ARM: zynq: PM: Enable A9 internal clock gating feature

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

arch/arm/mach-zynq/common.c

@@ -98,6 +98,11 @@ static int __init zynq_get_revision(void)
 	return revision;
 }
 
+static void __init zynq_init_late(void)
+{
+	zynq_core_pm_init();
+}
+
 /**
  * zynq_init_machine - System specific initialization, intended to be
  *		       called from board specific initialization.
@@ -204,6 +209,7 @@ DT_MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform")
 	.map_io		= zynq_map_io,
 	.init_irq	= zynq_irq_init,
 	.init_machine	= zynq_init_machine,
+	.init_late	= zynq_init_late,
 	.init_time	= zynq_timer_init,
 	.dt_compat	= zynq_dt_match,
 	.reserve	= zynq_memory_init,

arch/arm/mach-zynq/common.h

@@ -40,4 +40,15 @@ extern void __iomem *zynq_scu_base;
 /* Hotplug */
 extern void zynq_platform_cpu_die(unsigned int cpu);
 
+static inline void zynq_core_pm_init(void)
+{
+	/* A9 clock gating */
+	asm volatile ("mrc  p15, 0, r12, c15, c0, 0\n"
+		      "orr  r12, r12, #1\n"
+		      "mcr  p15, 0, r12, c15, c0, 0\n"
+		      : /* no outputs */
+		      : /* no inputs */
+		      : "r12");
+}
+
 #endif

arch/arm/mach-zynq/platsmp.c

@@ -112,6 +112,18 @@ static void __init zynq_smp_prepare_cpus(unsigned int max_cpus)
 	scu_enable(zynq_scu_base);
 }
 
+/**
+ * zynq_secondary_init - Initialize secondary CPU cores
+ * @cpu:	CPU that is initialized
+ *
+ * This function is in the hotplug path. Don't move it into the
+ * init section!!
+ */
+static void zynq_secondary_init(unsigned int cpu)
+{
+	zynq_core_pm_init();
+}
+
 #ifdef CONFIG_HOTPLUG_CPU
 static int zynq_cpu_kill(unsigned cpu)
 {
@@ -124,6 +136,7 @@ struct smp_operations zynq_smp_ops __initdata = {
 	.smp_init_cpus		= zynq_smp_init_cpus,
 	.smp_prepare_cpus	= zynq_smp_prepare_cpus,
 	.smp_boot_secondary	= zynq_boot_secondary,
+	.smp_secondary_init	= zynq_secondary_init,
 #ifdef CONFIG_HOTPLUG_CPU
 	.cpu_die		= zynq_platform_cpu_die,
 	.cpu_kill		= zynq_cpu_kill,