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>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index b74c8530e95..a88a799ed7c 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -117,6 +117,7 @@ struct sdhci_host {
 
 	unsigned int max_clk;	/* Max possible freq (MHz) */
 	unsigned int timeout_clk;	/* Timeout freq (KHz) */
+	unsigned int clk_mul;	/* Clock Muliplier value */
 
 	unsigned int clock;	/* Current clock (MHz) */
 	u8 pwr;			/* Current voltage */