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/* Project: OSLib
* Description: The OS Construction Kit
* Date: 1.6.2000
* Idea by: Luca Abeni & Gerardo Lamastra
*
* OSLib is an SO project aimed at developing a common, easy-to-use
* low-level infrastructure for developing OS kernels and Embedded
* Applications; it partially derives from the HARTIK project but it
* currently is independently developed.
*
* OSLib is distributed under GPL License, and some of its code has
* been derived from the Linux kernel source; also some important
* ideas come from studying the DJGPP go32 extender.
*
* We acknowledge the Linux Community, Free Software Foundation,
* D.J. Delorie and all the other developers who believe in the
* freedom of software and ideas.
*
* For legalese, check out the included GPL license.
*/
/* The Programmable Interrupt Timer management code */
#ifndef __PIT_H__
#define __PIT_H__
#include <ll/i386/defs.h>
BEGIN_DEF
#include <ll/i386/hw-data.h>
#include <ll/i386/hw-instr.h>
#define MIN_INT 200
#define TMR_CTRL 0x43 /* PIT Control port*/
#define TMR_CNT0 0x40 /* Counter 0 port */
#define TMR_CNT1 0x41 /* Counter 1 port */
#define TMR_CNT2 0x42 /* Counter 2 port */
#define TMR_SC0 0x00 /* Select Channel 0 */
#define TMR_SC1 0x40 /* Select Channel 1 */
#define TMR_SC2 0x80 /* Select Channel 2 */
#define TMR_LSB 0x10 /* R/W Least Significative Byte */
#define TMR_MSB 0x20 /* R/W Most Significative Byte */
#define TMR_BOTH 0x30 /* R/W Both Bytes */
#define TMR_LATCH 0x00 /* Latch Command */
#define TMR_READ 0xF0 /* Read Command */
#define TMR_CNT 0x20 /* Read Counter */
#define TMR_STAT 0x10 /* Read Status */
#define TMR_CH2 0x08 /* Read Channel 2 Counter/Status */
#define TMR_CH1 0x04 /* Read Channel 1 Counter/Status */
#define TMR_CH0 0x02 /* Read Channel 0 Counter/Status */
#define TMR_MD0 0x00 /* Mode 0 */
#define TMR_MD1 0x02 /* Mode 1 */
#define TMR_MD2 0x04 /* Mode 2 */
#define TMR_MD3 0x06 /* Mode 3 */
#define TMR_MD4 0x08 /* Mode 4 */
#define TMR_MD5 0x0A /* Mode 5 */
INLINE_OP int pit_init(BYTE channel, BYTE mode, WORD tconst)
{
BYTE v, ch;
WORD cnt;
switch (channel) {
case 0:
cnt = TMR_CNT0;
ch = TMR_SC0;
break;
case 1:
cnt = TMR_CNT1;
ch = TMR_SC1;
break;
case 2:
cnt = TMR_CNT2;
ch = TMR_SC2;
break;
default:
return -1;
}
/* VM_out(TMR_CTRL, 0x34); */
outp(TMR_CTRL, ch | TMR_BOTH | mode);
/* Load Time_const with 2 access to CTR */
v = (BYTE)(tconst);
outp(cnt, v);
v = (BYTE)(tconst >> 8);
outp(cnt, v);
return 1;
}
INLINE_OP int pit_setconstant(BYTE channel, DWORD c)
{
BYTE v;
WORD cnt;
WORD tconst;
if (c > 0xF000) {
tconst = 0xF000;
} else {
if (c < MIN_INT) {
tconst = MIN_INT;
} else {
tconst = c;
}
}
switch (channel) {
case 0:
cnt = TMR_CNT0;
break;
case 1:
cnt = TMR_CNT1;
break;
case 2:
cnt = TMR_CNT2;
break;
default:
return -1;
}
/* Load Time_const with 2 access to CTR */
v = (BYTE)(tconst);
outp(cnt, v);
v = (BYTE)(tconst >> 8);
outp(cnt, v);
return 1;
}
INLINE_OP WORD pit_read(BYTE channel)
{
WORD result;
WORD cnt;
BYTE ch;
BYTE str_msb, str_lsb;
switch (channel) {
case 0:
cnt = TMR_CNT0;
ch = TMR_CH0;
break;
case 1:
cnt = TMR_CNT1;
ch = TMR_CH1;
break;
case 2:
cnt = TMR_CNT2;
ch = TMR_CH2;
break;
default:
return 0;
}
/* Read Back Command on counter 0 */
#if 0
outp(TMR_CTRL, ch | TMR_LATCH | TMR_BOTH);
#else
outp(TMR_CTRL, TMR_READ - TMR_CNT + ch /*0xD2*/);
#endif
/* Read the latched value from STR */
str_lsb = inp(cnt);
str_msb = inp(cnt);
/* Combine the byte values to obtain a word */
result = ((WORD)str_msb << 8) | (WORD)str_lsb;
return result;
}
struct pitspec {
long units;
long gigas;
};
#define ADDPITSPEC(n, t) ((t)->units += (n), \
(t)->gigas += (t)->units / 1432809, \
(t)->units %= 1432809)
#define NULLPITSPEC(t) (t)->units = 0, (t)->gigas = 0
#define PITSPEC2USEC(t) ((((t)->units * 1000) / 1197) \
+ (((t)->gigas * 1000) * 1197))
#define CPPITSPEC(a, b) (b)->units = (a)->units, (b)->gigas = (a)->gigas
END_DEF
#endif /* __PIT_H__ */