xref: /openbmc/linux/drivers/soc/tegra/common.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014 NVIDIA CORPORATION.  All rights reserved.
4  */
5 
6 #define dev_fmt(fmt)	"tegra-soc: " fmt
7 
8 #include <linux/clk.h>
9 #include <linux/device.h>
10 #include <linux/export.h>
11 #include <linux/of.h>
12 #include <linux/pm_opp.h>
13 #include <linux/pm_runtime.h>
14 
15 #include <soc/tegra/common.h>
16 #include <soc/tegra/fuse.h>
17 
18 static const struct of_device_id tegra_machine_match[] = {
19 	{ .compatible = "nvidia,tegra20", },
20 	{ .compatible = "nvidia,tegra30", },
21 	{ .compatible = "nvidia,tegra114", },
22 	{ .compatible = "nvidia,tegra124", },
23 	{ .compatible = "nvidia,tegra132", },
24 	{ .compatible = "nvidia,tegra210", },
25 	{ }
26 };
27 
28 bool soc_is_tegra(void)
29 {
30 	const struct of_device_id *match;
31 	struct device_node *root;
32 
33 	root = of_find_node_by_path("/");
34 	if (!root)
35 		return false;
36 
37 	match = of_match_node(tegra_machine_match, root);
38 	of_node_put(root);
39 
40 	return match != NULL;
41 }
42 
43 static int tegra_core_dev_init_opp_state(struct device *dev)
44 {
45 	unsigned long rate;
46 	struct clk *clk;
47 	bool rpm_enabled;
48 	int err;
49 
50 	clk = devm_clk_get(dev, NULL);
51 	if (IS_ERR(clk)) {
52 		dev_err(dev, "failed to get clk: %pe\n", clk);
53 		return PTR_ERR(clk);
54 	}
55 
56 	rate = clk_get_rate(clk);
57 	if (!rate) {
58 		dev_err(dev, "failed to get clk rate\n");
59 		return -EINVAL;
60 	}
61 
62 	/*
63 	 * Runtime PM of the device must be enabled in order to set up
64 	 * GENPD's performance properly because GENPD core checks whether
65 	 * device is suspended and this check doesn't work while RPM is
66 	 * disabled. This makes sure the OPP vote below gets cached in
67 	 * GENPD for the device. Instead, the vote is done the next time
68 	 * the device gets runtime resumed.
69 	 */
70 	rpm_enabled = pm_runtime_enabled(dev);
71 	if (!rpm_enabled)
72 		pm_runtime_enable(dev);
73 
74 	/* should never happen in practice */
75 	if (!pm_runtime_enabled(dev)) {
76 		dev_WARN(dev, "failed to enable runtime PM\n");
77 		pm_runtime_disable(dev);
78 		return -EINVAL;
79 	}
80 
81 	/* first dummy rate-setting initializes voltage vote */
82 	err = dev_pm_opp_set_rate(dev, rate);
83 
84 	if (!rpm_enabled)
85 		pm_runtime_disable(dev);
86 
87 	if (err) {
88 		dev_err(dev, "failed to initialize OPP clock: %d\n", err);
89 		return err;
90 	}
91 
92 	return 0;
93 }
94 
95 /**
96  * devm_tegra_core_dev_init_opp_table() - initialize OPP table
97  * @dev: device for which OPP table is initialized
98  * @params: pointer to the OPP table configuration
99  *
100  * This function will initialize OPP table and sync OPP state of a Tegra SoC
101  * core device.
102  *
103  * Return: 0 on success or errorno.
104  */
105 int devm_tegra_core_dev_init_opp_table(struct device *dev,
106 				       struct tegra_core_opp_params *params)
107 {
108 	u32 hw_version;
109 	int err;
110 
111 	err = devm_pm_opp_set_clkname(dev, NULL);
112 	if (err) {
113 		dev_err(dev, "failed to set OPP clk: %d\n", err);
114 		return err;
115 	}
116 
117 	/* Tegra114+ doesn't support OPP yet */
118 	if (!of_machine_is_compatible("nvidia,tegra20") &&
119 	    !of_machine_is_compatible("nvidia,tegra30"))
120 		return -ENODEV;
121 
122 	if (of_machine_is_compatible("nvidia,tegra20"))
123 		hw_version = BIT(tegra_sku_info.soc_process_id);
124 	else
125 		hw_version = BIT(tegra_sku_info.soc_speedo_id);
126 
127 	err = devm_pm_opp_set_supported_hw(dev, &hw_version, 1);
128 	if (err) {
129 		dev_err(dev, "failed to set OPP supported HW: %d\n", err);
130 		return err;
131 	}
132 
133 	/*
134 	 * Older device-trees have an empty OPP table, we will get
135 	 * -ENODEV from devm_pm_opp_of_add_table() in this case.
136 	 */
137 	err = devm_pm_opp_of_add_table(dev);
138 	if (err) {
139 		if (err != -ENODEV)
140 			dev_err(dev, "failed to add OPP table: %d\n", err);
141 
142 		return err;
143 	}
144 
145 	if (params->init_state) {
146 		err = tegra_core_dev_init_opp_state(dev);
147 		if (err)
148 			return err;
149 	}
150 
151 	return 0;
152 }
153 EXPORT_SYMBOL_GPL(devm_tegra_core_dev_init_opp_table);
154