xref: /openbmc/linux/drivers/hwmon/via686a.c (revision 7e035230)
1 /*
2  * via686a.c - Part of lm_sensors, Linux kernel modules
3  *	       for hardware monitoring
4  *
5  * Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
6  *			      Kyösti Mälkki <kmalkki@cc.hut.fi>,
7  *			      Mark Studebaker <mdsxyz123@yahoo.com>,
8  *			      and Bob Dougherty <bobd@stanford.edu>
9  *
10  * (Some conversion-factor data were contributed by Jonathan Teh Soon Yew
11  * <j.teh@iname.com> and Alex van Kaam <darkside@chello.nl>.)
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26  */
27 
28 /*
29  * Supports the Via VT82C686A, VT82C686B south bridges.
30  * Reports all as a 686A.
31  * Warning - only supports a single device.
32  */
33 
34 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35 
36 #include <linux/module.h>
37 #include <linux/slab.h>
38 #include <linux/pci.h>
39 #include <linux/jiffies.h>
40 #include <linux/platform_device.h>
41 #include <linux/hwmon.h>
42 #include <linux/hwmon-sysfs.h>
43 #include <linux/err.h>
44 #include <linux/init.h>
45 #include <linux/mutex.h>
46 #include <linux/sysfs.h>
47 #include <linux/acpi.h>
48 #include <linux/io.h>
49 
50 
51 /*
52  * If force_addr is set to anything different from 0, we forcibly enable
53  * the device at the given address.
54  */
55 static unsigned short force_addr;
56 module_param(force_addr, ushort, 0);
57 MODULE_PARM_DESC(force_addr,
58 		 "Initialize the base address of the sensors");
59 
60 static struct platform_device *pdev;
61 
62 /*
63  * The Via 686a southbridge has a LM78-like chip integrated on the same IC.
64  * This driver is a customized copy of lm78.c
65  */
66 
67 /* Many VIA686A constants specified below */
68 
69 /* Length of ISA address segment */
70 #define VIA686A_EXTENT		0x80
71 #define VIA686A_BASE_REG	0x70
72 #define VIA686A_ENABLE_REG	0x74
73 
74 /* The VIA686A registers */
75 /* ins numbered 0-4 */
76 #define VIA686A_REG_IN_MAX(nr)	(0x2b + ((nr) * 2))
77 #define VIA686A_REG_IN_MIN(nr)	(0x2c + ((nr) * 2))
78 #define VIA686A_REG_IN(nr)	(0x22 + (nr))
79 
80 /* fans numbered 1-2 */
81 #define VIA686A_REG_FAN_MIN(nr)	(0x3a + (nr))
82 #define VIA686A_REG_FAN(nr)	(0x28 + (nr))
83 
84 /* temps numbered 1-3 */
85 static const u8 VIA686A_REG_TEMP[]	= { 0x20, 0x21, 0x1f };
86 static const u8 VIA686A_REG_TEMP_OVER[]	= { 0x39, 0x3d, 0x1d };
87 static const u8 VIA686A_REG_TEMP_HYST[]	= { 0x3a, 0x3e, 0x1e };
88 /* bits 7-6 */
89 #define VIA686A_REG_TEMP_LOW1	0x4b
90 /* 2 = bits 5-4, 3 = bits 7-6 */
91 #define VIA686A_REG_TEMP_LOW23	0x49
92 
93 #define VIA686A_REG_ALARM1	0x41
94 #define VIA686A_REG_ALARM2	0x42
95 #define VIA686A_REG_FANDIV	0x47
96 #define VIA686A_REG_CONFIG	0x40
97 /*
98  * The following register sets temp interrupt mode (bits 1-0 for temp1,
99  * 3-2 for temp2, 5-4 for temp3).  Modes are:
100  * 00 interrupt stays as long as value is out-of-range
101  * 01 interrupt is cleared once register is read (default)
102  * 10 comparator mode- like 00, but ignores hysteresis
103  * 11 same as 00
104  */
105 #define VIA686A_REG_TEMP_MODE		0x4b
106 /* We'll just assume that you want to set all 3 simultaneously: */
107 #define VIA686A_TEMP_MODE_MASK		0x3F
108 #define VIA686A_TEMP_MODE_CONTINUOUS	0x00
109 
110 /*
111  * Conversions. Limit checking is only done on the TO_REG
112  * variants.
113  *
114  ******** VOLTAGE CONVERSIONS (Bob Dougherty) ********
115  * From HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew):
116  * voltagefactor[0]=1.25/2628; (2628/1.25=2102.4)   // Vccp
117  * voltagefactor[1]=1.25/2628; (2628/1.25=2102.4)   // +2.5V
118  * voltagefactor[2]=1.67/2628; (2628/1.67=1573.7)   // +3.3V
119  * voltagefactor[3]=2.6/2628;  (2628/2.60=1010.8)   // +5V
120  * voltagefactor[4]=6.3/2628;  (2628/6.30=417.14)   // +12V
121  * in[i]=(data[i+2]*25.0+133)*voltagefactor[i];
122  * That is:
123  * volts = (25*regVal+133)*factor
124  * regVal = (volts/factor-133)/25
125  * (These conversions were contributed by Jonathan Teh Soon Yew
126  * <j.teh@iname.com>)
127  */
128 static inline u8 IN_TO_REG(long val, int inNum)
129 {
130 	/*
131 	 * To avoid floating point, we multiply constants by 10 (100 for +12V).
132 	 * Rounding is done (120500 is actually 133000 - 12500).
133 	 * Remember that val is expressed in 0.001V/bit, which is why we divide
134 	 * by an additional 10000 (100000 for +12V): 1000 for val and 10 (100)
135 	 * for the constants.
136 	 */
137 	if (inNum <= 1)
138 		return (u8)
139 		    SENSORS_LIMIT((val * 21024 - 1205000) / 250000, 0, 255);
140 	else if (inNum == 2)
141 		return (u8)
142 		    SENSORS_LIMIT((val * 15737 - 1205000) / 250000, 0, 255);
143 	else if (inNum == 3)
144 		return (u8)
145 		    SENSORS_LIMIT((val * 10108 - 1205000) / 250000, 0, 255);
146 	else
147 		return (u8)
148 		    SENSORS_LIMIT((val * 41714 - 12050000) / 2500000, 0, 255);
149 }
150 
151 static inline long IN_FROM_REG(u8 val, int inNum)
152 {
153 	/*
154 	 * To avoid floating point, we multiply constants by 10 (100 for +12V).
155 	 * We also multiply them by 1000 because we want 0.001V/bit for the
156 	 * output value. Rounding is done.
157 	 */
158 	if (inNum <= 1)
159 		return (long) ((250000 * val + 1330000 + 21024 / 2) / 21024);
160 	else if (inNum == 2)
161 		return (long) ((250000 * val + 1330000 + 15737 / 2) / 15737);
162 	else if (inNum == 3)
163 		return (long) ((250000 * val + 1330000 + 10108 / 2) / 10108);
164 	else
165 		return (long) ((2500000 * val + 13300000 + 41714 / 2) / 41714);
166 }
167 
168 /********* FAN RPM CONVERSIONS ********/
169 /*
170  * Higher register values = slower fans (the fan's strobe gates a counter).
171  * But this chip saturates back at 0, not at 255 like all the other chips.
172  * So, 0 means 0 RPM
173  */
174 static inline u8 FAN_TO_REG(long rpm, int div)
175 {
176 	if (rpm == 0)
177 		return 0;
178 	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
179 	return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 255);
180 }
181 
182 #define FAN_FROM_REG(val, div) ((val) == 0 ? 0 : (val) == 255 ? 0 : 1350000 / \
183 				((val) * (div)))
184 
185 /******** TEMP CONVERSIONS (Bob Dougherty) *********/
186 /*
187  * linear fits from HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew)
188  *	if(temp<169)
189  *		return double(temp)*0.427-32.08;
190  *	else if(temp>=169 && temp<=202)
191  *		return double(temp)*0.582-58.16;
192  *	else
193  *		return double(temp)*0.924-127.33;
194  *
195  * A fifth-order polynomial fits the unofficial data (provided by Alex van
196  * Kaam <darkside@chello.nl>) a bit better.  It also give more reasonable
197  * numbers on my machine (ie. they agree with what my BIOS tells me).
198  * Here's the fifth-order fit to the 8-bit data:
199  * temp = 1.625093e-10*val^5 - 1.001632e-07*val^4 + 2.457653e-05*val^3 -
200  *	2.967619e-03*val^2 + 2.175144e-01*val - 7.090067e+0.
201  *
202  * (2000-10-25- RFD: thanks to Uwe Andersen <uandersen@mayah.com> for
203  * finding my typos in this formula!)
204  *
205  * Alas, none of the elegant function-fit solutions will work because we
206  * aren't allowed to use floating point in the kernel and doing it with
207  * integers doesn't provide enough precision.  So we'll do boring old
208  * look-up table stuff.  The unofficial data (see below) have effectively
209  * 7-bit resolution (they are rounded to the nearest degree).  I'm assuming
210  * that the transfer function of the device is monotonic and smooth, so a
211  * smooth function fit to the data will allow us to get better precision.
212  * I used the 5th-order poly fit described above and solved for
213  * VIA register values 0-255.  I *10 before rounding, so we get tenth-degree
214  * precision.  (I could have done all 1024 values for our 10-bit readings,
215  * but the function is very linear in the useful range (0-80 deg C), so
216  * we'll just use linear interpolation for 10-bit readings.)  So, tempLUT
217  * is the temp at via register values 0-255:
218  */
219 static const s16 tempLUT[] = {
220 	-709, -688, -667, -646, -627, -607, -589, -570, -553, -536, -519,
221 	-503, -487, -471, -456, -442, -428, -414, -400, -387, -375,
222 	-362, -350, -339, -327, -316, -305, -295, -285, -275, -265,
223 	-255, -246, -237, -229, -220, -212, -204, -196, -188, -180,
224 	-173, -166, -159, -152, -145, -139, -132, -126, -120, -114,
225 	-108, -102, -96, -91, -85, -80, -74, -69, -64, -59, -54, -49,
226 	-44, -39, -34, -29, -25, -20, -15, -11, -6, -2, 3, 7, 12, 16,
227 	20, 25, 29, 33, 37, 42, 46, 50, 54, 59, 63, 67, 71, 75, 79, 84,
228 	88, 92, 96, 100, 104, 109, 113, 117, 121, 125, 130, 134, 138,
229 	142, 146, 151, 155, 159, 163, 168, 172, 176, 181, 185, 189,
230 	193, 198, 202, 206, 211, 215, 219, 224, 228, 232, 237, 241,
231 	245, 250, 254, 259, 263, 267, 272, 276, 281, 285, 290, 294,
232 	299, 303, 307, 312, 316, 321, 325, 330, 334, 339, 344, 348,
233 	353, 357, 362, 366, 371, 376, 380, 385, 390, 395, 399, 404,
234 	409, 414, 419, 423, 428, 433, 438, 443, 449, 454, 459, 464,
235 	469, 475, 480, 486, 491, 497, 502, 508, 514, 520, 526, 532,
236 	538, 544, 551, 557, 564, 571, 578, 584, 592, 599, 606, 614,
237 	621, 629, 637, 645, 654, 662, 671, 680, 689, 698, 708, 718,
238 	728, 738, 749, 759, 770, 782, 793, 805, 818, 830, 843, 856,
239 	870, 883, 898, 912, 927, 943, 958, 975, 991, 1008, 1026, 1044,
240 	1062, 1081, 1101, 1121, 1141, 1162, 1184, 1206, 1229, 1252,
241 	1276, 1301, 1326, 1352, 1378, 1406, 1434, 1462
242 };
243 
244 /*
245  * the original LUT values from Alex van Kaam <darkside@chello.nl>
246  * (for via register values 12-240):
247  * {-50,-49,-47,-45,-43,-41,-39,-38,-37,-35,-34,-33,-32,-31,
248  * -30,-29,-28,-27,-26,-25,-24,-24,-23,-22,-21,-20,-20,-19,-18,-17,-17,-16,-15,
249  * -15,-14,-14,-13,-12,-12,-11,-11,-10,-9,-9,-8,-8,-7,-7,-6,-6,-5,-5,-4,-4,-3,
250  * -3,-2,-2,-1,-1,0,0,1,1,1,3,3,3,4,4,4,5,5,5,6,6,7,7,8,8,9,9,9,10,10,11,11,12,
251  * 12,12,13,13,13,14,14,15,15,16,16,16,17,17,18,18,19,19,20,20,21,21,21,22,22,
252  * 22,23,23,24,24,25,25,26,26,26,27,27,27,28,28,29,29,30,30,30,31,31,32,32,33,
253  * 33,34,34,35,35,35,36,36,37,37,38,38,39,39,40,40,41,41,42,42,43,43,44,44,45,
254  * 45,46,46,47,48,48,49,49,50,51,51,52,52,53,53,54,55,55,56,57,57,58,59,59,60,
255  * 61,62,62,63,64,65,66,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,83,84,
256  * 85,86,88,89,91,92,94,96,97,99,101,103,105,107,109,110};
257  *
258  *
259  * Here's the reverse LUT.  I got it by doing a 6-th order poly fit (needed
260  * an extra term for a good fit to these inverse data!) and then
261  * solving for each temp value from -50 to 110 (the useable range for
262  * this chip).  Here's the fit:
263  * viaRegVal = -1.160370e-10*val^6 +3.193693e-08*val^5 - 1.464447e-06*val^4
264  * - 2.525453e-04*val^3 + 1.424593e-02*val^2 + 2.148941e+00*val +7.275808e+01)
265  * Note that n=161:
266  */
267 static const u8 viaLUT[] = {
268 	12, 12, 13, 14, 14, 15, 16, 16, 17, 18, 18, 19, 20, 20, 21, 22, 23,
269 	23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 39, 40,
270 	41, 43, 45, 46, 48, 49, 51, 53, 55, 57, 59, 60, 62, 64, 66,
271 	69, 71, 73, 75, 77, 79, 82, 84, 86, 88, 91, 93, 95, 98, 100,
272 	103, 105, 107, 110, 112, 115, 117, 119, 122, 124, 126, 129,
273 	131, 134, 136, 138, 140, 143, 145, 147, 150, 152, 154, 156,
274 	158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180,
275 	182, 183, 185, 187, 188, 190, 192, 193, 195, 196, 198, 199,
276 	200, 202, 203, 205, 206, 207, 208, 209, 210, 211, 212, 213,
277 	214, 215, 216, 217, 218, 219, 220, 221, 222, 222, 223, 224,
278 	225, 226, 226, 227, 228, 228, 229, 230, 230, 231, 232, 232,
279 	233, 233, 234, 235, 235, 236, 236, 237, 237, 238, 238, 239,
280 	239, 240
281 };
282 
283 /*
284  * Converting temps to (8-bit) hyst and over registers
285  * No interpolation here.
286  * The +50 is because the temps start at -50
287  */
288 static inline u8 TEMP_TO_REG(long val)
289 {
290 	return viaLUT[val <= -50000 ? 0 : val >= 110000 ? 160 :
291 		      (val < 0 ? val - 500 : val + 500) / 1000 + 50];
292 }
293 
294 /* for 8-bit temperature hyst and over registers */
295 #define TEMP_FROM_REG(val)	((long)tempLUT[val] * 100)
296 
297 /* for 10-bit temperature readings */
298 static inline long TEMP_FROM_REG10(u16 val)
299 {
300 	u16 eightBits = val >> 2;
301 	u16 twoBits = val & 3;
302 
303 	/* no interpolation for these */
304 	if (twoBits == 0 || eightBits == 255)
305 		return TEMP_FROM_REG(eightBits);
306 
307 	/* do some linear interpolation */
308 	return (tempLUT[eightBits] * (4 - twoBits) +
309 		tempLUT[eightBits + 1] * twoBits) * 25;
310 }
311 
312 #define DIV_FROM_REG(val) (1 << (val))
313 #define DIV_TO_REG(val) ((val) == 8 ? 3 : (val) == 4 ? 2 : (val) == 1 ? 0 : 1)
314 
315 /*
316  * For each registered chip, we need to keep some data in memory.
317  * The structure is dynamically allocated.
318  */
319 struct via686a_data {
320 	unsigned short addr;
321 	const char *name;
322 	struct device *hwmon_dev;
323 	struct mutex update_lock;
324 	char valid;		/* !=0 if following fields are valid */
325 	unsigned long last_updated;	/* In jiffies */
326 
327 	u8 in[5];		/* Register value */
328 	u8 in_max[5];		/* Register value */
329 	u8 in_min[5];		/* Register value */
330 	u8 fan[2];		/* Register value */
331 	u8 fan_min[2];		/* Register value */
332 	u16 temp[3];		/* Register value 10 bit */
333 	u8 temp_over[3];	/* Register value */
334 	u8 temp_hyst[3];	/* Register value */
335 	u8 fan_div[2];		/* Register encoding, shifted right */
336 	u16 alarms;		/* Register encoding, combined */
337 };
338 
339 static struct pci_dev *s_bridge;	/* pointer to the (only) via686a */
340 
341 static int via686a_probe(struct platform_device *pdev);
342 static int __devexit via686a_remove(struct platform_device *pdev);
343 
344 static inline int via686a_read_value(struct via686a_data *data, u8 reg)
345 {
346 	return inb_p(data->addr + reg);
347 }
348 
349 static inline void via686a_write_value(struct via686a_data *data, u8 reg,
350 				       u8 value)
351 {
352 	outb_p(value, data->addr + reg);
353 }
354 
355 static struct via686a_data *via686a_update_device(struct device *dev);
356 static void via686a_init_device(struct via686a_data *data);
357 
358 /* following are the sysfs callback functions */
359 
360 /* 7 voltage sensors */
361 static ssize_t show_in(struct device *dev, struct device_attribute *da,
362 		char *buf) {
363 	struct via686a_data *data = via686a_update_device(dev);
364 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
365 	int nr = attr->index;
366 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in[nr], nr));
367 }
368 
369 static ssize_t show_in_min(struct device *dev, struct device_attribute *da,
370 		char *buf) {
371 	struct via686a_data *data = via686a_update_device(dev);
372 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
373 	int nr = attr->index;
374 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_min[nr], nr));
375 }
376 
377 static ssize_t show_in_max(struct device *dev, struct device_attribute *da,
378 		char *buf) {
379 	struct via686a_data *data = via686a_update_device(dev);
380 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
381 	int nr = attr->index;
382 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_max[nr], nr));
383 }
384 
385 static ssize_t set_in_min(struct device *dev, struct device_attribute *da,
386 		const char *buf, size_t count) {
387 	struct via686a_data *data = dev_get_drvdata(dev);
388 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
389 	int nr = attr->index;
390 	unsigned long val;
391 	int err;
392 
393 	err = kstrtoul(buf, 10, &val);
394 	if (err)
395 		return err;
396 
397 	mutex_lock(&data->update_lock);
398 	data->in_min[nr] = IN_TO_REG(val, nr);
399 	via686a_write_value(data, VIA686A_REG_IN_MIN(nr),
400 			data->in_min[nr]);
401 	mutex_unlock(&data->update_lock);
402 	return count;
403 }
404 static ssize_t set_in_max(struct device *dev, struct device_attribute *da,
405 		const char *buf, size_t count) {
406 	struct via686a_data *data = dev_get_drvdata(dev);
407 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
408 	int nr = attr->index;
409 	unsigned long val;
410 	int err;
411 
412 	err = kstrtoul(buf, 10, &val);
413 	if (err)
414 		return err;
415 
416 	mutex_lock(&data->update_lock);
417 	data->in_max[nr] = IN_TO_REG(val, nr);
418 	via686a_write_value(data, VIA686A_REG_IN_MAX(nr),
419 			data->in_max[nr]);
420 	mutex_unlock(&data->update_lock);
421 	return count;
422 }
423 #define show_in_offset(offset)					\
424 static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO,		\
425 		show_in, NULL, offset);				\
426 static SENSOR_DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR,	\
427 		show_in_min, set_in_min, offset);		\
428 static SENSOR_DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR,	\
429 		show_in_max, set_in_max, offset);
430 
431 show_in_offset(0);
432 show_in_offset(1);
433 show_in_offset(2);
434 show_in_offset(3);
435 show_in_offset(4);
436 
437 /* 3 temperatures */
438 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
439 		char *buf) {
440 	struct via686a_data *data = via686a_update_device(dev);
441 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
442 	int nr = attr->index;
443 	return sprintf(buf, "%ld\n", TEMP_FROM_REG10(data->temp[nr]));
444 }
445 static ssize_t show_temp_over(struct device *dev, struct device_attribute *da,
446 		char *buf) {
447 	struct via686a_data *data = via686a_update_device(dev);
448 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
449 	int nr = attr->index;
450 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_over[nr]));
451 }
452 static ssize_t show_temp_hyst(struct device *dev, struct device_attribute *da,
453 		char *buf) {
454 	struct via686a_data *data = via686a_update_device(dev);
455 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
456 	int nr = attr->index;
457 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_hyst[nr]));
458 }
459 static ssize_t set_temp_over(struct device *dev, struct device_attribute *da,
460 		const char *buf, size_t count) {
461 	struct via686a_data *data = dev_get_drvdata(dev);
462 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
463 	int nr = attr->index;
464 	long val;
465 	int err;
466 
467 	err = kstrtol(buf, 10, &val);
468 	if (err)
469 		return err;
470 
471 	mutex_lock(&data->update_lock);
472 	data->temp_over[nr] = TEMP_TO_REG(val);
473 	via686a_write_value(data, VIA686A_REG_TEMP_OVER[nr],
474 			    data->temp_over[nr]);
475 	mutex_unlock(&data->update_lock);
476 	return count;
477 }
478 static ssize_t set_temp_hyst(struct device *dev, struct device_attribute *da,
479 		const char *buf, size_t count) {
480 	struct via686a_data *data = dev_get_drvdata(dev);
481 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
482 	int nr = attr->index;
483 	long val;
484 	int err;
485 
486 	err = kstrtol(buf, 10, &val);
487 	if (err)
488 		return err;
489 
490 	mutex_lock(&data->update_lock);
491 	data->temp_hyst[nr] = TEMP_TO_REG(val);
492 	via686a_write_value(data, VIA686A_REG_TEMP_HYST[nr],
493 			    data->temp_hyst[nr]);
494 	mutex_unlock(&data->update_lock);
495 	return count;
496 }
497 #define show_temp_offset(offset)					\
498 static SENSOR_DEVICE_ATTR(temp##offset##_input, S_IRUGO,		\
499 		show_temp, NULL, offset - 1);				\
500 static SENSOR_DEVICE_ATTR(temp##offset##_max, S_IRUGO | S_IWUSR,	\
501 		show_temp_over, set_temp_over, offset - 1);		\
502 static SENSOR_DEVICE_ATTR(temp##offset##_max_hyst, S_IRUGO | S_IWUSR,	\
503 		show_temp_hyst, set_temp_hyst, offset - 1);
504 
505 show_temp_offset(1);
506 show_temp_offset(2);
507 show_temp_offset(3);
508 
509 /* 2 Fans */
510 static ssize_t show_fan(struct device *dev, struct device_attribute *da,
511 		char *buf) {
512 	struct via686a_data *data = via686a_update_device(dev);
513 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
514 	int nr = attr->index;
515 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
516 				DIV_FROM_REG(data->fan_div[nr])));
517 }
518 static ssize_t show_fan_min(struct device *dev, struct device_attribute *da,
519 		char *buf) {
520 	struct via686a_data *data = via686a_update_device(dev);
521 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
522 	int nr = attr->index;
523 	return sprintf(buf, "%d\n",
524 		FAN_FROM_REG(data->fan_min[nr],
525 			     DIV_FROM_REG(data->fan_div[nr])));
526 }
527 static ssize_t show_fan_div(struct device *dev, struct device_attribute *da,
528 		char *buf) {
529 	struct via686a_data *data = via686a_update_device(dev);
530 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
531 	int nr = attr->index;
532 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
533 }
534 static ssize_t set_fan_min(struct device *dev, struct device_attribute *da,
535 		const char *buf, size_t count) {
536 	struct via686a_data *data = dev_get_drvdata(dev);
537 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
538 	int nr = attr->index;
539 	unsigned long val;
540 	int err;
541 
542 	err = kstrtoul(buf, 10, &val);
543 	if (err)
544 		return err;
545 
546 	mutex_lock(&data->update_lock);
547 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
548 	via686a_write_value(data, VIA686A_REG_FAN_MIN(nr+1), data->fan_min[nr]);
549 	mutex_unlock(&data->update_lock);
550 	return count;
551 }
552 static ssize_t set_fan_div(struct device *dev, struct device_attribute *da,
553 		const char *buf, size_t count) {
554 	struct via686a_data *data = dev_get_drvdata(dev);
555 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
556 	int nr = attr->index;
557 	int old;
558 	unsigned long val;
559 	int err;
560 
561 	err = kstrtoul(buf, 10, &val);
562 	if (err)
563 		return err;
564 
565 	mutex_lock(&data->update_lock);
566 	old = via686a_read_value(data, VIA686A_REG_FANDIV);
567 	data->fan_div[nr] = DIV_TO_REG(val);
568 	old = (old & 0x0f) | (data->fan_div[1] << 6) | (data->fan_div[0] << 4);
569 	via686a_write_value(data, VIA686A_REG_FANDIV, old);
570 	mutex_unlock(&data->update_lock);
571 	return count;
572 }
573 
574 #define show_fan_offset(offset)						\
575 static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO,			\
576 		show_fan, NULL, offset - 1);				\
577 static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,		\
578 		show_fan_min, set_fan_min, offset - 1);			\
579 static SENSOR_DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR,		\
580 		show_fan_div, set_fan_div, offset - 1);
581 
582 show_fan_offset(1);
583 show_fan_offset(2);
584 
585 /* Alarms */
586 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
587 			   char *buf)
588 {
589 	struct via686a_data *data = via686a_update_device(dev);
590 	return sprintf(buf, "%u\n", data->alarms);
591 }
592 
593 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
594 
595 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
596 			  char *buf)
597 {
598 	int bitnr = to_sensor_dev_attr(attr)->index;
599 	struct via686a_data *data = via686a_update_device(dev);
600 	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
601 }
602 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
603 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
604 static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2);
605 static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3);
606 static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 8);
607 static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 4);
608 static SENSOR_DEVICE_ATTR(temp2_alarm, S_IRUGO, show_alarm, NULL, 11);
609 static SENSOR_DEVICE_ATTR(temp3_alarm, S_IRUGO, show_alarm, NULL, 15);
610 static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 6);
611 static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 7);
612 
613 static ssize_t show_name(struct device *dev, struct device_attribute
614 			 *devattr, char *buf)
615 {
616 	struct via686a_data *data = dev_get_drvdata(dev);
617 	return sprintf(buf, "%s\n", data->name);
618 }
619 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
620 
621 static struct attribute *via686a_attributes[] = {
622 	&sensor_dev_attr_in0_input.dev_attr.attr,
623 	&sensor_dev_attr_in1_input.dev_attr.attr,
624 	&sensor_dev_attr_in2_input.dev_attr.attr,
625 	&sensor_dev_attr_in3_input.dev_attr.attr,
626 	&sensor_dev_attr_in4_input.dev_attr.attr,
627 	&sensor_dev_attr_in0_min.dev_attr.attr,
628 	&sensor_dev_attr_in1_min.dev_attr.attr,
629 	&sensor_dev_attr_in2_min.dev_attr.attr,
630 	&sensor_dev_attr_in3_min.dev_attr.attr,
631 	&sensor_dev_attr_in4_min.dev_attr.attr,
632 	&sensor_dev_attr_in0_max.dev_attr.attr,
633 	&sensor_dev_attr_in1_max.dev_attr.attr,
634 	&sensor_dev_attr_in2_max.dev_attr.attr,
635 	&sensor_dev_attr_in3_max.dev_attr.attr,
636 	&sensor_dev_attr_in4_max.dev_attr.attr,
637 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
638 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
639 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
640 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
641 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
642 
643 	&sensor_dev_attr_temp1_input.dev_attr.attr,
644 	&sensor_dev_attr_temp2_input.dev_attr.attr,
645 	&sensor_dev_attr_temp3_input.dev_attr.attr,
646 	&sensor_dev_attr_temp1_max.dev_attr.attr,
647 	&sensor_dev_attr_temp2_max.dev_attr.attr,
648 	&sensor_dev_attr_temp3_max.dev_attr.attr,
649 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
650 	&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
651 	&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
652 	&sensor_dev_attr_temp1_alarm.dev_attr.attr,
653 	&sensor_dev_attr_temp2_alarm.dev_attr.attr,
654 	&sensor_dev_attr_temp3_alarm.dev_attr.attr,
655 
656 	&sensor_dev_attr_fan1_input.dev_attr.attr,
657 	&sensor_dev_attr_fan2_input.dev_attr.attr,
658 	&sensor_dev_attr_fan1_min.dev_attr.attr,
659 	&sensor_dev_attr_fan2_min.dev_attr.attr,
660 	&sensor_dev_attr_fan1_div.dev_attr.attr,
661 	&sensor_dev_attr_fan2_div.dev_attr.attr,
662 	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
663 	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
664 
665 	&dev_attr_alarms.attr,
666 	&dev_attr_name.attr,
667 	NULL
668 };
669 
670 static const struct attribute_group via686a_group = {
671 	.attrs = via686a_attributes,
672 };
673 
674 static struct platform_driver via686a_driver = {
675 	.driver = {
676 		.owner	= THIS_MODULE,
677 		.name	= "via686a",
678 	},
679 	.probe		= via686a_probe,
680 	.remove		= __devexit_p(via686a_remove),
681 };
682 
683 
684 /* This is called when the module is loaded */
685 static int __devinit via686a_probe(struct platform_device *pdev)
686 {
687 	struct via686a_data *data;
688 	struct resource *res;
689 	int err;
690 
691 	/* Reserve the ISA region */
692 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
693 	if (!devm_request_region(&pdev->dev, res->start, VIA686A_EXTENT,
694 				 via686a_driver.driver.name)) {
695 		dev_err(&pdev->dev, "Region 0x%lx-0x%lx already in use!\n",
696 			(unsigned long)res->start, (unsigned long)res->end);
697 		return -ENODEV;
698 	}
699 
700 	data = devm_kzalloc(&pdev->dev, sizeof(struct via686a_data),
701 			    GFP_KERNEL);
702 	if (!data)
703 		return -ENOMEM;
704 
705 	platform_set_drvdata(pdev, data);
706 	data->addr = res->start;
707 	data->name = "via686a";
708 	mutex_init(&data->update_lock);
709 
710 	/* Initialize the VIA686A chip */
711 	via686a_init_device(data);
712 
713 	/* Register sysfs hooks */
714 	err = sysfs_create_group(&pdev->dev.kobj, &via686a_group);
715 	if (err)
716 		return err;
717 
718 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
719 	if (IS_ERR(data->hwmon_dev)) {
720 		err = PTR_ERR(data->hwmon_dev);
721 		goto exit_remove_files;
722 	}
723 
724 	return 0;
725 
726 exit_remove_files:
727 	sysfs_remove_group(&pdev->dev.kobj, &via686a_group);
728 	return err;
729 }
730 
731 static int __devexit via686a_remove(struct platform_device *pdev)
732 {
733 	struct via686a_data *data = platform_get_drvdata(pdev);
734 
735 	hwmon_device_unregister(data->hwmon_dev);
736 	sysfs_remove_group(&pdev->dev.kobj, &via686a_group);
737 
738 	return 0;
739 }
740 
741 static void via686a_update_fan_div(struct via686a_data *data)
742 {
743 	int reg = via686a_read_value(data, VIA686A_REG_FANDIV);
744 	data->fan_div[0] = (reg >> 4) & 0x03;
745 	data->fan_div[1] = reg >> 6;
746 }
747 
748 static void __devinit via686a_init_device(struct via686a_data *data)
749 {
750 	u8 reg;
751 
752 	/* Start monitoring */
753 	reg = via686a_read_value(data, VIA686A_REG_CONFIG);
754 	via686a_write_value(data, VIA686A_REG_CONFIG, (reg | 0x01) & 0x7F);
755 
756 	/* Configure temp interrupt mode for continuous-interrupt operation */
757 	reg = via686a_read_value(data, VIA686A_REG_TEMP_MODE);
758 	via686a_write_value(data, VIA686A_REG_TEMP_MODE,
759 			    (reg & ~VIA686A_TEMP_MODE_MASK)
760 			    | VIA686A_TEMP_MODE_CONTINUOUS);
761 
762 	/* Pre-read fan clock divisor values */
763 	via686a_update_fan_div(data);
764 }
765 
766 static struct via686a_data *via686a_update_device(struct device *dev)
767 {
768 	struct via686a_data *data = dev_get_drvdata(dev);
769 	int i;
770 
771 	mutex_lock(&data->update_lock);
772 
773 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
774 	    || !data->valid) {
775 		for (i = 0; i <= 4; i++) {
776 			data->in[i] =
777 			    via686a_read_value(data, VIA686A_REG_IN(i));
778 			data->in_min[i] = via686a_read_value(data,
779 							     VIA686A_REG_IN_MIN
780 							     (i));
781 			data->in_max[i] =
782 			    via686a_read_value(data, VIA686A_REG_IN_MAX(i));
783 		}
784 		for (i = 1; i <= 2; i++) {
785 			data->fan[i - 1] =
786 			    via686a_read_value(data, VIA686A_REG_FAN(i));
787 			data->fan_min[i - 1] = via686a_read_value(data,
788 						     VIA686A_REG_FAN_MIN(i));
789 		}
790 		for (i = 0; i <= 2; i++) {
791 			data->temp[i] = via686a_read_value(data,
792 						 VIA686A_REG_TEMP[i]) << 2;
793 			data->temp_over[i] =
794 			    via686a_read_value(data,
795 					       VIA686A_REG_TEMP_OVER[i]);
796 			data->temp_hyst[i] =
797 			    via686a_read_value(data,
798 					       VIA686A_REG_TEMP_HYST[i]);
799 		}
800 		/*
801 		 * add in lower 2 bits
802 		 * temp1 uses bits 7-6 of VIA686A_REG_TEMP_LOW1
803 		 * temp2 uses bits 5-4 of VIA686A_REG_TEMP_LOW23
804 		 * temp3 uses bits 7-6 of VIA686A_REG_TEMP_LOW23
805 		 */
806 		data->temp[0] |= (via686a_read_value(data,
807 						     VIA686A_REG_TEMP_LOW1)
808 				  & 0xc0) >> 6;
809 		data->temp[1] |=
810 		    (via686a_read_value(data, VIA686A_REG_TEMP_LOW23) &
811 		     0x30) >> 4;
812 		data->temp[2] |=
813 		    (via686a_read_value(data, VIA686A_REG_TEMP_LOW23) &
814 		     0xc0) >> 6;
815 
816 		via686a_update_fan_div(data);
817 		data->alarms =
818 		    via686a_read_value(data,
819 				       VIA686A_REG_ALARM1) |
820 		    (via686a_read_value(data, VIA686A_REG_ALARM2) << 8);
821 		data->last_updated = jiffies;
822 		data->valid = 1;
823 	}
824 
825 	mutex_unlock(&data->update_lock);
826 
827 	return data;
828 }
829 
830 static DEFINE_PCI_DEVICE_TABLE(via686a_pci_ids) = {
831 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4) },
832 	{ }
833 };
834 MODULE_DEVICE_TABLE(pci, via686a_pci_ids);
835 
836 static int __devinit via686a_device_add(unsigned short address)
837 {
838 	struct resource res = {
839 		.start	= address,
840 		.end	= address + VIA686A_EXTENT - 1,
841 		.name	= "via686a",
842 		.flags	= IORESOURCE_IO,
843 	};
844 	int err;
845 
846 	err = acpi_check_resource_conflict(&res);
847 	if (err)
848 		goto exit;
849 
850 	pdev = platform_device_alloc("via686a", address);
851 	if (!pdev) {
852 		err = -ENOMEM;
853 		pr_err("Device allocation failed\n");
854 		goto exit;
855 	}
856 
857 	err = platform_device_add_resources(pdev, &res, 1);
858 	if (err) {
859 		pr_err("Device resource addition failed (%d)\n", err);
860 		goto exit_device_put;
861 	}
862 
863 	err = platform_device_add(pdev);
864 	if (err) {
865 		pr_err("Device addition failed (%d)\n", err);
866 		goto exit_device_put;
867 	}
868 
869 	return 0;
870 
871 exit_device_put:
872 	platform_device_put(pdev);
873 exit:
874 	return err;
875 }
876 
877 static int __devinit via686a_pci_probe(struct pci_dev *dev,
878 				       const struct pci_device_id *id)
879 {
880 	u16 address, val;
881 
882 	if (force_addr) {
883 		address = force_addr & ~(VIA686A_EXTENT - 1);
884 		dev_warn(&dev->dev, "Forcing ISA address 0x%x\n", address);
885 		if (PCIBIOS_SUCCESSFUL !=
886 		    pci_write_config_word(dev, VIA686A_BASE_REG, address | 1))
887 			return -ENODEV;
888 	}
889 	if (PCIBIOS_SUCCESSFUL !=
890 	    pci_read_config_word(dev, VIA686A_BASE_REG, &val))
891 		return -ENODEV;
892 
893 	address = val & ~(VIA686A_EXTENT - 1);
894 	if (address == 0) {
895 		dev_err(&dev->dev, "base address not set - upgrade BIOS "
896 			"or use force_addr=0xaddr\n");
897 		return -ENODEV;
898 	}
899 
900 	if (PCIBIOS_SUCCESSFUL !=
901 	    pci_read_config_word(dev, VIA686A_ENABLE_REG, &val))
902 		return -ENODEV;
903 	if (!(val & 0x0001)) {
904 		if (!force_addr) {
905 			dev_warn(&dev->dev, "Sensors disabled, enable "
906 				 "with force_addr=0x%x\n", address);
907 			return -ENODEV;
908 		}
909 
910 		dev_warn(&dev->dev, "Enabling sensors\n");
911 		if (PCIBIOS_SUCCESSFUL !=
912 		    pci_write_config_word(dev, VIA686A_ENABLE_REG,
913 					  val | 0x0001))
914 			return -ENODEV;
915 	}
916 
917 	if (platform_driver_register(&via686a_driver))
918 		goto exit;
919 
920 	/* Sets global pdev as a side effect */
921 	if (via686a_device_add(address))
922 		goto exit_unregister;
923 
924 	/*
925 	 * Always return failure here.  This is to allow other drivers to bind
926 	 * to this pci device.  We don't really want to have control over the
927 	 * pci device, we only wanted to read as few register values from it.
928 	 */
929 	s_bridge = pci_dev_get(dev);
930 	return -ENODEV;
931 
932 exit_unregister:
933 	platform_driver_unregister(&via686a_driver);
934 exit:
935 	return -ENODEV;
936 }
937 
938 static struct pci_driver via686a_pci_driver = {
939 	.name		= "via686a",
940 	.id_table	= via686a_pci_ids,
941 	.probe		= via686a_pci_probe,
942 };
943 
944 static int __init sm_via686a_init(void)
945 {
946 	return pci_register_driver(&via686a_pci_driver);
947 }
948 
949 static void __exit sm_via686a_exit(void)
950 {
951 	pci_unregister_driver(&via686a_pci_driver);
952 	if (s_bridge != NULL) {
953 		platform_device_unregister(pdev);
954 		platform_driver_unregister(&via686a_driver);
955 		pci_dev_put(s_bridge);
956 		s_bridge = NULL;
957 	}
958 }
959 
960 MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>, "
961 	      "Mark Studebaker <mdsxyz123@yahoo.com> "
962 	      "and Bob Dougherty <bobd@stanford.edu>");
963 MODULE_DESCRIPTION("VIA 686A Sensor device");
964 MODULE_LICENSE("GPL");
965 
966 module_init(sm_via686a_init);
967 module_exit(sm_via686a_exit);
968