1 /* 2 * linux/arch/arm/mach-omap2/irq.c 3 * 4 * Interrupt handler for OMAP2 boards. 5 * 6 * Copyright (C) 2005 Nokia Corporation 7 * Author: Paul Mundt <paul.mundt@nokia.com> 8 * 9 * This file is subject to the terms and conditions of the GNU General Public 10 * License. See the file "COPYING" in the main directory of this archive 11 * for more details. 12 */ 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/init.h> 16 #include <linux/interrupt.h> 17 #include <linux/io.h> 18 19 #include <asm/exception.h> 20 #include <linux/irqchip.h> 21 #include <linux/irqdomain.h> 22 #include <linux/of.h> 23 #include <linux/of_address.h> 24 #include <linux/of_irq.h> 25 26 #include <linux/irqchip/irq-omap-intc.h> 27 28 /* selected INTC register offsets */ 29 30 #define INTC_REVISION 0x0000 31 #define INTC_SYSCONFIG 0x0010 32 #define INTC_SYSSTATUS 0x0014 33 #define INTC_SIR 0x0040 34 #define INTC_CONTROL 0x0048 35 #define INTC_PROTECTION 0x004C 36 #define INTC_IDLE 0x0050 37 #define INTC_THRESHOLD 0x0068 38 #define INTC_MIR0 0x0084 39 #define INTC_MIR_CLEAR0 0x0088 40 #define INTC_MIR_SET0 0x008c 41 #define INTC_PENDING_IRQ0 0x0098 42 #define INTC_PENDING_IRQ1 0x00b8 43 #define INTC_PENDING_IRQ2 0x00d8 44 #define INTC_PENDING_IRQ3 0x00f8 45 #define INTC_ILR0 0x0100 46 47 #define ACTIVEIRQ_MASK 0x7f /* omap2/3 active interrupt bits */ 48 #define SPURIOUSIRQ_MASK (0x1ffffff << 7) 49 #define INTCPS_NR_ILR_REGS 128 50 #define INTCPS_NR_MIR_REGS 4 51 52 #define INTC_IDLE_FUNCIDLE (1 << 0) 53 #define INTC_IDLE_TURBO (1 << 1) 54 55 #define INTC_PROTECTION_ENABLE (1 << 0) 56 57 struct omap_intc_regs { 58 u32 sysconfig; 59 u32 protection; 60 u32 idle; 61 u32 threshold; 62 u32 ilr[INTCPS_NR_ILR_REGS]; 63 u32 mir[INTCPS_NR_MIR_REGS]; 64 }; 65 static struct omap_intc_regs intc_context; 66 67 static struct irq_domain *domain; 68 static void __iomem *omap_irq_base; 69 static int omap_nr_pending; 70 static int omap_nr_irqs; 71 72 static void intc_writel(u32 reg, u32 val) 73 { 74 writel_relaxed(val, omap_irq_base + reg); 75 } 76 77 static u32 intc_readl(u32 reg) 78 { 79 return readl_relaxed(omap_irq_base + reg); 80 } 81 82 void omap_intc_save_context(void) 83 { 84 int i; 85 86 intc_context.sysconfig = 87 intc_readl(INTC_SYSCONFIG); 88 intc_context.protection = 89 intc_readl(INTC_PROTECTION); 90 intc_context.idle = 91 intc_readl(INTC_IDLE); 92 intc_context.threshold = 93 intc_readl(INTC_THRESHOLD); 94 95 for (i = 0; i < omap_nr_irqs; i++) 96 intc_context.ilr[i] = 97 intc_readl((INTC_ILR0 + 0x4 * i)); 98 for (i = 0; i < INTCPS_NR_MIR_REGS; i++) 99 intc_context.mir[i] = 100 intc_readl(INTC_MIR0 + (0x20 * i)); 101 } 102 103 void omap_intc_restore_context(void) 104 { 105 int i; 106 107 intc_writel(INTC_SYSCONFIG, intc_context.sysconfig); 108 intc_writel(INTC_PROTECTION, intc_context.protection); 109 intc_writel(INTC_IDLE, intc_context.idle); 110 intc_writel(INTC_THRESHOLD, intc_context.threshold); 111 112 for (i = 0; i < omap_nr_irqs; i++) 113 intc_writel(INTC_ILR0 + 0x4 * i, 114 intc_context.ilr[i]); 115 116 for (i = 0; i < INTCPS_NR_MIR_REGS; i++) 117 intc_writel(INTC_MIR0 + 0x20 * i, 118 intc_context.mir[i]); 119 /* MIRs are saved and restore with other PRCM registers */ 120 } 121 122 void omap3_intc_prepare_idle(void) 123 { 124 /* 125 * Disable autoidle as it can stall interrupt controller, 126 * cf. errata ID i540 for 3430 (all revisions up to 3.1.x) 127 */ 128 intc_writel(INTC_SYSCONFIG, 0); 129 intc_writel(INTC_IDLE, INTC_IDLE_TURBO); 130 } 131 132 void omap3_intc_resume_idle(void) 133 { 134 /* Re-enable autoidle */ 135 intc_writel(INTC_SYSCONFIG, 1); 136 intc_writel(INTC_IDLE, 0); 137 } 138 139 /* XXX: FIQ and additional INTC support (only MPU at the moment) */ 140 static void omap_ack_irq(struct irq_data *d) 141 { 142 intc_writel(INTC_CONTROL, 0x1); 143 } 144 145 static void omap_mask_ack_irq(struct irq_data *d) 146 { 147 irq_gc_mask_disable_reg(d); 148 omap_ack_irq(d); 149 } 150 151 static void __init omap_irq_soft_reset(void) 152 { 153 unsigned long tmp; 154 155 tmp = intc_readl(INTC_REVISION) & 0xff; 156 157 pr_info("IRQ: Found an INTC at 0x%p (revision %ld.%ld) with %d interrupts\n", 158 omap_irq_base, tmp >> 4, tmp & 0xf, omap_nr_irqs); 159 160 tmp = intc_readl(INTC_SYSCONFIG); 161 tmp |= 1 << 1; /* soft reset */ 162 intc_writel(INTC_SYSCONFIG, tmp); 163 164 while (!(intc_readl(INTC_SYSSTATUS) & 0x1)) 165 /* Wait for reset to complete */; 166 167 /* Enable autoidle */ 168 intc_writel(INTC_SYSCONFIG, 1 << 0); 169 } 170 171 int omap_irq_pending(void) 172 { 173 int i; 174 175 for (i = 0; i < omap_nr_pending; i++) 176 if (intc_readl(INTC_PENDING_IRQ0 + (0x20 * i))) 177 return 1; 178 return 0; 179 } 180 181 void omap3_intc_suspend(void) 182 { 183 /* A pending interrupt would prevent OMAP from entering suspend */ 184 omap_ack_irq(NULL); 185 } 186 187 static int __init omap_alloc_gc_of(struct irq_domain *d, void __iomem *base) 188 { 189 int ret; 190 int i; 191 192 ret = irq_alloc_domain_generic_chips(d, 32, 1, "INTC", 193 handle_level_irq, IRQ_NOREQUEST | IRQ_NOPROBE, 194 IRQ_LEVEL, 0); 195 if (ret) { 196 pr_warn("Failed to allocate irq chips\n"); 197 return ret; 198 } 199 200 for (i = 0; i < omap_nr_pending; i++) { 201 struct irq_chip_generic *gc; 202 struct irq_chip_type *ct; 203 204 gc = irq_get_domain_generic_chip(d, 32 * i); 205 gc->reg_base = base; 206 ct = gc->chip_types; 207 208 ct->type = IRQ_TYPE_LEVEL_MASK; 209 210 ct->chip.irq_ack = omap_mask_ack_irq; 211 ct->chip.irq_mask = irq_gc_mask_disable_reg; 212 ct->chip.irq_unmask = irq_gc_unmask_enable_reg; 213 214 ct->chip.flags |= IRQCHIP_SKIP_SET_WAKE; 215 216 ct->regs.enable = INTC_MIR_CLEAR0 + 32 * i; 217 ct->regs.disable = INTC_MIR_SET0 + 32 * i; 218 } 219 220 return 0; 221 } 222 223 static void __init omap_alloc_gc_legacy(void __iomem *base, 224 unsigned int irq_start, unsigned int num) 225 { 226 struct irq_chip_generic *gc; 227 struct irq_chip_type *ct; 228 229 gc = irq_alloc_generic_chip("INTC", 1, irq_start, base, 230 handle_level_irq); 231 ct = gc->chip_types; 232 ct->chip.irq_ack = omap_mask_ack_irq; 233 ct->chip.irq_mask = irq_gc_mask_disable_reg; 234 ct->chip.irq_unmask = irq_gc_unmask_enable_reg; 235 ct->chip.flags |= IRQCHIP_SKIP_SET_WAKE; 236 237 ct->regs.enable = INTC_MIR_CLEAR0; 238 ct->regs.disable = INTC_MIR_SET0; 239 irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE, 240 IRQ_NOREQUEST | IRQ_NOPROBE, 0); 241 } 242 243 static int __init omap_init_irq_of(struct device_node *node) 244 { 245 int ret; 246 247 omap_irq_base = of_iomap(node, 0); 248 if (WARN_ON(!omap_irq_base)) 249 return -ENOMEM; 250 251 domain = irq_domain_add_linear(node, omap_nr_irqs, 252 &irq_generic_chip_ops, NULL); 253 254 omap_irq_soft_reset(); 255 256 ret = omap_alloc_gc_of(domain, omap_irq_base); 257 if (ret < 0) 258 irq_domain_remove(domain); 259 260 return ret; 261 } 262 263 static int __init omap_init_irq_legacy(u32 base, struct device_node *node) 264 { 265 int j, irq_base; 266 267 omap_irq_base = ioremap(base, SZ_4K); 268 if (WARN_ON(!omap_irq_base)) 269 return -ENOMEM; 270 271 irq_base = irq_alloc_descs(-1, 0, omap_nr_irqs, 0); 272 if (irq_base < 0) { 273 pr_warn("Couldn't allocate IRQ numbers\n"); 274 irq_base = 0; 275 } 276 277 domain = irq_domain_add_legacy(node, omap_nr_irqs, irq_base, 0, 278 &irq_domain_simple_ops, NULL); 279 280 omap_irq_soft_reset(); 281 282 for (j = 0; j < omap_nr_irqs; j += 32) 283 omap_alloc_gc_legacy(omap_irq_base + j, j + irq_base, 32); 284 285 return 0; 286 } 287 288 static void __init omap_irq_enable_protection(void) 289 { 290 u32 reg; 291 292 reg = intc_readl(INTC_PROTECTION); 293 reg |= INTC_PROTECTION_ENABLE; 294 intc_writel(INTC_PROTECTION, reg); 295 } 296 297 static int __init omap_init_irq(u32 base, struct device_node *node) 298 { 299 int ret; 300 301 /* 302 * FIXME legacy OMAP DMA driver sitting under arch/arm/plat-omap/dma.c 303 * depends is still not ready for linear IRQ domains; because of that 304 * we need to temporarily "blacklist" OMAP2 and OMAP3 devices from using 305 * linear IRQ Domain until that driver is finally fixed. 306 */ 307 if (of_device_is_compatible(node, "ti,omap2-intc") || 308 of_device_is_compatible(node, "ti,omap3-intc")) { 309 struct resource res; 310 311 if (of_address_to_resource(node, 0, &res)) 312 return -ENOMEM; 313 314 base = res.start; 315 ret = omap_init_irq_legacy(base, node); 316 } else if (node) { 317 ret = omap_init_irq_of(node); 318 } else { 319 ret = omap_init_irq_legacy(base, NULL); 320 } 321 322 if (ret == 0) 323 omap_irq_enable_protection(); 324 325 return ret; 326 } 327 328 static asmlinkage void __exception_irq_entry 329 omap_intc_handle_irq(struct pt_regs *regs) 330 { 331 extern unsigned long irq_err_count; 332 u32 irqnr; 333 334 irqnr = intc_readl(INTC_SIR); 335 336 /* 337 * A spurious IRQ can result if interrupt that triggered the 338 * sorting is no longer active during the sorting (10 INTC 339 * functional clock cycles after interrupt assertion). Or a 340 * change in interrupt mask affected the result during sorting 341 * time. There is no special handling required except ignoring 342 * the SIR register value just read and retrying. 343 * See section 6.2.5 of AM335x TRM Literature Number: SPRUH73K 344 * 345 * Many a times, a spurious interrupt situation has been fixed 346 * by adding a flush for the posted write acking the IRQ in 347 * the device driver. Typically, this is going be the device 348 * driver whose interrupt was handled just before the spurious 349 * IRQ occurred. Pay attention to those device drivers if you 350 * run into hitting the spurious IRQ condition below. 351 */ 352 if (unlikely((irqnr & SPURIOUSIRQ_MASK) == SPURIOUSIRQ_MASK)) { 353 pr_err_once("%s: spurious irq!\n", __func__); 354 irq_err_count++; 355 omap_ack_irq(NULL); 356 return; 357 } 358 359 irqnr &= ACTIVEIRQ_MASK; 360 generic_handle_domain_irq(domain, irqnr); 361 } 362 363 static int __init intc_of_init(struct device_node *node, 364 struct device_node *parent) 365 { 366 int ret; 367 368 omap_nr_pending = 3; 369 omap_nr_irqs = 96; 370 371 if (WARN_ON(!node)) 372 return -ENODEV; 373 374 if (of_device_is_compatible(node, "ti,dm814-intc") || 375 of_device_is_compatible(node, "ti,dm816-intc") || 376 of_device_is_compatible(node, "ti,am33xx-intc")) { 377 omap_nr_irqs = 128; 378 omap_nr_pending = 4; 379 } 380 381 ret = omap_init_irq(-1, of_node_get(node)); 382 if (ret < 0) 383 return ret; 384 385 set_handle_irq(omap_intc_handle_irq); 386 387 return 0; 388 } 389 390 IRQCHIP_DECLARE(omap2_intc, "ti,omap2-intc", intc_of_init); 391 IRQCHIP_DECLARE(omap3_intc, "ti,omap3-intc", intc_of_init); 392 IRQCHIP_DECLARE(dm814x_intc, "ti,dm814-intc", intc_of_init); 393 IRQCHIP_DECLARE(dm816x_intc, "ti,dm816-intc", intc_of_init); 394 IRQCHIP_DECLARE(am33xx_intc, "ti,am33xx-intc", intc_of_init); 395