GPIOs

John Watlington wad at laptop.org
Fri Oct 9 11:16:07 EDT 2009


OK, taking Paul's comments into account, here is the new GPIO proposal
(dated 10/09/09, I'm still trying to see if we can make Mitch happy  
as well) :

The changes are:
- Moved the control signals for the internal and external SD ports
  and the WLAN around to match new port assignment.

- The power control for the internal SD port (MSD_PWROFF) is provided
  through a separate GPIO2 (instead of the faulty default output,  
SDIO2PWOFF).
  As there is an external pullup on this signal, there is no need to
  enable the (default off) internal pullup.    GPIO2 has been tested
  by Via to remain powered and glitch-free in states S0/S3.

- For B2 prototypes, I am proposing the use of GPIO2 as an ECO'd power
control signal for the WLAN.

- The DCONIRQ line has been moved (again).  On B2, the interrupt
  input chosen is synchronized by the RTC clock, preventing reliable
  detection of DCON interrupts (which are one video line in duration).
  This time, it is connected to GPIO12, which is only powered in S0
  but can generate SCI/SMI interrupts and is not "owned" by ACPI.

- The EC/CPU interrupt will also be routed to another pin capable
  of generating SCI/SMI interrupts that is not "owned" by ACPI at the
  request of pgf.   It is routed to SMBALRT#.

- The HDD_LED# signal is not moved.

Cheers,
wad

-------------- next part --------------
A non-text attachment was scrubbed...
Name: GPIO_XO15.pdf
Type: application/pdf
Size: 51470 bytes
Desc: not available
URL: <http://lists.laptop.org/pipermail/devel/attachments/20091009/84a96488/attachment.pdf>


More information about the Devel mailing list