kern.features.mmcam will be present and equal to 1 if the kernel has been
compiled with option MMCCAM.
This will help sdio-related userland tools to fail-fast if running on the kernel
without MMCCAM enabled.
Approved by: imp (mentor)
Differential Revision: https://reviews.freebsd.org/D12386
* Demote the level of several debug messages to CAM_DEBUG_TRACE
* Add detection for SDHC cards that can do 1.8V. No voltage switch sequence
is issued yet;
* Don't create a separate LUN for each SDIO function. We need just one to make
pass(4) attach;
* Remove obsolete mmc_sdio* files. SDIO functionality will be moved into the
separate device that will manage a new sdio(4) bus;
* Terminate probing if got no reply to CMD0;
* Make bcm2835 SDHCI host controller driver compile with 'option MMCCAM'.
Approved by: imp (mentor)
Differential Revision: https://reviews.freebsd.org/D12109
Implement the MMC/SD/SDIO protocol within a CAM framework. CAM's
flexible queueing will make it easier to write non-storage drivers
than the legacy stack. SDIO drivers from both the kernel and as
userland daemons are possible, though much of that functionality will
come later.
Some of the CAM integration isn't complete (there are sleeps in the
device probe state machine, for example), but those minor issues can
be improved in-tree more easily than out of tree and shouldn't gate
progress on other fronts. Appologies to reviews if specific items
have been overlooked.
Submitted by: Ilya Bakulin
Reviewed by: emaste, imp, mav, adrian, ian
Differential Review: https://reviews.freebsd.org/D4761
merge with first commit, various compile hacks.
