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 syscon_reboot_priv *priv = dev_get_priv(dev);
39 int err;
40 u32 phandle;
41 ofnode node;
42
43 err = ofnode_read_u32(dev_ofnode(dev), "regmap", &phandle);
44 if (err)
45 return err;
46
47 node = ofnode_get_by_phandle(phandle);
48 if (!ofnode_valid(node))
49 return -EINVAL;
50
51 priv->regmap = syscon_node_to_regmap(node);
52 if (!priv->regmap) {
53 pr_err("unable to find regmap\n");
54 return -ENODEV;
55 }
56
57 priv->offset = dev_read_u32_default(dev, "offset", 0);
58 priv->mask = dev_read_u32_default(dev, "mask", 0);
59
60 return 0;
61 }
62
63 static const struct udevice_id syscon_reboot_ids[] = {
64 { .compatible = "syscon-reboot" },
65 { /* sentinel */ }
66 };
67
68 U_BOOT_DRIVER(syscon_reboot) = {
69 .name = "syscon_reboot",
70 .id = UCLASS_SYSRESET,
71 .of_match = syscon_reboot_ids,
72 .probe = syscon_reboot_probe,
73 .priv_auto_alloc_size = sizeof(struct syscon_reboot_priv),
74 .ops = &syscon_reboot_ops,
75 };
76