315 lines
		
	
	
		
			8.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			315 lines
		
	
	
		
			8.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * cma101.c -- lo-level support for Cogent CMA101 development board.
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|  *
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|  * Copyright (c) 1996, 2001, 2002 Cygnus Support
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|  *
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|  * The authors hereby grant permission to use, copy, modify, distribute,
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|  * and license this software and its documentation for any purpose, provided
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|  * that existing copyright notices are retained in all copies and that this
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|  * notice is included verbatim in any distributions. No written agreement,
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|  * license, or royalty fee is required for any of the authorized uses.
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|  * Modifications to this software may be copyrighted by their authors
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|  * and need not follow the licensing terms described here, provided that
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|  * the new terms are clearly indicated on the first page of each file where
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|  * they apply.
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|  */
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| 
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| #ifdef __mips16
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| /* The assembler portions of this file need to be re-written to
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|    support mips16, if and when that seems useful.
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| */
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| #error cma101.c can not be compiled -mips16
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| #endif
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| 
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| 
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| #include <time.h>       /* standard ANSI time routines */
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| 
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| /* Normally these would appear in a header file for external
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|    use. However, we are only building a simple example world at the
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|    moment: */
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| 
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| #include "regs.S"
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| 
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| #if defined(MIPSEB)
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| #define BYTEREG(b,o)    ((volatile unsigned char *)(PHYS_TO_K1((b) + (o) + 7)))
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| #endif /* MIPSEB */
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| #if defined(MIPSEL)
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| #define BYTEREG(b,o)    ((volatile unsigned char *)(PHYS_TO_K1((b) + (o))))
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| #endif /* MIPSEL */
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| 
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| /* I/O addresses: */
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| #define RTCLOCK_BASE (0x0E800000) /* Mk48T02 NVRAM/RTC */
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| #define UART_BASE    (0x0E900000) /* NS16C552 DUART */
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| #define LCD_BASE     (0x0EB00000) /* Alphanumeric display */
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| 
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| /* LCD panel manifests: */
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| #define LCD_DATA     BYTEREG(LCD_BASE,0)
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| #define LCD_CMD      BYTEREG(LCD_BASE,8)
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| 
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| #define LCD_STAT_BUSY   (0x80)
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| #define LCD_SET_DDADDR  (0x80)
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| 
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| /* RTC manifests */
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| /* The lo-offsets are the NVRAM locations (0x7F8 bytes) */
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| #define RTC_CONTROL     BYTEREG(RTCLOCK_BASE,0x3FC0)
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| #define RTC_SECS        BYTEREG(RTCLOCK_BASE,0x3FC8)
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| #define RTC_MINS        BYTEREG(RTCLOCK_BASE,0x3FD0)
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| #define RTC_HOURS       BYTEREG(RTCLOCK_BASE,0x3FD8)
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| #define RTC_DAY         BYTEREG(RTCLOCK_BASE,0x3FE0)
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| #define RTC_DATE        BYTEREG(RTCLOCK_BASE,0x3FE8)
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| #define RTC_MONTH       BYTEREG(RTCLOCK_BASE,0x3FF0)
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| #define RTC_YEAR        BYTEREG(RTCLOCK_BASE,0x3FF8)
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| 
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| #define RTC_CTL_LOCK_READ       (0x40) /* lock RTC whilst reading */
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| #define RTC_CTL_LOCK_WRITE      (0x80) /* lock RTC whilst writing */
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| 
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| /* Macro to force out-standing memory transfers to complete before
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|    next sequence. For the moment we assume that the processor in the
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|    CMA101 board supports at least ISA II.  */
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| #define DOSYNC() asm(" .set mips2 ; sync ; .set mips0")
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| 
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| /* We disable interrupts by writing zero to all of the masks, and the
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|    global interrupt enable bit: */
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| #define INTDISABLE(sr,tmp) asm("\
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|  .set mips2 ; \
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|  mfc0 %0,$12 ; \
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|  lui %1,0xffff ; \
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|  ori %1,%1,0xfffe ; \
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|  and %1, %0, %1 ; \
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|  mtc0 %1,$12 ; \
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|  .set mips0" : "=d" (sr), "=d" (tmp))
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| #define INTRESTORE(sr) asm("\
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|  .set mips2 ; \
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|  mtc0 %0,$12 ; \
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|  .set mips0" : : "d" (sr))
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| 
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| /* TODO:FIXME: The CPU card support should be in separate source file
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|    from the standard CMA101 support provided in this file. */
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| 
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| /* The CMA101 board being used contains a CMA257 Vr4300 CPU:
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|    MasterClock is at 33MHz. PClock is derived from MasterClock by
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|    multiplying by the ratio defined by the DivMode pins:
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|    	DivMode(1:0)    MasterClock     PClock  Ratio
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|         00              100MHz          100MHz  1:1
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|         01              100MHz          150MHz  1.5:1
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|         10              100MHz          200MHz  2:1
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|         11              100Mhz          300MHz  3:1
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| 
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|    Are these pins reflected in the EC bits in the CONFIG register? or
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|    is that talking about a different clock multiplier?
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|    	110 = 1
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|         111 = 1.5
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|         000 = 2
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|         001 = 3
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|         (all other values are undefined)
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| */
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| 
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| #define MASTERCLOCK (33) /* ticks per uS */
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| unsigned int pclock; /* number of PClock ticks per uS */
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| void
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| set_pclock (void)
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| {
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|   unsigned int config;
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|   asm volatile ("mfc0 %0,$16 ; nop ; nop" : "=r" (config)); /* nasty CP0 register constant */
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|   switch ((config >> 28) & 0x7) {
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|     case 0x7 : /* 1.5:1 */
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|      pclock = (MASTERCLOCK + (MASTERCLOCK / 2));
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|      break;
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| 
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|     case 0x0 : /* 2:1 */
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|      pclock = (2 * MASTERCLOCK);
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|      break;
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| 
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|     case 0x1 : /* 3:1 */
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|      pclock = (3 * MASTERCLOCK);
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|      break;
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| 
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|     case 0x6 : /* 1:1 */
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|     default : /* invalid configuration, so assume the lowest */
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|      pclock = MASTERCLOCK;
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|      break;
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|   }
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| 
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|   return;
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| }
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| 
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| #define PCLOCK_WAIT(x)  __cpu_timer_poll((x) * pclock)
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| 
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| /* NOTE: On the Cogent CMA101 board the LCD controller will sometimes
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|    return not-busy, even though it is. The work-around is to perform a
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|    ~50uS delay before checking the busy signal. */
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| 
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| static int
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| lcd_busy (void)
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| {
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|   PCLOCK_WAIT(50); /* 50uS delay */
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|   return(*LCD_CMD & LCD_STAT_BUSY);
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| }
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| 
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| /* Note: This code *ASSUMES* that the LCD has already been initialised
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|    by the monitor. It only provides code to write to the LCD, and is
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|    not a complete device driver. */
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| 
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| void
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| lcd_display (int line, const char *msg)
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| {
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|   int n;
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| 
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|   if (lcd_busy ())
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|    return;
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| 
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|   *LCD_CMD = (LCD_SET_DDADDR | (line == 1 ? 0x40 : 0x00));
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| 
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|   for (n = 0; n < 16; n++) {
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|     if (lcd_busy ())
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|      return;
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|     if (*msg)
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|      *LCD_DATA = *msg++;
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|     else
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|      *LCD_DATA = ' ';
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|   }
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| 
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|   return;
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| }
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| 
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| #define SM_PATTERN (0x55AA55AA)
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| #define SM_INCR ((256 << 10) / sizeof(unsigned int)) /* 64K words */
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| 
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| extern unsigned int __buserr_count(void);
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| extern void __default_buserr_handler(void);
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| extern void __restore_buserr_handler(void);
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| 
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| /* Allow the user to provide his/her own defaults.  */
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| unsigned int __sizemem_default;
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| 
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| unsigned int
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| __sizemem ()
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| {
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|   volatile unsigned int *base;
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|   volatile unsigned int *probe;
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|   unsigned int baseorig;
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|   unsigned int sr;
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|   extern char end[];
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|   char *endptr = (char *)&end;
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|   int extra;
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| 
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|   /* If the linker script provided a value for the memory size (or the user
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|      overrode it in a debugger), use that.  */
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|   if (__sizemem_default)
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|     return __sizemem_default;
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| 
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|   /* If we are running in kernel segment 0 (possibly cached), try sizing memory
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|      in kernel segment 1 (uncached) to avoid some problems with monitors.  */
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|   if (endptr >= K0BASE_ADDR && endptr < K1BASE_ADDR)
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|     endptr = (endptr - K0BASE_ADDR) + K1BASE_ADDR;
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| 
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|   INTDISABLE(sr,baseorig); /* disable all interrupt masks */
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| 
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|   __default_buserr_handler();
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|   __cpu_flush();
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| 
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|   DOSYNC();
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| 
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|   /* _end is the end of the user program.  _end may not be properly aligned
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|      for an int pointer, so we adjust the address to make sure it is safe.
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|      We use void * arithmetic to avoid accidentally truncating the pointer.  */
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| 
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|   extra = ((int) endptr & (sizeof (int) - 1));
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|   base = ((void *) endptr + sizeof (int) - extra);
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|   baseorig = *base;
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| 
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|   *base = SM_PATTERN;
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|   /* This assumes that the instructions fetched between the store, and
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|      the following read will have changed the data bus contents: */
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|   if (*base == SM_PATTERN) {
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|     probe = base;
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|     for (;;) {
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|       unsigned int probeorig;
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|       probe += SM_INCR;
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|       probeorig = *probe;
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|       /* Check if a bus error occurred: */
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|       if (!__buserr_count()) {
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|         *probe = SM_PATTERN;
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|         DOSYNC();
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|         if (*probe == SM_PATTERN) {
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|           *probe = ~SM_PATTERN;
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|           DOSYNC();
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|           if (*probe == ~SM_PATTERN) {
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|             if (*base == SM_PATTERN) {
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|               *probe = probeorig;
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|               continue;
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|             }
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|           }
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|         }
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|         *probe = probeorig;
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|       }
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|       break;
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|     }
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|   }
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| 
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|   *base = baseorig;
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|   __restore_buserr_handler();
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|   __cpu_flush();
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| 
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|   DOSYNC();
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| 
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|   INTRESTORE(sr); /* restore interrupt mask to entry state */
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| 
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|   return((probe - base) * sizeof(unsigned int));
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| }
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| 
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| /* Provided as a function, so as to avoid reading the I/O location
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|    multiple times: */
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| static int
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| convertbcd(byte)
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|      unsigned char byte;
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| {
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|   return ((((byte >> 4) & 0xF) * 10) + (byte & 0xF));
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| }
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| 
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| time_t
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| time (_timer)
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|      time_t *_timer;
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| {
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|   time_t result = 0;
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|   struct tm tm;
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|   *RTC_CONTROL |= RTC_CTL_LOCK_READ;
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|   DOSYNC();
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| 
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|   tm.tm_sec = convertbcd(*RTC_SECS);
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|   tm.tm_min = convertbcd(*RTC_MINS);
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|   tm.tm_hour = convertbcd(*RTC_HOURS);
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|   tm.tm_mday = convertbcd(*RTC_DATE);
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|   tm.tm_mon = convertbcd(*RTC_MONTH);
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|   tm.tm_year = convertbcd(*RTC_YEAR);
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| 
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|   DOSYNC();
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|   *RTC_CONTROL &= ~(RTC_CTL_LOCK_READ | RTC_CTL_LOCK_WRITE);
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| 
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|   tm.tm_isdst = 0;
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| 
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|   /* Check for invalid time information */
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|   if ((tm.tm_sec < 60) && (tm.tm_min < 60) && (tm.tm_hour < 24)
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|       && (tm.tm_mday < 32) && (tm.tm_mon < 13)) {
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| 
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|     /* Get the correct year number, but keep it in YEAR-1900 form: */
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|     if (tm.tm_year < 70)
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|       tm.tm_year += 100;
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| 
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| #if 0 /* NOTE: mon_printf() can only accept 4 arguments (format string + 3 fields) */
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|     mon_printf("[DBG: s=%d m=%d h=%d]", tm.tm_sec, tm.tm_min, tm.tm_hour);
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|     mon_printf("[DBG: d=%d m=%d y=%d]", tm.tm_mday, tm.tm_mon, tm.tm_year);
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| #endif
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| 
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|     /* Convert the time-structure into a second count */
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|     result = mktime (&tm);
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|   }
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| 
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|   if (_timer != NULL)
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|     *_timer = result;
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| 
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|   return (result);
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| }
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| 
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| /*> EOF cma101.c <*/
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