mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-19 08:28:51 +09:00
143 lines
3.3 KiB
C
143 lines
3.3 KiB
C
/* Initializes CPU and basic hardware such as memory
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* controllers, IRQ controller and system timer 0.
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*
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* (C) Copyright 2007
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* Daniel Hellstrom, Gaisler Research, daniel@gaisler.com
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*
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*/
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#include <common.h>
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#include <asm/asi.h>
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#include <asm/leon.h>
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#include <config.h>
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DECLARE_GLOBAL_DATA_PTR;
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/* reset CPU (jump to 0, without reset) */
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void start(void);
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struct {
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gd_t gd_area;
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bd_t bd;
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} global_data;
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/*
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* Breath some life into the CPU...
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*
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* Set up the memory map,
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* initialize a bunch of registers.
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*
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* Run from FLASH/PROM:
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* - until memory controller is set up, only registers avaiable
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* - no global variables available for writing
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* - constants avaiable
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*/
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void cpu_init_f(void)
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{
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LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
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/* initialize the IRQMP */
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leon2->Interrupt_Force = 0;
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leon2->Interrupt_Pending = 0;
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leon2->Interrupt_Clear = 0xfffe; /* clear all old pending interrupts */
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leon2->Interrupt_Mask = 0xfffe0000; /* mask all IRQs */
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/* cache */
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/* I/O port setup */
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#ifdef LEON2_IO_PORT_DIR
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leon2->PIO_Direction = LEON2_IO_PORT_DIR;
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#endif
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#ifdef LEON2_IO_PORT_DATA
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leon2->PIO_Data = LEON2_IO_PORT_DATA;
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#endif
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#ifdef LEON2_IO_PORT_INT
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leon2->PIO_Interrupt = LEON2_IO_PORT_INT;
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#else
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leon2->PIO_Interrupt = 0;
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#endif
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}
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void cpu_init_f2(void)
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{
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}
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/*
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* initialize higher level parts of CPU like time base and timers
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*/
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int cpu_init_r(void)
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{
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LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
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/* initialize prescaler common to all timers to 1MHz */
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leon2->Scaler_Counter = leon2->Scaler_Reload =
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(((CONFIG_SYS_CLK_FREQ / 1000) + 500) / 1000) - 1;
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return (0);
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}
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/* Uses Timer 0 to get accurate
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* pauses. Max 2 raised to 32 ticks
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*
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*/
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void cpu_wait_ticks(unsigned long ticks)
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{
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unsigned long start = get_timer(0);
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while (get_timer(start) < ticks) ;
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}
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/* initiate and setup timer0 interrupt to 1MHz
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* Return irq number for timer int or a negative number for
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* dealing with self
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*/
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int timer_interrupt_init_cpu(void)
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{
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LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
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/* 1ms ticks */
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leon2->Timer_Counter_1 = 0;
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leon2->Timer_Reload_1 = 999; /* (((1000000 / 100) - 1)) */
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leon2->Timer_Control_1 =
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(LEON2_TIMER_CTRL_EN | LEON2_TIMER_CTRL_RS | LEON2_TIMER_CTRL_LD);
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return LEON2_TIMER1_IRQNO;
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}
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/*
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* This function is intended for SHORT delays only.
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*/
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unsigned long cpu_usec2ticks(unsigned long usec)
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{
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/* timer set to 1kHz ==> 1 clk tick = 1 msec */
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if (usec < 1000)
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return 1;
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return (usec / 1000);
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}
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unsigned long cpu_ticks2usec(unsigned long ticks)
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{
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/* 1tick = 1usec */
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return ticks * 1000;
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}
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