diff options
| author | Damien George | 2018-08-10 16:39:47 +1000 |
|---|---|---|
| committer | Damien George | 2018-08-10 16:39:47 +1000 |
| commit | 86e0b2553288bf40a22e1e91d161c075295dd4a7 (patch) | |
| tree | c4ed5fca5ca31b9d9d80202ed0f33fbeb1eb5ad9 | |
| parent | ca0d78cebb20ed67f78491a68b02272aba2ecd13 (diff) | |
stm32/spi: Round up prescaler calc to never exceed requested baudrate.
Requesting a baudrate of X should never configure the peripheral to have a
baudrate greater than X because connected hardware may not be able to
handle higher speeds. This patch makes sure to round the prescaler up so
that the actual baudrate is rounded down.
| -rw-r--r-- | ports/stm32/spi.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/ports/stm32/spi.c b/ports/stm32/spi.c index 7e9864bbc..1aa8d666f 100644 --- a/ports/stm32/spi.c +++ b/ports/stm32/spi.c @@ -214,7 +214,7 @@ STATIC void spi_set_params(const spi_t *spi_obj, uint32_t prescale, int32_t baud spi_clock = HAL_RCC_GetPCLK2Freq(); } #endif - prescale = spi_clock / baudrate; + prescale = (spi_clock + baudrate - 1) / baudrate; } if (prescale <= 2) { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2; } else if (prescale <= 4) { init->BaudRatePrescaler = SPI_BAUDRATEPRESCALER_4; } |