cpu/mpc8260/interrupts.c

   1 /*
   2  * (C) Copyright 2000-2002
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  *
  23  * Hacked for MPC8260 by Murray.Jensen@cmst.csiro.au, 22-Oct-00
  24  */
  25
  26 #include <common.h>
  27 #include <command.h>
  28 #include <mpc8260.h>
  29 #include <mpc8260_irq.h>
  30 #include <asm/processor.h>
  31
  32 DECLARE_GLOBAL_DATA_PTR;
  33
  34 /****************************************************************************/
  35
  36 struct irq_action {
  37         interrupt_handler_t *handler;
  38         void *arg;
  39         ulong count;
  40 };
  41
  42 static struct irq_action irq_handlers[NR_IRQS];
  43
  44 static ulong ppc_cached_irq_mask[NR_MASK_WORDS];
  45
  46 /****************************************************************************/
  47 /* this section was ripped out of arch/ppc/kernel/ppc8260_pic.c in the      */
  48 /* Linux/PPC 2.4.x source. There was no copyright notice in that file.      */
  49
  50 /* The 8260 internal interrupt controller.  It is usually
  51  * the only interrupt controller.
  52  * There are two 32-bit registers (high/low) for up to 64
  53  * possible interrupts.
  54  *
  55  * Now, the fun starts.....Interrupt Numbers DO NOT MAP
  56  * in a simple arithmetic fashion to mask or pending registers.
  57  * That is, interrupt 4 does not map to bit position 4.
  58  * We create two tables, indexed by vector number, to indicate
  59  * which register to use and which bit in the register to use.
  60  */
  61 static u_char irq_to_siureg[] = {
  62         1, 1, 1, 1, 1, 1, 1, 1,
  63         1, 1, 1, 1, 1, 1, 1, 1,
  64         0, 0, 0, 0, 0, 0, 0, 0,
  65         0, 0, 0, 0, 0, 0, 0, 0,
  66         1, 1, 1, 1, 1, 1, 1, 1,
  67         1, 1, 1, 1, 1, 1, 1, 1,
  68         0, 0, 0, 0, 0, 0, 0, 0,
  69         0, 0, 0, 0, 0, 0, 0, 0
  70 };
  71
  72 static u_char irq_to_siubit[] = {
  73         31, 16, 17, 18, 19, 20, 21, 22,
  74         23, 24, 25, 26, 27, 28, 29, 30,
  75         29, 30, 16, 17, 18, 19, 20, 21,
  76         22, 23, 24, 25, 26, 27, 28, 31,
  77         0, 1, 2, 3, 4, 5, 6, 7,
  78         8, 9, 10, 11, 12, 13, 14, 15,
  79         15, 14, 13, 12, 11, 10, 9, 8,
  80         7, 6, 5, 4, 3, 2, 1, 0
  81 };
  82
  83 static void m8260_mask_irq (unsigned int irq_nr)
  84 {
  85         volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
  86         int bit, word;
  87         volatile uint *simr;
  88
  89         bit = irq_to_siubit[irq_nr];
  90         word = irq_to_siureg[irq_nr];
  91
  92         simr = &(immr->im_intctl.ic_simrh);
  93         ppc_cached_irq_mask[word] &= ~(1 << (31 - bit));
  94         simr[word] = ppc_cached_irq_mask[word];
  95 }
  96
  97 static void m8260_unmask_irq (unsigned int irq_nr)
  98 {
  99         volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
 100         int bit, word;
 101         volatile uint *simr;
 102
 103         bit = irq_to_siubit[irq_nr];
 104         word = irq_to_siureg[irq_nr];
 105
 106         simr = &(immr->im_intctl.ic_simrh);
 107         ppc_cached_irq_mask[word] |= (1 << (31 - bit));
 108         simr[word] = ppc_cached_irq_mask[word];
 109 }
 110
 111 static void m8260_mask_and_ack (unsigned int irq_nr)
 112 {
 113         volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
 114         int bit, word;
 115         volatile uint *simr, *sipnr;
 116
 117         bit = irq_to_siubit[irq_nr];
 118         word = irq_to_siureg[irq_nr];
 119
 120         simr = &(immr->im_intctl.ic_simrh);
 121         sipnr = &(immr->im_intctl.ic_sipnrh);
 122         ppc_cached_irq_mask[word] &= ~(1 << (31 - bit));
 123         simr[word] = ppc_cached_irq_mask[word];
 124         sipnr[word] = 1 << (31 - bit);
 125 }
 126
 127 static int m8260_get_irq (struct pt_regs *regs)
 128 {
 129         volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
 130         int irq;
 131         unsigned long bits;
 132
 133         /* For MPC8260, read the SIVEC register and shift the bits down
 134          * to get the irq number.         */
 135         bits = immr->im_intctl.ic_sivec;
 136         irq = bits >> 26;
 137         return irq;
 138 }
 139
 140 /* end of code ripped out of arch/ppc/kernel/ppc8260_pic.c                  */
 141 /****************************************************************************/
 142
 143 int interrupt_init_cpu (unsigned *decrementer_count)
 144 {
 145         volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
 146
 147         *decrementer_count = (gd->bus_clk / 4) / CONFIG_SYS_HZ;
 148
 149         /* Initialize the default interrupt mapping priorities */
 150         immr->im_intctl.ic_sicr = 0;
 151         immr->im_intctl.ic_siprr = 0x05309770;
 152         immr->im_intctl.ic_scprrh = 0x05309770;
 153         immr->im_intctl.ic_scprrl = 0x05309770;
 154
 155         /* disable all interrupts and clear all pending bits */
 156         immr->im_intctl.ic_simrh = ppc_cached_irq_mask[0] = 0;
 157         immr->im_intctl.ic_simrl = ppc_cached_irq_mask[1] = 0;
 158         immr->im_intctl.ic_sipnrh = 0xffffffff;
 159         immr->im_intctl.ic_sipnrl = 0xffffffff;
 160
 161 #ifdef CONFIG_HYMOD
 162         /*
 163          * ensure all external interrupt sources default to trigger on
 164          * high-to-low transition (i.e. edge triggered active low)
 165          */
 166         immr->im_intctl.ic_siexr = -1;
 167 #endif
 168
 169         return (0);
 170 }
 171
 172 /****************************************************************************/
 173
 174 /*
 175  * Handle external interrupts
 176  */
 177 void external_interrupt (struct pt_regs *regs)
 178 {
 179         int irq, unmask = 1;
 180
 181         irq = m8260_get_irq (regs);
 182
 183         m8260_mask_and_ack (irq);
 184
 185         enable_interrupts ();
 186
 187         if (irq_handlers[irq].handler != NULL)
 188                 (*irq_handlers[irq].handler) (irq_handlers[irq].arg);
 189         else {
 190                 printf ("\nBogus External Interrupt IRQ %d\n", irq);
 191                 /*
 192                  * turn off the bogus interrupt, otherwise it
 193                  * might repeat forever
 194                  */
 195                 unmask = 0;
 196         }
 197
 198         if (unmask)
 199                 m8260_unmask_irq (irq);
 200 }
 201
 202 /****************************************************************************/
 203
 204 /*
 205  * Install and free an interrupt handler.
 206  */
 207
 208 void
 209 irq_install_handler (int irq, interrupt_handler_t * handler, void *arg)
 210 {
 211         if (irq < 0 || irq >= NR_IRQS) {
 212                 printf ("irq_install_handler: bad irq number %d\n", irq);
 213                 return;
 214         }
 215
 216         if (irq_handlers[irq].handler != NULL)
 217                 printf ("irq_install_handler: 0x%08lx replacing 0x%08lx\n",
 218                                 (ulong) handler, (ulong) irq_handlers[irq].handler);
 219
 220         irq_handlers[irq].handler = handler;
 221         irq_handlers[irq].arg = arg;
 222
 223         m8260_unmask_irq (irq);
 224 }
 225
 226 void irq_free_handler (int irq)
 227 {
 228         if (irq < 0 || irq >= NR_IRQS) {
 229                 printf ("irq_free_handler: bad irq number %d\n", irq);
 230                 return;
 231         }
 232
 233         m8260_mask_irq (irq);
 234
 235         irq_handlers[irq].handler = NULL;
 236         irq_handlers[irq].arg = NULL;
 237 }
 238
 239 /****************************************************************************/
 240
 241 void timer_interrupt_cpu (struct pt_regs *regs)
 242 {
 243         /* nothing to do here */
 244         return;
 245 }
 246
 247 /****************************************************************************/
 248
 249 #if defined(CONFIG_CMD_IRQ)
 250
 251 /* ripped this out of ppc4xx/interrupts.c */
 252
 253 /*******************************************************************************
 254 *
 255 * irqinfo - print information about PCI devices
 256 *
 257 */
 258 void
 259 do_irqinfo (cmd_tbl_t * cmdtp, bd_t * bd, int flag, int argc, char *argv[])
 260 {
 261         int irq, re_enable;
 262
 263         re_enable = disable_interrupts ();
 264
 265         puts ("\nInterrupt-Information:\n"
 266                 "Nr  Routine   Arg       Count\n");
 267
 268         for (irq = 0; irq < 32; irq++)
 269                 if (irq_handlers[irq].handler != NULL)
 270                         printf ("%02d  %08lx  %08lx  %ld\n", irq,
 271                                         (ulong) irq_handlers[irq].handler,
 272                                         (ulong) irq_handlers[irq].arg,
 273                                         irq_handlers[irq].count);
 274
 275         if (re_enable)
 276                 enable_interrupts ();
 277 }
 278
 279 #endif