arch/mips/lantiq/irq.c

   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
  13 #include <asm/bootinfo.h>
  14 #include <asm/irq_cpu.h>
  15
  16 #include <lantiq_soc.h>
  17 #include <irq.h>
  18
  19 /* register definitions */
  20 #define LTQ_ICU_IM0_ISR         0x0000
  21 #define LTQ_ICU_IM0_IER         0x0008
  22 #define LTQ_ICU_IM0_IOSR        0x0010
  23 #define LTQ_ICU_IM0_IRSR        0x0018
  24 #define LTQ_ICU_IM0_IMR         0x0020
  25 #define LTQ_ICU_IM1_ISR         0x0028
  26 #define LTQ_ICU_OFFSET          (LTQ_ICU_IM1_ISR - LTQ_ICU_IM0_ISR)
  27
  28 #define LTQ_EIU_EXIN_C          0x0000
  29 #define LTQ_EIU_EXIN_INIC       0x0004
  30 #define LTQ_EIU_EXIN_INEN       0x000C
  31
  32 /* irq numbers used by the external interrupt unit (EIU) */
  33 #define LTQ_EIU_IR0             (INT_NUM_IM4_IRL0 + 30)
  34 #define LTQ_EIU_IR1             (INT_NUM_IM3_IRL0 + 31)
  35 #define LTQ_EIU_IR2             (INT_NUM_IM1_IRL0 + 26)
  36 #define LTQ_EIU_IR3             INT_NUM_IM1_IRL0
  37 #define LTQ_EIU_IR4             (INT_NUM_IM1_IRL0 + 1)
  38 #define LTQ_EIU_IR5             (INT_NUM_IM1_IRL0 + 2)
  39 #define LTQ_EIU_IR6             (INT_NUM_IM2_IRL0 + 30)
  40
  41 #define MAX_EIU                 6
  42
  43 /* irqs generated by device attached to the EBU need to be acked in
  44  * a special manner
  45  */
  46 #define LTQ_ICU_EBU_IRQ         22
  47
  48 #define ltq_icu_w32(x, y)       ltq_w32((x), ltq_icu_membase + (y))
  49 #define ltq_icu_r32(x)          ltq_r32(ltq_icu_membase + (x))
  50
  51 #define ltq_eiu_w32(x, y)       ltq_w32((x), ltq_eiu_membase + (y))
  52 #define ltq_eiu_r32(x)          ltq_r32(ltq_eiu_membase + (x))
  53
  54 static unsigned short ltq_eiu_irq[MAX_EIU] = {
  55         LTQ_EIU_IR0,
  56         LTQ_EIU_IR1,
  57         LTQ_EIU_IR2,
  58         LTQ_EIU_IR3,
  59         LTQ_EIU_IR4,
  60         LTQ_EIU_IR5,
  61 };
  62
  63 static struct resource ltq_icu_resource = {
  64         .name   = "icu",
  65         .start  = LTQ_ICU_BASE_ADDR,
  66         .end    = LTQ_ICU_BASE_ADDR + LTQ_ICU_SIZE - 1,
  67         .flags  = IORESOURCE_MEM,
  68 };
  69
  70 static struct resource ltq_eiu_resource = {
  71         .name   = "eiu",
  72         .start  = LTQ_EIU_BASE_ADDR,
  73         .end    = LTQ_EIU_BASE_ADDR + LTQ_ICU_SIZE - 1,
  74         .flags  = IORESOURCE_MEM,
  75 };
  76
  77 static void __iomem *ltq_icu_membase;
  78 static void __iomem *ltq_eiu_membase;
  79
  80 void ltq_disable_irq(struct irq_data *d)
  81 {
  82         u32 ier = LTQ_ICU_IM0_IER;
  83         int irq_nr = d->irq - INT_NUM_IRQ0;
  84
  85         ier += LTQ_ICU_OFFSET * (irq_nr / INT_NUM_IM_OFFSET);
  86         irq_nr %= INT_NUM_IM_OFFSET;
  87         ltq_icu_w32(ltq_icu_r32(ier) & ~(1 << irq_nr), ier);
  88 }
  89
  90 void ltq_mask_and_ack_irq(struct irq_data *d)
  91 {
  92         u32 ier = LTQ_ICU_IM0_IER;
  93         u32 isr = LTQ_ICU_IM0_ISR;
  94         int irq_nr = d->irq - INT_NUM_IRQ0;
  95
  96         ier += LTQ_ICU_OFFSET * (irq_nr / INT_NUM_IM_OFFSET);
  97         isr += LTQ_ICU_OFFSET * (irq_nr / INT_NUM_IM_OFFSET);
  98         irq_nr %= INT_NUM_IM_OFFSET;
  99         ltq_icu_w32(ltq_icu_r32(ier) & ~(1 << irq_nr), ier);
 100         ltq_icu_w32((1 << irq_nr), isr);
 101 }
 102
 103 static void ltq_ack_irq(struct irq_data *d)
 104 {
 105         u32 isr = LTQ_ICU_IM0_ISR;
 106         int irq_nr = d->irq - INT_NUM_IRQ0;
 107
 108         isr += LTQ_ICU_OFFSET * (irq_nr / INT_NUM_IM_OFFSET);
 109         irq_nr %= INT_NUM_IM_OFFSET;
 110         ltq_icu_w32((1 << irq_nr), isr);
 111 }
 112
 113 void ltq_enable_irq(struct irq_data *d)
 114 {
 115         u32 ier = LTQ_ICU_IM0_IER;
 116         int irq_nr = d->irq - INT_NUM_IRQ0;
 117
 118         ier += LTQ_ICU_OFFSET  * (irq_nr / INT_NUM_IM_OFFSET);
 119         irq_nr %= INT_NUM_IM_OFFSET;
 120         ltq_icu_w32(ltq_icu_r32(ier) | (1 << irq_nr), ier);
 121 }
 122
 123 static unsigned int ltq_startup_eiu_irq(struct irq_data *d)
 124 {
 125         int i;
 126         int irq_nr = d->irq - INT_NUM_IRQ0;
 127
 128         ltq_enable_irq(d);
 129         for (i = 0; i < MAX_EIU; i++) {
 130                 if (irq_nr == ltq_eiu_irq[i]) {
 131                         /* low level - we should really handle set_type */
 132                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_C) |
 133                                 (0x6 << (i * 4)), LTQ_EIU_EXIN_C);
 134                         /* clear all pending */
 135                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INIC) & ~(1 << i),
 136                                 LTQ_EIU_EXIN_INIC);
 137                         /* enable */
 138                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | (1 << i),
 139                                 LTQ_EIU_EXIN_INEN);
 140                         break;
 141                 }
 142         }
 143
 144         return 0;
 145 }
 146
 147 static void ltq_shutdown_eiu_irq(struct irq_data *d)
 148 {
 149         int i;
 150         int irq_nr = d->irq - INT_NUM_IRQ0;
 151
 152         ltq_disable_irq(d);
 153         for (i = 0; i < MAX_EIU; i++) {
 154                 if (irq_nr == ltq_eiu_irq[i]) {
 155                         /* disable */
 156                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~(1 << i),
 157                                 LTQ_EIU_EXIN_INEN);
 158                         break;
 159                 }
 160         }
 161 }
 162
 163 static struct irq_chip ltq_irq_type = {
 164         "icu",
 165         .irq_enable = ltq_enable_irq,
 166         .irq_disable = ltq_disable_irq,
 167         .irq_unmask = ltq_enable_irq,
 168         .irq_ack = ltq_ack_irq,
 169         .irq_mask = ltq_disable_irq,
 170         .irq_mask_ack = ltq_mask_and_ack_irq,
 171 };
 172
 173 static struct irq_chip ltq_eiu_type = {
 174         "eiu",
 175         .irq_startup = ltq_startup_eiu_irq,
 176         .irq_shutdown = ltq_shutdown_eiu_irq,
 177         .irq_enable = ltq_enable_irq,
 178         .irq_disable = ltq_disable_irq,
 179         .irq_unmask = ltq_enable_irq,
 180         .irq_ack = ltq_ack_irq,
 181         .irq_mask = ltq_disable_irq,
 182         .irq_mask_ack = ltq_mask_and_ack_irq,
 183 };
 184
 185 static void ltq_hw_irqdispatch(int module)
 186 {
 187         u32 irq;
 188
 189         irq = ltq_icu_r32(LTQ_ICU_IM0_IOSR + (module * LTQ_ICU_OFFSET));
 190         if (irq == 0)
 191                 return;
 192
 193         /* silicon bug causes only the msb set to 1 to be valid. all
 194          * other bits might be bogus
 195          */
 196         irq = __fls(irq);
 197         do_IRQ((int)irq + INT_NUM_IM0_IRL0 + (INT_NUM_IM_OFFSET * module));
 198
 199         /* if this is a EBU irq, we need to ack it or get a deadlock */
 200         if ((irq == LTQ_ICU_EBU_IRQ) && (module == 0))
 201                 ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10,
 202                         LTQ_EBU_PCC_ISTAT);
 203 }
 204
 205 #define DEFINE_HWx_IRQDISPATCH(x)                                       \
 206         static void ltq_hw ## x ## _irqdispatch(void)                   \
 207         {                                                               \
 208                 ltq_hw_irqdispatch(x);                                  \
 209         }
 210 DEFINE_HWx_IRQDISPATCH(0)
 211 DEFINE_HWx_IRQDISPATCH(1)
 212 DEFINE_HWx_IRQDISPATCH(2)
 213 DEFINE_HWx_IRQDISPATCH(3)
 214 DEFINE_HWx_IRQDISPATCH(4)
 215
 216 static void ltq_hw5_irqdispatch(void)
 217 {
 218         do_IRQ(MIPS_CPU_TIMER_IRQ);
 219 }
 220
 221 asmlinkage void plat_irq_dispatch(void)
 222 {
 223         unsigned int pending = read_c0_status() & read_c0_cause() & ST0_IM;
 224         unsigned int i;
 225
 226         if (pending & CAUSEF_IP7) {
 227                 do_IRQ(MIPS_CPU_TIMER_IRQ);
 228                 goto out;
 229         } else {
 230                 for (i = 0; i < 5; i++) {
 231                         if (pending & (CAUSEF_IP2 << i)) {
 232                                 ltq_hw_irqdispatch(i);
 233                                 goto out;
 234                         }
 235                 }
 236         }
 237         pr_alert("Spurious IRQ: CAUSE=0x%08x\n", read_c0_status());
 238
 239 out:
 240         return;
 241 }
 242
 243 static struct irqaction cascade = {
 244         .handler = no_action,
 245         .flags = IRQF_DISABLED,
 246         .name = "cascade",
 247 };
 248
 249 void __init arch_init_irq(void)
 250 {
 251         int i;
 252
 253         if (insert_resource(&iomem_resource, &ltq_icu_resource) < 0)
 254                 panic("Failed to insert icu memory\n");
 255
 256         if (request_mem_region(ltq_icu_resource.start,
 257                         resource_size(&ltq_icu_resource), "icu") < 0)
 258                 panic("Failed to request icu memory\n");
 259
 260         ltq_icu_membase = ioremap_nocache(ltq_icu_resource.start,
 261                                 resource_size(&ltq_icu_resource));
 262         if (!ltq_icu_membase)
 263                 panic("Failed to remap icu memory\n");
 264
 265         if (insert_resource(&iomem_resource, &ltq_eiu_resource) < 0)
 266                 panic("Failed to insert eiu memory\n");
 267
 268         if (request_mem_region(ltq_eiu_resource.start,
 269                         resource_size(&ltq_eiu_resource), "eiu") < 0)
 270                 panic("Failed to request eiu memory\n");
 271
 272         ltq_eiu_membase = ioremap_nocache(ltq_eiu_resource.start,
 273                                 resource_size(&ltq_eiu_resource));
 274         if (!ltq_eiu_membase)
 275                 panic("Failed to remap eiu memory\n");
 276
 277         /* make sure all irqs are turned off by default */
 278         for (i = 0; i < 5; i++)
 279                 ltq_icu_w32(0, LTQ_ICU_IM0_IER + (i * LTQ_ICU_OFFSET));
 280
 281         /* clear all possibly pending interrupts */
 282         ltq_icu_w32(~0, LTQ_ICU_IM0_ISR + (i * LTQ_ICU_OFFSET));
 283
 284         mips_cpu_irq_init();
 285
 286         for (i = 2; i <= 6; i++)
 287                 setup_irq(i, &cascade);
 288
 289         if (cpu_has_vint) {
 290                 pr_info("Setting up vectored interrupts\n");
 291                 set_vi_handler(2, ltq_hw0_irqdispatch);
 292                 set_vi_handler(3, ltq_hw1_irqdispatch);
 293                 set_vi_handler(4, ltq_hw2_irqdispatch);
 294                 set_vi_handler(5, ltq_hw3_irqdispatch);
 295                 set_vi_handler(6, ltq_hw4_irqdispatch);
 296                 set_vi_handler(7, ltq_hw5_irqdispatch);
 297         }
 298
 299         for (i = INT_NUM_IRQ0;
 300                 i <= (INT_NUM_IRQ0 + (5 * INT_NUM_IM_OFFSET)); i++)
 301                 if ((i == LTQ_EIU_IR0) || (i == LTQ_EIU_IR1) ||
 302                         (i == LTQ_EIU_IR2))
 303                         irq_set_chip_and_handler(i, &ltq_eiu_type,
 304                                 handle_level_irq);
 305                 /* EIU3-5 only exist on ar9 and vr9 */
 306                 else if (((i == LTQ_EIU_IR3) || (i == LTQ_EIU_IR4) ||
 307                         (i == LTQ_EIU_IR5)) && (ltq_is_ar9() || ltq_is_vr9()))
 308                         irq_set_chip_and_handler(i, &ltq_eiu_type,
 309                                 handle_level_irq);
 310                 else
 311                         irq_set_chip_and_handler(i, &ltq_irq_type,
 312                                 handle_level_irq);
 313
 314 #if !defined(CONFIG_MIPS_MT_SMP) && !defined(CONFIG_MIPS_MT_SMTC)
 315         set_c0_status(IE_IRQ0 | IE_IRQ1 | IE_IRQ2 |
 316                 IE_IRQ3 | IE_IRQ4 | IE_IRQ5);
 317 #else
 318         set_c0_status(IE_SW0 | IE_SW1 | IE_IRQ0 | IE_IRQ1 |
 319                 IE_IRQ2 | IE_IRQ3 | IE_IRQ4 | IE_IRQ5);
 320 #endif
 321 }
 322
 323 unsigned int __cpuinit get_c0_compare_int(void)
 324 {
 325         return CP0_LEGACY_COMPARE_IRQ;
 326 }