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