Hi, [+cc people from linux-msm] On 24/06/2024 19:31, Jerome Brunet wrote:
Add support for the HW found in most Amlogic SoC dedicated to measure system clocks. This drivers aims to replace the one found in drivers/soc/amlogic/meson-clk-measure.c with following improvements: * Access to the measurements through the IIO API: Easier re-use of the results in userspace and other drivers * Controllable scale with raw measurements * Higher precision with processed measurements Jerome Brunet (2): dt-bindings: iio: frequency: add clock measure support iio: frequency: add amlogic clock measure support .../iio/frequency/amlogic,clk-msr-io.yaml | 50 ++ drivers/iio/frequency/Kconfig | 15 + drivers/iio/frequency/Makefile | 1 + drivers/iio/frequency/amlogic-clk-msr-io.c | 802 ++++++++++++++++++ 4 files changed, 868 insertions(+) create mode 100644 Documentation/devicetree/bindings/iio/frequency/amlogic,clk-msr-io.yaml create mode 100644 drivers/iio/frequency/amlogic-clk-msr-io.c
While I really appreciate the effort, and the code looks cool, the clkmsr is really a debug tool, and I'm not sure IIO is the right place for such debug tool ? There's almost the same interface on qcom SoCs (https://github.com/linux-msm/debugcc) but they chose to keep it in userspace until we find an appropriate way to expose this from the kernel the right way. If it enabled us to monitor a frequency input for a product use-case, IIO would be the appropriate interface, but AFAIK it's only internal clocks and thus I'm worried it's not the best way to expose those clocks. Neil
