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10#include <linux/err.h>
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/mod_devicetable.h>
15#include <linux/mfd/max77620.h>
16#include <linux/platform_device.h>
17#include <linux/regmap.h>
18#include <linux/slab.h>
19#include <linux/watchdog.h>
20
21static bool nowayout = WATCHDOG_NOWAYOUT;
22
23struct max77620_wdt {
24 struct device *dev;
25 struct regmap *rmap;
26 struct watchdog_device wdt_dev;
27};
28
29static int max77620_wdt_start(struct watchdog_device *wdt_dev)
30{
31 struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
32
33 return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
34 MAX77620_WDTEN, MAX77620_WDTEN);
35}
36
37static int max77620_wdt_stop(struct watchdog_device *wdt_dev)
38{
39 struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
40
41 return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
42 MAX77620_WDTEN, 0);
43}
44
45static int max77620_wdt_ping(struct watchdog_device *wdt_dev)
46{
47 struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
48
49 return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3,
50 MAX77620_WDTC_MASK, 0x1);
51}
52
53static int max77620_wdt_set_timeout(struct watchdog_device *wdt_dev,
54 unsigned int timeout)
55{
56 struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
57 unsigned int wdt_timeout;
58 u8 regval;
59 int ret;
60
61 switch (timeout) {
62 case 0 ... 2:
63 regval = MAX77620_TWD_2s;
64 wdt_timeout = 2;
65 break;
66
67 case 3 ... 16:
68 regval = MAX77620_TWD_16s;
69 wdt_timeout = 16;
70 break;
71
72 case 17 ... 64:
73 regval = MAX77620_TWD_64s;
74 wdt_timeout = 64;
75 break;
76
77 default:
78 regval = MAX77620_TWD_128s;
79 wdt_timeout = 128;
80 break;
81 }
82
83 ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3,
84 MAX77620_WDTC_MASK, 0x1);
85 if (ret < 0)
86 return ret;
87
88 ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
89 MAX77620_TWD_MASK, regval);
90 if (ret < 0)
91 return ret;
92
93 wdt_dev->timeout = wdt_timeout;
94
95 return 0;
96}
97
98static const struct watchdog_info max77620_wdt_info = {
99 .identity = "max77620-watchdog",
100 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
101};
102
103static const struct watchdog_ops max77620_wdt_ops = {
104 .start = max77620_wdt_start,
105 .stop = max77620_wdt_stop,
106 .ping = max77620_wdt_ping,
107 .set_timeout = max77620_wdt_set_timeout,
108};
109
110static int max77620_wdt_probe(struct platform_device *pdev)
111{
112 struct device *dev = &pdev->dev;
113 struct max77620_wdt *wdt;
114 struct watchdog_device *wdt_dev;
115 unsigned int regval;
116 int ret;
117
118 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
119 if (!wdt)
120 return -ENOMEM;
121
122 wdt->dev = dev;
123 wdt->rmap = dev_get_regmap(dev->parent, NULL);
124 if (!wdt->rmap) {
125 dev_err(wdt->dev, "Failed to get parent regmap\n");
126 return -ENODEV;
127 }
128
129 wdt_dev = &wdt->wdt_dev;
130 wdt_dev->info = &max77620_wdt_info;
131 wdt_dev->ops = &max77620_wdt_ops;
132 wdt_dev->min_timeout = 2;
133 wdt_dev->max_timeout = 128;
134 wdt_dev->max_hw_heartbeat_ms = 128 * 1000;
135
136 platform_set_drvdata(pdev, wdt);
137
138
139 ret = regmap_update_bits(wdt->rmap, MAX77620_REG_ONOFFCNFG2,
140 MAX77620_ONOFFCNFG2_WD_RST_WK,
141 MAX77620_ONOFFCNFG2_WD_RST_WK);
142 if (ret < 0) {
143 dev_err(wdt->dev, "Failed to set WD_RST_WK: %d\n", ret);
144 return ret;
145 }
146
147
148 ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
149 MAX77620_WDTOFFC | MAX77620_WDTSLPC,
150 MAX77620_WDTOFFC | MAX77620_WDTSLPC);
151 if (ret < 0) {
152 dev_err(wdt->dev, "Failed to set WDT OFF mode: %d\n", ret);
153 return ret;
154 }
155
156
157 ret = regmap_read(wdt->rmap, MAX77620_REG_CNFGGLBL2, ®val);
158 if (ret < 0) {
159 dev_err(wdt->dev, "Failed to read WDT CFG register: %d\n", ret);
160 return ret;
161 }
162
163 switch (regval & MAX77620_TWD_MASK) {
164 case MAX77620_TWD_2s:
165 wdt_dev->timeout = 2;
166 break;
167 case MAX77620_TWD_16s:
168 wdt_dev->timeout = 16;
169 break;
170 case MAX77620_TWD_64s:
171 wdt_dev->timeout = 64;
172 break;
173 default:
174 wdt_dev->timeout = 128;
175 break;
176 }
177
178 if (regval & MAX77620_WDTEN)
179 set_bit(WDOG_HW_RUNNING, &wdt_dev->status);
180
181 watchdog_set_nowayout(wdt_dev, nowayout);
182 watchdog_set_drvdata(wdt_dev, wdt);
183
184 watchdog_stop_on_unregister(wdt_dev);
185 return devm_watchdog_register_device(dev, wdt_dev);
186}
187
188static const struct platform_device_id max77620_wdt_devtype[] = {
189 { .name = "max77620-watchdog", },
190 { },
191};
192MODULE_DEVICE_TABLE(platform, max77620_wdt_devtype);
193
194static struct platform_driver max77620_wdt_driver = {
195 .driver = {
196 .name = "max77620-watchdog",
197 },
198 .probe = max77620_wdt_probe,
199 .id_table = max77620_wdt_devtype,
200};
201
202module_platform_driver(max77620_wdt_driver);
203
204MODULE_DESCRIPTION("Max77620 watchdog timer driver");
205
206module_param(nowayout, bool, 0);
207MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
208 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
209
210MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
211MODULE_LICENSE("GPL v2");
212
