Re: [PATCH 1/3] clk: qcom: smd-rpm: Add rate hooks for clk_smd_rpm_branch_ops

[Shawn Guo]

On Tue, Sep 14, 2021 at 02:56:28PM -0700, Stephen Boyd wrote:
> Quoting Shawn Guo (2021-09-13 19:55:52)
> > On QCM2290 platform, the clock xo_board runs at 38400000, while the
> > child clock bi_tcxo needs to run at 19200000.  That said,
> > clk_smd_rpm_branch_ops needs the capability of setting rate. Add rate
> > hooks into clk_smd_rpm_branch_ops to make it possible.
> 
> This doesn't sound right. The branch is a simple on/off. If xo_board is
> 38.4MHz, then there is an internal divider in the SoC that makes bi_tcxo
> (i.e. the root of the entire clk tree) be 19.2MHz. We don't model the
> divider, I guess because it isn't very important to. Instead, we tack on
> a divider field and implement recalc_rate op. See clk-rpmh.c in the qcom
> directory for this.

Thanks for the comment, Stephen!  To be honest, I copied the
implementation from vendor kernel, and wasn't really sure if it's
correct or the best.

So here is what I get based on your suggestion.  Let's me know if
it's how you wanted it to be.  Thanks!

Shawn

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