[v5,0/3] DCMI set minimum cpufreq requirement

Message ID 20200609115825.10748-1-benjamin.gaignard@st.com
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  • DCMI set minimum cpufreq requirement
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Benjamin Gaignard June 9, 2020, 11:58 a.m.
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 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          | 137 +++++++++++++++++++--
 3 files changed, 138 insertions(+), 8 deletions(-)