linux/drivers/irqchip/irq-bcm7120-l2.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Broadcom BCM7120 style Level 2 interrupt controller driver
   4 *
   5 * Copyright (C) 2014 Broadcom Corporation
   6 */
   7
   8#define pr_fmt(fmt)     KBUILD_MODNAME  ": " fmt
   9
  10#include <linux/init.h>
  11#include <linux/slab.h>
  12#include <linux/module.h>
  13#include <linux/kernel.h>
  14#include <linux/platform_device.h>
  15#include <linux/of.h>
  16#include <linux/of_irq.h>
  17#include <linux/of_address.h>
  18#include <linux/of_platform.h>
  19#include <linux/interrupt.h>
  20#include <linux/irq.h>
  21#include <linux/io.h>
  22#include <linux/irqdomain.h>
  23#include <linux/reboot.h>
  24#include <linux/bitops.h>
  25#include <linux/irqchip.h>
  26#include <linux/irqchip/chained_irq.h>
  27
  28/* Register offset in the L2 interrupt controller */
  29#define IRQEN           0x00
  30#define IRQSTAT         0x04
  31
  32#define MAX_WORDS       4
  33#define MAX_MAPPINGS    (MAX_WORDS * 2)
  34#define IRQS_PER_WORD   32
  35
  36struct bcm7120_l1_intc_data {
  37        struct bcm7120_l2_intc_data *b;
  38        u32 irq_map_mask[MAX_WORDS];
  39};
  40
  41struct bcm7120_l2_intc_data {
  42        unsigned int n_words;
  43        void __iomem *map_base[MAX_MAPPINGS];
  44        void __iomem *pair_base[MAX_WORDS];
  45        int en_offset[MAX_WORDS];
  46        int stat_offset[MAX_WORDS];
  47        struct irq_domain *domain;
  48        bool can_wake;
  49        u32 irq_fwd_mask[MAX_WORDS];
  50        struct bcm7120_l1_intc_data *l1_data;
  51        int num_parent_irqs;
  52        const __be32 *map_mask_prop;
  53};
  54
  55static void bcm7120_l2_intc_irq_handle(struct irq_desc *desc)
  56{
  57        struct bcm7120_l1_intc_data *data = irq_desc_get_handler_data(desc);
  58        struct bcm7120_l2_intc_data *b = data->b;
  59        struct irq_chip *chip = irq_desc_get_chip(desc);
  60        unsigned int idx;
  61
  62        chained_irq_enter(chip, desc);
  63
  64        for (idx = 0; idx < b->n_words; idx++) {
  65                int base = idx * IRQS_PER_WORD;
  66                struct irq_chip_generic *gc =
  67                        irq_get_domain_generic_chip(b->domain, base);
  68                unsigned long pending;
  69                int hwirq;
  70
  71                irq_gc_lock(gc);
  72                pending = irq_reg_readl(gc, b->stat_offset[idx]) &
  73                                            gc->mask_cache &
  74                                            data->irq_map_mask[idx];
  75                irq_gc_unlock(gc);
  76
  77                for_each_set_bit(hwirq, &pending, IRQS_PER_WORD)
  78                        generic_handle_domain_irq(b->domain, base + hwirq);
  79        }
  80
  81        chained_irq_exit(chip, desc);
  82}
  83
  84static void bcm7120_l2_intc_suspend(struct irq_chip_generic *gc)
  85{
  86        struct bcm7120_l2_intc_data *b = gc->private;
  87        struct irq_chip_type *ct = gc->chip_types;
  88
  89        irq_gc_lock(gc);
  90        if (b->can_wake)
  91                irq_reg_writel(gc, gc->mask_cache | gc->wake_active,
  92                               ct->regs.mask);
  93        irq_gc_unlock(gc);
  94}
  95
  96static void bcm7120_l2_intc_resume(struct irq_chip_generic *gc)
  97{
  98        struct irq_chip_type *ct = gc->chip_types;
  99
 100        /* Restore the saved mask */
 101        irq_gc_lock(gc);
 102        irq_reg_writel(gc, gc->mask_cache, ct->regs.mask);
 103        irq_gc_unlock(gc);
 104}
 105
 106static int bcm7120_l2_intc_init_one(struct device_node *dn,
 107                                        struct bcm7120_l2_intc_data *data,
 108                                        int irq, u32 *valid_mask)
 109{
 110        struct bcm7120_l1_intc_data *l1_data = &data->l1_data[irq];
 111        int parent_irq;
 112        unsigned int idx;
 113
 114        parent_irq = irq_of_parse_and_map(dn, irq);
 115        if (!parent_irq) {
 116                pr_err("failed to map interrupt %d\n", irq);
 117                return -EINVAL;
 118        }
 119
 120        /* For multiple parent IRQs with multiple words, this looks like:
 121         * <irq0_w0 irq0_w1 irq1_w0 irq1_w1 ...>
 122         *
 123         * We need to associate a given parent interrupt with its corresponding
 124         * map_mask in order to mask the status register with it because we
 125         * have the same handler being called for multiple parent interrupts.
 126         *
 127         * This is typically something needed on BCM7xxx (STB chips).
 128         */
 129        for (idx = 0; idx < data->n_words; idx++) {
 130                if (data->map_mask_prop) {
 131                        l1_data->irq_map_mask[idx] |=
 132                                be32_to_cpup(data->map_mask_prop +
 133                                             irq * data->n_words + idx);
 134                } else {
 135                        l1_data->irq_map_mask[idx] = 0xffffffff;
 136                }
 137                valid_mask[idx] |= l1_data->irq_map_mask[idx];
 138        }
 139
 140        l1_data->b = data;
 141
 142        irq_set_chained_handler_and_data(parent_irq,
 143                                         bcm7120_l2_intc_irq_handle, l1_data);
 144        if (data->can_wake)
 145                enable_irq_wake(parent_irq);
 146
 147        return 0;
 148}
 149
 150static int __init bcm7120_l2_intc_iomap_7120(struct device_node *dn,
 151                                             struct bcm7120_l2_intc_data *data)
 152{
 153        int ret;
 154
 155        data->map_base[0] = of_iomap(dn, 0);
 156        if (!data->map_base[0]) {
 157                pr_err("unable to map registers\n");
 158                return -ENOMEM;
 159        }
 160
 161        data->pair_base[0] = data->map_base[0];
 162        data->en_offset[0] = IRQEN;
 163        data->stat_offset[0] = IRQSTAT;
 164        data->n_words = 1;
 165
 166        ret = of_property_read_u32_array(dn, "brcm,int-fwd-mask",
 167                                         data->irq_fwd_mask, data->n_words);
 168        if (ret != 0 && ret != -EINVAL) {
 169                /* property exists but has the wrong number of words */
 170                pr_err("invalid brcm,int-fwd-mask property\n");
 171                return -EINVAL;
 172        }
 173
 174        data->map_mask_prop = of_get_property(dn, "brcm,int-map-mask", &ret);
 175        if (!data->map_mask_prop ||
 176            (ret != (sizeof(__be32) * data->num_parent_irqs * data->n_words))) {
 177                pr_err("invalid brcm,int-map-mask property\n");
 178                return -EINVAL;
 179        }
 180
 181        return 0;
 182}
 183
 184static int __init bcm7120_l2_intc_iomap_3380(struct device_node *dn,
 185                                             struct bcm7120_l2_intc_data *data)
 186{
 187        unsigned int gc_idx;
 188
 189        for (gc_idx = 0; gc_idx < MAX_WORDS; gc_idx++) {
 190                unsigned int map_idx = gc_idx * 2;
 191                void __iomem *en = of_iomap(dn, map_idx + 0);
 192                void __iomem *stat = of_iomap(dn, map_idx + 1);
 193                void __iomem *base = min(en, stat);
 194
 195                data->map_base[map_idx + 0] = en;
 196                data->map_base[map_idx + 1] = stat;
 197
 198                if (!base)
 199                        break;
 200
 201                data->pair_base[gc_idx] = base;
 202                data->en_offset[gc_idx] = en - base;
 203                data->stat_offset[gc_idx] = stat - base;
 204        }
 205
 206        if (!gc_idx) {
 207                pr_err("unable to map registers\n");
 208                return -EINVAL;
 209        }
 210
 211        data->n_words = gc_idx;
 212        return 0;
 213}
 214
 215static int __init bcm7120_l2_intc_probe(struct device_node *dn,
 216                                 struct device_node *parent,
 217                                 int (*iomap_regs_fn)(struct device_node *,
 218                                        struct bcm7120_l2_intc_data *),
 219                                 const char *intc_name)
 220{
 221        unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
 222        struct bcm7120_l2_intc_data *data;
 223        struct platform_device *pdev;
 224        struct irq_chip_generic *gc;
 225        struct irq_chip_type *ct;
 226        int ret = 0;
 227        unsigned int idx, irq, flags;
 228        u32 valid_mask[MAX_WORDS] = { };
 229
 230        data = kzalloc(sizeof(*data), GFP_KERNEL);
 231        if (!data)
 232                return -ENOMEM;
 233
 234        pdev = of_find_device_by_node(dn);
 235        if (!pdev) {
 236                ret = -ENODEV;
 237                goto out_free_data;
 238        }
 239
 240        data->num_parent_irqs = platform_irq_count(pdev);
 241        put_device(&pdev->dev);
 242        if (data->num_parent_irqs <= 0) {
 243                pr_err("invalid number of parent interrupts\n");
 244                ret = -ENOMEM;
 245                goto out_unmap;
 246        }
 247
 248        data->l1_data = kcalloc(data->num_parent_irqs, sizeof(*data->l1_data),
 249                                GFP_KERNEL);
 250        if (!data->l1_data) {
 251                ret = -ENOMEM;
 252                goto out_free_l1_data;
 253        }
 254
 255        ret = iomap_regs_fn(dn, data);
 256        if (ret < 0)
 257                goto out_free_l1_data;
 258
 259        data->can_wake = of_property_read_bool(dn, "brcm,irq-can-wake");
 260
 261        for (irq = 0; irq < data->num_parent_irqs; irq++) {
 262                ret = bcm7120_l2_intc_init_one(dn, data, irq, valid_mask);
 263                if (ret)
 264                        goto out_free_l1_data;
 265        }
 266
 267        data->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * data->n_words,
 268                                             &irq_generic_chip_ops, NULL);
 269        if (!data->domain) {
 270                ret = -ENOMEM;
 271                goto out_free_l1_data;
 272        }
 273
 274        /* MIPS chips strapped for BE will automagically configure the
 275         * peripheral registers for CPU-native byte order.
 276         */
 277        flags = IRQ_GC_INIT_MASK_CACHE;
 278        if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 279                flags |= IRQ_GC_BE_IO;
 280
 281        ret = irq_alloc_domain_generic_chips(data->domain, IRQS_PER_WORD, 1,
 282                                dn->full_name, handle_level_irq, clr, 0, flags);
 283        if (ret) {
 284                pr_err("failed to allocate generic irq chip\n");
 285                goto out_free_domain;
 286        }
 287
 288        for (idx = 0; idx < data->n_words; idx++) {
 289                irq = idx * IRQS_PER_WORD;
 290                gc = irq_get_domain_generic_chip(data->domain, irq);
 291
 292                gc->unused = 0xffffffff & ~valid_mask[idx];
 293                gc->private = data;
 294                ct = gc->chip_types;
 295
 296                gc->reg_base = data->pair_base[idx];
 297                ct->regs.mask = data->en_offset[idx];
 298
 299                /* gc->reg_base is defined and so is gc->writel */
 300                irq_reg_writel(gc, data->irq_fwd_mask[idx],
 301                               data->en_offset[idx]);
 302
 303                ct->chip.irq_mask = irq_gc_mask_clr_bit;
 304                ct->chip.irq_unmask = irq_gc_mask_set_bit;
 305                ct->chip.irq_ack = irq_gc_noop;
 306                gc->suspend = bcm7120_l2_intc_suspend;
 307                gc->resume = bcm7120_l2_intc_resume;
 308
 309                /*
 310                 * Initialize mask-cache, in case we need it for
 311                 * saving/restoring fwd mask even w/o any child interrupts
 312                 * installed
 313                 */
 314                gc->mask_cache = irq_reg_readl(gc, ct->regs.mask);
 315
 316                if (data->can_wake) {
 317                        /* This IRQ chip can wake the system, set all
 318                         * relevant child interrupts in wake_enabled mask
 319                         */
 320                        gc->wake_enabled = 0xffffffff;
 321                        gc->wake_enabled &= ~gc->unused;
 322                        ct->chip.irq_set_wake = irq_gc_set_wake;
 323                }
 324        }
 325
 326        pr_info("registered %s intc (%pOF, parent IRQ(s): %d)\n",
 327                intc_name, dn, data->num_parent_irqs);
 328
 329        return 0;
 330
 331out_free_domain:
 332        irq_domain_remove(data->domain);
 333out_free_l1_data:
 334        kfree(data->l1_data);
 335out_unmap:
 336        for (idx = 0; idx < MAX_MAPPINGS; idx++) {
 337                if (data->map_base[idx])
 338                        iounmap(data->map_base[idx]);
 339        }
 340out_free_data:
 341        kfree(data);
 342        return ret;
 343}
 344
 345static int __init bcm7120_l2_intc_probe_7120(struct device_node *dn,
 346                                             struct device_node *parent)
 347{
 348        return bcm7120_l2_intc_probe(dn, parent, bcm7120_l2_intc_iomap_7120,
 349                                     "BCM7120 L2");
 350}
 351
 352static int __init bcm7120_l2_intc_probe_3380(struct device_node *dn,
 353                                             struct device_node *parent)
 354{
 355        return bcm7120_l2_intc_probe(dn, parent, bcm7120_l2_intc_iomap_3380,
 356                                     "BCM3380 L2");
 357}
 358
 359IRQCHIP_PLATFORM_DRIVER_BEGIN(bcm7120_l2)
 360IRQCHIP_MATCH("brcm,bcm7120-l2-intc", bcm7120_l2_intc_probe_7120)
 361IRQCHIP_MATCH("brcm,bcm3380-l2-intc", bcm7120_l2_intc_probe_3380)
 362IRQCHIP_PLATFORM_DRIVER_END(bcm7120_l2)
 363MODULE_DESCRIPTION("Broadcom STB 7120-style L2 interrupt controller driver");
 364MODULE_LICENSE("GPL v2");
 365