From: Lokesh Vutla <lokeshvutla@ti.com>
Date: Tue, 11 May 2021 15:22:13 +0000 (-0500)
Subject: ram: k3-ddrss: Enable vtt regulator if present
X-Git-Tag: v2021.10~187^2~36
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2ce6dedf0b3cb8a4ff97f47061ca10526ea95370;p=platform%2Fkernel%2Fu-boot.git

ram: k3-ddrss: Enable vtt regulator if present

Attempt to get and enable a vtt regulator if one is provided from the
dts. If we do not find one, continue as not all platforms have this.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---

diff --git a/drivers/ram/k3-ddrss/k3-ddrss.c b/drivers/ram/k3-ddrss/k3-ddrss.c
index 8d9e7d2..cb8edcb 100644
--- a/drivers/ram/k3-ddrss/k3-ddrss.c
+++ b/drivers/ram/k3-ddrss/k3-ddrss.c
@@ -15,6 +15,7 @@
 #include <asm/io.h>
 #include <power-domain.h>
 #include <wait_bit.h>
+#include <power/regulator.h>
 
 #include "lpddr4_obj_if.h"
 #include "lpddr4_if.h"
@@ -40,6 +41,7 @@ struct k3_ddrss_desc {
 	u32 ddr_freq1;
 	u32 ddr_freq2;
 	u32 ddr_fhs_cnt;
+	struct udevice *vtt_supply;
 };
 
 static lpddr4_obj *driverdt;
@@ -215,6 +217,18 @@ static int k3_ddrss_power_on(struct k3_ddrss_desc *ddrss)
 		return ret;
 	}
 
+	ret = device_get_supply_regulator(ddrss->dev, "vtt-supply",
+					  &ddrss->vtt_supply);
+	if (ret) {
+		dev_dbg(ddrss->dev, "vtt-supply not found.\n");
+	} else {
+		ret = regulator_set_value(ddrss->vtt_supply, 3300000);
+		if (ret)
+			return ret;
+		dev_dbg(ddrss->dev, "VTT regulator enabled, volt = %d\n",
+			regulator_get_value(ddrss->vtt_supply));
+	}
+
 	return 0;
 }