David Wooff <http://www.calrec.com/images/siglogo.gif>
Software Development Engineer
Tel: +44 (0)1422 842159
Fax: +44 (0)1422 845244
Email: david.wo...@calrec.com
Web: www.calrec.com <http://www.calrec.com/>
CALREC AUDIO LTD Nutclough Mill Hebden Bridge W Yo
> Yes, it is safe. See kernel/workqueue.c:
> queue_work -> queue_work_on -> __queue_work -> spin_lock_irqsave
>
> Best regards,
>
> Daniel
Ah, I see now! I should examine the code a bit more readily in future.
Many thanks.
This electronic transmission is strictly confidential and intended sole
Hi David,
I have replied direct as well since the list sometimes bounces
me.
I tend to solve this problem using a kernel worker thread and
one or more message queues.
The interrupt and the user task can all send requests to the
message queue which wakes up the threa
Hello,
I have a "bottom half" processing function which I'm queueing from an
interrupt on a workqueue. Is it OK/safe to also queue the same function
on the same workqueue from the driver in response to an application
read/write? I have read LDD3 and looked for workqueues in the
documentation and
Hi,
if I have a set of (40) kfifos, can I point them all to use the same
spinlock? Having 40 separate spinlocks and only two threads accessing
the kfifos seems a little wasteful.
Thanks,
Dave W
This electronic transmission is strictly confidential and intended solely for
the addressee(s). If y
> Is this an Altera FPGA ?
Thanks Michael,
I probably should have ellaborated a little more. It is an Altera FPGA
as it happens, but it's irrelevant really because I'm running uClinux on
an ARM processor talking to the FPGA, so I could have said simply
"device". There is no NIOS or Avalon buss in
Hi,
re subject, would it be inappropriate to use read and write calls to
communicate with a 32 bit wide interface?
The fpga cannot accept byte accesses and nor do I want it to anyway.
So, should I control the file position so it can
only ever be on 32 bit boundaries and accept accesses in multiples
> >> e.g. if I use grep to find occurrences of say
> "gpio_request", I get a
> >> long list to search through, but I know many of the files are not
> >> even compiled into my build. Is there an easy way to find
> the real
> >> place where a function is coded for my particular build?
>
> I use to l
> I think LXR may be what you are looking for. If you only want
That looks helpful, thanks.
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the addressee(s). If you are not the intended addressee, you must not disclose,
copy or take any action in reliance of this e
Hi,
this may be a stupid question. As I look around the kernel and driver
source code I often find it difficult to find the "real" instance of a
function.
e.g. if I use grep to find occurrences of say "gpio_request", I get a
long list to search through, but I know many of the files are not even
co
Hi,
I noticed in the ARM specific code that there are functions like
at91_set_gpio Are these meant to be used directly or are they
referenced by the generic gpio code in some way?
Also, is there a way to write to a group of gpio pins e.g. a group of 8
configured as a byte?
Many thanks
P.S. Sor
> It sounds like ioctls are the way to talk to the FPGA, and
> your driver should take on the appearance of a platform or
> multifunction device driver (most likely the latter). I've
> written drivers like this in the past and it sounds like
> that's the way you're going to want to head if you want
> Try the char driver, it is simplest of three.
Sounds like a good plan. Thanks for your advice. I'm currently
following the ioctl route.
It's slightly complicated because my FPGA is effectively a bridge to a
number of hot-pluggable
backplane I/O cards. It seems to me that I should probably atte
> you need to create it yourself with `mknod`, or if you want
> to utilize the hotplug stack, you have to create some
> classes/devices using the kobject layer. /dev is not a
> pseudo file system (ignoring the devtmpfs in 2.6.32) which
> means *someone* has to create the device node. it's either
Hi,
would someone mind checking my module initialisation function in case I
have missed something?
It loads without error and the appropriate message is printed out on the
console, buit it does not appear in /dev.
I also do not see a modules directory in /lib (this was the subject of
another questi
Hello,
I have read that there are 3 types, char, block and network. Does it
follow that if I write a device driver for my custom FPGA that it MUST
fit in to this structure?
Assuming this to be the case, would it be best to use the char device
type and then use fseek to access a given address withi
ion "Enable loadable module support" in the Linux
Kernel Configuration that sets this symbol?
Regards,
Christian
-Ursprüngliche Nachricht-
Von: uclinux-dev-boun...@uclinux.org
[mailto:uclinux-dev-boun...@uclinux.org] Im Auftrag von David Wooff
Gesendet: Freitag, 11. Dezember 20
Thanks Christian,
I don't have a /lib/modules/ directory. I must be missing an option somewhere.
This is the output of my build:
[?]$ make ARCH=arm
CROSS_COMPILE=~/buildroot-v23434/build_arm/staging_dir/usr/bin/arm-linux-
scripts/kconfig/conf -s arch/arm/Kconfig
CHK include/linux/vers
Hi,
I have successfully built a simple driver module configured for built in
operation and it runs at startup - great so far.
I then built it for loadable operation and it builds ok. I am left with
a .ko file. When I download my new image to the target, I cannot see
the ko file in order to load
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