Merge pull request #121 from grissiom/device-ref-count
device: add ref_count support
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commit
198a6a162a
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@ -779,6 +779,7 @@ struct rt_device
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rt_uint16_t flag; /**< device flag */
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rt_uint16_t open_flag; /**< device open flag */
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rt_uint8_t ref_count; /**< reference count */
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rt_uint8_t device_id; /**< 0 - 255 */
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/* device call back */
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29
src/device.c
29
src/device.c
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@ -1,7 +1,7 @@
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/*
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* File : device.c
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* This file is part of RT-Thread RTOS
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* COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
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* COPYRIGHT (C) 2006 - 2013, RT-Thread Development Team
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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@ -24,6 +24,7 @@
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* 2012-10-20 Bernard add device check in register function,
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* provided by Rob <rdent@iinet.net.au>
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* 2012-12-25 Bernard return RT_EOK if the device interface not exist.
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* 2013-07-09 Grissiom add ref_count support
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*/
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#include <rtthread.h>
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@ -51,6 +52,7 @@ rt_err_t rt_device_register(rt_device_t dev,
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rt_object_init(&(dev->parent), RT_Object_Class_Device, name);
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dev->flag = flags;
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dev->ref_count = 0;
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return RT_EOK;
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}
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@ -237,6 +239,11 @@ rt_err_t rt_device_open(rt_device_t dev, rt_uint16_t oflag)
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return -RT_EBUSY;
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}
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dev->ref_count++;
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/* don't let bad things happen silently. If you are bitten by this assert,
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* please set the ref_count to a bigger type. */
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RT_ASSERT(dev->ref_count != 0);
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/* call device open interface */
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if (dev->open != RT_NULL)
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{
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@ -264,6 +271,14 @@ rt_err_t rt_device_close(rt_device_t dev)
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RT_ASSERT(dev != RT_NULL);
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if (dev->ref_count == 0)
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return -RT_ERROR;
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dev->ref_count--;
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if (dev->ref_count != 0)
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return RT_EOK;
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/* call device close interface */
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if (dev->close != RT_NULL)
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{
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@ -297,6 +312,12 @@ rt_size_t rt_device_read(rt_device_t dev,
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{
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RT_ASSERT(dev != RT_NULL);
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if (dev->ref_count == 0)
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{
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rt_set_errno(-RT_ERROR);
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return 0;
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}
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/* call device read interface */
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if (dev->read != RT_NULL)
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{
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@ -329,6 +350,12 @@ rt_size_t rt_device_write(rt_device_t dev,
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{
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RT_ASSERT(dev != RT_NULL);
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if (dev->ref_count == 0)
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{
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rt_set_errno(-RT_ERROR);
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return 0;
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}
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/* call device write interface */
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if (dev->write != RT_NULL)
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{
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