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kernel-fxtec-pro1x/drivers/usb/class/usbtmc.c
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop 
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00

1137 lines
27 KiB
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/**
* drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
*
* Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
* Copyright (C) 2008 Novell, Inc.
* Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
*
* 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.
*
* The GNU General Public License is available at
* http://www.gnu.org/copyleft/gpl.html.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/kref.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/usb.h>
#include <linux/usb/tmc.h>
#define USBTMC_MINOR_BASE 176
/*
* Size of driver internal IO buffer. Must be multiple of 4 and at least as
* large as wMaxPacketSize (which is usually 512 bytes).
*/
#define USBTMC_SIZE_IOBUFFER 2048
/* Default USB timeout (in milliseconds) */
#define USBTMC_TIMEOUT 5000
/*
* Maximum number of read cycles to empty bulk in endpoint during CLEAR and
* ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
* packet is never read.
*/
#define USBTMC_MAX_READS_TO_CLEAR_BULK_IN 100
static const struct usb_device_id usbtmc_devices[] = {
{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
{ 0, } /* terminating entry */
};
MODULE_DEVICE_TABLE(usb, usbtmc_devices);
/*
* This structure is the capabilities for the device
* See section 4.2.1.8 of the USBTMC specification,
* and section 4.2.2 of the USBTMC usb488 subclass
* specification for details.
*/
struct usbtmc_dev_capabilities {
__u8 interface_capabilities;
__u8 device_capabilities;
__u8 usb488_interface_capabilities;
__u8 usb488_device_capabilities;
};
/* This structure holds private data for each USBTMC device. One copy is
* allocated for each USBTMC device in the driver's probe function.
*/
struct usbtmc_device_data {
const struct usb_device_id *id;
struct usb_device *usb_dev;
struct usb_interface *intf;
unsigned int bulk_in;
unsigned int bulk_out;
u8 bTag;
u8 bTag_last_write; /* needed for abort */
u8 bTag_last_read; /* needed for abort */
/* attributes from the USB TMC spec for this device */
u8 TermChar;
bool TermCharEnabled;
bool auto_abort;
bool zombie; /* fd of disconnected device */
struct usbtmc_dev_capabilities capabilities;
struct kref kref;
struct mutex io_mutex; /* only one i/o function running at a time */
};
#define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
/* Forward declarations */
static struct usb_driver usbtmc_driver;
static void usbtmc_delete(struct kref *kref)
{
struct usbtmc_device_data *data = to_usbtmc_data(kref);
usb_put_dev(data->usb_dev);
kfree(data);
}
static int usbtmc_open(struct inode *inode, struct file *filp)
{
struct usb_interface *intf;
struct usbtmc_device_data *data;
int retval = 0;
intf = usb_find_interface(&usbtmc_driver, iminor(inode));
if (!intf) {
printk(KERN_ERR KBUILD_MODNAME
": can not find device for minor %d", iminor(inode));
retval = -ENODEV;
goto exit;
}
data = usb_get_intfdata(intf);
kref_get(&data->kref);
/* Store pointer in file structure's private data field */
filp->private_data = data;
exit:
return retval;
}
static int usbtmc_release(struct inode *inode, struct file *file)
{
struct usbtmc_device_data *data = file->private_data;
kref_put(&data->kref, usbtmc_delete);
return 0;
}
static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
{
u8 *buffer;
struct device *dev;
int rv;
int n;
int actual;
struct usb_host_interface *current_setting;
int max_size;
dev = &data->intf->dev;
buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
data->bTag_last_read, data->bulk_in,
buffer, 2, USBTMC_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
if (buffer[0] == USBTMC_STATUS_FAILED) {
rv = 0;
goto exit;
}
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
buffer[0]);
rv = -EPERM;
goto exit;
}
max_size = 0;
current_setting = data->intf->cur_altsetting;
for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
if (current_setting->endpoint[n].desc.bEndpointAddress ==
data->bulk_in)
max_size = le16_to_cpu(current_setting->endpoint[n].
desc.wMaxPacketSize);
if (max_size == 0) {
dev_err(dev, "Couldn't get wMaxPacketSize\n");
rv = -EPERM;
goto exit;
}
dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
n = 0;
do {
dev_dbg(dev, "Reading from bulk in EP\n");
rv = usb_bulk_msg(data->usb_dev,
usb_rcvbulkpipe(data->usb_dev,
data->bulk_in),
buffer, USBTMC_SIZE_IOBUFFER,
&actual, USBTMC_TIMEOUT);
n++;
if (rv < 0) {
dev_err(dev, "usb_bulk_msg returned %d\n", rv);
goto exit;
}
} while ((actual == max_size) &&
(n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
if (actual == max_size) {
dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
rv = -EPERM;
goto exit;
}
n = 0;
usbtmc_abort_bulk_in_status:
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
0, data->bulk_in, buffer, 0x08,
USBTMC_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
if (buffer[0] == USBTMC_STATUS_SUCCESS) {
rv = 0;
goto exit;
}
if (buffer[0] != USBTMC_STATUS_PENDING) {
dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
rv = -EPERM;
goto exit;
}
if (buffer[1] == 1)
do {
dev_dbg(dev, "Reading from bulk in EP\n");
rv = usb_bulk_msg(data->usb_dev,
usb_rcvbulkpipe(data->usb_dev,
data->bulk_in),
buffer, USBTMC_SIZE_IOBUFFER,
&actual, USBTMC_TIMEOUT);
n++;
if (rv < 0) {
dev_err(dev, "usb_bulk_msg returned %d\n", rv);
goto exit;
}
} while ((actual = max_size) &&
(n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
if (actual == max_size) {
dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
rv = -EPERM;
goto exit;
}
goto usbtmc_abort_bulk_in_status;
exit:
kfree(buffer);
return rv;
}
static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
{
struct device *dev;
u8 *buffer;
int rv;
int n;
dev = &data->intf->dev;
buffer = kmalloc(8, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
data->bTag_last_write, data->bulk_out,
buffer, 2, USBTMC_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
buffer[0]);
rv = -EPERM;
goto exit;
}
n = 0;
usbtmc_abort_bulk_out_check_status:
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
0, data->bulk_out, buffer, 0x08,
USBTMC_TIMEOUT);
n++;
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
if (buffer[0] == USBTMC_STATUS_SUCCESS)
goto usbtmc_abort_bulk_out_clear_halt;
if ((buffer[0] == USBTMC_STATUS_PENDING) &&
(n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
goto usbtmc_abort_bulk_out_check_status;
rv = -EPERM;
goto exit;
usbtmc_abort_bulk_out_clear_halt:
rv = usb_clear_halt(data->usb_dev,
usb_sndbulkpipe(data->usb_dev, data->bulk_out));
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
rv = 0;
exit:
kfree(buffer);
return rv;
}
static ssize_t usbtmc_read(struct file *filp, char __user *buf,
size_t count, loff_t *f_pos)
{
struct usbtmc_device_data *data;
struct device *dev;
u32 n_characters;
u8 *buffer;
int actual;
size_t done;
size_t remaining;
int retval;
size_t this_part;
/* Get pointer to private data structure */
data = filp->private_data;
dev = &data->intf->dev;
buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
mutex_lock(&data->io_mutex);
if (data->zombie) {
retval = -ENODEV;
goto exit;
}
remaining = count;
done = 0;
while (remaining > 0) {
if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
else
this_part = remaining;
/* Setup IO buffer for DEV_DEP_MSG_IN message
* Refer to class specs for details
*/
buffer[0] = 2;
buffer[1] = data->bTag;
buffer[2] = ~(data->bTag);
buffer[3] = 0; /* Reserved */
buffer[4] = (this_part) & 255;
buffer[5] = ((this_part) >> 8) & 255;
buffer[6] = ((this_part) >> 16) & 255;
buffer[7] = ((this_part) >> 24) & 255;
buffer[8] = data->TermCharEnabled * 2;
/* Use term character? */
buffer[9] = data->TermChar;
buffer[10] = 0; /* Reserved */
buffer[11] = 0; /* Reserved */
/* Send bulk URB */
retval = usb_bulk_msg(data->usb_dev,
usb_sndbulkpipe(data->usb_dev,
data->bulk_out),
buffer, 12, &actual, USBTMC_TIMEOUT);
/* Store bTag (in case we need to abort) */
data->bTag_last_write = data->bTag;
/* Increment bTag -- and increment again if zero */
data->bTag++;
if (!data->bTag)
(data->bTag)++;
if (retval < 0) {
dev_err(dev, "usb_bulk_msg returned %d\n", retval);
if (data->auto_abort)
usbtmc_ioctl_abort_bulk_out(data);
goto exit;
}
/* Send bulk URB */
retval = usb_bulk_msg(data->usb_dev,
usb_rcvbulkpipe(data->usb_dev,
data->bulk_in),
buffer, USBTMC_SIZE_IOBUFFER, &actual,
USBTMC_TIMEOUT);
/* Store bTag (in case we need to abort) */
data->bTag_last_read = data->bTag;
if (retval < 0) {
dev_err(dev, "Unable to read data, error %d\n", retval);
if (data->auto_abort)
usbtmc_ioctl_abort_bulk_in(data);
goto exit;
}
/* How many characters did the instrument send? */
n_characters = buffer[4] +
(buffer[5] << 8) +
(buffer[6] << 16) +
(buffer[7] << 24);
/* Ensure the instrument doesn't lie about it */
if(n_characters > actual - 12) {
dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12);
n_characters = actual - 12;
}
/* Ensure the instrument doesn't send more back than requested */
if(n_characters > this_part) {
dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part);
n_characters = this_part;
}
/* Bound amount of data received by amount of data requested */
if (n_characters > this_part)
n_characters = this_part;
/* Copy buffer to user space */
if (copy_to_user(buf + done, &buffer[12], n_characters)) {
/* There must have been an addressing problem */
retval = -EFAULT;
goto exit;
}
done += n_characters;
/* Terminate if end-of-message bit recieved from device */
if ((buffer[8] & 0x01) && (actual >= n_characters + 12))
remaining = 0;
else
remaining -= n_characters;
}
/* Update file position value */
*f_pos = *f_pos + done;
retval = done;
exit:
mutex_unlock(&data->io_mutex);
kfree(buffer);
return retval;
}
static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
size_t count, loff_t *f_pos)
{
struct usbtmc_device_data *data;
u8 *buffer;
int retval;
int actual;
unsigned long int n_bytes;
int remaining;
int done;
int this_part;
data = filp->private_data;
buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
mutex_lock(&data->io_mutex);
if (data->zombie) {
retval = -ENODEV;
goto exit;
}
remaining = count;
done = 0;
while (remaining > 0) {
if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
this_part = USBTMC_SIZE_IOBUFFER - 12;
buffer[8] = 0;
} else {
this_part = remaining;
buffer[8] = 1;
}
/* Setup IO buffer for DEV_DEP_MSG_OUT message */
buffer[0] = 1;
buffer[1] = data->bTag;
buffer[2] = ~(data->bTag);
buffer[3] = 0; /* Reserved */
buffer[4] = this_part & 255;
buffer[5] = (this_part >> 8) & 255;
buffer[6] = (this_part >> 16) & 255;
buffer[7] = (this_part >> 24) & 255;
/* buffer[8] is set above... */
buffer[9] = 0; /* Reserved */
buffer[10] = 0; /* Reserved */
buffer[11] = 0; /* Reserved */
if (copy_from_user(&buffer[12], buf + done, this_part)) {
retval = -EFAULT;
goto exit;
}
n_bytes = roundup(12 + this_part, 4);
memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
do {
retval = usb_bulk_msg(data->usb_dev,
usb_sndbulkpipe(data->usb_dev,
data->bulk_out),
buffer, n_bytes,
&actual, USBTMC_TIMEOUT);
if (retval != 0)
break;
n_bytes -= actual;
} while (n_bytes);
data->bTag_last_write = data->bTag;
data->bTag++;
if (!data->bTag)
data->bTag++;
if (retval < 0) {
dev_err(&data->intf->dev,
"Unable to send data, error %d\n", retval);
if (data->auto_abort)
usbtmc_ioctl_abort_bulk_out(data);
goto exit;
}
remaining -= this_part;
done += this_part;
}
retval = count;
exit:
mutex_unlock(&data->io_mutex);
kfree(buffer);
return retval;
}
static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
{
struct usb_host_interface *current_setting;
struct usb_endpoint_descriptor *desc;
struct device *dev;
u8 *buffer;
int rv;
int n;
int actual;
int max_size;
dev = &data->intf->dev;
dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_INITIATE_CLEAR,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, 0, buffer, 1, USBTMC_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
rv = -EPERM;
goto exit;
}
max_size = 0;
current_setting = data->intf->cur_altsetting;
for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
desc = &current_setting->endpoint[n].desc;
if (desc->bEndpointAddress == data->bulk_in)
max_size = le16_to_cpu(desc->wMaxPacketSize);
}
if (max_size == 0) {
dev_err(dev, "Couldn't get wMaxPacketSize\n");
rv = -EPERM;
goto exit;
}
dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
n = 0;
usbtmc_clear_check_status:
dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_CHECK_CLEAR_STATUS,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, 0, buffer, 2, USBTMC_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
if (buffer[0] == USBTMC_STATUS_SUCCESS)
goto usbtmc_clear_bulk_out_halt;
if (buffer[0] != USBTMC_STATUS_PENDING) {
dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
rv = -EPERM;
goto exit;
}
if (buffer[1] == 1)
do {
dev_dbg(dev, "Reading from bulk in EP\n");
rv = usb_bulk_msg(data->usb_dev,
usb_rcvbulkpipe(data->usb_dev,
data->bulk_in),
buffer, USBTMC_SIZE_IOBUFFER,
&actual, USBTMC_TIMEOUT);
n++;
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n",
rv);
goto exit;
}
} while ((actual == max_size) &&
(n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
if (actual == max_size) {
dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
rv = -EPERM;
goto exit;
}
goto usbtmc_clear_check_status;
usbtmc_clear_bulk_out_halt:
rv = usb_clear_halt(data->usb_dev,
usb_sndbulkpipe(data->usb_dev, data->bulk_out));
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
rv = 0;
exit:
kfree(buffer);
return rv;
}
static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
{
u8 *buffer;
int rv;
buffer = kmalloc(2, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_clear_halt(data->usb_dev,
usb_sndbulkpipe(data->usb_dev, data->bulk_out));
if (rv < 0) {
dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
rv);
goto exit;
}
rv = 0;
exit:
kfree(buffer);
return rv;
}
static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
{
u8 *buffer;
int rv;
buffer = kmalloc(2, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_clear_halt(data->usb_dev,
usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
if (rv < 0) {
dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
rv);
goto exit;
}
rv = 0;
exit:
kfree(buffer);
return rv;
}
static int get_capabilities(struct usbtmc_device_data *data)
{
struct device *dev = &data->usb_dev->dev;
char *buffer;
int rv = 0;
buffer = kmalloc(0x18, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_GET_CAPABILITIES,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, 0, buffer, 0x18, USBTMC_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto err_out;
}
dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
rv = -EPERM;
goto err_out;
}
dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
data->capabilities.interface_capabilities = buffer[4];
data->capabilities.device_capabilities = buffer[5];
data->capabilities.usb488_interface_capabilities = buffer[14];
data->capabilities.usb488_device_capabilities = buffer[15];
rv = 0;
err_out:
kfree(buffer);
return rv;
}
#define capability_attribute(name) \
static ssize_t show_##name(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
struct usb_interface *intf = to_usb_interface(dev); \
struct usbtmc_device_data *data = usb_get_intfdata(intf); \
\
return sprintf(buf, "%d\n", data->capabilities.name); \
} \
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
capability_attribute(interface_capabilities);
capability_attribute(device_capabilities);
capability_attribute(usb488_interface_capabilities);
capability_attribute(usb488_device_capabilities);
static struct attribute *capability_attrs[] = {
&dev_attr_interface_capabilities.attr,
&dev_attr_device_capabilities.attr,
&dev_attr_usb488_interface_capabilities.attr,
&dev_attr_usb488_device_capabilities.attr,
NULL,
};
static struct attribute_group capability_attr_grp = {
.attrs = capability_attrs,
};
static ssize_t show_TermChar(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usbtmc_device_data *data = usb_get_intfdata(intf);
return sprintf(buf, "%c\n", data->TermChar);
}
static ssize_t store_TermChar(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_interface *intf = to_usb_interface(dev);
struct usbtmc_device_data *data = usb_get_intfdata(intf);
if (count < 1)
return -EINVAL;
data->TermChar = buf[0];
return count;
}
static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
#define data_attribute(name) \
static ssize_t show_##name(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
struct usb_interface *intf = to_usb_interface(dev); \
struct usbtmc_device_data *data = usb_get_intfdata(intf); \
\
return sprintf(buf, "%d\n", data->name); \
} \
static ssize_t store_##name(struct device *dev, \
struct device_attribute *attr, \
const char *buf, size_t count) \
{ \
struct usb_interface *intf = to_usb_interface(dev); \
struct usbtmc_device_data *data = usb_get_intfdata(intf); \
ssize_t result; \
unsigned val; \
\
result = sscanf(buf, "%u\n", &val); \
if (result != 1) \
result = -EINVAL; \
data->name = val; \
if (result < 0) \
return result; \
else \
return count; \
} \
static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
data_attribute(TermCharEnabled);
data_attribute(auto_abort);
static struct attribute *data_attrs[] = {
&dev_attr_TermChar.attr,
&dev_attr_TermCharEnabled.attr,
&dev_attr_auto_abort.attr,
NULL,
};
static struct attribute_group data_attr_grp = {
.attrs = data_attrs,
};
static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
{
struct device *dev;
u8 *buffer;
int rv;
dev = &data->intf->dev;
buffer = kmalloc(2, GFP_KERNEL);
if (!buffer)
return -ENOMEM;
rv = usb_control_msg(data->usb_dev,
usb_rcvctrlpipe(data->usb_dev, 0),
USBTMC_REQUEST_INDICATOR_PULSE,
USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
0, 0, buffer, 0x01, USBTMC_TIMEOUT);
if (rv < 0) {
dev_err(dev, "usb_control_msg returned %d\n", rv);
goto exit;
}
dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
if (buffer[0] != USBTMC_STATUS_SUCCESS) {
dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
rv = -EPERM;
goto exit;
}
rv = 0;
exit:
kfree(buffer);
return rv;
}
static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct usbtmc_device_data *data;
int retval = -EBADRQC;
data = file->private_data;
mutex_lock(&data->io_mutex);
if (data->zombie) {
retval = -ENODEV;
goto skip_io_on_zombie;
}
switch (cmd) {
case USBTMC_IOCTL_CLEAR_OUT_HALT:
retval = usbtmc_ioctl_clear_out_halt(data);
break;
case USBTMC_IOCTL_CLEAR_IN_HALT:
retval = usbtmc_ioctl_clear_in_halt(data);
break;
case USBTMC_IOCTL_INDICATOR_PULSE:
retval = usbtmc_ioctl_indicator_pulse(data);
break;
case USBTMC_IOCTL_CLEAR:
retval = usbtmc_ioctl_clear(data);
break;
case USBTMC_IOCTL_ABORT_BULK_OUT:
retval = usbtmc_ioctl_abort_bulk_out(data);
break;
case USBTMC_IOCTL_ABORT_BULK_IN:
retval = usbtmc_ioctl_abort_bulk_in(data);
break;
}
skip_io_on_zombie:
mutex_unlock(&data->io_mutex);
return retval;
}
static const struct file_operations fops = {
.owner = THIS_MODULE,
.read = usbtmc_read,
.write = usbtmc_write,
.open = usbtmc_open,
.release = usbtmc_release,
.unlocked_ioctl = usbtmc_ioctl,
.llseek = default_llseek,
};
static struct usb_class_driver usbtmc_class = {
.name = "usbtmc%d",
.fops = &fops,
.minor_base = USBTMC_MINOR_BASE,
};
static int usbtmc_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
struct usbtmc_device_data *data;
struct usb_host_interface *iface_desc;
struct usb_endpoint_descriptor *endpoint;
int n;
int retcode;
dev_dbg(&intf->dev, "%s called\n", __func__);
data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
if (!data) {
dev_err(&intf->dev, "Unable to allocate kernel memory\n");
return -ENOMEM;
}
data->intf = intf;
data->id = id;
data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
usb_set_intfdata(intf, data);
kref_init(&data->kref);
mutex_init(&data->io_mutex);
data->zombie = 0;
/* Initialize USBTMC bTag and other fields */
data->bTag = 1;
data->TermCharEnabled = 0;
data->TermChar = '\n';
/* USBTMC devices have only one setting, so use that */
iface_desc = data->intf->cur_altsetting;
/* Find bulk in endpoint */
for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
endpoint = &iface_desc->endpoint[n].desc;
if (usb_endpoint_is_bulk_in(endpoint)) {
data->bulk_in = endpoint->bEndpointAddress;
dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
data->bulk_in);
break;
}
}
/* Find bulk out endpoint */
for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
endpoint = &iface_desc->endpoint[n].desc;
if (usb_endpoint_is_bulk_out(endpoint)) {
data->bulk_out = endpoint->bEndpointAddress;
dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
data->bulk_out);
break;
}
}
retcode = get_capabilities(data);
if (retcode)
dev_err(&intf->dev, "can't read capabilities\n");
else
retcode = sysfs_create_group(&intf->dev.kobj,
&capability_attr_grp);
retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
retcode = usb_register_dev(intf, &usbtmc_class);
if (retcode) {
dev_err(&intf->dev, "Not able to get a minor"
" (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
retcode);
goto error_register;
}
dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
return 0;
error_register:
sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
kref_put(&data->kref, usbtmc_delete);
return retcode;
}
static void usbtmc_disconnect(struct usb_interface *intf)
{
struct usbtmc_device_data *data;
dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
data = usb_get_intfdata(intf);
usb_deregister_dev(intf, &usbtmc_class);
sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
mutex_lock(&data->io_mutex);
data->zombie = 1;
mutex_unlock(&data->io_mutex);
kref_put(&data->kref, usbtmc_delete);
}
static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
{
/* this driver does not have pending URBs */
return 0;
}
static int usbtmc_resume(struct usb_interface *intf)
{
return 0;
}
static struct usb_driver usbtmc_driver = {
.name = "usbtmc",
.id_table = usbtmc_devices,
.probe = usbtmc_probe,
.disconnect = usbtmc_disconnect,
.suspend = usbtmc_suspend,
.resume = usbtmc_resume,
};
static int __init usbtmc_init(void)
{
int retcode;
retcode = usb_register(&usbtmc_driver);
if (retcode)
printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
return retcode;
}
module_init(usbtmc_init);
static void __exit usbtmc_exit(void)
{
usb_deregister(&usbtmc_driver);
}
module_exit(usbtmc_exit);
MODULE_LICENSE("GPL");
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