1 /*
2  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
3  * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <dm.h>
10 #include <regmap.h>
11 #include <syscon.h>
12 #include <sysreset.h>
13 #include <asm/io.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 struct sti_sysreset_priv {
18 	phys_addr_t base;
19 };
20 
21 static int sti_sysreset_request(struct udevice *dev, enum sysreset_t type)
22 {
23 	struct sti_sysreset_priv *priv = dev_get_priv(dev);
24 
25 	generic_clear_bit(0, (void __iomem *)priv->base);
26 
27 	return -EINPROGRESS;
28 }
29 
30 static int sti_sysreset_probe(struct udevice *dev)
31 {
32 	struct sti_sysreset_priv *priv = dev_get_priv(dev);
33 	struct udevice *syscon;
34 	struct regmap *regmap;
35 	struct fdtdec_phandle_args syscfg_phandle;
36 	int ret;
37 
38 	/* get corresponding syscon phandle */
39 	ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev_of_offset(dev),
40 					     "st,syscfg", NULL, 0, 0,
41 					     &syscfg_phandle);
42 	if (ret < 0) {
43 		pr_err("Can't get syscfg phandle: %d\n", ret);
44 		return ret;
45 	}
46 
47 	ret = uclass_get_device_by_of_offset(UCLASS_SYSCON,
48 					     syscfg_phandle.node,
49 					     &syscon);
50 	if (ret) {
51 		pr_err("%s: uclass_get_device_by_of_offset failed: %d\n",
52 		      __func__, ret);
53 		return ret;
54 	}
55 
56 	regmap = syscon_get_regmap(syscon);
57 	if (!regmap) {
58 		pr_err("unable to get regmap for %s\n", syscon->name);
59 		return -ENODEV;
60 	}
61 
62 	priv->base = regmap->base;
63 
64 	return 0;
65 }
66 
67 static struct sysreset_ops sti_sysreset = {
68 	.request	= sti_sysreset_request,
69 };
70 
71 static const struct udevice_id sti_sysreset_ids[] = {
72 	{ .compatible = "st,stih407-restart" },
73 	{ }
74 };
75 
76 U_BOOT_DRIVER(sysreset_sti) = {
77 	.name = "sysreset_sti",
78 	.id = UCLASS_SYSRESET,
79 	.ops = &sti_sysreset,
80 	.probe = sti_sysreset_probe,
81 	.of_match = sti_sysreset_ids,
82 	.priv_auto_alloc_size = sizeof(struct sti_sysreset_priv),
83 };
84