[PATCH 5.9 243/252] mmc: sdhci-of-arasan: Issue DLL reset explicitly

[Greg Kroah-Hartman]

From: Manish Narani <manish.narani@xxxxxxxxxx>

commit d06d60d52ec0b0eef702dd3e7b4699f0b589ad0f upstream.

In the current implementation DLL reset will be issued for
each ITAP and OTAP setting inside ATF, this is creating issues
in some scenarios and this sequence is not inline with the TRM.
To fix the issue, DLL reset should be removed from the ATF and
host driver will request it explicitly.
This patch update host driver to explicitly request for DLL reset
before ITAP (assert DLL) and after OTAP (release DLL) settings.

Fixes: a5c8b2ae2e51 ("mmc: sdhci-of-arasan: Add support for ZynqMP Platform Tap Delays Setup")
Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xxxxxxxxxx>
Signed-off-by: Manish Narani <manish.narani@xxxxxxxxxx>
Acked-by: Michal Simek <michal.simek@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/1605515565-117562-4-git-send-email-manish.narani@xxxxxxxxxx
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/mmc/host/sdhci-of-arasan.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -635,6 +635,9 @@ static int sdhci_zynqmp_sdcardclk_set_ph
 	if (ret)
 		pr_err("Error setting Output Tap Delay\n");
 
+	/* Release DLL Reset */
+	zynqmp_pm_sd_dll_reset(node_id, PM_DLL_RESET_RELEASE);
+
 	return ret;
 }
 
@@ -669,6 +672,9 @@ static int sdhci_zynqmp_sampleclk_set_ph
 	if (host->version < SDHCI_SPEC_300)
 		return 0;
 
+	/* Assert DLL Reset */
+	zynqmp_pm_sd_dll_reset(node_id, PM_DLL_RESET_ASSERT);
+
 	switch (host->timing) {
 	case MMC_TIMING_MMC_HS:
 	case MMC_TIMING_SD_HS: