记录在RT-Thread系统上移植TouchGFX的一个小坑

stm32新人一枚

这个帖子主要用来记录自己在RT-Thread上移植TouchGFX的一些坑。

RT-Thread和TouchGFX，以及相关的模块，都是在STM32CubeMx上配置的。

配置好之后，只需要对TouchGFX的“OSWrappers.cpp”文件进行修改，就可以正常使用了。

CSDN网站中有大神做过移植，详情在这里https://blog.csdn.net/sinat_31039061/article/details/105045469，
CSDN中这个帖子后来需要付费订阅了，但是百度还是能搜到另外一个网站可以看这个帖子：https://www.freesion.com/article/9090379134/

里边记录了OSWrappers.cpp的修改详细方法。

我自己按照帖子的方法移植之后，也能运行，只是有些小细节有问题。
后边贴的图片，是实拍图，红框里的字符会显示不全。而且经过排查，不是单片机运行速度或者RAM读写速度问题。



之后我又用STM32CubeMx重新配了一个FreeRTOS的工程，显示同样的内容，FreeRTOS的工程就很完美。
然后对比两个工程的OSWrappers.cpp，发现了端倪。
主要问题在于void OSWrappers::takeFrameBufferSemaphore()和void OSWrappers::giveFrameBufferSemaphore()中的信号量处理有问题。



这里贴出我修改后的代码（代码中重点修改的内容简单做了标注。其他部分的代码，也有根据FreeRTOS工程略做调整的部分，这里不再着重标注）

修改之后就可以完美运行了！

1. /**
   
2.   ******************************************************************************
   
3.   * File Name          : OSWrappers.cpp
   
4.   ******************************************************************************
   
5.   * @attention
   
6.   *
   
7.   * <h2><center>&#169; Copyright (c) 2020 STMicroelectronics.
   
8.   * All rights reserved.</center></h2>
   
9.   *
   
10.   * This software component is licensed by ST under Ultimate Liberty license
    
11.   * SLA0044, the "License"; You may not use this file except in compliance with
    
12.   * the License. You may obtain a copy of the License at:
    
13.   *                             www.st.com/SLA0044
    
14.   *
    
15.   ******************************************************************************
    
16.   */
    
17. 
    
18. /* USER CODE BEGIN target/OSWrappers.cpp */
    
19. 
    
20. #include <cassert>
    
21. #include <touchgfx/hal/HAL.hpp>
    
22. #include <touchgfx/hal/OSWrappers.hpp>
    
23. #include <rtthread.h>
    
24. using namespace touchgfx;
    
25. static rt_sem_t frame_buffer_sem;
    
26. static rt_sem_t vsync_sem;
    
27. /*
    
28. * Initialize frame buffer semaphore and queue/mutex for VSYNC signal.
    
29. */
    
30. void OSWrappers::initialize()
    
31. {
    
32.   frame_buffer_sem = rt_sem_create("gfx_sem", 1, RT_IPC_FLAG_PRIO);
    
33.   vsync_sem = rt_sem_create("vsync_sem", 1, RT_IPC_FLAG_PRIO);
    
34. }
    
35. 
    
36. /*
    
37. * Take the frame buffer semaphore. Blocks until semaphore is available.
    
38. */
    
39. 
    
40. /////////////////////////////////重点修改的内容/////////////////////////////////
    
41. 
    
42. void OSWrappers::takeFrameBufferSemaphore()
    
43. {
    
44.   rt_sem_take(frame_buffer_sem,RT_WAITING_FOREVER);
    
45. }
    
46. 
    
47. /*
    
48. * Release the frame buffer semaphore.
    
49. */
    
50. 
    
51. /////////////////////////////////重点修改的内容/////////////////////////////////
    
52. 
    
53. void OSWrappers::giveFrameBufferSemaphore()
    
54. {
    
55.   rt_sem_release(frame_buffer_sem);
    
56. }
    
57. 
    
58. /*
    
59. * Attempt to obtain the frame buffer semaphore. If semaphore is not available, do
    
60. * nothing.
    
61. *
    
62. * Note must return immediately! This function does not care who has the taken the semaphore,
    
63. * it only serves to make sure that the semaphore is taken by someone.
    
64. */
    
65. void OSWrappers::tryTakeFrameBufferSemaphore()
    
66. {
    
67.   rt_sem_trytake(frame_buffer_sem);
    
68. }
    
69. 
    
70. /*
    
71. * Release the frame buffer semaphore in a way that is safe in interrupt context. Called
    
72. * from ISR.
    
73. *
    
74. * Release the frame buffer semaphore in a way that is safe in interrupt context.
    
75. * Called from ISR.
    
76. */
    
77. void OSWrappers::giveFrameBufferSemaphoreFromISR()
    
78. {
    
79.   rt_sem_release(frame_buffer_sem);
    
80. }
    
81. 
    
82. /*
    
83. * Signal that a VSYNC has occurred. Should make the vsync queue/mutex available.
    
84. *
    
85. * Note This function is called from an ISR, and should (depending on OS) trigger a
    
86. * scheduling.
    
87. */
    
88. void OSWrappers::signalVSync()
    
89. {
    
90.   rt_sem_release(vsync_sem);
    
91. }
    
92. 
    
93. /*
    
94. * This function blocks until a VSYNC occurs.
    
95. *
    
96. * Note This function must first clear the mutex/queue and then wait for the next one to
    
97. * occur.
    
98. */
    
99. void OSWrappers::waitForVSync()
    
100. {
     
101.   rt_sem_take(vsync_sem,0);
     
102.   rt_sem_take(vsync_sem,RT_WAITING_FOREVER);
     
103. }
     
104. 
     
105. /*
     
106. * A function that causes executing task to sleep for a number of milliseconds.
     
107. *
     
108. * A function that causes executing task to sleep for a number of milliseconds.
     
109. * This function is OPTIONAL. It is only used by the TouchGFX in the case of
     
110. * a specific frame refresh strategy (REFRESH_STRATEGY_OPTIM_SINGLE_BUFFER_TFT_CTRL).
     
111. * Due to backwards compatibility, in order for this function to be useable by the HAL
     
112. * the function must be explicitly registered:
     
113. * hal.registerTaskDelayFunction(&OSWrappers::taskDelay)
     
114. *
     
115. * see HAL::setFrameRefreshStrategy(FrameRefreshStrategy s)
     
116. * see HAL::registerTaskDelayFunction(void (*delayF)(uint16_t))
     
117. */
     
118. void OSWrappers::taskDelay(uint16_t ms)
     
119. {
     
120.   rt_thread_mdelay(ms);
     
121. }
     
122. 
     
123. /* USER CODE END target/OSWrappers.cpp */
     
124. 
     
125. /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
     

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stm32新人一枚

再补充一个内容：

RT-Thread基础上使用TouchGFX的时候，需要在DMA2D中断和LTDC中断中加入RT-Thread中断管理的两个函数。
进中断的时候加rt_interrupt_enter();
出中断的时候加rt_interrupt_leave();

分别在
1.   TouchGFXGeneratedHAL.cpp文件中重写的void HAL_LTDC_LineEventCallback(LTDC_HandleTypeDef *hltdc)函数里
大概98行加rt_interrupt_enter();
118行，添加   rt_interrupt_leave();

1. void HAL_LTDC_LineEventCallback(LTDC_HandleTypeDef *hltdc)
   
2. {
   
3.     rt_interrupt_enter();
   
4.     if (LTDC->LIPCR == lcd_int_active_line)
   
5.     {
   
6.         //entering active area
   
7.         HAL_LTDC_ProgramLineEvent(hltdc, lcd_int_porch_line);
   
8.         HAL::getInstance()->vSync();
   
9.         OSWrappers::signalVSync();
   
10.         // Swap frame buffers immediately instead of waiting for the task to be scheduled in.
    
11.         // Note: task will also swap when it wakes up, but that operation is guarded and will not have
    
12.         // any effect if already swapped.
    
13.         HAL::getInstance()->swapFrameBuffers();
    
14.         GPIO::set(GPIO::VSYNC_FREQ);
    
15.     }
    
16.     else
    
17.     {
    
18.         //exiting active area
    
19.         HAL_LTDC_ProgramLineEvent(hltdc, lcd_int_active_line);
    
20.         GPIO::clear(GPIO::VSYNC_FREQ);
    
21.         HAL::getInstance()->frontPorchEntered();
    
22.     }
    
23.     rt_interrupt_leave();
    
24. }

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2.   STM32DMA.cpp文件中重写的void DMA2D_XferCpltCallback(DMA2D_HandleTypeDef* handle)函数里
57行，添加   rt_interrupt_enter();
60行，添加   rt_interrupt_leave();

1. static void DMA2D_XferCpltCallback(DMA2D_HandleTypeDef* handle)
   
2. {
   
3.     /* USER CODE BEGIN DMA2D_XferCpltCallback */
   
4.     // If the framebuffer is placed in Write Through cached memory (e.g. SRAM) then we need
   
5.     // to flush the Dcache prior to letting DMA2D accessing it. That's done
   
6.     // using SCB_CleanInvalidateDCache().
   
7. 
   
8.     // SCB_CleanInvalidateDCache();
   
9.     /* USER CODE END DMA2D_XferCpltCallback */
   
10.     rt_interrupt_enter();
    
11. 
    
12.     touchgfx::HAL::getInstance()->signalDMAInterrupt();
    
13.     rt_interrupt_leave();
    
14. }
    

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在使用RT-Thread的时候，要注意中断函数中，都要添加这两个中断管理函数，不然可能出奇怪的问题。

上边我提到的两个文件里没加中断管理的代码，就会导致触摸屏经常莫名其妙的没反应了，希望看到这个帖子的小伙伴们注意