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/* SMB handling routines for AMD7xx, by YRS 2002.07.
Information on how to access SMBus is provided
by ":p araffin.(Yoneya)", MANY THANKS!!
Common to AMD756/766/768 and NVidia nForce
SMBus IO method:
smb_base : Base Address
addr : Slave Device Address
cmd : Command Register
Note that SMBus Slave Device Address is totall 1byte data,
whose upper 7bits is for address and the lowest bit for read (=1)
and for write (=0).
The input "addr" in the following routines is this 1byte data,
where the lowest bit can be either 0 or 1.
7 0
+-+-+-+-+-+-+-+-+
| Slave addr. |f| f = 0 for write, =1 for read.
+-+-+-+-+-+-+-+-+
Do not confuse "Slave address" which is "addr(here)"/2!
*/
#ifdef SMB_DEBUG
extern int debug_flag;
#include <stdio.h>
#endif
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include "smbuses.h"
#include "io_cpu.h"
#define LSB 0x01
#define LOOP_COUNT 0x2000
/* command address */
#define SMBHSTS 0x0
#define SMBHCTRL 0x2
#define SMBHADDR 0x4
#define SMBHDATA 0x6
#define SMBHCMD 0x8
/* status flag */
#define SMBHSTS_TOSTS 0x20 /* ? not used */
#define SMBHSTS_DONE 0x10 /* host cycle (command) completed */
#define SMBHSTS_BUSY 0x08 /* host busy */
#define SMBHSTS_ERROR 0x04 /* device error */
#define SMBHSTS_COLLID 0x02 /* bus collision */
#define SMBHSTS_ABORT 0x01 /* abort */
#define SMBHSTS_CLEAR (SMBHSTS_TOSTS|SMBHSTS_DONE|SMBHSTS_ERROR|\
SMBHSTS_COLLID|SMBHSTS_ABORT) /* clear status*/
/* control command number */
#define SMBHCTRL_ABORT 0x20 /* abort */
#define SMBHCTRL_START 0x08 /* start command */
#define SMBHCTRL_WORD 0x03 /* word I/O */
#define SMBHCTRL_BYTE 0x02 /* byte I/O */
static int readbyte(int smb_base, int addr, int cmd)
{
u_char saddr = 2*(addr/2);
u_short dat;
int i;
top:
OUTw((u_short) smb_base, SMBHSTS_CLEAR); WAIT; WAIT;
for (i = 0; i < LOOP_COUNT; ++i) {
dat = INw((u_short) smb_base); WAIT; WAIT;
OUTw((u_short) smb_base, dat); WAIT; WAIT;
if (!(dat & (SMBHSTS_COLLID | SMBHSTS_BUSY)))
goto step;
if (!(dat & SMBHSTS_BUSY))
break;
}
OUTw((u_short) (smb_base + SMBHCTRL), SMBHCTRL_ABORT); WAIT; WAIT;
step:
OUTw((u_short) (smb_base + SMBHADDR), (saddr | LSB)); WAIT; WAIT;
OUTb((u_short) (smb_base + SMBHCMD), (u_char) cmd); WAIT; WAIT;
OUTw((u_short) (smb_base + SMBHCTRL),
(SMBHCTRL_START | SMBHCTRL_BYTE)); WAIT; WAIT;
for (i = 0; i < LOOP_COUNT; ++i) {
dat = INw((u_short) smb_base); WAIT; WAIT;
if (dat & SMBHSTS_COLLID) {
#ifdef SMB_DEBUG
if (debug_flag > 1)
fprintf(stderr, "\n OH! collision! = 0x%02X\n", dat);
#endif
goto top;
}
if (!(dat & SMBHSTS_BUSY) && (dat & (SMBHSTS_DONE | SMBHSTS_ERROR)))
break;
}
#ifdef SMB_DEBUG
if (debug_flag > 1)
fprintf(stderr, " Readbyte: flag = 0x%02X, loop#:%04d", dat, i);
#endif
if (dat & SMBHSTS_DONE) {
dat = INw((u_short) (smb_base + SMBHDATA)); WAIT; WAIT;
return (dat & 0x00FF);
} else
return -1;
}
static int readword(int smb_base, int addr, int cmd)
{
u_char saddr = 2*(addr/2);
u_short dat;
int i;
top:
OUTw((u_short) smb_base, SMBHSTS_CLEAR); WAIT; WAIT;
for (i = 0; i < LOOP_COUNT; ++i) {
dat = INw((u_short) smb_base); WAIT; WAIT;
OUTw((u_short) smb_base, dat); WAIT; WAIT;
if (!(dat & (SMBHSTS_COLLID | SMBHSTS_BUSY)))
goto step;
if (!(dat & SMBHSTS_BUSY))
break;
}
OUTw((u_short) (smb_base + SMBHCTRL), SMBHCTRL_ABORT); WAIT; WAIT;
step:
OUTw((u_short) (smb_base + SMBHADDR), (saddr | LSB)); WAIT; WAIT;
OUTb((u_short) (smb_base + SMBHCMD), (u_char) cmd); WAIT; WAIT;
OUTw((u_short) (smb_base + SMBHCTRL),
(SMBHCTRL_START | SMBHCTRL_WORD)); WAIT; WAIT;
for (i = 0; i < LOOP_COUNT; ++i) {
dat = INw((u_short) smb_base); WAIT; WAIT;
if (dat & SMBHSTS_COLLID)
goto top;
if (!(dat & SMBHSTS_BUSY) && (dat & (SMBHSTS_DONE | SMBHSTS_ERROR)))
break;
}
if (dat & SMBHSTS_DONE) {
dat = INw((u_short) (smb_base + SMBHDATA)); WAIT; WAIT;
return (dat & 0xFFFF);
} else
return -1;
}
static int writebyte(int smb_base, int addr, int cmd, int value)
{
u_char saddr = 2*(addr/2);
u_short dat;
int i;
OUTw((u_short) smb_base, SMBHSTS_CLEAR); WAIT; WAIT;
for (i = 0; i < LOOP_COUNT; ++i) {
dat = INw((u_short) smb_base); WAIT; WAIT;
OUTw((u_short) smb_base, dat); WAIT; WAIT;
if (!(dat & (SMBHSTS_COLLID | SMBHSTS_BUSY)))
goto step;
if (!(dat & SMBHSTS_BUSY))
break;
}
OUTw((u_short) (smb_base + SMBHCTRL), SMBHCTRL_ABORT); WAIT; WAIT;
step:
OUTw((u_short) (smb_base + SMBHADDR), saddr); WAIT; WAIT;
OUTb((u_short) (smb_base + SMBHCMD), (u_char) cmd); WAIT; WAIT;
OUTw((u_short) (smb_base + SMBHDATA), (u_char) value); WAIT; WAIT;
OUTw((u_short) (smb_base + SMBHCTRL),
(SMBHCTRL_START | SMBHCTRL_BYTE)); WAIT; WAIT;
for (i = 0; i < LOOP_COUNT; ++i) {
dat = INw((u_short) smb_base); WAIT; WAIT;
if (!(dat & SMBHSTS_BUSY) && (dat & (SMBHSTS_DONE | SMBHSTS_ERROR)))
break;
}
if (dat & SMBHSTS_DONE)
return 0;
else
return -1;
}
static int writeword(int smb_base, int addr, int cmd, int value)
{
u_char saddr = 2*(addr/2);
u_short dat;
int i;
OUTw((u_short) smb_base, SMBHSTS_CLEAR); WAIT; WAIT;
for (i = 0; i < LOOP_COUNT; ++i) {
dat = INw((u_short) smb_base); WAIT; WAIT;
OUTw((u_short) smb_base, dat); WAIT; WAIT;
if (!(dat & (SMBHSTS_COLLID | SMBHSTS_BUSY)))
goto step;
if (!(dat & SMBHSTS_BUSY))
break;
}
OUTw((u_short) (smb_base + SMBHCTRL), SMBHCTRL_ABORT); WAIT; WAIT;
step:
OUTw((u_short) (smb_base + SMBHADDR), saddr); WAIT; WAIT;
OUTb((u_short) (smb_base + SMBHCMD), (u_char) cmd); WAIT; WAIT;
OUTw((u_short) (smb_base + SMBHDATA), (u_short) value); WAIT; WAIT;
OUTw((u_short) (smb_base + SMBHCTRL),
(SMBHCTRL_START | SMBHCTRL_WORD)); WAIT; WAIT;
for (i = 0; i < LOOP_COUNT; ++i) {
dat = INw((u_short) smb_base); WAIT; WAIT;
if (!(dat & SMBHSTS_BUSY) && (dat & (SMBHSTS_DONE | SMBHSTS_ERROR)))
break;
}
if (dat & SMBHSTS_DONE)
return 0;
else
return -1;
}
struct smbus_io smbus_amd = {
readbyte, readword, writebyte, writeword
};
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