xref: /linux/drivers/irqchip/irq-gic-pm.c (revision ebf68996de0ab250c5d520eb2291ab65643e9a1e)
1 /*
2  * Copyright (C) 2016 NVIDIA CORPORATION, All Rights Reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 #include <linux/module.h>
17 #include <linux/clk.h>
18 #include <linux/of_device.h>
19 #include <linux/of_irq.h>
20 #include <linux/irqchip/arm-gic.h>
21 #include <linux/platform_device.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/slab.h>
24 
25 struct gic_clk_data {
26 	unsigned int num_clocks;
27 	const char *const *clocks;
28 };
29 
30 struct gic_chip_pm {
31 	struct gic_chip_data *chip_data;
32 	const struct gic_clk_data *clk_data;
33 	struct clk_bulk_data *clks;
34 };
35 
36 static int gic_runtime_resume(struct device *dev)
37 {
38 	struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
39 	struct gic_chip_data *gic = chip_pm->chip_data;
40 	const struct gic_clk_data *data = chip_pm->clk_data;
41 	int ret;
42 
43 	ret = clk_bulk_prepare_enable(data->num_clocks, chip_pm->clks);
44 	if (ret) {
45 		dev_err(dev, "clk_enable failed: %d\n", ret);
46 		return ret;
47 	}
48 
49 	/*
50 	 * On the very first resume, the pointer to chip_pm->chip_data
51 	 * will be NULL and this is intentional, because we do not
52 	 * want to restore the GIC on the very first resume. So if
53 	 * the pointer is not valid just return.
54 	 */
55 	if (!gic)
56 		return 0;
57 
58 	gic_dist_restore(gic);
59 	gic_cpu_restore(gic);
60 
61 	return 0;
62 }
63 
64 static int gic_runtime_suspend(struct device *dev)
65 {
66 	struct gic_chip_pm *chip_pm = dev_get_drvdata(dev);
67 	struct gic_chip_data *gic = chip_pm->chip_data;
68 	const struct gic_clk_data *data = chip_pm->clk_data;
69 
70 	gic_dist_save(gic);
71 	gic_cpu_save(gic);
72 
73 	clk_bulk_disable_unprepare(data->num_clocks, chip_pm->clks);
74 
75 	return 0;
76 }
77 
78 static int gic_probe(struct platform_device *pdev)
79 {
80 	struct device *dev = &pdev->dev;
81 	const struct gic_clk_data *data;
82 	struct gic_chip_pm *chip_pm;
83 	int ret, irq, i;
84 
85 	data = of_device_get_match_data(&pdev->dev);
86 	if (!data) {
87 		dev_err(&pdev->dev, "no device match found\n");
88 		return -ENODEV;
89 	}
90 
91 	chip_pm = devm_kzalloc(dev, sizeof(*chip_pm), GFP_KERNEL);
92 	if (!chip_pm)
93 		return -ENOMEM;
94 
95 	irq = irq_of_parse_and_map(dev->of_node, 0);
96 	if (!irq) {
97 		dev_err(dev, "no parent interrupt found!\n");
98 		return -EINVAL;
99 	}
100 
101 	chip_pm->clks = devm_kcalloc(dev, data->num_clocks,
102 				     sizeof(*chip_pm->clks), GFP_KERNEL);
103 	if (!chip_pm->clks)
104 		return -ENOMEM;
105 
106 	for (i = 0; i < data->num_clocks; i++)
107 		chip_pm->clks[i].id = data->clocks[i];
108 
109 	ret = devm_clk_bulk_get(dev, data->num_clocks, chip_pm->clks);
110 	if (ret)
111 		goto irq_dispose;
112 
113 	chip_pm->clk_data = data;
114 	dev_set_drvdata(dev, chip_pm);
115 
116 	pm_runtime_enable(dev);
117 
118 	ret = pm_runtime_get_sync(dev);
119 	if (ret < 0)
120 		goto rpm_disable;
121 
122 	ret = gic_of_init_child(dev, &chip_pm->chip_data, irq);
123 	if (ret)
124 		goto rpm_put;
125 
126 	pm_runtime_put(dev);
127 
128 	dev_info(dev, "GIC IRQ controller registered\n");
129 
130 	return 0;
131 
132 rpm_put:
133 	pm_runtime_put_sync(dev);
134 rpm_disable:
135 	pm_runtime_disable(dev);
136 irq_dispose:
137 	irq_dispose_mapping(irq);
138 
139 	return ret;
140 }
141 
142 static const struct dev_pm_ops gic_pm_ops = {
143 	SET_RUNTIME_PM_OPS(gic_runtime_suspend,
144 			   gic_runtime_resume, NULL)
145 	SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
146 				     pm_runtime_force_resume)
147 };
148 
149 static const char * const gic400_clocks[] = {
150 	"clk",
151 };
152 
153 static const struct gic_clk_data gic400_data = {
154 	.num_clocks = ARRAY_SIZE(gic400_clocks),
155 	.clocks = gic400_clocks,
156 };
157 
158 static const struct of_device_id gic_match[] = {
159 	{ .compatible = "nvidia,tegra210-agic",	.data = &gic400_data },
160 	{},
161 };
162 MODULE_DEVICE_TABLE(of, gic_match);
163 
164 static struct platform_driver gic_driver = {
165 	.probe		= gic_probe,
166 	.driver		= {
167 		.name	= "gic",
168 		.of_match_table	= gic_match,
169 		.pm	= &gic_pm_ops,
170 	}
171 };
172 
173 builtin_platform_driver(gic_driver);
174