xref: /openbmc/linux/drivers/hwmon/via686a.c (revision 2d8672c5a6ba0d3f1d8d3ad61ef67868941364f0)
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 /* Device address
54    Note that we can't determine the ISA address until we have initialized
55    our module */
56 static unsigned short address;
57 
58 /*
59    The Via 686a southbridge has a LM78-like chip integrated on the same IC.
60    This driver is a customized copy of lm78.c
61 */
62 
63 /* Many VIA686A constants specified below */
64 
65 /* Length of ISA address segment */
66 #define VIA686A_EXTENT		0x80
67 #define VIA686A_BASE_REG	0x70
68 #define VIA686A_ENABLE_REG	0x74
69 
70 /* The VIA686A registers */
71 /* ins numbered 0-4 */
72 #define VIA686A_REG_IN_MAX(nr)	(0x2b + ((nr) * 2))
73 #define VIA686A_REG_IN_MIN(nr)	(0x2c + ((nr) * 2))
74 #define VIA686A_REG_IN(nr)	(0x22 + (nr))
75 
76 /* fans numbered 1-2 */
77 #define VIA686A_REG_FAN_MIN(nr)	(0x3a + (nr))
78 #define VIA686A_REG_FAN(nr)	(0x28 + (nr))
79 
80 /* temps numbered 1-3 */
81 static const u8 VIA686A_REG_TEMP[]	= { 0x20, 0x21, 0x1f };
82 static const u8 VIA686A_REG_TEMP_OVER[]	= { 0x39, 0x3d, 0x1d };
83 static const u8 VIA686A_REG_TEMP_HYST[]	= { 0x3a, 0x3e, 0x1e };
84 /* bits 7-6 */
85 #define VIA686A_REG_TEMP_LOW1	0x4b
86 /* 2 = bits 5-4, 3 = bits 7-6 */
87 #define VIA686A_REG_TEMP_LOW23	0x49
88 
89 #define VIA686A_REG_ALARM1	0x41
90 #define VIA686A_REG_ALARM2	0x42
91 #define VIA686A_REG_FANDIV	0x47
92 #define VIA686A_REG_CONFIG	0x40
93 /* The following register sets temp interrupt mode (bits 1-0 for temp1,
94  3-2 for temp2, 5-4 for temp3).  Modes are:
95     00 interrupt stays as long as value is out-of-range
96     01 interrupt is cleared once register is read (default)
97     10 comparator mode- like 00, but ignores hysteresis
98     11 same as 00 */
99 #define VIA686A_REG_TEMP_MODE		0x4b
100 /* We'll just assume that you want to set all 3 simultaneously: */
101 #define VIA686A_TEMP_MODE_MASK		0x3F
102 #define VIA686A_TEMP_MODE_CONTINUOUS	0x00
103 
104 /* Conversions. Limit checking is only done on the TO_REG
105    variants.
106 
107 ********* VOLTAGE CONVERSIONS (Bob Dougherty) ********
108  From HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew):
109  voltagefactor[0]=1.25/2628; (2628/1.25=2102.4)   // Vccp
110  voltagefactor[1]=1.25/2628; (2628/1.25=2102.4)   // +2.5V
111  voltagefactor[2]=1.67/2628; (2628/1.67=1573.7)   // +3.3V
112  voltagefactor[3]=2.6/2628;  (2628/2.60=1010.8)   // +5V
113  voltagefactor[4]=6.3/2628;  (2628/6.30=417.14)   // +12V
114  in[i]=(data[i+2]*25.0+133)*voltagefactor[i];
115  That is:
116  volts = (25*regVal+133)*factor
117  regVal = (volts/factor-133)/25
118  (These conversions were contributed by Jonathan Teh Soon Yew
119  <j.teh@iname.com>) */
120 static inline u8 IN_TO_REG(long val, int inNum)
121 {
122 	/* To avoid floating point, we multiply constants by 10 (100 for +12V).
123 	   Rounding is done (120500 is actually 133000 - 12500).
124 	   Remember that val is expressed in 0.001V/bit, which is why we divide
125 	   by an additional 10000 (100000 for +12V): 1000 for val and 10 (100)
126 	   for the constants. */
127 	if (inNum <= 1)
128 		return (u8)
129 		    SENSORS_LIMIT((val * 21024 - 1205000) / 250000, 0, 255);
130 	else if (inNum == 2)
131 		return (u8)
132 		    SENSORS_LIMIT((val * 15737 - 1205000) / 250000, 0, 255);
133 	else if (inNum == 3)
134 		return (u8)
135 		    SENSORS_LIMIT((val * 10108 - 1205000) / 250000, 0, 255);
136 	else
137 		return (u8)
138 		    SENSORS_LIMIT((val * 41714 - 12050000) / 2500000, 0, 255);
139 }
140 
141 static inline long IN_FROM_REG(u8 val, int inNum)
142 {
143 	/* To avoid floating point, we multiply constants by 10 (100 for +12V).
144 	   We also multiply them by 1000 because we want 0.001V/bit for the
145 	   output value. Rounding is done. */
146 	if (inNum <= 1)
147 		return (long) ((250000 * val + 1330000 + 21024 / 2) / 21024);
148 	else if (inNum == 2)
149 		return (long) ((250000 * val + 1330000 + 15737 / 2) / 15737);
150 	else if (inNum == 3)
151 		return (long) ((250000 * val + 1330000 + 10108 / 2) / 10108);
152 	else
153 		return (long) ((2500000 * val + 13300000 + 41714 / 2) / 41714);
154 }
155 
156 /********* FAN RPM CONVERSIONS ********/
157 /* Higher register values = slower fans (the fan's strobe gates a counter).
158  But this chip saturates back at 0, not at 255 like all the other chips.
159  So, 0 means 0 RPM */
160 static inline u8 FAN_TO_REG(long rpm, int div)
161 {
162 	if (rpm == 0)
163 		return 0;
164 	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
165 	return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 255);
166 }
167 
168 #define FAN_FROM_REG(val,div) ((val)==0?0:(val)==255?0:1350000/((val)*(div)))
169 
170 /******** TEMP CONVERSIONS (Bob Dougherty) *********/
171 /* linear fits from HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew)
172       if(temp<169)
173 	      return double(temp)*0.427-32.08;
174       else if(temp>=169 && temp<=202)
175 	      return double(temp)*0.582-58.16;
176       else
177 	      return double(temp)*0.924-127.33;
178 
179  A fifth-order polynomial fits the unofficial data (provided by Alex van
180  Kaam <darkside@chello.nl>) a bit better.  It also give more reasonable
181  numbers on my machine (ie. they agree with what my BIOS tells me).
182  Here's the fifth-order fit to the 8-bit data:
183  temp = 1.625093e-10*val^5 - 1.001632e-07*val^4 + 2.457653e-05*val^3 -
184 	2.967619e-03*val^2 + 2.175144e-01*val - 7.090067e+0.
185 
186  (2000-10-25- RFD: thanks to Uwe Andersen <uandersen@mayah.com> for
187  finding my typos in this formula!)
188 
189  Alas, none of the elegant function-fit solutions will work because we
190  aren't allowed to use floating point in the kernel and doing it with
191  integers doesn't provide enough precision.  So we'll do boring old
192  look-up table stuff.  The unofficial data (see below) have effectively
193  7-bit resolution (they are rounded to the nearest degree).  I'm assuming
194  that the transfer function of the device is monotonic and smooth, so a
195  smooth function fit to the data will allow us to get better precision.
196  I used the 5th-order poly fit described above and solved for
197  VIA register values 0-255.  I *10 before rounding, so we get tenth-degree
198  precision.  (I could have done all 1024 values for our 10-bit readings,
199  but the function is very linear in the useful range (0-80 deg C), so
200  we'll just use linear interpolation for 10-bit readings.)  So, tempLUT
201  is the temp at via register values 0-255: */
202 static const long tempLUT[] =
203 { -709, -688, -667, -646, -627, -607, -589, -570, -553, -536, -519,
204 	-503, -487, -471, -456, -442, -428, -414, -400, -387, -375,
205 	-362, -350, -339, -327, -316, -305, -295, -285, -275, -265,
206 	-255, -246, -237, -229, -220, -212, -204, -196, -188, -180,
207 	-173, -166, -159, -152, -145, -139, -132, -126, -120, -114,
208 	-108, -102, -96, -91, -85, -80, -74, -69, -64, -59, -54, -49,
209 	-44, -39, -34, -29, -25, -20, -15, -11, -6, -2, 3, 7, 12, 16,
210 	20, 25, 29, 33, 37, 42, 46, 50, 54, 59, 63, 67, 71, 75, 79, 84,
211 	88, 92, 96, 100, 104, 109, 113, 117, 121, 125, 130, 134, 138,
212 	142, 146, 151, 155, 159, 163, 168, 172, 176, 181, 185, 189,
213 	193, 198, 202, 206, 211, 215, 219, 224, 228, 232, 237, 241,
214 	245, 250, 254, 259, 263, 267, 272, 276, 281, 285, 290, 294,
215 	299, 303, 307, 312, 316, 321, 325, 330, 334, 339, 344, 348,
216 	353, 357, 362, 366, 371, 376, 380, 385, 390, 395, 399, 404,
217 	409, 414, 419, 423, 428, 433, 438, 443, 449, 454, 459, 464,
218 	469, 475, 480, 486, 491, 497, 502, 508, 514, 520, 526, 532,
219 	538, 544, 551, 557, 564, 571, 578, 584, 592, 599, 606, 614,
220 	621, 629, 637, 645, 654, 662, 671, 680, 689, 698, 708, 718,
221 	728, 738, 749, 759, 770, 782, 793, 805, 818, 830, 843, 856,
222 	870, 883, 898, 912, 927, 943, 958, 975, 991, 1008, 1026, 1044,
223 	1062, 1081, 1101, 1121, 1141, 1162, 1184, 1206, 1229, 1252,
224 	1276, 1301, 1326, 1352, 1378, 1406, 1434, 1462
225 };
226 
227 /* the original LUT values from Alex van Kaam <darkside@chello.nl>
228    (for via register values 12-240):
229 {-50,-49,-47,-45,-43,-41,-39,-38,-37,-35,-34,-33,-32,-31,
230 -30,-29,-28,-27,-26,-25,-24,-24,-23,-22,-21,-20,-20,-19,-18,-17,-17,-16,-15,
231 -15,-14,-14,-13,-12,-12,-11,-11,-10,-9,-9,-8,-8,-7,-7,-6,-6,-5,-5,-4,-4,-3,
232 -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,
233 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,
234 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,
235 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,
236 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,
237 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,
238 85,86,88,89,91,92,94,96,97,99,101,103,105,107,109,110};
239 
240 
241  Here's the reverse LUT.  I got it by doing a 6-th order poly fit (needed
242  an extra term for a good fit to these inverse data!) and then
243  solving for each temp value from -50 to 110 (the useable range for
244  this chip).  Here's the fit:
245  viaRegVal = -1.160370e-10*val^6 +3.193693e-08*val^5 - 1.464447e-06*val^4
246  - 2.525453e-04*val^3 + 1.424593e-02*val^2 + 2.148941e+00*val +7.275808e+01)
247  Note that n=161: */
248 static const u8 viaLUT[] =
249 { 12, 12, 13, 14, 14, 15, 16, 16, 17, 18, 18, 19, 20, 20, 21, 22, 23,
250 	23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 39, 40,
251 	41, 43, 45, 46, 48, 49, 51, 53, 55, 57, 59, 60, 62, 64, 66,
252 	69, 71, 73, 75, 77, 79, 82, 84, 86, 88, 91, 93, 95, 98, 100,
253 	103, 105, 107, 110, 112, 115, 117, 119, 122, 124, 126, 129,
254 	131, 134, 136, 138, 140, 143, 145, 147, 150, 152, 154, 156,
255 	158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180,
256 	182, 183, 185, 187, 188, 190, 192, 193, 195, 196, 198, 199,
257 	200, 202, 203, 205, 206, 207, 208, 209, 210, 211, 212, 213,
258 	214, 215, 216, 217, 218, 219, 220, 221, 222, 222, 223, 224,
259 	225, 226, 226, 227, 228, 228, 229, 230, 230, 231, 232, 232,
260 	233, 233, 234, 235, 235, 236, 236, 237, 237, 238, 238, 239,
261 	239, 240
262 };
263 
264 /* Converting temps to (8-bit) hyst and over registers
265    No interpolation here.
266    The +50 is because the temps start at -50 */
267 static inline u8 TEMP_TO_REG(long val)
268 {
269 	return viaLUT[val <= -50000 ? 0 : val >= 110000 ? 160 :
270 		      (val < 0 ? val - 500 : val + 500) / 1000 + 50];
271 }
272 
273 /* for 8-bit temperature hyst and over registers */
274 #define TEMP_FROM_REG(val) (tempLUT[(val)] * 100)
275 
276 /* for 10-bit temperature readings */
277 static inline long TEMP_FROM_REG10(u16 val)
278 {
279 	u16 eightBits = val >> 2;
280 	u16 twoBits = val & 3;
281 
282 	/* no interpolation for these */
283 	if (twoBits == 0 || eightBits == 255)
284 		return TEMP_FROM_REG(eightBits);
285 
286 	/* do some linear interpolation */
287 	return (tempLUT[eightBits] * (4 - twoBits) +
288 		tempLUT[eightBits + 1] * twoBits) * 25;
289 }
290 
291 #define DIV_FROM_REG(val) (1 << (val))
292 #define DIV_TO_REG(val) ((val)==8?3:(val)==4?2:(val)==1?0:1)
293 
294 /* For the VIA686A, we need to keep some data in memory.
295    The structure is dynamically allocated, at the same time when a new
296    via686a client is allocated. */
297 struct via686a_data {
298 	struct i2c_client client;
299 	struct class_device *class_dev;
300 	struct semaphore update_lock;
301 	char valid;		/* !=0 if following fields are valid */
302 	unsigned long last_updated;	/* In jiffies */
303 
304 	u8 in[5];		/* Register value */
305 	u8 in_max[5];		/* Register value */
306 	u8 in_min[5];		/* Register value */
307 	u8 fan[2];		/* Register value */
308 	u8 fan_min[2];		/* Register value */
309 	u16 temp[3];		/* Register value 10 bit */
310 	u8 temp_over[3];	/* Register value */
311 	u8 temp_hyst[3];	/* Register value */
312 	u8 fan_div[2];		/* Register encoding, shifted right */
313 	u16 alarms;		/* Register encoding, combined */
314 };
315 
316 static struct pci_dev *s_bridge;	/* pointer to the (only) via686a */
317 
318 static int via686a_detect(struct i2c_adapter *adapter);
319 static int via686a_detach_client(struct i2c_client *client);
320 
321 static inline int via686a_read_value(struct i2c_client *client, u8 reg)
322 {
323 	return (inb_p(client->addr + reg));
324 }
325 
326 static inline void via686a_write_value(struct i2c_client *client, u8 reg,
327 				       u8 value)
328 {
329 	outb_p(value, client->addr + reg);
330 }
331 
332 static struct via686a_data *via686a_update_device(struct device *dev);
333 static void via686a_init_client(struct i2c_client *client);
334 
335 /* following are the sysfs callback functions */
336 
337 /* 7 voltage sensors */
338 static ssize_t show_in(struct device *dev, char *buf, int nr) {
339 	struct via686a_data *data = via686a_update_device(dev);
340 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in[nr], nr));
341 }
342 
343 static ssize_t show_in_min(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_min[nr], nr));
346 }
347 
348 static ssize_t show_in_max(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_max[nr], nr));
351 }
352 
353 static ssize_t set_in_min(struct device *dev, const char *buf,
354 		size_t count, int nr) {
355 	struct i2c_client *client = to_i2c_client(dev);
356 	struct via686a_data *data = i2c_get_clientdata(client);
357 	unsigned long val = simple_strtoul(buf, NULL, 10);
358 
359 	down(&data->update_lock);
360 	data->in_min[nr] = IN_TO_REG(val, nr);
361 	via686a_write_value(client, VIA686A_REG_IN_MIN(nr),
362 			data->in_min[nr]);
363 	up(&data->update_lock);
364 	return count;
365 }
366 static ssize_t set_in_max(struct device *dev, const char *buf,
367 		size_t count, int nr) {
368 	struct i2c_client *client = to_i2c_client(dev);
369 	struct via686a_data *data = i2c_get_clientdata(client);
370 	unsigned long val = simple_strtoul(buf, NULL, 10);
371 
372 	down(&data->update_lock);
373 	data->in_max[nr] = IN_TO_REG(val, nr);
374 	via686a_write_value(client, VIA686A_REG_IN_MAX(nr),
375 			data->in_max[nr]);
376 	up(&data->update_lock);
377 	return count;
378 }
379 #define show_in_offset(offset)					\
380 static ssize_t 							\
381 	show_in##offset (struct device *dev, struct device_attribute *attr, char *buf)		\
382 {								\
383 	return show_in(dev, buf, offset);			\
384 }								\
385 static ssize_t 							\
386 	show_in##offset##_min (struct device *dev, struct device_attribute *attr, char *buf)	\
387 {								\
388 	return show_in_min(dev, buf, offset);		\
389 }								\
390 static ssize_t 							\
391 	show_in##offset##_max (struct device *dev, struct device_attribute *attr, char *buf)	\
392 {								\
393 	return show_in_max(dev, buf, offset);		\
394 }								\
395 static ssize_t set_in##offset##_min (struct device *dev, struct device_attribute *attr, 	\
396 		const char *buf, size_t count) 			\
397 {								\
398 	return set_in_min(dev, buf, count, offset);		\
399 }								\
400 static ssize_t set_in##offset##_max (struct device *dev, struct device_attribute *attr,	\
401 			const char *buf, size_t count)		\
402 {								\
403 	return set_in_max(dev, buf, count, offset);		\
404 }								\
405 static DEVICE_ATTR(in##offset##_input, S_IRUGO, show_in##offset, NULL);\
406 static DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR, 	\
407 		show_in##offset##_min, set_in##offset##_min);	\
408 static DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR, 	\
409 		show_in##offset##_max, set_in##offset##_max);
410 
411 show_in_offset(0);
412 show_in_offset(1);
413 show_in_offset(2);
414 show_in_offset(3);
415 show_in_offset(4);
416 
417 /* 3 temperatures */
418 static ssize_t show_temp(struct device *dev, char *buf, int nr) {
419 	struct via686a_data *data = via686a_update_device(dev);
420 	return sprintf(buf, "%ld\n", TEMP_FROM_REG10(data->temp[nr]));
421 }
422 static ssize_t show_temp_over(struct device *dev, char *buf, int nr) {
423 	struct via686a_data *data = via686a_update_device(dev);
424 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_over[nr]));
425 }
426 static ssize_t show_temp_hyst(struct device *dev, char *buf, int nr) {
427 	struct via686a_data *data = via686a_update_device(dev);
428 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_hyst[nr]));
429 }
430 static ssize_t set_temp_over(struct device *dev, const char *buf,
431 		size_t count, int nr) {
432 	struct i2c_client *client = to_i2c_client(dev);
433 	struct via686a_data *data = i2c_get_clientdata(client);
434 	int val = simple_strtol(buf, NULL, 10);
435 
436 	down(&data->update_lock);
437 	data->temp_over[nr] = TEMP_TO_REG(val);
438 	via686a_write_value(client, VIA686A_REG_TEMP_OVER[nr],
439 			    data->temp_over[nr]);
440 	up(&data->update_lock);
441 	return count;
442 }
443 static ssize_t set_temp_hyst(struct device *dev, const char *buf,
444 		size_t count, int nr) {
445 	struct i2c_client *client = to_i2c_client(dev);
446 	struct via686a_data *data = i2c_get_clientdata(client);
447 	int val = simple_strtol(buf, NULL, 10);
448 
449 	down(&data->update_lock);
450 	data->temp_hyst[nr] = TEMP_TO_REG(val);
451 	via686a_write_value(client, VIA686A_REG_TEMP_HYST[nr],
452 			    data->temp_hyst[nr]);
453 	up(&data->update_lock);
454 	return count;
455 }
456 #define show_temp_offset(offset)					\
457 static ssize_t show_temp_##offset (struct device *dev, struct device_attribute *attr, char *buf)	\
458 {									\
459 	return show_temp(dev, buf, offset - 1);				\
460 }									\
461 static ssize_t								\
462 show_temp_##offset##_over (struct device *dev, struct device_attribute *attr, char *buf)		\
463 {									\
464 	return show_temp_over(dev, buf, offset - 1);			\
465 }									\
466 static ssize_t								\
467 show_temp_##offset##_hyst (struct device *dev, struct device_attribute *attr, char *buf)		\
468 {									\
469 	return show_temp_hyst(dev, buf, offset - 1);			\
470 }									\
471 static ssize_t set_temp_##offset##_over (struct device *dev, struct device_attribute *attr, 		\
472 		const char *buf, size_t count) 				\
473 {									\
474 	return set_temp_over(dev, buf, count, offset - 1);		\
475 }									\
476 static ssize_t set_temp_##offset##_hyst (struct device *dev, struct device_attribute *attr, 		\
477 		const char *buf, size_t count) 				\
478 {									\
479 	return set_temp_hyst(dev, buf, count, offset - 1);		\
480 }									\
481 static DEVICE_ATTR(temp##offset##_input, S_IRUGO, show_temp_##offset, NULL);\
482 static DEVICE_ATTR(temp##offset##_max, S_IRUGO | S_IWUSR, 		\
483 		show_temp_##offset##_over, set_temp_##offset##_over);	\
484 static DEVICE_ATTR(temp##offset##_max_hyst, S_IRUGO | S_IWUSR, 		\
485 		show_temp_##offset##_hyst, set_temp_##offset##_hyst);
486 
487 show_temp_offset(1);
488 show_temp_offset(2);
489 show_temp_offset(3);
490 
491 /* 2 Fans */
492 static ssize_t show_fan(struct device *dev, char *buf, int nr) {
493 	struct via686a_data *data = via686a_update_device(dev);
494 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
495 				DIV_FROM_REG(data->fan_div[nr])) );
496 }
497 static ssize_t show_fan_min(struct device *dev, char *buf, int nr) {
498 	struct via686a_data *data = via686a_update_device(dev);
499 	return sprintf(buf, "%d\n",
500 		FAN_FROM_REG(data->fan_min[nr], DIV_FROM_REG(data->fan_div[nr])) );
501 }
502 static ssize_t show_fan_div(struct device *dev, char *buf, int nr) {
503 	struct via686a_data *data = via686a_update_device(dev);
504 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]) );
505 }
506 static ssize_t set_fan_min(struct device *dev, const char *buf,
507 		size_t count, int nr) {
508 	struct i2c_client *client = to_i2c_client(dev);
509 	struct via686a_data *data = i2c_get_clientdata(client);
510 	int val = simple_strtol(buf, NULL, 10);
511 
512 	down(&data->update_lock);
513 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
514 	via686a_write_value(client, VIA686A_REG_FAN_MIN(nr+1), data->fan_min[nr]);
515 	up(&data->update_lock);
516 	return count;
517 }
518 static ssize_t set_fan_div(struct device *dev, const char *buf,
519 		size_t count, int nr) {
520 	struct i2c_client *client = to_i2c_client(dev);
521 	struct via686a_data *data = i2c_get_clientdata(client);
522 	int val = simple_strtol(buf, NULL, 10);
523 	int old;
524 
525 	down(&data->update_lock);
526 	old = via686a_read_value(client, VIA686A_REG_FANDIV);
527 	data->fan_div[nr] = DIV_TO_REG(val);
528 	old = (old & 0x0f) | (data->fan_div[1] << 6) | (data->fan_div[0] << 4);
529 	via686a_write_value(client, VIA686A_REG_FANDIV, old);
530 	up(&data->update_lock);
531 	return count;
532 }
533 
534 #define show_fan_offset(offset)						\
535 static ssize_t show_fan_##offset (struct device *dev, struct device_attribute *attr, char *buf)	\
536 {									\
537 	return show_fan(dev, buf, offset - 1);				\
538 }									\
539 static ssize_t show_fan_##offset##_min (struct device *dev, struct device_attribute *attr, char *buf)	\
540 {									\
541 	return show_fan_min(dev, buf, offset - 1);			\
542 }									\
543 static ssize_t show_fan_##offset##_div (struct device *dev, struct device_attribute *attr, char *buf)	\
544 {									\
545 	return show_fan_div(dev, buf, offset - 1);			\
546 }									\
547 static ssize_t set_fan_##offset##_min (struct device *dev, struct device_attribute *attr, 		\
548 	const char *buf, size_t count) 					\
549 {									\
550 	return set_fan_min(dev, buf, count, offset - 1);		\
551 }									\
552 static ssize_t set_fan_##offset##_div (struct device *dev, struct device_attribute *attr, 		\
553 		const char *buf, size_t count) 				\
554 {									\
555 	return set_fan_div(dev, buf, count, offset - 1);		\
556 }									\
557 static DEVICE_ATTR(fan##offset##_input, S_IRUGO, show_fan_##offset, NULL);\
558 static DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR, 		\
559 		show_fan_##offset##_min, set_fan_##offset##_min);	\
560 static DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR, 		\
561 		show_fan_##offset##_div, set_fan_##offset##_div);
562 
563 show_fan_offset(1);
564 show_fan_offset(2);
565 
566 /* Alarms */
567 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf) {
568 	struct via686a_data *data = via686a_update_device(dev);
569 	return sprintf(buf, "%u\n", data->alarms);
570 }
571 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
572 
573 /* The driver. I choose to use type i2c_driver, as at is identical to both
574    smbus_driver and isa_driver, and clients could be of either kind */
575 static struct i2c_driver via686a_driver = {
576 	.owner		= THIS_MODULE,
577 	.name		= "via686a",
578 	.attach_adapter	= via686a_detect,
579 	.detach_client	= via686a_detach_client,
580 };
581 
582 
583 /* This is called when the module is loaded */
584 static int via686a_detect(struct i2c_adapter *adapter)
585 {
586 	struct i2c_client *new_client;
587 	struct via686a_data *data;
588 	int err = 0;
589 	const char client_name[] = "via686a";
590 	u16 val;
591 
592 	/* 8231 requires multiple of 256, we enforce that on 686 as well */
593 	if (force_addr)
594 		address = force_addr & 0xFF00;
595 
596 	if (force_addr) {
597 		dev_warn(&adapter->dev, "forcing ISA address 0x%04X\n",
598 			 address);
599 		if (PCIBIOS_SUCCESSFUL !=
600 		    pci_write_config_word(s_bridge, VIA686A_BASE_REG, address))
601 			return -ENODEV;
602 	}
603 	if (PCIBIOS_SUCCESSFUL !=
604 	    pci_read_config_word(s_bridge, VIA686A_ENABLE_REG, &val))
605 		return -ENODEV;
606 	if (!(val & 0x0001)) {
607 		dev_warn(&adapter->dev, "enabling sensors\n");
608 		if (PCIBIOS_SUCCESSFUL !=
609 		    pci_write_config_word(s_bridge, VIA686A_ENABLE_REG,
610 					  val | 0x0001))
611 			return -ENODEV;
612 	}
613 
614 	/* Reserve the ISA region */
615 	if (!request_region(address, VIA686A_EXTENT, via686a_driver.name)) {
616 		dev_err(&adapter->dev, "region 0x%x already in use!\n",
617 			address);
618 		return -ENODEV;
619 	}
620 
621 	if (!(data = kmalloc(sizeof(struct via686a_data), GFP_KERNEL))) {
622 		err = -ENOMEM;
623 		goto exit_release;
624 	}
625 	memset(data, 0, sizeof(struct via686a_data));
626 
627 	new_client = &data->client;
628 	i2c_set_clientdata(new_client, data);
629 	new_client->addr = address;
630 	new_client->adapter = adapter;
631 	new_client->driver = &via686a_driver;
632 	new_client->flags = 0;
633 
634 	/* Fill in the remaining client fields and put into the global list */
635 	strlcpy(new_client->name, client_name, I2C_NAME_SIZE);
636 
637 	data->valid = 0;
638 	init_MUTEX(&data->update_lock);
639 	/* Tell the I2C layer a new client has arrived */
640 	if ((err = i2c_attach_client(new_client)))
641 		goto exit_free;
642 
643 	/* Initialize the VIA686A chip */
644 	via686a_init_client(new_client);
645 
646 	/* Register sysfs hooks */
647 	data->class_dev = hwmon_device_register(&new_client->dev);
648 	if (IS_ERR(data->class_dev)) {
649 		err = PTR_ERR(data->class_dev);
650 		goto exit_detach;
651 	}
652 
653 	device_create_file(&new_client->dev, &dev_attr_in0_input);
654 	device_create_file(&new_client->dev, &dev_attr_in1_input);
655 	device_create_file(&new_client->dev, &dev_attr_in2_input);
656 	device_create_file(&new_client->dev, &dev_attr_in3_input);
657 	device_create_file(&new_client->dev, &dev_attr_in4_input);
658 	device_create_file(&new_client->dev, &dev_attr_in0_min);
659 	device_create_file(&new_client->dev, &dev_attr_in1_min);
660 	device_create_file(&new_client->dev, &dev_attr_in2_min);
661 	device_create_file(&new_client->dev, &dev_attr_in3_min);
662 	device_create_file(&new_client->dev, &dev_attr_in4_min);
663 	device_create_file(&new_client->dev, &dev_attr_in0_max);
664 	device_create_file(&new_client->dev, &dev_attr_in1_max);
665 	device_create_file(&new_client->dev, &dev_attr_in2_max);
666 	device_create_file(&new_client->dev, &dev_attr_in3_max);
667 	device_create_file(&new_client->dev, &dev_attr_in4_max);
668 	device_create_file(&new_client->dev, &dev_attr_temp1_input);
669 	device_create_file(&new_client->dev, &dev_attr_temp2_input);
670 	device_create_file(&new_client->dev, &dev_attr_temp3_input);
671 	device_create_file(&new_client->dev, &dev_attr_temp1_max);
672 	device_create_file(&new_client->dev, &dev_attr_temp2_max);
673 	device_create_file(&new_client->dev, &dev_attr_temp3_max);
674 	device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
675 	device_create_file(&new_client->dev, &dev_attr_temp2_max_hyst);
676 	device_create_file(&new_client->dev, &dev_attr_temp3_max_hyst);
677 	device_create_file(&new_client->dev, &dev_attr_fan1_input);
678 	device_create_file(&new_client->dev, &dev_attr_fan2_input);
679 	device_create_file(&new_client->dev, &dev_attr_fan1_min);
680 	device_create_file(&new_client->dev, &dev_attr_fan2_min);
681 	device_create_file(&new_client->dev, &dev_attr_fan1_div);
682 	device_create_file(&new_client->dev, &dev_attr_fan2_div);
683 	device_create_file(&new_client->dev, &dev_attr_alarms);
684 
685 	return 0;
686 
687 exit_detach:
688 	i2c_detach_client(new_client);
689 exit_free:
690 	kfree(data);
691 exit_release:
692 	release_region(address, VIA686A_EXTENT);
693 	return err;
694 }
695 
696 static int via686a_detach_client(struct i2c_client *client)
697 {
698 	struct via686a_data *data = i2c_get_clientdata(client);
699 	int err;
700 
701 	hwmon_device_unregister(data->class_dev);
702 
703 	if ((err = i2c_detach_client(client))) {
704 		dev_err(&client->dev,
705 		"Client deregistration failed, client not detached.\n");
706 		return err;
707 	}
708 
709 	release_region(client->addr, VIA686A_EXTENT);
710 	kfree(data);
711 
712 	return 0;
713 }
714 
715 /* Called when we have found a new VIA686A. Set limits, etc. */
716 static void via686a_init_client(struct i2c_client *client)
717 {
718 	u8 reg;
719 
720 	/* Start monitoring */
721 	reg = via686a_read_value(client, VIA686A_REG_CONFIG);
722 	via686a_write_value(client, VIA686A_REG_CONFIG, (reg|0x01)&0x7F);
723 
724 	/* Configure temp interrupt mode for continuous-interrupt operation */
725 	via686a_write_value(client, VIA686A_REG_TEMP_MODE,
726 			    via686a_read_value(client, VIA686A_REG_TEMP_MODE) &
727 			    !(VIA686A_TEMP_MODE_MASK | VIA686A_TEMP_MODE_CONTINUOUS));
728 }
729 
730 static struct via686a_data *via686a_update_device(struct device *dev)
731 {
732 	struct i2c_client *client = to_i2c_client(dev);
733 	struct via686a_data *data = i2c_get_clientdata(client);
734 	int i;
735 
736 	down(&data->update_lock);
737 
738 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
739 	    || !data->valid) {
740 		for (i = 0; i <= 4; i++) {
741 			data->in[i] =
742 			    via686a_read_value(client, VIA686A_REG_IN(i));
743 			data->in_min[i] = via686a_read_value(client,
744 							     VIA686A_REG_IN_MIN
745 							     (i));
746 			data->in_max[i] =
747 			    via686a_read_value(client, VIA686A_REG_IN_MAX(i));
748 		}
749 		for (i = 1; i <= 2; i++) {
750 			data->fan[i - 1] =
751 			    via686a_read_value(client, VIA686A_REG_FAN(i));
752 			data->fan_min[i - 1] = via686a_read_value(client,
753 						     VIA686A_REG_FAN_MIN(i));
754 		}
755 		for (i = 0; i <= 2; i++) {
756 			data->temp[i] = via686a_read_value(client,
757 						 VIA686A_REG_TEMP[i]) << 2;
758 			data->temp_over[i] =
759 			    via686a_read_value(client,
760 					       VIA686A_REG_TEMP_OVER[i]);
761 			data->temp_hyst[i] =
762 			    via686a_read_value(client,
763 					       VIA686A_REG_TEMP_HYST[i]);
764 		}
765 		/* add in lower 2 bits
766 		   temp1 uses bits 7-6 of VIA686A_REG_TEMP_LOW1
767 		   temp2 uses bits 5-4 of VIA686A_REG_TEMP_LOW23
768 		   temp3 uses bits 7-6 of VIA686A_REG_TEMP_LOW23
769 		 */
770 		data->temp[0] |= (via686a_read_value(client,
771 						     VIA686A_REG_TEMP_LOW1)
772 				  & 0xc0) >> 6;
773 		data->temp[1] |=
774 		    (via686a_read_value(client, VIA686A_REG_TEMP_LOW23) &
775 		     0x30) >> 4;
776 		data->temp[2] |=
777 		    (via686a_read_value(client, VIA686A_REG_TEMP_LOW23) &
778 		     0xc0) >> 6;
779 
780 		i = via686a_read_value(client, VIA686A_REG_FANDIV);
781 		data->fan_div[0] = (i >> 4) & 0x03;
782 		data->fan_div[1] = i >> 6;
783 		data->alarms =
784 		    via686a_read_value(client,
785 				       VIA686A_REG_ALARM1) |
786 		    (via686a_read_value(client, VIA686A_REG_ALARM2) << 8);
787 		data->last_updated = jiffies;
788 		data->valid = 1;
789 	}
790 
791 	up(&data->update_lock);
792 
793 	return data;
794 }
795 
796 static struct pci_device_id via686a_pci_ids[] = {
797 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4) },
798 	{ 0, }
799 };
800 
801 MODULE_DEVICE_TABLE(pci, via686a_pci_ids);
802 
803 static int __devinit via686a_pci_probe(struct pci_dev *dev,
804 				       const struct pci_device_id *id)
805 {
806 	u16 val;
807 
808 	if (PCIBIOS_SUCCESSFUL !=
809 	    pci_read_config_word(dev, VIA686A_BASE_REG, &val))
810 		return -ENODEV;
811 
812 	address = val & ~(VIA686A_EXTENT - 1);
813 	if (address == 0 && force_addr == 0) {
814 		dev_err(&dev->dev, "base address not set - upgrade BIOS "
815 			"or use force_addr=0xaddr\n");
816 		return -ENODEV;
817 	}
818 
819 	if (!address) {
820 		dev_err(&dev->dev, "No Via 686A sensors found.\n");
821 		return -ENODEV;
822 	}
823 
824 	s_bridge = pci_dev_get(dev);
825 	if (i2c_isa_add_driver(&via686a_driver)) {
826 		pci_dev_put(s_bridge);
827 		s_bridge = NULL;
828 	}
829 
830 	/* Always return failure here.  This is to allow other drivers to bind
831 	 * to this pci device.  We don't really want to have control over the
832 	 * pci device, we only wanted to read as few register values from it.
833 	 */
834 	return -ENODEV;
835 }
836 
837 static struct pci_driver via686a_pci_driver = {
838 	.name		= "via686a",
839 	.id_table	= via686a_pci_ids,
840 	.probe		= via686a_pci_probe,
841 };
842 
843 static int __init sm_via686a_init(void)
844 {
845 	return pci_register_driver(&via686a_pci_driver);
846 }
847 
848 static void __exit sm_via686a_exit(void)
849 {
850 	pci_unregister_driver(&via686a_pci_driver);
851 	if (s_bridge != NULL) {
852 		i2c_isa_del_driver(&via686a_driver);
853 		pci_dev_put(s_bridge);
854 		s_bridge = NULL;
855 	}
856 }
857 
858 MODULE_AUTHOR("Ky�sti M�lkki <kmalkki@cc.hut.fi>, "
859 	      "Mark Studebaker <mdsxyz123@yahoo.com> "
860 	      "and Bob Dougherty <bobd@stanford.edu>");
861 MODULE_DESCRIPTION("VIA 686A Sensor device");
862 MODULE_LICENSE("GPL");
863 
864 module_init(sm_via686a_init);
865 module_exit(sm_via686a_exit);
866