/******************************************************************************
*
* $Id$
*
* Copyright (C) 2006-2012 Florian Pose, Ingenieurgemeinschaft IgH
*
* This file is part of the IgH EtherCAT Master.
*
* The IgH EtherCAT Master is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2, as
* published by the Free Software Foundation.
*
* The IgH EtherCAT Master 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 the IgH EtherCAT Master; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* ---
*
* The license mentioned above concerns the source code only. Using the
* EtherCAT technology and brand is only permitted in compliance with the
* industrial property and similar rights of Beckhoff Automation GmbH.
*
*****************************************************************************/
/**
\file
EtherCAT master character device.
*/
/*****************************************************************************/
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include "cdev.h"
#include "master.h"
#include "slave_config.h"
#include "voe_handler.h"
#include "ethernet.h"
#include "ioctl.h"
/** Set to 1 to enable device operations debugging.
*/
#define DEBUG 0
/*****************************************************************************/
static int eccdev_open(struct inode *, struct file *);
static int eccdev_release(struct inode *, struct file *);
static long eccdev_ioctl(struct file *, unsigned int, unsigned long);
static int eccdev_mmap(struct file *, struct vm_area_struct *);
/** This is the kernel version from which the .fault member of the
* vm_operations_struct is usable.
*/
#define PAGE_FAULT_VERSION KERNEL_VERSION(2, 6, 23)
#if LINUX_VERSION_CODE >= PAGE_FAULT_VERSION
static int eccdev_vma_fault(struct vm_area_struct *, struct vm_fault *);
#else
static struct page *eccdev_vma_nopage(
struct vm_area_struct *, unsigned long, int *);
#endif
/*****************************************************************************/
/** File operation callbacks for the EtherCAT character device.
*/
static struct file_operations eccdev_fops = {
.owner = THIS_MODULE,
.open = eccdev_open,
.release = eccdev_release,
.unlocked_ioctl = eccdev_ioctl,
.mmap = eccdev_mmap
};
/** Callbacks for a virtual memory area retrieved with ecdevc_mmap().
*/
struct vm_operations_struct eccdev_vm_ops = {
#if LINUX_VERSION_CODE >= PAGE_FAULT_VERSION
.fault = eccdev_vma_fault
#else
.nopage = eccdev_vma_nopage
#endif
};
/*****************************************************************************/
/** Private data structure for file handles.
*/
typedef struct {
ec_cdev_t *cdev; /**< Character device. */
ec_ioctl_context_t ctx; /**< Context. */
} ec_cdev_priv_t;
/*****************************************************************************/
/** Constructor.
*
* \return 0 in case of success, else < 0
*/
int ec_cdev_init(
ec_cdev_t *cdev, /**< EtherCAT master character device. */
ec_master_t *master, /**< Parent master. */
dev_t dev_num /**< Device number. */
)
{
int ret;
cdev->master = master;
cdev_init(&cdev->cdev, &eccdev_fops);
cdev->cdev.owner = THIS_MODULE;
ret = cdev_add(&cdev->cdev,
MKDEV(MAJOR(dev_num), master->index), 1);
if (ret) {
EC_MASTER_ERR(master, "Failed to add character device!\n");
}
return ret;
}
/*****************************************************************************/
/** Destructor.
*/
void ec_cdev_clear(ec_cdev_t *cdev /**< EtherCAT XML device */)
{
cdev_del(&cdev->cdev);
}
/******************************************************************************
* File operations
*****************************************************************************/
/** Called when the cdev is opened.
*/
int eccdev_open(struct inode *inode, struct file *filp)
{
ec_cdev_t *cdev = container_of(inode->i_cdev, ec_cdev_t, cdev);
ec_cdev_priv_t *priv;
priv = kmalloc(sizeof(ec_cdev_priv_t), GFP_KERNEL);
if (!priv) {
EC_MASTER_ERR(cdev->master,
"Failed to allocate memory for private data structure.\n");
return -ENOMEM;
}
priv->cdev = cdev;
priv->ctx.writable = (filp->f_mode & FMODE_WRITE) != 0;
priv->ctx.requested = 0;
priv->ctx.process_data = NULL;
priv->ctx.process_data_size = 0;
filp->private_data = priv;
#if DEBUG
EC_MASTER_DBG(cdev->master, 0, "File opened.\n");
#endif
return 0;
}
/*****************************************************************************/
/** Called when the cdev is closed.
*/
int eccdev_release(struct inode *inode, struct file *filp)
{
ec_cdev_priv_t *priv = (ec_cdev_priv_t *) filp->private_data;
ec_master_t *master = priv->cdev->master;
if (priv->ctx.requested) {
ecrt_release_master(master);
}
if (priv->ctx.process_data) {
vfree(priv->ctx.process_data);
}
#if DEBUG
EC_MASTER_DBG(master, 0, "File closed.\n");
#endif
kfree(priv);
return 0;
}
/*****************************************************************************/
/** Called when an ioctl() command is issued.
*/
long eccdev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
ec_cdev_priv_t *priv = (ec_cdev_priv_t *) filp->private_data;
#if DEBUG
EC_MASTER_DBG(priv->cdev->master, 0,
"ioctl(filp = 0x%p, cmd = 0x%08x (0x%02x), arg = 0x%lx)\n",
filp, cmd, _IOC_NR(cmd), arg);
#endif
return ec_ioctl(priv->cdev->master, &priv->ctx, cmd, (void __user *) arg);
}
/*****************************************************************************/
#ifndef VM_DONTDUMP
/** VM_RESERVED disappeared in 3.7.
*/
#define VM_DONTDUMP VM_RESERVED
#endif
/** Memory-map callback for the EtherCAT character device.
*
* The actual mapping will be done in the eccdev_vma_nopage() callback of the
* virtual memory area.
*
* \return Always zero (success).
*/
int eccdev_mmap(
struct file *filp,
struct vm_area_struct *vma
)
{
ec_cdev_priv_t *priv = (ec_cdev_priv_t *) filp->private_data;
EC_MASTER_DBG(priv->cdev->master, 1, "mmap()\n");
vma->vm_ops = &eccdev_vm_ops;
vma->vm_flags |= VM_DONTDUMP; /* Pages will not be swapped out */
vma->vm_private_data = priv;
return 0;
}
/*****************************************************************************/
#if LINUX_VERSION_CODE >= PAGE_FAULT_VERSION
/** Page fault callback for a virtual memory area.
*
* Called at the first access on a virtual-memory area retrieved with
* ecdev_mmap().
*
* \return Zero on success, otherwise a negative error code.
*/
static int eccdev_vma_fault(
struct vm_area_struct *vma, /**< Virtual memory area. */
struct vm_fault *vmf /**< Fault data. */
)
{
unsigned long offset = vmf->pgoff << PAGE_SHIFT;
ec_cdev_priv_t *priv = (ec_cdev_priv_t *) vma->vm_private_data;
struct page *page;
if (offset >= priv->ctx.process_data_size) {
return VM_FAULT_SIGBUS;
}
page = vmalloc_to_page(priv->ctx.process_data + offset);
if (!page) {
return VM_FAULT_SIGBUS;
}
get_page(page);
vmf->page = page;
EC_MASTER_DBG(priv->cdev->master, 1, "Vma fault, virtual_address = %p,"
" offset = %lu, page = %p\n", vmf->virtual_address, offset, page);
return 0;
}
#else
/** Nopage callback for a virtual memory area.
*
* Called at the first access on a virtual-memory area retrieved with
* ecdev_mmap().
*/
struct page *eccdev_vma_nopage(
struct vm_area_struct *vma, /**< Virtual memory area initialized by
the kernel. */
unsigned long address, /**< Requested virtual address. */
int *type /**< Type output parameter. */
)
{
unsigned long offset;
struct page *page = NOPAGE_SIGBUS;
ec_cdev_priv_t *priv = (ec_cdev_priv_t *) vma->vm_private_data;
ec_master_t *master = priv->cdev->master;
offset = (address - vma->vm_start) + (vma->vm_pgoff << PAGE_SHIFT);
if (offset >= priv->ctx.process_data_size)
return NOPAGE_SIGBUS;
page = vmalloc_to_page(priv->ctx.process_data + offset);
EC_MASTER_DBG(master, 1, "Nopage fault vma, address = %#lx,"
" offset = %#lx, page = %p\n", address, offset, page);
get_page(page);
if (type)
*type = VM_FAULT_MINOR;
return page;
}
#endif
/*****************************************************************************/