diff options
| -rw-r--r-- | chip/stm32/uart.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/chip/stm32/uart.c b/chip/stm32/uart.c index 2e3d875243..6dec7e41e1 100644 --- a/chip/stm32/uart.c +++ b/chip/stm32/uart.c @@ -194,7 +194,20 @@ DECLARE_IRQ(STM32_IRQ_USART(UARTN), uart_interrupt, 2); */ static void uart_freq_change(void) { - int div = DIV_ROUND_NEAREST(clock_get_freq(), CONFIG_UART_BAUD_RATE); + int freq; + int div; + +#if defined(CHIP_FAMILY_STM32F0) && (UARTN <= 2) + /* + * UART is clocked from HSI (8MHz) to allow it to work when waking + * up from sleep + */ + freq = 8000000; +#else + /* UART clocked from the main clock */ + freq = clock_get_freq(); +#endif + div = DIV_ROUND_NEAREST(freq, CONFIG_UART_BAUD_RATE); #if defined(CHIP_FAMILY_STM32L) || defined(CHIP_FAMILY_STM32F0) if (div / 16 > 0) { @@ -223,6 +236,14 @@ DECLARE_HOOK(HOOK_FREQ_CHANGE, uart_freq_change, HOOK_PRIO_DEFAULT); void uart_init(void) { /* Enable USART clock */ +#ifdef CHIP_FAMILY_STM32F0 +#if (UARTN == 1) + STM32_RCC_CFGR3 |= 0x0003; /* USART1 clock source from HSI(8MHz) */ +#elif (UARTN == 2) + STM32_RCC_CFGR3 |= 0x0300; /* USART2 clock source from HSI(8MHz) */ +#endif /* UARTN */ +#endif /* CHIP_FAMILY_STM32F0 */ + #if (UARTN == 1) STM32_RCC_APB2ENR |= STM32_RCC_PB2_USART1; #else |