MMC: added alternative MMC driver
mmc: Disable CMD23 transfers on all cards
Pending wire-level investigation of these types of transfers
and associated errors on bcm2835-mmc, disable for now. Fallback of
CMD18/CMD25 transfers will be used automatically by the MMC layer.
Reported/Tested-by: Gellert Weisz <gellert@raspberrypi.org>
mmc: bcm2835-mmc: enable DT support for all architectures
Both ARCH_BCM2835 and ARCH_BCM270x are built with OF now.
Enable Device Tree support for all architectures.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
mmc: bcm2835-mmc: fix probe error handling
Probe error handling is broken in several places.
Simplify error handling by using device managed functions.
Replace pr_{err,info} with dev_{err,info}.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
bcm2835-mmc: Add locks when accessing sdhost registers
bcm2835-mmc: Add range of debug options for slowing things down
bcm2835-mmc: Add option to disable some delays
bcm2835-mmc: Add option to disable MMC_QUIRK_BLK_NO_CMD23
bcm2835-mmc: Default to disabling MMC_QUIRK_BLK_NO_CMD23
bcm2835-mmc: Adding overclocking option
Allow a different clock speed to be substitued for a requested 50MHz.
This option is exposed using the "overclock_50" DT parameter.
Note that the mmc interface is restricted to EVEN integer divisions of
250MHz, and the highest sensible option is 63 (250/4 = 62.5), the
next being 125 (250/2) which is much too high.
Use at your own risk.
bcm2835-mmc: Round up the overclock, so 62 works for 62.5Mhz
Also only warn once for each overclock setting.
mmc: bcm2835-mmc: Make available on ARCH_BCM2835
Make the bcm2835-mmc driver available for use on ARCH_BCM2835.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
BCM270x_DT: add bcm2835-mmc entry
Add Device Tree entry for bcm2835-mmc.
In non-DT mode, don't add the device in the board file.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
bcm2835-mmc: Don't overwrite MMC capabilities from DT
bcm2835-mmc: Don't override bus width capabilities from devicetree
Take out the force setting of the MMC_CAP_4_BIT_DATA host capability
so that the result read from devicetree via mmc_of_parse() is
preserved.
bcm2835-mmc: Only claim one DMA channel
With both MMC controllers enabled there are few DMA channels left. The
bcm2835-mmc driver only uses DMA in one direction at a time, so it
doesn't need to claim two channels.
See: https://github.com/raspberrypi/linux/issues/1327
Signed-off-by: Phil Elwell <phil@raspberrypi.org>
bcm2835-mmc: New timer API
mmc: bcm2835-mmc: Support underclocking
Support underclocking of the SD bus using the max-frequency DT property
(which currently has no DT parameter). The sd_overclock parameter
already provides another way to achieve the same thing which should be
equivalent in end result, but it is a bug not to support max-frequency
as well.
See: https://github.com/raspberrypi/linux/issues/2350
Signed-off-by: Phil Elwell <phil@raspberrypi.org>