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_INEN 0x000C 37 38 /* irq numbers used by the external interrupt unit (EIU) */ 39 #define LTQ_EIU_IR0 (INT_NUM_IM4_IRL0 + 30) 40 #define LTQ_EIU_IR1 (INT_NUM_IM3_IRL0 + 31) 41 #define LTQ_EIU_IR2 (INT_NUM_IM1_IRL0 + 26) 42 #define LTQ_EIU_IR3 INT_NUM_IM1_IRL0 43 #define LTQ_EIU_IR4 (INT_NUM_IM1_IRL0 + 1) 44 #define LTQ_EIU_IR5 (INT_NUM_IM1_IRL0 + 2) 45 #define LTQ_EIU_IR6 (INT_NUM_IM2_IRL0 + 30) 46 #define XWAY_EXIN_COUNT 3 47 #define MAX_EIU 6 48 49 /* the performance counter */ 50 #define LTQ_PERF_IRQ (INT_NUM_IM4_IRL0 + 31) 51 52 /* 53 * irqs generated by devices attached to the EBU need to be acked in 54 * a special manner 55 */ 56 #define LTQ_ICU_EBU_IRQ 22 57 58 #define ltq_icu_w32(x, y) ltq_w32((x), ltq_icu_membase + (y)) 59 #define ltq_icu_r32(x) ltq_r32(ltq_icu_membase + (x)) 60 61 #define ltq_eiu_w32(x, y) ltq_w32((x), ltq_eiu_membase + (y)) 62 #define ltq_eiu_r32(x) ltq_r32(ltq_eiu_membase + (x)) 63 64 /* our 2 ipi interrupts for VSMP */ 65 #define MIPS_CPU_IPI_RESCHED_IRQ 0 66 #define MIPS_CPU_IPI_CALL_IRQ 1 67 68 /* we have a cascade of 8 irqs */ 69 #define MIPS_CPU_IRQ_CASCADE 8 70 71 #if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC) 72 int gic_present; 73 #endif 74 75 static unsigned short ltq_eiu_irq[MAX_EIU] = { 76 LTQ_EIU_IR0, 77 LTQ_EIU_IR1, 78 LTQ_EIU_IR2, 79 LTQ_EIU_IR3, 80 LTQ_EIU_IR4, 81 LTQ_EIU_IR5, 82 }; 83 84 static int exin_avail; 85 static void __iomem *ltq_icu_membase; 86 static void __iomem *ltq_eiu_membase; 87 88 void ltq_disable_irq(struct irq_data *d) 89 { 90 u32 ier = LTQ_ICU_IM0_IER; 91 int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; 92 93 ier += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET); 94 offset %= INT_NUM_IM_OFFSET; 95 ltq_icu_w32(ltq_icu_r32(ier) & ~BIT(offset), ier); 96 } 97 98 void ltq_mask_and_ack_irq(struct irq_data *d) 99 { 100 u32 ier = LTQ_ICU_IM0_IER; 101 u32 isr = LTQ_ICU_IM0_ISR; 102 int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; 103 104 ier += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET); 105 isr += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET); 106 offset %= INT_NUM_IM_OFFSET; 107 ltq_icu_w32(ltq_icu_r32(ier) & ~BIT(offset), ier); 108 ltq_icu_w32(BIT(offset), isr); 109 } 110 111 static void ltq_ack_irq(struct irq_data *d) 112 { 113 u32 isr = LTQ_ICU_IM0_ISR; 114 int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; 115 116 isr += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET); 117 offset %= INT_NUM_IM_OFFSET; 118 ltq_icu_w32(BIT(offset), isr); 119 } 120 121 void ltq_enable_irq(struct irq_data *d) 122 { 123 u32 ier = LTQ_ICU_IM0_IER; 124 int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE; 125 126 ier += LTQ_ICU_OFFSET * (offset / INT_NUM_IM_OFFSET); 127 offset %= INT_NUM_IM_OFFSET; 128 ltq_icu_w32(ltq_icu_r32(ier) | BIT(offset), ier); 129 } 130 131 static unsigned int ltq_startup_eiu_irq(struct irq_data *d) 132 { 133 int i; 134 135 ltq_enable_irq(d); 136 for (i = 0; i < MAX_EIU; i++) { 137 if (d->hwirq == ltq_eiu_irq[i]) { 138 /* low level - we should really handle set_type */ 139 ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_C) | 140 (0x6 << (i * 4)), LTQ_EIU_EXIN_C); 141 /* clear all pending */ 142 ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INIC) & ~BIT(i), 143 LTQ_EIU_EXIN_INIC); 144 /* enable */ 145 ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | BIT(i), 146 LTQ_EIU_EXIN_INEN); 147 break; 148 } 149 } 150 151 return 0; 152 } 153 154 static void ltq_shutdown_eiu_irq(struct irq_data *d) 155 { 156 int i; 157 158 ltq_disable_irq(d); 159 for (i = 0; i < MAX_EIU; i++) { 160 if (d->hwirq == ltq_eiu_irq[i]) { 161 /* disable */ 162 ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~BIT(i), 163 LTQ_EIU_EXIN_INEN); 164 break; 165 } 166 } 167 } 168 169 static struct irq_chip ltq_irq_type = { 170 "icu", 171 .irq_enable = ltq_enable_irq, 172 .irq_disable = ltq_disable_irq, 173 .irq_unmask = ltq_enable_irq, 174 .irq_ack = ltq_ack_irq, 175 .irq_mask = ltq_disable_irq, 176 .irq_mask_ack = ltq_mask_and_ack_irq, 177 }; 178 179 static struct irq_chip ltq_eiu_type = { 180 "eiu", 181 .irq_startup = ltq_startup_eiu_irq, 182 .irq_shutdown = ltq_shutdown_eiu_irq, 183 .irq_enable = ltq_enable_irq, 184 .irq_disable = ltq_disable_irq, 185 .irq_unmask = ltq_enable_irq, 186 .irq_ack = ltq_ack_irq, 187 .irq_mask = ltq_disable_irq, 188 .irq_mask_ack = ltq_mask_and_ack_irq, 189 }; 190 191 static void ltq_hw_irqdispatch(int module) 192 { 193 u32 irq; 194 195 irq = ltq_icu_r32(LTQ_ICU_IM0_IOSR + (module * LTQ_ICU_OFFSET)); 196 if (irq == 0) 197 return; 198 199 /* 200 * silicon bug causes only the msb set to 1 to be valid. all 201 * other bits might be bogus 202 */ 203 irq = __fls(irq); 204 do_IRQ((int)irq + MIPS_CPU_IRQ_CASCADE + (INT_NUM_IM_OFFSET * module)); 205 206 /* if this is a EBU irq, we need to ack it or get a deadlock */ 207 if ((irq == LTQ_ICU_EBU_IRQ) && (module == 0) && LTQ_EBU_PCC_ISTAT) 208 ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10, 209 LTQ_EBU_PCC_ISTAT); 210 } 211 212 #define DEFINE_HWx_IRQDISPATCH(x) \ 213 static void ltq_hw ## x ## _irqdispatch(void) \ 214 { \ 215 ltq_hw_irqdispatch(x); \ 216 } 217 DEFINE_HWx_IRQDISPATCH(0) 218 DEFINE_HWx_IRQDISPATCH(1) 219 DEFINE_HWx_IRQDISPATCH(2) 220 DEFINE_HWx_IRQDISPATCH(3) 221 DEFINE_HWx_IRQDISPATCH(4) 222 223 static void ltq_hw5_irqdispatch(void) 224 { 225 do_IRQ(MIPS_CPU_TIMER_IRQ); 226 } 227 228 #ifdef CONFIG_MIPS_MT_SMP 229 void __init arch_init_ipiirq(int irq, struct irqaction *action) 230 { 231 setup_irq(irq, action); 232 irq_set_handler(irq, handle_percpu_irq); 233 } 234 235 static void ltq_sw0_irqdispatch(void) 236 { 237 do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ); 238 } 239 240 static void ltq_sw1_irqdispatch(void) 241 { 242 do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ); 243 } 244 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id) 245 { 246 scheduler_ipi(); 247 return IRQ_HANDLED; 248 } 249 250 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id) 251 { 252 smp_call_function_interrupt(); 253 return IRQ_HANDLED; 254 } 255 256 static struct irqaction irq_resched = { 257 .handler = ipi_resched_interrupt, 258 .flags = IRQF_PERCPU, 259 .name = "IPI_resched" 260 }; 261 262 static struct irqaction irq_call = { 263 .handler = ipi_call_interrupt, 264 .flags = IRQF_PERCPU, 265 .name = "IPI_call" 266 }; 267 #endif 268 269 asmlinkage void plat_irq_dispatch(void) 270 { 271 unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM; 272 unsigned int i; 273 274 if (pending & CAUSEF_IP7) { 275 do_IRQ(MIPS_CPU_TIMER_IRQ); 276 goto out; 277 } else { 278 for (i = 0; i < 5; i++) { 279 if (pending & (CAUSEF_IP2 << i)) { 280 ltq_hw_irqdispatch(i); 281 goto out; 282 } 283 } 284 } 285 pr_alert("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status()); 286 287 out: 288 return; 289 } 290 291 static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) 292 { 293 struct irq_chip *chip = <q_irq_type; 294 int i; 295 296 for (i = 0; i < exin_avail; i++) 297 if (hw == ltq_eiu_irq[i]) 298 chip = <q_eiu_type; 299 300 irq_set_chip_and_handler(hw, chip, handle_level_irq); 301 302 return 0; 303 } 304 305 static const struct irq_domain_ops irq_domain_ops = { 306 .xlate = irq_domain_xlate_onetwocell, 307 .map = icu_map, 308 }; 309 310 static struct irqaction cascade = { 311 .handler = no_action, 312 .name = "cascade", 313 }; 314 315 int __init icu_of_init(struct device_node *node, struct device_node *parent) 316 { 317 struct device_node *eiu_node; 318 struct resource res; 319 int i; 320 321 if (of_address_to_resource(node, 0, &res)) 322 panic("Failed to get icu memory range"); 323 324 if (request_mem_region(res.start, resource_size(&res), res.name) < 0) 325 pr_err("Failed to request icu memory"); 326 327 ltq_icu_membase = ioremap_nocache(res.start, resource_size(&res)); 328 if (!ltq_icu_membase) 329 panic("Failed to remap icu memory"); 330 331 /* the external interrupts are optional and xway only */ 332 eiu_node = of_find_compatible_node(NULL, NULL, "lantiq,eiu"); 333 if (eiu_node && of_address_to_resource(eiu_node, 0, &res)) { 334 /* find out how many external irq sources we have */ 335 const __be32 *count = of_get_property(node, 336 "lantiq,count", NULL); 337 338 if (count) 339 exin_avail = *count; 340 if (exin_avail > MAX_EIU) 341 exin_avail = MAX_EIU; 342 343 if (request_mem_region(res.start, resource_size(&res), 344 res.name) < 0) 345 pr_err("Failed to request eiu memory"); 346 347 ltq_eiu_membase = ioremap_nocache(res.start, 348 resource_size(&res)); 349 if (!ltq_eiu_membase) 350 panic("Failed to remap eiu memory"); 351 } 352 353 /* turn off all irqs by default */ 354 for (i = 0; i < 5; i++) { 355 /* make sure all irqs are turned off by default */ 356 ltq_icu_w32(0, LTQ_ICU_IM0_IER + (i * LTQ_ICU_OFFSET)); 357 /* clear all possibly pending interrupts */ 358 ltq_icu_w32(~0, LTQ_ICU_IM0_ISR + (i * LTQ_ICU_OFFSET)); 359 } 360 361 mips_cpu_irq_init(); 362 363 for (i = 2; i <= 6; i++) 364 setup_irq(i, &cascade); 365 366 if (cpu_has_vint) { 367 pr_info("Setting up vectored interrupts\n"); 368 set_vi_handler(2, ltq_hw0_irqdispatch); 369 set_vi_handler(3, ltq_hw1_irqdispatch); 370 set_vi_handler(4, ltq_hw2_irqdispatch); 371 set_vi_handler(5, ltq_hw3_irqdispatch); 372 set_vi_handler(6, ltq_hw4_irqdispatch); 373 set_vi_handler(7, ltq_hw5_irqdispatch); 374 } 375 376 irq_domain_add_linear(node, 6 * INT_NUM_IM_OFFSET, 377 &irq_domain_ops, 0); 378 379 #if defined(CONFIG_MIPS_MT_SMP) 380 if (cpu_has_vint) { 381 pr_info("Setting up IPI vectored interrupts\n"); 382 set_vi_handler(MIPS_CPU_IPI_RESCHED_IRQ, ltq_sw0_irqdispatch); 383 set_vi_handler(MIPS_CPU_IPI_CALL_IRQ, ltq_sw1_irqdispatch); 384 } 385 arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ, 386 &irq_resched); 387 arch_init_ipiirq(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ, &irq_call); 388 #endif 389 390 #if !defined(CONFIG_MIPS_MT_SMP) && !defined(CONFIG_MIPS_MT_SMTC) 391 set_c0_status(IE_IRQ0 | IE_IRQ1 | IE_IRQ2 | 392 IE_IRQ3 | IE_IRQ4 | IE_IRQ5); 393 #else 394 set_c0_status(IE_SW0 | IE_SW1 | IE_IRQ0 | IE_IRQ1 | 395 IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5); 396 #endif 397 398 /* tell oprofile which irq to use */ 399 cp0_perfcount_irq = LTQ_PERF_IRQ; 400 return 0; 401 } 402 403 unsigned int __cpuinit get_c0_compare_int(void) 404 { 405 return CP0_LEGACY_COMPARE_IRQ; 406 } 407 408 static struct of_device_id __initdata of_irq_ids[] = { 409 { .compatible = "lantiq,icu", .data = icu_of_init }, 410 {}, 411 }; 412 413 void __init arch_init_irq(void) 414 { 415 of_irq_init(of_irq_ids); 416 } 417