aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/staging/meilhaus/meslock.c
diff options
context:
space:
mode:
authorDavid Kiliani <mail@davidkiliani.de>2008-11-01 00:39:12 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2009-01-06 13:52:29 -0800
commit3fedd14818592016f7ffd84dfe134881b3896ecf (patch)
tree22574873dc7d844d4cc33d04f7e6ba03f23c639e /drivers/staging/meilhaus/meslock.c
parentStaging: asus_oled: fix build dependancy (diff)
downloadlinux-dev-3fedd14818592016f7ffd84dfe134881b3896ecf.tar.xz
linux-dev-3fedd14818592016f7ffd84dfe134881b3896ecf.zip
Staging: Add the Meilhaus ME-IDS driver package
Originally written by Guenter Gebhardt <g.gebhardt@meilhaus.de> and Krzysztof Gantzke <k.gantzke@meilhaus.de> This is the drv/lnx/mod directory of ME-IDS 1.2.9 tarball with some files from drv/lnx/include. Signed-off-by: David Kiliani <mail@davidkiliani.de> Cc: Guenter Gebhardt <g.gebhardt@meilhaus.de> Cc: Krzysztof Gantzke <k.gantzke@meilhaus.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging/meilhaus/meslock.c')
-rw-r--r--drivers/staging/meilhaus/meslock.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/staging/meilhaus/meslock.c b/drivers/staging/meilhaus/meslock.c
new file mode 100644
index 000000000000..5230b89b45b5
--- /dev/null
+++ b/drivers/staging/meilhaus/meslock.c
@@ -0,0 +1,136 @@
+/**
+ * @file meslock.c
+ *
+ * @brief Implements the subdevice lock class.
+ * @note Copyright (C) 2006 Meilhaus Electronic GmbH (support@meilhaus.de)
+ * @author Guenter Gebhardt
+ */
+
+/*
+ * Copyright (C) 2006 Meilhaus Electronic GmbH (support@meilhaus.de)
+ *
+ * This file 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.
+ */
+
+#include <linux/spinlock.h>
+
+#include "medefines.h"
+#include "meerror.h"
+
+#include "medebug.h"
+#include "meslock.h"
+
+int me_slock_enter(struct me_slock *slock, struct file *filep)
+{
+ PDEBUG_LOCKS("executed.\n");
+
+ spin_lock(&slock->spin_lock);
+
+ if ((slock->filep) != NULL && (slock->filep != filep)) {
+ PERROR("Subdevice is locked by another process.\n");
+ spin_unlock(&slock->spin_lock);
+ return ME_ERRNO_LOCKED;
+ }
+
+ slock->count++;
+
+ spin_unlock(&slock->spin_lock);
+
+ return ME_ERRNO_SUCCESS;
+}
+
+int me_slock_exit(struct me_slock *slock, struct file *filep)
+{
+ PDEBUG_LOCKS("executed.\n");
+
+ spin_lock(&slock->spin_lock);
+ slock->count--;
+ spin_unlock(&slock->spin_lock);
+
+ return ME_ERRNO_SUCCESS;
+}
+
+int me_slock_lock(struct me_slock *slock, struct file *filep, int lock)
+{
+ PDEBUG_LOCKS("executed.\n");
+
+ switch (lock) {
+
+ case ME_LOCK_RELEASE:
+ spin_lock(&slock->spin_lock);
+
+ if (slock->filep == filep)
+ slock->filep = NULL;
+
+ spin_unlock(&slock->spin_lock);
+
+ break;
+
+ case ME_LOCK_SET:
+ spin_lock(&slock->spin_lock);
+
+ if (slock->count) {
+ spin_unlock(&slock->spin_lock);
+ PERROR("Subdevice is used by another process.\n");
+ return ME_ERRNO_USED;
+ } else if (slock->filep == NULL)
+ slock->filep = filep;
+ else if (slock->filep != filep) {
+ spin_unlock(&slock->spin_lock);
+ PERROR("Subdevice is locked by another process.\n");
+ return ME_ERRNO_LOCKED;
+ }
+
+ spin_unlock(&slock->spin_lock);
+
+ break;
+
+ case ME_LOCK_CHECK:
+ spin_lock(&slock->spin_lock);
+
+ if (slock->count) {
+ spin_unlock(&slock->spin_lock);
+ return ME_ERRNO_USED;
+ } else if ((slock->filep != NULL) && (slock->filep != filep)) {
+ spin_unlock(&slock->spin_lock);
+ return ME_ERRNO_LOCKED;
+ }
+
+ spin_unlock(&slock->spin_lock);
+
+ break;
+
+ default:
+ break;
+ }
+
+ return ME_ERRNO_SUCCESS;
+}
+
+void me_slock_deinit(struct me_slock *slock)
+{
+ PDEBUG_LOCKS("executed.\n");
+}
+
+int me_slock_init(me_slock_t * slock)
+{
+ PDEBUG_LOCKS("executed.\n");
+
+ slock->filep = NULL;
+ slock->count = 0;
+ spin_lock_init(&slock->spin_lock);
+
+ return 0;
+}