2 * MOXA ART SoCs watchdog driver.
4 * Copyright (C) 2013 Jonas Jensen
6 * Jonas Jensen <jonas.jensen@gmail.com>
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
13 #include <linux/clk.h>
15 #include <linux/module.h>
16 #include <linux/err.h>
17 #include <linux/kernel.h>
18 #include <linux/platform_device.h>
19 #include <linux/watchdog.h>
20 #include <linux/moduleparam.h>
24 #define REG_ENABLE 0xC
26 struct moxart_wdt_dev
{
27 struct watchdog_device dev
;
29 unsigned int clock_frequency
;
34 static int moxart_wdt_restart(struct watchdog_device
*wdt_dev
)
36 struct moxart_wdt_dev
*moxart_wdt
= watchdog_get_drvdata(wdt_dev
);
38 writel(1, moxart_wdt
->base
+ REG_COUNT
);
39 writel(0x5ab9, moxart_wdt
->base
+ REG_MODE
);
40 writel(0x03, moxart_wdt
->base
+ REG_ENABLE
);
45 static int moxart_wdt_stop(struct watchdog_device
*wdt_dev
)
47 struct moxart_wdt_dev
*moxart_wdt
= watchdog_get_drvdata(wdt_dev
);
49 writel(0, moxart_wdt
->base
+ REG_ENABLE
);
54 static int moxart_wdt_start(struct watchdog_device
*wdt_dev
)
56 struct moxart_wdt_dev
*moxart_wdt
= watchdog_get_drvdata(wdt_dev
);
58 writel(moxart_wdt
->clock_frequency
* wdt_dev
->timeout
,
59 moxart_wdt
->base
+ REG_COUNT
);
60 writel(0x5ab9, moxart_wdt
->base
+ REG_MODE
);
61 writel(0x03, moxart_wdt
->base
+ REG_ENABLE
);
66 static int moxart_wdt_set_timeout(struct watchdog_device
*wdt_dev
,
69 wdt_dev
->timeout
= timeout
;
74 static const struct watchdog_info moxart_wdt_info
= {
75 .identity
= "moxart-wdt",
76 .options
= WDIOF_SETTIMEOUT
| WDIOF_KEEPALIVEPING
|
80 static const struct watchdog_ops moxart_wdt_ops
= {
82 .start
= moxart_wdt_start
,
83 .stop
= moxart_wdt_stop
,
84 .set_timeout
= moxart_wdt_set_timeout
,
85 .restart
= moxart_wdt_restart
,
88 static int moxart_wdt_probe(struct platform_device
*pdev
)
90 struct moxart_wdt_dev
*moxart_wdt
;
91 struct device
*dev
= &pdev
->dev
;
92 struct device_node
*node
= dev
->of_node
;
96 unsigned int max_timeout
;
97 bool nowayout
= WATCHDOG_NOWAYOUT
;
99 moxart_wdt
= devm_kzalloc(dev
, sizeof(*moxart_wdt
), GFP_KERNEL
);
103 platform_set_drvdata(pdev
, moxart_wdt
);
105 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
106 moxart_wdt
->base
= devm_ioremap_resource(dev
, res
);
107 if (IS_ERR(moxart_wdt
->base
))
108 return PTR_ERR(moxart_wdt
->base
);
110 clk
= of_clk_get(node
, 0);
112 pr_err("%s: of_clk_get failed\n", __func__
);
116 moxart_wdt
->clock_frequency
= clk_get_rate(clk
);
117 if (moxart_wdt
->clock_frequency
== 0) {
118 pr_err("%s: incorrect clock frequency\n", __func__
);
122 max_timeout
= UINT_MAX
/ moxart_wdt
->clock_frequency
;
124 moxart_wdt
->dev
.info
= &moxart_wdt_info
;
125 moxart_wdt
->dev
.ops
= &moxart_wdt_ops
;
126 moxart_wdt
->dev
.timeout
= max_timeout
;
127 moxart_wdt
->dev
.min_timeout
= 1;
128 moxart_wdt
->dev
.max_timeout
= max_timeout
;
129 moxart_wdt
->dev
.parent
= dev
;
131 watchdog_init_timeout(&moxart_wdt
->dev
, heartbeat
, dev
);
132 watchdog_set_nowayout(&moxart_wdt
->dev
, nowayout
);
133 watchdog_set_restart_priority(&moxart_wdt
->dev
, 128);
135 watchdog_set_drvdata(&moxart_wdt
->dev
, moxart_wdt
);
137 err
= watchdog_register_device(&moxart_wdt
->dev
);
141 dev_dbg(dev
, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
142 moxart_wdt
->dev
.timeout
, nowayout
);
147 static int moxart_wdt_remove(struct platform_device
*pdev
)
149 struct moxart_wdt_dev
*moxart_wdt
= platform_get_drvdata(pdev
);
151 moxart_wdt_stop(&moxart_wdt
->dev
);
156 static const struct of_device_id moxart_watchdog_match
[] = {
157 { .compatible
= "moxa,moxart-watchdog" },
160 MODULE_DEVICE_TABLE(of
, moxart_watchdog_match
);
162 static struct platform_driver moxart_wdt_driver
= {
163 .probe
= moxart_wdt_probe
,
164 .remove
= moxart_wdt_remove
,
166 .name
= "moxart-watchdog",
167 .of_match_table
= moxart_watchdog_match
,
170 module_platform_driver(moxart_wdt_driver
);
172 module_param(heartbeat
, int, 0);
173 MODULE_PARM_DESC(heartbeat
, "Watchdog heartbeat in seconds");
175 MODULE_DESCRIPTION("MOXART watchdog driver");
176 MODULE_LICENSE("GPL");
177 MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");