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/of.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/interrupt.h>
  25 #include <linux/ioport.h>
  26 #include <linux/io.h>
  27 #include <linux/irq.h>
  28 #include <linux/irqdomain.h>
  29 #include <linux/err.h>
  30 #include <linux/slab.h>
  31 #include <linux/module.h>
  32 #include <linux/platform_data/irq-renesas-intc-irqpin.h>
  33
  34 #define INTC_IRQPIN_MAX 8 /* maximum 8 interrupts per driver instance */
  35
  36 #define INTC_IRQPIN_REG_SENSE 0 /* ICRn */
  37 #define INTC_IRQPIN_REG_PRIO 1 /* INTPRInn */
  38 #define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
  39 #define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
  40 #define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
  41 #define INTC_IRQPIN_REG_NR 5
  42
  43 /* INTC external IRQ PIN hardware register access:
  44  *
  45  * SENSE is read-write 32-bit with 2-bits or 4-bits per IRQ (*)
  46  * PRIO is read-write 32-bit with 4-bits per IRQ (**)
  47  * SOURCE is read-only 32-bit or 8-bit with 1-bit per IRQ (***)
  48  * MASK is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
  49  * CLEAR is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
  50  *
  51  * (*) May be accessed by more than one driver instance - lock needed
  52  * (**) Read-modify-write access by one driver instance - lock needed
  53  * (***) Accessed by one driver instance only - no locking needed
  54  */
  55
  56 struct intc_irqpin_iomem {
  57         void __iomem *iomem;
  58         unsigned long (*read)(void __iomem *iomem);
  59         void (*write)(void __iomem *iomem, unsigned long data);
  60         int width;
  61 };
  62
  63 struct intc_irqpin_irq {
  64         int hw_irq;
  65         int requested_irq;
  66         int domain_irq;
  67         struct intc_irqpin_priv *p;
  68 };
  69
  70 struct intc_irqpin_priv {
  71         struct intc_irqpin_iomem iomem[INTC_IRQPIN_REG_NR];
  72         struct intc_irqpin_irq irq[INTC_IRQPIN_MAX];
  73         struct renesas_intc_irqpin_config config;
  74         unsigned int number_of_irqs;
  75         struct platform_device *pdev;
  76         struct irq_chip irq_chip;
  77         struct irq_domain *irq_domain;
  78         bool shared_irqs;
  79         u8 shared_irq_mask;
  80 };
  81
  82 static unsigned long intc_irqpin_read32(void __iomem *iomem)
  83 {
  84         return ioread32(iomem);
  85 }
  86
  87 static unsigned long intc_irqpin_read8(void __iomem *iomem)
  88 {
  89         return ioread8(iomem);
  90 }
  91
  92 static void intc_irqpin_write32(void __iomem *iomem, unsigned long data)
  93 {
  94         iowrite32(data, iomem);
  95 }
  96
  97 static void intc_irqpin_write8(void __iomem *iomem, unsigned long data)
  98 {
  99         iowrite8(data, iomem);
 100 }
 101
 102 static inline unsigned long intc_irqpin_read(struct intc_irqpin_priv *p,
 103                                              int reg)
 104 {
 105         struct intc_irqpin_iomem *i = &p->iomem[reg];
 106
 107         return i->read(i->iomem);
 108 }
 109
 110 static inline void intc_irqpin_write(struct intc_irqpin_priv *p,
 111                                      int reg, unsigned long data)
 112 {
 113         struct intc_irqpin_iomem *i = &p->iomem[reg];
 114
 115         i->write(i->iomem, data);
 116 }
 117
 118 static inline unsigned long intc_irqpin_hwirq_mask(struct intc_irqpin_priv *p,
 119                                                    int reg, int hw_irq)
 120 {
 121         return BIT((p->iomem[reg].width - 1) - hw_irq);
 122 }
 123
 124 static inline void intc_irqpin_irq_write_hwirq(struct intc_irqpin_priv *p,
 125                                                int reg, int hw_irq)
 126 {
 127         intc_irqpin_write(p, reg, intc_irqpin_hwirq_mask(p, reg, hw_irq));
 128 }
 129
 130 static DEFINE_RAW_SPINLOCK(intc_irqpin_lock); /* only used by slow path */
 131
 132 static void intc_irqpin_read_modify_write(struct intc_irqpin_priv *p,
 133                                           int reg, int shift,
 134                                           int width, int value)
 135 {
 136         unsigned long flags;
 137         unsigned long tmp;
 138
 139         raw_spin_lock_irqsave(&intc_irqpin_lock, flags);
 140
 141         tmp = intc_irqpin_read(p, reg);
 142         tmp &= ~(((1 << width) - 1) << shift);
 143         tmp |= value << shift;
 144         intc_irqpin_write(p, reg, tmp);
 145
 146         raw_spin_unlock_irqrestore(&intc_irqpin_lock, flags);
 147 }
 148
 149 static void intc_irqpin_mask_unmask_prio(struct intc_irqpin_priv *p,
 150                                          int irq, int do_mask)
 151 {
 152         /* The PRIO register is assumed to be 32-bit with fixed 4-bit fields. */
 153         int bitfield_width = 4;
 154         int shift = 32 - (irq + 1) * bitfield_width;
 155
 156         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
 157                                       shift, bitfield_width,
 158                                       do_mask ? 0 : (1 << bitfield_width) - 1);
 159 }
 160
 161 static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
 162 {
 163         /* The SENSE register is assumed to be 32-bit. */
 164         int bitfield_width = p->config.sense_bitfield_width;
 165         int shift = 32 - (irq + 1) * bitfield_width;
 166
 167         dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);
 168
 169         if (value >= (1 << bitfield_width))
 170                 return -EINVAL;
 171
 172         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
 173                                       bitfield_width, value);
 174         return 0;
 175 }
 176
 177 static void intc_irqpin_dbg(struct intc_irqpin_irq *i, char *str)
 178 {
 179         dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
 180                 str, i->requested_irq, i->hw_irq, i->domain_irq);
 181 }
 182
 183 static void intc_irqpin_irq_enable(struct irq_data *d)
 184 {
 185         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 186         int hw_irq = irqd_to_hwirq(d);
 187
 188         intc_irqpin_dbg(&p->irq[hw_irq], "enable");
 189         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
 190 }
 191
 192 static void intc_irqpin_irq_disable(struct irq_data *d)
 193 {
 194         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 195         int hw_irq = irqd_to_hwirq(d);
 196
 197         intc_irqpin_dbg(&p->irq[hw_irq], "disable");
 198         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
 199 }
 200
 201 static void intc_irqpin_shared_irq_enable(struct irq_data *d)
 202 {
 203         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 204         int hw_irq = irqd_to_hwirq(d);
 205
 206         intc_irqpin_dbg(&p->irq[hw_irq], "shared enable");
 207         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
 208
 209         p->shared_irq_mask &= ~BIT(hw_irq);
 210 }
 211
 212 static void intc_irqpin_shared_irq_disable(struct irq_data *d)
 213 {
 214         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 215         int hw_irq = irqd_to_hwirq(d);
 216
 217         intc_irqpin_dbg(&p->irq[hw_irq], "shared disable");
 218         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
 219
 220         p->shared_irq_mask |= BIT(hw_irq);
 221 }
 222
 223 static void intc_irqpin_irq_enable_force(struct irq_data *d)
 224 {
 225         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 226         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
 227
 228         intc_irqpin_irq_enable(d);
 229
 230         /* enable interrupt through parent interrupt controller,
 231          * assumes non-shared interrupt with 1:1 mapping
 232          * needed for busted IRQs on some SoCs like sh73a0
 233          */
 234         irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
 235 }
 236
 237 static void intc_irqpin_irq_disable_force(struct irq_data *d)
 238 {
 239         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 240         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
 241
 242         /* disable interrupt through parent interrupt controller,
 243          * assumes non-shared interrupt with 1:1 mapping
 244          * needed for busted IRQs on some SoCs like sh73a0
 245          */
 246         irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
 247         intc_irqpin_irq_disable(d);
 248 }
 249
 250 #define INTC_IRQ_SENSE_VALID 0x10
 251 #define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)
 252
 253 static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
 254         [IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
 255         [IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
 256         [IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
 257         [IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
 258         [IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
 259 };
 260
 261 static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
 262 {
 263         unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
 264         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 265
 266         if (!(value & INTC_IRQ_SENSE_VALID))
 267                 return -EINVAL;
 268
 269         return intc_irqpin_set_sense(p, irqd_to_hwirq(d),
 270                                      value ^ INTC_IRQ_SENSE_VALID);
 271 }
 272
 273 static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
 274 {
 275         struct intc_irqpin_irq *i = dev_id;
 276         struct intc_irqpin_priv *p = i->p;
 277         unsigned long bit;
 278
 279         intc_irqpin_dbg(i, "demux1");
 280         bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, i->hw_irq);
 281
 282         if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
 283                 intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, ~bit);
 284                 intc_irqpin_dbg(i, "demux2");
 285                 generic_handle_irq(i->domain_irq);
 286                 return IRQ_HANDLED;
 287         }
 288         return IRQ_NONE;
 289 }
 290
 291 static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
 292 {
 293         struct intc_irqpin_priv *p = dev_id;
 294         unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
 295         irqreturn_t status = IRQ_NONE;
 296         int k;
 297
 298         for (k = 0; k < 8; k++) {
 299                 if (reg_source & BIT(7 - k)) {
 300                         if (BIT(k) & p->shared_irq_mask)
 301                                 continue;
 302
 303                         status |= intc_irqpin_irq_handler(irq, &p->irq[k]);
 304                 }
 305         }
 306
 307         return status;
 308 }
 309
 310 static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
 311                                       irq_hw_number_t hw)
 312 {
 313         struct intc_irqpin_priv *p = h->host_data;
 314
 315         p->irq[hw].domain_irq = virq;
 316         p->irq[hw].hw_irq = hw;
 317
 318         intc_irqpin_dbg(&p->irq[hw], "map");
 319         irq_set_chip_data(virq, h->host_data);
 320         irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
 321         set_irq_flags(virq, IRQF_VALID); /* kill me now */
 322         return 0;
 323 }
 324
 325 static struct irq_domain_ops intc_irqpin_irq_domain_ops = {
 326         .map    = intc_irqpin_irq_domain_map,
 327         .xlate  = irq_domain_xlate_twocell,
 328 };
 329
 330 static int intc_irqpin_probe(struct platform_device *pdev)
 331 {
 332         struct renesas_intc_irqpin_config *pdata = pdev->dev.platform_data;
 333         struct intc_irqpin_priv *p;
 334         struct intc_irqpin_iomem *i;
 335         struct resource *io[INTC_IRQPIN_REG_NR];
 336         struct resource *irq;
 337         struct irq_chip *irq_chip;
 338         void (*enable_fn)(struct irq_data *d);
 339         void (*disable_fn)(struct irq_data *d);
 340         const char *name = dev_name(&pdev->dev);
 341         int ref_irq;
 342         int ret;
 343         int k;
 344
 345         p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
 346         if (!p) {
 347                 dev_err(&pdev->dev, "failed to allocate driver data\n");
 348                 ret = -ENOMEM;
 349                 goto err0;
 350         }
 351
 352         /* deal with driver instance configuration */
 353         if (pdata) {
 354                 memcpy(&p->config, pdata, sizeof(*pdata));
 355         } else {
 356                 of_property_read_u32(pdev->dev.of_node, "sense-bitfield-width",
 357                                      &p->config.sense_bitfield_width);
 358                 p->config.control_parent = of_property_read_bool(pdev->dev.of_node,
 359                                                                  "control-parent");
 360         }
 361         if (!p->config.sense_bitfield_width)
 362                 p->config.sense_bitfield_width = 4; /* default to 4 bits */
 363
 364         p->pdev = pdev;
 365         platform_set_drvdata(pdev, p);
 366
 367         /* get hold of manadatory IOMEM */
 368         for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 369                 io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
 370                 if (!io[k]) {
 371                         dev_err(&pdev->dev, "not enough IOMEM resources\n");
 372                         ret = -EINVAL;
 373                         goto err0;
 374                 }
 375         }
 376
 377         /* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
 378         for (k = 0; k < INTC_IRQPIN_MAX; k++) {
 379                 irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
 380                 if (!irq)
 381                         break;
 382
 383                 p->irq[k].p = p;
 384                 p->irq[k].requested_irq = irq->start;
 385         }
 386
 387         p->number_of_irqs = k;
 388         if (p->number_of_irqs < 1) {
 389                 dev_err(&pdev->dev, "not enough IRQ resources\n");
 390                 ret = -EINVAL;
 391                 goto err0;
 392         }
 393
 394         /* ioremap IOMEM and setup read/write callbacks */
 395         for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 396                 i = &p->iomem[k];
 397
 398                 switch (resource_size(io[k])) {
 399                 case 1:
 400                         i->width = 8;
 401                         i->read = intc_irqpin_read8;
 402                         i->write = intc_irqpin_write8;
 403                         break;
 404                 case 4:
 405                         i->width = 32;
 406                         i->read = intc_irqpin_read32;
 407                         i->write = intc_irqpin_write32;
 408                         break;
 409                 default:
 410                         dev_err(&pdev->dev, "IOMEM size mismatch\n");
 411                         ret = -EINVAL;
 412                         goto err0;
 413                 }
 414
 415                 i->iomem = devm_ioremap_nocache(&pdev->dev, io[k]->start,
 416                                                 resource_size(io[k]));
 417                 if (!i->iomem) {
 418                         dev_err(&pdev->dev, "failed to remap IOMEM\n");
 419                         ret = -ENXIO;
 420                         goto err0;
 421                 }
 422         }
 423
 424         /* mask all interrupts using priority */
 425         for (k = 0; k < p->number_of_irqs; k++)
 426                 intc_irqpin_mask_unmask_prio(p, k, 1);
 427
 428         /* clear all pending interrupts */
 429         intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, 0x0);
 430
 431         /* scan for shared interrupt lines */
 432         ref_irq = p->irq[0].requested_irq;
 433         p->shared_irqs = true;
 434         for (k = 1; k < p->number_of_irqs; k++) {
 435                 if (ref_irq != p->irq[k].requested_irq) {
 436                         p->shared_irqs = false;
 437                         break;
 438                 }
 439         }
 440
 441         /* use more severe masking method if requested */
 442         if (p->config.control_parent) {
 443                 enable_fn = intc_irqpin_irq_enable_force;
 444                 disable_fn = intc_irqpin_irq_disable_force;
 445         } else if (!p->shared_irqs) {
 446                 enable_fn = intc_irqpin_irq_enable;
 447                 disable_fn = intc_irqpin_irq_disable;
 448         } else {
 449                 enable_fn = intc_irqpin_shared_irq_enable;
 450                 disable_fn = intc_irqpin_shared_irq_disable;
 451         }
 452
 453         irq_chip = &p->irq_chip;
 454         irq_chip->name = name;
 455         irq_chip->irq_mask = disable_fn;
 456         irq_chip->irq_unmask = enable_fn;
 457         irq_chip->irq_enable = enable_fn;
 458         irq_chip->irq_disable = disable_fn;
 459         irq_chip->irq_set_type = intc_irqpin_irq_set_type;
 460         irq_chip->flags = IRQCHIP_SKIP_SET_WAKE;
 461
 462         p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
 463                                               p->number_of_irqs,
 464                                               p->config.irq_base,
 465                                               &intc_irqpin_irq_domain_ops, p);
 466         if (!p->irq_domain) {
 467                 ret = -ENXIO;
 468                 dev_err(&pdev->dev, "cannot initialize irq domain\n");
 469                 goto err0;
 470         }
 471
 472         if (p->shared_irqs) {
 473                 /* request one shared interrupt */
 474                 if (devm_request_irq(&pdev->dev, p->irq[0].requested_irq,
 475                                 intc_irqpin_shared_irq_handler,
 476                                 IRQF_SHARED, name, p)) {
 477                         dev_err(&pdev->dev, "failed to request low IRQ\n");
 478                         ret = -ENOENT;
 479                         goto err1;
 480                 }
 481         } else {
 482                 /* request interrupts one by one */
 483                 for (k = 0; k < p->number_of_irqs; k++) {
 484                         if (devm_request_irq(&pdev->dev,
 485                                         p->irq[k].requested_irq,
 486                                         intc_irqpin_irq_handler,
 487                                         0, name, &p->irq[k])) {
 488                                 dev_err(&pdev->dev,
 489                                         "failed to request low IRQ\n");
 490                                 ret = -ENOENT;
 491                                 goto err1;
 492                         }
 493                 }
 494         }
 495
 496         /* unmask all interrupts on prio level */
 497         for (k = 0; k < p->number_of_irqs; k++)
 498                 intc_irqpin_mask_unmask_prio(p, k, 0);
 499
 500         dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
 501
 502         /* warn in case of mismatch if irq base is specified */
 503         if (p->config.irq_base) {
 504                 if (p->config.irq_base != p->irq[0].domain_irq)
 505                         dev_warn(&pdev->dev, "irq base mismatch (%d/%d)\n",
 506                                  p->config.irq_base, p->irq[0].domain_irq);
 507         }
 508
 509         return 0;
 510
 511 err1:
 512         irq_domain_remove(p->irq_domain);
 513 err0:
 514         return ret;
 515 }
 516
 517 static int intc_irqpin_remove(struct platform_device *pdev)
 518 {
 519         struct intc_irqpin_priv *p = platform_get_drvdata(pdev);
 520
 521         irq_domain_remove(p->irq_domain);
 522
 523         return 0;
 524 }
 525
 526 static const struct of_device_id intc_irqpin_dt_ids[] = {
 527         { .compatible = "renesas,intc-irqpin", },
 528         {},
 529 };
 530 MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
 531
 532 static struct platform_driver intc_irqpin_device_driver = {
 533         .probe          = intc_irqpin_probe,
 534         .remove         = intc_irqpin_remove,
 535         .driver         = {
 536                 .name   = "renesas_intc_irqpin",
 537                 .of_match_table = intc_irqpin_dt_ids,
 538                 .owner  = THIS_MODULE,
 539         }
 540 };
 541
 542 static int __init intc_irqpin_init(void)
 543 {
 544         return platform_driver_register(&intc_irqpin_device_driver);
 545 }
 546 postcore_initcall(intc_irqpin_init);
 547
 548 static void __exit intc_irqpin_exit(void)
 549 {
 550         platform_driver_unregister(&intc_irqpin_device_driver);
 551 }
 552 module_exit(intc_irqpin_exit);
 553
 554 MODULE_AUTHOR("Magnus Damm");
 555 MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
 556 MODULE_LICENSE("GPL v2");