added an old version of mikmod for dos

[dosdemo] / libs / mikmod / drvdos / dosirq.h

diff --git a/libs/mikmod/drvdos/dosirq.h b/libs/mikmod/drvdos/dosirq.h
new file mode 100644 (file)
index 0000000..eaf60a1
--- /dev/null
+++ b/libs/mikmod/drvdos/dosirq.h
@@ -0,0 +1,122 @@
+/*
+    Interface for IRQ routines on DOS
+    Copyright (C) 1999 by Andrew Zabolotny, <bit@eltech.ru>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library 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
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public
+    License along with this library; if not, write to the Free
+    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifndef __DOSIRQ_H__
+#define __DOSIRQ_H__
+
+#include <pc.h>
+
+#define PIC1_BASE      0x20            /* PIC1 base */
+#define PIC2_BASE      0xA0            /* PIC2 base */
+
+struct irq_handle {
+       void (*c_handler) ();           /* The real interrupt handler */
+       unsigned long handler_size;     /* The size of interrupt handler */
+       unsigned long handler;          /* Interrupt wrapper address */
+       unsigned long prev_selector;    /* Selector of previous handler */
+       unsigned long prev_offset;      /* Offset of previous handler */
+       unsigned char irq_num;          /* IRQ number */
+       unsigned char int_num;          /* Interrupt number */
+       unsigned char pic_base;         /* PIC base (0x20 or 0xA0) */
+       unsigned char pic_mask;         /* Old PIC mask state */
+};
+
+/* Return the enabled state for specific IRQ */
+static inline unsigned char irq_state(struct irq_handle * irq)
+{
+       return ((~inportb(irq->pic_base + 1)) & (0x01 << (irq->irq_num & 7)));
+}
+
+/* Acknowledge the end of interrupt */
+static inline void _irq_ack(int irqno)
+{
+       outportb(irqno > 7 ? PIC2_BASE : PIC1_BASE, 0x60 | (irqno & 7));
+       /* For second controller we also should acknowledge first controller */
+       if (irqno > 7)
+               outportb(PIC1_BASE, 0x20);      /* 0x20, 0x62? */
+}
+
+/* Acknowledge the end of interrupt */
+static inline void irq_ack(struct irq_handle * irq)
+{
+       outportb(irq->pic_base, 0x60 | (irq->irq_num & 7));
+       /* For second controller we also should acknowledge first controller */
+       if (irq->pic_base != PIC1_BASE)
+               outportb(PIC1_BASE, 0x20);      /* 0x20, 0x62? */
+}
+
+/* Mask (disable) the particular IRQ given his ordinal */
+static inline void _irq_disable(int irqno)
+{
+       unsigned int port_no = (irqno < 8 ? PIC1_BASE : PIC2_BASE) + 1;
+       outportb(port_no, inportb(port_no) | (1 << (irqno & 7)));
+}
+
+/* Unmask (enable) the particular IRQ given its ordinal */
+static inline void _irq_enable(int irqno)
+{
+       unsigned int port_no = (irqno < 8 ? PIC1_BASE : PIC2_BASE) + 1;
+       outportb(port_no, inportb(port_no) & ~(1 << (irqno & 7)));
+}
+
+/* Mask (disable) the particular IRQ given its irq_handle structure */
+static inline void irq_disable(struct irq_handle * irq)
+{
+       outportb(irq->pic_base + 1,
+                 inportb(irq->pic_base + 1) | (1 << (irq->irq_num & 7)));
+}
+
+/* Unmask (enable) the particular IRQ given its irq_handle structure */
+static inline void irq_enable(struct irq_handle * irq)
+{
+       outportb(irq->pic_base + 1,
+                 inportb(irq->pic_base + 1) & ~(1 << (irq->irq_num & 7)));
+}
+
+/* Check if a specific IRQ is pending: return 0 is no */
+static inline int irq_check(struct irq_handle * irq)
+{
+       outportb(irq->pic_base, 0x0B);  /* Read IRR vector */
+       return (inportb(irq->pic_base) & (1 << (irq->irq_num & 7)));
+}
+
+/* Hook a specific IRQ; NOTE: IRQ is disabled upon return, irq_enable() it */
+extern struct irq_handle *irq_hook(int irqno, void (*handler)(),
+                                   unsigned long size);
+/* Unhook a previously hooked IRQ */
+extern void irq_unhook(struct irq_handle * irq);
+/* Start IRQ detection process (IRQ list is given with irq mask) */
+/* irq_confirm should return "1" if the IRQ really comes from the device */
+extern void irq_detect_start(unsigned int irqs,
+                             int (*irq_confirm) (int irqno));
+/* Finish IRQ detection process */
+extern void irq_detect_end();
+/* Get the count of specific irqno that happened */
+extern int irq_detect_get(int irqno, unsigned int *irqmask);
+/* Clear IRQ counters */
+extern void irq_detect_clear();
+
+/* The size of interrupt stack */
+extern unsigned int __irq_stack_size;
+/* The number of nested interrupts that can be handled */
+extern unsigned int __irq_stack_count;
+
+#endif /* __DOSIRQ_H__ */
+
+/* ex:set ts=4: */