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 <john@phrozen.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_INC        0x0008
  37 #define LTQ_EIU_EXIN_INEN       0x000C
  38
  39 /* number of external interrupts */
  40 #define MAX_EIU                 6
  41
  42 /* the performance counter */
  43 #define LTQ_PERF_IRQ            (INT_NUM_IM4_IRL0 + 31)
  44
  45 /*
  46  * irqs generated by devices attached to the EBU need to be acked in
  47  * a special manner
  48  */
  49 #define LTQ_ICU_EBU_IRQ         22
  50
  51 #define ltq_icu_w32(m, x, y)    ltq_w32((x), ltq_icu_membase[m] + (y))
  52 #define ltq_icu_r32(m, x)       ltq_r32(ltq_icu_membase[m] + (x))
  53
  54 #define ltq_eiu_w32(x, y)       ltq_w32((x), ltq_eiu_membase + (y))
  55 #define ltq_eiu_r32(x)          ltq_r32(ltq_eiu_membase + (x))
  56
  57 /* our 2 ipi interrupts for VSMP */
  58 #define MIPS_CPU_IPI_RESCHED_IRQ        0
  59 #define MIPS_CPU_IPI_CALL_IRQ           1
  60
  61 /* we have a cascade of 8 irqs */
  62 #define MIPS_CPU_IRQ_CASCADE            8
  63
  64 static int exin_avail;
  65 static u32 ltq_eiu_irq[MAX_EIU];
  66 static void __iomem *ltq_icu_membase[MAX_IM];
  67 static void __iomem *ltq_eiu_membase;
  68 static struct irq_domain *ltq_domain;
  69 static int ltq_perfcount_irq;
  70
  71 int ltq_eiu_get_irq(int exin)
  72 {
  73         if (exin < exin_avail)
  74                 return ltq_eiu_irq[exin];
  75         return -1;
  76 }
  77
  78 void ltq_disable_irq(struct irq_data *d)
  79 {
  80         u32 ier = LTQ_ICU_IM0_IER;
  81         int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
  82         int im = offset / INT_NUM_IM_OFFSET;
  83
  84         offset %= INT_NUM_IM_OFFSET;
  85         ltq_icu_w32(im, ltq_icu_r32(im, ier) & ~BIT(offset), ier);
  86 }
  87
  88 void ltq_mask_and_ack_irq(struct irq_data *d)
  89 {
  90         u32 ier = LTQ_ICU_IM0_IER;
  91         u32 isr = LTQ_ICU_IM0_ISR;
  92         int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
  93         int im = offset / INT_NUM_IM_OFFSET;
  94
  95         offset %= INT_NUM_IM_OFFSET;
  96         ltq_icu_w32(im, ltq_icu_r32(im, ier) & ~BIT(offset), ier);
  97         ltq_icu_w32(im, BIT(offset), isr);
  98 }
  99
 100 static void ltq_ack_irq(struct irq_data *d)
 101 {
 102         u32 isr = LTQ_ICU_IM0_ISR;
 103         int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
 104         int im = offset / INT_NUM_IM_OFFSET;
 105
 106         offset %= INT_NUM_IM_OFFSET;
 107         ltq_icu_w32(im, BIT(offset), isr);
 108 }
 109
 110 void ltq_enable_irq(struct irq_data *d)
 111 {
 112         u32 ier = LTQ_ICU_IM0_IER;
 113         int offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
 114         int im = offset / INT_NUM_IM_OFFSET;
 115
 116         offset %= INT_NUM_IM_OFFSET;
 117         ltq_icu_w32(im, ltq_icu_r32(im, ier) | BIT(offset), ier);
 118 }
 119
 120 static int ltq_eiu_settype(struct irq_data *d, unsigned int type)
 121 {
 122         int i;
 123
 124         for (i = 0; i < exin_avail; i++) {
 125                 if (d->hwirq == ltq_eiu_irq[i]) {
 126                         int val = 0;
 127                         int edge = 0;
 128
 129                         switch (type) {
 130                         case IRQF_TRIGGER_NONE:
 131                                 break;
 132                         case IRQF_TRIGGER_RISING:
 133                                 val = 1;
 134                                 edge = 1;
 135                                 break;
 136                         case IRQF_TRIGGER_FALLING:
 137                                 val = 2;
 138                                 edge = 1;
 139                                 break;
 140                         case IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING:
 141                                 val = 3;
 142                                 edge = 1;
 143                                 break;
 144                         case IRQF_TRIGGER_HIGH:
 145                                 val = 5;
 146                                 break;
 147                         case IRQF_TRIGGER_LOW:
 148                                 val = 6;
 149                                 break;
 150                         default:
 151                                 pr_err("invalid type %d for irq %ld\n",
 152                                         type, d->hwirq);
 153                                 return -EINVAL;
 154                         }
 155
 156                         if (edge)
 157                                 irq_set_handler(d->hwirq, handle_edge_irq);
 158
 159                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_C) |
 160                                 (val << (i * 4)), LTQ_EIU_EXIN_C);
 161                 }
 162         }
 163
 164         return 0;
 165 }
 166
 167 static unsigned int ltq_startup_eiu_irq(struct irq_data *d)
 168 {
 169         int i;
 170
 171         ltq_enable_irq(d);
 172         for (i = 0; i < exin_avail; i++) {
 173                 if (d->hwirq == ltq_eiu_irq[i]) {
 174                         /* by default we are low level triggered */
 175                         ltq_eiu_settype(d, IRQF_TRIGGER_LOW);
 176                         /* clear all pending */
 177                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INC) & ~BIT(i),
 178                                 LTQ_EIU_EXIN_INC);
 179                         /* enable */
 180                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | BIT(i),
 181                                 LTQ_EIU_EXIN_INEN);
 182                         break;
 183                 }
 184         }
 185
 186         return 0;
 187 }
 188
 189 static void ltq_shutdown_eiu_irq(struct irq_data *d)
 190 {
 191         int i;
 192
 193         ltq_disable_irq(d);
 194         for (i = 0; i < exin_avail; i++) {
 195                 if (d->hwirq == ltq_eiu_irq[i]) {
 196                         /* disable */
 197                         ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~BIT(i),
 198                                 LTQ_EIU_EXIN_INEN);
 199                         break;
 200                 }
 201         }
 202 }
 203
 204 static struct irq_chip ltq_irq_type = {
 205         .name = "icu",
 206         .irq_enable = ltq_enable_irq,
 207         .irq_disable = ltq_disable_irq,
 208         .irq_unmask = ltq_enable_irq,
 209         .irq_ack = ltq_ack_irq,
 210         .irq_mask = ltq_disable_irq,
 211         .irq_mask_ack = ltq_mask_and_ack_irq,
 212 };
 213
 214 static struct irq_chip ltq_eiu_type = {
 215         .name = "eiu",
 216         .irq_startup = ltq_startup_eiu_irq,
 217         .irq_shutdown = ltq_shutdown_eiu_irq,
 218         .irq_enable = ltq_enable_irq,
 219         .irq_disable = ltq_disable_irq,
 220         .irq_unmask = ltq_enable_irq,
 221         .irq_ack = ltq_ack_irq,
 222         .irq_mask = ltq_disable_irq,
 223         .irq_mask_ack = ltq_mask_and_ack_irq,
 224         .irq_set_type = ltq_eiu_settype,
 225 };
 226
 227 static void ltq_hw_irq_handler(struct irq_desc *desc)
 228 {
 229         int module = irq_desc_get_irq(desc) - 2;
 230         u32 irq;
 231         int hwirq;
 232
 233         irq = ltq_icu_r32(module, LTQ_ICU_IM0_IOSR);
 234         if (irq == 0)
 235                 return;
 236
 237         /*
 238          * silicon bug causes only the msb set to 1 to be valid. all
 239          * other bits might be bogus
 240          */
 241         irq = __fls(irq);
 242         hwirq = irq + MIPS_CPU_IRQ_CASCADE + (INT_NUM_IM_OFFSET * module);
 243         generic_handle_irq(irq_linear_revmap(ltq_domain, hwirq));
 244
 245         /* if this is a EBU irq, we need to ack it or get a deadlock */
 246         if ((irq == LTQ_ICU_EBU_IRQ) && (module == 0) && LTQ_EBU_PCC_ISTAT)
 247                 ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10,
 248                         LTQ_EBU_PCC_ISTAT);
 249 }
 250
 251 static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
 252 {
 253         struct irq_chip *chip = &ltq_irq_type;
 254         int i;
 255
 256         if (hw < MIPS_CPU_IRQ_CASCADE)
 257                 return 0;
 258
 259         for (i = 0; i < exin_avail; i++)
 260                 if (hw == ltq_eiu_irq[i])
 261                         chip = &ltq_eiu_type;
 262
 263         irq_set_chip_and_handler(irq, chip, handle_level_irq);
 264
 265         return 0;
 266 }
 267
 268 static const struct irq_domain_ops irq_domain_ops = {
 269         .xlate = irq_domain_xlate_onetwocell,
 270         .map = icu_map,
 271 };
 272
 273 int __init icu_of_init(struct device_node *node, struct device_node *parent)
 274 {
 275         struct device_node *eiu_node;
 276         struct resource res;
 277         int i, ret;
 278
 279         for (i = 0; i < MAX_IM; i++) {
 280                 if (of_address_to_resource(node, i, &res))
 281                         panic("Failed to get icu memory range");
 282
 283                 if (!request_mem_region(res.start, resource_size(&res),
 284                                         res.name))
 285                         pr_err("Failed to request icu memory");
 286
 287                 ltq_icu_membase[i] = ioremap_nocache(res.start,
 288                                         resource_size(&res));
 289                 if (!ltq_icu_membase[i])
 290                         panic("Failed to remap icu memory");
 291         }
 292
 293         /* turn off all irqs by default */
 294         for (i = 0; i < MAX_IM; i++) {
 295                 /* make sure all irqs are turned off by default */
 296                 ltq_icu_w32(i, 0, LTQ_ICU_IM0_IER);
 297                 /* clear all possibly pending interrupts */
 298                 ltq_icu_w32(i, ~0, LTQ_ICU_IM0_ISR);
 299         }
 300
 301         mips_cpu_irq_init();
 302
 303         for (i = 0; i < MAX_IM; i++)
 304                 irq_set_chained_handler(i + 2, ltq_hw_irq_handler);
 305
 306         ltq_domain = irq_domain_add_linear(node,
 307                 (MAX_IM * INT_NUM_IM_OFFSET) + MIPS_CPU_IRQ_CASCADE,
 308                 &irq_domain_ops, 0);
 309
 310         /* tell oprofile which irq to use */
 311         ltq_perfcount_irq = irq_create_mapping(ltq_domain, LTQ_PERF_IRQ);
 312
 313         /* the external interrupts are optional and xway only */
 314         eiu_node = of_find_compatible_node(NULL, NULL, "lantiq,eiu-xway");
 315         if (eiu_node && !of_address_to_resource(eiu_node, 0, &res)) {
 316                 /* find out how many external irq sources we have */
 317                 exin_avail = of_property_count_u32_elems(eiu_node,
 318                                                          "lantiq,eiu-irqs");
 319
 320                 if (exin_avail > MAX_EIU)
 321                         exin_avail = MAX_EIU;
 322
 323                 ret = of_property_read_u32_array(eiu_node, "lantiq,eiu-irqs",
 324                                                 ltq_eiu_irq, exin_avail);
 325                 if (ret)
 326                         panic("failed to load external irq resources");
 327
 328                 if (!request_mem_region(res.start, resource_size(&res),
 329                                                         res.name))
 330                         pr_err("Failed to request eiu memory");
 331
 332                 ltq_eiu_membase = ioremap_nocache(res.start,
 333                                                         resource_size(&res));
 334                 if (!ltq_eiu_membase)
 335                         panic("Failed to remap eiu memory");
 336         }
 337
 338         return 0;
 339 }
 340
 341 int get_c0_perfcount_int(void)
 342 {
 343         return ltq_perfcount_irq;
 344 }
 345 EXPORT_SYMBOL_GPL(get_c0_perfcount_int);
 346
 347 unsigned int get_c0_compare_int(void)
 348 {
 349         return CP0_LEGACY_COMPARE_IRQ;
 350 }
 351
 352 static struct of_device_id __initdata of_irq_ids[] = {
 353         { .compatible = "lantiq,icu", .data = icu_of_init },
 354         {},
 355 };
 356
 357 void __init arch_init_irq(void)
 358 {
 359         of_irq_init(of_irq_ids);
 360 }