mx6: soc: Switch to cold reset

Disable the warm reset and enable the cold reset for a more reliable
restart ('reset'). This is taken from the Linux kernel, see imx_src_init()
in arch/arm/mach-imx/src.c.

Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>

arch/arm/cpu/armv7/mx6/soc.c

@@ -288,6 +288,22 @@ static void set_preclk_from_osc(void)
 }
 #endif
 
+#define SRC_SCR_WARM_RESET_ENABLE	0
+
+static void init_src(void)
+{
+	struct src *src_regs = (struct src *)SRC_BASE_ADDR;
+	u32 val;
+
+	/*
+	 * force warm reset sources to generate cold reset
+	 * for a more reliable restart
+	 */
+	val = readl(&src_regs->scr);
+	val &= ~(1 << SRC_SCR_WARM_RESET_ENABLE);
+	writel(val, &src_regs->scr);
+}
+
 int arch_cpu_init(void)
 {
 	init_aips();
@@ -322,6 +338,8 @@ int arch_cpu_init(void)
 	mxs_dma_init();
 #endif
 
+	init_src();
+
 	return 0;
 }