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         int bitfield_width = 4; /* PRIO assumed to have fixed bitfield width */
 153         int shift = (7 - irq) * bitfield_width; /* PRIO assumed to be 32-bit */
 154
 155         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
 156                                       shift, bitfield_width,
 157                                       do_mask ? 0 : (1 << bitfield_width) - 1);
 158 }
 159
 160 static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
 161 {
 162         int bitfield_width = p->config.sense_bitfield_width;
 163         int shift = (7 - irq) * bitfield_width; /* SENSE assumed to be 32-bit */
 164
 165         dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);
 166
 167         if (value >= (1 << bitfield_width))
 168                 return -EINVAL;
 169
 170         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
 171                                       bitfield_width, value);
 172         return 0;
 173 }
 174
 175 static void intc_irqpin_dbg(struct intc_irqpin_irq *i, char *str)
 176 {
 177         dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
 178                 str, i->requested_irq, i->hw_irq, i->domain_irq);
 179 }
 180
 181 static void intc_irqpin_irq_enable(struct irq_data *d)
 182 {
 183         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 184         int hw_irq = irqd_to_hwirq(d);
 185
 186         intc_irqpin_dbg(&p->irq[hw_irq], "enable");
 187         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
 188 }
 189
 190 static void intc_irqpin_irq_disable(struct irq_data *d)
 191 {
 192         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 193         int hw_irq = irqd_to_hwirq(d);
 194
 195         intc_irqpin_dbg(&p->irq[hw_irq], "disable");
 196         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
 197 }
 198
 199 static void intc_irqpin_shared_irq_enable(struct irq_data *d)
 200 {
 201         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 202         int hw_irq = irqd_to_hwirq(d);
 203
 204         intc_irqpin_dbg(&p->irq[hw_irq], "shared enable");
 205         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
 206
 207         p->shared_irq_mask &= ~BIT(hw_irq);
 208 }
 209
 210 static void intc_irqpin_shared_irq_disable(struct irq_data *d)
 211 {
 212         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 213         int hw_irq = irqd_to_hwirq(d);
 214
 215         intc_irqpin_dbg(&p->irq[hw_irq], "shared disable");
 216         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
 217
 218         p->shared_irq_mask |= BIT(hw_irq);
 219 }
 220
 221 static void intc_irqpin_irq_enable_force(struct irq_data *d)
 222 {
 223         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 224         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
 225
 226         intc_irqpin_irq_enable(d);
 227
 228         /* enable interrupt through parent interrupt controller,
 229          * assumes non-shared interrupt with 1:1 mapping
 230          * needed for busted IRQs on some SoCs like sh73a0
 231          */
 232         irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
 233 }
 234
 235 static void intc_irqpin_irq_disable_force(struct irq_data *d)
 236 {
 237         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 238         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
 239
 240         /* disable interrupt through parent interrupt controller,
 241          * assumes non-shared interrupt with 1:1 mapping
 242          * needed for busted IRQs on some SoCs like sh73a0
 243          */
 244         irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
 245         intc_irqpin_irq_disable(d);
 246 }
 247
 248 #define INTC_IRQ_SENSE_VALID 0x10
 249 #define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)
 250
 251 static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
 252         [IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
 253         [IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
 254         [IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
 255         [IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
 256         [IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
 257 };
 258
 259 static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
 260 {
 261         unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
 262         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 263
 264         if (!(value & INTC_IRQ_SENSE_VALID))
 265                 return -EINVAL;
 266
 267         return intc_irqpin_set_sense(p, irqd_to_hwirq(d),
 268                                      value ^ INTC_IRQ_SENSE_VALID);
 269 }
 270
 271 static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
 272 {
 273         struct intc_irqpin_irq *i = dev_id;
 274         struct intc_irqpin_priv *p = i->p;
 275         unsigned long bit;
 276
 277         intc_irqpin_dbg(i, "demux1");
 278         bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, i->hw_irq);
 279
 280         if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
 281                 intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, ~bit);
 282                 intc_irqpin_dbg(i, "demux2");
 283                 generic_handle_irq(i->domain_irq);
 284                 return IRQ_HANDLED;
 285         }
 286         return IRQ_NONE;
 287 }
 288
 289 static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
 290 {
 291         struct intc_irqpin_priv *p = dev_id;
 292         unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
 293         irqreturn_t status = IRQ_NONE;
 294         int k;
 295
 296         for (k = 0; k < 8; k++) {
 297                 if (reg_source & BIT(7 - k)) {
 298                         if (BIT(k) & p->shared_irq_mask)
 299                                 continue;
 300
 301                         status |= intc_irqpin_irq_handler(irq, &p->irq[k]);
 302                 }
 303         }
 304
 305         return status;
 306 }
 307
 308 static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
 309                                       irq_hw_number_t hw)
 310 {
 311         struct intc_irqpin_priv *p = h->host_data;
 312
 313         p->irq[hw].domain_irq = virq;
 314         p->irq[hw].hw_irq = hw;
 315
 316         intc_irqpin_dbg(&p->irq[hw], "map");
 317         irq_set_chip_data(virq, h->host_data);
 318         irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
 319         set_irq_flags(virq, IRQF_VALID); /* kill me now */
 320         return 0;
 321 }
 322
 323 static struct irq_domain_ops intc_irqpin_irq_domain_ops = {
 324         .map    = intc_irqpin_irq_domain_map,
 325         .xlate  = irq_domain_xlate_twocell,
 326 };
 327
 328 static int intc_irqpin_probe(struct platform_device *pdev)
 329 {
 330         struct renesas_intc_irqpin_config *pdata = pdev->dev.platform_data;
 331         struct intc_irqpin_priv *p;
 332         struct intc_irqpin_iomem *i;
 333         struct resource *io[INTC_IRQPIN_REG_NR];
 334         struct resource *irq;
 335         struct irq_chip *irq_chip;
 336         void (*enable_fn)(struct irq_data *d);
 337         void (*disable_fn)(struct irq_data *d);
 338         const char *name = dev_name(&pdev->dev);
 339         int ref_irq;
 340         int ret;
 341         int k;
 342
 343         p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
 344         if (!p) {
 345                 dev_err(&pdev->dev, "failed to allocate driver data\n");
 346                 ret = -ENOMEM;
 347                 goto err0;
 348         }
 349
 350         /* deal with driver instance configuration */
 351         if (pdata) {
 352                 memcpy(&p->config, pdata, sizeof(*pdata));
 353         } else {
 354                 of_property_read_u32(pdev->dev.of_node, "sense-bitfield-width",
 355                                      &p->config.sense_bitfield_width);
 356                 p->config.control_parent = of_property_read_bool(pdev->dev.of_node,
 357                                                                  "control-parent");
 358         }
 359         if (!p->config.sense_bitfield_width)
 360                 p->config.sense_bitfield_width = 4; /* default to 4 bits */
 361
 362         p->pdev = pdev;
 363         platform_set_drvdata(pdev, p);
 364
 365         /* get hold of manadatory IOMEM */
 366         for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 367                 io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
 368                 if (!io[k]) {
 369                         dev_err(&pdev->dev, "not enough IOMEM resources\n");
 370                         ret = -EINVAL;
 371                         goto err0;
 372                 }
 373         }
 374
 375         /* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
 376         for (k = 0; k < INTC_IRQPIN_MAX; k++) {
 377                 irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
 378                 if (!irq)
 379                         break;
 380
 381                 p->irq[k].p = p;
 382                 p->irq[k].requested_irq = irq->start;
 383         }
 384
 385         p->number_of_irqs = k;
 386         if (p->number_of_irqs < 1) {
 387                 dev_err(&pdev->dev, "not enough IRQ resources\n");
 388                 ret = -EINVAL;
 389                 goto err0;
 390         }
 391
 392         /* ioremap IOMEM and setup read/write callbacks */
 393         for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 394                 i = &p->iomem[k];
 395
 396                 switch (resource_size(io[k])) {
 397                 case 1:
 398                         i->width = 8;
 399                         i->read = intc_irqpin_read8;
 400                         i->write = intc_irqpin_write8;
 401                         break;
 402                 case 4:
 403                         i->width = 32;
 404                         i->read = intc_irqpin_read32;
 405                         i->write = intc_irqpin_write32;
 406                         break;
 407                 default:
 408                         dev_err(&pdev->dev, "IOMEM size mismatch\n");
 409                         ret = -EINVAL;
 410                         goto err0;
 411                 }
 412
 413                 i->iomem = devm_ioremap_nocache(&pdev->dev, io[k]->start,
 414                                                 resource_size(io[k]));
 415                 if (!i->iomem) {
 416                         dev_err(&pdev->dev, "failed to remap IOMEM\n");
 417                         ret = -ENXIO;
 418                         goto err0;
 419                 }
 420         }
 421
 422         /* mask all interrupts using priority */
 423         for (k = 0; k < p->number_of_irqs; k++)
 424                 intc_irqpin_mask_unmask_prio(p, k, 1);
 425
 426         /* clear all pending interrupts */
 427         intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, 0x0);
 428
 429         /* scan for shared interrupt lines */
 430         ref_irq = p->irq[0].requested_irq;
 431         p->shared_irqs = true;
 432         for (k = 1; k < p->number_of_irqs; k++) {
 433                 if (ref_irq != p->irq[k].requested_irq) {
 434                         p->shared_irqs = false;
 435                         break;
 436                 }
 437         }
 438
 439         /* use more severe masking method if requested */
 440         if (p->config.control_parent) {
 441                 enable_fn = intc_irqpin_irq_enable_force;
 442                 disable_fn = intc_irqpin_irq_disable_force;
 443         } else if (!p->shared_irqs) {
 444                 enable_fn = intc_irqpin_irq_enable;
 445                 disable_fn = intc_irqpin_irq_disable;
 446         } else {
 447                 enable_fn = intc_irqpin_shared_irq_enable;
 448                 disable_fn = intc_irqpin_shared_irq_disable;
 449         }
 450
 451         irq_chip = &p->irq_chip;
 452         irq_chip->name = name;
 453         irq_chip->irq_mask = disable_fn;
 454         irq_chip->irq_unmask = enable_fn;
 455         irq_chip->irq_enable = enable_fn;
 456         irq_chip->irq_disable = disable_fn;
 457         irq_chip->irq_set_type = intc_irqpin_irq_set_type;
 458         irq_chip->flags = IRQCHIP_SKIP_SET_WAKE;
 459
 460         p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
 461                                               p->number_of_irqs,
 462                                               p->config.irq_base,
 463                                               &intc_irqpin_irq_domain_ops, p);
 464         if (!p->irq_domain) {
 465                 ret = -ENXIO;
 466                 dev_err(&pdev->dev, "cannot initialize irq domain\n");
 467                 goto err0;
 468         }
 469
 470         if (p->shared_irqs) {
 471                 /* request one shared interrupt */
 472                 if (devm_request_irq(&pdev->dev, p->irq[0].requested_irq,
 473                                 intc_irqpin_shared_irq_handler,
 474                                 IRQF_SHARED, name, p)) {
 475                         dev_err(&pdev->dev, "failed to request low IRQ\n");
 476                         ret = -ENOENT;
 477                         goto err1;
 478                 }
 479         } else {
 480                 /* request interrupts one by one */
 481                 for (k = 0; k < p->number_of_irqs; k++) {
 482                         if (devm_request_irq(&pdev->dev,
 483                                         p->irq[k].requested_irq,
 484                                         intc_irqpin_irq_handler,
 485                                         0, name, &p->irq[k])) {
 486                                 dev_err(&pdev->dev,
 487                                         "failed to request low IRQ\n");
 488                                 ret = -ENOENT;
 489                                 goto err1;
 490                         }
 491                 }
 492         }
 493
 494         /* unmask all interrupts on prio level */
 495         for (k = 0; k < p->number_of_irqs; k++)
 496                 intc_irqpin_mask_unmask_prio(p, k, 0);
 497
 498         dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
 499
 500         /* warn in case of mismatch if irq base is specified */
 501         if (p->config.irq_base) {
 502                 if (p->config.irq_base != p->irq[0].domain_irq)
 503                         dev_warn(&pdev->dev, "irq base mismatch (%d/%d)\n",
 504                                  p->config.irq_base, p->irq[0].domain_irq);
 505         }
 506
 507         return 0;
 508
 509 err1:
 510         irq_domain_remove(p->irq_domain);
 511 err0:
 512         return ret;
 513 }
 514
 515 static int intc_irqpin_remove(struct platform_device *pdev)
 516 {
 517         struct intc_irqpin_priv *p = platform_get_drvdata(pdev);
 518
 519         irq_domain_remove(p->irq_domain);
 520
 521         return 0;
 522 }
 523
 524 static const struct of_device_id intc_irqpin_dt_ids[] = {
 525         { .compatible = "renesas,intc-irqpin", },
 526         {},
 527 };
 528 MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
 529
 530 static struct platform_driver intc_irqpin_device_driver = {
 531         .probe          = intc_irqpin_probe,
 532         .remove         = intc_irqpin_remove,
 533         .driver         = {
 534                 .name   = "renesas_intc_irqpin",
 535                 .of_match_table = intc_irqpin_dt_ids,
 536                 .owner  = THIS_MODULE,
 537         }
 538 };
 539
 540 static int __init intc_irqpin_init(void)
 541 {
 542         return platform_driver_register(&intc_irqpin_device_driver);
 543 }
 544 postcore_initcall(intc_irqpin_init);
 545
 546 static void __exit intc_irqpin_exit(void)
 547 {
 548         platform_driver_unregister(&intc_irqpin_device_driver);
 549 }
 550 module_exit(intc_irqpin_exit);
 551
 552 MODULE_AUTHOR("Magnus Damm");
 553 MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
 554 MODULE_LICENSE("GPL v2");