From 881e935abcd33e152b7b1aa6fc358f6638cbb1f5 Mon Sep 17 00:00:00 2001
From: Florian Pose <fp@igh-essen.com>
Date: Tue, 19 Sep 2006 14:08:31 +0000
Subject: [PATCH] Allow only one open() on XML device.
---
master/xmldev.c | 21 +++++++++++++++++++++
master/xmldev.h | 3 +++
2 files changed, 24 insertions(+)
diff --git a/master/xmldev.c b/master/xmldev.c
index 58bae23b..17c8ae75 100644
--- a/master/xmldev.c
+++ b/master/xmldev.c
@@ -74,6 +74,7 @@ int ec_xmldev_init(ec_xmldev_t *xmldev, /**< EtherCAT XML device */
dev_t dev_num /**< device number */
)
{
+ atomic_set(&xmldev->available, 1);
cdev_init(&xmldev->cdev, &fops);
xmldev->cdev.owner = THIS_MODULE;
if (cdev_add(&xmldev->cdev,
@@ -97,11 +98,29 @@ void ec_xmldev_clear(ec_xmldev_t *xmldev /**< EtherCAT XML device */)
/*****************************************************************************/
+int ec_xmldev_request(ec_xmldev_t *xmldev,
+ uint32_t vendor_id,
+ uint32_t product_code
+ )
+{
+ return 1;
+}
+
+/******************************************************************************
+ * file_operations
+ *****************************************************************************/
+
int ecxmldev_open(struct inode *inode, struct file *filp)
{
ec_xmldev_t *xmldev;
xmldev = container_of(inode->i_cdev, ec_xmldev_t, cdev);
+
+ if (!atomic_dec_and_test(&xmldev->available)) {
+ atomic_inc(&xmldev->available);
+ return -EBUSY;
+ }
+
filp->private_data = xmldev;
EC_DBG("File opened.\n");
@@ -113,6 +132,8 @@ int ecxmldev_open(struct inode *inode, struct file *filp)
int ecxmldev_release(struct inode *inode, struct file *filp)
{
+ ec_xmldev_t *xmldev = container_of(inode->i_cdev, ec_xmldev_t, cdev);
+ atomic_inc(&xmldev->available);
EC_DBG("File closed.\n");
return 0;
}
diff --git a/master/xmldev.h b/master/xmldev.h
index 9b8ea775..2d70c9c5 100644
--- a/master/xmldev.h
+++ b/master/xmldev.h
@@ -57,6 +57,7 @@ typedef struct
{
ec_master_t *master; /**< master owning the device */
struct cdev cdev; /**< character device */
+ atomic_t available; /**< allow only one open() */
}
ec_xmldev_t;
@@ -65,6 +66,8 @@ ec_xmldev_t;
int ec_xmldev_init(ec_xmldev_t *, ec_master_t *, dev_t);
void ec_xmldev_clear(ec_xmldev_t *);
+int ec_xmldev_request(ec_xmldev_t *, uint32_t, uint32_t);
+
/*****************************************************************************/
#endif
--
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