[RFC PATCH 03/13] drivers: mmc: host: sdhci_am654: Add missing OTAP/ITAP enable

[Judith Mendez]

Currently the OTAP/ITAP delay enable functionality is missing in
the am654_set_clock function which is used for MMC0 on AM62p
and AM64x devices. The OTAP delay is not enabled when timing <
SDR25 bus speed mode. The ITAP delay is not enabled for all bus
speed modes.

Add this OTAP/ITAP delay functionality according to the datasheet
[1] OTAPDLYENA and ITAPDLYENA for MMC0.

[1] https://www.ti.com/lit/ds/symlink/am62p.pdf

Signed-off-by: Judith Mendez <jm@xxxxxx>
---
 drivers/mmc/host/sdhci_am654.c | 48 +++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 21 deletions(-)

diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
index 0a1ed2ae2eef..35e02f4128a7 100644
--- a/drivers/mmc/host/sdhci_am654.c
+++ b/drivers/mmc/host/sdhci_am654.c
@@ -143,6 +143,7 @@ struct sdhci_am654_data {
 	struct regmap *base;
 	int otap_del_sel[ARRAY_SIZE(td)];
 	int itap_del_sel[ARRAY_SIZE(td)];
+	u8 itap_del_ena[ARRAY_SIZE(td)];
 	int clkbuf_sel;
 	int trm_icp;
 	int drv_strength;
@@ -171,11 +172,13 @@ struct sdhci_am654_driver_data {
 };
 
 static void sdhci_am654_write_itapdly(struct sdhci_am654_data *sdhci_am654,
-				      u32 itapdly)
+				      u32 itapdly, u32 enable)
 {
 	/* Set ITAPCHGWIN before writing to ITAPDLY */
 	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK,
 			   0x1 << ITAPCHGWIN_SHIFT);
+	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYENA_MASK,
+			   enable << ITAPDLYENA_SHIFT);
 	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYSEL_MASK,
 			   itapdly << ITAPDLYSEL_SHIFT);
 	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPCHGWIN_MASK, 0);
@@ -249,7 +252,8 @@ static void sdhci_am654_setup_dll(struct sdhci_host *host, unsigned int clock,
 		return;
 	}
 
-	sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing]);
+	sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing],
+				  sdhci_am654->itap_del_ena[timing]);
 }
 
 static void sdhci_am654_setup_delay_chain(struct sdhci_am654_data *sdhci_am654,
@@ -263,8 +267,8 @@ static void sdhci_am654_setup_delay_chain(struct sdhci_am654_data *sdhci_am654,
 	mask = SELDLYTXCLK_MASK | SELDLYRXCLK_MASK;
 	regmap_update_bits(sdhci_am654->base, PHY_CTRL5, mask, val);
 
-	sdhci_am654_write_itapdly(sdhci_am654,
-				  sdhci_am654->itap_del_sel[timing]);
+	sdhci_am654_write_itapdly(sdhci_am654, sdhci_am654->itap_del_sel[timing],
+				  sdhci_am654->itap_del_ena[timing]);
 }
 
 static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
@@ -273,20 +277,17 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
 	struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
 	unsigned char timing = host->mmc->ios.timing;
 	u32 otap_del_sel;
-	u32 otap_del_ena;
 	u32 mask, val;
 
 	regmap_update_bits(sdhci_am654->base, PHY_CTRL1, ENDLL_MASK, 0);
 
 	sdhci_set_clock(host, clock);
 
-	/* Setup DLL Output TAP delay */
+	/* Setup Output TAP delay */
 	otap_del_sel = sdhci_am654->otap_del_sel[timing];
-	otap_del_ena = (timing > MMC_TIMING_UHS_SDR25) ? 1 : 0;
 
 	mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
-	val = (otap_del_ena << OTAPDLYENA_SHIFT) |
-	      (otap_del_sel << OTAPDLYSEL_SHIFT);
+	val = (0x1 << OTAPDLYENA_SHIFT) | (otap_del_sel << OTAPDLYSEL_SHIFT);
 
 	/* Write to STRBSEL for HS400 speed mode */
 	if (timing == MMC_TIMING_MMC_HS400) {
@@ -319,14 +320,20 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
 	struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
 	unsigned char timing = host->mmc->ios.timing;
 	u32 otap_del_sel;
+	u32 itap_del_ena;
 	u32 mask, val;
 
-	/* Setup DLL Output TAP delay */
+	/* Setup Output TAP delay */
 	otap_del_sel = sdhci_am654->otap_del_sel[timing];
 
 	mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
-	val = (0x1 << OTAPDLYENA_SHIFT) |
-	      (otap_del_sel << OTAPDLYSEL_SHIFT);
+	val = (0x1 << OTAPDLYENA_SHIFT) | (otap_del_sel << OTAPDLYSEL_SHIFT);
+
+	itap_del_ena = sdhci_am654->itap_del_ena[timing];
+
+	mask |= ITAPDLYENA_MASK;
+	val |= (itap_del_ena << ITAPDLYENA_SHIFT);
+
 	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val);
 
 	regmap_update_bits(sdhci_am654->base, PHY_CTRL5, CLKBUFSEL_MASK,
@@ -503,12 +510,8 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
 	for (i = 0; i < ITAPDLY_LENGTH; i++)
 		memset(&fail_window[i], 0, sizeof(fail_window[0]));
 
-	/* Enable ITAPDLY */
-	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYENA_MASK,
-			   1 << ITAPDLYENA_SHIFT);
-
 	for (itap = 0; itap < ITAPDLY_LENGTH; itap++) {
-		sdhci_am654_write_itapdly(sdhci_am654, itap);
+		sdhci_am654_write_itapdly(sdhci_am654, itap, 1);
 
 		curr_pass = !mmc_send_tuning(host->mmc, opcode, NULL);
 
@@ -532,7 +535,7 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
 	itap = calculate_itap(host, &fail_window[0], fail_index,
 			      (sdhci_am654->dll_enable ? true : false));
 
-	sdhci_am654_write_itapdly(sdhci_am654, itap);
+	sdhci_am654_write_itapdly(sdhci_am654, itap, 1);
 
 	return 0;
 }
@@ -681,9 +684,12 @@ static int sdhci_am654_get_otap_delay(struct sdhci_host *host,
 				host->mmc->caps2 &= ~td[i].capability;
 		}
 
-		if (td[i].itap_binding)
-			device_property_read_u32(dev, td[i].itap_binding,
-						 &sdhci_am654->itap_del_sel[i]);
+		if (td[i].itap_binding) {
+			ret = device_property_read_u32(dev, td[i].itap_binding,
+						       &sdhci_am654->itap_del_sel[i]);
+				if (!ret)
+					sdhci_am654->itap_del_ena[i] = 0x1;
+		}
 	}
 
 	return 0;
-- 
2.34.1