On Mon, Jun 18, 2012 at 23:01:45, Stephen Warren wrote:

On 06/18/2012 02:03 AM, Laxman Dewangan wrote:

quoted

Rakesh Kumar wrote at Monday, June 18, 2012 1:11 PM:

quoted

Stephen Warren wrote:

quoted

Now if this means adding a child node under the SDIO controller to 
represent the attached device, and storing any settings required 
by that device in that child node, that's probably a reasonable 
basic approach.

BTW, which GPIO is the power GPIO; is it WF_EN on the schematic?
That seems reasonable to represent as a GPIO rather than a 
regulator since it connects directly into the WiFi device as a 
GPIO, and its use within the WiFi device can indeed be governed 
purely internally to the WiFi driver/HW. However, if this is some 
GPIO that controls the power to e.g. VBAT3V3_IN_WF, VDDIO_WF, or 
other power supply to the WiFi card, then it'd be better 
represented as a regulator, since the control point is outside the 
WiFi device.

Tegra uses two GPIO (WF_EN and WF_RST) to power on and reset 
bcm4329 card. In case of bcm4329, these two lines are shorted. 
Tegra does not control VBAT3V3_IN_WF, VDDIO_WF, or other power 
supply to the WiFi card based on these GPIO. Uses of these GPIO are 
internal to WiFi HW.  It is reasonable to represent as a GPU rather 
than regulator.

If it is for power then it has to go via regulator. It does not make 
sense to directly control the gpio inside the wifi driver.

As far as the board goes, WF_EN is just a GPIO signal to the WiFi card; 
it doesn't gate power to the card. If it gates power inside the card, 
that's an internal implementation detail of the card, and something I'd 
be fine with the driver knowing directly, and hence I'm OK with representing
this as a GPIO rather than a regulator - that's what it is externally to the WiFi device.

Because these gpio is just for wifi device, could we use the rfkill-gpio driver for this isse? We just need to add DT support in rfkill-gpio driver and add a device node in the DT. And the user also can use the rfkill interface to control the wifi device.

(BTW everyone, many of the emails in this thread are awfully formatted 
- top-posted and not word- wrapped. It's very hard to read them... I tried to reformat everything and fix it in this email)