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* arch/m68k/atari/ataints.c -- Atari Linux interrupt handling code
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* Added support for TT interrupts; setup for TT SCU (may someone has
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* twiddled there and we won't get the right interrupts :-()
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* Major change: The device-independent code in m68k/ints.c didn't know
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* about non-autovec ints yet. It hardcoded the number of possible ints to
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* 7 (IRQ1...IRQ7). But the Atari has lots of non-autovec ints! I made the
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* number of possible ints a constant defined in interrupt.h, which is
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* 47 for the Atari. So we can call request_irq() for all Atari interrupts
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* just the normal way. Additionally, all vectors >= 48 are initialized to
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* call trap() instead of inthandler(). This must be changed here, too.
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* 1995-07-16 Lars Brinkhoff <f93labr@dd.chalmers.se>:
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* Corrected a bug in atari_add_isr() which rejected all SCC
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* interrupt sources if there were no TT MFP!
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* 12/13/95: New interface functions atari_level_triggered_int() and
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* atari_register_vme_int() as support for level triggered VME interrupts.
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* Total rewrite of Atari interrupt handling, for new scheme see comments
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* 1996-09-03 lars brinkhoff <f93labr@dd.chalmers.se>:
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* Added new function atari_unregister_vme_int(), and
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* modified atari_register_vme_int() as well as IS_VALID_INTNO()
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/kernel_stat.h>
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#include <linux/init.h>
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#include <linux/seq_file.h>
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#include <linux/module.h>
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#include <asm/system.h>
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#include <asm/traps.h>
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#include <asm/atarihw.h>
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#include <asm/atariints.h>
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#include <asm/atari_stdma.h>
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#include <asm/entry.h>
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* Atari interrupt handling scheme:
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* --------------------------------
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* All interrupt source have an internal number (defined in
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* <asm/atariints.h>): Autovector interrupts are 1..7, then follow ST-MFP,
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* TT-MFP, SCC, and finally VME interrupts. Vector numbers for the latter can
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* be allocated by atari_register_vme_int().
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* Bitmap for free interrupt vector numbers
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* (new vectors starting from 0x70 can be allocated by
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* atari_register_vme_int())
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static int free_vme_vec_bitmap;
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* HBL IRQ handler for Falcon. Nobody needs it :-)
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* ++andreas: raise ipl to disable further HBLANK interrupts.
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asmlinkage void falcon_hblhandler(void);
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"falcon_hblhandler:\n\t"
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"orw #0x200,%sp@\n\t" /* set saved ipl to 2 */
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extern void atari_microwire_cmd(int cmd);
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extern int atari_SCC_reset_done;
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static unsigned int atari_irq_startup(struct irq_data *data)
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unsigned int irq = data->irq;
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m68k_irq_startup(data);
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atari_turnon_irq(irq);
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atari_enable_irq(irq);
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static void atari_irq_shutdown(struct irq_data *data)
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unsigned int irq = data->irq;
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atari_disable_irq(irq);
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atari_turnoff_irq(irq);
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m68k_irq_shutdown(data);
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if (irq == IRQ_AUTO_4)
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vectors[VEC_INT4] = falcon_hblhandler;
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static void atari_irq_enable(struct irq_data *data)
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atari_enable_irq(data->irq);
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static void atari_irq_disable(struct irq_data *data)
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atari_disable_irq(data->irq);
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static struct irq_chip atari_irq_chip = {
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.irq_startup = atari_irq_startup,
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.irq_shutdown = atari_irq_shutdown,
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.irq_enable = atari_irq_enable,
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.irq_disable = atari_irq_disable,
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* void atari_init_IRQ (void)
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* This function should be called during kernel startup to initialize
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* the atari IRQ handling routines.
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void __init atari_init_IRQ(void)
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m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER);
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m68k_setup_irq_controller(&atari_irq_chip, handle_simple_irq, 1,
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NUM_ATARI_SOURCES - 1);
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/* Initialize the MFP(s) */
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#ifdef ATARI_USE_SOFTWARE_EOI
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st_mfp.vec_adr = 0x48; /* Software EOI-Mode */
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st_mfp.vec_adr = 0x40; /* Automatic EOI-Mode */
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st_mfp.int_en_a = 0x00; /* turn off MFP-Ints */
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st_mfp.int_en_b = 0x00;
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st_mfp.int_mk_a = 0xff; /* no Masking */
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st_mfp.int_mk_b = 0xff;
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if (ATARIHW_PRESENT(TT_MFP)) {
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#ifdef ATARI_USE_SOFTWARE_EOI
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tt_mfp.vec_adr = 0x58; /* Software EOI-Mode */
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tt_mfp.vec_adr = 0x50; /* Automatic EOI-Mode */
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tt_mfp.int_en_a = 0x00; /* turn off MFP-Ints */
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tt_mfp.int_en_b = 0x00;
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tt_mfp.int_mk_a = 0xff; /* no Masking */
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tt_mfp.int_mk_b = 0xff;
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if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) {
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atari_scc.cha_a_ctrl = 9;
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atari_scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */
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if (ATARIHW_PRESENT(SCU)) {
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/* init the SCU if present */
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tt_scu.sys_mask = 0x10; /* enable VBL (for the cursor) and
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* disable HSYNC interrupts (who
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* needs them?) MFP and SCC are
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* enabled in VME mask
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tt_scu.vme_mask = 0x60; /* enable MFP and SCC ints */
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/* If no SCU and no Hades, the HSYNC interrupt needs to be
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* disabled this way. (Else _inthandler in kernel/sys_call.S
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vectors[VEC_INT2] = falcon_hblhandler;
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vectors[VEC_INT4] = falcon_hblhandler;
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if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) {
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/* Initialize the LM1992 Sound Controller to enable
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the PSG sound. This is misplaced here, it should
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be in an atasound_init(), that doesn't exist yet. */
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atari_microwire_cmd(MW_LM1992_PSG_HIGH);
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/* Initialize the PSG: all sounds off, both ports output */
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sound_ym.rd_data_reg_sel = 7;
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sound_ym.wd_data = 0xff;
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* atari_register_vme_int() returns the number of a free interrupt vector for
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* hardware with a programmable int vector (probably a VME board).
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unsigned long atari_register_vme_int(void)
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for (i = 0; i < 32; i++)
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if ((free_vme_vec_bitmap & (1 << i)) == 0)
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free_vme_vec_bitmap |= 1 << i;
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return VME_SOURCE_BASE + i;
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EXPORT_SYMBOL(atari_register_vme_int);
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void atari_unregister_vme_int(unsigned long irq)
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if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) {
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irq -= VME_SOURCE_BASE;
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free_vme_vec_bitmap &= ~(1 << irq);
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EXPORT_SYMBOL(atari_unregister_vme_int);