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authorAxel Haslam <ahaslam@baylibre.com>2025-10-06 11:25:41 -0300
committerMark Brown <broonie@kernel.org>2025-10-13 11:27:52 +0100
commitb83fb1b14c06bdd765903ac852ba20a14e24f227 (patch)
treea1ddfb2a34f2f5390a496bd941428e85dbb6e32d
parent3d66d3dbd514c8b6018d65bb413c5e92af6516f6 (diff)
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 <dlechner@baylibre.com> Signed-off-by: Axel Haslam <ahaslam@baylibre.com> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com> Link: https://patch.msgid.link/cd315e95c0bd8523f00e91c400abcd6a418e5924.1759760519.git.marcelo.schmitt@analog.com Signed-off-by: Mark Brown <broonie@kernel.org>
-rw-r--r--drivers/spi/spi-offload-trigger-pwm.c3
-rw-r--r--include/linux/spi/offload/types.h9
2 files changed, 12 insertions, 0 deletions
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 {