2 * CPU idle driver for Tegra CPUs
4 * Copyright (c) 2010-2012, NVIDIA Corporation.
5 * Copyright (c) 2011 Google, Inc.
6 * Author: Colin Cross <ccross@android.com>
7 * Gary King <gking@nvidia.com>
9 * Rework for 3.3 by Peter De Schrijver <pdeschrijver@nvidia.com>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful, but WITHOUT
17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/cpuidle.h>
25 #include <linux/cpu_pm.h>
26 #include <linux/clockchips.h>
28 #include <asm/cpuidle.h>
29 #include <asm/proc-fns.h>
30 #include <asm/suspend.h>
31 #include <asm/smp_plat.h>
35 #include "tegra_cpu_car.h"
37 #ifdef CONFIG_PM_SLEEP
38 static int tegra30_idle_lp2(struct cpuidle_device
*dev
,
39 struct cpuidle_driver
*drv
,
43 static struct cpuidle_driver tegra_idle_driver
= {
46 .en_core_tk_irqen
= 1,
47 #ifdef CONFIG_PM_SLEEP
53 [0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
54 #ifdef CONFIG_PM_SLEEP
56 .enter
= tegra30_idle_lp2
,
58 .target_residency
= 2200,
60 .flags
= CPUIDLE_FLAG_TIME_VALID
,
61 .name
= "powered-down",
62 .desc
= "CPU power gated",
68 static DEFINE_PER_CPU(struct cpuidle_device
, tegra_idle_device
);
70 #ifdef CONFIG_PM_SLEEP
71 static bool tegra30_cpu_cluster_power_down(struct cpuidle_device
*dev
,
72 struct cpuidle_driver
*drv
,
75 struct cpuidle_state
*state
= &drv
->states
[index
];
76 u32 cpu_on_time
= state
->exit_latency
;
77 u32 cpu_off_time
= state
->target_residency
- state
->exit_latency
;
79 /* All CPUs entering LP2 is not working.
80 * Don't let CPU0 enter LP2 when any secondary CPU is online.
82 if (num_online_cpus() > 1 || !tegra_cpu_rail_off_ready()) {
87 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER
, &dev
->cpu
);
89 tegra_idle_lp2_last(cpu_on_time
, cpu_off_time
);
91 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT
, &dev
->cpu
);
97 static bool tegra30_cpu_core_power_down(struct cpuidle_device
*dev
,
98 struct cpuidle_driver
*drv
,
101 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER
, &dev
->cpu
);
105 save_cpu_arch_register();
107 cpu_suspend(0, tegra30_sleep_cpu_secondary_finish
);
109 restore_cpu_arch_register();
111 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT
, &dev
->cpu
);
116 static inline bool tegra30_cpu_core_power_down(struct cpuidle_device
*dev
,
117 struct cpuidle_driver
*drv
,
124 static int __cpuinit
tegra30_idle_lp2(struct cpuidle_device
*dev
,
125 struct cpuidle_driver
*drv
,
128 u32 cpu
= is_smp() ? cpu_logical_map(dev
->cpu
) : dev
->cpu
;
129 bool entered_lp2
= false;
134 last_cpu
= tegra_set_cpu_in_lp2(cpu
);
139 entered_lp2
= tegra30_cpu_cluster_power_down(dev
, drv
,
144 entered_lp2
= tegra30_cpu_core_power_down(dev
, drv
, index
);
148 tegra_clear_cpu_in_lp2(cpu
);
154 return (entered_lp2
) ? index
: 0;
158 int __init
tegra30_cpuidle_init(void)
162 struct cpuidle_device
*dev
;
163 struct cpuidle_driver
*drv
= &tegra_idle_driver
;
165 #ifdef CONFIG_PM_SLEEP
166 tegra_tear_down_cpu
= tegra30_tear_down_cpu
;
169 ret
= cpuidle_register_driver(&tegra_idle_driver
);
171 pr_err("CPUidle driver registration failed\n");
175 for_each_possible_cpu(cpu
) {
176 dev
= &per_cpu(tegra_idle_device
, cpu
);
179 dev
->state_count
= drv
->state_count
;
180 ret
= cpuidle_register_device(dev
);
182 pr_err("CPU%u: CPUidle device registration failed\n",