> [Álvaro Lopes So 23. August 2009]: > > Christoph Mair wrote: > > > Hello, > > > > > > I have some questions regarding the GSENSOR_3V3 line: > > > Under normal conditions I measured 2.8V. > > We need to check what's the correct setting for LDO1 voltage, in PMU. > 2.8 sounds fishy. FIxed with kernel patch. Now i get ~3.4V which seems to be ok.
> > > In suspend, the voltage drops to > > > 2.4V. I thought the the line would carry 3.3V when powered on and ~0V in > > > suspend. Why isn't that the case? > > ACK. > For suspend I suspect a reverse feed thru SPI_MOSI1 and/or SPI_CLK1 lines > which might be at high (1) level even though LDO1 is powered down. If that's > the case then it needs a fix urgently. Some of he kernel guys need to check > that. > Another more unlikely scenario is suspend reprograms LDO1 out voltage to 2V4. > Even more unlikely seems you overload the powerrail (>50mA) during suspend > only. <snip> > > Suspend is also defined by software. Typically this would be set to GPIO1 > input, which is controlled by CPU (PWREN signal). Maybe someone can confirm > this. > > I'm not completely convinced about that. Alas we have no generic application > notes for GTA02-hw, so you can only guess what's the supposed way to manage > things. My guess however would be to switch LDO1 down directly via > PMU-register by writing over I2C. The purpose of PWNEN is a little bit > cloudy to me. There is some communication on the I2C bus approx. 13ms before the voltage drop. The last message starts with: 11100110<ACK>00000111<ACK>10110011<ACK>11111101<ACK> .. 0x6E, 0x07, 0xB3, 0xFD .. And is therefore addressed to the PMU. I can try to decode the rest, if it may be useful. (The actual decoding was done in my head, so there may be some bit errors ;) ) > > This line powers two LIS302DL accelerometers, which draw 0.4mA max each. > This gives less than 1mA. This gives enough room for power output, so either > your > > problem lies in VB_SYS (not enough current to feed the LDOs), > > unlikely, FR wouldn't work at all of that was the case I guess. > > > a shortened caps (C1718), broken LIS203DL... > > hmm, doesn't make a good story with the whole bunch of observed strange > behaviour > > > > What voltage do you see in VB_SYS, on those scenarios ? Can you also check > voltahe PMU GPIO1 pin (TP1740) when phone is in suspend mode ? I will check the voltage at TP1704 now. Christoph _______________________________________________ hardware mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/hardware
