Hi, Franky On Thu, Jun 14, 2012 at 01:33:13, Franky Lin wrote: >Hi Wei, > >On 06/13/2012 03:40 AM, Wei Ni wrote: >> In the brcmfmac init routine, it call sdio_register_driver() to >> register driver, if the wifi device is powered on, then the mmc >> driver will enumerate it, and call the probe callback routine. >> >> On the Cardhu, the wifi's power is controlled by two gpios >> (power-gpio and reset-gpio), the default state is power-off. >> So we need to power on it before calling sdio_register_driver(), >> if not, the mmc driver can't enumerate it, and will not call >> the probe routine. >> This power on sequence is: >> set power-gpio to 1 ; >> mdelay(100) ; >> set reset-gpio to 1 ; >> mdelay(200); >> >> My question is where to power on the wifi. We may have three places >> to power on it: >> 1. power on it in the brcmfmac driver before calling >> sdio_register_driver(). But I think this power sequence is special for >> tegra30 cardhu, it's not good to add it in the generic wifi driver, >> because different board may use the different way to power on the wifi. >> 2. power on it in the mmc driver. In our tegra SD driver, it has >> power-gpios property, which allow the slot to be powered. But this power is >> for mmc slot, could we add this wifi power sequence in the tegra SD driver? >> 3. hard-coded into DT. Set these gpios in the DT, something like >> pinmux settings, but in this way, it's not good to put the mdelay() value >> in the DT. > >We introduced oob interrupt support in 3.5 [1]. We are using a virtual >platform device to retrieve board specific oob interrupt GPIO setting. >You should be able to implement the power control in this way as well. >Brcmfmac gets the GPIOs through platform device interface, powers up >the chip and triggers a card detection. Then 4329 should be enumerated >by MMC stack. The reason we didn't implement this is the card detection. >Some design doesn't have hardware card detection since the WiFi chip is >already on board. And the current MMC stack doesn't have virtual card >detection interface. Wei: Yes, in OOB mode, it's easy to add a device node in the DT, to pass the gpio property to brcmfmac driver. But the NO-OOB mode doesn’t use the virtual platform device, so we can't pass the gpio to driver. We need to find a way to support these two mode both. Could we use the virtual platform device both for OOB and NO-OOB mode? so that we can implement power control in these two mode, and we can add a flags to control if need to power on or not. BTW, does that power on sequence is generally for 4329? > >Franky > >[1]: http://www.spinics.net/lists/linux-wireless/msg89335.html -- 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
