xref: /openbmc/linux/drivers/hwmon/via686a.c (revision fde0950903ce8cc38a91dd095280decceda2ff82)
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 			Ky�sti M�lkki <kmalkki@cc.hut.fi>,
7 			Mark Studebaker <mdsxyz123@yahoo.com>,
8 			and Bob Dougherty <bobd@stanford.edu>
9     (Some conversion-factor data were contributed by Jonathan Teh Soon Yew
10     <j.teh@iname.com> and Alex van Kaam <darkside@chello.nl>.)
11 
12     This program is free software; you can redistribute it and/or modify
13     it under the terms of the GNU General Public License as published by
14     the Free Software Foundation; either version 2 of the License, or
15     (at your option) any later version.
16 
17     This program is distributed in the hope that it will be useful,
18     but WITHOUT ANY WARRANTY; without even the implied warranty of
19     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20     GNU General Public License for more details.
21 
22     You should have received a copy of the GNU General Public License
23     along with this program; if not, write to the Free Software
24     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26 
27 /*
28     Supports the Via VT82C686A, VT82C686B south bridges.
29     Reports all as a 686A.
30     Warning - only supports a single device.
31 */
32 
33 #include <linux/module.h>
34 #include <linux/slab.h>
35 #include <linux/pci.h>
36 #include <linux/jiffies.h>
37 #include <linux/i2c.h>
38 #include <linux/i2c-isa.h>
39 #include <linux/i2c-sensor.h>
40 #include <linux/hwmon.h>
41 #include <linux/err.h>
42 #include <linux/init.h>
43 #include <asm/io.h>
44 
45 
46 /* If force_addr is set to anything different from 0, we forcibly enable
47    the device at the given address. */
48 static unsigned short force_addr = 0;
49 module_param(force_addr, ushort, 0);
50 MODULE_PARM_DESC(force_addr,
51 		 "Initialize the base address of the sensors");
52 
53 /* Addresses to scan.
54    Note that we can't determine the ISA address until we have initialized
55    our module */
56 static unsigned short normal_i2c[] = { I2C_CLIENT_END };
57 static unsigned int normal_isa[] = { 0x0000, I2C_CLIENT_ISA_END };
58 
59 /* Insmod parameters */
60 SENSORS_INSMOD_1(via686a);
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 /* The following register sets temp interrupt mode (bits 1-0 for temp1,
98  3-2 for temp2, 5-4 for temp3).  Modes are:
99     00 interrupt stays as long as value is out-of-range
100     01 interrupt is cleared once register is read (default)
101     10 comparator mode- like 00, but ignores hysteresis
102     11 same as 00 */
103 #define VIA686A_REG_TEMP_MODE		0x4b
104 /* We'll just assume that you want to set all 3 simultaneously: */
105 #define VIA686A_TEMP_MODE_MASK		0x3F
106 #define VIA686A_TEMP_MODE_CONTINUOUS	0x00
107 
108 /* Conversions. Limit checking is only done on the TO_REG
109    variants.
110 
111 ********* VOLTAGE CONVERSIONS (Bob Dougherty) ********
112  From HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew):
113  voltagefactor[0]=1.25/2628; (2628/1.25=2102.4)   // Vccp
114  voltagefactor[1]=1.25/2628; (2628/1.25=2102.4)   // +2.5V
115  voltagefactor[2]=1.67/2628; (2628/1.67=1573.7)   // +3.3V
116  voltagefactor[3]=2.6/2628;  (2628/2.60=1010.8)   // +5V
117  voltagefactor[4]=6.3/2628;  (2628/6.30=417.14)   // +12V
118  in[i]=(data[i+2]*25.0+133)*voltagefactor[i];
119  That is:
120  volts = (25*regVal+133)*factor
121  regVal = (volts/factor-133)/25
122  (These conversions were contributed by Jonathan Teh Soon Yew
123  <j.teh@iname.com>) */
124 static inline u8 IN_TO_REG(long val, int inNum)
125 {
126 	/* To avoid floating point, we multiply constants by 10 (100 for +12V).
127 	   Rounding is done (120500 is actually 133000 - 12500).
128 	   Remember that val is expressed in 0.001V/bit, which is why we divide
129 	   by an additional 10000 (100000 for +12V): 1000 for val and 10 (100)
130 	   for the constants. */
131 	if (inNum <= 1)
132 		return (u8)
133 		    SENSORS_LIMIT((val * 21024 - 1205000) / 250000, 0, 255);
134 	else if (inNum == 2)
135 		return (u8)
136 		    SENSORS_LIMIT((val * 15737 - 1205000) / 250000, 0, 255);
137 	else if (inNum == 3)
138 		return (u8)
139 		    SENSORS_LIMIT((val * 10108 - 1205000) / 250000, 0, 255);
140 	else
141 		return (u8)
142 		    SENSORS_LIMIT((val * 41714 - 12050000) / 2500000, 0, 255);
143 }
144 
145 static inline long IN_FROM_REG(u8 val, int inNum)
146 {
147 	/* To avoid floating point, we multiply constants by 10 (100 for +12V).
148 	   We also multiply them by 1000 because we want 0.001V/bit for the
149 	   output value. Rounding is done. */
150 	if (inNum <= 1)
151 		return (long) ((250000 * val + 1330000 + 21024 / 2) / 21024);
152 	else if (inNum == 2)
153 		return (long) ((250000 * val + 1330000 + 15737 / 2) / 15737);
154 	else if (inNum == 3)
155 		return (long) ((250000 * val + 1330000 + 10108 / 2) / 10108);
156 	else
157 		return (long) ((2500000 * val + 13300000 + 41714 / 2) / 41714);
158 }
159 
160 /********* FAN RPM CONVERSIONS ********/
161 /* Higher register values = slower fans (the fan's strobe gates a counter).
162  But this chip saturates back at 0, not at 255 like all the other chips.
163  So, 0 means 0 RPM */
164 static inline u8 FAN_TO_REG(long rpm, int div)
165 {
166 	if (rpm == 0)
167 		return 0;
168 	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
169 	return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 255);
170 }
171 
172 #define FAN_FROM_REG(val,div) ((val)==0?0:(val)==255?0:1350000/((val)*(div)))
173 
174 /******** TEMP CONVERSIONS (Bob Dougherty) *********/
175 /* linear fits from HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew)
176       if(temp<169)
177 	      return double(temp)*0.427-32.08;
178       else if(temp>=169 && temp<=202)
179 	      return double(temp)*0.582-58.16;
180       else
181 	      return double(temp)*0.924-127.33;
182 
183  A fifth-order polynomial fits the unofficial data (provided by Alex van
184  Kaam <darkside@chello.nl>) a bit better.  It also give more reasonable
185  numbers on my machine (ie. they agree with what my BIOS tells me).
186  Here's the fifth-order fit to the 8-bit data:
187  temp = 1.625093e-10*val^5 - 1.001632e-07*val^4 + 2.457653e-05*val^3 -
188 	2.967619e-03*val^2 + 2.175144e-01*val - 7.090067e+0.
189 
190  (2000-10-25- RFD: thanks to Uwe Andersen <uandersen@mayah.com> for
191  finding my typos in this formula!)
192 
193  Alas, none of the elegant function-fit solutions will work because we
194  aren't allowed to use floating point in the kernel and doing it with
195  integers doesn't provide enough precision.  So we'll do boring old
196  look-up table stuff.  The unofficial data (see below) have effectively
197  7-bit resolution (they are rounded to the nearest degree).  I'm assuming
198  that the transfer function of the device is monotonic and smooth, so a
199  smooth function fit to the data will allow us to get better precision.
200  I used the 5th-order poly fit described above and solved for
201  VIA register values 0-255.  I *10 before rounding, so we get tenth-degree
202  precision.  (I could have done all 1024 values for our 10-bit readings,
203  but the function is very linear in the useful range (0-80 deg C), so
204  we'll just use linear interpolation for 10-bit readings.)  So, tempLUT
205  is the temp at via register values 0-255: */
206 static const long tempLUT[] =
207 { -709, -688, -667, -646, -627, -607, -589, -570, -553, -536, -519,
208 	-503, -487, -471, -456, -442, -428, -414, -400, -387, -375,
209 	-362, -350, -339, -327, -316, -305, -295, -285, -275, -265,
210 	-255, -246, -237, -229, -220, -212, -204, -196, -188, -180,
211 	-173, -166, -159, -152, -145, -139, -132, -126, -120, -114,
212 	-108, -102, -96, -91, -85, -80, -74, -69, -64, -59, -54, -49,
213 	-44, -39, -34, -29, -25, -20, -15, -11, -6, -2, 3, 7, 12, 16,
214 	20, 25, 29, 33, 37, 42, 46, 50, 54, 59, 63, 67, 71, 75, 79, 84,
215 	88, 92, 96, 100, 104, 109, 113, 117, 121, 125, 130, 134, 138,
216 	142, 146, 151, 155, 159, 163, 168, 172, 176, 181, 185, 189,
217 	193, 198, 202, 206, 211, 215, 219, 224, 228, 232, 237, 241,
218 	245, 250, 254, 259, 263, 267, 272, 276, 281, 285, 290, 294,
219 	299, 303, 307, 312, 316, 321, 325, 330, 334, 339, 344, 348,
220 	353, 357, 362, 366, 371, 376, 380, 385, 390, 395, 399, 404,
221 	409, 414, 419, 423, 428, 433, 438, 443, 449, 454, 459, 464,
222 	469, 475, 480, 486, 491, 497, 502, 508, 514, 520, 526, 532,
223 	538, 544, 551, 557, 564, 571, 578, 584, 592, 599, 606, 614,
224 	621, 629, 637, 645, 654, 662, 671, 680, 689, 698, 708, 718,
225 	728, 738, 749, 759, 770, 782, 793, 805, 818, 830, 843, 856,
226 	870, 883, 898, 912, 927, 943, 958, 975, 991, 1008, 1026, 1044,
227 	1062, 1081, 1101, 1121, 1141, 1162, 1184, 1206, 1229, 1252,
228 	1276, 1301, 1326, 1352, 1378, 1406, 1434, 1462
229 };
230 
231 /* the original LUT values from Alex van Kaam <darkside@chello.nl>
232    (for via register values 12-240):
233 {-50,-49,-47,-45,-43,-41,-39,-38,-37,-35,-34,-33,-32,-31,
234 -30,-29,-28,-27,-26,-25,-24,-24,-23,-22,-21,-20,-20,-19,-18,-17,-17,-16,-15,
235 -15,-14,-14,-13,-12,-12,-11,-11,-10,-9,-9,-8,-8,-7,-7,-6,-6,-5,-5,-4,-4,-3,
236 -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,
237 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,
238 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,
239 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,
240 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,
241 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,
242 85,86,88,89,91,92,94,96,97,99,101,103,105,107,109,110};
243 
244 
245  Here's the reverse LUT.  I got it by doing a 6-th order poly fit (needed
246  an extra term for a good fit to these inverse data!) and then
247  solving for each temp value from -50 to 110 (the useable range for
248  this chip).  Here's the fit:
249  viaRegVal = -1.160370e-10*val^6 +3.193693e-08*val^5 - 1.464447e-06*val^4
250  - 2.525453e-04*val^3 + 1.424593e-02*val^2 + 2.148941e+00*val +7.275808e+01)
251  Note that n=161: */
252 static const u8 viaLUT[] =
253 { 12, 12, 13, 14, 14, 15, 16, 16, 17, 18, 18, 19, 20, 20, 21, 22, 23,
254 	23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 39, 40,
255 	41, 43, 45, 46, 48, 49, 51, 53, 55, 57, 59, 60, 62, 64, 66,
256 	69, 71, 73, 75, 77, 79, 82, 84, 86, 88, 91, 93, 95, 98, 100,
257 	103, 105, 107, 110, 112, 115, 117, 119, 122, 124, 126, 129,
258 	131, 134, 136, 138, 140, 143, 145, 147, 150, 152, 154, 156,
259 	158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180,
260 	182, 183, 185, 187, 188, 190, 192, 193, 195, 196, 198, 199,
261 	200, 202, 203, 205, 206, 207, 208, 209, 210, 211, 212, 213,
262 	214, 215, 216, 217, 218, 219, 220, 221, 222, 222, 223, 224,
263 	225, 226, 226, 227, 228, 228, 229, 230, 230, 231, 232, 232,
264 	233, 233, 234, 235, 235, 236, 236, 237, 237, 238, 238, 239,
265 	239, 240
266 };
267 
268 /* Converting temps to (8-bit) hyst and over registers
269    No interpolation here.
270    The +50 is because the temps start at -50 */
271 static inline u8 TEMP_TO_REG(long val)
272 {
273 	return viaLUT[val <= -50000 ? 0 : val >= 110000 ? 160 :
274 		      (val < 0 ? val - 500 : val + 500) / 1000 + 50];
275 }
276 
277 /* for 8-bit temperature hyst and over registers */
278 #define TEMP_FROM_REG(val) (tempLUT[(val)] * 100)
279 
280 /* for 10-bit temperature readings */
281 static inline long TEMP_FROM_REG10(u16 val)
282 {
283 	u16 eightBits = val >> 2;
284 	u16 twoBits = val & 3;
285 
286 	/* no interpolation for these */
287 	if (twoBits == 0 || eightBits == 255)
288 		return TEMP_FROM_REG(eightBits);
289 
290 	/* do some linear interpolation */
291 	return (tempLUT[eightBits] * (4 - twoBits) +
292 		tempLUT[eightBits + 1] * twoBits) * 25;
293 }
294 
295 #define DIV_FROM_REG(val) (1 << (val))
296 #define DIV_TO_REG(val) ((val)==8?3:(val)==4?2:(val)==1?0:1)
297 
298 /* For the VIA686A, we need to keep some data in memory.
299    The structure is dynamically allocated, at the same time when a new
300    via686a client is allocated. */
301 struct via686a_data {
302 	struct i2c_client client;
303 	struct class_device *class_dev;
304 	struct semaphore update_lock;
305 	char valid;		/* !=0 if following fields are valid */
306 	unsigned long last_updated;	/* In jiffies */
307 
308 	u8 in[5];		/* Register value */
309 	u8 in_max[5];		/* Register value */
310 	u8 in_min[5];		/* Register value */
311 	u8 fan[2];		/* Register value */
312 	u8 fan_min[2];		/* Register value */
313 	u16 temp[3];		/* Register value 10 bit */
314 	u8 temp_over[3];	/* Register value */
315 	u8 temp_hyst[3];	/* Register value */
316 	u8 fan_div[2];		/* Register encoding, shifted right */
317 	u16 alarms;		/* Register encoding, combined */
318 };
319 
320 static struct pci_dev *s_bridge;	/* pointer to the (only) via686a */
321 
322 static int via686a_attach_adapter(struct i2c_adapter *adapter);
323 static int via686a_detect(struct i2c_adapter *adapter, int address, int kind);
324 static int via686a_detach_client(struct i2c_client *client);
325 
326 static inline int via686a_read_value(struct i2c_client *client, u8 reg)
327 {
328 	return (inb_p(client->addr + reg));
329 }
330 
331 static inline void via686a_write_value(struct i2c_client *client, u8 reg,
332 				       u8 value)
333 {
334 	outb_p(value, client->addr + reg);
335 }
336 
337 static struct via686a_data *via686a_update_device(struct device *dev);
338 static void via686a_init_client(struct i2c_client *client);
339 
340 /* following are the sysfs callback functions */
341 
342 /* 7 voltage sensors */
343 static ssize_t show_in(struct device *dev, char *buf, int nr) {
344 	struct via686a_data *data = via686a_update_device(dev);
345 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in[nr], nr));
346 }
347 
348 static ssize_t show_in_min(struct device *dev, char *buf, int nr) {
349 	struct via686a_data *data = via686a_update_device(dev);
350 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_min[nr], nr));
351 }
352 
353 static ssize_t show_in_max(struct device *dev, char *buf, int nr) {
354 	struct via686a_data *data = via686a_update_device(dev);
355 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_max[nr], nr));
356 }
357 
358 static ssize_t set_in_min(struct device *dev, const char *buf,
359 		size_t count, int nr) {
360 	struct i2c_client *client = to_i2c_client(dev);
361 	struct via686a_data *data = i2c_get_clientdata(client);
362 	unsigned long val = simple_strtoul(buf, NULL, 10);
363 
364 	down(&data->update_lock);
365 	data->in_min[nr] = IN_TO_REG(val, nr);
366 	via686a_write_value(client, VIA686A_REG_IN_MIN(nr),
367 			data->in_min[nr]);
368 	up(&data->update_lock);
369 	return count;
370 }
371 static ssize_t set_in_max(struct device *dev, const char *buf,
372 		size_t count, int nr) {
373 	struct i2c_client *client = to_i2c_client(dev);
374 	struct via686a_data *data = i2c_get_clientdata(client);
375 	unsigned long val = simple_strtoul(buf, NULL, 10);
376 
377 	down(&data->update_lock);
378 	data->in_max[nr] = IN_TO_REG(val, nr);
379 	via686a_write_value(client, VIA686A_REG_IN_MAX(nr),
380 			data->in_max[nr]);
381 	up(&data->update_lock);
382 	return count;
383 }
384 #define show_in_offset(offset)					\
385 static ssize_t 							\
386 	show_in##offset (struct device *dev, struct device_attribute *attr, char *buf)		\
387 {								\
388 	return show_in(dev, buf, offset);			\
389 }								\
390 static ssize_t 							\
391 	show_in##offset##_min (struct device *dev, struct device_attribute *attr, char *buf)	\
392 {								\
393 	return show_in_min(dev, buf, offset);		\
394 }								\
395 static ssize_t 							\
396 	show_in##offset##_max (struct device *dev, struct device_attribute *attr, char *buf)	\
397 {								\
398 	return show_in_max(dev, buf, offset);		\
399 }								\
400 static ssize_t set_in##offset##_min (struct device *dev, struct device_attribute *attr, 	\
401 		const char *buf, size_t count) 			\
402 {								\
403 	return set_in_min(dev, buf, count, offset);		\
404 }								\
405 static ssize_t set_in##offset##_max (struct device *dev, struct device_attribute *attr,	\
406 			const char *buf, size_t count)		\
407 {								\
408 	return set_in_max(dev, buf, count, offset);		\
409 }								\
410 static DEVICE_ATTR(in##offset##_input, S_IRUGO, show_in##offset, NULL);\
411 static DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR, 	\
412 		show_in##offset##_min, set_in##offset##_min);	\
413 static DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR, 	\
414 		show_in##offset##_max, set_in##offset##_max);
415 
416 show_in_offset(0);
417 show_in_offset(1);
418 show_in_offset(2);
419 show_in_offset(3);
420 show_in_offset(4);
421 
422 /* 3 temperatures */
423 static ssize_t show_temp(struct device *dev, char *buf, int nr) {
424 	struct via686a_data *data = via686a_update_device(dev);
425 	return sprintf(buf, "%ld\n", TEMP_FROM_REG10(data->temp[nr]));
426 }
427 static ssize_t show_temp_over(struct device *dev, char *buf, int nr) {
428 	struct via686a_data *data = via686a_update_device(dev);
429 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_over[nr]));
430 }
431 static ssize_t show_temp_hyst(struct device *dev, char *buf, int nr) {
432 	struct via686a_data *data = via686a_update_device(dev);
433 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_hyst[nr]));
434 }
435 static ssize_t set_temp_over(struct device *dev, const char *buf,
436 		size_t count, int nr) {
437 	struct i2c_client *client = to_i2c_client(dev);
438 	struct via686a_data *data = i2c_get_clientdata(client);
439 	int val = simple_strtol(buf, NULL, 10);
440 
441 	down(&data->update_lock);
442 	data->temp_over[nr] = TEMP_TO_REG(val);
443 	via686a_write_value(client, VIA686A_REG_TEMP_OVER[nr],
444 			    data->temp_over[nr]);
445 	up(&data->update_lock);
446 	return count;
447 }
448 static ssize_t set_temp_hyst(struct device *dev, const char *buf,
449 		size_t count, int nr) {
450 	struct i2c_client *client = to_i2c_client(dev);
451 	struct via686a_data *data = i2c_get_clientdata(client);
452 	int val = simple_strtol(buf, NULL, 10);
453 
454 	down(&data->update_lock);
455 	data->temp_hyst[nr] = TEMP_TO_REG(val);
456 	via686a_write_value(client, VIA686A_REG_TEMP_HYST[nr],
457 			    data->temp_hyst[nr]);
458 	up(&data->update_lock);
459 	return count;
460 }
461 #define show_temp_offset(offset)					\
462 static ssize_t show_temp_##offset (struct device *dev, struct device_attribute *attr, char *buf)	\
463 {									\
464 	return show_temp(dev, buf, offset - 1);				\
465 }									\
466 static ssize_t								\
467 show_temp_##offset##_over (struct device *dev, struct device_attribute *attr, char *buf)		\
468 {									\
469 	return show_temp_over(dev, buf, offset - 1);			\
470 }									\
471 static ssize_t								\
472 show_temp_##offset##_hyst (struct device *dev, struct device_attribute *attr, char *buf)		\
473 {									\
474 	return show_temp_hyst(dev, buf, offset - 1);			\
475 }									\
476 static ssize_t set_temp_##offset##_over (struct device *dev, struct device_attribute *attr, 		\
477 		const char *buf, size_t count) 				\
478 {									\
479 	return set_temp_over(dev, buf, count, offset - 1);		\
480 }									\
481 static ssize_t set_temp_##offset##_hyst (struct device *dev, struct device_attribute *attr, 		\
482 		const char *buf, size_t count) 				\
483 {									\
484 	return set_temp_hyst(dev, buf, count, offset - 1);		\
485 }									\
486 static DEVICE_ATTR(temp##offset##_input, S_IRUGO, show_temp_##offset, NULL);\
487 static DEVICE_ATTR(temp##offset##_max, S_IRUGO | S_IWUSR, 		\
488 		show_temp_##offset##_over, set_temp_##offset##_over);	\
489 static DEVICE_ATTR(temp##offset##_max_hyst, S_IRUGO | S_IWUSR, 		\
490 		show_temp_##offset##_hyst, set_temp_##offset##_hyst);
491 
492 show_temp_offset(1);
493 show_temp_offset(2);
494 show_temp_offset(3);
495 
496 /* 2 Fans */
497 static ssize_t show_fan(struct device *dev, char *buf, int nr) {
498 	struct via686a_data *data = via686a_update_device(dev);
499 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
500 				DIV_FROM_REG(data->fan_div[nr])) );
501 }
502 static ssize_t show_fan_min(struct device *dev, char *buf, int nr) {
503 	struct via686a_data *data = via686a_update_device(dev);
504 	return sprintf(buf, "%d\n",
505 		FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr])) );
506 }
507 static ssize_t show_fan_div(struct device *dev, char *buf, int nr) {
508 	struct via686a_data *data = via686a_update_device(dev);
509 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]) );
510 }
511 static ssize_t set_fan_min(struct device *dev, const char *buf,
512 		size_t count, int nr) {
513 	struct i2c_client *client = to_i2c_client(dev);
514 	struct via686a_data *data = i2c_get_clientdata(client);
515 	int val = simple_strtol(buf, NULL, 10);
516 
517 	down(&data->update_lock);
518 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
519 	via686a_write_value(client, VIA686A_REG_FAN_MIN(nr+1), data->fan_min[nr]);
520 	up(&data->update_lock);
521 	return count;
522 }
523 static ssize_t set_fan_div(struct device *dev, const char *buf,
524 		size_t count, int nr) {
525 	struct i2c_client *client = to_i2c_client(dev);
526 	struct via686a_data *data = i2c_get_clientdata(client);
527 	int val = simple_strtol(buf, NULL, 10);
528 	int old;
529 
530 	down(&data->update_lock);
531 	old = via686a_read_value(client, VIA686A_REG_FANDIV);
532 	data->fan_div[nr] = DIV_TO_REG(val);
533 	old = (old & 0x0f) | (data->fan_div[1] << 6) | (data->fan_div[0] << 4);
534 	via686a_write_value(client, VIA686A_REG_FANDIV, old);
535 	up(&data->update_lock);
536 	return count;
537 }
538 
539 #define show_fan_offset(offset)						\
540 static ssize_t show_fan_##offset (struct device *dev, struct device_attribute *attr, char *buf)	\
541 {									\
542 	return show_fan(dev, buf, offset - 1);				\
543 }									\
544 static ssize_t show_fan_##offset##_min (struct device *dev, struct device_attribute *attr, char *buf)	\
545 {									\
546 	return show_fan_min(dev, buf, offset - 1);			\
547 }									\
548 static ssize_t show_fan_##offset##_div (struct device *dev, struct device_attribute *attr, char *buf)	\
549 {									\
550 	return show_fan_div(dev, buf, offset - 1);			\
551 }									\
552 static ssize_t set_fan_##offset##_min (struct device *dev, struct device_attribute *attr, 		\
553 	const char *buf, size_t count) 					\
554 {									\
555 	return set_fan_min(dev, buf, count, offset - 1);		\
556 }									\
557 static ssize_t set_fan_##offset##_div (struct device *dev, struct device_attribute *attr, 		\
558 		const char *buf, size_t count) 				\
559 {									\
560 	return set_fan_div(dev, buf, count, offset - 1);		\
561 }									\
562 static DEVICE_ATTR(fan##offset##_input, S_IRUGO, show_fan_##offset, NULL);\
563 static DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR, 		\
564 		show_fan_##offset##_min, set_fan_##offset##_min);	\
565 static DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR, 		\
566 		show_fan_##offset##_div, set_fan_##offset##_div);
567 
568 show_fan_offset(1);
569 show_fan_offset(2);
570 
571 /* Alarms */
572 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf) {
573 	struct via686a_data *data = via686a_update_device(dev);
574 	return sprintf(buf, "%u\n", data->alarms);
575 }
576 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
577 
578 /* The driver. I choose to use type i2c_driver, as at is identical to both
579    smbus_driver and isa_driver, and clients could be of either kind */
580 static struct i2c_driver via686a_driver = {
581 	.owner		= THIS_MODULE,
582 	.name		= "via686a",
583 	.id		= I2C_DRIVERID_VIA686A,
584 	.flags		= I2C_DF_NOTIFY,
585 	.attach_adapter	= via686a_attach_adapter,
586 	.detach_client	= via686a_detach_client,
587 };
588 
589 
590 /* This is called when the module is loaded */
591 static int via686a_attach_adapter(struct i2c_adapter *adapter)
592 {
593 	if (!(adapter->class & I2C_CLASS_HWMON))
594 		return 0;
595 	return i2c_detect(adapter, &addr_data, via686a_detect);
596 }
597 
598 static int via686a_detect(struct i2c_adapter *adapter, int address, int kind)
599 {
600 	struct i2c_client *new_client;
601 	struct via686a_data *data;
602 	int err = 0;
603 	const char client_name[] = "via686a";
604 	u16 val;
605 
606 	/* Make sure we are probing the ISA bus!!  */
607 	if (!i2c_is_isa_adapter(adapter)) {
608 		dev_err(&adapter->dev,
609 		"via686a_detect called for an I2C bus adapter?!?\n");
610 		return 0;
611 	}
612 
613 	/* 8231 requires multiple of 256, we enforce that on 686 as well */
614 	if (force_addr)
615 		address = force_addr & 0xFF00;
616 
617 	if (force_addr) {
618 		dev_warn(&adapter->dev, "forcing ISA address 0x%04X\n",
619 			 address);
620 		if (PCIBIOS_SUCCESSFUL !=
621 		    pci_write_config_word(s_bridge, VIA686A_BASE_REG, address))
622 			return -ENODEV;
623 	}
624 	if (PCIBIOS_SUCCESSFUL !=
625 	    pci_read_config_word(s_bridge, VIA686A_ENABLE_REG, &val))
626 		return -ENODEV;
627 	if (!(val & 0x0001)) {
628 		dev_warn(&adapter->dev, "enabling sensors\n");
629 		if (PCIBIOS_SUCCESSFUL !=
630 		    pci_write_config_word(s_bridge, VIA686A_ENABLE_REG,
631 					  val | 0x0001))
632 			return -ENODEV;
633 	}
634 
635 	/* Reserve the ISA region */
636 	if (!request_region(address, VIA686A_EXTENT, via686a_driver.name)) {
637 		dev_err(&adapter->dev, "region 0x%x already in use!\n",
638 			address);
639 		return -ENODEV;
640 	}
641 
642 	if (!(data = kmalloc(sizeof(struct via686a_data), GFP_KERNEL))) {
643 		err = -ENOMEM;
644 		goto exit_release;
645 	}
646 	memset(data, 0, sizeof(struct via686a_data));
647 
648 	new_client = &data->client;
649 	i2c_set_clientdata(new_client, data);
650 	new_client->addr = address;
651 	new_client->adapter = adapter;
652 	new_client->driver = &via686a_driver;
653 	new_client->flags = 0;
654 
655 	/* Fill in the remaining client fields and put into the global list */
656 	strlcpy(new_client->name, client_name, I2C_NAME_SIZE);
657 
658 	data->valid = 0;
659 	init_MUTEX(&data->update_lock);
660 	/* Tell the I2C layer a new client has arrived */
661 	if ((err = i2c_attach_client(new_client)))
662 		goto exit_free;
663 
664 	/* Initialize the VIA686A chip */
665 	via686a_init_client(new_client);
666 
667 	/* Register sysfs hooks */
668 	data->class_dev = hwmon_device_register(&new_client->dev);
669 	if (IS_ERR(data->class_dev)) {
670 		err = PTR_ERR(data->class_dev);
671 		goto exit_detach;
672 	}
673 
674 	device_create_file(&new_client->dev, &dev_attr_in0_input);
675 	device_create_file(&new_client->dev, &dev_attr_in1_input);
676 	device_create_file(&new_client->dev, &dev_attr_in2_input);
677 	device_create_file(&new_client->dev, &dev_attr_in3_input);
678 	device_create_file(&new_client->dev, &dev_attr_in4_input);
679 	device_create_file(&new_client->dev, &dev_attr_in0_min);
680 	device_create_file(&new_client->dev, &dev_attr_in1_min);
681 	device_create_file(&new_client->dev, &dev_attr_in2_min);
682 	device_create_file(&new_client->dev, &dev_attr_in3_min);
683 	device_create_file(&new_client->dev, &dev_attr_in4_min);
684 	device_create_file(&new_client->dev, &dev_attr_in0_max);
685 	device_create_file(&new_client->dev, &dev_attr_in1_max);
686 	device_create_file(&new_client->dev, &dev_attr_in2_max);
687 	device_create_file(&new_client->dev, &dev_attr_in3_max);
688 	device_create_file(&new_client->dev, &dev_attr_in4_max);
689 	device_create_file(&new_client->dev, &dev_attr_temp1_input);
690 	device_create_file(&new_client->dev, &dev_attr_temp2_input);
691 	device_create_file(&new_client->dev, &dev_attr_temp3_input);
692 	device_create_file(&new_client->dev, &dev_attr_temp1_max);
693 	device_create_file(&new_client->dev, &dev_attr_temp2_max);
694 	device_create_file(&new_client->dev, &dev_attr_temp3_max);
695 	device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
696 	device_create_file(&new_client->dev, &dev_attr_temp2_max_hyst);
697 	device_create_file(&new_client->dev, &dev_attr_temp3_max_hyst);
698 	device_create_file(&new_client->dev, &dev_attr_fan1_input);
699 	device_create_file(&new_client->dev, &dev_attr_fan2_input);
700 	device_create_file(&new_client->dev, &dev_attr_fan1_min);
701 	device_create_file(&new_client->dev, &dev_attr_fan2_min);
702 	device_create_file(&new_client->dev, &dev_attr_fan1_div);
703 	device_create_file(&new_client->dev, &dev_attr_fan2_div);
704 	device_create_file(&new_client->dev, &dev_attr_alarms);
705 
706 	return 0;
707 
708 exit_detach:
709 	i2c_detach_client(new_client);
710 exit_free:
711 	kfree(data);
712 exit_release:
713 	release_region(address, VIA686A_EXTENT);
714 	return err;
715 }
716 
717 static int via686a_detach_client(struct i2c_client *client)
718 {
719 	struct via686a_data *data = i2c_get_clientdata(client);
720 	int err;
721 
722 	hwmon_device_unregister(data->class_dev);
723 
724 	if ((err = i2c_detach_client(client))) {
725 		dev_err(&client->dev,
726 		"Client deregistration failed, client not detached.\n");
727 		return err;
728 	}
729 
730 	release_region(client->addr, VIA686A_EXTENT);
731 	kfree(data);
732 
733 	return 0;
734 }
735 
736 /* Called when we have found a new VIA686A. Set limits, etc. */
737 static void via686a_init_client(struct i2c_client *client)
738 {
739 	u8 reg;
740 
741 	/* Start monitoring */
742 	reg = via686a_read_value(client, VIA686A_REG_CONFIG);
743 	via686a_write_value(client, VIA686A_REG_CONFIG, (reg|0x01)&0x7F);
744 
745 	/* Configure temp interrupt mode for continuous-interrupt operation */
746 	via686a_write_value(client, VIA686A_REG_TEMP_MODE,
747 			    via686a_read_value(client, VIA686A_REG_TEMP_MODE) &
748 			    !(VIA686A_TEMP_MODE_MASK | VIA686A_TEMP_MODE_CONTINUOUS));
749 }
750 
751 static struct via686a_data *via686a_update_device(struct device *dev)
752 {
753 	struct i2c_client *client = to_i2c_client(dev);
754 	struct via686a_data *data = i2c_get_clientdata(client);
755 	int i;
756 
757 	down(&data->update_lock);
758 
759 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
760 	    || !data->valid) {
761 		for (i = 0; i <= 4; i++) {
762 			data->in[i] =
763 			    via686a_read_value(client, VIA686A_REG_IN(i));
764 			data->in_min[i] = via686a_read_value(client,
765 							     VIA686A_REG_IN_MIN
766 							     (i));
767 			data->in_max[i] =
768 			    via686a_read_value(client, VIA686A_REG_IN_MAX(i));
769 		}
770 		for (i = 1; i <= 2; i++) {
771 			data->fan[i - 1] =
772 			    via686a_read_value(client, VIA686A_REG_FAN(i));
773 			data->fan_min[i - 1] = via686a_read_value(client,
774 						     VIA686A_REG_FAN_MIN(i));
775 		}
776 		for (i = 0; i <= 2; i++) {
777 			data->temp[i] = via686a_read_value(client,
778 						 VIA686A_REG_TEMP[i]) << 2;
779 			data->temp_over[i] =
780 			    via686a_read_value(client,
781 					       VIA686A_REG_TEMP_OVER[i]);
782 			data->temp_hyst[i] =
783 			    via686a_read_value(client,
784 					       VIA686A_REG_TEMP_HYST[i]);
785 		}
786 		/* add in lower 2 bits
787 		   temp1 uses bits 7-6 of VIA686A_REG_TEMP_LOW1
788 		   temp2 uses bits 5-4 of VIA686A_REG_TEMP_LOW23
789 		   temp3 uses bits 7-6 of VIA686A_REG_TEMP_LOW23
790 		 */
791 		data->temp[0] |= (via686a_read_value(client,
792 						     VIA686A_REG_TEMP_LOW1)
793 				  & 0xc0) >> 6;
794 		data->temp[1] |=
795 		    (via686a_read_value(client, VIA686A_REG_TEMP_LOW23) &
796 		     0x30) >> 4;
797 		data->temp[2] |=
798 		    (via686a_read_value(client, VIA686A_REG_TEMP_LOW23) &
799 		     0xc0) >> 6;
800 
801 		i = via686a_read_value(client, VIA686A_REG_FANDIV);
802 		data->fan_div[0] = (i >> 4) & 0x03;
803 		data->fan_div[1] = i >> 6;
804 		data->alarms =
805 		    via686a_read_value(client,
806 				       VIA686A_REG_ALARM1) |
807 		    (via686a_read_value(client, VIA686A_REG_ALARM2) << 8);
808 		data->last_updated = jiffies;
809 		data->valid = 1;
810 	}
811 
812 	up(&data->update_lock);
813 
814 	return data;
815 }
816 
817 static struct pci_device_id via686a_pci_ids[] = {
818 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4) },
819 	{ 0, }
820 };
821 
822 MODULE_DEVICE_TABLE(pci, via686a_pci_ids);
823 
824 static int __devinit via686a_pci_probe(struct pci_dev *dev,
825 				       const struct pci_device_id *id)
826 {
827 	u16 val;
828 	int addr = 0;
829 
830 	if (PCIBIOS_SUCCESSFUL !=
831 	    pci_read_config_word(dev, VIA686A_BASE_REG, &val))
832 		return -ENODEV;
833 
834 	addr = val & ~(VIA686A_EXTENT - 1);
835 	if (addr == 0 && force_addr == 0) {
836 		dev_err(&dev->dev, "base address not set - upgrade BIOS "
837 			"or use force_addr=0xaddr\n");
838 		return -ENODEV;
839 	}
840 	if (force_addr)
841 		addr = force_addr;	/* so detect will get called */
842 
843 	if (!addr) {
844 		dev_err(&dev->dev, "No Via 686A sensors found.\n");
845 		return -ENODEV;
846 	}
847 	normal_isa[0] = addr;
848 
849 	s_bridge = pci_dev_get(dev);
850 	if (i2c_isa_add_driver(&via686a_driver)) {
851 		pci_dev_put(s_bridge);
852 		s_bridge = NULL;
853 	}
854 
855 	/* Always return failure here.  This is to allow other drivers to bind
856 	 * to this pci device.  We don't really want to have control over the
857 	 * pci device, we only wanted to read as few register values from it.
858 	 */
859 	return -ENODEV;
860 }
861 
862 static struct pci_driver via686a_pci_driver = {
863 	.name		= "via686a",
864 	.id_table	= via686a_pci_ids,
865 	.probe		= via686a_pci_probe,
866 };
867 
868 static int __init sm_via686a_init(void)
869 {
870 	return pci_register_driver(&via686a_pci_driver);
871 }
872 
873 static void __exit sm_via686a_exit(void)
874 {
875 	pci_unregister_driver(&via686a_pci_driver);
876 	if (s_bridge != NULL) {
877 		i2c_isa_del_driver(&via686a_driver);
878 		pci_dev_put(s_bridge);
879 		s_bridge = NULL;
880 	}
881 }
882 
883 MODULE_AUTHOR("Ky�sti M�lkki <kmalkki@cc.hut.fi>, "
884 	      "Mark Studebaker <mdsxyz123@yahoo.com> "
885 	      "and Bob Dougherty <bobd@stanford.edu>");
886 MODULE_DESCRIPTION("VIA 686A Sensor device");
887 MODULE_LICENSE("GPL");
888 
889 module_init(sm_via686a_init);
890 module_exit(sm_via686a_exit);
891