Re: [PATCH 5/9] TWL4030: read and write module ISRs to clear them at init

Peter 'p2' De Schrijver
2008-07-18T09:12:47Z

On Thu, Jul 17, 2008 at 07:34:52PM -0600, ext Paul Walmsley wrote:
> TWL4030 interrupt status register bits can be cleared in one of two ways:
> either by reading from the register, or by writing a 1 to the
> appropriate bit(s) in the register. This behavior can be altered at any
> time by the <twlmodule>_SIH_CTRL.COR register bit ("clear-on-read").
>
> twl4030-core.c does not touch these *_SIH_CTRL registers during boot,
> and the TWL4030 TRM is deeply confused as to whether COR=1 means that
> the registers are cleared on reads, or cleared on writes.
>

That's true. But reality is fortunately not so confused :) COR=1 means
all IRQs are acknowledged when reading the corresponding ISR. COR=0
means you need to write 1 to the bits in the ISR for interrupts you want to
acknowledge.

Hope this helps,

Cheers,

Peter.

--
goa is a state of mind