1 /* linux/drivers/watchdog/rk29_wdt.c
3 * Copyright (C) 2011 ROCKCHIP, Inc.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/types.h>
25 #include <linux/timer.h>
26 #include <linux/miscdevice.h>
27 #include <linux/watchdog.h>
29 #include <linux/init.h>
30 #include <linux/platform_device.h>
31 #include <linux/interrupt.h>
32 #include <linux/clk.h>
33 #include <linux/uaccess.h>
36 #include <asm/mach/map.h>
43 /* RK29 registers define */
44 #define RK29_WDT_CR 0X00
45 #define RK29_WDT_TORR 0X04
46 #define RK29_WDT_CCVR 0X08
47 #define RK29_WDT_CRR 0X0C
48 #define RK29_WDT_STAT 0X10
49 #define RK29_WDT_EOI 0X14
52 #define RK29_RESPONSE_MODE 1
53 #define RK29_RESET_PULSE 4
55 //THAT wdt's clock is 24MHZ
56 #define RK29_WDT_2730US 0
57 #define RK29_WDT_5460US 1
58 #define RK29_WDT_10920US 2
59 #define RK29_WDT_21840US 3
60 #define RK29_WDT_43680US 4
61 #define RK29_WDT_87360US 5
62 #define RK29_WDT_174720US 6
63 #define RK29_WDT_349440US 7
64 #define RK29_WDT_698880US 8
65 #define RK29_WDT_1397760US 9
66 #define RK29_WDT_2795520US 10
67 #define RK29_WDT_5591040US 11
68 #define RK29_WDT_11182080US 12
69 #define RK29_WDT_22364160US 13
70 #define RK29_WDT_44728320US 14
71 #define RK29_WDT_89456640US 15
74 #define CONFIG_RK29_WATCHDOG_ATBOOT (1)
75 #define CONFIG_RK29_WATCHDOG_DEFAULT_TIME 10 //unit second
76 #define CONFIG_RK29_WATCHDOG_DEBUG 1
79 static int nowayout = WATCHDOG_NOWAYOUT;
80 static int tmr_margin = 100;//CONFIG_RK29_WATCHDOG_DEFAULT_TIME;
81 #ifdef CONFIG_RK29_WATCHDOG_ATBOOT
82 static int tmr_atboot = 1;
84 static int tmr_atboot = 0;
87 static int soft_noboot;
89 #ifdef CONFIG_RK29_WATCHDOG_DEBUG
95 module_param(tmr_margin, int, 0);
96 module_param(tmr_atboot, int, 0);
97 module_param(nowayout, int, 0);
98 module_param(soft_noboot, int, 0);
99 module_param(debug, int, 0);
101 MODULE_PARM_DESC(tmr_margin, "Watchdog tmr_margin in seconds. default="
102 __MODULE_STRING(CONFIG_RK29_WATCHDOG_DEFAULT_TIME) ")");
103 MODULE_PARM_DESC(tmr_atboot,
104 "Watchdog is started at boot time if set to 1, default="
105 __MODULE_STRING(CONFIG_RK29_WATCHDOG_ATBOOT));
106 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
107 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
108 MODULE_PARM_DESC(soft_noboot, "Watchdog action, set to 1 to ignore reboots, "
109 "0 to reboot (default depends on ONLY_TESTING)");
110 MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug, (default 0)");
113 static unsigned long open_lock;
114 static struct device *wdt_dev; /* platform device attached to */
115 static struct resource *wdt_mem;
116 static struct resource *wdt_irq;
117 static struct clk *wdt_clock;
118 static void __iomem *wdt_base;
119 static char expect_close;
122 /* watchdog control routines */
124 #define DBG(msg...) do { \
126 printk(KERN_INFO msg); \
130 #define wdt_writel(v, offset) do { \
131 writel_relaxed(v, wdt_base + offset);\
135 #define wdt_writel(v, offset) do { \
136 writel_relaxed(v, wdt_base + offset);\
142 void rk29_wdt_keepalive(void)
145 wdt_writel(0x76, RK29_WDT_CRR);
148 static void __rk29_wdt_stop(void)
150 rk29_wdt_keepalive(); //feed dog
151 wdt_writel(0x0a, RK29_WDT_CR);
154 void rk29_wdt_stop(void)
157 clk_disable_unprepare(wdt_clock);
160 /* timeout unit second */
161 int rk29_wdt_set_heartbeat(int timeout)
163 unsigned int count = 0;
164 unsigned int torr = 0, acc = 1, maxtime = 0;
165 unsigned int freq = clk_get_rate(wdt_clock);
169 //0x80000000 is the max count of watch dog
170 maxtime = 0x80000000 / freq + 1;
171 if(timeout > maxtime)
174 count = timeout * freq;
184 DBG("%s:torr:%d, count:%d, maxtime:%d s\n", __func__, torr, count, maxtime);
185 wdt_writel(torr, RK29_WDT_TORR);
189 void rk29_wdt_start(void)
192 clk_prepare_enable(wdt_clock);
193 rk29_wdt_set_heartbeat(tmr_margin);
194 wtcon = (RK29_WDT_EN << 0) | (RK29_RESPONSE_MODE << 1) | (RK29_RESET_PULSE << 2);
195 wdt_writel(wtcon, RK29_WDT_CR);
199 * /dev/watchdog handling
202 static int rk29_wdt_open(struct inode *inode, struct file *file)
204 DBG("%s\n", __func__);
205 if (test_and_set_bit(0, &open_lock))
209 __module_get(THIS_MODULE);
213 /* start the timer */
215 return nonseekable_open(inode, file);
218 static int rk29_wdt_release(struct inode *inode, struct file *file)
221 * Shut off the timer.
222 * Lock it in if it's a module and we set nowayout
224 DBG("%s\n", __func__);
225 if (expect_close == 42)
228 dev_err(wdt_dev, "Unexpected close, not stopping watchdog\n");
229 rk29_wdt_keepalive();
232 clear_bit(0, &open_lock);
236 static ssize_t rk29_wdt_write(struct file *file, const char __user *data,
237 size_t len, loff_t *ppos)
242 DBG("%s\n", __func__);
247 /* In case it was set long ago */
250 for (i = 0; i != len; i++) {
253 if (get_user(c, data + i))
259 rk29_wdt_keepalive();
264 #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
266 static const struct watchdog_info rk29_wdt_ident = {
268 .firmware_version = 0,
269 .identity = "rk29 Watchdog",
273 static long rk29_wdt_ioctl(struct file *file, unsigned int cmd,
276 void __user *argp = (void __user *)arg;
277 int __user *p = argp;
279 DBG("%s\n", __func__);
281 case WDIOC_GETSUPPORT:
282 return copy_to_user(argp, &rk29_wdt_ident,
283 sizeof(rk29_wdt_ident)) ? -EFAULT : 0;
284 case WDIOC_GETSTATUS:
285 case WDIOC_GETBOOTSTATUS:
286 return put_user(0, p);
287 case WDIOC_KEEPALIVE:
288 DBG("%s:rk29_wdt_keepalive\n", __func__);
289 rk29_wdt_keepalive();
291 case WDIOC_SETTIMEOUT:
292 if (get_user(new_margin, p))
294 if (rk29_wdt_set_heartbeat(new_margin))
296 rk29_wdt_keepalive();
297 return put_user(tmr_margin, p);
298 case WDIOC_GETTIMEOUT:
299 return put_user(tmr_margin, p);
307 /* kernel interface */
309 static const struct file_operations rk29_wdt_fops = {
310 .owner = THIS_MODULE,
312 .write = rk29_wdt_write,
313 .unlocked_ioctl = rk29_wdt_ioctl,
314 .open = rk29_wdt_open,
315 .release = rk29_wdt_release,
318 static struct miscdevice rk29_wdt_miscdev = {
319 .minor = WATCHDOG_MINOR,
321 .fops = &rk29_wdt_fops,
325 /* interrupt handler code */
327 static irqreturn_t rk29_wdt_irq_handler(int irqno, void *param)
329 DBG("RK29_wdt:watchdog timer expired (irq)\n");
330 rk29_wdt_keepalive();
335 /* device interface */
337 static int rk29_wdt_probe(struct platform_device *pdev)
339 struct resource *res;
345 wdt_dev = &pdev->dev;
347 /* get the memory region for the watchdog timer */
348 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
350 dev_err(dev, "no memory resource specified\n");
354 wdt_base = devm_request_and_ioremap(&pdev->dev, res);
355 if (wdt_base == NULL) {
356 dev_err(dev, "failed to ioremap() region\n");
361 if(!of_property_read_u32(pdev->dev.of_node, "rockchip,atboot", &val))
366 if(!of_property_read_u32(pdev->dev.of_node, "rockchip,timeout", &val))
371 if(!of_property_read_u32(pdev->dev.of_node, "rockchip,debug", &val))
375 DBG("probe: mapped wdt_base=%p\n", wdt_base);
377 of_property_read_u32(pdev->dev.of_node, "rockchip,irq", &val);
380 #ifdef CONFIG_RK29_FEED_DOG_BY_INTE
383 //printk("atboot:%d, timeout:%ds, debug:%d, irq:%d\n", tmr_atboot, tmr_margin, debug, val);
386 wdt_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
387 if (wdt_irq == NULL) {
388 dev_err(dev, "no irq resource specified\n");
392 ret = request_irq(wdt_irq->start, rk29_wdt_irq_handler, 0, pdev->name, pdev);
394 dev_err(dev, "failed to install irq (%d)\n", ret);
399 wdt_clock = devm_clk_get(&pdev->dev, "pclk_wdt");
400 if (IS_ERR(wdt_clock)) {
401 dev_err(dev, "failed to find watchdog clock source\n");
402 ret = PTR_ERR(wdt_clock);
406 ret = misc_register(&rk29_wdt_miscdev);
408 dev_err(dev, "cannot register miscdev on minor=%d (%d)\n",
409 WATCHDOG_MINOR, ret);
412 if (tmr_atboot && started == 0) {
413 dev_info(dev, "starting watchdog timer\n");
415 } else if (!tmr_atboot) {
416 /* if we're not enabling the watchdog, then ensure it is
417 * disabled if it has been left running from the bootloader
425 free_irq(wdt_irq->start, pdev);
429 static int rk29_wdt_remove(struct platform_device *dev)
432 free_irq(wdt_irq->start, dev);
434 clk_disable_unprepare(wdt_clock);
436 misc_deregister(&rk29_wdt_miscdev);
440 static void rk29_wdt_shutdown(struct platform_device *dev)
447 static int rk29_wdt_suspend(struct platform_device *dev, pm_message_t state)
453 static int rk29_wdt_resume(struct platform_device *dev)
460 #define rk29_wdt_suspend NULL
461 #define rk29_wdt_resume NULL
462 #endif /* CONFIG_PM */
465 static const struct of_device_id of_rk29_wdt_match[] = {
466 { .compatible = "rockchip,watch dog" },
470 static struct platform_driver rk29_wdt_driver = {
471 .probe = rk29_wdt_probe,
472 .remove = rk29_wdt_remove,
473 .shutdown = rk29_wdt_shutdown,
474 .suspend = rk29_wdt_suspend,
475 .resume = rk29_wdt_resume,
477 .owner = THIS_MODULE,
479 .of_match_table = of_rk29_wdt_match,
486 static char banner[] __initdata =
487 KERN_INFO "RK29 Watchdog Timer, (c) 2011 Rockchip Electronics\n";
489 static int __init watchdog_init(void)
492 return platform_driver_register(&rk29_wdt_driver);
495 static void __exit watchdog_exit(void)
497 platform_driver_unregister(&rk29_wdt_driver);
500 subsys_initcall(watchdog_init);
501 module_exit(watchdog_exit);
503 MODULE_AUTHOR("hhb@rock-chips.com");
504 MODULE_DESCRIPTION("RK29 Watchdog Device Driver");
505 MODULE_LICENSE("GPL");
506 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
507 MODULE_ALIAS("platform:rk29-wdt");