On 07/06/2010 03:53 PM, ext Ohad Ben-Cohen wrote:
Hi Roger,
On Tue, Jul 6, 2010 at 1:35 PM, Roger Quadros<roger.quadros@xxxxxxxxx> wrote:
My point is that shouldn't this be handled by SDIO core?
Care to explain what you mean / give a code example ?
If the Power enable GPIO can be treated as SDIO slot supply (i.e. vmmc), then
the SDIO/MMC core should tackle it, just like it deals with supply for slots
with removable cards.
see mmc_regulator_set_ocr()
mmc_power_up()
mmc_set_ios()
in drivers/mmc/core/core.c
and omap_hsmmc_set_ios()
in drivers/mmc/host/omap_hsmmc.c
If there are no users for the SDIO function and the card, doesn't the SDIO
core power down the slot and take care of re-initialization when it is
powered up?
You need card detect events in order to trigger card& sdio function
initialization and removals.
Please share any alternative approach you may be thinking on.
OK, this is how I see it.
- Treat the non-removable card as non-removable. So no need to do card detect
emulation.
- Treat the GPIO power enable on wl1271 as VMMC supply. Use fixed regulator
framework to define this regulator & supply. Even though you mention that it is
not actually a supply, it fits well in the fixed supply framework.
- When the host controller is enumerated, the mmc core will power up the slot,
find the sdio card, and probe the function driver (i.e. wl1271_sdio).
- if interface is not in use, the function driver must release the sdio host,
and this should eventually disable the vmmc supply.
- Whenever the wlan interface must be brought up, wl1271_sdio, can claim the
sdio host. this will cause the vmmc supply to be enabled, for as long as the
interface is up.
Does this address all issues?
regards,
-roger
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