Browse Source
git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4604 7fd9a85b-ad96-42d3-883c-3090e2eb8679sbg
patacongo
13 years ago
6 changed files with 678 additions and 10 deletions
@ -0,0 +1,572 @@
@@ -0,0 +1,572 @@
|
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/****************************************************************************
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* drivers/watchdog.c |
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* |
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* Copyright (C) 2012 Gregory Nutt. All rights reserved. |
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* Author: Gregory Nutt <gnutt@nuttx.org> |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* 3. Neither the name NuttX nor the names of its contributors may be |
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* used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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* POSSIBILITY OF SUCH DAMAGE. |
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* |
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****************************************************************************/ |
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|
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/****************************************************************************
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* Included Files |
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****************************************************************************/ |
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#include <nuttx/config.h> |
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#include <sys/types.h> |
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#include <stdint.h> |
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#include <stdbool.h> |
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#include <string.h> |
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#include <semaphore.h> |
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#include <fcntl.h> |
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#include <assert.h> |
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#include <errno.h> |
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#include <debug.h> |
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|
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#include <nuttx/fs/fs.h> |
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#include <nuttx/irq.h> |
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#include <nuttx/kmalloc.h> |
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#include <nuttx/watchdog.h> |
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#ifdef CONFIG_WATCHDOG |
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/****************************************************************************
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* Pre-processor Definitions |
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****************************************************************************/ |
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/* Debug ********************************************************************/ |
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/* Non-standard debug that may be enabled just for testing PWM */ |
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#ifdef CONFIG_DEBUG_WATCHDOG |
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# define wddbg dbg |
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# define wdvdbg vdbg |
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# define wdlldbg lldbg |
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# define wdllvdbg llvdbg |
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#else |
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# define wddbg(x...) |
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# define wdvdbg(x...) |
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# define wdlldbg(x...) |
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# define wdllvdbg(x...) |
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#endif |
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|
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/****************************************************************************
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* Private Type Definitions |
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****************************************************************************/ |
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/* This structure describes the state of the upper half driver */ |
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struct watchdog_upperhalf_s |
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{ |
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uint8_t crefs; /* The number of times the device has been opened */ |
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sem_t exclsem; /* Supports mutual exclusion */ |
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FAR char *path; /* Registration path */ |
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/* The contained lower-half driver */ |
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FAR struct watchdog_lowerhalf_s *lower; |
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}; |
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/****************************************************************************
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* Private Function Prototypes |
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****************************************************************************/ |
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static int wdog_open(FAR struct file *filep); |
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static int wdog_close(FAR struct file *filep); |
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static ssize_t wdog_read(FAR struct file *filep, FAR char *buffer, size_t buflen); |
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static ssize_t wdog_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); |
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static int wdog_ioctl(FAR struct file *filep, int cmd, unsigned long arg); |
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/****************************************************************************
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* Private Data |
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****************************************************************************/ |
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static const struct file_operations g_wdogops = |
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{ |
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wdog_open, /* open */ |
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wdog_close, /* close */ |
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wdog_read, /* read */ |
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wdog_write, /* write */ |
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0, /* seek */ |
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wdog_ioctl /* ioctl */ |
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#ifndef CONFIG_DISABLE_POLL |
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, 0 /* poll */ |
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#endif |
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}; |
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/****************************************************************************
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* Private Functions |
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****************************************************************************/ |
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|
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/************************************************************************************
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* Name: wdog_open |
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* |
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* Description: |
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* This function is called whenever the watchdog timer device is opened. |
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* |
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************************************************************************************/ |
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static int wdog_open(FAR struct file *filep) |
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{ |
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FAR struct inode *inode = filep->f_inode; |
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FAR struct watchdog_upperhalf_s *upper = inode->i_private; |
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uint8_t tmp; |
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int ret; |
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wdvdbg("crefs: %d\n", upper->crefs); |
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/* Get exclusive access to the device structures */ |
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ret = sem_wait(&upper->exclsem); |
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if (ret < 0) |
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{ |
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ret = -errno; |
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goto errout; |
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} |
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|
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/* Increment the count of references to the device. If this the first
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* time that the driver has been opened for this device, then initialize |
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* the device. |
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*/ |
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tmp = upper->crefs + 1; |
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if (tmp == 0) |
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{ |
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/* More than 255 opens; uint8_t overflows to zero */ |
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ret = -EMFILE; |
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goto errout_with_sem; |
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} |
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/* Save the new open count */ |
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upper->crefs = tmp; |
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ret = OK; |
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errout_with_sem: |
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sem_post(&upper->exclsem); |
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errout: |
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return ret; |
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} |
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|
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/************************************************************************************
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* Name: wdog_close |
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* |
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* Description: |
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* This function is called when the watchdog timer device is closed. |
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* |
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************************************************************************************/ |
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static int wdog_close(FAR struct file *filep) |
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{ |
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FAR struct inode *inode = filep->f_inode; |
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FAR struct watchdog_upperhalf_s *upper = inode->i_private; |
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int ret; |
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wdvdbg("crefs: %d\n", upper->crefs); |
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/* Get exclusive access to the device structures */ |
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ret = sem_wait(&upper->exclsem); |
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if (ret < 0) |
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{ |
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ret = -errno; |
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goto errout; |
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} |
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|
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/* Decrement the references to the driver. If the reference count will
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* decrement to 0, then uninitialize the driver. |
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*/ |
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if (upper->crefs > 0) |
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{ |
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upper->crefs--; |
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} |
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sem_post(&upper->exclsem); |
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ret = OK; |
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errout: |
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return ret; |
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} |
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/************************************************************************************
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* Name: wdog_read |
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* |
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* Description: |
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* A dummy read method. This is provided only to satsify the VFS layer. |
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* |
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************************************************************************************/ |
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static ssize_t wdog_read(FAR struct file *filep, FAR char *buffer, size_t buflen) |
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{ |
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/* Return zero -- usually meaning end-of-file */ |
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return 0; |
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} |
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/************************************************************************************
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* Name: wdog_write |
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* |
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* Description: |
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* A dummy write method. This is provided only to satsify the VFS layer. |
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* |
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************************************************************************************/ |
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static ssize_t wdog_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) |
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{ |
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return 0; |
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} |
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|
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/************************************************************************************
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* Name: wdog_ioctl |
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* |
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* Description: |
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* The standard ioctl method. This is where ALL of the watchdog timer work is |
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* done. |
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*
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************************************************************************************/ |
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static int wdog_ioctl(FAR struct file *filep, int cmd, unsigned long arg) |
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{ |
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FAR struct inode *inode = filep->f_inode; |
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FAR struct watchdog_upperhalf_s *upper = inode->i_private; |
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FAR struct watchdog_lowerhalf_s *lower = upper->lower; |
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int ret; |
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wdvdbg("cmd: %d arg: %ld\n", cmd, arg); |
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DEBUGASSERT(upper && lower); |
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/* Get exclusive access to the device structures */ |
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ret = sem_wait(&upper->exclsem); |
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if (ret < 0) |
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{ |
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return ret; |
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} |
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/* Handle built-in ioctl commands */ |
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switch (cmd) |
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{ |
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/* cmd: WDIOC_START
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* Description: Start the watchdog timer |
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* Argument: Ignored |
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*/ |
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case WDIOC_START: |
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{ |
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/* Start the watchdog timer, resetting the time to the current timeout */ |
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DEBUGASSERT(lower->ops->start); /* Required */ |
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ret = lower->ops->start(lower); |
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} |
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break; |
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/* cmd: WDIOC_STOP
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* Description: Stop the watchdog timer |
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* Argument: Ignored |
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*/ |
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case WDIOC_STOP: |
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{ |
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/* Stop the watchdog timer */ |
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DEBUGASSERT(lower->ops->stop); /* Required */ |
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ret = lower->ops->stop(lower); |
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} |
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break; |
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|
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/* cmd: WDIOC_GETSTATUS
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* Description: et the status of the watchdog timer. |
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* Argument: A writeable pointer to struct watchdog_status_s. |
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*/ |
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|
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case WDIOC_GETSTATUS: |
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{ |
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FAR struct watchdog_status_s *status; |
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|
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/* Get the current watchdog timer status */ |
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if (lower->ops->getstatus) /* Optional */ |
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{ |
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status = (FAR struct watchdog_status_s *)((uintptr_t)arg); |
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if (status) |
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{ |
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ret = lower->ops->getstatus(lower, status); |
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} |
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else |
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{ |
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ret = -EINVAL; |
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} |
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} |
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else |
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{ |
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ret = -ENOSYS; |
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} |
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} |
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break; |
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|
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/* cmd: WDIOC_SETTIMEOUT
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* Description: Reset the watchdog timeout to this value |
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* Argument: A 32-bit timeout value in milliseconds. |
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*/ |
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case WDIOC_SETTIMEOUT: |
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{ |
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/* Set a new timeout value (and reset the watchdog timer) */ |
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if (lower->ops->settimeout) /* Optional */ |
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{ |
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ret = lower->ops->settimeout(lower, (uint32_t)arg); |
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} |
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else |
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{ |
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ret = -ENOSYS; |
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} |
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} |
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break; |
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|
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/* cmd: WDIOC_CAPTURE
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* Description: Do not reset. Instead, called this handler. |
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* Argument: A pointer to struct watchdog_capture_s. |
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*/ |
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case WDIOC_CAPTURE: |
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{ |
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FAR struct watchdog_capture_s *capture; |
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/* Don't reset on watchdog timer timeout; instead, call this user
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* provider timeout handler. NOTE: Providing handler==NULL will |
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* restore the reset behavior. |
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*/ |
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if (lower->ops->capture) /* Optional */ |
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{ |
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capture = (FAR struct watchdog_capture_s *)((uintptr_t)arg); |
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if (capture) |
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{ |
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capture->oldhandler = |
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lower->ops->capture(lower, capture->newhandler); |
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ret = OK; |
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} |
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else |
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{ |
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ret = -EINVAL; |
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} |
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} |
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else |
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{ |
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ret = -ENOSYS; |
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} |
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} |
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break; |
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|
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/* cmd: WDIOC_KEEPALIVE
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* Description: Reset the watchdog timer ("ping", "pet the dog") |
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* Argument: Argument: Ignored |
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*/ |
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case WDIOC_KEEPALIVE: |
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{ |
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/* Reset the watchdog timer to the current timeout value, prevent any
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* imminent watchdog timeouts. This is sometimes referred as |
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* "pinging" the watchdog timer or "petting the dog". |
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*/ |
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if (lower->ops->keepalive) /* Optional */ |
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{ |
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ret = lower->ops->keepalive(lower); |
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} |
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else |
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{ |
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ret = -ENOSYS; |
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} |
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} |
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break; |
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/* Any unrecognized IOCTL commands might be platform-specific ioctl commands */ |
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default: |
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{ |
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wdvdbg("Forwarding unrecognized cmd: %d arg: %ld\n", cmd, arg); |
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/* An ioctl commands that are not recognized by the "upper-half"
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* driver are forwarded to the lower half driver through this |
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* method. |
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*/ |
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if (lower->ops->ioctl) /* Optional */ |
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{ |
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ret = lower->ops->ioctl(lower, cmd, arg); |
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} |
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else |
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{ |
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ret = -ENOSYS; |
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} |
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} |
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break; |
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} |
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sem_post(&upper->exclsem); |
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return ret; |
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} |
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/****************************************************************************
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* Public Functions |
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****************************************************************************/ |
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/****************************************************************************
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* Name: watchdog_register |
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* |
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* Description: |
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* This function binds an instance of a "lower half" watchdog driver with the |
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* "upper half" watchdog device and registers that device so that can be used |
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* by application code. |
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* |
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* When this function is called, the "lower half" driver should be in the |
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* disabled state (as if the stop() method had already been called). |
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* |
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* Input parameters: |
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* dev path - The full path to the driver to be registers in the NuttX |
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* pseudo-filesystem. The recommended convention is to name all watchdog |
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* drivers as "/dev/watchdog0", "/dev/watchdog1", etc. where the driver |
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* path differs only in the "minor" number at the end of the device name. |
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* lower - A pointer to an instance of lower half watchdog driver. This |
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* instance is bound to the watchdog driver and must persists as long as |
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* the driver persists. |
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* |
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* Returned Value: |
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* On success, a non-NULL handle is returned to the caller. In the event |
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* of any failure, a NULL value is returned. |
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* |
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****************************************************************************/ |
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FAR void *watchdog_register(FAR const char *path, |
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FAR struct watchdog_lowerhalf_s *lower) |
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{ |
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FAR struct watchdog_upperhalf_s *upper; |
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int ret; |
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DEBUGASSERT(path && lower); |
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/* Allocate the upper-half data structure */ |
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upper = (FAR struct watchdog_upperhalf_s *) |
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kzalloc(sizeof(struct watchdog_upperhalf_s)); |
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if (!upper) |
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{ |
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wddbg("Upper half allocation failed\n"); |
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goto errout; |
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} |
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/* Initialize the watchdog timer device structure (it was already zeroed
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* by kzalloc()). |
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*/ |
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sem_init(&upper->exclsem, 0, 1); |
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upper->lower = lower; |
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/* Copy the registration path */ |
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upper->path = strdup(path); |
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if (!upper->path) |
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{ |
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wddbg("Path allocation failed\n"); |
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goto errout_with_upper; |
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} |
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/* Register the watchdog timer device */ |
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wdvdbg("Registering %s\n", path); |
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ret = register_driver(path, &g_wdogops, 0666, upper); |
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if (ret < 0) |
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{ |
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wddbg("register_driver failed: %d\n", ret); |
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goto errout_with_path; |
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} |
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return (FAR void *)upper; |
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errout_with_path: |
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kfree(upper->path); |
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errout_with_upper: |
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sem_destroy(&upper->exclsem); |
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kfree(upper); |
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|
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errout: |
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return NULL; |
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} |
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|
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/****************************************************************************
|
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* Name: watchdog_unregister |
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* |
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* Description: |
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* This function can be called to disable and unregister the watchdog |
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* device driver. |
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* |
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* Input parameters: |
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* handle - This is the handle that was returned by watchdog_register() |
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* |
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* Returned Value: |
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* None |
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* |
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****************************************************************************/ |
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|
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void watchdog_unregister(FAR void *handle) |
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{ |
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FAR struct watchdog_upperhalf_s *upper; |
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FAR struct watchdog_lowerhalf_s *lower; |
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wdvdbg("cmd: %d arg: %ld\n", cmd, arg); |
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|
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/* Recover the pointer to the upper-half driver state */ |
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upper = (FAR struct watchdog_upperhalf_s *)handle; |
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lower = upper->lower; |
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DEBUGASSERT(upper && lower); |
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|
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/* Disable the watchdog timer */ |
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|
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DEBUGASSERT(lower->ops->stop); /* Required */ |
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(void)lower->ops->stop(lower); |
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/* Unregister the watchdog timer device */ |
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|
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(void)unregister_driver(upper->path); |
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|
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/* Then free all of the driver resources */ |
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|
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kfree(upper->path); |
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sem_destroy(&upper->exclsem); |
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kfree(upper); |
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} |
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|
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#endif /* CONFIG_WATCHDOG */ |
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