ARM: tegra: functions to access the flowcontroller

Introduce some functions to write to the flowcontroller registers. The
flowcontroller controls CPU sleepstates and wakeup.

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/mach-tegra/Makefile

@@ -8,6 +8,7 @@ obj-y                                   += timer.o
 obj-y                                   += pinmux.o
 obj-y					+= fuse.o
 obj-y					+= pmc.o
+obj-y					+= flowctrl.o
 obj-$(CONFIG_CPU_IDLE)			+= cpuidle.o
 obj-$(CONFIG_CPU_IDLE)			+= sleep.o
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= powergate.o

arch/arm/mach-tegra/flowctrl.c

@@ -0,0 +1,62 @@
+/*
+ * arch/arm/mach-tegra/flowctrl.c
+ *
+ * functions and macros to control the flowcontroller
+ *
+ * Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+
+#include <mach/iomap.h>
+
+#include "flowctrl.h"
+
+u8 flowctrl_offset_halt_cpu[] = {
+	FLOW_CTRL_HALT_CPU0_EVENTS,
+	FLOW_CTRL_HALT_CPU1_EVENTS,
+	FLOW_CTRL_HALT_CPU1_EVENTS + 8,
+	FLOW_CTRL_HALT_CPU1_EVENTS + 16,
+};
+
+u8 flowctrl_offset_cpu_csr[] = {
+	FLOW_CTRL_CPU0_CSR,
+	FLOW_CTRL_CPU1_CSR,
+	FLOW_CTRL_CPU1_CSR + 8,
+	FLOW_CTRL_CPU1_CSR + 16,
+};
+
+static void flowctrl_update(u8 offset, u32 value)
+{
+	void __iomem *addr = IO_ADDRESS(TEGRA_FLOW_CTRL_BASE) + offset;
+
+	writel(value, addr);
+
+	/* ensure the update has reached the flow controller */
+	wmb();
+	readl_relaxed(addr);
+}
+
+void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value)
+{
+	return flowctrl_update(flowctrl_offset_halt_cpu[cpuid], value);
+}
+
+void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value)
+{
+	return flowctrl_update(flowctrl_offset_cpu_csr[cpuid], value);
+}

arch/arm/mach-tegra/flowctrl.h

@@ -34,4 +34,9 @@
 #define FLOW_CTRL_HALT_CPU1_EVENTS	0x14
 #define FLOW_CTRL_CPU1_CSR		0x18
 
+#ifndef __ASSEMBLY__
+void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value);
+void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value);
+#endif
+
 #endif