| Peter De Schrijver | 22b8b85 | 2012-01-26 18:22:03 +0200 | [diff] [blame] | 1 | /* |
| 2 | * arch/arm/mach-tegra/cpuidle.c |
| 3 | * |
| 4 | * CPU idle driver for Tegra CPUs |
| 5 | * |
| 6 | * Copyright (c) 2010-2012, NVIDIA Corporation. |
| 7 | * Copyright (c) 2011 Google, Inc. |
| 8 | * Author: Colin Cross <ccross@android.com> |
| 9 | * Gary King <gking@nvidia.com> |
| 10 | * |
| 11 | * Rework for 3.3 by Peter De Schrijver <pdeschrijver@nvidia.com> |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or modify |
| 14 | * it under the terms of the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 2 of the License, or |
| 16 | * (at your option) any later version. |
| 17 | * |
| 18 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 19 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 20 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 21 | * more details. |
| 22 | */ |
| 23 | |
| 24 | #include <linux/kernel.h> |
| 25 | #include <linux/module.h> |
| 26 | #include <linux/cpu.h> |
| 27 | #include <linux/cpuidle.h> |
| 28 | #include <linux/hrtimer.h> |
| 29 | |
| 30 | #include <mach/iomap.h> |
| 31 | |
| 32 | extern void tegra_cpu_wfi(void); |
| 33 | |
| 34 | static int tegra_idle_enter_lp3(struct cpuidle_device *dev, |
| 35 | struct cpuidle_driver *drv, int index); |
| 36 | |
| 37 | struct cpuidle_driver tegra_idle_driver = { |
| 38 | .name = "tegra_idle", |
| 39 | .owner = THIS_MODULE, |
| 40 | .state_count = 1, |
| 41 | .states = { |
| 42 | [0] = { |
| 43 | .enter = tegra_idle_enter_lp3, |
| 44 | .exit_latency = 10, |
| 45 | .target_residency = 10, |
| 46 | .power_usage = 600, |
| 47 | .flags = CPUIDLE_FLAG_TIME_VALID, |
| 48 | .name = "LP3", |
| 49 | .desc = "CPU flow-controlled", |
| 50 | }, |
| 51 | }, |
| 52 | }; |
| 53 | |
| 54 | static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device); |
| 55 | |
| 56 | static int tegra_idle_enter_lp3(struct cpuidle_device *dev, |
| 57 | struct cpuidle_driver *drv, int index) |
| 58 | { |
| 59 | ktime_t enter, exit; |
| 60 | s64 us; |
| 61 | |
| 62 | local_irq_disable(); |
| 63 | local_fiq_disable(); |
| 64 | |
| 65 | enter = ktime_get(); |
| 66 | |
| 67 | tegra_cpu_wfi(); |
| 68 | |
| 69 | exit = ktime_sub(ktime_get(), enter); |
| 70 | us = ktime_to_us(exit); |
| 71 | |
| 72 | local_fiq_enable(); |
| 73 | local_irq_enable(); |
| 74 | |
| 75 | dev->last_residency = us; |
| 76 | |
| 77 | return index; |
| 78 | } |
| 79 | |
| 80 | static int __init tegra_cpuidle_init(void) |
| 81 | { |
| 82 | int ret; |
| 83 | unsigned int cpu; |
| 84 | struct cpuidle_device *dev; |
| 85 | struct cpuidle_driver *drv = &tegra_idle_driver; |
| 86 | |
| 87 | ret = cpuidle_register_driver(&tegra_idle_driver); |
| 88 | if (ret) { |
| 89 | pr_err("CPUidle driver registration failed\n"); |
| 90 | return ret; |
| 91 | } |
| 92 | |
| 93 | for_each_possible_cpu(cpu) { |
| 94 | dev = &per_cpu(tegra_idle_device, cpu); |
| 95 | dev->cpu = cpu; |
| 96 | |
| 97 | dev->state_count = drv->state_count; |
| 98 | ret = cpuidle_register_device(dev); |
| 99 | if (ret) { |
| 100 | pr_err("CPU%u: CPUidle device registration failed\n", |
| 101 | cpu); |
| 102 | return ret; |
| 103 | } |
| 104 | } |
| 105 | return 0; |
| 106 | } |
| 107 | device_initcall(tegra_cpuidle_init); |