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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Atheros AR71XX/AR724X/AR913X built-in hardware watchdog timer.
4 *
5 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
6 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
7 *
8 * This driver was based on: drivers/watchdog/ixp4xx_wdt.c
9 * Author: Deepak Saxena <dsaxena@plexity.net>
10 * Copyright 2004 (c) MontaVista, Software, Inc.
11 *
12 * which again was based on sa1100 driver,
13 * Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/bitops.h>
19#include <linux/delay.h>
20#include <linux/errno.h>
21#include <linux/fs.h>
22#include <linux/io.h>
23#include <linux/kernel.h>
24#include <linux/miscdevice.h>
25#include <linux/module.h>
26#include <linux/moduleparam.h>
27#include <linux/platform_device.h>
28#include <linux/types.h>
29#include <linux/watchdog.h>
30#include <linux/clk.h>
31#include <linux/err.h>
32#include <linux/of.h>
33#include <linux/of_platform.h>
34#include <linux/uaccess.h>
35
36#define DRIVER_NAME "ath79-wdt"
37
38#define WDT_TIMEOUT 15 /* seconds */
39
40#define WDOG_REG_CTRL 0x00
41#define WDOG_REG_TIMER 0x04
42
43#define WDOG_CTRL_LAST_RESET BIT(31)
44#define WDOG_CTRL_ACTION_MASK 3
45#define WDOG_CTRL_ACTION_NONE 0 /* no action */
46#define WDOG_CTRL_ACTION_GPI 1 /* general purpose interrupt */
47#define WDOG_CTRL_ACTION_NMI 2 /* NMI */
48#define WDOG_CTRL_ACTION_FCR 3 /* full chip reset */
49
50static bool nowayout = WATCHDOG_NOWAYOUT;
51module_param(nowayout, bool, 0);
52MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
53 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
54
55static int timeout = WDT_TIMEOUT;
56module_param(timeout, int, 0);
57MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds "
58 "(default=" __MODULE_STRING(WDT_TIMEOUT) "s)");
59
60static unsigned long wdt_flags;
61
62#define WDT_FLAGS_BUSY 0
63#define WDT_FLAGS_EXPECT_CLOSE 1
64
65static struct clk *wdt_clk;
66static unsigned long wdt_freq;
67static int boot_status;
68static int max_timeout;
69static void __iomem *wdt_base;
70
71static inline void ath79_wdt_wr(unsigned reg, u32 val)
72{
73 iowrite32(val, wdt_base + reg);
74}
75
76static inline u32 ath79_wdt_rr(unsigned reg)
77{
78 return ioread32(wdt_base + reg);
79}
80
81static inline void ath79_wdt_keepalive(void)
82{
83 ath79_wdt_wr(WDOG_REG_TIMER, wdt_freq * timeout);
84 /* flush write */
85 ath79_wdt_rr(WDOG_REG_TIMER);
86}
87
88static inline void ath79_wdt_enable(void)
89{
90 ath79_wdt_keepalive();
91
92 /*
93 * Updating the TIMER register requires a few microseconds
94 * on the AR934x SoCs at least. Use a small delay to ensure
95 * that the TIMER register is updated within the hardware
96 * before enabling the watchdog.
97 */
98 udelay(2);
99
100 ath79_wdt_wr(WDOG_REG_CTRL, WDOG_CTRL_ACTION_FCR);
101 /* flush write */
102 ath79_wdt_rr(WDOG_REG_CTRL);
103}
104
105static inline void ath79_wdt_disable(void)
106{
107 ath79_wdt_wr(WDOG_REG_CTRL, WDOG_CTRL_ACTION_NONE);
108 /* flush write */
109 ath79_wdt_rr(WDOG_REG_CTRL);
110}
111
112static int ath79_wdt_set_timeout(int val)
113{
114 if (val < 1 || val > max_timeout)
115 return -EINVAL;
116
117 timeout = val;
118 ath79_wdt_keepalive();
119
120 return 0;
121}
122
123static int ath79_wdt_open(struct inode *inode, struct file *file)
124{
125 if (test_and_set_bit(WDT_FLAGS_BUSY, &wdt_flags))
126 return -EBUSY;
127
128 clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags);
129 ath79_wdt_enable();
130
131 return stream_open(inode, file);
132}
133
134static int ath79_wdt_release(struct inode *inode, struct file *file)
135{
136 if (test_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags))
137 ath79_wdt_disable();
138 else {
139 pr_crit("device closed unexpectedly, watchdog timer will not stop!\n");
140 ath79_wdt_keepalive();
141 }
142
143 clear_bit(WDT_FLAGS_BUSY, &wdt_flags);
144 clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags);
145
146 return 0;
147}
148
149static ssize_t ath79_wdt_write(struct file *file, const char *data,
150 size_t len, loff_t *ppos)
151{
152 if (len) {
153 if (!nowayout) {
154 size_t i;
155
156 clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags);
157
158 for (i = 0; i != len; i++) {
159 char c;
160
161 if (get_user(c, data + i))
162 return -EFAULT;
163
164 if (c == 'V')
165 set_bit(WDT_FLAGS_EXPECT_CLOSE,
166 &wdt_flags);
167 }
168 }
169
170 ath79_wdt_keepalive();
171 }
172
173 return len;
174}
175
176static const struct watchdog_info ath79_wdt_info = {
177 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
178 WDIOF_MAGICCLOSE | WDIOF_CARDRESET,
179 .firmware_version = 0,
180 .identity = "ATH79 watchdog",
181};
182
183static long ath79_wdt_ioctl(struct file *file, unsigned int cmd,
184 unsigned long arg)
185{
186 void __user *argp = (void __user *)arg;
187 int __user *p = argp;
188 int err;
189 int t;
190
191 switch (cmd) {
192 case WDIOC_GETSUPPORT:
193 err = copy_to_user(argp, &ath79_wdt_info,
194 sizeof(ath79_wdt_info)) ? -EFAULT : 0;
195 break;
196
197 case WDIOC_GETSTATUS:
198 err = put_user(0, p);
199 break;
200
201 case WDIOC_GETBOOTSTATUS:
202 err = put_user(boot_status, p);
203 break;
204
205 case WDIOC_KEEPALIVE:
206 ath79_wdt_keepalive();
207 err = 0;
208 break;
209
210 case WDIOC_SETTIMEOUT:
211 err = get_user(t, p);
212 if (err)
213 break;
214
215 err = ath79_wdt_set_timeout(t);
216 if (err)
217 break;
218 fallthrough;
219
220 case WDIOC_GETTIMEOUT:
221 err = put_user(timeout, p);
222 break;
223
224 default:
225 err = -ENOTTY;
226 break;
227 }
228
229 return err;
230}
231
232static const struct file_operations ath79_wdt_fops = {
233 .owner = THIS_MODULE,
234 .llseek = no_llseek,
235 .write = ath79_wdt_write,
236 .unlocked_ioctl = ath79_wdt_ioctl,
237 .compat_ioctl = compat_ptr_ioctl,
238 .open = ath79_wdt_open,
239 .release = ath79_wdt_release,
240};
241
242static struct miscdevice ath79_wdt_miscdev = {
243 .minor = WATCHDOG_MINOR,
244 .name = "watchdog",
245 .fops = &ath79_wdt_fops,
246};
247
248static int ath79_wdt_probe(struct platform_device *pdev)
249{
250 u32 ctrl;
251 int err;
252
253 if (wdt_base)
254 return -EBUSY;
255
256 wdt_base = devm_platform_ioremap_resource(pdev, 0);
257 if (IS_ERR(wdt_base))
258 return PTR_ERR(wdt_base);
259
260 wdt_clk = devm_clk_get_enabled(&pdev->dev, "wdt");
261 if (IS_ERR(wdt_clk))
262 return PTR_ERR(wdt_clk);
263
264 wdt_freq = clk_get_rate(wdt_clk);
265 if (!wdt_freq)
266 return -EINVAL;
267
268 max_timeout = (0xfffffffful / wdt_freq);
269 if (timeout < 1 || timeout > max_timeout) {
270 timeout = max_timeout;
271 dev_info(&pdev->dev,
272 "timeout value must be 0 < timeout < %d, using %d\n",
273 max_timeout, timeout);
274 }
275
276 ctrl = ath79_wdt_rr(WDOG_REG_CTRL);
277 boot_status = (ctrl & WDOG_CTRL_LAST_RESET) ? WDIOF_CARDRESET : 0;
278
279 err = misc_register(&ath79_wdt_miscdev);
280 if (err) {
281 dev_err(&pdev->dev,
282 "unable to register misc device, err=%d\n", err);
283 return err;
284 }
285
286 return 0;
287}
288
289static void ath79_wdt_remove(struct platform_device *pdev)
290{
291 misc_deregister(&ath79_wdt_miscdev);
292}
293
294static void ath79_wdt_shutdown(struct platform_device *pdev)
295{
296 ath79_wdt_disable();
297}
298
299#ifdef CONFIG_OF
300static const struct of_device_id ath79_wdt_match[] = {
301 { .compatible = "qca,ar7130-wdt" },
302 {},
303};
304MODULE_DEVICE_TABLE(of, ath79_wdt_match);
305#endif
306
307static struct platform_driver ath79_wdt_driver = {
308 .probe = ath79_wdt_probe,
309 .remove_new = ath79_wdt_remove,
310 .shutdown = ath79_wdt_shutdown,
311 .driver = {
312 .name = DRIVER_NAME,
313 .of_match_table = of_match_ptr(ath79_wdt_match),
314 },
315};
316
317module_platform_driver(ath79_wdt_driver);
318
319MODULE_DESCRIPTION("Atheros AR71XX/AR724X/AR913X hardware watchdog driver");
320MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org");
321MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org");
322MODULE_LICENSE("GPL v2");
323MODULE_ALIAS("platform:" DRIVER_NAME);
1/*
2 * Atheros AR71XX/AR724X/AR913X built-in hardware watchdog timer.
3 *
4 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org>
5 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org>
6 *
7 * This driver was based on: drivers/watchdog/ixp4xx_wdt.c
8 * Author: Deepak Saxena <dsaxena@plexity.net>
9 * Copyright 2004 (c) MontaVista, Software, Inc.
10 *
11 * which again was based on sa1100 driver,
12 * Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
13 *
14 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License version 2 as published
16 * by the Free Software Foundation.
17 *
18 */
19
20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include <linux/bitops.h>
23#include <linux/errno.h>
24#include <linux/fs.h>
25#include <linux/io.h>
26#include <linux/kernel.h>
27#include <linux/miscdevice.h>
28#include <linux/module.h>
29#include <linux/moduleparam.h>
30#include <linux/platform_device.h>
31#include <linux/types.h>
32#include <linux/watchdog.h>
33#include <linux/clk.h>
34#include <linux/err.h>
35#include <linux/of.h>
36#include <linux/of_platform.h>
37
38#define DRIVER_NAME "ath79-wdt"
39
40#define WDT_TIMEOUT 15 /* seconds */
41
42#define WDOG_REG_CTRL 0x00
43#define WDOG_REG_TIMER 0x04
44
45#define WDOG_CTRL_LAST_RESET BIT(31)
46#define WDOG_CTRL_ACTION_MASK 3
47#define WDOG_CTRL_ACTION_NONE 0 /* no action */
48#define WDOG_CTRL_ACTION_GPI 1 /* general purpose interrupt */
49#define WDOG_CTRL_ACTION_NMI 2 /* NMI */
50#define WDOG_CTRL_ACTION_FCR 3 /* full chip reset */
51
52static bool nowayout = WATCHDOG_NOWAYOUT;
53module_param(nowayout, bool, 0);
54MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
55 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
56
57static int timeout = WDT_TIMEOUT;
58module_param(timeout, int, 0);
59MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds "
60 "(default=" __MODULE_STRING(WDT_TIMEOUT) "s)");
61
62static unsigned long wdt_flags;
63
64#define WDT_FLAGS_BUSY 0
65#define WDT_FLAGS_EXPECT_CLOSE 1
66
67static struct clk *wdt_clk;
68static unsigned long wdt_freq;
69static int boot_status;
70static int max_timeout;
71static void __iomem *wdt_base;
72
73static inline void ath79_wdt_wr(unsigned reg, u32 val)
74{
75 iowrite32(val, wdt_base + reg);
76}
77
78static inline u32 ath79_wdt_rr(unsigned reg)
79{
80 return ioread32(wdt_base + reg);
81}
82
83static inline void ath79_wdt_keepalive(void)
84{
85 ath79_wdt_wr(WDOG_REG_TIMER, wdt_freq * timeout);
86 /* flush write */
87 ath79_wdt_rr(WDOG_REG_TIMER);
88}
89
90static inline void ath79_wdt_enable(void)
91{
92 ath79_wdt_keepalive();
93 ath79_wdt_wr(WDOG_REG_CTRL, WDOG_CTRL_ACTION_FCR);
94 /* flush write */
95 ath79_wdt_rr(WDOG_REG_CTRL);
96}
97
98static inline void ath79_wdt_disable(void)
99{
100 ath79_wdt_wr(WDOG_REG_CTRL, WDOG_CTRL_ACTION_NONE);
101 /* flush write */
102 ath79_wdt_rr(WDOG_REG_CTRL);
103}
104
105static int ath79_wdt_set_timeout(int val)
106{
107 if (val < 1 || val > max_timeout)
108 return -EINVAL;
109
110 timeout = val;
111 ath79_wdt_keepalive();
112
113 return 0;
114}
115
116static int ath79_wdt_open(struct inode *inode, struct file *file)
117{
118 if (test_and_set_bit(WDT_FLAGS_BUSY, &wdt_flags))
119 return -EBUSY;
120
121 clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags);
122 ath79_wdt_enable();
123
124 return nonseekable_open(inode, file);
125}
126
127static int ath79_wdt_release(struct inode *inode, struct file *file)
128{
129 if (test_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags))
130 ath79_wdt_disable();
131 else {
132 pr_crit("device closed unexpectedly, watchdog timer will not stop!\n");
133 ath79_wdt_keepalive();
134 }
135
136 clear_bit(WDT_FLAGS_BUSY, &wdt_flags);
137 clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags);
138
139 return 0;
140}
141
142static ssize_t ath79_wdt_write(struct file *file, const char *data,
143 size_t len, loff_t *ppos)
144{
145 if (len) {
146 if (!nowayout) {
147 size_t i;
148
149 clear_bit(WDT_FLAGS_EXPECT_CLOSE, &wdt_flags);
150
151 for (i = 0; i != len; i++) {
152 char c;
153
154 if (get_user(c, data + i))
155 return -EFAULT;
156
157 if (c == 'V')
158 set_bit(WDT_FLAGS_EXPECT_CLOSE,
159 &wdt_flags);
160 }
161 }
162
163 ath79_wdt_keepalive();
164 }
165
166 return len;
167}
168
169static const struct watchdog_info ath79_wdt_info = {
170 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
171 WDIOF_MAGICCLOSE | WDIOF_CARDRESET,
172 .firmware_version = 0,
173 .identity = "ATH79 watchdog",
174};
175
176static long ath79_wdt_ioctl(struct file *file, unsigned int cmd,
177 unsigned long arg)
178{
179 void __user *argp = (void __user *)arg;
180 int __user *p = argp;
181 int err;
182 int t;
183
184 switch (cmd) {
185 case WDIOC_GETSUPPORT:
186 err = copy_to_user(argp, &ath79_wdt_info,
187 sizeof(ath79_wdt_info)) ? -EFAULT : 0;
188 break;
189
190 case WDIOC_GETSTATUS:
191 err = put_user(0, p);
192 break;
193
194 case WDIOC_GETBOOTSTATUS:
195 err = put_user(boot_status, p);
196 break;
197
198 case WDIOC_KEEPALIVE:
199 ath79_wdt_keepalive();
200 err = 0;
201 break;
202
203 case WDIOC_SETTIMEOUT:
204 err = get_user(t, p);
205 if (err)
206 break;
207
208 err = ath79_wdt_set_timeout(t);
209 if (err)
210 break;
211
212 /* fallthrough */
213 case WDIOC_GETTIMEOUT:
214 err = put_user(timeout, p);
215 break;
216
217 default:
218 err = -ENOTTY;
219 break;
220 }
221
222 return err;
223}
224
225static const struct file_operations ath79_wdt_fops = {
226 .owner = THIS_MODULE,
227 .llseek = no_llseek,
228 .write = ath79_wdt_write,
229 .unlocked_ioctl = ath79_wdt_ioctl,
230 .open = ath79_wdt_open,
231 .release = ath79_wdt_release,
232};
233
234static struct miscdevice ath79_wdt_miscdev = {
235 .minor = WATCHDOG_MINOR,
236 .name = "watchdog",
237 .fops = &ath79_wdt_fops,
238};
239
240static int ath79_wdt_probe(struct platform_device *pdev)
241{
242 struct resource *res;
243 u32 ctrl;
244 int err;
245
246 if (wdt_base)
247 return -EBUSY;
248
249 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
250 wdt_base = devm_ioremap_resource(&pdev->dev, res);
251 if (IS_ERR(wdt_base))
252 return PTR_ERR(wdt_base);
253
254 wdt_clk = devm_clk_get(&pdev->dev, "wdt");
255 if (IS_ERR(wdt_clk))
256 return PTR_ERR(wdt_clk);
257
258 err = clk_enable(wdt_clk);
259 if (err)
260 return err;
261
262 wdt_freq = clk_get_rate(wdt_clk);
263 if (!wdt_freq) {
264 err = -EINVAL;
265 goto err_clk_disable;
266 }
267
268 max_timeout = (0xfffffffful / wdt_freq);
269 if (timeout < 1 || timeout > max_timeout) {
270 timeout = max_timeout;
271 dev_info(&pdev->dev,
272 "timeout value must be 0 < timeout < %d, using %d\n",
273 max_timeout, timeout);
274 }
275
276 ctrl = ath79_wdt_rr(WDOG_REG_CTRL);
277 boot_status = (ctrl & WDOG_CTRL_LAST_RESET) ? WDIOF_CARDRESET : 0;
278
279 err = misc_register(&ath79_wdt_miscdev);
280 if (err) {
281 dev_err(&pdev->dev,
282 "unable to register misc device, err=%d\n", err);
283 goto err_clk_disable;
284 }
285
286 return 0;
287
288err_clk_disable:
289 clk_disable(wdt_clk);
290 return err;
291}
292
293static int ath79_wdt_remove(struct platform_device *pdev)
294{
295 misc_deregister(&ath79_wdt_miscdev);
296 clk_disable(wdt_clk);
297 return 0;
298}
299
300static void ath97_wdt_shutdown(struct platform_device *pdev)
301{
302 ath79_wdt_disable();
303}
304
305#ifdef CONFIG_OF
306static const struct of_device_id ath79_wdt_match[] = {
307 { .compatible = "qca,ar7130-wdt" },
308 {},
309};
310MODULE_DEVICE_TABLE(of, ath79_wdt_match);
311#endif
312
313static struct platform_driver ath79_wdt_driver = {
314 .probe = ath79_wdt_probe,
315 .remove = ath79_wdt_remove,
316 .shutdown = ath97_wdt_shutdown,
317 .driver = {
318 .name = DRIVER_NAME,
319 .owner = THIS_MODULE,
320 .of_match_table = of_match_ptr(ath79_wdt_match),
321 },
322};
323
324module_platform_driver(ath79_wdt_driver);
325
326MODULE_DESCRIPTION("Atheros AR71XX/AR724X/AR913X hardware watchdog driver");
327MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org");
328MODULE_AUTHOR("Imre Kaloz <kaloz@openwrt.org");
329MODULE_LICENSE("GPL v2");
330MODULE_ALIAS("platform:" DRIVER_NAME);