From f7c6aa94ea4414cab29ea95e5cf23d6843ca43df Mon Sep 17 00:00:00 2001 From: David Kiliani Date: Sat, 1 Nov 2008 00:39:12 +0100 Subject: Staging: Add the Meilhaus ME-IDS driver package Originally written by Guenter Gebhardt and Krzysztof Gantzke 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 Cc: Guenter Gebhardt Cc: Krzysztof Gantzke Signed-off-by: Greg Kroah-Hartman --- drivers/staging/meilhaus/meslock.c | 136 +++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 drivers/staging/meilhaus/meslock.c (limited to 'drivers/staging/meilhaus/meslock.c') 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 + +#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; +} -- cgit v1.2.3