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Diffstat (limited to 'libgloss/mips/cma101.c')
| -rw-r--r-- | libgloss/mips/cma101.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/libgloss/mips/cma101.c b/libgloss/mips/cma101.c new file mode 100644 index 0000000..0a70440 --- /dev/null +++ b/libgloss/mips/cma101.c @@ -0,0 +1,300 @@ +/* + * cma101.c -- lo-level support for Cogent CMA101 development board. + * + * Copyright (c) 1996 Cygnus Support + * + * The authors hereby grant permission to use, copy, modify, distribute, + * and license this software and its documentation for any purpose, provided + * that existing copyright notices are retained in all copies and that this + * notice is included verbatim in any distributions. No written agreement, + * license, or royalty fee is required for any of the authorized uses. + * Modifications to this software may be copyrighted by their authors + * and need not follow the licensing terms described here, provided that + * the new terms are clearly indicated on the first page of each file where + * they apply. + */ + +#ifdef __mips16 +/* The assembler portions of this file need to be re-written to + support mips16, if and when that seems useful. +*/ +#error cma101.c can not be compiled -mips16 +#endif + + +#include <time.h> /* standard ANSI time routines */ + +/* Normally these would appear in a header file for external + use. However, we are only building a simple example world at the + moment: */ + +#include "regs.S" + +#if defined(MIPSEB) +#define BYTEREG(b,o) ((volatile unsigned char *)(PHYS_TO_K1((b) + (o) + 7))) +#endif /* MIPSEB */ +#if defined(MIPSEL) +#define BYTEREG(b,o) ((volatile unsigned char *)(PHYS_TO_K1((b) + (o)))) +#endif /* MIPSEL */ + +/* I/O addresses: */ +#define RTCLOCK_BASE (0x0E800000) /* Mk48T02 NVRAM/RTC */ +#define UART_BASE (0x0E900000) /* NS16C552 DUART */ +#define LCD_BASE (0x0EB00000) /* Alphanumeric display */ + +/* LCD panel manifests: */ +#define LCD_DATA BYTEREG(LCD_BASE,0) +#define LCD_CMD BYTEREG(LCD_BASE,8) + +#define LCD_STAT_BUSY (0x80) +#define LCD_SET_DDADDR (0x80) + +/* RTC manifests */ +/* The lo-offsets are the NVRAM locations (0x7F8 bytes) */ +#define RTC_CONTROL BYTEREG(RTCLOCK_BASE,0x3FC0) +#define RTC_SECS BYTEREG(RTCLOCK_BASE,0x3FC8) +#define RTC_MINS BYTEREG(RTCLOCK_BASE,0x3FD0) +#define RTC_HOURS BYTEREG(RTCLOCK_BASE,0x3FD8) +#define RTC_DAY BYTEREG(RTCLOCK_BASE,0x3FE0) +#define RTC_DATE BYTEREG(RTCLOCK_BASE,0x3FE8) +#define RTC_MONTH BYTEREG(RTCLOCK_BASE,0x3FF0) +#define RTC_YEAR BYTEREG(RTCLOCK_BASE,0x3FF8) + +#define RTC_CTL_LOCK_READ (0x40) /* lock RTC whilst reading */ +#define RTC_CTL_LOCK_WRITE (0x80) /* lock RTC whilst writing */ + +/* Macro to force out-standing memory transfers to complete before + next sequence. For the moment we assume that the processor in the + CMA101 board supports at least ISA II. */ +#define DOSYNC() asm(" .set mips2 ; sync ; .set mips0") + +/* We disable interrupts by writing zero to all of the masks, and the + global interrupt enable bit: */ +#define INTDISABLE(sr,tmp) asm("\ + .set mips2 ; \ + mfc0 %0,$12 ; \ + lui %1,0xffff ; \ + ori %1,%1,0xfffe ; \ + and %1, %0, %1 ; \ + mtc0 %1,$12 ; \ + .set mips0" : "=d" (sr), "=d" (tmp)) +#define INTRESTORE(sr) asm("\ + .set mips2 ; \ + mtc0 %0,$12 ; \ + .set mips0" : : "d" (sr)) + +/* TODO:FIXME: The CPU card support should be in separate source file + from the standard CMA101 support provided in this file. */ + +/* The CMA101 board being used contains a CMA257 Vr4300 CPU: + MasterClock is at 33MHz. PClock is derived from MasterClock by + multiplying by the ratio defined by the DivMode pins: + DivMode(1:0) MasterClock PClock Ratio + 00 100MHz 100MHz 1:1 + 01 100MHz 150MHz 1.5:1 + 10 100MHz 200MHz 2:1 + 11 100Mhz 300MHz 3:1 + + Are these pins reflected in the EC bits in the CONFIG register? or + is that talking about a different clock multiplier? + 110 = 1 + 111 = 1.5 + 000 = 2 + 001 = 3 + (all other values are undefined) +*/ + +#define MASTERCLOCK (33) /* ticks per uS */ +unsigned int pclock; /* number of PClock ticks per uS */ +void +set_pclock (void) +{ + unsigned int config; + asm volatile ("mfc0 %0,$16 ; nop ; nop" : "=r" (config)); /* nasty CP0 register constant */ + switch ((config >> 28) & 0x7) { + case 0x7 : /* 1.5:1 */ + pclock = (MASTERCLOCK + (MASTERCLOCK / 2)); + break; + + case 0x0 : /* 2:1 */ + pclock = (2 * MASTERCLOCK); + break; + + case 0x1 : /* 3:1 */ + pclock = (3 * MASTERCLOCK); + break; + + case 0x6 : /* 1:1 */ + default : /* invalid configuration, so assume the lowest */ + pclock = MASTERCLOCK; + break; + } + + return; +} + +#define PCLOCK_WAIT(x) __cpu_timer_poll((x) * pclock) + +/* NOTE: On the Cogent CMA101 board the LCD controller will sometimes + return not-busy, even though it is. The work-around is to perform a + ~50uS delay before checking the busy signal. */ + +static int +lcd_busy (void) +{ + PCLOCK_WAIT(50); /* 50uS delay */ + return(*LCD_CMD & LCD_STAT_BUSY); +} + +/* Note: This code *ASSUMES* that the LCD has already been initialised + by the monitor. It only provides code to write to the LCD, and is + not a complete device driver. */ + +void +lcd_display (int line, const char *msg) +{ + int n; + + if (lcd_busy ()) + return; + + *LCD_CMD = (LCD_SET_DDADDR | (line == 1 ? 0x40 : 0x00)); + + for (n = 0; n < 16; n++) { + if (lcd_busy ()) + return; + if (*msg) + *LCD_DATA = *msg++; + else + *LCD_DATA = ' '; + } + + return; +} + +#define SM_PATTERN (0x55AA55AA) +#define SM_INCR ((256 << 10) / sizeof(unsigned int)) /* 64K words */ + +extern unsigned int __buserr_count(void); +extern void __default_buserr_handler(void); +extern void __restore_buserr_handler(void); + +unsigned int +__sizemem () +{ + volatile unsigned int *base; + volatile unsigned int *probe; + unsigned int baseorig; + unsigned int sr; + extern void *end; + int extra; + + INTDISABLE(sr,baseorig); /* disable all interrupt masks */ + + __default_buserr_handler(); + __cpu_flush(); + + DOSYNC(); + + /* _end is the end of the user program. _end may not be properly aligned + for an int pointer, so we adjust the address to make sure it is safe. + We use void * arithmetic to avoid accidentally truncating the pointer. */ + + extra = ((int) &end & (sizeof (int) - 1)); + base = ((void *) &end + sizeof (int) - extra); + baseorig = *base; + + *base = SM_PATTERN; + /* This assumes that the instructions fetched between the store, and + the following read will have changed the data bus contents: */ + if (*base == SM_PATTERN) { + probe = base; + for (;;) { + unsigned int probeorig; + probe += SM_INCR; + probeorig = *probe; + /* Check if a bus error occurred: */ + if (!__buserr_count()) { + *probe = SM_PATTERN; + DOSYNC(); + if (*probe == SM_PATTERN) { + *probe = ~SM_PATTERN; + DOSYNC(); + if (*probe == ~SM_PATTERN) { + if (*base == SM_PATTERN) { + *probe = probeorig; + continue; + } + } + } + *probe = probeorig; + } + break; + } + } + + *base = baseorig; + __restore_buserr_handler(); + __cpu_flush(); + + DOSYNC(); + + INTRESTORE(sr); /* restore interrupt mask to entry state */ + + return((probe - base) * sizeof(unsigned int)); +} + +/* Provided as a function, so as to avoid reading the I/O location + multiple times: */ +static int +convertbcd(byte) + unsigned char byte; +{ + return ((((byte >> 4) & 0xF) * 10) + (byte & 0xF)); +} + +time_t +time (_timer) + time_t *_timer; +{ + time_t result = 0; + struct tm tm; + *RTC_CONTROL |= RTC_CTL_LOCK_READ; + DOSYNC(); + + tm.tm_sec = convertbcd(*RTC_SECS); + tm.tm_min = convertbcd(*RTC_MINS); + tm.tm_hour = convertbcd(*RTC_HOURS); + tm.tm_mday = convertbcd(*RTC_DATE); + tm.tm_mon = convertbcd(*RTC_MONTH); + tm.tm_year = convertbcd(*RTC_YEAR); + + DOSYNC(); + *RTC_CONTROL &= ~(RTC_CTL_LOCK_READ | RTC_CTL_LOCK_WRITE); + + tm.tm_isdst = 0; + + /* Check for invalid time information */ + if ((tm.tm_sec < 60) && (tm.tm_min < 60) && (tm.tm_hour < 24) + && (tm.tm_mday < 32) && (tm.tm_mon < 13)) { + + /* Get the correct year number, but keep it in YEAR-1900 form: */ + if (tm.tm_year < 70) + tm.tm_year += 100; + +#if 0 /* NOTE: mon_printf() can only accept 4 arguments (format string + 3 fields) */ + mon_printf("[DBG: s=%d m=%d h=%d]", tm.tm_sec, tm.tm_min, tm.tm_hour); + mon_printf("[DBG: d=%d m=%d y=%d]", tm.tm_mday, tm.tm_mon, tm.tm_year); +#endif + + /* Convert the time-structure into a second count */ + result = mktime (&tm); + } + + if (_timer != NULL) + *_timer = result; + + return (result); +} + +/*> EOF cma101.c <*/ |