sync to 0616, retaining local diffs

1 files changed, 100 insertions, 0 deletions

diff --git a/sys/arch/alpha/isa/timerreg.h b/sys/arch/alpha/isa/timerreg.h
new file mode 100644
index 00000000000..04f2804f2b7
--- /dev/null
+++ b/sys/arch/alpha/isa/timerreg.h
@@ -0,0 +1,100 @@
+/*	$NetBSD: timerreg.h,v 1.1 1996/04/12 01:54:56 cgd Exp $	*/
+
+/*-
+ * Copyright (c) 1993 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by the University of
+ *      California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Register definitions for the Intel 8253 Programmable Interval Timer.
+ *
+ * This chip has three independent 16-bit down counters that can be
+ * read on the fly.  There are three mode registers and three countdown
+ * registers.  The countdown registers are addressed directly, via the
+ * first three I/O ports.  The three mode registers are accessed via
+ * the fourth I/O port, with two bits in the mode byte indicating the
+ * register.  (Why are hardware interfaces always so braindead?).
+ *
+ * To write a value into the countdown register, the mode register
+ * is first programmed with a command indicating the which byte of
+ * the two byte register is to be modified.  The three possibilities
+ * are load msb (TMR_MR_MSB), load lsb (TMR_MR_LSB), or load lsb then
+ * msb (TMR_MR_BOTH).
+ *
+ * To read the current value ("on the fly") from the countdown register,
+ * you write a "latch" command into the mode register, then read the stable
+ * value from the corresponding I/O port.  For example, you write
+ * TMR_MR_LATCH into the corresponding mode register.  Presumably,
+ * after doing this, a write operation to the I/O port would result
+ * in undefined behavior (but hopefully not fry the chip).
+ * Reading in this manner has no side effects.
+ *
+ * The outputs of the three timers are connected as follows:
+ *
+ *	 timer 0 -> irq 0
+ *	 timer 1 -> dma chan 0 (for dram refresh)
+ * 	 timer 2 -> speaker (via keyboard controller)
+ *
+ * Timer 0 is used to call hardclock.
+ * Timer 2 is used to generate console beeps.
+ */
+
+/*
+ * Frequency of all three count-down timers; (TIMER_FREQ/freq) is the
+ * appropriate count to generate a frequency of freq hz.
+ */
+#ifndef TIMER_FREQ
+#define	TIMER_FREQ	1193182
+#endif
+#define TIMER_DIV(x) ((TIMER_FREQ+(x)/2)/(x))
+
+/*
+ * Macros for specifying values to be written into a mode register.
+ */
+#define	TIMER_CNTR0	0		/* timer 0 counter port */
+#define	TIMER_CNTR1	1		/* timer 1 counter port */
+#define	TIMER_CNTR2	2		/* timer 2 counter port */
+#define	TIMER_MODE	3		/* timer mode port */
+#define		TIMER_SEL0	0x00	/* select counter 0 */
+#define		TIMER_SEL1	0x40	/* select counter 1 */
+#define		TIMER_SEL2	0x80	/* select counter 2 */
+#define		TIMER_INTTC	0x00	/* mode 0, intr on terminal cnt */
+#define		TIMER_ONESHOT	0x02	/* mode 1, one shot */
+#define		TIMER_RATEGEN	0x04	/* mode 2, rate generator */
+#define		TIMER_SQWAVE	0x06	/* mode 3, square wave */
+#define		TIMER_SWSTROBE	0x08	/* mode 4, s/w triggered strobe */
+#define		TIMER_HWSTROBE	0x0a	/* mode 5, h/w triggered strobe */
+#define		TIMER_LATCH	0x00	/* latch counter for reading */
+#define		TIMER_LSB	0x10	/* r/w counter LSB */
+#define		TIMER_MSB	0x20	/* r/w counter MSB */
+#define		TIMER_16BIT	0x30	/* r/w counter 16 bits, LSB first */
+#define		TIMER_BCD	0x01	/* count in BCD */
+