1 /*
2  * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
3  *
4  * Derived from linux/drivers/power/reset/syscon-reboot.c:
5  *	Copyright (C) 2013, Applied Micro Circuits Corporation
6  *	Author: Feng Kan <fkan@apm.com>
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #include <common.h>
12 #include <dm.h>
13 #include <errno.h>
14 #include <regmap.h>
15 #include <sysreset.h>
16 #include <syscon.h>
17 
18 struct syscon_reboot_priv {
19 	struct regmap *regmap;
20 	unsigned int offset;
21 	unsigned int mask;
22 };
23 
24 static int syscon_reboot_request(struct udevice *dev, enum sysreset_t type)
25 {
26 	struct syscon_reboot_priv *priv = dev_get_priv(dev);
27 
28 	regmap_write(priv->regmap, priv->offset, priv->mask);
29 
30 	return -EINPROGRESS;
31 }
32 
33 static struct sysreset_ops syscon_reboot_ops = {
34 	.request = syscon_reboot_request,
35 };
36 
37 int syscon_reboot_probe(struct udevice *dev)
38 {
39 	struct udevice *syscon;
40 	struct syscon_reboot_priv *priv = dev_get_priv(dev);
41 	int err;
42 
43 	err = uclass_get_device_by_phandle(UCLASS_SYSCON, dev,
44 					   "regmap", &syscon);
45 	if (err) {
46 		pr_err("unable to find syscon device\n");
47 		return err;
48 	}
49 
50 	priv->regmap = syscon_get_regmap(syscon);
51 	if (!priv->regmap) {
52 		pr_err("unable to find regmap\n");
53 		return -ENODEV;
54 	}
55 
56 	priv->offset = dev_read_u32_default(dev, "offset", 0);
57 	priv->mask = dev_read_u32_default(dev, "mask", 0);
58 
59 	return 0;
60 }
61 
62 static const struct udevice_id syscon_reboot_ids[] = {
63 	{ .compatible = "syscon-reboot" },
64 	{ /* sentinel */ }
65 };
66 
67 U_BOOT_DRIVER(syscon_reboot) = {
68 	.name = "syscon_reboot",
69 	.id = UCLASS_SYSRESET,
70 	.of_match = syscon_reboot_ids,
71 	.probe = syscon_reboot_probe,
72 	.priv_auto_alloc_size = sizeof(struct syscon_reboot_priv),
73 	.ops = &syscon_reboot_ops,
74 };
75