drivers/irqchip/irq-bcm7120-l2.c

   1 /*
   2  * Broadcom BCM7120 style Level 2 interrupt controller driver
   3  *
   4  * Copyright (C) 2014 Broadcom Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #define pr_fmt(fmt)     KBUILD_MODNAME  ": " fmt
  12
  13 #include <linux/init.h>
  14 #include <linux/slab.h>
  15 #include <linux/module.h>
  16 #include <linux/kconfig.h>
  17 #include <linux/kernel.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/of.h>
  20 #include <linux/of_irq.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_platform.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/irq.h>
  25 #include <linux/io.h>
  26 #include <linux/irqdomain.h>
  27 #include <linux/reboot.h>
  28 #include <linux/bitops.h>
  29 #include <linux/irqchip.h>
  30 #include <linux/irqchip/chained_irq.h>
  31
  32 /* Register offset in the L2 interrupt controller */
  33 #define IRQEN           0x00
  34 #define IRQSTAT         0x04
  35
  36 #define MAX_WORDS       4
  37 #define MAX_MAPPINGS    (MAX_WORDS * 2)
  38 #define IRQS_PER_WORD   32
  39
  40 struct bcm7120_l1_intc_data {
  41         struct bcm7120_l2_intc_data *b;
  42         u32 irq_map_mask[MAX_WORDS];
  43 };
  44
  45 struct bcm7120_l2_intc_data {
  46         unsigned int n_words;
  47         void __iomem *map_base[MAX_MAPPINGS];
  48         void __iomem *pair_base[MAX_WORDS];
  49         int en_offset[MAX_WORDS];
  50         int stat_offset[MAX_WORDS];
  51         struct irq_domain *domain;
  52         bool can_wake;
  53         u32 irq_fwd_mask[MAX_WORDS];
  54         struct bcm7120_l1_intc_data *l1_data;
  55         int num_parent_irqs;
  56         const __be32 *map_mask_prop;
  57 };
  58
  59 static void bcm7120_l2_intc_irq_handle(struct irq_desc *desc)
  60 {
  61         struct bcm7120_l1_intc_data *data = irq_desc_get_handler_data(desc);
  62         struct bcm7120_l2_intc_data *b = data->b;
  63         struct irq_chip *chip = irq_desc_get_chip(desc);
  64         unsigned int idx;
  65
  66         chained_irq_enter(chip, desc);
  67
  68         for (idx = 0; idx < b->n_words; idx++) {
  69                 int base = idx * IRQS_PER_WORD;
  70                 struct irq_chip_generic *gc =
  71                         irq_get_domain_generic_chip(b->domain, base);
  72                 unsigned long pending;
  73                 int hwirq;
  74
  75                 irq_gc_lock(gc);
  76                 pending = irq_reg_readl(gc, b->stat_offset[idx]) &
  77                                             gc->mask_cache &
  78                                             data->irq_map_mask[idx];
  79                 irq_gc_unlock(gc);
  80
  81                 for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
  82                         generic_handle_irq(irq_find_mapping(b->domain,
  83                                            base + hwirq));
  84                 }
  85         }
  86
  87         chained_irq_exit(chip, desc);
  88 }
  89
  90 static void bcm7120_l2_intc_suspend(struct irq_chip_generic *gc)
  91 {
  92         struct bcm7120_l2_intc_data *b = gc->private;
  93         struct irq_chip_type *ct = gc->chip_types;
  94
  95         irq_gc_lock(gc);
  96         if (b->can_wake)
  97                 irq_reg_writel(gc, gc->mask_cache | gc->wake_active,
  98                                ct->regs.mask);
  99         irq_gc_unlock(gc);
 100 }
 101
 102 static void bcm7120_l2_intc_resume(struct irq_chip_generic *gc)
 103 {
 104         struct irq_chip_type *ct = gc->chip_types;
 105
 106         /* Restore the saved mask */
 107         irq_gc_lock(gc);
 108         irq_reg_writel(gc, gc->mask_cache, ct->regs.mask);
 109         irq_gc_unlock(gc);
 110 }
 111
 112 static int bcm7120_l2_intc_init_one(struct device_node *dn,
 113                                         struct bcm7120_l2_intc_data *data,
 114                                         int irq, u32 *valid_mask)
 115 {
 116         struct bcm7120_l1_intc_data *l1_data = &data->l1_data[irq];
 117         int parent_irq;
 118         unsigned int idx;
 119
 120         parent_irq = irq_of_parse_and_map(dn, irq);
 121         if (!parent_irq) {
 122                 pr_err("failed to map interrupt %d\n", irq);
 123                 return -EINVAL;
 124         }
 125
 126         /* For multiple parent IRQs with multiple words, this looks like:
 127          * <irq0_w0 irq0_w1 irq1_w0 irq1_w1 ...>
 128          *
 129          * We need to associate a given parent interrupt with its corresponding
 130          * map_mask in order to mask the status register with it because we
 131          * have the same handler being called for multiple parent interrupts.
 132          *
 133          * This is typically something needed on BCM7xxx (STB chips).
 134          */
 135         for (idx = 0; idx < data->n_words; idx++) {
 136                 if (data->map_mask_prop) {
 137                         l1_data->irq_map_mask[idx] |=
 138                                 be32_to_cpup(data->map_mask_prop +
 139                                              irq * data->n_words + idx);
 140                 } else {
 141                         l1_data->irq_map_mask[idx] = 0xffffffff;
 142                 }
 143                 valid_mask[idx] |= l1_data->irq_map_mask[idx];
 144         }
 145
 146         l1_data->b = data;
 147
 148         irq_set_chained_handler_and_data(parent_irq,
 149                                          bcm7120_l2_intc_irq_handle, l1_data);
 150         return 0;
 151 }
 152
 153 static int __init bcm7120_l2_intc_iomap_7120(struct device_node *dn,
 154                                              struct bcm7120_l2_intc_data *data)
 155 {
 156         int ret;
 157
 158         data->map_base[0] = of_iomap(dn, 0);
 159         if (!data->map_base[0]) {
 160                 pr_err("unable to map registers\n");
 161                 return -ENOMEM;
 162         }
 163
 164         data->pair_base[0] = data->map_base[0];
 165         data->en_offset[0] = IRQEN;
 166         data->stat_offset[0] = IRQSTAT;
 167         data->n_words = 1;
 168
 169         ret = of_property_read_u32_array(dn, "brcm,int-fwd-mask",
 170                                          data->irq_fwd_mask, data->n_words);
 171         if (ret != 0 && ret != -EINVAL) {
 172                 /* property exists but has the wrong number of words */
 173                 pr_err("invalid brcm,int-fwd-mask property\n");
 174                 return -EINVAL;
 175         }
 176
 177         data->map_mask_prop = of_get_property(dn, "brcm,int-map-mask", &ret);
 178         if (!data->map_mask_prop ||
 179             (ret != (sizeof(__be32) * data->num_parent_irqs * data->n_words))) {
 180                 pr_err("invalid brcm,int-map-mask property\n");
 181                 return -EINVAL;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static int __init bcm7120_l2_intc_iomap_3380(struct device_node *dn,
 188                                              struct bcm7120_l2_intc_data *data)
 189 {
 190         unsigned int gc_idx;
 191
 192         for (gc_idx = 0; gc_idx < MAX_WORDS; gc_idx++) {
 193                 unsigned int map_idx = gc_idx * 2;
 194                 void __iomem *en = of_iomap(dn, map_idx + 0);
 195                 void __iomem *stat = of_iomap(dn, map_idx + 1);
 196                 void __iomem *base = min(en, stat);
 197
 198                 data->map_base[map_idx + 0] = en;
 199                 data->map_base[map_idx + 1] = stat;
 200
 201                 if (!base)
 202                         break;
 203
 204                 data->pair_base[gc_idx] = base;
 205                 data->en_offset[gc_idx] = en - base;
 206                 data->stat_offset[gc_idx] = stat - base;
 207         }
 208
 209         if (!gc_idx) {
 210                 pr_err("unable to map registers\n");
 211                 return -EINVAL;
 212         }
 213
 214         data->n_words = gc_idx;
 215         return 0;
 216 }
 217
 218 int __init bcm7120_l2_intc_probe(struct device_node *dn,
 219                                  struct device_node *parent,
 220                                  int (*iomap_regs_fn)(struct device_node *,
 221                                         struct bcm7120_l2_intc_data *),
 222                                  const char *intc_name)
 223 {
 224         unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
 225         struct bcm7120_l2_intc_data *data;
 226         struct irq_chip_generic *gc;
 227         struct irq_chip_type *ct;
 228         int ret = 0;
 229         unsigned int idx, irq, flags;
 230         u32 valid_mask[MAX_WORDS] = { };
 231
 232         data = kzalloc(sizeof(*data), GFP_KERNEL);
 233         if (!data)
 234                 return -ENOMEM;
 235
 236         data->num_parent_irqs = of_irq_count(dn);
 237         if (data->num_parent_irqs <= 0) {
 238                 pr_err("invalid number of parent interrupts\n");
 239                 ret = -ENOMEM;
 240                 goto out_unmap;
 241         }
 242
 243         data->l1_data = kcalloc(data->num_parent_irqs, sizeof(*data->l1_data),
 244                                 GFP_KERNEL);
 245         if (!data->l1_data) {
 246                 ret = -ENOMEM;
 247                 goto out_free_l1_data;
 248         }
 249
 250         ret = iomap_regs_fn(dn, data);
 251         if (ret < 0)
 252                 goto out_free_l1_data;
 253
 254         for (idx = 0; idx < data->n_words; idx++) {
 255                 __raw_writel(data->irq_fwd_mask[idx],
 256                              data->pair_base[idx] +
 257                              data->en_offset[idx]);
 258         }
 259
 260         for (irq = 0; irq < data->num_parent_irqs; irq++) {
 261                 ret = bcm7120_l2_intc_init_one(dn, data, irq, valid_mask);
 262                 if (ret)
 263                         goto out_free_l1_data;
 264         }
 265
 266         data->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * data->n_words,
 267                                              &irq_generic_chip_ops, NULL);
 268         if (!data->domain) {
 269                 ret = -ENOMEM;
 270                 goto out_free_l1_data;
 271         }
 272
 273         /* MIPS chips strapped for BE will automagically configure the
 274          * peripheral registers for CPU-native byte order.
 275          */
 276         flags = IRQ_GC_INIT_MASK_CACHE;
 277         if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 278                 flags |= IRQ_GC_BE_IO;
 279
 280         ret = irq_alloc_domain_generic_chips(data->domain, IRQS_PER_WORD, 1,
 281                                 dn->full_name, handle_level_irq, clr, 0, flags);
 282         if (ret) {
 283                 pr_err("failed to allocate generic irq chip\n");
 284                 goto out_free_domain;
 285         }
 286
 287         if (of_property_read_bool(dn, "brcm,irq-can-wake"))
 288                 data->can_wake = true;
 289
 290         for (idx = 0; idx < data->n_words; idx++) {
 291                 irq = idx * IRQS_PER_WORD;
 292                 gc = irq_get_domain_generic_chip(data->domain, irq);
 293
 294                 gc->unused = 0xffffffff & ~valid_mask[idx];
 295                 gc->private = data;
 296                 ct = gc->chip_types;
 297
 298                 gc->reg_base = data->pair_base[idx];
 299                 ct->regs.mask = data->en_offset[idx];
 300
 301                 ct->chip.irq_mask = irq_gc_mask_clr_bit;
 302                 ct->chip.irq_unmask = irq_gc_mask_set_bit;
 303                 ct->chip.irq_ack = irq_gc_noop;
 304                 gc->suspend = bcm7120_l2_intc_suspend;
 305                 gc->resume = bcm7120_l2_intc_resume;
 306
 307                 /*
 308                  * Initialize mask-cache, in case we need it for
 309                  * saving/restoring fwd mask even w/o any child interrupts
 310                  * installed
 311                  */
 312                 gc->mask_cache = irq_reg_readl(gc, ct->regs.mask);
 313
 314                 if (data->can_wake) {
 315                         /* This IRQ chip can wake the system, set all
 316                          * relevant child interupts in wake_enabled mask
 317                          */
 318                         gc->wake_enabled = 0xffffffff;
 319                         gc->wake_enabled &= ~gc->unused;
 320                         ct->chip.irq_set_wake = irq_gc_set_wake;
 321                 }
 322         }
 323
 324         pr_info("registered %s intc (mem: 0x%p, parent IRQ(s): %d)\n",
 325                         intc_name, data->map_base[0], data->num_parent_irqs);
 326
 327         return 0;
 328
 329 out_free_domain:
 330         irq_domain_remove(data->domain);
 331 out_free_l1_data:
 332         kfree(data->l1_data);
 333 out_unmap:
 334         for (idx = 0; idx < MAX_MAPPINGS; idx++) {
 335                 if (data->map_base[idx])
 336                         iounmap(data->map_base[idx]);
 337         }
 338         kfree(data);
 339         return ret;
 340 }
 341
 342 int __init bcm7120_l2_intc_probe_7120(struct device_node *dn,
 343                                       struct device_node *parent)
 344 {
 345         return bcm7120_l2_intc_probe(dn, parent, bcm7120_l2_intc_iomap_7120,
 346                                      "BCM7120 L2");
 347 }
 348
 349 int __init bcm7120_l2_intc_probe_3380(struct device_node *dn,
 350                                       struct device_node *parent)
 351 {
 352         return bcm7120_l2_intc_probe(dn, parent, bcm7120_l2_intc_iomap_3380,
 353                                      "BCM3380 L2");
 354 }
 355
 356 IRQCHIP_DECLARE(bcm7120_l2_intc, "brcm,bcm7120-l2-intc",
 357                 bcm7120_l2_intc_probe_7120);
 358
 359 IRQCHIP_DECLARE(bcm3380_l2_intc, "brcm,bcm3380-l2-intc",
 360                 bcm7120_l2_intc_probe_3380);