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authorThomas Bushnell <thomas@gnu.org>1997-02-25 21:28:37 +0000
committerThomas Bushnell <thomas@gnu.org>1997-02-25 21:28:37 +0000
commitf07a4c844da9f0ecae5bbee1ab94be56505f26f7 (patch)
tree12b07c7e578fc1a5f53dbfde2632408491ff2a70 /chips/mc_clock.h
Initial source
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+/*
+ * Mach Operating System
+ * Copyright (c) 1991,1990 Carnegie Mellon University
+ * All Rights Reserved.
+ *
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
+ * School of Computer Science
+ * Carnegie Mellon University
+ * Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
+/*
+ * File: mc_clock.h
+ * Author: Alessandro Forin
+ * Date: 8/90
+ *
+ * Definitions for the MC146818 Clock Driver
+ */
+
+/*
+ * Functions this module implements
+ */
+
+extern void resettodr(/* */); /* reset time-of-day register */
+extern void startrtclock(/* */); /* start real-time clock */
+extern void stopclocks(/* */); /* stop real-time clock */
+extern boolean_t ackrtclock(/* */); /* acknowledge interrupt, if any */
+extern boolean_t todr_running; /* status */
+
+extern boolean_t mc_new_century; /* patch this after year 2000 (honest!) */
+
+extern void delay(/* int usecs */); /* waste that many microseconds */
+extern void config_delay(/* int speed */); /* for delay() */
+#define MC_DELAY_PMAX 8
+#define MC_DELAY_3MAX 12
+
+extern void set_clock_addr(/* vm_offset_t addr */); /* RAM location */
+
+/*
+ * Real-Time Clock plus RAM device (MC146818)
+ */
+
+/*
+ * RAM Memory Map (as seen by the chip)
+ */
+typedef struct {
+ volatile unsigned char mc_second;
+ volatile unsigned char mc_alarm_second;
+ volatile unsigned char mc_minute;
+ volatile unsigned char mc_alarm_minute;
+ volatile unsigned char mc_hour;
+ volatile unsigned char mc_alarm_hour;
+ volatile unsigned char mc_day_of_week;
+ volatile unsigned char mc_day_of_month;
+ volatile unsigned char mc_month;
+ volatile unsigned char mc_year;
+ volatile unsigned char mc_register_A;
+ volatile unsigned char mc_register_B;
+ volatile unsigned char mc_register_C;
+ volatile unsigned char mc_register_D;
+ unsigned char mc_non_volatile_ram[50];
+} mc_clock_t;
+
+/*
+ * Register A defines (read/write)
+ */
+
+#define MC_REG_A_RS 0x0f /* Interrupt rate (and SQwave) select */
+#define MC_REG_A_DV 0x70 /* Divider select */
+#define MC_REG_A_UIP 0x80 /* Update In Progress (read-only bit) */
+
+/* Time base configuration */
+#define MC_BASE_4_MHz 0x00
+#define MC_BASE_1_MHz 0x10
+#define MC_BASE_32_KHz 0x20
+#define MC_BASE_NONE 0x60 /* actually, both of these reset */
+#define MC_BASE_RESET 0x70
+
+/* Interrupt rate table */
+#define MC_RATE_NONE 0x0 /* disabled */
+#define MC_RATE_1 0x1 /* 256Hz if MC_BASE_32_KHz, else 32768Hz */
+#define MC_RATE_2 0x2 /* 128Hz if MC_BASE_32_KHz, else 16384Hz */
+#define MC_RATE_8192_Hz 0x3 /* Tpi: 122.070 usecs */
+#define MC_RATE_4096_Hz 0x4 /* Tpi: 244.141 usecs */
+#define MC_RATE_2048_Hz 0x5 /* Tpi: 488.281 usecs */
+#define MC_RATE_1024_Hz 0x6 /* Tpi: 976.562 usecs */
+#define MC_RATE_512_Hz 0x7 /* Tpi: 1.953125 ms */
+#define MC_RATE_256_Hz 0x8 /* Tpi: 3.90625 ms */
+#define MC_RATE_128_Hz 0x9 /* Tpi: 7.8125 ms */
+#define MC_RATE_64_Hz 0xa /* Tpi: 15.625 ms */
+#define MC_RATE_32_Hz 0xb /* Tpi: 31.25 ms */
+#define MC_RATE_16_Hz 0xc /* Tpi: 62.5 ms */
+#define MC_RATE_8_Hz 0xd /* Tpi: 125 ms */
+#define MC_RATE_4_Hz 0xe /* Tpi: 250 ms */
+#define MC_RATE_2_Hz 0xf /* Tpi: 500 ms */
+
+/* Update cycle time */
+#define MC_UPD_4_MHz 248 /* usecs */
+#define MC_UPD_1_MHz 248 /* usecs */
+#define MC_UPD_32_KHz 1984 /* usecs */
+#define MC_UPD_MINIMUM 244 /* usecs, guaranteed if UIP=0 */
+
+/*
+ * Register B defines (read/write)
+ */
+
+#define MC_REG_B_DSE 0x01 /* Daylight Savings Enable */
+#define MC_REG_B_24HM 0x02 /* 24/12 Hour Mode */
+#define MC_REG_B_DM 0x04 /* Data Mode, 1=Binary 0=BCD */
+#define MC_REG_B_SQWE 0x08 /* Sqare Wave Enable */
+#define MC_REG_B_UIE 0x10 /* Update-ended Interrupt Enable */
+#define MC_REG_B_AIE 0x20 /* Alarm Interrupt Enable */
+#define MC_REG_B_PIE 0x40 /* Periodic Interrupt Enable */
+#define MC_REG_B_SET 0x80 /* Set NVram info, e.g. update time or ..*/
+#define MC_REG_B_STOP MC_REG_B_SET /* Stop updating the timing info */
+
+/*
+ * Register C defines (read-only)
+ */
+
+#define MC_REG_C_ZEROES 0x0f /* Reads as zero bits */
+#define MC_REG_C_UF 0x10 /* Update-ended interrupt flag */
+#define MC_REG_C_AF 0x20 /* Alarm interrupt flag */
+#define MC_REG_C_PF 0x40 /* Periodic interrupt flag */
+#define MC_REG_C_IRQF 0x80 /* Interrupt request flag */
+
+/*
+ * Register D defines (read-only)
+ */
+
+#define MC_REG_D_ZEROES 0x7f /* Reads as zero bits */
+#define MC_REG_D_VRT 0x80 /* Valid RAM and Time */
+