mmc: support hs400 enhanced strobe mode
authorPeng Fan <peng.fan@nxp.com>
Wed, 10 Jul 2019 06:43:07 +0000 (14:43 +0800)
committerPeng Fan <peng.fan@nxp.com>
Mon, 15 Jul 2019 02:30:08 +0000 (10:30 +0800)
commit44acd492480f8c8047326f3cb02d3e4d3760ecd0
tree903240d5b3fac9eacf60a5899ff655b67967f6c8
parent8277171663084e20c0eca7c0b9681019f1a2a353
mmc: support hs400 enhanced strobe mode

eMMC 5.1+ supports HS400 Enhances Strobe mode without the need for
tuning procedure.
The flow is as following:
 - set HS_TIMIMG (Highspeed)
 - Host change freq to <= 52Mhz
 - set the bus width to Enhanced strobe and DDR8Bit(CMD6),
   EXT_CSD[183] = 0x86 instead of 0x80
 - set HS_TIMING to 0x3 (HS400)
 - Host change freq to <= 200Mhz
 - Host select HS400 enhanced strobe complete

Signed-off-by: Peng Fan <peng.fan@nxp.com>
drivers/mmc/Kconfig
drivers/mmc/mmc-uclass.c
drivers/mmc/mmc.c
include/mmc.h