From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
To: Luo Jie <jie.luo@oss.qualcomm.com>,
Bjorn Andersson <andersson@kernel.org>,
Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>, Luo Jie <quic_luoj@quicinc.com>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Konrad Dybcio <konradybcio@kernel.org>
Cc: linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
quic_kkumarcs@quicinc.com, quic_linchen@quicinc.com,
quic_leiwei@quicinc.com, quic_pavir@quicinc.com,
quic_suruchia@quicinc.com
Subject: Re: [PATCH 1/5] clk: qcom: cmnpll: Account for reference clock divider
Date: Fri, 28 Nov 2025 12:38:47 +0100 [thread overview]
Message-ID: <2d83f0d3-4798-4183-9e3d-9972db706cdb@oss.qualcomm.com> (raw)
In-Reply-To: <20251128-qcom_ipq5332_cmnpll-v1-1-55127ba85613@oss.qualcomm.com>
On 11/28/25 9:40 AM, Luo Jie wrote:
> The clk_cmn_pll_recalc_rate() function must account for the reference clock
> divider programmed in CMN_PLL_REFCLK_CONFIG. Without this fix, platforms
> with a reference divider other than 1 calculate incorrect CMN PLL rates.
> For example, on IPQ5332 where the reference divider is 2, the computed rate
> becomes twice the actual output.
>
> Read CMN_PLL_REFCLK_DIV and divide the parent rate by this value before
> applying the 2 * FACTOR scaling. This yields the correct rate calculation:
> rate = (parent_rate / ref_div) * 2 * factor.
>
> Maintain backward compatibility with earlier platforms (e.g. IPQ9574,
> IPQ5424, IPQ5018) that use ref_div = 1.
I'm not sure how to interpret this. Is the value fixed on these platforms
you mentioned, and always shows up as 0?
Konrad
next prev parent reply other threads:[~2025-11-28 11:38 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-28 8:40 [PATCH 0/5] Add CMN PLL clock controller support for IPQ5332 Luo Jie
2025-11-28 8:40 ` [PATCH 1/5] clk: qcom: cmnpll: Account for reference clock divider Luo Jie
2025-11-28 11:38 ` Konrad Dybcio [this message]
2025-11-28 14:29 ` Jie Luo
2025-12-01 13:42 ` Konrad Dybcio
2025-12-04 7:44 ` Jie Luo
2025-12-04 10:16 ` Konrad Dybcio
2025-11-28 8:40 ` [PATCH 2/5] dt-bindings: clock: qcom: Add CMN PLL support for IPQ5332 SoC Luo Jie
2025-11-28 9:18 ` Rob Herring (Arm)
2025-11-28 9:39 ` Krzysztof Kozlowski
2025-11-28 8:40 ` [PATCH 3/5] clk: qcom: cmnpll: Add IPQ5332 SoC support Luo Jie
2025-12-01 13:52 ` Konrad Dybcio
2025-12-04 8:09 ` Jie Luo
2025-12-04 13:48 ` Konrad Dybcio
2025-12-05 12:11 ` Jie Luo
2025-11-28 8:40 ` [PATCH 4/5] arm64: dts: ipq5332: Add CMN PLL node for networking hardware Luo Jie
2025-12-01 13:52 ` Konrad Dybcio
2025-12-04 7:46 ` Jie Luo
2025-11-28 8:40 ` [PATCH 5/5] arm64: dts: qcom: Represent xo_board as fixed-factor clock on IPQ5332 Luo Jie
2025-12-01 13:53 ` Konrad Dybcio
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2d83f0d3-4798-4183-9e3d-9972db706cdb@oss.qualcomm.com \
--to=konrad.dybcio@oss.qualcomm.com \
--cc=andersson@kernel.org \
--cc=conor+dt@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=jie.luo@oss.qualcomm.com \
--cc=konradybcio@kernel.org \
--cc=krzk+dt@kernel.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-clk@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mturquette@baylibre.com \
--cc=quic_kkumarcs@quicinc.com \
--cc=quic_leiwei@quicinc.com \
--cc=quic_linchen@quicinc.com \
--cc=quic_luoj@quicinc.com \
--cc=quic_pavir@quicinc.com \
--cc=quic_suruchia@quicinc.com \
--cc=robh@kernel.org \
--cc=sboyd@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox