diff options
| author | Shawn Lin <shawn.lin@rock-chips.com> | 2016-05-26 09:56:22 +0800 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2016-07-25 10:34:05 +0200 |
| commit | 81ac2af65793ecfbd79875d45043ff4adc0982b8 (patch) | |
| tree | 69b4cce8998d3921d6b04720e658a6d6593e8d4c /drivers/mmc/core/core.c | |
| parent | ef29c0e273b874018f1802d12957d22008138240 (diff) | |
| download | linux-81ac2af65793ecfbd79875d45043ff4adc0982b8.tar.bz2 | |
mmc: core: implement enhanced strobe support
Controllers use data strobe line to latch data from devices
under hs400 mode, but not for cmd line. So since emmc 5.1, JEDEC
introduces enhanced strobe mode for latching cmd response from
emmc devices to host controllers. This new feature is optional,
so it depends both on device's cap and host's cap to decide
whether to use it or not.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc/core/core.c')
| -rw-r--r-- | drivers/mmc/core/core.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 8b4dfd45433b..e8641873dee7 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1127,6 +1127,15 @@ void mmc_set_initial_state(struct mmc_host *host) host->ios.bus_width = MMC_BUS_WIDTH_1; host->ios.timing = MMC_TIMING_LEGACY; host->ios.drv_type = 0; + host->ios.enhanced_strobe = false; + + /* + * Make sure we are in non-enhanced strobe mode before we + * actually enable it in ext_csd. + */ + if ((host->caps2 & MMC_CAP2_HS400_ES) && + host->ops->hs400_enhanced_strobe) + host->ops->hs400_enhanced_strobe(host, &host->ios); mmc_set_ios(host); } |