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Vitaly Wool9325fa32006-06-26 19:31:49 +04001/*
2 * drivers/char/watchdog/pnx4008_wdt.c
3 *
4 * Watchdog driver for PNX4008 board
5 *
6 * Authors: Dmitry Chigirev <source@mvista.com>,
7 * Vitaly Wool <vitalywool@gmail.com>
8 * Based on sa1100 driver,
9 * Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
10 *
11 * 2005-2006 (c) MontaVista Software, Inc. This file is licensed under
12 * the terms of the GNU General Public License version 2. This program
13 * is licensed "as is" without any warranty of any kind, whether express
14 * or implied.
15 */
16
Vitaly Wool9325fa32006-06-26 19:31:49 +040017#include <linux/module.h>
18#include <linux/moduleparam.h>
19#include <linux/types.h>
20#include <linux/kernel.h>
21#include <linux/fs.h>
22#include <linux/miscdevice.h>
23#include <linux/watchdog.h>
24#include <linux/init.h>
25#include <linux/bitops.h>
26#include <linux/ioport.h>
27#include <linux/device.h>
28#include <linux/platform_device.h>
29#include <linux/clk.h>
Wim Van Sebroeck99d28532006-09-10 12:48:15 +020030#include <linux/spinlock.h>
Vitaly Wool9325fa32006-06-26 19:31:49 +040031
32#include <asm/hardware.h>
33#include <asm/uaccess.h>
34#include <asm/io.h>
35
36#define MODULE_NAME "PNX4008-WDT: "
37
38/* WatchDog Timer - Chapter 23 Page 207 */
39
40#define DEFAULT_HEARTBEAT 19
41#define MAX_HEARTBEAT 60
42
43/* Watchdog timer register set definition */
44#define WDTIM_INT(p) ((p) + 0x0)
45#define WDTIM_CTRL(p) ((p) + 0x4)
46#define WDTIM_COUNTER(p) ((p) + 0x8)
47#define WDTIM_MCTRL(p) ((p) + 0xC)
48#define WDTIM_MATCH0(p) ((p) + 0x10)
49#define WDTIM_EMR(p) ((p) + 0x14)
50#define WDTIM_PULSE(p) ((p) + 0x18)
51#define WDTIM_RES(p) ((p) + 0x1C)
52
53/* WDTIM_INT bit definitions */
54#define MATCH_INT 1
55
56/* WDTIM_CTRL bit definitions */
57#define COUNT_ENAB 1
58#define RESET_COUNT (1<<1)
59#define DEBUG_EN (1<<2)
60
61/* WDTIM_MCTRL bit definitions */
62#define MR0_INT 1
63#undef RESET_COUNT0
64#define RESET_COUNT0 (1<<2)
65#define STOP_COUNT0 (1<<2)
66#define M_RES1 (1<<3)
67#define M_RES2 (1<<4)
68#define RESFRC1 (1<<5)
69#define RESFRC2 (1<<6)
70
71/* WDTIM_EMR bit definitions */
72#define EXT_MATCH0 1
73#define MATCH_OUTPUT_HIGH (2<<4) /*a MATCH_CTRL setting */
74
75/* WDTIM_RES bit definitions */
76#define WDOG_RESET 1 /* read only */
77
78#define WDOG_COUNTER_RATE 13000000 /*the counter clock is 13 MHz fixed */
79
Wim Van Sebroeck28981722006-07-03 09:03:47 +020080static int nowayout = WATCHDOG_NOWAYOUT;
Vitaly Wool9325fa32006-06-26 19:31:49 +040081static int heartbeat = DEFAULT_HEARTBEAT;
82
Alexey Dobriyanc7dfd0c2007-11-01 16:27:08 -070083static DEFINE_SPINLOCK(io_lock);
Vitaly Wool9325fa32006-06-26 19:31:49 +040084static unsigned long wdt_status;
85#define WDT_IN_USE 0
86#define WDT_OK_TO_CLOSE 1
87#define WDT_REGION_INITED 2
88#define WDT_DEVICE_INITED 3
89
90static unsigned long boot_status;
91
92static struct resource *wdt_mem;
93static void __iomem *wdt_base;
94struct clk *wdt_clk;
95
96static void wdt_enable(void)
97{
Wim Van Sebroeck99d28532006-09-10 12:48:15 +020098 spin_lock(&io_lock);
99
Vitaly Wool9325fa32006-06-26 19:31:49 +0400100 if (wdt_clk)
101 clk_set_rate(wdt_clk, 1);
102
103 /* stop counter, initiate counter reset */
104 __raw_writel(RESET_COUNT, WDTIM_CTRL(wdt_base));
105 /*wait for reset to complete. 100% guarantee event */
Vitaly Wool65a64ec2006-09-11 14:42:39 +0400106 while (__raw_readl(WDTIM_COUNTER(wdt_base)))
107 cpu_relax();
Vitaly Wool9325fa32006-06-26 19:31:49 +0400108 /* internal and external reset, stop after that */
109 __raw_writel(M_RES2 | STOP_COUNT0 | RESET_COUNT0,
110 WDTIM_MCTRL(wdt_base));
111 /* configure match output */
112 __raw_writel(MATCH_OUTPUT_HIGH, WDTIM_EMR(wdt_base));
113 /* clear interrupt, just in case */
114 __raw_writel(MATCH_INT, WDTIM_INT(wdt_base));
115 /* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */
116 __raw_writel(0xFFFF, WDTIM_PULSE(wdt_base));
117 __raw_writel(heartbeat * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
118 /*enable counter, stop when debugger active */
119 __raw_writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));
Wim Van Sebroeck99d28532006-09-10 12:48:15 +0200120
121 spin_unlock(&io_lock);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400122}
123
124static void wdt_disable(void)
125{
Wim Van Sebroeck99d28532006-09-10 12:48:15 +0200126 spin_lock(&io_lock);
127
Vitaly Wool9325fa32006-06-26 19:31:49 +0400128 __raw_writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */
129 if (wdt_clk)
130 clk_set_rate(wdt_clk, 0);
Wim Van Sebroeck99d28532006-09-10 12:48:15 +0200131
132 spin_unlock(&io_lock);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400133}
134
135static int pnx4008_wdt_open(struct inode *inode, struct file *file)
136{
137 if (test_and_set_bit(WDT_IN_USE, &wdt_status))
138 return -EBUSY;
139
140 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
141
142 wdt_enable();
143
144 return nonseekable_open(inode, file);
145}
146
147static ssize_t
148pnx4008_wdt_write(struct file *file, const char *data, size_t len,
149 loff_t * ppos)
150{
Vitaly Wool9325fa32006-06-26 19:31:49 +0400151 if (len) {
152 if (!nowayout) {
153 size_t i;
154
155 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
156
157 for (i = 0; i != len; i++) {
158 char c;
159
160 if (get_user(c, data + i))
161 return -EFAULT;
162 if (c == 'V')
163 set_bit(WDT_OK_TO_CLOSE, &wdt_status);
164 }
165 }
166 wdt_enable();
167 }
168
169 return len;
170}
171
172static struct watchdog_info ident = {
173 .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
174 WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
175 .identity = "PNX4008 Watchdog",
176};
177
178static int
179pnx4008_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
180 unsigned long arg)
181{
Wim Van Sebroeckf3118962006-09-13 21:27:29 +0200182 int ret = -ENOTTY;
Vitaly Wool9325fa32006-06-26 19:31:49 +0400183 int time;
184
185 switch (cmd) {
186 case WDIOC_GETSUPPORT:
187 ret = copy_to_user((struct watchdog_info *)arg, &ident,
188 sizeof(ident)) ? -EFAULT : 0;
189 break;
190
191 case WDIOC_GETSTATUS:
192 ret = put_user(0, (int *)arg);
193 break;
194
195 case WDIOC_GETBOOTSTATUS:
196 ret = put_user(boot_status, (int *)arg);
197 break;
198
199 case WDIOC_SETTIMEOUT:
200 ret = get_user(time, (int *)arg);
201 if (ret)
202 break;
203
204 if (time <= 0 || time > MAX_HEARTBEAT) {
205 ret = -EINVAL;
206 break;
207 }
208
209 heartbeat = time;
210 wdt_enable();
211 /* Fall through */
212
213 case WDIOC_GETTIMEOUT:
214 ret = put_user(heartbeat, (int *)arg);
215 break;
216
217 case WDIOC_KEEPALIVE:
218 wdt_enable();
219 ret = 0;
220 break;
221 }
222 return ret;
223}
224
225static int pnx4008_wdt_release(struct inode *inode, struct file *file)
226{
227 if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status))
228 printk(KERN_WARNING "WATCHDOG: Device closed unexpectdly\n");
229
230 wdt_disable();
231 clear_bit(WDT_IN_USE, &wdt_status);
232 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
233
234 return 0;
235}
236
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800237static const struct file_operations pnx4008_wdt_fops = {
Vitaly Wool9325fa32006-06-26 19:31:49 +0400238 .owner = THIS_MODULE,
239 .llseek = no_llseek,
240 .write = pnx4008_wdt_write,
241 .ioctl = pnx4008_wdt_ioctl,
242 .open = pnx4008_wdt_open,
243 .release = pnx4008_wdt_release,
244};
245
246static struct miscdevice pnx4008_wdt_miscdev = {
247 .minor = WATCHDOG_MINOR,
248 .name = "watchdog",
249 .fops = &pnx4008_wdt_fops,
250};
251
252static int pnx4008_wdt_probe(struct platform_device *pdev)
253{
254 int ret = 0, size;
255 struct resource *res;
256
257 if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
258 heartbeat = DEFAULT_HEARTBEAT;
259
260 printk(KERN_INFO MODULE_NAME
261 "PNX4008 Watchdog Timer: heartbeat %d sec\n", heartbeat);
262
263 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
264 if (res == NULL) {
265 printk(KERN_INFO MODULE_NAME
266 "failed to get memory region resouce\n");
267 return -ENOENT;
268 }
269
270 size = res->end - res->start + 1;
271 wdt_mem = request_mem_region(res->start, size, pdev->name);
272
273 if (wdt_mem == NULL) {
274 printk(KERN_INFO MODULE_NAME "failed to get memory region\n");
275 return -ENOENT;
276 }
277 wdt_base = (void __iomem *)IO_ADDRESS(res->start);
278
279 wdt_clk = clk_get(&pdev->dev, "wdt_ck");
Akinobu Mita9cd44612006-12-19 17:51:44 +0900280 if (IS_ERR(wdt_clk)) {
281 ret = PTR_ERR(wdt_clk);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400282 release_resource(wdt_mem);
283 kfree(wdt_mem);
284 goto out;
285 } else
286 clk_set_rate(wdt_clk, 1);
287
288 ret = misc_register(&pnx4008_wdt_miscdev);
289 if (ret < 0) {
290 printk(KERN_ERR MODULE_NAME "cannot register misc device\n");
291 release_resource(wdt_mem);
292 kfree(wdt_mem);
293 clk_set_rate(wdt_clk, 0);
294 } else {
295 boot_status = (__raw_readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
296 WDIOF_CARDRESET : 0;
297 wdt_disable(); /*disable for now */
298 set_bit(WDT_DEVICE_INITED, &wdt_status);
299 }
300
301out:
302 return ret;
303}
304
305static int pnx4008_wdt_remove(struct platform_device *pdev)
306{
Wim Van Sebroeckf6764492006-07-30 20:06:07 +0200307 misc_deregister(&pnx4008_wdt_miscdev);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400308 if (wdt_clk) {
309 clk_set_rate(wdt_clk, 0);
310 clk_put(wdt_clk);
311 wdt_clk = NULL;
312 }
Wim Van Sebroeckf6764492006-07-30 20:06:07 +0200313 if (wdt_mem) {
314 release_resource(wdt_mem);
315 kfree(wdt_mem);
316 wdt_mem = NULL;
317 }
Vitaly Wool9325fa32006-06-26 19:31:49 +0400318 return 0;
319}
320
321static struct platform_driver platform_wdt_driver = {
322 .driver = {
323 .name = "watchdog",
Kay Sieversf37d1932008-04-10 21:29:23 -0700324 .owner = THIS_MODULE,
Vitaly Wool9325fa32006-06-26 19:31:49 +0400325 },
326 .probe = pnx4008_wdt_probe,
327 .remove = pnx4008_wdt_remove,
328};
329
330static int __init pnx4008_wdt_init(void)
331{
332 return platform_driver_register(&platform_wdt_driver);
333}
334
335static void __exit pnx4008_wdt_exit(void)
336{
Florian Fainellibb0a38d2007-10-17 15:42:22 +0200337 platform_driver_unregister(&platform_wdt_driver);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400338}
339
340module_init(pnx4008_wdt_init);
341module_exit(pnx4008_wdt_exit);
342
343MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
344MODULE_DESCRIPTION("PNX4008 Watchdog Driver");
345
346module_param(heartbeat, int, 0);
347MODULE_PARM_DESC(heartbeat,
348 "Watchdog heartbeat period in seconds from 1 to "
349 __MODULE_STRING(MAX_HEARTBEAT) ", default "
350 __MODULE_STRING(DEFAULT_HEARTBEAT));
351
352module_param(nowayout, int, 0);
353MODULE_PARM_DESC(nowayout,
354 "Set to 1 to keep watchdog running after device release");
355
356MODULE_LICENSE("GPL");
357MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Kay Sieversf37d1932008-04-10 21:29:23 -0700358MODULE_ALIAS("platform:watchdog");