1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2010 Google, Inc.
4  *
5  * Author:
6  *	Colin Cross <ccross@google.com>
7  *	Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation
8  */
9 
10 #include <linux/bits.h>
11 #include <linux/cpu.h>
12 #include <linux/err.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/of_device.h>
16 #include <linux/platform_device.h>
17 #include <linux/pm_opp.h>
18 #include <linux/types.h>
19 
20 #include <soc/tegra/common.h>
21 #include <soc/tegra/fuse.h>
22 
23 static bool cpu0_node_has_opp_v2_prop(void)
24 {
25 	struct device_node *np = of_cpu_device_node_get(0);
26 	bool ret = false;
27 
28 	if (of_get_property(np, "operating-points-v2", NULL))
29 		ret = true;
30 
31 	of_node_put(np);
32 	return ret;
33 }
34 
35 static void tegra20_cpufreq_put_supported_hw(void *opp_table)
36 {
37 	dev_pm_opp_put_supported_hw(opp_table);
38 }
39 
40 static void tegra20_cpufreq_dt_unregister(void *cpufreq_dt)
41 {
42 	platform_device_unregister(cpufreq_dt);
43 }
44 
45 static int tegra20_cpufreq_probe(struct platform_device *pdev)
46 {
47 	struct platform_device *cpufreq_dt;
48 	struct opp_table *opp_table;
49 	struct device *cpu_dev;
50 	u32 versions[2];
51 	int err;
52 
53 	if (!cpu0_node_has_opp_v2_prop()) {
54 		dev_err(&pdev->dev, "operating points not found\n");
55 		dev_err(&pdev->dev, "please update your device tree\n");
56 		return -ENODEV;
57 	}
58 
59 	if (of_machine_is_compatible("nvidia,tegra20")) {
60 		versions[0] = BIT(tegra_sku_info.cpu_process_id);
61 		versions[1] = BIT(tegra_sku_info.soc_speedo_id);
62 	} else {
63 		versions[0] = BIT(tegra_sku_info.cpu_process_id);
64 		versions[1] = BIT(tegra_sku_info.cpu_speedo_id);
65 	}
66 
67 	dev_info(&pdev->dev, "hardware version 0x%x 0x%x\n",
68 		 versions[0], versions[1]);
69 
70 	cpu_dev = get_cpu_device(0);
71 	if (WARN_ON(!cpu_dev))
72 		return -ENODEV;
73 
74 	opp_table = dev_pm_opp_set_supported_hw(cpu_dev, versions, 2);
75 	err = PTR_ERR_OR_ZERO(opp_table);
76 	if (err) {
77 		dev_err(&pdev->dev, "failed to set supported hw: %d\n", err);
78 		return err;
79 	}
80 
81 	err = devm_add_action_or_reset(&pdev->dev,
82 				       tegra20_cpufreq_put_supported_hw,
83 				       opp_table);
84 	if (err)
85 		return err;
86 
87 	cpufreq_dt = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
88 	err = PTR_ERR_OR_ZERO(cpufreq_dt);
89 	if (err) {
90 		dev_err(&pdev->dev,
91 			"failed to create cpufreq-dt device: %d\n", err);
92 		return err;
93 	}
94 
95 	err = devm_add_action_or_reset(&pdev->dev,
96 				       tegra20_cpufreq_dt_unregister,
97 				       cpufreq_dt);
98 	if (err)
99 		return err;
100 
101 	return 0;
102 }
103 
104 static struct platform_driver tegra20_cpufreq_driver = {
105 	.probe		= tegra20_cpufreq_probe,
106 	.driver		= {
107 		.name	= "tegra20-cpufreq",
108 	},
109 };
110 module_platform_driver(tegra20_cpufreq_driver);
111 
112 MODULE_ALIAS("platform:tegra20-cpufreq");
113 MODULE_AUTHOR("Colin Cross <ccross@android.com>");
114 MODULE_DESCRIPTION("NVIDIA Tegra20 cpufreq driver");
115 MODULE_LICENSE("GPL");
116