mmc: sdhci-omap: Workaround errata regarding SDR104/HS200 tuning failures (i929)

Errata i929 in certain OMAP5/DRA7XX/AM57XX silicon revisions
(SPRZ426D - November 2014 - Revised February 2018 [1]) mentions
unexpected tuning pattern errors. A small failure band may be present
in the tuning range which may be missed by the current algorithm.
Furthermore, the failure bands vary with temperature leading to
different optimum tuning values for different temperatures.

As suggested in the related Application Report (SPRACA9B - October 2017
- Revised July 2018 [2]), tuning should be done in two stages.
In stage 1, assign the optimum ratio in the maximum pass window for the
current temperature. In stage 2, if the chosen value is close to the
small failure band, move away from it in the appropriate direction.

References:
[1] http://www.ti.com/lit/pdf/sprz426
[2] http://www.ti.com/lit/pdf/SPRACA9

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index ada79f8face6..e26b8145efb3 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -977,6 +977,8 @@ config MMC_SDHCI_XENON
 config MMC_SDHCI_OMAP
 	tristate "TI SDHCI Controller Support"
 	depends on MMC_SDHCI_PLTFM && OF
+	select THERMAL
+	select TI_SOC_THERMAL
 	help
 	  This selects the Secure Digital Host Controller Interface (SDHCI)
 	  support present in TI's DRA7 SOCs. The controller supports