xref: /linux/drivers/hwmon/vt8231.c (revision 87c2ce3b9305b9b723faeedf6e32ef703ec9b33a)
1 /*
2 	vt8231.c - Part of lm_sensors, Linux kernel modules
3 				for hardware monitoring
4 
5 	Copyright (c) 2005 Roger Lucas <roger@planbit.co.uk>
6 	Copyright (c) 2002 Mark D. Studebaker <mdsxyz123@yahoo.com>
7 			   Aaron M. Marsh <amarsh@sdf.lonestar.org>
8 
9 	This program is free software; you can redistribute it and/or modify
10 	it under the terms of the GNU General Public License as published by
11 	the Free Software Foundation; either version 2 of the License, or
12 	(at your option) any later version.
13 
14 	This program is distributed in the hope that it will be useful,
15 	but WITHOUT ANY WARRANTY; without even the implied warranty of
16 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 	GNU General Public License for more details.
18 
19 	You should have received a copy of the GNU General Public License
20 	along with this program; if not, write to the Free Software
21 	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23 
24 /* Supports VIA VT8231 South Bridge embedded sensors
25 */
26 
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/pci.h>
31 #include <linux/jiffies.h>
32 #include <linux/i2c.h>
33 #include <linux/i2c-isa.h>
34 #include <linux/hwmon.h>
35 #include <linux/hwmon-sysfs.h>
36 #include <linux/hwmon-vid.h>
37 #include <linux/err.h>
38 #include <asm/io.h>
39 
40 static int force_addr;
41 module_param(force_addr, int, 0);
42 MODULE_PARM_DESC(force_addr, "Initialize the base address of the sensors");
43 
44 /* Device address
45    Note that we can't determine the ISA address until we have initialized
46    our module */
47 static unsigned short isa_address;
48 
49 #define VT8231_EXTENT 0x80
50 #define VT8231_BASE_REG 0x70
51 #define VT8231_ENABLE_REG 0x74
52 
53 /* The VT8231 registers
54 
55    The reset value for the input channel configuration is used (Reg 0x4A=0x07)
56    which sets the selected inputs marked with '*' below if multiple options are
57    possible:
58 
59 	            Voltage Mode	  Temperature Mode
60 	Sensor	      Linux Id	      Linux Id        VIA Id
61 	--------      --------	      --------        ------
62 	CPU Diode	N/A		temp1		0
63 	UIC1		in0		temp2 *		1
64 	UIC2		in1 *		temp3   	2
65 	UIC3		in2 *		temp4		3
66 	UIC4		in3 *		temp5		4
67 	UIC5		in4 *		temp6		5
68 	3.3V		in5		N/A
69 
70    Note that the BIOS may set the configuration register to a different value
71    to match the motherboard configuration.
72 */
73 
74 /* fans numbered 0-1 */
75 #define VT8231_REG_FAN_MIN(nr)	(0x3b + (nr))
76 #define VT8231_REG_FAN(nr)	(0x29 + (nr))
77 
78 /* Voltage inputs numbered 0-5 */
79 
80 static const u8 regvolt[]    = { 0x21, 0x22, 0x23, 0x24, 0x25, 0x26 };
81 static const u8 regvoltmax[] = { 0x3d, 0x2b, 0x2d, 0x2f, 0x31, 0x33 };
82 static const u8 regvoltmin[] = { 0x3e, 0x2c, 0x2e, 0x30, 0x32, 0x34 };
83 
84 /* Temperatures are numbered 1-6 according to the Linux kernel specification.
85 **
86 ** In the VIA datasheet, however, the temperatures are numbered from zero.
87 ** Since it is important that this driver can easily be compared to the VIA
88 ** datasheet, we will use the VIA numbering within this driver and map the
89 ** kernel sysfs device name to the VIA number in the sysfs callback.
90 */
91 
92 #define VT8231_REG_TEMP_LOW01	0x49
93 #define VT8231_REG_TEMP_LOW25	0x4d
94 
95 static const u8 regtemp[]    = { 0x1f, 0x21, 0x22, 0x23, 0x24, 0x25 };
96 static const u8 regtempmax[] = { 0x39, 0x3d, 0x2b, 0x2d, 0x2f, 0x31 };
97 static const u8 regtempmin[] = { 0x3a, 0x3e, 0x2c, 0x2e, 0x30, 0x32 };
98 
99 #define TEMP_FROM_REG(reg)		(((253 * 4 - (reg)) * 550 + 105) / 210)
100 #define TEMP_MAXMIN_FROM_REG(reg)	(((253 - (reg)) * 2200 + 105) / 210)
101 #define TEMP_MAXMIN_TO_REG(val)		(253 - ((val) * 210 + 1100) / 2200)
102 
103 #define VT8231_REG_CONFIG 0x40
104 #define VT8231_REG_ALARM1 0x41
105 #define VT8231_REG_ALARM2 0x42
106 #define VT8231_REG_FANDIV 0x47
107 #define VT8231_REG_UCH_CONFIG 0x4a
108 #define VT8231_REG_TEMP1_CONFIG 0x4b
109 #define VT8231_REG_TEMP2_CONFIG 0x4c
110 
111 /* temps 0-5 as numbered in VIA datasheet - see later for mapping to Linux
112 ** numbering
113 */
114 #define ISTEMP(i, ch_config) ((i) == 0 ? 1 : \
115 			      ((ch_config) >> ((i)+1)) & 0x01)
116 /* voltages 0-5 */
117 #define ISVOLT(i, ch_config) ((i) == 5 ? 1 : \
118 			      !(((ch_config) >> ((i)+2)) & 0x01))
119 
120 #define DIV_FROM_REG(val) (1 << (val))
121 
122 /* NB  The values returned here are NOT temperatures.  The calibration curves
123 **     for the thermistor curves are board-specific and must go in the
124 **     sensors.conf file.  Temperature sensors are actually ten bits, but the
125 **     VIA datasheet only considers the 8 MSBs obtained from the regtemp[]
126 **     register.  The temperature value returned should have a magnitude of 3,
127 **     so we use the VIA scaling as the "true" scaling and use the remaining 2
128 **     LSBs as fractional precision.
129 **
130 **     All the on-chip hardware temperature comparisons for the alarms are only
131 **     8-bits wide, and compare against the 8 MSBs of the temperature.  The bits
132 **     in the registers VT8231_REG_TEMP_LOW01 and VT8231_REG_TEMP_LOW25 are
133 **     ignored.
134 */
135 
136 /******** FAN RPM CONVERSIONS ********
137 ** This chip saturates back at 0, not at 255 like many the other chips.
138 ** So, 0 means 0 RPM
139 */
140 static inline u8 FAN_TO_REG(long rpm, int div)
141 {
142 	if (rpm == 0)
143 		return 0;
144 	return SENSORS_LIMIT(1310720 / (rpm * div), 1, 255);
145 }
146 
147 #define FAN_FROM_REG(val, div) ((val) == 0 ? 0 : 1310720 / ((val) * (div)))
148 
149 struct vt8231_data {
150 	struct i2c_client client;
151 	struct semaphore update_lock;
152 	struct class_device *class_dev;
153 	char valid;		/* !=0 if following fields are valid */
154 	unsigned long last_updated;	/* In jiffies */
155 
156 	u8 in[6];		/* Register value */
157 	u8 in_max[6];		/* Register value */
158 	u8 in_min[6];		/* Register value */
159 	u16 temp[6];		/* Register value 10 bit, right aligned */
160 	u8 temp_max[6];		/* Register value */
161 	u8 temp_min[6];		/* Register value */
162 	u8 fan[2];		/* Register value */
163 	u8 fan_min[2];		/* Register value */
164 	u8 fan_div[2];		/* Register encoding, shifted right */
165 	u16 alarms;		/* Register encoding */
166 	u8 uch_config;
167 };
168 
169 static struct pci_dev *s_bridge;
170 static int vt8231_detect(struct i2c_adapter *adapter);
171 static int vt8231_detach_client(struct i2c_client *client);
172 static struct vt8231_data *vt8231_update_device(struct device *dev);
173 static void vt8231_init_client(struct i2c_client *client);
174 
175 static inline int vt8231_read_value(struct i2c_client *client, u8 reg)
176 {
177 	return inb_p(client->addr + reg);
178 }
179 
180 static inline void vt8231_write_value(struct i2c_client *client, u8 reg,
181 					u8 value)
182 {
183 	outb_p(value, client->addr + reg);
184 }
185 
186 /* following are the sysfs callback functions */
187 static ssize_t show_in(struct device *dev, struct device_attribute *attr,
188 		char *buf)
189 {
190 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
191 	int nr = sensor_attr->index;
192 	struct vt8231_data *data = vt8231_update_device(dev);
193 
194 	return sprintf(buf, "%d\n", ((data->in[nr] - 3) * 10000) / 958);
195 }
196 
197 static ssize_t show_in_min(struct device *dev, struct device_attribute *attr,
198 		char *buf)
199 {
200 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
201 	int nr = sensor_attr->index;
202 	struct vt8231_data *data = vt8231_update_device(dev);
203 
204 	return sprintf(buf, "%d\n", ((data->in_min[nr] - 3) * 10000) / 958);
205 }
206 
207 static ssize_t show_in_max(struct device *dev, struct device_attribute *attr,
208 		char *buf)
209 {
210 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
211 	int nr = sensor_attr->index;
212 	struct vt8231_data *data = vt8231_update_device(dev);
213 
214 	return sprintf(buf, "%d\n", (((data->in_max[nr] - 3) * 10000) / 958));
215 }
216 
217 static ssize_t set_in_min(struct device *dev, struct device_attribute *attr,
218 		const char *buf, size_t count)
219 {
220 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
221 	int nr = sensor_attr->index;
222 	struct i2c_client *client = to_i2c_client(dev);
223 	struct vt8231_data *data = i2c_get_clientdata(client);
224 	unsigned long val = simple_strtoul(buf, NULL, 10);
225 
226 	down(&data->update_lock);
227 	data->in_min[nr] = SENSORS_LIMIT(((val * 958) / 10000) + 3, 0, 255);
228 	vt8231_write_value(client, regvoltmin[nr], data->in_min[nr]);
229 	up(&data->update_lock);
230 	return count;
231 }
232 
233 static ssize_t set_in_max(struct device *dev, struct device_attribute *attr,
234 		const char *buf, size_t count)
235 {
236 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
237 	int nr = sensor_attr->index;
238 	struct i2c_client *client = to_i2c_client(dev);
239 	struct vt8231_data *data = i2c_get_clientdata(client);
240 	unsigned long val = simple_strtoul(buf, NULL, 10);
241 
242 	down(&data->update_lock);
243 	data->in_max[nr] = SENSORS_LIMIT(((val * 958) / 10000) + 3, 0, 255);
244 	vt8231_write_value(client, regvoltmax[nr], data->in_max[nr]);
245 	up(&data->update_lock);
246 	return count;
247 }
248 
249 /* Special case for input 5 as this has 3.3V scaling built into the chip */
250 static ssize_t show_in5(struct device *dev, struct device_attribute *attr,
251 		char *buf)
252 {
253 	struct vt8231_data *data = vt8231_update_device(dev);
254 
255 	return sprintf(buf, "%d\n",
256 		(((data->in[5] - 3) * 10000 * 54) / (958 * 34)));
257 }
258 
259 static ssize_t show_in5_min(struct device *dev, struct device_attribute *attr,
260 		char *buf)
261 {
262 	struct vt8231_data *data = vt8231_update_device(dev);
263 
264 	return sprintf(buf, "%d\n",
265 		(((data->in_min[5] - 3) * 10000 * 54) / (958 * 34)));
266 }
267 
268 static ssize_t show_in5_max(struct device *dev, struct device_attribute *attr,
269 		char *buf)
270 {
271 	struct vt8231_data *data = vt8231_update_device(dev);
272 
273 	return sprintf(buf, "%d\n",
274 		(((data->in_max[5] - 3) * 10000 * 54) / (958 * 34)));
275 }
276 
277 static ssize_t set_in5_min(struct device *dev, struct device_attribute *attr,
278 		const char *buf, size_t count)
279 {
280 	struct i2c_client *client = to_i2c_client(dev);
281 	struct vt8231_data *data = i2c_get_clientdata(client);
282 	unsigned long val = simple_strtoul(buf, NULL, 10);
283 
284 	down(&data->update_lock);
285 	data->in_min[5] = SENSORS_LIMIT(((val * 958 * 34) / (10000 * 54)) + 3,
286 					0, 255);
287 	vt8231_write_value(client, regvoltmin[5], data->in_min[5]);
288 	up(&data->update_lock);
289 	return count;
290 }
291 
292 static ssize_t set_in5_max(struct device *dev, struct device_attribute *attr,
293 		const char *buf, size_t count)
294 {
295 	struct i2c_client *client = to_i2c_client(dev);
296 	struct vt8231_data *data = i2c_get_clientdata(client);
297 	unsigned long val = simple_strtoul(buf, NULL, 10);
298 
299 	down(&data->update_lock);
300 	data->in_max[5] = SENSORS_LIMIT(((val * 958 * 34) / (10000 * 54)) + 3,
301 					0, 255);
302 	vt8231_write_value(client, regvoltmax[5], data->in_max[5]);
303 	up(&data->update_lock);
304 	return count;
305 }
306 
307 #define define_voltage_sysfs(offset)				\
308 static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO,		\
309 		show_in, NULL, offset);				\
310 static SENSOR_DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR,	\
311 		show_in_min, set_in_min, offset);		\
312 static SENSOR_DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR,	\
313 		show_in_max, set_in_max, offset)
314 
315 define_voltage_sysfs(0);
316 define_voltage_sysfs(1);
317 define_voltage_sysfs(2);
318 define_voltage_sysfs(3);
319 define_voltage_sysfs(4);
320 
321 static DEVICE_ATTR(in5_input, S_IRUGO, show_in5, NULL);
322 static DEVICE_ATTR(in5_min, S_IRUGO | S_IWUSR, show_in5_min, set_in5_min);
323 static DEVICE_ATTR(in5_max, S_IRUGO | S_IWUSR, show_in5_max, set_in5_max);
324 
325 /* Temperatures */
326 static ssize_t show_temp0(struct device *dev, struct device_attribute *attr,
327 		char *buf)
328 {
329 	struct vt8231_data *data = vt8231_update_device(dev);
330 	return sprintf(buf, "%d\n", data->temp[0] * 250);
331 }
332 
333 static ssize_t show_temp0_max(struct device *dev, struct device_attribute *attr,
334 		char *buf)
335 {
336 	struct vt8231_data *data = vt8231_update_device(dev);
337 	return sprintf(buf, "%d\n", data->temp_max[0] * 1000);
338 }
339 
340 static ssize_t show_temp0_min(struct device *dev, struct device_attribute *attr,
341 		char *buf)
342 {
343 	struct vt8231_data *data = vt8231_update_device(dev);
344 	return sprintf(buf, "%d\n", data->temp_min[0] * 1000);
345 }
346 
347 static ssize_t set_temp0_max(struct device *dev, struct device_attribute *attr,
348 		const char *buf, size_t count)
349 {
350 	struct i2c_client *client = to_i2c_client(dev);
351 	struct vt8231_data *data = i2c_get_clientdata(client);
352 	int val = simple_strtol(buf, NULL, 10);
353 
354 	down(&data->update_lock);
355 	data->temp_max[0] = SENSORS_LIMIT((val + 500) / 1000, 0, 255);
356 	vt8231_write_value(client, regtempmax[0], data->temp_max[0]);
357 	up(&data->update_lock);
358 	return count;
359 }
360 static ssize_t set_temp0_min(struct device *dev, struct device_attribute *attr,
361 		const char *buf, size_t count)
362 {
363 	struct i2c_client *client = to_i2c_client(dev);
364 	struct vt8231_data *data = i2c_get_clientdata(client);
365 	int val = simple_strtol(buf, NULL, 10);
366 
367 	down(&data->update_lock);
368 	data->temp_min[0] = SENSORS_LIMIT((val + 500) / 1000, 0, 255);
369 	vt8231_write_value(client, regtempmin[0], data->temp_min[0]);
370 	up(&data->update_lock);
371 	return count;
372 }
373 
374 static ssize_t show_temp(struct device *dev, struct device_attribute *attr,
375 		char *buf)
376 {
377 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
378 	int nr = sensor_attr->index;
379 	struct vt8231_data *data = vt8231_update_device(dev);
380 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[nr]));
381 }
382 
383 static ssize_t show_temp_max(struct device *dev, struct device_attribute *attr,
384 		char *buf)
385 {
386 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
387 	int nr = sensor_attr->index;
388 	struct vt8231_data *data = vt8231_update_device(dev);
389 	return sprintf(buf, "%d\n", TEMP_MAXMIN_FROM_REG(data->temp_max[nr]));
390 }
391 
392 static ssize_t show_temp_min(struct device *dev, struct device_attribute *attr,
393 		char *buf)
394 {
395 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
396 	int nr = sensor_attr->index;
397 	struct vt8231_data *data = vt8231_update_device(dev);
398 	return sprintf(buf, "%d\n", TEMP_MAXMIN_FROM_REG(data->temp_min[nr]));
399 }
400 
401 static ssize_t set_temp_max(struct device *dev, struct device_attribute *attr,
402 		const char *buf, size_t count)
403 {
404 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
405 	int nr = sensor_attr->index;
406 	struct i2c_client *client = to_i2c_client(dev);
407 	struct vt8231_data *data = i2c_get_clientdata(client);
408 	int val = simple_strtol(buf, NULL, 10);
409 
410 	down(&data->update_lock);
411 	data->temp_max[nr] = SENSORS_LIMIT(TEMP_MAXMIN_TO_REG(val), 0, 255);
412 	vt8231_write_value(client, regtempmax[nr], data->temp_max[nr]);
413 	up(&data->update_lock);
414 	return count;
415 }
416 static ssize_t set_temp_min(struct device *dev, struct device_attribute *attr,
417 		const char *buf, size_t count)
418 {
419 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
420 	int nr = sensor_attr->index;
421 	struct i2c_client *client = to_i2c_client(dev);
422 	struct vt8231_data *data = i2c_get_clientdata(client);
423 	int val = simple_strtol(buf, NULL, 10);
424 
425 	down(&data->update_lock);
426 	data->temp_min[nr] = SENSORS_LIMIT(TEMP_MAXMIN_TO_REG(val), 0, 255);
427 	vt8231_write_value(client, regtempmin[nr], data->temp_min[nr]);
428 	up(&data->update_lock);
429 	return count;
430 }
431 
432 /* Note that these map the Linux temperature sensor numbering (1-6) to the VIA
433 ** temperature sensor numbering (0-5)
434 */
435 #define define_temperature_sysfs(offset)				\
436 static SENSOR_DEVICE_ATTR(temp##offset##_input, S_IRUGO,		\
437 		show_temp, NULL, offset - 1);				\
438 static SENSOR_DEVICE_ATTR(temp##offset##_max, S_IRUGO | S_IWUSR,	\
439 		show_temp_max, set_temp_max, offset - 1);		\
440 static SENSOR_DEVICE_ATTR(temp##offset##_min, S_IRUGO | S_IWUSR,	\
441 		show_temp_min, set_temp_min, offset - 1)
442 
443 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp0, NULL);
444 static DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR, show_temp0_max, set_temp0_max);
445 static DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR, show_temp0_min, set_temp0_min);
446 
447 define_temperature_sysfs(2);
448 define_temperature_sysfs(3);
449 define_temperature_sysfs(4);
450 define_temperature_sysfs(5);
451 define_temperature_sysfs(6);
452 
453 #define CFG_INFO_TEMP(id)	{ &sensor_dev_attr_temp##id##_input.dev_attr, \
454 				&sensor_dev_attr_temp##id##_min.dev_attr, \
455 				&sensor_dev_attr_temp##id##_max.dev_attr }
456 #define CFG_INFO_VOLT(id)	{ &sensor_dev_attr_in##id##_input.dev_attr, \
457 				&sensor_dev_attr_in##id##_min.dev_attr, \
458 				&sensor_dev_attr_in##id##_max.dev_attr }
459 
460 struct str_device_attr_table {
461 	struct device_attribute *input;
462 	struct device_attribute *min;
463 	struct device_attribute *max;
464 };
465 
466 static struct str_device_attr_table cfg_info_temp[] = {
467 	{ &dev_attr_temp1_input, &dev_attr_temp1_min, &dev_attr_temp1_max },
468 	CFG_INFO_TEMP(2),
469 	CFG_INFO_TEMP(3),
470 	CFG_INFO_TEMP(4),
471 	CFG_INFO_TEMP(5),
472 	CFG_INFO_TEMP(6)
473 };
474 
475 static struct str_device_attr_table cfg_info_volt[] = {
476 	CFG_INFO_VOLT(0),
477 	CFG_INFO_VOLT(1),
478 	CFG_INFO_VOLT(2),
479 	CFG_INFO_VOLT(3),
480 	CFG_INFO_VOLT(4),
481 	{ &dev_attr_in5_input, &dev_attr_in5_min, &dev_attr_in5_max }
482 };
483 
484 /* Fans */
485 static ssize_t show_fan(struct device *dev, struct device_attribute *attr,
486 		char *buf)
487 {
488 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
489 	int nr = sensor_attr->index;
490 	struct vt8231_data *data = vt8231_update_device(dev);
491 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
492 				DIV_FROM_REG(data->fan_div[nr])));
493 }
494 
495 static ssize_t show_fan_min(struct device *dev, struct device_attribute *attr,
496 		char *buf)
497 {
498 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
499 	int nr = sensor_attr->index;
500 	struct vt8231_data *data = vt8231_update_device(dev);
501 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan_min[nr],
502 			DIV_FROM_REG(data->fan_div[nr])));
503 }
504 
505 static ssize_t show_fan_div(struct device *dev, struct device_attribute *attr,
506 		char *buf)
507 {
508 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
509 	int nr = sensor_attr->index;
510 	struct vt8231_data *data = vt8231_update_device(dev);
511 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[nr]));
512 }
513 
514 static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr,
515 		const char *buf, size_t count)
516 {
517 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
518 	int nr = sensor_attr->index;
519 	struct i2c_client *client = to_i2c_client(dev);
520 	struct vt8231_data *data = i2c_get_clientdata(client);
521 	int val = simple_strtoul(buf, NULL, 10);
522 
523 	down(&data->update_lock);
524 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
525 	vt8231_write_value(client, VT8231_REG_FAN_MIN(nr), data->fan_min[nr]);
526 	up(&data->update_lock);
527 	return count;
528 }
529 
530 static ssize_t set_fan_div(struct device *dev, struct device_attribute *attr,
531 		const char *buf, size_t count)
532 {
533 	struct i2c_client *client = to_i2c_client(dev);
534 	struct vt8231_data *data = i2c_get_clientdata(client);
535 	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
536 	unsigned long val = simple_strtoul(buf, NULL, 10);
537 	int nr = sensor_attr->index;
538 	int old = vt8231_read_value(client, VT8231_REG_FANDIV);
539 	long min = FAN_FROM_REG(data->fan_min[nr],
540 				 DIV_FROM_REG(data->fan_div[nr]));
541 
542 	down(&data->update_lock);
543 	switch (val) {
544 	case 1: data->fan_div[nr] = 0; break;
545 	case 2: data->fan_div[nr] = 1; break;
546 	case 4: data->fan_div[nr] = 2; break;
547 	case 8: data->fan_div[nr] = 3; break;
548 	default:
549 		dev_err(&client->dev, "fan_div value %ld not supported."
550 		        "Choose one of 1, 2, 4 or 8!\n", val);
551 		up(&data->update_lock);
552 		return -EINVAL;
553 	}
554 
555 	/* Correct the fan minimum speed */
556 	data->fan_min[nr] = FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
557 	vt8231_write_value(client, VT8231_REG_FAN_MIN(nr), data->fan_min[nr]);
558 
559 	old = (old & 0x0f) | (data->fan_div[1] << 6) | (data->fan_div[0] << 4);
560 	vt8231_write_value(client, VT8231_REG_FANDIV, old);
561 	up(&data->update_lock);
562 	return count;
563 }
564 
565 
566 #define define_fan_sysfs(offset)					\
567 static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO,			\
568 		show_fan, NULL, offset - 1);				\
569 static SENSOR_DEVICE_ATTR(fan##offset##_div, S_IRUGO | S_IWUSR,		\
570 		show_fan_div, set_fan_div, offset - 1);			\
571 static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,		\
572 		show_fan_min, set_fan_min, offset - 1)
573 
574 define_fan_sysfs(1);
575 define_fan_sysfs(2);
576 
577 /* Alarms */
578 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
579 			   char *buf)
580 {
581 	struct vt8231_data *data = vt8231_update_device(dev);
582 	return sprintf(buf, "%d\n", data->alarms);
583 }
584 
585 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
586 
587 static struct i2c_driver vt8231_driver = {
588 	.driver = {
589 		.name	= "vt8231",
590 	},
591 	.attach_adapter	= vt8231_detect,
592 	.detach_client	= vt8231_detach_client,
593 };
594 
595 static struct pci_device_id vt8231_pci_ids[] = {
596 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8231_4) },
597 	{ 0, }
598 };
599 
600 MODULE_DEVICE_TABLE(pci, vt8231_pci_ids);
601 
602 static int __devinit vt8231_pci_probe(struct pci_dev *dev,
603 			 	      const struct pci_device_id *id);
604 
605 static struct pci_driver vt8231_pci_driver = {
606 	.name		= "vt8231",
607 	.id_table	= vt8231_pci_ids,
608 	.probe		= vt8231_pci_probe,
609 };
610 
611 int vt8231_detect(struct i2c_adapter *adapter)
612 {
613 	struct i2c_client *client;
614 	struct vt8231_data *data;
615 	int err = 0, i;
616 	u16 val;
617 
618 	/* 8231 requires multiple of 256 */
619 	if (force_addr)	{
620 		isa_address = force_addr & 0xFF00;
621 		dev_warn(&adapter->dev, "forcing ISA address 0x%04X\n",
622 				 isa_address);
623 		if (PCIBIOS_SUCCESSFUL != pci_write_config_word(s_bridge,
624 						VT8231_BASE_REG, isa_address))
625 			return -ENODEV;
626 	}
627 
628 	if (PCIBIOS_SUCCESSFUL !=
629 		pci_read_config_word(s_bridge, VT8231_ENABLE_REG, &val))
630 		return -ENODEV;
631 
632 	if (!(val & 0x0001)) {
633 		dev_warn(&adapter->dev, "enabling sensors\n");
634 		if (PCIBIOS_SUCCESSFUL !=
635 			pci_write_config_word(s_bridge, VT8231_ENABLE_REG,
636 							  val | 0x0001))
637 			return -ENODEV;
638 	}
639 
640 	/* Reserve the ISA region */
641 	if (!request_region(isa_address, VT8231_EXTENT,
642 			    vt8231_pci_driver.name)) {
643 		dev_err(&adapter->dev, "region 0x%x already in use!\n",
644 			   isa_address);
645 		return -ENODEV;
646 	}
647 
648 	if (!(data = kzalloc(sizeof(struct vt8231_data), GFP_KERNEL))) {
649 		err = -ENOMEM;
650 		goto exit_release;
651 	}
652 
653 	client = &data->client;
654 	i2c_set_clientdata(client, data);
655 	client->addr = isa_address;
656 	client->adapter = adapter;
657 	client->driver = &vt8231_driver;
658 	client->dev.parent = &adapter->dev;
659 
660 	/* Fill in the remaining client fields and put into the global list */
661 	strlcpy(client->name, "vt8231", I2C_NAME_SIZE);
662 
663 	init_MUTEX(&data->update_lock);
664 
665 	/* Tell the I2C layer a new client has arrived */
666 	if ((err = i2c_attach_client(client)))
667 		goto exit_free;
668 
669 	vt8231_init_client(client);
670 
671 	/* Register sysfs hooks */
672 	data->class_dev = hwmon_device_register(&client->dev);
673 	if (IS_ERR(data->class_dev)) {
674 		err = PTR_ERR(data->class_dev);
675 		goto exit_detach;
676 	}
677 
678 	/* Must update device information to find out the config field */
679 	data->uch_config = vt8231_read_value(client, VT8231_REG_UCH_CONFIG);
680 
681 	for (i = 0; i < ARRAY_SIZE(cfg_info_temp); i++) {
682 		if (ISTEMP(i, data->uch_config)) {
683 			device_create_file(&client->dev,
684 					   cfg_info_temp[i].input);
685 			device_create_file(&client->dev, cfg_info_temp[i].max);
686 			device_create_file(&client->dev, cfg_info_temp[i].min);
687 		}
688 	}
689 
690 	for (i = 0; i < ARRAY_SIZE(cfg_info_volt); i++) {
691 		if (ISVOLT(i, data->uch_config)) {
692 			device_create_file(&client->dev,
693 					   cfg_info_volt[i].input);
694 			device_create_file(&client->dev, cfg_info_volt[i].max);
695 			device_create_file(&client->dev, cfg_info_volt[i].min);
696 		}
697 	}
698 
699 	device_create_file(&client->dev, &sensor_dev_attr_fan1_input.dev_attr);
700 	device_create_file(&client->dev, &sensor_dev_attr_fan2_input.dev_attr);
701 	device_create_file(&client->dev, &sensor_dev_attr_fan1_min.dev_attr);
702 	device_create_file(&client->dev, &sensor_dev_attr_fan2_min.dev_attr);
703 	device_create_file(&client->dev, &sensor_dev_attr_fan1_div.dev_attr);
704 	device_create_file(&client->dev, &sensor_dev_attr_fan2_div.dev_attr);
705 
706 	device_create_file(&client->dev, &dev_attr_alarms);
707 	return 0;
708 
709 exit_detach:
710 	i2c_detach_client(client);
711 exit_free:
712 	kfree(data);
713 exit_release:
714 	release_region(isa_address, VT8231_EXTENT);
715 	return err;
716 }
717 
718 static int vt8231_detach_client(struct i2c_client *client)
719 {
720 	struct vt8231_data *data = i2c_get_clientdata(client);
721 	int err;
722 
723 	hwmon_device_unregister(data->class_dev);
724 
725 	if ((err = i2c_detach_client(client))) {
726 		return err;
727 	}
728 
729 	release_region(client->addr, VT8231_EXTENT);
730 	kfree(data);
731 
732 	return 0;
733 }
734 
735 static void vt8231_init_client(struct i2c_client *client)
736 {
737 	vt8231_write_value(client, VT8231_REG_TEMP1_CONFIG, 0);
738 	vt8231_write_value(client, VT8231_REG_TEMP2_CONFIG, 0);
739 }
740 
741 static struct vt8231_data *vt8231_update_device(struct device *dev)
742 {
743 	struct i2c_client *client = to_i2c_client(dev);
744 	struct vt8231_data *data = i2c_get_clientdata(client);
745 	int i;
746 	u16 low;
747 
748 	down(&data->update_lock);
749 
750 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
751 	    || !data->valid) {
752 		for (i = 0; i < 6; i++) {
753 			if (ISVOLT(i, data->uch_config)) {
754 				data->in[i] = vt8231_read_value(client,
755 						regvolt[i]);
756 				data->in_min[i] = vt8231_read_value(client,
757 						regvoltmin[i]);
758 				data->in_max[i] = vt8231_read_value(client,
759 						regvoltmax[i]);
760 			}
761 		}
762 		for (i = 0; i < 2; i++) {
763 			data->fan[i] = vt8231_read_value(client,
764 						VT8231_REG_FAN(i));
765 			data->fan_min[i] = vt8231_read_value(client,
766 						VT8231_REG_FAN_MIN(i));
767 		}
768 
769 		low = vt8231_read_value(client, VT8231_REG_TEMP_LOW01);
770 		low = (low >> 6) | ((low & 0x30) >> 2)
771 		    | (vt8231_read_value(client, VT8231_REG_TEMP_LOW25) << 4);
772 		for (i = 0; i < 6; i++) {
773 			if (ISTEMP(i, data->uch_config)) {
774 				data->temp[i] = (vt8231_read_value(client,
775 						       regtemp[i]) << 2)
776 						| ((low >> (2 * i)) & 0x03);
777 				data->temp_max[i] = vt8231_read_value(client,
778 						      regtempmax[i]);
779 				data->temp_min[i] = vt8231_read_value(client,
780 						      regtempmin[i]);
781 			}
782 		}
783 
784 		i = vt8231_read_value(client, VT8231_REG_FANDIV);
785 		data->fan_div[0] = (i >> 4) & 0x03;
786 		data->fan_div[1] = i >> 6;
787 		data->alarms = vt8231_read_value(client, VT8231_REG_ALARM1) |
788 			(vt8231_read_value(client, VT8231_REG_ALARM2) << 8);
789 
790 		/* Set alarm flags correctly */
791 		if (!data->fan[0] && data->fan_min[0]) {
792 			data->alarms |= 0x40;
793 		} else if (data->fan[0] && !data->fan_min[0]) {
794 			data->alarms &= ~0x40;
795 		}
796 
797 		if (!data->fan[1] && data->fan_min[1]) {
798 			data->alarms |= 0x80;
799 		} else if (data->fan[1] && !data->fan_min[1]) {
800 			data->alarms &= ~0x80;
801 		}
802 
803 		data->last_updated = jiffies;
804 		data->valid = 1;
805 	}
806 
807 	up(&data->update_lock);
808 
809 	return data;
810 }
811 
812 static int __devinit vt8231_pci_probe(struct pci_dev *dev,
813 				const struct pci_device_id *id)
814 {
815 	u16 val;
816 
817 	if (PCIBIOS_SUCCESSFUL != pci_read_config_word(dev, VT8231_BASE_REG,
818 							&val))
819 		return -ENODEV;
820 
821 	isa_address = val & ~(VT8231_EXTENT - 1);
822 	if (isa_address == 0 && force_addr == 0) {
823 		dev_err(&dev->dev, "base address not set -\
824 				 upgrade BIOS or use force_addr=0xaddr\n");
825 		return -ENODEV;
826 	}
827 
828 	s_bridge = pci_dev_get(dev);
829 
830 	if (i2c_isa_add_driver(&vt8231_driver)) {
831 		pci_dev_put(s_bridge);
832 		s_bridge = NULL;
833 	}
834 
835 	/* Always return failure here.  This is to allow other drivers to bind
836 	 * to this pci device.  We don't really want to have control over the
837 	 * pci device, we only wanted to read as few register values from it.
838 	 */
839 	return -ENODEV;
840 }
841 
842 static int __init sm_vt8231_init(void)
843 {
844 	return pci_register_driver(&vt8231_pci_driver);
845 }
846 
847 static void __exit sm_vt8231_exit(void)
848 {
849 	pci_unregister_driver(&vt8231_pci_driver);
850 	if (s_bridge != NULL) {
851 		i2c_isa_del_driver(&vt8231_driver);
852 		pci_dev_put(s_bridge);
853 		s_bridge = NULL;
854 	}
855 }
856 
857 MODULE_AUTHOR("Roger Lucas <roger@planbit.co.uk>");
858 MODULE_DESCRIPTION("VT8231 sensors");
859 MODULE_LICENSE("GPL");
860 
861 module_init(sm_vt8231_init);
862 module_exit(sm_vt8231_exit);
863