via686a.c

《linux驱动程序设计从入门到精通》一书中所有的程序代码含驱动和相应的应用程序

/*
    via686a.c - Part of lm_sensors, Linux kernel modules
                for hardware monitoring
                
    Copyright (c) 1998 - 2002  Frodo Looijaard <[e-mail]>,
                        Ky鰏ti M鋖kki <[e-mail]>,
			Mark Studebaker <[e-mail]>,
			and Bob Dougherty <[e-mail]>
    (Some conversion-factor data were contributed by Jonathan Teh Soon Yew 
    <[e-mail]> and Alex van Kaam <[e-mail]>.)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/*
    Supports the Via VT82C686A, VT82C686B south bridges.
    Reports all as a 686A.
    Warning - only supports a single device.
*/

#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/i2c-sensor.h>
#include <linux/init.h>
#include <asm/io.h>


/* If force_addr is set to anything different from 0, we forcibly enable
   the device at the given address. */
static int force_addr = 0;
MODULE_PARM(force_addr, "i");
MODULE_PARM_DESC(force_addr,
		 "Initialize the base address of the sensors");

/* Addresses to scan.
   Note that we can't determine the ISA address until we have initialized
   our module */
static unsigned short normal_i2c[] = { I2C_CLIENT_END };
static unsigned short normal_i2c_range[] = { I2C_CLIENT_END };
static unsigned int normal_isa[] = { 0x0000, I2C_CLIENT_ISA_END };
static unsigned int normal_isa_range[] = { I2C_CLIENT_ISA_END };

/* Insmod parameters */
SENSORS_INSMOD_1(via686a);

/*
   The Via 686a southbridge has a LM78-like chip integrated on the same IC.
   This driver is a customized copy of lm78.c
*/

/* Many VIA686A constants specified below */

/* Length of ISA address segment */
#define VIA686A_EXTENT 0x80
#define VIA686A_BASE_REG 0x70
#define VIA686A_ENABLE_REG 0x74

/* The VIA686A registers */
/* ins numbered 0-4 */
#define VIA686A_REG_IN_MAX(nr) (0x2b + ((nr) * 2))
#define VIA686A_REG_IN_MIN(nr) (0x2c + ((nr) * 2))
#define VIA686A_REG_IN(nr)     (0x22 + (nr))

/* fans numbered 1-2 */
#define VIA686A_REG_FAN_MIN(nr) (0x3a + (nr))
#define VIA686A_REG_FAN(nr)     (0x28 + (nr))

/* the following values are as speced by VIA: */
static const u8 regtemp[] = { 0x20, 0x21, 0x1f };
static const u8 regover[] = { 0x39, 0x3d, 0x1d };
static const u8 reghyst[] = { 0x3a, 0x3e, 0x1e };

/* temps numbered 1-3 */
#define VIA686A_REG_TEMP(nr)		(regtemp[nr])
#define VIA686A_REG_TEMP_OVER(nr)	(regover[nr])
#define VIA686A_REG_TEMP_HYST(nr)	(reghyst[nr])
#define VIA686A_REG_TEMP_LOW1	0x4b	// bits 7-6
#define VIA686A_REG_TEMP_LOW23	0x49	// 2 = bits 5-4, 3 = bits 7-6

#define VIA686A_REG_ALARM1 0x41
#define VIA686A_REG_ALARM2 0x42
#define VIA686A_REG_FANDIV 0x47
#define VIA686A_REG_CONFIG 0x40
/* The following register sets temp interrupt mode (bits 1-0 for temp1, 
 3-2 for temp2, 5-4 for temp3).  Modes are:
    00 interrupt stays as long as value is out-of-range
    01 interrupt is cleared once register is read (default)
    10 comparator mode- like 00, but ignores hysteresis
    11 same as 00 */
#define VIA686A_REG_TEMP_MODE 0x4b
/* We'll just assume that you want to set all 3 simultaneously: */
#define VIA686A_TEMP_MODE_MASK 0x3F
#define VIA686A_TEMP_MODE_CONTINUOUS (0x00)

/* Conversions. Limit checking is only done on the TO_REG
   variants. 

********* VOLTAGE CONVERSIONS (Bob Dougherty) ********
 From HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew):
 voltagefactor[0]=1.25/2628; (2628/1.25=2102.4)   // Vccp
 voltagefactor[1]=1.25/2628; (2628/1.25=2102.4)   // +2.5V
 voltagefactor[2]=1.67/2628; (2628/1.67=1573.7)   // +3.3V
 voltagefactor[3]=2.6/2628;  (2628/2.60=1010.8)   // +5V
 voltagefactor[4]=6.3/2628;  (2628/6.30=417.14)   // +12V
 in[i]=(data[i+2]*25.0+133)*voltagefactor[i];
 That is:
 volts = (25*regVal+133)*factor
 regVal = (volts/factor-133)/25
 (These conversions were contributed by Jonathan Teh Soon Yew 
 <[e-mail]>) */
static inline u8 IN_TO_REG(long val, int inNum)
{
	/* To avoid floating point, we multiply constants by 10 (100 for +12V).
	   Rounding is done (120500 is actually 133000 - 12500).
	   Remember that val is expressed in 0.001V/bit, which is why we divide
	   by an additional 10000 (100000 for +12V): 1000 for val and 10 (100)
	   for the constants. */
	if (inNum <= 1)
		return (u8)
		    SENSORS_LIMIT((val * 21024 - 1205000) / 250000, 0, 255);
	else if (inNum == 2)
		return (u8)
		    SENSORS_LIMIT((val * 15737 - 1205000) / 250000, 0, 255);
	else if (inNum == 3)
		return (u8)
		    SENSORS_LIMIT((val * 10108 - 1205000) / 250000, 0, 255);
	else
		return (u8)
		    SENSORS_LIMIT((val * 41714 - 12050000) / 2500000, 0, 255);
}

static inline long IN_FROM_REG(u8 val, int inNum)
{
	/* To avoid floating point, we multiply constants by 10 (100 for +12V).
	   We also multiply them by 1000 because we want 0.001V/bit for the
	   output value. Rounding is done. */
	if (inNum <= 1)
		return (long) ((250000 * val + 1330000 + 21024 / 2) / 21024);
	else if (inNum == 2)
		return (long) ((250000 * val + 1330000 + 15737 / 2) / 15737);
	else if (inNum == 3)
		return (long) ((250000 * val + 1330000 + 10108 / 2) / 10108);
	else
		return (long) ((2500000 * val + 13300000 + 41714 / 2) / 41714);
}

/********* FAN RPM CONVERSIONS ********/
/* Higher register values = slower fans (the fan's strobe gates a counter).
 But this chip saturates back at 0, not at 255 like all the other chips.
 So, 0 means 0 RPM */
static inline u8 FAN_TO_REG(long rpm, int div)
{
	if (rpm == 0)
		return 0;
	rpm = SENSORS_LIMIT(rpm, 1, 1000000);
	return SENSORS_LIMIT((1350000 + rpm * div / 2) / (rpm * div), 1, 255);
}

#define FAN_FROM_REG(val,div) ((val)==0?0:(val)==255?0:1350000/((val)*(div)))

/******** TEMP CONVERSIONS (Bob Dougherty) *********/
/* linear fits from HWMon.cpp (Copyright 1998-2000 Jonathan Teh Soon Yew)
      if(temp<169)
              return double(temp)*0.427-32.08;
      else if(temp>=169 && temp<=202)
              return double(temp)*0.582-58.16;
      else
              return double(temp)*0.924-127.33;

 A fifth-order polynomial fits the unofficial data (provided by Alex van 
 Kaam <[e-mail]>) a bit better.  It also give more reasonable 
 numbers on my machine (ie. they agree with what my BIOS tells me).  
 Here's the fifth-order fit to the 8-bit data:
 temp = 1.625093e-10*val^5 - 1.001632e-07*val^4 + 2.457653e-05*val^3 - 
        2.967619e-03*val^2 + 2.175144e-01*val - 7.090067e+0.

 (2000-10-25- RFD: thanks to Uwe Andersen <[e-mail]> for 
 finding my typos in this formula!)

 Alas, none of the elegant function-fit solutions will work because we 
 aren't allowed to use floating point in the kernel and doing it with 
 integers doesn't rpovide enough precision.  So we'll do boring old 
 look-up table stuff.  The unofficial data (see below) have effectively 
 7-bit resolution (they are rounded to the nearest degree).  I'm assuming 
 that the transfer function of the device is monotonic and smooth, so a 
 smooth function fit to the data will allow us to get better precision.  
 I used the 5th-order poly fit described above and solved for
 VIA register values 0-255.  I *10 before rounding, so we get tenth-degree 
 precision.  (I could have done all 1024 values for our 10-bit readings, 
 but the function is very linear in the useful range (0-80 deg C), so 
 we'll just use linear interpolation for 10-bit readings.)  So, tempLUT 
 is the temp at via register values 0-255: */
static const long tempLUT[] =
    { -709, -688, -667, -646, -627, -607, -589, -570, -553, -536, -519,
	    -503, -487, -471, -456, -442, -428, -414, -400, -387, -375,
	    -362, -350, -339, -327, -316, -305, -295, -285, -275, -265,
	    -255, -246, -237, -229, -220, -212, -204, -196, -188, -180,
	    -173, -166, -159, -152, -145, -139, -132, -126, -120, -114,
	    -108, -102, -96, -91, -85, -80, -74, -69, -64, -59, -54, -49,
	    -44, -39, -34, -29, -25, -20, -15, -11, -6, -2, 3, 7, 12, 16,
	    20, 25, 29, 33, 37, 42, 46, 50, 54, 59, 63, 67, 71, 75, 79, 84,
	    88, 92, 96, 100, 104, 109, 113, 117, 121, 125, 130, 134, 138,
	    142, 146, 151, 155, 159, 163, 168, 172, 176, 181, 185, 189,
	    193, 198, 202, 206, 211, 215, 219, 224, 228, 232, 237, 241,
	    245, 250, 254, 259, 263, 267, 272, 276, 281, 285, 290, 294,
	    299, 303, 307, 312, 316, 321, 325, 330, 334, 339, 344, 348,
	    353, 357, 362, 366, 371, 376, 380, 385, 390, 395, 399, 404,
	    409, 414, 419, 423, 428, 433, 438, 443, 449, 454, 459, 464,
	    469, 475, 480, 486, 491, 497, 502, 508, 514, 520, 526, 532,
	    538, 544, 551, 557, 564, 571, 578, 584, 592, 599, 606, 614,
	    621, 629, 637, 645, 654, 662, 671, 680, 689, 698, 708, 718,
	    728, 738, 749, 759, 770, 782, 793, 805, 818, 830, 843, 856,
	    870, 883, 898, 912, 927, 943, 958, 975, 991, 1008, 1026, 1044,
	    1062, 1081, 1101, 1121, 1141, 1162, 1184, 1206, 1229, 1252,
	    1276, 1301, 1326, 1352, 1378, 1406, 1434, 1462
};

/* the original LUT values from Alex van Kaam <[e-mail]> 
   (for via register values 12-240):
{-50,-49,-47,-45,-43,-41,-39,-38,-37,-35,-34,-33,-32,-31,
-30,-29,-28,-27,-26,-25,-24,-24,-23,-22,-21,-20,-20,-19,-18,-17,-17,-16,-15,
-15,-14,-14,-13,-12,-12,-11,-11,-10,-9,-9,-8,-8,-7,-7,-6,-6,-5,-5,-4,-4,-3,
-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,
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,
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,
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,
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,
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,
85,86,88,89,91,92,94,96,97,99,101,103,105,107,109,110};


 Here's the reverse LUT.  I got it by doing a 6-th order poly fit (needed
 an extra term for a good fit to these inverse data!) and then 
 solving for each temp value from -50 to 110 (the useable range for 
 this chip).  Here's the fit: 
 viaRegVal = -1.160370e-10*val^6 +3.193693e-08*val^5 - 1.464447e-06*val^4 
 - 2.525453e-04*val^3 + 1.424593e-02*val^2 + 2.148941e+00*val +7.275808e+01)
 Note that n=161: */
static const u8 viaLUT[] =
    { 12, 12, 13, 14, 14, 15, 16, 16, 17, 18, 18, 19, 20, 20, 21, 22, 23,
	    23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 37, 39, 40,
	    41, 43, 45, 46, 48, 49, 51, 53, 55, 57, 59, 60, 62, 64, 66,
	    69, 71, 73, 75, 77, 79, 82, 84, 86, 88, 91, 93, 95, 98, 100,
	    103, 105, 107, 110, 112, 115, 117, 119, 122, 124, 126, 129,
	    131, 134, 136, 138, 140, 143, 145, 147, 150, 152, 154, 156,
	    158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180,
	    182, 183, 185, 187, 188, 190, 192, 193, 195, 196, 198, 199,
	    200, 202, 203, 205, 206, 207, 208, 209, 210, 211, 212, 213,
	    214, 215, 216, 217, 218, 219, 220, 221, 222, 222, 223, 224,
	    225, 226, 226, 227, 228, 228, 229, 230, 230, 231, 232, 232,
	    233, 233, 234, 235, 235, 236, 236, 237, 237, 238, 238, 239,
	    239, 240
};

/* Converting temps to (8-bit) hyst and over registers
   No interpolation here.
   The +50 is because the temps start at -50 */
static inline u8 TEMP_TO_REG(long val)
{
	return viaLUT[val <= -50000 ? 0 : val >= 110000 ? 160 : 
		      (val < 0 ? val - 500 : val + 500) / 1000 + 50];
}

/* for 8-bit temperature hyst and over registers */
#define TEMP_FROM_REG(val) (tempLUT[(val)] * 100)

/* for 10-bit temperature readings */
static inline long TEMP_FROM_REG10(u16 val)
{
	u16 eightBits = val >> 2;