1. #include <gpio.h>
2. #include <delay.h>
3. #include <irq.h>
4. #include <stm32.h>
5. #include <string.h>
6. #include "queue.h"
7. #include "uart.h"
8. #include "leds.h"
9.  
10. #define RED_LED_GPIO GPIOA
11. #define RED_LED_PIN 6
12.  
13. #define RedLEDon() RED_LED_GPIO->BSRRH = 1 << RED_LED_PIN
14. #define RedLEDoff() RED_LED_GPIO->BSRRL = 1 << RED_LED_PIN
15.  
16. #define USART_Mode_Rx_Tx (USART_CR1_RE | USART_CR1_TE)
17. #define USART_Enable USART_CR1_UE
18. #define USART_WordLength_8b 0x0000
19. #define USART_Parity_No 0x0000
20. #define USART_StopBits_1 0x0000
21. #define USART_FlowControl_None 0x0000
22.  
23. #define HSI_HZ 16000000U
24. #define PCLK2_HZ HSI_HZ
25.  
26. #define USART1_GPIO GPIOA
27. #define USART1_TXD_PIN 9
28. #define USART1_RXD_PIN 10
29.  
30. #define BUFF_SIZE 100
31.  
32. char buffer[BUFF_SIZE];
33. Queue queue;
34. char buff[2] = "\0";
35.  
36. static void enableUSART() { USART1->CR1 |= USART_CR1_UE; }
37.  
38. static void initDMA2() {
39.   RCC->AHB1ENR |= RCC_AHB1ENR_DMA2EN;
40.  
41.   DMA2_Stream7->CR =
42.       4U << 25 | DMA_SxCR_PL_1 | DMA_SxCR_MINC | DMA_SxCR_DIR_0 | DMA_SxCR_TCIE;
43.   DMA2_Stream7->PAR = (uint32_t)&USART1->DR;
44.  
45.   DMA2_Stream5->CR = 4U << 25 | DMA_SxCR_PL_1 | DMA_SxCR_MINC | DMA_SxCR_TCIE;
46.   DMA2_Stream5->PAR = (uint32_t)&USART1->DR;
47.  
48.   DMA2->HIFCR = DMA_HIFCR_CTCIF7 | DMA_HIFCR_CTCIF5;
49.   NVIC_EnableIRQ(DMA2_Stream5_IRQn);
50.   // DMA2->HIFCR = DMA_HIFCR_CTCIF7;
51.   NVIC_EnableIRQ(DMA2_Stream7_IRQn);
52. }
53.  
54. static int busyDMA() { return (DMA2_Stream7->CR & DMA_SxCR_EN); }
55.  
56. static void sendDMA(char *msg, uint32_t len) {
57.   DMA2_Stream7->M0AR = (uint32_t)msg;
58.   DMA2_Stream7->NDTR = len;
59.   DMA2_Stream7->CR |= DMA_SxCR_EN;
60. }
61.  
62. static void recvDMA(char *msg) {
63.   DMA2_Stream5->M0AR = (uint32_t)msg;
64.   DMA2_Stream5->NDTR = 2;
65.   DMA2_Stream5->CR |= DMA_SxCR_EN;
66. }
67.  
68. void initUSART1() {
69.   uint32_t const baudrate = 9600U;
70.  
71.   RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN;
72.   RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
73.  
74.   USART1->BRR = (PCLK2_HZ + (baudrate / 2U)) / baudrate;
75.   USART1->CR1 = USART_Mode_Rx_Tx | USART_WordLength_8b | USART_Parity_No;
76.   USART1->CR2 = USART_StopBits_1;
77.   USART1->CR3 = USART_CR3_DMAT | USART_CR3_DMAR;
78.  
79.   GPIOafConfigure(USART1_GPIO, USART1_TXD_PIN, GPIO_OType_PP, GPIO_Fast_Speed,
80.                   GPIO_PuPd_NOPULL, GPIO_AF_USART1);
81.  
82.   GPIOafConfigure(USART1_GPIO, USART1_RXD_PIN, GPIO_OType_PP, GPIO_Fast_Speed,
83.                   GPIO_PuPd_UP, GPIO_AF_USART1);
84.  
85.   initDMA2();
86.   enableUSART();
87.   initQueue(&queue);
88.   recvDMA(buff);
89. }
90.  
91. void DMA2_Stream7_IRQHandler() {
92.   uint32_t isr = DMA2->HISR;
93.   if (isr & DMA_HISR_TCIF7) {
94.     DMA2->HIFCR = DMA_HIFCR_CTCIF7;
95.  
96.     if (!isEmptyQueue(&queue)) {
97.       uint32_t len = getStrQueue(&queue, buffer, BUFF_SIZE);
98.       sendDMA(buffer, len);
99.     }
100.   }
101. }
102.  
103. void DMA2_Stream5_IRQHandler() {
104.   uint32_t isr = DMA2->HISR;
105.   if (isr & DMA_HISR_TCIF5) {
106.     DMA2->HIFCR = DMA_HIFCR_CTCIF5;
107.     sendUSART(buff);
108.     parseCmdLed(buff);
109.     recvDMA(buff);
110.   }
111. }
112.  
113. void sendUSART(char *msg) {
114.   // toggleLed(RED);
115.   if (busyDMA()) {
116.     putStrQueue(&queue, msg);
117.   } else {
118.     sendDMA(msg, strlen(msg));
119.   }
120. }
121.