1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd. |
4 | * http://www.samsung.com |
5 | * |
6 | * Coupled cpuidle support based on the work of: |
7 | * Colin Cross <ccross@android.com> |
8 | * Daniel Lezcano <daniel.lezcano@linaro.org> |
9 | */ |
10 | |
11 | #include <linux/cpuidle.h> |
12 | #include <linux/cpu_pm.h> |
13 | #include <linux/export.h> |
14 | #include <linux/init.h> |
15 | #include <linux/platform_device.h> |
16 | #include <linux/of.h> |
17 | #include <linux/platform_data/cpuidle-exynos.h> |
18 | |
19 | #include <asm/suspend.h> |
20 | #include <asm/cpuidle.h> |
21 | |
22 | static atomic_t exynos_idle_barrier; |
23 | |
24 | static struct cpuidle_exynos_data *exynos_cpuidle_pdata; |
25 | static void (*exynos_enter_aftr)(void); |
26 | |
27 | static int exynos_enter_coupled_lowpower(struct cpuidle_device *dev, |
28 | struct cpuidle_driver *drv, |
29 | int index) |
30 | { |
31 | int ret; |
32 | |
33 | exynos_cpuidle_pdata->pre_enter_aftr(); |
34 | |
35 | /* |
36 | * Waiting all cpus to reach this point at the same moment |
37 | */ |
38 | cpuidle_coupled_parallel_barrier(dev, a: &exynos_idle_barrier); |
39 | |
40 | /* |
41 | * Both cpus will reach this point at the same time |
42 | */ |
43 | ret = dev->cpu ? exynos_cpuidle_pdata->cpu1_powerdown() |
44 | : exynos_cpuidle_pdata->cpu0_enter_aftr(); |
45 | if (ret) |
46 | index = ret; |
47 | |
48 | /* |
49 | * Waiting all cpus to finish the power sequence before going further |
50 | */ |
51 | cpuidle_coupled_parallel_barrier(dev, a: &exynos_idle_barrier); |
52 | |
53 | exynos_cpuidle_pdata->post_enter_aftr(); |
54 | |
55 | return index; |
56 | } |
57 | |
58 | static int exynos_enter_lowpower(struct cpuidle_device *dev, |
59 | struct cpuidle_driver *drv, |
60 | int index) |
61 | { |
62 | int new_index = index; |
63 | |
64 | /* AFTR can only be entered when cores other than CPU0 are offline */ |
65 | if (num_online_cpus() > 1 || dev->cpu != 0) |
66 | new_index = drv->safe_state_index; |
67 | |
68 | if (new_index == 0) |
69 | return arm_cpuidle_simple_enter(dev, drv, new_index); |
70 | |
71 | exynos_enter_aftr(); |
72 | |
73 | return new_index; |
74 | } |
75 | |
76 | static struct cpuidle_driver exynos_idle_driver = { |
77 | .name = "exynos_idle" , |
78 | .owner = THIS_MODULE, |
79 | .states = { |
80 | [0] = ARM_CPUIDLE_WFI_STATE, |
81 | [1] = { |
82 | .enter = exynos_enter_lowpower, |
83 | .exit_latency = 300, |
84 | .target_residency = 10000, |
85 | .name = "C1" , |
86 | .desc = "ARM power down" , |
87 | }, |
88 | }, |
89 | .state_count = 2, |
90 | .safe_state_index = 0, |
91 | }; |
92 | |
93 | static struct cpuidle_driver exynos_coupled_idle_driver = { |
94 | .name = "exynos_coupled_idle" , |
95 | .owner = THIS_MODULE, |
96 | .states = { |
97 | [0] = ARM_CPUIDLE_WFI_STATE, |
98 | [1] = { |
99 | .enter = exynos_enter_coupled_lowpower, |
100 | .exit_latency = 5000, |
101 | .target_residency = 10000, |
102 | .flags = CPUIDLE_FLAG_COUPLED | |
103 | CPUIDLE_FLAG_TIMER_STOP, |
104 | .name = "C1" , |
105 | .desc = "ARM power down" , |
106 | }, |
107 | }, |
108 | .state_count = 2, |
109 | .safe_state_index = 0, |
110 | }; |
111 | |
112 | static int exynos_cpuidle_probe(struct platform_device *pdev) |
113 | { |
114 | int ret; |
115 | |
116 | if (IS_ENABLED(CONFIG_SMP) && |
117 | (of_machine_is_compatible(compat: "samsung,exynos4210" ) || |
118 | of_machine_is_compatible(compat: "samsung,exynos3250" ))) { |
119 | exynos_cpuidle_pdata = pdev->dev.platform_data; |
120 | |
121 | ret = cpuidle_register(drv: &exynos_coupled_idle_driver, |
122 | cpu_possible_mask); |
123 | } else { |
124 | exynos_enter_aftr = (void *)(pdev->dev.platform_data); |
125 | |
126 | ret = cpuidle_register(drv: &exynos_idle_driver, NULL); |
127 | } |
128 | |
129 | if (ret) { |
130 | dev_err(&pdev->dev, "failed to register cpuidle driver\n" ); |
131 | return ret; |
132 | } |
133 | |
134 | return 0; |
135 | } |
136 | |
137 | static struct platform_driver exynos_cpuidle_driver = { |
138 | .probe = exynos_cpuidle_probe, |
139 | .driver = { |
140 | .name = "exynos_cpuidle" , |
141 | }, |
142 | }; |
143 | builtin_platform_driver(exynos_cpuidle_driver); |
144 | |