drivers/irqchip/irq-bcm7038-l1.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Broadcom BCM7038 style Level 1 interrupt controller driver
   4  *
   5  * Copyright (C) 2014 Broadcom Corporation
   6  * Author: Kevin Cernekee
   7  */
   8
   9 #define pr_fmt(fmt)     KBUILD_MODNAME  ": " fmt
  10
  11 #include <linux/bitops.h>
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/io.h>
  16 #include <linux/ioport.h>
  17 #include <linux/irq.h>
  18 #include <linux/irqdomain.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_irq.h>
  22 #include <linux/of_address.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/slab.h>
  25 #include <linux/smp.h>
  26 #include <linux/types.h>
  27 #include <linux/irqchip.h>
  28 #include <linux/irqchip/chained_irq.h>
  29 #include <linux/syscore_ops.h>
  30
  31 #define IRQS_PER_WORD           32
  32 #define REG_BYTES_PER_IRQ_WORD  (sizeof(u32) * 4)
  33 #define MAX_WORDS               8
  34
  35 struct bcm7038_l1_cpu;
  36
  37 struct bcm7038_l1_chip {
  38         raw_spinlock_t          lock;
  39         unsigned int            n_words;
  40         struct irq_domain       *domain;
  41         struct bcm7038_l1_cpu   *cpus[NR_CPUS];
  42 #ifdef CONFIG_PM_SLEEP
  43         struct list_head        list;
  44         u32                     wake_mask[MAX_WORDS];
  45 #endif
  46         u32                     irq_fwd_mask[MAX_WORDS];
  47         u8                      affinity[MAX_WORDS * IRQS_PER_WORD];
  48 };
  49
  50 struct bcm7038_l1_cpu {
  51         void __iomem            *map_base;
  52         u32                     mask_cache[];
  53 };
  54
  55 /*
  56  * STATUS/MASK_STATUS/MASK_SET/MASK_CLEAR are packed one right after another:
  57  *
  58  * 7038:
  59  *   0x1000_1400: W0_STATUS
  60  *   0x1000_1404: W1_STATUS
  61  *   0x1000_1408: W0_MASK_STATUS
  62  *   0x1000_140c: W1_MASK_STATUS
  63  *   0x1000_1410: W0_MASK_SET
  64  *   0x1000_1414: W1_MASK_SET
  65  *   0x1000_1418: W0_MASK_CLEAR
  66  *   0x1000_141c: W1_MASK_CLEAR
  67  *
  68  * 7445:
  69  *   0xf03e_1500: W0_STATUS
  70  *   0xf03e_1504: W1_STATUS
  71  *   0xf03e_1508: W2_STATUS
  72  *   0xf03e_150c: W3_STATUS
  73  *   0xf03e_1510: W4_STATUS
  74  *   0xf03e_1514: W0_MASK_STATUS
  75  *   0xf03e_1518: W1_MASK_STATUS
  76  *   [...]
  77  */
  78
  79 static inline unsigned int reg_status(struct bcm7038_l1_chip *intc,
  80                                       unsigned int word)
  81 {
  82         return (0 * intc->n_words + word) * sizeof(u32);
  83 }
  84
  85 static inline unsigned int reg_mask_status(struct bcm7038_l1_chip *intc,
  86                                            unsigned int word)
  87 {
  88         return (1 * intc->n_words + word) * sizeof(u32);
  89 }
  90
  91 static inline unsigned int reg_mask_set(struct bcm7038_l1_chip *intc,
  92                                         unsigned int word)
  93 {
  94         return (2 * intc->n_words + word) * sizeof(u32);
  95 }
  96
  97 static inline unsigned int reg_mask_clr(struct bcm7038_l1_chip *intc,
  98                                         unsigned int word)
  99 {
 100         return (3 * intc->n_words + word) * sizeof(u32);
 101 }
 102
 103 static inline u32 l1_readl(void __iomem *reg)
 104 {
 105         if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 106                 return ioread32be(reg);
 107         else
 108                 return readl(reg);
 109 }
 110
 111 static inline void l1_writel(u32 val, void __iomem *reg)
 112 {
 113         if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
 114                 iowrite32be(val, reg);
 115         else
 116                 writel(val, reg);
 117 }
 118
 119 static void bcm7038_l1_irq_handle(struct irq_desc *desc)
 120 {
 121         struct bcm7038_l1_chip *intc = irq_desc_get_handler_data(desc);
 122         struct bcm7038_l1_cpu *cpu;
 123         struct irq_chip *chip = irq_desc_get_chip(desc);
 124         unsigned int idx;
 125
 126 #if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
 127         cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
 128 #else
 129         cpu = intc->cpus[0];
 130 #endif
 131
 132         chained_irq_enter(chip, desc);
 133
 134         for (idx = 0; idx < intc->n_words; idx++) {
 135                 int base = idx * IRQS_PER_WORD;
 136                 unsigned long pending, flags;
 137                 int hwirq;
 138
 139                 raw_spin_lock_irqsave(&intc->lock, flags);
 140                 pending = l1_readl(cpu->map_base + reg_status(intc, idx)) &
 141                           ~cpu->mask_cache[idx];
 142                 raw_spin_unlock_irqrestore(&intc->lock, flags);
 143
 144                 for_each_set_bit(hwirq, &pending, IRQS_PER_WORD)
 145                         generic_handle_domain_irq(intc->domain, base + hwirq);
 146         }
 147
 148         chained_irq_exit(chip, desc);
 149 }
 150
 151 static void __bcm7038_l1_unmask(struct irq_data *d, unsigned int cpu_idx)
 152 {
 153         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 154         u32 word = d->hwirq / IRQS_PER_WORD;
 155         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 156
 157         intc->cpus[cpu_idx]->mask_cache[word] &= ~mask;
 158         l1_writel(mask, intc->cpus[cpu_idx]->map_base +
 159                         reg_mask_clr(intc, word));
 160 }
 161
 162 static void __bcm7038_l1_mask(struct irq_data *d, unsigned int cpu_idx)
 163 {
 164         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 165         u32 word = d->hwirq / IRQS_PER_WORD;
 166         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 167
 168         intc->cpus[cpu_idx]->mask_cache[word] |= mask;
 169         l1_writel(mask, intc->cpus[cpu_idx]->map_base +
 170                         reg_mask_set(intc, word));
 171 }
 172
 173 static void bcm7038_l1_unmask(struct irq_data *d)
 174 {
 175         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 176         unsigned long flags;
 177
 178         raw_spin_lock_irqsave(&intc->lock, flags);
 179         __bcm7038_l1_unmask(d, intc->affinity[d->hwirq]);
 180         raw_spin_unlock_irqrestore(&intc->lock, flags);
 181 }
 182
 183 static void bcm7038_l1_mask(struct irq_data *d)
 184 {
 185         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 186         unsigned long flags;
 187
 188         raw_spin_lock_irqsave(&intc->lock, flags);
 189         __bcm7038_l1_mask(d, intc->affinity[d->hwirq]);
 190         raw_spin_unlock_irqrestore(&intc->lock, flags);
 191 }
 192
 193 #if defined(CONFIG_MIPS) && defined(CONFIG_SMP)
 194 static int bcm7038_l1_set_affinity(struct irq_data *d,
 195                                    const struct cpumask *dest,
 196                                    bool force)
 197 {
 198         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 199         unsigned long flags;
 200         irq_hw_number_t hw = d->hwirq;
 201         u32 word = hw / IRQS_PER_WORD;
 202         u32 mask = BIT(hw % IRQS_PER_WORD);
 203         unsigned int first_cpu = cpumask_any_and(dest, cpu_online_mask);
 204         bool was_disabled;
 205
 206         raw_spin_lock_irqsave(&intc->lock, flags);
 207
 208         was_disabled = !!(intc->cpus[intc->affinity[hw]]->mask_cache[word] &
 209                           mask);
 210         __bcm7038_l1_mask(d, intc->affinity[hw]);
 211         intc->affinity[hw] = first_cpu;
 212         if (!was_disabled)
 213                 __bcm7038_l1_unmask(d, first_cpu);
 214
 215         raw_spin_unlock_irqrestore(&intc->lock, flags);
 216         irq_data_update_effective_affinity(d, cpumask_of(first_cpu));
 217
 218         return 0;
 219 }
 220 #endif
 221
 222 static int __init bcm7038_l1_init_one(struct device_node *dn,
 223                                       unsigned int idx,
 224                                       struct bcm7038_l1_chip *intc)
 225 {
 226         struct resource res;
 227         resource_size_t sz;
 228         struct bcm7038_l1_cpu *cpu;
 229         unsigned int i, n_words, parent_irq;
 230         int ret;
 231
 232         if (of_address_to_resource(dn, idx, &res))
 233                 return -EINVAL;
 234         sz = resource_size(&res);
 235         n_words = sz / REG_BYTES_PER_IRQ_WORD;
 236
 237         if (n_words > MAX_WORDS)
 238                 return -EINVAL;
 239         else if (!intc->n_words)
 240                 intc->n_words = n_words;
 241         else if (intc->n_words != n_words)
 242                 return -EINVAL;
 243
 244         ret = of_property_read_u32_array(dn , "brcm,int-fwd-mask",
 245                                          intc->irq_fwd_mask, n_words);
 246         if (ret != 0 && ret != -EINVAL) {
 247                 /* property exists but has the wrong number of words */
 248                 pr_err("invalid brcm,int-fwd-mask property\n");
 249                 return -EINVAL;
 250         }
 251
 252         cpu = intc->cpus[idx] = kzalloc(struct_size(cpu, mask_cache, n_words),
 253                                         GFP_KERNEL);
 254         if (!cpu)
 255                 return -ENOMEM;
 256
 257         cpu->map_base = ioremap(res.start, sz);
 258         if (!cpu->map_base)
 259                 return -ENOMEM;
 260
 261         for (i = 0; i < n_words; i++) {
 262                 l1_writel(~intc->irq_fwd_mask[i],
 263                           cpu->map_base + reg_mask_set(intc, i));
 264                 l1_writel(intc->irq_fwd_mask[i],
 265                           cpu->map_base + reg_mask_clr(intc, i));
 266                 cpu->mask_cache[i] = ~intc->irq_fwd_mask[i];
 267         }
 268
 269         parent_irq = irq_of_parse_and_map(dn, idx);
 270         if (!parent_irq) {
 271                 pr_err("failed to map parent interrupt %d\n", parent_irq);
 272                 return -EINVAL;
 273         }
 274
 275         if (of_property_read_bool(dn, "brcm,irq-can-wake"))
 276                 enable_irq_wake(parent_irq);
 277
 278         irq_set_chained_handler_and_data(parent_irq, bcm7038_l1_irq_handle,
 279                                          intc);
 280
 281         return 0;
 282 }
 283
 284 #ifdef CONFIG_PM_SLEEP
 285 /*
 286  * We keep a list of bcm7038_l1_chip used for suspend/resume. This hack is
 287  * used because the struct chip_type suspend/resume hooks are not called
 288  * unless chip_type is hooked onto a generic_chip. Since this driver does
 289  * not use generic_chip, we need to manually hook our resume/suspend to
 290  * syscore_ops.
 291  */
 292 static LIST_HEAD(bcm7038_l1_intcs_list);
 293 static DEFINE_RAW_SPINLOCK(bcm7038_l1_intcs_lock);
 294
 295 static int bcm7038_l1_suspend(void)
 296 {
 297         struct bcm7038_l1_chip *intc;
 298         int boot_cpu, word;
 299         u32 val;
 300
 301         /* Wakeup interrupt should only come from the boot cpu */
 302 #if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
 303         boot_cpu = cpu_logical_map(0);
 304 #else
 305         boot_cpu = 0;
 306 #endif
 307
 308         list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
 309                 for (word = 0; word < intc->n_words; word++) {
 310                         val = intc->wake_mask[word] | intc->irq_fwd_mask[word];
 311                         l1_writel(~val,
 312                                 intc->cpus[boot_cpu]->map_base + reg_mask_set(intc, word));
 313                         l1_writel(val,
 314                                 intc->cpus[boot_cpu]->map_base + reg_mask_clr(intc, word));
 315                 }
 316         }
 317
 318         return 0;
 319 }
 320
 321 static void bcm7038_l1_resume(void)
 322 {
 323         struct bcm7038_l1_chip *intc;
 324         int boot_cpu, word;
 325
 326 #if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
 327         boot_cpu = cpu_logical_map(0);
 328 #else
 329         boot_cpu = 0;
 330 #endif
 331
 332         list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
 333                 for (word = 0; word < intc->n_words; word++) {
 334                         l1_writel(intc->cpus[boot_cpu]->mask_cache[word],
 335                                 intc->cpus[boot_cpu]->map_base + reg_mask_set(intc, word));
 336                         l1_writel(~intc->cpus[boot_cpu]->mask_cache[word],
 337                                 intc->cpus[boot_cpu]->map_base + reg_mask_clr(intc, word));
 338                 }
 339         }
 340 }
 341
 342 static struct syscore_ops bcm7038_l1_syscore_ops = {
 343         .suspend        = bcm7038_l1_suspend,
 344         .resume         = bcm7038_l1_resume,
 345 };
 346
 347 static int bcm7038_l1_set_wake(struct irq_data *d, unsigned int on)
 348 {
 349         struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
 350         unsigned long flags;
 351         u32 word = d->hwirq / IRQS_PER_WORD;
 352         u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
 353
 354         raw_spin_lock_irqsave(&intc->lock, flags);
 355         if (on)
 356                 intc->wake_mask[word] |= mask;
 357         else
 358                 intc->wake_mask[word] &= ~mask;
 359         raw_spin_unlock_irqrestore(&intc->lock, flags);
 360
 361         return 0;
 362 }
 363 #endif
 364
 365 static struct irq_chip bcm7038_l1_irq_chip = {
 366         .name                   = "bcm7038-l1",
 367         .irq_mask               = bcm7038_l1_mask,
 368         .irq_unmask             = bcm7038_l1_unmask,
 369 #if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
 370         .irq_set_affinity       = bcm7038_l1_set_affinity,
 371 #endif
 372 #ifdef CONFIG_PM_SLEEP
 373         .irq_set_wake           = bcm7038_l1_set_wake,
 374 #endif
 375 };
 376
 377 static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
 378                           irq_hw_number_t hw_irq)
 379 {
 380         struct bcm7038_l1_chip *intc = d->host_data;
 381         u32 mask = BIT(hw_irq % IRQS_PER_WORD);
 382         u32 word = hw_irq / IRQS_PER_WORD;
 383
 384         if (intc->irq_fwd_mask[word] & mask)
 385                 return -EPERM;
 386
 387         irq_set_chip_and_handler(virq, &bcm7038_l1_irq_chip, handle_level_irq);
 388         irq_set_chip_data(virq, d->host_data);
 389         irqd_set_single_target(irq_get_irq_data(virq));
 390         return 0;
 391 }
 392
 393 static const struct irq_domain_ops bcm7038_l1_domain_ops = {
 394         .xlate                  = irq_domain_xlate_onecell,
 395         .map                    = bcm7038_l1_map,
 396 };
 397
 398 static int __init bcm7038_l1_of_init(struct device_node *dn,
 399                               struct device_node *parent)
 400 {
 401         struct bcm7038_l1_chip *intc;
 402         int idx, ret;
 403
 404         intc = kzalloc(sizeof(*intc), GFP_KERNEL);
 405         if (!intc)
 406                 return -ENOMEM;
 407
 408         raw_spin_lock_init(&intc->lock);
 409         for_each_possible_cpu(idx) {
 410                 ret = bcm7038_l1_init_one(dn, idx, intc);
 411                 if (ret < 0) {
 412                         if (idx)
 413                                 break;
 414                         pr_err("failed to remap intc L1 registers\n");
 415                         goto out_free;
 416                 }
 417         }
 418
 419         intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
 420                                              &bcm7038_l1_domain_ops,
 421                                              intc);
 422         if (!intc->domain) {
 423                 ret = -ENOMEM;
 424                 goto out_unmap;
 425         }
 426
 427 #ifdef CONFIG_PM_SLEEP
 428         /* Add bcm7038_l1_chip into a list */
 429         raw_spin_lock(&bcm7038_l1_intcs_lock);
 430         list_add_tail(&intc->list, &bcm7038_l1_intcs_list);
 431         raw_spin_unlock(&bcm7038_l1_intcs_lock);
 432
 433         if (list_is_singular(&bcm7038_l1_intcs_list))
 434                 register_syscore_ops(&bcm7038_l1_syscore_ops);
 435 #endif
 436
 437         pr_info("registered BCM7038 L1 intc (%pOF, IRQs: %d)\n",
 438                 dn, IRQS_PER_WORD * intc->n_words);
 439
 440         return 0;
 441
 442 out_unmap:
 443         for_each_possible_cpu(idx) {
 444                 struct bcm7038_l1_cpu *cpu = intc->cpus[idx];
 445
 446                 if (cpu) {
 447                         if (cpu->map_base)
 448                                 iounmap(cpu->map_base);
 449                         kfree(cpu);
 450                 }
 451         }
 452 out_free:
 453         kfree(intc);
 454         return ret;
 455 }
 456
 457 IRQCHIP_PLATFORM_DRIVER_BEGIN(bcm7038_l1)
 458 IRQCHIP_MATCH("brcm,bcm7038-l1-intc", bcm7038_l1_of_init)
 459 IRQCHIP_PLATFORM_DRIVER_END(bcm7038_l1)
 460 MODULE_DESCRIPTION("Broadcom STB 7038-style L1/L2 interrupt controller");
 461 MODULE_LICENSE("GPL v2");