On 06/15/2012 12:09 AM, Wei Ni wrote: > On Thu, Jun 14, 2012 at 23:54:22, Stephen Warren wrote: >>>>> The core of the issue is that: >>> >>>>> * Tegra30 support is via device tree. * We have an SDIO bus, and >>>>> the WiFi device attached to that bus is enumerable. * Since the >>>>> WiFi device is enumerable, no node exists in the DT to represent >>>>> it. * However, the driver for the WiFi device needs certain >>>>> information, such as the reset GPIO ID and perhaps power GPIO. >>> >>>> PCI devices are also enumerable and yet they can be matched up with >>>> nodes in the device tree. Perhaps something similar could be added >>>> for the SDIO bus? >>> >>> This seems to make the most sense - pushing this through the >>> regulator API is just a bodge. >> >> Yes, that seems reasonable. >> >> Presumably the power GPIO should be a fixed regulator though, since it >> is a power control not just a plain old GPIO? That said, the current driver apparently deals with this as a GPIO already. >> >> The reset GPIO can separately/directly controlled by the WiFi driver though. > > I talked with Franky, this power sequence is generally for 4329, so it mean this sequence can be put into the wifi driver. > We can use the virtual platform device both for OOB and non OOB. > I will send out patches later. Can you please expand on what a "virtual platform device" is; device tree typically represents real hardware rather than anything "virtual". 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. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
