arch/mips/lantiq/irq.c

   1 /*
   2  *  This program is free software; you can redistribute it and/or modify it
   3  *  under the terms of the GNU General Public License version 2 as published
   4  *  by the Free Software Foundation.
   5  *
   6  * Copyright (C) 2010 John Crispin <blogic@openwrt.org>
   7  * Copyright (C) 2010 Thomas Langer <thomas.langer@lantiq.com>
   8  */
   9
  10 #include <linux/interrupt.h>
  11 #include <linux/ioport.h>
  12 #include <linux/sched.h>
  13 #include <linux/irqdomain.h>
  14 #include <linux/of_platform.h>
  15 #include <linux/of_address.h>
  16 #include <linux/of_irq.h>
  17
  18 #include <asm/bootinfo.h>
  19 #include <asm/irq_cpu.h>
  20
  21 #include <lantiq_soc.h>
  22 #include <irq.h>
  23
  24 /* register definitions - internal irqs */
  25 #define LTQ_ICU_IM0_ISR         0x0000
  26 #define LTQ_ICU_IM0_IER         0x0008
  27 #define LTQ_ICU_IM0_IOSR        0x0010
  28 #define LTQ_ICU_IM0_IRSR        0x0018
  29 #define LTQ_ICU_IM0_IMR         0x0020
  30 #define LTQ_ICU_IM1_ISR         0x0028
  31 #define LTQ_ICU_OFFSET          (LTQ_ICU_IM1_ISR - LTQ_ICU_IM0_ISR)
  32
  33 /* register definitions - external irqs */
  34 #define LTQ_EIU_EXIN_C          0x0000
  35 #define LTQ_EIU_EXIN_INIC       0x0004
  36 #define LTQ_EIU_EXIN_INC        0x0008
  37 #define LTQ_EIU_EXIN_INEN       0x000C
  38
  39 /* number of external interrupts */
  40 #define MAX_EIU                 6
  41
  42 /* the performance counter */
  43 #define LTQ_PERF_IRQ            (INT_NUM_IM4_IRL0 + 31)
  44
  45 /*
  46  * irqs generated by devices attached to the EBU need to be acked in
  47  * a special manner
  48  */
  49 #define LTQ_ICU_EBU_IRQ         22
  50
  51 #define ltq_icu_w32(m, x, y)    ltq_w32((x), ltq_icu_membase[m] + (y))
  52 #define ltq_icu_r32(m, x)       ltq_r32(ltq_icu_membase[m] + (x))
  53
  54 #define ltq_eiu_w32(x, y)       ltq_w32((x), ltq_eiu_membase + (y))
  55 #define ltq_eiu_r32(x)          ltq_r32(ltq_eiu_membase + (x))
  56
  57 /* our 2 ipi interrupts for VSMP */
  58 #define MIPS_CPU_IPI_RESCHED_IRQ        0
  59 #define MIPS_CPU_IPI_CALL_IRQ           1
  60
  61 /* we have a cascade of 8 irqs */
  62 #define MIPS_CPU_IRQ_CASCADE            8
  63
  64 #if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC)
  65 int gic_present;
  66 #endif
  67
  68 static int exin_avail;
  69 static struct resource ltq_eiu_irq[MAX_EIU];
  70 static void __iomem *ltq_icu_membase[MAX_IM];
  71 static void __iomem *ltq_eiu_membase;
  72 static struct irq_domain *ltq_domain;
  73
  74 int ltq_eiu_get_irq(int exin)
  75 {
  76         if (exin < exin_avail)
  77                 return ltq_eiu_irq[exin].start;
  78         return -1;
  79 }
  80
  81 void ltq_disable_irq(struct irq_data *d)
  82 {
  83         u32 ier = LTQ_ICU_IM0_IER;
  84         int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
  85         int im = offset / INT_NUM_IM_OFFSET;
  86
  87         offset %= INT_NUM_IM_OFFSET;
  88         ltq_icu_w32(im, ltq_icu_r32(im, ier) & ~BIT(offset), ier);
  89 }
  90
  91 void ltq_mask_and_ack_irq(struct irq_data *d)
  92 {
  93         u32 ier = LTQ_ICU_IM0_IER;
  94         u32 isr = LTQ_ICU_IM0_ISR;
  95         int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
  96         int im = offset / INT_NUM_IM_OFFSET;
  97
  98         offset %= INT_NUM_IM_OFFSET;
  99         ltq_icu_w32(im, ltq_icu_r32(im, ier) & ~BIT(offset), ier);
 100         ltq_icu_w32(im, BIT(offset), isr);
 101 }
 102
 103 static void ltq_ack_irq(struct irq_data *d)
 104 {
 105         u32 isr = LTQ_ICU_IM0_ISR;
 106         int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
 107         int im = offset / INT_NUM_IM_OFFSET;
 108
 109         offset %= INT_NUM_IM_OFFSET;
 110         ltq_icu_w32(im, BIT(offset), isr);
 111 }
 112
 113 void ltq_enable_irq(struct irq_data *d)
 114 {
 115         u32 ier = LTQ_ICU_IM0_IER;
 116         int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
 117         int im = offset / INT_NUM_IM_OFFSET;
 118
 119         offset %= INT_NUM_IM_OFFSET;
 120         ltq_icu_w32(im, ltq_icu_r32(im, ier) | BIT(offset), ier);
 121 }
 122
 123 static int ltq_eiu_settype(struct irq_data *d, unsigned int type)
 124 {
 125         int i;
 126
 127         for (i = 0; i < MAX_EIU; i++) {
 128                 if (d->hwirq == ltq_eiu_irq[i].start) {
 129                         int val = 0;
 130                         int edge = 0;
 131
 132                         switch (type) {
 133                         case IRQF_TRIGGER_NONE:
 134                                 break;
 135                         case IRQF_TRIGGER_RISING:
 136                                 val = 1;
 137                                 edge = 1;
 138                                 break;
 139                         case IRQF_TRIGGER_FALLING:
 140                                 val = 2;
 141                                 edge = 1;
 142                                 break;
 143                         case IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING:
 144                                 val = 3;
 145                                 edge = 1;
 146                                 break;
 147                         case IRQF_TRIGGER_HIGH:
 148                                 val = 5;
 149                                 break;
 150                         case IRQF_TRIGGER_LOW:
 151                                 val = 6;
 152                                 break;
 153                         default:
 154                                 pr_err("invalid type %d for irq %ld\n",
 155                                         type, d->hwirq);
 156                                 return -EINVAL;
 157                         }
 158
 159                         if (edge)
 160                                 irq_set_handler(d->hwirq, handle_edge_irq);
 161
 162                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_C) |
 163                                 (val << (i * 4)), LTQ_EIU_EXIN_C);
 164                 }
 165         }
 166
 167         return 0;
 168 }
 169
 170 static unsigned int ltq_startup_eiu_irq(struct irq_data *d)
 171 {
 172         int i;
 173
 174         ltq_enable_irq(d);
 175         for (i = 0; i < MAX_EIU; i++) {
 176                 if (d->hwirq == ltq_eiu_irq[i].start) {
 177                         /* by default we are low level triggered */
 178                         ltq_eiu_settype(d, IRQF_TRIGGER_LOW);
 179                         /* clear all pending */
 180                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INC) & ~BIT(i),
 181                                 LTQ_EIU_EXIN_INC);
 182                         /* enable */
 183                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | BIT(i),
 184                                 LTQ_EIU_EXIN_INEN);
 185                         break;
 186                 }
 187         }
 188
 189         return 0;
 190 }
 191
 192 static void ltq_shutdown_eiu_irq(struct irq_data *d)
 193 {
 194         int i;
 195
 196         ltq_disable_irq(d);
 197         for (i = 0; i < MAX_EIU; i++) {
 198                 if (d->hwirq == ltq_eiu_irq[i].start) {
 199                         /* disable */
 200                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~BIT(i),
 201                                 LTQ_EIU_EXIN_INEN);
 202                         break;
 203                 }
 204         }
 205 }
 206
 207 static struct irq_chip ltq_irq_type = {
 208         "icu",
 209         .irq_enable = ltq_enable_irq,
 210         .irq_disable = ltq_disable_irq,
 211         .irq_unmask = ltq_enable_irq,
 212         .irq_ack = ltq_ack_irq,
 213         .irq_mask = ltq_disable_irq,
 214         .irq_mask_ack = ltq_mask_and_ack_irq,
 215 };
 216
 217 static struct irq_chip ltq_eiu_type = {
 218         "eiu",
 219         .irq_startup = ltq_startup_eiu_irq,
 220         .irq_shutdown = ltq_shutdown_eiu_irq,
 221         .irq_enable = ltq_enable_irq,
 222         .irq_disable = ltq_disable_irq,
 223         .irq_unmask = ltq_enable_irq,
 224         .irq_ack = ltq_ack_irq,
 225         .irq_mask = ltq_disable_irq,
 226         .irq_mask_ack = ltq_mask_and_ack_irq,
 227         .irq_set_type = ltq_eiu_settype,
 228 };
 229
 230 static void ltq_hw_irqdispatch(int module)
 231 {
 232         u32 irq;
 233
 234         irq = ltq_icu_r32(module, LTQ_ICU_IM0_IOSR);
 235         if (irq == 0)
 236                 return;
 237
 238         /*
 239          * silicon bug causes only the msb set to 1 to be valid. all
 240          * other bits might be bogus
 241          */
 242         irq = __fls(irq);
 243         do_IRQ((int)irq + MIPS_CPU_IRQ_CASCADE + (INT_NUM_IM_OFFSET * module));
 244
 245         /* if this is a EBU irq, we need to ack it or get a deadlock */
 246         if ((irq == LTQ_ICU_EBU_IRQ) && (module == 0) && LTQ_EBU_PCC_ISTAT)
 247                 ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10,
 248                         LTQ_EBU_PCC_ISTAT);
 249 }
 250
 251 #define DEFINE_HWx_IRQDISPATCH(x)                                       \
 252         static void ltq_hw ## x ## _irqdispatch(void)                   \
 253         {                                                               \
 254                 ltq_hw_irqdispatch(x);                                  \
 255         }
 256 DEFINE_HWx_IRQDISPATCH(0)
 257 DEFINE_HWx_IRQDISPATCH(1)
 258 DEFINE_HWx_IRQDISPATCH(2)
 259 DEFINE_HWx_IRQDISPATCH(3)
 260 DEFINE_HWx_IRQDISPATCH(4)
 261
 262 #if MIPS_CPU_TIMER_IRQ == 7
 263 static void ltq_hw5_irqdispatch(void)
 264 {
 265         do_IRQ(MIPS_CPU_TIMER_IRQ);
 266 }
 267 #else
 268 DEFINE_HWx_IRQDISPATCH(5)
 269 #endif
 270
 271 #ifdef CONFIG_MIPS_MT_SMP
 272 void __init arch_init_ipiirq(int irq, struct irqaction *action)
 273 {
 274         setup_irq(irq, action);
 275         irq_set_handler(irq, handle_percpu_irq);
 276 }
 277
 278 static void ltq_sw0_irqdispatch(void)
 279 {
 280         do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ);
 281 }
 282
 283 static void ltq_sw1_irqdispatch(void)
 284 {
 285         do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ);
 286 }
 287 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
 288 {
 289         scheduler_ipi();
 290         return IRQ_HANDLED;
 291 }
 292
 293 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
 294 {
 295         smp_call_function_interrupt();
 296         return IRQ_HANDLED;
 297 }
 298
 299 static struct irqaction irq_resched = {
 300         .handler        = ipi_resched_interrupt,
 301         .flags          = IRQF_PERCPU,
 302         .name           = "IPI_resched"
 303 };
 304
 305 static struct irqaction irq_call = {
 306         .handler        = ipi_call_interrupt,
 307         .flags          = IRQF_PERCPU,
 308         .name           = "IPI_call"
 309 };
 310 #endif
 311
 312 asmlinkage void plat_irq_dispatch(void)
 313 {
 314         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
 315         unsigned int i;
 316
 317         if ((MIPS_CPU_TIMER_IRQ == 7) && (pending & CAUSEF_IP7)) {
 318                 do_IRQ(MIPS_CPU_TIMER_IRQ);
 319                 goto out;
 320         } else {
 321                 for (i = 0; i < MAX_IM; i++) {
 322                         if (pending & (CAUSEF_IP2 << i)) {
 323                                 ltq_hw_irqdispatch(i);
 324                                 goto out;
 325                         }
 326                 }
 327         }
 328         pr_alert("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status());
 329
 330 out:
 331         return;
 332 }
 333
 334 static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
 335 {
 336         struct irq_chip *chip = &ltq_irq_type;
 337         int i;
 338
 339         if (hw < MIPS_CPU_IRQ_CASCADE)
 340                 return 0;
 341
 342         for (i = 0; i < exin_avail; i++)
 343                 if (hw == ltq_eiu_irq[i].start)
 344                         chip = &ltq_eiu_type;
 345
 346         irq_set_chip_and_handler(hw, chip, handle_level_irq);
 347
 348         return 0;
 349 }
 350
 351 static const struct irq_domain_ops irq_domain_ops = {
 352         .xlate = irq_domain_xlate_onetwocell,
 353         .map = icu_map,
 354 };
 355
 356 static struct irqaction cascade = {
 357         .handler = no_action,
 358         .name = "cascade",
 359 };
 360
 361 int __init icu_of_init(struct device_node *node, struct device_node *parent)
 362 {
 363         struct device_node *eiu_node;
 364         struct resource res;
 365         int i, ret;
 366
 367         for (i = 0; i < MAX_IM; i++) {
 368                 if (of_address_to_resource(node, i, &res))
 369                         panic("Failed to get icu memory range");
 370
 371                 if (request_mem_region(res.start, resource_size(&res),
 372                                         res.name) < 0)
 373                         pr_err("Failed to request icu memory");
 374
 375                 ltq_icu_membase[i] = ioremap_nocache(res.start,
 376                                         resource_size(&res));
 377                 if (!ltq_icu_membase[i])
 378                         panic("Failed to remap icu memory");
 379         }
 380
 381         /* the external interrupts are optional and xway only */
 382         eiu_node = of_find_compatible_node(NULL, NULL, "lantiq,eiu-xway");
 383         if (eiu_node && !of_address_to_resource(eiu_node, 0, &res)) {
 384                 /* find out how many external irq sources we have */
 385                 exin_avail = of_irq_count(eiu_node);
 386
 387                 if (exin_avail > MAX_EIU)
 388                         exin_avail = MAX_EIU;
 389
 390                 ret = of_irq_to_resource_table(eiu_node,
 391                                                 ltq_eiu_irq, exin_avail);
 392                 if (ret != exin_avail)
 393                         panic("failed to load external irq resources");
 394
 395                 if (request_mem_region(res.start, resource_size(&res),
 396                                                         res.name) < 0)
 397                         pr_err("Failed to request eiu memory");
 398
 399                 ltq_eiu_membase = ioremap_nocache(res.start,
 400                                                         resource_size(&res));
 401                 if (!ltq_eiu_membase)
 402                         panic("Failed to remap eiu memory");
 403         }
 404
 405         /* turn off all irqs by default */
 406         for (i = 0; i < MAX_IM; i++) {
 407                 /* make sure all irqs are turned off by default */
 408                 ltq_icu_w32(i, 0, LTQ_ICU_IM0_IER);
 409                 /* clear all possibly pending interrupts */
 410                 ltq_icu_w32(i, ~0, LTQ_ICU_IM0_ISR);
 411         }
 412
 413         mips_cpu_irq_init();
 414
 415         for (i = 0; i < MAX_IM; i++)
 416                 setup_irq(i + 2, &cascade);
 417
 418         if (cpu_has_vint) {
 419                 pr_info("Setting up vectored interrupts\n");
 420                 set_vi_handler(2, ltq_hw0_irqdispatch);
 421                 set_vi_handler(3, ltq_hw1_irqdispatch);
 422                 set_vi_handler(4, ltq_hw2_irqdispatch);
 423                 set_vi_handler(5, ltq_hw3_irqdispatch);
 424                 set_vi_handler(6, ltq_hw4_irqdispatch);
 425                 set_vi_handler(7, ltq_hw5_irqdispatch);
 426         }
 427
 428         ltq_domain = irq_domain_add_linear(node,
 429                 (MAX_IM * INT_NUM_IM_OFFSET) + MIPS_CPU_IRQ_CASCADE,
 430                 &irq_domain_ops, 0);
 431
 432 #if defined(CONFIG_MIPS_MT_SMP)
 433         if (cpu_has_vint) {
 434                 pr_info("Setting up IPI vectored interrupts\n");
 435                 set_vi_handler(MIPS_CPU_IPI_RESCHED_IRQ, ltq_sw0_irqdispatch);
 436                 set_vi_handler(MIPS_CPU_IPI_CALL_IRQ, ltq_sw1_irqdispatch);
 437         }
 438         arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ,
 439                 &irq_resched);
 440         arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ, &irq_call);
 441 #endif
 442
 443 #if !defined(CONFIG_MIPS_MT_SMP) && !defined(CONFIG_MIPS_MT_SMTC)
 444         set_c0_status(IE_IRQ0 | IE_IRQ1 | IE_IRQ2 |
 445                 IE_IRQ3 | IE_IRQ4 | IE_IRQ5);
 446 #else
 447         set_c0_status(IE_SW0 | IE_SW1 | IE_IRQ0 | IE_IRQ1 |
 448                 IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5);
 449 #endif
 450
 451         /* tell oprofile which irq to use */
 452         cp0_perfcount_irq = irq_create_mapping(ltq_domain, LTQ_PERF_IRQ);
 453
 454         /*
 455          * if the timer irq is not one of the mips irqs we need to
 456          * create a mapping
 457          */
 458         if (MIPS_CPU_TIMER_IRQ != 7)
 459                 irq_create_mapping(ltq_domain, MIPS_CPU_TIMER_IRQ);
 460
 461         return 0;
 462 }
 463
 464 unsigned int get_c0_compare_int(void)
 465 {
 466         return MIPS_CPU_TIMER_IRQ;
 467 }
 468
 469 static struct of_device_id __initdata of_irq_ids[] = {
 470         { .compatible = "lantiq,icu", .data = icu_of_init },
 471         {},
 472 };
 473
 474 void __init arch_init_irq(void)
 475 {
 476         of_irq_init(of_irq_ids);
 477 }