1
2
3
4
5
6
7
8
9
10#include <linux/io.h>
11#include <linux/module.h>
12#include <linux/notifier.h>
13#include <linux/reboot.h>
14#include <linux/regmap.h>
15#include <linux/mfd/syscon.h>
16#include <linux/of_platform.h>
17
18#define RSTYPE_RG 0x0
19#define RSCTRL_RG 0x4
20#define RSCFG_RG 0x8
21#define RSISO_RG 0xc
22
23#define RSCTRL_KEY_MASK 0x0000ffff
24#define RSCTRL_RESET_MASK BIT(16)
25#define RSCTRL_KEY 0x5a69
26
27#define RSMUX_OMODE_MASK 0xe
28#define RSMUX_OMODE_RESET_ON 0xa
29#define RSMUX_OMODE_RESET_OFF 0x0
30#define RSMUX_LOCK_MASK 0x1
31#define RSMUX_LOCK_SET 0x1
32
33#define RSCFG_RSTYPE_SOFT 0x300f
34#define RSCFG_RSTYPE_HARD 0x0
35
36#define WDT_MUX_NUMBER 0x4
37
38static int rspll_offset;
39static struct regmap *pllctrl_regs;
40
41
42
43
44
45
46static inline int rsctrl_enable_rspll_write(void)
47{
48 return regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG,
49 RSCTRL_KEY_MASK, RSCTRL_KEY);
50}
51
52static int rsctrl_restart_handler(struct notifier_block *this,
53 unsigned long mode, void *cmd)
54{
55
56 rsctrl_enable_rspll_write();
57
58
59 regmap_update_bits(pllctrl_regs, rspll_offset + RSCTRL_RG,
60 RSCTRL_RESET_MASK, 0);
61
62 return NOTIFY_DONE;
63}
64
65static struct notifier_block rsctrl_restart_nb = {
66 .notifier_call = rsctrl_restart_handler,
67 .priority = 128,
68};
69
70static const struct of_device_id rsctrl_of_match[] = {
71 {.compatible = "ti,keystone-reset", },
72 {},
73};
74MODULE_DEVICE_TABLE(of, rsctrl_of_match);
75
76static int rsctrl_probe(struct platform_device *pdev)
77{
78 int i;
79 int ret;
80 u32 val;
81 unsigned int rg;
82 u32 rsmux_offset;
83 struct regmap *devctrl_regs;
84 struct device *dev = &pdev->dev;
85 struct device_node *np = dev->of_node;
86
87 if (!np)
88 return -ENODEV;
89
90
91 pllctrl_regs = syscon_regmap_lookup_by_phandle(np, "ti,syscon-pll");
92 if (IS_ERR(pllctrl_regs))
93 return PTR_ERR(pllctrl_regs);
94
95 devctrl_regs = syscon_regmap_lookup_by_phandle(np, "ti,syscon-dev");
96 if (IS_ERR(devctrl_regs))
97 return PTR_ERR(devctrl_regs);
98
99 ret = of_property_read_u32_index(np, "ti,syscon-pll", 1, &rspll_offset);
100 if (ret) {
101 dev_err(dev, "couldn't read the reset pll offset!\n");
102 return -EINVAL;
103 }
104
105 ret = of_property_read_u32_index(np, "ti,syscon-dev", 1, &rsmux_offset);
106 if (ret) {
107 dev_err(dev, "couldn't read the rsmux offset!\n");
108 return -EINVAL;
109 }
110
111
112 val = of_property_read_bool(np, "ti,soft-reset");
113 val = val ? RSCFG_RSTYPE_SOFT : RSCFG_RSTYPE_HARD;
114
115 ret = rsctrl_enable_rspll_write();
116 if (ret)
117 return ret;
118
119 ret = regmap_write(pllctrl_regs, rspll_offset + RSCFG_RG, val);
120 if (ret)
121 return ret;
122
123
124 ret = regmap_write(pllctrl_regs, rspll_offset + RSISO_RG, 0);
125 if (ret)
126 return ret;
127
128
129 for (i = 0; i < WDT_MUX_NUMBER; i++) {
130 ret = of_property_read_u32_index(np, "ti,wdt-list", i, &val);
131 if (ret == -EOVERFLOW && !i) {
132 dev_err(dev, "ti,wdt-list property has to contain at"
133 "least one entry\n");
134 return -EINVAL;
135 } else if (ret) {
136 break;
137 }
138
139 if (val >= WDT_MUX_NUMBER) {
140 dev_err(dev, "ti,wdt-list property can contain "
141 "only numbers < 4\n");
142 return -EINVAL;
143 }
144
145 rg = rsmux_offset + val * 4;
146
147 ret = regmap_update_bits(devctrl_regs, rg, RSMUX_OMODE_MASK,
148 RSMUX_OMODE_RESET_ON |
149 RSMUX_LOCK_SET);
150 if (ret)
151 return ret;
152 }
153
154 ret = register_restart_handler(&rsctrl_restart_nb);
155 if (ret)
156 dev_err(dev, "cannot register restart handler (err=%d)\n", ret);
157
158 return ret;
159}
160
161static struct platform_driver rsctrl_driver = {
162 .probe = rsctrl_probe,
163 .driver = {
164 .name = KBUILD_MODNAME,
165 .of_match_table = rsctrl_of_match,
166 },
167};
168module_platform_driver(rsctrl_driver);
169
170MODULE_AUTHOR("Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>");
171MODULE_DESCRIPTION("Texas Instruments keystone reset driver");
172MODULE_LICENSE("GPL v2");
173MODULE_ALIAS("platform:" KBUILD_MODNAME);
174
