Bugfixes... the host capabilties from FDT data are stored in host.caps, not
host.host_ocr, examine the correct field when setting up the hardware. Also,
the offset for the capabilties register should be 0x140, not 0x240.
TI sdhci driver improvements, mostly related to fdt data...
Use the published compatible strings (our own invention, "ti,mmchs" is
still accepted as well, for now).
Don't blindly turn on 8-bit bus mode, because even though the controller
supports it, the board has to be wired appropriately as well. Use the
published property (bus-width=<n>) and honor all the valid values (1,4,8).
The eMMC device on a Beaglebone Black is wired for 8-bit, update the dts.
The mmchs controller can inherently do both 1.8v and 3.0v on the first
device and 1.8v only on other devices, unless an external transceiver is
used. Set the voltage automatically for the first device and honor
the published fdt property (ti,dualvolt) for other devices.
The MMCHS hardware is pretty much a standard SDHCI v2.0 controller with a
couple quirks, which are now supported by sdhci(4) as of r254507.
This should work for all TI SoCs that use the MMCHS hardware, but it has
only been tested on AM335x right now, so this enables it on those platforms
but leaves the existing ti_mmchs driver in place for other OMAP variants
until they can be tested.
This initial incarnation lacks DMA support (coming soon). Even without it
this improves performance pretty noticibly over the ti_mmchs driver,
primarily because it now does multiblock IO.
