pwm: stm32: Use input prescaler to improve period capture

Using input prescaler, capture unit will trigger DMA once every
configurable /2, /4 or /8 events (rising edge). This helps improve
period (only) capture accuracy at high rates.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Fabrice Gasnier 2018-05-16 09:36:00 +02:00 committed by Lee Jones
parent d66ffb91c3
commit ab3a897847
2 changed files with 62 additions and 2 deletions

View file

@ -82,6 +82,7 @@
#define TIM_DCR_DBL GENMASK(12, 8) /* DMA burst len */
#define MAX_TIM_PSC 0xFFFF
#define MAX_TIM_ICPSC 0x3
#define TIM_CR2_MMS_SHIFT 4
#define TIM_CR2_MMS2_SHIFT 20
#define TIM_SMCR_TS_SHIFT 4