parport: remove superfluous local variable
[linux-2.6] / drivers / hwmon / hdaps.c
1 /*
2  * drivers/hwmon/hdaps.c - driver for IBM's Hard Drive Active Protection System
3  *
4  * Copyright (C) 2005 Robert Love <rml@novell.com>
5  * Copyright (C) 2005 Jesper Juhl <jesper.juhl@gmail.com>
6  *
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.
10  *
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
13  * and error.
14  *
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.
18  *
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
22  * more details.
23  *
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
27  */
28
29 #include <linux/delay.h>
30 #include <linux/platform_device.h>
31 #include <linux/input-polldev.h>
32 #include <linux/kernel.h>
33 #include <linux/mutex.h>
34 #include <linux/module.h>
35 #include <linux/timer.h>
36 #include <linux/dmi.h>
37 #include <linux/jiffies.h>
38
39 #include <asm/io.h>
40
41 #define HDAPS_LOW_PORT          0x1600  /* first port used by hdaps */
42 #define HDAPS_NR_PORTS          0x30    /* number of ports: 0x1600 - 0x162f */
43
44 #define HDAPS_PORT_STATE        0x1611  /* device state */
45 #define HDAPS_PORT_YPOS         0x1612  /* y-axis position */
46 #define HDAPS_PORT_XPOS         0x1614  /* x-axis position */
47 #define HDAPS_PORT_TEMP1        0x1616  /* device temperature, in Celsius */
48 #define HDAPS_PORT_YVAR         0x1617  /* y-axis variance (what is this?) */
49 #define HDAPS_PORT_XVAR         0x1619  /* x-axis variance (what is this?) */
50 #define HDAPS_PORT_TEMP2        0x161b  /* device temperature (again?) */
51 #define HDAPS_PORT_UNKNOWN      0x161c  /* what is this? */
52 #define HDAPS_PORT_KMACT        0x161d  /* keyboard or mouse activity */
53
54 #define STATE_FRESH             0x50    /* accelerometer data is fresh */
55
56 #define KEYBD_MASK              0x20    /* set if keyboard activity */
57 #define MOUSE_MASK              0x40    /* set if mouse activity */
58 #define KEYBD_ISSET(n)          (!! (n & KEYBD_MASK))   /* keyboard used? */
59 #define MOUSE_ISSET(n)          (!! (n & MOUSE_MASK))   /* mouse used? */
60
61 #define INIT_TIMEOUT_MSECS      4000    /* wait up to 4s for device init ... */
62 #define INIT_WAIT_MSECS         200     /* ... in 200ms increments */
63
64 #define HDAPS_POLL_INTERVAL     50      /* poll for input every 1/20s (50 ms)*/
65 #define HDAPS_INPUT_FUZZ        4       /* input event threshold */
66 #define HDAPS_INPUT_FLAT        4
67
68 static struct platform_device *pdev;
69 static struct input_polled_dev *hdaps_idev;
70 static unsigned int hdaps_invert;
71 static u8 km_activity;
72 static int rest_x;
73 static int rest_y;
74
75 static DEFINE_MUTEX(hdaps_mtx);
76
77 /*
78  * __get_latch - Get the value from a given port.  Callers must hold hdaps_mtx.
79  */
80 static inline u8 __get_latch(u16 port)
81 {
82         return inb(port) & 0xff;
83 }
84
85 /*
86  * __check_latch - Check a port latch for a given value.  Returns zero if the
87  * port contains the given value.  Callers must hold hdaps_mtx.
88  */
89 static inline int __check_latch(u16 port, u8 val)
90 {
91         if (__get_latch(port) == val)
92                 return 0;
93         return -EINVAL;
94 }
95
96 /*
97  * __wait_latch - Wait up to 100us for a port latch to get a certain value,
98  * returning zero if the value is obtained.  Callers must hold hdaps_mtx.
99  */
100 static int __wait_latch(u16 port, u8 val)
101 {
102         unsigned int i;
103
104         for (i = 0; i < 20; i++) {
105                 if (!__check_latch(port, val))
106                         return 0;
107                 udelay(5);
108         }
109
110         return -EIO;
111 }
112
113 /*
114  * __device_refresh - request a refresh from the accelerometer.  Does not wait
115  * for refresh to complete.  Callers must hold hdaps_mtx.
116  */
117 static void __device_refresh(void)
118 {
119         udelay(200);
120         if (inb(0x1604) != STATE_FRESH) {
121                 outb(0x11, 0x1610);
122                 outb(0x01, 0x161f);
123         }
124 }
125
126 /*
127  * __device_refresh_sync - request a synchronous refresh from the
128  * accelerometer.  We wait for the refresh to complete.  Returns zero if
129  * successful and nonzero on error.  Callers must hold hdaps_mtx.
130  */
131 static int __device_refresh_sync(void)
132 {
133         __device_refresh();
134         return __wait_latch(0x1604, STATE_FRESH);
135 }
136
137 /*
138  * __device_complete - indicate to the accelerometer that we are done reading
139  * data, and then initiate an async refresh.  Callers must hold hdaps_mtx.
140  */
141 static inline void __device_complete(void)
142 {
143         inb(0x161f);
144         inb(0x1604);
145         __device_refresh();
146 }
147
148 /*
149  * hdaps_readb_one - reads a byte from a single I/O port, placing the value in
150  * the given pointer.  Returns zero on success or a negative error on failure.
151  * Can sleep.
152  */
153 static int hdaps_readb_one(unsigned int port, u8 *val)
154 {
155         int ret;
156
157         mutex_lock(&hdaps_mtx);
158
159         /* do a sync refresh -- we need to be sure that we read fresh data */
160         ret = __device_refresh_sync();
161         if (ret)
162                 goto out;
163
164         *val = inb(port);
165         __device_complete();
166
167 out:
168         mutex_unlock(&hdaps_mtx);
169         return ret;
170 }
171
172 /* __hdaps_read_pair - internal lockless helper for hdaps_read_pair(). */
173 static int __hdaps_read_pair(unsigned int port1, unsigned int port2,
174                              int *x, int *y)
175 {
176         /* do a sync refresh -- we need to be sure that we read fresh data */
177         if (__device_refresh_sync())
178                 return -EIO;
179
180         *y = inw(port2);
181         *x = inw(port1);
182         km_activity = inb(HDAPS_PORT_KMACT);
183         __device_complete();
184
185         /* if hdaps_invert is set, negate the two values */
186         if (hdaps_invert) {
187                 *x = -*x;
188                 *y = -*y;
189         }
190
191         return 0;
192 }
193
194 /*
195  * hdaps_read_pair - reads the values from a pair of ports, placing the values
196  * in the given pointers.  Returns zero on success.  Can sleep.
197  */
198 static int hdaps_read_pair(unsigned int port1, unsigned int port2,
199                            int *val1, int *val2)
200 {
201         int ret;
202
203         mutex_lock(&hdaps_mtx);
204         ret = __hdaps_read_pair(port1, port2, val1, val2);
205         mutex_unlock(&hdaps_mtx);
206
207         return ret;
208 }
209
210 /*
211  * hdaps_device_init - initialize the accelerometer.  Returns zero on success
212  * and negative error code on failure.  Can sleep.
213  */
214 static int hdaps_device_init(void)
215 {
216         int total, ret = -ENXIO;
217
218         mutex_lock(&hdaps_mtx);
219
220         outb(0x13, 0x1610);
221         outb(0x01, 0x161f);
222         if (__wait_latch(0x161f, 0x00))
223                 goto out;
224
225         /*
226          * Most ThinkPads return 0x01.
227          *
228          * Others--namely the R50p, T41p, and T42p--return 0x03.  These laptops
229          * have "inverted" axises.
230          *
231          * The 0x02 value occurs when the chip has been previously initialized.
232          */
233         if (__check_latch(0x1611, 0x03) &&
234                      __check_latch(0x1611, 0x02) &&
235                      __check_latch(0x1611, 0x01))
236                 goto out;
237
238         printk(KERN_DEBUG "hdaps: initial latch check good (0x%02x).\n",
239                __get_latch(0x1611));
240
241         outb(0x17, 0x1610);
242         outb(0x81, 0x1611);
243         outb(0x01, 0x161f);
244         if (__wait_latch(0x161f, 0x00))
245                 goto out;
246         if (__wait_latch(0x1611, 0x00))
247                 goto out;
248         if (__wait_latch(0x1612, 0x60))
249                 goto out;
250         if (__wait_latch(0x1613, 0x00))
251                 goto out;
252         outb(0x14, 0x1610);
253         outb(0x01, 0x1611);
254         outb(0x01, 0x161f);
255         if (__wait_latch(0x161f, 0x00))
256                 goto out;
257         outb(0x10, 0x1610);
258         outb(0xc8, 0x1611);
259         outb(0x00, 0x1612);
260         outb(0x02, 0x1613);
261         outb(0x01, 0x161f);
262         if (__wait_latch(0x161f, 0x00))
263                 goto out;
264         if (__device_refresh_sync())
265                 goto out;
266         if (__wait_latch(0x1611, 0x00))
267                 goto out;
268
269         /* we have done our dance, now let's wait for the applause */
270         for (total = INIT_TIMEOUT_MSECS; total > 0; total -= INIT_WAIT_MSECS) {
271                 int x, y;
272
273                 /* a read of the device helps push it into action */
274                 __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
275                 if (!__wait_latch(0x1611, 0x02)) {
276                         ret = 0;
277                         break;
278                 }
279
280                 msleep(INIT_WAIT_MSECS);
281         }
282
283 out:
284         mutex_unlock(&hdaps_mtx);
285         return ret;
286 }
287
288
289 /* Device model stuff */
290
291 static int hdaps_probe(struct platform_device *dev)
292 {
293         int ret;
294
295         ret = hdaps_device_init();
296         if (ret)
297                 return ret;
298
299         printk(KERN_INFO "hdaps: device successfully initialized.\n");
300         return 0;
301 }
302
303 static int hdaps_resume(struct platform_device *dev)
304 {
305         return hdaps_device_init();
306 }
307
308 static struct platform_driver hdaps_driver = {
309         .probe = hdaps_probe,
310         .resume = hdaps_resume,
311         .driver = {
312                 .name = "hdaps",
313                 .owner = THIS_MODULE,
314         },
315 };
316
317 /*
318  * hdaps_calibrate - Set our "resting" values.  Callers must hold hdaps_mtx.
319  */
320 static void hdaps_calibrate(void)
321 {
322         __hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &rest_x, &rest_y);
323 }
324
325 static void hdaps_mousedev_poll(struct input_polled_dev *dev)
326 {
327         struct input_dev *input_dev = dev->input;
328         int x, y;
329
330         mutex_lock(&hdaps_mtx);
331
332         if (__hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y))
333                 goto out;
334
335         input_report_abs(input_dev, ABS_X, x - rest_x);
336         input_report_abs(input_dev, ABS_Y, y - rest_y);
337         input_sync(input_dev);
338
339 out:
340         mutex_unlock(&hdaps_mtx);
341 }
342
343
344 /* Sysfs Files */
345
346 static ssize_t hdaps_position_show(struct device *dev,
347                                    struct device_attribute *attr, char *buf)
348 {
349         int ret, x, y;
350
351         ret = hdaps_read_pair(HDAPS_PORT_XPOS, HDAPS_PORT_YPOS, &x, &y);
352         if (ret)
353                 return ret;
354
355         return sprintf(buf, "(%d,%d)\n", x, y);
356 }
357
358 static ssize_t hdaps_variance_show(struct device *dev,
359                                    struct device_attribute *attr, char *buf)
360 {
361         int ret, x, y;
362
363         ret = hdaps_read_pair(HDAPS_PORT_XVAR, HDAPS_PORT_YVAR, &x, &y);
364         if (ret)
365                 return ret;
366
367         return sprintf(buf, "(%d,%d)\n", x, y);
368 }
369
370 static ssize_t hdaps_temp1_show(struct device *dev,
371                                 struct device_attribute *attr, char *buf)
372 {
373         u8 temp;
374         int ret;
375
376         ret = hdaps_readb_one(HDAPS_PORT_TEMP1, &temp);
377         if (ret < 0)
378                 return ret;
379
380         return sprintf(buf, "%u\n", temp);
381 }
382
383 static ssize_t hdaps_temp2_show(struct device *dev,
384                                 struct device_attribute *attr, char *buf)
385 {
386         u8 temp;
387         int ret;
388
389         ret = hdaps_readb_one(HDAPS_PORT_TEMP2, &temp);
390         if (ret < 0)
391                 return ret;
392
393         return sprintf(buf, "%u\n", temp);
394 }
395
396 static ssize_t hdaps_keyboard_activity_show(struct device *dev,
397                                             struct device_attribute *attr,
398                                             char *buf)
399 {
400         return sprintf(buf, "%u\n", KEYBD_ISSET(km_activity));
401 }
402
403 static ssize_t hdaps_mouse_activity_show(struct device *dev,
404                                          struct device_attribute *attr,
405                                          char *buf)
406 {
407         return sprintf(buf, "%u\n", MOUSE_ISSET(km_activity));
408 }
409
410 static ssize_t hdaps_calibrate_show(struct device *dev,
411                                     struct device_attribute *attr, char *buf)
412 {
413         return sprintf(buf, "(%d,%d)\n", rest_x, rest_y);
414 }
415
416 static ssize_t hdaps_calibrate_store(struct device *dev,
417                                      struct device_attribute *attr,
418                                      const char *buf, size_t count)
419 {
420         mutex_lock(&hdaps_mtx);
421         hdaps_calibrate();
422         mutex_unlock(&hdaps_mtx);
423
424         return count;
425 }
426
427 static ssize_t hdaps_invert_show(struct device *dev,
428                                  struct device_attribute *attr, char *buf)
429 {
430         return sprintf(buf, "%u\n", hdaps_invert);
431 }
432
433 static ssize_t hdaps_invert_store(struct device *dev,
434                                   struct device_attribute *attr,
435                                   const char *buf, size_t count)
436 {
437         int invert;
438
439         if (sscanf(buf, "%d", &invert) != 1 || (invert != 1 && invert != 0))
440                 return -EINVAL;
441
442         hdaps_invert = invert;
443         hdaps_calibrate();
444
445         return count;
446 }
447
448 static DEVICE_ATTR(position, 0444, hdaps_position_show, NULL);
449 static DEVICE_ATTR(variance, 0444, hdaps_variance_show, NULL);
450 static DEVICE_ATTR(temp1, 0444, hdaps_temp1_show, NULL);
451 static DEVICE_ATTR(temp2, 0444, hdaps_temp2_show, NULL);
452 static DEVICE_ATTR(keyboard_activity, 0444, hdaps_keyboard_activity_show, NULL);
453 static DEVICE_ATTR(mouse_activity, 0444, hdaps_mouse_activity_show, NULL);
454 static DEVICE_ATTR(calibrate, 0644, hdaps_calibrate_show,hdaps_calibrate_store);
455 static DEVICE_ATTR(invert, 0644, hdaps_invert_show, hdaps_invert_store);
456
457 static struct attribute *hdaps_attributes[] = {
458         &dev_attr_position.attr,
459         &dev_attr_variance.attr,
460         &dev_attr_temp1.attr,
461         &dev_attr_temp2.attr,
462         &dev_attr_keyboard_activity.attr,
463         &dev_attr_mouse_activity.attr,
464         &dev_attr_calibrate.attr,
465         &dev_attr_invert.attr,
466         NULL,
467 };
468
469 static struct attribute_group hdaps_attribute_group = {
470         .attrs = hdaps_attributes,
471 };
472
473
474 /* Module stuff */
475
476 /* hdaps_dmi_match - found a match.  return one, short-circuiting the hunt. */
477 static int __init hdaps_dmi_match(const struct dmi_system_id *id)
478 {
479         printk(KERN_INFO "hdaps: %s detected.\n", id->ident);
480         return 1;
481 }
482
483 /* hdaps_dmi_match_invert - found an inverted match. */
484 static int __init hdaps_dmi_match_invert(const struct dmi_system_id *id)
485 {
486         hdaps_invert = 1;
487         printk(KERN_INFO "hdaps: inverting axis readings.\n");
488         return hdaps_dmi_match(id);
489 }
490
491 #define HDAPS_DMI_MATCH_NORMAL(vendor, model) {         \
492         .ident = vendor " " model,                      \
493         .callback = hdaps_dmi_match,                    \
494         .matches = {                                    \
495                 DMI_MATCH(DMI_BOARD_VENDOR, vendor),    \
496                 DMI_MATCH(DMI_PRODUCT_VERSION, model)   \
497         }                                               \
498 }
499
500 #define HDAPS_DMI_MATCH_INVERT(vendor, model) {         \
501         .ident = vendor " " model,                      \
502         .callback = hdaps_dmi_match_invert,             \
503         .matches = {                                    \
504                 DMI_MATCH(DMI_BOARD_VENDOR, vendor),    \
505                 DMI_MATCH(DMI_PRODUCT_VERSION, model)   \
506         }                                               \
507 }
508
509 /* Note that HDAPS_DMI_MATCH_NORMAL("ThinkPad T42") would match
510    "ThinkPad T42p", so the order of the entries matters.
511    If your ThinkPad is not recognized, please update to latest
512    BIOS. This is especially the case for some R52 ThinkPads. */
513 static struct dmi_system_id __initdata hdaps_whitelist[] = {
514         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad R50p"),
515         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R50"),
516         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R51"),
517         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad R52"),
518         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad R61i"),
519         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad R61"),
520         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad T41p"),
521         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T41"),
522         HDAPS_DMI_MATCH_INVERT("IBM", "ThinkPad T42p"),
523         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T42"),
524         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad T43"),
525         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T60"),
526         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T61p"),
527         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad T61"),
528         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad X40"),
529         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad X41"),
530         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X60"),
531         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X61s"),
532         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad X61"),
533         HDAPS_DMI_MATCH_NORMAL("IBM", "ThinkPad Z60m"),
534         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad Z61m"),
535         HDAPS_DMI_MATCH_INVERT("LENOVO", "ThinkPad Z61p"),
536         { .ident = NULL }
537 };
538
539 static int __init hdaps_init(void)
540 {
541         struct input_dev *idev;
542         int ret;
543
544         if (!dmi_check_system(hdaps_whitelist)) {
545                 printk(KERN_WARNING "hdaps: supported laptop not found!\n");
546                 ret = -ENODEV;
547                 goto out;
548         }
549
550         if (!request_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS, "hdaps")) {
551                 ret = -ENXIO;
552                 goto out;
553         }
554
555         ret = platform_driver_register(&hdaps_driver);
556         if (ret)
557                 goto out_region;
558
559         pdev = platform_device_register_simple("hdaps", -1, NULL, 0);
560         if (IS_ERR(pdev)) {
561                 ret = PTR_ERR(pdev);
562                 goto out_driver;
563         }
564
565         ret = sysfs_create_group(&pdev->dev.kobj, &hdaps_attribute_group);
566         if (ret)
567                 goto out_device;
568
569         hdaps_idev = input_allocate_polled_device();
570         if (!hdaps_idev) {
571                 ret = -ENOMEM;
572                 goto out_group;
573         }
574
575         hdaps_idev->poll = hdaps_mousedev_poll;
576         hdaps_idev->poll_interval = HDAPS_POLL_INTERVAL;
577
578         /* initial calibrate for the input device */
579         hdaps_calibrate();
580
581         /* initialize the input class */
582         idev = hdaps_idev->input;
583         idev->name = "hdaps";
584         idev->phys = "isa1600/input0";
585         idev->id.bustype = BUS_ISA;
586         idev->dev.parent = &pdev->dev;
587         idev->evbit[0] = BIT_MASK(EV_ABS);
588         input_set_abs_params(idev, ABS_X,
589                         -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
590         input_set_abs_params(idev, ABS_Y,
591                         -256, 256, HDAPS_INPUT_FUZZ, HDAPS_INPUT_FLAT);
592
593         ret = input_register_polled_device(hdaps_idev);
594         if (ret)
595                 goto out_idev;
596
597         printk(KERN_INFO "hdaps: driver successfully loaded.\n");
598         return 0;
599
600 out_idev:
601         input_free_polled_device(hdaps_idev);
602 out_group:
603         sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
604 out_device:
605         platform_device_unregister(pdev);
606 out_driver:
607         platform_driver_unregister(&hdaps_driver);
608 out_region:
609         release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
610 out:
611         printk(KERN_WARNING "hdaps: driver init failed (ret=%d)!\n", ret);
612         return ret;
613 }
614
615 static void __exit hdaps_exit(void)
616 {
617         input_unregister_polled_device(hdaps_idev);
618         input_free_polled_device(hdaps_idev);
619         sysfs_remove_group(&pdev->dev.kobj, &hdaps_attribute_group);
620         platform_device_unregister(pdev);
621         platform_driver_unregister(&hdaps_driver);
622         release_region(HDAPS_LOW_PORT, HDAPS_NR_PORTS);
623
624         printk(KERN_INFO "hdaps: driver unloaded.\n");
625 }
626
627 module_init(hdaps_init);
628 module_exit(hdaps_exit);
629
630 module_param_named(invert, hdaps_invert, bool, 0);
631 MODULE_PARM_DESC(invert, "invert data along each axis");
632
633 MODULE_AUTHOR("Robert Love");
634 MODULE_DESCRIPTION("IBM Hard Drive Active Protection System (HDAPS) driver");
635 MODULE_LICENSE("GPL v2");