1 // SPDX-License-Identifier: GPL-2.0
2 /* power.c: Power management driver.
3 *
4 * Copyright (C) 1999, 2007, 2008 David S. Miller (davem@davemloft.net)
5 */
6
7 #include <linux/kernel.h>
8 #include <linux/export.h>
9 #include <linux/init.h>
10 #include <linux/interrupt.h>
11 #include <linux/reboot.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14
15 #include <asm/prom.h>
16 #include <asm/io.h>
17
18 static void __iomem *power_reg;
19
20 static irqreturn_t power_handler(int irq, void *dev_id)
21 {
22 orderly_poweroff(true);
23
24 /* FIXME: Check registers for status... */
25 return IRQ_HANDLED;
26 }
27
28 static int has_button_interrupt(unsigned int irq, struct device_node *dp)
29 {
30 if (irq == 0xffffffff)
31 return 0;
32 if (!of_property_read_bool(dp, "button"))
33 return 0;
34
35 return 1;
36 }
37
38 static int power_probe(struct platform_device *op)
39 {
40 struct resource *res = &op->resource[0];
41 unsigned int irq = op->archdata.irqs[0];
42
43 power_reg = of_ioremap(res, 0, 0x4, "power");
44
45 printk(KERN_INFO "%pOFn: Control reg at %llx\n",
46 op->dev.of_node, res->start);
47
48 if (has_button_interrupt(irq, op->dev.of_node)) {
49 if (request_irq(irq,
50 power_handler, 0, "power", NULL) < 0)
51 printk(KERN_ERR "power: Cannot setup IRQ handler.\n");
52 }
53
54 return 0;
55 }
56
57 static const struct of_device_id power_match[] = {
58 {
59 .name = "power",
60 },
61 {},
62 };
63
64 static struct platform_driver power_driver = {
65 .probe = power_probe,
66 .driver = {
67 .name = "power",
68 .of_match_table = power_match,
69 },
70 };
71
72 builtin_platform_driver(power_driver);
73
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