Intro and some questions

Intro and some questions

[NeonJohn]

Greetings,

I just discovered this list while beating my head against the wall
(kernel noobs do that a lot, I hear).  I thought I'd introduce myself.

I'm mainly an EE but with fairly extensive Unix and Linux user space
coding and with embedded system programming.  I'm a newborn infant when
it comes to the kernel.

I'm working with the BeagleBone and Robert Nelson's Angstrom derivative

https://github.com/RobertCNelson/stable-kernel

I intend to embed the BB in our new product if I can solve a small
problem.  The BB has 2 SPI ports, 1 with 1 chip select and the other
with 2.  Only one port is supported in the standard kernel.  I found
some info that guided me into activating the new port and having all
three devices enumerated in /dev.

What I have not yet been able to do is figure out how to enable that
second chip select line.  So my first question is, where do I start
looking for the existing code?  I'm hoping that I'll be lucky enough to
reuse that code, changing a bit or two in the CPU register.

Thanks,
John

-- 
John DeArmond
Tellico Plains, Occupied TN
http://www.fluxeon.com      <-- THE source for induction heaters
http://www.neon-john.com    <-- email from here
http://www.johndearmond.com <-- Best damned Blog on the net
PGP key: wwwkeys.pgp.net: BCB68D77

Intro and some questions

[anish singh]

On Wed, Feb 20, 2013 at 1:01 PM, NeonJohn <jgd@neon-john.com> wrote:
> Greetings,
>
> I just discovered this list while beating my head against the wall
> (kernel noobs do that a lot, I hear).  I thought I'd introduce myself.
>
> I'm mainly an EE but with fairly extensive Unix and Linux user space
> coding and with embedded system programming.  I'm a newborn infant when
> it comes to the kernel.
>
> I'm working with the BeagleBone and Robert Nelson's Angstrom derivative
>
> https://github.com/RobertCNelson/stable-kernel
>
> I intend to embed the BB in our new product if I can solve a small
> problem.  The BB has 2 SPI ports, 1 with 1 chip select and the other
> with 2.  Only one port is supported in the standard kernel.  I found
> some info that guided me into activating the new port and having all
> three devices enumerated in /dev.
Which three devices?
>
> What I have not yet been able to do is figure out how to enable that
> second chip select line.  So my first question is, where do I start
What does this second chip select line does?
> looking for the existing code?  I'm hoping that I'll be lucky enough to
> reuse that code, changing a bit or two in the CPU register.
Can you show us the schematic?
>
> Thanks,
> John
>
> --
> John DeArmond
> Tellico Plains, Occupied TN
> http://www.fluxeon.com      <-- THE source for induction heaters
> http://www.neon-john.com    <-- email from here
> http://www.johndearmond.com <-- Best damned Blog on the net
> PGP key: wwwkeys.pgp.net: BCB68D77
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Intro and some questions

[NeonJohn]

On 02/20/2013 09:51 PM, anish singh wrote:

>> I intend to embed the BB in our new product if I can solve a small
>> problem.  The BB has 2 SPI ports, 1 with 1 chip select and the other
>> with 2.  Only one port is supported in the standard kernel.  I found
>> some info that guided me into activating the new port and having all
>> three devices enumerated in /dev.

> Which three devices?

Not that it matters but a 1 MS/S A/D converter, a DDS synthesizer and a
bit of an FPGA that fans out one word of data to 16 control lines.

>>
>> What I have not yet been able to do is figure out how to enable that
>> second chip select line.  So my first question is, where do I start

> What does this second chip select line does?

Pick one of the three functions above.

>> looking for the existing code?  I'm hoping that I'll be lucky enough to
>> reuse that code, changing a bit or two in the CPU register.

> Can you show us the schematic?

No, it's still just a pencil sketch.  But I don't need a completed
schematic to know that I need 3 SPI channels and the Bone only has one
enabled by default.  I've enabled the other port.  Now I need to figure
out how to enable that port's second chip select line.  That was my
question.  Any suggestions?

John


-- 
John DeArmond
Tellico Plains, Occupied TN
http://www.fluxeon.com      <-- THE source for induction heaters
http://www.neon-john.com    <-- email from here
http://www.johndearmond.com <-- Best damned Blog on the net
PGP key: wwwkeys.pgp.net: BCB68D77

Intro and some questions

[NeonJohn]

On 02/23/2013 11:38 AM, NeonJohn wrote:

> No, it's still just a pencil sketch.  But I don't need a completed
> schematic to know that I need 3 SPI channels and the Bone only has one
> enabled by default.  I've enabled the other port.  Now I need to figure
> out how to enable that port's second chip select line.  That was my
> question.  Any suggestions?

Update:  I got 'er dun today :-)  I now have 3 nice SPI ports operating
on the BeagleBone.

John


-- 
John DeArmond
Tellico Plains, Occupied TN
http://www.fluxeon.com      <-- THE source for induction heaters
http://www.neon-john.com    <-- email from here
http://www.johndearmond.com <-- Best damned Blog on the net
PGP key: wwwkeys.pgp.net: BCB68D77