[PATCH 1/9] ARM: zynq: PM: Enable A9 internal clock gating feature

From: Soren Brinkmann
Date: Wed Aug 20 2014 - 16:44:57 EST


Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>
---
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!!
+ */
+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 +132,7 @@ 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,
--
2.0.1.1.gfbfc394

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