xref: /openbmc/linux/drivers/irqchip/irq-gic-pm.c (revision 2326f3cd)
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 		return ret;
35 
36 	/*
37 	 * On the very first resume, the pointer to chip_pm->chip_data
38 	 * will be NULL and this is intentional, because we do not
39 	 * want to restore the GIC on the very first resume. So if
40 	 * the pointer is not valid just return.
41 	 */
42 	if (!gic)
43 		return 0;
44 
45 	gic_dist_restore(gic);
46 	gic_cpu_restore(gic);
47 
48 	return 0;
49 }
50 
51 static int gic_runtime_suspend(struct device *dev)
52 {
53 	struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
54 	struct gic_chip_data *gic = chip_pm->chip_data;
55 	const struct gic_clk_data *data = chip_pm->clk_data;
56 
57 	gic_dist_save(gic);
58 	gic_cpu_save(gic);
59 
60 	clk_bulk_disable_unprepare(data->num_clocks, chip_pm->clks);
61 
62 	return 0;
63 }
64 
65 static int gic_probe(struct platform_device *pdev)
66 {
67 	struct device *dev = &pdev->dev;
68 	const struct gic_clk_data *data;
69 	struct gic_chip_pm *chip_pm;
70 	int ret, irq, i;
71 
72 	data = of_device_get_match_data(&pdev->dev);
73 	if (!data) {
74 		dev_err(&pdev->dev, "no device match found\n");
75 		return -ENODEV;
76 	}
77 
78 	chip_pm = devm_kzalloc(dev, sizeof(*chip_pm), GFP_KERNEL);
79 	if (!chip_pm)
80 		return -ENOMEM;
81 
82 	irq = irq_of_parse_and_map(dev->of_node, 0);
83 	if (!irq) {
84 		dev_err(dev, "no parent interrupt found!\n");
85 		return -EINVAL;
86 	}
87 
88 	chip_pm->clks = devm_kcalloc(dev, data->num_clocks,
89 				     sizeof(*chip_pm->clks), GFP_KERNEL);
90 	if (!chip_pm->clks)
91 		return -ENOMEM;
92 
93 	for (i = 0; i < data->num_clocks; i++)
94 		chip_pm->clks[i].id = data->clocks[i];
95 
96 	ret = devm_clk_bulk_get(dev, data->num_clocks, chip_pm->clks);
97 	if (ret)
98 		goto irq_dispose;
99 
100 	chip_pm->clk_data = data;
101 	dev_set_drvdata(dev, chip_pm);
102 
103 	pm_runtime_enable(dev);
104 
105 	ret = pm_runtime_get_sync(dev);
106 	if (ret < 0)
107 		goto rpm_disable;
108 
109 	ret = gic_of_init_child(dev, &chip_pm->chip_data, irq);
110 	if (ret)
111 		goto rpm_put;
112 
113 	pm_runtime_put(dev);
114 
115 	dev_info(dev, "GIC IRQ controller registered\n");
116 
117 	return 0;
118 
119 rpm_put:
120 	pm_runtime_put_sync(dev);
121 rpm_disable:
122 	pm_runtime_disable(dev);
123 irq_dispose:
124 	irq_dispose_mapping(irq);
125 
126 	return ret;
127 }
128 
129 static const struct dev_pm_ops gic_pm_ops = {
130 	SET_RUNTIME_PM_OPS(gic_runtime_suspend,
131 			   gic_runtime_resume, NULL)
132 	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
133 				     pm_runtime_force_resume)
134 };
135 
136 static const char * const gic400_clocks[] = {
137 	"clk",
138 };
139 
140 static const struct gic_clk_data gic400_data = {
141 	.num_clocks = ARRAY_SIZE(gic400_clocks),
142 	.clocks = gic400_clocks,
143 };
144 
145 static const struct of_device_id gic_match[] = {
146 	{ .compatible = "nvidia,tegra210-agic",	.data = &gic400_data },
147 	{},
148 };
149 MODULE_DEVICE_TABLE(of, gic_match);
150 
151 static struct platform_driver gic_driver = {
152 	.probe		= gic_probe,
153 	.driver		= {
154 		.name	= "gic",
155 		.of_match_table	= gic_match,
156 		.pm	= &gic_pm_ops,
157 	}
158 };
159 
160 builtin_platform_driver(gic_driver);
161