kernel-fxtec-pro1x/drivers/usb/class/cdc-acm.c

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/*
* cdc-acm.c
*
* Copyright (c) 1999 Armin Fuerst <fuerst@in.tum.de>
* Copyright (c) 1999 Pavel Machek <pavel@suse.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>
*
* USB Abstract Control Model driver for USB modems and ISDN adapters
*
* Sponsored by SuSE
*
* ChangeLog:
* v0.9 - thorough cleaning, URBification, almost a rewrite
* v0.10 - some more cleanups
* v0.11 - fixed flow control, read error doesn't stop reads
* v0.12 - added TIOCM ioctls, added break handling, made struct acm kmalloced
* v0.13 - added termios, added hangup
* v0.14 - sized down struct acm
* v0.15 - fixed flow control again - characters could be lost
* v0.16 - added code for modems with swapped data and control interfaces
* v0.17 - added new style probing
* v0.18 - fixed new style probing for devices with more configurations
* v0.19 - fixed CLOCAL handling (thanks to Richard Shih-Ping Chan)
* v0.20 - switched to probing on interface (rather than device) class
* v0.21 - revert to probing on device for devices with multiple configs
* v0.22 - probe only the control interface. if usbcore doesn't choose the
* config we want, sysadmin changes bConfigurationValue in sysfs.
* v0.23 - use softirq for rx processing, as needed by tty layer
* v0.24 - change probe method to evaluate CDC union descriptor
* v0.25 - downstream tasks paralelized to maximize throughput
* v0.26 - multiple write urbs, writesize increased
*/
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#undef DEBUG
#undef VERBOSE_DEBUG
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <linux/list.h>
#include "cdc-acm.h"
#define ACM_CLOSE_TIMEOUT 15 /* seconds to let writes drain */
/*
* Version Information
*/
#define DRIVER_VERSION "v0.26"
#define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek"
#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 struct acm *acm_table[ACM_TTY_MINORS];
static DEFINE_MUTEX(open_mutex);
#define ACM_READY(acm) (acm && acm->dev && acm->used)
#ifdef VERBOSE_DEBUG
#define verbose 1
#else
#define verbose 0
#endif
/*
* Functions for ACM control messages.
*/
static int acm_ctrl_msg(struct acm *acm, int request, int value, void *buf, int len)
{
int retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
request, USB_RT_ACM, value,
acm->control->altsetting[0].desc.bInterfaceNumber,
buf, len, 5000);
dbg("acm_control_msg: rq: 0x%02x val: %#x len: %#x result: %d", request, value, len, retval);
return retval < 0 ? retval : 0;
}
/* devices aren't required to support these requests.
* the cdc acm descriptor tells whether they do...
*/
#define acm_set_control(acm, control) \
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)
/*
* 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 = 1;
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++) {
n -= acm->wb[i].use;
}
spin_unlock_irqrestore(&acm->write_lock, flags);
return n;
}
/*
USB: cdc-acm.c: fix recursive lock in acm_start_wb error path Fixes an obvious bug in cdc-acm by avoiding a recursive lock on acm_start_wb()'s error path. Should apply towards 2.6.27 stable and 2.6.28. ============================================= [ INFO: possible recursive locking detected ] 2.6.27-2-pae #109 --------------------------------------------- python/31449 is trying to acquire lock: (&acm->write_lock){++..}, at: [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] but task is already holding lock: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] other info that might help us debug this: 2 locks held by python/31449: #0: (&tty->atomic_write_lock){--..}, at: [<c0260fae>] tty_write_lock+0x14/0x3b #1: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] stack backtrace: Pid: 31449, comm: python Not tainted 2.6.27-2-pae #109 [<c030f42f>] ? printk+0xf/0x18 [<c0149f33>] __lock_acquire+0xc7b/0x1316 [<c014a63e>] lock_acquire+0x70/0x97 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<c0312109>] _spin_lock_irqsave+0x37/0x47 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a055d>] acm_tty_write+0x143/0x167 [cdc_acm] [<c0262a98>] write_chan+0x1cd/0x297 [<c012527e>] ? default_wake_function+0x0/0xd [<c026111e>] tty_write+0x149/0x1b9 [<c02628cb>] ? write_chan+0x0/0x297 [<c01912c5>] ? rw_verify_area+0x76/0x98 [<c0260fd5>] ? tty_write+0x0/0x1b9 [<c01919ba>] vfs_write+0x8c/0x136 [<c0191afd>] sys_write+0x3b/0x60 [<c0103beb>] sysenter_do_call+0x12/0x3f ======================= Signed-off-by: Brandon Philips <bphilips@suse.de> Cc: Oliver Neukum <oliver@neukum.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-11-06 12:19:11 -07:00
* Finish write. Caller must hold acm->write_lock
*/
static void acm_write_done(struct acm *acm, struct acm_wb *wb)
{
wb->use = 0;
acm->transmitting--;
}
/*
* 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;
if ((rc = usb_submit_urb(wb->urb, GFP_ATOMIC)) < 0) {
dbg("usb_submit_urb(write bulk) failed: %d", rc);
acm_write_done(acm, wb);
}
return rc;
}
static int acm_write_start(struct acm *acm, int wbn)
{
unsigned long flags;
struct acm_wb *wb = &acm->wb[wbn];
int rc;
spin_lock_irqsave(&acm->write_lock, flags);
if (!acm->dev) {
wb->use = 0;
spin_unlock_irqrestore(&acm->write_lock, flags);
return -ENODEV;
}
dbg("%s susp_count: %d", __func__, acm->susp_count);
if (acm->susp_count) {
acm->delayed_wb = wb;
schedule_work(&acm->waker);
spin_unlock_irqrestore(&acm->write_lock, flags);
return 0; /* A white lie */
}
usb_mark_last_busy(acm->dev);
rc = acm_start_wb(acm, wb);
spin_unlock_irqrestore(&acm->write_lock, flags);
return rc;
}
/*
* attributes exported through sysfs
*/
static ssize_t show_caps
(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(bmCapabilities, S_IRUGO, show_caps, NULL);
static ssize_t show_country_codes
(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(wCountryCodes, S_IRUGO, show_country_codes, NULL);
static ssize_t show_country_rel_date
(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(iCountryCodeRelDate, S_IRUGO, show_country_rel_date, NULL);
/*
* Interrupt handlers for various ACM device responses
*/
/* control interface reports status changes with "interrupt" transfers */
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 07:55:46 -06:00
static void acm_ctrl_irq(struct urb *urb)
{
struct acm *acm = urb->context;
struct usb_cdc_notification *dr = urb->transfer_buffer;
unsigned char *data;
int newctrl;
int retval;
int status = urb->status;
switch (status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dbg("%s - urb shutting down with status: %d", __func__, status);
return;
default:
dbg("%s - nonzero urb status received: %d", __func__, status);
goto exit;
}
if (!ACM_READY(acm))
goto exit;
data = (unsigned char *)(dr + 1);
switch (dr->bNotificationType) {
case USB_CDC_NOTIFY_NETWORK_CONNECTION:
dbg("%s network", dr->wValue ? "connected to" : "disconnected from");
break;
case USB_CDC_NOTIFY_SERIAL_STATE:
newctrl = get_unaligned_le16(data);
if (acm->tty && !acm->clocal && (acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
dbg("calling hangup");
tty_hangup(acm->tty);
}
acm->ctrlin = newctrl;
dbg("input control lines: dcd%c dsr%c break%c ring%c framing%c parity%c overrun%c",
acm->ctrlin & ACM_CTRL_DCD ? '+' : '-', acm->ctrlin & ACM_CTRL_DSR ? '+' : '-',
acm->ctrlin & ACM_CTRL_BRK ? '+' : '-', acm->ctrlin & ACM_CTRL_RI ? '+' : '-',
acm->ctrlin & ACM_CTRL_FRAMING ? '+' : '-', acm->ctrlin & ACM_CTRL_PARITY ? '+' : '-',
acm->ctrlin & ACM_CTRL_OVERRUN ? '+' : '-');
break;
default:
dbg("unknown notification %d received: index %d len %d data0 %d data1 %d",
dr->bNotificationType, dr->wIndex,
dr->wLength, data[0], data[1]);
break;
}
exit:
usb_mark_last_busy(acm->dev);
retval = usb_submit_urb (urb, GFP_ATOMIC);
if (retval)
dev_err(&urb->dev->dev, "%s - usb_submit_urb failed with "
"result %d", __func__, retval);
}
/* data interface returns incoming bytes, or we got unthrottled */
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 07:55:46 -06:00
static void acm_read_bulk(struct urb *urb)
{
struct acm_rb *buf;
struct acm_ru *rcv = urb->context;
struct acm *acm = rcv->instance;
int status = urb->status;
dbg("Entering acm_read_bulk with status %d", status);
if (!ACM_READY(acm)) {
dev_dbg(&acm->data->dev, "Aborting, acm not ready");
return;
}
usb_mark_last_busy(acm->dev);
if (status)
dev_dbg(&acm->data->dev, "bulk rx status %d\n", status);
buf = rcv->buffer;
buf->size = urb->actual_length;
if (likely(status == 0)) {
spin_lock(&acm->read_lock);
acm->processing++;
list_add_tail(&rcv->list, &acm->spare_read_urbs);
list_add_tail(&buf->list, &acm->filled_read_bufs);
spin_unlock(&acm->read_lock);
} else {
/* we drop the buffer due to an error */
spin_lock(&acm->read_lock);
list_add_tail(&rcv->list, &acm->spare_read_urbs);
list_add(&buf->list, &acm->spare_read_bufs);
spin_unlock(&acm->read_lock);
/* nevertheless the tasklet must be kicked unconditionally
so the queue cannot dry up */
}
if (likely(!acm->susp_count))
tasklet_schedule(&acm->urb_task);
}
static void acm_rx_tasklet(unsigned long _acm)
{
struct acm *acm = (void *)_acm;
struct acm_rb *buf;
struct tty_struct *tty = acm->tty;
struct acm_ru *rcv;
unsigned long flags;
unsigned char throttled;
dbg("Entering acm_rx_tasklet");
if (!ACM_READY(acm))
{
dbg("acm_rx_tasklet: ACM not ready");
return;
}
spin_lock_irqsave(&acm->throttle_lock, flags);
throttled = acm->throttle;
spin_unlock_irqrestore(&acm->throttle_lock, flags);
if (throttled)
{
dbg("acm_rx_tasklet: throttled");
return;
}
next_buffer:
spin_lock_irqsave(&acm->read_lock, flags);
if (list_empty(&acm->filled_read_bufs)) {
spin_unlock_irqrestore(&acm->read_lock, flags);
goto urbs;
}
buf = list_entry(acm->filled_read_bufs.next,
struct acm_rb, list);
list_del(&buf->list);
spin_unlock_irqrestore(&acm->read_lock, flags);
dbg("acm_rx_tasklet: procesing buf 0x%p, size = %d", buf, buf->size);
[PATCH] TTY layer buffering revamp The API and code have been through various bits of initial review by serial driver people but they definitely need to live somewhere for a while so the unconverted drivers can get knocked into shape, existing drivers that have been updated can be better tuned and bugs whacked out. This replaces the tty flip buffers with kmalloc objects in rings. In the normal situation for an IRQ driven serial port at typical speeds the behaviour is pretty much the same, two buffers end up allocated and the kernel cycles between them as before. When there are delays or at high speed we now behave far better as the buffer pool can grow a bit rather than lose characters. This also means that we can operate at higher speeds reliably. For drivers that receive characters in blocks (DMA based, USB and especially virtualisation) the layer allows a lot of driver specific code that works around the tty layer with private secondary queues to be removed. The IBM folks need this sort of layer, the smart serial port people do, the virtualisers do (because a virtualised tty typically operates at infinite speed rather than emulating 9600 baud). Finally many drivers had invalid and unsafe attempts to avoid buffer overflows by directly invoking tty methods extracted out of the innards of work queue structs. These are no longer needed and all go away. That fixes various random hangs with serial ports on overflow. The other change in here is to optimise the receive_room path that is used by some callers. It turns out that only one ldisc uses receive room except asa constant and it updates it far far less than the value is read. We thus make it a variable not a function call. I expect the code to contain bugs due to the size alone but I'll be watching and squashing them and feeding out new patches as it goes. Because the buffers now dynamically expand you should only run out of buffering when the kernel runs out of memory for real. That means a lot of the horrible hacks high performance drivers used to do just aren't needed any more. Description: tty_insert_flip_char is an old API and continues to work as before, as does tty_flip_buffer_push() [this is why many drivers dont need modification]. It does now also return the number of chars inserted There are also tty_buffer_request_room(tty, len) which asks for a buffer block of the length requested and returns the space found. This improves efficiency with hardware that knows how much to transfer. and tty_insert_flip_string_flags(tty, str, flags, len) to insert a string of characters and flags For a smart interface the usual code is len = tty_request_buffer_room(tty, amount_hardware_says); tty_insert_flip_string(tty, buffer_from_card, len); More description! At the moment tty buffers are attached directly to the tty. This is causing a lot of the problems related to tty layer locking, also problems at high speed and also with bursty data (such as occurs in virtualised environments) I'm working on ripping out the flip buffers and replacing them with a pool of dynamically allocated buffers. This allows both for old style "byte I/O" devices and also helps virtualisation and smart devices where large blocks of data suddenely materialise and need storing. So far so good. Lots of drivers reference tty->flip.*. Several of them also call directly and unsafely into function pointers it provides. This will all break. Most drivers can use tty_insert_flip_char which can be kept as an API but others need more. At the moment I've added the following interfaces, if people think more will be needed now is a good time to say int tty_buffer_request_room(tty, size) Try and ensure at least size bytes are available, returns actual room (may be zero). At the moment it just uses the flipbuf space but that will change. Repeated calls without characters being added are not cumulative. (ie if you call it with 1, 1, 1, and then 4 you'll have four characters of space. The other functions will also try and grow buffers in future but this will be a more efficient way when you know block sizes. int tty_insert_flip_char(tty, ch, flag) As before insert a character if there is room. Now returns 1 for success, 0 for failure. int tty_insert_flip_string(tty, str, len) Insert a block of non error characters. Returns the number inserted. int tty_prepare_flip_string(tty, strptr, len) Adjust the buffer to allow len characters to be added. Returns a buffer pointer in strptr and the length available. This allows for hardware that needs to use functions like insl or mencpy_fromio. Signed-off-by: Alan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-09 21:54:13 -07:00
tty_buffer_request_room(tty, buf->size);
spin_lock_irqsave(&acm->throttle_lock, flags);
throttled = acm->throttle;
spin_unlock_irqrestore(&acm->throttle_lock, flags);
if (!throttled)
[PATCH] TTY layer buffering revamp The API and code have been through various bits of initial review by serial driver people but they definitely need to live somewhere for a while so the unconverted drivers can get knocked into shape, existing drivers that have been updated can be better tuned and bugs whacked out. This replaces the tty flip buffers with kmalloc objects in rings. In the normal situation for an IRQ driven serial port at typical speeds the behaviour is pretty much the same, two buffers end up allocated and the kernel cycles between them as before. When there are delays or at high speed we now behave far better as the buffer pool can grow a bit rather than lose characters. This also means that we can operate at higher speeds reliably. For drivers that receive characters in blocks (DMA based, USB and especially virtualisation) the layer allows a lot of driver specific code that works around the tty layer with private secondary queues to be removed. The IBM folks need this sort of layer, the smart serial port people do, the virtualisers do (because a virtualised tty typically operates at infinite speed rather than emulating 9600 baud). Finally many drivers had invalid and unsafe attempts to avoid buffer overflows by directly invoking tty methods extracted out of the innards of work queue structs. These are no longer needed and all go away. That fixes various random hangs with serial ports on overflow. The other change in here is to optimise the receive_room path that is used by some callers. It turns out that only one ldisc uses receive room except asa constant and it updates it far far less than the value is read. We thus make it a variable not a function call. I expect the code to contain bugs due to the size alone but I'll be watching and squashing them and feeding out new patches as it goes. Because the buffers now dynamically expand you should only run out of buffering when the kernel runs out of memory for real. That means a lot of the horrible hacks high performance drivers used to do just aren't needed any more. Description: tty_insert_flip_char is an old API and continues to work as before, as does tty_flip_buffer_push() [this is why many drivers dont need modification]. It does now also return the number of chars inserted There are also tty_buffer_request_room(tty, len) which asks for a buffer block of the length requested and returns the space found. This improves efficiency with hardware that knows how much to transfer. and tty_insert_flip_string_flags(tty, str, flags, len) to insert a string of characters and flags For a smart interface the usual code is len = tty_request_buffer_room(tty, amount_hardware_says); tty_insert_flip_string(tty, buffer_from_card, len); More description! At the moment tty buffers are attached directly to the tty. This is causing a lot of the problems related to tty layer locking, also problems at high speed and also with bursty data (such as occurs in virtualised environments) I'm working on ripping out the flip buffers and replacing them with a pool of dynamically allocated buffers. This allows both for old style "byte I/O" devices and also helps virtualisation and smart devices where large blocks of data suddenely materialise and need storing. So far so good. Lots of drivers reference tty->flip.*. Several of them also call directly and unsafely into function pointers it provides. This will all break. Most drivers can use tty_insert_flip_char which can be kept as an API but others need more. At the moment I've added the following interfaces, if people think more will be needed now is a good time to say int tty_buffer_request_room(tty, size) Try and ensure at least size bytes are available, returns actual room (may be zero). At the moment it just uses the flipbuf space but that will change. Repeated calls without characters being added are not cumulative. (ie if you call it with 1, 1, 1, and then 4 you'll have four characters of space. The other functions will also try and grow buffers in future but this will be a more efficient way when you know block sizes. int tty_insert_flip_char(tty, ch, flag) As before insert a character if there is room. Now returns 1 for success, 0 for failure. int tty_insert_flip_string(tty, str, len) Insert a block of non error characters. Returns the number inserted. int tty_prepare_flip_string(tty, strptr, len) Adjust the buffer to allow len characters to be added. Returns a buffer pointer in strptr and the length available. This allows for hardware that needs to use functions like insl or mencpy_fromio. Signed-off-by: Alan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: John Hawkes <hawkes@sgi.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-09 21:54:13 -07:00
tty_insert_flip_string(tty, buf->base, buf->size);
tty_flip_buffer_push(tty);
if (throttled) {
dbg("Throttling noticed");
spin_lock_irqsave(&acm->read_lock, flags);
list_add(&buf->list, &acm->filled_read_bufs);
spin_unlock_irqrestore(&acm->read_lock, flags);
return;
}
spin_lock_irqsave(&acm->read_lock, flags);
list_add(&buf->list, &acm->spare_read_bufs);
spin_unlock_irqrestore(&acm->read_lock, flags);
goto next_buffer;
urbs:
while (!list_empty(&acm->spare_read_bufs)) {
spin_lock_irqsave(&acm->read_lock, flags);
if (list_empty(&acm->spare_read_urbs)) {
acm->processing = 0;
spin_unlock_irqrestore(&acm->read_lock, flags);
return;
}
rcv = list_entry(acm->spare_read_urbs.next,
struct acm_ru, list);
list_del(&rcv->list);
spin_unlock_irqrestore(&acm->read_lock, flags);
buf = list_entry(acm->spare_read_bufs.next,
struct acm_rb, list);
list_del(&buf->list);
rcv->buffer = buf;
usb_fill_bulk_urb(rcv->urb, acm->dev,
acm->rx_endpoint,
buf->base,
acm->readsize,
acm_read_bulk, rcv);
rcv->urb->transfer_dma = buf->dma;
rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
/* This shouldn't kill the driver as unsuccessful URBs are returned to the
free-urbs-pool and resubmited ASAP */
spin_lock_irqsave(&acm->read_lock, flags);
if (acm->susp_count || usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
list_add(&buf->list, &acm->spare_read_bufs);
list_add(&rcv->list, &acm->spare_read_urbs);
acm->processing = 0;
spin_unlock_irqrestore(&acm->read_lock, flags);
return;
} else {
spin_unlock_irqrestore(&acm->read_lock, flags);
dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
}
}
spin_lock_irqsave(&acm->read_lock, flags);
acm->processing = 0;
spin_unlock_irqrestore(&acm->read_lock, flags);
}
/* data interface wrote those outgoing bytes */
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 07:55:46 -06:00
static void acm_write_bulk(struct urb *urb)
{
struct acm_wb *wb = urb->context;
struct acm *acm = wb->instance;
USB: cdc-acm.c: fix recursive lock in acm_start_wb error path Fixes an obvious bug in cdc-acm by avoiding a recursive lock on acm_start_wb()'s error path. Should apply towards 2.6.27 stable and 2.6.28. ============================================= [ INFO: possible recursive locking detected ] 2.6.27-2-pae #109 --------------------------------------------- python/31449 is trying to acquire lock: (&acm->write_lock){++..}, at: [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] but task is already holding lock: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] other info that might help us debug this: 2 locks held by python/31449: #0: (&tty->atomic_write_lock){--..}, at: [<c0260fae>] tty_write_lock+0x14/0x3b #1: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] stack backtrace: Pid: 31449, comm: python Not tainted 2.6.27-2-pae #109 [<c030f42f>] ? printk+0xf/0x18 [<c0149f33>] __lock_acquire+0xc7b/0x1316 [<c014a63e>] lock_acquire+0x70/0x97 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<c0312109>] _spin_lock_irqsave+0x37/0x47 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a055d>] acm_tty_write+0x143/0x167 [cdc_acm] [<c0262a98>] write_chan+0x1cd/0x297 [<c012527e>] ? default_wake_function+0x0/0xd [<c026111e>] tty_write+0x149/0x1b9 [<c02628cb>] ? write_chan+0x0/0x297 [<c01912c5>] ? rw_verify_area+0x76/0x98 [<c0260fd5>] ? tty_write+0x0/0x1b9 [<c01919ba>] vfs_write+0x8c/0x136 [<c0191afd>] sys_write+0x3b/0x60 [<c0103beb>] sysenter_do_call+0x12/0x3f ======================= Signed-off-by: Brandon Philips <bphilips@suse.de> Cc: Oliver Neukum <oliver@neukum.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-11-06 12:19:11 -07:00
unsigned long flags;
if (verbose || urb->status
|| (urb->actual_length != urb->transfer_buffer_length))
dev_dbg(&acm->data->dev, "tx %d/%d bytes -- > %d\n",
urb->actual_length,
urb->transfer_buffer_length,
urb->status);
USB: cdc-acm.c: fix recursive lock in acm_start_wb error path Fixes an obvious bug in cdc-acm by avoiding a recursive lock on acm_start_wb()'s error path. Should apply towards 2.6.27 stable and 2.6.28. ============================================= [ INFO: possible recursive locking detected ] 2.6.27-2-pae #109 --------------------------------------------- python/31449 is trying to acquire lock: (&acm->write_lock){++..}, at: [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] but task is already holding lock: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] other info that might help us debug this: 2 locks held by python/31449: #0: (&tty->atomic_write_lock){--..}, at: [<c0260fae>] tty_write_lock+0x14/0x3b #1: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] stack backtrace: Pid: 31449, comm: python Not tainted 2.6.27-2-pae #109 [<c030f42f>] ? printk+0xf/0x18 [<c0149f33>] __lock_acquire+0xc7b/0x1316 [<c014a63e>] lock_acquire+0x70/0x97 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<c0312109>] _spin_lock_irqsave+0x37/0x47 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a055d>] acm_tty_write+0x143/0x167 [cdc_acm] [<c0262a98>] write_chan+0x1cd/0x297 [<c012527e>] ? default_wake_function+0x0/0xd [<c026111e>] tty_write+0x149/0x1b9 [<c02628cb>] ? write_chan+0x0/0x297 [<c01912c5>] ? rw_verify_area+0x76/0x98 [<c0260fd5>] ? tty_write+0x0/0x1b9 [<c01919ba>] vfs_write+0x8c/0x136 [<c0191afd>] sys_write+0x3b/0x60 [<c0103beb>] sysenter_do_call+0x12/0x3f ======================= Signed-off-by: Brandon Philips <bphilips@suse.de> Cc: Oliver Neukum <oliver@neukum.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-11-06 12:19:11 -07:00
spin_lock_irqsave(&acm->write_lock, flags);
acm_write_done(acm, wb);
USB: cdc-acm.c: fix recursive lock in acm_start_wb error path Fixes an obvious bug in cdc-acm by avoiding a recursive lock on acm_start_wb()'s error path. Should apply towards 2.6.27 stable and 2.6.28. ============================================= [ INFO: possible recursive locking detected ] 2.6.27-2-pae #109 --------------------------------------------- python/31449 is trying to acquire lock: (&acm->write_lock){++..}, at: [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] but task is already holding lock: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] other info that might help us debug this: 2 locks held by python/31449: #0: (&tty->atomic_write_lock){--..}, at: [<c0260fae>] tty_write_lock+0x14/0x3b #1: (&acm->write_lock){++..}, at: [<f89a04fb>] acm_tty_write+0xe1/0x167 [cdc_acm] stack backtrace: Pid: 31449, comm: python Not tainted 2.6.27-2-pae #109 [<c030f42f>] ? printk+0xf/0x18 [<c0149f33>] __lock_acquire+0xc7b/0x1316 [<c014a63e>] lock_acquire+0x70/0x97 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<c0312109>] _spin_lock_irqsave+0x37/0x47 [<f89a0348>] ? acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a0348>] acm_start_wb+0x5c/0x7b [cdc_acm] [<f89a055d>] acm_tty_write+0x143/0x167 [cdc_acm] [<c0262a98>] write_chan+0x1cd/0x297 [<c012527e>] ? default_wake_function+0x0/0xd [<c026111e>] tty_write+0x149/0x1b9 [<c02628cb>] ? write_chan+0x0/0x297 [<c01912c5>] ? rw_verify_area+0x76/0x98 [<c0260fd5>] ? tty_write+0x0/0x1b9 [<c01919ba>] vfs_write+0x8c/0x136 [<c0191afd>] sys_write+0x3b/0x60 [<c0103beb>] sysenter_do_call+0x12/0x3f ======================= Signed-off-by: Brandon Philips <bphilips@suse.de> Cc: Oliver Neukum <oliver@neukum.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-11-06 12:19:11 -07:00
spin_unlock_irqrestore(&acm->write_lock, flags);
if (ACM_READY(acm))
schedule_work(&acm->work);
else
wake_up_interruptible(&acm->drain_wait);
}
static void acm_softint(struct work_struct *work)
{
struct acm *acm = container_of(work, struct acm, work);
dev_vdbg(&acm->data->dev, "tx work\n");
if (!ACM_READY(acm))
return;
tty_wakeup(acm->tty);
}
static void acm_waker(struct work_struct *waker)
{
struct acm *acm = container_of(waker, struct acm, waker);
int rv;
rv = usb_autopm_get_interface(acm->control);
if (rv < 0) {
dev_err(&acm->dev->dev, "Autopm failure in %s\n", __func__);
return;
}
if (acm->delayed_wb) {
acm_start_wb(acm, acm->delayed_wb);
acm->delayed_wb = NULL;
}
usb_autopm_put_interface(acm->control);
}
/*
* TTY handlers
*/
static int acm_tty_open(struct tty_struct *tty, struct file *filp)
{
struct acm *acm;
int rv = -EINVAL;
int i;
dbg("Entering acm_tty_open.");
mutex_lock(&open_mutex);
acm = acm_table[tty->index];
if (!acm || !acm->dev)
goto err_out;
else
rv = 0;
set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
tty->driver_data = acm;
acm->tty = tty;
if (usb_autopm_get_interface(acm->control) < 0)
goto early_bail;
else
acm->control->needs_remote_wakeup = 1;
mutex_lock(&acm->mutex);
if (acm->used++) {
usb_autopm_put_interface(acm->control);
goto done;
}
acm->ctrlurb->dev = acm->dev;
if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
dbg("usb_submit_urb(ctrl irq) failed");
goto bail_out;
}
if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) &&
(acm->ctrl_caps & USB_CDC_CAP_LINE))
goto full_bailout;
usb_autopm_put_interface(acm->control);
INIT_LIST_HEAD(&acm->spare_read_urbs);
INIT_LIST_HEAD(&acm->spare_read_bufs);
INIT_LIST_HEAD(&acm->filled_read_bufs);
for (i = 0; i < acm->rx_buflimit; i++) {
list_add(&(acm->ru[i].list), &acm->spare_read_urbs);
}
for (i = 0; i < acm->rx_buflimit; i++) {
list_add(&(acm->rb[i].list), &acm->spare_read_bufs);
}
acm->throttle = 0;
tasklet_schedule(&acm->urb_task);
done:
mutex_unlock(&acm->mutex);
err_out:
mutex_unlock(&open_mutex);
return rv;
full_bailout:
usb_kill_urb(acm->ctrlurb);
bail_out:
usb_autopm_put_interface(acm->control);
acm->used--;
mutex_unlock(&acm->mutex);
early_bail:
mutex_unlock(&open_mutex);
return -EIO;
}
static void acm_tty_unregister(struct acm *acm)
{
int i,nr;
nr = acm->rx_buflimit;
tty_unregister_device(acm_tty_driver, acm->minor);
usb_put_intf(acm->control);
acm_table[acm->minor] = NULL;
usb_free_urb(acm->ctrlurb);
for (i = 0; i < ACM_NW; i++)
usb_free_urb(acm->wb[i].urb);
for (i = 0; i < nr; i++)
usb_free_urb(acm->ru[i].urb);
kfree(acm->country_codes);
kfree(acm);
}
static int acm_tty_chars_in_buffer(struct tty_struct *tty);
static void acm_tty_close(struct tty_struct *tty, struct file *filp)
{
struct acm *acm = tty->driver_data;
int i,nr;
if (!acm || !acm->used)
return;
nr = acm->rx_buflimit;
mutex_lock(&open_mutex);
if (!--acm->used) {
if (acm->dev) {
usb_autopm_get_interface(acm->control);
acm_set_control(acm, acm->ctrlout = 0);
/* try letting the last writes drain naturally */
wait_event_interruptible_timeout(acm->drain_wait,
(ACM_NW == acm_wb_is_avail(acm))
|| !acm->dev,
ACM_CLOSE_TIMEOUT * HZ);
usb_kill_urb(acm->ctrlurb);
for (i = 0; i < ACM_NW; i++)
usb_kill_urb(acm->wb[i].urb);
for (i = 0; i < nr; i++)
usb_kill_urb(acm->ru[i].urb);
acm->control->needs_remote_wakeup = 0;
usb_autopm_put_interface(acm->control);
} else
acm_tty_unregister(acm);
}
mutex_unlock(&open_mutex);
}
static int acm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
struct acm *acm = tty->driver_data;
int stat;
unsigned long flags;
int wbn;
struct acm_wb *wb;
dbg("Entering acm_tty_write to write %d bytes,", count);
if (!ACM_READY(acm))
return -EINVAL;
if (!count)
return 0;
spin_lock_irqsave(&acm->write_lock, flags);
if ((wbn = acm_wb_alloc(acm)) < 0) {
spin_unlock_irqrestore(&acm->write_lock, flags);
return 0;
}
wb = &acm->wb[wbn];
count = (count > acm->writesize) ? acm->writesize : count;
dbg("Get %d bytes...", count);
memcpy(wb->buf, buf, count);
wb->len = count;
spin_unlock_irqrestore(&acm->write_lock, flags);
if ((stat = acm_write_start(acm, wbn)) < 0)
return stat;
return count;
}
static int acm_tty_write_room(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
if (!ACM_READY(acm))
return -EINVAL;
/*
* 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 int acm_tty_chars_in_buffer(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
if (!ACM_READY(acm))
return -EINVAL;
/*
* 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;
if (!ACM_READY(acm))
return;
spin_lock_bh(&acm->throttle_lock);
acm->throttle = 1;
spin_unlock_bh(&acm->throttle_lock);
}
static void acm_tty_unthrottle(struct tty_struct *tty)
{
struct acm *acm = tty->driver_data;
if (!ACM_READY(acm))
return;
spin_lock_bh(&acm->throttle_lock);
acm->throttle = 0;
spin_unlock_bh(&acm->throttle_lock);
tasklet_schedule(&acm->urb_task);
}
static int acm_tty_break_ctl(struct tty_struct *tty, int state)
{
struct acm *acm = tty->driver_data;
int retval;
if (!ACM_READY(acm))
return -EINVAL;
retval = acm_send_break(acm, state ? 0xffff : 0);
if (retval < 0)
dbg("send break failed");
return retval;
}
static int acm_tty_tiocmget(struct tty_struct *tty, struct file *file)
{
struct acm *acm = tty->driver_data;
if (!ACM_READY(acm))
return -EINVAL;
return (acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
(acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
(acm->ctrlin & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
(acm->ctrlin & ACM_CTRL_RI ? TIOCM_RI : 0) |
(acm->ctrlin & ACM_CTRL_DCD ? TIOCM_CD : 0) |
TIOCM_CTS;
}
static int acm_tty_tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear)
{
struct acm *acm = tty->driver_data;
unsigned int newctrl;
if (!ACM_READY(acm))
return -EINVAL;
newctrl = acm->ctrlout;
set = (set & TIOCM_DTR ? ACM_CTRL_DTR : 0) | (set & TIOCM_RTS ? ACM_CTRL_RTS : 0);
clear = (clear & TIOCM_DTR ? ACM_CTRL_DTR : 0) | (clear & TIOCM_RTS ? ACM_CTRL_RTS : 0);
newctrl = (newctrl & ~clear) | set;
if (acm->ctrlout == newctrl)
return 0;
return acm_set_control(acm, acm->ctrlout = newctrl);
}
static int acm_tty_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
{
struct acm *acm = tty->driver_data;
if (!ACM_READY(acm))
return -EINVAL;
return -ENOIOCTLCMD;
}
static const __u32 acm_tty_speed[] = {
0, 50, 75, 110, 134, 150, 200, 300, 600,
1200, 1800, 2400, 4800, 9600, 19200, 38400,
57600, 115200, 230400, 460800, 500000, 576000,
921600, 1000000, 1152000, 1500000, 2000000,
2500000, 3000000, 3500000, 4000000
};
static const __u8 acm_tty_size[] = {
5, 6, 7, 8
};
static void acm_tty_set_termios(struct tty_struct *tty, struct ktermios *termios_old)
{
struct acm *acm = tty->driver_data;
struct ktermios *termios = tty->termios;
struct usb_cdc_line_coding newline;
int newctrl = acm->ctrlout;
if (!ACM_READY(acm))
return;
newline.dwDTERate = cpu_to_le32p(acm_tty_speed +
(termios->c_cflag & CBAUD & ~CBAUDEX) + (termios->c_cflag & CBAUDEX ? 15 : 0));
newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
newline.bParityType = termios->c_cflag & PARENB ?
(termios->c_cflag & PARODD ? 1 : 2) + (termios->c_cflag & CMSPAR ? 2 : 0) : 0;
newline.bDataBits = acm_tty_size[(termios->c_cflag & CSIZE) >> 4];
acm->clocal = ((termios->c_cflag & CLOCAL) != 0);
if (!newline.dwDTERate) {
newline.dwDTERate = acm->line.dwDTERate;
newctrl &= ~ACM_CTRL_DTR;
} else newctrl |= ACM_CTRL_DTR;
if (newctrl != acm->ctrlout)
acm_set_control(acm, acm->ctrlout = newctrl);
if (memcmp(&acm->line, &newline, sizeof newline)) {
memcpy(&acm->line, &newline, sizeof newline);
dbg("set line: %d %d %d %d", le32_to_cpu(newline.dwDTERate),
newline.bCharFormat, newline.bParityType,
newline.bDataBits);
acm_set_line(acm, &acm->line);
}
}
/*
* USB probe and disconnect routines.
*/
/* Little helpers: write/read buffers free */
static void acm_write_buffers_free(struct acm *acm)
{
int i;
struct acm_wb *wb;
struct usb_device *usb_dev = interface_to_usbdev(acm->control);
for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
usb_buffer_free(usb_dev, acm->writesize, wb->buf, wb->dmah);
}
}
static void acm_read_buffers_free(struct acm *acm)
{
struct usb_device *usb_dev = interface_to_usbdev(acm->control);
int i, n = acm->rx_buflimit;
for (i = 0; i < n; i++)
usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
}
/* Little helper: write buffers allocate */
static int acm_write_buffers_alloc(struct acm *acm)
{
int i;
struct acm_wb *wb;
for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
wb->buf = usb_buffer_alloc(acm->dev, acm->writesize, GFP_KERNEL,
&wb->dmah);
if (!wb->buf) {
while (i != 0) {
--i;
--wb;
usb_buffer_free(acm->dev, acm->writesize,
wb->buf, wb->dmah);
}
return -ENOMEM;
}
}
return 0;
}
static int acm_probe (struct usb_interface *intf,
const struct usb_device_id *id)
{
struct usb_cdc_union_desc *union_header = NULL;
struct usb_cdc_country_functional_desc *cfd = NULL;
unsigned char *buffer = intf->altsetting->extra;
int buflen = intf->altsetting->extralen;
struct usb_interface *control_interface;
struct usb_interface *data_interface;
struct usb_endpoint_descriptor *epctrl;
struct usb_endpoint_descriptor *epread;
struct usb_endpoint_descriptor *epwrite;
struct usb_device *usb_dev = interface_to_usbdev(intf);
struct acm *acm;
int minor;
int ctrlsize,readsize;
u8 *buf;
u8 ac_management_function = 0;
u8 call_management_function = 0;
int call_interface_num = -1;
int data_interface_num;
unsigned long quirks;
int num_rx_buf;
int i;
/* normal quirks */
quirks = (unsigned long)id->driver_info;
num_rx_buf = (quirks == SINGLE_RX_URB) ? 1 : ACM_NR;
/* handle quirks deadly to normal probing*/
if (quirks == NO_UNION_NORMAL) {
data_interface = usb_ifnum_to_if(usb_dev, 1);
control_interface = usb_ifnum_to_if(usb_dev, 0);
goto skip_normal_probe;
}
/* normal probing*/
if (!buffer) {
dev_err(&intf->dev, "Weird descriptor references\n");
return -EINVAL;
}
if (!buflen) {
if (intf->cur_altsetting->endpoint->extralen && intf->cur_altsetting->endpoint->extra) {
dev_dbg(&intf->dev,"Seeking extra descriptors on endpoint\n");
buflen = intf->cur_altsetting->endpoint->extralen;
buffer = intf->cur_altsetting->endpoint->extra;
} else {
dev_err(&intf->dev,
"Zero length descriptor references\n");
return -EINVAL;
}
}
while (buflen > 0) {
if (buffer [1] != USB_DT_CS_INTERFACE) {
dev_err(&intf->dev, "skipping garbage\n");
goto next_desc;
}
switch (buffer [2]) {
case USB_CDC_UNION_TYPE: /* we've found it */
if (union_header) {
dev_err(&intf->dev, "More than one "
"union descriptor, "
"skipping ...\n");
goto next_desc;
}
union_header = (struct usb_cdc_union_desc *)
buffer;
break;
case USB_CDC_COUNTRY_TYPE: /* export through sysfs*/
cfd = (struct usb_cdc_country_functional_desc *)buffer;
break;
case USB_CDC_HEADER_TYPE: /* maybe check version */
break; /* for now we ignore it */
case USB_CDC_ACM_TYPE:
ac_management_function = buffer[3];
break;
case USB_CDC_CALL_MANAGEMENT_TYPE:
call_management_function = buffer[3];
call_interface_num = buffer[4];
if ((call_management_function & 3) != 3)
dev_err(&intf->dev, "This device "
"cannot do calls on its own. "
"It is no modem.\n");
break;
default:
/* there are LOTS more CDC descriptors that
* could legitimately be found here.
*/
dev_dbg(&intf->dev, "Ignoring descriptor: "
"type %02x, length %d\n",
buffer[2], buffer[0]);
break;
}
next_desc:
buflen -= buffer[0];
buffer += buffer[0];
}
if (!union_header) {
if (call_interface_num > 0) {
dev_dbg(&intf->dev,"No union descriptor, using call management descriptor\n");
data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
control_interface = intf;
} else {
dev_dbg(&intf->dev,"No union descriptor, giving up\n");
return -ENODEV;
}
} else {
control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
if (!control_interface || !data_interface) {
dev_dbg(&intf->dev,"no interfaces\n");
return -ENODEV;
}
}
if (data_interface_num != call_interface_num)
dev_dbg(&intf->dev,"Separate call control interface. That is not fully supported.\n");
skip_normal_probe:
/*workaround for switched interfaces */
if (data_interface->cur_altsetting->desc.bInterfaceClass != CDC_DATA_INTERFACE_TYPE) {
if (control_interface->cur_altsetting->desc.bInterfaceClass == CDC_DATA_INTERFACE_TYPE) {
struct usb_interface *t;
dev_dbg(&intf->dev,"Your device has switched interfaces.\n");
t = control_interface;
control_interface = data_interface;
data_interface = t;
} else {
return -EINVAL;
}
}
/* Accept probe requests only for the control interface */
if (intf != control_interface)
return -ENODEV;
if (usb_interface_claimed(data_interface)) { /* valid in this context */
dev_dbg(&intf->dev,"The data interface isn't available\n");
return -EBUSY;
}
if (data_interface->cur_altsetting->desc.bNumEndpoints < 2)
return -EINVAL;
epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
epread = &data_interface->cur_altsetting->endpoint[0].desc;
epwrite = &data_interface->cur_altsetting->endpoint[1].desc;
/* workaround for switched endpoints */
if (!usb_endpoint_dir_in(epread)) {
/* descriptors are swapped */
struct usb_endpoint_descriptor *t;
dev_dbg(&intf->dev,"The data interface has switched endpoints\n");
t = epread;
epread = epwrite;
epwrite = t;
}
dbg("interfaces are valid");
for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);
if (minor == ACM_TTY_MINORS) {
dev_err(&intf->dev, "no more free acm devices\n");
return -ENODEV;
}
if (!(acm = kzalloc(sizeof(struct acm), GFP_KERNEL))) {
dev_dbg(&intf->dev, "out of memory (acm kzalloc)\n");
goto alloc_fail;
}
ctrlsize = le16_to_cpu(epctrl->wMaxPacketSize);
readsize = le16_to_cpu(epread->wMaxPacketSize)* ( quirks == SINGLE_RX_URB ? 1 : 2);
acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize) * 20;
acm->control = control_interface;
acm->data = data_interface;
acm->minor = minor;
acm->dev = usb_dev;
acm->ctrl_caps = ac_management_function;
acm->ctrlsize = ctrlsize;
acm->readsize = readsize;
acm->rx_buflimit = num_rx_buf;
acm->urb_task.func = acm_rx_tasklet;
acm->urb_task.data = (unsigned long) acm;
INIT_WORK(&acm->work, acm_softint);
INIT_WORK(&acm->waker, acm_waker);
init_waitqueue_head(&acm->drain_wait);
spin_lock_init(&acm->throttle_lock);
spin_lock_init(&acm->write_lock);
spin_lock_init(&acm->read_lock);
mutex_init(&acm->mutex);
acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
buf = usb_buffer_alloc(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
if (!buf) {
dev_dbg(&intf->dev, "out of memory (ctrl buffer alloc)\n");
goto alloc_fail2;
}
acm->ctrl_buffer = buf;
if (acm_write_buffers_alloc(acm) < 0) {
dev_dbg(&intf->dev, "out of memory (write buffer alloc)\n");
goto alloc_fail4;
}
acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
if (!acm->ctrlurb) {
dev_dbg(&intf->dev, "out of memory (ctrlurb kmalloc)\n");
goto alloc_fail5;
}
for (i = 0; i < num_rx_buf; i++) {
struct acm_ru *rcv = &(acm->ru[i]);
if (!(rcv->urb = usb_alloc_urb(0, GFP_KERNEL))) {
dev_dbg(&intf->dev, "out of memory (read urbs usb_alloc_urb)\n");
goto alloc_fail7;
}
rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
rcv->instance = acm;
}
for (i = 0; i < num_rx_buf; i++) {
struct acm_rb *rb = &(acm->rb[i]);
rb->base = usb_buffer_alloc(acm->dev, readsize,
GFP_KERNEL, &rb->dma);
if (!rb->base) {
dev_dbg(&intf->dev, "out of memory (read bufs usb_buffer_alloc)\n");
goto alloc_fail7;
}
}
for(i = 0; i < ACM_NW; i++)
{
struct acm_wb *snd = &(acm->wb[i]);
if (!(snd->urb = usb_alloc_urb(0, GFP_KERNEL))) {
dev_dbg(&intf->dev, "out of memory (write urbs usb_alloc_urb)");
goto alloc_fail7;
}
usb_fill_bulk_urb(snd->urb, usb_dev, usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
NULL, acm->writesize, acm_write_bulk, snd);
snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
snd->instance = acm;
}
usb_set_intfdata (intf, acm);
i = device_create_file(&intf->dev, &dev_attr_bmCapabilities);
if (i < 0)
goto alloc_fail8;
if (cfd) { /* export the country data */
acm->country_codes = kmalloc(cfd->bLength - 4, GFP_KERNEL);
if (!acm->country_codes)
goto skip_countries;
acm->country_code_size = cfd->bLength - 4;
memcpy(acm->country_codes, (u8 *)&cfd->wCountyCode0, cfd->bLength - 4);
acm->country_rel_date = cfd->iCountryCodeRelDate;
i = device_create_file(&intf->dev, &dev_attr_wCountryCodes);
if (i < 0) {
kfree(acm->country_codes);
goto skip_countries;
}
i = device_create_file(&intf->dev, &dev_attr_iCountryCodeRelDate);
if (i < 0) {
kfree(acm->country_codes);
goto skip_countries;
}
}
skip_countries:
usb_fill_int_urb(acm->ctrlurb, usb_dev, usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm, epctrl->bInterval);
acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
acm->ctrlurb->transfer_dma = acm->ctrl_dma;
dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
acm_set_control(acm, acm->ctrlout);
acm->line.dwDTERate = cpu_to_le32(9600);
acm->line.bDataBits = 8;
acm_set_line(acm, &acm->line);
usb_driver_claim_interface(&acm_driver, data_interface, acm);
usb_set_intfdata(data_interface, acm);
usb_get_intf(control_interface);
tty_register_device(acm_tty_driver, minor, &control_interface->dev);
acm_table[minor] = acm;
return 0;
alloc_fail8:
for (i = 0; i < ACM_NW; i++)
usb_free_urb(acm->wb[i].urb);
alloc_fail7:
acm_read_buffers_free(acm);
for (i = 0; i < num_rx_buf; i++)
usb_free_urb(acm->ru[i].urb);
usb_free_urb(acm->ctrlurb);
alloc_fail5:
acm_write_buffers_free(acm);
alloc_fail4:
usb_buffer_free(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
alloc_fail2:
kfree(acm);
alloc_fail:
return -ENOMEM;
}
static void stop_data_traffic(struct acm *acm)
{
int i;
dbg("Entering stop_data_traffic");
tasklet_disable(&acm->urb_task);
usb_kill_urb(acm->ctrlurb);
for(i = 0; i < ACM_NW; i++)
usb_kill_urb(acm->wb[i].urb);
for (i = 0; i < acm->rx_buflimit; i++)
usb_kill_urb(acm->ru[i].urb);
tasklet_enable(&acm->urb_task);
cancel_work_sync(&acm->work);
cancel_work_sync(&acm->waker);
}
static void acm_disconnect(struct usb_interface *intf)
{
struct acm *acm = usb_get_intfdata(intf);
struct usb_device *usb_dev = interface_to_usbdev(intf);
/* sibling interface is already cleaning up */
if (!acm)
return;
mutex_lock(&open_mutex);
if (acm->country_codes){
device_remove_file(&acm->control->dev,
&dev_attr_wCountryCodes);
device_remove_file(&acm->control->dev,
&dev_attr_iCountryCodeRelDate);
}
device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
acm->dev = NULL;
usb_set_intfdata(acm->control, NULL);
usb_set_intfdata(acm->data, NULL);
stop_data_traffic(acm);
acm_write_buffers_free(acm);
usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
acm_read_buffers_free(acm);
usb_driver_release_interface(&acm_driver, intf == acm->control ?
acm->data : acm->control);
if (!acm->used) {
acm_tty_unregister(acm);
mutex_unlock(&open_mutex);
return;
}
mutex_unlock(&open_mutex);
if (acm->tty)
tty_hangup(acm->tty);
}
#ifdef CONFIG_PM
static int acm_suspend(struct usb_interface *intf, pm_message_t message)
{
struct acm *acm = usb_get_intfdata(intf);
int cnt;
if (message.event & PM_EVENT_AUTO) {
int b;
spin_lock_irq(&acm->read_lock);
spin_lock(&acm->write_lock);
b = acm->processing + acm->transmitting;
spin_unlock(&acm->write_lock);
spin_unlock_irq(&acm->read_lock);
if (b)
return -EBUSY;
}
spin_lock_irq(&acm->read_lock);
spin_lock(&acm->write_lock);
cnt = acm->susp_count++;
spin_unlock(&acm->write_lock);
spin_unlock_irq(&acm->read_lock);
if (cnt)
return 0;
/*
we treat opened interfaces differently,
we must guard against open
*/
mutex_lock(&acm->mutex);
if (acm->used)
stop_data_traffic(acm);
mutex_unlock(&acm->mutex);
return 0;
}
static int acm_resume(struct usb_interface *intf)
{
struct acm *acm = usb_get_intfdata(intf);
int rv = 0;
int cnt;
spin_lock_irq(&acm->read_lock);
acm->susp_count -= 1;
cnt = acm->susp_count;
spin_unlock_irq(&acm->read_lock);
if (cnt)
return 0;
mutex_lock(&acm->mutex);
if (acm->used) {
rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
if (rv < 0)
goto err_out;
tasklet_schedule(&acm->urb_task);
}
err_out:
mutex_unlock(&acm->mutex);
return rv;
}
#endif /* CONFIG_PM */
/*
* USB driver structure.
*/
static struct usb_device_id acm_ids[] = {
/* quirky and broken devices */
{ USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x0e8d, 0x0003), /* FIREFLY, MediaTek Inc; andrey.arapov@gmail.com */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x0e8d, 0x3329), /* MediaTek Inc GPS */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x079b, 0x000f), /* BT On-Air USB MODEM */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x0ace, 0x1602), /* ZyDAS 56K USB MODEM */
.driver_info = SINGLE_RX_URB,
},
{ USB_DEVICE(0x0ace, 0x1608), /* ZyDAS 56K USB MODEM */
.driver_info = SINGLE_RX_URB, /* firmware bug */
},
{ USB_DEVICE(0x0ace, 0x1611), /* ZyDAS 56K USB MODEM - new version */
.driver_info = SINGLE_RX_URB, /* firmware bug */
},
{ USB_DEVICE(0x22b8, 0x7000), /* Motorola Q Phone */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x0803, 0x3095), /* Zoom Telephonics Model 3095F USB MODEM */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x0572, 0x1321), /* Conexant USB MODEM CX93010 */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x0572, 0x1324), /* Conexant USB MODEM RD02-D400 */
.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
},
{ USB_DEVICE(0x22b8, 0x6425), /* Motorola MOTOMAGX phones */
},
{ USB_DEVICE(0x0572, 0x1329), /* Hummingbird huc56s (Conexant) */
.driver_info = NO_UNION_NORMAL, /* union descriptor misplaced on
data interface instead of
communications interface.
Maybe we should define a new
quirk for this. */
},
/* control interfaces with various AT-command sets */
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_ACM_PROTO_AT_V25TER) },
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_ACM_PROTO_AT_PCCA101) },
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_ACM_PROTO_AT_GSM) },
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_ACM_PROTO_AT_3G ) },
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
USB_CDC_ACM_PROTO_AT_CDMA) },
/* NOTE: COMM/ACM/0xff is likely MSFT RNDIS ... NOT a modem!! */
{ }
};
MODULE_DEVICE_TABLE (usb, acm_ids);
static struct usb_driver acm_driver = {
.name = "cdc_acm",
.probe = acm_probe,
.disconnect = acm_disconnect,
#ifdef CONFIG_PM
.suspend = acm_suspend,
.resume = acm_resume,
#endif
.id_table = acm_ids,
#ifdef CONFIG_PM
.supports_autosuspend = 1,
#endif
};
/*
* TTY driver structures.
*/
static const struct tty_operations acm_ops = {
.open = acm_tty_open,
.close = acm_tty_close,
.write = acm_tty_write,
.write_room = acm_tty_write_room,
.ioctl = acm_tty_ioctl,
.throttle = acm_tty_throttle,
.unthrottle = acm_tty_unthrottle,
.chars_in_buffer = acm_tty_chars_in_buffer,
.break_ctl = acm_tty_break_ctl,
.set_termios = acm_tty_set_termios,
.tiocmget = acm_tty_tiocmget,
.tiocmset = acm_tty_tiocmset,
};
/*
* Init / exit.
*/
static int __init acm_init(void)
{
int retval;
acm_tty_driver = alloc_tty_driver(ACM_TTY_MINORS);
if (!acm_tty_driver)
return -ENOMEM;
acm_tty_driver->owner = THIS_MODULE,
acm_tty_driver->driver_name = "acm",
acm_tty_driver->name = "ttyACM",
acm_tty_driver->major = ACM_TTY_MAJOR,
acm_tty_driver->minor_start = 0,
acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
acm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
acm_tty_driver->init_termios = tty_std_termios;
acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
tty_set_operations(acm_tty_driver, &acm_ops);
retval = tty_register_driver(acm_tty_driver);
if (retval) {
put_tty_driver(acm_tty_driver);
return retval;
}
retval = usb_register(&acm_driver);
if (retval) {
tty_unregister_driver(acm_tty_driver);
put_tty_driver(acm_tty_driver);
return retval;
}
printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
DRIVER_DESC "\n");
return 0;
}
static void __exit acm_exit(void)
{
usb_deregister(&acm_driver);
tty_unregister_driver(acm_tty_driver);
put_tty_driver(acm_tty_driver);
}
module_init(acm_init);
module_exit(acm_exit);
MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(ACM_TTY_MAJOR);