ARM: imx: add cpuidle support for i.mx6sx

Add cpuidle support for i.MX6SX, derive from i.MX6Q's
cpuidle, two levels supported:

1. WFI;
2. WAIT mode.
Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>

arch/arm/mach-imx/cpuidle-imx6q.c

@@ -13,6 +13,7 @@
 
 #include "common.h"
 #include "cpuidle.h"
+#include "hardware.h"
 
 static atomic_t master = ATOMIC_INIT(0);
 static DEFINE_SPINLOCK(master_lock);
@@ -66,7 +67,8 @@ static struct cpuidle_driver imx6q_cpuidle_driver = {
 int __init imx6q_cpuidle_init(void)
 {
 	/* Need to enable SCU standby for entering WAIT modes */
-	imx_scu_standby_enable();
+	if (!cpu_is_imx6sx())
+		imx_scu_standby_enable();
 
 	/* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
 	imx6q_set_int_mem_clk_lpm();

arch/arm/mach-imx/mach-imx6sx.c

@@ -12,6 +12,7 @@
 #include <asm/mach/map.h>
 
 #include "common.h"
+#include "cpuidle.h"
 
 static void __init imx6sx_init_machine(void)
 {
@@ -38,6 +39,11 @@ static void __init imx6sx_init_irq(void)
 	irqchip_init();
 }
 
+static void __init imx6sx_init_late(void)
+{
+	imx6q_cpuidle_init();
+}
+
 static const char *imx6sx_dt_compat[] __initconst = {
 	"fsl,imx6sx",
 	NULL,
@@ -48,5 +54,6 @@ DT_MACHINE_START(IMX6SX, "Freescale i.MX6 SoloX (Device Tree)")
 	.init_irq	= imx6sx_init_irq,
 	.init_machine	= imx6sx_init_machine,
 	.dt_compat	= imx6sx_dt_compat,
+	.init_late	= imx6sx_init_late,
 	.restart	= mxc_restart,
 MACHINE_END