Cleanup serial and lpt timers.
Separate out the 18.2Hz timer check into its own code.
Cleanup serial return codes.
Use a real timers for lpt port.
Replace lpt "nop" call with udelay(5).
Move irq_enable() into calls that need it.
diff --git a/src/ioport.h b/src/ioport.h
index 73cf8ad..3bfacae 100644
--- a/src/ioport.h
+++ b/src/ioport.h
@@ -34,8 +34,10 @@
#define PORT_DMA2_MODE_REG 0x00d6
#define PORT_DMA2_MASTER_CLEAR 0x00da
#define PORT_MATH_CLEAR 0x00f0
+#define PORT_LPT2 0x0278
#define PORT_SERIAL4 0x02e8
#define PORT_SERIAL2 0x02f8
+#define PORT_LPT1 0x0378
#define PORT_SERIAL3 0x03e8
#define PORT_FD_DOR 0x03f2
#define PORT_FD_STATUS 0x03f4
diff --git a/src/serial.c b/src/serial.c
index 550762e..a24f83f 100644
--- a/src/serial.c
+++ b/src/serial.c
@@ -9,6 +9,31 @@
#include "util.h" // debug_enter
#include "bregs.h" // struct bregs
+// Timers based on 18.2Hz clock irq.
+struct tick_timer_s {
+ u16 last_tick, remaining;
+};
+
+struct tick_timer_s
+initTickTimer(u16 count)
+{
+ struct tick_timer_s tt = {GET_BDA(timer_counter), count};
+ return tt;
+}
+
+int
+checkTickTimer(struct tick_timer_s *tt)
+{
+ u16 timer = GET_BDA(timer_counter);
+ if (tt->last_tick != timer) {
+ tt->last_tick = timer;
+ tt->last_tick--;
+ if (!tt->last_tick)
+ return 1;
+ }
+ return 0;
+}
+
/****************************************************************
* COM ports
@@ -92,20 +117,24 @@
u16 addr = getComAddr(regs);
if (!addr)
return;
- u16 timer = GET_BDA(timer_counter);
- u16 timeout = GET_BDA(com_timeout[regs->dx]);
- while (((inb(addr+SEROFF_LSR) & 0x60) != 0x60) && (timeout)) {
- u16 val16 = GET_BDA(timer_counter);
- if (val16 != timer) {
- timer = val16;
- timeout--;
+ struct tick_timer_s tt = initTickTimer(GET_BDA(com_timeout[regs->dx]));
+ irq_enable();
+ for (;;) {
+ u8 lsr = inb(addr+SEROFF_LSR);
+ if ((lsr & 0x60) == 0x60) {
+ // Success - can write data
+ outb(regs->al, addr+SEROFF_DATA);
+ // XXX - reread lsr?
+ regs->ah = lsr;
+ break;
+ }
+ if (checkTickTimer(&tt)) {
+ // Timed out - can't write data.
+ regs->ah = lsr | 0x80;
+ break;
}
}
- if (timeout)
- outb(regs->al, addr+SEROFF_DATA);
- regs->ah = inb(addr+SEROFF_LSR);
- if (!timeout)
- regs->ah |= 0x80;
+ irq_disable();
set_success(regs);
}
@@ -116,21 +145,23 @@
u16 addr = getComAddr(regs);
if (!addr)
return;
- u16 timer = GET_BDA(timer_counter);
- u16 timeout = GET_BDA(com_timeout[regs->dx]);
- while (((inb(addr+SEROFF_LSR) & 0x01) == 0) && (timeout)) {
- u16 val16 = GET_BDA(timer_counter);
- if (val16 != timer) {
- timer = val16;
- timeout--;
+ struct tick_timer_s tt = initTickTimer(GET_BDA(com_timeout[regs->dx]));
+ irq_enable();
+ for (;;) {
+ u8 lsr = inb(addr+SEROFF_LSR);
+ if (lsr & 0x01) {
+ // Success - can read data
+ regs->al = inb(addr+SEROFF_DATA);
+ regs->ah = lsr;
+ break;
+ }
+ if (checkTickTimer(&tt)) {
+ // Timed out - can't read data.
+ regs->ah = lsr | 0x80;
+ break;
}
}
- if (timeout) {
- regs->ah = 0;
- regs->al = inb(addr+SEROFF_DATA);
- } else {
- regs->ah = inb(addr+SEROFF_LSR);
- }
+ irq_disable();
set_success(regs);
}
@@ -163,8 +194,6 @@
return;
}
- irq_enable();
-
switch (regs->ah) {
case 0x00: handle_1400(regs); break;
case 0x01: handle_1401(regs); break;
@@ -205,8 +234,8 @@
dprintf(3, "init lpt\n");
u16 count = 0;
- count += detect_parport(0x378, 0x14, count);
- count += detect_parport(0x278, 0x14, count);
+ count += detect_parport(PORT_LPT1, 0x14, count);
+ count += detect_parport(PORT_LPT2, 0x14, count);
dprintf(1, "Found %d lpt ports\n", count);
// Equipment word bits 14..15 determing # parallel ports
@@ -227,16 +256,6 @@
return addr;
}
-static void
-lpt_ret(struct bregs *regs, u16 addr, u16 timeout)
-{
- u8 val8 = inb(addr+1);
- regs->ah = (val8 ^ 0x48);
- if (!timeout)
- regs->ah |= 0x01;
- set_success(regs);
-}
-
// INT 17 - PRINTER - WRITE CHARACTER
static void
handle_1700(struct bregs *regs)
@@ -244,18 +263,32 @@
u16 addr = getLptAddr(regs);
if (!addr)
return;
- u16 timeout = GET_BDA(lpt_timeout[regs->dx]) << 8;
+
+ struct tick_timer_s tt = initTickTimer(GET_BDA(lpt_timeout[regs->dx]));
+ irq_enable();
outb(regs->al, addr);
u8 val8 = inb(addr+2);
outb(val8 | 0x01, addr+2); // send strobe
- nop();
+ udelay(5);
outb(val8 & ~0x01, addr+2);
- // XXX - implement better timeout code.
- while (((inb(addr+1) & 0x40) == 0x40) && (timeout))
- timeout--;
- lpt_ret(regs, addr, timeout);
+ for (;;) {
+ u8 v = inb(addr+1);
+ if (!(v & 0x40)) {
+ // Success
+ regs->ah = v ^ 0x48;
+ break;
+ }
+ if (checkTickTimer(&tt)) {
+ // Timeout
+ regs->ah = (v ^ 0x48) | 0x01;
+ break;
+ }
+ }
+
+ irq_disable();
+ set_success(regs);
}
// INT 17 - PRINTER - INITIALIZE PORT
@@ -265,14 +298,14 @@
u16 addr = getLptAddr(regs);
if (!addr)
return;
- u16 timeout = GET_BDA(lpt_timeout[regs->dx]) << 8;
u8 val8 = inb(addr+2);
outb(val8 & ~0x04, addr+2); // send init
- nop();
+ udelay(5);
outb(val8 | 0x04, addr+2);
- lpt_ret(regs, addr, timeout);
+ regs->ah = inb(addr+1) ^ 0x48;
+ set_success(regs);
}
// INT 17 - PRINTER - GET STATUS
@@ -282,9 +315,8 @@
u16 addr = getLptAddr(regs);
if (!addr)
return;
- u16 timeout = GET_BDA(lpt_timeout[regs->dx]) << 8;
-
- lpt_ret(regs, addr, timeout);
+ regs->ah = inb(addr+1) ^ 0x48;
+ set_success(regs);
}
static void
@@ -304,8 +336,6 @@
return;
}
- irq_enable();
-
switch (regs->ah) {
case 0x00: handle_1700(regs); break;
case 0x01: handle_1701(regs); break;