mx7ulp: Only enable LDO if it is not already enabled

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@foundries.io>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Tested-by: Jorge Ramirez-Ortiz <jorge@foundries.io>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

diff --git a/arch/arm/mach-imx/mx7ulp/soc.c b/arch/arm/mach-imx/mx7ulp/soc.c
index d8d6916..0d39dab 100644 (file)
--- a/arch/arm/mach-imx/mx7ulp/soc.c
+++ b/arch/arm/mach-imx/mx7ulp/soc.c
@@ -118,12 +118,26 @@ void init_wdog(void)
        disable_wdog(WDG2_RBASE);
 }
 
+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_SPL) || (defined(CONFIG_SPL) && defined(CONFIG_SPL_BUILD))
 #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);
 
@@ -193,17 +207,6 @@ const char *get_imx_type(u32 imxtype)
        return "7ULP";
 }
 
-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;