Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/***************************************************************************
3 * Copyright (C) 2010-2012 Hans de Goede <hdegoede@redhat.com> *
4 * *
5 ***************************************************************************/
6
7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8
9#include <linux/module.h>
10#include <linux/init.h>
11#include <linux/platform_device.h>
12#include <linux/regmap.h>
13#include <linux/err.h>
14#include <linux/io.h>
15#include <linux/acpi.h>
16#include <linux/delay.h>
17#include <linux/fs.h>
18#include <linux/watchdog.h>
19#include <linux/uaccess.h>
20#include <linux/slab.h>
21#include "sch56xx-common.h"
22
23/* Insmod parameters */
24static bool nowayout = WATCHDOG_NOWAYOUT;
25module_param(nowayout, bool, 0);
26MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
27 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
28
29#define SIO_SCH56XX_LD_EM 0x0C /* Embedded uController Logical Dev */
30#define SIO_UNLOCK_KEY 0x55 /* Key to enable Super-I/O */
31#define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */
32
33#define SIO_REG_LDSEL 0x07 /* Logical device select */
34#define SIO_REG_DEVID 0x20 /* Device ID */
35#define SIO_REG_ENABLE 0x30 /* Logical device enable */
36#define SIO_REG_ADDR 0x66 /* Logical device address (2 bytes) */
37
38#define SIO_SCH5627_ID 0xC6 /* Chipset ID */
39#define SIO_SCH5636_ID 0xC7 /* Chipset ID */
40
41#define REGION_LENGTH 10
42
43#define SCH56XX_CMD_READ 0x02
44#define SCH56XX_CMD_WRITE 0x03
45
46/* Watchdog registers */
47#define SCH56XX_REG_WDOG_PRESET 0x58B
48#define SCH56XX_REG_WDOG_CONTROL 0x58C
49#define SCH56XX_WDOG_TIME_BASE_SEC 0x01
50#define SCH56XX_REG_WDOG_OUTPUT_ENABLE 0x58E
51#define SCH56XX_WDOG_OUTPUT_ENABLE 0x02
52
53struct sch56xx_watchdog_data {
54 u16 addr;
55 struct mutex *io_lock;
56 struct watchdog_info wdinfo;
57 struct watchdog_device wddev;
58 u8 watchdog_preset;
59 u8 watchdog_control;
60 u8 watchdog_output_enable;
61};
62
63struct sch56xx_bus_context {
64 struct mutex *lock; /* Used to serialize access to the mailbox registers */
65 u16 addr;
66};
67
68static struct platform_device *sch56xx_pdev;
69
70/* Super I/O functions */
71static inline int superio_inb(int base, int reg)
72{
73 outb(reg, base);
74 return inb(base + 1);
75}
76
77static inline int superio_enter(int base)
78{
79 /* Don't step on other drivers' I/O space by accident */
80 if (!request_muxed_region(base, 2, "sch56xx")) {
81 pr_err("I/O address 0x%04x already in use\n", base);
82 return -EBUSY;
83 }
84
85 outb(SIO_UNLOCK_KEY, base);
86
87 return 0;
88}
89
90static inline void superio_select(int base, int ld)
91{
92 outb(SIO_REG_LDSEL, base);
93 outb(ld, base + 1);
94}
95
96static inline void superio_exit(int base)
97{
98 outb(SIO_LOCK_KEY, base);
99 release_region(base, 2);
100}
101
102static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v)
103{
104 u8 val;
105 int i;
106 /*
107 * According to SMSC for the commands we use the maximum time for
108 * the EM to respond is 15 ms, but testing shows in practice it
109 * responds within 15-32 reads, so we first busy poll, and if
110 * that fails sleep a bit and try again until we are way past
111 * the 15 ms maximum response time.
112 */
113 const int max_busy_polls = 64;
114 const int max_lazy_polls = 32;
115
116 /* (Optional) Write-Clear the EC to Host Mailbox Register */
117 val = inb(addr + 1);
118 outb(val, addr + 1);
119
120 /* Set Mailbox Address Pointer to first location in Region 1 */
121 outb(0x00, addr + 2);
122 outb(0x80, addr + 3);
123
124 /* Write Request Packet Header */
125 outb(cmd, addr + 4); /* VREG Access Type read:0x02 write:0x03 */
126 outb(0x01, addr + 5); /* # of Entries: 1 Byte (8-bit) */
127 outb(0x04, addr + 2); /* Mailbox AP to first data entry loc. */
128
129 /* Write Value field */
130 if (cmd == SCH56XX_CMD_WRITE)
131 outb(v, addr + 4);
132
133 /* Write Address field */
134 outb(reg & 0xff, addr + 6);
135 outb(reg >> 8, addr + 7);
136
137 /* Execute the Random Access Command */
138 outb(0x01, addr); /* Write 01h to the Host-to-EC register */
139
140 /* EM Interface Polling "Algorithm" */
141 for (i = 0; i < max_busy_polls + max_lazy_polls; i++) {
142 if (i >= max_busy_polls)
143 usleep_range(1000, 2000);
144 /* Read Interrupt source Register */
145 val = inb(addr + 8);
146 /* Write Clear the interrupt source bits */
147 if (val)
148 outb(val, addr + 8);
149 /* Command Completed ? */
150 if (val & 0x01)
151 break;
152 }
153 if (i == max_busy_polls + max_lazy_polls) {
154 pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n",
155 reg, 1);
156 return -EIO;
157 }
158
159 /*
160 * According to SMSC we may need to retry this, but sofar I've always
161 * seen this succeed in 1 try.
162 */
163 for (i = 0; i < max_busy_polls; i++) {
164 /* Read EC-to-Host Register */
165 val = inb(addr + 1);
166 /* Command Completed ? */
167 if (val == 0x01)
168 break;
169
170 if (i == 0)
171 pr_warn("EC reports: 0x%02x reading virtual register 0x%04hx\n",
172 (unsigned int)val, reg);
173 }
174 if (i == max_busy_polls) {
175 pr_err("Max retries exceeded reading virtual register 0x%04hx (%d)\n",
176 reg, 2);
177 return -EIO;
178 }
179
180 /*
181 * According to the SMSC app note we should now do:
182 *
183 * Set Mailbox Address Pointer to first location in Region 1 *
184 * outb(0x00, addr + 2);
185 * outb(0x80, addr + 3);
186 *
187 * But if we do that things don't work, so let's not.
188 */
189
190 /* Read Value field */
191 if (cmd == SCH56XX_CMD_READ)
192 return inb(addr + 4);
193
194 return 0;
195}
196
197int sch56xx_read_virtual_reg(u16 addr, u16 reg)
198{
199 return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0);
200}
201EXPORT_SYMBOL(sch56xx_read_virtual_reg);
202
203int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val)
204{
205 return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val);
206}
207EXPORT_SYMBOL(sch56xx_write_virtual_reg);
208
209int sch56xx_read_virtual_reg16(u16 addr, u16 reg)
210{
211 int lsb, msb;
212
213 /* Read LSB first, this will cause the matching MSB to be latched */
214 lsb = sch56xx_read_virtual_reg(addr, reg);
215 if (lsb < 0)
216 return lsb;
217
218 msb = sch56xx_read_virtual_reg(addr, reg + 1);
219 if (msb < 0)
220 return msb;
221
222 return lsb | (msb << 8);
223}
224EXPORT_SYMBOL(sch56xx_read_virtual_reg16);
225
226int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg,
227 int high_nibble)
228{
229 int msb, lsn;
230
231 /* Read MSB first, this will cause the matching LSN to be latched */
232 msb = sch56xx_read_virtual_reg(addr, msb_reg);
233 if (msb < 0)
234 return msb;
235
236 lsn = sch56xx_read_virtual_reg(addr, lsn_reg);
237 if (lsn < 0)
238 return lsn;
239
240 if (high_nibble)
241 return (msb << 4) | (lsn >> 4);
242 else
243 return (msb << 4) | (lsn & 0x0f);
244}
245EXPORT_SYMBOL(sch56xx_read_virtual_reg12);
246
247/*
248 * Regmap support
249 */
250
251int sch56xx_regmap_read16(struct regmap *map, unsigned int reg, unsigned int *val)
252{
253 int lsb, msb, ret;
254
255 /* See sch56xx_read_virtual_reg16() */
256 ret = regmap_read(map, reg, &lsb);
257 if (ret < 0)
258 return ret;
259
260 ret = regmap_read(map, reg + 1, &msb);
261 if (ret < 0)
262 return ret;
263
264 *val = lsb | (msb << 8);
265
266 return 0;
267}
268EXPORT_SYMBOL(sch56xx_regmap_read16);
269
270int sch56xx_regmap_write16(struct regmap *map, unsigned int reg, unsigned int val)
271{
272 int ret;
273
274 ret = regmap_write(map, reg, val & 0xff);
275 if (ret < 0)
276 return ret;
277
278 return regmap_write(map, reg + 1, (val >> 8) & 0xff);
279}
280EXPORT_SYMBOL(sch56xx_regmap_write16);
281
282static int sch56xx_reg_write(void *context, unsigned int reg, unsigned int val)
283{
284 struct sch56xx_bus_context *bus = context;
285 int ret;
286
287 mutex_lock(bus->lock);
288 ret = sch56xx_write_virtual_reg(bus->addr, (u16)reg, (u8)val);
289 mutex_unlock(bus->lock);
290
291 return ret;
292}
293
294static int sch56xx_reg_read(void *context, unsigned int reg, unsigned int *val)
295{
296 struct sch56xx_bus_context *bus = context;
297 int ret;
298
299 mutex_lock(bus->lock);
300 ret = sch56xx_read_virtual_reg(bus->addr, (u16)reg);
301 mutex_unlock(bus->lock);
302
303 if (ret < 0)
304 return ret;
305
306 *val = ret;
307
308 return 0;
309}
310
311static void sch56xx_free_context(void *context)
312{
313 kfree(context);
314}
315
316static const struct regmap_bus sch56xx_bus = {
317 .reg_write = sch56xx_reg_write,
318 .reg_read = sch56xx_reg_read,
319 .free_context = sch56xx_free_context,
320 .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
321 .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
322};
323
324struct regmap *devm_regmap_init_sch56xx(struct device *dev, struct mutex *lock, u16 addr,
325 const struct regmap_config *config)
326{
327 struct sch56xx_bus_context *context;
328 struct regmap *map;
329
330 if (config->reg_bits != 16 && config->val_bits != 8)
331 return ERR_PTR(-EOPNOTSUPP);
332
333 context = kzalloc(sizeof(*context), GFP_KERNEL);
334 if (!context)
335 return ERR_PTR(-ENOMEM);
336
337 context->lock = lock;
338 context->addr = addr;
339
340 map = devm_regmap_init(dev, &sch56xx_bus, context, config);
341 if (IS_ERR(map))
342 kfree(context);
343
344 return map;
345}
346EXPORT_SYMBOL(devm_regmap_init_sch56xx);
347
348/*
349 * Watchdog routines
350 */
351
352static int watchdog_set_timeout(struct watchdog_device *wddev,
353 unsigned int timeout)
354{
355 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
356 unsigned int resolution;
357 u8 control;
358 int ret;
359
360 /* 1 second or 60 second resolution? */
361 if (timeout <= 255)
362 resolution = 1;
363 else
364 resolution = 60;
365
366 if (timeout < resolution || timeout > (resolution * 255))
367 return -EINVAL;
368
369 if (resolution == 1)
370 control = data->watchdog_control | SCH56XX_WDOG_TIME_BASE_SEC;
371 else
372 control = data->watchdog_control & ~SCH56XX_WDOG_TIME_BASE_SEC;
373
374 if (data->watchdog_control != control) {
375 mutex_lock(data->io_lock);
376 ret = sch56xx_write_virtual_reg(data->addr,
377 SCH56XX_REG_WDOG_CONTROL,
378 control);
379 mutex_unlock(data->io_lock);
380 if (ret)
381 return ret;
382
383 data->watchdog_control = control;
384 }
385
386 /*
387 * Remember new timeout value, but do not write as that (re)starts
388 * the watchdog countdown.
389 */
390 data->watchdog_preset = DIV_ROUND_UP(timeout, resolution);
391 wddev->timeout = data->watchdog_preset * resolution;
392
393 return 0;
394}
395
396static int watchdog_start(struct watchdog_device *wddev)
397{
398 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
399 int ret;
400 u8 val;
401
402 /*
403 * The sch56xx's watchdog cannot really be started / stopped
404 * it is always running, but we can avoid the timer expiring
405 * from causing a system reset by clearing the output enable bit.
406 *
407 * The sch56xx's watchdog will set the watchdog event bit, bit 0
408 * of the second interrupt source register (at base-address + 9),
409 * when the timer expires.
410 *
411 * This will only cause a system reset if the 0-1 flank happens when
412 * output enable is true. Setting output enable after the flank will
413 * not cause a reset, nor will the timer expiring a second time.
414 * This means we must clear the watchdog event bit in case it is set.
415 *
416 * The timer may still be running (after a recent watchdog_stop) and
417 * mere milliseconds away from expiring, so the timer must be reset
418 * first!
419 */
420
421 mutex_lock(data->io_lock);
422
423 /* 1. Reset the watchdog countdown counter */
424 ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET,
425 data->watchdog_preset);
426 if (ret)
427 goto leave;
428
429 /* 2. Enable output */
430 val = data->watchdog_output_enable | SCH56XX_WDOG_OUTPUT_ENABLE;
431 ret = sch56xx_write_virtual_reg(data->addr,
432 SCH56XX_REG_WDOG_OUTPUT_ENABLE, val);
433 if (ret)
434 goto leave;
435
436 data->watchdog_output_enable = val;
437
438 /* 3. Clear the watchdog event bit if set */
439 val = inb(data->addr + 9);
440 if (val & 0x01)
441 outb(0x01, data->addr + 9);
442
443leave:
444 mutex_unlock(data->io_lock);
445 return ret;
446}
447
448static int watchdog_trigger(struct watchdog_device *wddev)
449{
450 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
451 int ret;
452
453 /* Reset the watchdog countdown counter */
454 mutex_lock(data->io_lock);
455 ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET,
456 data->watchdog_preset);
457 mutex_unlock(data->io_lock);
458
459 return ret;
460}
461
462static int watchdog_stop(struct watchdog_device *wddev)
463{
464 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
465 int ret = 0;
466 u8 val;
467
468 val = data->watchdog_output_enable & ~SCH56XX_WDOG_OUTPUT_ENABLE;
469 mutex_lock(data->io_lock);
470 ret = sch56xx_write_virtual_reg(data->addr,
471 SCH56XX_REG_WDOG_OUTPUT_ENABLE, val);
472 mutex_unlock(data->io_lock);
473 if (ret)
474 return ret;
475
476 data->watchdog_output_enable = val;
477 return 0;
478}
479
480static const struct watchdog_ops watchdog_ops = {
481 .owner = THIS_MODULE,
482 .start = watchdog_start,
483 .stop = watchdog_stop,
484 .ping = watchdog_trigger,
485 .set_timeout = watchdog_set_timeout,
486};
487
488void sch56xx_watchdog_register(struct device *parent, u16 addr, u32 revision,
489 struct mutex *io_lock, int check_enabled)
490{
491 struct sch56xx_watchdog_data *data;
492 int err, control, output_enable;
493
494 /* Cache the watchdog registers */
495 mutex_lock(io_lock);
496 control =
497 sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_CONTROL);
498 output_enable =
499 sch56xx_read_virtual_reg(addr, SCH56XX_REG_WDOG_OUTPUT_ENABLE);
500 mutex_unlock(io_lock);
501
502 if (control < 0)
503 return;
504 if (output_enable < 0)
505 return;
506 if (check_enabled && !(output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)) {
507 pr_warn("Watchdog not enabled by BIOS, not registering\n");
508 return;
509 }
510
511 data = devm_kzalloc(parent, sizeof(struct sch56xx_watchdog_data), GFP_KERNEL);
512 if (!data)
513 return;
514
515 data->addr = addr;
516 data->io_lock = io_lock;
517
518 strscpy(data->wdinfo.identity, "sch56xx watchdog", sizeof(data->wdinfo.identity));
519 data->wdinfo.firmware_version = revision;
520 data->wdinfo.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT;
521 if (!nowayout)
522 data->wdinfo.options |= WDIOF_MAGICCLOSE;
523
524 data->wddev.info = &data->wdinfo;
525 data->wddev.ops = &watchdog_ops;
526 data->wddev.parent = parent;
527 data->wddev.timeout = 60;
528 data->wddev.min_timeout = 1;
529 data->wddev.max_timeout = 255 * 60;
530 watchdog_set_nowayout(&data->wddev, nowayout);
531 if (output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)
532 set_bit(WDOG_HW_RUNNING, &data->wddev.status);
533
534 /* Since the watchdog uses a downcounter there is no register to read
535 the BIOS set timeout from (if any was set at all) ->
536 Choose a preset which will give us a 1 minute timeout */
537 if (control & SCH56XX_WDOG_TIME_BASE_SEC)
538 data->watchdog_preset = 60; /* seconds */
539 else
540 data->watchdog_preset = 1; /* minute */
541
542 data->watchdog_control = control;
543 data->watchdog_output_enable = output_enable;
544
545 watchdog_set_drvdata(&data->wddev, data);
546 err = devm_watchdog_register_device(parent, &data->wddev);
547 if (err) {
548 pr_err("Registering watchdog chardev: %d\n", err);
549 devm_kfree(parent, data);
550 }
551}
552EXPORT_SYMBOL(sch56xx_watchdog_register);
553
554/*
555 * platform dev find, add and remove functions
556 */
557
558static int __init sch56xx_find(int sioaddr, const char **name)
559{
560 u8 devid;
561 unsigned short address;
562 int err;
563
564 err = superio_enter(sioaddr);
565 if (err)
566 return err;
567
568 devid = superio_inb(sioaddr, SIO_REG_DEVID);
569 switch (devid) {
570 case SIO_SCH5627_ID:
571 *name = "sch5627";
572 break;
573 case SIO_SCH5636_ID:
574 *name = "sch5636";
575 break;
576 default:
577 pr_debug("Unsupported device id: 0x%02x\n",
578 (unsigned int)devid);
579 err = -ENODEV;
580 goto exit;
581 }
582
583 superio_select(sioaddr, SIO_SCH56XX_LD_EM);
584
585 if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) {
586 pr_warn("Device not activated\n");
587 err = -ENODEV;
588 goto exit;
589 }
590
591 /*
592 * Warning the order of the low / high byte is the other way around
593 * as on most other superio devices!!
594 */
595 address = superio_inb(sioaddr, SIO_REG_ADDR) |
596 superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8;
597 if (address == 0) {
598 pr_warn("Base address not set\n");
599 err = -ENODEV;
600 goto exit;
601 }
602 err = address;
603
604exit:
605 superio_exit(sioaddr);
606 return err;
607}
608
609static int __init sch56xx_device_add(int address, const char *name)
610{
611 struct resource res = {
612 .start = address,
613 .end = address + REGION_LENGTH - 1,
614 .name = name,
615 .flags = IORESOURCE_IO,
616 };
617 int err;
618
619 err = acpi_check_resource_conflict(&res);
620 if (err)
621 return err;
622
623 sch56xx_pdev = platform_device_register_simple(name, -1, &res, 1);
624
625 return PTR_ERR_OR_ZERO(sch56xx_pdev);
626}
627
628static int __init sch56xx_init(void)
629{
630 int address;
631 const char *name = NULL;
632
633 address = sch56xx_find(0x4e, &name);
634 if (address < 0)
635 address = sch56xx_find(0x2e, &name);
636 if (address < 0)
637 return address;
638
639 return sch56xx_device_add(address, name);
640}
641
642static void __exit sch56xx_exit(void)
643{
644 platform_device_unregister(sch56xx_pdev);
645}
646
647MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code");
648MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
649MODULE_LICENSE("GPL");
650
651module_init(sch56xx_init);
652module_exit(sch56xx_exit);
1/***************************************************************************
2 * Copyright (C) 2010-2011 Hans de Goede <hdegoede@redhat.com> *
3 * *
4 * This program is free software; you can redistribute it and/or modify *
5 * it under the terms of the GNU General Public License as published by *
6 * the Free Software Foundation; either version 2 of the License, or *
7 * (at your option) any later version. *
8 * *
9 * This program is distributed in the hope that it will be useful, *
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
12 * GNU General Public License for more details. *
13 * *
14 * You should have received a copy of the GNU General Public License *
15 * along with this program; if not, write to the *
16 * Free Software Foundation, Inc., *
17 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
18 ***************************************************************************/
19
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 "sch56xx-common.h"
30
31#define SIO_SCH56XX_LD_EM 0x0C /* Embedded uController Logical Dev */
32#define SIO_UNLOCK_KEY 0x55 /* Key to enable Super-I/O */
33#define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */
34
35#define SIO_REG_LDSEL 0x07 /* Logical device select */
36#define SIO_REG_DEVID 0x20 /* Device ID */
37#define SIO_REG_ENABLE 0x30 /* Logical device enable */
38#define SIO_REG_ADDR 0x66 /* Logical device address (2 bytes) */
39
40#define SIO_SCH5627_ID 0xC6 /* Chipset ID */
41#define SIO_SCH5636_ID 0xC7 /* Chipset ID */
42
43#define REGION_LENGTH 9
44
45#define SCH56XX_CMD_READ 0x02
46#define SCH56XX_CMD_WRITE 0x03
47
48static struct platform_device *sch56xx_pdev;
49
50/* Super I/O functions */
51static inline int superio_inb(int base, int reg)
52{
53 outb(reg, base);
54 return inb(base + 1);
55}
56
57static inline int superio_enter(int base)
58{
59 /* Don't step on other drivers' I/O space by accident */
60 if (!request_muxed_region(base, 2, "sch56xx")) {
61 pr_err("I/O address 0x%04x already in use\n", base);
62 return -EBUSY;
63 }
64
65 outb(SIO_UNLOCK_KEY, base);
66
67 return 0;
68}
69
70static inline void superio_select(int base, int ld)
71{
72 outb(SIO_REG_LDSEL, base);
73 outb(ld, base + 1);
74}
75
76static inline void superio_exit(int base)
77{
78 outb(SIO_LOCK_KEY, base);
79 release_region(base, 2);
80}
81
82static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v)
83{
84 u8 val;
85 int i;
86 /*
87 * According to SMSC for the commands we use the maximum time for
88 * the EM to respond is 15 ms, but testing shows in practice it
89 * responds within 15-32 reads, so we first busy poll, and if
90 * that fails sleep a bit and try again until we are way past
91 * the 15 ms maximum response time.
92 */
93 const int max_busy_polls = 64;
94 const int max_lazy_polls = 32;
95
96 /* (Optional) Write-Clear the EC to Host Mailbox Register */
97 val = inb(addr + 1);
98 outb(val, addr + 1);
99
100 /* Set Mailbox Address Pointer to first location in Region 1 */
101 outb(0x00, addr + 2);
102 outb(0x80, addr + 3);
103
104 /* Write Request Packet Header */
105 outb(cmd, addr + 4); /* VREG Access Type read:0x02 write:0x03 */
106 outb(0x01, addr + 5); /* # of Entries: 1 Byte (8-bit) */
107 outb(0x04, addr + 2); /* Mailbox AP to first data entry loc. */
108
109 /* Write Value field */
110 if (cmd == SCH56XX_CMD_WRITE)
111 outb(v, addr + 4);
112
113 /* Write Address field */
114 outb(reg & 0xff, addr + 6);
115 outb(reg >> 8, addr + 7);
116
117 /* Execute the Random Access Command */
118 outb(0x01, addr); /* Write 01h to the Host-to-EC register */
119
120 /* EM Interface Polling "Algorithm" */
121 for (i = 0; i < max_busy_polls + max_lazy_polls; i++) {
122 if (i >= max_busy_polls)
123 msleep(1);
124 /* Read Interrupt source Register */
125 val = inb(addr + 8);
126 /* Write Clear the interrupt source bits */
127 if (val)
128 outb(val, addr + 8);
129 /* Command Completed ? */
130 if (val & 0x01)
131 break;
132 }
133 if (i == max_busy_polls + max_lazy_polls) {
134 pr_err("Max retries exceeded reading virtual "
135 "register 0x%04hx (%d)\n", reg, 1);
136 return -EIO;
137 }
138
139 /*
140 * According to SMSC we may need to retry this, but sofar I've always
141 * seen this succeed in 1 try.
142 */
143 for (i = 0; i < max_busy_polls; i++) {
144 /* Read EC-to-Host Register */
145 val = inb(addr + 1);
146 /* Command Completed ? */
147 if (val == 0x01)
148 break;
149
150 if (i == 0)
151 pr_warn("EC reports: 0x%02x reading virtual register "
152 "0x%04hx\n", (unsigned int)val, reg);
153 }
154 if (i == max_busy_polls) {
155 pr_err("Max retries exceeded reading virtual "
156 "register 0x%04hx (%d)\n", reg, 2);
157 return -EIO;
158 }
159
160 /*
161 * According to the SMSC app note we should now do:
162 *
163 * Set Mailbox Address Pointer to first location in Region 1 *
164 * outb(0x00, addr + 2);
165 * outb(0x80, addr + 3);
166 *
167 * But if we do that things don't work, so let's not.
168 */
169
170 /* Read Value field */
171 if (cmd == SCH56XX_CMD_READ)
172 return inb(addr + 4);
173
174 return 0;
175}
176
177int sch56xx_read_virtual_reg(u16 addr, u16 reg)
178{
179 return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0);
180}
181EXPORT_SYMBOL(sch56xx_read_virtual_reg);
182
183int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val)
184{
185 return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val);
186}
187EXPORT_SYMBOL(sch56xx_write_virtual_reg);
188
189int sch56xx_read_virtual_reg16(u16 addr, u16 reg)
190{
191 int lsb, msb;
192
193 /* Read LSB first, this will cause the matching MSB to be latched */
194 lsb = sch56xx_read_virtual_reg(addr, reg);
195 if (lsb < 0)
196 return lsb;
197
198 msb = sch56xx_read_virtual_reg(addr, reg + 1);
199 if (msb < 0)
200 return msb;
201
202 return lsb | (msb << 8);
203}
204EXPORT_SYMBOL(sch56xx_read_virtual_reg16);
205
206int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg,
207 int high_nibble)
208{
209 int msb, lsn;
210
211 /* Read MSB first, this will cause the matching LSN to be latched */
212 msb = sch56xx_read_virtual_reg(addr, msb_reg);
213 if (msb < 0)
214 return msb;
215
216 lsn = sch56xx_read_virtual_reg(addr, lsn_reg);
217 if (lsn < 0)
218 return lsn;
219
220 if (high_nibble)
221 return (msb << 4) | (lsn >> 4);
222 else
223 return (msb << 4) | (lsn & 0x0f);
224}
225EXPORT_SYMBOL(sch56xx_read_virtual_reg12);
226
227static int __init sch56xx_find(int sioaddr, unsigned short *address,
228 const char **name)
229{
230 u8 devid;
231 int err;
232
233 err = superio_enter(sioaddr);
234 if (err)
235 return err;
236
237 devid = superio_inb(sioaddr, SIO_REG_DEVID);
238 switch (devid) {
239 case SIO_SCH5627_ID:
240 *name = "sch5627";
241 break;
242 case SIO_SCH5636_ID:
243 *name = "sch5636";
244 break;
245 default:
246 pr_debug("Unsupported device id: 0x%02x\n",
247 (unsigned int)devid);
248 err = -ENODEV;
249 goto exit;
250 }
251
252 superio_select(sioaddr, SIO_SCH56XX_LD_EM);
253
254 if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) {
255 pr_warn("Device not activated\n");
256 err = -ENODEV;
257 goto exit;
258 }
259
260 /*
261 * Warning the order of the low / high byte is the other way around
262 * as on most other superio devices!!
263 */
264 *address = superio_inb(sioaddr, SIO_REG_ADDR) |
265 superio_inb(sioaddr, SIO_REG_ADDR + 1) << 8;
266 if (*address == 0) {
267 pr_warn("Base address not set\n");
268 err = -ENODEV;
269 goto exit;
270 }
271
272exit:
273 superio_exit(sioaddr);
274 return err;
275}
276
277static int __init sch56xx_device_add(unsigned short address, const char *name)
278{
279 struct resource res = {
280 .start = address,
281 .end = address + REGION_LENGTH - 1,
282 .flags = IORESOURCE_IO,
283 };
284 int err;
285
286 sch56xx_pdev = platform_device_alloc(name, address);
287 if (!sch56xx_pdev)
288 return -ENOMEM;
289
290 res.name = sch56xx_pdev->name;
291 err = acpi_check_resource_conflict(&res);
292 if (err)
293 goto exit_device_put;
294
295 err = platform_device_add_resources(sch56xx_pdev, &res, 1);
296 if (err) {
297 pr_err("Device resource addition failed\n");
298 goto exit_device_put;
299 }
300
301 err = platform_device_add(sch56xx_pdev);
302 if (err) {
303 pr_err("Device addition failed\n");
304 goto exit_device_put;
305 }
306
307 return 0;
308
309exit_device_put:
310 platform_device_put(sch56xx_pdev);
311
312 return err;
313}
314
315static int __init sch56xx_init(void)
316{
317 int err;
318 unsigned short address;
319 const char *name;
320
321 err = sch56xx_find(0x4e, &address, &name);
322 if (err)
323 err = sch56xx_find(0x2e, &address, &name);
324 if (err)
325 return err;
326
327 return sch56xx_device_add(address, name);
328}
329
330static void __exit sch56xx_exit(void)
331{
332 platform_device_unregister(sch56xx_pdev);
333}
334
335MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code");
336MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
337MODULE_LICENSE("GPL");
338
339module_init(sch56xx_init);
340module_exit(sch56xx_exit);