[PATCH v4] clk: allow reentrant calls into the clk framework
Viresh Kumar
viresh.kumar at linaro.org
Wed Mar 27 05:55:24 EDT 2013
On 27 March 2013 15:10, Thomas Gleixner <tglx at linutronix.de> wrote:
> On Wed, 27 Mar 2013, Mike Turquette wrote:
>
>> Reentrancy into the clock framework from the clk.h api is necessary
>> for clocks that are prepared and unprepared via i2c_transfer (which
>> includes many PMICs and discrete audio chips) as well as for several
>> other use cases.
>
> That explanation sucks.
>
> Why does an i2c clock need reentrancy? Just because it's i2c or what?
I am noway connected to this development but was just going through
your mail and i think i might know the answer why is this required.
Consider an example where an external chip has clock controller and has
bits which can be programmed to enable/disable clock. And this chip is
connected via spi/i2c to SoC.
clk_prepare(peripheral on external chip)
-> i2c_xfer(to write to external chips register)
-> clk_enable(i2c controller)
->controller-xfer-routine.. and finally we enable clk here...
Sorry if i am on the wrong side :)
--
viresh
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