From: Dmitry Osipenko <digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>,
Thierry Reding
<thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Peter De Schrijver
<pdeschrijver-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>,
Prashant Gaikwad
<pgaikwad-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>,
Michael Turquette
<mturquette-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>,
Stephen Boyd <sboyd-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH v4] clk: tegra: pll: Improve PLLM enable-state detection
Date: Tue, 14 Jul 2020 12:36:51 +0300 [thread overview]
Message-ID: <4abe7959-3c69-7b05-e9af-565957bafbcd@gmail.com> (raw)
In-Reply-To: <93106a4c-b0fb-3bbf-49cb-bfe348b1ffc7-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
14.07.2020 11:20, Jon Hunter пишет:
>
> On 09/07/2020 18:20, Dmitry Osipenko wrote:
>> Power Management Controller (PMC) can override the PLLM clock settings,
>> including the enable-state. Although PMC could only act as a second level
>> gate, meaning that PLLM needs to be enabled by the Clock and Reset
>> Controller (CaR) anyways if we want it to be enabled. Hence, when PLLM is
>> overridden by PMC, it needs to be enabled by CaR and ungated by PMC in
>> order to be functional. Please note that this patch doesn't fix any known
>> problem, and thus, it's merely a minor improvement.
>>
>> Link: https://lore.kernel.org/linux-arm-kernel/20191210120909.GA2703785@ulmo/T/
>> Signed-off-by: Dmitry Osipenko <digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> ---
>>
>> Changelog:
>>
>> v4: - Renamed pllm_pmc_clk_enabled() to pllm_clk_is_gated_by_pmc() as
>> it was suggested by Jon Hunter in the review comment to v3.
>>
>> v3: - Dropped unintended code change that was accidentally added to v2.
>>
>> v2: - Added clarifying comment to the code.
>>
>> - Prettified the code.
>>
>> drivers/clk/tegra/clk-pll.c | 20 +++++++++++++++-----
>> 1 file changed, 15 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/clk/tegra/clk-pll.c b/drivers/clk/tegra/clk-pll.c
>> index b2d39a66f0fa..ff13b371e176 100644
>> --- a/drivers/clk/tegra/clk-pll.c
>> +++ b/drivers/clk/tegra/clk-pll.c
>> @@ -327,16 +327,26 @@ int tegra_pll_wait_for_lock(struct tegra_clk_pll *pll)
>> return clk_pll_wait_for_lock(pll);
>> }
>>
>> +static bool pllm_clk_is_gated_by_pmc(struct tegra_clk_pll *pll)
>> +{
>> + u32 val = readl_relaxed(pll->pmc + PMC_PLLP_WB0_OVERRIDE);
>> +
>> + return (val & PMC_PLLP_WB0_OVERRIDE_PLLM_OVERRIDE) &&
>> + !(val & PMC_PLLP_WB0_OVERRIDE_PLLM_ENABLE);
>> +}
>> +
>> static int clk_pll_is_enabled(struct clk_hw *hw)
>> {
>> struct tegra_clk_pll *pll = to_clk_pll(hw);
>> u32 val;
>>
>> - if (pll->params->flags & TEGRA_PLLM) {
>> - val = readl_relaxed(pll->pmc + PMC_PLLP_WB0_OVERRIDE);
>> - if (val & PMC_PLLP_WB0_OVERRIDE_PLLM_OVERRIDE)
>> - return val & PMC_PLLP_WB0_OVERRIDE_PLLM_ENABLE ? 1 : 0;
>> - }
>> + /*
>> + * Power Management Controller (PMC) can override the PLLM clock
>> + * settings, including the enable-state. The PLLM is enabled when
>> + * PLLM's CaR state is ON and when PLLM isn't gated by PMC.
>> + */
>> + if ((pll->params->flags & TEGRA_PLLM) && pllm_clk_is_gated_by_pmc(pll))
>> + return 0;
>>
>> val = pll_readl_base(pll);
>
>
> Thanks! This looks good to me. However, I just want to do a bit of
> testing on Tegra124 (hopefully this week).
Okay, thank you :)
next prev parent reply other threads:[~2020-07-14 9:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-09 17:20 [PATCH v4] clk: tegra: pll: Improve PLLM enable-state detection Dmitry Osipenko
[not found] ` <20200709172057.13951-1-digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2020-07-14 8:20 ` Jon Hunter
[not found] ` <93106a4c-b0fb-3bbf-49cb-bfe348b1ffc7-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2020-07-14 9:36 ` Dmitry Osipenko [this message]
2020-07-17 16:55 ` Jon Hunter
[not found] ` <997361b8-4466-cdf0-beeb-eedcbeb48597-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2020-07-17 20:15 ` Dmitry Osipenko
2020-07-28 1:21 ` Stephen Boyd
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=4abe7959-3c69-7b05-e9af-565957bafbcd@gmail.com \
--to=digetx-re5jqeeqqe8avxtiumwx3w@public.gmane.org \
--cc=jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org \
--cc=linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=mturquette-rdvid1DuHRBWk0Htik3J/w@public.gmane.org \
--cc=pdeschrijver-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org \
--cc=pgaikwad-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org \
--cc=sboyd-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org \
--cc=thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.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;
as well as URLs for NNTP newsgroup(s).