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

Benjamin Gaignard benjamin.gaignard at st.com
Wed Jul 1 08:59:15 EDT 2020


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(-)

-- 
2.15.0




More information about the linux-arm-kernel mailing list