On 03/05/2016 06:58 PM, Jonathan Cameron wrote:
On 02/03/16 16:21, Michael Hennerich wrote:
On 02/27/2016 06:50 PM, Jonathan Cameron wrote:
On 25/02/16 13:36, michael.hennerich@xxxxxxxxxx wrote:
From: Paul Cercueil <paul.cercueil@xxxxxxxxxx>
This patch adds support for the AD5592R (spi) and AD5593R (i2c)
ADC/DAC devices.
Signed-off-by: Paul Cercueil <paul.cercueil@xxxxxxxxxx>
Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
A few bits inline.
I'll need a gpio review on this (looks fine to me but it does contain
a gpiochip driver.) Not to mention the question of whether they will
be happy with a gpio chip hiding in iio (rather than via an mfd with a
separate driver - which feels like overkill here).
The big question to my mind is whether we can take the view this won't
be the last multipurpose chip we will see so do we need to sort the
binding out to make it generic? It'll be a bit of a pain for you
but I think we can do it fairly easily.
(either way I'll also need a device tree ack on this one!)
So then we get into the question of the best way of doing the bindings.
The gpio approach seems a little limiting for things as flexible as
this but we should certainly be using their macros where relevant.
Hi Jonathan,
Thanks for the review.
The problem is see is that using GPIOF_OPEN_DRAIN, will simulate OPEN DRAIN behaviour only, by configuring the device for input when outputing logic high.
Is it actually documented as such anywhere? (that's hideous!)
In fact it is -
www.kernel.org/doc/Documentation/gpio/gpio-legacy.txt
"When setting the flag as GPIOF_OPEN_DRAIN then it will assume that pins is
open drain type. Such pins will not be driven to 1 in output mode. It is
require to connect pull-up on such pins. By enabling this flag, gpio lib
will
make the direction to input when it is asked to set value of 1 in output
mode
to make the pin HIGH. The pin is make to LOW by driving value 0 in
output mode."
And that's exactly what the gpiolib code does.
--
Greetings,
Michael
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