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/ptrace.h> 21 #include <asm/traps.h> 22 23 #include <asm/q40_master.h> 24 #include <asm/q40ints.h> 25 26 /* 27 * Q40 IRQs are defined as follows: 28 * 3,4,5,6,7,10,11,14,15 : ISA dev IRQs 29 * 16-31: reserved 30 * 32 : keyboard int 31 * 33 : frame int (50/200 Hz periodic timer) 32 * 34 : sample int (10/20 KHz periodic timer) 33 * 34 */ 35 36 static void q40_irq_handler(unsigned int, struct pt_regs *fp); 37 static void q40_irq_enable(struct irq_data *data); 38 static void q40_irq_disable(struct irq_data *data); 39 40 unsigned short q40_ablecount[35]; 41 unsigned short q40_state[35]; 42 43 static unsigned int q40_irq_startup(struct irq_data *data) 44 { 45 unsigned int irq = data->irq; 46 47 /* test for ISA ints not implemented by HW */ 48 switch (irq) { 49 case 1: case 2: case 8: case 9: 50 case 11: case 12: case 13: 51 pr_warn("%s: ISA IRQ %d not implemented by HW\n", __func__, 52 irq); 53 /* FIXME return -ENXIO; */ 54 } 55 return 0; 56 } 57 58 static void q40_irq_shutdown(struct irq_data *data) 59 { 60 } 61 62 static struct irq_chip q40_irq_chip = { 63 .name = "q40", 64 .irq_startup = q40_irq_startup, 65 .irq_shutdown = q40_irq_shutdown, 66 .irq_enable = q40_irq_enable, 67 .irq_disable = q40_irq_disable, 68 }; 69 70 /* 71 * void q40_init_IRQ (void) 72 * 73 * Parameters: None 74 * 75 * Returns: Nothing 76 * 77 * This function is called during kernel startup to initialize 78 * the q40 IRQ handling routines. 79 */ 80 81 static int disabled; 82 83 void __init q40_init_IRQ(void) 84 { 85 m68k_setup_irq_controller(&q40_irq_chip, handle_simple_irq, 1, 86 Q40_IRQ_MAX); 87 88 /* setup handler for ISA ints */ 89 m68k_setup_auto_interrupt(q40_irq_handler); 90 91 m68k_irq_startup_irq(IRQ_AUTO_2); 92 m68k_irq_startup_irq(IRQ_AUTO_4); 93 94 /* now enable some ints.. */ 95 master_outb(1, EXT_ENABLE_REG); /* ISA IRQ 5-15 */ 96 97 /* make sure keyboard IRQ is disabled */ 98 master_outb(0, KEY_IRQ_ENABLE_REG); 99 } 100 101 102 /* 103 * this stuff doesn't really belong here.. 104 */ 105 106 int ql_ticks; /* 200Hz ticks since last jiffie */ 107 static int sound_ticks; 108 109 #define SVOL 45 110 111 void q40_mksound(unsigned int hz, unsigned int ticks) 112 { 113 /* for now ignore hz, except that hz==0 switches off sound */ 114 /* simply alternate the ampl (128-SVOL)-(128+SVOL)-..-.. at 200Hz */ 115 if (hz == 0) { 116 if (sound_ticks) 117 sound_ticks = 1; 118 119 *DAC_LEFT = 128; 120 *DAC_RIGHT = 128; 121 122 return; 123 } 124 /* sound itself is done in q40_timer_int */ 125 if (sound_ticks == 0) 126 sound_ticks = 1000; /* pretty long beep */ 127 sound_ticks = ticks << 1; 128 } 129 130 static irq_handler_t q40_timer_routine; 131 132 static irqreturn_t q40_timer_int (int irq, void * dev) 133 { 134 ql_ticks = ql_ticks ? 0 : 1; 135 if (sound_ticks) { 136 unsigned char sval=(sound_ticks & 1) ? 128-SVOL : 128+SVOL; 137 sound_ticks--; 138 *DAC_LEFT=sval; 139 *DAC_RIGHT=sval; 140 } 141 142 if (!ql_ticks) 143 q40_timer_routine(irq, dev); 144 return IRQ_HANDLED; 145 } 146 147 void q40_sched_init (irq_handler_t timer_routine) 148 { 149 int timer_irq; 150 151 q40_timer_routine = timer_routine; 152 timer_irq = Q40_IRQ_FRAME; 153 154 if (request_irq(timer_irq, q40_timer_int, 0, 155 "timer", q40_timer_int)) 156 panic("Couldn't register timer int"); 157 158 master_outb(-1, FRAME_CLEAR_REG); 159 master_outb( 1, FRAME_RATE_REG); 160 } 161 162 163 /* 164 * tables to translate bits into IRQ numbers 165 * it is a good idea to order the entries by priority 166 * 167 */ 168 169 struct IRQ_TABLE{ unsigned mask; int irq ;}; 170 #if 0 171 static struct IRQ_TABLE iirqs[]={ 172 {Q40_IRQ_FRAME_MASK,Q40_IRQ_FRAME}, 173 {Q40_IRQ_KEYB_MASK,Q40_IRQ_KEYBOARD}, 174 {0,0}}; 175 #endif 176 static struct IRQ_TABLE eirqs[] = { 177 { .mask = Q40_IRQ3_MASK, .irq = 3 }, /* ser 1 */ 178 { .mask = Q40_IRQ4_MASK, .irq = 4 }, /* ser 2 */ 179 { .mask = Q40_IRQ14_MASK, .irq = 14 }, /* IDE 1 */ 180 { .mask = Q40_IRQ15_MASK, .irq = 15 }, /* IDE 2 */ 181 { .mask = Q40_IRQ6_MASK, .irq = 6 }, /* floppy, handled elsewhere */ 182 { .mask = Q40_IRQ7_MASK, .irq = 7 }, /* par */ 183 { .mask = Q40_IRQ5_MASK, .irq = 5 }, 184 { .mask = Q40_IRQ10_MASK, .irq = 10 }, 185 {0,0} 186 }; 187 188 /* complain only this many times about spurious ints : */ 189 static int ccleirq=60; /* ISA dev IRQs*/ 190 /*static int cclirq=60;*/ /* internal */ 191 192 /* FIXME: add shared ints,mask,unmask,probing.... */ 193 194 #define IRQ_INPROGRESS 1 195 /*static unsigned short saved_mask;*/ 196 //static int do_tint=0; 197 198 #define DEBUG_Q40INT 199 /*#define IP_USE_DISABLE *//* would be nice, but crashes ???? */ 200 201 static int mext_disabled=0; /* ext irq disabled by master chip? */ 202 static int aliased_irq=0; /* how many times inside handler ?*/ 203 204 205 /* got interrupt, dispatch to ISA or keyboard/timer IRQs */ 206 static void q40_irq_handler(unsigned int irq, struct pt_regs *fp) 207 { 208 unsigned mir, mer; 209 int i; 210 211 //repeat: 212 mir = master_inb(IIRQ_REG); 213 #ifdef CONFIG_BLK_DEV_FD 214 if ((mir & Q40_IRQ_EXT_MASK) && 215 (master_inb(EIRQ_REG) & Q40_IRQ6_MASK)) { 216 floppy_hardint(); 217 return; 218 } 219 #endif 220 switch (irq) { 221 case 4: 222 case 6: 223 do_IRQ(Q40_IRQ_SAMPLE, fp); 224 return; 225 } 226 if (mir & Q40_IRQ_FRAME_MASK) { 227 do_IRQ(Q40_IRQ_FRAME, fp); 228 master_outb(-1, FRAME_CLEAR_REG); 229 } 230 if ((mir & Q40_IRQ_SER_MASK) || (mir & Q40_IRQ_EXT_MASK)) { 231 mer = master_inb(EIRQ_REG); 232 for (i = 0; eirqs[i].mask; i++) { 233 if (mer & eirqs[i].mask) { 234 irq = eirqs[i].irq; 235 /* 236 * There is a little mess wrt which IRQ really caused this irq request. The 237 * main problem is that IIRQ_REG and EIRQ_REG reflect the state when they 238 * are read - which is long after the request came in. In theory IRQs should 239 * not just go away but they occasionally do 240 */ 241 if (irq > 4 && irq <= 15 && mext_disabled) { 242 /*aliased_irq++;*/ 243 goto iirq; 244 } 245 if (q40_state[irq] & IRQ_INPROGRESS) { 246 /* some handlers do local_irq_enable() for irq latency reasons, */ 247 /* however reentering an active irq handler is not permitted */ 248 #ifdef IP_USE_DISABLE 249 /* in theory this is the better way to do it because it still */ 250 /* lets through eg the serial irqs, unfortunately it crashes */ 251 disable_irq(irq); 252 disabled = 1; 253 #else 254 /*pr_warn("IRQ_INPROGRESS detected for irq %d, disabling - %s disabled\n", 255 irq, disabled ? "already" : "not yet"); */ 256 fp->sr = (((fp->sr) & (~0x700))+0x200); 257 disabled = 1; 258 #endif 259 goto iirq; 260 } 261 q40_state[irq] |= IRQ_INPROGRESS; 262 do_IRQ(irq, fp); 263 q40_state[irq] &= ~IRQ_INPROGRESS; 264 265 /* naively enable everything, if that fails than */ 266 /* this function will be reentered immediately thus */ 267 /* getting another chance to disable the IRQ */ 268 269 if (disabled) { 270 #ifdef IP_USE_DISABLE 271 if (irq > 4) { 272 disabled = 0; 273 enable_irq(irq); 274 } 275 #else 276 disabled = 0; 277 /*pr_info("reenabling irq %d\n", irq); */ 278 #endif 279 } 280 // used to do 'goto repeat;' here, this delayed bh processing too long 281 return; 282 } 283 } 284 if (mer && ccleirq > 0 && !aliased_irq) { 285 pr_warn("ISA interrupt from unknown source? EIRQ_REG = %x\n", 286 mer); 287 ccleirq--; 288 } 289 } 290 iirq: 291 mir = master_inb(IIRQ_REG); 292 /* should test whether keyboard irq is really enabled, doing it in defhand */ 293 if (mir & Q40_IRQ_KEYB_MASK) 294 do_IRQ(Q40_IRQ_KEYBOARD, fp); 295 296 return; 297 } 298 299 void q40_irq_enable(struct irq_data *data) 300 { 301 unsigned int irq = data->irq; 302 303 if (irq >= 5 && irq <= 15) { 304 mext_disabled--; 305 if (mext_disabled > 0) 306 pr_warn("q40_irq_enable : nested disable/enable\n"); 307 if (mext_disabled == 0) 308 master_outb(1, EXT_ENABLE_REG); 309 } 310 } 311 312 313 void q40_irq_disable(struct irq_data *data) 314 { 315 unsigned int irq = data->irq; 316 317 /* disable ISA iqs : only do something if the driver has been 318 * verified to be Q40 "compatible" - right now IDE, NE2K 319 * Any driver should not attempt to sleep across disable_irq !! 320 */ 321 322 if (irq >= 5 && irq <= 15) { 323 master_outb(0, EXT_ENABLE_REG); 324 mext_disabled++; 325 if (mext_disabled > 1) 326 pr_info("disable_irq nesting count %d\n", 327 mext_disabled); 328 } 329 } 330