perf bench futex: Cache align the worker struct
[linux/fpc-iii.git] / drivers / hwmon / sch56xx-common.c
blob68c350c704fba85ff517f0d5f726ed53d367e45d
1 /***************************************************************************
2 * Copyright (C) 2010-2012 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 ***************************************************************************/
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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"
36 /* Insmod parameters */
37 static int nowayout = WATCHDOG_NOWAYOUT;
38 module_param(nowayout, int, 0);
39 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
40 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
42 #define SIO_SCH56XX_LD_EM 0x0C /* Embedded uController Logical Dev */
43 #define SIO_UNLOCK_KEY 0x55 /* Key to enable Super-I/O */
44 #define SIO_LOCK_KEY 0xAA /* Key to disable Super-I/O */
46 #define SIO_REG_LDSEL 0x07 /* Logical device select */
47 #define SIO_REG_DEVID 0x20 /* Device ID */
48 #define SIO_REG_ENABLE 0x30 /* Logical device enable */
49 #define SIO_REG_ADDR 0x66 /* Logical device address (2 bytes) */
51 #define SIO_SCH5627_ID 0xC6 /* Chipset ID */
52 #define SIO_SCH5636_ID 0xC7 /* Chipset ID */
54 #define REGION_LENGTH 10
56 #define SCH56XX_CMD_READ 0x02
57 #define SCH56XX_CMD_WRITE 0x03
59 /* Watchdog registers */
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
66 struct 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;
76 static struct platform_device *sch56xx_pdev;
78 /* Super I/O functions */
79 static inline int superio_inb(int base, int reg)
81 outb(reg, base);
82 return inb(base + 1);
85 static inline int superio_enter(int base)
87 /* Don't step on other drivers' I/O space by accident */
88 if (!request_muxed_region(base, 2, "sch56xx")) {
89 pr_err("I/O address 0x%04x already in use\n", base);
90 return -EBUSY;
93 outb(SIO_UNLOCK_KEY, base);
95 return 0;
98 static inline void superio_select(int base, int ld)
100 outb(SIO_REG_LDSEL, base);
101 outb(ld, base + 1);
104 static inline void superio_exit(int base)
106 outb(SIO_LOCK_KEY, base);
107 release_region(base, 2);
110 static int sch56xx_send_cmd(u16 addr, u8 cmd, u16 reg, u8 v)
112 u8 val;
113 int i;
115 * According to SMSC for the commands we use the maximum time for
116 * the EM to respond is 15 ms, but testing shows in practice it
117 * responds within 15-32 reads, so we first busy poll, and if
118 * that fails sleep a bit and try again until we are way past
119 * the 15 ms maximum response time.
121 const int max_busy_polls = 64;
122 const int max_lazy_polls = 32;
124 /* (Optional) Write-Clear the EC to Host Mailbox Register */
125 val = inb(addr + 1);
126 outb(val, addr + 1);
128 /* Set Mailbox Address Pointer to first location in Region 1 */
129 outb(0x00, addr + 2);
130 outb(0x80, addr + 3);
132 /* Write Request Packet Header */
133 outb(cmd, addr + 4); /* VREG Access Type read:0x02 write:0x03 */
134 outb(0x01, addr + 5); /* # of Entries: 1 Byte (8-bit) */
135 outb(0x04, addr + 2); /* Mailbox AP to first data entry loc. */
137 /* Write Value field */
138 if (cmd == SCH56XX_CMD_WRITE)
139 outb(v, addr + 4);
141 /* Write Address field */
142 outb(reg & 0xff, addr + 6);
143 outb(reg >> 8, addr + 7);
145 /* Execute the Random Access Command */
146 outb(0x01, addr); /* Write 01h to the Host-to-EC register */
148 /* EM Interface Polling "Algorithm" */
149 for (i = 0; i < max_busy_polls + max_lazy_polls; i++) {
150 if (i >= max_busy_polls)
151 msleep(1);
152 /* Read Interrupt source Register */
153 val = inb(addr + 8);
154 /* Write Clear the interrupt source bits */
155 if (val)
156 outb(val, addr + 8);
157 /* Command Completed ? */
158 if (val & 0x01)
159 break;
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;
168 * According to SMSC we may need to retry this, but sofar I've always
169 * seen this succeed in 1 try.
171 for (i = 0; i < max_busy_polls; i++) {
172 /* Read EC-to-Host Register */
173 val = inb(addr + 1);
174 /* Command Completed ? */
175 if (val == 0x01)
176 break;
178 if (i == 0)
179 pr_warn("EC reports: 0x%02x reading virtual register 0x%04hx\n",
180 (unsigned int)val, reg);
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;
189 * According to the SMSC app note we should now do:
191 * Set Mailbox Address Pointer to first location in Region 1 *
192 * outb(0x00, addr + 2);
193 * outb(0x80, addr + 3);
195 * But if we do that things don't work, so let's not.
198 /* Read Value field */
199 if (cmd == SCH56XX_CMD_READ)
200 return inb(addr + 4);
202 return 0;
205 int sch56xx_read_virtual_reg(u16 addr, u16 reg)
207 return sch56xx_send_cmd(addr, SCH56XX_CMD_READ, reg, 0);
209 EXPORT_SYMBOL(sch56xx_read_virtual_reg);
211 int sch56xx_write_virtual_reg(u16 addr, u16 reg, u8 val)
213 return sch56xx_send_cmd(addr, SCH56XX_CMD_WRITE, reg, val);
215 EXPORT_SYMBOL(sch56xx_write_virtual_reg);
217 int sch56xx_read_virtual_reg16(u16 addr, u16 reg)
219 int lsb, msb;
221 /* Read LSB first, this will cause the matching MSB to be latched */
222 lsb = sch56xx_read_virtual_reg(addr, reg);
223 if (lsb < 0)
224 return lsb;
226 msb = sch56xx_read_virtual_reg(addr, reg + 1);
227 if (msb < 0)
228 return msb;
230 return lsb | (msb << 8);
232 EXPORT_SYMBOL(sch56xx_read_virtual_reg16);
234 int sch56xx_read_virtual_reg12(u16 addr, u16 msb_reg, u16 lsn_reg,
235 int high_nibble)
237 int msb, lsn;
239 /* Read MSB first, this will cause the matching LSN to be latched */
240 msb = sch56xx_read_virtual_reg(addr, msb_reg);
241 if (msb < 0)
242 return msb;
244 lsn = sch56xx_read_virtual_reg(addr, lsn_reg);
245 if (lsn < 0)
246 return lsn;
248 if (high_nibble)
249 return (msb << 4) | (lsn >> 4);
250 else
251 return (msb << 4) | (lsn & 0x0f);
253 EXPORT_SYMBOL(sch56xx_read_virtual_reg12);
256 * Watchdog routines
259 static int watchdog_set_timeout(struct watchdog_device *wddev,
260 unsigned int timeout)
262 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
263 unsigned int resolution;
264 u8 control;
265 int ret;
267 /* 1 second or 60 second resolution? */
268 if (timeout <= 255)
269 resolution = 1;
270 else
271 resolution = 60;
273 if (timeout < resolution || timeout > (resolution * 255))
274 return -EINVAL;
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;
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;
290 data->watchdog_control = control;
294 * Remember new timeout value, but do not write as that (re)starts
295 * the watchdog countdown.
297 data->watchdog_preset = DIV_ROUND_UP(timeout, resolution);
298 wddev->timeout = data->watchdog_preset * resolution;
300 return 0;
303 static int watchdog_start(struct watchdog_device *wddev)
305 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
306 int ret;
307 u8 val;
310 * The sch56xx's watchdog cannot really be started / stopped
311 * it is always running, but we can avoid the timer expiring
312 * from causing a system reset by clearing the output enable bit.
314 * The sch56xx's watchdog will set the watchdog event bit, bit 0
315 * of the second interrupt source register (at base-address + 9),
316 * when the timer expires.
318 * This will only cause a system reset if the 0-1 flank happens when
319 * output enable is true. Setting output enable after the flank will
320 * not cause a reset, nor will the timer expiring a second time.
321 * This means we must clear the watchdog event bit in case it is set.
323 * The timer may still be running (after a recent watchdog_stop) and
324 * mere milliseconds away from expiring, so the timer must be reset
325 * first!
328 mutex_lock(data->io_lock);
330 /* 1. Reset the watchdog countdown counter */
331 ret = sch56xx_write_virtual_reg(data->addr, SCH56XX_REG_WDOG_PRESET,
332 data->watchdog_preset);
333 if (ret)
334 goto leave;
336 /* 2. Enable output */
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;
343 data->watchdog_output_enable = val;
345 /* 3. Clear the watchdog event bit if set */
346 val = inb(data->addr + 9);
347 if (val & 0x01)
348 outb(0x01, data->addr + 9);
350 leave:
351 mutex_unlock(data->io_lock);
352 return ret;
355 static int watchdog_trigger(struct watchdog_device *wddev)
357 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
358 int ret;
360 /* Reset the watchdog countdown counter */
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);
366 return ret;
369 static int watchdog_stop(struct watchdog_device *wddev)
371 struct sch56xx_watchdog_data *data = watchdog_get_drvdata(wddev);
372 int ret = 0;
373 u8 val;
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;
383 data->watchdog_output_enable = val;
384 return 0;
387 static 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,
395 struct sch56xx_watchdog_data *sch56xx_watchdog_register(struct device *parent,
396 u16 addr, u32 revision, struct mutex *io_lock, int check_enabled)
398 struct sch56xx_watchdog_data *data;
399 int err, control, output_enable;
401 /* Cache the watchdog registers */
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);
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;
418 data = kzalloc(sizeof(struct sch56xx_watchdog_data), GFP_KERNEL);
419 if (!data)
420 return NULL;
422 data->addr = addr;
423 data->io_lock = io_lock;
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;
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);
443 /* Since the watchdog uses a downcounter there is no register to read
444 the BIOS set timeout from (if any was set at all) ->
445 Choose a preset which will give us a 1 minute timeout */
446 if (control & SCH56XX_WDOG_TIME_BASE_SEC)
447 data->watchdog_preset = 60; /* seconds */
448 else
449 data->watchdog_preset = 1; /* minute */
451 data->watchdog_control = control;
452 data->watchdog_output_enable = output_enable;
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;
462 return data;
464 EXPORT_SYMBOL(sch56xx_watchdog_register);
466 void sch56xx_watchdog_unregister(struct sch56xx_watchdog_data *data)
468 watchdog_unregister_device(&data->wddev);
469 kfree(data);
471 EXPORT_SYMBOL(sch56xx_watchdog_unregister);
474 * platform dev find, add and remove functions
477 static int __init sch56xx_find(int sioaddr, const char **name)
479 u8 devid;
480 unsigned short address;
481 int err;
483 err = superio_enter(sioaddr);
484 if (err)
485 return err;
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;
502 superio_select(sioaddr, SIO_SCH56XX_LD_EM);
504 if (!(superio_inb(sioaddr, SIO_REG_ENABLE) & 0x01)) {
505 pr_warn("Device not activated\n");
506 err = -ENODEV;
507 goto exit;
511 * Warning the order of the low / high byte is the other way around
512 * as on most other superio devices!!
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;
521 err = address;
523 exit:
524 superio_exit(sioaddr);
525 return err;
528 static int __init sch56xx_device_add(int address, const char *name)
530 struct resource res = {
531 .start = address,
532 .end = address + REGION_LENGTH - 1,
533 .flags = IORESOURCE_IO,
535 int err;
537 sch56xx_pdev = platform_device_alloc(name, address);
538 if (!sch56xx_pdev)
539 return -ENOMEM;
541 res.name = sch56xx_pdev->name;
542 err = acpi_check_resource_conflict(&res);
543 if (err)
544 goto exit_device_put;
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;
552 err = platform_device_add(sch56xx_pdev);
553 if (err) {
554 pr_err("Device addition failed\n");
555 goto exit_device_put;
558 return 0;
560 exit_device_put:
561 platform_device_put(sch56xx_pdev);
563 return err;
566 static int __init sch56xx_init(void)
568 int address;
569 const char *name = NULL;
571 address = sch56xx_find(0x4e, &name);
572 if (address < 0)
573 address = sch56xx_find(0x2e, &name);
574 if (address < 0)
575 return address;
577 return sch56xx_device_add(address, name);
580 static void __exit sch56xx_exit(void)
582 platform_device_unregister(sch56xx_pdev);
585 MODULE_DESCRIPTION("SMSC SCH56xx Hardware Monitoring Common Code");
586 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
587 MODULE_LICENSE("GPL");
589 module_init(sch56xx_init);
590 module_exit(sch56xx_exit);