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alistair23-linux/drivers/usb/serial/cyberjack.c
David Howells 7d12e780e0 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 15:10:12 +01:00

510 lines
14 KiB
C
Raw Blame History

/*
* REINER SCT cyberJack pinpad/e-com USB Chipcard Reader Driver
*
* Copyright (C) 2001 REINER SCT
* Author: Matthias Bruestle
*
* Contact: support@reiner-sct.com (see MAINTAINERS)
*
* This program is largely derived from work by the linux-usb group
* and associated source files. Please see the usb/serial files for
* individual credits and copyrights.
*
* 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.
*
* Thanks to Greg Kroah-Hartman (greg@kroah.com) for his help and
* patience.
*
* In case of problems, please write to the contact e-mail address
* mentioned above.
*
* Please note that later models of the cyberjack reader family are
* supported by a libusb-based userspace device driver.
*
* Homepage: http://www.reiner-sct.de/support/treiber_cyberjack.php#linux
*/
#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/spinlock.h>
#include <asm/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#define CYBERJACK_LOCAL_BUF_SIZE 32
static int debug;
/*
* Version Information
*/
#define DRIVER_VERSION "v1.01"
#define DRIVER_AUTHOR "Matthias Bruestle"
#define DRIVER_DESC "REINER SCT cyberJack pinpad/e-com USB Chipcard Reader Driver"
#define CYBERJACK_VENDOR_ID 0x0C4B
#define CYBERJACK_PRODUCT_ID 0x0100
/* Function prototypes */
static int cyberjack_startup (struct usb_serial *serial);
static void cyberjack_shutdown (struct usb_serial *serial);
static int cyberjack_open (struct usb_serial_port *port, struct file *filp);
static void cyberjack_close (struct usb_serial_port *port, struct file *filp);
static int cyberjack_write (struct usb_serial_port *port, const unsigned char *buf, int count);
static int cyberjack_write_room( struct usb_serial_port *port );
static void cyberjack_read_int_callback (struct urb *urb);
static void cyberjack_read_bulk_callback (struct urb *urb);
static void cyberjack_write_bulk_callback (struct urb *urb);
static struct usb_device_id id_table [] = {
{ USB_DEVICE(CYBERJACK_VENDOR_ID, CYBERJACK_PRODUCT_ID) },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE (usb, id_table);
static struct usb_driver cyberjack_driver = {
.name = "cyberjack",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.id_table = id_table,
.no_dynamic_id = 1,
};
static struct usb_serial_driver cyberjack_device = {
.driver = {
.owner = THIS_MODULE,
.name = "cyberjack",
},
.description = "Reiner SCT Cyberjack USB card reader",
.id_table = id_table,
.num_interrupt_in = 1,
.num_bulk_in = 1,
.num_bulk_out = 1,
.num_ports = 1,
.attach = cyberjack_startup,
.shutdown = cyberjack_shutdown,
.open = cyberjack_open,
.close = cyberjack_close,
.write = cyberjack_write,
.write_room = cyberjack_write_room,
.read_int_callback = cyberjack_read_int_callback,
.read_bulk_callback = cyberjack_read_bulk_callback,
.write_bulk_callback = cyberjack_write_bulk_callback,
};
struct cyberjack_private {
spinlock_t lock; /* Lock for SMP */
short rdtodo; /* Bytes still to read */
unsigned char wrbuf[5*64]; /* Buffer for collecting data to write */
short wrfilled; /* Overall data size we already got */
short wrsent; /* Data already sent */
};
/* do some startup allocations not currently performed by usb_serial_probe() */
static int cyberjack_startup (struct usb_serial *serial)
{
struct cyberjack_private *priv;
int i;
dbg("%s", __FUNCTION__);
/* allocate the private data structure */
priv = kmalloc(sizeof(struct cyberjack_private), GFP_KERNEL);
if (!priv)
return -ENOMEM;
/* set initial values */
spin_lock_init(&priv->lock);
priv->rdtodo = 0;
priv->wrfilled = 0;
priv->wrsent = 0;
usb_set_serial_port_data(serial->port[0], priv);
init_waitqueue_head(&serial->port[0]->write_wait);
for (i = 0; i < serial->num_ports; ++i) {
int result;
serial->port[i]->interrupt_in_urb->dev = serial->dev;
result = usb_submit_urb(serial->port[i]->interrupt_in_urb,
GFP_KERNEL);
if (result)
err(" usb_submit_urb(read int) failed");
dbg("%s - usb_submit_urb(int urb)", __FUNCTION__);
}
return( 0 );
}
static void cyberjack_shutdown (struct usb_serial *serial)
{
int i;
dbg("%s", __FUNCTION__);
for (i=0; i < serial->num_ports; ++i) {
usb_kill_urb(serial->port[i]->interrupt_in_urb);
/* My special items, the standard routines free my urbs */
kfree(usb_get_serial_port_data(serial->port[i]));
usb_set_serial_port_data(serial->port[i], NULL);
}
}
static int cyberjack_open (struct usb_serial_port *port, struct file *filp)
{
struct cyberjack_private *priv;
unsigned long flags;
int result = 0;
dbg("%s - port %d", __FUNCTION__, port->number);
dbg("%s - usb_clear_halt", __FUNCTION__ );
usb_clear_halt(port->serial->dev, port->write_urb->pipe);
/* force low_latency on so that our tty_push actually forces
* the data through, otherwise it is scheduled, and with high
* data rates (like with OHCI) data can get lost.
*/
port->tty->low_latency = 1;
priv = usb_get_serial_port_data(port);
spin_lock_irqsave(&priv->lock, flags);
priv->rdtodo = 0;
priv->wrfilled = 0;
priv->wrsent = 0;
spin_unlock_irqrestore(&priv->lock, flags);
return result;
}
static void cyberjack_close (struct usb_serial_port *port, struct file *filp)
{
dbg("%s - port %d", __FUNCTION__, port->number);
if (port->serial->dev) {
/* shutdown any bulk reads that might be going on */
usb_kill_urb(port->write_urb);
usb_kill_urb(port->read_urb);
}
}
static int cyberjack_write (struct usb_serial_port *port, const unsigned char *buf, int count)
{
struct usb_serial *serial = port->serial;
struct cyberjack_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
int result;
int wrexpected;
dbg("%s - port %d", __FUNCTION__, port->number);
if (count == 0) {
dbg("%s - write request of 0 bytes", __FUNCTION__);
return (0);
}
spin_lock_bh(&port->lock);
if (port->write_urb_busy) {
spin_unlock_bh(&port->lock);
dbg("%s - already writing", __FUNCTION__);
return 0;
}
port->write_urb_busy = 1;
spin_unlock_bh(&port->lock);
spin_lock_irqsave(&priv->lock, flags);
if( (count+priv->wrfilled)>sizeof(priv->wrbuf) ) {
/* To much data for buffer. Reset buffer. */
priv->wrfilled=0;
spin_unlock_irqrestore(&priv->lock, flags);
port->write_urb_busy = 0;
return (0);
}
/* Copy data */
memcpy (priv->wrbuf+priv->wrfilled, buf, count);
usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count,
priv->wrbuf+priv->wrfilled);
priv->wrfilled += count;
if( priv->wrfilled >= 3 ) {
wrexpected = ((int)priv->wrbuf[2]<<8)+priv->wrbuf[1]+3;
dbg("%s - expected data: %d", __FUNCTION__, wrexpected);
} else {
wrexpected = sizeof(priv->wrbuf);
}
if( priv->wrfilled >= wrexpected ) {
/* We have enough data to begin transmission */
int length;
dbg("%s - transmitting data (frame 1)", __FUNCTION__);
length = (wrexpected > port->bulk_out_size) ? port->bulk_out_size : wrexpected;
memcpy (port->write_urb->transfer_buffer, priv->wrbuf, length );
priv->wrsent=length;
/* set up our urb */
usb_fill_bulk_urb(port->write_urb, serial->dev,
usb_sndbulkpipe(serial->dev, port->bulk_out_endpointAddress),
port->write_urb->transfer_buffer, length,
((serial->type->write_bulk_callback) ?
serial->type->write_bulk_callback :
cyberjack_write_bulk_callback),
port);
/* send the data out the bulk port */
result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
if (result) {
err("%s - failed submitting write urb, error %d", __FUNCTION__, result);
/* Throw away data. No better idea what to do with it. */
priv->wrfilled=0;
priv->wrsent=0;
spin_unlock_irqrestore(&priv->lock, flags);
port->write_urb_busy = 0;
return 0;
}
dbg("%s - priv->wrsent=%d", __FUNCTION__,priv->wrsent);
dbg("%s - priv->wrfilled=%d", __FUNCTION__,priv->wrfilled);
if( priv->wrsent>=priv->wrfilled ) {
dbg("%s - buffer cleaned", __FUNCTION__);
memset( priv->wrbuf, 0, sizeof(priv->wrbuf) );
priv->wrfilled=0;
priv->wrsent=0;
}
}
spin_unlock_irqrestore(&priv->lock, flags);
return (count);
}
static int cyberjack_write_room( struct usb_serial_port *port )
{
return CYBERJACK_LOCAL_BUF_SIZE;
}
static void cyberjack_read_int_callback( struct urb *urb )
{
struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
struct cyberjack_private *priv = usb_get_serial_port_data(port);
unsigned char *data = urb->transfer_buffer;
int result;
dbg("%s - port %d", __FUNCTION__, port->number);
/* the urb might have been killed. */
if (urb->status)
return;
usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
/* React only to interrupts signaling a bulk_in transfer */
if( (urb->actual_length==4) && (data[0]==0x01) ) {
short old_rdtodo;
int result;
/* This is a announcement of coming bulk_ins. */
unsigned short size = ((unsigned short)data[3]<<8)+data[2]+3;
spin_lock(&priv->lock);
old_rdtodo = priv->rdtodo;
if( (old_rdtodo+size)<(old_rdtodo) ) {
dbg( "To many bulk_in urbs to do." );
spin_unlock(&priv->lock);
goto resubmit;
}
/* "+=" is probably more fault tollerant than "=" */
priv->rdtodo += size;
dbg("%s - rdtodo: %d", __FUNCTION__, priv->rdtodo);
spin_unlock(&priv->lock);
if( !old_rdtodo ) {
port->read_urb->dev = port->serial->dev;
result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
if( result )
err("%s - failed resubmitting read urb, error %d", __FUNCTION__, result);
dbg("%s - usb_submit_urb(read urb)", __FUNCTION__);
}
}
resubmit:
port->interrupt_in_urb->dev = port->serial->dev;
result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
if (result)
err(" usb_submit_urb(read int) failed");
dbg("%s - usb_submit_urb(int urb)", __FUNCTION__);
}
static void cyberjack_read_bulk_callback (struct urb *urb)
{
struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
struct cyberjack_private *priv = usb_get_serial_port_data(port);
struct tty_struct *tty;
unsigned char *data = urb->transfer_buffer;
short todo;
int result;
dbg("%s - port %d", __FUNCTION__, port->number);
usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
if (urb->status) {
dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
return;
}
tty = port->tty;
if (!tty) {
dbg("%s - ignoring since device not open\n", __FUNCTION__);
return;
}
if (urb->actual_length) {
tty_buffer_request_room(tty, urb->actual_length);
tty_insert_flip_string(tty, data, urb->actual_length);
tty_flip_buffer_push(tty);
}
spin_lock(&priv->lock);
/* Reduce urbs to do by one. */
priv->rdtodo-=urb->actual_length;
/* Just to be sure */
if ( priv->rdtodo<0 ) priv->rdtodo = 0;
todo = priv->rdtodo;
spin_unlock(&priv->lock);
dbg("%s - rdtodo: %d", __FUNCTION__, todo);
/* Continue to read if we have still urbs to do. */
if( todo /* || (urb->actual_length==port->bulk_in_endpointAddress)*/ ) {
port->read_urb->dev = port->serial->dev;
result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
if (result)
err("%s - failed resubmitting read urb, error %d", __FUNCTION__, result);
dbg("%s - usb_submit_urb(read urb)", __FUNCTION__);
}
}
static void cyberjack_write_bulk_callback (struct urb *urb)
{
struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
struct cyberjack_private *priv = usb_get_serial_port_data(port);
dbg("%s - port %d", __FUNCTION__, port->number);
port->write_urb_busy = 0;
if (urb->status) {
dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
return;
}
spin_lock(&priv->lock);
/* only do something if we have more data to send */
if( priv->wrfilled ) {
int length, blksize, result;
dbg("%s - transmitting data (frame n)", __FUNCTION__);
length = ((priv->wrfilled - priv->wrsent) > port->bulk_out_size) ?
port->bulk_out_size : (priv->wrfilled - priv->wrsent);
memcpy (port->write_urb->transfer_buffer, priv->wrbuf + priv->wrsent,
length );
priv->wrsent+=length;
/* set up our urb */
usb_fill_bulk_urb(port->write_urb, port->serial->dev,
usb_sndbulkpipe(port->serial->dev, port->bulk_out_endpointAddress),
port->write_urb->transfer_buffer, length,
((port->serial->type->write_bulk_callback) ?
port->serial->type->write_bulk_callback :
cyberjack_write_bulk_callback),
port);
/* send the data out the bulk port */
result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
if (result) {
err("%s - failed submitting write urb, error %d", __FUNCTION__, result);
/* Throw away data. No better idea what to do with it. */
priv->wrfilled=0;
priv->wrsent=0;
goto exit;
}
dbg("%s - priv->wrsent=%d", __FUNCTION__,priv->wrsent);
dbg("%s - priv->wrfilled=%d", __FUNCTION__,priv->wrfilled);
blksize = ((int)priv->wrbuf[2]<<8)+priv->wrbuf[1]+3;
if( (priv->wrsent>=priv->wrfilled) || (priv->wrsent>=blksize) ) {
dbg("%s - buffer cleaned", __FUNCTION__);
memset( priv->wrbuf, 0, sizeof(priv->wrbuf) );
priv->wrfilled=0;
priv->wrsent=0;
}
}
exit:
spin_unlock(&priv->lock);
usb_serial_port_softint(port);
}
static int __init cyberjack_init (void)
{
int retval;
retval = usb_serial_register(&cyberjack_device);
if (retval)
goto failed_usb_serial_register;
retval = usb_register(&cyberjack_driver);
if (retval)
goto failed_usb_register;
info(DRIVER_VERSION " " DRIVER_AUTHOR);
info(DRIVER_DESC);
return 0;
failed_usb_register:
usb_serial_deregister(&cyberjack_device);
failed_usb_serial_register:
return retval;
}
static void __exit cyberjack_exit (void)
{
usb_deregister (&cyberjack_driver);
usb_serial_deregister (&cyberjack_device);
}
module_init(cyberjack_init);
module_exit(cyberjack_exit);
MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_VERSION( DRIVER_VERSION );
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");
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