tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/bitfield.h>
4#include <linux/cpufreq.h>
5#include <linux/module.h>
6#include <linux/platform_device.h>
7#include <linux/pm_domain.h>
8#include <linux/pm_runtime.h>
9#include <linux/slab.h>
10
11#include "cpufreq-dt.h"
12
13struct airoha_cpufreq_priv {
14 int opp_token;
15 struct dev_pm_domain_list *pd_list;
16 struct platform_device *cpufreq_dt;
17};
18
19static struct platform_device *cpufreq_pdev;
20
21/* NOP function to disable OPP from setting clock */
22static int airoha_cpufreq_config_clks_nop(struct device *dev,
23 struct opp_table *opp_table,
24 struct dev_pm_opp *opp,
25 void *data, bool scaling_down)
26{
27 return 0;
28}
29
30static const char * const airoha_cpufreq_clk_names[] = { "cpu", NULL };
31static const char * const airoha_cpufreq_pd_names[] = { "perf" };
32
33static int airoha_cpufreq_probe(struct platform_device *pdev)
34{
35 const struct dev_pm_domain_attach_data attach_data = {
36 .pd_names = airoha_cpufreq_pd_names,
37 .num_pd_names = ARRAY_SIZE(airoha_cpufreq_pd_names),
38 .pd_flags = PD_FLAG_DEV_LINK_ON | PD_FLAG_REQUIRED_OPP,
39 };
40 struct dev_pm_opp_config config = {
41 .clk_names = airoha_cpufreq_clk_names,
42 .config_clks = airoha_cpufreq_config_clks_nop,
43 };
44 struct platform_device *cpufreq_dt;
45 struct airoha_cpufreq_priv *priv;
46 struct device *dev = &pdev->dev;
47 struct device *cpu_dev;
48 int ret;
49
50 /* CPUs refer to the same OPP table */
51 cpu_dev = get_cpu_device(0);
52 if (!cpu_dev)
53 return -ENODEV;
54
55 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
56 if (!priv)
57 return -ENOMEM;
58
59 /* Set OPP table conf with NOP config_clks */
60 priv->opp_token = dev_pm_opp_set_config(cpu_dev, &config);
61 if (priv->opp_token < 0)
62 return dev_err_probe(dev, priv->opp_token, "Failed to set OPP config\n");
63
64 /* Attach PM for OPP */
65 ret = dev_pm_domain_attach_list(cpu_dev, &attach_data,
66 &priv->pd_list);
67 if (ret)
68 goto clear_opp_config;
69
70 cpufreq_dt = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
71 ret = PTR_ERR_OR_ZERO(cpufreq_dt);
72 if (ret) {
73 dev_err(dev, "failed to create cpufreq-dt device: %d\n", ret);
74 goto detach_pm;
75 }
76
77 priv->cpufreq_dt = cpufreq_dt;
78 platform_set_drvdata(pdev, priv);
79
80 return 0;
81
82detach_pm:
83 dev_pm_domain_detach_list(priv->pd_list);
84clear_opp_config:
85 dev_pm_opp_clear_config(priv->opp_token);
86
87 return ret;
88}
89
90static void airoha_cpufreq_remove(struct platform_device *pdev)
91{
92 struct airoha_cpufreq_priv *priv = platform_get_drvdata(pdev);
93
94 platform_device_unregister(priv->cpufreq_dt);
95
96 dev_pm_domain_detach_list(priv->pd_list);
97
98 dev_pm_opp_clear_config(priv->opp_token);
99}
100
101static struct platform_driver airoha_cpufreq_driver = {
102 .probe = airoha_cpufreq_probe,
103 .remove = airoha_cpufreq_remove,
104 .driver = {
105 .name = "airoha-cpufreq",
106 },
107};
108
109static const struct of_device_id airoha_cpufreq_match_list[] __initconst = {
110 { .compatible = "airoha,an7583" },
111 { .compatible = "airoha,en7581" },
112 {},
113};
114MODULE_DEVICE_TABLE(of, airoha_cpufreq_match_list);
115
116static int __init airoha_cpufreq_init(void)
117{
118 struct device_node *np = of_find_node_by_path("/");
119 const struct of_device_id *match;
120 int ret;
121
122 if (!np)
123 return -ENODEV;
124
125 match = of_match_node(airoha_cpufreq_match_list, np);
126 of_node_put(np);
127 if (!match)
128 return -ENODEV;
129
130 ret = platform_driver_register(&airoha_cpufreq_driver);
131 if (unlikely(ret < 0))
132 return ret;
133
134 cpufreq_pdev = platform_device_register_data(NULL, "airoha-cpufreq",
135 -1, match, sizeof(*match));
136 ret = PTR_ERR_OR_ZERO(cpufreq_pdev);
137 if (ret)
138 platform_driver_unregister(&airoha_cpufreq_driver);
139
140 return ret;
141}
142module_init(airoha_cpufreq_init);
143
144static void __exit airoha_cpufreq_exit(void)
145{
146 platform_device_unregister(cpufreq_pdev);
147 platform_driver_unregister(&airoha_cpufreq_driver);
148}
149module_exit(airoha_cpufreq_exit);
150
151MODULE_AUTHOR("Christian Marangi <ansuelsmth@gmail.com>");
152MODULE_DESCRIPTION("CPUfreq driver for Airoha SoCs");
153MODULE_LICENSE("GPL");