I am wondering if anyone in the Linux community has an power
consumption numbers for the board (xM revB) in off with full
retention. I was able to get it down to ~40ma (@5v) with all LEDs, HUB
etc off. Just wondering if this seems reasionable. I was doing this
under Windows CE and would like a compairson.
One other note, it sure would have been nice if the USBHOST_PWR_EN
signal was connected to TPS65950 pad that can be multiplexed as a GPIO
(like G11). While it can be controlled as an LED it sure is painfull
from a software point of view and makes things needlessly complicated.
I am not following you. USBHOST_PWR_EN turns of the power to the entire USB HUB. It is not an LED control only function. What else would you like it to do in addition to turning off all the power tho the USB HUB?
USBHOST_PWR_EN signal goes to LEDA/VIBRA.P on the TPS65950. To turn
the power off to the HUB you basically have to program the LEDA
registers as a PWM with 100% duty cycle to drive the line low. If it
were on a PAD that can be multiplexed as a GPIO the calls throught the
GPIO API would have been much eaiser.
Go it. We use the VIBRA pin because it can handle the high voltage and saves us an additional part on the board. I will consider it on the next spin, if there is one. We just finished up what is expected to be the last spin a couple of weeks ago.
What high voltage? As far as I can see it only goes to the shutdown of
the hub voltage LDO.
A pullup to VBAT is being controlled. VBAT is 4.2V. The GPIOs on the TPS65950 is rated at 1.8V.