xref: /openbmc/linux/drivers/irqchip/irq-gic-pm.c (revision e5bd61e8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2016 NVIDIA CORPORATION, All Rights Reserved.
4  */
5 #include <linux/module.h>
6 #include <linux/clk.h>
7 #include <linux/of_device.h>
8 #include <linux/of_irq.h>
9 #include <linux/irqchip/arm-gic.h>
10 #include <linux/platform_device.h>
11 #include <linux/pm_runtime.h>
12 #include <linux/slab.h>
13 
14 struct gic_clk_data {
15 	unsigned int num_clocks;
16 	const char *const *clocks;
17 };
18 
19 struct gic_chip_pm {
20 	struct gic_chip_data *chip_data;
21 	const struct gic_clk_data *clk_data;
22 	struct clk_bulk_data *clks;
23 };
24 
25 static int gic_runtime_resume(struct device *dev)
26 {
27 	struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
28 	struct gic_chip_data *gic = chip_pm->chip_data;
29 	const struct gic_clk_data *data = chip_pm->clk_data;
30 	int ret;
31 
32 	ret = clk_bulk_prepare_enable(data->num_clocks, chip_pm->clks);
33 	if (ret) {
34 		dev_err(dev, "clk_enable failed: %d\n", ret);
35 		return ret;
36 	}
37 
38 	/*
39 	 * On the very first resume, the pointer to chip_pm->chip_data
40 	 * will be NULL and this is intentional, because we do not
41 	 * want to restore the GIC on the very first resume. So if
42 	 * the pointer is not valid just return.
43 	 */
44 	if (!gic)
45 		return 0;
46 
47 	gic_dist_restore(gic);
48 	gic_cpu_restore(gic);
49 
50 	return 0;
51 }
52 
53 static int gic_runtime_suspend(struct device *dev)
54 {
55 	struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
56 	struct gic_chip_data *gic = chip_pm->chip_data;
57 	const struct gic_clk_data *data = chip_pm->clk_data;
58 
59 	gic_dist_save(gic);
60 	gic_cpu_save(gic);
61 
62 	clk_bulk_disable_unprepare(data->num_clocks, chip_pm->clks);
63 
64 	return 0;
65 }
66 
67 static int gic_probe(struct platform_device *pdev)
68 {
69 	struct device *dev = &pdev->dev;
70 	const struct gic_clk_data *data;
71 	struct gic_chip_pm *chip_pm;
72 	int ret, irq, i;
73 
74 	data = of_device_get_match_data(&pdev->dev);
75 	if (!data) {
76 		dev_err(&pdev->dev, "no device match found\n");
77 		return -ENODEV;
78 	}
79 
80 	chip_pm = devm_kzalloc(dev, sizeof(*chip_pm), GFP_KERNEL);
81 	if (!chip_pm)
82 		return -ENOMEM;
83 
84 	irq = irq_of_parse_and_map(dev->of_node, 0);
85 	if (!irq) {
86 		dev_err(dev, "no parent interrupt found!\n");
87 		return -EINVAL;
88 	}
89 
90 	chip_pm->clks = devm_kcalloc(dev, data->num_clocks,
91 				     sizeof(*chip_pm->clks), GFP_KERNEL);
92 	if (!chip_pm->clks)
93 		return -ENOMEM;
94 
95 	for (i = 0; i < data->num_clocks; i++)
96 		chip_pm->clks[i].id = data->clocks[i];
97 
98 	ret = devm_clk_bulk_get(dev, data->num_clocks, chip_pm->clks);
99 	if (ret)
100 		goto irq_dispose;
101 
102 	chip_pm->clk_data = data;
103 	dev_set_drvdata(dev, chip_pm);
104 
105 	pm_runtime_enable(dev);
106 
107 	ret = pm_runtime_get_sync(dev);
108 	if (ret < 0)
109 		goto rpm_disable;
110 
111 	ret = gic_of_init_child(dev, &chip_pm->chip_data, irq);
112 	if (ret)
113 		goto rpm_put;
114 
115 	pm_runtime_put(dev);
116 
117 	dev_info(dev, "GIC IRQ controller registered\n");
118 
119 	return 0;
120 
121 rpm_put:
122 	pm_runtime_put_sync(dev);
123 rpm_disable:
124 	pm_runtime_disable(dev);
125 irq_dispose:
126 	irq_dispose_mapping(irq);
127 
128 	return ret;
129 }
130 
131 static const struct dev_pm_ops gic_pm_ops = {
132 	SET_RUNTIME_PM_OPS(gic_runtime_suspend,
133 			   gic_runtime_resume, NULL)
134 	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
135 				     pm_runtime_force_resume)
136 };
137 
138 static const char * const gic400_clocks[] = {
139 	"clk",
140 };
141 
142 static const struct gic_clk_data gic400_data = {
143 	.num_clocks = ARRAY_SIZE(gic400_clocks),
144 	.clocks = gic400_clocks,
145 };
146 
147 static const struct of_device_id gic_match[] = {
148 	{ .compatible = "nvidia,tegra210-agic",	.data = &gic400_data },
149 	{},
150 };
151 MODULE_DEVICE_TABLE(of, gic_match);
152 
153 static struct platform_driver gic_driver = {
154 	.probe		= gic_probe,
155 	.driver		= {
156 		.name	= "gic",
157 		.of_match_table	= gic_match,
158 		.pm	= &gic_pm_ops,
159 	}
160 };
161 
162 builtin_platform_driver(gic_driver);
163