[PATCH v6 0/3] DCMI set minimum cpufreq requirement

From: Benjamin Gaignard
Date: Wed Jun 10 2020 - 08:25:32 EST


This series allow to STM32 camera interface (DCMI) to require a minimum
frequency to the CPUs before start streaming frames from the sensor.
The minimum frequency requirement is provided in the devide-tree node.

Setting a minimum frequency for the CPUs is needed to ensure a quick handling
of the interrupts between two sensor frames and avoid dropping half of them.

version 6:
- come back to version 4 and follow Valentin's suggestions about notifier

version 5:
- add a mutex to protect dcmi_irq_notifier_notify()
- register notifier a probe time

version 4:
- simplify irq affinity handling by using only dcmi_irq_notifier_notify()

version 3:
- add a cpumask field to track boosted CPUs
- add irq_affinity_notify callback
- protect cpumask field with a mutex

Benjamin Gaignard (3):
dt-bindings: media: stm32-dcmi: Add DCMI min frequency property
media: stm32-dcmi: Set minimum cpufreq requirement
ARM: dts: stm32: Set DCMI frequency requirement for stm32mp15x

.../devicetree/bindings/media/st,stm32-dcmi.yaml | 8 ++
arch/arm/boot/dts/stm32mp151.dtsi | 1 +
drivers/media/platform/stm32/stm32-dcmi.c | 138 +++++++++++++++++++--
3 files changed, 139 insertions(+), 8 deletions(-)

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2.15.0