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Florian Fainelli03ec5852008-02-25 13:11:31 +01001/*
2 * IDT Interprise 79RC32434 watchdog driver
3 *
4 * Copyright (C) 2006, Ondrej Zajicek <santiago@crfreenet.org>
5 * Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
6 *
7 * based on
8 * SoftDog 0.05: A Software Watchdog Device
9 *
Alan Cox29fa0582008-10-27 15:17:56 +000010 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
11 * All Rights Reserved.
Florian Fainelli03ec5852008-02-25 13:11:31 +010012 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
17 *
18 */
19
Phil Sutter9b655e02009-02-08 16:44:42 +010020#include <linux/module.h> /* For module specific items */
21#include <linux/moduleparam.h> /* For new moduleparam's */
22#include <linux/types.h> /* For standard types (like size_t) */
23#include <linux/errno.h> /* For the -ENODEV/... values */
24#include <linux/kernel.h> /* For printk/panic/... */
25#include <linux/fs.h> /* For file operations */
26#include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV
27 (WATCHDOG_MINOR) */
28#include <linux/watchdog.h> /* For the watchdog specific items */
29#include <linux/init.h> /* For __init/__exit/... */
30#include <linux/platform_device.h> /* For platform_driver framework */
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +000031#include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
Phil Sutter9b655e02009-02-08 16:44:42 +010032#include <linux/uaccess.h> /* For copy_to_user/put_user/... */
Florian Fainelli03ec5852008-02-25 13:11:31 +010033
Phil Sutter9b655e02009-02-08 16:44:42 +010034#include <asm/mach-rc32434/integ.h> /* For the Watchdog registers */
35
36#define PFX KBUILD_MODNAME ": "
Florian Fainelli03ec5852008-02-25 13:11:31 +010037
Wim Van Sebroeckf296b142009-02-23 13:08:37 +000038#define VERSION "1.0"
Florian Fainelli03ec5852008-02-25 13:11:31 +010039
40static struct {
Florian Fainelli03ec5852008-02-25 13:11:31 +010041 unsigned long inuse;
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +000042 spinlock_t io_lock;
Florian Fainelli03ec5852008-02-25 13:11:31 +010043} rc32434_wdt_device;
44
45static struct integ __iomem *wdt_reg;
Florian Fainelli03ec5852008-02-25 13:11:31 +010046
47static int expect_close;
Phil Sutter0af98d32009-02-08 16:44:42 +010048
49/* Board internal clock speed in Hz,
50 * the watchdog timer ticks at. */
51extern unsigned int idt_cpu_freq;
52
53/* translate wtcompare value to seconds and vice versa */
54#define WTCOMP2SEC(x) (x / idt_cpu_freq)
55#define SEC2WTCOMP(x) (x * idt_cpu_freq)
56
57/* Use a default timeout of 20s. This should be
58 * safe for CPU clock speeds up to 400MHz, as
59 * ((2 ^ 32) - 1) / (400MHz / 2) = 21s. */
60#define WATCHDOG_TIMEOUT 20
61
62static int timeout = WATCHDOG_TIMEOUT;
Phil Sutter08eb2e02009-02-08 16:44:42 +010063module_param(timeout, int, 0);
64MODULE_PARM_DESC(timeout, "Watchdog timeout value, in seconds (default="
65 WATCHDOG_TIMEOUT ")");
Florian Fainelli03ec5852008-02-25 13:11:31 +010066
67static int nowayout = WATCHDOG_NOWAYOUT;
68module_param(nowayout, int, 0);
69MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
70 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
71
Phil Sutter0af98d32009-02-08 16:44:42 +010072/* apply or and nand masks to data read from addr and write back */
73#define SET_BITS(addr, or, nand) \
74 writel((readl(&addr) | or) & ~nand, &addr)
Florian Fainelli03ec5852008-02-25 13:11:31 +010075
Phil Sutter08eb2e02009-02-08 16:44:42 +010076static int rc32434_wdt_set(int new_timeout)
77{
78 int max_to = WTCOMP2SEC((u32)-1);
79
80 if (new_timeout < 0 || new_timeout > max_to) {
81 printk(KERN_ERR PFX "timeout value must be between 0 and %d",
82 max_to);
83 return -EINVAL;
84 }
85 timeout = new_timeout;
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +000086 spin_lock(&rc32434_wdt_device.io_lock);
Phil Sutter08eb2e02009-02-08 16:44:42 +010087 writel(SEC2WTCOMP(timeout), &wdt_reg->wtcompare);
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +000088 spin_unlock(&rc32434_wdt_device.io_lock);
Phil Sutter08eb2e02009-02-08 16:44:42 +010089
90 return 0;
91}
92
Florian Fainelli03ec5852008-02-25 13:11:31 +010093static void rc32434_wdt_start(void)
94{
Phil Sutter0af98d32009-02-08 16:44:42 +010095 u32 or, nand;
Florian Fainelli03ec5852008-02-25 13:11:31 +010096
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +000097 spin_lock(&rc32434_wdt_device.io_lock);
98
Phil Sutter0af98d32009-02-08 16:44:42 +010099 /* zero the counter before enabling */
100 writel(0, &wdt_reg->wtcount);
Florian Fainelli03ec5852008-02-25 13:11:31 +0100101
Phil Sutter0af98d32009-02-08 16:44:42 +0100102 /* don't generate a non-maskable interrupt,
103 * do a warm reset instead */
104 nand = 1 << RC32434_ERR_WNE;
105 or = 1 << RC32434_ERR_WRE;
Florian Fainelli03ec5852008-02-25 13:11:31 +0100106
Phil Sutter0af98d32009-02-08 16:44:42 +0100107 /* reset the ERRCS timeout bit in case it's set */
108 nand |= 1 << RC32434_ERR_WTO;
109
110 SET_BITS(wdt_reg->errcs, or, nand);
111
Phil Sutter08eb2e02009-02-08 16:44:42 +0100112 /* set the timeout (either default or based on module param) */
113 rc32434_wdt_set(timeout);
114
Phil Sutter0af98d32009-02-08 16:44:42 +0100115 /* reset WTC timeout bit and enable WDT */
116 nand = 1 << RC32434_WTC_TO;
117 or = 1 << RC32434_WTC_EN;
118
119 SET_BITS(wdt_reg->wtc, or, nand);
Phil Sutter9b655e02009-02-08 16:44:42 +0100120
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +0000121 spin_unlock(&rc32434_wdt_device.io_lock);
Phil Sutter9b655e02009-02-08 16:44:42 +0100122 printk(KERN_INFO PFX "Started watchdog timer.\n");
Florian Fainelli03ec5852008-02-25 13:11:31 +0100123}
124
125static void rc32434_wdt_stop(void)
126{
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +0000127 spin_lock(&rc32434_wdt_device.io_lock);
128
Phil Sutter0af98d32009-02-08 16:44:42 +0100129 /* Disable WDT */
130 SET_BITS(wdt_reg->wtc, 0, 1 << RC32434_WTC_EN);
Phil Sutter9b655e02009-02-08 16:44:42 +0100131
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +0000132 spin_unlock(&rc32434_wdt_device.io_lock);
Phil Sutter9b655e02009-02-08 16:44:42 +0100133 printk(KERN_INFO PFX "Stopped watchdog timer.\n");
Phil Sutter0af98d32009-02-08 16:44:42 +0100134}
Florian Fainelli03ec5852008-02-25 13:11:31 +0100135
Phil Sutter0af98d32009-02-08 16:44:42 +0100136static void rc32434_wdt_ping(void)
Florian Fainelli03ec5852008-02-25 13:11:31 +0100137{
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +0000138 spin_lock(&rc32434_wdt_device.io_lock);
Florian Fainelli03ec5852008-02-25 13:11:31 +0100139 writel(0, &wdt_reg->wtcount);
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +0000140 spin_unlock(&rc32434_wdt_device.io_lock);
Florian Fainelli03ec5852008-02-25 13:11:31 +0100141}
142
143static int rc32434_wdt_open(struct inode *inode, struct file *file)
144{
145 if (test_and_set_bit(0, &rc32434_wdt_device.inuse))
146 return -EBUSY;
147
148 if (nowayout)
149 __module_get(THIS_MODULE);
150
Phil Sutter0af98d32009-02-08 16:44:42 +0100151 rc32434_wdt_start();
152 rc32434_wdt_ping();
153
Florian Fainelli03ec5852008-02-25 13:11:31 +0100154 return nonseekable_open(inode, file);
155}
156
157static int rc32434_wdt_release(struct inode *inode, struct file *file)
158{
Phil Sutter0af98d32009-02-08 16:44:42 +0100159 if (expect_close == 42) {
Florian Fainelli03ec5852008-02-25 13:11:31 +0100160 rc32434_wdt_stop();
Florian Fainelli03ec5852008-02-25 13:11:31 +0100161 module_put(THIS_MODULE);
Phil Sutter0af98d32009-02-08 16:44:42 +0100162 } else {
Phil Sutter9b655e02009-02-08 16:44:42 +0100163 printk(KERN_CRIT PFX
164 "device closed unexpectedly. WDT will not stop!\n");
Phil Sutter0af98d32009-02-08 16:44:42 +0100165 rc32434_wdt_ping();
166 }
Florian Fainelli03ec5852008-02-25 13:11:31 +0100167 clear_bit(0, &rc32434_wdt_device.inuse);
168 return 0;
169}
170
171static ssize_t rc32434_wdt_write(struct file *file, const char *data,
172 size_t len, loff_t *ppos)
173{
174 if (len) {
175 if (!nowayout) {
176 size_t i;
177
178 /* In case it was set long ago */
179 expect_close = 0;
180
181 for (i = 0; i != len; i++) {
182 char c;
183 if (get_user(c, data + i))
184 return -EFAULT;
185 if (c == 'V')
Phil Sutter0af98d32009-02-08 16:44:42 +0100186 expect_close = 42;
Florian Fainelli03ec5852008-02-25 13:11:31 +0100187 }
188 }
Phil Sutter0af98d32009-02-08 16:44:42 +0100189 rc32434_wdt_ping();
Florian Fainelli03ec5852008-02-25 13:11:31 +0100190 return len;
191 }
192 return 0;
193}
194
Wim Van Sebroeck7275fc82008-09-18 12:26:15 +0000195static long rc32434_wdt_ioctl(struct file *file, unsigned int cmd,
196 unsigned long arg)
Florian Fainelli03ec5852008-02-25 13:11:31 +0100197{
198 void __user *argp = (void __user *)arg;
199 int new_timeout;
200 unsigned int value;
201 static struct watchdog_info ident = {
202 .options = WDIOF_SETTIMEOUT |
203 WDIOF_KEEPALIVEPING |
204 WDIOF_MAGICCLOSE,
205 .identity = "RC32434_WDT Watchdog",
206 };
207 switch (cmd) {
Phil Sutter9b655e02009-02-08 16:44:42 +0100208 case WDIOC_GETSUPPORT:
209 if (copy_to_user(argp, &ident, sizeof(ident)))
210 return -EFAULT;
Florian Fainelli03ec5852008-02-25 13:11:31 +0100211 break;
212 case WDIOC_GETSTATUS:
213 case WDIOC_GETBOOTSTATUS:
Phil Sutter0af98d32009-02-08 16:44:42 +0100214 value = 0;
Florian Fainelli03ec5852008-02-25 13:11:31 +0100215 if (copy_to_user(argp, &value, sizeof(int)))
216 return -EFAULT;
217 break;
Florian Fainelli03ec5852008-02-25 13:11:31 +0100218 case WDIOC_SETOPTIONS:
219 if (copy_from_user(&value, argp, sizeof(int)))
220 return -EFAULT;
221 switch (value) {
222 case WDIOS_ENABLECARD:
223 rc32434_wdt_start();
224 break;
225 case WDIOS_DISABLECARD:
226 rc32434_wdt_stop();
Phil Sutter0af98d32009-02-08 16:44:42 +0100227 break;
Florian Fainelli03ec5852008-02-25 13:11:31 +0100228 default:
229 return -EINVAL;
230 }
231 break;
Phil Sutter9b655e02009-02-08 16:44:42 +0100232 case WDIOC_KEEPALIVE:
233 rc32434_wdt_ping();
234 break;
Florian Fainelli03ec5852008-02-25 13:11:31 +0100235 case WDIOC_SETTIMEOUT:
236 if (copy_from_user(&new_timeout, argp, sizeof(int)))
237 return -EFAULT;
Phil Sutter0af98d32009-02-08 16:44:42 +0100238 if (rc32434_wdt_set(new_timeout))
Florian Fainelli03ec5852008-02-25 13:11:31 +0100239 return -EINVAL;
Phil Sutter0af98d32009-02-08 16:44:42 +0100240 /* Fall through */
Florian Fainelli03ec5852008-02-25 13:11:31 +0100241 case WDIOC_GETTIMEOUT:
242 return copy_to_user(argp, &timeout, sizeof(int));
243 default:
244 return -ENOTTY;
245 }
246
247 return 0;
248}
249
Wim Van Sebroeckd5c26a52009-03-18 08:18:43 +0000250static const struct file_operations rc32434_wdt_fops = {
Florian Fainelli03ec5852008-02-25 13:11:31 +0100251 .owner = THIS_MODULE,
252 .llseek = no_llseek,
253 .write = rc32434_wdt_write,
Wim Van Sebroeck7275fc82008-09-18 12:26:15 +0000254 .unlocked_ioctl = rc32434_wdt_ioctl,
Florian Fainelli03ec5852008-02-25 13:11:31 +0100255 .open = rc32434_wdt_open,
256 .release = rc32434_wdt_release,
257};
258
259static struct miscdevice rc32434_wdt_miscdev = {
260 .minor = WATCHDOG_MINOR,
261 .name = "watchdog",
262 .fops = &rc32434_wdt_fops,
263};
264
Phil Sutter9b655e02009-02-08 16:44:42 +0100265static char banner[] __devinitdata = KERN_INFO PFX
266 "Watchdog Timer version " VERSION ", timer margin: %d sec\n";
Florian Fainelli03ec5852008-02-25 13:11:31 +0100267
Phil Sutterd9a87982009-02-08 16:44:42 +0100268static int __devinit rc32434_wdt_probe(struct platform_device *pdev)
Florian Fainelli03ec5852008-02-25 13:11:31 +0100269{
270 int ret;
271 struct resource *r;
272
Phil Sutter0af98d32009-02-08 16:44:42 +0100273 r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rb532_wdt_res");
Florian Fainelli03ec5852008-02-25 13:11:31 +0100274 if (!r) {
Phil Sutter9b655e02009-02-08 16:44:42 +0100275 printk(KERN_ERR PFX "failed to retrieve resources\n");
Florian Fainelli03ec5852008-02-25 13:11:31 +0100276 return -ENODEV;
277 }
278
279 wdt_reg = ioremap_nocache(r->start, r->end - r->start);
280 if (!wdt_reg) {
Phil Sutter9b655e02009-02-08 16:44:42 +0100281 printk(KERN_ERR PFX "failed to remap I/O resources\n");
Florian Fainelli03ec5852008-02-25 13:11:31 +0100282 return -ENXIO;
283 }
284
Wim Van Sebroecke455b6b2009-02-23 13:08:36 +0000285 spin_lock_init(&rc32434_wdt_device.io_lock);
286
Wim Van Sebroeckf296b142009-02-23 13:08:37 +0000287 /* Make sure the watchdog is not running */
288 rc32434_wdt_stop();
289
Phil Sutter08eb2e02009-02-08 16:44:42 +0100290 /* Check that the heartbeat value is within it's range;
291 * if not reset to the default */
292 if (rc32434_wdt_set(timeout)) {
293 rc32434_wdt_set(WATCHDOG_TIMEOUT);
294 printk(KERN_INFO PFX
295 "timeout value must be between 0 and %d\n",
296 WTCOMP2SEC((u32)-1));
297 }
298
Florian Fainelli03ec5852008-02-25 13:11:31 +0100299 ret = misc_register(&rc32434_wdt_miscdev);
Florian Fainelli03ec5852008-02-25 13:11:31 +0100300 if (ret < 0) {
Phil Sutter9b655e02009-02-08 16:44:42 +0100301 printk(KERN_ERR PFX "failed to register watchdog device\n");
Florian Fainelli03ec5852008-02-25 13:11:31 +0100302 goto unmap;
303 }
304
Florian Fainelli03ec5852008-02-25 13:11:31 +0100305 printk(banner, timeout);
306
307 return 0;
308
309unmap:
310 iounmap(wdt_reg);
311 return ret;
312}
313
Phil Sutterd9a87982009-02-08 16:44:42 +0100314static int __devexit rc32434_wdt_remove(struct platform_device *pdev)
Florian Fainelli03ec5852008-02-25 13:11:31 +0100315{
Florian Fainelli03ec5852008-02-25 13:11:31 +0100316 misc_deregister(&rc32434_wdt_miscdev);
Florian Fainelli03ec5852008-02-25 13:11:31 +0100317 iounmap(wdt_reg);
Florian Fainelli03ec5852008-02-25 13:11:31 +0100318 return 0;
319}
320
Wim Van Sebroeck0aaae662009-02-23 13:08:35 +0000321static void rc32434_wdt_shutdown(struct platform_device *pdev)
322{
323 rc32434_wdt_stop();
324}
325
Phil Sutter9b655e02009-02-08 16:44:42 +0100326static struct platform_driver rc32434_wdt_driver = {
Wim Van Sebroeck0aaae662009-02-23 13:08:35 +0000327 .probe = rc32434_wdt_probe,
328 .remove = __devexit_p(rc32434_wdt_remove),
329 .shutdown = rc32434_wdt_shutdown,
330 .driver = {
331 .name = "rc32434_wdt",
Florian Fainelli03ec5852008-02-25 13:11:31 +0100332 }
333};
334
335static int __init rc32434_wdt_init(void)
336{
Phil Sutter9b655e02009-02-08 16:44:42 +0100337 return platform_driver_register(&rc32434_wdt_driver);
Florian Fainelli03ec5852008-02-25 13:11:31 +0100338}
339
340static void __exit rc32434_wdt_exit(void)
341{
Phil Sutter9b655e02009-02-08 16:44:42 +0100342 platform_driver_unregister(&rc32434_wdt_driver);
Florian Fainelli03ec5852008-02-25 13:11:31 +0100343}
344
345module_init(rc32434_wdt_init);
346module_exit(rc32434_wdt_exit);
347
348MODULE_AUTHOR("Ondrej Zajicek <santiago@crfreenet.org>,"
349 "Florian Fainelli <florian@openwrt.org>");
350MODULE_DESCRIPTION("Driver for the IDT RC32434 SoC watchdog");
351MODULE_LICENSE("GPL");
352MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);