2 * drivers/hwmon/hdaps.c - driver for IBM's Hard Drive Active Protection System
4 * Copyright (C) 2005 Robert Love <rml@novell.com>
5 * Copyright (C) 2005 Jesper Juhl <jesper.juhl@gmail.com>
7 * The HardDisk Active Protection System (hdaps) is present in IBM ThinkPads
8 * starting with the R40, T41, and X40. It provides a basic two-axis
9 * accelerometer and other data, such as the device's temperature.
11 * This driver is based on the document by Mark A. Smith available at
12 * http://www.almaden.ibm.com/cs/people/marksmith/tpaps.html and a lot of trial
15 * This program is free software; you can redistribute it and/or modify it
16 * under the terms of the GNU General Public License v2 as published by the
17 * Free Software Foundation.
19 * This program is distributed in the hope that it will be useful, but WITHOUT
20 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
21 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
24 * You should have received a copy of the GNU General Public License along with
25 * this program; if not, write to the Free Software Foundation, Inc.,
26 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
29 #include <linux/delay.h>
30 #include <linux/platform_device.h>
31 #include <linux/input.h>
32 #include <linux/kernel.h>
33 #include <linux/module.h>
34 #include <linux/timer.h>
35 #include <linux/dmi.h>
38 #define HDAPS_LOW_PORT 0x1600 /* first port used by hdaps */
39 #define HDAPS_NR_PORTS 0x30 /* number of ports: 0x1600 - 0x162f */
41 #define HDAPS_PORT_STATE 0x1611 /* device state */
42 #define HDAPS_PORT_YPOS 0x1612 /* y-axis position */
43 #define HDAPS_PORT_XPOS 0x1614 /* x-axis position */
44 #define HDAPS_PORT_TEMP1 0x1616 /* device temperature, in celcius */
45 #define HDAPS_PORT_YVAR 0x1617 /* y-axis variance (what is this?) */
46 #define HDAPS_PORT_XVAR 0x1619 /* x-axis variance (what is this?) */
47 #define HDAPS_PORT_TEMP2 0x161b /* device temperature (again?) */
48 #define HDAPS_PORT_UNKNOWN 0x161c /* what is this? */
49 #define HDAPS_PORT_KMACT 0x161d /* keyboard or mouse activity */
51 #define STATE_FRESH 0x50 /* accelerometer data is fresh */
53 #define KEYBD_MASK 0x20 /* set if keyboard activity */
54 #define MOUSE_MASK 0x40 /* set if mouse activity */
55 #define KEYBD_ISSET(n) (!! (n & KEYBD_MASK)) /* keyboard used? */
56 #define MOUSE_ISSET(n) (!! (n & MOUSE_MASK)) /* mouse used? */
58 #define INIT_TIMEOUT_MSECS 4000 /* wait up to 4s for device init ... */
59 #define INIT_WAIT_MSECS 200 /* ... in 200ms increments */
61 #define HDAPS_POLL_PERIOD (HZ/20) /* poll for input every 1/20s */
62 #define HDAPS_INPUT_FUZZ 4 /* input event threshold */
64 static struct timer_list hdaps_timer;
65 static struct platform_device *pdev;
66 static unsigned int hdaps_invert;
67 static u8 km_activity;
71 static DECLARE_MUTEX(hdaps_sem);
74 * __get_latch - Get the value from a given port. Callers must hold hdaps_sem.
76 static inline u8 __get_latch(u16 port)
78 return inb(port) & 0xff;
82 * __check_latch - Check a port latch for a given value. Returns zero if the
83 * port contains the given value. Callers must hold hdaps_sem.
85 static inline int __check_latch(u16 port, u8 val)
87 if (__get_latch(port) == val)
93 * __wait_latch - Wait up to 100us for a port latch to get a certain value,
94 * returning zero if the value is obtained. Callers must hold hdaps_sem.
96 static int __wait_latch(u16 port, u8 val)
100 for (i = 0; i < 20; i++) {
101 if (!__check_latch(port, val))
110 * __device_refresh - request a refresh from the accelerometer. Does not wait
111 * for refresh to complete. Callers must hold hdaps_sem.
113 static void __device_refresh(void)
116 if (inb(0x1604) != STATE_FRESH) {
123 * __device_refresh_sync - request a synchronous refresh from the
124 * accelerometer. We wait for the refresh to complete. Returns zero if
125 * successful and nonzero on error. Callers must hold hdaps_sem.
127 static int __device_refresh_sync(void)
130 return __wait_latch(0x1604, STATE_FRESH);
134 * __device_complete - indicate to the accelerometer that we are done reading
135 * data, and then initiate an async refresh. Callers must hold hdaps_sem.
137 static inline void __device_complete(void)
145 * hdaps_readb_one - reads a byte from a single I/O port, placing the value in
146 * the given pointer. Returns zero on success or a negative error on failure.
149 static int hdaps_readb_one(unsigned int port, u8 *val)
155 /* do a sync refresh -- we need to be sure that we read fresh data */
156 ret = __device_refresh_sync();
168 /* __hdaps_read_pair - internal lockless helper for hdaps_read_pair(). */
169 static int __hdaps_read_pair(unsigned int port1, unsigned int port2,
172 /* do a sync refresh -- we need to be sure that we read fresh data */
173 if (__device_refresh_sync())
178 km_activity = inb(HDAPS_PORT_KMACT);
181 /* if hdaps_invert is set, negate the two values */
191 * hdaps_read_pair - reads the values from a pair of ports, placing the values
192 * in the given pointers. Returns zero on success. Can sleep.
194 static int hdaps_read_pair(unsigned int port1, unsigned int port2,
195 int *val1, int *val2)
200 ret = __hdaps_read_pair(port1, port2, val1, val2);
207 * hdaps_device_init - initialize the accelerometer. Returns zero on success
208 * and negative error code on failure. Can sleep.
210 static int hdaps_device_init(void)
212 int total, ret = -ENXIO;
218 if (__wait_latch(0x161f, 0x00))
222 * Most ThinkPads return 0x01.
224 * Others--namely the R50p, T41p, and T42p--return 0x03. These laptops
225 * have "inverted" axises.
227 * The 0x02 value occurs when the chip has been previously initialized.
229 if (__check_latch(0x1611, 0x03) &&
230 __check_latch(0x1611, 0x02) &&
231 __check_latch(0x1611, 0x01))
234 printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x).\n",
235 __get_latch(0x1611));
240 if (__wait_latch(0x161f, 0x00))
242 if (__wait_latch(0x1611, 0x00))
244 if (__wait_latch(0x1612, 0x60))
246 if (__wait_latch(0x1613, 0x00))
251 if (__wait_latch(0x161f, 0x00))
258 if (__wait_latch(0x161f, 0x00))
260 if (__device_refresh_sync())
262 if (__wait_latch(0x1611, 0x00))
265 /* we have done our dance, now let's wait for the applause */
266 for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
269 /* a read of the device helps push it into action */
270 __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
271 if (!__wait_latch(0x1611, 0x02)) {
276 msleep(INIT_WAIT_MSECS);
285 /* Device model stuff */
287 static int hdaps_probe(struct platform_device *dev)
291 ret = hdaps_device_init();
295 printk(KERN_INFO "hdaps: device successfully initialized.\n");
299 static int hdaps_resume(struct platform_device *dev)
301 return hdaps_device_init();
304 static struct platform_driver hdaps_driver = {
305 .probe = hdaps_probe,
306 .resume = hdaps_resume,
309 .owner = THIS_MODULE,
313 /* Input class stuff */
315 static struct input_dev hdaps_idev = {
317 .evbit = { BIT(EV_ABS) },
318 .absbit = { BIT(ABS_X) | BIT(ABS_Y) },
319 .absmin = { [ABS_X] = -256, [ABS_Y] = -256 },
320 .absmax = { [ABS_X] = 256, [ABS_Y] = 256 },
321 .absfuzz = { [ABS_X] = HDAPS_INPUT_FUZZ, [ABS_Y] = HDAPS_INPUT_FUZZ },
322 .absflat = { [ABS_X] = HDAPS_INPUT_FUZZ, [ABS_Y] = HDAPS_INPUT_FUZZ },
326 * hdaps_calibrate - Set our "resting" values. Callers must hold hdaps_sem.
328 static void hdaps_calibrate(void)
330 __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &rest_x, &rest_y);
333 static void hdaps_mousedev_poll(unsigned long unused)
337 /* Cannot sleep. Try nonblockingly. If we fail, try again later. */
338 if (down_trylock(&hdaps_sem)) {
339 mod_timer(&hdaps_timer,jiffies + HDAPS_POLL_PERIOD);
343 if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
346 input_report_abs(&hdaps_idev, ABS_X, x - rest_x);
347 input_report_abs(&hdaps_idev, ABS_Y, y - rest_y);
348 input_sync(&hdaps_idev);
350 mod_timer(&hdaps_timer, jiffies + HDAPS_POLL_PERIOD);
359 static ssize_t hdaps_position_show(struct device *dev,
360 struct device_attribute *attr, char *buf)
364 ret = hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
368 return sprintf(buf, "(%d,%d)\n", x, y);
371 static ssize_t hdaps_variance_show(struct device *dev,
372 struct device_attribute *attr, char *buf)
376 ret = hdaps_read_pair(HDAPS_PORT_XVAR, HDAPS_PORT_YVAR, &x, &y);
380 return sprintf(buf, "(%d,%d)\n", x, y);
383 static ssize_t hdaps_temp1_show(struct device *dev,
384 struct device_attribute *attr, char *buf)
389 ret = hdaps_readb_one(HDAPS_PORT_TEMP1, &temp);
393 return sprintf(buf, "%u\n", temp);
396 static ssize_t hdaps_temp2_show(struct device *dev,
397 struct device_attribute *attr, char *buf)
402 ret = hdaps_readb_one(HDAPS_PORT_TEMP2, &temp);
406 return sprintf(buf, "%u\n", temp);
409 static ssize_t hdaps_keyboard_activity_show(struct device *dev,
410 struct device_attribute *attr,
413 return sprintf(buf, "%u\n", KEYBD_ISSET(km_activity));
416 static ssize_t hdaps_mouse_activity_show(struct device *dev,
417 struct device_attribute *attr,
420 return sprintf(buf, "%u\n", MOUSE_ISSET(km_activity));
423 static ssize_t hdaps_calibrate_show(struct device *dev,
424 struct device_attribute *attr, char *buf)
426 return sprintf(buf, "(%d,%d)\n", rest_x, rest_y);
429 static ssize_t hdaps_calibrate_store(struct device *dev,
430 struct device_attribute *attr,
431 const char *buf, size_t count)
440 static ssize_t hdaps_invert_show(struct device *dev,
441 struct device_attribute *attr, char *buf)
443 return sprintf(buf, "%u\n", hdaps_invert);
446 static ssize_t hdaps_invert_store(struct device *dev,
447 struct device_attribute *attr,
448 const char *buf, size_t count)
452 if (sscanf(buf, "%d", &invert) != 1 || (invert != 1 && invert != 0))
455 hdaps_invert = invert;
461 static DEVICE_ATTR(position, 0444, hdaps_position_show, NULL);
462 static DEVICE_ATTR(variance, 0444, hdaps_variance_show, NULL);
463 static DEVICE_ATTR(temp1, 0444, hdaps_temp1_show, NULL);
464 static DEVICE_ATTR(temp2, 0444, hdaps_temp2_show, NULL);
465 static DEVICE_ATTR(keyboard_activity, 0444, hdaps_keyboard_activity_show, NULL);
466 static DEVICE_ATTR(mouse_activity, 0444, hdaps_mouse_activity_show, NULL);
467 static DEVICE_ATTR(calibrate, 0644, hdaps_calibrate_show,hdaps_calibrate_store);
468 static DEVICE_ATTR(invert, 0644, hdaps_invert_show, hdaps_invert_store);
470 static struct attribute *hdaps_attributes[] = {
471 &dev_attr_position.attr,
472 &dev_attr_variance.attr,
473 &dev_attr_temp1.attr,
474 &dev_attr_temp2.attr,
475 &dev_attr_keyboard_activity.attr,
476 &dev_attr_mouse_activity.attr,
477 &dev_attr_calibrate.attr,
478 &dev_attr_invert.attr,
482 static struct attribute_group hdaps_attribute_group = {
483 .attrs = hdaps_attributes,
489 /* hdaps_dmi_match - found a match. return one, short-circuiting the hunt. */
490 static int hdaps_dmi_match(struct dmi_system_id *id)
492 printk(KERN_INFO "hdaps: %s detected.\n", id->ident);
496 /* hdaps_dmi_match_invert - found an inverted match. */
497 static int hdaps_dmi_match_invert(struct dmi_system_id *id)
500 printk(KERN_INFO "hdaps: inverting axis readings.\n");
501 return hdaps_dmi_match(id);
504 #define HDAPS_DMI_MATCH_NORMAL(model) { \
505 .ident = "IBM " model, \
506 .callback = hdaps_dmi_match, \
508 DMI_MATCH(DMI_BOARD_VENDOR, "IBM"), \
509 DMI_MATCH(DMI_PRODUCT_VERSION, model) \
513 #define HDAPS_DMI_MATCH_INVERT(model) { \
514 .ident = "IBM " model, \
515 .callback = hdaps_dmi_match_invert, \
517 DMI_MATCH(DMI_BOARD_VENDOR, "IBM"), \
518 DMI_MATCH(DMI_PRODUCT_VERSION, model) \
522 static int __init hdaps_init(void)
526 /* Note that DMI_MATCH(...,"ThinkPad T42") will match "ThinkPad T42p" */
527 struct dmi_system_id hdaps_whitelist[] = {
528 HDAPS_DMI_MATCH_INVERT("ThinkPad R50p"),
529 HDAPS_DMI_MATCH_NORMAL("ThinkPad R50"),
530 HDAPS_DMI_MATCH_NORMAL("ThinkPad R51"),
531 HDAPS_DMI_MATCH_NORMAL("ThinkPad R52"),
532 HDAPS_DMI_MATCH_INVERT("ThinkPad T41p"),
533 HDAPS_DMI_MATCH_NORMAL("ThinkPad T41"),
534 HDAPS_DMI_MATCH_INVERT("ThinkPad T42p"),
535 HDAPS_DMI_MATCH_NORMAL("ThinkPad T42"),
536 HDAPS_DMI_MATCH_NORMAL("ThinkPad T43"),
537 HDAPS_DMI_MATCH_NORMAL("ThinkPad X40"),
538 HDAPS_DMI_MATCH_NORMAL("ThinkPad X41 Tablet"),
539 HDAPS_DMI_MATCH_NORMAL("ThinkPad X41"),
543 if (!dmi_check_system(hdaps_whitelist)) {
544 printk(KERN_WARNING "hdaps: supported laptop not found!\n");
549 if (!request_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS, "hdaps")) {
554 ret = platform_driver_register(&hdaps_driver);
558 pdev = platform_device_register_simple("hdaps", -1, NULL, 0);
564 ret = sysfs_create_group(&pdev->dev.kobj, &hdaps_attribute_group);
568 /* initial calibrate for the input device */
571 /* initialize the input class */
572 hdaps_idev.dev = &pdev->dev;
573 input_register_device(&hdaps_idev);
575 /* start up our timer for the input device */
576 init_timer(&hdaps_timer);
577 hdaps_timer.function = hdaps_mousedev_poll;
578 hdaps_timer.expires = jiffies + HDAPS_POLL_PERIOD;
579 add_timer(&hdaps_timer);
581 printk(KERN_INFO "hdaps: driver successfully loaded.\n");
585 platform_device_unregister(pdev);
587 platform_driver_unregister(&hdaps_driver);
589 release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
591 printk(KERN_WARNING "hdaps: driver init failed (ret=%d)!\n", ret);
595 static void __exit hdaps_exit(void)
597 del_timer_sync(&hdaps_timer);
598 input_unregister_device(&hdaps_idev);
599 sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
600 platform_device_unregister(pdev);
601 platform_driver_unregister(&hdaps_driver);
602 release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
604 printk(KERN_INFO "hdaps: driver unloaded.\n");
607 module_init(hdaps_init);
608 module_exit(hdaps_exit);
610 module_param_named(invert, hdaps_invert, bool, 0);
611 MODULE_PARM_DESC(invert, "invert data along each axis");
613 MODULE_AUTHOR("Robert Love");
614 MODULE_DESCRIPTION("IBM Hard Drive Active Protection System (HDAPS) driver");
615 MODULE_LICENSE("GPL v2");