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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Watchdog driver for Technologic Systems TS-72xx based SBCs
4 * (TS-7200, TS-7250 and TS-7260). These boards have external
5 * glue logic CPLD chip, which includes programmable watchdog
6 * timer.
7 *
8 * Copyright (c) 2009 Mika Westerberg <[email protected]>
9 *
10 * This driver is based on ep93xx_wdt and wm831x_wdt drivers.
11 *
12 */
13
14#include <linux/platform_device.h>
15#include <linux/module.h>
16#include <linux/watchdog.h>
17#include <linux/io.h>
18
19#define TS72XX_WDT_DEFAULT_TIMEOUT 30
20
21static int timeout;
22module_param(timeout, int, 0);
23MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");
24
25static bool nowayout = WATCHDOG_NOWAYOUT;
26module_param(nowayout, bool, 0);
27MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
28
29/* priv->control_reg */
30#define TS72XX_WDT_CTRL_DISABLE 0x00
31#define TS72XX_WDT_CTRL_250MS 0x01
32#define TS72XX_WDT_CTRL_500MS 0x02
33#define TS72XX_WDT_CTRL_1SEC 0x03
34#define TS72XX_WDT_CTRL_RESERVED 0x04
35#define TS72XX_WDT_CTRL_2SEC 0x05
36#define TS72XX_WDT_CTRL_4SEC 0x06
37#define TS72XX_WDT_CTRL_8SEC 0x07
38
39/* priv->feed_reg */
40#define TS72XX_WDT_FEED_VAL 0x05
41
42struct ts72xx_wdt_priv {
43 void __iomem *control_reg;
44 void __iomem *feed_reg;
45 struct watchdog_device wdd;
46 unsigned char regval;
47};
48
49static int ts72xx_wdt_start(struct watchdog_device *wdd)
50{
51 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
52
53 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);
54 writeb(priv->regval, priv->control_reg);
55
56 return 0;
57}
58
59static int ts72xx_wdt_stop(struct watchdog_device *wdd)
60{
61 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
62
63 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);
64 writeb(TS72XX_WDT_CTRL_DISABLE, priv->control_reg);
65
66 return 0;
67}
68
69static int ts72xx_wdt_ping(struct watchdog_device *wdd)
70{
71 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
72
73 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);
74
75 return 0;
76}
77
78static int ts72xx_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
79{
80 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
81
82 if (to == 1) {
83 priv->regval = TS72XX_WDT_CTRL_1SEC;
84 } else if (to == 2) {
85 priv->regval = TS72XX_WDT_CTRL_2SEC;
86 } else if (to <= 4) {
87 priv->regval = TS72XX_WDT_CTRL_4SEC;
88 to = 4;
89 } else {
90 priv->regval = TS72XX_WDT_CTRL_8SEC;
91 if (to <= 8)
92 to = 8;
93 }
94
95 wdd->timeout = to;
96
97 if (watchdog_active(wdd)) {
98 ts72xx_wdt_stop(wdd);
99 ts72xx_wdt_start(wdd);
100 }
101
102 return 0;
103}
104
105static const struct watchdog_info ts72xx_wdt_ident = {
106 .options = WDIOF_KEEPALIVEPING |
107 WDIOF_SETTIMEOUT |
108 WDIOF_MAGICCLOSE,
109 .firmware_version = 1,
110 .identity = "TS-72XX WDT",
111};
112
113static const struct watchdog_ops ts72xx_wdt_ops = {
114 .owner = THIS_MODULE,
115 .start = ts72xx_wdt_start,
116 .stop = ts72xx_wdt_stop,
117 .ping = ts72xx_wdt_ping,
118 .set_timeout = ts72xx_wdt_settimeout,
119};
120
121static int ts72xx_wdt_probe(struct platform_device *pdev)
122{
123 struct device *dev = &pdev->dev;
124 struct ts72xx_wdt_priv *priv;
125 struct watchdog_device *wdd;
126 int ret;
127
128 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
129 if (!priv)
130 return -ENOMEM;
131
132 priv->control_reg = devm_platform_ioremap_resource(pdev, 0);
133 if (IS_ERR(priv->control_reg))
134 return PTR_ERR(priv->control_reg);
135
136 priv->feed_reg = devm_platform_ioremap_resource(pdev, 1);
137 if (IS_ERR(priv->feed_reg))
138 return PTR_ERR(priv->feed_reg);
139
140 wdd = &priv->wdd;
141 wdd->info = &ts72xx_wdt_ident;
142 wdd->ops = &ts72xx_wdt_ops;
143 wdd->min_timeout = 1;
144 wdd->max_hw_heartbeat_ms = 8000;
145 wdd->parent = dev;
146
147 watchdog_set_nowayout(wdd, nowayout);
148
149 wdd->timeout = TS72XX_WDT_DEFAULT_TIMEOUT;
150 watchdog_init_timeout(wdd, timeout, dev);
151
152 watchdog_set_drvdata(wdd, priv);
153
154 ret = devm_watchdog_register_device(dev, wdd);
155 if (ret)
156 return ret;
157
158 dev_info(dev, "TS-72xx Watchdog driver\n");
159
160 return 0;
161}
162
163static const struct of_device_id ts72xx_wdt_of_ids[] = {
164 { .compatible = "technologic,ts7200-wdt" },
165 { /* sentinel */ }
166};
167MODULE_DEVICE_TABLE(of, ts72xx_wdt_of_ids);
168
169static struct platform_driver ts72xx_wdt_driver = {
170 .probe = ts72xx_wdt_probe,
171 .driver = {
172 .name = "ts72xx-wdt",
173 .of_match_table = ts72xx_wdt_of_ids,
174 },
175};
176
177module_platform_driver(ts72xx_wdt_driver);
178
179MODULE_AUTHOR("Mika Westerberg <[email protected]>");
180MODULE_DESCRIPTION("TS-72xx SBC Watchdog");
181MODULE_LICENSE("GPL");
182MODULE_ALIAS("platform:ts72xx-wdt");