On 27 March 2013 15:10, Thomas Gleixner tglx@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