tree d8170541551dca7abcefa118c4681d7294e3456d
parent 4d55c5a13a189a80d40383f02c8026f9a87d7c87
author Arindam Nath <arindam.nath@amd.com> 1304578146 +0530
committer Chris Ball <cjb@laptop.org> 1306295628 -0400

mmc: sdhci: add support for programmable clock mode

Host Controller v3.00 supports programmable clock mode as an optional
feature. The support for this mode is indicated by non-zero value in
bits 48-55 of the Capabilities register. If supported, the actual
value of Clock Multiplier is one more than the value provided in the
bit fields. We only set Clock Generator Select (bit 5) and SDCLK
Frequency Select (bits 8-15) of the Clock Control register in case
Preset Value Enable is not set, otherwise these fields are automatically
set by the Host Controller based on the UHS mode selected. Also, since
the maximum and minimum clock frequency in this mode can be
(Base Clock * Clock Mul) and (Base Clock * Clock Mul)/1024 respectively,
f_max and f_min have been recalculated to reflect this change.

Tested by Zhangfei Gao with a Toshiba uhs card and general hs card,
on mmp2 in SDMA mode.

Signed-off-by: Arindam Nath <arindam.nath@amd.com>
Reviewed-by: Philip Rakity <prakity@marvell.com>
Tested-by: Philip Rakity <prakity@marvell.com>
Acked-by: Zhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>