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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Watchdog driver for Cirrus Logic EP93xx family of devices.
4 *
5 * Copyright (c) 2004 Ray Lehtiniemi
6 * Copyright (c) 2006 Tower Technologies
7 * Based on ep93xx driver, bits from alim7101_wdt.c
8 *
9 * Authors: Ray Lehtiniemi <rayl@mail.com>,
10 * Alessandro Zummo <a.zummo@towertech.it>
11 *
12 * Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
13 * Convert to a platform device and use the watchdog framework API
14 *
15 * This watchdog fires after 250msec, which is a too short interval
16 * for us to rely on the user space daemon alone. So we ping the
17 * wdt each ~200msec and eventually stop doing it if the user space
18 * daemon dies.
19 */
20
21#include <linux/platform_device.h>
22#include <linux/module.h>
23#include <linux/watchdog.h>
24#include <linux/io.h>
25
26/* default timeout (secs) */
27#define WDT_TIMEOUT 30
28
29static bool nowayout = WATCHDOG_NOWAYOUT;
30module_param(nowayout, bool, 0);
31MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
32
33static unsigned int timeout;
34module_param(timeout, uint, 0);
35MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");
36
37#define EP93XX_WATCHDOG 0x00
38#define EP93XX_WDSTATUS 0x04
39
40struct ep93xx_wdt_priv {
41 void __iomem *mmio;
42 struct watchdog_device wdd;
43};
44
45static int ep93xx_wdt_start(struct watchdog_device *wdd)
46{
47 struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
48
49 writel(0xaaaa, priv->mmio + EP93XX_WATCHDOG);
50
51 return 0;
52}
53
54static int ep93xx_wdt_stop(struct watchdog_device *wdd)
55{
56 struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
57
58 writel(0xaa55, priv->mmio + EP93XX_WATCHDOG);
59
60 return 0;
61}
62
63static int ep93xx_wdt_ping(struct watchdog_device *wdd)
64{
65 struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
66
67 writel(0x5555, priv->mmio + EP93XX_WATCHDOG);
68
69 return 0;
70}
71
72static const struct watchdog_info ep93xx_wdt_ident = {
73 .options = WDIOF_CARDRESET |
74 WDIOF_SETTIMEOUT |
75 WDIOF_MAGICCLOSE |
76 WDIOF_KEEPALIVEPING,
77 .identity = "EP93xx Watchdog",
78};
79
80static const struct watchdog_ops ep93xx_wdt_ops = {
81 .owner = THIS_MODULE,
82 .start = ep93xx_wdt_start,
83 .stop = ep93xx_wdt_stop,
84 .ping = ep93xx_wdt_ping,
85};
86
87static int ep93xx_wdt_probe(struct platform_device *pdev)
88{
89 struct device *dev = &pdev->dev;
90 struct ep93xx_wdt_priv *priv;
91 struct watchdog_device *wdd;
92 unsigned long val;
93 int ret;
94
95 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
96 if (!priv)
97 return -ENOMEM;
98
99 priv->mmio = devm_platform_ioremap_resource(pdev, 0);
100 if (IS_ERR(priv->mmio))
101 return PTR_ERR(priv->mmio);
102
103 val = readl(priv->mmio + EP93XX_WATCHDOG);
104
105 wdd = &priv->wdd;
106 wdd->bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
107 wdd->info = &ep93xx_wdt_ident;
108 wdd->ops = &ep93xx_wdt_ops;
109 wdd->min_timeout = 1;
110 wdd->max_hw_heartbeat_ms = 200;
111 wdd->parent = dev;
112
113 watchdog_set_nowayout(wdd, nowayout);
114
115 wdd->timeout = WDT_TIMEOUT;
116 watchdog_init_timeout(wdd, timeout, dev);
117
118 watchdog_set_drvdata(wdd, priv);
119
120 ret = devm_watchdog_register_device(dev, wdd);
121 if (ret)
122 return ret;
123
124 dev_info(dev, "EP93XX watchdog driver %s\n",
125 (val & 0x08) ? " (nCS1 disable detected)" : "");
126
127 return 0;
128}
129
130static struct platform_driver ep93xx_wdt_driver = {
131 .driver = {
132 .name = "ep93xx-wdt",
133 },
134 .probe = ep93xx_wdt_probe,
135};
136
137module_platform_driver(ep93xx_wdt_driver);
138
139MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>");
140MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
141MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
142MODULE_DESCRIPTION("EP93xx Watchdog");
143MODULE_LICENSE("GPL");
1/*
2 * Watchdog driver for Cirrus Logic EP93xx family of devices.
3 *
4 * Copyright (c) 2004 Ray Lehtiniemi
5 * Copyright (c) 2006 Tower Technologies
6 * Based on ep93xx driver, bits from alim7101_wdt.c
7 *
8 * Authors: Ray Lehtiniemi <rayl@mail.com>,
9 * Alessandro Zummo <a.zummo@towertech.it>
10 *
11 * Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
12 * Convert to a platform device and use the watchdog framework API
13 *
14 * This file is licensed under the terms of the GNU General Public
15 * License version 2. This program is licensed "as is" without any
16 * warranty of any kind, whether express or implied.
17 *
18 * This watchdog fires after 250msec, which is a too short interval
19 * for us to rely on the user space daemon alone. So we ping the
20 * wdt each ~200msec and eventually stop doing it if the user space
21 * daemon dies.
22 */
23
24#include <linux/platform_device.h>
25#include <linux/module.h>
26#include <linux/watchdog.h>
27#include <linux/io.h>
28
29/* default timeout (secs) */
30#define WDT_TIMEOUT 30
31
32static bool nowayout = WATCHDOG_NOWAYOUT;
33module_param(nowayout, bool, 0);
34MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
35
36static unsigned int timeout;
37module_param(timeout, uint, 0);
38MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");
39
40#define EP93XX_WATCHDOG 0x00
41#define EP93XX_WDSTATUS 0x04
42
43struct ep93xx_wdt_priv {
44 void __iomem *mmio;
45 struct watchdog_device wdd;
46};
47
48static int ep93xx_wdt_start(struct watchdog_device *wdd)
49{
50 struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
51
52 writel(0xaaaa, priv->mmio + EP93XX_WATCHDOG);
53
54 return 0;
55}
56
57static int ep93xx_wdt_stop(struct watchdog_device *wdd)
58{
59 struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
60
61 writel(0xaa55, priv->mmio + EP93XX_WATCHDOG);
62
63 return 0;
64}
65
66static int ep93xx_wdt_ping(struct watchdog_device *wdd)
67{
68 struct ep93xx_wdt_priv *priv = watchdog_get_drvdata(wdd);
69
70 writel(0x5555, priv->mmio + EP93XX_WATCHDOG);
71
72 return 0;
73}
74
75static const struct watchdog_info ep93xx_wdt_ident = {
76 .options = WDIOF_CARDRESET |
77 WDIOF_SETTIMEOUT |
78 WDIOF_MAGICCLOSE |
79 WDIOF_KEEPALIVEPING,
80 .identity = "EP93xx Watchdog",
81};
82
83static const struct watchdog_ops ep93xx_wdt_ops = {
84 .owner = THIS_MODULE,
85 .start = ep93xx_wdt_start,
86 .stop = ep93xx_wdt_stop,
87 .ping = ep93xx_wdt_ping,
88};
89
90static int ep93xx_wdt_probe(struct platform_device *pdev)
91{
92 struct device *dev = &pdev->dev;
93 struct ep93xx_wdt_priv *priv;
94 struct watchdog_device *wdd;
95 unsigned long val;
96 int ret;
97
98 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
99 if (!priv)
100 return -ENOMEM;
101
102 priv->mmio = devm_platform_ioremap_resource(pdev, 0);
103 if (IS_ERR(priv->mmio))
104 return PTR_ERR(priv->mmio);
105
106 val = readl(priv->mmio + EP93XX_WATCHDOG);
107
108 wdd = &priv->wdd;
109 wdd->bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
110 wdd->info = &ep93xx_wdt_ident;
111 wdd->ops = &ep93xx_wdt_ops;
112 wdd->min_timeout = 1;
113 wdd->max_hw_heartbeat_ms = 200;
114 wdd->parent = dev;
115
116 watchdog_set_nowayout(wdd, nowayout);
117
118 wdd->timeout = WDT_TIMEOUT;
119 watchdog_init_timeout(wdd, timeout, dev);
120
121 watchdog_set_drvdata(wdd, priv);
122
123 ret = devm_watchdog_register_device(dev, wdd);
124 if (ret)
125 return ret;
126
127 dev_info(dev, "EP93XX watchdog driver %s\n",
128 (val & 0x08) ? " (nCS1 disable detected)" : "");
129
130 return 0;
131}
132
133static struct platform_driver ep93xx_wdt_driver = {
134 .driver = {
135 .name = "ep93xx-wdt",
136 },
137 .probe = ep93xx_wdt_probe,
138};
139
140module_platform_driver(ep93xx_wdt_driver);
141
142MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>");
143MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
144MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
145MODULE_DESCRIPTION("EP93xx Watchdog");
146MODULE_LICENSE("GPL");