drivers/irqchip/irq-renesas-intc-irqpin.c

   1 /*
   2  * Renesas INTC External IRQ Pin Driver
   3  *
   4  *  Copyright (C) 2013 Magnus Damm
   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 as published by
   8  * the Free Software Foundation; either version 2 of the License
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include <linux/init.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/ioport.h>
  25 #include <linux/io.h>
  26 #include <linux/irq.h>
  27 #include <linux/irqdomain.h>
  28 #include <linux/err.h>
  29 #include <linux/slab.h>
  30 #include <linux/module.h>
  31 #include <linux/platform_data/irq-renesas-intc-irqpin.h>
  32
  33 #define INTC_IRQPIN_MAX 8 /* maximum 8 interrupts per driver instance */
  34
  35 #define INTC_IRQPIN_REG_SENSE 0 /* ICRn */
  36 #define INTC_IRQPIN_REG_PRIO 1 /* INTPRInn */
  37 #define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
  38 #define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
  39 #define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
  40 #define INTC_IRQPIN_REG_NR 5
  41
  42 /* INTC external IRQ PIN hardware register access:
  43  *
  44  * SENSE is read-write 32-bit with 2-bits or 4-bits per IRQ (*)
  45  * PRIO is read-write 32-bit with 4-bits per IRQ (**)
  46  * SOURCE is read-only 32-bit or 8-bit with 1-bit per IRQ (***)
  47  * MASK is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
  48  * CLEAR is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
  49  *
  50  * (*) May be accessed by more than one driver instance - lock needed
  51  * (**) Read-modify-write access by one driver instance - lock needed
  52  * (***) Accessed by one driver instance only - no locking needed
  53  */
  54
  55 struct intc_irqpin_iomem {
  56         void __iomem *iomem;
  57         unsigned long (*read)(void __iomem *iomem);
  58         void (*write)(void __iomem *iomem, unsigned long data);
  59         int width;
  60 };
  61
  62 struct intc_irqpin_irq {
  63         int hw_irq;
  64         int requested_irq;
  65         int domain_irq;
  66         struct intc_irqpin_priv *p;
  67 };
  68
  69 struct intc_irqpin_priv {
  70         struct intc_irqpin_iomem iomem[INTC_IRQPIN_REG_NR];
  71         struct intc_irqpin_irq irq[INTC_IRQPIN_MAX];
  72         struct renesas_intc_irqpin_config config;
  73         unsigned int number_of_irqs;
  74         struct platform_device *pdev;
  75         struct irq_chip irq_chip;
  76         struct irq_domain *irq_domain;
  77         bool shared_irqs;
  78         u8 shared_irq_mask;
  79 };
  80
  81 static unsigned long intc_irqpin_read32(void __iomem *iomem)
  82 {
  83         return ioread32(iomem);
  84 }
  85
  86 static unsigned long intc_irqpin_read8(void __iomem *iomem)
  87 {
  88         return ioread8(iomem);
  89 }
  90
  91 static void intc_irqpin_write32(void __iomem *iomem, unsigned long data)
  92 {
  93         iowrite32(data, iomem);
  94 }
  95
  96 static void intc_irqpin_write8(void __iomem *iomem, unsigned long data)
  97 {
  98         iowrite8(data, iomem);
  99 }
 100
 101 static inline unsigned long intc_irqpin_read(struct intc_irqpin_priv *p,
 102                                              int reg)
 103 {
 104         struct intc_irqpin_iomem *i = &p->iomem[reg];
 105
 106         return i->read(i->iomem);
 107 }
 108
 109 static inline void intc_irqpin_write(struct intc_irqpin_priv *p,
 110                                      int reg, unsigned long data)
 111 {
 112         struct intc_irqpin_iomem *i = &p->iomem[reg];
 113
 114         i->write(i->iomem, data);
 115 }
 116
 117 static inline unsigned long intc_irqpin_hwirq_mask(struct intc_irqpin_priv *p,
 118                                                    int reg, int hw_irq)
 119 {
 120         return BIT((p->iomem[reg].width - 1) - hw_irq);
 121 }
 122
 123 static inline void intc_irqpin_irq_write_hwirq(struct intc_irqpin_priv *p,
 124                                                int reg, int hw_irq)
 125 {
 126         intc_irqpin_write(p, reg, intc_irqpin_hwirq_mask(p, reg, hw_irq));
 127 }
 128
 129 static DEFINE_RAW_SPINLOCK(intc_irqpin_lock); /* only used by slow path */
 130
 131 static void intc_irqpin_read_modify_write(struct intc_irqpin_priv *p,
 132                                           int reg, int shift,
 133                                           int width, int value)
 134 {
 135         unsigned long flags;
 136         unsigned long tmp;
 137
 138         raw_spin_lock_irqsave(&intc_irqpin_lock, flags);
 139
 140         tmp = intc_irqpin_read(p, reg);
 141         tmp &= ~(((1 << width) - 1) << shift);
 142         tmp |= value << shift;
 143         intc_irqpin_write(p, reg, tmp);
 144
 145         raw_spin_unlock_irqrestore(&intc_irqpin_lock, flags);
 146 }
 147
 148 static void intc_irqpin_mask_unmask_prio(struct intc_irqpin_priv *p,
 149                                          int irq, int do_mask)
 150 {
 151         int bitfield_width = 4; /* PRIO assumed to have fixed bitfield width */
 152         int shift = (7 - irq) * bitfield_width; /* PRIO assumed to be 32-bit */
 153
 154         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
 155                                       shift, bitfield_width,
 156                                       do_mask ? 0 : (1 << bitfield_width) - 1);
 157 }
 158
 159 static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
 160 {
 161         int bitfield_width = p->config.sense_bitfield_width;
 162         int shift = (7 - irq) * bitfield_width; /* SENSE assumed to be 32-bit */
 163
 164         dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);
 165
 166         if (value >= (1 << bitfield_width))
 167                 return -EINVAL;
 168
 169         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
 170                                       bitfield_width, value);
 171         return 0;
 172 }
 173
 174 static void intc_irqpin_dbg(struct intc_irqpin_irq *i, char *str)
 175 {
 176         dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
 177                 str, i->requested_irq, i->hw_irq, i->domain_irq);
 178 }
 179
 180 static void intc_irqpin_irq_enable(struct irq_data *d)
 181 {
 182         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 183         int hw_irq = irqd_to_hwirq(d);
 184
 185         intc_irqpin_dbg(&p->irq[hw_irq], "enable");
 186         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
 187 }
 188
 189 static void intc_irqpin_irq_disable(struct irq_data *d)
 190 {
 191         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 192         int hw_irq = irqd_to_hwirq(d);
 193
 194         intc_irqpin_dbg(&p->irq[hw_irq], "disable");
 195         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
 196 }
 197
 198 static void intc_irqpin_shared_irq_enable(struct irq_data *d)
 199 {
 200         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 201         int hw_irq = irqd_to_hwirq(d);
 202
 203         intc_irqpin_dbg(&p->irq[hw_irq], "shared enable");
 204         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
 205
 206         p->shared_irq_mask &= ~BIT(hw_irq);
 207 }
 208
 209 static void intc_irqpin_shared_irq_disable(struct irq_data *d)
 210 {
 211         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 212         int hw_irq = irqd_to_hwirq(d);
 213
 214         intc_irqpin_dbg(&p->irq[hw_irq], "shared disable");
 215         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
 216
 217         p->shared_irq_mask |= BIT(hw_irq);
 218 }
 219
 220 static void intc_irqpin_irq_enable_force(struct irq_data *d)
 221 {
 222         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 223         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
 224
 225         intc_irqpin_irq_enable(d);
 226
 227         /* enable interrupt through parent interrupt controller,
 228          * assumes non-shared interrupt with 1:1 mapping
 229          * needed for busted IRQs on some SoCs like sh73a0
 230          */
 231         irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
 232 }
 233
 234 static void intc_irqpin_irq_disable_force(struct irq_data *d)
 235 {
 236         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 237         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
 238
 239         /* disable interrupt through parent interrupt controller,
 240          * assumes non-shared interrupt with 1:1 mapping
 241          * needed for busted IRQs on some SoCs like sh73a0
 242          */
 243         irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
 244         intc_irqpin_irq_disable(d);
 245 }
 246
 247 #define INTC_IRQ_SENSE_VALID 0x10
 248 #define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)
 249
 250 static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
 251         [IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
 252         [IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
 253         [IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
 254         [IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
 255         [IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
 256 };
 257
 258 static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
 259 {
 260         unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
 261         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 262
 263         if (!(value & INTC_IRQ_SENSE_VALID))
 264                 return -EINVAL;
 265
 266         return intc_irqpin_set_sense(p, irqd_to_hwirq(d),
 267                                      value ^ INTC_IRQ_SENSE_VALID);
 268 }
 269
 270 static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
 271 {
 272         struct intc_irqpin_irq *i = dev_id;
 273         struct intc_irqpin_priv *p = i->p;
 274         unsigned long bit;
 275
 276         intc_irqpin_dbg(i, "demux1");
 277         bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, i->hw_irq);
 278
 279         if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
 280                 intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, ~bit);
 281                 intc_irqpin_dbg(i, "demux2");
 282                 generic_handle_irq(i->domain_irq);
 283                 return IRQ_HANDLED;
 284         }
 285         return IRQ_NONE;
 286 }
 287
 288 static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
 289 {
 290         struct intc_irqpin_priv *p = dev_id;
 291         unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
 292         irqreturn_t status = IRQ_NONE;
 293         int k;
 294
 295         for (k = 0; k < 8; k++) {
 296                 if (reg_source & BIT(7 - k)) {
 297                         if (BIT(k) & p->shared_irq_mask)
 298                                 continue;
 299
 300                         status |= intc_irqpin_irq_handler(irq, &p->irq[k]);
 301                 }
 302         }
 303
 304         return status;
 305 }
 306
 307 static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
 308                                       irq_hw_number_t hw)
 309 {
 310         struct intc_irqpin_priv *p = h->host_data;
 311
 312         p->irq[hw].domain_irq = virq;
 313         p->irq[hw].hw_irq = hw;
 314
 315         intc_irqpin_dbg(&p->irq[hw], "map");
 316         irq_set_chip_data(virq, h->host_data);
 317         irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
 318         set_irq_flags(virq, IRQF_VALID); /* kill me now */
 319         return 0;
 320 }
 321
 322 static struct irq_domain_ops intc_irqpin_irq_domain_ops = {
 323         .map    = intc_irqpin_irq_domain_map,
 324         .xlate  = irq_domain_xlate_twocell,
 325 };
 326
 327 static int intc_irqpin_probe(struct platform_device *pdev)
 328 {
 329         struct renesas_intc_irqpin_config *pdata = pdev->dev.platform_data;
 330         struct intc_irqpin_priv *p;
 331         struct intc_irqpin_iomem *i;
 332         struct resource *io[INTC_IRQPIN_REG_NR];
 333         struct resource *irq;
 334         struct irq_chip *irq_chip;
 335         void (*enable_fn)(struct irq_data *d);
 336         void (*disable_fn)(struct irq_data *d);
 337         const char *name = dev_name(&pdev->dev);
 338         int ref_irq;
 339         int ret;
 340         int k;
 341
 342         p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
 343         if (!p) {
 344                 dev_err(&pdev->dev, "failed to allocate driver data\n");
 345                 ret = -ENOMEM;
 346                 goto err0;
 347         }
 348
 349         /* deal with driver instance configuration */
 350         if (pdata)
 351                 memcpy(&p->config, pdata, sizeof(*pdata));
 352         if (!p->config.sense_bitfield_width)
 353                 p->config.sense_bitfield_width = 4; /* default to 4 bits */
 354
 355         p->pdev = pdev;
 356         platform_set_drvdata(pdev, p);
 357
 358         /* get hold of manadatory IOMEM */
 359         for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 360                 io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
 361                 if (!io[k]) {
 362                         dev_err(&pdev->dev, "not enough IOMEM resources\n");
 363                         ret = -EINVAL;
 364                         goto err0;
 365                 }
 366         }
 367
 368         /* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
 369         for (k = 0; k < INTC_IRQPIN_MAX; k++) {
 370                 irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
 371                 if (!irq)
 372                         break;
 373
 374                 p->irq[k].p = p;
 375                 p->irq[k].requested_irq = irq->start;
 376         }
 377
 378         p->number_of_irqs = k;
 379         if (p->number_of_irqs < 1) {
 380                 dev_err(&pdev->dev, "not enough IRQ resources\n");
 381                 ret = -EINVAL;
 382                 goto err0;
 383         }
 384
 385         /* ioremap IOMEM and setup read/write callbacks */
 386         for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 387                 i = &p->iomem[k];
 388
 389                 switch (resource_size(io[k])) {
 390                 case 1:
 391                         i->width = 8;
 392                         i->read = intc_irqpin_read8;
 393                         i->write = intc_irqpin_write8;
 394                         break;
 395                 case 4:
 396                         i->width = 32;
 397                         i->read = intc_irqpin_read32;
 398                         i->write = intc_irqpin_write32;
 399                         break;
 400                 default:
 401                         dev_err(&pdev->dev, "IOMEM size mismatch\n");
 402                         ret = -EINVAL;
 403                         goto err0;
 404                 }
 405
 406                 i->iomem = devm_ioremap_nocache(&pdev->dev, io[k]->start,
 407                                                 resource_size(io[k]));
 408                 if (!i->iomem) {
 409                         dev_err(&pdev->dev, "failed to remap IOMEM\n");
 410                         ret = -ENXIO;
 411                         goto err0;
 412                 }
 413         }
 414
 415         /* mask all interrupts using priority */
 416         for (k = 0; k < p->number_of_irqs; k++)
 417                 intc_irqpin_mask_unmask_prio(p, k, 1);
 418
 419         /* clear all pending interrupts */
 420         intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, 0x0);
 421
 422         /* scan for shared interrupt lines */
 423         ref_irq = p->irq[0].requested_irq;
 424         p->shared_irqs = true;
 425         for (k = 1; k < p->number_of_irqs; k++) {
 426                 if (ref_irq != p->irq[k].requested_irq) {
 427                         p->shared_irqs = false;
 428                         break;
 429                 }
 430         }
 431
 432         /* use more severe masking method if requested */
 433         if (p->config.control_parent) {
 434                 enable_fn = intc_irqpin_irq_enable_force;
 435                 disable_fn = intc_irqpin_irq_disable_force;
 436         } else if (!p->shared_irqs) {
 437                 enable_fn = intc_irqpin_irq_enable;
 438                 disable_fn = intc_irqpin_irq_disable;
 439         } else {
 440                 enable_fn = intc_irqpin_shared_irq_enable;
 441                 disable_fn = intc_irqpin_shared_irq_disable;
 442         }
 443
 444         irq_chip = &p->irq_chip;
 445         irq_chip->name = name;
 446         irq_chip->irq_mask = disable_fn;
 447         irq_chip->irq_unmask = enable_fn;
 448         irq_chip->irq_enable = enable_fn;
 449         irq_chip->irq_disable = disable_fn;
 450         irq_chip->irq_set_type = intc_irqpin_irq_set_type;
 451         irq_chip->flags = IRQCHIP_SKIP_SET_WAKE;
 452
 453         p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
 454                                               p->number_of_irqs,
 455                                               p->config.irq_base,
 456                                               &intc_irqpin_irq_domain_ops, p);
 457         if (!p->irq_domain) {
 458                 ret = -ENXIO;
 459                 dev_err(&pdev->dev, "cannot initialize irq domain\n");
 460                 goto err0;
 461         }
 462
 463         if (p->shared_irqs) {
 464                 /* request one shared interrupt */
 465                 if (devm_request_irq(&pdev->dev, p->irq[0].requested_irq,
 466                                 intc_irqpin_shared_irq_handler,
 467                                 IRQF_SHARED, name, p)) {
 468                         dev_err(&pdev->dev, "failed to request low IRQ\n");
 469                         ret = -ENOENT;
 470                         goto err1;
 471                 }
 472         } else {
 473                 /* request interrupts one by one */
 474                 for (k = 0; k < p->number_of_irqs; k++) {
 475                         if (devm_request_irq(&pdev->dev,
 476                                         p->irq[k].requested_irq,
 477                                         intc_irqpin_irq_handler,
 478                                         0, name, &p->irq[k])) {
 479                                 dev_err(&pdev->dev,
 480                                         "failed to request low IRQ\n");
 481                                 ret = -ENOENT;
 482                                 goto err1;
 483                         }
 484                 }
 485         }
 486
 487         /* unmask all interrupts on prio level */
 488         for (k = 0; k < p->number_of_irqs; k++)
 489                 intc_irqpin_mask_unmask_prio(p, k, 0);
 490
 491         dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
 492
 493         /* warn in case of mismatch if irq base is specified */
 494         if (p->config.irq_base) {
 495                 if (p->config.irq_base != p->irq[0].domain_irq)
 496                         dev_warn(&pdev->dev, "irq base mismatch (%d/%d)\n",
 497                                  p->config.irq_base, p->irq[0].domain_irq);
 498         }
 499
 500         return 0;
 501
 502 err1:
 503         irq_domain_remove(p->irq_domain);
 504 err0:
 505         return ret;
 506 }
 507
 508 static int intc_irqpin_remove(struct platform_device *pdev)
 509 {
 510         struct intc_irqpin_priv *p = platform_get_drvdata(pdev);
 511
 512         irq_domain_remove(p->irq_domain);
 513
 514         return 0;
 515 }
 516
 517 static const struct of_device_id intc_irqpin_dt_ids[] = {
 518         { .compatible = "renesas,intc-irqpin", },
 519         {},
 520 };
 521 MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
 522
 523 static struct platform_driver intc_irqpin_device_driver = {
 524         .probe          = intc_irqpin_probe,
 525         .remove         = intc_irqpin_remove,
 526         .driver         = {
 527                 .name   = "renesas_intc_irqpin",
 528                 .of_match_table = intc_irqpin_dt_ids,
 529                 .owner  = THIS_MODULE,
 530         }
 531 };
 532
 533 static int __init intc_irqpin_init(void)
 534 {
 535         return platform_driver_register(&intc_irqpin_device_driver);
 536 }
 537 postcore_initcall(intc_irqpin_init);
 538
 539 static void __exit intc_irqpin_exit(void)
 540 {
 541         platform_driver_unregister(&intc_irqpin_device_driver);
 542 }
 543 module_exit(intc_irqpin_exit);
 544
 545 MODULE_AUTHOR("Magnus Damm");
 546 MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
 547 MODULE_LICENSE("GPL v2");