summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-tegra/cpuidle.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-tegra/cpuidle.c')
-rw-r--r--arch/arm/mach-tegra/cpuidle.c107
1 files changed, 107 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/cpuidle.c b/arch/arm/mach-tegra/cpuidle.c
new file mode 100644
index 0000000..d83a8c0
--- /dev/null
+++ b/arch/arm/mach-tegra/cpuidle.c
@@ -0,0 +1,107 @@
+/*
+ * arch/arm/mach-tegra/cpuidle.c
+ *
+ * CPU idle driver for Tegra CPUs
+ *
+ * Copyright (c) 2010-2012, NVIDIA Corporation.
+ * Copyright (c) 2011 Google, Inc.
+ * Author: Colin Cross <ccross@android.com>
+ * Gary King <gking@nvidia.com>
+ *
+ * Rework for 3.3 by Peter De Schrijver <pdeschrijver@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/cpu.h>
+#include <linux/cpuidle.h>
+#include <linux/hrtimer.h>
+
+#include <mach/iomap.h>
+
+extern void tegra_cpu_wfi(void);
+
+static int tegra_idle_enter_lp3(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index);
+
+struct cpuidle_driver tegra_idle_driver = {
+ .name = "tegra_idle",
+ .owner = THIS_MODULE,
+ .state_count = 1,
+ .states = {
+ [0] = {
+ .enter = tegra_idle_enter_lp3,
+ .exit_latency = 10,
+ .target_residency = 10,
+ .power_usage = 600,
+ .flags = CPUIDLE_FLAG_TIME_VALID,
+ .name = "LP3",
+ .desc = "CPU flow-controlled",
+ },
+ },
+};
+
+static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device);
+
+static int tegra_idle_enter_lp3(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ ktime_t enter, exit;
+ s64 us;
+
+ local_irq_disable();
+ local_fiq_disable();
+
+ enter = ktime_get();
+
+ tegra_cpu_wfi();
+
+ exit = ktime_sub(ktime_get(), enter);
+ us = ktime_to_us(exit);
+
+ local_fiq_enable();
+ local_irq_enable();
+
+ dev->last_residency = us;
+
+ return index;
+}
+
+static int __init tegra_cpuidle_init(void)
+{
+ int ret;
+ unsigned int cpu;
+ struct cpuidle_device *dev;
+ struct cpuidle_driver *drv = &tegra_idle_driver;
+
+ ret = cpuidle_register_driver(&tegra_idle_driver);
+ if (ret) {
+ pr_err("CPUidle driver registration failed\n");
+ return ret;
+ }
+
+ for_each_possible_cpu(cpu) {
+ dev = &per_cpu(tegra_idle_device, cpu);
+ dev->cpu = cpu;
+
+ dev->state_count = drv->state_count;
+ ret = cpuidle_register_device(dev);
+ if (ret) {
+ pr_err("CPU%u: CPUidle device registration failed\n",
+ cpu);
+ return ret;
+ }
+ }
+ return 0;
+}
+device_initcall(tegra_cpuidle_init);