On 08/20/2012 06:26 PM, Kevin Wells wrote:
quoted
quoted
quoted
This patch for i2c-pnx affects PNX4008 and LPC32xx (and LPC31xx,
not yet in mainline). Can you please test and double-check the
manuals of PNX4008 and LPC31xx? I only found this via the manual
of LPC32xx but assume it's the same for the others, also.
Thanks in advance!
Kevin, since the other manuals seem to be not easily available, can
you please check?
Yes, would be great if someone at NXP could confirm that PNX actually
uses the same IP core for the I2C controller as LPCs do (which is
currently assumed by Linux anyway).
I've never had my hands on a PNX4008 chip at NXP, but I do believe they
are the same IP. That specific I2C IP was used in a number of NXP/Phillips
chips besides the PNX4008/LPC32xx. I don't think there are any PNX4008's in
the wild, and even working in NXP, I can't find any non-marketing reference
material for that part (including the user manual).
Considering this, it might be a good idea to remove support for PNX4008
(arch/arm/mach-pnx4008/) altogether. It's hard to maintain support for
hardware which isn't available, even at NXP. It would also simplify
maintenance of mach-lpc32xx because the overlap currently makes me
always wonder if the respective changes still work with mach-pnx4008.
Any opposition?
Roland
PS: I just wonder how mach-pnx4008 came into the kernel at all...
On Monday 20 August 2012, Roland Stigge wrote:
On 08/20/2012 06:26 PM, Kevin Wells wrote:
quoted
I've never had my hands on a PNX4008 chip at NXP, but I do believe they
are the same IP. That specific I2C IP was used in a number of NXP/Phillips
chips besides the PNX4008/LPC32xx. I don't think there are any PNX4008's in
the wild, and even working in NXP, I can't find any non-marketing reference
material for that part (including the user manual).
Considering this, it might be a good idea to remove support for PNX4008
(arch/arm/mach-pnx4008/) altogether. It's hard to maintain support for
hardware which isn't available, even at NXP. It would also simplify
maintenance of mach-lpc32xx because the overlap currently makes me
always wonder if the respective changes still work with mach-pnx4008.
Any opposition?
PS: I just wonder how mach-pnx4008 came into the kernel at all...
According to the git logs, Vitaly Wool originally added support for the
platform in 2006 when working at MontaVista, and that year was also the
last time he or anyone else from that company contributed anything in
that directory. Russell was the only other person to make substantial
contributions to it, but they all seem to be cross-platform changes.
In the platform code, there is only a single board number reserved,
with the name of the SoC: MACHINE_START(PNX4008, "Philips PNX4008").
This indicates that whoever was actually using the code did not have
their board code upstream and relied on out-of-tree patches for the
platform.
From all I can tell, the PNX4008 family probably went to ST-Ericsson,
not to NXP in the various acquisitions and mergers that happened
around NXP. This explains why Kevin has no documentation or hardware
for it. On the ST-Ericsson web site, I could find some information
about the PNX4908, presumably a follow-on chip, but not about PNX4008,
so I guess the company also considers the product line dead.
Finally, the chips seems to be targetted at mobile phones and was
introduced seven years ago, which is multiple generations of
products in that market, so probably people stopped caring about
them long ago, unlike embedded chips from the same era for other
markets.
I'd say let's wait for Vitaly to reply on this matter, if he doesn't
care about the code, we can kill it off in 3.7 or 3.8.
Arnd