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From: "Peter 'p2' De Schrijver" <peter.de-schrijver@nokia.com>
To: ext Paul Walmsley <paul@pwsan.com>
Cc: linux-omap@vger.kernel.org
Subject: Re: [PATCH 5/9] TWL4030: read and write module ISRs to clear them at init
Date: Fri, 18 Jul 2008 12:12:34 +0300	[thread overview]
Message-ID: <20080718091234.GA4602@codecarver.research.nokia.com> (raw)
In-Reply-To: <20080718013451.18943.18579.stgit@localhost.localdomain>

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

  reply	other threads:[~2008-07-18  9:12 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-07-18  1:34 [PATCH 0/9] TWL4030 bugfixes and cleanups Paul Walmsley
2008-07-18  1:34 ` [PATCH 1/9] TWL4030: remove superfluous PWR interrupt status clear before masking Paul Walmsley
2008-07-18  1:34 ` [PATCH 2/9] TWL4030: clear TWL GPIO interrupt status registers Paul Walmsley
2008-07-18  1:34 ` [PATCH 3/9] TWL4030: use correct register addresses for BCI IMR registers Paul Walmsley
2008-07-18  1:34 ` [PATCH 4/9] TWL4030: clear MADC interrupt status registers upon init Paul Walmsley
2008-07-18  1:34 ` [PATCH 5/9] TWL4030: read and write module ISRs to clear them at init Paul Walmsley
2008-07-18  9:12   ` Peter 'p2' De Schrijver [this message]
2008-07-22  0:30     ` Paul Walmsley
2008-07-18  1:34 ` [PATCH 6/9] TWL4030: change init-time IMR mask code to WARN if error Paul Walmsley
2008-07-18  1:34 ` [PATCH 7/9] TWL4030: move TWL module register defs into separate include files Paul Walmsley
2008-07-18  1:34 ` [PATCH 8/9] TWL4030: use symbolic ISR/IMR register names during twl_init_irq() Paul Walmsley
2008-07-18  1:34 ` [PATCH 9/9] TWL4030: convert early interrupt mask/clear funcs to use array Paul Walmsley

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