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