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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>
Alan Cox84ca9952008-05-19 14:07:48 +010031#include <linux/uaccess.h>
32#include <linux/io.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090033#include <linux/slab.h>
Russell Kinga09e64f2008-08-05 16:14:15 +010034#include <mach/hardware.h>
Vitaly Wool9325fa32006-06-26 19:31:49 +040035
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
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000058#define RESET_COUNT (1 << 1)
59#define DEBUG_EN (1 << 2)
Vitaly Wool9325fa32006-06-26 19:31:49 +040060
61/* WDTIM_MCTRL bit definitions */
62#define MR0_INT 1
63#undef RESET_COUNT0
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000064#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)
Vitaly Wool9325fa32006-06-26 19:31:49 +040070
71/* WDTIM_EMR bit definitions */
72#define EXT_MATCH0 1
Wim Van Sebroeck143a2e52009-03-18 08:35:09 +000073#define MATCH_OUTPUT_HIGH (2 << 4) /*a MATCH_CTRL setting */
Vitaly Wool9325fa32006-06-26 19:31:49 +040074
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 /* stop counter, initiate counter reset */
101 __raw_writel(RESET_COUNT, WDTIM_CTRL(wdt_base));
102 /*wait for reset to complete. 100% guarantee event */
Vitaly Wool65a64ec2006-09-11 14:42:39 +0400103 while (__raw_readl(WDTIM_COUNTER(wdt_base)))
104 cpu_relax();
Vitaly Wool9325fa32006-06-26 19:31:49 +0400105 /* internal and external reset, stop after that */
106 __raw_writel(M_RES2 | STOP_COUNT0 | RESET_COUNT0,
107 WDTIM_MCTRL(wdt_base));
108 /* configure match output */
109 __raw_writel(MATCH_OUTPUT_HIGH, WDTIM_EMR(wdt_base));
110 /* clear interrupt, just in case */
111 __raw_writel(MATCH_INT, WDTIM_INT(wdt_base));
112 /* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */
113 __raw_writel(0xFFFF, WDTIM_PULSE(wdt_base));
114 __raw_writel(heartbeat * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
115 /*enable counter, stop when debugger active */
116 __raw_writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));
Wim Van Sebroeck99d28532006-09-10 12:48:15 +0200117
118 spin_unlock(&io_lock);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400119}
120
121static void wdt_disable(void)
122{
Wim Van Sebroeck99d28532006-09-10 12:48:15 +0200123 spin_lock(&io_lock);
124
Vitaly Wool9325fa32006-06-26 19:31:49 +0400125 __raw_writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */
Wim Van Sebroeck99d28532006-09-10 12:48:15 +0200126
127 spin_unlock(&io_lock);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400128}
129
130static int pnx4008_wdt_open(struct inode *inode, struct file *file)
131{
Russell King24fd1ed2009-11-20 13:04:14 +0000132 int ret;
133
Vitaly Wool9325fa32006-06-26 19:31:49 +0400134 if (test_and_set_bit(WDT_IN_USE, &wdt_status))
135 return -EBUSY;
136
137 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
138
Russell King24fd1ed2009-11-20 13:04:14 +0000139 ret = clk_enable(wdt_clk);
140 if (ret) {
141 clear_bit(WDT_IN_USE, &wdt_status);
142 return ret;
143 }
144
Vitaly Wool9325fa32006-06-26 19:31:49 +0400145 wdt_enable();
146
147 return nonseekable_open(inode, file);
148}
149
Alan Cox84ca9952008-05-19 14:07:48 +0100150static ssize_t pnx4008_wdt_write(struct file *file, const char *data,
151 size_t len, loff_t *ppos)
Vitaly Wool9325fa32006-06-26 19:31:49 +0400152{
Vitaly Wool9325fa32006-06-26 19:31:49 +0400153 if (len) {
154 if (!nowayout) {
155 size_t i;
156
157 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
158
159 for (i = 0; i != len; i++) {
160 char c;
161
162 if (get_user(c, data + i))
163 return -EFAULT;
164 if (c == 'V')
165 set_bit(WDT_OK_TO_CLOSE, &wdt_status);
166 }
167 }
168 wdt_enable();
169 }
170
171 return len;
172}
173
Alan Cox84ca9952008-05-19 14:07:48 +0100174static const struct watchdog_info ident = {
Vitaly Wool9325fa32006-06-26 19:31:49 +0400175 .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
176 WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
177 .identity = "PNX4008 Watchdog",
178};
179
Wim Van Sebroeck7275fc82008-09-18 12:26:15 +0000180static long pnx4008_wdt_ioctl(struct file *file, unsigned int cmd,
181 unsigned long arg)
Vitaly Wool9325fa32006-06-26 19:31:49 +0400182{
Wim Van Sebroeckf3118962006-09-13 21:27:29 +0200183 int ret = -ENOTTY;
Vitaly Wool9325fa32006-06-26 19:31:49 +0400184 int time;
185
186 switch (cmd) {
187 case WDIOC_GETSUPPORT:
188 ret = copy_to_user((struct watchdog_info *)arg, &ident,
189 sizeof(ident)) ? -EFAULT : 0;
190 break;
191
192 case WDIOC_GETSTATUS:
193 ret = put_user(0, (int *)arg);
194 break;
195
196 case WDIOC_GETBOOTSTATUS:
197 ret = put_user(boot_status, (int *)arg);
198 break;
199
Wim Van Sebroeck0c060902008-07-18 11:41:17 +0000200 case WDIOC_KEEPALIVE:
201 wdt_enable();
202 ret = 0;
203 break;
204
Vitaly Wool9325fa32006-06-26 19:31:49 +0400205 case WDIOC_SETTIMEOUT:
206 ret = get_user(time, (int *)arg);
207 if (ret)
208 break;
209
210 if (time <= 0 || time > MAX_HEARTBEAT) {
211 ret = -EINVAL;
212 break;
213 }
214
215 heartbeat = time;
216 wdt_enable();
217 /* Fall through */
218
219 case WDIOC_GETTIMEOUT:
220 ret = put_user(heartbeat, (int *)arg);
221 break;
Vitaly Wool9325fa32006-06-26 19:31:49 +0400222 }
223 return ret;
224}
225
226static int pnx4008_wdt_release(struct inode *inode, struct file *file)
227{
228 if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status))
229 printk(KERN_WARNING "WATCHDOG: Device closed unexpectdly\n");
230
231 wdt_disable();
Russell King24fd1ed2009-11-20 13:04:14 +0000232 clk_disable(wdt_clk);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400233 clear_bit(WDT_IN_USE, &wdt_status);
234 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
235
236 return 0;
237}
238
Arjan van de Ven2b8693c2007-02-12 00:55:32 -0800239static const struct file_operations pnx4008_wdt_fops = {
Vitaly Wool9325fa32006-06-26 19:31:49 +0400240 .owner = THIS_MODULE,
241 .llseek = no_llseek,
242 .write = pnx4008_wdt_write,
Alan Cox84ca9952008-05-19 14:07:48 +0100243 .unlocked_ioctl = pnx4008_wdt_ioctl,
Vitaly Wool9325fa32006-06-26 19:31:49 +0400244 .open = pnx4008_wdt_open,
245 .release = pnx4008_wdt_release,
246};
247
248static struct miscdevice pnx4008_wdt_miscdev = {
249 .minor = WATCHDOG_MINOR,
250 .name = "watchdog",
251 .fops = &pnx4008_wdt_fops,
252};
253
Wim Van Sebroeckb6bf2912009-04-14 20:30:55 +0000254static int __devinit pnx4008_wdt_probe(struct platform_device *pdev)
Vitaly Wool9325fa32006-06-26 19:31:49 +0400255{
256 int ret = 0, size;
257 struct resource *res;
258
259 if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
260 heartbeat = DEFAULT_HEARTBEAT;
261
262 printk(KERN_INFO MODULE_NAME
263 "PNX4008 Watchdog Timer: heartbeat %d sec\n", heartbeat);
264
265 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
266 if (res == NULL) {
267 printk(KERN_INFO MODULE_NAME
268 "failed to get memory region resouce\n");
269 return -ENOENT;
270 }
271
H Hartley Sweetenb782a562009-12-04 12:24:04 -0500272 size = resource_size(res);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400273 wdt_mem = request_mem_region(res->start, size, pdev->name);
274
275 if (wdt_mem == NULL) {
276 printk(KERN_INFO MODULE_NAME "failed to get memory region\n");
277 return -ENOENT;
278 }
279 wdt_base = (void __iomem *)IO_ADDRESS(res->start);
280
Russell King9bb787f2009-11-20 13:07:28 +0000281 wdt_clk = clk_get(&pdev->dev, NULL);
Akinobu Mita9cd44612006-12-19 17:51:44 +0900282 if (IS_ERR(wdt_clk)) {
283 ret = PTR_ERR(wdt_clk);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400284 release_resource(wdt_mem);
285 kfree(wdt_mem);
286 goto out;
Russell King24fd1ed2009-11-20 13:04:14 +0000287 }
288
289 ret = clk_enable(wdt_clk);
290 if (ret) {
291 release_resource(wdt_mem);
292 kfree(wdt_mem);
293 goto out;
294 }
Vitaly Wool9325fa32006-06-26 19:31:49 +0400295
296 ret = misc_register(&pnx4008_wdt_miscdev);
297 if (ret < 0) {
298 printk(KERN_ERR MODULE_NAME "cannot register misc device\n");
299 release_resource(wdt_mem);
300 kfree(wdt_mem);
Russell King24fd1ed2009-11-20 13:04:14 +0000301 clk_disable(wdt_clk);
302 clk_put(wdt_clk);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400303 } else {
304 boot_status = (__raw_readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
305 WDIOF_CARDRESET : 0;
306 wdt_disable(); /*disable for now */
Russell King24fd1ed2009-11-20 13:04:14 +0000307 clk_disable(wdt_clk);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400308 set_bit(WDT_DEVICE_INITED, &wdt_status);
309 }
310
311out:
312 return ret;
313}
314
Wim Van Sebroeckb6bf2912009-04-14 20:30:55 +0000315static int __devexit pnx4008_wdt_remove(struct platform_device *pdev)
Vitaly Wool9325fa32006-06-26 19:31:49 +0400316{
Wim Van Sebroeckf6764492006-07-30 20:06:07 +0200317 misc_deregister(&pnx4008_wdt_miscdev);
Russell King24fd1ed2009-11-20 13:04:14 +0000318
319 clk_disable(wdt_clk);
320 clk_put(wdt_clk);
321
Wim Van Sebroeckf6764492006-07-30 20:06:07 +0200322 if (wdt_mem) {
323 release_resource(wdt_mem);
324 kfree(wdt_mem);
325 wdt_mem = NULL;
326 }
Vitaly Wool9325fa32006-06-26 19:31:49 +0400327 return 0;
328}
329
330static struct platform_driver platform_wdt_driver = {
331 .driver = {
Russell King1508c992009-11-20 13:07:57 +0000332 .name = "pnx4008-watchdog",
Kay Sieversf37d1932008-04-10 21:29:23 -0700333 .owner = THIS_MODULE,
Vitaly Wool9325fa32006-06-26 19:31:49 +0400334 },
335 .probe = pnx4008_wdt_probe,
Wim Van Sebroeckb6bf2912009-04-14 20:30:55 +0000336 .remove = __devexit_p(pnx4008_wdt_remove),
Vitaly Wool9325fa32006-06-26 19:31:49 +0400337};
338
339static int __init pnx4008_wdt_init(void)
340{
341 return platform_driver_register(&platform_wdt_driver);
342}
343
344static void __exit pnx4008_wdt_exit(void)
345{
Florian Fainellibb0a38d2007-10-17 15:42:22 +0200346 platform_driver_unregister(&platform_wdt_driver);
Vitaly Wool9325fa32006-06-26 19:31:49 +0400347}
348
349module_init(pnx4008_wdt_init);
350module_exit(pnx4008_wdt_exit);
351
352MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
353MODULE_DESCRIPTION("PNX4008 Watchdog Driver");
354
355module_param(heartbeat, int, 0);
356MODULE_PARM_DESC(heartbeat,
357 "Watchdog heartbeat period in seconds from 1 to "
358 __MODULE_STRING(MAX_HEARTBEAT) ", default "
359 __MODULE_STRING(DEFAULT_HEARTBEAT));
360
361module_param(nowayout, int, 0);
362MODULE_PARM_DESC(nowayout,
363 "Set to 1 to keep watchdog running after device release");
364
365MODULE_LICENSE("GPL");
366MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Russell King1508c992009-11-20 13:07:57 +0000367MODULE_ALIAS("platform:pnx4008-watchdog");