2 * sunxi Watchdog Driver
4 * Copyright (c) 2013 Carlo Caione
5 * 2012 Henrik Nordstrom
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 * (c) Copyright 2010 Novell, Inc.
16 #include <linux/clk.h>
17 #include <linux/delay.h>
18 #include <linux/err.h>
19 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/notifier.h>
26 #include <linux/platform_device.h>
27 #include <linux/reboot.h>
28 #include <linux/types.h>
29 #include <linux/watchdog.h>
31 #define WDT_MAX_TIMEOUT 16
32 #define WDT_MIN_TIMEOUT 1
33 #define WDT_MODE_TIMEOUT(n) ((n) << 3)
34 #define WDT_TIMEOUT_MASK WDT_MODE_TIMEOUT(0x0F)
37 #define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
40 #define WDT_MODE_EN (1 << 0)
41 #define WDT_MODE_RST_EN (1 << 1)
43 #define DRV_NAME "sunxi-wdt"
44 #define DRV_VERSION "1.0"
46 static bool nowayout
= WATCHDOG_NOWAYOUT
;
47 static unsigned int timeout
= WDT_MAX_TIMEOUT
;
49 struct sunxi_wdt_dev
{
50 struct watchdog_device wdt_dev
;
51 void __iomem
*wdt_base
;
52 struct notifier_block restart_handler
;
56 * wdt_timeout_map maps the watchdog timer interval value in seconds to
57 * the value of the register WDT_MODE bit 3:6
59 * [timeout seconds] = register value
63 static const int wdt_timeout_map
[] = {
78 static int sunxi_restart_handle(struct notifier_block
*this, unsigned long mode
,
81 struct sunxi_wdt_dev
*sunxi_wdt
= container_of(this,
84 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
86 /* Enable timer and set reset bit in the watchdog */
87 writel(WDT_MODE_EN
| WDT_MODE_RST_EN
, wdt_base
+ WDT_MODE
);
90 * Restart the watchdog. The default (and lowest) interval
91 * value for the watchdog is 0.5s.
93 writel(WDT_CTRL_RELOAD
, wdt_base
+ WDT_CTRL
);
97 writel(WDT_MODE_EN
| WDT_MODE_RST_EN
, wdt_base
+ WDT_MODE
);
102 static int sunxi_wdt_ping(struct watchdog_device
*wdt_dev
)
104 struct sunxi_wdt_dev
*sunxi_wdt
= watchdog_get_drvdata(wdt_dev
);
105 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
107 iowrite32(WDT_CTRL_RELOAD
, wdt_base
+ WDT_CTRL
);
112 static int sunxi_wdt_set_timeout(struct watchdog_device
*wdt_dev
,
113 unsigned int timeout
)
115 struct sunxi_wdt_dev
*sunxi_wdt
= watchdog_get_drvdata(wdt_dev
);
116 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
119 if (wdt_timeout_map
[timeout
] == 0)
122 sunxi_wdt
->wdt_dev
.timeout
= timeout
;
124 reg
= ioread32(wdt_base
+ WDT_MODE
);
125 reg
&= ~WDT_TIMEOUT_MASK
;
126 reg
|= WDT_MODE_TIMEOUT(wdt_timeout_map
[timeout
]);
127 iowrite32(reg
, wdt_base
+ WDT_MODE
);
129 sunxi_wdt_ping(wdt_dev
);
134 static int sunxi_wdt_stop(struct watchdog_device
*wdt_dev
)
136 struct sunxi_wdt_dev
*sunxi_wdt
= watchdog_get_drvdata(wdt_dev
);
137 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
139 iowrite32(0, wdt_base
+ WDT_MODE
);
144 static int sunxi_wdt_start(struct watchdog_device
*wdt_dev
)
147 struct sunxi_wdt_dev
*sunxi_wdt
= watchdog_get_drvdata(wdt_dev
);
148 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
151 ret
= sunxi_wdt_set_timeout(&sunxi_wdt
->wdt_dev
,
152 sunxi_wdt
->wdt_dev
.timeout
);
156 reg
= ioread32(wdt_base
+ WDT_MODE
);
157 reg
|= (WDT_MODE_RST_EN
| WDT_MODE_EN
);
158 iowrite32(reg
, wdt_base
+ WDT_MODE
);
163 static const struct watchdog_info sunxi_wdt_info
= {
164 .identity
= DRV_NAME
,
165 .options
= WDIOF_SETTIMEOUT
|
166 WDIOF_KEEPALIVEPING
|
170 static const struct watchdog_ops sunxi_wdt_ops
= {
171 .owner
= THIS_MODULE
,
172 .start
= sunxi_wdt_start
,
173 .stop
= sunxi_wdt_stop
,
174 .ping
= sunxi_wdt_ping
,
175 .set_timeout
= sunxi_wdt_set_timeout
,
178 static int sunxi_wdt_probe(struct platform_device
*pdev
)
180 struct sunxi_wdt_dev
*sunxi_wdt
;
181 struct resource
*res
;
184 sunxi_wdt
= devm_kzalloc(&pdev
->dev
, sizeof(*sunxi_wdt
), GFP_KERNEL
);
188 platform_set_drvdata(pdev
, sunxi_wdt
);
190 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
191 sunxi_wdt
->wdt_base
= devm_ioremap_resource(&pdev
->dev
, res
);
192 if (IS_ERR(sunxi_wdt
->wdt_base
))
193 return PTR_ERR(sunxi_wdt
->wdt_base
);
195 sunxi_wdt
->wdt_dev
.info
= &sunxi_wdt_info
;
196 sunxi_wdt
->wdt_dev
.ops
= &sunxi_wdt_ops
;
197 sunxi_wdt
->wdt_dev
.timeout
= WDT_MAX_TIMEOUT
;
198 sunxi_wdt
->wdt_dev
.max_timeout
= WDT_MAX_TIMEOUT
;
199 sunxi_wdt
->wdt_dev
.min_timeout
= WDT_MIN_TIMEOUT
;
200 sunxi_wdt
->wdt_dev
.parent
= &pdev
->dev
;
202 watchdog_init_timeout(&sunxi_wdt
->wdt_dev
, timeout
, &pdev
->dev
);
203 watchdog_set_nowayout(&sunxi_wdt
->wdt_dev
, nowayout
);
205 watchdog_set_drvdata(&sunxi_wdt
->wdt_dev
, sunxi_wdt
);
207 sunxi_wdt_stop(&sunxi_wdt
->wdt_dev
);
209 err
= watchdog_register_device(&sunxi_wdt
->wdt_dev
);
213 sunxi_wdt
->restart_handler
.notifier_call
= sunxi_restart_handle
;
214 sunxi_wdt
->restart_handler
.priority
= 128;
215 err
= register_restart_handler(&sunxi_wdt
->restart_handler
);
218 "cannot register restart handler (err=%d)\n", err
);
220 dev_info(&pdev
->dev
, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
221 sunxi_wdt
->wdt_dev
.timeout
, nowayout
);
226 static int sunxi_wdt_remove(struct platform_device
*pdev
)
228 struct sunxi_wdt_dev
*sunxi_wdt
= platform_get_drvdata(pdev
);
230 unregister_restart_handler(&sunxi_wdt
->restart_handler
);
232 watchdog_unregister_device(&sunxi_wdt
->wdt_dev
);
233 watchdog_set_drvdata(&sunxi_wdt
->wdt_dev
, NULL
);
238 static void sunxi_wdt_shutdown(struct platform_device
*pdev
)
240 struct sunxi_wdt_dev
*sunxi_wdt
= platform_get_drvdata(pdev
);
242 sunxi_wdt_stop(&sunxi_wdt
->wdt_dev
);
245 static const struct of_device_id sunxi_wdt_dt_ids
[] = {
246 { .compatible
= "allwinner,sun4i-a10-wdt" },
249 MODULE_DEVICE_TABLE(of
, sunxi_wdt_dt_ids
);
251 static struct platform_driver sunxi_wdt_driver
= {
252 .probe
= sunxi_wdt_probe
,
253 .remove
= sunxi_wdt_remove
,
254 .shutdown
= sunxi_wdt_shutdown
,
256 .owner
= THIS_MODULE
,
258 .of_match_table
= sunxi_wdt_dt_ids
,
262 module_platform_driver(sunxi_wdt_driver
);
264 module_param(timeout
, uint
, 0);
265 MODULE_PARM_DESC(timeout
, "Watchdog heartbeat in seconds");
267 module_param(nowayout
, bool, 0);
268 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started "
269 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT
) ")");
271 MODULE_LICENSE("GPL");
272 MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");
273 MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
274 MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
275 MODULE_VERSION(DRV_VERSION
);