kernel/linux/arch/arm/mach-rpc/riscpc.c

   1 /*
   2  *  linux/arch/arm/mach-rpc/riscpc.c
   3  *
   4  *  Copyright (C) 1998-2001 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  Architecture specific fixups.
  11  */
  12 #include <linux/kernel.h>
  13 #include <linux/tty.h>
  14 #include <linux/delay.h>
  15 #include <linux/pm.h>
  16 #include <linux/init.h>
  17 #include <linux/sched.h>
  18 #include <linux/interrupt.h>
  19
  20 #include <asm/elf.h>
  21 #include <asm/io.h>
  22 #include <asm/mach-types.h>
  23 #include <asm/hardware.h>
  24 #include <asm/page.h>
  25 #include <asm/domain.h>
  26 #include <asm/setup.h>
  27
  28 #include <asm/mach/map.h>
  29 #include <asm/mach/arch.h>
  30 #include <asm/mach/time.h>
  31
  32 extern void rpc_init_irq(void);
  33
  34 extern unsigned int vram_size;
  35
  36 #if 0
  37
  38 unsigned int memc_ctrl_reg;
  39 unsigned int number_mfm_drives;
  40
  41 static int __init parse_tag_acorn(const struct tag *tag)
  42 {
  43         memc_ctrl_reg = tag->u.acorn.memc_control_reg;
  44         number_mfm_drives = tag->u.acorn.adfsdrives;
  45
  46         switch (tag->u.acorn.vram_pages) {
  47         case 512:
  48                 vram_size += PAGE_SIZE * 256;
  49         case 256:
  50                 vram_size += PAGE_SIZE * 256;
  51         default:
  52                 break;
  53         }
  54 #if 0
  55         if (vram_size) {
  56                 desc->video_start = 0x02000000;
  57                 desc->video_end   = 0x02000000 + vram_size;
  58         }
  59 #endif
  60         return 0;
  61 }
  62
  63 __tagtable(ATAG_ACORN, parse_tag_acorn);
  64
  65 #endif
  66
  67 static struct map_desc rpc_io_desc[] __initdata = {
  68  { SCREEN_BASE, SCREEN_START,   2*1048576, MT_DEVICE }, /* VRAM         */
  69  { IO_BASE,     IO_START,       IO_SIZE  , MT_DEVICE }, /* IO space             */
  70  { EASI_BASE,   EASI_START,     EASI_SIZE, MT_DEVICE }  /* EASI space   */
  71 };
  72
  73 void __init rpc_map_io(void)
  74 {
  75         iotable_init(rpc_io_desc, ARRAY_SIZE(rpc_io_desc));
  76
  77         /*
  78          * Turn off floppy.
  79          */
  80         outb(0xc, 0x3f2);
  81
  82         /*
  83          * RiscPC can't handle half-word loads and stores
  84          */
  85         elf_hwcap &= ~HWCAP_HALF;
  86 }
  87
  88 static irqreturn_t
  89 rpc_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
  90 {
  91         timer_tick(regs);
  92
  93         return IRQ_HANDLED;
  94 }
  95
  96 static struct irqaction rpc_timer_irq = {
  97         .name           = "RiscPC Timer Tick",
  98         .flags          = SA_INTERRUPT,
  99         .handler        = rpc_timer_interrupt
 100 };
 101
 102 /*
 103  * Set up timer interrupt.
 104  */
 105 void __init rpc_init_time(void)
 106 {
 107         extern void ioctime_init(void);
 108         ioctime_init();
 109
 110         setup_irq(IRQ_TIMER, &rpc_timer_irq);
 111 }
 112
 113 MACHINE_START(RISCPC, "Acorn-RiscPC")
 114         MAINTAINER("Russell King")
 115         BOOT_MEM(0x10000000, 0x03000000, 0xe0000000)
 116         BOOT_PARAMS(0x10000100)
 117         DISABLE_PARPORT(0)
 118         DISABLE_PARPORT(1)
 119         MAPIO(rpc_map_io)
 120         INITIRQ(rpc_init_irq)
 121         INITTIME(rpc_init_time)
 122 MACHINE_END