Root/target/linux/cns3xxx/patches-2.6.31/209-cns3xxx_watchdog_support.patch

1--- /dev/null
2+++ b/drivers/watchdog/cns3xxx_wdt.c
3@@ -0,0 +1,465 @@
4+/*******************************************************************************
5+ *
6+ * drivers/watchdog/cns3xxx_wdt.c
7+ *
8+ * Watchdog timer driver for the CNS3XXX SOCs
9+ *
10+ * Author: Scott Shu
11+ *
12+ * Copyright (c) 2008 Cavium Networks
13+ *
14+ * This file is free software; you can redistribute it and/or modify
15+ * it under the terms of the GNU General Public License, Version 2, as
16+ * published by the Free Software Foundation.
17+ *
18+ * This file is distributed in the hope that it will be useful,
19+ * but AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty of
20+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
21+ * NONINFRINGEMENT. See the GNU General Public License for more details.
22+ *
23+ * You should have received a copy of the GNU General Public License
24+ * along with this file; if not, write to the Free Software
25+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA or
26+ * visit http://www.gnu.org/licenses/.
27+ *
28+ * This file may also be available under a different license from Cavium.
29+ * Contact Cavium Networks for more information
30+ *
31+ ******************************************************************************/
32+
33+#include <linux/module.h>
34+#include <linux/moduleparam.h>
35+#include <linux/types.h>
36+#include <linux/miscdevice.h>
37+#include <linux/watchdog.h>
38+#include <linux/fs.h>
39+#include <linux/reboot.h>
40+#include <linux/init.h>
41+#include <linux/interrupt.h>
42+#include <linux/platform_device.h>
43+#include <linux/io.h>
44+#include <linux/uaccess.h>
45+
46+#include <asm/hardware/arm_twd.h>
47+
48+struct cns3xxx_wdt {
49+ unsigned long timer_alive;
50+ struct device *dev;
51+ void __iomem *base;
52+ int irq;
53+ unsigned int perturb;
54+ char expect_close;
55+};
56+
57+static struct platform_device *cns3xxx_wdt_dev;
58+extern unsigned int twd_timer_rate;
59+static spinlock_t wdt_lock;
60+
61+#define TIMER_MARGIN 60
62+static int cns3xxx_margin = TIMER_MARGIN;
63+module_param(cns3xxx_margin, int, 0);
64+MODULE_PARM_DESC(cns3xxx_margin,
65+ "CNS3XXX timer margin in seconds. (0 < cns3xxx_margin < 65536, default="
66+ __MODULE_STRING(TIMER_MARGIN) ")");
67+
68+static int nowayout = WATCHDOG_NOWAYOUT;
69+module_param(nowayout, int, 0);
70+MODULE_PARM_DESC(nowayout,
71+ "Watchdog cannot be stopped once started (default="
72+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
73+
74+#define ONLY_TESTING 0
75+static int cns3xxx_noboot = ONLY_TESTING;
76+module_param(cns3xxx_noboot, int, 0);
77+MODULE_PARM_DESC(cns3xxx_noboot, "CNS3XXX watchdog action, "
78+ "set to 1 to ignore reboots, 0 to reboot (default="
79+ __MODULE_STRING(ONLY_TESTING) ")");
80+
81+/*
82+ * This is the interrupt handler. Note that we only use this
83+ * in testing mode, so don't actually do a reboot here.
84+ */
85+static irqreturn_t cns3xxx_wdt_fire(int irq, void *arg)
86+{
87+ struct cns3xxx_wdt *wdt = arg;
88+
89+ /* Check it really was our interrupt */
90+ if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
91+ dev_printk(KERN_CRIT, wdt->dev,
92+ "Triggered - Reboot ignored.\n");
93+ /* Clear the interrupt on the watchdog */
94+ writel(1, wdt->base + TWD_WDOG_INTSTAT);
95+ return IRQ_HANDLED;
96+ }
97+ return IRQ_NONE;
98+}
99+
100+/*
101+ * cns3xxx_wdt_keepalive - reload the timer
102+ *
103+ * Note that the spec says a DIFFERENT value must be written to the reload
104+ * register each time. The "perturb" variable deals with this by adding 1
105+ * to the count every other time the function is called.
106+ */
107+static void cns3xxx_wdt_keepalive(struct cns3xxx_wdt *wdt)
108+{
109+ unsigned int count;
110+
111+ /* Assume prescale is set to 256 */
112+ count = (twd_timer_rate / 256) * cns3xxx_margin;
113+
114+ /* Reload the counter */
115+ spin_lock(&wdt_lock);
116+ writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
117+ wdt->perturb = wdt->perturb ? 0 : 1;
118+ spin_unlock(&wdt_lock);
119+}
120+
121+static void cns3xxx_wdt_stop(struct cns3xxx_wdt *wdt)
122+{
123+ spin_lock(&wdt_lock);
124+ writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
125+ writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
126+ writel(0x0, wdt->base + TWD_WDOG_CONTROL);
127+ spin_unlock(&wdt_lock);
128+}
129+
130+static void cns3xxx_wdt_start(struct cns3xxx_wdt *wdt)
131+{
132+ dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");
133+
134+ //spin_lock(&wdt_lock);
135+ /* This loads the count register but does NOT start the count yet */
136+ cns3xxx_wdt_keepalive(wdt);
137+ spin_lock(&wdt_lock);
138+
139+ if (cns3xxx_noboot) {
140+ /* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
141+ writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
142+ } else {
143+ /* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
144+ writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
145+ }
146+ spin_unlock(&wdt_lock);
147+}
148+
149+static int cns3xxx_wdt_set_heartbeat(int t)
150+{
151+ if (t < 0x0001 || t > 0xFFFF)
152+ return -EINVAL;
153+
154+ cns3xxx_margin = t;
155+ return 0;
156+}
157+
158+/*
159+ * /dev/watchdog handling
160+ */
161+static int cns3xxx_wdt_open(struct inode *inode, struct file *file)
162+{
163+ struct cns3xxx_wdt *wdt = platform_get_drvdata(cns3xxx_wdt_dev);
164+
165+ if (test_and_set_bit(0, &wdt->timer_alive))
166+ return -EBUSY;
167+
168+ if (nowayout)
169+ __module_get(THIS_MODULE);
170+
171+ file->private_data = wdt;
172+
173+ /*
174+ * Activate timer
175+ */
176+ cns3xxx_wdt_start(wdt);
177+
178+ return nonseekable_open(inode, file);
179+}
180+
181+static int cns3xxx_wdt_release(struct inode *inode, struct file *file)
182+{
183+ struct cns3xxx_wdt *wdt = file->private_data;
184+
185+ /*
186+ * Shut off the timer.
187+ * Lock it in if it's a module and we set nowayout
188+ */
189+ if (wdt->expect_close == 42)
190+ cns3xxx_wdt_stop(wdt);
191+ else {
192+ dev_printk(KERN_CRIT, wdt->dev,
193+ "unexpected close, not stopping watchdog!\n");
194+ cns3xxx_wdt_keepalive(wdt);
195+ }
196+ clear_bit(0, &wdt->timer_alive);
197+ wdt->expect_close = 0;
198+ return 0;
199+}
200+
201+static ssize_t cns3xxx_wdt_write(struct file *file, const char *data,
202+ size_t len, loff_t *ppos)
203+{
204+ struct cns3xxx_wdt *wdt = file->private_data;
205+
206+ /*
207+ * Refresh the timer.
208+ */
209+ if (len) {
210+ if (!nowayout) {
211+ size_t i;
212+
213+ /* In case it was set long ago */
214+ wdt->expect_close = 0;
215+
216+ for (i = 0; i != len; i++) {
217+ char c;
218+
219+ if (get_user(c, data + i))
220+ return -EFAULT;
221+ if (c == 'V')
222+ wdt->expect_close = 42;
223+ }
224+ }
225+ cns3xxx_wdt_keepalive(wdt);
226+ }
227+ return len;
228+}
229+
230+static struct watchdog_info ident = {
231+ .options = WDIOF_SETTIMEOUT |
232+ WDIOF_KEEPALIVEPING |
233+ WDIOF_MAGICCLOSE,
234+ .identity = "CNS3XXX Watchdog",
235+};
236+
237+static long cns3xxx_wdt_ioctl(struct file *file, unsigned int cmd,
238+ unsigned long arg)
239+{
240+ struct cns3xxx_wdt *wdt = file->private_data;
241+ int ret;
242+ union {
243+ struct watchdog_info ident;
244+ int i;
245+ } uarg;
246+
247+ if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
248+ return -ENOTTY;
249+
250+ if (_IOC_DIR(cmd) & _IOC_WRITE) {
251+ ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
252+ if (ret)
253+ return -EFAULT;
254+ }
255+
256+ switch (cmd) {
257+ case WDIOC_GETSUPPORT:
258+ uarg.ident = ident;
259+ ret = 0;
260+ break;
261+
262+ case WDIOC_GETSTATUS:
263+ case WDIOC_GETBOOTSTATUS:
264+ uarg.i = 0;
265+ ret = 0;
266+ break;
267+
268+ case WDIOC_SETOPTIONS:
269+ ret = -EINVAL;
270+ if (uarg.i & WDIOS_DISABLECARD) {
271+ cns3xxx_wdt_stop(wdt);
272+ ret = 0;
273+ }
274+ if (uarg.i & WDIOS_ENABLECARD) {
275+ cns3xxx_wdt_start(wdt);
276+ ret = 0;
277+ }
278+ break;
279+
280+ case WDIOC_KEEPALIVE:
281+ cns3xxx_wdt_keepalive(wdt);
282+ ret = 0;
283+ break;
284+
285+ case WDIOC_SETTIMEOUT:
286+ ret = cns3xxx_wdt_set_heartbeat(uarg.i);
287+ if (ret)
288+ break;
289+
290+ cns3xxx_wdt_keepalive(wdt);
291+ /* Fall */
292+ case WDIOC_GETTIMEOUT:
293+ uarg.i = cns3xxx_margin;
294+ ret = 0;
295+ break;
296+
297+ default:
298+ return -ENOTTY;
299+ }
300+
301+ if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
302+ ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
303+ if (ret)
304+ ret = -EFAULT;
305+ }
306+ return ret;
307+}
308+
309+/*
310+ * System shutdown handler. Turn off the watchdog if we're
311+ * restarting or halting the system.
312+ */
313+static void cns3xxx_wdt_shutdown(struct platform_device *dev)
314+{
315+ struct cns3xxx_wdt *wdt = platform_get_drvdata(dev);
316+
317+ if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT)
318+ cns3xxx_wdt_stop(wdt);
319+}
320+
321+/*
322+ * Kernel Interfaces
323+ */
324+static const struct file_operations cns3xxx_wdt_fops = {
325+ .owner = THIS_MODULE,
326+ .llseek = no_llseek,
327+ .write = cns3xxx_wdt_write,
328+ .unlocked_ioctl = cns3xxx_wdt_ioctl,
329+ .open = cns3xxx_wdt_open,
330+ .release = cns3xxx_wdt_release,
331+};
332+
333+static struct miscdevice cns3xxx_wdt_miscdev = {
334+ .minor = WATCHDOG_MINOR,
335+ .name = "watchdog",
336+ .fops = &cns3xxx_wdt_fops,
337+};
338+
339+static int __devinit cns3xxx_wdt_probe(struct platform_device *dev)
340+{
341+ struct cns3xxx_wdt *wdt;
342+ struct resource *res;
343+ int ret;
344+
345+ /* We only accept one device, and it must have an id of -1 */
346+ if (dev->id != -1)
347+ return -ENODEV;
348+
349+ res = platform_get_resource(dev, IORESOURCE_MEM, 0);
350+ if (!res) {
351+ ret = -ENODEV;
352+ goto err_out;
353+ }
354+
355+ wdt = kzalloc(sizeof(struct cns3xxx_wdt), GFP_KERNEL);
356+ if (!wdt) {
357+ ret = -ENOMEM;
358+ goto err_out;
359+ }
360+
361+ wdt->dev = &dev->dev;
362+ wdt->irq = platform_get_irq(dev, 0);
363+ if (wdt->irq < 0) {
364+ ret = -ENXIO;
365+ goto err_free;
366+ }
367+ wdt->base = ioremap(res->start, res->end - res->start + 1);
368+ if (!wdt->base) {
369+ ret = -ENOMEM;
370+ goto err_free;
371+ }
372+
373+ cns3xxx_wdt_miscdev.parent = &dev->dev;
374+ ret = misc_register(&cns3xxx_wdt_miscdev);
375+ if (ret) {
376+ dev_printk(KERN_ERR, wdt->dev,
377+ "cannot register miscdev on minor=%d (err=%d)\n",
378+ WATCHDOG_MINOR, ret);
379+ goto err_misc;
380+ }
381+
382+ ret = request_irq(wdt->irq, cns3xxx_wdt_fire, IRQF_DISABLED,
383+ dev->name, wdt);
384+ if (ret) {
385+ dev_printk(KERN_ERR, wdt->dev,
386+ "cannot register IRQ%d for watchdog\n", wdt->irq);
387+ goto err_irq;
388+ }
389+
390+ cns3xxx_wdt_stop(wdt);
391+ platform_set_drvdata(dev, wdt);
392+ cns3xxx_wdt_dev = dev;
393+
394+ return 0;
395+
396+err_irq:
397+ misc_deregister(&cns3xxx_wdt_miscdev);
398+err_misc:
399+ platform_set_drvdata(dev, NULL);
400+ iounmap(wdt->base);
401+err_free:
402+ kfree(wdt);
403+err_out:
404+ return ret;
405+}
406+
407+static int __devexit cns3xxx_wdt_remove(struct platform_device *dev)
408+{
409+ struct cns3xxx_wdt *wdt = platform_get_drvdata(dev);
410+
411+ platform_set_drvdata(dev, NULL);
412+
413+ misc_deregister(&cns3xxx_wdt_miscdev);
414+
415+ cns3xxx_wdt_dev = NULL;
416+
417+ free_irq(wdt->irq, wdt);
418+ iounmap(wdt->base);
419+ kfree(wdt);
420+ return 0;
421+}
422+
423+
424+static struct platform_driver cns3xxx_wdt_driver = {
425+ .probe = cns3xxx_wdt_probe,
426+ .remove = __devexit_p(cns3xxx_wdt_remove),
427+ .shutdown = cns3xxx_wdt_shutdown,
428+ .driver = {
429+ .owner = THIS_MODULE,
430+ .name = "cns3xxx-wdt",
431+ },
432+};
433+
434+static char banner[] __initdata = KERN_INFO
435+ "CNS3XXX Watchdog Timer, noboot=%d margin=%d sec (nowayout= %d)\n";
436+
437+static int __init cns3xxx_wdt_init(void)
438+{
439+ /*
440+ * Check that the margin value is within it's range;
441+ * if not reset to the default
442+ */
443+ if (cns3xxx_wdt_set_heartbeat(cns3xxx_margin)) {
444+ cns3xxx_wdt_set_heartbeat(TIMER_MARGIN);
445+ printk(KERN_INFO "cns3xxx_margin value must be 0 < cns3xxx_margin < 65536, using %d\n",
446+ TIMER_MARGIN);
447+ }
448+
449+ printk(banner, cns3xxx_noboot, cns3xxx_margin, nowayout);
450+
451+ spin_lock_init(&wdt_lock);
452+
453+ return platform_driver_register(&cns3xxx_wdt_driver);
454+}
455+
456+static void __exit cns3xxx_wdt_exit(void)
457+{
458+ platform_driver_unregister(&cns3xxx_wdt_driver);
459+}
460+
461+module_init(cns3xxx_wdt_init);
462+module_exit(cns3xxx_wdt_exit);
463+
464+MODULE_AUTHOR("Scott Shu");
465+MODULE_DESCRIPTION("CNS3XXX Watchdog Device Driver");
466+MODULE_LICENSE("GPL");
467+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
468+MODULE_ALIAS("platform:cns3xxx-wdt");
469--- a/drivers/watchdog/Kconfig
470+++ b/drivers/watchdog/Kconfig
471@@ -231,6 +231,15 @@ config DAVINCI_WATCHDOG
472       NOTE: once enabled, this timer cannot be disabled.
473       Say N if you are unsure.
474 
475+config CNS3XXX_WATCHDOG
476+ tristate "CNS3XXX watchdog"
477+ depends on ARCH_CNS3XXX && LOCAL_TIMERS
478+ help
479+ Watchdog timer embedded into the CNS3XXX SoCs system.
480+
481+ To compile this driver as a module, choose M here: the
482+ module will be called cns3xxx_wdt.
483+
484 config ORION_WATCHDOG
485     tristate "Orion watchdog"
486     depends on ARCH_ORION5X || ARCH_KIRKWOOD
487--- a/drivers/watchdog/Makefile
488+++ b/drivers/watchdog/Makefile
489@@ -41,6 +41,7 @@ obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_
490 obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
491 obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
492 obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o
493+obj-$(CONFIG_CNS3XXX_WATCHDOG) += cns3xxx_wdt.o
494 obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
495 obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
496 obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
497

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