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/system.h>
  46 #include <asm/traps.h>
  47
  48 #include <asm/atarihw.h>
  49 #include <asm/atariints.h>
  50 #include <asm/atari_stdma.h>
  51 #include <asm/irq.h>
  52 #include <asm/entry.h>
  53
  54
  55 /*
  56  * Atari interrupt handling scheme:
  57  * --------------------------------
  58  *
  59  * All interrupt source have an internal number (defined in
  60  * <asm/atariints.h>): Autovector interrupts are 1..7, then follow ST-MFP,
  61  * TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can
  62  * be allocated by atari_register_vme_int().
  63  */
  64
  65 /*
  66  * Bitmap for free interrupt vector numbers
  67  * (new vectors starting from 0x70 can be allocated by
  68  * atari_register_vme_int())
  69  */
  70 static int free_vme_vec_bitmap;
  71
  72 /* GK:
  73  * HBL IRQ handler for Falcon. Nobody needs it :-)
  74  * ++andreas: raise ipl to disable further HBLANK interrupts.
  75  */
  76 asmlinkage void falcon_hblhandler(void);
  77 asm(".text\n"
  78 __ALIGN_STR "\n\t"
  79 "falcon_hblhandler:\n\t"
  80         "orw    #0x200,%sp@\n\t"        /* set saved ipl to 2 */
  81         "rte");
  82
  83 extern void atari_microwire_cmd(int cmd);
  84
  85 extern int atari_SCC_reset_done;
  86
  87 static unsigned int atari_irq_startup(struct irq_data *data)
  88 {
  89         unsigned int irq = data->irq;
  90
  91         m68k_irq_startup(data);
  92         atari_turnon_irq(irq);
  93         atari_enable_irq(irq);
  94         return 0;
  95 }
  96
  97 static void atari_irq_shutdown(struct irq_data *data)
  98 {
  99         unsigned int irq = data->irq;
 100
 101         atari_disable_irq(irq);
 102         atari_turnoff_irq(irq);
 103         m68k_irq_shutdown(data);
 104
 105         if (irq == IRQ_AUTO_4)
 106             vectors[VEC_INT4] = falcon_hblhandler;
 107 }
 108
 109 static void atari_irq_enable(struct irq_data *data)
 110 {
 111         atari_enable_irq(data->irq);
 112 }
 113
 114 static void atari_irq_disable(struct irq_data *data)
 115 {
 116         atari_disable_irq(data->irq);
 117 }
 118
 119 static struct irq_chip atari_irq_chip = {
 120         .name           = "atari",
 121         .irq_startup    = atari_irq_startup,
 122         .irq_shutdown   = atari_irq_shutdown,
 123         .irq_enable     = atari_irq_enable,
 124         .irq_disable    = atari_irq_disable,
 125 };
 126
 127 /*
 128  * void atari_init_IRQ (void)
 129  *
 130  * Parameters:  None
 131  *
 132  * Returns:     Nothing
 133  *
 134  * This function should be called during kernel startup to initialize
 135  * the atari IRQ handling routines.
 136  */
 137
 138 void __init atari_init_IRQ(void)
 139 {
 140         m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER);
 141         m68k_setup_irq_controller(&atari_irq_chip, handle_simple_irq, 1,
 142                                   NUM_ATARI_SOURCES - 1);
 143
 144         /* Initialize the MFP(s) */
 145
 146 #ifdef ATARI_USE_SOFTWARE_EOI
 147         st_mfp.vec_adr  = 0x48; /* Software EOI-Mode */
 148 #else
 149         st_mfp.vec_adr  = 0x40; /* Automatic EOI-Mode */
 150 #endif
 151         st_mfp.int_en_a = 0x00; /* turn off MFP-Ints */
 152         st_mfp.int_en_b = 0x00;
 153         st_mfp.int_mk_a = 0xff; /* no Masking */
 154         st_mfp.int_mk_b = 0xff;
 155
 156         if (ATARIHW_PRESENT(TT_MFP)) {
 157 #ifdef ATARI_USE_SOFTWARE_EOI
 158                 tt_mfp.vec_adr  = 0x58;         /* Software EOI-Mode */
 159 #else
 160                 tt_mfp.vec_adr  = 0x50;         /* Automatic EOI-Mode */
 161 #endif
 162                 tt_mfp.int_en_a = 0x00;         /* turn off MFP-Ints */
 163                 tt_mfp.int_en_b = 0x00;
 164                 tt_mfp.int_mk_a = 0xff;         /* no Masking */
 165                 tt_mfp.int_mk_b = 0xff;
 166         }
 167
 168         if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) {
 169                 atari_scc.cha_a_ctrl = 9;
 170                 MFPDELAY();
 171                 atari_scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */
 172         }
 173
 174         if (ATARIHW_PRESENT(SCU)) {
 175                 /* init the SCU if present */
 176                 tt_scu.sys_mask = 0x10;         /* enable VBL (for the cursor) and
 177                                                                          * disable HSYNC interrupts (who
 178                                                                          * needs them?)  MFP and SCC are
 179                                                                          * enabled in VME mask
 180                                                                          */
 181                 tt_scu.vme_mask = 0x60;         /* enable MFP and SCC ints */
 182         } else {
 183                 /* If no SCU and no Hades, the HSYNC interrupt needs to be
 184                  * disabled this way. (Else _inthandler in kernel/sys_call.S
 185                  * gets overruns)
 186                  */
 187
 188                 vectors[VEC_INT2] = falcon_hblhandler;
 189                 vectors[VEC_INT4] = falcon_hblhandler;
 190         }
 191
 192         if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) {
 193                 /* Initialize the LM1992 Sound Controller to enable
 194                    the PSG sound.  This is misplaced here, it should
 195                    be in an atasound_init(), that doesn't exist yet. */
 196                 atari_microwire_cmd(MW_LM1992_PSG_HIGH);
 197         }
 198
 199         stdma_init();
 200
 201         /* Initialize the PSG: all sounds off, both ports output */
 202         sound_ym.rd_data_reg_sel = 7;
 203         sound_ym.wd_data = 0xff;
 204 }
 205
 206
 207 /*
 208  * atari_register_vme_int() returns the number of a free interrupt vector for
 209  * hardware with a programmable int vector (probably a VME board).
 210  */
 211
 212 unsigned long atari_register_vme_int(void)
 213 {
 214         int i;
 215
 216         for (i = 0; i < 32; i++)
 217                 if ((free_vme_vec_bitmap & (1 << i)) == 0)
 218                         break;
 219
 220         if (i == 16)
 221                 return 0;
 222
 223         free_vme_vec_bitmap |= 1 << i;
 224         return VME_SOURCE_BASE + i;
 225 }
 226 EXPORT_SYMBOL(atari_register_vme_int);
 227
 228
 229 void atari_unregister_vme_int(unsigned long irq)
 230 {
 231         if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) {
 232                 irq -= VME_SOURCE_BASE;
 233                 free_vme_vec_bitmap &= ~(1 << irq);
 234         }
 235 }
 236 EXPORT_SYMBOL(atari_unregister_vme_int);
 237
 238