[PATCH v2] mmc: fsl_esdhc_imx: add wait_dat0() support

[haibo.chen at nxp.com]

From: Haibo Chen <haibo.chen at nxp.com>

Add wait_dat0() support, upper layer will use this callback.

Signed-off-by: Haibo Chen <haibo.chen at nxp.com>
---
 drivers/mmc/fsl_esdhc_imx.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/mmc/fsl_esdhc_imx.c b/drivers/mmc/fsl_esdhc_imx.c
index 22040c67a8..3843d61d71 100644
--- a/drivers/mmc/fsl_esdhc_imx.c
+++ b/drivers/mmc/fsl_esdhc_imx.c
@@ -1646,6 +1646,28 @@ static int fsl_esdhc_set_enhanced_strobe(struct udevice *dev)
 }
 #endif
 
+static int fsl_esdhc_wait_dat0(struct udevice *dev, int state,
+				int timeout_us)
+{
+	int ret = -ETIMEDOUT;
+	bool dat0_high;
+	bool target_dat0_high = !!state;
+	struct fsl_esdhc_priv *priv = dev_get_priv(dev);
+	struct fsl_esdhc *regs = priv->esdhc_regs;
+
+	timeout_us = DIV_ROUND_UP(timeout_us, 10); /* check every 10 us. */
+	while (timeout_us--) {
+		dat0_high = !!(esdhc_read32(&regs->prsstat) & PRSSTAT_DAT0);
+		if (dat0_high == target_dat0_high) {
+			ret = 0;
+			break;
+		}
+		udelay(10);
+	}
+
+	return ret;
+}
+
 static const struct dm_mmc_ops fsl_esdhc_ops = {
 	.get_cd		= fsl_esdhc_get_cd,
 	.send_cmd	= fsl_esdhc_send_cmd,
@@ -1656,6 +1678,7 @@ static const struct dm_mmc_ops fsl_esdhc_ops = {
 #if CONFIG_IS_ENABLED(MMC_HS400_ES_SUPPORT)
 	.set_enhanced_strobe = fsl_esdhc_set_enhanced_strobe,
 #endif
+	.wait_dat0 = fsl_esdhc_wait_dat0,
 };
 #endif
 
-- 
2.17.1