drivers/irqchip/irq-omap-intc.c

   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 /* Define these here for now until we drop all board-files */
  27 #define OMAP24XX_IC_BASE        0x480fe000
  28 #define OMAP34XX_IC_BASE        0x48200000
  29
  30 /* selected INTC register offsets */
  31
  32 #define INTC_REVISION           0x0000
  33 #define INTC_SYSCONFIG          0x0010
  34 #define INTC_SYSSTATUS          0x0014
  35 #define INTC_SIR                0x0040
  36 #define INTC_CONTROL            0x0048
  37 #define INTC_PROTECTION         0x004C
  38 #define INTC_IDLE               0x0050
  39 #define INTC_THRESHOLD          0x0068
  40 #define INTC_MIR0               0x0084
  41 #define INTC_MIR_CLEAR0         0x0088
  42 #define INTC_MIR_SET0           0x008c
  43 #define INTC_PENDING_IRQ0       0x0098
  44 #define INTC_PENDING_IRQ1       0x00b8
  45 #define INTC_PENDING_IRQ2       0x00d8
  46 #define INTC_PENDING_IRQ3       0x00f8
  47 #define INTC_ILR0               0x0100
  48
  49 #define ACTIVEIRQ_MASK          0x7f    /* omap2/3 active interrupt bits */
  50 #define SPURIOUSIRQ_MASK        (0x1ffffff << 7)
  51 #define INTCPS_NR_ILR_REGS      128
  52 #define INTCPS_NR_MIR_REGS      4
  53
  54 #define INTC_IDLE_FUNCIDLE      (1 << 0)
  55 #define INTC_IDLE_TURBO         (1 << 1)
  56
  57 #define INTC_PROTECTION_ENABLE  (1 << 0)
  58
  59 struct omap_intc_regs {
  60         u32 sysconfig;
  61         u32 protection;
  62         u32 idle;
  63         u32 threshold;
  64         u32 ilr[INTCPS_NR_ILR_REGS];
  65         u32 mir[INTCPS_NR_MIR_REGS];
  66 };
  67 static struct omap_intc_regs intc_context;
  68
  69 static struct irq_domain *domain;
  70 static void __iomem *omap_irq_base;
  71 static int omap_nr_pending = 3;
  72 static int omap_nr_irqs = 96;
  73
  74 static void intc_writel(u32 reg, u32 val)
  75 {
  76         writel_relaxed(val, omap_irq_base + reg);
  77 }
  78
  79 static u32 intc_readl(u32 reg)
  80 {
  81         return readl_relaxed(omap_irq_base + reg);
  82 }
  83
  84 void omap_intc_save_context(void)
  85 {
  86         int i;
  87
  88         intc_context.sysconfig =
  89                 intc_readl(INTC_SYSCONFIG);
  90         intc_context.protection =
  91                 intc_readl(INTC_PROTECTION);
  92         intc_context.idle =
  93                 intc_readl(INTC_IDLE);
  94         intc_context.threshold =
  95                 intc_readl(INTC_THRESHOLD);
  96
  97         for (i = 0; i < omap_nr_irqs; i++)
  98                 intc_context.ilr[i] =
  99                         intc_readl((INTC_ILR0 + 0x4 * i));
 100         for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
 101                 intc_context.mir[i] =
 102                         intc_readl(INTC_MIR0 + (0x20 * i));
 103 }
 104
 105 void omap_intc_restore_context(void)
 106 {
 107         int i;
 108
 109         intc_writel(INTC_SYSCONFIG, intc_context.sysconfig);
 110         intc_writel(INTC_PROTECTION, intc_context.protection);
 111         intc_writel(INTC_IDLE, intc_context.idle);
 112         intc_writel(INTC_THRESHOLD, intc_context.threshold);
 113
 114         for (i = 0; i < omap_nr_irqs; i++)
 115                 intc_writel(INTC_ILR0 + 0x4 * i,
 116                                 intc_context.ilr[i]);
 117
 118         for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
 119                 intc_writel(INTC_MIR0 + 0x20 * i,
 120                         intc_context.mir[i]);
 121         /* MIRs are saved and restore with other PRCM registers */
 122 }
 123
 124 void omap3_intc_prepare_idle(void)
 125 {
 126         /*
 127          * Disable autoidle as it can stall interrupt controller,
 128          * cf. errata ID i540 for 3430 (all revisions up to 3.1.x)
 129          */
 130         intc_writel(INTC_SYSCONFIG, 0);
 131         intc_writel(INTC_IDLE, INTC_IDLE_TURBO);
 132 }
 133
 134 void omap3_intc_resume_idle(void)
 135 {
 136         /* Re-enable autoidle */
 137         intc_writel(INTC_SYSCONFIG, 1);
 138         intc_writel(INTC_IDLE, 0);
 139 }
 140
 141 /* XXX: FIQ and additional INTC support (only MPU at the moment) */
 142 static void omap_ack_irq(struct irq_data *d)
 143 {
 144         intc_writel(INTC_CONTROL, 0x1);
 145 }
 146
 147 static void omap_mask_ack_irq(struct irq_data *d)
 148 {
 149         irq_gc_mask_disable_reg(d);
 150         omap_ack_irq(d);
 151 }
 152
 153 static void __init omap_irq_soft_reset(void)
 154 {
 155         unsigned long tmp;
 156
 157         tmp = intc_readl(INTC_REVISION) & 0xff;
 158
 159         pr_info("IRQ: Found an INTC at 0x%p (revision %ld.%ld) with %d interrupts\n",
 160                 omap_irq_base, tmp >> 4, tmp & 0xf, omap_nr_irqs);
 161
 162         tmp = intc_readl(INTC_SYSCONFIG);
 163         tmp |= 1 << 1;  /* soft reset */
 164         intc_writel(INTC_SYSCONFIG, tmp);
 165
 166         while (!(intc_readl(INTC_SYSSTATUS) & 0x1))
 167                 /* Wait for reset to complete */;
 168
 169         /* Enable autoidle */
 170         intc_writel(INTC_SYSCONFIG, 1 << 0);
 171 }
 172
 173 int omap_irq_pending(void)
 174 {
 175         int i;
 176
 177         for (i = 0; i < omap_nr_pending; i++)
 178                 if (intc_readl(INTC_PENDING_IRQ0 + (0x20 * i)))
 179                         return 1;
 180         return 0;
 181 }
 182
 183 void omap3_intc_suspend(void)
 184 {
 185         /* A pending interrupt would prevent OMAP from entering suspend */
 186         omap_ack_irq(NULL);
 187 }
 188
 189 static int __init omap_alloc_gc_of(struct irq_domain *d, void __iomem *base)
 190 {
 191         int ret;
 192         int i;
 193
 194         ret = irq_alloc_domain_generic_chips(d, 32, 1, "INTC",
 195                         handle_level_irq, IRQ_NOREQUEST | IRQ_NOPROBE,
 196                         IRQ_LEVEL, 0);
 197         if (ret) {
 198                 pr_warn("Failed to allocate irq chips\n");
 199                 return ret;
 200         }
 201
 202         for (i = 0; i < omap_nr_pending; i++) {
 203                 struct irq_chip_generic *gc;
 204                 struct irq_chip_type *ct;
 205
 206                 gc = irq_get_domain_generic_chip(d, 32 * i);
 207                 gc->reg_base = base;
 208                 ct = gc->chip_types;
 209
 210                 ct->type = IRQ_TYPE_LEVEL_MASK;
 211                 ct->handler = handle_level_irq;
 212
 213                 ct->chip.irq_ack = omap_mask_ack_irq;
 214                 ct->chip.irq_mask = irq_gc_mask_disable_reg;
 215                 ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
 216
 217                 ct->chip.flags |= IRQCHIP_SKIP_SET_WAKE;
 218
 219                 ct->regs.enable = INTC_MIR_CLEAR0 + 32 * i;
 220                 ct->regs.disable = INTC_MIR_SET0 + 32 * i;
 221         }
 222
 223         return 0;
 224 }
 225
 226 static void __init omap_alloc_gc_legacy(void __iomem *base,
 227                 unsigned int irq_start, unsigned int num)
 228 {
 229         struct irq_chip_generic *gc;
 230         struct irq_chip_type *ct;
 231
 232         gc = irq_alloc_generic_chip("INTC", 1, irq_start, base,
 233                         handle_level_irq);
 234         ct = gc->chip_types;
 235         ct->chip.irq_ack = omap_mask_ack_irq;
 236         ct->chip.irq_mask = irq_gc_mask_disable_reg;
 237         ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
 238         ct->chip.flags |= IRQCHIP_SKIP_SET_WAKE;
 239
 240         ct->regs.enable = INTC_MIR_CLEAR0;
 241         ct->regs.disable = INTC_MIR_SET0;
 242         irq_setup_generic_chip(gc, IRQ_MSK(num), IRQ_GC_INIT_MASK_CACHE,
 243                         IRQ_NOREQUEST | IRQ_NOPROBE, 0);
 244 }
 245
 246 static int __init omap_init_irq_of(struct device_node *node)
 247 {
 248         int ret;
 249
 250         omap_irq_base = of_iomap(node, 0);
 251         if (WARN_ON(!omap_irq_base))
 252                 return -ENOMEM;
 253
 254         domain = irq_domain_add_linear(node, omap_nr_irqs,
 255                         &irq_generic_chip_ops, NULL);
 256
 257         omap_irq_soft_reset();
 258
 259         ret = omap_alloc_gc_of(domain, omap_irq_base);
 260         if (ret < 0)
 261                 irq_domain_remove(domain);
 262
 263         return ret;
 264 }
 265
 266 static int __init omap_init_irq_legacy(u32 base, struct device_node *node)
 267 {
 268         int j, irq_base;
 269
 270         omap_irq_base = ioremap(base, SZ_4K);
 271         if (WARN_ON(!omap_irq_base))
 272                 return -ENOMEM;
 273
 274         irq_base = irq_alloc_descs(-1, 0, omap_nr_irqs, 0);
 275         if (irq_base < 0) {
 276                 pr_warn("Couldn't allocate IRQ numbers\n");
 277                 irq_base = 0;
 278         }
 279
 280         domain = irq_domain_add_legacy(node, omap_nr_irqs, irq_base, 0,
 281                         &irq_domain_simple_ops, NULL);
 282
 283         omap_irq_soft_reset();
 284
 285         for (j = 0; j < omap_nr_irqs; j += 32)
 286                 omap_alloc_gc_legacy(omap_irq_base + j, j + irq_base, 32);
 287
 288         return 0;
 289 }
 290
 291 static void __init omap_irq_enable_protection(void)
 292 {
 293         u32 reg;
 294
 295         reg = intc_readl(INTC_PROTECTION);
 296         reg |= INTC_PROTECTION_ENABLE;
 297         intc_writel(INTC_PROTECTION, reg);
 298 }
 299
 300 static int __init omap_init_irq(u32 base, struct device_node *node)
 301 {
 302         int ret;
 303
 304         /*
 305          * FIXME legacy OMAP DMA driver sitting under arch/arm/plat-omap/dma.c
 306          * depends is still not ready for linear IRQ domains; because of that
 307          * we need to temporarily "blacklist" OMAP2 and OMAP3 devices from using
 308          * linear IRQ Domain until that driver is finally fixed.
 309          */
 310         if (of_device_is_compatible(node, "ti,omap2-intc") ||
 311                         of_device_is_compatible(node, "ti,omap3-intc")) {
 312                 struct resource res;
 313
 314                 if (of_address_to_resource(node, 0, &res))
 315                         return -ENOMEM;
 316
 317                 base = res.start;
 318                 ret = omap_init_irq_legacy(base, node);
 319         } else if (node) {
 320                 ret = omap_init_irq_of(node);
 321         } else {
 322                 ret = omap_init_irq_legacy(base, NULL);
 323         }
 324
 325         if (ret == 0)
 326                 omap_irq_enable_protection();
 327
 328         return ret;
 329 }
 330
 331 static asmlinkage void __exception_irq_entry
 332 omap_intc_handle_irq(struct pt_regs *regs)
 333 {
 334         extern unsigned long irq_err_count;
 335         u32 irqnr;
 336
 337         irqnr = intc_readl(INTC_SIR);
 338
 339         /*
 340          * A spurious IRQ can result if interrupt that triggered the
 341          * sorting is no longer active during the sorting (10 INTC
 342          * functional clock cycles after interrupt assertion). Or a
 343          * change in interrupt mask affected the result during sorting
 344          * time. There is no special handling required except ignoring
 345          * the SIR register value just read and retrying.
 346          * See section 6.2.5 of AM335x TRM Literature Number: SPRUH73K
 347          *
 348          * Many a times, a spurious interrupt situation has been fixed
 349          * by adding a flush for the posted write acking the IRQ in
 350          * the device driver. Typically, this is going be the device
 351          * driver whose interrupt was handled just before the spurious
 352          * IRQ occurred. Pay attention to those device drivers if you
 353          * run into hitting the spurious IRQ condition below.
 354          */
 355         if (unlikely((irqnr & SPURIOUSIRQ_MASK) == SPURIOUSIRQ_MASK)) {
 356                 pr_err_once("%s: spurious irq!\n", __func__);
 357                 irq_err_count++;
 358                 omap_ack_irq(NULL);
 359                 return;
 360         }
 361
 362         irqnr &= ACTIVEIRQ_MASK;
 363         handle_domain_irq(domain, irqnr, regs);
 364 }
 365
 366 void __init omap3_init_irq(void)
 367 {
 368         omap_nr_irqs = 96;
 369         omap_nr_pending = 3;
 370         omap_init_irq(OMAP34XX_IC_BASE, NULL);
 371         set_handle_irq(omap_intc_handle_irq);
 372 }
 373
 374 static int __init intc_of_init(struct device_node *node,
 375                              struct device_node *parent)
 376 {
 377         int ret;
 378
 379         omap_nr_pending = 3;
 380         omap_nr_irqs = 96;
 381
 382         if (WARN_ON(!node))
 383                 return -ENODEV;
 384
 385         if (of_device_is_compatible(node, "ti,dm814-intc") ||
 386             of_device_is_compatible(node, "ti,dm816-intc") ||
 387             of_device_is_compatible(node, "ti,am33xx-intc")) {
 388                 omap_nr_irqs = 128;
 389                 omap_nr_pending = 4;
 390         }
 391
 392         ret = omap_init_irq(-1, of_node_get(node));
 393         if (ret < 0)
 394                 return ret;
 395
 396         set_handle_irq(omap_intc_handle_irq);
 397
 398         return 0;
 399 }
 400
 401 IRQCHIP_DECLARE(omap2_intc, "ti,omap2-intc", intc_of_init);
 402 IRQCHIP_DECLARE(omap3_intc, "ti,omap3-intc", intc_of_init);
 403 IRQCHIP_DECLARE(dm814x_intc, "ti,dm814-intc", intc_of_init);
 404 IRQCHIP_DECLARE(dm816x_intc, "ti,dm816-intc", intc_of_init);
 405 IRQCHIP_DECLARE(am33xx_intc, "ti,am33xx-intc", intc_of_init);