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From: Judith Mendez <jm@ti.com>
To: Ulf Hansson <ulf.hansson@linaro.org>,
        Adrian Hunter
	<adrian.hunter@intel.com>
CC: Andrew Davis <afd@ti.com>, <linux-mmc@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH v3 3/7] mmc: sdhci_am654: Add OTAP/ITAP delay enable
Date: Thu, 7 Mar 2024 18:57:42 -0600
Message-ID: <20240308005746.1059813-4-jm@ti.com>
In-Reply-To: <20240308005746.1059813-1-jm@ti.com>
References: <20240308005746.1059813-1-jm@ti.com>
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Currently the OTAP/ITAP delay enable functionality is incorrect in
the am654_set_clock function. The OTAP delay is not enabled when
timing < SDR25 bus speed mode. The ITAP delay is not enabled for
timings that do not carry out tuning.

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

Fixes: 8ee5fc0e0b3b ("mmc: sdhci_am654: Update OTAPDLY writes")
Signed-off-by: Judith Mendez <jm@ti.com>
---
Changelog:
v2->v3:
- Save all ITAPDLYENA changes in itap_del_ena[]
---
 drivers/mmc/host/sdhci_am654.c | 40 ++++++++++++++++++++++------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
index 896d4660b535..e7ff6b841c4d 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)];
+	u32 itap_del_ena[ARRAY_SIZE(td)];
 	int clkbuf_sel;
 	int trm_icp;
 	int drv_strength;
@@ -239,11 +240,13 @@ static void sdhci_am654_setup_dll(struct sdhci_host *host, unsigned int clock)
 }
 
 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,
 			   1 << 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);
@@ -260,8 +263,8 @@ 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)
@@ -270,7 +273,6 @@ 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);
@@ -279,10 +281,9 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
 
 	/* Setup DLL 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) |
+	val = (0x1 << OTAPDLYENA_SHIFT) |
 	      (otap_del_sel << OTAPDLYSEL_SHIFT);
 
 	/* Write to STRBSEL for HS400 speed mode */
@@ -300,7 +301,8 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock)
 	if (timing > MMC_TIMING_UHS_SDR25 && clock >= CLOCK_TOO_SLOW_HZ) {
 		sdhci_am654_setup_dll(host, clock);
 		sdhci_am654->dll_enable = true;
-		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]);
 	} else {
 		sdhci_am654_setup_delay_chain(sdhci_am654, timing);
 	}
@@ -316,6 +318,7 @@ 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 */
@@ -324,6 +327,12 @@ static void sdhci_j721e_4bit_set_clock(struct sdhci_host *host,
 	mask = OTAPDLYENA_MASK | OTAPDLYSEL_MASK;
 	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,
@@ -478,6 +487,7 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 	struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host);
+	unsigned char timing = host->mmc->ios.timing;
 	struct window fail_window[ITAPDLY_LENGTH];
 	u8 curr_pass, itap;
 	u8 fail_index = 0;
@@ -486,11 +496,10 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
 	memset(fail_window, 0, sizeof(fail_window));
 
 	/* Enable ITAPDLY */
-	regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYENA_MASK,
-			   1 << ITAPDLYENA_SHIFT);
+	sdhci_am654->itap_del_ena[timing] = 0x1;
 
 	for (itap = 0; itap < ITAPDLY_LENGTH; itap++) {
-		sdhci_am654_write_itapdly(sdhci_am654, itap);
+		sdhci_am654_write_itapdly(sdhci_am654, itap, sdhci_am654->itap_del_ena[timing]);
 
 		curr_pass = !mmc_send_tuning(host->mmc, opcode, NULL);
 
@@ -514,7 +523,7 @@ static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host,
 	itap = sdhci_am654_calculate_itap(host, fail_window, fail_index,
 					  sdhci_am654->dll_enable);
 
-	sdhci_am654_write_itapdly(sdhci_am654, itap);
+	sdhci_am654_write_itapdly(sdhci_am654, itap, sdhci_am654->itap_del_ena[timing]);
 
 	return 0;
 }
@@ -663,9 +672,12 @@ 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;
-- 
2.43.2