Re: UIO device tree bindings.

From: Pavel Machek
Date: Tue Apr 02 2013 - 09:46:51 EST


Hi!

> > > Or maybe we can do some magic with module parameter. That should be
> > > enough for expected use.
> > >
> > I don't think that would make a difference. I mean, just take ns16550 as another
> > example. No one has problems declaring some block of hardware addresses to be
> > compatible with "ns16550", even though it can be anything including a memory
> > block on one of the FPGAs or ASICs we are talking about here, it can be anything
> > but a NS16550, and many of the actual "compatible" strings are not defined
> > anythere either.
> >
> > So there is no problem with "ata-generic" and "ns16550", and no one cares if
> > "fsl,mpc8349emitx-pata" or "xlnx,xps-uart16550-2.00.b" is defined or not, but
> > "generic-uio" together with "ptx,c64fpga001" is unacceptable.
> >
> > I think it has more to do with the uio driver not being an actual driver, but
> > the kernel part of a user-space driver, though that is just a wild guess.
>
> Well, it turned out that adding module parameter was not that much
> work... and yes I believe it is a tiny bit cleaner.
>
> Here's updated patch, if you can please test this one.
>
> [You can just pass "uio_of_genirq.of_id=generic-uio" to get previous
> behaviour. But don't tell anyone :-)]

Actually, looking at it some more, perhaps even solution is possible?
(This will need uio_pdrv_genirq.of_id=generic-uio .)

Unfortunately, I don't have easy way to test this :-(. So feedback is
essential.

Signed-off-by: Pavel Machek <pavel@xxxxxxx>

diff --git a/drivers/uio/uio_pdrv_genirq.c b/drivers/uio/uio_pdrv_genirq.c
index 4a50ead..64b6dac 100644
--- a/drivers/uio/uio_pdrv_genirq.c
+++ b/drivers/uio/uio_pdrv_genirq.c
@@ -271,9 +273,13 @@ static const struct dev_pm_ops uio_pdrv_genirq_dev_pm_ops = {

#ifdef CONFIG_OF
static const struct of_device_id uio_of_genirq_match[] = {
- { /* empty for now */ },
+ { /* This is filled with module_parm */ },
+ { /* Sentinel */ },
};
MODULE_DEVICE_TABLE(of, uio_of_genirq_match);
+
+module_param_string(of_id, uio_of_genirq_match[0].compatible, 128, 0);
+MODULE_PARM_DESC(of_id, "Openfirmware id of the device to be handled by uio");
#else
# define uio_of_genirq_match NULL
#endif

--
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