arch/m68k/atari/ataints.c

   1 /*
   2  * arch/m68k/atari/ataints.c -- Atari Linux interrupt handling code
   3  *
   4  * 5/2/94 Roman Hodek:
   5  *  Added support for TT interrupts; setup for TT SCU (may someone has
   6  *  twiddled there and we won't get the right interrupts :-()
   7  *
   8  *  Major change: The device-independent code in m68k/ints.c didn't know
   9  *  about non-autovec ints yet. It hardcoded the number of possible ints to
  10  *  7 (IRQ1...IRQ7). But the Atari has lots of non-autovec ints! I made the
  11  *  number of possible ints a constant defined in interrupt.h, which is
  12  *  47 for the Atari. So we can call request_irq() for all Atari interrupts
  13  *  just the normal way. Additionally, all vectors >= 48 are initialized to
  14  *  call trap() instead of inthandler(). This must be changed here, too.
  15  *
  16  * 1995-07-16 Lars Brinkhoff <f93labr@dd.chalmers.se>:
  17  *  Corrected a bug in atari_add_isr() which rejected all SCC
  18  *  interrupt sources if there were no TT MFP!
  19  *
  20  * 12/13/95: New interface functions atari_level_triggered_int() and
  21  *  atari_register_vme_int() as support for level triggered VME interrupts.
  22  *
  23  * 02/12/96: (Roman)
  24  *  Total rewrite of Atari interrupt handling, for new scheme see comments
  25  *  below.
  26  *
  27  * 1996-09-03 lars brinkhoff <f93labr@dd.chalmers.se>:
  28  *  Added new function atari_unregister_vme_int(), and
  29  *  modified atari_register_vme_int() as well as IS_VALID_INTNO()
  30  *  to work with it.
  31  *
  32  * This file is subject to the terms and conditions of the GNU General Public
  33  * License.  See the file COPYING in the main directory of this archive
  34  * for more details.
  35  *
  36  */
  37
  38 #include <linux/types.h>
  39 #include <linux/kernel.h>
  40 #include <linux/kernel_stat.h>
  41 #include <linux/init.h>
  42 #include <linux/seq_file.h>
  43 #include <linux/module.h>
  44
  45 #include <asm/traps.h>
  46
  47 #include <asm/atarihw.h>
  48 #include <asm/atariints.h>
  49 #include <asm/atari_stdma.h>
  50 #include <asm/irq.h>
  51 #include <asm/entry.h>
  52
  53
  54 /*
  55  * Atari interrupt handling scheme:
  56  * --------------------------------
  57  *
  58  * All interrupt source have an internal number (defined in
  59  * <asm/atariints.h>): Autovector interrupts are 1..7, then follow ST-MFP,
  60  * TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can
  61  * be allocated by atari_register_vme_int().
  62  */
  63
  64 /*
  65  * Bitmap for free interrupt vector numbers
  66  * (new vectors starting from 0x70 can be allocated by
  67  * atari_register_vme_int())
  68  */
  69 static int free_vme_vec_bitmap;
  70
  71 /* GK:
  72  * HBL IRQ handler for Falcon. Nobody needs it :-)
  73  * ++andreas: raise ipl to disable further HBLANK interrupts.
  74  */
  75 asmlinkage void falcon_hblhandler(void);
  76 asm(".text\n"
  77 __ALIGN_STR "\n\t"
  78 "falcon_hblhandler:\n\t"
  79         "orw    #0x200,%sp@\n\t"        /* set saved ipl to 2 */
  80         "rte");
  81
  82 extern void atari_microwire_cmd(int cmd);
  83
  84 static unsigned int atari_irq_startup(struct irq_data *data)
  85 {
  86         unsigned int irq = data->irq;
  87
  88         m68k_irq_startup(data);
  89         atari_turnon_irq(irq);
  90         atari_enable_irq(irq);
  91         return 0;
  92 }
  93
  94 static void atari_irq_shutdown(struct irq_data *data)
  95 {
  96         unsigned int irq = data->irq;
  97
  98         atari_disable_irq(irq);
  99         atari_turnoff_irq(irq);
 100         m68k_irq_shutdown(data);
 101
 102         if (irq == IRQ_AUTO_4)
 103             vectors[VEC_INT4] = falcon_hblhandler;
 104 }
 105
 106 static void atari_irq_enable(struct irq_data *data)
 107 {
 108         atari_enable_irq(data->irq);
 109 }
 110
 111 static void atari_irq_disable(struct irq_data *data)
 112 {
 113         atari_disable_irq(data->irq);
 114 }
 115
 116 static struct irq_chip atari_irq_chip = {
 117         .name           = "atari",
 118         .irq_startup    = atari_irq_startup,
 119         .irq_shutdown   = atari_irq_shutdown,
 120         .irq_enable     = atari_irq_enable,
 121         .irq_disable    = atari_irq_disable,
 122 };
 123
 124 /*
 125  * void atari_init_IRQ (void)
 126  *
 127  * Parameters:  None
 128  *
 129  * Returns:     Nothing
 130  *
 131  * This function should be called during kernel startup to initialize
 132  * the atari IRQ handling routines.
 133  */
 134
 135 void __init atari_init_IRQ(void)
 136 {
 137         m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER);
 138         m68k_setup_irq_controller(&atari_irq_chip, handle_simple_irq, 1,
 139                                   NUM_ATARI_SOURCES - 1);
 140
 141         /* Initialize the MFP(s) */
 142
 143 #ifdef ATARI_USE_SOFTWARE_EOI
 144         st_mfp.vec_adr  = 0x48; /* Software EOI-Mode */
 145 #else
 146         st_mfp.vec_adr  = 0x40; /* Automatic EOI-Mode */
 147 #endif
 148         st_mfp.int_en_a = 0x00; /* turn off MFP-Ints */
 149         st_mfp.int_en_b = 0x00;
 150         st_mfp.int_mk_a = 0xff; /* no Masking */
 151         st_mfp.int_mk_b = 0xff;
 152
 153         if (ATARIHW_PRESENT(TT_MFP)) {
 154 #ifdef ATARI_USE_SOFTWARE_EOI
 155                 tt_mfp.vec_adr  = 0x58;         /* Software EOI-Mode */
 156 #else
 157                 tt_mfp.vec_adr  = 0x50;         /* Automatic EOI-Mode */
 158 #endif
 159                 tt_mfp.int_en_a = 0x00;         /* turn off MFP-Ints */
 160                 tt_mfp.int_en_b = 0x00;
 161                 tt_mfp.int_mk_a = 0xff;         /* no Masking */
 162                 tt_mfp.int_mk_b = 0xff;
 163         }
 164
 165         if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) {
 166                 atari_scc.cha_a_ctrl = 9;
 167                 MFPDELAY();
 168                 atari_scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */
 169         }
 170
 171         if (ATARIHW_PRESENT(SCU)) {
 172                 /* init the SCU if present */
 173                 tt_scu.sys_mask = 0x10;         /* enable VBL (for the cursor) and
 174                                                                          * disable HSYNC interrupts (who
 175                                                                          * needs them?)  MFP and SCC are
 176                                                                          * enabled in VME mask
 177                                                                          */
 178                 tt_scu.vme_mask = 0x60;         /* enable MFP and SCC ints */
 179         } else {
 180                 /* If no SCU and no Hades, the HSYNC interrupt needs to be
 181                  * disabled this way. (Else _inthandler in kernel/sys_call.S
 182                  * gets overruns)
 183                  */
 184
 185                 vectors[VEC_INT2] = falcon_hblhandler;
 186                 vectors[VEC_INT4] = falcon_hblhandler;
 187         }
 188
 189         if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) {
 190                 /* Initialize the LM1992 Sound Controller to enable
 191                    the PSG sound.  This is misplaced here, it should
 192                    be in an atasound_init(), that doesn't exist yet. */
 193                 atari_microwire_cmd(MW_LM1992_PSG_HIGH);
 194         }
 195
 196         stdma_init();
 197
 198         /* Initialize the PSG: all sounds off, both ports output */
 199         sound_ym.rd_data_reg_sel = 7;
 200         sound_ym.wd_data = 0xff;
 201 }
 202
 203
 204 /*
 205  * atari_register_vme_int() returns the number of a free interrupt vector for
 206  * hardware with a programmable int vector (probably a VME board).
 207  */
 208
 209 unsigned int atari_register_vme_int(void)
 210 {
 211         int i;
 212
 213         for (i = 0; i < 32; i++)
 214                 if ((free_vme_vec_bitmap & (1 << i)) == 0)
 215                         break;
 216
 217         if (i == 16)
 218                 return 0;
 219
 220         free_vme_vec_bitmap |= 1 << i;
 221         return VME_SOURCE_BASE + i;
 222 }
 223 EXPORT_SYMBOL(atari_register_vme_int);
 224
 225
 226 void atari_unregister_vme_int(unsigned int irq)
 227 {
 228         if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) {
 229                 irq -= VME_SOURCE_BASE;
 230                 free_vme_vec_bitmap &= ~(1 << irq);
 231         }
 232 }
 233 EXPORT_SYMBOL(atari_unregister_vme_int);
 234
 235