear = (clear & TIOCM_DTR ? USB_CDC_CTRL_DTR : 0) |
(clear & TIOCM_RTS ? USB_CDC_CTRL_RTS : 0);
newctrl = (newctrl & ~clear) | set;
if (acm->ctrlout == newctrl)
return 0;
return acm_set_control(acm, acm->ctrlout = newctrl);
}
static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
{
struct acm *acm = tty->driver_data;
ss->line = acm->minor;
mutex_lock(&acm->port.mutex);
ss->close_delay = jiffies_to_msecs(acm->port.close_delay) / 10;
ss->closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
ASYNC_CLOSING_WAIT_NONE :
jiffies_to_msecs(acm->port.closing_wait) / 10;
mutex_unlock(&acm->port.mutex);
return 0;
}
static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
{
struct acm *acm = tty->driver_data;
unsigned int closing_wait, close_delay;
int retval = 0;
close_delay = msecs_to_jiffies(ss->close_delay * 10);
closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
ASYNC_CLOSING_WAIT_NONE :
msecs_to_jiffies(ss->closing_wait * 10);
mutex_lock(&acm->port.mutex);
if (!capable(CAP_SYS_ADMIN)) {
if ((close_delay != acm->port.close_delay) ||
(closing_wait != acm->port.closing_wait))
retval = -EPERM;
} else {
acm->port.close_delay = close_delay;
acm->port.closing_wait = closing_wait;
}
mutex_unlock(&acm->port.mutex);
return retval;
}
static int wait_serial_change(struct acm *acm, unsigned long arg)