From b83fb1b14c06bdd765903ac852ba20a14e24f227 Mon Sep 17 00:00:00 2001 From: Axel Haslam Date: Mon, 6 Oct 2025 11:25:41 -0300 Subject: [PATCH] spi: offload: Add offset parameter Add an offset parameter that can be passed in the periodic trigger. This is useful for example when ADC drivers implement a separate periodic signal to trigger conversion and need offload to read the result with some delay. While at it, add some documentation to offload periodic trigger parameters. Reviewed-by: David Lechner Signed-off-by: Axel Haslam Signed-off-by: Marcelo Schmitt Link: https://patch.msgid.link/cd315e95c0bd8523f00e91c400abcd6a418e5924.1759760519.git.marcelo.schmitt@analog.com Signed-off-by: Mark Brown --- drivers/spi/spi-offload-trigger-pwm.c | 3 +++ include/linux/spi/offload/types.h | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/drivers/spi/spi-offload-trigger-pwm.c b/drivers/spi/spi-offload-trigger-pwm.c index 805ed41560df..3e8c19227edb 100644 --- a/drivers/spi/spi-offload-trigger-pwm.c +++ b/drivers/spi/spi-offload-trigger-pwm.c @@ -51,12 +51,14 @@ static int spi_offload_trigger_pwm_validate(struct spi_offload_trigger *trigger, wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic->frequency_hz); /* REVISIT: 50% duty-cycle for now - may add config parameter later */ wf.duty_length_ns = wf.period_length_ns / 2; + wf.duty_offset_ns = periodic->offset_ns; ret = pwm_round_waveform_might_sleep(st->pwm, &wf); if (ret < 0) return ret; periodic->frequency_hz = DIV_ROUND_UP_ULL(NSEC_PER_SEC, wf.period_length_ns); + periodic->offset_ns = wf.duty_offset_ns; return 0; } @@ -77,6 +79,7 @@ static int spi_offload_trigger_pwm_enable(struct spi_offload_trigger *trigger, wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic->frequency_hz); /* REVISIT: 50% duty-cycle for now - may add config parameter later */ wf.duty_length_ns = wf.period_length_ns / 2; + wf.duty_offset_ns = periodic->offset_ns; return pwm_set_waveform_might_sleep(st->pwm, &wf, false); } diff --git a/include/linux/spi/offload/types.h b/include/linux/spi/offload/types.h index 6f7892347871..cd61f8adb7a5 100644 --- a/include/linux/spi/offload/types.h +++ b/include/linux/spi/offload/types.h @@ -57,8 +57,17 @@ enum spi_offload_trigger_type { SPI_OFFLOAD_TRIGGER_PERIODIC, }; +/** + * spi_offload_trigger_periodic - configuration parameters for periodic triggers + * @frequency_hz: The rate that the trigger should fire in Hz. + * @offset_ns: A delay in nanoseconds between when this trigger fires + * compared to another trigger. This requires specialized hardware + * that supports such synchronization with a delay between two or + * more triggers. Set to 0 when not needed. + */ struct spi_offload_trigger_periodic { u64 frequency_hz; + u64 offset_ns; }; struct spi_offload_trigger_config {