1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/arm-smccc.h>
4#include <linux/bitfield.h>
5#include <linux/clk-provider.h>
6#include <linux/module.h>
7#include <linux/platform_device.h>
8#include <linux/pm_domain.h>
9#include <linux/slab.h>
10
11#define AIROHA_SIP_AVS_HANDLE 0x82000301
12#define AIROHA_AVS_OP_BASE 0xddddddd0
13#define AIROHA_AVS_OP_MASK GENMASK(1, 0)
14#define AIROHA_AVS_OP_FREQ_DYN_ADJ (AIROHA_AVS_OP_BASE | \
15 FIELD_PREP(AIROHA_AVS_OP_MASK, 0x1))
16#define AIROHA_AVS_OP_GET_FREQ (AIROHA_AVS_OP_BASE | \
17 FIELD_PREP(AIROHA_AVS_OP_MASK, 0x2))
18
19struct airoha_cpu_pmdomain_priv {
20 struct clk_hw hw;
21 struct generic_pm_domain pd;
22};
23
24static long airoha_cpu_pmdomain_clk_round(struct clk_hw *hw, unsigned long rate,
25 unsigned long *parent_rate)
26{
27 return rate;
28}
29
30static unsigned long airoha_cpu_pmdomain_clk_get(struct clk_hw *hw,
31 unsigned long parent_rate)
32{
33 struct arm_smccc_res res;
34
35 arm_smccc_1_1_invoke(AIROHA_SIP_AVS_HANDLE, AIROHA_AVS_OP_GET_FREQ,
36 0, 0, 0, 0, 0, 0, &res);
37
38 /* SMCCC returns freq in MHz */
39 return (int)(res.a0 * 1000 * 1000);
40}
41
42/* Airoha CPU clk SMCC is always enabled */
43static int airoha_cpu_pmdomain_clk_is_enabled(struct clk_hw *hw)
44{
45 return true;
46}
47
48static const struct clk_ops airoha_cpu_pmdomain_clk_ops = {
49 .recalc_rate = airoha_cpu_pmdomain_clk_get,
50 .is_enabled = airoha_cpu_pmdomain_clk_is_enabled,
51 .round_rate = airoha_cpu_pmdomain_clk_round,
52};
53
54static int airoha_cpu_pmdomain_set_performance_state(struct generic_pm_domain *domain,
55 unsigned int state)
56{
57 struct arm_smccc_res res;
58
59 arm_smccc_1_1_invoke(AIROHA_SIP_AVS_HANDLE, AIROHA_AVS_OP_FREQ_DYN_ADJ,
60 0, state, 0, 0, 0, 0, &res);
61
62 /* SMC signal correct apply by unsetting BIT 0 */
63 return res.a0 & BIT(0) ? -EINVAL : 0;
64}
65
66static int airoha_cpu_pmdomain_probe(struct platform_device *pdev)
67{
68 struct airoha_cpu_pmdomain_priv *priv;
69 struct device *dev = &pdev->dev;
70 const struct clk_init_data init = {
71 .name = "cpu",
72 .ops = &airoha_cpu_pmdomain_clk_ops,
73 /* Clock with no set_rate, can't cache */
74 .flags = CLK_GET_RATE_NOCACHE,
75 };
76 struct generic_pm_domain *pd;
77 int ret;
78
79 priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL);
80 if (!priv)
81 return -ENOMEM;
82
83 /* Init and register a get-only clk for Cpufreq */
84 priv->hw.init = &init;
85 ret = devm_clk_hw_register(dev, hw: &priv->hw);
86 if (ret)
87 return ret;
88
89 ret = devm_of_clk_add_hw_provider(dev, get: of_clk_hw_simple_get,
90 data: &priv->hw);
91 if (ret)
92 return ret;
93
94 /* Init and register a PD for CPU */
95 pd = &priv->pd;
96 pd->name = "cpu_pd";
97 pd->flags = GENPD_FLAG_ALWAYS_ON;
98 pd->set_performance_state = airoha_cpu_pmdomain_set_performance_state;
99
100 ret = pm_genpd_init(genpd: pd, NULL, is_off: false);
101 if (ret)
102 return ret;
103
104 ret = of_genpd_add_provider_simple(np: dev->of_node, genpd: pd);
105 if (ret)
106 goto err_add_provider;
107
108 platform_set_drvdata(pdev, data: priv);
109
110 return 0;
111
112err_add_provider:
113 pm_genpd_remove(genpd: pd);
114
115 return ret;
116}
117
118static void airoha_cpu_pmdomain_remove(struct platform_device *pdev)
119{
120 struct airoha_cpu_pmdomain_priv *priv = platform_get_drvdata(pdev);
121
122 of_genpd_del_provider(np: pdev->dev.of_node);
123 pm_genpd_remove(genpd: &priv->pd);
124}
125
126static const struct of_device_id airoha_cpu_pmdomain_of_match[] = {
127 { .compatible = "airoha,en7581-cpufreq" },
128 { },
129};
130MODULE_DEVICE_TABLE(of, airoha_cpu_pmdomain_of_match);
131
132static struct platform_driver airoha_cpu_pmdomain_driver = {
133 .probe = airoha_cpu_pmdomain_probe,
134 .remove = airoha_cpu_pmdomain_remove,
135 .driver = {
136 .name = "airoha-cpu-pmdomain",
137 .of_match_table = airoha_cpu_pmdomain_of_match,
138 },
139};
140module_platform_driver(airoha_cpu_pmdomain_driver);
141
142MODULE_AUTHOR("Christian Marangi <ansuelsmth@gmail.com>");
143MODULE_DESCRIPTION("CPU PM domain driver for Airoha SoCs");
144MODULE_LICENSE("GPL");
145

source code of linux/drivers/pmdomain/mediatek/airoha-cpu-pmdomain.c