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ARM: tegra: cpuidle driver for tegra 

CPUidle driver for tegra. In this version only LP3 (clockgating) is supported.

Based on work by:

Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>

Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Olof Johansson <olof@lixom.net>
This commit is contained in:
Peter De Schrijver 2012-01-26 18:22:03 +02:00 committed by Olof Johansson
parent c76fcc8af1
commit 22b8b85d90
2 changed files with 109 additions and 0 deletions
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2
arch/arm/mach-tegra/Makefile
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@ -7,6 +7,8 @@ obj-y += clock.o
obj-y += timer.o
obj-y += pinmux.o
obj-y += fuse.o
obj-y += cpuidle.o
obj-y += sleep.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += powergate.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_clocks.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_emc.o

107
arch/arm/mach-tegra/cpuidle.c Normal file
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@ -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);