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1/*
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
17#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>
30#include <linux/spinlock.h>
31#include <linux/uaccess.h>
32#include <linux/io.h>
33#include <linux/slab.h>
34#include <mach/hardware.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
80static int nowayout = WATCHDOG_NOWAYOUT;
81static int heartbeat = DEFAULT_HEARTBEAT;
82
83static DEFINE_SPINLOCK(io_lock);
84static 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{
98 spin_lock(&io_lock);
99
100 /* stop counter, initiate counter reset */
101 __raw_writel(RESET_COUNT, WDTIM_CTRL(wdt_base));
102 /*wait for reset to complete. 100% guarantee event */
103 while (__raw_readl(WDTIM_COUNTER(wdt_base)))
104 cpu_relax();
105 /* 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));
117
118 spin_unlock(&io_lock);
119}
120
121static void wdt_disable(void)
122{
123 spin_lock(&io_lock);
124
125 __raw_writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */
126
127 spin_unlock(&io_lock);
128}
129
130static int pnx4008_wdt_open(struct inode *inode, struct file *file)
131{
132 int ret;
133
134 if (test_and_set_bit(WDT_IN_USE, &wdt_status))
135 return -EBUSY;
136
137 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
138
139 ret = clk_enable(wdt_clk);
140 if (ret) {
141 clear_bit(WDT_IN_USE, &wdt_status);
142 return ret;
143 }
144
145 wdt_enable();
146
147 return nonseekable_open(inode, file);
148}
149
150static ssize_t pnx4008_wdt_write(struct file *file, const char *data,
151 size_t len, loff_t *ppos)
152{
153 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
174static const struct watchdog_info ident = {
175 .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
176 WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
177 .identity = "PNX4008 Watchdog",
178};
179
180static long pnx4008_wdt_ioctl(struct file *file, unsigned int cmd,
181 unsigned long arg)
182{
183 int ret = -ENOTTY;
184 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
200 case WDIOC_KEEPALIVE:
201 wdt_enable();
202 ret = 0;
203 break;
204
205 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;
222 }
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();
232 clk_disable(wdt_clk);
233 clear_bit(WDT_IN_USE, &wdt_status);
234 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
235
236 return 0;
237}
238
239static const struct file_operations pnx4008_wdt_fops = {
240 .owner = THIS_MODULE,
241 .llseek = no_llseek,
242 .write = pnx4008_wdt_write,
243 .unlocked_ioctl = pnx4008_wdt_ioctl,
244 .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
254static int __devinit pnx4008_wdt_probe(struct platform_device *pdev)
255{
256 int ret = 0, size;
257
258 if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
259 heartbeat = DEFAULT_HEARTBEAT;
260
261 printk(KERN_INFO MODULE_NAME
262 "PNX4008 Watchdog Timer: heartbeat %d sec\n", heartbeat);
263
264 wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
265 if (wdt_mem == NULL) {
266 printk(KERN_INFO MODULE_NAME
267 "failed to get memory region resouce\n");
268 return -ENOENT;
269 }
270
271 size = resource_size(wdt_mem);
272
273 if (!request_mem_region(wdt_mem->start, size, pdev->name)) {
274 printk(KERN_INFO MODULE_NAME "failed to get memory region\n");
275 return -ENOENT;
276 }
277 wdt_base = (void __iomem *)IO_ADDRESS(wdt_mem->start);
278
279 wdt_clk = clk_get(&pdev->dev, NULL);
280 if (IS_ERR(wdt_clk)) {
281 ret = PTR_ERR(wdt_clk);
282 release_mem_region(wdt_mem->start, size);
283 wdt_mem = NULL;
284 goto out;
285 }
286
287 ret = clk_enable(wdt_clk);
288 if (ret) {
289 release_mem_region(wdt_mem->start, size);
290 wdt_mem = NULL;
291 clk_put(wdt_clk);
292 goto out;
293 }
294
295 ret = misc_register(&pnx4008_wdt_miscdev);
296 if (ret < 0) {
297 printk(KERN_ERR MODULE_NAME "cannot register misc device\n");
298 release_mem_region(wdt_mem->start, size);
299 wdt_mem = NULL;
300 clk_disable(wdt_clk);
301 clk_put(wdt_clk);
302 } else {
303 boot_status = (__raw_readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
304 WDIOF_CARDRESET : 0;
305 wdt_disable(); /*disable for now */
306 clk_disable(wdt_clk);
307 set_bit(WDT_DEVICE_INITED, &wdt_status);
308 }
309
310out:
311 return ret;
312}
313
314static int __devexit pnx4008_wdt_remove(struct platform_device *pdev)
315{
316 misc_deregister(&pnx4008_wdt_miscdev);
317
318 clk_disable(wdt_clk);
319 clk_put(wdt_clk);
320
321 if (wdt_mem) {
322 release_mem_region(wdt_mem->start, resource_size(wdt_mem));
323 wdt_mem = NULL;
324 }
325 return 0;
326}
327
328static struct platform_driver platform_wdt_driver = {
329 .driver = {
330 .name = "pnx4008-watchdog",
331 .owner = THIS_MODULE,
332 },
333 .probe = pnx4008_wdt_probe,
334 .remove = __devexit_p(pnx4008_wdt_remove),
335};
336
337static int __init pnx4008_wdt_init(void)
338{
339 return platform_driver_register(&platform_wdt_driver);
340}
341
342static void __exit pnx4008_wdt_exit(void)
343{
344 platform_driver_unregister(&platform_wdt_driver);
345}
346
347module_init(pnx4008_wdt_init);
348module_exit(pnx4008_wdt_exit);
349
350MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
351MODULE_DESCRIPTION("PNX4008 Watchdog Driver");
352
353module_param(heartbeat, int, 0);
354MODULE_PARM_DESC(heartbeat,
355 "Watchdog heartbeat period in seconds from 1 to "
356 __MODULE_STRING(MAX_HEARTBEAT) ", default "
357 __MODULE_STRING(DEFAULT_HEARTBEAT));
358
359module_param(nowayout, int, 0);
360MODULE_PARM_DESC(nowayout,
361 "Set to 1 to keep watchdog running after device release");
362
363MODULE_LICENSE("GPL");
364MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
365MODULE_ALIAS("platform:pnx4008-watchdog");
1/*
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.
12 *
13 * (C) 2012 Wolfram Sang, Pengutronix
14 *
15 * This file is licensed under the terms of the GNU General Public License
16 * version 2. This program is licensed "as is" without any warranty of any
17 * kind, whether express or implied.
18 */
19
20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include <linux/module.h>
23#include <linux/moduleparam.h>
24#include <linux/types.h>
25#include <linux/kernel.h>
26#include <linux/watchdog.h>
27#include <linux/platform_device.h>
28#include <linux/clk.h>
29#include <linux/spinlock.h>
30#include <linux/io.h>
31#include <linux/slab.h>
32#include <linux/err.h>
33#include <linux/of.h>
34#include <linux/delay.h>
35#include <linux/reboot.h>
36#include <mach/hardware.h>
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
80static bool nowayout = WATCHDOG_NOWAYOUT;
81static unsigned int heartbeat = DEFAULT_HEARTBEAT;
82
83static DEFINE_SPINLOCK(io_lock);
84static void __iomem *wdt_base;
85static struct clk *wdt_clk;
86
87static int pnx4008_wdt_start(struct watchdog_device *wdd)
88{
89 spin_lock(&io_lock);
90
91 /* stop counter, initiate counter reset */
92 writel(RESET_COUNT, WDTIM_CTRL(wdt_base));
93 /*wait for reset to complete. 100% guarantee event */
94 while (readl(WDTIM_COUNTER(wdt_base)))
95 cpu_relax();
96 /* internal and external reset, stop after that */
97 writel(M_RES2 | STOP_COUNT0 | RESET_COUNT0, WDTIM_MCTRL(wdt_base));
98 /* configure match output */
99 writel(MATCH_OUTPUT_HIGH, WDTIM_EMR(wdt_base));
100 /* clear interrupt, just in case */
101 writel(MATCH_INT, WDTIM_INT(wdt_base));
102 /* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */
103 writel(0xFFFF, WDTIM_PULSE(wdt_base));
104 writel(wdd->timeout * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
105 /*enable counter, stop when debugger active */
106 writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));
107
108 spin_unlock(&io_lock);
109 return 0;
110}
111
112static int pnx4008_wdt_stop(struct watchdog_device *wdd)
113{
114 spin_lock(&io_lock);
115
116 writel(0, WDTIM_CTRL(wdt_base)); /*stop counter */
117
118 spin_unlock(&io_lock);
119 return 0;
120}
121
122static int pnx4008_wdt_set_timeout(struct watchdog_device *wdd,
123 unsigned int new_timeout)
124{
125 wdd->timeout = new_timeout;
126 return 0;
127}
128
129static int pnx4008_restart_handler(struct watchdog_device *wdd,
130 unsigned long mode, void *cmd)
131{
132 const char *boot_cmd = cmd;
133
134 /*
135 * Verify if a "cmd" passed from the userspace program rebooting
136 * the system; if available, handle it.
137 * - For details, see the 'reboot' syscall in kernel/reboot.c
138 * - If the received "cmd" is not supported, use the default mode.
139 */
140 if (boot_cmd) {
141 if (boot_cmd[0] == 'h')
142 mode = REBOOT_HARD;
143 else if (boot_cmd[0] == 's')
144 mode = REBOOT_SOFT;
145 }
146
147 if (mode == REBOOT_SOFT) {
148 /* Force match output active */
149 writel(EXT_MATCH0, WDTIM_EMR(wdt_base));
150 /* Internal reset on match output (RESOUT_N not asserted) */
151 writel(M_RES1, WDTIM_MCTRL(wdt_base));
152 } else {
153 /* Instant assert of RESETOUT_N with pulse length 1mS */
154 writel(13000, WDTIM_PULSE(wdt_base));
155 writel(M_RES2 | RESFRC1 | RESFRC2, WDTIM_MCTRL(wdt_base));
156 }
157
158 /* Wait for watchdog to reset system */
159 mdelay(1000);
160
161 return NOTIFY_DONE;
162}
163
164static const struct watchdog_info pnx4008_wdt_ident = {
165 .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
166 WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
167 .identity = "PNX4008 Watchdog",
168};
169
170static const struct watchdog_ops pnx4008_wdt_ops = {
171 .owner = THIS_MODULE,
172 .start = pnx4008_wdt_start,
173 .stop = pnx4008_wdt_stop,
174 .set_timeout = pnx4008_wdt_set_timeout,
175 .restart = pnx4008_restart_handler,
176};
177
178static struct watchdog_device pnx4008_wdd = {
179 .info = &pnx4008_wdt_ident,
180 .ops = &pnx4008_wdt_ops,
181 .timeout = DEFAULT_HEARTBEAT,
182 .min_timeout = 1,
183 .max_timeout = MAX_HEARTBEAT,
184};
185
186static int pnx4008_wdt_probe(struct platform_device *pdev)
187{
188 struct resource *r;
189 int ret = 0;
190
191 watchdog_init_timeout(&pnx4008_wdd, heartbeat, &pdev->dev);
192
193 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
194 wdt_base = devm_ioremap_resource(&pdev->dev, r);
195 if (IS_ERR(wdt_base))
196 return PTR_ERR(wdt_base);
197
198 wdt_clk = devm_clk_get(&pdev->dev, NULL);
199 if (IS_ERR(wdt_clk))
200 return PTR_ERR(wdt_clk);
201
202 ret = clk_prepare_enable(wdt_clk);
203 if (ret)
204 return ret;
205
206 pnx4008_wdd.bootstatus = (readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
207 WDIOF_CARDRESET : 0;
208 pnx4008_wdd.parent = &pdev->dev;
209 watchdog_set_nowayout(&pnx4008_wdd, nowayout);
210 watchdog_set_restart_priority(&pnx4008_wdd, 128);
211
212 pnx4008_wdt_stop(&pnx4008_wdd); /* disable for now */
213
214 ret = watchdog_register_device(&pnx4008_wdd);
215 if (ret < 0) {
216 dev_err(&pdev->dev, "cannot register watchdog device\n");
217 goto disable_clk;
218 }
219
220 dev_info(&pdev->dev, "heartbeat %d sec\n", pnx4008_wdd.timeout);
221
222 return 0;
223
224disable_clk:
225 clk_disable_unprepare(wdt_clk);
226 return ret;
227}
228
229static int pnx4008_wdt_remove(struct platform_device *pdev)
230{
231 watchdog_unregister_device(&pnx4008_wdd);
232
233 clk_disable_unprepare(wdt_clk);
234
235 return 0;
236}
237
238#ifdef CONFIG_OF
239static const struct of_device_id pnx4008_wdt_match[] = {
240 { .compatible = "nxp,pnx4008-wdt" },
241 { }
242};
243MODULE_DEVICE_TABLE(of, pnx4008_wdt_match);
244#endif
245
246static struct platform_driver platform_wdt_driver = {
247 .driver = {
248 .name = "pnx4008-watchdog",
249 .of_match_table = of_match_ptr(pnx4008_wdt_match),
250 },
251 .probe = pnx4008_wdt_probe,
252 .remove = pnx4008_wdt_remove,
253};
254
255module_platform_driver(platform_wdt_driver);
256
257MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
258MODULE_AUTHOR("Wolfram Sang <kernel@pengutronix.de>");
259MODULE_DESCRIPTION("PNX4008 Watchdog Driver");
260
261module_param(heartbeat, uint, 0);
262MODULE_PARM_DESC(heartbeat,
263 "Watchdog heartbeat period in seconds from 1 to "
264 __MODULE_STRING(MAX_HEARTBEAT) ", default "
265 __MODULE_STRING(DEFAULT_HEARTBEAT));
266
267module_param(nowayout, bool, 0);
268MODULE_PARM_DESC(nowayout,
269 "Set to 1 to keep watchdog running after device release");
270
271MODULE_LICENSE("GPL");
272MODULE_ALIAS("platform:pnx4008-watchdog");