soc/tegra: Move Tegra flowctrl driver

The flowctrl driver is required for both ARM and ARM64 Tegra devices
and in order to enable support for it for ARM64, move the Tegra flowctrl
driver into drivers/soc/tegra.

By moving the flowctrl driver, tegra_flowctrl_init() is now called by
via an early initcall and to prevent this function from attempting to
mapping IO space for a non-Tegra device, a test for 'soc_is_tegra()'
is also added.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index fffad24..3b33f0bb 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -2,7 +2,6 @@
 
 obj-y                                   += io.o
 obj-y                                   += irq.o
-obj-y					+= flowctrl.o
 obj-y					+= pm.o
 obj-y					+= reset.o
 obj-y					+= reset-handler.o
diff --git a/arch/arm/mach-tegra/cpuidle-tegra20.c b/arch/arm/mach-tegra/cpuidle-tegra20.c
index afcee04..76e4c83 100644
--- a/arch/arm/mach-tegra/cpuidle-tegra20.c
+++ b/arch/arm/mach-tegra/cpuidle-tegra20.c
@@ -26,12 +26,13 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 
+#include <soc/tegra/flowctrl.h>
+
 #include <asm/cpuidle.h>
 #include <asm/smp_plat.h>
 #include <asm/suspend.h>
 
 #include "cpuidle.h"
-#include "flowctrl.h"
 #include "iomap.h"
 #include "irq.h"
 #include "pm.h"
diff --git a/arch/arm/mach-tegra/platsmp.c b/arch/arm/mach-tegra/platsmp.c
index 75620ae..b5a2afe 100644
--- a/arch/arm/mach-tegra/platsmp.c
+++ b/arch/arm/mach-tegra/platsmp.c
@@ -21,6 +21,7 @@
 #include <linux/jiffies.h>
 #include <linux/smp.h>
 
+#include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 #include <soc/tegra/pmc.h>
 
@@ -30,7 +31,6 @@
 #include <asm/smp_scu.h>
 
 #include "common.h"
-#include "flowctrl.h"
 #include "iomap.h"
 #include "reset.h"
 
diff --git a/arch/arm/mach-tegra/pm.c b/arch/arm/mach-tegra/pm.c
index b0f48a3..1ad5719 100644
--- a/arch/arm/mach-tegra/pm.c
+++ b/arch/arm/mach-tegra/pm.c
@@ -27,6 +27,7 @@
 #include <linux/spinlock.h>
 #include <linux/suspend.h>
 
+#include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 #include <soc/tegra/pm.h>
 #include <soc/tegra/pmc.h>
@@ -38,7 +39,6 @@
 #include <asm/suspend.h>
 #include <asm/tlbflush.h>
 
-#include "flowctrl.h"
 #include "iomap.h"
 #include "pm.h"
 #include "reset.h"
diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
index e3070fda..805f306 100644
--- a/arch/arm/mach-tegra/reset-handler.S
+++ b/arch/arm/mach-tegra/reset-handler.S
@@ -17,12 +17,12 @@
 #include <linux/init.h>
 #include <linux/linkage.h>
 
+#include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 
 #include <asm/asm-offsets.h>
 #include <asm/cache.h>
 
-#include "flowctrl.h"
 #include "iomap.h"
 #include "reset.h"
 #include "sleep.h"
diff --git a/arch/arm/mach-tegra/sleep-tegra20.S b/arch/arm/mach-tegra/sleep-tegra20.S
index f5d1966..5c8e638 100644
--- a/arch/arm/mach-tegra/sleep-tegra20.S
+++ b/arch/arm/mach-tegra/sleep-tegra20.S
@@ -20,6 +20,8 @@
 
 #include <linux/linkage.h>
 
+#include <soc/tegra/flowctrl.h>
+
 #include <asm/assembler.h>
 #include <asm/proc-fns.h>
 #include <asm/cp15.h>
@@ -27,7 +29,6 @@
 
 #include "irammap.h"
 #include "sleep.h"
-#include "flowctrl.h"
 
 #define EMC_CFG				0xc
 #define EMC_ADR_CFG			0x10
diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
index 16e5ff0..dd4a67d 100644
--- a/arch/arm/mach-tegra/sleep-tegra30.S
+++ b/arch/arm/mach-tegra/sleep-tegra30.S
@@ -16,13 +16,13 @@
 
 #include <linux/linkage.h>
 
+#include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 
 #include <asm/asm-offsets.h>
 #include <asm/assembler.h>
 #include <asm/cache.h>
 
-#include "flowctrl.h"
 #include "irammap.h"
 #include "sleep.h"
 
diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c
index e01cbca..649e9e8 100644
--- a/arch/arm/mach-tegra/tegra.c
+++ b/arch/arm/mach-tegra/tegra.c
@@ -48,7 +48,6 @@
 #include "board.h"
 #include "common.h"
 #include "cpuidle.h"
-#include "flowctrl.h"
 #include "iomap.h"
 #include "irq.h"
 #include "pm.h"
@@ -75,7 +74,6 @@
 {
 	of_register_trusted_foundations();
 	tegra_cpu_reset_handler_init();
-	tegra_flowctrl_init();
 }
 
 static void __init tegra_dt_init_irq(void)
diff --git a/drivers/soc/tegra/Kconfig b/drivers/soc/tegra/Kconfig
index 208d6ed..c7e8ddf 100644
--- a/drivers/soc/tegra/Kconfig
+++ b/drivers/soc/tegra/Kconfig
@@ -12,6 +12,7 @@
 	select PINCTRL_TEGRA20
 	select PL310_ERRATA_727915 if CACHE_L2X0
 	select PL310_ERRATA_769419 if CACHE_L2X0
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help
@@ -24,6 +25,7 @@
 	select ARM_ERRATA_764369 if SMP
 	select PINCTRL_TEGRA30
 	select PL310_ERRATA_769419 if CACHE_L2X0
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help
@@ -35,6 +37,7 @@
 	select ARM_ERRATA_798181 if SMP
 	select HAVE_ARM_ARCH_TIMER
 	select PINCTRL_TEGRA114
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help
@@ -45,6 +48,7 @@
 	bool "Enable support for Tegra124 family"
 	select HAVE_ARM_ARCH_TIMER
 	select PINCTRL_TEGRA124
+	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
 	select TEGRA_TIMER
 	help
@@ -101,6 +105,9 @@
 endif
 endif
 
+config SOC_TEGRA_FLOWCTRL
+	bool
+
 config SOC_TEGRA_PMC
 	bool
 
diff --git a/drivers/soc/tegra/Makefile b/drivers/soc/tegra/Makefile
index b4425e4..4f81dd5 100644
--- a/drivers/soc/tegra/Makefile
+++ b/drivers/soc/tegra/Makefile
@@ -1,5 +1,6 @@
 obj-y += fuse/
 
 obj-y += common.o
+obj-$(CONFIG_SOC_TEGRA_FLOWCTRL) += flowctrl.o
 obj-$(CONFIG_SOC_TEGRA_PMC) += pmc.o
 obj-$(CONFIG_SOC_TEGRA_PMC_TEGRA186) += pmc-tegra186.o
diff --git a/arch/arm/mach-tegra/flowctrl.c b/drivers/soc/tegra/flowctrl.c
similarity index 89%
rename from arch/arm/mach-tegra/flowctrl.c
rename to drivers/soc/tegra/flowctrl.c
index 475e783..3a5a1cb 100644
--- a/arch/arm/mach-tegra/flowctrl.c
+++ b/drivers/soc/tegra/flowctrl.c
@@ -1,7 +1,7 @@
 /*
- * arch/arm/mach-tegra/flowctrl.c
+ * drivers/soc/tegra/flowctrl.c
  *
- * functions and macros to control the flowcontroller
+ * Functions and macros to control the flowcontroller
  *
  * Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
  *
@@ -25,10 +25,10 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 
+#include <soc/tegra/common.h>
+#include <soc/tegra/flowctrl.h>
 #include <soc/tegra/fuse.h>
 
-#include "flowctrl.h"
-
 static u8 flowctrl_offset_halt_cpu[] = {
 	FLOW_CTRL_HALT_CPU0_EVENTS,
 	FLOW_CTRL_HALT_CPU1_EVENTS,
@@ -47,6 +47,10 @@
 
 static void flowctrl_update(u8 offset, u32 value)
 {
+	if (WARN_ONCE(!tegra_flowctrl_base,
+		      "Tegra flowctrl not initialised!\n"))
+		return;
+
 	writel(value, tegra_flowctrl_base + offset);
 
 	/* ensure the update has reached the flow controller */
@@ -58,6 +62,10 @@
 {
 	u8 offset = flowctrl_offset_cpu_csr[cpuid];
 
+	if (WARN_ONCE(!tegra_flowctrl_base,
+		      "Tegra flowctrl not initialised!\n"))
+		return 0;
+
 	return readl(tegra_flowctrl_base + offset);
 }
 
@@ -148,13 +156,16 @@
 	{ }
 };
 
-void __init tegra_flowctrl_init(void)
+static int __init tegra_flowctrl_init(void)
 {
 	/* hardcoded fallback if device tree node is missing */
 	unsigned long base = 0x60007000;
 	unsigned long size = SZ_4K;
 	struct device_node *np;
 
+	if (!soc_is_tegra())
+		return 0;
+
 	np = of_find_matching_node(NULL, matches);
 	if (np) {
 		struct resource res;
@@ -168,4 +179,9 @@
 	}
 
 	tegra_flowctrl_base = ioremap_nocache(base, size);
+	if (!tegra_flowctrl_base)
+		return -ENXIO;
+
+	return 0;
 }
+early_initcall(tegra_flowctrl_init);
diff --git a/arch/arm/mach-tegra/flowctrl.h b/include/soc/tegra/flowctrl.h
similarity index 77%
rename from arch/arm/mach-tegra/flowctrl.h
rename to include/soc/tegra/flowctrl.h
index 73a9c50..8f86aea 100644
--- a/arch/arm/mach-tegra/flowctrl.h
+++ b/include/soc/tegra/flowctrl.h
@@ -1,7 +1,5 @@
 /*
- * arch/arm/mach-tegra/flowctrl.h
- *
- * functions and macros to control the flowcontroller
+ * Functions and macros to control the flowcontroller
  *
  * Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
  *
@@ -18,8 +16,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef __MACH_TEGRA_FLOWCTRL_H
-#define __MACH_TEGRA_FLOWCTRL_H
+#ifndef __SOC_TEGRA_FLOWCTRL_H__
+#define __SOC_TEGRA_FLOWCTRL_H__
 
 #define FLOW_CTRL_HALT_CPU0_EVENTS	0x0
 #define FLOW_CTRL_WAITEVENT		(2 << 29)
@@ -53,14 +51,32 @@
 #define TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP	(0xF << 8)
 
 #ifndef __ASSEMBLY__
+#ifdef CONFIG_SOC_TEGRA_FLOWCTRL
 u32 flowctrl_read_cpu_csr(unsigned int cpuid);
 void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value);
 void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value);
 
 void flowctrl_cpu_suspend_enter(unsigned int cpuid);
 void flowctrl_cpu_suspend_exit(unsigned int cpuid);
+#else
+static inline u32 flowctrl_read_cpu_csr(unsigned int cpuid)
+{
+	return 0;
+}
 
-void tegra_flowctrl_init(void);
-#endif
+static inline void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value)
+{
+}
 
-#endif
+static inline void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value) {}
+
+static inline void flowctrl_cpu_suspend_enter(unsigned int cpuid)
+{
+}
+
+static inline void flowctrl_cpu_suspend_exit(unsigned int cpuid)
+{
+}
+#endif /* CONFIG_SOC_TEGRA_FLOWCTRL */
+#endif /* __ASSEMBLY */
+#endif /* __SOC_TEGRA_FLOWCTRL_H__ */