mmc: sdhci-esdhc-imx: add DCMD support for CMDQ

Currently, USDHC do not generate transfer complete interrupt
when send a non-data-command with R1b response. But if want
to support DCMD in CMDQ, need to change this, the DCMD IC
logic require the USDHC to enable this function, otherwise
DCMD will never get a CC(command complete) interrupt.

This patch set ESDHC_VEND_SPEC2_EN_BUSY_IRQ and add DCMD support.
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

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

@@ -78,6 +78,9 @@
 #define ESDHC_STROBE_DLL_STS_REF_LOCK	(1 << 1)
 #define ESDHC_STROBE_DLL_STS_SLV_LOCK	0x1
 
+#define ESDHC_VEND_SPEC2		0xc8
+#define ESDHC_VEND_SPEC2_EN_BUSY_IRQ	(1 << 8)
+
 #define ESDHC_TUNING_CTRL		0xcc
 #define ESDHC_STD_TUNING_EN		(1 << 24)
 /* NOTE: the minimum valid tuning start tap for mx6sl is 1 */
@@ -1178,6 +1181,23 @@ static void sdhci_esdhc_imx_hwinit(struct sdhci_host *host)
 		/* disable DLL_CTRL delay line settings */
 		writel(0x0, host->ioaddr + ESDHC_DLL_CTRL);
 
+		/*
+		 * For the case of command with busy, if set the bit
+		 * ESDHC_VEND_SPEC2_EN_BUSY_IRQ, USDHC will generate a
+		 * transfer complete interrupt when busy is deasserted.
+		 * When CQHCI use DCMD to send a CMD need R1b respons,
+		 * CQHCI require to set ESDHC_VEND_SPEC2_EN_BUSY_IRQ,
+		 * otherwise DCMD will always meet timeout waiting for
+		 * hardware interrupt issue.
+		 */
+		if (imx_data->socdata->flags & ESDHC_FLAG_CQHCI) {
+			tmp = readl(host->ioaddr + ESDHC_VEND_SPEC2);
+			tmp |= ESDHC_VEND_SPEC2_EN_BUSY_IRQ;
+			writel(tmp, host->ioaddr + ESDHC_VEND_SPEC2);
+
+			host->quirks &= ~SDHCI_QUIRK_NO_BUSY_IRQ;
+		}
+
 		if (imx_data->socdata->flags & ESDHC_FLAG_STD_TUNING) {
 			tmp = readl(host->ioaddr + ESDHC_TUNING_CTRL);
 			tmp |= ESDHC_STD_TUNING_EN |
@@ -1478,7 +1498,7 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 	}
 
 	if (imx_data->socdata->flags & ESDHC_FLAG_CQHCI) {
-		host->mmc->caps2 |= MMC_CAP2_CQE;
+		host->mmc->caps2 |= MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD;
 		cq_host = devm_kzalloc(&pdev->dev, sizeof(*cq_host), GFP_KERNEL);
 		if (IS_ERR(cq_host)) {
 			err = PTR_ERR(cq_host);