arch/sparc/cpu/leon2/cpu_init.c

   1 /* Initializes CPU and basic hardware such as memory
   2  * controllers, IRQ controller and system timer 0.
   3  *
   4  * (C) Copyright 2007
   5  * Daniel Hellstrom, Gaisler Research, daniel@gaisler.com
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #include <common.h>
  11 #include <asm/asi.h>
  12 #include <asm/leon.h>
  13
  14 #include <config.h>
  15
  16 DECLARE_GLOBAL_DATA_PTR;
  17
  18 /* reset CPU (jump to 0, without reset) */
  19 void start(void);
  20
  21 struct {
  22         gd_t gd_area;
  23         bd_t bd;
  24 } global_data;
  25
  26 /*
  27  * Breath some life into the CPU...
  28  *
  29  * Set up the memory map,
  30  * initialize a bunch of registers.
  31  *
  32  * Run from FLASH/PROM:
  33  *  - until memory controller is set up, only registers available
  34  *  - no global variables available for writing
  35  *  - constants available
  36  */
  37
  38 void cpu_init_f(void)
  39 {
  40         LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
  41
  42         /* initialize the IRQMP */
  43         leon2->Interrupt_Force = 0;
  44         leon2->Interrupt_Pending = 0;
  45         leon2->Interrupt_Clear = 0xfffe;        /* clear all old pending interrupts */
  46         leon2->Interrupt_Mask = 0xfffe0000;     /* mask all IRQs */
  47
  48         /* cache */
  49
  50        /* I/O port setup */
  51 #ifdef LEON2_IO_PORT_DIR
  52        leon2->PIO_Direction = LEON2_IO_PORT_DIR;
  53 #endif
  54 #ifdef LEON2_IO_PORT_DATA
  55        leon2->PIO_Data = LEON2_IO_PORT_DATA;
  56 #endif
  57 #ifdef LEON2_IO_PORT_INT
  58        leon2->PIO_Interrupt = LEON2_IO_PORT_INT;
  59 #else
  60        leon2->PIO_Interrupt = 0;
  61 #endif
  62 }
  63
  64 void cpu_init_f2(void)
  65 {
  66
  67 }
  68
  69 /*
  70  * initialize higher level parts of CPU like time base and timers
  71  */
  72 int cpu_init_r(void)
  73 {
  74         LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
  75
  76         /* initialize prescaler common to all timers to 1MHz */
  77         leon2->Scaler_Counter = leon2->Scaler_Reload =
  78             (((CONFIG_SYS_CLK_FREQ / 1000) + 500) / 1000) - 1;
  79
  80         return (0);
  81 }
  82
  83 /* Uses Timer 0 to get accurate
  84  * pauses. Max 2 raised to 32 ticks
  85  *
  86  */
  87 void cpu_wait_ticks(unsigned long ticks)
  88 {
  89         unsigned long start = get_timer(0);
  90         while (get_timer(start) < ticks) ;
  91 }
  92
  93 /* initiate and setup timer0 interrupt to 1MHz
  94  * Return irq number for timer int or a negative number for
  95  * dealing with self
  96  */
  97 int timer_interrupt_init_cpu(void)
  98 {
  99         LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
 100
 101         /* 1ms ticks */
 102         leon2->Timer_Counter_1 = 0;
 103         leon2->Timer_Reload_1 = 999;    /* (((1000000 / 100) - 1)) */
 104         leon2->Timer_Control_1 =
 105             (LEON2_TIMER_CTRL_EN | LEON2_TIMER_CTRL_RS | LEON2_TIMER_CTRL_LD);
 106
 107         return LEON2_TIMER1_IRQNO;
 108 }
 109
 110 /*
 111  * This function is intended for SHORT delays only.
 112  */
 113 unsigned long cpu_usec2ticks(unsigned long usec)
 114 {
 115         /* timer set to 1kHz ==> 1 clk tick = 1 msec */
 116         if (usec < 1000)
 117                 return 1;
 118         return (usec / 1000);
 119 }
 120
 121 unsigned long cpu_ticks2usec(unsigned long ticks)
 122 {
 123         /* 1tick = 1usec */
 124         return ticks * 1000;
 125 }