Thread (26 messages) 26 messages, 3 authors, 2012-08-21

Re: [RFC/PATCH 4/4] gpio: smscece: Add support for gpio IO expander feature

From: Felipe Balbi <hidden>
Date: 2012-08-21 12:26:22
Also in: linux-arm-kernel, linux-input, linux-omap, lkml

On Tue, Aug 21, 2012 at 05:50:28PM +0530, Poddar, Sourav wrote:
Hi,

On Tue, Aug 21, 2012 at 5:30 PM, Felipe Balbi [off-list ref] wrote:
quoted
Hi,

On Tue, Aug 21, 2012 at 05:17:37PM +0530, Poddar, Sourav wrote:
quoted
quoted
quoted
+     if (type & IRQ_TYPE_LEVEL_HIGH)
+             sg->int_lvl[bank] |= bit;
+     else if (type & IRQ_TYPE_LEVEL_LOW)
+             sg->int_lvl[bank] &= ~bit;
+     else
+             return -EINVAL;
this looks wrong. You could have a user who wants to trigger on both
HIGH and LOW levels, no ?
Yes, I think there can be a scenario where gpio_keys are attached
to this driver and signals a "key press" at low and "key release" at
high. ?
 Will figure out a way to add support to check for case where
both High and low levels are used.
could probably be done on a separate patch, maybe... Just now I saw that
HIGH and LOW levels use the same bit.
If I am understanding correctly, if they both uses the same bit we cannot
use both for a particular user. ?
we can, it's just a bit more complex. If a user request both LOW and
HIGH, then you start with HIGH, once it triggers, before calling the
nested IRQ handler, you need to change it LOW. When low triggers, before
calling the nested IRQ handler, you need to change it to HIGH again. And
so on. I'm just not sure if that's valid on linux IRQ subsystem.

Anyone ?

-- 
balbi

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