arch/arm/mach-omap2/irq.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/init.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <mach/hardware.h>
  18 #include <asm/mach/irq.h>
  19
  20
  21 /* selected INTC register offsets */
  22
  23 #define INTC_REVISION           0x0000
  24 #define INTC_SYSCONFIG          0x0010
  25 #define INTC_SYSSTATUS          0x0014
  26 #define INTC_SIR                0x0040
  27 #define INTC_CONTROL            0x0048
  28 #define INTC_PROTECTION         0x004C
  29 #define INTC_IDLE               0x0050
  30 #define INTC_THRESHOLD          0x0068
  31 #define INTC_MIR0               0x0084
  32 #define INTC_MIR_CLEAR0         0x0088
  33 #define INTC_MIR_SET0           0x008c
  34 #define INTC_PENDING_IRQ0       0x0098
  35 /* Number of IRQ state bits in each MIR register */
  36 #define IRQ_BITS_PER_REG        32
  37
  38 /*
  39  * OMAP2 has a number of different interrupt controllers, each interrupt
  40  * controller is identified as its own "bank". Register definitions are
  41  * fairly consistent for each bank, but not all registers are implemented
  42  * for each bank.. when in doubt, consult the TRM.
  43  */
  44 static struct omap_irq_bank {
  45         void __iomem *base_reg;
  46         unsigned int nr_irqs;
  47 } __attribute__ ((aligned(4))) irq_banks[] = {
  48         {
  49                 /* MPU INTC */
  50                 .nr_irqs        = 96,
  51         },
  52 };
  53
  54 /* Structure to save interrupt controller context */
  55 struct omap3_intc_regs {
  56         u32 sysconfig;
  57         u32 protection;
  58         u32 idle;
  59         u32 threshold;
  60         u32 ilr[INTCPS_NR_IRQS];
  61         u32 mir[INTCPS_NR_MIR_REGS];
  62 };
  63
  64 static struct omap3_intc_regs intc_context[ARRAY_SIZE(irq_banks)];
  65
  66 /* INTC bank register get/set */
  67
  68 static void intc_bank_write_reg(u32 val, struct omap_irq_bank *bank, u16 reg)
  69 {
  70         __raw_writel(val, bank->base_reg + reg);
  71 }
  72
  73 static u32 intc_bank_read_reg(struct omap_irq_bank *bank, u16 reg)
  74 {
  75         return __raw_readl(bank->base_reg + reg);
  76 }
  77
  78 static int previous_irq;
  79
  80 /*
  81  * On 34xx we can get occasional spurious interrupts if the ack from
  82  * an interrupt handler does not get posted before we unmask. Warn about
  83  * the interrupt handlers that need to flush posted writes.
  84  */
  85 static int omap_check_spurious(unsigned int irq)
  86 {
  87         u32 sir, spurious;
  88
  89         sir = intc_bank_read_reg(&irq_banks[0], INTC_SIR);
  90         spurious = sir >> 7;
  91
  92         if (spurious) {
  93                 printk(KERN_WARNING "Spurious irq %i: 0x%08x, please flush "
  94                                         "posted write for irq %i\n",
  95                                         irq, sir, previous_irq);
  96                 return spurious;
  97         }
  98
  99         return 0;
 100 }
 101
 102 /* XXX: FIQ and additional INTC support (only MPU at the moment) */
 103 static void omap_ack_irq(struct irq_data *d)
 104 {
 105         intc_bank_write_reg(0x1, &irq_banks[0], INTC_CONTROL);
 106 }
 107
 108 static void omap_mask_irq(struct irq_data *d)
 109 {
 110         unsigned int irq = d->irq;
 111         int offset = irq & (~(IRQ_BITS_PER_REG - 1));
 112
 113         if (cpu_is_omap34xx()) {
 114                 int spurious = 0;
 115
 116                 /*
 117                  * INT_34XX_GPT12_IRQ is also the spurious irq. Maybe because
 118                  * it is the highest irq number?
 119                  */
 120                 if (irq == INT_34XX_GPT12_IRQ)
 121                         spurious = omap_check_spurious(irq);
 122
 123                 if (!spurious)
 124                         previous_irq = irq;
 125         }
 126
 127         irq &= (IRQ_BITS_PER_REG - 1);
 128
 129         intc_bank_write_reg(1 << irq, &irq_banks[0], INTC_MIR_SET0 + offset);
 130 }
 131
 132 static void omap_unmask_irq(struct irq_data *d)
 133 {
 134         unsigned int irq = d->irq;
 135         int offset = irq & (~(IRQ_BITS_PER_REG - 1));
 136
 137         irq &= (IRQ_BITS_PER_REG - 1);
 138
 139         intc_bank_write_reg(1 << irq, &irq_banks[0], INTC_MIR_CLEAR0 + offset);
 140 }
 141
 142 static void omap_mask_ack_irq(struct irq_data *d)
 143 {
 144         omap_mask_irq(d);
 145         omap_ack_irq(d);
 146 }
 147
 148 static struct irq_chip omap_irq_chip = {
 149         .name           = "INTC",
 150         .irq_ack        = omap_mask_ack_irq,
 151         .irq_mask       = omap_mask_irq,
 152         .irq_unmask     = omap_unmask_irq,
 153 };
 154
 155 static void __init omap_irq_bank_init_one(struct omap_irq_bank *bank)
 156 {
 157         unsigned long tmp;
 158
 159         tmp = intc_bank_read_reg(bank, INTC_REVISION) & 0xff;
 160         printk(KERN_INFO "IRQ: Found an INTC at 0x%p "
 161                          "(revision %ld.%ld) with %d interrupts\n",
 162                          bank->base_reg, tmp >> 4, tmp & 0xf, bank->nr_irqs);
 163
 164         tmp = intc_bank_read_reg(bank, INTC_SYSCONFIG);
 165         tmp |= 1 << 1;  /* soft reset */
 166         intc_bank_write_reg(tmp, bank, INTC_SYSCONFIG);
 167
 168         while (!(intc_bank_read_reg(bank, INTC_SYSSTATUS) & 0x1))
 169                 /* Wait for reset to complete */;
 170
 171         /* Enable autoidle */
 172         intc_bank_write_reg(1 << 0, bank, INTC_SYSCONFIG);
 173 }
 174
 175 int omap_irq_pending(void)
 176 {
 177         int i;
 178
 179         for (i = 0; i < ARRAY_SIZE(irq_banks); i++) {
 180                 struct omap_irq_bank *bank = irq_banks + i;
 181                 int irq;
 182
 183                 for (irq = 0; irq < bank->nr_irqs; irq += 32)
 184                         if (intc_bank_read_reg(bank, INTC_PENDING_IRQ0 +
 185                                                ((irq >> 5) << 5)))
 186                                 return 1;
 187         }
 188         return 0;
 189 }
 190
 191 void __init omap_init_irq(void)
 192 {
 193         unsigned long nr_of_irqs = 0;
 194         unsigned int nr_banks = 0;
 195         int i;
 196
 197         for (i = 0; i < ARRAY_SIZE(irq_banks); i++) {
 198                 unsigned long base = 0;
 199                 struct omap_irq_bank *bank = irq_banks + i;
 200
 201                 if (cpu_is_omap24xx())
 202                         base = OMAP24XX_IC_BASE;
 203                 else if (cpu_is_omap34xx())
 204                         base = OMAP34XX_IC_BASE;
 205
 206                 BUG_ON(!base);
 207
 208                 /* Static mapping, never released */
 209                 bank->base_reg = ioremap(base, SZ_4K);
 210                 if (!bank->base_reg) {
 211                         printk(KERN_ERR "Could not ioremap irq bank%i\n", i);
 212                         continue;
 213                 }
 214
 215                 omap_irq_bank_init_one(bank);
 216
 217                 nr_of_irqs += bank->nr_irqs;
 218                 nr_banks++;
 219         }
 220
 221         printk(KERN_INFO "Total of %ld interrupts on %d active controller%s\n",
 222                nr_of_irqs, nr_banks, nr_banks > 1 ? "s" : "");
 223
 224         for (i = 0; i < nr_of_irqs; i++) {
 225                 set_irq_chip(i, &omap_irq_chip);
 226                 set_irq_handler(i, handle_level_irq);
 227                 set_irq_flags(i, IRQF_VALID);
 228         }
 229 }
 230
 231 #ifdef CONFIG_ARCH_OMAP3
 232 void omap_intc_save_context(void)
 233 {
 234         int ind = 0, i = 0;
 235         for (ind = 0; ind < ARRAY_SIZE(irq_banks); ind++) {
 236                 struct omap_irq_bank *bank = irq_banks + ind;
 237                 intc_context[ind].sysconfig =
 238                         intc_bank_read_reg(bank, INTC_SYSCONFIG);
 239                 intc_context[ind].protection =
 240                         intc_bank_read_reg(bank, INTC_PROTECTION);
 241                 intc_context[ind].idle =
 242                         intc_bank_read_reg(bank, INTC_IDLE);
 243                 intc_context[ind].threshold =
 244                         intc_bank_read_reg(bank, INTC_THRESHOLD);
 245                 for (i = 0; i < INTCPS_NR_IRQS; i++)
 246                         intc_context[ind].ilr[i] =
 247                                 intc_bank_read_reg(bank, (0x100 + 0x4*i));
 248                 for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
 249                         intc_context[ind].mir[i] =
 250                                 intc_bank_read_reg(&irq_banks[0], INTC_MIR0 +
 251                                 (0x20 * i));
 252         }
 253 }
 254
 255 void omap_intc_restore_context(void)
 256 {
 257         int ind = 0, i = 0;
 258
 259         for (ind = 0; ind < ARRAY_SIZE(irq_banks); ind++) {
 260                 struct omap_irq_bank *bank = irq_banks + ind;
 261                 intc_bank_write_reg(intc_context[ind].sysconfig,
 262                                         bank, INTC_SYSCONFIG);
 263                 intc_bank_write_reg(intc_context[ind].sysconfig,
 264                                         bank, INTC_SYSCONFIG);
 265                 intc_bank_write_reg(intc_context[ind].protection,
 266                                         bank, INTC_PROTECTION);
 267                 intc_bank_write_reg(intc_context[ind].idle,
 268                                         bank, INTC_IDLE);
 269                 intc_bank_write_reg(intc_context[ind].threshold,
 270                                         bank, INTC_THRESHOLD);
 271                 for (i = 0; i < INTCPS_NR_IRQS; i++)
 272                         intc_bank_write_reg(intc_context[ind].ilr[i],
 273                                 bank, (0x100 + 0x4*i));
 274                 for (i = 0; i < INTCPS_NR_MIR_REGS; i++)
 275                         intc_bank_write_reg(intc_context[ind].mir[i],
 276                                  &irq_banks[0], INTC_MIR0 + (0x20 * i));
 277         }
 278         /* MIRs are saved and restore with other PRCM registers */
 279 }
 280
 281 void omap3_intc_suspend(void)
 282 {
 283         /* A pending interrupt would prevent OMAP from entering suspend */
 284         omap_ack_irq(0);
 285 }
 286
 287 void omap3_intc_prepare_idle(void)
 288 {
 289         /*
 290          * Disable autoidle as it can stall interrupt controller,
 291          * cf. errata ID i540 for 3430 (all revisions up to 3.1.x)
 292          */
 293         intc_bank_write_reg(0, &irq_banks[0], INTC_SYSCONFIG);
 294 }
 295
 296 void omap3_intc_resume_idle(void)
 297 {
 298         /* Re-enable autoidle */
 299         intc_bank_write_reg(1, &irq_banks[0], INTC_SYSCONFIG);
 300 }
 301 #endif /* CONFIG_ARCH_OMAP3 */