1 /*
2  * Tegra ACONNECT Bus Driver
3  *
4  * Copyright (C) 2016, NVIDIA CORPORATION.  All rights reserved.
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License.  See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/module.h>
13 #include <linux/of_platform.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_runtime.h>
16 
17 struct tegra_aconnect {
18 	struct clk	*ape_clk;
19 	struct clk	*apb2ape_clk;
20 };
21 
tegra_aconnect_probe(struct platform_device * pdev)22 static int tegra_aconnect_probe(struct platform_device *pdev)
23 {
24 	struct tegra_aconnect *aconnect;
25 
26 	if (!pdev->dev.of_node)
27 		return -EINVAL;
28 
29 	aconnect = devm_kzalloc(&pdev->dev, sizeof(struct tegra_aconnect),
30 				GFP_KERNEL);
31 	if (!aconnect)
32 		return -ENOMEM;
33 
34 	aconnect->ape_clk = devm_clk_get(&pdev->dev, "ape");
35 	if (IS_ERR(aconnect->ape_clk)) {
36 		dev_err(&pdev->dev, "Can't retrieve ape clock\n");
37 		return PTR_ERR(aconnect->ape_clk);
38 	}
39 
40 	aconnect->apb2ape_clk = devm_clk_get(&pdev->dev, "apb2ape");
41 	if (IS_ERR(aconnect->apb2ape_clk)) {
42 		dev_err(&pdev->dev, "Can't retrieve apb2ape clock\n");
43 		return PTR_ERR(aconnect->apb2ape_clk);
44 	}
45 
46 	dev_set_drvdata(&pdev->dev, aconnect);
47 	pm_runtime_enable(&pdev->dev);
48 
49 	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
50 
51 	dev_info(&pdev->dev, "Tegra ACONNECT bus registered\n");
52 
53 	return 0;
54 }
55 
tegra_aconnect_remove(struct platform_device * pdev)56 static int tegra_aconnect_remove(struct platform_device *pdev)
57 {
58 	pm_runtime_disable(&pdev->dev);
59 
60 	return 0;
61 }
62 
tegra_aconnect_runtime_resume(struct device * dev)63 static int tegra_aconnect_runtime_resume(struct device *dev)
64 {
65 	struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
66 	int ret;
67 
68 	ret = clk_prepare_enable(aconnect->ape_clk);
69 	if (ret) {
70 		dev_err(dev, "ape clk_enable failed: %d\n", ret);
71 		return ret;
72 	}
73 
74 	ret = clk_prepare_enable(aconnect->apb2ape_clk);
75 	if (ret) {
76 		clk_disable_unprepare(aconnect->ape_clk);
77 		dev_err(dev, "apb2ape clk_enable failed: %d\n", ret);
78 		return ret;
79 	}
80 
81 	return 0;
82 }
83 
tegra_aconnect_runtime_suspend(struct device * dev)84 static int tegra_aconnect_runtime_suspend(struct device *dev)
85 {
86 	struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
87 
88 	clk_disable_unprepare(aconnect->ape_clk);
89 	clk_disable_unprepare(aconnect->apb2ape_clk);
90 
91 	return 0;
92 }
93 
94 static const struct dev_pm_ops tegra_aconnect_pm_ops = {
95 	SET_RUNTIME_PM_OPS(tegra_aconnect_runtime_suspend,
96 			   tegra_aconnect_runtime_resume, NULL)
97 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
98 				      pm_runtime_force_resume)
99 };
100 
101 static const struct of_device_id tegra_aconnect_of_match[] = {
102 	{ .compatible = "nvidia,tegra210-aconnect", },
103 	{ }
104 };
105 MODULE_DEVICE_TABLE(of, tegra_aconnect_of_match);
106 
107 static struct platform_driver tegra_aconnect_driver = {
108 	.probe = tegra_aconnect_probe,
109 	.remove = tegra_aconnect_remove,
110 	.driver = {
111 		.name = "tegra-aconnect",
112 		.of_match_table = tegra_aconnect_of_match,
113 		.pm = &tegra_aconnect_pm_ops,
114 	},
115 };
116 module_platform_driver(tegra_aconnect_driver);
117 
118 MODULE_DESCRIPTION("NVIDIA Tegra ACONNECT Bus Driver");
119 MODULE_AUTHOR("Jon Hunter <jonathanh@nvidia.com>");
120 MODULE_LICENSE("GPL v2");
121