On Thu, 2014-08-21 at 02:19PM +0200, Michal Simek wrote:

On 08/20/2014 10:41 PM, Soren Brinkmann wrote:

quoted

Signed-off-by: Soren Brinkmann <redacted>
---
 arch/arm/mach-zynq/common.c  |  6 ++++++
 arch/arm/mach-zynq/common.h  | 11 +++++++++++
 arch/arm/mach-zynq/platsmp.c |  9 +++++++++
 3 files changed, 26 insertions(+)

diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c
index 31a6fa40ba37..3cb7c198615a 100644
--- a/arch/arm/mach-zynq/common.c
+++ b/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,

diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h
index f652f0a884a6..596ef0b5067c 100644
--- a/arch/arm/mach-zynq/common.h
+++ b/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

diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c
index abc82ef085c1..616b99e07c60 100644
--- a/arch/arm/mach-zynq/platsmp.c
+++ b/arch/arm/mach-zynq/platsmp.c

@@ -112,6 +112,14 @@ static void __init zynq_smp_prepare_cpus(unsigned int max_cpus)
 	scu_enable(zynq_scu_base);
 }
 
+/*
+ * This function is in the hotplug path. Don't move it into the init section!!
+ */

Worth to use kernel-doc format here.

The secondary init function is kind of documented in
arch/arm/include/asm/smp.h as part of the smp_operations struct. Do you
want more documentation here?
	
	S?ren