[PATCH] mx7ulp: Only enable LDO if it is not already enabled

[Fabio Estevam]

LDO mode may be already enabled by the ROM and enabling it again
can cause U-Boot to hang.

Avoid this problem by only enabling LDO mode if it is initially disabled.

Reported-by: Jorge Ramirez-Ortiz <jorge at foundries.io>
Signed-off-by: Fabio Estevam <festevam at gmail.com>
---
 arch/arm/mach-imx/mx7ulp/soc.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/arch/arm/mach-imx/mx7ulp/soc.c b/arch/arm/mach-imx/mx7ulp/soc.c
index 8345b01398..4d84193dec 100644
--- a/arch/arm/mach-imx/mx7ulp/soc.c
+++ b/arch/arm/mach-imx/mx7ulp/soc.c
@@ -117,11 +117,28 @@ void init_wdog(void)
 	disable_wdog(WDG2_RBASE);
 }
 
+#define PMC0_BASE_ADDR		0x410a1000
+#define PMC0_CTRL		0x28
+#define PMC0_CTRL_LDOEN		BIT(31)
+
+static bool ldo_mode_is_enabled(void)
+{
+	unsigned int reg;
+
+	reg = readl(PMC0_BASE_ADDR + PMC0_CTRL);
+	if (reg & PMC0_CTRL_LDOEN)
+		return true;
+	else
+		return false;
+}
 #if defined(CONFIG_LDO_ENABLED_MODE)
 static void init_ldo_mode(void)
 {
 	unsigned int reg;
 
+	if (ldo_mode_is_enabled())
+		return;
+
 	/* Set LDOOKDIS */
 	setbits_le32(PMC0_BASE_ADDR + PMC0_CTRL, PMC0_CTRL_LDOOKDIS);
 
@@ -190,21 +207,6 @@ const char *get_imx_type(u32 imxtype)
 	return "7ULP";
 }
 
-#define PMC0_BASE_ADDR		0x410a1000
-#define PMC0_CTRL		0x28
-#define PMC0_CTRL_LDOEN		BIT(31)
-
-static bool ldo_mode_is_enabled(void)
-{
-	unsigned int reg;
-
-	reg = readl(PMC0_BASE_ADDR + PMC0_CTRL);
-	if (reg & PMC0_CTRL_LDOEN)
-		return true;
-	else
-		return false;
-}
-
 int print_cpuinfo(void)
 {
 	u32 cpurev;
-- 
2.17.1