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From: Stephen Boyd <>
To: Shawn Guo <>
Cc: Rob Herring <>,
	Bjorn Andersson <>,
	Loic Poulain <>,,,,,
	Shawn Guo <>
Subject: Re: [PATCH 1/3] clk: qcom: smd-rpm: Add rate hooks for clk_smd_rpm_branch_ops
Date: Tue, 14 Sep 2021 14:56:28 -0700	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

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.

  reply	other threads:[~2021-09-14 21:56 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-14  2:55 [PATCH 0/3] Add QCM2290 RPM clocks support Shawn Guo
2021-09-14  2:55 ` [PATCH 1/3] clk: qcom: smd-rpm: Add rate hooks for clk_smd_rpm_branch_ops Shawn Guo
2021-09-14 21:56   ` Stephen Boyd [this message]
2021-09-15 15:05     ` Shawn Guo
2021-09-15 17:23       ` Bjorn Andersson
2021-09-15 17:44         ` Bjorn Andersson
2021-09-16  5:04         ` Shawn Guo
2021-09-15  2:55   ` Bjorn Andersson
2021-09-15 15:12     ` Shawn Guo
2021-09-14  2:55 ` [PATCH 2/3] dt-bindings: clk: qcom,rpmcc: Document QCM2290 compatible Shawn Guo
2021-09-14  2:55 ` [PATCH 3/3] clk: qcom: smd-rpm: Add QCM2290 RPM clock support Shawn Guo

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