[U-Boot] [PATCH 2/4] dm: mmc: fsl_esdhc: handle vqmmc supply

[Peng Fan]

Handle vqmmc supply. Some boards have a fixed I/O voltage
at 1.8V for emmc, so the usdhc also needs to be configured
as 1.8V by setting VSELECT bit. The vs18_enable is the one
that used to checking whether setting VSELECT or not in
the driver. So if vqmmc supply is 1.8V, set vs18_enable,
the driver will set VSELECT.

Signed-off-by: Peng Fan <peng.fan at nxp.com>
Cc: Jaehoon Chung <jh80.chung at samsung.com>
Cc: York Sun <york.sun at nxp.com>
Cc: Stefano Babic <sbabic at denx.de>
---
 drivers/mmc/fsl_esdhc.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c
index bddfe24..9ebde32 100644
--- a/drivers/mmc/fsl_esdhc.c
+++ b/drivers/mmc/fsl_esdhc.c
@@ -968,6 +968,7 @@ static int fsl_esdhc_probe(struct udevice *dev)
 	struct fsl_esdhc_priv *priv = dev_get_priv(dev);
 	const void *fdt = gd->fdt_blob;
 	int node = dev_of_offset(dev);
+	struct udevice *vqmmc_dev;
 	fdt_addr_t addr;
 	unsigned int val;
 	int ret;
@@ -1005,6 +1006,23 @@ static int fsl_esdhc_probe(struct udevice *dev)
 	if (ret)
 		priv->wp_enable = 0;
 #endif
+
+	priv->vs18_enable = 0;
+
+#ifdef CONFIG_DM_REGULATOR
+	/*
+	 * If emmc I/O has a fixed voltage at 1.8V, this must be provided,
+	 * otherwise, emmc will work abnormally.
+	 */
+	ret = device_get_supply_regulator(dev, "vqmmc-supply", &vqmmc_dev);
+	if (ret) {
+		dev_dbg("no vqmmc-supply\n");
+	} else {
+		if (regulator_get_value(vqmmc_dev) == 1800000)
+			priv->vs18_enable = 1;
+	}
+#endif
+
 	/*
 	 * TODO:
 	 * Because lack of clk driver, if SDHC clk is not enabled,
-- 
2.6.2