/* * arch/m68k/atari/ataints.c -- Atari Linux interrupt handling code * * 5/2/94 Roman Hodek: * Added support for TT interrupts; setup for TT SCU (may someone has * twiddled there and we won't get the right interrupts :-() * * Major change: The device-independent code in m68k/ints.c didn't know * about non-autovec ints yet. It hardcoded the number of possible ints to * 7 (IRQ1...IRQ7). But the Atari has lots of non-autovec ints! I made the * number of possible ints a constant defined in interrupt.h, which is * 47 for the Atari. So we can call request_irq() for all Atari interrupts * just the normal way. Additionally, all vectors >= 48 are initialized to * call trap() instead of inthandler(). This must be changed here, too. * * 1995-07-16 Lars Brinkhoff : * Corrected a bug in atari_add_isr() which rejected all SCC * interrupt sources if there were no TT MFP! * * 12/13/95: New interface functions atari_level_triggered_int() and * atari_register_vme_int() as support for level triggered VME interrupts. * * 02/12/96: (Roman) * Total rewrite of Atari interrupt handling, for new scheme see comments * below. * * 1996-09-03 lars brinkhoff : * Added new function atari_unregister_vme_int(), and * modified atari_register_vme_int() as well as IS_VALID_INTNO() * to work with it. * * This file is subject to the terms and conditions of the GNU General Public * License. See the file COPYING in the main directory of this archive * for more details. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Atari interrupt handling scheme: * -------------------------------- * * All interrupt source have an internal number (defined in * ): Autovector interrupts are 1..7, then follow ST-MFP, * TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can * be allocated by atari_register_vme_int(). */ /* * Bitmap for free interrupt vector numbers * (new vectors starting from 0x70 can be allocated by * atari_register_vme_int()) */ static int free_vme_vec_bitmap; /* GK: * HBL IRQ handler for Falcon. Nobody needs it :-) * ++andreas: raise ipl to disable further HBLANK interrupts. */ asmlinkage void falcon_hblhandler(void); asm(".text\n" __ALIGN_STR "\n\t" "falcon_hblhandler:\n\t" "orw #0x200,%sp@\n\t" /* set saved ipl to 2 */ "rte"); extern void atari_microwire_cmd(int cmd); static unsigned int atari_irq_startup(struct irq_data *data) { unsigned int irq = data->irq; m68k_irq_startup(data); atari_turnon_irq(irq); atari_enable_irq(irq); return 0; } static void atari_irq_shutdown(struct irq_data *data) { unsigned int irq = data->irq; atari_disable_irq(irq); atari_turnoff_irq(irq); m68k_irq_shutdown(data); if (irq == IRQ_AUTO_4) vectors[VEC_INT4] = falcon_hblhandler; } static void atari_irq_enable(struct irq_data *data) { atari_enable_irq(data->irq); } static void atari_irq_disable(struct irq_data *data) { atari_disable_irq(data->irq); } static struct irq_chip atari_irq_chip = { .name = "atari", .irq_startup = atari_irq_startup, .irq_shutdown = atari_irq_shutdown, .irq_enable = atari_irq_enable, .irq_disable = atari_irq_disable, }; /* * void atari_init_IRQ (void) * * Parameters: None * * Returns: Nothing * * This function should be called during kernel startup to initialize * the atari IRQ handling routines. */ void __init atari_init_IRQ(void) { m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER); m68k_setup_irq_controller(&atari_irq_chip, handle_simple_irq, 1, NUM_ATARI_SOURCES - 1); /* Initialize the MFP(s) */ #ifdef ATARI_USE_SOFTWARE_EOI st_mfp.vec_adr = 0x48; /* Software EOI-Mode */ #else st_mfp.vec_adr = 0x40; /* Automatic EOI-Mode */ #endif st_mfp.int_en_a = 0x00; /* turn off MFP-Ints */ st_mfp.int_en_b = 0x00; st_mfp.int_mk_a = 0xff; /* no Masking */ st_mfp.int_mk_b = 0xff; if (ATARIHW_PRESENT(TT_MFP)) { #ifdef ATARI_USE_SOFTWARE_EOI tt_mfp.vec_adr = 0x58; /* Software EOI-Mode */ #else tt_mfp.vec_adr = 0x50; /* Automatic EOI-Mode */ #endif tt_mfp.int_en_a = 0x00; /* turn off MFP-Ints */ tt_mfp.int_en_b = 0x00; tt_mfp.int_mk_a = 0xff; /* no Masking */ tt_mfp.int_mk_b = 0xff; } if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) { atari_scc.cha_a_ctrl = 9; MFPDELAY(); atari_scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */ } if (ATARIHW_PRESENT(SCU)) { /* init the SCU if present */ tt_scu.sys_mask = 0x10; /* enable VBL (for the cursor) and * disable HSYNC interrupts (who * needs them?) MFP and SCC are * enabled in VME mask */ tt_scu.vme_mask = 0x60; /* enable MFP and SCC ints */ } else { /* If no SCU and no Hades, the HSYNC interrupt needs to be * disabled this way. (Else _inthandler in kernel/sys_call.S * gets overruns) */ vectors[VEC_INT2] = falcon_hblhandler; vectors[VEC_INT4] = falcon_hblhandler; } if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) { /* Initialize the LM1992 Sound Controller to enable the PSG sound. This is misplaced here, it should be in an atasound_init(), that doesn't exist yet. */ atari_microwire_cmd(MW_LM1992_PSG_HIGH); } stdma_init(); /* Initialize the PSG: all sounds off, both ports output */ sound_ym.rd_data_reg_sel = 7; sound_ym.wd_data = 0xff; } /* * atari_register_vme_int() returns the number of a free interrupt vector for * hardware with a programmable int vector (probably a VME board). */ unsigned long atari_register_vme_int(void) { int i; for (i = 0; i < 32; i++) if ((free_vme_vec_bitmap & (1 << i)) == 0) break; if (i == 16) return 0; free_vme_vec_bitmap |= 1 << i; return VME_SOURCE_BASE + i; } EXPORT_SYMBOL(atari_register_vme_int); void atari_unregister_vme_int(unsigned long irq) { if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) { irq -= VME_SOURCE_BASE; free_vme_vec_bitmap &= ~(1 << irq); } } EXPORT_SYMBOL(atari_unregister_vme_int);