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_device.h>
13
14 #include <asm/prom.h>
15 #include <asm/io.h>
16
17 static void __iomem *power_reg;
18
power_handler(int irq,void * dev_id)19 static irqreturn_t power_handler(int irq, void *dev_id)
20 {
21 orderly_poweroff(true);
22
23 /* FIXME: Check registers for status... */
24 return IRQ_HANDLED;
25 }
26
has_button_interrupt(unsigned int irq,struct device_node * dp)27 static int has_button_interrupt(unsigned int irq, struct device_node *dp)
28 {
29 if (irq == 0xffffffff)
30 return 0;
31 if (!of_find_property(dp, "button", NULL))
32 return 0;
33
34 return 1;
35 }
36
power_probe(struct platform_device * op)37 static int power_probe(struct platform_device *op)
38 {
39 struct resource *res = &op->resource[0];
40 unsigned int irq = op->archdata.irqs[0];
41
42 power_reg = of_ioremap(res, 0, 0x4, "power");
43
44 printk(KERN_INFO "%pOFn: Control reg at %llx\n",
45 op->dev.of_node, res->start);
46
47 if (has_button_interrupt(irq, op->dev.of_node)) {
48 if (request_irq(irq,
49 power_handler, 0, "power", NULL) < 0)
50 printk(KERN_ERR "power: Cannot setup IRQ handler.\n");
51 }
52
53 return 0;
54 }
55
56 static const struct of_device_id power_match[] = {
57 {
58 .name = "power",
59 },
60 {},
61 };
62
63 static struct platform_driver power_driver = {
64 .probe = power_probe,
65 .driver = {
66 .name = "power",
67 .of_match_table = power_match,
68 },
69 };
70
71 builtin_platform_driver(power_driver);
72