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20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/platform_device.h>
25#include <linux/err.h>
26#include <linux/io.h>
27#include <linux/acpi.h>
28#include <linux/delay.h>
29#include <linux/fs.h>
30#include <linux/watchdog.h>
31#include <linux/miscdevice.h>
32#include <linux/uaccess.h>
33#include <linux/slab.h>
34#include "sch56xx-common.h"
35
36
37static int nowayout = WATCHDOG_NOWAYOUT;
38module_param(nowayout, int, 0);
39MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
40 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
41
42#define SIO_SCH56XX_LD_EM 0x0C
43#define SIO_UNLOCK_KEY 0x55
44#define SIO_LOCK_KEY 0xAA
45
46#define SIO_REG_LDSEL 0x07
47#define SIO_REG_DEVID 0x20
48#define SIO_REG_ENABLE 0x30
49#define SIO_REG_ADDR 0x66
50
51#define SIO_SCH5627_ID 0xC6
52#define SIO_SCH5636_ID 0xC7
53
54#define REGION_LENGTH 10
55
56#define SCH56XX_CMD_READ 0x02
57#define SCH56XX_CMD_WRITE 0x03
58
59
60#define SCH56XX_REG_WDOG_PRESET 0x58B
61#define SCH56XX_REG_WDOG_CONTROL 0x58C
62#define SCH56XX_WDOG_TIME_BASE_SEC 0x01
63#define SCH56XX_REG_WDOG_OUTPUT_ENABLE 0x58E
64#define SCH56XX_WDOG_OUTPUT_ENABLE 0x02
65
66struct sch56xx_watchdog_data {
67 u16 addr;
68 struct mutex *io_lock;
69 struct watchdog_info wdinfo;
70 struct watchdog_device wddev;
71 u8 watchdog_preset;
72 u8 watchdog_control;
73 u8 watchdog_output_enable;
74};
75
76static struct platform_device *sch56xx_pdev;
77
78
79static inline int superio_inb(int base, int reg)
80{
81 outb(reg, base);
82 return inb(base + 1);
83}
84
85static inline int superio_enter(int base)
86{
87
88 if (!request_muxed_region(base, 2, "sch56xx")) {
89 pr_err("I/O address 0x%04x already in use\n", base);
90 return -EBUSY;
91 }
92
93 outb(SIO_UNLOCK_KEY, base);
94
95 return 0;
96}
97
98static inline void superio_select(int base, int ld)
99{
100 outb(SIO_REG_LDSEL, base);
101 outb(ld, base + 1);
102}
103
104static inline void superio_exit(int base)
105{
106 outb(SIO_LOCK_KEY, base);
107 release_region(base, 2);
108}
109
110static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v)
111{
112 u8 val;
113 int i;
114
115
116
117
118
119
120
121 const int max_busy_polls = 64;
122 const int max_lazy_polls = 32;
123
124
125 val = inb(addr + 1);
126 outb(val, addr + 1);
127
128
129 outb(0x00, addr + 2);
130 outb(0x80, addr + 3);
131
132
133 outb(cmd, addr + 4);
134 outb(0x01, addr + 5);
135 outb(0x04, addr + 2);
136
137
138 if (cmd == SCH56XX_CMD_WRITE)
139 outb(v, addr + 4);
140
141
142 outb(reg & 0xff, addr + 6);
143 outb(reg >> 8, addr + 7);
144
145
146 outb(0x01, addr);
147
148
149 for (i = 0; i < max_busy_polls + max_lazy_polls; i++) {
150 if (i >= max_busy_polls)
151 msleep(1);
152
153 val = inb(addr + 8);
154
155 if (val)
156 outb(val, addr + 8);
157
158 if (val & 0x01)
159 break;
160 }
161 if (i == max_busy_polls + max_lazy_polls) {
162 pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n",
163 reg, 1);
164 return -EIO;
165 }
166
167
168
169
170
171 for (i = 0; i < max_busy_polls; i++) {
172
173 val = inb(addr + 1);
174
175 if (val == 0x01)
176 break;
177
178 if (i == 0)
179 pr_warn("EC reports: 0x%02x reading virtual register 0x%04hx\n",
180 (unsigned int)val, reg);
181 }
182 if (i == max_busy_polls) {
183 pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n",
184 reg, 2);
185 return -EIO;
186 }
187
188
189
190
191
192
193
194
195
196
197
198
199 if (cmd == SCH56XX_CMD_READ)
200 return inb(addr + 4);
201
202 return 0;
203}
204
205int sch56xx_read_virtual_reg(u16 addr, u16 reg)
206{
207 return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0);
208}
209EXPORT_SYMBOL(sch56xx_read_virtual_reg);
210
211int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val)
212{
213 return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val);
214}
215EXPORT_SYMBOL(sch56xx_write_virtual_reg);
216
217int sch56xx_read_virtual_reg16(u16 addr, u16 reg)
218{
219 int lsb, msb;
220
221
222 lsb = sch56xx_read_virtual_reg(addr, reg);
223 if (lsb < 0)
224 return lsb;
225
226 msb = sch56xx_read_virtual_reg(addr, reg + 1);
227 if (msb < 0)
228 return msb;
229
230 return lsb | (msb << 8);
231}
232EXPORT_SYMBOL(sch56xx_read_virtual_reg16);
233
234int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg,
235 int high_nibble)
236{
237 int msb, lsn;
238
239
240 msb = sch56xx_read_virtual_reg(addr, msb_reg);
241 if (msb < 0)
242 return msb;
243
244 lsn = sch56xx_read_virtual_reg(addr, lsn_reg);
245 if (lsn < 0)
246 return lsn;
247
248 if (high_nibble)
249 return (msb << 4) | (lsn >> 4);
250 else
251 return (msb << 4) | (lsn & 0x0f);
252}
253EXPORT_SYMBOL(sch56xx_read_virtual_reg12);
254
255
256
257
258
259static int watchdog_set_timeout(struct watchdog_device *wddev,
260 unsigned int timeout)
261{
262 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
263 unsigned int resolution;
264 u8 control;
265 int ret;
266
267
268 if (timeout <= 255)
269 resolution = 1;
270 else
271 resolution = 60;
272
273 if (timeout < resolution || timeout > (resolution * 255))
274 return -EINVAL;
275
276 if (resolution == 1)
277 control = data->watchdog_control | SCH56XX_WDOG_TIME_BASE_SEC;
278 else
279 control = data->watchdog_control & ~SCH56XX_WDOG_TIME_BASE_SEC;
280
281 if (data->watchdog_control != control) {
282 mutex_lock(data->io_lock);
283 ret = sch56xx_write_virtual_reg(data->addr,
284 SCH56XX_REG_WDOG_CONTROL,
285 control);
286 mutex_unlock(data->io_lock);
287 if (ret)
288 return ret;
289
290 data->watchdog_control = control;
291 }
292
293
294
295
296
297 data->watchdog_preset = DIV_ROUND_UP(timeout, resolution);
298 wddev->timeout = data->watchdog_preset * resolution;
299
300 return 0;
301}
302
303static int watchdog_start(struct watchdog_device *wddev)
304{
305 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
306 int ret;
307 u8 val;
308
309
310
311
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313
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315
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326
327
328 mutex_lock(data->io_lock);
329
330
331 ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET,
332 data->watchdog_preset);
333 if (ret)
334 goto leave;
335
336
337 val = data->watchdog_output_enable | SCH56XX_WDOG_OUTPUT_ENABLE;
338 ret = sch56xx_write_virtual_reg(data->addr,
339 SCH56XX_REG_WDOG_OUTPUT_ENABLE, val);
340 if (ret)
341 goto leave;
342
343 data->watchdog_output_enable = val;
344
345
346 val = inb(data->addr + 9);
347 if (val & 0x01)
348 outb(0x01, data->addr + 9);
349
350leave:
351 mutex_unlock(data->io_lock);
352 return ret;
353}
354
355static int watchdog_trigger(struct watchdog_device *wddev)
356{
357 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
358 int ret;
359
360
361 mutex_lock(data->io_lock);
362 ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET,
363 data->watchdog_preset);
364 mutex_unlock(data->io_lock);
365
366 return ret;
367}
368
369static int watchdog_stop(struct watchdog_device *wddev)
370{
371 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
372 int ret = 0;
373 u8 val;
374
375 val = data->watchdog_output_enable & ~SCH56XX_WDOG_OUTPUT_ENABLE;
376 mutex_lock(data->io_lock);
377 ret = sch56xx_write_virtual_reg(data->addr,
378 SCH56XX_REG_WDOG_OUTPUT_ENABLE, val);
379 mutex_unlock(data->io_lock);
380 if (ret)
381 return ret;
382
383 data->watchdog_output_enable = val;
384 return 0;
385}
386
387static const struct watchdog_ops watchdog_ops = {
388 .owner = THIS_MODULE,
389 .start = watchdog_start,
390 .stop = watchdog_stop,
391 .ping = watchdog_trigger,
392 .set_timeout = watchdog_set_timeout,
393};
394
395struct sch56xx_watchdog_data *sch56xx_watchdog_register(struct device *parent,
396 u16 addr, u32 revision, struct mutex *io_lock, int check_enabled)
397{
398 struct sch56xx_watchdog_data *data;
399 int err, control, output_enable;
400
401
402 mutex_lock(io_lock);
403 control =
404 sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_CONTROL);
405 output_enable =
406 sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_OUTPUT_ENABLE);
407 mutex_unlock(io_lock);
408
409 if (control < 0)
410 return NULL;
411 if (output_enable < 0)
412 return NULL;
413 if (check_enabled && !(output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)) {
414 pr_warn("Watchdog not enabled by BIOS, not registering\n");
415 return NULL;
416 }
417
418 data = kzalloc(sizeof(struct sch56xx_watchdog_data), GFP_KERNEL);
419 if (!data)
420 return NULL;
421
422 data->addr = addr;
423 data->io_lock = io_lock;
424
425 strlcpy(data->wdinfo.identity, "sch56xx watchdog",
426 sizeof(data->wdinfo.identity));
427 data->wdinfo.firmware_version = revision;
428 data->wdinfo.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT;
429 if (!nowayout)
430 data->wdinfo.options |= WDIOF_MAGICCLOSE;
431
432 data->wddev.info = &data->wdinfo;
433 data->wddev.ops = &watchdog_ops;
434 data->wddev.parent = parent;
435 data->wddev.timeout = 60;
436 data->wddev.min_timeout = 1;
437 data->wddev.max_timeout = 255 * 60;
438 if (nowayout)
439 set_bit(WDOG_NO_WAY_OUT, &data->wddev.status);
440 if (output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)
441 set_bit(WDOG_ACTIVE, &data->wddev.status);
442
443
444
445
446 if (control & SCH56XX_WDOG_TIME_BASE_SEC)
447 data->watchdog_preset = 60;
448 else
449 data->watchdog_preset = 1;
450
451 data->watchdog_control = control;
452 data->watchdog_output_enable = output_enable;
453
454 watchdog_set_drvdata(&data->wddev, data);
455 err = watchdog_register_device(&data->wddev);
456 if (err) {
457 pr_err("Registering watchdog chardev: %d\n", err);
458 kfree(data);
459 return NULL;
460 }
461
462 return data;
463}
464EXPORT_SYMBOL(sch56xx_watchdog_register);
465
466void sch56xx_watchdog_unregister(struct sch56xx_watchdog_data *data)
467{
468 watchdog_unregister_device(&data->wddev);
469 kfree(data);
470}
471EXPORT_SYMBOL(sch56xx_watchdog_unregister);
472
473
474
475
476
477static int __init sch56xx_find(int sioaddr, const char **name)
478{
479 u8 devid;
480 unsigned short address;
481 int err;
482
483 err = superio_enter(sioaddr);
484 if (err)
485 return err;
486
487 devid = superio_inb(sioaddr, SIO_REG_DEVID);
488 switch (devid) {
489 case SIO_SCH5627_ID:
490 *name = "sch5627";
491 break;
492 case SIO_SCH5636_ID:
493 *name = "sch5636";
494 break;
495 default:
496 pr_debug("Unsupported device id: 0x%02x\n",
497 (unsigned int)devid);
498 err = -ENODEV;
499 goto exit;
500 }
501
502 superio_select(sioaddr, SIO_SCH56XX_LD_EM);
503
504 if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) {
505 pr_warn("Device not activated\n");
506 err = -ENODEV;
507 goto exit;
508 }
509
510
511
512
513
514 address = superio_inb(sioaddr, SIO_REG_ADDR) |
515 superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8;
516 if (address == 0) {
517 pr_warn("Base address not set\n");
518 err = -ENODEV;
519 goto exit;
520 }
521 err = address;
522
523exit:
524 superio_exit(sioaddr);
525 return err;
526}
527
528static int __init sch56xx_device_add(int address, const char *name)
529{
530 struct resource res = {
531 .start = address,
532 .end = address + REGION_LENGTH - 1,
533 .flags = IORESOURCE_IO,
534 };
535 int err;
536
537 sch56xx_pdev = platform_device_alloc(name, address);
538 if (!sch56xx_pdev)
539 return -ENOMEM;
540
541 res.name = sch56xx_pdev->name;
542 err = acpi_check_resource_conflict(&res);
543 if (err)
544 goto exit_device_put;
545
546 err = platform_device_add_resources(sch56xx_pdev, &res, 1);
547 if (err) {
548 pr_err("Device resource addition failed\n");
549 goto exit_device_put;
550 }
551
552 err = platform_device_add(sch56xx_pdev);
553 if (err) {
554 pr_err("Device addition failed\n");
555 goto exit_device_put;
556 }
557
558 return 0;
559
560exit_device_put:
561 platform_device_put(sch56xx_pdev);
562
563 return err;
564}
565
566static int __init sch56xx_init(void)
567{
568 int address;
569 const char *name = NULL;
570
571 address = sch56xx_find(0x4e, &name);
572 if (address < 0)
573 address = sch56xx_find(0x2e, &name);
574 if (address < 0)
575 return address;
576
577 return sch56xx_device_add(address, name);
578}
579
580static void __exit sch56xx_exit(void)
581{
582 platform_device_unregister(sch56xx_pdev);
583}
584
585MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code");
586MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
587MODULE_LICENSE("GPL");
588
589module_init(sch56xx_init);
590module_exit(sch56xx_exit);
591