diff options
| -rw-r--r-- | stmhal/hal/l4/inc/stm32l4xx_hal_uart.h | 5 | ||||
| -rw-r--r-- | stmhal/hal/l4/src/stm32l4xx_hal_uart.c | 38 |
2 files changed, 42 insertions, 1 deletions
diff --git a/stmhal/hal/l4/inc/stm32l4xx_hal_uart.h b/stmhal/hal/l4/inc/stm32l4xx_hal_uart.h index e56aa9ef94..b890c3d987 100644 --- a/stmhal/hal/l4/inc/stm32l4xx_hal_uart.h +++ b/stmhal/hal/l4/inc/stm32l4xx_hal_uart.h @@ -962,7 +962,8 @@ typedef struct * @param __BAUD__: Baud rate set by the user. * @retval Division result */ -#define UART_DIV_LPUART(__PCLK__, __BAUD__) (((uint64_t)(__PCLK__)*256)/((__BAUD__))) +/* FIXME tobbad Adapted to avoid 64 bit division. */ +#define UART_DIV_LPUART(__PCLK__, __BAUD__) HAL_UART_CalcBrr((__PCLK__), (__BAUD__)) /** @brief BRR division operation to set BRR register in 8-bit oversampling mode. * @param __PCLK__: UART clock. @@ -1369,6 +1370,8 @@ void UART_AdvFeatureConfig(UART_HandleTypeDef *huart); /** * @} */ +/* Functions added by micropython */ +uint32_t HAL_UART_CalcBrr(uint32_t fck, uint32_t baud); #ifdef __cplusplus } diff --git a/stmhal/hal/l4/src/stm32l4xx_hal_uart.c b/stmhal/hal/l4/src/stm32l4xx_hal_uart.c index e35c4db8e5..2b0d76d301 100644 --- a/stmhal/hal/l4/src/stm32l4xx_hal_uart.c +++ b/stmhal/hal/l4/src/stm32l4xx_hal_uart.c @@ -2101,6 +2101,44 @@ static HAL_StatusTypeDef UART_Receive_IT(UART_HandleTypeDef *huart) } } + +/** + * @brief Calculate register BRR value without using uint64. + * @note This function is added by the micropython project. + * @param fck: Input clock frequency to the uart block in Hz. + * @param baud: baud rate should be one of {300, 600, 1200, 2400, 4800, 9600, 19200, 57600, 115200}. + * @retval BRR value + */ +uint32_t HAL_UART_CalcBrr(uint32_t fck, uint32_t baud) +{ + const struct + { + uint32_t limit; + uint32_t div; + } comDiv[]= { + {1<<31, 300 }, /* must be >= 256 */ + {1<<30, 150 }, /* must be >= 128 */ + {1<<29, 75 }, /* must be >= 64 */ + {1<<28, 50 }, /* must be >= 32 */ + {1<<27, 20 }, /* must be >= 16 */ + {1<<26, 10 }, /* must be >= 8 */ + {1<<25, 5 }, /* must be >= 4 */ + {1<<24, 2 } /* must be >= 2 */ + }; + const uint32_t comDivCnt = sizeof(comDiv)/sizeof(comDiv[0]); + uint8_t i; + for (i=0; i<comDivCnt ;i++) + { + if (fck >= comDiv[i].limit) + { + fck /= comDiv[i].div; + baud /= comDiv[i].div; + break; + } + } + return (fck<<8)/baud; +} + /** * @} */ |