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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * hdaps.c - driver for IBM's Hard Drive Active Protection System
4 *
5 * Copyright (C) 2005 Robert Love <[email protected]>
6 * Copyright (C) 2005 Jesper Juhl <[email protected]>
7 *
8 * The HardDisk Active Protection System (hdaps) is present in IBM ThinkPads
9 * starting with the R40, T41, and X40. It provides a basic two-axis
10 * accelerometer and other data, such as the device's temperature.
11 *
12 * This driver is based on the document by Mark A. Smith available at
13 * http://www.almaden.ibm.com/cs/people/marksmith/tpaps.html and a lot of trial
14 * and error.
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/delay.h>
20#include <linux/platform_device.h>
21#include <linux/input.h>
22#include <linux/kernel.h>
23#include <linux/mutex.h>
24#include <linux/module.h>
25#include <linux/timer.h>
26#include <linux/dmi.h>
27#include <linux/jiffies.h>
28#include <linux/io.h>
29
30#define HDAPS_LOW_PORT 0x1600 /* first port used by hdaps */
31#define HDAPS_NR_PORTS 0x30 /* number of ports: 0x1600 - 0x162f */
32
33#define HDAPS_PORT_STATE 0x1611 /* device state */
34#define HDAPS_PORT_YPOS 0x1612 /* y-axis position */
35#define HDAPS_PORT_XPOS 0x1614 /* x-axis position */
36#define HDAPS_PORT_TEMP1 0x1616 /* device temperature, in Celsius */
37#define HDAPS_PORT_YVAR 0x1617 /* y-axis variance (what is this?) */
38#define HDAPS_PORT_XVAR 0x1619 /* x-axis variance (what is this?) */
39#define HDAPS_PORT_TEMP2 0x161b /* device temperature (again?) */
40#define HDAPS_PORT_UNKNOWN 0x161c /* what is this? */
41#define HDAPS_PORT_KMACT 0x161d /* keyboard or mouse activity */
42
43#define STATE_FRESH 0x50 /* accelerometer data is fresh */
44
45#define KEYBD_MASK 0x20 /* set if keyboard activity */
46#define MOUSE_MASK 0x40 /* set if mouse activity */
47#define KEYBD_ISSET(n) (!! (n & KEYBD_MASK)) /* keyboard used? */
48#define MOUSE_ISSET(n) (!! (n & MOUSE_MASK)) /* mouse used? */
49
50#define INIT_TIMEOUT_MSECS 4000 /* wait up to 4s for device init ... */
51#define INIT_WAIT_MSECS 200 /* ... in 200ms increments */
52
53#define HDAPS_POLL_INTERVAL 50 /* poll for input every 1/20s (50 ms)*/
54#define HDAPS_INPUT_FUZZ 4 /* input event threshold */
55#define HDAPS_INPUT_FLAT 4
56
57#define HDAPS_X_AXIS (1 << 0)
58#define HDAPS_Y_AXIS (1 << 1)
59#define HDAPS_BOTH_AXES (HDAPS_X_AXIS | HDAPS_Y_AXIS)
60
61static struct platform_device *pdev;
62static struct input_dev *hdaps_idev;
63static unsigned int hdaps_invert;
64static u8 km_activity;
65static int rest_x;
66static int rest_y;
67
68static DEFINE_MUTEX(hdaps_mtx);
69
70/*
71 * __get_latch - Get the value from a given port. Callers must hold hdaps_mtx.
72 */
73static inline u8 __get_latch(u16 port)
74{
75 return inb(port) & 0xff;
76}
77
78/*
79 * __check_latch - Check a port latch for a given value. Returns zero if the
80 * port contains the given value. Callers must hold hdaps_mtx.
81 */
82static inline int __check_latch(u16 port, u8 val)
83{
84 if (__get_latch(port) == val)
85 return 0;
86 return -EINVAL;
87}
88
89/*
90 * __wait_latch - Wait up to 100us for a port latch to get a certain value,
91 * returning zero if the value is obtained. Callers must hold hdaps_mtx.
92 */
93static int __wait_latch(u16 port, u8 val)
94{
95 unsigned int i;
96
97 for (i = 0; i < 20; i++) {
98 if (!__check_latch(port, val))
99 return 0;
100 udelay(5);
101 }
102
103 return -EIO;
104}
105
106/*
107 * __device_refresh - request a refresh from the accelerometer. Does not wait
108 * for refresh to complete. Callers must hold hdaps_mtx.
109 */
110static void __device_refresh(void)
111{
112 udelay(200);
113 if (inb(0x1604) != STATE_FRESH) {
114 outb(0x11, 0x1610);
115 outb(0x01, 0x161f);
116 }
117}
118
119/*
120 * __device_refresh_sync - request a synchronous refresh from the
121 * accelerometer. We wait for the refresh to complete. Returns zero if
122 * successful and nonzero on error. Callers must hold hdaps_mtx.
123 */
124static int __device_refresh_sync(void)
125{
126 __device_refresh();
127 return __wait_latch(0x1604, STATE_FRESH);
128}
129
130/*
131 * __device_complete - indicate to the accelerometer that we are done reading
132 * data, and then initiate an async refresh. Callers must hold hdaps_mtx.
133 */
134static inline void __device_complete(void)
135{
136 inb(0x161f);
137 inb(0x1604);
138 __device_refresh();
139}
140
141/*
142 * hdaps_readb_one - reads a byte from a single I/O port, placing the value in
143 * the given pointer. Returns zero on success or a negative error on failure.
144 * Can sleep.
145 */
146static int hdaps_readb_one(unsigned int port, u8 *val)
147{
148 int ret;
149
150 mutex_lock(&hdaps_mtx);
151
152 /* do a sync refresh -- we need to be sure that we read fresh data */
153 ret = __device_refresh_sync();
154 if (ret)
155 goto out;
156
157 *val = inb(port);
158 __device_complete();
159
160out:
161 mutex_unlock(&hdaps_mtx);
162 return ret;
163}
164
165/* __hdaps_read_pair - internal lockless helper for hdaps_read_pair(). */
166static int __hdaps_read_pair(unsigned int port1, unsigned int port2,
167 int *x, int *y)
168{
169 /* do a sync refresh -- we need to be sure that we read fresh data */
170 if (__device_refresh_sync())
171 return -EIO;
172
173 *y = inw(port2);
174 *x = inw(port1);
175 km_activity = inb(HDAPS_PORT_KMACT);
176 __device_complete();
177
178 /* hdaps_invert is a bitvector to negate the axes */
179 if (hdaps_invert & HDAPS_X_AXIS)
180 *x = -*x;
181 if (hdaps_invert & HDAPS_Y_AXIS)
182 *y = -*y;
183
184 return 0;
185}
186
187/*
188 * hdaps_read_pair - reads the values from a pair of ports, placing the values
189 * in the given pointers. Returns zero on success. Can sleep.
190 */
191static int hdaps_read_pair(unsigned int port1, unsigned int port2,
192 int *val1, int *val2)
193{
194 int ret;
195
196 mutex_lock(&hdaps_mtx);
197 ret = __hdaps_read_pair(port1, port2, val1, val2);
198 mutex_unlock(&hdaps_mtx);
199
200 return ret;
201}
202
203/*
204 * hdaps_device_init - initialize the accelerometer. Returns zero on success
205 * and negative error code on failure. Can sleep.
206 */
207static int hdaps_device_init(void)
208{
209 int total, ret = -ENXIO;
210
211 mutex_lock(&hdaps_mtx);
212
213 outb(0x13, 0x1610);
214 outb(0x01, 0x161f);
215 if (__wait_latch(0x161f, 0x00))
216 goto out;
217
218 /*
219 * Most ThinkPads return 0x01.
220 *
221 * Others--namely the R50p, T41p, and T42p--return 0x03. These laptops
222 * have "inverted" axises.
223 *
224 * The 0x02 value occurs when the chip has been previously initialized.
225 */
226 if (__check_latch(0x1611, 0x03) &&
227 __check_latch(0x1611, 0x02) &&
228 __check_latch(0x1611, 0x01))
229 goto out;
230
231 printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x)\n",
232 __get_latch(0x1611));
233
234 outb(0x17, 0x1610);
235 outb(0x81, 0x1611);
236 outb(0x01, 0x161f);
237 if (__wait_latch(0x161f, 0x00))
238 goto out;
239 if (__wait_latch(0x1611, 0x00))
240 goto out;
241 if (__wait_latch(0x1612, 0x60))
242 goto out;
243 if (__wait_latch(0x1613, 0x00))
244 goto out;
245 outb(0x14, 0x1610);
246 outb(0x01, 0x1611);
247 outb(0x01, 0x161f);
248 if (__wait_latch(0x161f, 0x00))
249 goto out;
250 outb(0x10, 0x1610);
251 outb(0xc8, 0x1611);
252 outb(0x00, 0x1612);
253 outb(0x02, 0x1613);
254 outb(0x01, 0x161f);
255 if (__wait_latch(0x161f, 0x00))
256 goto out;
257 if (__device_refresh_sync())
258 goto out;
259 if (__wait_latch(0x1611, 0x00))
260 goto out;
261
262 /* we have done our dance, now let's wait for the applause */
263 for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
264 int x, y;
265
266 /* a read of the device helps push it into action */
267 __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
268 if (!__wait_latch(0x1611, 0x02)) {
269 ret = 0;
270 break;
271 }
272
273 msleep(INIT_WAIT_MSECS);
274 }
275
276out:
277 mutex_unlock(&hdaps_mtx);
278 return ret;
279}
280
281
282/* Device model stuff */
283
284static int hdaps_probe(struct platform_device *dev)
285{
286 int ret;
287
288 ret = hdaps_device_init();
289 if (ret)
290 return ret;
291
292 pr_info("device successfully initialized\n");
293 return 0;
294}
295
296#ifdef CONFIG_PM_SLEEP
297static int hdaps_resume(struct device *dev)
298{
299 return hdaps_device_init();
300}
301#endif
302
303static SIMPLE_DEV_PM_OPS(hdaps_pm, NULL, hdaps_resume);
304
305static struct platform_driver hdaps_driver = {
306 .probe = hdaps_probe,
307 .driver = {
308 .name = "hdaps",
309 .pm = &hdaps_pm,
310 },
311};
312
313/*
314 * hdaps_calibrate - Set our "resting" values. Callers must hold hdaps_mtx.
315 */
316static void hdaps_calibrate(void)
317{
318 __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &rest_x, &rest_y);
319}
320
321static void hdaps_mousedev_poll(struct input_dev *input_dev)
322{
323 int x, y;
324
325 mutex_lock(&hdaps_mtx);
326
327 if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
328 goto out;
329
330 input_report_abs(input_dev, ABS_X, x - rest_x);
331 input_report_abs(input_dev, ABS_Y, y - rest_y);
332 input_sync(input_dev);
333
334out:
335 mutex_unlock(&hdaps_mtx);
336}
337
338
339/* Sysfs Files */
340
341static ssize_t hdaps_position_show(struct device *dev,
342 struct device_attribute *attr, char *buf)
343{
344 int ret, x, y;
345
346 ret = hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
347 if (ret)
348 return ret;
349
350 return sprintf(buf, "(%d,%d)\n", x, y);
351}
352
353static ssize_t hdaps_variance_show(struct device *dev,
354 struct device_attribute *attr, char *buf)
355{
356 int ret, x, y;
357
358 ret = hdaps_read_pair(HDAPS_PORT_XVAR, HDAPS_PORT_YVAR, &x, &y);
359 if (ret)
360 return ret;
361
362 return sprintf(buf, "(%d,%d)\n", x, y);
363}
364
365static ssize_t hdaps_temp1_show(struct device *dev,
366 struct device_attribute *attr, char *buf)
367{
368 u8 temp;
369 int ret;
370
371 ret = hdaps_readb_one(HDAPS_PORT_TEMP1, &temp);
372 if (ret)
373 return ret;
374
375 return sprintf(buf, "%u\n", temp);
376}
377
378static ssize_t hdaps_temp2_show(struct device *dev,
379 struct device_attribute *attr, char *buf)
380{
381 u8 temp;
382 int ret;
383
384 ret = hdaps_readb_one(HDAPS_PORT_TEMP2, &temp);
385 if (ret)
386 return ret;
387
388 return sprintf(buf, "%u\n", temp);
389}
390
391static ssize_t hdaps_keyboard_activity_show(struct device *dev,
392 struct device_attribute *attr,
393 char *buf)
394{
395 return sprintf(buf, "%u\n", KEYBD_ISSET(km_activity));
396}
397
398static ssize_t hdaps_mouse_activity_show(struct device *dev,
399 struct device_attribute *attr,
400 char *buf)
401{
402 return sprintf(buf, "%u\n", MOUSE_ISSET(km_activity));
403}
404
405static ssize_t hdaps_calibrate_show(struct device *dev,
406 struct device_attribute *attr, char *buf)
407{
408 return sprintf(buf, "(%d,%d)\n", rest_x, rest_y);
409}
410
411static ssize_t hdaps_calibrate_store(struct device *dev,
412 struct device_attribute *attr,
413 const char *buf, size_t count)
414{
415 mutex_lock(&hdaps_mtx);
416 hdaps_calibrate();
417 mutex_unlock(&hdaps_mtx);
418
419 return count;
420}
421
422static ssize_t hdaps_invert_show(struct device *dev,
423 struct device_attribute *attr, char *buf)
424{
425 return sprintf(buf, "%u\n", hdaps_invert);
426}
427
428static ssize_t hdaps_invert_store(struct device *dev,
429 struct device_attribute *attr,
430 const char *buf, size_t count)
431{
432 int invert;
433
434 if (sscanf(buf, "%d", &invert) != 1 ||
435 invert < 0 || invert > HDAPS_BOTH_AXES)
436 return -EINVAL;
437
438 hdaps_invert = invert;
439 hdaps_calibrate();
440
441 return count;
442}
443
444static DEVICE_ATTR(position, 0444, hdaps_position_show, NULL);
445static DEVICE_ATTR(variance, 0444, hdaps_variance_show, NULL);
446static DEVICE_ATTR(temp1, 0444, hdaps_temp1_show, NULL);
447static DEVICE_ATTR(temp2, 0444, hdaps_temp2_show, NULL);
448static DEVICE_ATTR(keyboard_activity, 0444, hdaps_keyboard_activity_show, NULL);
449static DEVICE_ATTR(mouse_activity, 0444, hdaps_mouse_activity_show, NULL);
450static DEVICE_ATTR(calibrate, 0644, hdaps_calibrate_show,hdaps_calibrate_store);
451static DEVICE_ATTR(invert, 0644, hdaps_invert_show, hdaps_invert_store);
452
453static struct attribute *hdaps_attributes[] = {
454 &dev_attr_position.attr,
455 &dev_attr_variance.attr,
456 &dev_attr_temp1.attr,
457 &dev_attr_temp2.attr,
458 &dev_attr_keyboard_activity.attr,
459 &dev_attr_mouse_activity.attr,
460 &dev_attr_calibrate.attr,
461 &dev_attr_invert.attr,
462 NULL,
463};
464
465static const struct attribute_group hdaps_attribute_group = {
466 .attrs = hdaps_attributes,
467};
468
469
470/* Module stuff */
471
472/* hdaps_dmi_match - found a match. return one, short-circuiting the hunt. */
473static int __init hdaps_dmi_match(const struct dmi_system_id *id)
474{
475 pr_info("%s detected\n", id->ident);
476 return 1;
477}
478
479/* hdaps_dmi_match_invert - found an inverted match. */
480static int __init hdaps_dmi_match_invert(const struct dmi_system_id *id)
481{
482 hdaps_invert = (unsigned long)id->driver_data;
483 pr_info("inverting axis (%u) readings\n", hdaps_invert);
484 return hdaps_dmi_match(id);
485}
486
487#define HDAPS_DMI_MATCH_INVERT(vendor, model, axes) { \
488 .ident = vendor " " model, \
489 .callback = hdaps_dmi_match_invert, \
490 .driver_data = (void *)axes, \
491 .matches = { \
492 DMI_MATCH(DMI_BOARD_VENDOR, vendor), \
493 DMI_MATCH(DMI_PRODUCT_VERSION, model) \
494 } \
495}
496
497#define HDAPS_DMI_MATCH_NORMAL(vendor, model) \
498 HDAPS_DMI_MATCH_INVERT(vendor, model, 0)
499
500/* Note that HDAPS_DMI_MATCH_NORMAL("ThinkPad T42") would match
501 "ThinkPad T42p", so the order of the entries matters.
502 If your ThinkPad is not recognized, please update to latest
503 BIOS. This is especially the case for some R52 ThinkPads. */
504static const struct dmi_system_id hdaps_whitelist[] __initconst = {
505 HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad R50p", HDAPS_BOTH_AXES),
506 HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R50"),
507 HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R51"),
508 HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R52"),
509 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad R61i", HDAPS_BOTH_AXES),
510 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad R61", HDAPS_BOTH_AXES),
511 HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad T41p", HDAPS_BOTH_AXES),
512 HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T41"),
513 HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad T42p", HDAPS_BOTH_AXES),
514 HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T42"),
515 HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T43"),
516 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T400", HDAPS_BOTH_AXES),
517 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T60", HDAPS_BOTH_AXES),
518 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T61p", HDAPS_BOTH_AXES),
519 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T61", HDAPS_BOTH_AXES),
520 HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad X40"),
521 HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad X41", HDAPS_Y_AXIS),
522 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X60", HDAPS_BOTH_AXES),
523 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X61s", HDAPS_BOTH_AXES),
524 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X61", HDAPS_BOTH_AXES),
525 HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad Z60m"),
526 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad Z61m", HDAPS_BOTH_AXES),
527 HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad Z61p", HDAPS_BOTH_AXES),
528 { .ident = NULL }
529};
530
531static int __init hdaps_init(void)
532{
533 int ret;
534
535 if (!dmi_check_system(hdaps_whitelist)) {
536 pr_warn("supported laptop not found!\n");
537 ret = -ENODEV;
538 goto out;
539 }
540
541 if (!request_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS, "hdaps")) {
542 ret = -ENXIO;
543 goto out;
544 }
545
546 ret = platform_driver_register(&hdaps_driver);
547 if (ret)
548 goto out_region;
549
550 pdev = platform_device_register_simple("hdaps", PLATFORM_DEVID_NONE, NULL, 0);
551 if (IS_ERR(pdev)) {
552 ret = PTR_ERR(pdev);
553 goto out_driver;
554 }
555
556 ret = sysfs_create_group(&pdev->dev.kobj, &hdaps_attribute_group);
557 if (ret)
558 goto out_device;
559
560 hdaps_idev = input_allocate_device();
561 if (!hdaps_idev) {
562 ret = -ENOMEM;
563 goto out_group;
564 }
565
566 /* initial calibrate for the input device */
567 hdaps_calibrate();
568
569 /* initialize the input class */
570 hdaps_idev->name = "hdaps";
571 hdaps_idev->phys = "isa1600/input0";
572 hdaps_idev->id.bustype = BUS_ISA;
573 hdaps_idev->dev.parent = &pdev->dev;
574 input_set_abs_params(hdaps_idev, ABS_X,
575 -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
576 input_set_abs_params(hdaps_idev, ABS_Y,
577 -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
578
579 ret = input_setup_polling(hdaps_idev, hdaps_mousedev_poll);
580 if (ret)
581 goto out_idev;
582
583 input_set_poll_interval(hdaps_idev, HDAPS_POLL_INTERVAL);
584
585 ret = input_register_device(hdaps_idev);
586 if (ret)
587 goto out_idev;
588
589 pr_info("driver successfully loaded\n");
590 return 0;
591
592out_idev:
593 input_free_device(hdaps_idev);
594out_group:
595 sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
596out_device:
597 platform_device_unregister(pdev);
598out_driver:
599 platform_driver_unregister(&hdaps_driver);
600out_region:
601 release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
602out:
603 pr_warn("driver init failed (ret=%d)!\n", ret);
604 return ret;
605}
606
607static void __exit hdaps_exit(void)
608{
609 input_unregister_device(hdaps_idev);
610 sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
611 platform_device_unregister(pdev);
612 platform_driver_unregister(&hdaps_driver);
613 release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
614
615 pr_info("driver unloaded\n");
616}
617
618module_init(hdaps_init);
619module_exit(hdaps_exit);
620
621module_param_named(invert, hdaps_invert, int, 0);
622MODULE_PARM_DESC(invert, "invert data along each axis. 1 invert x-axis, "
623 "2 invert y-axis, 3 invert both axes.");
624
625MODULE_AUTHOR("Robert Love");
626MODULE_DESCRIPTION("IBM Hard Drive Active Protection System (HDAPS) driver");
627MODULE_LICENSE("GPL v2");