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 static unsigned int atari_irq_startup(struct irq_data *data) 86 { 87 unsigned int irq = data->irq; 88 89 m68k_irq_startup(data); 90 atari_turnon_irq(irq); 91 atari_enable_irq(irq); 92 return 0; 93 } 94 95 static void atari_irq_shutdown(struct irq_data *data) 96 { 97 unsigned int irq = data->irq; 98 99 atari_disable_irq(irq); 100 atari_turnoff_irq(irq); 101 m68k_irq_shutdown(data); 102 103 if (irq == IRQ_AUTO_4) 104 vectors[VEC_INT4] = falcon_hblhandler; 105 } 106 107 static void atari_irq_enable(struct irq_data *data) 108 { 109 atari_enable_irq(data->irq); 110 } 111 112 static void atari_irq_disable(struct irq_data *data) 113 { 114 atari_disable_irq(data->irq); 115 } 116 117 static struct irq_chip atari_irq_chip = { 118 .name = "atari", 119 .irq_startup = atari_irq_startup, 120 .irq_shutdown = atari_irq_shutdown, 121 .irq_enable = atari_irq_enable, 122 .irq_disable = atari_irq_disable, 123 }; 124 125 /* 126 * void atari_init_IRQ (void) 127 * 128 * Parameters: None 129 * 130 * Returns: Nothing 131 * 132 * This function should be called during kernel startup to initialize 133 * the atari IRQ handling routines. 134 */ 135 136 void __init atari_init_IRQ(void) 137 { 138 m68k_setup_user_interrupt(VEC_USER, NUM_ATARI_SOURCES - IRQ_USER); 139 m68k_setup_irq_controller(&atari_irq_chip, handle_simple_irq, 1, 140 NUM_ATARI_SOURCES - 1); 141 142 /* Initialize the MFP(s) */ 143 144 #ifdef ATARI_USE_SOFTWARE_EOI 145 st_mfp.vec_adr = 0x48; /* Software EOI-Mode */ 146 #else 147 st_mfp.vec_adr = 0x40; /* Automatic EOI-Mode */ 148 #endif 149 st_mfp.int_en_a = 0x00; /* turn off MFP-Ints */ 150 st_mfp.int_en_b = 0x00; 151 st_mfp.int_mk_a = 0xff; /* no Masking */ 152 st_mfp.int_mk_b = 0xff; 153 154 if (ATARIHW_PRESENT(TT_MFP)) { 155 #ifdef ATARI_USE_SOFTWARE_EOI 156 tt_mfp.vec_adr = 0x58; /* Software EOI-Mode */ 157 #else 158 tt_mfp.vec_adr = 0x50; /* Automatic EOI-Mode */ 159 #endif 160 tt_mfp.int_en_a = 0x00; /* turn off MFP-Ints */ 161 tt_mfp.int_en_b = 0x00; 162 tt_mfp.int_mk_a = 0xff; /* no Masking */ 163 tt_mfp.int_mk_b = 0xff; 164 } 165 166 if (ATARIHW_PRESENT(SCC) && !atari_SCC_reset_done) { 167 atari_scc.cha_a_ctrl = 9; 168 MFPDELAY(); 169 atari_scc.cha_a_ctrl = (char) 0xc0; /* hardware reset */ 170 } 171 172 if (ATARIHW_PRESENT(SCU)) { 173 /* init the SCU if present */ 174 tt_scu.sys_mask = 0x10; /* enable VBL (for the cursor) and 175 * disable HSYNC interrupts (who 176 * needs them?) MFP and SCC are 177 * enabled in VME mask 178 */ 179 tt_scu.vme_mask = 0x60; /* enable MFP and SCC ints */ 180 } else { 181 /* If no SCU and no Hades, the HSYNC interrupt needs to be 182 * disabled this way. (Else _inthandler in kernel/sys_call.S 183 * gets overruns) 184 */ 185 186 vectors[VEC_INT2] = falcon_hblhandler; 187 vectors[VEC_INT4] = falcon_hblhandler; 188 } 189 190 if (ATARIHW_PRESENT(PCM_8BIT) && ATARIHW_PRESENT(MICROWIRE)) { 191 /* Initialize the LM1992 Sound Controller to enable 192 the PSG sound. This is misplaced here, it should 193 be in an atasound_init(), that doesn't exist yet. */ 194 atari_microwire_cmd(MW_LM1992_PSG_HIGH); 195 } 196 197 stdma_init(); 198 199 /* Initialize the PSG: all sounds off, both ports output */ 200 sound_ym.rd_data_reg_sel = 7; 201 sound_ym.wd_data = 0xff; 202 } 203 204 205 /* 206 * atari_register_vme_int() returns the number of a free interrupt vector for 207 * hardware with a programmable int vector (probably a VME board). 208 */ 209 210 unsigned long atari_register_vme_int(void) 211 { 212 int i; 213 214 for (i = 0; i < 32; i++) 215 if ((free_vme_vec_bitmap & (1 << i)) == 0) 216 break; 217 218 if (i == 16) 219 return 0; 220 221 free_vme_vec_bitmap |= 1 << i; 222 return VME_SOURCE_BASE + i; 223 } 224 EXPORT_SYMBOL(atari_register_vme_int); 225 226 227 void atari_unregister_vme_int(unsigned long irq) 228 { 229 if (irq >= VME_SOURCE_BASE && irq < VME_SOURCE_BASE + VME_MAX_SOURCES) { 230 irq -= VME_SOURCE_BASE; 231 free_vme_vec_bitmap &= ~(1 << irq); 232 } 233 } 234 EXPORT_SYMBOL(atari_unregister_vme_int); 235 236 237