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STM32: add lpuart_clock_source config 

Keep same clock configuration as done before this PR (LSE and PCLK1).
Use a JSON file to change it.
pull/7326/head
bcostm 2018-06-20 10:53:06 +02:00
parent 2be3c13534
commit 9be8541a30
2 changed files with 31 additions and 8 deletions
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35
targets/TARGET_STM/serial_api.c
View File

@ -32,6 +32,11 @@
#include "serial_api_hal.h"
// Possible choices of the LPUART_CLOCK_SOURCE configuration set in json file
#define USE_LPUART_CLK_LSE 0x01
#define USE_LPUART_CLK_PCLK1 0x02
#define USE_LPUART_CLK_HSI 0x04
int stdio_uart_inited = 0; // used in platform/mbed_board.c and platform/mbed_retarget.cpp
serial_t stdio_uart;
@ -367,29 +372,43 @@ void serial_baud(serial_t *obj, int baudrate)
struct serial_s *obj_s = SERIAL_S(obj);
obj_s->baudrate = baudrate;
#if defined(LPUART1_BASE)
/* Note that LPUART clock source must be in the range [3 x baud rate, 4096 x baud rate], check Ref Manual */
if (obj_s->uart == LPUART_1) {
/* If baudrate is lower than 9600 try to change to LSE */
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LPUART1;
#if ((MBED_CONF_TARGET_LPUART_CLOCK_SOURCE) & USE_LPUART_CLK_LSE)
if (baudrate <= 9600 && __HAL_RCC_GET_FLAG(RCC_FLAG_LSERDY)) {
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LPUART1;
PeriphClkInitStruct.Lpuart1ClockSelection = RCC_LPUART1CLKSOURCE_LSE;
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
} else {
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LPUART1;
PeriphClkInitStruct.Lpuart1ClockSelection = RCC_LPUART1CLKSOURCE_PCLK1;
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
if (init_uart(obj) == HAL_OK) {
return;
}
}
#endif
#if ((MBED_CONF_TARGET_LPUART_CLOCK_SOURCE) & USE_LPUART_CLK_PCLK1)
PeriphClkInitStruct.Lpuart1ClockSelection = RCC_LPUART1CLKSOURCE_PCLK1;
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
if (init_uart(obj) == HAL_OK) {
return;
}
/* Change LPUART clock source and try again */
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LPUART1;
#endif
#if ((MBED_CONF_TARGET_LPUART_CLOCK_SOURCE) & USE_LPUART_CLK_HSI)
if (__HAL_RCC_GET_FLAG(RCC_FLAG_HSIRDY)) {
PeriphClkInitStruct.Lpuart1ClockSelection = RCC_LPUART1CLKSOURCE_HSI;
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
if (init_uart(obj) == HAL_OK) {
return;
}
}
#endif
// Last chance using SYSCLK
PeriphClkInitStruct.Lpuart1ClockSelection = RCC_LPUART1CLKSOURCE_SYSCLK;
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
}
#endif /* LPUART1_BASE */
if (init_uart(obj) != HAL_OK) {
debug("Cannot initialize UART with baud rate %u\n", baudrate);
}

4
targets/targets.json
View File

@ -730,6 +730,10 @@
"help": "Define if a Low Speed External xtal (LSE) is available on the board (0 = No, 1 = Yes). If Yes, the LSE will be used to clock the RTC, LPUART, ... otherwise the Low Speed Internal clock (LSI) will be used",
"value": "1"
},
"lpuart_clock_source": {
"help": "Define the LPUART clock source. Mask values: USE_LPUART_CLK_LSE, USE_LPUART_CLK_PCLK1, USE_LPUART_CLK_HSI",
"value": "USE_LPUART_CLK_LSE|USE_LPUART_CLK_PCLK1"
},
"stdio_uart_tx": {
"help": "default TX STDIO pins is defined in PinNames.h file, but it can be overridden"
},