count is only ever used by assigning to old_len if count == 0, and
then old_len isn't ever used at all.  So, both are redundant.  Fixes:

drivers/mmc/host/dw_mmc.c: In function ‘dw_mci_read_data_pio’:
drivers/mmc/host/dw_mmc.c:1034:32: warning: variable ‘old_len’ set but
not used [-Wunused-but-set-variable]
Signed-off-by: NChris Ball <cjb@laptop.org>
Acked-by: NWill Newton <will.newton@imgtec.com>

This patch adds DDR mode support to dw_mmc.

If we set any bit in UHS_REG bit[16:31], the card of that slot is
supported for DDR mode.  For example, if UHS_REG[16] is set, card
number 0 is DDR mode.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Acked-by: NWill Newton <will.newton@imgtec.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

This patch adds support for 8-bit buswidth.
dw_mmc can use 8-bit buswidth and set to CTYPE_8BIT in card-type register.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Acked-by: NWill Newton <will.newton@imgtec.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

Setting this bit in the clock enable register will stop the clock
when the card is in the IDLE state.
Signed-off-by: NWill Newton <will.newton@imgtec.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

We need to run the card detect tasklet at the end of slot initialisation
as it is possible that a card has been inserted prior to boot, so we don't
see an insertion interrupt and now the card is sitting there inserted but
with no power to it.
Signed-off-by: NNeil Jones <neil.jones@imgtec.com>
Signed-off-by: NWill Newton <will.newton@imgtec.com>
Reviewed-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NChris Ball <cjb@laptop.org>

This adds the mmc host driver for the Synopsys DesignWare mmc
host controller, found in a number of embedded SoC designs.
Signed-off-by: NWill Newton <will.newton@imgtec.com>
Reviewed-by: NMatt Fleming <matt@console-pimps.org>
Reviewed-by: NChris Ball <cjb@laptop.org>
Signed-off-by: NChris Ball <cjb@laptop.org>