xref: /linux/drivers/hwmon/via686a.c (revision 3f0a50f345f78183f6e9b39c2f45ca5dcaa511ca)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * via686a.c - Part of lm_sensors, Linux kernel modules
4  *	       for hardware monitoring
5  *
6  * Copyright (c) 1998 - 2002  Frodo Looijaard <frodol@dds.nl>,
7  *			      Kyösti Mälkki <kmalkki@cc.hut.fi>,
8  *			      Mark Studebaker <mdsxyz123@yahoo.com>,
9  *			      and Bob Dougherty <bobd@stanford.edu>
10  *
11  * (Some conversion-factor data were contributed by Jonathan Teh Soon Yew
12  * <j.teh@iname.com> and Alex van Kaam <darkside@chello.nl>.)
13  */
14 
15 /*
16  * Supports the Via VT82C686A, VT82C686B south bridges.
17  * Reports all as a 686A.
18  * Warning - only supports a single device.
19  */
20 
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22 
23 #include <linux/module.h>
24 #include <linux/slab.h>
25 #include <linux/pci.h>
26 #include <linux/jiffies.h>
27 #include <linux/platform_device.h>
28 #include <linux/hwmon.h>
29 #include <linux/hwmon-sysfs.h>
30 #include <linux/err.h>
31 #include <linux/init.h>
32 #include <linux/mutex.h>
33 #include <linux/sysfs.h>
34 #include <linux/acpi.h>
35 #include <linux/io.h>
36 
37 /*
38  * If force_addr is set to anything different from 0, we forcibly enable
39  * the device at the given address.
40  */
41 static unsigned short force_addr;
42 module_param(force_addr, ushort, 0);
43 MODULE_PARM_DESC(force_addr,
44 		 "Initialize the base address of the sensors");
45 
46 static struct platform_device *pdev;
47 
48 /*
49  * The Via 686a southbridge has a LM78-like chip integrated on the same IC.
50  * This driver is a customized copy of lm78.c
51  */
52 
53 /* Many VIA686A constants specified below */
54 
55 /* Length of ISA address segment */
56 #define VIA686A_EXTENT		0x80
57 #define VIA686A_BASE_REG	0x70
58 #define VIA686A_ENABLE_REG	0x74
59 
60 /* The VIA686A registers */
61 /* ins numbered 0-4 */
62 #define VIA686A_REG_IN_MAX(nr)	(0x2b + ((nr) * 2))
63 #define VIA686A_REG_IN_MIN(nr)	(0x2c + ((nr) * 2))
64 #define VIA686A_REG_IN(nr)	(0x22 + (nr))
65 
66 /* fans numbered 1-2 */
67 #define VIA686A_REG_FAN_MIN(nr)	(0x3a + (nr))
68 #define VIA686A_REG_FAN(nr)	(0x28 + (nr))
69 
70 /* temps numbered 1-3 */
71 static const u8 VIA686A_REG_TEMP[]	= { 0x20, 0x21, 0x1f };
72 static const u8 VIA686A_REG_TEMP_OVER[]	= { 0x39, 0x3d, 0x1d };
73 static const u8 VIA686A_REG_TEMP_HYST[]	= { 0x3a, 0x3e, 0x1e };
74 /* bits 7-6 */
75 #define VIA686A_REG_TEMP_LOW1	0x4b
76 /* 2 = bits 5-4, 3 = bits 7-6 */
77 #define VIA686A_REG_TEMP_LOW23	0x49
78 
79 #define VIA686A_REG_ALARM1	0x41
80 #define VIA686A_REG_ALARM2	0x42
81 #define VIA686A_REG_FANDIV	0x47
82 #define VIA686A_REG_CONFIG	0x40
83 /*
84  * The following register sets temp interrupt mode (bits 1-0 for temp1,
85  * 3-2 for temp2, 5-4 for temp3).  Modes are:
86  * 00 interrupt stays as long as value is out-of-range
87  * 01 interrupt is cleared once register is read (default)
88  * 10 comparator mode- like 00, but ignores hysteresis
89  * 11 same as 00
90  */
91 #define VIA686A_REG_TEMP_MODE		0x4b
92 /* We'll just assume that you want to set all 3 simultaneously: */
93 #define VIA686A_TEMP_MODE_MASK		0x3F
94 #define VIA686A_TEMP_MODE_CONTINUOUS	0x00
95 
96 /*
97  * Conversions. Limit checking is only done on the TO_REG
98  * variants.
99  *
100  ******** VOLTAGE CONVERSIONS (Bob Dougherty) ********
101  * From HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew):
102  * voltagefactor[0]=1.25/2628; (2628/1.25=2102.4)   // Vccp
103  * voltagefactor[1]=1.25/2628; (2628/1.25=2102.4)   // +2.5V
104  * voltagefactor[2]=1.67/2628; (2628/1.67=1573.7)   // +3.3V
105  * voltagefactor[3]=2.6/2628;  (2628/2.60=1010.8)   // +5V
106  * voltagefactor[4]=6.3/2628;  (2628/6.30=417.14)   // +12V
107  * in[i]=(data[i+2]*25.0+133)*voltagefactor[i];
108  * That is:
109  * volts = (25*regVal+133)*factor
110  * regVal = (volts/factor-133)/25
111  * (These conversions were contributed by Jonathan Teh Soon Yew
112  * <j.teh@iname.com>)
113  */
114 static inline u8 IN_TO_REG(long val, int in_num)
115 {
116 	/*
117 	 * To avoid floating point, we multiply constants by 10 (100 for +12V).
118 	 * Rounding is done (120500 is actually 133000 - 12500).
119 	 * Remember that val is expressed in 0.001V/bit, which is why we divide
120 	 * by an additional 10000 (100000 for +12V): 1000 for val and 10 (100)
121 	 * for the constants.
122 	 */
123 	if (in_num <= 1)
124 		return (u8) clamp_val((val * 21024 - 1205000) / 250000, 0, 255);
125 	else if (in_num == 2)
126 		return (u8) clamp_val((val * 15737 - 1205000) / 250000, 0, 255);
127 	else if (in_num == 3)
128 		return (u8) clamp_val((val * 10108 - 1205000) / 250000, 0, 255);
129 	else
130 		return (u8) clamp_val((val * 41714 - 12050000) / 2500000, 0,
131 				      255);
132 }
133 
134 static inline long IN_FROM_REG(u8 val, int in_num)
135 {
136 	/*
137 	 * To avoid floating point, we multiply constants by 10 (100 for +12V).
138 	 * We also multiply them by 1000 because we want 0.001V/bit for the
139 	 * output value. Rounding is done.
140 	 */
141 	if (in_num <= 1)
142 		return (long) ((250000 * val + 1330000 + 21024 / 2) / 21024);
143 	else if (in_num == 2)
144 		return (long) ((250000 * val + 1330000 + 15737 / 2) / 15737);
145 	else if (in_num == 3)
146 		return (long) ((250000 * val + 1330000 + 10108 / 2) / 10108);
147 	else
148 		return (long) ((2500000 * val + 13300000 + 41714 / 2) / 41714);
149 }
150 
151 /********* FAN RPM CONVERSIONS ********/
152 /*
153  * Higher register values = slower fans (the fan's strobe gates a counter).
154  * But this chip saturates back at 0, not at 255 like all the other chips.
155  * So, 0 means 0 RPM
156  */
157 static inline u8 FAN_TO_REG(long rpm, int div)
158 {
159 	if (rpm == 0)
160 		return 0;
161 	rpm = clamp_val(rpm, 1, 1000000);
162 	return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 255);
163 }
164 
165 #define FAN_FROM_REG(val, div) ((val) == 0 ? 0 : (val) == 255 ? 0 : 1350000 / \
166 				((val) * (div)))
167 
168 /******** TEMP CONVERSIONS (Bob Dougherty) *********/
169 /*
170  * linear fits from HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew)
171  *	if(temp<169)
172  *		return double(temp)*0.427-32.08;
173  *	else if(temp>=169 && temp<=202)
174  *		return double(temp)*0.582-58.16;
175  *	else
176  *		return double(temp)*0.924-127.33;
177  *
178  * A fifth-order polynomial fits the unofficial data (provided by Alex van
179  * Kaam <darkside@chello.nl>) a bit better.  It also give more reasonable
180  * numbers on my machine (ie. they agree with what my BIOS tells me).
181  * Here's the fifth-order fit to the 8-bit data:
182  * temp = 1.625093e-10*val^5 - 1.001632e-07*val^4 + 2.457653e-05*val^3 -
183  *	2.967619e-03*val^2 + 2.175144e-01*val - 7.090067e+0.
184  *
185  * (2000-10-25- RFD: thanks to Uwe Andersen <uandersen@mayah.com> for
186  * finding my typos in this formula!)
187  *
188  * Alas, none of the elegant function-fit solutions will work because we
189  * aren't allowed to use floating point in the kernel and doing it with
190  * integers doesn't provide enough precision.  So we'll do boring old
191  * look-up table stuff.  The unofficial data (see below) have effectively
192  * 7-bit resolution (they are rounded to the nearest degree).  I'm assuming
193  * that the transfer function of the device is monotonic and smooth, so a
194  * smooth function fit to the data will allow us to get better precision.
195  * I used the 5th-order poly fit described above and solved for
196  * VIA register values 0-255.  I *10 before rounding, so we get tenth-degree
197  * precision.  (I could have done all 1024 values for our 10-bit readings,
198  * but the function is very linear in the useful range (0-80 deg C), so
199  * we'll just use linear interpolation for 10-bit readings.)  So, temp_lut
200  * is the temp at via register values 0-255:
201  */
202 static const s16 temp_lut[] = {
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 /*
228  * the original LUT values from Alex van Kaam <darkside@chello.nl>
229  * (for via register values 12-240):
230  * {-50,-49,-47,-45,-43,-41,-39,-38,-37,-35,-34,-33,-32,-31,
231  * -30,-29,-28,-27,-26,-25,-24,-24,-23,-22,-21,-20,-20,-19,-18,-17,-17,-16,-15,
232  * -15,-14,-14,-13,-12,-12,-11,-11,-10,-9,-9,-8,-8,-7,-7,-6,-6,-5,-5,-4,-4,-3,
233  * -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,
234  * 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,
235  * 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,
236  * 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,
237  * 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,
238  * 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,
239  * 85,86,88,89,91,92,94,96,97,99,101,103,105,107,109,110};
240  *
241  *
242  * Here's the reverse LUT.  I got it by doing a 6-th order poly fit (needed
243  * an extra term for a good fit to these inverse data!) and then
244  * solving for each temp value from -50 to 110 (the useable range for
245  * this chip).  Here's the fit:
246  * viaRegVal = -1.160370e-10*val^6 +3.193693e-08*val^5 - 1.464447e-06*val^4
247  * - 2.525453e-04*val^3 + 1.424593e-02*val^2 + 2.148941e+00*val +7.275808e+01)
248  * Note that n=161:
249  */
250 static const u8 via_lut[] = {
251 	12, 12, 13, 14, 14, 15, 16, 16, 17, 18, 18, 19, 20, 20, 21, 22, 23,
252 	23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 39, 40,
253 	41, 43, 45, 46, 48, 49, 51, 53, 55, 57, 59, 60, 62, 64, 66,
254 	69, 71, 73, 75, 77, 79, 82, 84, 86, 88, 91, 93, 95, 98, 100,
255 	103, 105, 107, 110, 112, 115, 117, 119, 122, 124, 126, 129,
256 	131, 134, 136, 138, 140, 143, 145, 147, 150, 152, 154, 156,
257 	158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180,
258 	182, 183, 185, 187, 188, 190, 192, 193, 195, 196, 198, 199,
259 	200, 202, 203, 205, 206, 207, 208, 209, 210, 211, 212, 213,
260 	214, 215, 216, 217, 218, 219, 220, 221, 222, 222, 223, 224,
261 	225, 226, 226, 227, 228, 228, 229, 230, 230, 231, 232, 232,
262 	233, 233, 234, 235, 235, 236, 236, 237, 237, 238, 238, 239,
263 	239, 240
264 };
265 
266 /*
267  * Converting temps to (8-bit) hyst and over registers
268  * No interpolation here.
269  * The +50 is because the temps start at -50
270  */
271 static inline u8 TEMP_TO_REG(long val)
272 {
273 	return via_lut[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)	((long)temp_lut[val] * 100)
279 
280 /* for 10-bit temperature readings */
281 static inline long TEMP_FROM_REG10(u16 val)
282 {
283 	u16 eight_bits = val >> 2;
284 	u16 two_bits = val & 3;
285 
286 	/* no interpolation for these */
287 	if (two_bits == 0 || eight_bits == 255)
288 		return TEMP_FROM_REG(eight_bits);
289 
290 	/* do some linear interpolation */
291 	return (temp_lut[eight_bits] * (4 - two_bits) +
292 		temp_lut[eight_bits + 1] * two_bits) * 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 /*
299  * For each registered chip, we need to keep some data in memory.
300  * The structure is dynamically allocated.
301  */
302 struct via686a_data {
303 	unsigned short addr;
304 	const char *name;
305 	struct device *hwmon_dev;
306 	struct mutex update_lock;
307 	bool valid;		/* true if following fields are valid */
308 	unsigned long last_updated;	/* In jiffies */
309 
310 	u8 in[5];		/* Register value */
311 	u8 in_max[5];		/* Register value */
312 	u8 in_min[5];		/* Register value */
313 	u8 fan[2];		/* Register value */
314 	u8 fan_min[2];		/* Register value */
315 	u16 temp[3];		/* Register value 10 bit */
316 	u8 temp_over[3];	/* Register value */
317 	u8 temp_hyst[3];	/* Register value */
318 	u8 fan_div[2];		/* Register encoding, shifted right */
319 	u16 alarms;		/* Register encoding, combined */
320 };
321 
322 static struct pci_dev *s_bridge;	/* pointer to the (only) via686a */
323 
324 static int via686a_probe(struct platform_device *pdev);
325 static int via686a_remove(struct platform_device *pdev);
326 
327 static inline int via686a_read_value(struct via686a_data *data, u8 reg)
328 {
329 	return inb_p(data->addr + reg);
330 }
331 
332 static inline void via686a_write_value(struct via686a_data *data, u8 reg,
333 				       u8 value)
334 {
335 	outb_p(value, data->addr + reg);
336 }
337 
338 static struct via686a_data *via686a_update_device(struct device *dev);
339 static void via686a_init_device(struct via686a_data *data);
340 
341 /* following are the sysfs callback functions */
342 
343 /* 7 voltage sensors */
344 static ssize_t in_show(struct device *dev, struct device_attribute *da,
345 		       char *buf) {
346 	struct via686a_data *data = via686a_update_device(dev);
347 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
348 	int nr = attr->index;
349 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in[nr], nr));
350 }
351 
352 static ssize_t in_min_show(struct device *dev, struct device_attribute *da,
353 			   char *buf) {
354 	struct via686a_data *data = via686a_update_device(dev);
355 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
356 	int nr = attr->index;
357 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_min[nr], nr));
358 }
359 
360 static ssize_t in_max_show(struct device *dev, struct device_attribute *da,
361 			   char *buf) {
362 	struct via686a_data *data = via686a_update_device(dev);
363 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
364 	int nr = attr->index;
365 	return sprintf(buf, "%ld\n", IN_FROM_REG(data->in_max[nr], nr));
366 }
367 
368 static ssize_t in_min_store(struct device *dev, struct device_attribute *da,
369 			    const char *buf, size_t count) {
370 	struct via686a_data *data = dev_get_drvdata(dev);
371 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
372 	int nr = attr->index;
373 	unsigned long val;
374 	int err;
375 
376 	err = kstrtoul(buf, 10, &val);
377 	if (err)
378 		return err;
379 
380 	mutex_lock(&data->update_lock);
381 	data->in_min[nr] = IN_TO_REG(val, nr);
382 	via686a_write_value(data, VIA686A_REG_IN_MIN(nr),
383 			data->in_min[nr]);
384 	mutex_unlock(&data->update_lock);
385 	return count;
386 }
387 static ssize_t in_max_store(struct device *dev, struct device_attribute *da,
388 			    const char *buf, size_t count) {
389 	struct via686a_data *data = dev_get_drvdata(dev);
390 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
391 	int nr = attr->index;
392 	unsigned long val;
393 	int err;
394 
395 	err = kstrtoul(buf, 10, &val);
396 	if (err)
397 		return err;
398 
399 	mutex_lock(&data->update_lock);
400 	data->in_max[nr] = IN_TO_REG(val, nr);
401 	via686a_write_value(data, VIA686A_REG_IN_MAX(nr),
402 			data->in_max[nr]);
403 	mutex_unlock(&data->update_lock);
404 	return count;
405 }
406 
407 static SENSOR_DEVICE_ATTR_RO(in0_input, in, 0);
408 static SENSOR_DEVICE_ATTR_RW(in0_min, in_min, 0);
409 static SENSOR_DEVICE_ATTR_RW(in0_max, in_max, 0);
410 static SENSOR_DEVICE_ATTR_RO(in1_input, in, 1);
411 static SENSOR_DEVICE_ATTR_RW(in1_min, in_min, 1);
412 static SENSOR_DEVICE_ATTR_RW(in1_max, in_max, 1);
413 static SENSOR_DEVICE_ATTR_RO(in2_input, in, 2);
414 static SENSOR_DEVICE_ATTR_RW(in2_min, in_min, 2);
415 static SENSOR_DEVICE_ATTR_RW(in2_max, in_max, 2);
416 static SENSOR_DEVICE_ATTR_RO(in3_input, in, 3);
417 static SENSOR_DEVICE_ATTR_RW(in3_min, in_min, 3);
418 static SENSOR_DEVICE_ATTR_RW(in3_max, in_max, 3);
419 static SENSOR_DEVICE_ATTR_RO(in4_input, in, 4);
420 static SENSOR_DEVICE_ATTR_RW(in4_min, in_min, 4);
421 static SENSOR_DEVICE_ATTR_RW(in4_max, in_max, 4);
422 
423 /* 3 temperatures */
424 static ssize_t temp_show(struct device *dev, struct device_attribute *da,
425 			 char *buf) {
426 	struct via686a_data *data = via686a_update_device(dev);
427 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
428 	int nr = attr->index;
429 	return sprintf(buf, "%ld\n", TEMP_FROM_REG10(data->temp[nr]));
430 }
431 static ssize_t temp_over_show(struct device *dev, struct device_attribute *da,
432 			      char *buf) {
433 	struct via686a_data *data = via686a_update_device(dev);
434 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
435 	int nr = attr->index;
436 	return sprintf(buf, "%ld\n", TEMP_FROM_REG(data->temp_over[nr]));
437 }
438 static ssize_t temp_hyst_show(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_REG(data->temp_hyst[nr]));
444 }
445 static ssize_t temp_over_store(struct device *dev,
446 			       struct device_attribute *da, const char *buf,
447 			       size_t count) {
448 	struct via686a_data *data = dev_get_drvdata(dev);
449 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
450 	int nr = attr->index;
451 	long val;
452 	int err;
453 
454 	err = kstrtol(buf, 10, &val);
455 	if (err)
456 		return err;
457 
458 	mutex_lock(&data->update_lock);
459 	data->temp_over[nr] = TEMP_TO_REG(val);
460 	via686a_write_value(data, VIA686A_REG_TEMP_OVER[nr],
461 			    data->temp_over[nr]);
462 	mutex_unlock(&data->update_lock);
463 	return count;
464 }
465 static ssize_t temp_hyst_store(struct device *dev,
466 			       struct device_attribute *da, const char *buf,
467 			       size_t count) {
468 	struct via686a_data *data = dev_get_drvdata(dev);
469 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
470 	int nr = attr->index;
471 	long val;
472 	int err;
473 
474 	err = kstrtol(buf, 10, &val);
475 	if (err)
476 		return err;
477 
478 	mutex_lock(&data->update_lock);
479 	data->temp_hyst[nr] = TEMP_TO_REG(val);
480 	via686a_write_value(data, VIA686A_REG_TEMP_HYST[nr],
481 			    data->temp_hyst[nr]);
482 	mutex_unlock(&data->update_lock);
483 	return count;
484 }
485 
486 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
487 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp_over, 0);
488 static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, temp_hyst, 0);
489 static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
490 static SENSOR_DEVICE_ATTR_RW(temp2_max, temp_over, 1);
491 static SENSOR_DEVICE_ATTR_RW(temp2_max_hyst, temp_hyst, 1);
492 static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 2);
493 static SENSOR_DEVICE_ATTR_RW(temp3_max, temp_over, 2);
494 static SENSOR_DEVICE_ATTR_RW(temp3_max_hyst, temp_hyst, 2);
495 
496 /* 2 Fans */
497 static ssize_t fan_show(struct device *dev, struct device_attribute *da,
498 			char *buf) {
499 	struct via686a_data *data = via686a_update_device(dev);
500 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
501 	int nr = attr->index;
502 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
503 				DIV_FROM_REG(data->fan_div[nr])));
504 }
505 static ssize_t fan_min_show(struct device *dev, struct device_attribute *da,
506 			    char *buf) {
507 	struct via686a_data *data = via686a_update_device(dev);
508 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
509 	int nr = attr->index;
510 	return sprintf(buf, "%d\n",
511 		FAN_FROM_REG(data->fan_min[nr],
512 			     DIV_FROM_REG(data->fan_div[nr])));
513 }
514 static ssize_t fan_div_show(struct device *dev, struct device_attribute *da,
515 			    char *buf) {
516 	struct via686a_data *data = via686a_update_device(dev);
517 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
518 	int nr = attr->index;
519 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
520 }
521 static ssize_t fan_min_store(struct device *dev, struct device_attribute *da,
522 			     const char *buf, size_t count) {
523 	struct via686a_data *data = dev_get_drvdata(dev);
524 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
525 	int nr = attr->index;
526 	unsigned long val;
527 	int err;
528 
529 	err = kstrtoul(buf, 10, &val);
530 	if (err)
531 		return err;
532 
533 	mutex_lock(&data->update_lock);
534 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
535 	via686a_write_value(data, VIA686A_REG_FAN_MIN(nr+1), data->fan_min[nr]);
536 	mutex_unlock(&data->update_lock);
537 	return count;
538 }
539 static ssize_t fan_div_store(struct device *dev, struct device_attribute *da,
540 			     const char *buf, size_t count) {
541 	struct via686a_data *data = dev_get_drvdata(dev);
542 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
543 	int nr = attr->index;
544 	int old;
545 	unsigned long val;
546 	int err;
547 
548 	err = kstrtoul(buf, 10, &val);
549 	if (err)
550 		return err;
551 
552 	mutex_lock(&data->update_lock);
553 	old = via686a_read_value(data, VIA686A_REG_FANDIV);
554 	data->fan_div[nr] = DIV_TO_REG(val);
555 	old = (old & 0x0f) | (data->fan_div[1] << 6) | (data->fan_div[0] << 4);
556 	via686a_write_value(data, VIA686A_REG_FANDIV, old);
557 	mutex_unlock(&data->update_lock);
558 	return count;
559 }
560 
561 static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0);
562 static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0);
563 static SENSOR_DEVICE_ATTR_RW(fan1_div, fan_div, 0);
564 static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1);
565 static SENSOR_DEVICE_ATTR_RW(fan2_min, fan_min, 1);
566 static SENSOR_DEVICE_ATTR_RW(fan2_div, fan_div, 1);
567 
568 /* Alarms */
569 static ssize_t alarms_show(struct device *dev, struct device_attribute *attr,
570 			   char *buf)
571 {
572 	struct via686a_data *data = via686a_update_device(dev);
573 	return sprintf(buf, "%u\n", data->alarms);
574 }
575 
576 static DEVICE_ATTR_RO(alarms);
577 
578 static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
579 			  char *buf)
580 {
581 	int bitnr = to_sensor_dev_attr(attr)->index;
582 	struct via686a_data *data = via686a_update_device(dev);
583 	return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
584 }
585 static SENSOR_DEVICE_ATTR_RO(in0_alarm, alarm, 0);
586 static SENSOR_DEVICE_ATTR_RO(in1_alarm, alarm, 1);
587 static SENSOR_DEVICE_ATTR_RO(in2_alarm, alarm, 2);
588 static SENSOR_DEVICE_ATTR_RO(in3_alarm, alarm, 3);
589 static SENSOR_DEVICE_ATTR_RO(in4_alarm, alarm, 8);
590 static SENSOR_DEVICE_ATTR_RO(temp1_alarm, alarm, 4);
591 static SENSOR_DEVICE_ATTR_RO(temp2_alarm, alarm, 11);
592 static SENSOR_DEVICE_ATTR_RO(temp3_alarm, alarm, 15);
593 static SENSOR_DEVICE_ATTR_RO(fan1_alarm, alarm, 6);
594 static SENSOR_DEVICE_ATTR_RO(fan2_alarm, alarm, 7);
595 
596 static ssize_t name_show(struct device *dev, struct device_attribute
597 			 *devattr, char *buf)
598 {
599 	struct via686a_data *data = dev_get_drvdata(dev);
600 	return sprintf(buf, "%s\n", data->name);
601 }
602 static DEVICE_ATTR_RO(name);
603 
604 static struct attribute *via686a_attributes[] = {
605 	&sensor_dev_attr_in0_input.dev_attr.attr,
606 	&sensor_dev_attr_in1_input.dev_attr.attr,
607 	&sensor_dev_attr_in2_input.dev_attr.attr,
608 	&sensor_dev_attr_in3_input.dev_attr.attr,
609 	&sensor_dev_attr_in4_input.dev_attr.attr,
610 	&sensor_dev_attr_in0_min.dev_attr.attr,
611 	&sensor_dev_attr_in1_min.dev_attr.attr,
612 	&sensor_dev_attr_in2_min.dev_attr.attr,
613 	&sensor_dev_attr_in3_min.dev_attr.attr,
614 	&sensor_dev_attr_in4_min.dev_attr.attr,
615 	&sensor_dev_attr_in0_max.dev_attr.attr,
616 	&sensor_dev_attr_in1_max.dev_attr.attr,
617 	&sensor_dev_attr_in2_max.dev_attr.attr,
618 	&sensor_dev_attr_in3_max.dev_attr.attr,
619 	&sensor_dev_attr_in4_max.dev_attr.attr,
620 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
621 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
622 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
623 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
624 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
625 
626 	&sensor_dev_attr_temp1_input.dev_attr.attr,
627 	&sensor_dev_attr_temp2_input.dev_attr.attr,
628 	&sensor_dev_attr_temp3_input.dev_attr.attr,
629 	&sensor_dev_attr_temp1_max.dev_attr.attr,
630 	&sensor_dev_attr_temp2_max.dev_attr.attr,
631 	&sensor_dev_attr_temp3_max.dev_attr.attr,
632 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
633 	&sensor_dev_attr_temp2_max_hyst.dev_attr.attr,
634 	&sensor_dev_attr_temp3_max_hyst.dev_attr.attr,
635 	&sensor_dev_attr_temp1_alarm.dev_attr.attr,
636 	&sensor_dev_attr_temp2_alarm.dev_attr.attr,
637 	&sensor_dev_attr_temp3_alarm.dev_attr.attr,
638 
639 	&sensor_dev_attr_fan1_input.dev_attr.attr,
640 	&sensor_dev_attr_fan2_input.dev_attr.attr,
641 	&sensor_dev_attr_fan1_min.dev_attr.attr,
642 	&sensor_dev_attr_fan2_min.dev_attr.attr,
643 	&sensor_dev_attr_fan1_div.dev_attr.attr,
644 	&sensor_dev_attr_fan2_div.dev_attr.attr,
645 	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
646 	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
647 
648 	&dev_attr_alarms.attr,
649 	&dev_attr_name.attr,
650 	NULL
651 };
652 
653 static const struct attribute_group via686a_group = {
654 	.attrs = via686a_attributes,
655 };
656 
657 static struct platform_driver via686a_driver = {
658 	.driver = {
659 		.name	= "via686a",
660 	},
661 	.probe		= via686a_probe,
662 	.remove		= via686a_remove,
663 };
664 
665 /* This is called when the module is loaded */
666 static int via686a_probe(struct platform_device *pdev)
667 {
668 	struct via686a_data *data;
669 	struct resource *res;
670 	int err;
671 
672 	/* Reserve the ISA region */
673 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
674 	if (!devm_request_region(&pdev->dev, res->start, VIA686A_EXTENT,
675 				 via686a_driver.driver.name)) {
676 		dev_err(&pdev->dev, "Region 0x%lx-0x%lx already in use!\n",
677 			(unsigned long)res->start, (unsigned long)res->end);
678 		return -ENODEV;
679 	}
680 
681 	data = devm_kzalloc(&pdev->dev, sizeof(struct via686a_data),
682 			    GFP_KERNEL);
683 	if (!data)
684 		return -ENOMEM;
685 
686 	platform_set_drvdata(pdev, data);
687 	data->addr = res->start;
688 	data->name = "via686a";
689 	mutex_init(&data->update_lock);
690 
691 	/* Initialize the VIA686A chip */
692 	via686a_init_device(data);
693 
694 	/* Register sysfs hooks */
695 	err = sysfs_create_group(&pdev->dev.kobj, &via686a_group);
696 	if (err)
697 		return err;
698 
699 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
700 	if (IS_ERR(data->hwmon_dev)) {
701 		err = PTR_ERR(data->hwmon_dev);
702 		goto exit_remove_files;
703 	}
704 
705 	return 0;
706 
707 exit_remove_files:
708 	sysfs_remove_group(&pdev->dev.kobj, &via686a_group);
709 	return err;
710 }
711 
712 static int via686a_remove(struct platform_device *pdev)
713 {
714 	struct via686a_data *data = platform_get_drvdata(pdev);
715 
716 	hwmon_device_unregister(data->hwmon_dev);
717 	sysfs_remove_group(&pdev->dev.kobj, &via686a_group);
718 
719 	return 0;
720 }
721 
722 static void via686a_update_fan_div(struct via686a_data *data)
723 {
724 	int reg = via686a_read_value(data, VIA686A_REG_FANDIV);
725 	data->fan_div[0] = (reg >> 4) & 0x03;
726 	data->fan_div[1] = reg >> 6;
727 }
728 
729 static void via686a_init_device(struct via686a_data *data)
730 {
731 	u8 reg;
732 
733 	/* Start monitoring */
734 	reg = via686a_read_value(data, VIA686A_REG_CONFIG);
735 	via686a_write_value(data, VIA686A_REG_CONFIG, (reg | 0x01) & 0x7F);
736 
737 	/* Configure temp interrupt mode for continuous-interrupt operation */
738 	reg = via686a_read_value(data, VIA686A_REG_TEMP_MODE);
739 	via686a_write_value(data, VIA686A_REG_TEMP_MODE,
740 			    (reg & ~VIA686A_TEMP_MODE_MASK)
741 			    | VIA686A_TEMP_MODE_CONTINUOUS);
742 
743 	/* Pre-read fan clock divisor values */
744 	via686a_update_fan_div(data);
745 }
746 
747 static struct via686a_data *via686a_update_device(struct device *dev)
748 {
749 	struct via686a_data *data = dev_get_drvdata(dev);
750 	int i;
751 
752 	mutex_lock(&data->update_lock);
753 
754 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
755 	    || !data->valid) {
756 		for (i = 0; i <= 4; i++) {
757 			data->in[i] =
758 			    via686a_read_value(data, VIA686A_REG_IN(i));
759 			data->in_min[i] = via686a_read_value(data,
760 							     VIA686A_REG_IN_MIN
761 							     (i));
762 			data->in_max[i] =
763 			    via686a_read_value(data, VIA686A_REG_IN_MAX(i));
764 		}
765 		for (i = 1; i <= 2; i++) {
766 			data->fan[i - 1] =
767 			    via686a_read_value(data, VIA686A_REG_FAN(i));
768 			data->fan_min[i - 1] = via686a_read_value(data,
769 						     VIA686A_REG_FAN_MIN(i));
770 		}
771 		for (i = 0; i <= 2; i++) {
772 			data->temp[i] = via686a_read_value(data,
773 						 VIA686A_REG_TEMP[i]) << 2;
774 			data->temp_over[i] =
775 			    via686a_read_value(data,
776 					       VIA686A_REG_TEMP_OVER[i]);
777 			data->temp_hyst[i] =
778 			    via686a_read_value(data,
779 					       VIA686A_REG_TEMP_HYST[i]);
780 		}
781 		/*
782 		 * add in lower 2 bits
783 		 * temp1 uses bits 7-6 of VIA686A_REG_TEMP_LOW1
784 		 * temp2 uses bits 5-4 of VIA686A_REG_TEMP_LOW23
785 		 * temp3 uses bits 7-6 of VIA686A_REG_TEMP_LOW23
786 		 */
787 		data->temp[0] |= (via686a_read_value(data,
788 						     VIA686A_REG_TEMP_LOW1)
789 				  & 0xc0) >> 6;
790 		data->temp[1] |=
791 		    (via686a_read_value(data, VIA686A_REG_TEMP_LOW23) &
792 		     0x30) >> 4;
793 		data->temp[2] |=
794 		    (via686a_read_value(data, VIA686A_REG_TEMP_LOW23) &
795 		     0xc0) >> 6;
796 
797 		via686a_update_fan_div(data);
798 		data->alarms =
799 		    via686a_read_value(data,
800 				       VIA686A_REG_ALARM1) |
801 		    (via686a_read_value(data, VIA686A_REG_ALARM2) << 8);
802 		data->last_updated = jiffies;
803 		data->valid = true;
804 	}
805 
806 	mutex_unlock(&data->update_lock);
807 
808 	return data;
809 }
810 
811 static const struct pci_device_id via686a_pci_ids[] = {
812 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_82C686_4) },
813 	{ }
814 };
815 MODULE_DEVICE_TABLE(pci, via686a_pci_ids);
816 
817 static int via686a_device_add(unsigned short address)
818 {
819 	struct resource res = {
820 		.start	= address,
821 		.end	= address + VIA686A_EXTENT - 1,
822 		.name	= "via686a",
823 		.flags	= IORESOURCE_IO,
824 	};
825 	int err;
826 
827 	err = acpi_check_resource_conflict(&res);
828 	if (err)
829 		goto exit;
830 
831 	pdev = platform_device_alloc("via686a", address);
832 	if (!pdev) {
833 		err = -ENOMEM;
834 		pr_err("Device allocation failed\n");
835 		goto exit;
836 	}
837 
838 	err = platform_device_add_resources(pdev, &res, 1);
839 	if (err) {
840 		pr_err("Device resource addition failed (%d)\n", err);
841 		goto exit_device_put;
842 	}
843 
844 	err = platform_device_add(pdev);
845 	if (err) {
846 		pr_err("Device addition failed (%d)\n", err);
847 		goto exit_device_put;
848 	}
849 
850 	return 0;
851 
852 exit_device_put:
853 	platform_device_put(pdev);
854 exit:
855 	return err;
856 }
857 
858 static int via686a_pci_probe(struct pci_dev *dev,
859 				       const struct pci_device_id *id)
860 {
861 	u16 address, val;
862 
863 	if (force_addr) {
864 		address = force_addr & ~(VIA686A_EXTENT - 1);
865 		dev_warn(&dev->dev, "Forcing ISA address 0x%x\n", address);
866 		if (PCIBIOS_SUCCESSFUL !=
867 		    pci_write_config_word(dev, VIA686A_BASE_REG, address | 1))
868 			return -ENODEV;
869 	}
870 	if (PCIBIOS_SUCCESSFUL !=
871 	    pci_read_config_word(dev, VIA686A_BASE_REG, &val))
872 		return -ENODEV;
873 
874 	address = val & ~(VIA686A_EXTENT - 1);
875 	if (address == 0) {
876 		dev_err(&dev->dev,
877 			"base address not set - upgrade BIOS or use force_addr=0xaddr\n");
878 		return -ENODEV;
879 	}
880 
881 	if (PCIBIOS_SUCCESSFUL !=
882 	    pci_read_config_word(dev, VIA686A_ENABLE_REG, &val))
883 		return -ENODEV;
884 	if (!(val & 0x0001)) {
885 		if (!force_addr) {
886 			dev_warn(&dev->dev,
887 				 "Sensors disabled, enable with force_addr=0x%x\n",
888 				 address);
889 			return -ENODEV;
890 		}
891 
892 		dev_warn(&dev->dev, "Enabling sensors\n");
893 		if (PCIBIOS_SUCCESSFUL !=
894 		    pci_write_config_word(dev, VIA686A_ENABLE_REG,
895 					  val | 0x0001))
896 			return -ENODEV;
897 	}
898 
899 	if (platform_driver_register(&via686a_driver))
900 		goto exit;
901 
902 	/* Sets global pdev as a side effect */
903 	if (via686a_device_add(address))
904 		goto exit_unregister;
905 
906 	/*
907 	 * Always return failure here.  This is to allow other drivers to bind
908 	 * to this pci device.  We don't really want to have control over the
909 	 * pci device, we only wanted to read as few register values from it.
910 	 */
911 	s_bridge = pci_dev_get(dev);
912 	return -ENODEV;
913 
914 exit_unregister:
915 	platform_driver_unregister(&via686a_driver);
916 exit:
917 	return -ENODEV;
918 }
919 
920 static struct pci_driver via686a_pci_driver = {
921 	.name		= "via686a",
922 	.id_table	= via686a_pci_ids,
923 	.probe		= via686a_pci_probe,
924 };
925 
926 static int __init sm_via686a_init(void)
927 {
928 	return pci_register_driver(&via686a_pci_driver);
929 }
930 
931 static void __exit sm_via686a_exit(void)
932 {
933 	pci_unregister_driver(&via686a_pci_driver);
934 	if (s_bridge != NULL) {
935 		platform_device_unregister(pdev);
936 		platform_driver_unregister(&via686a_driver);
937 		pci_dev_put(s_bridge);
938 		s_bridge = NULL;
939 	}
940 }
941 
942 MODULE_AUTHOR("Kyösti Mälkki <kmalkki@cc.hut.fi>, "
943 	      "Mark Studebaker <mdsxyz123@yahoo.com> "
944 	      "and Bob Dougherty <bobd@stanford.edu>");
945 MODULE_DESCRIPTION("VIA 686A Sensor device");
946 MODULE_LICENSE("GPL");
947 
948 module_init(sm_via686a_init);
949 module_exit(sm_via686a_exit);
950