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linux-next/drivers/usb/serial/ir-usb.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

626 lines
16 KiB
C
Raw Blame History

/*
* USB IR Dongle driver
*
* Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
* Copyright (C) 2002 Gary Brubaker (xavyer@ix.netcom.com)
*
* 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 driver allows a USB IrDA device to be used as a "dumb" serial device.
* This can be useful if you do not have access to a full IrDA stack on the
* other side of the connection. If you do have an IrDA stack on both devices,
* please use the usb-irda driver, as it contains the proper error checking and
* other goodness of a full IrDA stack.
*
* Portions of this driver were taken from drivers/net/irda/irda-usb.c, which
* was written by Roman Weissgaerber <weissg@vienna.at>, Dag Brattli
* <dag@brattli.net>, and Jean Tourrilhes <jt@hpl.hp.com>
*
* See Documentation/usb/usb-serial.txt for more information on using this driver
*
* 2002_Mar_07 greg kh
* moved some needed structures and #define values from the
* net/irda/irda-usb.h file into our file, as we don't want to depend on
* that codebase compiling correctly :)
*
* 2002_Jan_14 gb
* Added module parameter to force specific number of XBOFs.
* Added ir_xbof_change().
* Reorganized read_bulk_callback error handling.
* Switched from FILL_BULK_URB() to usb_fill_bulk_urb().
*
* 2001_Nov_08 greg kh
* Changed the irda_usb_find_class_desc() function based on comments and
* code from Martin Diehl.
*
* 2001_Nov_01 greg kh
* Added support for more IrDA USB devices.
* Added support for zero packet. Added buffer override paramater, so
* users can transfer larger packets at once if they wish. Both patches
* came from Dag Brattli <dag@obexcode.com>.
*
* 2001_Oct_07 greg kh
* initial version released.
*/
#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>
/*
* Version Information
*/
#define DRIVER_VERSION "v0.4"
#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>"
#define DRIVER_DESC "USB IR Dongle driver"
/* USB IrDA class spec information */
#define USB_CLASS_IRDA 0x02
#define USB_DT_IRDA 0x21
#define IU_REQ_GET_CLASS_DESC 0x06
#define SPEED_2400 0x01
#define SPEED_9600 0x02
#define SPEED_19200 0x03
#define SPEED_38400 0x04
#define SPEED_57600 0x05
#define SPEED_115200 0x06
#define SPEED_576000 0x07
#define SPEED_1152000 0x08
#define SPEED_4000000 0x09
struct irda_class_desc {
u8 bLength;
u8 bDescriptorType;
u16 bcdSpecRevision;
u8 bmDataSize;
u8 bmWindowSize;
u8 bmMinTurnaroundTime;
u16 wBaudRate;
u8 bmAdditionalBOFs;
u8 bIrdaRateSniff;
u8 bMaxUnicastList;
} __attribute__ ((packed));
static int debug;
/* if overridden by the user, then use their value for the size of the read and
* write urbs */
static int buffer_size;
/* if overridden by the user, then use the specified number of XBOFs */
static int xbof = -1;
static int ir_startup (struct usb_serial *serial);
static int ir_open (struct usb_serial_port *port, struct file *filep);
static void ir_close (struct usb_serial_port *port, struct file *filep);
static int ir_write (struct usb_serial_port *port, const unsigned char *buf, int count);
static void ir_write_bulk_callback (struct urb *urb);
static void ir_read_bulk_callback (struct urb *urb);
static void ir_set_termios (struct usb_serial_port *port, struct termios *old_termios);
static u8 ir_baud = 0;
static u8 ir_xbof = 0;
static u8 ir_add_bof = 0;
static struct usb_device_id id_table [] = {
{ USB_DEVICE(0x050f, 0x0180) }, /* KC Technology, KC-180 */
{ USB_DEVICE(0x08e9, 0x0100) }, /* XTNDAccess */
{ USB_DEVICE(0x09c4, 0x0011) }, /* ACTiSys ACT-IR2000U */
{ USB_INTERFACE_INFO (USB_CLASS_APP_SPEC, USB_CLASS_IRDA, 0) },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE (usb, id_table);
static struct usb_driver ir_driver = {
.name = "ir-usb",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.id_table = id_table,
.no_dynamic_id = 1,
};
static struct usb_serial_driver ir_device = {
.driver = {
.owner = THIS_MODULE,
.name = "ir-usb",
},
.description = "IR Dongle",
.id_table = id_table,
.num_interrupt_in = 1,
.num_bulk_in = 1,
.num_bulk_out = 1,
.num_ports = 1,
.set_termios = ir_set_termios,
.attach = ir_startup,
.open = ir_open,
.close = ir_close,
.write = ir_write,
.write_bulk_callback = ir_write_bulk_callback,
.read_bulk_callback = ir_read_bulk_callback,
};
static inline void irda_usb_dump_class_desc(struct irda_class_desc *desc)
{
dbg("bLength=%x", desc->bLength);
dbg("bDescriptorType=%x", desc->bDescriptorType);
dbg("bcdSpecRevision=%x", desc->bcdSpecRevision);
dbg("bmDataSize=%x", desc->bmDataSize);
dbg("bmWindowSize=%x", desc->bmWindowSize);
dbg("bmMinTurnaroundTime=%d", desc->bmMinTurnaroundTime);
dbg("wBaudRate=%x", desc->wBaudRate);
dbg("bmAdditionalBOFs=%x", desc->bmAdditionalBOFs);
dbg("bIrdaRateSniff=%x", desc->bIrdaRateSniff);
dbg("bMaxUnicastList=%x", desc->bMaxUnicastList);
}
/*------------------------------------------------------------------*/
/*
* Function irda_usb_find_class_desc(dev, ifnum)
*
* Returns instance of IrDA class descriptor, or NULL if not found
*
* The class descriptor is some extra info that IrDA USB devices will
* offer to us, describing their IrDA characteristics. We will use that in
* irda_usb_init_qos()
*
* Based on the same function in drivers/net/irda/irda-usb.c
*/
static struct irda_class_desc *irda_usb_find_class_desc(struct usb_device *dev, unsigned int ifnum)
{
struct irda_class_desc *desc;
int ret;
desc = kzalloc(sizeof (struct irda_class_desc), GFP_KERNEL);
if (desc == NULL)
return NULL;
ret = usb_control_msg(dev, usb_rcvctrlpipe(dev,0),
IU_REQ_GET_CLASS_DESC,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, ifnum, desc, sizeof(*desc), 1000);
dbg("%s - ret=%d", __FUNCTION__, ret);
if (ret < sizeof(*desc)) {
dbg("%s - class descriptor read %s (%d)",
__FUNCTION__,
(ret<0) ? "failed" : "too short",
ret);
goto error;
}
if (desc->bDescriptorType != USB_DT_IRDA) {
dbg("%s - bad class descriptor type", __FUNCTION__);
goto error;
}
irda_usb_dump_class_desc(desc);
return desc;
error:
kfree(desc);
return NULL;
}
static u8 ir_xbof_change(u8 xbof)
{
u8 result;
/* reference irda-usb.c */
switch(xbof) {
case 48: result = 0x10; break;
case 28:
case 24: result = 0x20; break;
default:
case 12: result = 0x30; break;
case 5:
case 6: result = 0x40; break;
case 3: result = 0x50; break;
case 2: result = 0x60; break;
case 1: result = 0x70; break;
case 0: result = 0x80; break;
}
return(result);
}
static int ir_startup (struct usb_serial *serial)
{
struct irda_class_desc *irda_desc;
irda_desc = irda_usb_find_class_desc (serial->dev, 0);
if (irda_desc == NULL) {
dev_err (&serial->dev->dev, "IRDA class descriptor not found, device not bound\n");
return -ENODEV;
}
dbg ("%s - Baud rates supported:%s%s%s%s%s%s%s%s%s",
__FUNCTION__,
(irda_desc->wBaudRate & 0x0001) ? " 2400" : "",
(irda_desc->wBaudRate & 0x0002) ? " 9600" : "",
(irda_desc->wBaudRate & 0x0004) ? " 19200" : "",
(irda_desc->wBaudRate & 0x0008) ? " 38400" : "",
(irda_desc->wBaudRate & 0x0010) ? " 57600" : "",
(irda_desc->wBaudRate & 0x0020) ? " 115200" : "",
(irda_desc->wBaudRate & 0x0040) ? " 576000" : "",
(irda_desc->wBaudRate & 0x0080) ? " 1152000" : "",
(irda_desc->wBaudRate & 0x0100) ? " 4000000" : "");
switch( irda_desc->bmAdditionalBOFs ) {
case 0x01: ir_add_bof = 48; break;
case 0x02: ir_add_bof = 24; break;
case 0x04: ir_add_bof = 12; break;
case 0x08: ir_add_bof = 6; break;
case 0x10: ir_add_bof = 3; break;
case 0x20: ir_add_bof = 2; break;
case 0x40: ir_add_bof = 1; break;
case 0x80: ir_add_bof = 0; break;
default:;
}
kfree (irda_desc);
return 0;
}
static int ir_open (struct usb_serial_port *port, struct file *filp)
{
char *buffer;
int result = 0;
dbg("%s - port %d", __FUNCTION__, port->number);
if (buffer_size) {
/* override the default buffer sizes */
buffer = kmalloc (buffer_size, GFP_KERNEL);
if (!buffer) {
dev_err (&port->dev, "%s - out of memory.\n", __FUNCTION__);
return -ENOMEM;
}
kfree (port->read_urb->transfer_buffer);
port->read_urb->transfer_buffer = buffer;
port->read_urb->transfer_buffer_length = buffer_size;
buffer = kmalloc (buffer_size, GFP_KERNEL);
if (!buffer) {
dev_err (&port->dev, "%s - out of memory.\n", __FUNCTION__);
return -ENOMEM;
}
kfree (port->write_urb->transfer_buffer);
port->write_urb->transfer_buffer = buffer;
port->write_urb->transfer_buffer_length = buffer_size;
port->bulk_out_size = buffer_size;
}
/* Start reading from the device */
usb_fill_bulk_urb (
port->read_urb,
port->serial->dev,
usb_rcvbulkpipe(port->serial->dev, port->bulk_in_endpointAddress),
port->read_urb->transfer_buffer,
port->read_urb->transfer_buffer_length,
ir_read_bulk_callback,
port);
result = usb_submit_urb(port->read_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev, "%s - failed submitting read urb, error %d\n", __FUNCTION__, result);
return result;
}
static void ir_close (struct usb_serial_port *port, struct file * filp)
{
dbg("%s - port %d", __FUNCTION__, port->number);
/* shutdown our bulk read */
usb_kill_urb(port->read_urb);
}
static int ir_write (struct usb_serial_port *port, const unsigned char *buf, int count)
{
unsigned char *transfer_buffer;
int result;
int transfer_size;
dbg("%s - port = %d, count = %d", __FUNCTION__, port->number, count);
if (!port->tty) {
dev_err (&port->dev, "%s - no tty???\n", __FUNCTION__);
return 0;
}
if (count == 0)
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);
transfer_buffer = port->write_urb->transfer_buffer;
transfer_size = min(count, port->bulk_out_size - 1);
/*
* The first byte of the packet we send to the device contains an
* inband header which indicates an additional number of BOFs and
* a baud rate change.
*
* See section 5.4.2.2 of the USB IrDA spec.
*/
*transfer_buffer = ir_xbof | ir_baud;
++transfer_buffer;
memcpy (transfer_buffer, buf, transfer_size);
usb_fill_bulk_urb (
port->write_urb,
port->serial->dev,
usb_sndbulkpipe(port->serial->dev,
port->bulk_out_endpointAddress),
port->write_urb->transfer_buffer,
transfer_size + 1,
ir_write_bulk_callback,
port);
port->write_urb->transfer_flags = URB_ZERO_PACKET;
result = usb_submit_urb (port->write_urb, GFP_ATOMIC);
if (result) {
port->write_urb_busy = 0;
dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
} else
result = transfer_size;
return result;
}
static void ir_write_bulk_callback (struct urb *urb)
{
struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
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;
}
usb_serial_debug_data (
debug,
&port->dev,
__FUNCTION__,
urb->actual_length,
urb->transfer_buffer);
usb_serial_port_softint(port);
}
static void ir_read_bulk_callback (struct urb *urb)
{
struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
struct tty_struct *tty;
unsigned char *data = urb->transfer_buffer;
int result;
dbg("%s - port %d", __FUNCTION__, port->number);
if (!port->open_count) {
dbg("%s - port closed.", __FUNCTION__);
return;
}
switch (urb->status) {
case 0: /* Successful */
/*
* The first byte of the packet we get from the device
* contains a busy indicator and baud rate change.
* See section 5.4.1.2 of the USB IrDA spec.
*/
if ((*data & 0x0f) > 0)
ir_baud = *data & 0x0f;
usb_serial_debug_data (
debug,
&port->dev,
__FUNCTION__,
urb->actual_length,
data);
/*
* Bypass flip-buffers, and feed the ldisc directly
* due to our potentially large buffer size. Since we
* used to set low_latency, this is exactly what the
* tty layer did anyway :)
*/
tty = port->tty;
/*
* FIXME: must not do this in IRQ context
*/
tty->ldisc.receive_buf(
tty,
data+1,
NULL,
urb->actual_length-1);
/*
* No break here.
* We want to resubmit the urb so we can read
* again.
*/
case -EPROTO: /* taking inspiration from pl2303.c */
/* Continue trying to always read */
usb_fill_bulk_urb (
port->read_urb,
port->serial->dev,
usb_rcvbulkpipe(port->serial->dev,
port->bulk_in_endpointAddress),
port->read_urb->transfer_buffer,
port->read_urb->transfer_buffer_length,
ir_read_bulk_callback,
port);
result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
if (result)
dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n",
__FUNCTION__, result);
break ;
default:
dbg("%s - nonzero read bulk status received: %d",
__FUNCTION__,
urb->status);
break ;
}
return;
}
static void ir_set_termios (struct usb_serial_port *port, struct termios *old_termios)
{
unsigned char *transfer_buffer;
unsigned int cflag;
int result;
dbg("%s - port %d", __FUNCTION__, port->number);
if ((!port->tty) || (!port->tty->termios)) {
dbg("%s - no tty structures", __FUNCTION__);
return;
}
cflag = port->tty->termios->c_cflag;
/* check that they really want us to change something */
if (old_termios) {
if ((cflag == old_termios->c_cflag) &&
(RELEVANT_IFLAG(port->tty->termios->c_iflag) == RELEVANT_IFLAG(old_termios->c_iflag))) {
dbg("%s - nothing to change...", __FUNCTION__);
return;
}
}
/* All we can change is the baud rate */
if (cflag & CBAUD) {
dbg ("%s - asking for baud %d",
__FUNCTION__,
tty_get_baud_rate(port->tty));
/*
* FIXME, we should compare the baud request against the
* capability stated in the IR header that we got in the
* startup function.
*/
switch (cflag & CBAUD) {
case B2400: ir_baud = SPEED_2400; break;
default:
case B9600: ir_baud = SPEED_9600; break;
case B19200: ir_baud = SPEED_19200; break;
case B38400: ir_baud = SPEED_38400; break;
case B57600: ir_baud = SPEED_57600; break;
case B115200: ir_baud = SPEED_115200; break;
case B576000: ir_baud = SPEED_576000; break;
case B1152000: ir_baud = SPEED_1152000; break;
#ifdef B4000000
case B4000000: ir_baud = SPEED_4000000; break;
#endif
}
if (xbof == -1) {
ir_xbof = ir_xbof_change(ir_add_bof);
} else {
ir_xbof = ir_xbof_change(xbof) ;
}
/* Notify the tty driver that the termios have changed. */
port->tty->ldisc.set_termios(port->tty, NULL);
/* FIXME need to check to see if our write urb is busy right
* now, or use a urb pool.
*
* send the baud change out on an "empty" data packet
*/
transfer_buffer = port->write_urb->transfer_buffer;
*transfer_buffer = ir_xbof | ir_baud;
usb_fill_bulk_urb (
port->write_urb,
port->serial->dev,
usb_sndbulkpipe(port->serial->dev,
port->bulk_out_endpointAddress),
port->write_urb->transfer_buffer,
1,
ir_write_bulk_callback,
port);
port->write_urb->transfer_flags = URB_ZERO_PACKET;
result = usb_submit_urb (port->write_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
}
return;
}
static int __init ir_init (void)
{
int retval;
retval = usb_serial_register(&ir_device);
if (retval)
goto failed_usb_serial_register;
retval = usb_register(&ir_driver);
if (retval)
goto failed_usb_register;
info(DRIVER_DESC " " DRIVER_VERSION);
return 0;
failed_usb_register:
usb_serial_deregister(&ir_device);
failed_usb_serial_register:
return retval;
}
static void __exit ir_exit (void)
{
usb_deregister (&ir_driver);
usb_serial_deregister (&ir_device);
}
module_init(ir_init);
module_exit(ir_exit);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");
module_param(xbof, int, 0);
MODULE_PARM_DESC(xbof, "Force specific number of XBOFs");
module_param(buffer_size, int, 0);
MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");
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