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(force: 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(np: dp, propname: "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, dp: op->dev.of_node)) { |
49 | if (request_irq(irq, |
50 | handler: power_handler, flags: 0, name: "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 | |