On 08/19/2015 11:41 AM, Stephen Warren wrote:
On 08/19/2015 07:56 AM, Thierry Reding wrote:
On Wed, Jul 29, 2015 at 02:16:33PM -0600, Stephen Warren wrote:
From: Stephen Warren <swar...@nvidia.com>

Signed-off-by: Stephen Warren <swar...@nvidia.com>
---
v2: Use named constants for PMIC I2C and register addresses.
---
  arch/arm/dts/Makefile                              |   1 +
  arch/arm/dts/tegra210-p2371-0000.dts               |  59 +++++
  arch/arm/mach-tegra/tegra210/Kconfig               |   6 +
  board/nvidia/p2371-0000/Kconfig                    |  12 +
  board/nvidia/p2371-0000/MAINTAINERS                |   6 +
  board/nvidia/p2371-0000/Makefile                   |   8 +
  board/nvidia/p2371-0000/p2371-0000.c               |  51 ++++
  board/nvidia/p2371-0000/pinmux-config-p2371-0000.h | 260
+++++++++++++++++++++
  configs/p2371-0000_defconfig                       |  16 ++
...

Sorry for being late on this. I just rebased my tree on origin/master
and got rid of my preliminary P2371 patches in favour of this only to
notice that it doesn't work the way it used to.
...
diff --git a/include/configs/p2371-0000.h b/include/configs/p2371-0000.h
[...]
+#define COUNTER_FREQUENCY    38400000

As far as I know the system counter is actually clocked by clk_m, which
on most (all?) Tegra210 platforms will be configured to run at half the
oscillator frequency (19.2 MHz). This is corroborated by the fact that
running:

    # sleep 5

actually takes 10 seconds rather than the expected 5. Changing the above
to 19200000 fixes that.

That's odd. I just tested this on p2371-2180 which should have the same
basic clock/crystal setup, and "sleep 10" takes 10 seconds. What SW are
you using as the primary bootloader? I'm using nvtboot from our internal
L4T main branch. Once that's released, I would expect people to use that
same thing (and NVIDIAns can use it already:-)

So, COUNTER_FREQUENCY is only used if U-Boot is started in EL3, to program the cntfrq_el0 register. Since I'm booting a secure monitor first, U-Boot is starting in EL2 for me, and COUNTER_FREQUENCY isn't actually used. I've confirmed in the TRM that clk_m does run at half the crystal rate, and that the secure monitor is indeed setting cntfrq_el0 is 19.2MHz rather than 38.4MHz. I'll send a patch to correct this.
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