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 */
63 #define HDAPS_INPUT_FLAT 4
65 static struct timer_list hdaps_timer;
66 static struct platform_device *pdev;
67 static struct input_dev *hdaps_idev;
68 static unsigned int hdaps_invert;
69 static u8 km_activity;
73 static DECLARE_MUTEX(hdaps_sem);
76 * __get_latch - Get the value from a given port. Callers must hold hdaps_sem.
78 static inline u8 __get_latch(u16 port)
80 return inb(port) & 0xff;
84 * __check_latch - Check a port latch for a given value. Returns zero if the
85 * port contains the given value. Callers must hold hdaps_sem.
87 static inline int __check_latch(u16 port, u8 val)
89 if (__get_latch(port) == val)
95 * __wait_latch - Wait up to 100us for a port latch to get a certain value,
96 * returning zero if the value is obtained. Callers must hold hdaps_sem.
98 static int __wait_latch(u16 port, u8 val)
102 for (i = 0; i < 20; i++) {
103 if (!__check_latch(port, val))
112 * __device_refresh - request a refresh from the accelerometer. Does not wait
113 * for refresh to complete. Callers must hold hdaps_sem.
115 static void __device_refresh(void)
118 if (inb(0x1604) != STATE_FRESH) {
125 * __device_refresh_sync - request a synchronous refresh from the
126 * accelerometer. We wait for the refresh to complete. Returns zero if
127 * successful and nonzero on error. Callers must hold hdaps_sem.
129 static int __device_refresh_sync(void)
132 return __wait_latch(0x1604, STATE_FRESH);
136 * __device_complete - indicate to the accelerometer that we are done reading
137 * data, and then initiate an async refresh. Callers must hold hdaps_sem.
139 static inline void __device_complete(void)
147 * hdaps_readb_one - reads a byte from a single I/O port, placing the value in
148 * the given pointer. Returns zero on success or a negative error on failure.
151 static int hdaps_readb_one(unsigned int port, u8 *val)
157 /* do a sync refresh -- we need to be sure that we read fresh data */
158 ret = __device_refresh_sync();
170 /* __hdaps_read_pair - internal lockless helper for hdaps_read_pair(). */
171 static int __hdaps_read_pair(unsigned int port1, unsigned int port2,
174 /* do a sync refresh -- we need to be sure that we read fresh data */
175 if (__device_refresh_sync())
180 km_activity = inb(HDAPS_PORT_KMACT);
183 /* if hdaps_invert is set, negate the two values */
193 * hdaps_read_pair - reads the values from a pair of ports, placing the values
194 * in the given pointers. Returns zero on success. Can sleep.
196 static int hdaps_read_pair(unsigned int port1, unsigned int port2,
197 int *val1, int *val2)
202 ret = __hdaps_read_pair(port1, port2, val1, val2);
209 * hdaps_device_init - initialize the accelerometer. Returns zero on success
210 * and negative error code on failure. Can sleep.
212 static int hdaps_device_init(void)
214 int total, ret = -ENXIO;
220 if (__wait_latch(0x161f, 0x00))
224 * Most ThinkPads return 0x01.
226 * Others--namely the R50p, T41p, and T42p--return 0x03. These laptops
227 * have "inverted" axises.
229 * The 0x02 value occurs when the chip has been previously initialized.
231 if (__check_latch(0x1611, 0x03) &&
232 __check_latch(0x1611, 0x02) &&
233 __check_latch(0x1611, 0x01))
236 printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x).\n",
237 __get_latch(0x1611));
242 if (__wait_latch(0x161f, 0x00))
244 if (__wait_latch(0x1611, 0x00))
246 if (__wait_latch(0x1612, 0x60))
248 if (__wait_latch(0x1613, 0x00))
253 if (__wait_latch(0x161f, 0x00))
260 if (__wait_latch(0x161f, 0x00))
262 if (__device_refresh_sync())
264 if (__wait_latch(0x1611, 0x00))
267 /* we have done our dance, now let's wait for the applause */
268 for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
271 /* a read of the device helps push it into action */
272 __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
273 if (!__wait_latch(0x1611, 0x02)) {
278 msleep(INIT_WAIT_MSECS);
287 /* Device model stuff */
289 static int hdaps_probe(struct platform_device *dev)
293 ret = hdaps_device_init();
297 printk(KERN_INFO "hdaps: device successfully initialized.\n");
301 static int hdaps_resume(struct platform_device *dev)
303 return hdaps_device_init();
306 static struct platform_driver hdaps_driver = {
307 .probe = hdaps_probe,
308 .resume = hdaps_resume,
311 .owner = THIS_MODULE,
316 * hdaps_calibrate - Set our "resting" values. Callers must hold hdaps_sem.
318 static void hdaps_calibrate(void)
320 __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &rest_x, &rest_y);
323 static void hdaps_mousedev_poll(unsigned long unused)
327 /* Cannot sleep. Try nonblockingly. If we fail, try again later. */
328 if (down_trylock(&hdaps_sem)) {
329 mod_timer(&hdaps_timer,jiffies + HDAPS_POLL_PERIOD);
333 if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
336 input_report_abs(hdaps_idev, ABS_X, x - rest_x);
337 input_report_abs(hdaps_idev, ABS_Y, y - rest_y);
338 input_sync(hdaps_idev);
340 mod_timer(&hdaps_timer, jiffies + HDAPS_POLL_PERIOD);
349 static ssize_t hdaps_position_show(struct device *dev,
350 struct device_attribute *attr, char *buf)
354 ret = hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
358 return sprintf(buf, "(%d,%d)\n", x, y);
361 static ssize_t hdaps_variance_show(struct device *dev,
362 struct device_attribute *attr, char *buf)
366 ret = hdaps_read_pair(HDAPS_PORT_XVAR, HDAPS_PORT_YVAR, &x, &y);
370 return sprintf(buf, "(%d,%d)\n", x, y);
373 static ssize_t hdaps_temp1_show(struct device *dev,
374 struct device_attribute *attr, char *buf)
379 ret = hdaps_readb_one(HDAPS_PORT_TEMP1, &temp);
383 return sprintf(buf, "%u\n", temp);
386 static ssize_t hdaps_temp2_show(struct device *dev,
387 struct device_attribute *attr, char *buf)
392 ret = hdaps_readb_one(HDAPS_PORT_TEMP2, &temp);
396 return sprintf(buf, "%u\n", temp);
399 static ssize_t hdaps_keyboard_activity_show(struct device *dev,
400 struct device_attribute *attr,
403 return sprintf(buf, "%u\n", KEYBD_ISSET(km_activity));
406 static ssize_t hdaps_mouse_activity_show(struct device *dev,
407 struct device_attribute *attr,
410 return sprintf(buf, "%u\n", MOUSE_ISSET(km_activity));
413 static ssize_t hdaps_calibrate_show(struct device *dev,
414 struct device_attribute *attr, char *buf)
416 return sprintf(buf, "(%d,%d)\n", rest_x, rest_y);
419 static ssize_t hdaps_calibrate_store(struct device *dev,
420 struct device_attribute *attr,
421 const char *buf, size_t count)
430 static ssize_t hdaps_invert_show(struct device *dev,
431 struct device_attribute *attr, char *buf)
433 return sprintf(buf, "%u\n", hdaps_invert);
436 static ssize_t hdaps_invert_store(struct device *dev,
437 struct device_attribute *attr,
438 const char *buf, size_t count)
442 if (sscanf(buf, "%d", &invert) != 1 || (invert != 1 && invert != 0))
445 hdaps_invert = invert;
451 static DEVICE_ATTR(position, 0444, hdaps_position_show, NULL);
452 static DEVICE_ATTR(variance, 0444, hdaps_variance_show, NULL);
453 static DEVICE_ATTR(temp1, 0444, hdaps_temp1_show, NULL);
454 static DEVICE_ATTR(temp2, 0444, hdaps_temp2_show, NULL);
455 static DEVICE_ATTR(keyboard_activity, 0444, hdaps_keyboard_activity_show, NULL);
456 static DEVICE_ATTR(mouse_activity, 0444, hdaps_mouse_activity_show, NULL);
457 static DEVICE_ATTR(calibrate, 0644, hdaps_calibrate_show,hdaps_calibrate_store);
458 static DEVICE_ATTR(invert, 0644, hdaps_invert_show, hdaps_invert_store);
460 static struct attribute *hdaps_attributes[] = {
461 &dev_attr_position.attr,
462 &dev_attr_variance.attr,
463 &dev_attr_temp1.attr,
464 &dev_attr_temp2.attr,
465 &dev_attr_keyboard_activity.attr,
466 &dev_attr_mouse_activity.attr,
467 &dev_attr_calibrate.attr,
468 &dev_attr_invert.attr,
472 static struct attribute_group hdaps_attribute_group = {
473 .attrs = hdaps_attributes,
479 /* hdaps_dmi_match - found a match. return one, short-circuiting the hunt. */
480 static int hdaps_dmi_match(struct dmi_system_id *id)
482 printk(KERN_INFO "hdaps: %s detected.\n", id->ident);
486 /* hdaps_dmi_match_invert - found an inverted match. */
487 static int hdaps_dmi_match_invert(struct dmi_system_id *id)
490 printk(KERN_INFO "hdaps: inverting axis readings.\n");
491 return hdaps_dmi_match(id);
494 #define HDAPS_DMI_MATCH_NORMAL(model) { \
495 .ident = "IBM " model, \
496 .callback = hdaps_dmi_match, \
498 DMI_MATCH(DMI_BOARD_VENDOR, "IBM"), \
499 DMI_MATCH(DMI_PRODUCT_VERSION, model) \
503 #define HDAPS_DMI_MATCH_INVERT(model) { \
504 .ident = "IBM " model, \
505 .callback = hdaps_dmi_match_invert, \
507 DMI_MATCH(DMI_BOARD_VENDOR, "IBM"), \
508 DMI_MATCH(DMI_PRODUCT_VERSION, model) \
512 static int __init hdaps_init(void)
516 /* Note that DMI_MATCH(...,"ThinkPad T42") will match "ThinkPad T42p" */
517 struct dmi_system_id hdaps_whitelist[] = {
518 HDAPS_DMI_MATCH_INVERT("ThinkPad R50p"),
519 HDAPS_DMI_MATCH_NORMAL("ThinkPad R50"),
520 HDAPS_DMI_MATCH_NORMAL("ThinkPad R51"),
521 HDAPS_DMI_MATCH_NORMAL("ThinkPad R52"),
522 HDAPS_DMI_MATCH_INVERT("ThinkPad T41p"),
523 HDAPS_DMI_MATCH_NORMAL("ThinkPad T41"),
524 HDAPS_DMI_MATCH_INVERT("ThinkPad T42p"),
525 HDAPS_DMI_MATCH_NORMAL("ThinkPad T42"),
526 HDAPS_DMI_MATCH_NORMAL("ThinkPad T43"),
527 HDAPS_DMI_MATCH_NORMAL("ThinkPad X40"),
528 HDAPS_DMI_MATCH_NORMAL("ThinkPad X41 Tablet"),
529 HDAPS_DMI_MATCH_NORMAL("ThinkPad X41"),
533 if (!dmi_check_system(hdaps_whitelist)) {
534 printk(KERN_WARNING "hdaps: supported laptop not found!\n");
539 if (!request_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS, "hdaps")) {
544 ret = platform_driver_register(&hdaps_driver);
548 pdev = platform_device_register_simple("hdaps", -1, NULL, 0);
554 ret = sysfs_create_group(&pdev->dev.kobj, &hdaps_attribute_group);
558 hdaps_idev = input_allocate_device();
564 /* initial calibrate for the input device */
567 /* initialize the input class */
568 hdaps_idev->name = "hdaps";
569 hdaps_idev->cdev.dev = &pdev->dev;
570 hdaps_idev->evbit[0] = BIT(EV_ABS);
571 input_set_abs_params(hdaps_idev, ABS_X,
572 -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
573 input_set_abs_params(hdaps_idev, ABS_Y,
574 -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
576 input_register_device(hdaps_idev);
578 /* start up our timer for the input device */
579 init_timer(&hdaps_timer);
580 hdaps_timer.function = hdaps_mousedev_poll;
581 hdaps_timer.expires = jiffies + HDAPS_POLL_PERIOD;
582 add_timer(&hdaps_timer);
584 printk(KERN_INFO "hdaps: driver successfully loaded.\n");
588 sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
590 platform_device_unregister(pdev);
592 platform_driver_unregister(&hdaps_driver);
594 release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
596 printk(KERN_WARNING "hdaps: driver init failed (ret=%d)!\n", ret);
600 static void __exit hdaps_exit(void)
602 del_timer_sync(&hdaps_timer);
603 input_unregister_device(hdaps_idev);
604 sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
605 platform_device_unregister(pdev);
606 platform_driver_unregister(&hdaps_driver);
607 release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
609 printk(KERN_INFO "hdaps: driver unloaded.\n");
612 module_init(hdaps_init);
613 module_exit(hdaps_exit);
615 module_param_named(invert, hdaps_invert, bool, 0);
616 MODULE_PARM_DESC(invert, "invert data along each axis");
618 MODULE_AUTHOR("Robert Love");
619 MODULE_DESCRIPTION("IBM Hard Drive Active Protection System (HDAPS) driver");
620 MODULE_LICENSE("GPL v2");