blob: 68c41fa2be27bde7fdea632bdc72840b8de61fcf [file] [log] [blame]
Laxman Dewanganff3bb2f2016-06-09 18:59:05 +05301/*
2 * Maxim MAX77620 Watchdog Driver
3 *
4 * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved.
5 *
6 * Author: Laxman Dewangan <ldewangan@nvidia.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/err.h>
14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/mfd/max77620.h>
18#include <linux/platform_device.h>
19#include <linux/regmap.h>
20#include <linux/slab.h>
21#include <linux/watchdog.h>
22
23static bool nowayout = WATCHDOG_NOWAYOUT;
24
25struct max77620_wdt {
26 struct device *dev;
27 struct regmap *rmap;
28 struct watchdog_device wdt_dev;
29};
30
31static int max77620_wdt_start(struct watchdog_device *wdt_dev)
32{
33 struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
34
35 return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
36 MAX77620_WDTEN, MAX77620_WDTEN);
37}
38
39static int max77620_wdt_stop(struct watchdog_device *wdt_dev)
40{
41 struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
42
43 return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
44 MAX77620_WDTEN, 0);
45}
46
47static int max77620_wdt_ping(struct watchdog_device *wdt_dev)
48{
49 struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
50
51 return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3,
52 MAX77620_WDTC_MASK, 0x1);
53}
54
55static int max77620_wdt_set_timeout(struct watchdog_device *wdt_dev,
56 unsigned int timeout)
57{
58 struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev);
59 unsigned int wdt_timeout;
60 u8 regval;
61 int ret;
62
63 switch (timeout) {
64 case 0 ... 2:
65 regval = MAX77620_TWD_2s;
66 wdt_timeout = 2;
67 break;
68
69 case 3 ... 16:
70 regval = MAX77620_TWD_16s;
71 wdt_timeout = 16;
72 break;
73
74 case 17 ... 64:
75 regval = MAX77620_TWD_64s;
76 wdt_timeout = 64;
77 break;
78
79 default:
80 regval = MAX77620_TWD_128s;
81 wdt_timeout = 128;
82 break;
83 }
84
85 ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3,
86 MAX77620_WDTC_MASK, 0x1);
87 if (ret < 0)
88 return ret;
89
90 ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
91 MAX77620_TWD_MASK, regval);
92 if (ret < 0)
93 return ret;
94
95 wdt_dev->timeout = wdt_timeout;
96
97 return 0;
98}
99
100static const struct watchdog_info max77620_wdt_info = {
101 .identity = "max77620-watchdog",
102 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
103};
104
105static const struct watchdog_ops max77620_wdt_ops = {
106 .start = max77620_wdt_start,
107 .stop = max77620_wdt_stop,
108 .ping = max77620_wdt_ping,
109 .set_timeout = max77620_wdt_set_timeout,
110};
111
112static int max77620_wdt_probe(struct platform_device *pdev)
113{
114 struct max77620_wdt *wdt;
115 struct watchdog_device *wdt_dev;
116 unsigned int regval;
117 int ret;
118
119 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
120 if (!wdt)
121 return -ENOMEM;
122
123 wdt->dev = &pdev->dev;
124 wdt->rmap = dev_get_regmap(pdev->dev.parent, NULL);
125 if (!wdt->rmap) {
126 dev_err(wdt->dev, "Failed to get parent regmap\n");
127 return -ENODEV;
128 }
129
130 wdt_dev = &wdt->wdt_dev;
131 wdt_dev->info = &max77620_wdt_info;
132 wdt_dev->ops = &max77620_wdt_ops;
133 wdt_dev->min_timeout = 2;
134 wdt_dev->max_timeout = 128;
135 wdt_dev->max_hw_heartbeat_ms = 128 * 1000;
136
137 platform_set_drvdata(pdev, wdt);
138
139 /* Enable WD_RST_WK - WDT expire results in a restart */
140 ret = regmap_update_bits(wdt->rmap, MAX77620_REG_ONOFFCNFG2,
141 MAX77620_ONOFFCNFG2_WD_RST_WK,
142 MAX77620_ONOFFCNFG2_WD_RST_WK);
143 if (ret < 0) {
144 dev_err(wdt->dev, "Failed to set WD_RST_WK: %d\n", ret);
145 return ret;
146 }
147
148 /* Set WDT clear in OFF and sleep mode */
149 ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2,
150 MAX77620_WDTOFFC | MAX77620_WDTSLPC,
151 MAX77620_WDTOFFC | MAX77620_WDTSLPC);
152 if (ret < 0) {
153 dev_err(wdt->dev, "Failed to set WDT OFF mode: %d\n", ret);
154 return ret;
155 }
156
157 /* Check if WDT running and if yes then set flags properly */
158 ret = regmap_read(wdt->rmap, MAX77620_REG_CNFGGLBL2, &regval);
159 if (ret < 0) {
160 dev_err(wdt->dev, "Failed to read WDT CFG register: %d\n", ret);
161 return ret;
162 }
163
164 switch (regval & MAX77620_TWD_MASK) {
165 case MAX77620_TWD_2s:
166 wdt_dev->timeout = 2;
167 break;
168 case MAX77620_TWD_16s:
169 wdt_dev->timeout = 16;
170 break;
171 case MAX77620_TWD_64s:
172 wdt_dev->timeout = 64;
173 break;
174 default:
175 wdt_dev->timeout = 128;
176 break;
177 }
178
179 if (regval & MAX77620_WDTEN)
180 set_bit(WDOG_HW_RUNNING, &wdt_dev->status);
181
182 watchdog_set_nowayout(wdt_dev, nowayout);
183 watchdog_set_drvdata(wdt_dev, wdt);
184
185 ret = watchdog_register_device(wdt_dev);
186 if (ret < 0) {
187 dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret);
188 return ret;
189 }
190
191 return 0;
192}
193
194static int max77620_wdt_remove(struct platform_device *pdev)
195{
196 struct max77620_wdt *wdt = platform_get_drvdata(pdev);
197
198 max77620_wdt_stop(&wdt->wdt_dev);
199 watchdog_unregister_device(&wdt->wdt_dev);
200
201 return 0;
202}
203
204static struct platform_device_id max77620_wdt_devtype[] = {
205 { .name = "max77620-watchdog", },
206 { },
207};
Javier Martinez Canillasf99524d2016-10-14 12:23:51 -0300208MODULE_DEVICE_TABLE(platform, max77620_wdt_devtype);
Laxman Dewanganff3bb2f2016-06-09 18:59:05 +0530209
210static struct platform_driver max77620_wdt_driver = {
211 .driver = {
212 .name = "max77620-watchdog",
213 },
214 .probe = max77620_wdt_probe,
215 .remove = max77620_wdt_remove,
216 .id_table = max77620_wdt_devtype,
217};
218
219module_platform_driver(max77620_wdt_driver);
220
221MODULE_DESCRIPTION("Max77620 watchdog timer driver");
222
223module_param(nowayout, bool, 0);
224MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
225 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
226
227MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
228MODULE_LICENSE("GPL v2");