1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2014 STMicroelectronics
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Power off Restart driver, used in STMicroelectronics devices.
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Author: Christophe Kerello <christophe.kerello@st.com>
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/module.h>
11*4882a593Smuzhiyun #include <linux/of.h>
12*4882a593Smuzhiyun #include <linux/of_platform.h>
13*4882a593Smuzhiyun #include <linux/platform_device.h>
14*4882a593Smuzhiyun #include <linux/mfd/syscon.h>
15*4882a593Smuzhiyun #include <linux/reboot.h>
16*4882a593Smuzhiyun #include <linux/regmap.h>
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun struct reset_syscfg {
19*4882a593Smuzhiyun struct regmap *regmap;
20*4882a593Smuzhiyun /* syscfg used for reset */
21*4882a593Smuzhiyun unsigned int offset_rst;
22*4882a593Smuzhiyun unsigned int mask_rst;
23*4882a593Smuzhiyun /* syscfg used for unmask the reset */
24*4882a593Smuzhiyun unsigned int offset_rst_msk;
25*4882a593Smuzhiyun unsigned int mask_rst_msk;
26*4882a593Smuzhiyun };
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun /* STiH407 */
29*4882a593Smuzhiyun #define STIH407_SYSCFG_4000 0x0
30*4882a593Smuzhiyun #define STIH407_SYSCFG_4008 0x20
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun static struct reset_syscfg stih407_reset = {
33*4882a593Smuzhiyun .offset_rst = STIH407_SYSCFG_4000,
34*4882a593Smuzhiyun .mask_rst = BIT(0),
35*4882a593Smuzhiyun .offset_rst_msk = STIH407_SYSCFG_4008,
36*4882a593Smuzhiyun .mask_rst_msk = BIT(0)
37*4882a593Smuzhiyun };
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun static struct reset_syscfg *st_restart_syscfg;
41*4882a593Smuzhiyun
st_restart(struct notifier_block * this,unsigned long mode,void * cmd)42*4882a593Smuzhiyun static int st_restart(struct notifier_block *this, unsigned long mode,
43*4882a593Smuzhiyun void *cmd)
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun /* reset syscfg updated */
46*4882a593Smuzhiyun regmap_update_bits(st_restart_syscfg->regmap,
47*4882a593Smuzhiyun st_restart_syscfg->offset_rst,
48*4882a593Smuzhiyun st_restart_syscfg->mask_rst,
49*4882a593Smuzhiyun 0);
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun /* unmask the reset */
52*4882a593Smuzhiyun regmap_update_bits(st_restart_syscfg->regmap,
53*4882a593Smuzhiyun st_restart_syscfg->offset_rst_msk,
54*4882a593Smuzhiyun st_restart_syscfg->mask_rst_msk,
55*4882a593Smuzhiyun 0);
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun return NOTIFY_DONE;
58*4882a593Smuzhiyun }
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun static struct notifier_block st_restart_nb = {
61*4882a593Smuzhiyun .notifier_call = st_restart,
62*4882a593Smuzhiyun .priority = 192,
63*4882a593Smuzhiyun };
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun static const struct of_device_id st_reset_of_match[] = {
66*4882a593Smuzhiyun {
67*4882a593Smuzhiyun .compatible = "st,stih407-restart",
68*4882a593Smuzhiyun .data = (void *)&stih407_reset,
69*4882a593Smuzhiyun },
70*4882a593Smuzhiyun {}
71*4882a593Smuzhiyun };
72*4882a593Smuzhiyun
st_reset_probe(struct platform_device * pdev)73*4882a593Smuzhiyun static int st_reset_probe(struct platform_device *pdev)
74*4882a593Smuzhiyun {
75*4882a593Smuzhiyun struct device_node *np = pdev->dev.of_node;
76*4882a593Smuzhiyun const struct of_device_id *match;
77*4882a593Smuzhiyun struct device *dev = &pdev->dev;
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun match = of_match_device(st_reset_of_match, dev);
80*4882a593Smuzhiyun if (!match)
81*4882a593Smuzhiyun return -ENODEV;
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun st_restart_syscfg = (struct reset_syscfg *)match->data;
84*4882a593Smuzhiyun
85*4882a593Smuzhiyun st_restart_syscfg->regmap =
86*4882a593Smuzhiyun syscon_regmap_lookup_by_phandle(np, "st,syscfg");
87*4882a593Smuzhiyun if (IS_ERR(st_restart_syscfg->regmap)) {
88*4882a593Smuzhiyun dev_err(dev, "No syscfg phandle specified\n");
89*4882a593Smuzhiyun return PTR_ERR(st_restart_syscfg->regmap);
90*4882a593Smuzhiyun }
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun return register_restart_handler(&st_restart_nb);
93*4882a593Smuzhiyun }
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun static struct platform_driver st_reset_driver = {
96*4882a593Smuzhiyun .probe = st_reset_probe,
97*4882a593Smuzhiyun .driver = {
98*4882a593Smuzhiyun .name = "st_reset",
99*4882a593Smuzhiyun .of_match_table = st_reset_of_match,
100*4882a593Smuzhiyun },
101*4882a593Smuzhiyun };
102*4882a593Smuzhiyun
st_reset_init(void)103*4882a593Smuzhiyun static int __init st_reset_init(void)
104*4882a593Smuzhiyun {
105*4882a593Smuzhiyun return platform_driver_register(&st_reset_driver);
106*4882a593Smuzhiyun }
107*4882a593Smuzhiyun
108*4882a593Smuzhiyun device_initcall(st_reset_init);
109*4882a593Smuzhiyun
110*4882a593Smuzhiyun MODULE_AUTHOR("Christophe Kerello <christophe.kerello@st.com>");
111*4882a593Smuzhiyun MODULE_DESCRIPTION("STMicroelectronics Power off Restart driver");
112*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
113