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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * i6300esb: Watchdog timer driver for Intel 6300ESB chipset
4 *
5 * (c) Copyright 2004 Google Inc.
6 * (c) Copyright 2005 David Härdeman <david@2gen.com>
7 *
8 * based on i810-tco.c which is in turn based on softdog.c
9 *
10 * The timer is implemented in the following I/O controller hubs:
11 * (See the intel documentation on http://developer.intel.com.)
12 * 6300ESB chip : document number 300641-004
13 *
14 * 2004YYZZ Ross Biro
15 * Initial version 0.01
16 * 2004YYZZ Ross Biro
17 * Version 0.02
18 * 20050210 David Härdeman <david@2gen.com>
19 * Ported driver to kernel 2.6
20 * 20171016 Radu Rendec <rrendec@arista.com>
21 * Change driver to use the watchdog subsystem
22 * Add support for multiple 6300ESB devices
23 */
24
25/*
26 * Includes, defines, variables, module parameters, ...
27 */
28
29#include <linux/module.h>
30#include <linux/types.h>
31#include <linux/kernel.h>
32#include <linux/fs.h>
33#include <linux/mm.h>
34#include <linux/miscdevice.h>
35#include <linux/watchdog.h>
36#include <linux/pci.h>
37#include <linux/ioport.h>
38#include <linux/uaccess.h>
39#include <linux/io.h>
40
41/* Module and version information */
42#define ESB_MODULE_NAME "i6300ESB timer"
43
44/* PCI configuration registers */
45#define ESB_CONFIG_REG 0x60 /* Config register */
46#define ESB_LOCK_REG 0x68 /* WDT lock register */
47
48/* Memory mapped registers */
49#define ESB_TIMER1_REG(w) ((w)->base + 0x00)/* Timer1 value after each reset */
50#define ESB_TIMER2_REG(w) ((w)->base + 0x04)/* Timer2 value after each reset */
51#define ESB_GINTSR_REG(w) ((w)->base + 0x08)/* General Interrupt Status Reg */
52#define ESB_RELOAD_REG(w) ((w)->base + 0x0c)/* Reload register */
53
54/* Lock register bits */
55#define ESB_WDT_FUNC (0x01 << 2) /* Watchdog functionality */
56#define ESB_WDT_ENABLE (0x01 << 1) /* Enable WDT */
57#define ESB_WDT_LOCK (0x01 << 0) /* Lock (nowayout) */
58
59/* Config register bits */
60#define ESB_WDT_REBOOT (0x01 << 5) /* Enable reboot on timeout */
61#define ESB_WDT_FREQ (0x01 << 2) /* Decrement frequency */
62#define ESB_WDT_INTTYPE (0x03 << 0) /* Interrupt type on timer1 timeout */
63
64/* Reload register bits */
65#define ESB_WDT_TIMEOUT (0x01 << 9) /* Watchdog timed out */
66#define ESB_WDT_RELOAD (0x01 << 8) /* prevent timeout */
67
68/* Magic constants */
69#define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */
70#define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */
71
72/* module parameters */
73/* 30 sec default heartbeat (1 < heartbeat < 2*1023) */
74#define ESB_HEARTBEAT_MIN 1
75#define ESB_HEARTBEAT_MAX 2046
76#define ESB_HEARTBEAT_DEFAULT 30
77#define ESB_HEARTBEAT_RANGE __MODULE_STRING(ESB_HEARTBEAT_MIN) \
78 "<heartbeat<" __MODULE_STRING(ESB_HEARTBEAT_MAX)
79static int heartbeat; /* in seconds */
80module_param(heartbeat, int, 0);
81MODULE_PARM_DESC(heartbeat,
82 "Watchdog heartbeat in seconds. (" ESB_HEARTBEAT_RANGE
83 ", default=" __MODULE_STRING(ESB_HEARTBEAT_DEFAULT) ")");
84
85static bool nowayout = WATCHDOG_NOWAYOUT;
86module_param(nowayout, bool, 0);
87MODULE_PARM_DESC(nowayout,
88 "Watchdog cannot be stopped once started (default="
89 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
90
91/* internal variables */
92struct esb_dev {
93 struct watchdog_device wdd;
94 void __iomem *base;
95 struct pci_dev *pdev;
96};
97
98#define to_esb_dev(wptr) container_of(wptr, struct esb_dev, wdd)
99
100/*
101 * Some i6300ESB specific functions
102 */
103
104/*
105 * Prepare for reloading the timer by unlocking the proper registers.
106 * This is performed by first writing 0x80 followed by 0x86 to the
107 * reload register. After this the appropriate registers can be written
108 * to once before they need to be unlocked again.
109 */
110static inline void esb_unlock_registers(struct esb_dev *edev)
111{
112 writew(ESB_UNLOCK1, ESB_RELOAD_REG(edev));
113 writew(ESB_UNLOCK2, ESB_RELOAD_REG(edev));
114}
115
116static int esb_timer_start(struct watchdog_device *wdd)
117{
118 struct esb_dev *edev = to_esb_dev(wdd);
119 int _wdd_nowayout = test_bit(WDOG_NO_WAY_OUT, &wdd->status);
120 u8 val;
121
122 esb_unlock_registers(edev);
123 writew(ESB_WDT_RELOAD, ESB_RELOAD_REG(edev));
124 /* Enable or Enable + Lock? */
125 val = ESB_WDT_ENABLE | (_wdd_nowayout ? ESB_WDT_LOCK : 0x00);
126 pci_write_config_byte(edev->pdev, ESB_LOCK_REG, val);
127 return 0;
128}
129
130static int esb_timer_stop(struct watchdog_device *wdd)
131{
132 struct esb_dev *edev = to_esb_dev(wdd);
133 u8 val;
134
135 /* First, reset timers as suggested by the docs */
136 esb_unlock_registers(edev);
137 writew(ESB_WDT_RELOAD, ESB_RELOAD_REG(edev));
138 /* Then disable the WDT */
139 pci_write_config_byte(edev->pdev, ESB_LOCK_REG, 0x0);
140 pci_read_config_byte(edev->pdev, ESB_LOCK_REG, &val);
141
142 /* Returns 0 if the timer was disabled, non-zero otherwise */
143 return val & ESB_WDT_ENABLE;
144}
145
146static int esb_timer_keepalive(struct watchdog_device *wdd)
147{
148 struct esb_dev *edev = to_esb_dev(wdd);
149
150 esb_unlock_registers(edev);
151 writew(ESB_WDT_RELOAD, ESB_RELOAD_REG(edev));
152 /* FIXME: Do we need to flush anything here? */
153 return 0;
154}
155
156static int esb_timer_set_heartbeat(struct watchdog_device *wdd,
157 unsigned int time)
158{
159 struct esb_dev *edev = to_esb_dev(wdd);
160 u32 val;
161
162 /* We shift by 9, so if we are passed a value of 1 sec,
163 * val will be 1 << 9 = 512, then write that to two
164 * timers => 2 * 512 = 1024 (which is decremented at 1KHz)
165 */
166 val = time << 9;
167
168 /* Write timer 1 */
169 esb_unlock_registers(edev);
170 writel(val, ESB_TIMER1_REG(edev));
171
172 /* Write timer 2 */
173 esb_unlock_registers(edev);
174 writel(val, ESB_TIMER2_REG(edev));
175
176 /* Reload */
177 esb_unlock_registers(edev);
178 writew(ESB_WDT_RELOAD, ESB_RELOAD_REG(edev));
179
180 /* FIXME: Do we need to flush everything out? */
181
182 /* Done */
183 wdd->timeout = time;
184 return 0;
185}
186
187/*
188 * Watchdog Subsystem Interfaces
189 */
190
191static struct watchdog_info esb_info = {
192 .identity = ESB_MODULE_NAME,
193 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
194};
195
196static const struct watchdog_ops esb_ops = {
197 .owner = THIS_MODULE,
198 .start = esb_timer_start,
199 .stop = esb_timer_stop,
200 .set_timeout = esb_timer_set_heartbeat,
201 .ping = esb_timer_keepalive,
202};
203
204/*
205 * Data for PCI driver interface
206 */
207static const struct pci_device_id esb_pci_tbl[] = {
208 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_9), },
209 { 0, }, /* End of list */
210};
211MODULE_DEVICE_TABLE(pci, esb_pci_tbl);
212
213/*
214 * Init & exit routines
215 */
216
217static unsigned char esb_getdevice(struct esb_dev *edev)
218{
219 if (pci_enable_device(edev->pdev)) {
220 dev_err(&edev->pdev->dev, "failed to enable device\n");
221 goto err_devput;
222 }
223
224 if (pci_request_region(edev->pdev, 0, ESB_MODULE_NAME)) {
225 dev_err(&edev->pdev->dev, "failed to request region\n");
226 goto err_disable;
227 }
228
229 edev->base = pci_ioremap_bar(edev->pdev, 0);
230 if (edev->base == NULL) {
231 /* Something's wrong here, BASEADDR has to be set */
232 dev_err(&edev->pdev->dev, "failed to get BASEADDR\n");
233 goto err_release;
234 }
235
236 /* Done */
237 dev_set_drvdata(&edev->pdev->dev, edev);
238 return 1;
239
240err_release:
241 pci_release_region(edev->pdev, 0);
242err_disable:
243 pci_disable_device(edev->pdev);
244err_devput:
245 return 0;
246}
247
248static void esb_initdevice(struct esb_dev *edev)
249{
250 u8 val1;
251 u16 val2;
252
253 /*
254 * Config register:
255 * Bit 5 : 0 = Enable WDT_OUTPUT
256 * Bit 2 : 0 = set the timer frequency to the PCI clock
257 * divided by 2^15 (approx 1KHz).
258 * Bits 1:0 : 11 = WDT_INT_TYPE Disabled.
259 * The watchdog has two timers, it can be setup so that the
260 * expiry of timer1 results in an interrupt and the expiry of
261 * timer2 results in a reboot. We set it to not generate
262 * any interrupts as there is not much we can do with it
263 * right now.
264 */
265 pci_write_config_word(edev->pdev, ESB_CONFIG_REG, 0x0003);
266
267 /* Check that the WDT isn't already locked */
268 pci_read_config_byte(edev->pdev, ESB_LOCK_REG, &val1);
269 if (val1 & ESB_WDT_LOCK)
270 dev_warn(&edev->pdev->dev, "nowayout already set\n");
271
272 /* Set the timer to watchdog mode and disable it for now */
273 pci_write_config_byte(edev->pdev, ESB_LOCK_REG, 0x00);
274
275 /* Check if the watchdog was previously triggered */
276 esb_unlock_registers(edev);
277 val2 = readw(ESB_RELOAD_REG(edev));
278 if (val2 & ESB_WDT_TIMEOUT)
279 edev->wdd.bootstatus = WDIOF_CARDRESET;
280
281 /* Reset WDT_TIMEOUT flag and timers */
282 esb_unlock_registers(edev);
283 writew((ESB_WDT_TIMEOUT | ESB_WDT_RELOAD), ESB_RELOAD_REG(edev));
284
285 /* And set the correct timeout value */
286 esb_timer_set_heartbeat(&edev->wdd, edev->wdd.timeout);
287}
288
289static int esb_probe(struct pci_dev *pdev,
290 const struct pci_device_id *ent)
291{
292 struct esb_dev *edev;
293 int ret;
294
295 edev = devm_kzalloc(&pdev->dev, sizeof(*edev), GFP_KERNEL);
296 if (!edev)
297 return -ENOMEM;
298
299 /* Check whether or not the hardware watchdog is there */
300 edev->pdev = pdev;
301 if (!esb_getdevice(edev))
302 return -ENODEV;
303
304 /* Initialize the watchdog and make sure it does not run */
305 edev->wdd.info = &esb_info;
306 edev->wdd.ops = &esb_ops;
307 edev->wdd.min_timeout = ESB_HEARTBEAT_MIN;
308 edev->wdd.max_timeout = ESB_HEARTBEAT_MAX;
309 edev->wdd.timeout = ESB_HEARTBEAT_DEFAULT;
310 watchdog_init_timeout(&edev->wdd, heartbeat, NULL);
311 watchdog_set_nowayout(&edev->wdd, nowayout);
312 watchdog_stop_on_reboot(&edev->wdd);
313 watchdog_stop_on_unregister(&edev->wdd);
314 esb_initdevice(edev);
315
316 /* Register the watchdog so that userspace has access to it */
317 ret = watchdog_register_device(&edev->wdd);
318 if (ret != 0)
319 goto err_unmap;
320 dev_info(&pdev->dev,
321 "initialized. heartbeat=%d sec (nowayout=%d)\n",
322 edev->wdd.timeout, nowayout);
323 return 0;
324
325err_unmap:
326 iounmap(edev->base);
327 pci_release_region(edev->pdev, 0);
328 pci_disable_device(edev->pdev);
329 return ret;
330}
331
332static void esb_remove(struct pci_dev *pdev)
333{
334 struct esb_dev *edev = dev_get_drvdata(&pdev->dev);
335
336 watchdog_unregister_device(&edev->wdd);
337 iounmap(edev->base);
338 pci_release_region(edev->pdev, 0);
339 pci_disable_device(edev->pdev);
340}
341
342static struct pci_driver esb_driver = {
343 .name = ESB_MODULE_NAME,
344 .id_table = esb_pci_tbl,
345 .probe = esb_probe,
346 .remove = esb_remove,
347};
348
349module_pci_driver(esb_driver);
350
351MODULE_AUTHOR("Ross Biro and David Härdeman");
352MODULE_DESCRIPTION("Watchdog driver for Intel 6300ESB chipsets");
353MODULE_LICENSE("GPL");
1/*
2 * i6300esb: Watchdog timer driver for Intel 6300ESB chipset
3 *
4 * (c) Copyright 2004 Google Inc.
5 * (c) Copyright 2005 David Härdeman <david@2gen.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * based on i810-tco.c which is in turn based on softdog.c
13 *
14 * The timer is implemented in the following I/O controller hubs:
15 * (See the intel documentation on http://developer.intel.com.)
16 * 6300ESB chip : document number 300641-004
17 *
18 * 2004YYZZ Ross Biro
19 * Initial version 0.01
20 * 2004YYZZ Ross Biro
21 * Version 0.02
22 * 20050210 David Härdeman <david@2gen.com>
23 * Ported driver to kernel 2.6
24 */
25
26/*
27 * Includes, defines, variables, module parameters, ...
28 */
29
30#include <linux/module.h>
31#include <linux/types.h>
32#include <linux/kernel.h>
33#include <linux/fs.h>
34#include <linux/mm.h>
35#include <linux/miscdevice.h>
36#include <linux/watchdog.h>
37#include <linux/init.h>
38#include <linux/pci.h>
39#include <linux/ioport.h>
40#include <linux/uaccess.h>
41#include <linux/io.h>
42
43/* Module and version information */
44#define ESB_VERSION "0.05"
45#define ESB_MODULE_NAME "i6300ESB timer"
46#define ESB_DRIVER_NAME ESB_MODULE_NAME ", v" ESB_VERSION
47#define PFX ESB_MODULE_NAME ": "
48
49/* PCI configuration registers */
50#define ESB_CONFIG_REG 0x60 /* Config register */
51#define ESB_LOCK_REG 0x68 /* WDT lock register */
52
53/* Memory mapped registers */
54#define ESB_TIMER1_REG (BASEADDR + 0x00)/* Timer1 value after each reset */
55#define ESB_TIMER2_REG (BASEADDR + 0x04)/* Timer2 value after each reset */
56#define ESB_GINTSR_REG (BASEADDR + 0x08)/* General Interrupt Status Register */
57#define ESB_RELOAD_REG (BASEADDR + 0x0c)/* Reload register */
58
59/* Lock register bits */
60#define ESB_WDT_FUNC (0x01 << 2) /* Watchdog functionality */
61#define ESB_WDT_ENABLE (0x01 << 1) /* Enable WDT */
62#define ESB_WDT_LOCK (0x01 << 0) /* Lock (nowayout) */
63
64/* Config register bits */
65#define ESB_WDT_REBOOT (0x01 << 5) /* Enable reboot on timeout */
66#define ESB_WDT_FREQ (0x01 << 2) /* Decrement frequency */
67#define ESB_WDT_INTTYPE (0x03 << 0) /* Interrupt type on timer1 timeout */
68
69/* Reload register bits */
70#define ESB_WDT_TIMEOUT (0x01 << 9) /* Watchdog timed out */
71#define ESB_WDT_RELOAD (0x01 << 8) /* prevent timeout */
72
73/* Magic constants */
74#define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */
75#define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */
76
77/* internal variables */
78static void __iomem *BASEADDR;
79static DEFINE_SPINLOCK(esb_lock); /* Guards the hardware */
80static unsigned long timer_alive;
81static struct pci_dev *esb_pci;
82static unsigned short triggered; /* The status of the watchdog upon boot */
83static char esb_expect_close;
84
85/* We can only use 1 card due to the /dev/watchdog restriction */
86static int cards_found;
87
88/* module parameters */
89/* 30 sec default heartbeat (1 < heartbeat < 2*1023) */
90#define WATCHDOG_HEARTBEAT 30
91static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
92module_param(heartbeat, int, 0);
93MODULE_PARM_DESC(heartbeat,
94 "Watchdog heartbeat in seconds. (1<heartbeat<2046, default="
95 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
96
97static int nowayout = WATCHDOG_NOWAYOUT;
98module_param(nowayout, int, 0);
99MODULE_PARM_DESC(nowayout,
100 "Watchdog cannot be stopped once started (default="
101 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
102
103/*
104 * Some i6300ESB specific functions
105 */
106
107/*
108 * Prepare for reloading the timer by unlocking the proper registers.
109 * This is performed by first writing 0x80 followed by 0x86 to the
110 * reload register. After this the appropriate registers can be written
111 * to once before they need to be unlocked again.
112 */
113static inline void esb_unlock_registers(void)
114{
115 writew(ESB_UNLOCK1, ESB_RELOAD_REG);
116 writew(ESB_UNLOCK2, ESB_RELOAD_REG);
117}
118
119static int esb_timer_start(void)
120{
121 u8 val;
122
123 spin_lock(&esb_lock);
124 esb_unlock_registers();
125 writew(ESB_WDT_RELOAD, ESB_RELOAD_REG);
126 /* Enable or Enable + Lock? */
127 val = ESB_WDT_ENABLE | (nowayout ? ESB_WDT_LOCK : 0x00);
128 pci_write_config_byte(esb_pci, ESB_LOCK_REG, val);
129 spin_unlock(&esb_lock);
130 return 0;
131}
132
133static int esb_timer_stop(void)
134{
135 u8 val;
136
137 spin_lock(&esb_lock);
138 /* First, reset timers as suggested by the docs */
139 esb_unlock_registers();
140 writew(ESB_WDT_RELOAD, ESB_RELOAD_REG);
141 /* Then disable the WDT */
142 pci_write_config_byte(esb_pci, ESB_LOCK_REG, 0x0);
143 pci_read_config_byte(esb_pci, ESB_LOCK_REG, &val);
144 spin_unlock(&esb_lock);
145
146 /* Returns 0 if the timer was disabled, non-zero otherwise */
147 return val & ESB_WDT_ENABLE;
148}
149
150static void esb_timer_keepalive(void)
151{
152 spin_lock(&esb_lock);
153 esb_unlock_registers();
154 writew(ESB_WDT_RELOAD, ESB_RELOAD_REG);
155 /* FIXME: Do we need to flush anything here? */
156 spin_unlock(&esb_lock);
157}
158
159static int esb_timer_set_heartbeat(int time)
160{
161 u32 val;
162
163 if (time < 0x1 || time > (2 * 0x03ff))
164 return -EINVAL;
165
166 spin_lock(&esb_lock);
167
168 /* We shift by 9, so if we are passed a value of 1 sec,
169 * val will be 1 << 9 = 512, then write that to two
170 * timers => 2 * 512 = 1024 (which is decremented at 1KHz)
171 */
172 val = time << 9;
173
174 /* Write timer 1 */
175 esb_unlock_registers();
176 writel(val, ESB_TIMER1_REG);
177
178 /* Write timer 2 */
179 esb_unlock_registers();
180 writel(val, ESB_TIMER2_REG);
181
182 /* Reload */
183 esb_unlock_registers();
184 writew(ESB_WDT_RELOAD, ESB_RELOAD_REG);
185
186 /* FIXME: Do we need to flush everything out? */
187
188 /* Done */
189 heartbeat = time;
190 spin_unlock(&esb_lock);
191 return 0;
192}
193
194/*
195 * /dev/watchdog handling
196 */
197
198static int esb_open(struct inode *inode, struct file *file)
199{
200 /* /dev/watchdog can only be opened once */
201 if (test_and_set_bit(0, &timer_alive))
202 return -EBUSY;
203
204 /* Reload and activate timer */
205 esb_timer_start();
206
207 return nonseekable_open(inode, file);
208}
209
210static int esb_release(struct inode *inode, struct file *file)
211{
212 /* Shut off the timer. */
213 if (esb_expect_close == 42)
214 esb_timer_stop();
215 else {
216 printk(KERN_CRIT PFX
217 "Unexpected close, not stopping watchdog!\n");
218 esb_timer_keepalive();
219 }
220 clear_bit(0, &timer_alive);
221 esb_expect_close = 0;
222 return 0;
223}
224
225static ssize_t esb_write(struct file *file, const char __user *data,
226 size_t len, loff_t *ppos)
227{
228 /* See if we got the magic character 'V' and reload the timer */
229 if (len) {
230 if (!nowayout) {
231 size_t i;
232
233 /* note: just in case someone wrote the magic character
234 * five months ago... */
235 esb_expect_close = 0;
236
237 /* scan to see whether or not we got the
238 * magic character */
239 for (i = 0; i != len; i++) {
240 char c;
241 if (get_user(c, data + i))
242 return -EFAULT;
243 if (c == 'V')
244 esb_expect_close = 42;
245 }
246 }
247
248 /* someone wrote to us, we should reload the timer */
249 esb_timer_keepalive();
250 }
251 return len;
252}
253
254static long esb_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
255{
256 int new_options, retval = -EINVAL;
257 int new_heartbeat;
258 void __user *argp = (void __user *)arg;
259 int __user *p = argp;
260 static const struct watchdog_info ident = {
261 .options = WDIOF_SETTIMEOUT |
262 WDIOF_KEEPALIVEPING |
263 WDIOF_MAGICCLOSE,
264 .firmware_version = 0,
265 .identity = ESB_MODULE_NAME,
266 };
267
268 switch (cmd) {
269 case WDIOC_GETSUPPORT:
270 return copy_to_user(argp, &ident,
271 sizeof(ident)) ? -EFAULT : 0;
272
273 case WDIOC_GETSTATUS:
274 return put_user(0, p);
275
276 case WDIOC_GETBOOTSTATUS:
277 return put_user(triggered, p);
278
279 case WDIOC_SETOPTIONS:
280 {
281 if (get_user(new_options, p))
282 return -EFAULT;
283
284 if (new_options & WDIOS_DISABLECARD) {
285 esb_timer_stop();
286 retval = 0;
287 }
288
289 if (new_options & WDIOS_ENABLECARD) {
290 esb_timer_start();
291 retval = 0;
292 }
293 return retval;
294 }
295 case WDIOC_KEEPALIVE:
296 esb_timer_keepalive();
297 return 0;
298
299 case WDIOC_SETTIMEOUT:
300 {
301 if (get_user(new_heartbeat, p))
302 return -EFAULT;
303 if (esb_timer_set_heartbeat(new_heartbeat))
304 return -EINVAL;
305 esb_timer_keepalive();
306 /* Fall */
307 }
308 case WDIOC_GETTIMEOUT:
309 return put_user(heartbeat, p);
310 default:
311 return -ENOTTY;
312 }
313}
314
315/*
316 * Kernel Interfaces
317 */
318
319static const struct file_operations esb_fops = {
320 .owner = THIS_MODULE,
321 .llseek = no_llseek,
322 .write = esb_write,
323 .unlocked_ioctl = esb_ioctl,
324 .open = esb_open,
325 .release = esb_release,
326};
327
328static struct miscdevice esb_miscdev = {
329 .minor = WATCHDOG_MINOR,
330 .name = "watchdog",
331 .fops = &esb_fops,
332};
333
334/*
335 * Data for PCI driver interface
336 */
337static DEFINE_PCI_DEVICE_TABLE(esb_pci_tbl) = {
338 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_9), },
339 { 0, }, /* End of list */
340};
341MODULE_DEVICE_TABLE(pci, esb_pci_tbl);
342
343/*
344 * Init & exit routines
345 */
346
347static unsigned char __devinit esb_getdevice(struct pci_dev *pdev)
348{
349 if (pci_enable_device(pdev)) {
350 printk(KERN_ERR PFX "failed to enable device\n");
351 goto err_devput;
352 }
353
354 if (pci_request_region(pdev, 0, ESB_MODULE_NAME)) {
355 printk(KERN_ERR PFX "failed to request region\n");
356 goto err_disable;
357 }
358
359 BASEADDR = pci_ioremap_bar(pdev, 0);
360 if (BASEADDR == NULL) {
361 /* Something's wrong here, BASEADDR has to be set */
362 printk(KERN_ERR PFX "failed to get BASEADDR\n");
363 goto err_release;
364 }
365
366 /* Done */
367 esb_pci = pdev;
368 return 1;
369
370err_release:
371 pci_release_region(pdev, 0);
372err_disable:
373 pci_disable_device(pdev);
374err_devput:
375 return 0;
376}
377
378static void __devinit esb_initdevice(void)
379{
380 u8 val1;
381 u16 val2;
382
383 /*
384 * Config register:
385 * Bit 5 : 0 = Enable WDT_OUTPUT
386 * Bit 2 : 0 = set the timer frequency to the PCI clock
387 * divided by 2^15 (approx 1KHz).
388 * Bits 1:0 : 11 = WDT_INT_TYPE Disabled.
389 * The watchdog has two timers, it can be setup so that the
390 * expiry of timer1 results in an interrupt and the expiry of
391 * timer2 results in a reboot. We set it to not generate
392 * any interrupts as there is not much we can do with it
393 * right now.
394 */
395 pci_write_config_word(esb_pci, ESB_CONFIG_REG, 0x0003);
396
397 /* Check that the WDT isn't already locked */
398 pci_read_config_byte(esb_pci, ESB_LOCK_REG, &val1);
399 if (val1 & ESB_WDT_LOCK)
400 printk(KERN_WARNING PFX "nowayout already set\n");
401
402 /* Set the timer to watchdog mode and disable it for now */
403 pci_write_config_byte(esb_pci, ESB_LOCK_REG, 0x00);
404
405 /* Check if the watchdog was previously triggered */
406 esb_unlock_registers();
407 val2 = readw(ESB_RELOAD_REG);
408 if (val2 & ESB_WDT_TIMEOUT)
409 triggered = WDIOF_CARDRESET;
410
411 /* Reset WDT_TIMEOUT flag and timers */
412 esb_unlock_registers();
413 writew((ESB_WDT_TIMEOUT | ESB_WDT_RELOAD), ESB_RELOAD_REG);
414
415 /* And set the correct timeout value */
416 esb_timer_set_heartbeat(heartbeat);
417}
418
419static int __devinit esb_probe(struct pci_dev *pdev,
420 const struct pci_device_id *ent)
421{
422 int ret;
423
424 cards_found++;
425 if (cards_found == 1)
426 printk(KERN_INFO PFX "Intel 6300ESB WatchDog Timer Driver v%s\n",
427 ESB_VERSION);
428
429 if (cards_found > 1) {
430 printk(KERN_ERR PFX "This driver only supports 1 device\n");
431 return -ENODEV;
432 }
433
434 /* Check whether or not the hardware watchdog is there */
435 if (!esb_getdevice(pdev) || esb_pci == NULL)
436 return -ENODEV;
437
438 /* Check that the heartbeat value is within it's range;
439 if not reset to the default */
440 if (heartbeat < 0x1 || heartbeat > 2 * 0x03ff) {
441 heartbeat = WATCHDOG_HEARTBEAT;
442 printk(KERN_INFO PFX
443 "heartbeat value must be 1<heartbeat<2046, using %d\n",
444 heartbeat);
445 }
446
447 /* Initialize the watchdog and make sure it does not run */
448 esb_initdevice();
449
450 /* Register the watchdog so that userspace has access to it */
451 ret = misc_register(&esb_miscdev);
452 if (ret != 0) {
453 printk(KERN_ERR PFX
454 "cannot register miscdev on minor=%d (err=%d)\n",
455 WATCHDOG_MINOR, ret);
456 goto err_unmap;
457 }
458 printk(KERN_INFO PFX
459 "initialized (0x%p). heartbeat=%d sec (nowayout=%d)\n",
460 BASEADDR, heartbeat, nowayout);
461 return 0;
462
463err_unmap:
464 iounmap(BASEADDR);
465 pci_release_region(esb_pci, 0);
466 pci_disable_device(esb_pci);
467 esb_pci = NULL;
468 return ret;
469}
470
471static void __devexit esb_remove(struct pci_dev *pdev)
472{
473 /* Stop the timer before we leave */
474 if (!nowayout)
475 esb_timer_stop();
476
477 /* Deregister */
478 misc_deregister(&esb_miscdev);
479 iounmap(BASEADDR);
480 pci_release_region(esb_pci, 0);
481 pci_disable_device(esb_pci);
482 esb_pci = NULL;
483}
484
485static void esb_shutdown(struct pci_dev *pdev)
486{
487 esb_timer_stop();
488}
489
490static struct pci_driver esb_driver = {
491 .name = ESB_MODULE_NAME,
492 .id_table = esb_pci_tbl,
493 .probe = esb_probe,
494 .remove = __devexit_p(esb_remove),
495 .shutdown = esb_shutdown,
496};
497
498static int __init watchdog_init(void)
499{
500 return pci_register_driver(&esb_driver);
501}
502
503static void __exit watchdog_cleanup(void)
504{
505 pci_unregister_driver(&esb_driver);
506 printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
507}
508
509module_init(watchdog_init);
510module_exit(watchdog_cleanup);
511
512MODULE_AUTHOR("Ross Biro and David Härdeman");
513MODULE_DESCRIPTION("Watchdog driver for Intel 6300ESB chipsets");
514MODULE_LICENSE("GPL");
515MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);