mmc: sd: set current limit for uhs cards
authorArindam Nath <arindam.nath@amd.com>
Thu, 5 May 2011 06:49:02 +0000 (12:19 +0530)
committerChris Ball <cjb@laptop.org>
Wed, 25 May 2011 03:53:45 +0000 (23:53 -0400)
commit5371c927bcd06a5c9dd6785bab2d452b87d9abc6
tree71add97be08e93fcb5ac2bfcc44fc66d8f2b92df
parent49c468fcf878d2c86e31920cf54aa90c88418a66
mmc: sd: set current limit for uhs cards

We decide on the current limit to be set for the card based on the
Capability of Host Controller to provide current at 1.8V signalling,
and the maximum current limit of the card as indicated by CMD6
mode 0. We then set the current limit for the card using CMD6 mode 1.
As per the Physical Layer Spec v3.01, the current limit switch is
only applicable for SDR50, SDR104, and DDR50 bus speed modes. For
other UHS-I modes, we set the default current limit of 200mA.

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>
drivers/mmc/core/sd.c
drivers/mmc/host/sdhci.c
include/linux/mmc/card.h
include/linux/mmc/host.h