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, 2015
   5  * Daniel Hellstrom, Cobham Gaisler, 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 /*
  22  * Breath some life into the CPU...
  23  *
  24  * Set up the memory map,
  25  * initialize a bunch of registers.
  26  *
  27  * Run from FLASH/PROM:
  28  *  - until memory controller is set up, only registers available
  29  *  - no global variables available for writing
  30  *  - constants available
  31  */
  32
  33 void cpu_init_f(void)
  34 {
  35         LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
  36
  37         /* initialize the IRQMP */
  38         leon2->Interrupt_Force = 0;
  39         leon2->Interrupt_Pending = 0;
  40         leon2->Interrupt_Clear = 0xfffe;        /* clear all old pending interrupts */
  41         leon2->Interrupt_Mask = 0xfffe0000;     /* mask all IRQs */
  42
  43         /* cache */
  44
  45         /* I/O port setup */
  46 #ifdef LEON2_IO_PORT_DIR
  47         leon2->PIO_Direction = LEON2_IO_PORT_DIR;
  48 #endif
  49 #ifdef LEON2_IO_PORT_DATA
  50         leon2->PIO_Data = LEON2_IO_PORT_DATA;
  51 #endif
  52 #ifdef LEON2_IO_PORT_INT
  53         leon2->PIO_Interrupt = LEON2_IO_PORT_INT;
  54 #else
  55         leon2->PIO_Interrupt = 0;
  56 #endif
  57 }
  58
  59 void cpu_init_f2(void)
  60 {
  61
  62 }
  63
  64 int arch_cpu_init(void)
  65 {
  66         gd->cpu_clk = CONFIG_SYS_CLK_FREQ;
  67         gd->bus_clk = CONFIG_SYS_CLK_FREQ;
  68         gd->ram_size = CONFIG_SYS_SDRAM_SIZE;
  69
  70         return 0;
  71 }
  72
  73 /*
  74  * initialize higher level parts of CPU like time base and timers
  75  */
  76 int cpu_init_r(void)
  77 {
  78         LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
  79
  80         /* initialize prescaler common to all timers to 1MHz */
  81         leon2->Scaler_Counter = leon2->Scaler_Reload =
  82             (((CONFIG_SYS_CLK_FREQ / 1000) + 500) / 1000) - 1;
  83
  84         return (0);
  85 }
  86
  87 /* Uses Timer 0 to get accurate
  88  * pauses. Max 2 raised to 32 ticks
  89  *
  90  */
  91 void cpu_wait_ticks(unsigned long ticks)
  92 {
  93         unsigned long start = get_timer(0);
  94         while (get_timer(start) < ticks) ;
  95 }
  96
  97 /* initiate and setup timer0 interrupt to configured HZ. Base clock is 1MHz.
  98  * Return irq number for timer int or a negative number for
  99  * dealing with self
 100  */
 101 int timer_interrupt_init_cpu(void)
 102 {
 103         LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
 104
 105         /* SYS_HZ ticks per second */
 106         leon2->Timer_Counter_1 = 0;
 107         leon2->Timer_Reload_1 = (TIMER_BASE_CLK / CONFIG_SYS_HZ) - 1;
 108         leon2->Timer_Control_1 =
 109             (LEON2_TIMER_CTRL_EN | LEON2_TIMER_CTRL_RS | LEON2_TIMER_CTRL_LD);
 110
 111         return LEON2_TIMER1_IRQNO;
 112 }
 113
 114 ulong get_tbclk(void)
 115 {
 116         return TIMER_BASE_CLK;
 117 }
 118
 119 /*
 120  * This function is intended for SHORT delays only.
 121  */
 122 unsigned long cpu_usec2ticks(unsigned long usec)
 123 {
 124         if (usec < US_PER_TICK)
 125                 return 1;
 126         return usec / US_PER_TICK;
 127 }
 128
 129 unsigned long cpu_ticks2usec(unsigned long ticks)
 130 {
 131         return ticks * US_PER_TICK;
 132 }