ref: 9f76a7f6819ac04552b4fb6588156f3e4089d1d7
dir: /os/pc/devlm78.c/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "io.h"
#include "ureg.h"
#include "../port/error.h"
/* this driver doesn't implement the management interrupts. we
* leave the LM78 interrupts set to whatever the BIOS did. we do
* allow reading and writing the the readouts and alarm values.
* Read(2)ing or write(2)ing at offset 0x0-0x1f, is
* equivalent to reading or writing lm78 registers 0x20-0x3f.
*/
enum
{
/* address of chip on serial interface */
Serialaddr= 0x2d,
/* parallel access registers */
Rpaddr= 0x5,
Bbusy= (1<<7),
Rpdata= 0x6,
/* internal register addresses */
Rconfig= 0x40,
Bstart= (1<<0),
Bsmiena= (1<<1),
Birqena= (1<<2),
Bintclr= (1<<3),
Breset= (1<<4),
Bnmi= (1<<5), /* if set, use nmi, else irq */
Bpowbypass= (1<<6),
Binit= (1<<7),
Ristat1= 0x41,
Ristat2= 0x42,
Rsmimask1= 0x43,
Rsmimask2= 0x44,
Rnmimask1= 0x45,
Rnmimask2= 0x46,
Rvidfan= 0x47, /* set fan counter, and read voltage level */
Mvid= 0x0f,
Mfan= 0xf0,
Raddr= 0x48, /* address used on serial bus */
Rresetid= 0x49, /* chip reset and ID register */
Rpost= 0x00, /* start of post ram */
Rvalue= 0x20, /* start of value ram */
VRsize= 0x20, /* size of value ram */
};
enum
{
Qdir,
Qlm78vram,
};
static Dirtab lm78dir[] = {
".", { Qdir, 0, QTDIR}, 0, 0555,
"lm78vram", { Qlm78vram, 0 }, 0, 0444,
};
/* interface type */
enum
{
None= 0,
Smbus,
Parallel,
};
static struct {
QLock;
int probed;
int ifc; /* which interface is connected */
SMBus *smbus; /* serial interface */
int port; /* parallel interface */
} lm78;
extern SMBus* piix4smbus(void);
/* wait for device to become quiescent and then set the */
/* register address */
static void
setreg(int reg)
{
int tries;
for(tries = 0; tries < 1000000; tries++)
if((inb(lm78.port+Rpaddr) & Bbusy) == 0){
outb(lm78.port+Rpaddr, reg);
return;
}
error("lm78 broken");
}
/* routines that actually touch the device */
static void
lm78wrreg(int reg, uchar val)
{
if(waserror()){
qunlock(&lm78);
nexterror();
}
qlock(&lm78);
switch(lm78.ifc){
case Smbus:
lm78.smbus->transact(lm78.smbus, SMBbytewrite, Serialaddr, reg, &val);
break;
case Parallel:
setreg(reg);
outb(lm78.port+Rpdata, val);
break;
default:
error(Enodev);
break;
}
qunlock(&lm78);
poperror();
}
static int
lm78rdreg(int reg)
{
uchar val;
if(waserror()){
qunlock(&lm78);
nexterror();
}
qlock(&lm78);
switch(lm78.ifc){
case Smbus:
lm78.smbus->transact(lm78.smbus, SMBsend, Serialaddr, reg, nil);
lm78.smbus->transact(lm78.smbus, SMBrecv, Serialaddr, 0, &val);
break;
case Parallel:
setreg(reg);
val = inb(lm78.port+Rpdata);
break;
default:
error(Enodev);
break;
}
qunlock(&lm78);
poperror();
return val;
}
/* start the chip monitoring but don't change any smi
* interrupts and/or alarms that the BIOS may have set up.
* this isn't locked because it's thought to be idempotent
*/
static void
lm78enable(void)
{
uchar config;
if(lm78.ifc == None)
error(Enodev);
if(lm78.probed == 0){
/* make sure its really there */
if(lm78rdreg(Raddr) != Serialaddr){
lm78.ifc = None;
error(Enodev);
} else {
/* start the sampling */
config = lm78rdreg(Rconfig);
config = (config | Bstart) & ~(Bintclr|Binit);
lm78wrreg(Rconfig, config);
pprint("Rvidfan %2.2ux\n", lm78rdreg(Rconfig), lm78rdreg(Rvidfan));
}
lm78.probed = 1;
}
}
enum
{
IntelVendID= 0x8086,
PiixID= 0x122E,
Piix3ID= 0x7000,
Piix4PMID= 0x7113, /* PIIX4 power management function */
PCSC= 0x78, /* programmable chip select control register */
PCSC8bytes= 0x01,
};
/* figure out what kind of interface we could have */
void
lm78reset(void)
{
int pcs;
Pcidev *p;
lm78.ifc = None;
p = nil;
while((p = pcimatch(p, IntelVendID, 0)) != nil){
switch(p->did){
/* these bridges use the PCSC to map the lm78 into port space. */
/* for this case the lm78's CS# select is connected to the PIIX's */
/* PCS# output and the bottom 3 bits of address are passed to the */
/* LM78's A0-A2 inputs. */
case PiixID:
case Piix3ID:
pcs = pcicfgr16(p, PCSC);
if(pcs & 3) {
/* already enabled */
lm78.port = pcs & ~3;
lm78.ifc = Parallel;
return;
}
/* enable the chip, use default address 0x50 */
pcicfgw16(p, PCSC, 0x50|PCSC8bytes);
pcs = pcicfgr16(p, PCSC);
lm78.port = pcs & ~3;
lm78.ifc = Parallel;
return;
/* this bridge puts the lm78's serial interface on the smbus */
case Piix4PMID:
lm78.smbus = piix4smbus();
if(lm78.smbus == nil)
continue;
print("found piix4 smbus, base %lud\n", lm78.smbus->base);
lm78.ifc = Smbus;
return;
}
}
}
Walkqid *
lm78walk(Chan* c, Chan *nc, char** name, int nname)
{
return devwalk(c, nc, name, nname, lm78dir, nelem(lm78dir), devgen);
}
static int
lm78stat(Chan* c, uchar* dp, int n)
{
return devstat(c, dp, n, lm78dir, nelem(lm78dir), devgen);
}
static Chan*
lm78open(Chan* c, int omode)
{
return devopen(c, omode, lm78dir, nelem(lm78dir), devgen);
}
static void
lm78close(Chan*)
{
}
enum
{
Linelen= 25,
};
static long
lm78read(Chan *c, void *a, long n, vlong offset)
{
uchar *va = a;
int off, e;
off = offset;
switch((ulong)c->qid.path){
case Qdir:
return devdirread(c, a, n, lm78dir, nelem(lm78dir), devgen);
case Qlm78vram:
if(off >= VRsize)
return 0;
e = off + n;
if(e > VRsize)
e = VRsize;
for(; off < e; off++)
*va++ = lm78rdreg(Rvalue+off);
return (int)(va - (uchar*)a);
}
return 0;
}
static long
lm78write(Chan *c, void *a, long n, vlong offset)
{
uchar *va = a;
int off, e;
off = offset;
switch((ulong)c->qid.path){
default:
error(Eperm);
case Qlm78vram:
if(off >= VRsize)
return 0;
e = off + n;
if(e > VRsize)
e = VRsize;
for(; off < e; off++)
lm78wrreg(Rvalue+off, *va++);
return va - (uchar*)a;
}
return 0;
}
extern Dev lm78devtab;
static Chan*
lm78attach(char* spec)
{
lm78enable();
return devattach(lm78devtab.dc, spec);
}
Dev lm78devtab = {
'T',
"lm78",
lm78reset,
devinit,
devshutdown,
lm78attach,
lm78walk,
lm78stat,
lm78open,
devcreate,
lm78close,
lm78read,
devbread,
lm78write,
devbwrite,
devremove,
devwstat,
};