openwrt/target/linux/layerscape/patches-5.4/816-sdhc-0003-LF-605-mmc-sdhci-of-esdhc-update-tuning-erratum-A-00.patch

From f3d460fb85677a5f62324771e5715ceb11726ecc Mon Sep 17 00:00:00 2001
From: Yangbo Lu <yangbo.lu@nxp.com>
Date: Thu, 12 Dec 2019 15:52:19 +0800
Subject: [PATCH] LF-605 mmc: sdhci-of-esdhc: update tuning erratum A-008171

There is an official update for eSDHC tuning erratum A-008171.
This patch is to implement the changes,
- Affect all revisions of SoC.
- Changes for tuning window checking.
- Hardware hits a new condition that tuning succeeds although
  the eSDHC might not have tuned properly for type2 SoCs
  (soc_tuning_erratum_type2[] array in driver). So check
  tuning window after tuning succeeds.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
 drivers/mmc/host/sdhci-of-esdhc.c | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -854,20 +854,20 @@ static int esdhc_signal_voltage_switch(s
 }
 
 static struct soc_device_attribute soc_tuning_erratum_type1[] = {
-	{ .family = "QorIQ T1023", .revision = "1.0", },
-	{ .family = "QorIQ T1040", .revision = "1.0", },
-	{ .family = "QorIQ T2080", .revision = "1.0", },
-	{ .family = "QorIQ LS1021A", .revision = "1.0", },
+	{ .family = "QorIQ T1023", },
+	{ .family = "QorIQ T1040", },
+	{ .family = "QorIQ T2080", },
+	{ .family = "QorIQ LS1021A", },
 	{ },
 };
 
 static struct soc_device_attribute soc_tuning_erratum_type2[] = {
-	{ .family = "QorIQ LS1012A", .revision = "1.0", },
-	{ .family = "QorIQ LS1043A", .revision = "1.*", },
-	{ .family = "QorIQ LS1046A", .revision = "1.0", },
-	{ .family = "QorIQ LS1080A", .revision = "1.0", },
-	{ .family = "QorIQ LS2080A", .revision = "1.0", },
-	{ .family = "QorIQ LA1575A", .revision = "1.0", },
+	{ .family = "QorIQ LS1012A", },
+	{ .family = "QorIQ LS1043A", },
+	{ .family = "QorIQ LS1046A", },
+	{ .family = "QorIQ LS1080A", },
+	{ .family = "QorIQ LS2080A", },
+	{ .family = "QorIQ LA1575A", },
 	{ },
 };
 
@@ -935,13 +935,13 @@ static void esdhc_prepare_sw_tuning(stru
 	/* Write 32'hFFFF_FFFF to IRQSTAT register */
 	sdhci_writel(host, 0xFFFFFFFF, SDHCI_INT_STATUS);
 
-	/* If TBSTAT[15:8]-TBSTAT[7:0] > 4 * div_ratio
-	 * or TBSTAT[7:0]-TBSTAT[15:8] > 4 * div_ratio,
+	/* If TBSTAT[15:8]-TBSTAT[7:0] > (4 * div_ratio) + 2
+	 * or TBSTAT[7:0]-TBSTAT[15:8] > (4 * div_ratio) + 2,
 	 * then program TBPTR[TB_WNDW_END_PTR] = 4 * div_ratio
 	 * and program TBPTR[TB_WNDW_START_PTR] = 8 * div_ratio.
 	 */
 
-	if (abs(start_ptr - end_ptr) > (4 * esdhc->div_ratio)) {
+	if (abs(start_ptr - end_ptr) > (4 * esdhc->div_ratio + 2)) {
 		*window_start = 8 * esdhc->div_ratio;
 		*window_end = 4 * esdhc->div_ratio;
 	} else {
@@ -1014,6 +1014,19 @@ static int esdhc_execute_tuning(struct m
 		if (ret)
 			break;
 
+		/* For type2 affected platforms of the tuning erratum,
+		 * tuning may succeed although eSDHC might not have
+		 * tuned properly. Need to check tuning window.
+		 */
+		if (esdhc->quirk_tuning_erratum_type2 &&
+		    !host->tuning_err) {
+			esdhc_tuning_window_ptr(host, &window_start,
+						&window_end);
+			if (abs(window_start - window_end) >
+			    (4 * esdhc->div_ratio + 2))
+				host->tuning_err = -EAGAIN;
+		}
+
 		/* If HW tuning fails and triggers erratum,
 		 * try workaround.
 		 */