[alsa-devel] A few general questions (my first driver): Marian MARC4
I have a Marian Marc4 card. I have the documentation for this card, which has been on their web site for quite some time. I want to write a driver for this card. This is my first ALSA driver, but it isn't my first kernel driver.
Anyway, I can't google any mention of this family of cards on this mailing list, which seems a bit odd. I did find some mentions on linux-audio-developer, about the documentation, but no mention there of prior work on this family.
However, I did find a MARC8 driver on sourceforge (http:// sourceforge.net/projects/marc8-driver). Does anyone know anything about this? I'm vary curious about why I've never seen it mentioned here before. The license is listed as GPL. The Marian Marc8 was formerly known as the Sek'd Siena, but again I can't find any real mention of that in the archives. Does anyone have any idea why the MARC8 wasn't mentioned and merged into the main ALSA sources?
I did go ahead and add some Marian product information to the support matrix on the alsa wiki, including a link to the sourceforge page.
My plan is to add MARC4 to the MARC8 driver. The register layout is basically the same, adjusted for the 4 versus 8 channels. Both cards use the same PLX chip. The biggest difference is in the layout of the play/capture RAM area, which is because of the 4 versus 8 channels. It seems silly to make two separate drivers. I would like to see my results eventually merged into the main ALSA. I'm hoping that if I get these into the main tree that I would then be able to get some support from Marian in the form of clearance (and a card) to do the Trace D4 and D4 SRC, and possibly even documentation and hardware for the UCON CX.
Anyway, moving on to my specific questions.
First, is it appropriate to put support for two device IDs in the same file? The examples I tried looking at ended up being a single device id, differentiated by a subvendor ID.
Second, is it wrong to use the same structures, but with an enum field in the main snd_marc device structure that points out which card I'm talking about, then else where switching on that enum to figure out how many channels I need to operate on?
Third, once I get this functional on my MARC4 card, how hard is it likely to be to get it accepted? I don't expect low standards for code that is accepted, but I'd like to have some idea how picky the process may be.
At Fri, 20 Jun 2008 02:07:49 -0400, Joshua Boyd wrote:
I have a Marian Marc4 card. I have the documentation for this card, which has been on their web site for quite some time. I want to write a driver for this card. This is my first ALSA driver, but it isn't my first kernel driver.
Anyway, I can't google any mention of this family of cards on this mailing list, which seems a bit odd. I did find some mentions on linux-audio-developer, about the documentation, but no mention there of prior work on this family.
However, I did find a MARC8 driver on sourceforge (http:// sourceforge.net/projects/marc8-driver). Does anyone know anything about this? I'm vary curious about why I've never seen it mentioned here before. The license is listed as GPL. The Marian Marc8 was formerly known as the Sek'd Siena, but again I can't find any real mention of that in the archives. Does anyone have any idea why the MARC8 wasn't mentioned and merged into the main ALSA sources?
AFAIK, no one suggested or posted the patches to ALSA developers. So it's a totally unknown project.
I did go ahead and add some Marian product information to the support matrix on the alsa wiki, including a link to the sourceforge page.
My plan is to add MARC4 to the MARC8 driver. The register layout is basically the same, adjusted for the 4 versus 8 channels. Both cards use the same PLX chip. The biggest difference is in the layout of the play/capture RAM area, which is because of the 4 versus 8 channels. It seems silly to make two separate drivers. I would like to see my results eventually merged into the main ALSA. I'm hoping that if I get these into the main tree that I would then be able to get some support from Marian in the form of clearance (and a card) to do the Trace D4 and D4 SRC, and possibly even documentation and hardware for the UCON CX.
Anyway, moving on to my specific questions.
First, is it appropriate to put support for two device IDs in the same file? The examples I tried looking at ended up being a single device id, differentiated by a subvendor ID.
It's no problem.
Second, is it wrong to use the same structures, but with an enum field in the main snd_marc device structure that points out which card I'm talking about, then else where switching on that enum to figure out how many channels I need to operate on?
Nothing wrong. Passing driver_data in pci_device_id table is a common technique.
Third, once I get this functional on my MARC4 card, how hard is it likely to be to get it accepted? I don't expect low standards for code that is accepted, but I'd like to have some idea how picky the process may be.
This really depends on the code quality. Of course, the most important criteria is that the driver works without problems, though :)
Anyway, a good hint can be found in Documentation/CodingStyle in linux kernel tree. At least, check $LINUX/scripts/checkpatch.pl before submitting your patch.
thanks,
Takashi
participants (2)
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Joshua Boyd -
Takashi Iwai