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>
25 #include <linux/of_device.h>
26 #include <linux/platform_device.h>
27 #include <linux/types.h>
28 #include <linux/watchdog.h>
30 #define WDT_MAX_TIMEOUT 16
31 #define WDT_MIN_TIMEOUT 1
32 #define WDT_TIMEOUT_MASK 0x0F
34 #define WDT_CTRL_RELOAD ((1 << 0) | (0x0a57 << 1))
36 #define WDT_MODE_EN (1 << 0)
38 #define DRV_NAME "sunxi-wdt"
39 #define DRV_VERSION "1.0"
41 static bool nowayout
= WATCHDOG_NOWAYOUT
;
42 static unsigned int timeout
= WDT_MAX_TIMEOUT
;
45 * This structure stores the register offsets for different variants
46 * of Allwinner's watchdog hardware.
48 struct sunxi_wdt_reg
{
57 struct sunxi_wdt_dev
{
58 struct watchdog_device wdt_dev
;
59 void __iomem
*wdt_base
;
60 const struct sunxi_wdt_reg
*wdt_regs
;
64 * wdt_timeout_map maps the watchdog timer interval value in seconds to
65 * the value of the register WDT_MODE at bits .wdt_timeout_shift ~ +3
67 * [timeout seconds] = register value
71 static const int wdt_timeout_map
[] = {
86 static int sunxi_wdt_restart(struct watchdog_device
*wdt_dev
)
88 struct sunxi_wdt_dev
*sunxi_wdt
= watchdog_get_drvdata(wdt_dev
);
89 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
90 const struct sunxi_wdt_reg
*regs
= sunxi_wdt
->wdt_regs
;
93 /* Set system reset function */
94 val
= readl(wdt_base
+ regs
->wdt_cfg
);
95 val
&= ~(regs
->wdt_reset_mask
);
96 val
|= regs
->wdt_reset_val
;
97 writel(val
, wdt_base
+ regs
->wdt_cfg
);
99 /* Set lowest timeout and enable watchdog */
100 val
= readl(wdt_base
+ regs
->wdt_mode
);
101 val
&= ~(WDT_TIMEOUT_MASK
<< regs
->wdt_timeout_shift
);
103 writel(val
, wdt_base
+ regs
->wdt_mode
);
106 * Restart the watchdog. The default (and lowest) interval
107 * value for the watchdog is 0.5s.
109 writel(WDT_CTRL_RELOAD
, wdt_base
+ regs
->wdt_ctrl
);
113 val
= readl(wdt_base
+ regs
->wdt_mode
);
115 writel(val
, wdt_base
+ regs
->wdt_mode
);
120 static int sunxi_wdt_ping(struct watchdog_device
*wdt_dev
)
122 struct sunxi_wdt_dev
*sunxi_wdt
= watchdog_get_drvdata(wdt_dev
);
123 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
124 const struct sunxi_wdt_reg
*regs
= sunxi_wdt
->wdt_regs
;
126 writel(WDT_CTRL_RELOAD
, wdt_base
+ regs
->wdt_ctrl
);
131 static int sunxi_wdt_set_timeout(struct watchdog_device
*wdt_dev
,
132 unsigned int timeout
)
134 struct sunxi_wdt_dev
*sunxi_wdt
= watchdog_get_drvdata(wdt_dev
);
135 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
136 const struct sunxi_wdt_reg
*regs
= sunxi_wdt
->wdt_regs
;
139 if (wdt_timeout_map
[timeout
] == 0)
142 sunxi_wdt
->wdt_dev
.timeout
= timeout
;
144 reg
= readl(wdt_base
+ regs
->wdt_mode
);
145 reg
&= ~(WDT_TIMEOUT_MASK
<< regs
->wdt_timeout_shift
);
146 reg
|= wdt_timeout_map
[timeout
] << regs
->wdt_timeout_shift
;
147 writel(reg
, wdt_base
+ regs
->wdt_mode
);
149 sunxi_wdt_ping(wdt_dev
);
154 static int sunxi_wdt_stop(struct watchdog_device
*wdt_dev
)
156 struct sunxi_wdt_dev
*sunxi_wdt
= watchdog_get_drvdata(wdt_dev
);
157 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
158 const struct sunxi_wdt_reg
*regs
= sunxi_wdt
->wdt_regs
;
160 writel(0, wdt_base
+ regs
->wdt_mode
);
165 static int sunxi_wdt_start(struct watchdog_device
*wdt_dev
)
168 struct sunxi_wdt_dev
*sunxi_wdt
= watchdog_get_drvdata(wdt_dev
);
169 void __iomem
*wdt_base
= sunxi_wdt
->wdt_base
;
170 const struct sunxi_wdt_reg
*regs
= sunxi_wdt
->wdt_regs
;
173 ret
= sunxi_wdt_set_timeout(&sunxi_wdt
->wdt_dev
,
174 sunxi_wdt
->wdt_dev
.timeout
);
178 /* Set system reset function */
179 reg
= readl(wdt_base
+ regs
->wdt_cfg
);
180 reg
&= ~(regs
->wdt_reset_mask
);
181 reg
|= regs
->wdt_reset_val
;
182 writel(reg
, wdt_base
+ regs
->wdt_cfg
);
184 /* Enable watchdog */
185 reg
= readl(wdt_base
+ regs
->wdt_mode
);
187 writel(reg
, wdt_base
+ regs
->wdt_mode
);
192 static const struct watchdog_info sunxi_wdt_info
= {
193 .identity
= DRV_NAME
,
194 .options
= WDIOF_SETTIMEOUT
|
195 WDIOF_KEEPALIVEPING
|
199 static const struct watchdog_ops sunxi_wdt_ops
= {
200 .owner
= THIS_MODULE
,
201 .start
= sunxi_wdt_start
,
202 .stop
= sunxi_wdt_stop
,
203 .ping
= sunxi_wdt_ping
,
204 .set_timeout
= sunxi_wdt_set_timeout
,
205 .restart
= sunxi_wdt_restart
,
208 static const struct sunxi_wdt_reg sun4i_wdt_reg
= {
212 .wdt_timeout_shift
= 3,
213 .wdt_reset_mask
= 0x02,
214 .wdt_reset_val
= 0x02,
217 static const struct sunxi_wdt_reg sun6i_wdt_reg
= {
221 .wdt_timeout_shift
= 4,
222 .wdt_reset_mask
= 0x03,
223 .wdt_reset_val
= 0x01,
226 static const struct of_device_id sunxi_wdt_dt_ids
[] = {
227 { .compatible
= "allwinner,sun4i-a10-wdt", .data
= &sun4i_wdt_reg
},
228 { .compatible
= "allwinner,sun6i-a31-wdt", .data
= &sun6i_wdt_reg
},
231 MODULE_DEVICE_TABLE(of
, sunxi_wdt_dt_ids
);
233 static int sunxi_wdt_probe(struct platform_device
*pdev
)
235 struct sunxi_wdt_dev
*sunxi_wdt
;
236 const struct of_device_id
*device
;
237 struct resource
*res
;
240 sunxi_wdt
= devm_kzalloc(&pdev
->dev
, sizeof(*sunxi_wdt
), GFP_KERNEL
);
244 platform_set_drvdata(pdev
, sunxi_wdt
);
246 device
= of_match_device(sunxi_wdt_dt_ids
, &pdev
->dev
);
250 sunxi_wdt
->wdt_regs
= device
->data
;
252 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
253 sunxi_wdt
->wdt_base
= devm_ioremap_resource(&pdev
->dev
, res
);
254 if (IS_ERR(sunxi_wdt
->wdt_base
))
255 return PTR_ERR(sunxi_wdt
->wdt_base
);
257 sunxi_wdt
->wdt_dev
.info
= &sunxi_wdt_info
;
258 sunxi_wdt
->wdt_dev
.ops
= &sunxi_wdt_ops
;
259 sunxi_wdt
->wdt_dev
.timeout
= WDT_MAX_TIMEOUT
;
260 sunxi_wdt
->wdt_dev
.max_timeout
= WDT_MAX_TIMEOUT
;
261 sunxi_wdt
->wdt_dev
.min_timeout
= WDT_MIN_TIMEOUT
;
262 sunxi_wdt
->wdt_dev
.parent
= &pdev
->dev
;
264 watchdog_init_timeout(&sunxi_wdt
->wdt_dev
, timeout
, &pdev
->dev
);
265 watchdog_set_nowayout(&sunxi_wdt
->wdt_dev
, nowayout
);
266 watchdog_set_restart_priority(&sunxi_wdt
->wdt_dev
, 128);
268 watchdog_set_drvdata(&sunxi_wdt
->wdt_dev
, sunxi_wdt
);
270 sunxi_wdt_stop(&sunxi_wdt
->wdt_dev
);
272 err
= watchdog_register_device(&sunxi_wdt
->wdt_dev
);
276 dev_info(&pdev
->dev
, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
277 sunxi_wdt
->wdt_dev
.timeout
, nowayout
);
282 static int sunxi_wdt_remove(struct platform_device
*pdev
)
284 struct sunxi_wdt_dev
*sunxi_wdt
= platform_get_drvdata(pdev
);
286 watchdog_unregister_device(&sunxi_wdt
->wdt_dev
);
287 watchdog_set_drvdata(&sunxi_wdt
->wdt_dev
, NULL
);
292 static void sunxi_wdt_shutdown(struct platform_device
*pdev
)
294 struct sunxi_wdt_dev
*sunxi_wdt
= platform_get_drvdata(pdev
);
296 sunxi_wdt_stop(&sunxi_wdt
->wdt_dev
);
299 static struct platform_driver sunxi_wdt_driver
= {
300 .probe
= sunxi_wdt_probe
,
301 .remove
= sunxi_wdt_remove
,
302 .shutdown
= sunxi_wdt_shutdown
,
305 .of_match_table
= sunxi_wdt_dt_ids
,
309 module_platform_driver(sunxi_wdt_driver
);
311 module_param(timeout
, uint
, 0);
312 MODULE_PARM_DESC(timeout
, "Watchdog heartbeat in seconds");
314 module_param(nowayout
, bool, 0);
315 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started "
316 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT
) ")");
318 MODULE_LICENSE("GPL");
319 MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>");
320 MODULE_AUTHOR("Henrik Nordstrom <henrik@henriknordstrom.net>");
321 MODULE_DESCRIPTION("sunxi WatchDog Timer Driver");
322 MODULE_VERSION(DRV_VERSION
);