xref: /openbmc/linux/drivers/irqchip/irq-gic-pm.c (revision 2891f2d5)
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_clock.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/slab.h>
25 
26 struct gic_clk_data {
27 	unsigned int num_clocks;
28 	const char *const *clocks;
29 };
30 
31 static int gic_runtime_resume(struct device *dev)
32 {
33 	struct gic_chip_data *gic = dev_get_drvdata(dev);
34 	int ret;
35 
36 	ret = pm_clk_resume(dev);
37 	if (ret)
38 		return ret;
39 
40 	/*
41 	 * On the very first resume, the pointer to the driver data
42 	 * will be NULL and this is intentional, because we do not
43 	 * want to restore the GIC on the very first resume. So if
44 	 * the pointer is not valid just return.
45 	 */
46 	if (!gic)
47 		return 0;
48 
49 	gic_dist_restore(gic);
50 	gic_cpu_restore(gic);
51 
52 	return 0;
53 }
54 
55 static int gic_runtime_suspend(struct device *dev)
56 {
57 	struct gic_chip_data *gic = dev_get_drvdata(dev);
58 
59 	gic_dist_save(gic);
60 	gic_cpu_save(gic);
61 
62 	return pm_clk_suspend(dev);
63 }
64 
65 static int gic_get_clocks(struct device *dev, const struct gic_clk_data *data)
66 {
67 	unsigned int i;
68 	int ret;
69 
70 	if (!dev || !data)
71 		return -EINVAL;
72 
73 	ret = pm_clk_create(dev);
74 	if (ret)
75 		return ret;
76 
77 	for (i = 0; i < data->num_clocks; i++) {
78 		ret = of_pm_clk_add_clk(dev, data->clocks[i]);
79 		if (ret) {
80 			dev_err(dev, "failed to add clock %s\n",
81 				data->clocks[i]);
82 			pm_clk_destroy(dev);
83 			return ret;
84 		}
85 	}
86 
87 	return 0;
88 }
89 
90 static int gic_probe(struct platform_device *pdev)
91 {
92 	struct device *dev = &pdev->dev;
93 	const struct gic_clk_data *data;
94 	struct gic_chip_data *gic;
95 	int ret, irq;
96 
97 	data = of_device_get_match_data(&pdev->dev);
98 	if (!data) {
99 		dev_err(&pdev->dev, "no device match found\n");
100 		return -ENODEV;
101 	}
102 
103 	irq = irq_of_parse_and_map(dev->of_node, 0);
104 	if (!irq) {
105 		dev_err(dev, "no parent interrupt found!\n");
106 		return -EINVAL;
107 	}
108 
109 	ret = gic_get_clocks(dev, data);
110 	if (ret)
111 		goto irq_dispose;
112 
113 	pm_runtime_enable(dev);
114 
115 	ret = pm_runtime_get_sync(dev);
116 	if (ret < 0)
117 		goto rpm_disable;
118 
119 	ret = gic_of_init_child(dev, &gic, irq);
120 	if (ret)
121 		goto rpm_put;
122 
123 	platform_set_drvdata(pdev, gic);
124 
125 	pm_runtime_put(dev);
126 
127 	dev_info(dev, "GIC IRQ controller registered\n");
128 
129 	return 0;
130 
131 rpm_put:
132 	pm_runtime_put_sync(dev);
133 rpm_disable:
134 	pm_runtime_disable(dev);
135 	pm_clk_destroy(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 };
146 
147 static const char * const gic400_clocks[] = {
148 	"clk",
149 };
150 
151 static const struct gic_clk_data gic400_data = {
152 	.num_clocks = ARRAY_SIZE(gic400_clocks),
153 	.clocks = gic400_clocks,
154 };
155 
156 static const struct of_device_id gic_match[] = {
157 	{ .compatible = "nvidia,tegra210-agic",	.data = &gic400_data },
158 	{},
159 };
160 MODULE_DEVICE_TABLE(of, gic_match);
161 
162 static struct platform_driver gic_driver = {
163 	.probe		= gic_probe,
164 	.driver		= {
165 		.name	= "gic",
166 		.of_match_table	= gic_match,
167 		.pm	= &gic_pm_ops,
168 	}
169 };
170 
171 builtin_platform_driver(gic_driver);
172