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alistair23-linux/drivers/usb/serial/ipw.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

494 lines
14 KiB
C
Raw Blame History

/*
* IPWireless 3G UMTS TDD Modem driver (USB connected)
*
* Copyright (C) 2004 Roelf Diedericks <roelfd@inet.co.za>
* Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* All information about the device was acquired using SnoopyPro
* on MSFT's O/S, and examing the MSFT drivers' debug output
* (insanely left _on_ in the enduser version)
*
* It was written out of frustration with the IPWireless USB modem
* supplied by Axity3G/Sentech South Africa not supporting
* Linux whatsoever.
*
* Nobody provided any proprietary information that was not already
* available for this device.
*
* The modem adheres to the "3GPP TS 27.007 AT command set for 3G
* User Equipment (UE)" standard, available from
* http://www.3gpp.org/ftp/Specs/html-info/27007.htm
*
* The code was only tested the IPWireless handheld modem distributed
* in South Africa by Sentech.
*
* It may work for Woosh Inc in .nz too, as it appears they use the
* same kit.
*
* There is still some work to be done in terms of handling
* DCD, DTR, RTS, CTS which are currently faked.
* It's good enough for PPP at this point. It's based off all kinds of
* code found in usb/serial and usb/class
*
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <asm/uaccess.h>
/*
* Version Information
*/
#define DRIVER_VERSION "v0.3"
#define DRIVER_AUTHOR "Roelf Diedericks"
#define DRIVER_DESC "IPWireless tty driver"
#define IPW_TTY_MAJOR 240 /* real device node major id, experimental range */
#define IPW_TTY_MINORS 256 /* we support 256 devices, dunno why, it'd be insane :) */
#define USB_IPW_MAGIC 0x6d02 /* magic number for ipw struct */
/* Message sizes */
#define EVENT_BUFFER_SIZE 0xFF
#define CHAR2INT16(c1,c0) (((u32)((c1) & 0xff) << 8) + (u32)((c0) & 0xff))
#define NUM_BULK_URBS 24
#define NUM_CONTROL_URBS 16
/* vendor/product pairs that are known work with this driver*/
#define IPW_VID 0x0bc3
#define IPW_PID 0x0001
/* Vendor commands: */
/* baud rates */
enum {
ipw_sio_b256000 = 0x000e,
ipw_sio_b128000 = 0x001d,
ipw_sio_b115200 = 0x0020,
ipw_sio_b57600 = 0x0040,
ipw_sio_b56000 = 0x0042,
ipw_sio_b38400 = 0x0060,
ipw_sio_b19200 = 0x00c0,
ipw_sio_b14400 = 0x0100,
ipw_sio_b9600 = 0x0180,
ipw_sio_b4800 = 0x0300,
ipw_sio_b2400 = 0x0600,
ipw_sio_b1200 = 0x0c00,
ipw_sio_b600 = 0x1800
};
/* data bits */
#define ipw_dtb_7 0x700
#define ipw_dtb_8 0x810 // ok so the define is misleading, I know, but forces 8,n,1
// I mean, is there a point to any other setting these days? :)
/* usb control request types : */
#define IPW_SIO_RXCTL 0x00 // control bulk rx channel transmissions, value=1/0 (on/off)
#define IPW_SIO_SET_BAUD 0x01 // set baud, value=requested ipw_sio_bxxxx
#define IPW_SIO_SET_LINE 0x03 // set databits, parity. value=ipw_dtb_x
#define IPW_SIO_SET_PIN 0x03 // set/clear dtr/rts value=ipw_pin_xxx
#define IPW_SIO_POLL 0x08 // get serial port status byte, call with value=0
#define IPW_SIO_INIT 0x11 // initializes ? value=0 (appears as first thing todo on open)
#define IPW_SIO_PURGE 0x12 // purge all transmissions?, call with value=numchar_to_purge
#define IPW_SIO_HANDFLOW 0x13 // set xon/xoff limits value=0, and a buffer of 0x10 bytes
#define IPW_SIO_SETCHARS 0x13 // set the flowcontrol special chars, value=0, buf=6 bytes,
// last 2 bytes contain flowcontrol chars e.g. 00 00 00 00 11 13
/* values used for request IPW_SIO_SET_PIN */
#define IPW_PIN_SETDTR 0x101
#define IPW_PIN_SETRTS 0x202
#define IPW_PIN_CLRDTR 0x100
#define IPW_PIN_CLRRTS 0x200 // unconfirmed
/* values used for request IPW_SIO_RXCTL */
#define IPW_RXBULK_ON 1
#define IPW_RXBULK_OFF 0
/* various 16 byte hardcoded transferbuffers used by flow control */
#define IPW_BYTES_FLOWINIT { 0x01, 0, 0, 0, 0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
/* Interpretation of modem status lines */
/* These need sorting out by individually connecting pins and checking
* results. FIXME!
* When data is being sent we see 0x30 in the lower byte; this must
* contain DSR and CTS ...
*/
#define IPW_DSR ((1<<4) | (1<<5))
#define IPW_CTS ((1<<5) | (1<<4))
#define IPW_WANTS_TO_SEND 0x30
//#define IPW_DTR /* Data Terminal Ready */
//#define IPW_CTS /* Clear To Send */
//#define IPW_CD /* Carrier Detect */
//#define IPW_DSR /* Data Set Ready */
//#define IPW_RxD /* Receive pin */
//#define IPW_LE
//#define IPW_RTS
//#define IPW_ST
//#define IPW_SR
//#define IPW_RI /* Ring Indicator */
static struct usb_device_id usb_ipw_ids[] = {
{ USB_DEVICE(IPW_VID, IPW_PID) },
{ },
};
MODULE_DEVICE_TABLE(usb, usb_ipw_ids);
static struct usb_driver usb_ipw_driver = {
.name = "ipwtty",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.id_table = usb_ipw_ids,
.no_dynamic_id = 1,
};
static int debug;
static void ipw_read_bulk_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
unsigned char *data = urb->transfer_buffer;
struct tty_struct *tty;
int result;
dbg("%s - port %d", __FUNCTION__, port->number);
if (urb->status) {
dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
return;
}
usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
tty = port->tty;
if (tty && 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);
}
/* 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,
ipw_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);
return;
}
static int ipw_open(struct usb_serial_port *port, struct file *filp)
{
struct usb_device *dev = port->serial->dev;
u8 buf_flow_static[16] = IPW_BYTES_FLOWINIT;
u8 *buf_flow_init;
int result;
dbg("%s", __FUNCTION__);
buf_flow_init = kmalloc(16, GFP_KERNEL);
if (!buf_flow_init)
return -ENOMEM;
memcpy(buf_flow_init, buf_flow_static, 16);
if (port->tty)
port->tty->low_latency = 1;
/* --1: Tell the modem to initialize (we think) From sniffs this is always the
* first thing that gets sent to the modem during opening of the device */
dbg("%s: Sending SIO_INIT (we guess)",__FUNCTION__);
result = usb_control_msg(dev, usb_sndctrlpipe(dev,0),
IPW_SIO_INIT,
USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
0,
0, /* index */
NULL,
0,
100000);
if (result < 0)
dev_err(&port->dev, "Init of modem failed (error = %d)", result);
/* reset the bulk pipes */
usb_clear_halt(dev, usb_rcvbulkpipe(dev, port->bulk_in_endpointAddress));
usb_clear_halt(dev, usb_sndbulkpipe(dev, port->bulk_out_endpointAddress));
/*--2: Start reading from the device */
dbg("%s: setting up bulk read callback",__FUNCTION__);
usb_fill_bulk_urb(port->read_urb, dev,
usb_rcvbulkpipe(dev, port->bulk_in_endpointAddress),
port->bulk_in_buffer,
port->bulk_in_size,
ipw_read_bulk_callback, port);
result = usb_submit_urb(port->read_urb, GFP_KERNEL);
if (result < 0)
dbg("%s - usb_submit_urb(read bulk) failed with status %d", __FUNCTION__, result);
/*--3: Tell the modem to open the floodgates on the rx bulk channel */
dbg("%s:asking modem for RxRead (RXBULK_ON)",__FUNCTION__);
result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
IPW_SIO_RXCTL,
USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
IPW_RXBULK_ON,
0, /* index */
NULL,
0,
100000);
if (result < 0)
dev_err(&port->dev, "Enabling bulk RxRead failed (error = %d)", result);
/*--4: setup the initial flowcontrol */
dbg("%s:setting init flowcontrol (%s)",__FUNCTION__,buf_flow_init);
result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
IPW_SIO_HANDFLOW,
USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
0,
0,
buf_flow_init,
0x10,
200000);
if (result < 0)
dev_err(&port->dev, "initial flowcontrol failed (error = %d)", result);
/*--5: raise the dtr */
dbg("%s:raising dtr",__FUNCTION__);
result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
IPW_SIO_SET_PIN,
USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
IPW_PIN_SETDTR,
0,
NULL,
0,
200000);
if (result < 0)
dev_err(&port->dev, "setting dtr failed (error = %d)", result);
/*--6: raise the rts */
dbg("%s:raising rts",__FUNCTION__);
result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
IPW_SIO_SET_PIN,
USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
IPW_PIN_SETRTS,
0,
NULL,
0,
200000);
if (result < 0)
dev_err(&port->dev, "setting dtr failed (error = %d)", result);
kfree(buf_flow_init);
return 0;
}
static void ipw_close(struct usb_serial_port *port, struct file * filp)
{
struct usb_device *dev = port->serial->dev;
int result;
if (tty_hung_up_p(filp)) {
dbg("%s: tty_hung_up_p ...", __FUNCTION__);
return;
}
/*--1: drop the dtr */
dbg("%s:dropping dtr",__FUNCTION__);
result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
IPW_SIO_SET_PIN,
USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
IPW_PIN_CLRDTR,
0,
NULL,
0,
200000);
if (result < 0)
dev_err(&port->dev, "dropping dtr failed (error = %d)", result);
/*--2: drop the rts */
dbg("%s:dropping rts",__FUNCTION__);
result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
IPW_SIO_SET_PIN, USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
IPW_PIN_CLRRTS,
0,
NULL,
0,
200000);
if (result < 0)
dev_err(&port->dev, "dropping rts failed (error = %d)", result);
/*--3: purge */
dbg("%s:sending purge",__FUNCTION__);
result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
IPW_SIO_PURGE, USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
0x03,
0,
NULL,
0,
200000);
if (result < 0)
dev_err(&port->dev, "purge failed (error = %d)", result);
/* send RXBULK_off (tell modem to stop transmitting bulk data on rx chan) */
result = usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
IPW_SIO_RXCTL,
USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT,
IPW_RXBULK_OFF,
0, /* index */
NULL,
0,
100000);
if (result < 0)
dev_err(&port->dev, "Disabling bulk RxRead failed (error = %d)", result);
/* shutdown any in-flight urbs that we know about */
usb_kill_urb(port->read_urb);
usb_kill_urb(port->write_urb);
}
static void ipw_write_bulk_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
dbg("%s", __FUNCTION__);
port->write_urb_busy = 0;
if (urb->status)
dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
usb_serial_port_softint(port);
}
static int ipw_write(struct usb_serial_port *port, const unsigned char *buf, int count)
{
struct usb_device *dev = port->serial->dev;
int ret;
dbg("%s: TOP: count=%d, in_interrupt=%ld", __FUNCTION__,
count, in_interrupt() );
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);
count = min(count, port->bulk_out_size);
memcpy(port->bulk_out_buffer, buf, count);
dbg("%s count now:%d", __FUNCTION__, count);
usb_fill_bulk_urb(port->write_urb, dev,
usb_sndbulkpipe(dev, port->bulk_out_endpointAddress),
port->write_urb->transfer_buffer,
count,
ipw_write_bulk_callback,
port);
ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
if (ret != 0) {
port->write_urb_busy = 0;
dbg("%s - usb_submit_urb(write bulk) failed with error = %d", __FUNCTION__, ret);
return ret;
}
dbg("%s returning %d", __FUNCTION__, count);
return count;
}
static int ipw_probe(struct usb_serial_port *port)
{
return 0;
}
static int ipw_disconnect(struct usb_serial_port *port)
{
usb_set_serial_port_data(port, NULL);
return 0;
}
static struct usb_serial_driver ipw_device = {
.driver = {
.owner = THIS_MODULE,
.name = "ipw",
},
.description = "IPWireless converter",
.id_table = usb_ipw_ids,
.num_interrupt_in = NUM_DONT_CARE,
.num_bulk_in = 1,
.num_bulk_out = 1,
.num_ports = 1,
.open = ipw_open,
.close = ipw_close,
.port_probe = ipw_probe,
.port_remove = ipw_disconnect,
.write = ipw_write,
.write_bulk_callback = ipw_write_bulk_callback,
.read_bulk_callback = ipw_read_bulk_callback,
};
static int usb_ipw_init(void)
{
int retval;
retval = usb_serial_register(&ipw_device);
if (retval)
return retval;
retval = usb_register(&usb_ipw_driver);
if (retval) {
usb_serial_deregister(&ipw_device);
return retval;
}
info(DRIVER_DESC " " DRIVER_VERSION);
return 0;
}
static void usb_ipw_exit(void)
{
usb_deregister(&usb_ipw_driver);
usb_serial_deregister(&ipw_device);
}
module_init(usb_ipw_init);
module_exit(usb_ipw_exit);
/* Module information */
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");
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