1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved. |
4 | * Copyright (c) 2014,2015, Linaro Ltd. |
5 | * |
6 | * SAW power controller driver |
7 | */ |
8 | |
9 | #include <linux/kernel.h> |
10 | #include <linux/init.h> |
11 | #include <linux/io.h> |
12 | #include <linux/slab.h> |
13 | #include <linux/of.h> |
14 | #include <linux/of_platform.h> |
15 | #include <linux/err.h> |
16 | #include <linux/platform_device.h> |
17 | #include <linux/cpuidle.h> |
18 | #include <linux/cpu_pm.h> |
19 | #include <linux/firmware/qcom/qcom_scm.h> |
20 | #include <soc/qcom/spm.h> |
21 | |
22 | #include <asm/proc-fns.h> |
23 | #include <asm/suspend.h> |
24 | |
25 | #include "dt_idle_states.h" |
26 | |
27 | struct cpuidle_qcom_spm_data { |
28 | struct cpuidle_driver cpuidle_driver; |
29 | struct spm_driver_data *spm; |
30 | }; |
31 | |
32 | static int qcom_pm_collapse(unsigned long int unused) |
33 | { |
34 | qcom_scm_cpu_power_down(QCOM_SCM_CPU_PWR_DOWN_L2_ON); |
35 | |
36 | /* |
37 | * Returns here only if there was a pending interrupt and we did not |
38 | * power down as a result. |
39 | */ |
40 | return -1; |
41 | } |
42 | |
43 | static int qcom_cpu_spc(struct spm_driver_data *drv) |
44 | { |
45 | int ret; |
46 | |
47 | spm_set_low_power_mode(drv, mode: PM_SLEEP_MODE_SPC); |
48 | ret = cpu_suspend(0, qcom_pm_collapse); |
49 | /* |
50 | * ARM common code executes WFI without calling into our driver and |
51 | * if the SPM mode is not reset, then we may accidently power down the |
52 | * cpu when we intended only to gate the cpu clock. |
53 | * Ensure the state is set to standby before returning. |
54 | */ |
55 | spm_set_low_power_mode(drv, mode: PM_SLEEP_MODE_STBY); |
56 | |
57 | return ret; |
58 | } |
59 | |
60 | static __cpuidle int spm_enter_idle_state(struct cpuidle_device *dev, |
61 | struct cpuidle_driver *drv, int idx) |
62 | { |
63 | struct cpuidle_qcom_spm_data *data = container_of(drv, struct cpuidle_qcom_spm_data, |
64 | cpuidle_driver); |
65 | |
66 | return CPU_PM_CPU_IDLE_ENTER_PARAM(qcom_cpu_spc, idx, data->spm); |
67 | } |
68 | |
69 | static struct cpuidle_driver qcom_spm_idle_driver = { |
70 | .name = "qcom_spm" , |
71 | .owner = THIS_MODULE, |
72 | .states[0] = { |
73 | .enter = spm_enter_idle_state, |
74 | .exit_latency = 1, |
75 | .target_residency = 1, |
76 | .power_usage = UINT_MAX, |
77 | .name = "WFI" , |
78 | .desc = "ARM WFI" , |
79 | } |
80 | }; |
81 | |
82 | static const struct of_device_id qcom_idle_state_match[] = { |
83 | { .compatible = "qcom,idle-state-spc" , .data = spm_enter_idle_state }, |
84 | { }, |
85 | }; |
86 | |
87 | static int spm_cpuidle_register(struct device *cpuidle_dev, int cpu) |
88 | { |
89 | struct platform_device *pdev = NULL; |
90 | struct device_node *cpu_node, *saw_node; |
91 | struct cpuidle_qcom_spm_data *data = NULL; |
92 | int ret; |
93 | |
94 | cpu_node = of_cpu_device_node_get(cpu); |
95 | if (!cpu_node) |
96 | return -ENODEV; |
97 | |
98 | saw_node = of_parse_phandle(np: cpu_node, phandle_name: "qcom,saw" , index: 0); |
99 | if (!saw_node) |
100 | return -ENODEV; |
101 | |
102 | pdev = of_find_device_by_node(np: saw_node); |
103 | of_node_put(node: saw_node); |
104 | of_node_put(node: cpu_node); |
105 | if (!pdev) |
106 | return -ENODEV; |
107 | |
108 | data = devm_kzalloc(dev: cpuidle_dev, size: sizeof(*data), GFP_KERNEL); |
109 | if (!data) |
110 | return -ENOMEM; |
111 | |
112 | data->spm = dev_get_drvdata(dev: &pdev->dev); |
113 | if (!data->spm) |
114 | return -EINVAL; |
115 | |
116 | data->cpuidle_driver = qcom_spm_idle_driver; |
117 | data->cpuidle_driver.cpumask = (struct cpumask *)cpumask_of(cpu); |
118 | |
119 | ret = dt_init_idle_driver(drv: &data->cpuidle_driver, |
120 | matches: qcom_idle_state_match, start_idx: 1); |
121 | if (ret <= 0) |
122 | return ret ? : -ENODEV; |
123 | |
124 | return cpuidle_register(drv: &data->cpuidle_driver, NULL); |
125 | } |
126 | |
127 | static int spm_cpuidle_drv_probe(struct platform_device *pdev) |
128 | { |
129 | int cpu, ret; |
130 | |
131 | if (!qcom_scm_is_available()) |
132 | return -EPROBE_DEFER; |
133 | |
134 | ret = qcom_scm_set_warm_boot_addr(entry: cpu_resume_arm); |
135 | if (ret) |
136 | return dev_err_probe(dev: &pdev->dev, err: ret, fmt: "set warm boot addr failed" ); |
137 | |
138 | for_each_possible_cpu(cpu) { |
139 | ret = spm_cpuidle_register(cpuidle_dev: &pdev->dev, cpu); |
140 | if (ret && ret != -ENODEV) { |
141 | dev_err(&pdev->dev, |
142 | "Cannot register for CPU%d: %d\n" , cpu, ret); |
143 | } |
144 | } |
145 | |
146 | return 0; |
147 | } |
148 | |
149 | static struct platform_driver spm_cpuidle_driver = { |
150 | .probe = spm_cpuidle_drv_probe, |
151 | .driver = { |
152 | .name = "qcom-spm-cpuidle" , |
153 | .suppress_bind_attrs = true, |
154 | }, |
155 | }; |
156 | |
157 | static bool __init qcom_spm_find_any_cpu(void) |
158 | { |
159 | struct device_node *cpu_node, *saw_node; |
160 | |
161 | for_each_of_cpu_node(cpu_node) { |
162 | saw_node = of_parse_phandle(np: cpu_node, phandle_name: "qcom,saw" , index: 0); |
163 | if (of_device_is_available(device: saw_node)) { |
164 | of_node_put(node: saw_node); |
165 | of_node_put(node: cpu_node); |
166 | return true; |
167 | } |
168 | of_node_put(node: saw_node); |
169 | } |
170 | return false; |
171 | } |
172 | |
173 | static int __init qcom_spm_cpuidle_init(void) |
174 | { |
175 | struct platform_device *pdev; |
176 | int ret; |
177 | |
178 | ret = platform_driver_register(&spm_cpuidle_driver); |
179 | if (ret) |
180 | return ret; |
181 | |
182 | /* Make sure there is actually any CPU managed by the SPM */ |
183 | if (!qcom_spm_find_any_cpu()) |
184 | return 0; |
185 | |
186 | pdev = platform_device_register_simple(name: "qcom-spm-cpuidle" , |
187 | id: -1, NULL, num: 0); |
188 | if (IS_ERR(ptr: pdev)) { |
189 | platform_driver_unregister(&spm_cpuidle_driver); |
190 | return PTR_ERR(ptr: pdev); |
191 | } |
192 | |
193 | return 0; |
194 | } |
195 | device_initcall(qcom_spm_cpuidle_init); |
196 | |