BBB/I2C: Read PMIC data

[Winston Smith]

On Fri, May 2, 2014 at 1:59 AM, Sulev-Madis Silber (ketas)
<madis555 at hot.ee> wrote:
> Could you look into reading data from PMIC? I tried... there is all the
> code that shows power status on boot... there are PMIC I2C specs...
> there is your code... however I clearly can't write C enough to get that
> one byte out of PMIC and displayed in human-readable form.

Hmmm ... I'm reading reg 0x0 (CHIPID) and 0xA (STATUS) from the PMIC @
address 0x24 on I2C0, but I get strange values:

root at beaglebone:~ # ./bbb_pmic
TPS65217 PMIC @ address 24:
ChipID: 3D (Unknown) rev 1.13
Status: 00


0x3D isn't a valid CHIPID according to the TPS65217 datasheet; and
0x00 doesn't look like a valid value for the status register (there
should be some 1's in there to indicate the ACPWR or USBPWR).

I wonder if the device has been "claimed" by the kernel and is inaccessible?