Re: [Patch v6 6/9] cpufreq: tegra194: add OPP support and set bandwidth
From: Viresh Kumar
Date: Tue Apr 18 2023 - 05:13:26 EST
On 11-04-23, 16:29, Sumit Gupta wrote:
> Add support to use OPP table from DT in Tegra194 cpufreq driver.
> Tegra SoC's receive the frequency lookup table (LUT) from BPMP-FW.
> Cross check the OPP's present in DT against the LUT from BPMP-FW
> and enable only those DT OPP's which are present in LUT also.
>
> The OPP table in DT has CPU Frequency to bandwidth mapping where
> the bandwidth value is per MC channel. DRAM bandwidth depends on the
> number of MC channels which can vary as per the boot configuration.
> This per channel bandwidth from OPP table will be later converted by
> MC driver to final bandwidth value by multiplying with number of
> channels before sending the request to BPMP-FW.
>
> If OPP table is not present in DT, then use the LUT from BPMP-FW
> directy as the CPU frequency table and not do the DRAM frequency
> scaling which is same as the current behavior.
>
> Now, as the CPU Frequency table is being controlling through OPP
> table in DT. Keeping fewer entries in the table will create less
> frequency steps and can help to scale fast to high frequencies
> when required.
>
> Signed-off-by: Sumit Gupta <sumitg@xxxxxxxxxx>
> ---
> drivers/cpufreq/tegra194-cpufreq.c | 156 ++++++++++++++++++++++++++---
> 1 file changed, 143 insertions(+), 13 deletions(-)
Can this be applied independently of the rest of the series ?
--
viresh