1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
4  * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <regmap.h>
10 #include <syscon.h>
11 #include <sysreset.h>
12 #include <asm/io.h>
13 
14 DECLARE_GLOBAL_DATA_PTR;
15 
16 struct sti_sysreset_priv {
17 	phys_addr_t base;
18 };
19 
20 static int sti_sysreset_request(struct udevice *dev, enum sysreset_t type)
21 {
22 	struct sti_sysreset_priv *priv = dev_get_priv(dev);
23 
24 	generic_clear_bit(0, (void __iomem *)priv->base);
25 
26 	return -EINPROGRESS;
27 }
28 
29 static int sti_sysreset_probe(struct udevice *dev)
30 {
31 	struct sti_sysreset_priv *priv = dev_get_priv(dev);
32 	struct udevice *syscon;
33 	struct regmap *regmap;
34 	struct fdtdec_phandle_args syscfg_phandle;
35 	int ret;
36 
37 	/* get corresponding syscon phandle */
38 	ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev_of_offset(dev),
39 					     "st,syscfg", NULL, 0, 0,
40 					     &syscfg_phandle);
41 	if (ret < 0) {
42 		pr_err("Can't get syscfg phandle: %d\n", ret);
43 		return ret;
44 	}
45 
46 	ret = uclass_get_device_by_of_offset(UCLASS_SYSCON,
47 					     syscfg_phandle.node,
48 					     &syscon);
49 	if (ret) {
50 		pr_err("%s: uclass_get_device_by_of_offset failed: %d\n",
51 		      __func__, ret);
52 		return ret;
53 	}
54 
55 	regmap = syscon_get_regmap(syscon);
56 	if (!regmap) {
57 		pr_err("unable to get regmap for %s\n", syscon->name);
58 		return -ENODEV;
59 	}
60 
61 	priv->base = regmap->ranges[0].start;
62 
63 	return 0;
64 }
65 
66 static struct sysreset_ops sti_sysreset = {
67 	.request	= sti_sysreset_request,
68 };
69 
70 static const struct udevice_id sti_sysreset_ids[] = {
71 	{ .compatible = "st,stih407-restart" },
72 	{ }
73 };
74 
75 U_BOOT_DRIVER(sysreset_sti) = {
76 	.name = "sysreset_sti",
77 	.id = UCLASS_SYSRESET,
78 	.ops = &sti_sysreset,
79 	.probe = sti_sysreset_probe,
80 	.of_match = sti_sysreset_ids,
81 	.priv_auto_alloc_size = sizeof(struct sti_sysreset_priv),
82 };
83