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 #define TIMER_BASE_CLK 1000000
  17 #define US_PER_TICK (1000000 / CONFIG_SYS_HZ)
  18
  19 DECLARE_GLOBAL_DATA_PTR;
  20
  21 /* reset CPU (jump to 0, without reset) */
  22 void start(void);
  23
  24 struct {
  25         gd_t gd_area;
  26         bd_t bd;
  27 } global_data;
  28
  29 /*
  30  * Breath some life into the CPU...
  31  *
  32  * Set up the memory map,
  33  * initialize a bunch of registers.
  34  *
  35  * Run from FLASH/PROM:
  36  *  - until memory controller is set up, only registers available
  37  *  - no global variables available for writing
  38  *  - constants available
  39  */
  40
  41 void cpu_init_f(void)
  42 {
  43         LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
  44
  45         /* initialize the IRQMP */
  46         leon2->Interrupt_Force = 0;
  47         leon2->Interrupt_Pending = 0;
  48         leon2->Interrupt_Clear = 0xfffe;        /* clear all old pending interrupts */
  49         leon2->Interrupt_Mask = 0xfffe0000;     /* mask all IRQs */
  50
  51         /* cache */
  52
  53        /* I/O port setup */
  54 #ifdef LEON2_IO_PORT_DIR
  55        leon2->PIO_Direction = LEON2_IO_PORT_DIR;
  56 #endif
  57 #ifdef LEON2_IO_PORT_DATA
  58        leon2->PIO_Data = LEON2_IO_PORT_DATA;
  59 #endif
  60 #ifdef LEON2_IO_PORT_INT
  61        leon2->PIO_Interrupt = LEON2_IO_PORT_INT;
  62 #else
  63        leon2->PIO_Interrupt = 0;
  64 #endif
  65 }
  66
  67 void cpu_init_f2(void)
  68 {
  69
  70 }
  71
  72 /*
  73  * initialize higher level parts of CPU like time base and timers
  74  */
  75 int cpu_init_r(void)
  76 {
  77         LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
  78
  79         /* initialize prescaler common to all timers to 1MHz */
  80         leon2->Scaler_Counter = leon2->Scaler_Reload =
  81             (((CONFIG_SYS_CLK_FREQ / 1000) + 500) / 1000) - 1;
  82
  83         return (0);
  84 }
  85
  86 /* Uses Timer 0 to get accurate
  87  * pauses. Max 2 raised to 32 ticks
  88  *
  89  */
  90 void cpu_wait_ticks(unsigned long ticks)
  91 {
  92         unsigned long start = get_timer(0);
  93         while (get_timer(start) < ticks) ;
  94 }
  95
  96 /* initiate and setup timer0 interrupt to configured HZ. Base clock is 1MHz.
  97  * Return irq number for timer int or a negative number for
  98  * dealing with self
  99  */
 100 int timer_interrupt_init_cpu(void)
 101 {
 102         LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
 103
 104         /* SYS_HZ ticks per second */
 105         leon2->Timer_Counter_1 = 0;
 106         leon2->Timer_Reload_1 = (TIMER_BASE_CLK / CONFIG_SYS_HZ) - 1;
 107         leon2->Timer_Control_1 =
 108             (LEON2_TIMER_CTRL_EN | LEON2_TIMER_CTRL_RS | LEON2_TIMER_CTRL_LD);
 109
 110         return LEON2_TIMER1_IRQNO;
 111 }
 112
 113 ulong get_tbclk(void)
 114 {
 115         return TIMER_BASE_CLK;
 116 }
 117
 118 /*
 119  * This function is intended for SHORT delays only.
 120  */
 121 unsigned long cpu_usec2ticks(unsigned long usec)
 122 {
 123         if (usec < US_PER_TICK)
 124                 return 1;
 125         return usec / US_PER_TICK;
 126 }
 127
 128 unsigned long cpu_ticks2usec(unsigned long ticks)
 129 {
 130         return ticks * US_PER_TICK;
 131 }