mmc: sdhci-of-esdhc: add erratum A008171 support

In tuning mode of operation, when TBCTL[TB_EN] is set, eSDHC may report
one of the following errors :
1)Tuning error while running tuning operation where SYSCTL2[SAMPCLKSEL]
will not get set even when SYSCTL2[EXTN] is reset. OR
2)Data transaction error (e.g. IRQSTAT[DCE], IRQSTAT[DEBE]) during data
transaction errors.
This issue occurs when the data window sampled within eSDHC is in full
cycle. So, in that case, eSDHC is not able to find out the start and
end points of the data window and sets the sampling pointer at default
location (which is middle of the internal SD clock). If this sampling
point coincides with the data eye boundary, then it can result in the
above mentioned errors. Impact: Tuning mode of operation for SDR50,
SDR104 or HS200 speed modes may not work properly
Workaround: In case eSDHC reports tuning error or data errors in tuning
mode of operation, by add the erratum A008171 support to fix the issue.

Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-esdhc.h

@@ -60,6 +60,7 @@
 /* Tuning Block Control Register */
 #define ESDHC_TBCTL			0x120
 #define ESDHC_TB_EN			0x00000004
+#define ESDHC_TBPTR			0x128
 
 /* Control Register for DMA transfer */
 #define ESDHC_DMA_SYSCTL		0x40c

drivers/mmc/host/sdhci-of-esdhc.c

@@ -78,8 +78,10 @@ struct sdhci_esdhc {
 	u8 vendor_ver;
 	u8 spec_ver;
 	bool quirk_incorrect_hostver;
+	bool quirk_fixup_tuning;
 	unsigned int peripheral_clock;
 	const struct esdhc_clk_fixup *clk_fixup;
+	u32 div_ratio;
 };
 
 /**
@@ -580,6 +582,7 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
 	dev_dbg(mmc_dev(host->mmc), "desired SD clock: %d, actual: %d\n",
 		clock, host->max_clk / pre_div / div);
 	host->mmc->actual_clock = host->max_clk / pre_div / div;
+	esdhc->div_ratio = pre_div * div;
 	pre_div >>= 1;
 	div--;
 
@@ -712,9 +715,24 @@ static int esdhc_signal_voltage_switch(struct mmc_host *mmc,
 	}
 }
 
+static struct soc_device_attribute soc_fixup_tuning[] = {
+	{ .family = "QorIQ T1040", .revision = "1.0", },
+	{ .family = "QorIQ T2080", .revision = "1.0", },
+	{ .family = "QorIQ T1023", .revision = "1.0", },
+	{ .family = "QorIQ LS1021A", .revision = "1.0", },
+	{ .family = "QorIQ LS1080A", .revision = "1.0", },
+	{ .family = "QorIQ LS2080A", .revision = "1.0", },
+	{ .family = "QorIQ LS1012A", .revision = "1.0", },
+	{ .family = "QorIQ LS1043A", .revision = "1.*", },
+	{ .family = "QorIQ LS1046A", .revision = "1.0", },
+	{ },
+};
+
 static int esdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
 {
 	struct sdhci_host *host = mmc_priv(mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_esdhc *esdhc = sdhci_pltfm_priv(pltfm_host);
 	u32 val;
 
 	/* Use tuning block for tuning procedure */
@@ -728,7 +746,26 @@ static int esdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
 	sdhci_writel(host, val, ESDHC_TBCTL);
 	esdhc_clock_enable(host, true);
 
-	return sdhci_execute_tuning(mmc, opcode);
+	sdhci_execute_tuning(mmc, opcode);
+	if (host->tuning_err == -EAGAIN && esdhc->quirk_fixup_tuning) {
+
+		/* program TBPTR[TB_WNDW_END_PTR] = 3*DIV_RATIO and
+		 * program TBPTR[TB_WNDW_START_PTR] = 5*DIV_RATIO
+		 */
+		val = sdhci_readl(host, ESDHC_TBPTR);
+		val = (val & ~((0x7f << 8) | 0x7f)) |
+		(3 * esdhc->div_ratio) | ((5 * esdhc->div_ratio) << 8);
+		sdhci_writel(host, val, ESDHC_TBPTR);
+
+		/* program the software tuning mode by setting
+		 * TBCTL[TB_MODE]=2'h3
+		 */
+		val = sdhci_readl(host, ESDHC_TBCTL);
+		val |= 0x3;
+		sdhci_writel(host, val, ESDHC_TBCTL);
+		sdhci_execute_tuning(mmc, opcode);
+	}
+	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -903,6 +940,11 @@ static int sdhci_esdhc_probe(struct platform_device *pdev)
 
 	pltfm_host = sdhci_priv(host);
 	esdhc = sdhci_pltfm_priv(pltfm_host);
+	if (soc_device_match(soc_fixup_tuning))
+		esdhc->quirk_fixup_tuning = true;
+	else
+		esdhc->quirk_fixup_tuning = false;
+
 	if (esdhc->vendor_ver == VENDOR_V_22)
 		host->quirks2 |= SDHCI_QUIRK2_HOST_NO_CMD23;