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Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks

From Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Newsgroups linux.kernel
Subject Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks
Date 2016-12-19 17:20 +0100
Message-ID <sQ8Po-1KN-29@gated-at.bofh.it> (permalink)
References (2 earlier) <sNIml-28A-5@gated-at.bofh.it> <sO4Ge-7q4-9@gated-at.bofh.it> <sOT61-7h7-7@gated-at.bofh.it> <sPc8F-2S1-5@gated-at.bofh.it> <sPnGO-1Ui-9@gated-at.bofh.it>
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On 12/17/16 7:57 AM, Andy Shevchenko wrote:
> On Sat, Dec 17, 2016 at 3:33 AM, Stephen Boyd <sboyd@codeaurora.org> wrote:
>> On 12/15, Pierre-Louis Bossart wrote:
>
>>> Clients use devm_clk_get() with a "pmc_plt_clk_<n>"
>>> argument.
>>
>> This is the problem. Clients should be calling clk_get() like:
>>
>>         clk_get(dev, "signal name in datasheet")
>>
>> where the first argument is the device and the second argument is
>> some string that is meaningful to the device, not the system as a
>> whole. The way clkdev is intended is so that the dev argument's
>> dev_name() is combined with the con_id that matches some signale
>> name in the datasheet. This way when the same IP is put into some
>> other chip, the globally unique name doesn't need to change, just
>> the device name that's registered with the lookup. Obviously this
>> breaks down quite badly when dev_name() isn't stable. Is that
>> happening here?
>
> PMC Atom is a PCI device and thus each platform would have different
> dev_name(). Do you want to list all in each consumer if consumer wants
> to work on all of them or I missed something?
>
> So, the question is how clock getting will look like to work on
> currently both CherryTrail and BayTrail.

The name pmc_plt_clk_<n> follows the data sheet specification, where 
this convention is suggested:
   PLT_CLK[2:0] - Camera
   PLT_CLK[3] - Audio Codec
   PLT_CLK[4] -
   PLT_CLK[5] - COMMs

These clocks are not internal but are made available to external 
components through dedicated physical pins on the package, this external 
visibility limits the scope for confusions, variations. I have not seen 
any skews where these clocks and pins were changed at all.

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Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Andy Shevchenko <andy.shevchenko@gmail.com> - 2016-12-13 00:40 +0100
  Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> - 2016-12-13 01:20 +0100
    Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Andy Shevchenko <andy.shevchenko@gmail.com> - 2016-12-13 01:30 +0100
      Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Darren Hart <dvhart@infradead.org> - 2016-12-16 19:40 +0100
        Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Andy Shevchenko <andy.shevchenko@gmail.com> - 2016-12-16 19:50 +0100
          Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Darren Hart <dvhart@infradead.org> - 2016-12-16 20:30 +0100
            Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Andy Shevchenko <andy.shevchenko@gmail.com> - 2016-12-16 23:30 +0100
              Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Darren Hart <dvhart@infradead.org> - 2016-12-17 00:00 +0100
        Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Mark Brown <broonie@kernel.org> - 2016-12-19 12:10 +0100
    Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Andy Shevchenko <andy.shevchenko@gmail.com> - 2016-12-13 02:20 +0100
  Re: [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Stephen Boyd <sboyd@codeaurora.org> - 2016-12-14 00:30 +0100
    Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform  clocks Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> - 2016-12-16 06:20 +0100
      Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Andy Shevchenko <andy.shevchenko@gmail.com> - 2016-12-16 09:50 +0100
        Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform  clocks Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> - 2016-12-16 16:00 +0100
      Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform  clocks Stephen Boyd <sboyd@codeaurora.org> - 2016-12-17 02:40 +0100
        Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Andy Shevchenko <andy.shevchenko@gmail.com> - 2016-12-17 15:00 +0100
          Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform  clocks Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> - 2016-12-19 17:20 +0100
            Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform  clocks Stephen Boyd <sboyd@codeaurora.org> - 2016-12-22 00:10 +0100
              Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform  clocks Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> - 2016-12-22 02:10 +0100
                Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform  clocks Stephen Boyd <sboyd@codeaurora.org> - 2016-12-22 19:30 +0100
                Re: [alsa-devel] [PATCH v6 1/3] clk: x86: Add Atom PMC platform clocks Andy Shevchenko <andy.shevchenko@gmail.com> - 2016-12-22 19:50 +0100

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