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linux/drivers/usb/image/mdc800.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

1089 lines
24 KiB
C
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/*
* copyright (C) 1999/2000 by Henning Zabel <henning@uni-paderborn.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.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* USB-Kernel Driver for the Mustek MDC800 Digital Camera
* (c) 1999/2000 Henning Zabel <henning@uni-paderborn.de>
*
*
* The driver brings the USB functions of the MDC800 to Linux.
* To use the Camera you must support the USB Protocol of the camera
* to the Kernel Node.
* The Driver uses a misc device Node. Create it with :
* mknod /dev/mustek c 180 32
*
* The driver supports only one camera.
*
* Fix: mdc800 used sleep_on and slept with io_lock held.
* Converted sleep_on to waitqueues with schedule_timeout and made io_lock
* a semaphore from a spinlock.
* by Oliver Neukum <oliver@neukum.name>
* (02/12/2001)
*
* Identify version on module load.
* (08/04/2001) gb
*
* version 0.7.5
* Fixed potential SMP races with Spinlocks.
* Thanks to Oliver Neukum <oliver@neukum.name> who
* noticed the race conditions.
* (30/10/2000)
*
* Fixed: Setting urb->dev before submitting urb.
* by Greg KH <greg@kroah.com>
* (13/10/2000)
*
* version 0.7.3
* bugfix : The mdc800->state field gets set to READY after the
* the diconnect function sets it to NOT_CONNECTED. This makes the
* driver running like the camera is connected and causes some
* hang ups.
*
* version 0.7.1
* MOD_INC and MOD_DEC are changed in usb_probe to prevent load/unload
* problems when compiled as Module.
* (04/04/2000)
*
* The mdc800 driver gets assigned the USB Minor 32-47. The Registration
* was updated to use these values.
* (26/03/2000)
*
* The Init und Exit Module Function are updated.
* (01/03/2000)
*
* version 0.7.0
* Rewrite of the driver : The driver now uses URB's. The old stuff
* has been removed.
*
* version 0.6.0
* Rewrite of this driver: The Emulation of the rs232 protocoll
* has been removed from the driver. A special executeCommand function
* for this driver is included to gphoto.
* The driver supports two kind of communication to bulk endpoints.
* Either with the dev->bus->ops->bulk... or with callback function.
* (09/11/1999)
*
* version 0.5.0:
* first Version that gets a version number. Most of the needed
* functions work.
* (20/10/1999)
*/
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/random.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/usb.h>
#include <linux/fs.h>
/*
* Version Information
*/
#define DRIVER_VERSION "v0.7.5 (30/10/2000)"
#define DRIVER_AUTHOR "Henning Zabel <henning@uni-paderborn.de>"
#define DRIVER_DESC "USB Driver for Mustek MDC800 Digital Camera"
/* Vendor and Product Information */
#define MDC800_VENDOR_ID 0x055f
#define MDC800_PRODUCT_ID 0xa800
/* Timeouts (msec) */
#define TO_DOWNLOAD_GET_READY 1500
#define TO_DOWNLOAD_GET_BUSY 1500
#define TO_WRITE_GET_READY 1000
#define TO_DEFAULT_COMMAND 5000
#define TO_READ_FROM_IRQ TO_DEFAULT_COMMAND
#define TO_GET_READY TO_DEFAULT_COMMAND
/* Minor Number of the device (create with mknod /dev/mustek c 180 32) */
#define MDC800_DEVICE_MINOR_BASE 32
/**************************************************************************
Data and structs
***************************************************************************/
typedef enum {
NOT_CONNECTED, READY, WORKING, DOWNLOAD
} mdc800_state;
/* Data for the driver */
struct mdc800_data
{
struct usb_device * dev; // Device Data
mdc800_state state;
unsigned int endpoint [4];
struct urb * irq_urb;
wait_queue_head_t irq_wait;
int irq_woken;
char* irq_urb_buffer;
int camera_busy; // is camera busy ?
int camera_request_ready; // Status to synchronize with irq
char camera_response [8]; // last Bytes send after busy
struct urb * write_urb;
char* write_urb_buffer;
wait_queue_head_t write_wait;
int written;
struct urb * download_urb;
char* download_urb_buffer;
wait_queue_head_t download_wait;
int downloaded;
int download_left; // Bytes left to download ?
/* Device Data */
char out [64]; // Answer Buffer
int out_ptr; // Index to the first not readen byte
int out_count; // Bytes in the buffer
int open; // Camera device open ?
struct mutex io_lock; // IO -lock
char in [8]; // Command Input Buffer
int in_count;
int pic_index; // Cache for the Imagesize (-1 for nothing cached )
int pic_len;
int minor;
};
/* Specification of the Endpoints */
static struct usb_endpoint_descriptor mdc800_ed [4] =
{
{
.bLength = 0,
.bDescriptorType = 0,
.bEndpointAddress = 0x01,
.bmAttributes = 0x02,
.wMaxPacketSize = cpu_to_le16(8),
.bInterval = 0,
.bRefresh = 0,
.bSynchAddress = 0,
},
{
.bLength = 0,
.bDescriptorType = 0,
.bEndpointAddress = 0x82,
.bmAttributes = 0x03,
.wMaxPacketSize = cpu_to_le16(8),
.bInterval = 0,
.bRefresh = 0,
.bSynchAddress = 0,
},
{
.bLength = 0,
.bDescriptorType = 0,
.bEndpointAddress = 0x03,
.bmAttributes = 0x02,
.wMaxPacketSize = cpu_to_le16(64),
.bInterval = 0,
.bRefresh = 0,
.bSynchAddress = 0,
},
{
.bLength = 0,
.bDescriptorType = 0,
.bEndpointAddress = 0x84,
.bmAttributes = 0x02,
.wMaxPacketSize = cpu_to_le16(64),
.bInterval = 0,
.bRefresh = 0,
.bSynchAddress = 0,
},
};
/* The Variable used by the driver */
static struct mdc800_data* mdc800;
/***************************************************************************
The USB Part of the driver
****************************************************************************/
static int mdc800_endpoint_equals (struct usb_endpoint_descriptor *a,struct usb_endpoint_descriptor *b)
{
return (
( a->bEndpointAddress == b->bEndpointAddress )
&& ( a->bmAttributes == b->bmAttributes )
&& ( a->wMaxPacketSize == b->wMaxPacketSize )
);
}
/*
* Checks whether the camera responds busy
*/
static int mdc800_isBusy (char* ch)
{
int i=0;
while (i<8)
{
if (ch [i] != (char)0x99)
return 0;
i++;
}
return 1;
}
/*
* Checks whether the Camera is ready
*/
static int mdc800_isReady (char *ch)
{
int i=0;
while (i<8)
{
if (ch [i] != (char)0xbb)
return 0;
i++;
}
return 1;
}
/*
* USB IRQ Handler for InputLine
*/
static void mdc800_usb_irq (struct urb *urb)
{
int data_received=0, wake_up;
unsigned char* b=urb->transfer_buffer;
struct mdc800_data* mdc800=urb->context;
int status = urb->status;
if (status >= 0) {
//dbg ("%i %i %i %i %i %i %i %i \n",b[0],b[1],b[2],b[3],b[4],b[5],b[6],b[7]);
if (mdc800_isBusy (b))
{
if (!mdc800->camera_busy)
{
mdc800->camera_busy=1;
dbg ("gets busy");
}
}
else
{
if (mdc800->camera_busy && mdc800_isReady (b))
{
mdc800->camera_busy=0;
dbg ("gets ready");
}
}
if (!(mdc800_isBusy (b) || mdc800_isReady (b)))
{
/* Store Data in camera_answer field */
dbg ("%i %i %i %i %i %i %i %i ",b[0],b[1],b[2],b[3],b[4],b[5],b[6],b[7]);
memcpy (mdc800->camera_response,b,8);
data_received=1;
}
}
wake_up= ( mdc800->camera_request_ready > 0 )
&&
(
((mdc800->camera_request_ready == 1) && (!mdc800->camera_busy))
||
((mdc800->camera_request_ready == 2) && data_received)
||
((mdc800->camera_request_ready == 3) && (mdc800->camera_busy))
||
(status < 0)
);
if (wake_up)
{
mdc800->camera_request_ready=0;
mdc800->irq_woken=1;
wake_up (&mdc800->irq_wait);
}
}
/*
* Waits a while until the irq responds that camera is ready
*
* mode : 0: Wait for camera gets ready
* 1: Wait for receiving data
* 2: Wait for camera gets busy
*
* msec: Time to wait
*/
static int mdc800_usb_waitForIRQ (int mode, int msec)
{
mdc800->camera_request_ready=1+mode;
wait_event_timeout(mdc800->irq_wait, mdc800->irq_woken, msec*HZ/1000);
mdc800->irq_woken = 0;
if (mdc800->camera_request_ready>0)
{
mdc800->camera_request_ready=0;
dev_err(&mdc800->dev->dev, "timeout waiting for camera.\n");
return -1;
}
if (mdc800->state == NOT_CONNECTED)
{
printk(KERN_WARNING "mdc800: Camera gets disconnected "
"during waiting for irq.\n");
mdc800->camera_request_ready=0;
return -2;
}
return 0;
}
/*
* The write_urb callback function
*/
static void mdc800_usb_write_notify (struct urb *urb)
{
struct mdc800_data* mdc800=urb->context;
int status = urb->status;
if (status != 0)
dev_err(&mdc800->dev->dev,
"writing command fails (status=%i)\n", status);
else
mdc800->state=READY;
mdc800->written = 1;
wake_up (&mdc800->write_wait);
}
/*
* The download_urb callback function
*/
static void mdc800_usb_download_notify (struct urb *urb)
{
struct mdc800_data* mdc800=urb->context;
int status = urb->status;
if (status == 0) {
/* Fill output buffer with these data */
memcpy (mdc800->out, urb->transfer_buffer, 64);
mdc800->out_count=64;
mdc800->out_ptr=0;
mdc800->download_left-=64;
if (mdc800->download_left == 0)
{
mdc800->state=READY;
}
} else {
dev_err(&mdc800->dev->dev,
"request bytes fails (status:%i)\n", status);
}
mdc800->downloaded = 1;
wake_up (&mdc800->download_wait);
}
/***************************************************************************
Probing for the Camera
***************************************************************************/
static struct usb_driver mdc800_usb_driver;
static const struct file_operations mdc800_device_ops;
static struct usb_class_driver mdc800_class = {
.name = "mdc800%d",
.fops = &mdc800_device_ops,
.minor_base = MDC800_DEVICE_MINOR_BASE,
};
/*
* Callback to search the Mustek MDC800 on the USB Bus
*/
static int mdc800_usb_probe (struct usb_interface *intf,
const struct usb_device_id *id)
{
int i,j;
struct usb_host_interface *intf_desc;
struct usb_device *dev = interface_to_usbdev (intf);
int irq_interval=0;
int retval;
dbg ("(mdc800_usb_probe) called.");
if (mdc800->dev != NULL)
{
dev_warn(&intf->dev, "only one Mustek MDC800 is supported.\n");
return -ENODEV;
}
if (dev->descriptor.bNumConfigurations != 1)
{
dev_err(&intf->dev,
"probe fails -> wrong Number of Configuration\n");
return -ENODEV;
}
intf_desc = intf->cur_altsetting;
if (
( intf_desc->desc.bInterfaceClass != 0xff )
|| ( intf_desc->desc.bInterfaceSubClass != 0 )
|| ( intf_desc->desc.bInterfaceProtocol != 0 )
|| ( intf_desc->desc.bNumEndpoints != 4)
)
{
dev_err(&intf->dev, "probe fails -> wrong Interface\n");
return -ENODEV;
}
/* Check the Endpoints */
for (i=0; i<4; i++)
{
mdc800->endpoint[i]=-1;
for (j=0; j<4; j++)
{
if (mdc800_endpoint_equals (&intf_desc->endpoint [j].desc,&mdc800_ed [i]))
{
mdc800->endpoint[i]=intf_desc->endpoint [j].desc.bEndpointAddress ;
if (i==1)
{
irq_interval=intf_desc->endpoint [j].desc.bInterval;
}
}
}
if (mdc800->endpoint[i] == -1)
{
dev_err(&intf->dev, "probe fails -> Wrong Endpoints.\n");
return -ENODEV;
}
}
dev_info(&intf->dev, "Found Mustek MDC800 on USB.\n");
mutex_lock(&mdc800->io_lock);
retval = usb_register_dev(intf, &mdc800_class);
if (retval) {
dev_err(&intf->dev, "Not able to get a minor for this device.\n");
mutex_unlock(&mdc800->io_lock);
return -ENODEV;
}
mdc800->dev=dev;
mdc800->open=0;
/* Setup URB Structs */
usb_fill_int_urb (
mdc800->irq_urb,
mdc800->dev,
usb_rcvintpipe (mdc800->dev,mdc800->endpoint [1]),
mdc800->irq_urb_buffer,
8,
mdc800_usb_irq,
mdc800,
irq_interval
);
usb_fill_bulk_urb (
mdc800->write_urb,
mdc800->dev,
usb_sndbulkpipe (mdc800->dev, mdc800->endpoint[0]),
mdc800->write_urb_buffer,
8,
mdc800_usb_write_notify,
mdc800
);
usb_fill_bulk_urb (
mdc800->download_urb,
mdc800->dev,
usb_rcvbulkpipe (mdc800->dev, mdc800->endpoint [3]),
mdc800->download_urb_buffer,
64,
mdc800_usb_download_notify,
mdc800
);
mdc800->state=READY;
mutex_unlock(&mdc800->io_lock);
usb_set_intfdata(intf, mdc800);
return 0;
}
/*
* Disconnect USB device (maybe the MDC800)
*/
static void mdc800_usb_disconnect (struct usb_interface *intf)
{
struct mdc800_data* mdc800 = usb_get_intfdata(intf);
dbg ("(mdc800_usb_disconnect) called");
if (mdc800) {
if (mdc800->state == NOT_CONNECTED)
return;
usb_deregister_dev(intf, &mdc800_class);
/* must be under lock to make sure no URB
is submitted after usb_kill_urb() */
mutex_lock(&mdc800->io_lock);
mdc800->state=NOT_CONNECTED;
usb_kill_urb(mdc800->irq_urb);
usb_kill_urb(mdc800->write_urb);
usb_kill_urb(mdc800->download_urb);
mutex_unlock(&mdc800->io_lock);
mdc800->dev = NULL;
usb_set_intfdata(intf, NULL);
}
dev_info(&intf->dev, "Mustek MDC800 disconnected from USB.\n");
}
/***************************************************************************
The Misc device Part (file_operations)
****************************************************************************/
/*
* This Function calc the Answersize for a command.
*/
static int mdc800_getAnswerSize (char command)
{
switch ((unsigned char) command)
{
case 0x2a:
case 0x49:
case 0x51:
case 0x0d:
case 0x20:
case 0x07:
case 0x01:
case 0x25:
case 0x00:
return 8;
case 0x05:
case 0x3e:
return mdc800->pic_len;
case 0x09:
return 4096;
default:
return 0;
}
}
/*
* Init the device: (1) alloc mem (2) Increase MOD Count ..
*/
static int mdc800_device_open (struct inode* inode, struct file *file)
{
int retval=0;
int errn=0;
mutex_lock(&mdc800->io_lock);
if (mdc800->state == NOT_CONNECTED)
{
errn=-EBUSY;
goto error_out;
}
if (mdc800->open)
{
errn=-EBUSY;
goto error_out;
}
mdc800->in_count=0;
mdc800->out_count=0;
mdc800->out_ptr=0;
mdc800->pic_index=0;
mdc800->pic_len=-1;
mdc800->download_left=0;
mdc800->camera_busy=0;
mdc800->camera_request_ready=0;
retval=0;
mdc800->irq_urb->dev = mdc800->dev;
retval = usb_submit_urb (mdc800->irq_urb, GFP_KERNEL);
if (retval) {
dev_err(&mdc800->dev->dev,
"request USB irq fails (submit_retval=%i).\n", retval);
errn = -EIO;
goto error_out;
}
mdc800->open=1;
dbg ("Mustek MDC800 device opened.");
error_out:
mutex_unlock(&mdc800->io_lock);
return errn;
}
/*
* Close the Camera and release Memory
*/
static int mdc800_device_release (struct inode* inode, struct file *file)
{
int retval=0;
dbg ("Mustek MDC800 device closed.");
mutex_lock(&mdc800->io_lock);
if (mdc800->open && (mdc800->state != NOT_CONNECTED))
{
usb_kill_urb(mdc800->irq_urb);
usb_kill_urb(mdc800->write_urb);
usb_kill_urb(mdc800->download_urb);
mdc800->open=0;
}
else
{
retval=-EIO;
}
mutex_unlock(&mdc800->io_lock);
return retval;
}
/*
* The Device read callback Function
*/
static ssize_t mdc800_device_read (struct file *file, char __user *buf, size_t len, loff_t *pos)
{
size_t left=len, sts=len; /* single transfer size */
char __user *ptr = buf;
int retval;
mutex_lock(&mdc800->io_lock);
if (mdc800->state == NOT_CONNECTED)
{
mutex_unlock(&mdc800->io_lock);
return -EBUSY;
}
if (mdc800->state == WORKING)
{
printk(KERN_WARNING "mdc800: Illegal State \"working\""
"reached during read ?!\n");
mutex_unlock(&mdc800->io_lock);
return -EBUSY;
}
if (!mdc800->open)
{
mutex_unlock(&mdc800->io_lock);
return -EBUSY;
}
while (left)
{
if (signal_pending (current))
{
mutex_unlock(&mdc800->io_lock);
return -EINTR;
}
sts=left > (mdc800->out_count-mdc800->out_ptr)?mdc800->out_count-mdc800->out_ptr:left;
if (sts <= 0)
{
/* Too less Data in buffer */
if (mdc800->state == DOWNLOAD)
{
mdc800->out_count=0;
mdc800->out_ptr=0;
/* Download -> Request new bytes */
mdc800->download_urb->dev = mdc800->dev;
retval = usb_submit_urb (mdc800->download_urb, GFP_KERNEL);
if (retval) {
dev_err(&mdc800->dev->dev,
"Can't submit download urb "
"(retval=%i)\n", retval);
mutex_unlock(&mdc800->io_lock);
return len-left;
}
wait_event_timeout(mdc800->download_wait, mdc800->downloaded,
TO_DOWNLOAD_GET_READY*HZ/1000);
mdc800->downloaded = 0;
if (mdc800->download_urb->status != 0)
{
dev_err(&mdc800->dev->dev,
"request download-bytes fails "
"(status=%i)\n",
mdc800->download_urb->status);
mutex_unlock(&mdc800->io_lock);
return len-left;
}
}
else
{
/* No more bytes -> that's an error*/
mutex_unlock(&mdc800->io_lock);
return -EIO;
}
}
else
{
/* Copy Bytes */
if (copy_to_user(ptr, &mdc800->out [mdc800->out_ptr],
sts)) {
mutex_unlock(&mdc800->io_lock);
return -EFAULT;
}
ptr+=sts;
left-=sts;
mdc800->out_ptr+=sts;
}
}
mutex_unlock(&mdc800->io_lock);
return len-left;
}
/*
* The Device write callback Function
* If a 8Byte Command is received, it will be send to the camera.
* After this the driver initiates the request for the answer or
* just waits until the camera becomes ready.
*/
static ssize_t mdc800_device_write (struct file *file, const char __user *buf, size_t len, loff_t *pos)
{
size_t i=0;
int retval;
mutex_lock(&mdc800->io_lock);
if (mdc800->state != READY)
{
mutex_unlock(&mdc800->io_lock);
return -EBUSY;
}
if (!mdc800->open )
{
mutex_unlock(&mdc800->io_lock);
return -EBUSY;
}
while (i<len)
{
unsigned char c;
if (signal_pending (current))
{
mutex_unlock(&mdc800->io_lock);
return -EINTR;
}
if(get_user(c, buf+i))
{
mutex_unlock(&mdc800->io_lock);
return -EFAULT;
}
/* check for command start */
if (c == 0x55)
{
mdc800->in_count=0;
mdc800->out_count=0;
mdc800->out_ptr=0;
mdc800->download_left=0;
}
/* save command byte */
if (mdc800->in_count < 8)
{
mdc800->in[mdc800->in_count] = c;
mdc800->in_count++;
}
else
{
mutex_unlock(&mdc800->io_lock);
return -EIO;
}
/* Command Buffer full ? -> send it to camera */
if (mdc800->in_count == 8)
{
int answersize;
if (mdc800_usb_waitForIRQ (0,TO_GET_READY))
{
dev_err(&mdc800->dev->dev,
"Camera didn't get ready.\n");
mutex_unlock(&mdc800->io_lock);
return -EIO;
}
answersize=mdc800_getAnswerSize (mdc800->in[1]);
mdc800->state=WORKING;
memcpy (mdc800->write_urb->transfer_buffer, mdc800->in,8);
mdc800->write_urb->dev = mdc800->dev;
retval = usb_submit_urb (mdc800->write_urb, GFP_KERNEL);
if (retval) {
dev_err(&mdc800->dev->dev,
"submitting write urb fails "
"(retval=%i)\n", retval);
mutex_unlock(&mdc800->io_lock);
return -EIO;
}
wait_event_timeout(mdc800->write_wait, mdc800->written, TO_WRITE_GET_READY*HZ/1000);
mdc800->written = 0;
if (mdc800->state == WORKING)
{
usb_kill_urb(mdc800->write_urb);
mutex_unlock(&mdc800->io_lock);
return -EIO;
}
switch ((unsigned char) mdc800->in[1])
{
case 0x05: /* Download Image */
case 0x3e: /* Take shot in Fine Mode (WCam Mode) */
if (mdc800->pic_len < 0)
{
dev_err(&mdc800->dev->dev,
"call 0x07 before "
"0x05,0x3e\n");
mdc800->state=READY;
mutex_unlock(&mdc800->io_lock);
return -EIO;
}
mdc800->pic_len=-1;
case 0x09: /* Download Thumbnail */
mdc800->download_left=answersize+64;
mdc800->state=DOWNLOAD;
mdc800_usb_waitForIRQ (0,TO_DOWNLOAD_GET_BUSY);
break;
default:
if (answersize)
{
if (mdc800_usb_waitForIRQ (1,TO_READ_FROM_IRQ))
{
dev_err(&mdc800->dev->dev, "requesting answer from irq fails\n");
mutex_unlock(&mdc800->io_lock);
return -EIO;
}
/* Write dummy data, (this is ugly but part of the USB Protocol */
/* if you use endpoint 1 as bulk and not as irq) */
memcpy (mdc800->out, mdc800->camera_response,8);
/* This is the interpreted answer */
memcpy (&mdc800->out[8], mdc800->camera_response,8);
mdc800->out_ptr=0;
mdc800->out_count=16;
/* Cache the Imagesize, if command was getImageSize */
if (mdc800->in [1] == (char) 0x07)
{
mdc800->pic_len=(int) 65536*(unsigned char) mdc800->camera_response[0]+256*(unsigned char) mdc800->camera_response[1]+(unsigned char) mdc800->camera_response[2];
dbg ("cached imagesize = %i",mdc800->pic_len);
}
}
else
{
if (mdc800_usb_waitForIRQ (0,TO_DEFAULT_COMMAND))
{
dev_err(&mdc800->dev->dev, "Command Timeout.\n");
mutex_unlock(&mdc800->io_lock);
return -EIO;
}
}
mdc800->state=READY;
break;
}
}
i++;
}
mutex_unlock(&mdc800->io_lock);
return i;
}
/***************************************************************************
Init and Cleanup this driver (Structs and types)
****************************************************************************/
/* File Operations of this drivers */
static const struct file_operations mdc800_device_ops =
{
.owner = THIS_MODULE,
.read = mdc800_device_read,
.write = mdc800_device_write,
.open = mdc800_device_open,
.release = mdc800_device_release,
.llseek = noop_llseek,
};
static const struct usb_device_id mdc800_table[] = {
{ USB_DEVICE(MDC800_VENDOR_ID, MDC800_PRODUCT_ID) },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE (usb, mdc800_table);
/*
* USB Driver Struct for this device
*/
static struct usb_driver mdc800_usb_driver =
{
.name = "mdc800",
.probe = mdc800_usb_probe,
.disconnect = mdc800_usb_disconnect,
.id_table = mdc800_table
};
/************************************************************************
Init and Cleanup this driver (Main Functions)
*************************************************************************/
static int __init usb_mdc800_init (void)
{
int retval = -ENODEV;
/* Allocate Memory */
mdc800=kzalloc (sizeof (struct mdc800_data), GFP_KERNEL);
if (!mdc800)
goto cleanup_on_fail;
mdc800->dev = NULL;
mdc800->state=NOT_CONNECTED;
mutex_init (&mdc800->io_lock);
init_waitqueue_head (&mdc800->irq_wait);
init_waitqueue_head (&mdc800->write_wait);
init_waitqueue_head (&mdc800->download_wait);
mdc800->irq_woken = 0;
mdc800->downloaded = 0;
mdc800->written = 0;
mdc800->irq_urb_buffer=kmalloc (8, GFP_KERNEL);
if (!mdc800->irq_urb_buffer)
goto cleanup_on_fail;
mdc800->write_urb_buffer=kmalloc (8, GFP_KERNEL);
if (!mdc800->write_urb_buffer)
goto cleanup_on_fail;
mdc800->download_urb_buffer=kmalloc (64, GFP_KERNEL);
if (!mdc800->download_urb_buffer)
goto cleanup_on_fail;
mdc800->irq_urb=usb_alloc_urb (0, GFP_KERNEL);
if (!mdc800->irq_urb)
goto cleanup_on_fail;
mdc800->download_urb=usb_alloc_urb (0, GFP_KERNEL);
if (!mdc800->download_urb)
goto cleanup_on_fail;
mdc800->write_urb=usb_alloc_urb (0, GFP_KERNEL);
if (!mdc800->write_urb)
goto cleanup_on_fail;
/* Register the driver */
retval = usb_register(&mdc800_usb_driver);
if (retval)
goto cleanup_on_fail;
printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
DRIVER_DESC "\n");
return 0;
/* Clean driver up, when something fails */
cleanup_on_fail:
if (mdc800 != NULL)
{
printk(KERN_ERR "mdc800: can't alloc memory!\n");
kfree(mdc800->download_urb_buffer);
kfree(mdc800->write_urb_buffer);
kfree(mdc800->irq_urb_buffer);
usb_free_urb(mdc800->write_urb);
usb_free_urb(mdc800->download_urb);
usb_free_urb(mdc800->irq_urb);
kfree (mdc800);
}
mdc800 = NULL;
return retval;
}
static void __exit usb_mdc800_cleanup (void)
{
usb_deregister (&mdc800_usb_driver);
usb_free_urb (mdc800->irq_urb);
usb_free_urb (mdc800->download_urb);
usb_free_urb (mdc800->write_urb);
kfree (mdc800->irq_urb_buffer);
kfree (mdc800->write_urb_buffer);
kfree (mdc800->download_urb_buffer);
kfree (mdc800);
mdc800 = NULL;
}
module_init (usb_mdc800_init);
module_exit (usb_mdc800_cleanup);
MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");
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