drivers/irqchip/irq-mvebu-sei.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #define pr_fmt(fmt) "mvebu-sei: " fmt
   4
   5 #include <linux/interrupt.h>
   6 #include <linux/irq.h>
   7 #include <linux/irqchip.h>
   8 #include <linux/irqchip/chained_irq.h>
   9 #include <linux/irqdomain.h>
  10 #include <linux/kernel.h>
  11 #include <linux/msi.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/of_address.h>
  14 #include <linux/of_irq.h>
  15 #include <linux/of_platform.h>
  16
  17 /* Cause register */
  18 #define GICP_SECR(idx)          (0x0  + ((idx) * 0x4))
  19 /* Mask register */
  20 #define GICP_SEMR(idx)          (0x20 + ((idx) * 0x4))
  21 #define GICP_SET_SEI_OFFSET     0x30
  22
  23 #define SEI_IRQ_COUNT_PER_REG   32
  24 #define SEI_IRQ_REG_COUNT       2
  25 #define SEI_IRQ_COUNT           (SEI_IRQ_COUNT_PER_REG * SEI_IRQ_REG_COUNT)
  26 #define SEI_IRQ_REG_IDX(irq_id) ((irq_id) / SEI_IRQ_COUNT_PER_REG)
  27 #define SEI_IRQ_REG_BIT(irq_id) ((irq_id) % SEI_IRQ_COUNT_PER_REG)
  28
  29 struct mvebu_sei_interrupt_range {
  30         u32 first;
  31         u32 size;
  32 };
  33
  34 struct mvebu_sei_caps {
  35         struct mvebu_sei_interrupt_range ap_range;
  36         struct mvebu_sei_interrupt_range cp_range;
  37 };
  38
  39 struct mvebu_sei {
  40         struct device *dev;
  41         void __iomem *base;
  42         struct resource *res;
  43         struct irq_domain *sei_domain;
  44         struct irq_domain *ap_domain;
  45         struct irq_domain *cp_domain;
  46         const struct mvebu_sei_caps *caps;
  47
  48         /* Lock on MSI allocations/releases */
  49         struct mutex cp_msi_lock;
  50         DECLARE_BITMAP(cp_msi_bitmap, SEI_IRQ_COUNT);
  51
  52         /* Lock on IRQ masking register */
  53         raw_spinlock_t mask_lock;
  54 };
  55
  56 static void mvebu_sei_ack_irq(struct irq_data *d)
  57 {
  58         struct mvebu_sei *sei = irq_data_get_irq_chip_data(d);
  59         u32 reg_idx = SEI_IRQ_REG_IDX(d->hwirq);
  60
  61         writel_relaxed(BIT(SEI_IRQ_REG_BIT(d->hwirq)),
  62                        sei->base + GICP_SECR(reg_idx));
  63 }
  64
  65 static void mvebu_sei_mask_irq(struct irq_data *d)
  66 {
  67         struct mvebu_sei *sei = irq_data_get_irq_chip_data(d);
  68         u32 reg, reg_idx = SEI_IRQ_REG_IDX(d->hwirq);
  69         unsigned long flags;
  70
  71         /* 1 disables the interrupt */
  72         raw_spin_lock_irqsave(&sei->mask_lock, flags);
  73         reg = readl_relaxed(sei->base + GICP_SEMR(reg_idx));
  74         reg |= BIT(SEI_IRQ_REG_BIT(d->hwirq));
  75         writel_relaxed(reg, sei->base + GICP_SEMR(reg_idx));
  76         raw_spin_unlock_irqrestore(&sei->mask_lock, flags);
  77 }
  78
  79 static void mvebu_sei_unmask_irq(struct irq_data *d)
  80 {
  81         struct mvebu_sei *sei = irq_data_get_irq_chip_data(d);
  82         u32 reg, reg_idx = SEI_IRQ_REG_IDX(d->hwirq);
  83         unsigned long flags;
  84
  85         /* 0 enables the interrupt */
  86         raw_spin_lock_irqsave(&sei->mask_lock, flags);
  87         reg = readl_relaxed(sei->base + GICP_SEMR(reg_idx));
  88         reg &= ~BIT(SEI_IRQ_REG_BIT(d->hwirq));
  89         writel_relaxed(reg, sei->base + GICP_SEMR(reg_idx));
  90         raw_spin_unlock_irqrestore(&sei->mask_lock, flags);
  91 }
  92
  93 static int mvebu_sei_set_affinity(struct irq_data *d,
  94                                   const struct cpumask *mask_val,
  95                                   bool force)
  96 {
  97         return -EINVAL;
  98 }
  99
 100 static int mvebu_sei_set_irqchip_state(struct irq_data *d,
 101                                        enum irqchip_irq_state which,
 102                                        bool state)
 103 {
 104         /* We can only clear the pending state by acking the interrupt */
 105         if (which != IRQCHIP_STATE_PENDING || state)
 106                 return -EINVAL;
 107
 108         mvebu_sei_ack_irq(d);
 109         return 0;
 110 }
 111
 112 static struct irq_chip mvebu_sei_irq_chip = {
 113         .name                   = "SEI",
 114         .irq_ack                = mvebu_sei_ack_irq,
 115         .irq_mask               = mvebu_sei_mask_irq,
 116         .irq_unmask             = mvebu_sei_unmask_irq,
 117         .irq_set_affinity       = mvebu_sei_set_affinity,
 118         .irq_set_irqchip_state  = mvebu_sei_set_irqchip_state,
 119 };
 120
 121 static int mvebu_sei_ap_set_type(struct irq_data *data, unsigned int type)
 122 {
 123         if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_HIGH)
 124                 return -EINVAL;
 125
 126         return 0;
 127 }
 128
 129 static struct irq_chip mvebu_sei_ap_irq_chip = {
 130         .name                   = "AP SEI",
 131         .irq_ack                = irq_chip_ack_parent,
 132         .irq_mask               = irq_chip_mask_parent,
 133         .irq_unmask             = irq_chip_unmask_parent,
 134         .irq_set_affinity       = irq_chip_set_affinity_parent,
 135         .irq_set_type           = mvebu_sei_ap_set_type,
 136 };
 137
 138 static void mvebu_sei_cp_compose_msi_msg(struct irq_data *data,
 139                                          struct msi_msg *msg)
 140 {
 141         struct mvebu_sei *sei = data->chip_data;
 142         phys_addr_t set = sei->res->start + GICP_SET_SEI_OFFSET;
 143
 144         msg->data = data->hwirq + sei->caps->cp_range.first;
 145         msg->address_lo = lower_32_bits(set);
 146         msg->address_hi = upper_32_bits(set);
 147 }
 148
 149 static int mvebu_sei_cp_set_type(struct irq_data *data, unsigned int type)
 150 {
 151         if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_EDGE_RISING)
 152                 return -EINVAL;
 153
 154         return 0;
 155 }
 156
 157 static struct irq_chip mvebu_sei_cp_irq_chip = {
 158         .name                   = "CP SEI",
 159         .irq_ack                = irq_chip_ack_parent,
 160         .irq_mask               = irq_chip_mask_parent,
 161         .irq_unmask             = irq_chip_unmask_parent,
 162         .irq_set_affinity       = irq_chip_set_affinity_parent,
 163         .irq_set_type           = mvebu_sei_cp_set_type,
 164         .irq_compose_msi_msg    = mvebu_sei_cp_compose_msi_msg,
 165 };
 166
 167 static int mvebu_sei_domain_alloc(struct irq_domain *domain, unsigned int virq,
 168                                   unsigned int nr_irqs, void *arg)
 169 {
 170         struct mvebu_sei *sei = domain->host_data;
 171         struct irq_fwspec *fwspec = arg;
 172
 173         /* Not much to do, just setup the irqdata */
 174         irq_domain_set_hwirq_and_chip(domain, virq, fwspec->param[0],
 175                                       &mvebu_sei_irq_chip, sei);
 176
 177         return 0;
 178 }
 179
 180 static void mvebu_sei_domain_free(struct irq_domain *domain, unsigned int virq,
 181                                   unsigned int nr_irqs)
 182 {
 183         int i;
 184
 185         for (i = 0; i < nr_irqs; i++) {
 186                 struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
 187                 irq_set_handler(virq + i, NULL);
 188                 irq_domain_reset_irq_data(d);
 189         }
 190 }
 191
 192 static const struct irq_domain_ops mvebu_sei_domain_ops = {
 193         .alloc  = mvebu_sei_domain_alloc,
 194         .free   = mvebu_sei_domain_free,
 195 };
 196
 197 static int mvebu_sei_ap_translate(struct irq_domain *domain,
 198                                   struct irq_fwspec *fwspec,
 199                                   unsigned long *hwirq,
 200                                   unsigned int *type)
 201 {
 202         *hwirq = fwspec->param[0];
 203         *type  = IRQ_TYPE_LEVEL_HIGH;
 204
 205         return 0;
 206 }
 207
 208 static int mvebu_sei_ap_alloc(struct irq_domain *domain, unsigned int virq,
 209                               unsigned int nr_irqs, void *arg)
 210 {
 211         struct mvebu_sei *sei = domain->host_data;
 212         struct irq_fwspec fwspec;
 213         unsigned long hwirq;
 214         unsigned int type;
 215         int err;
 216
 217         mvebu_sei_ap_translate(domain, arg, &hwirq, &type);
 218
 219         fwspec.fwnode = domain->parent->fwnode;
 220         fwspec.param_count = 1;
 221         fwspec.param[0] = hwirq + sei->caps->ap_range.first;
 222
 223         err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
 224         if (err)
 225                 return err;
 226
 227         irq_domain_set_info(domain, virq, hwirq,
 228                             &mvebu_sei_ap_irq_chip, sei,
 229                             handle_level_irq, NULL, NULL);
 230         irq_set_probe(virq);
 231
 232         return 0;
 233 }
 234
 235 static const struct irq_domain_ops mvebu_sei_ap_domain_ops = {
 236         .translate      = mvebu_sei_ap_translate,
 237         .alloc          = mvebu_sei_ap_alloc,
 238         .free           = irq_domain_free_irqs_parent,
 239 };
 240
 241 static void mvebu_sei_cp_release_irq(struct mvebu_sei *sei, unsigned long hwirq)
 242 {
 243         mutex_lock(&sei->cp_msi_lock);
 244         clear_bit(hwirq, sei->cp_msi_bitmap);
 245         mutex_unlock(&sei->cp_msi_lock);
 246 }
 247
 248 static int mvebu_sei_cp_domain_alloc(struct irq_domain *domain,
 249                                      unsigned int virq, unsigned int nr_irqs,
 250                                      void *args)
 251 {
 252         struct mvebu_sei *sei = domain->host_data;
 253         struct irq_fwspec fwspec;
 254         unsigned long hwirq;
 255         int ret;
 256
 257         /* The software only supports single allocations for now */
 258         if (nr_irqs != 1)
 259                 return -ENOTSUPP;
 260
 261         mutex_lock(&sei->cp_msi_lock);
 262         hwirq = find_first_zero_bit(sei->cp_msi_bitmap,
 263                                     sei->caps->cp_range.size);
 264         if (hwirq < sei->caps->cp_range.size)
 265                 set_bit(hwirq, sei->cp_msi_bitmap);
 266         mutex_unlock(&sei->cp_msi_lock);
 267
 268         if (hwirq == sei->caps->cp_range.size)
 269                 return -ENOSPC;
 270
 271         fwspec.fwnode = domain->parent->fwnode;
 272         fwspec.param_count = 1;
 273         fwspec.param[0] = hwirq + sei->caps->cp_range.first;
 274
 275         ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
 276         if (ret)
 277                 goto free_irq;
 278
 279         irq_domain_set_info(domain, virq, hwirq,
 280                             &mvebu_sei_cp_irq_chip, sei,
 281                             handle_edge_irq, NULL, NULL);
 282
 283         return 0;
 284
 285 free_irq:
 286         mvebu_sei_cp_release_irq(sei, hwirq);
 287         return ret;
 288 }
 289
 290 static void mvebu_sei_cp_domain_free(struct irq_domain *domain,
 291                                      unsigned int virq, unsigned int nr_irqs)
 292 {
 293         struct mvebu_sei *sei = domain->host_data;
 294         struct irq_data *d = irq_domain_get_irq_data(domain, virq);
 295
 296         if (nr_irqs != 1 || d->hwirq >= sei->caps->cp_range.size) {
 297                 dev_err(sei->dev, "Invalid hwirq %lu\n", d->hwirq);
 298                 return;
 299         }
 300
 301         mvebu_sei_cp_release_irq(sei, d->hwirq);
 302         irq_domain_free_irqs_parent(domain, virq, 1);
 303 }
 304
 305 static const struct irq_domain_ops mvebu_sei_cp_domain_ops = {
 306         .alloc  = mvebu_sei_cp_domain_alloc,
 307         .free   = mvebu_sei_cp_domain_free,
 308 };
 309
 310 static struct irq_chip mvebu_sei_msi_irq_chip = {
 311         .name           = "SEI pMSI",
 312         .irq_ack        = irq_chip_ack_parent,
 313         .irq_set_type   = irq_chip_set_type_parent,
 314 };
 315
 316 static struct msi_domain_ops mvebu_sei_msi_ops = {
 317 };
 318
 319 static struct msi_domain_info mvebu_sei_msi_domain_info = {
 320         .flags  = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS,
 321         .ops    = &mvebu_sei_msi_ops,
 322         .chip   = &mvebu_sei_msi_irq_chip,
 323 };
 324
 325 static void mvebu_sei_handle_cascade_irq(struct irq_desc *desc)
 326 {
 327         struct mvebu_sei *sei = irq_desc_get_handler_data(desc);
 328         struct irq_chip *chip = irq_desc_get_chip(desc);
 329         u32 idx;
 330
 331         chained_irq_enter(chip, desc);
 332
 333         for (idx = 0; idx < SEI_IRQ_REG_COUNT; idx++) {
 334                 unsigned long irqmap;
 335                 int bit;
 336
 337                 irqmap = readl_relaxed(sei->base + GICP_SECR(idx));
 338                 for_each_set_bit(bit, &irqmap, SEI_IRQ_COUNT_PER_REG) {
 339                         unsigned long hwirq;
 340                         unsigned int virq;
 341
 342                         hwirq = idx * SEI_IRQ_COUNT_PER_REG + bit;
 343                         virq = irq_find_mapping(sei->sei_domain, hwirq);
 344                         if (likely(virq)) {
 345                                 generic_handle_irq(virq);
 346                                 continue;
 347                         }
 348
 349                         dev_warn(sei->dev,
 350                                  "Spurious IRQ detected (hwirq %lu)\n", hwirq);
 351                 }
 352         }
 353
 354         chained_irq_exit(chip, desc);
 355 }
 356
 357 static void mvebu_sei_reset(struct mvebu_sei *sei)
 358 {
 359         u32 reg_idx;
 360
 361         /* Clear IRQ cause registers, mask all interrupts */
 362         for (reg_idx = 0; reg_idx < SEI_IRQ_REG_COUNT; reg_idx++) {
 363                 writel_relaxed(0xFFFFFFFF, sei->base + GICP_SECR(reg_idx));
 364                 writel_relaxed(0xFFFFFFFF, sei->base + GICP_SEMR(reg_idx));
 365         }
 366 }
 367
 368 static int mvebu_sei_probe(struct platform_device *pdev)
 369 {
 370         struct device_node *node = pdev->dev.of_node;
 371         struct irq_domain *plat_domain;
 372         struct mvebu_sei *sei;
 373         u32 parent_irq;
 374         int ret;
 375
 376         sei = devm_kzalloc(&pdev->dev, sizeof(*sei), GFP_KERNEL);
 377         if (!sei)
 378                 return -ENOMEM;
 379
 380         sei->dev = &pdev->dev;
 381
 382         mutex_init(&sei->cp_msi_lock);
 383         raw_spin_lock_init(&sei->mask_lock);
 384
 385         sei->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 386         sei->base = devm_ioremap_resource(sei->dev, sei->res);
 387         if (IS_ERR(sei->base)) {
 388                 dev_err(sei->dev, "Failed to remap SEI resource\n");
 389                 return PTR_ERR(sei->base);
 390         }
 391
 392         /* Retrieve the SEI capabilities with the interrupt ranges */
 393         sei->caps = of_device_get_match_data(&pdev->dev);
 394         if (!sei->caps) {
 395                 dev_err(sei->dev,
 396                         "Could not retrieve controller capabilities\n");
 397                 return -EINVAL;
 398         }
 399
 400         /*
 401          * Reserve the single (top-level) parent SPI IRQ from which all the
 402          * interrupts handled by this driver will be signaled.
 403          */
 404         parent_irq = irq_of_parse_and_map(node, 0);
 405         if (parent_irq <= 0) {
 406                 dev_err(sei->dev, "Failed to retrieve top-level SPI IRQ\n");
 407                 return -ENODEV;
 408         }
 409
 410         /* Create the root SEI domain */
 411         sei->sei_domain = irq_domain_create_linear(of_node_to_fwnode(node),
 412                                                    (sei->caps->ap_range.size +
 413                                                     sei->caps->cp_range.size),
 414                                                    &mvebu_sei_domain_ops,
 415                                                    sei);
 416         if (!sei->sei_domain) {
 417                 dev_err(sei->dev, "Failed to create SEI IRQ domain\n");
 418                 ret = -ENOMEM;
 419                 goto dispose_irq;
 420         }
 421
 422         irq_domain_update_bus_token(sei->sei_domain, DOMAIN_BUS_NEXUS);
 423
 424         /* Create the 'wired' domain */
 425         sei->ap_domain = irq_domain_create_hierarchy(sei->sei_domain, 0,
 426                                                      sei->caps->ap_range.size,
 427                                                      of_node_to_fwnode(node),
 428                                                      &mvebu_sei_ap_domain_ops,
 429                                                      sei);
 430         if (!sei->ap_domain) {
 431                 dev_err(sei->dev, "Failed to create AP IRQ domain\n");
 432                 ret = -ENOMEM;
 433                 goto remove_sei_domain;
 434         }
 435
 436         irq_domain_update_bus_token(sei->ap_domain, DOMAIN_BUS_WIRED);
 437
 438         /* Create the 'MSI' domain */
 439         sei->cp_domain = irq_domain_create_hierarchy(sei->sei_domain, 0,
 440                                                      sei->caps->cp_range.size,
 441                                                      of_node_to_fwnode(node),
 442                                                      &mvebu_sei_cp_domain_ops,
 443                                                      sei);
 444         if (!sei->cp_domain) {
 445                 pr_err("Failed to create CPs IRQ domain\n");
 446                 ret = -ENOMEM;
 447                 goto remove_ap_domain;
 448         }
 449
 450         irq_domain_update_bus_token(sei->cp_domain, DOMAIN_BUS_GENERIC_MSI);
 451
 452         plat_domain = platform_msi_create_irq_domain(of_node_to_fwnode(node),
 453                                                      &mvebu_sei_msi_domain_info,
 454                                                      sei->cp_domain);
 455         if (!plat_domain) {
 456                 pr_err("Failed to create CPs MSI domain\n");
 457                 ret = -ENOMEM;
 458                 goto remove_cp_domain;
 459         }
 460
 461         mvebu_sei_reset(sei);
 462
 463         irq_set_chained_handler_and_data(parent_irq,
 464                                          mvebu_sei_handle_cascade_irq,
 465                                          sei);
 466
 467         return 0;
 468
 469 remove_cp_domain:
 470         irq_domain_remove(sei->cp_domain);
 471 remove_ap_domain:
 472         irq_domain_remove(sei->ap_domain);
 473 remove_sei_domain:
 474         irq_domain_remove(sei->sei_domain);
 475 dispose_irq:
 476         irq_dispose_mapping(parent_irq);
 477
 478         return ret;
 479 }
 480
 481 static struct mvebu_sei_caps mvebu_sei_ap806_caps = {
 482         .ap_range = {
 483                 .first = 0,
 484                 .size = 21,
 485         },
 486         .cp_range = {
 487                 .first = 21,
 488                 .size = 43,
 489         },
 490 };
 491
 492 static const struct of_device_id mvebu_sei_of_match[] = {
 493         {
 494                 .compatible = "marvell,ap806-sei",
 495                 .data = &mvebu_sei_ap806_caps,
 496         },
 497         {},
 498 };
 499
 500 static struct platform_driver mvebu_sei_driver = {
 501         .probe  = mvebu_sei_probe,
 502         .driver = {
 503                 .name = "mvebu-sei",
 504                 .of_match_table = mvebu_sei_of_match,
 505         },
 506 };
 507 builtin_platform_driver(mvebu_sei_driver);