1 /* 2 * arch/m68k/q40/q40ints.c 3 * 4 * Copyright (C) 1999,2001 Richard Zidlicky 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file COPYING in the main directory of this archive 8 * for more details. 9 * 10 * .. used to be loosely based on bvme6000ints.c 11 * 12 */ 13 14 #include <linux/types.h> 15 #include <linux/kernel.h> 16 #include <linux/errno.h> 17 #include <linux/interrupt.h> 18 #include <linux/irq.h> 19 20 #include <asm/machdep.h> 21 #include <asm/ptrace.h> 22 #include <asm/traps.h> 23 24 #include <asm/q40_master.h> 25 #include <asm/q40ints.h> 26 27 #include "q40.h" 28 29 /* 30 * Q40 IRQs are defined as follows: 31 * 3,4,5,6,7,10,11,14,15 : ISA dev IRQs 32 * 16-31: reserved 33 * 32 : keyboard int 34 * 33 : frame int (50/200 Hz periodic timer) 35 * 34 : sample int (10/20 KHz periodic timer) 36 * 37 */ 38 39 static void q40_irq_handler(unsigned int, struct pt_regs *fp); 40 static void q40_irq_enable(struct irq_data *data); 41 static void q40_irq_disable(struct irq_data *data); 42 43 unsigned short q40_ablecount[35]; 44 unsigned short q40_state[35]; 45 46 static unsigned int q40_irq_startup(struct irq_data *data) 47 { 48 unsigned int irq = data->irq; 49 50 /* test for ISA ints not implemented by HW */ 51 switch (irq) { 52 case 1: case 2: case 8: case 9: 53 case 11: case 12: case 13: 54 pr_warn("%s: ISA IRQ %d not implemented by HW\n", __func__, 55 irq); 56 /* FIXME return -ENXIO; */ 57 } 58 return 0; 59 } 60 61 static void q40_irq_shutdown(struct irq_data *data) 62 { 63 } 64 65 static struct irq_chip q40_irq_chip = { 66 .name = "q40", 67 .irq_startup = q40_irq_startup, 68 .irq_shutdown = q40_irq_shutdown, 69 .irq_enable = q40_irq_enable, 70 .irq_disable = q40_irq_disable, 71 }; 72 73 /* 74 * void q40_init_IRQ (void) 75 * 76 * Parameters: None 77 * 78 * Returns: Nothing 79 * 80 * This function is called during kernel startup to initialize 81 * the q40 IRQ handling routines. 82 */ 83 84 static int disabled; 85 86 void __init q40_init_IRQ(void) 87 { 88 m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1, 89 Q40_IRQ_MAX); 90 91 /* setup handler for ISA ints */ 92 m68k_setup_auto_interrupt(q40_irq_handler); 93 94 m68k_irq_startup_irq(IRQ_AUTO_2); 95 m68k_irq_startup_irq(IRQ_AUTO_4); 96 97 /* now enable some ints.. */ 98 master_outb(1, EXT_ENABLE_REG); /* ISA IRQ 5-15 */ 99 100 /* make sure keyboard IRQ is disabled */ 101 master_outb(0, KEY_IRQ_ENABLE_REG); 102 } 103 104 105 /* 106 * this stuff doesn't really belong here.. 107 */ 108 109 int ql_ticks; /* 200Hz ticks since last jiffy */ 110 static int sound_ticks; 111 112 #define SVOL 45 113 114 void q40_mksound(unsigned int hz, unsigned int ticks) 115 { 116 /* for now ignore hz, except that hz==0 switches off sound */ 117 /* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */ 118 if (hz == 0) { 119 if (sound_ticks) 120 sound_ticks = 1; 121 122 *DAC_LEFT = 128; 123 *DAC_RIGHT = 128; 124 125 return; 126 } 127 /* sound itself is done in q40_timer_int */ 128 if (sound_ticks == 0) 129 sound_ticks = 1000; /* pretty long beep */ 130 sound_ticks = ticks << 1; 131 } 132 133 static irqreturn_t q40_timer_int(int irq, void *dev_id) 134 { 135 ql_ticks = ql_ticks ? 0 : 1; 136 if (sound_ticks) { 137 unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL; 138 sound_ticks--; 139 *DAC_LEFT=sval; 140 *DAC_RIGHT=sval; 141 } 142 143 if (!ql_ticks) { 144 unsigned long flags; 145 146 local_irq_save(flags); 147 legacy_timer_tick(1); 148 timer_heartbeat(); 149 local_irq_restore(flags); 150 } 151 return IRQ_HANDLED; 152 } 153 154 void q40_sched_init (void) 155 { 156 int timer_irq; 157 158 timer_irq = Q40_IRQ_FRAME; 159 160 if (request_irq(timer_irq, q40_timer_int, 0, "timer", NULL)) 161 panic("Couldn't register timer int"); 162 163 master_outb(-1, FRAME_CLEAR_REG); 164 master_outb( 1, FRAME_RATE_REG); 165 } 166 167 168 /* 169 * tables to translate bits into IRQ numbers 170 * it is a good idea to order the entries by priority 171 * 172 */ 173 174 struct IRQ_TABLE{ unsigned mask; int irq ;}; 175 #if 0 176 static struct IRQ_TABLE iirqs[]={ 177 {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME}, 178 {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD}, 179 {0,0}}; 180 #endif 181 static struct IRQ_TABLE eirqs[] = { 182 { .mask = Q40_IRQ3_MASK, .irq = 3 }, /* ser 1 */ 183 { .mask = Q40_IRQ4_MASK, .irq = 4 }, /* ser 2 */ 184 { .mask = Q40_IRQ14_MASK, .irq = 14 }, /* IDE 1 */ 185 { .mask = Q40_IRQ15_MASK, .irq = 15 }, /* IDE 2 */ 186 { .mask = Q40_IRQ6_MASK, .irq = 6 }, /* floppy, handled elsewhere */ 187 { .mask = Q40_IRQ7_MASK, .irq = 7 }, /* par */ 188 { .mask = Q40_IRQ5_MASK, .irq = 5 }, 189 { .mask = Q40_IRQ10_MASK, .irq = 10 }, 190 {0,0} 191 }; 192 193 /* complain only this many times about spurious ints : */ 194 static int ccleirq=60; /* ISA dev IRQs*/ 195 /*static int cclirq=60;*/ /* internal */ 196 197 /* FIXME: add shared ints,mask,unmask,probing.... */ 198 199 #define IRQ_INPROGRESS 1 200 /*static unsigned short saved_mask;*/ 201 //static int do_tint=0; 202 203 #define DEBUG_Q40INT 204 /*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */ 205 206 static int mext_disabled; /* ext irq disabled by master chip? */ 207 static int aliased_irq; /* how many times inside handler ?*/ 208 209 210 /* got interrupt, dispatch to ISA or keyboard/timer IRQs */ 211 static void q40_irq_handler(unsigned int irq, struct pt_regs *fp) 212 { 213 unsigned mir, mer; 214 int i; 215 216 //repeat: 217 mir = master_inb(IIRQ_REG); 218 #ifdef CONFIG_BLK_DEV_FD 219 if ((mir & Q40_IRQ_EXT_MASK) && 220 (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) { 221 floppy_hardint(); 222 return; 223 } 224 #endif 225 switch (irq) { 226 case 4: 227 case 6: 228 do_IRQ(Q40_IRQ_SAMPLE, fp); 229 return; 230 } 231 if (mir & Q40_IRQ_FRAME_MASK) { 232 do_IRQ(Q40_IRQ_FRAME, fp); 233 master_outb(-1, FRAME_CLEAR_REG); 234 } 235 if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) { 236 mer = master_inb(EIRQ_REG); 237 for (i = 0; eirqs[i].mask; i++) { 238 if (mer & eirqs[i].mask) { 239 irq = eirqs[i].irq; 240 /* 241 * There is a little mess wrt which IRQ really caused this irq request. The 242 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they 243 * are read - which is long after the request came in. In theory IRQs should 244 * not just go away but they occasionally do 245 */ 246 if (irq > 4 && irq <= 15 && mext_disabled) { 247 /*aliased_irq++;*/ 248 goto iirq; 249 } 250 if (q40_state[irq] & IRQ_INPROGRESS) { 251 /* some handlers do local_irq_enable() for irq latency reasons, */ 252 /* however reentering an active irq handler is not permitted */ 253 #ifdef IP_USE_DISABLE 254 /* in theory this is the better way to do it because it still */ 255 /* lets through eg the serial irqs, unfortunately it crashes */ 256 disable_irq(irq); 257 disabled = 1; 258 #else 259 /*pr_warn("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n", 260 irq, disabled ? "already" : "not yet"); */ 261 fp->sr = (((fp->sr) & (~0x700))+0x200); 262 disabled = 1; 263 #endif 264 goto iirq; 265 } 266 q40_state[irq] |= IRQ_INPROGRESS; 267 do_IRQ(irq, fp); 268 q40_state[irq] &= ~IRQ_INPROGRESS; 269 270 /* naively enable everything, if that fails than */ 271 /* this function will be reentered immediately thus */ 272 /* getting another chance to disable the IRQ */ 273 274 if (disabled) { 275 #ifdef IP_USE_DISABLE 276 if (irq > 4) { 277 disabled = 0; 278 enable_irq(irq); 279 } 280 #else 281 disabled = 0; 282 /*pr_info("reenabling irq %d\n", irq); */ 283 #endif 284 } 285 // used to do 'goto repeat;' here, this delayed bh processing too long 286 return; 287 } 288 } 289 if (mer && ccleirq > 0 && !aliased_irq) { 290 pr_warn("ISA interrupt from unknown source? EIRQ_REG = %x\n", 291 mer); 292 ccleirq--; 293 } 294 } 295 iirq: 296 mir = master_inb(IIRQ_REG); 297 /* should test whether keyboard irq is really enabled, doing it in defhand */ 298 if (mir & Q40_IRQ_KEYB_MASK) 299 do_IRQ(Q40_IRQ_KEYBOARD, fp); 300 301 return; 302 } 303 304 void q40_irq_enable(struct irq_data *data) 305 { 306 unsigned int irq = data->irq; 307 308 if (irq >= 5 && irq <= 15) { 309 mext_disabled--; 310 if (mext_disabled > 0) 311 pr_warn("q40_irq_enable : nested disable/enable\n"); 312 if (mext_disabled == 0) 313 master_outb(1, EXT_ENABLE_REG); 314 } 315 } 316 317 318 void q40_irq_disable(struct irq_data *data) 319 { 320 unsigned int irq = data->irq; 321 322 /* disable ISA iqs : only do something if the driver has been 323 * verified to be Q40 "compatible" - right now IDE, NE2K 324 * Any driver should not attempt to sleep across disable_irq !! 325 */ 326 327 if (irq >= 5 && irq <= 15) { 328 master_outb(0, EXT_ENABLE_REG); 329 mext_disabled++; 330 if (mext_disabled > 1) 331 pr_info("disable_irq nesting count %d\n", 332 mext_disabled); 333 } 334 } 335