On Thu, Nov 17, 2022 at 11:01:41AM +0530, Manivannan Sadhasivam wrote: > Hello, > > This series adds clock provider support to the Qcom CPUFreq driver for > supplying the clocks to the CPU cores in Qcom SoCs. > > The Qualcomm platforms making use of CPUFreq HW Engine (EPSS/OSM) supply > clocks to the CPU cores. But this is not represented clearly in devicetree. > There is no clock coming out of the CPUFreq HW node to the CPU. This created > an issue [1] with the OPP core when a recent enhancement series was submitted. > Eventhough the issue got fixed in the OPP framework in the meantime, that's > not a proper solution and this series aims to fix it properly. > > There was also an attempt made by Viresh [2] to fix the issue by moving the > clocks supplied to the CPUFreq HW node to the CPU. But that was not accepted > since those clocks belong to the CPUFreq HW node only. > > The proposal here is to add clock provider support to the Qcom CPUFreq HW > driver to supply clocks to the CPUs that comes out of the EPSS/OSM block. > This correctly reflects the hardware implementation. > > The clock provider is a simple one that just provides the frequency of the > clocks supplied to each frequency domain in the SoC using .recalc_rate() > callback. The frequency supplied by the driver will be the actual frequency > that comes out of the EPSS/OSM block after the DCVS operation. This frequency > is not same as what the CPUFreq framework has set but it is the one that gets > supplied to the CPUs after throttling by LMh. > > This series has been tested on SM8450 based dev board with the OPP hack removed > and hence there is a DTS change only for that platform. Once this series gets > accepted, rest of the platform DTS can also be modified and finally the hack on > the OPP core can be dropped. > > Thanks, > Mani > > [1] https://lore.kernel.org/lkml/YsxSkswzsqgMOc0l@xxxxxxxxxxxxxxxxxxxx/ > [2] https://lore.kernel.org/lkml/20220801054255.GA12039@thinkpad/t/ > > Changes in v7: > > * Added a patch that returns the throttled frequency for cpufreq_driver->get() > callback (Sudeep & Viresh) > * Added error check for kasprintf and allocated the clk name locally > > Changes in v6: > > * Removed the local variable clk_name (Matthias) > * Added the clock id to the error message of devm_clk_hw_register() > > Changes in v5: > > * Switched to Hz unit for the CPU clocks > > Changes in v4: > > * Rebased on top of cpufreq/arm/linux-next branch > > Changes in v3: > > * Submitted the cpufreq driver cleanup patches as a separate series as > suggested by Viresh > * Removed static keyword from clk_init_data declaration > > Changes in v2: > > * Moved the qcom_cpufreq_data allocation to probe > * Added single clock provider with multiple clks for each freq domain > * Moved soc_data to qcom_cpufreq struct > * Added Rob's review for binding > > Manivannan Sadhasivam (4): > dt-bindings: cpufreq: cpufreq-qcom-hw: Add cpufreq clock provider > arm64: dts: qcom: sm8450: Supply clock from cpufreq node to CPUs > cpufreq: qcom-hw: Add CPU clock provider support Why do you need the above 3 changes if the below(4/4) will ensure cpufreq_get(cpu) returns the clock frequency. I was expecting to drop the whole "confusing" clock bindings and the unnecessary clock provider. Can't we just use cpufreq_get(cpu) ? -- Regards, Sudeep
