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authorHans-Christian Egtvedt <hcegtvedt@atmel.com>2007-06-07 19:06:41 -0400
committerWim Van Sebroeck <wim@iguana.be>2007-06-10 15:49:20 -0400
commita9cb3959ace112295fdb65c99a2928eedba06926 (patch)
tree40767f7c8fb62ac6da3f2657204c87a343837f28 /drivers/char/watchdog
parent10a29304f496ddef58473e6c53b5e66d9685536d (diff)
[WATCHDOG] Watchdog driver for AT32AP700X devices
Add support for the built in watchdog in AT32AP700X devices. Tested on AT32AP7000 and ATSTK1000. Hardware documentation can be found in the AT32AP7000 datasheet. Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com> Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/char/watchdog')
-rw-r--r--drivers/char/watchdog/Kconfig20
-rw-r--r--drivers/char/watchdog/Makefile3
-rw-r--r--drivers/char/watchdog/at32ap700x_wdt.c313
3 files changed, 336 insertions, 0 deletions
diff --git a/drivers/char/watchdog/Kconfig b/drivers/char/watchdog/Kconfig
index 53f5538c0c05..520afb8e5234 100644
--- a/drivers/char/watchdog/Kconfig
+++ b/drivers/char/watchdog/Kconfig
@@ -187,6 +187,26 @@ config PNX4008_WATCHDOG
187 187
188 Say N if you are unsure. 188 Say N if you are unsure.
189 189
190# AVR32 Architecture
191
192config AT32AP700X_WDT
193 tristate "AT32AP700x watchdog"
194 depends on WATCHDOG && CPU_AT32AP7000
195 help
196 Watchdog timer embedded into AT32AP700x devices. This will reboot
197 your system when the timeout is reached.
198
199config AT32AP700X_WDT_TIMEOUT
200 int "Timeout value for AT32AP700x watchdog"
201 depends on AT32AP700X_WDT
202 default "2"
203 range 1 2
204 help
205 Sets the timeout value for the watchdog in AT32AP700x devices.
206 Limited by hardware to be 1 or 2 seconds.
207
208 Set to 2 seconds by default.
209
190# X86 (i386 + ia64 + x86_64) Architecture 210# X86 (i386 + ia64 + x86_64) Architecture
191 211
192config ACQUIRE_WDT 212config ACQUIRE_WDT
diff --git a/drivers/char/watchdog/Makefile b/drivers/char/watchdog/Makefile
index d90f649038c2..3907ec04a4e5 100644
--- a/drivers/char/watchdog/Makefile
+++ b/drivers/char/watchdog/Makefile
@@ -36,6 +36,9 @@ obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o
36obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o 36obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o
37obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o 37obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
38 38
39# AVR32 Architecture
40obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
41
39# X86 (i386 + ia64 + x86_64) Architecture 42# X86 (i386 + ia64 + x86_64) Architecture
40obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o 43obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
41obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o 44obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o
diff --git a/drivers/char/watchdog/at32ap700x_wdt.c b/drivers/char/watchdog/at32ap700x_wdt.c
new file mode 100644
index 000000000000..036d83bcb50c
--- /dev/null
+++ b/drivers/char/watchdog/at32ap700x_wdt.c
@@ -0,0 +1,313 @@
1/*
2 * Watchdog driver for Atmel AT32AP700X devices
3 *
4 * Copyright (C) 2005-2006 Atmel Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/init.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/moduleparam.h>
15#include <linux/miscdevice.h>
16#include <linux/fs.h>
17#include <linux/platform_device.h>
18#include <linux/watchdog.h>
19
20#include <asm/uaccess.h>
21#include <asm/io.h>
22
23#define TIMEOUT_MIN 1
24#define TIMEOUT_DEFAULT CONFIG_AT32AP700X_WDT_TIMEOUT
25#define TIMEOUT_MAX 2
26
27/* Watchdog registers and write/read macro */
28#define WDT_CTRL 0x00
29#define WDT_CTRL_EN 0
30#define WDT_CTRL_PSEL 8
31#define WDT_CTRL_KEY 24
32
33#define WDT_CLR 0x04
34
35#define WDT_BIT(name) (1 << WDT_##name)
36#define WDT_BF(name,value) ((value) << WDT_##name)
37
38#define wdt_readl(dev,reg) \
39 __raw_readl((dev)->regs + WDT_##reg)
40#define wdt_writel(dev,reg,value) \
41 __raw_writel((value), (dev)->regs + WDT_##reg)
42
43struct wdt_at32ap700x {
44 void __iomem *regs;
45 int timeout;
46 int users;
47 struct miscdevice miscdev;
48};
49
50static struct wdt_at32ap700x *wdt;
51
52/*
53 * Disable the watchdog.
54 */
55static void inline at32_wdt_stop(void)
56{
57 unsigned long psel = wdt_readl(wdt, CTRL) & WDT_BF(CTRL_PSEL, 0x0f);
58 wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0x55));
59 wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0xaa));
60}
61
62/*
63 * Enable and reset the watchdog.
64 */
65static void inline at32_wdt_start(void)
66{
67 /* 0xf is 2^16 divider = 2 sec, 0xe is 2^15 divider = 1 sec */
68 unsigned long psel = (wdt->timeout > 1) ? 0xf : 0xe;
69
70 wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN)
71 | WDT_BF(CTRL_PSEL, psel)
72 | WDT_BF(CTRL_KEY, 0x55));
73 wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN)
74 | WDT_BF(CTRL_PSEL, psel)
75 | WDT_BF(CTRL_KEY, 0xaa));
76}
77
78/*
79 * Pat the watchdog timer.
80 */
81static void inline at32_wdt_pat(void)
82{
83 wdt_writel(wdt, CLR, 0x42);
84}
85
86/*
87 * Watchdog device is opened, and watchdog starts running.
88 */
89static int at32_wdt_open(struct inode *inode, struct file *file)
90{
91 if (test_and_set_bit(1, &wdt->users))
92 return -EBUSY;
93
94 at32_wdt_start();
95 return nonseekable_open(inode, file);
96}
97
98/*
99 * Close the watchdog device. If CONFIG_WATCHDOG_NOWAYOUT is _not_ defined then
100 * the watchdog is also disabled.
101 */
102static int at32_wdt_close(struct inode *inode, struct file *file)
103{
104#ifndef CONFIG_WATCHDOG_NOWAYOUT
105 at32_wdt_stop();
106#endif
107 clear_bit(1, &wdt->users);
108 return 0;
109}
110
111/*
112 * Change the watchdog time interval.
113 */
114static int at32_wdt_settimeout(int time)
115{
116 /*
117 * All counting occurs at 1 / SLOW_CLOCK (32 kHz) and max prescaler is
118 * 2 ^ 16 allowing up to 2 seconds timeout.
119 */
120 if ((time < TIMEOUT_MIN) || (time > TIMEOUT_MAX))
121 return -EINVAL;
122
123 /* Set new watchdog time. It will be used when at32_wdt_start() is called. */
124 wdt->timeout = time;
125 return 0;
126}
127
128static struct watchdog_info at32_wdt_info = {
129 .identity = "at32ap700x watchdog",
130 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
131};
132
133/*
134 * Handle commands from user-space.
135 */
136static int at32_wdt_ioctl(struct inode *inode, struct file *file,
137 unsigned int cmd, unsigned long arg)
138{
139 int ret = -ENOTTY;
140 int time;
141 void __user *argp = (void __user *)arg;
142 int __user *p = argp;
143
144 switch(cmd) {
145 case WDIOC_KEEPALIVE:
146 at32_wdt_pat();
147 ret = 0;
148 break;
149 case WDIOC_GETSUPPORT:
150 ret = copy_to_user(argp, &at32_wdt_info,
151 sizeof(at32_wdt_info)) ? -EFAULT : 0;
152 break;
153 case WDIOC_SETTIMEOUT:
154 ret = get_user(time, p);
155 if (ret)
156 break;
157 ret = at32_wdt_settimeout(time);
158 if (ret)
159 break;
160 /* Enable new time value */
161 at32_wdt_start();
162 /* fall through */
163 case WDIOC_GETTIMEOUT:
164 ret = put_user(wdt->timeout, p);
165 break;
166 case WDIOC_GETSTATUS: /* fall through */
167 case WDIOC_GETBOOTSTATUS:
168 ret = put_user(0, p);
169 break;
170 case WDIOC_SETOPTIONS:
171 ret = get_user(time, p);
172 if (ret)
173 break;
174 if (time & WDIOS_DISABLECARD)
175 at32_wdt_stop();
176 if (time & WDIOS_ENABLECARD)
177 at32_wdt_start();
178 ret = 0;
179 break;
180 }
181
182 return ret;
183}
184
185static ssize_t at32_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
186{
187 at32_wdt_pat();
188 return len;
189}
190
191static const struct file_operations at32_wdt_fops = {
192 .owner = THIS_MODULE,
193 .llseek = no_llseek,
194 .ioctl = at32_wdt_ioctl,
195 .open = at32_wdt_open,
196 .release = at32_wdt_close,
197 .write = at32_wdt_write,
198};
199
200static int __init at32_wdt_probe(struct platform_device *pdev)
201{
202 struct resource *regs;
203 int ret;
204
205 if (wdt) {
206 dev_dbg(&pdev->dev, "only 1 wdt instance supported.\n");
207 return -EBUSY;
208 }
209
210 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
211 if (!regs) {
212 dev_dbg(&pdev->dev, "missing mmio resource\n");
213 return -ENXIO;
214 }
215
216 wdt = kzalloc(sizeof(struct wdt_at32ap700x), GFP_KERNEL);
217 if (!wdt) {
218 dev_dbg(&pdev->dev, "no memory for wdt structure\n");
219 return -ENOMEM;
220 }
221
222 wdt->regs = ioremap(regs->start, regs->end - regs->start + 1);
223 wdt->users = 0;
224 wdt->miscdev.minor = WATCHDOG_MINOR;
225 wdt->miscdev.name = "watchdog";
226 wdt->miscdev.fops = &at32_wdt_fops;
227
228 if (at32_wdt_settimeout(TIMEOUT_DEFAULT)) {
229 at32_wdt_settimeout(TIMEOUT_MAX);
230 dev_dbg(&pdev->dev,
231 "default timeout invalid, set to %d sec.\n",
232 TIMEOUT_MAX);
233 }
234
235 ret = misc_register(&wdt->miscdev);
236 if (ret) {
237 dev_dbg(&pdev->dev, "failed to register wdt miscdev\n");
238 goto err_register;
239 }
240
241 platform_set_drvdata(pdev, wdt);
242 wdt->miscdev.parent = &pdev->dev;
243 dev_info(&pdev->dev, "AT32AP700X WDT at 0x%p\n", wdt->regs);
244
245 return 0;
246
247err_register:
248 kfree(wdt);
249 wdt = NULL;
250 return ret;
251}
252
253static int __exit at32_wdt_remove(struct platform_device *pdev)
254{
255 if (wdt && platform_get_drvdata(pdev) == wdt) {
256 misc_deregister(&wdt->miscdev);
257 kfree(wdt);
258 wdt = NULL;
259 platform_set_drvdata(pdev, NULL);
260 }
261
262 return 0;
263}
264
265static void at32_wdt_shutdown(struct platform_device *pdev)
266{
267 at32_wdt_stop();
268}
269
270#ifdef CONFIG_PM
271static int at32_wdt_suspend(struct platform_device *pdev, pm_message_t message)
272{
273 at32_wdt_stop();
274 return 0;
275}
276
277static int at32_wdt_resume(struct platform_device *pdev)
278{
279 if (wdt->users)
280 at32_wdt_start();
281 return 0;
282}
283#endif
284
285static struct platform_driver at32_wdt_driver = {
286 .remove = __exit_p(at32_wdt_remove),
287#ifdef CONFIG_PM
288 .suspend = at32_wdt_suspend,
289 .resume = at32_wdt_resume,
290#endif
291 .driver = {
292 .name = "at32_wdt",
293 .owner = THIS_MODULE,
294 },
295 .shutdown = at32_wdt_shutdown,
296};
297
298static int __init at32_wdt_init(void)
299{
300 return platform_driver_probe(&at32_wdt_driver, at32_wdt_probe);
301}
302module_init(at32_wdt_init);
303
304static void __exit at32_wdt_exit(void)
305{
306 platform_driver_unregister(&at32_wdt_driver);
307}
308module_exit(at32_wdt_exit);
309
310MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
311MODULE_DESCRIPTION("Watchdog driver for Atmel AT32AP700X");
312MODULE_LICENSE("GPL");
313MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);