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 #ifdef CONFIG_MIPS_MT_SMP 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 static int ltq_perfcount_irq; 74 75 int ltq_eiu_get_irq(int exin) 76 { 77 if (exin < exin_avail) 78 return ltq_eiu_irq[exin].start; 79 return -1; 80 } 81 82 void ltq_disable_irq(struct irq_data *d) 83 { 84 u32 ier = LTQ_ICU_IM0_IER; 85 int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; 86 int im = offset / INT_NUM_IM_OFFSET; 87 88 offset %= INT_NUM_IM_OFFSET; 89 ltq_icu_w32(im, ltq_icu_r32(im, ier) & ~BIT(offset), ier); 90 } 91 92 void ltq_mask_and_ack_irq(struct irq_data *d) 93 { 94 u32 ier = LTQ_ICU_IM0_IER; 95 u32 isr = LTQ_ICU_IM0_ISR; 96 int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; 97 int im = offset / INT_NUM_IM_OFFSET; 98 99 offset %= INT_NUM_IM_OFFSET; 100 ltq_icu_w32(im, ltq_icu_r32(im, ier) & ~BIT(offset), ier); 101 ltq_icu_w32(im, BIT(offset), isr); 102 } 103 104 static void ltq_ack_irq(struct irq_data *d) 105 { 106 u32 isr = LTQ_ICU_IM0_ISR; 107 int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; 108 int im = offset / INT_NUM_IM_OFFSET; 109 110 offset %= INT_NUM_IM_OFFSET; 111 ltq_icu_w32(im, BIT(offset), isr); 112 } 113 114 void ltq_enable_irq(struct irq_data *d) 115 { 116 u32 ier = LTQ_ICU_IM0_IER; 117 int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; 118 int im = offset / INT_NUM_IM_OFFSET; 119 120 offset %= INT_NUM_IM_OFFSET; 121 ltq_icu_w32(im, ltq_icu_r32(im, ier) | BIT(offset), ier); 122 } 123 124 static int ltq_eiu_settype(struct irq_data *d, unsigned int type) 125 { 126 int i; 127 128 for (i = 0; i < MAX_EIU; i++) { 129 if (d->hwirq == ltq_eiu_irq[i].start) { 130 int val = 0; 131 int edge = 0; 132 133 switch (type) { 134 case IRQF_TRIGGER_NONE: 135 break; 136 case IRQF_TRIGGER_RISING: 137 val = 1; 138 edge = 1; 139 break; 140 case IRQF_TRIGGER_FALLING: 141 val = 2; 142 edge = 1; 143 break; 144 case IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING: 145 val = 3; 146 edge = 1; 147 break; 148 case IRQF_TRIGGER_HIGH: 149 val = 5; 150 break; 151 case IRQF_TRIGGER_LOW: 152 val = 6; 153 break; 154 default: 155 pr_err("invalid type %d for irq %ld\n", 156 type, d->hwirq); 157 return -EINVAL; 158 } 159 160 if (edge) 161 irq_set_handler(d->hwirq, handle_edge_irq); 162 163 ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_C) | 164 (val << (i * 4)), LTQ_EIU_EXIN_C); 165 } 166 } 167 168 return 0; 169 } 170 171 static unsigned int ltq_startup_eiu_irq(struct irq_data *d) 172 { 173 int i; 174 175 ltq_enable_irq(d); 176 for (i = 0; i < MAX_EIU; i++) { 177 if (d->hwirq == ltq_eiu_irq[i].start) { 178 /* by default we are low level triggered */ 179 ltq_eiu_settype(d, IRQF_TRIGGER_LOW); 180 /* clear all pending */ 181 ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INC) & ~BIT(i), 182 LTQ_EIU_EXIN_INC); 183 /* enable */ 184 ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | BIT(i), 185 LTQ_EIU_EXIN_INEN); 186 break; 187 } 188 } 189 190 return 0; 191 } 192 193 static void ltq_shutdown_eiu_irq(struct irq_data *d) 194 { 195 int i; 196 197 ltq_disable_irq(d); 198 for (i = 0; i < MAX_EIU; i++) { 199 if (d->hwirq == ltq_eiu_irq[i].start) { 200 /* disable */ 201 ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~BIT(i), 202 LTQ_EIU_EXIN_INEN); 203 break; 204 } 205 } 206 } 207 208 static struct irq_chip ltq_irq_type = { 209 "icu", 210 .irq_enable = ltq_enable_irq, 211 .irq_disable = ltq_disable_irq, 212 .irq_unmask = ltq_enable_irq, 213 .irq_ack = ltq_ack_irq, 214 .irq_mask = ltq_disable_irq, 215 .irq_mask_ack = ltq_mask_and_ack_irq, 216 }; 217 218 static struct irq_chip ltq_eiu_type = { 219 "eiu", 220 .irq_startup = ltq_startup_eiu_irq, 221 .irq_shutdown = ltq_shutdown_eiu_irq, 222 .irq_enable = ltq_enable_irq, 223 .irq_disable = ltq_disable_irq, 224 .irq_unmask = ltq_enable_irq, 225 .irq_ack = ltq_ack_irq, 226 .irq_mask = ltq_disable_irq, 227 .irq_mask_ack = ltq_mask_and_ack_irq, 228 .irq_set_type = ltq_eiu_settype, 229 }; 230 231 static void ltq_hw_irqdispatch(int module) 232 { 233 u32 irq; 234 235 irq = ltq_icu_r32(module, LTQ_ICU_IM0_IOSR); 236 if (irq == 0) 237 return; 238 239 /* 240 * silicon bug causes only the msb set to 1 to be valid. all 241 * other bits might be bogus 242 */ 243 irq = __fls(irq); 244 do_IRQ((int)irq + MIPS_CPU_IRQ_CASCADE + (INT_NUM_IM_OFFSET * module)); 245 246 /* if this is a EBU irq, we need to ack it or get a deadlock */ 247 if ((irq == LTQ_ICU_EBU_IRQ) && (module == 0) && LTQ_EBU_PCC_ISTAT) 248 ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10, 249 LTQ_EBU_PCC_ISTAT); 250 } 251 252 #define DEFINE_HWx_IRQDISPATCH(x) \ 253 static void ltq_hw ## x ## _irqdispatch(void) \ 254 { \ 255 ltq_hw_irqdispatch(x); \ 256 } 257 DEFINE_HWx_IRQDISPATCH(0) 258 DEFINE_HWx_IRQDISPATCH(1) 259 DEFINE_HWx_IRQDISPATCH(2) 260 DEFINE_HWx_IRQDISPATCH(3) 261 DEFINE_HWx_IRQDISPATCH(4) 262 263 #if MIPS_CPU_TIMER_IRQ == 7 264 static void ltq_hw5_irqdispatch(void) 265 { 266 do_IRQ(MIPS_CPU_TIMER_IRQ); 267 } 268 #else 269 DEFINE_HWx_IRQDISPATCH(5) 270 #endif 271 272 #ifdef CONFIG_MIPS_MT_SMP 273 void __init arch_init_ipiirq(int irq, struct irqaction *action) 274 { 275 setup_irq(irq, action); 276 irq_set_handler(irq, handle_percpu_irq); 277 } 278 279 static void ltq_sw0_irqdispatch(void) 280 { 281 do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ); 282 } 283 284 static void ltq_sw1_irqdispatch(void) 285 { 286 do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ); 287 } 288 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id) 289 { 290 scheduler_ipi(); 291 return IRQ_HANDLED; 292 } 293 294 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id) 295 { 296 smp_call_function_interrupt(); 297 return IRQ_HANDLED; 298 } 299 300 static struct irqaction irq_resched = { 301 .handler = ipi_resched_interrupt, 302 .flags = IRQF_PERCPU, 303 .name = "IPI_resched" 304 }; 305 306 static struct irqaction irq_call = { 307 .handler = ipi_call_interrupt, 308 .flags = IRQF_PERCPU, 309 .name = "IPI_call" 310 }; 311 #endif 312 313 asmlinkage void plat_irq_dispatch(void) 314 { 315 unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM; 316 unsigned int i; 317 318 if ((MIPS_CPU_TIMER_IRQ == 7) && (pending & CAUSEF_IP7)) { 319 do_IRQ(MIPS_CPU_TIMER_IRQ); 320 goto out; 321 } else { 322 for (i = 0; i < MAX_IM; i++) { 323 if (pending & (CAUSEF_IP2 << i)) { 324 ltq_hw_irqdispatch(i); 325 goto out; 326 } 327 } 328 } 329 pr_alert("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status()); 330 331 out: 332 return; 333 } 334 335 static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) 336 { 337 struct irq_chip *chip = <q_irq_type; 338 int i; 339 340 if (hw < MIPS_CPU_IRQ_CASCADE) 341 return 0; 342 343 for (i = 0; i < exin_avail; i++) 344 if (hw == ltq_eiu_irq[i].start) 345 chip = <q_eiu_type; 346 347 irq_set_chip_and_handler(hw, chip, handle_level_irq); 348 349 return 0; 350 } 351 352 static const struct irq_domain_ops irq_domain_ops = { 353 .xlate = irq_domain_xlate_onetwocell, 354 .map = icu_map, 355 }; 356 357 static struct irqaction cascade = { 358 .handler = no_action, 359 .name = "cascade", 360 }; 361 362 int __init icu_of_init(struct device_node *node, struct device_node *parent) 363 { 364 struct device_node *eiu_node; 365 struct resource res; 366 int i, ret; 367 368 for (i = 0; i < MAX_IM; i++) { 369 if (of_address_to_resource(node, i, &res)) 370 panic("Failed to get icu memory range"); 371 372 if (request_mem_region(res.start, resource_size(&res), 373 res.name) < 0) 374 pr_err("Failed to request icu memory"); 375 376 ltq_icu_membase[i] = ioremap_nocache(res.start, 377 resource_size(&res)); 378 if (!ltq_icu_membase[i]) 379 panic("Failed to remap icu memory"); 380 } 381 382 /* turn off all irqs by default */ 383 for (i = 0; i < MAX_IM; i++) { 384 /* make sure all irqs are turned off by default */ 385 ltq_icu_w32(i, 0, LTQ_ICU_IM0_IER); 386 /* clear all possibly pending interrupts */ 387 ltq_icu_w32(i, ~0, LTQ_ICU_IM0_ISR); 388 } 389 390 mips_cpu_irq_init(); 391 392 for (i = 0; i < MAX_IM; i++) 393 setup_irq(i + 2, &cascade); 394 395 if (cpu_has_vint) { 396 pr_info("Setting up vectored interrupts\n"); 397 set_vi_handler(2, ltq_hw0_irqdispatch); 398 set_vi_handler(3, ltq_hw1_irqdispatch); 399 set_vi_handler(4, ltq_hw2_irqdispatch); 400 set_vi_handler(5, ltq_hw3_irqdispatch); 401 set_vi_handler(6, ltq_hw4_irqdispatch); 402 set_vi_handler(7, ltq_hw5_irqdispatch); 403 } 404 405 ltq_domain = irq_domain_add_linear(node, 406 (MAX_IM * INT_NUM_IM_OFFSET) + MIPS_CPU_IRQ_CASCADE, 407 &irq_domain_ops, 0); 408 409 #if defined(CONFIG_MIPS_MT_SMP) 410 if (cpu_has_vint) { 411 pr_info("Setting up IPI vectored interrupts\n"); 412 set_vi_handler(MIPS_CPU_IPI_RESCHED_IRQ, ltq_sw0_irqdispatch); 413 set_vi_handler(MIPS_CPU_IPI_CALL_IRQ, ltq_sw1_irqdispatch); 414 } 415 arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ, 416 &irq_resched); 417 arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ, &irq_call); 418 #endif 419 420 #ifndef CONFIG_MIPS_MT_SMP 421 set_c0_status(IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | 422 IE_IRQ3 | IE_IRQ4 | IE_IRQ5); 423 #else 424 set_c0_status(IE_SW0 | IE_SW1 | IE_IRQ0 | IE_IRQ1 | 425 IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5); 426 #endif 427 428 /* tell oprofile which irq to use */ 429 ltq_perfcount_irq = irq_create_mapping(ltq_domain, LTQ_PERF_IRQ); 430 431 /* 432 * if the timer irq is not one of the mips irqs we need to 433 * create a mapping 434 */ 435 if (MIPS_CPU_TIMER_IRQ != 7) 436 irq_create_mapping(ltq_domain, MIPS_CPU_TIMER_IRQ); 437 438 /* the external interrupts are optional and xway only */ 439 eiu_node = of_find_compatible_node(NULL, NULL, "lantiq,eiu-xway"); 440 if (eiu_node && !of_address_to_resource(eiu_node, 0, &res)) { 441 /* find out how many external irq sources we have */ 442 exin_avail = of_irq_count(eiu_node); 443 444 if (exin_avail > MAX_EIU) 445 exin_avail = MAX_EIU; 446 447 ret = of_irq_to_resource_table(eiu_node, 448 ltq_eiu_irq, exin_avail); 449 if (ret != exin_avail) 450 panic("failed to load external irq resources"); 451 452 if (request_mem_region(res.start, resource_size(&res), 453 res.name) < 0) 454 pr_err("Failed to request eiu memory"); 455 456 ltq_eiu_membase = ioremap_nocache(res.start, 457 resource_size(&res)); 458 if (!ltq_eiu_membase) 459 panic("Failed to remap eiu memory"); 460 } 461 462 return 0; 463 } 464 465 int get_c0_perfcount_int(void) 466 { 467 return ltq_perfcount_irq; 468 } 469 470 unsigned int get_c0_compare_int(void) 471 { 472 return MIPS_CPU_TIMER_IRQ; 473 } 474 475 static struct of_device_id __initdata of_irq_ids[] = { 476 { .compatible = "lantiq,icu", .data = icu_of_init }, 477 {}, 478 }; 479 480 void __init arch_init_irq(void) 481 { 482 of_irq_init(of_irq_ids); 483 } 484