cpu/mpc86xx/interrupts.c

   1 /*
   2  * (C) Copyright 2000-2002
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * (C) Copyright 2002 (440 port)
   6  * Scott McNutt, Artesyn Communication Producs, smcnutt@artsyncp.com
   7  *
   8  * (C) Copyright 2003 Motorola Inc. (MPC85xx port)
   9  * Xianghua Xiao (X.Xiao@motorola.com)
  10  *
  11  * (C) Copyright 2004 Freescale Semiconductor. (MPC86xx Port)
  12  * Jeff Brown
  13  * Srikanth Srinivasan (srikanth.srinivasan@freescale.com)
  14  *
  15  * See file CREDITS for list of people who contributed to this
  16  * project.
  17  *
  18  * This program is free software; you can redistribute it and/or
  19  * modify it under the terms of the GNU General Public License as
  20  * published by the Free Software Foundation; either version 2 of
  21  * the License, or (at your option) any later version.
  22  *
  23  * This program is distributed in the hope that it will be useful,
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  * GNU General Public License for more details.
  27  *
  28  * You should have received a copy of the GNU General Public License
  29  * along with this program; if not, write to the Free Software
  30  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  31  * MA 02111-1307 USA
  32  */
  33
  34 #include <common.h>
  35 #include <mpc86xx.h>
  36 #include <command.h>
  37 #include <asm/processor.h>
  38 #include <ppc_asm.tmpl>
  39
  40 unsigned long decrementer_count;    /* count value for 1e6/HZ microseconds */
  41 unsigned long timestamp;
  42
  43
  44 static __inline__ unsigned long get_msr(void)
  45 {
  46         unsigned long msr;
  47
  48         asm volatile ("mfmsr %0":"=r" (msr):);
  49
  50         return msr;
  51 }
  52
  53 static __inline__ void set_msr(unsigned long msr)
  54 {
  55         asm volatile ("mtmsr %0"::"r" (msr));
  56 }
  57
  58 static __inline__ unsigned long get_dec(void)
  59 {
  60         unsigned long val;
  61
  62         asm volatile ("mfdec %0":"=r" (val):);
  63
  64         return val;
  65 }
  66
  67 static __inline__ void set_dec(unsigned long val)
  68 {
  69         if (val)
  70                 asm volatile ("mtdec %0"::"r" (val));
  71 }
  72
  73 /* interrupt is not supported yet */
  74 int interrupt_init_cpu(unsigned long *decrementer_count)
  75 {
  76         return 0;
  77 }
  78
  79 int interrupt_init(void)
  80 {
  81         int ret;
  82
  83         /*
  84          * The IRQ0 on Rev 2 is pulled high (low in Rev 1.x) to
  85          * implement PEX10 errata.  As INT is active high, it
  86          * will cause core to take 0x500 interrupt.
  87          *
  88          * Due to the PIC's default pass through mode, as soon
  89          * as interrupts are enabled (MSR[EE] = 1), an interrupt
  90          * will be taken and u-boot will hang.  This is due to a
  91          * hardware change (per an errata fix) on new revisions
  92          * of the board with Rev 2.x parts.
  93          *
  94          * Setting the PIC to mixed mode prevents the hang.
  95          */
  96         if ((get_svr() & 0xf0) == 0x20) {
  97                 volatile immap_t *immr = (immap_t *)CFG_IMMR;
  98                 immr->im_pic.gcr = MPC86xx_PICGCR_RST;
  99                 while (immr->im_pic.gcr & MPC86xx_PICGCR_RST);
 100                 immr->im_pic.gcr = MPC86xx_PICGCR_MODE;
 101         }
 102
 103         /* call cpu specific function from $(CPU)/interrupts.c */
 104         ret = interrupt_init_cpu(&decrementer_count);
 105
 106         if (ret)
 107                 return ret;
 108
 109         decrementer_count = get_tbclk() / CFG_HZ;
 110         debug("interrupt init: tbclk() = %d MHz, decrementer_count = %ld\n",
 111               (get_tbclk() / 1000000),
 112               decrementer_count);
 113
 114         set_dec(decrementer_count);
 115
 116         set_msr(get_msr() | MSR_EE);
 117
 118         debug("MSR = 0x%08lx, Decrementer reg = 0x%08lx\n",
 119               get_msr(),
 120               get_dec());
 121
 122         return 0;
 123 }
 124
 125 void enable_interrupts(void)
 126 {
 127         set_msr(get_msr() | MSR_EE);
 128 }
 129
 130 /* returns flag if MSR_EE was set before */
 131 int disable_interrupts(void)
 132 {
 133         ulong msr = get_msr();
 134
 135         set_msr(msr & ~MSR_EE);
 136         return (msr & MSR_EE) != 0;
 137 }
 138
 139 void increment_timestamp(void)
 140 {
 141         timestamp++;
 142 }
 143
 144 /*
 145  * timer_interrupt - gets called when the decrementer overflows,
 146  * with interrupts disabled.
 147  * Trivial implementation - no need to be really accurate.
 148  */
 149 void timer_interrupt_cpu(struct pt_regs *regs)
 150 {
 151         /* nothing to do here */
 152 }
 153
 154 void timer_interrupt(struct pt_regs *regs)
 155 {
 156         /* call cpu specific function from $(CPU)/interrupts.c */
 157         timer_interrupt_cpu(regs);
 158
 159         timestamp++;
 160
 161         ppcDcbf((unsigned long)&timestamp);
 162
 163         /* Restore Decrementer Count */
 164         set_dec(decrementer_count);
 165
 166 #if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
 167         if ((timestamp % (CFG_WATCHDOG_FREQ)) == 0)
 168                 WATCHDOG_RESET();
 169 #endif /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
 170
 171 #ifdef CONFIG_STATUS_LED
 172         status_led_tick(timestamp);
 173 #endif /* CONFIG_STATUS_LED */
 174
 175 #ifdef CONFIG_SHOW_ACTIVITY
 176         board_show_activity(timestamp);
 177 #endif /* CONFIG_SHOW_ACTIVITY */
 178
 179 }
 180
 181 void reset_timer(void)
 182 {
 183         timestamp = 0;
 184 }
 185
 186 ulong get_timer(ulong base)
 187 {
 188         return timestamp - base;
 189 }
 190
 191 void set_timer(ulong t)
 192 {
 193         timestamp = t;
 194 }
 195
 196 /*
 197  * Install and free a interrupt handler. Not implemented yet.
 198  */
 199
 200 void irq_install_handler(int vec, interrupt_handler_t *handler, void *arg)
 201 {
 202 }
 203
 204 void irq_free_handler(int vec)
 205 {
 206 }
 207
 208 /*
 209  * irqinfo - print information about PCI devices,not implemented.
 210  */
 211 int do_irqinfo(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 212 {
 213         printf("\nInterrupt-unsupported:\n");
 214
 215         return 0;
 216 }
 217
 218 /*
 219  * Handle external interrupts
 220  */
 221 void external_interrupt(struct pt_regs *regs)
 222 {
 223         puts("external_interrupt (oops!)\n");
 224 }