airoha-cpufreq.c

  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");