]> git.kernelconcepts.de Git - karo-tx-linux.git/blob - drivers/cpuidle/cpuidle-exynos.c
Merge tag 'v4.4.8' into release/qcomlt-4.4
[karo-tx-linux.git] / drivers / cpuidle / cpuidle-exynos.c
1 /*
2  * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd.
3  *              http://www.samsung.com
4  *
5  * Coupled cpuidle support based on the work of:
6  *      Colin Cross <ccross@android.com>
7  *      Daniel Lezcano <daniel.lezcano@linaro.org>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12 */
13
14 #include <linux/cpuidle.h>
15 #include <linux/cpu_pm.h>
16 #include <linux/export.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
19 #include <linux/of.h>
20 #include <linux/platform_data/cpuidle-exynos.h>
21
22 #include <asm/suspend.h>
23 #include <asm/cpuidle.h>
24
25 static atomic_t exynos_idle_barrier;
26
27 static struct cpuidle_exynos_data *exynos_cpuidle_pdata;
28 static void (*exynos_enter_aftr)(void);
29
30 static int exynos_enter_coupled_lowpower(struct cpuidle_device *dev,
31                                          struct cpuidle_driver *drv,
32                                          int index)
33 {
34         int ret;
35
36         exynos_cpuidle_pdata->pre_enter_aftr();
37
38         /*
39          * Waiting all cpus to reach this point at the same moment
40          */
41         cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
42
43         /*
44          * Both cpus will reach this point at the same time
45          */
46         ret = dev->cpu ? exynos_cpuidle_pdata->cpu1_powerdown()
47                        : exynos_cpuidle_pdata->cpu0_enter_aftr();
48         if (ret)
49                 index = ret;
50
51         /*
52          * Waiting all cpus to finish the power sequence before going further
53          */
54         cpuidle_coupled_parallel_barrier(dev, &exynos_idle_barrier);
55
56         exynos_cpuidle_pdata->post_enter_aftr();
57
58         return index;
59 }
60
61 static int exynos_enter_lowpower(struct cpuidle_device *dev,
62                                 struct cpuidle_driver *drv,
63                                 int index)
64 {
65         int new_index = index;
66
67         /* AFTR can only be entered when cores other than CPU0 are offline */
68         if (num_online_cpus() > 1 || dev->cpu != 0)
69                 new_index = drv->safe_state_index;
70
71         if (new_index == 0)
72                 return arm_cpuidle_simple_enter(dev, drv, new_index);
73
74         exynos_enter_aftr();
75
76         return new_index;
77 }
78
79 static struct cpuidle_driver exynos_idle_driver = {
80         .name                   = "exynos_idle",
81         .owner                  = THIS_MODULE,
82         .states = {
83                 [0] = ARM_CPUIDLE_WFI_STATE,
84                 [1] = {
85                         .enter                  = exynos_enter_lowpower,
86                         .exit_latency           = 300,
87                         .target_residency       = 100000,
88                         .name                   = "C1",
89                         .desc                   = "ARM power down",
90                 },
91         },
92         .state_count = 2,
93         .safe_state_index = 0,
94 };
95
96 static struct cpuidle_driver exynos_coupled_idle_driver = {
97         .name                   = "exynos_coupled_idle",
98         .owner                  = THIS_MODULE,
99         .states = {
100                 [0] = ARM_CPUIDLE_WFI_STATE,
101                 [1] = {
102                         .enter                  = exynos_enter_coupled_lowpower,
103                         .exit_latency           = 5000,
104                         .target_residency       = 10000,
105                         .flags                  = CPUIDLE_FLAG_COUPLED |
106                                                   CPUIDLE_FLAG_TIMER_STOP,
107                         .name                   = "C1",
108                         .desc                   = "ARM power down",
109                 },
110         },
111         .state_count = 2,
112         .safe_state_index = 0,
113 };
114
115 static int exynos_cpuidle_probe(struct platform_device *pdev)
116 {
117         int ret;
118
119         if (IS_ENABLED(CONFIG_SMP) &&
120             of_machine_is_compatible("samsung,exynos4210")) {
121                 exynos_cpuidle_pdata = pdev->dev.platform_data;
122
123                 ret = cpuidle_register(&exynos_coupled_idle_driver,
124                                        cpu_possible_mask);
125         } else {
126                 exynos_enter_aftr = (void *)(pdev->dev.platform_data);
127
128                 ret = cpuidle_register(&exynos_idle_driver, NULL);
129         }
130
131         if (ret) {
132                 dev_err(&pdev->dev, "failed to register cpuidle driver\n");
133                 return ret;
134         }
135
136         return 0;
137 }
138
139 static struct platform_driver exynos_cpuidle_driver = {
140         .probe  = exynos_cpuidle_probe,
141         .driver = {
142                 .name = "exynos_cpuidle",
143         },
144 };
145
146 module_platform_driver(exynos_cpuidle_driver);