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/clk.h>
  21 #include <linux/init.h>
  22 #include <linux/of.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/ioport.h>
  27 #include <linux/io.h>
  28 #include <linux/irq.h>
  29 #include <linux/irqdomain.h>
  30 #include <linux/err.h>
  31 #include <linux/slab.h>
  32 #include <linux/module.h>
  33 #include <linux/platform_data/irq-renesas-intc-irqpin.h>
  34 #include <linux/pm_runtime.h>
  35
  36 #define INTC_IRQPIN_MAX 8 /* maximum 8 interrupts per driver instance */
  37
  38 #define INTC_IRQPIN_REG_SENSE 0 /* ICRn */
  39 #define INTC_IRQPIN_REG_PRIO 1 /* INTPRInn */
  40 #define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
  41 #define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
  42 #define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
  43 #define INTC_IRQPIN_REG_NR 5
  44
  45 /* INTC external IRQ PIN hardware register access:
  46  *
  47  * SENSE is read-write 32-bit with 2-bits or 4-bits per IRQ (*)
  48  * PRIO is read-write 32-bit with 4-bits per IRQ (**)
  49  * SOURCE is read-only 32-bit or 8-bit with 1-bit per IRQ (***)
  50  * MASK is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
  51  * CLEAR is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
  52  *
  53  * (*) May be accessed by more than one driver instance - lock needed
  54  * (**) Read-modify-write access by one driver instance - lock needed
  55  * (***) Accessed by one driver instance only - no locking needed
  56  */
  57
  58 struct intc_irqpin_iomem {
  59         void __iomem *iomem;
  60         unsigned long (*read)(void __iomem *iomem);
  61         void (*write)(void __iomem *iomem, unsigned long data);
  62         int width;
  63 };
  64
  65 struct intc_irqpin_irq {
  66         int hw_irq;
  67         int requested_irq;
  68         int domain_irq;
  69         struct intc_irqpin_priv *p;
  70 };
  71
  72 struct intc_irqpin_priv {
  73         struct intc_irqpin_iomem iomem[INTC_IRQPIN_REG_NR];
  74         struct intc_irqpin_irq irq[INTC_IRQPIN_MAX];
  75         struct renesas_intc_irqpin_config config;
  76         unsigned int number_of_irqs;
  77         struct platform_device *pdev;
  78         struct irq_chip irq_chip;
  79         struct irq_domain *irq_domain;
  80         struct clk *clk;
  81         bool shared_irqs;
  82         u8 shared_irq_mask;
  83 };
  84
  85 static unsigned long intc_irqpin_read32(void __iomem *iomem)
  86 {
  87         return ioread32(iomem);
  88 }
  89
  90 static unsigned long intc_irqpin_read8(void __iomem *iomem)
  91 {
  92         return ioread8(iomem);
  93 }
  94
  95 static void intc_irqpin_write32(void __iomem *iomem, unsigned long data)
  96 {
  97         iowrite32(data, iomem);
  98 }
  99
 100 static void intc_irqpin_write8(void __iomem *iomem, unsigned long data)
 101 {
 102         iowrite8(data, iomem);
 103 }
 104
 105 static inline unsigned long intc_irqpin_read(struct intc_irqpin_priv *p,
 106                                              int reg)
 107 {
 108         struct intc_irqpin_iomem *i = &p->iomem[reg];
 109
 110         return i->read(i->iomem);
 111 }
 112
 113 static inline void intc_irqpin_write(struct intc_irqpin_priv *p,
 114                                      int reg, unsigned long data)
 115 {
 116         struct intc_irqpin_iomem *i = &p->iomem[reg];
 117
 118         i->write(i->iomem, data);
 119 }
 120
 121 static inline unsigned long intc_irqpin_hwirq_mask(struct intc_irqpin_priv *p,
 122                                                    int reg, int hw_irq)
 123 {
 124         return BIT((p->iomem[reg].width - 1) - hw_irq);
 125 }
 126
 127 static inline void intc_irqpin_irq_write_hwirq(struct intc_irqpin_priv *p,
 128                                                int reg, int hw_irq)
 129 {
 130         intc_irqpin_write(p, reg, intc_irqpin_hwirq_mask(p, reg, hw_irq));
 131 }
 132
 133 static DEFINE_RAW_SPINLOCK(intc_irqpin_lock); /* only used by slow path */
 134
 135 static void intc_irqpin_read_modify_write(struct intc_irqpin_priv *p,
 136                                           int reg, int shift,
 137                                           int width, int value)
 138 {
 139         unsigned long flags;
 140         unsigned long tmp;
 141
 142         raw_spin_lock_irqsave(&intc_irqpin_lock, flags);
 143
 144         tmp = intc_irqpin_read(p, reg);
 145         tmp &= ~(((1 << width) - 1) << shift);
 146         tmp |= value << shift;
 147         intc_irqpin_write(p, reg, tmp);
 148
 149         raw_spin_unlock_irqrestore(&intc_irqpin_lock, flags);
 150 }
 151
 152 static void intc_irqpin_mask_unmask_prio(struct intc_irqpin_priv *p,
 153                                          int irq, int do_mask)
 154 {
 155         /* The PRIO register is assumed to be 32-bit with fixed 4-bit fields. */
 156         int bitfield_width = 4;
 157         int shift = 32 - (irq + 1) * bitfield_width;
 158
 159         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
 160                                       shift, bitfield_width,
 161                                       do_mask ? 0 : (1 << bitfield_width) - 1);
 162 }
 163
 164 static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
 165 {
 166         /* The SENSE register is assumed to be 32-bit. */
 167         int bitfield_width = p->config.sense_bitfield_width;
 168         int shift = 32 - (irq + 1) * bitfield_width;
 169
 170         dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);
 171
 172         if (value >= (1 << bitfield_width))
 173                 return -EINVAL;
 174
 175         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
 176                                       bitfield_width, value);
 177         return 0;
 178 }
 179
 180 static void intc_irqpin_dbg(struct intc_irqpin_irq *i, char *str)
 181 {
 182         dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
 183                 str, i->requested_irq, i->hw_irq, i->domain_irq);
 184 }
 185
 186 static void intc_irqpin_irq_enable(struct irq_data *d)
 187 {
 188         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 189         int hw_irq = irqd_to_hwirq(d);
 190
 191         intc_irqpin_dbg(&p->irq[hw_irq], "enable");
 192         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
 193 }
 194
 195 static void intc_irqpin_irq_disable(struct irq_data *d)
 196 {
 197         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 198         int hw_irq = irqd_to_hwirq(d);
 199
 200         intc_irqpin_dbg(&p->irq[hw_irq], "disable");
 201         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
 202 }
 203
 204 static void intc_irqpin_shared_irq_enable(struct irq_data *d)
 205 {
 206         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 207         int hw_irq = irqd_to_hwirq(d);
 208
 209         intc_irqpin_dbg(&p->irq[hw_irq], "shared enable");
 210         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
 211
 212         p->shared_irq_mask &= ~BIT(hw_irq);
 213 }
 214
 215 static void intc_irqpin_shared_irq_disable(struct irq_data *d)
 216 {
 217         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 218         int hw_irq = irqd_to_hwirq(d);
 219
 220         intc_irqpin_dbg(&p->irq[hw_irq], "shared disable");
 221         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
 222
 223         p->shared_irq_mask |= BIT(hw_irq);
 224 }
 225
 226 static void intc_irqpin_irq_enable_force(struct irq_data *d)
 227 {
 228         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 229         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
 230
 231         intc_irqpin_irq_enable(d);
 232
 233         /* enable interrupt through parent interrupt controller,
 234          * assumes non-shared interrupt with 1:1 mapping
 235          * needed for busted IRQs on some SoCs like sh73a0
 236          */
 237         irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
 238 }
 239
 240 static void intc_irqpin_irq_disable_force(struct irq_data *d)
 241 {
 242         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 243         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
 244
 245         /* disable interrupt through parent interrupt controller,
 246          * assumes non-shared interrupt with 1:1 mapping
 247          * needed for busted IRQs on some SoCs like sh73a0
 248          */
 249         irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
 250         intc_irqpin_irq_disable(d);
 251 }
 252
 253 #define INTC_IRQ_SENSE_VALID 0x10
 254 #define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)
 255
 256 static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
 257         [IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
 258         [IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
 259         [IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
 260         [IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
 261         [IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
 262 };
 263
 264 static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
 265 {
 266         unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
 267         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 268
 269         if (!(value & INTC_IRQ_SENSE_VALID))
 270                 return -EINVAL;
 271
 272         return intc_irqpin_set_sense(p, irqd_to_hwirq(d),
 273                                      value ^ INTC_IRQ_SENSE_VALID);
 274 }
 275
 276 static int intc_irqpin_irq_set_wake(struct irq_data *d, unsigned int on)
 277 {
 278         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
 279
 280         if (!p->clk)
 281                 return 0;
 282
 283         if (on)
 284                 clk_enable(p->clk);
 285         else
 286                 clk_disable(p->clk);
 287
 288         return 0;
 289 }
 290
 291 static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
 292 {
 293         struct intc_irqpin_irq *i = dev_id;
 294         struct intc_irqpin_priv *p = i->p;
 295         unsigned long bit;
 296
 297         intc_irqpin_dbg(i, "demux1");
 298         bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, i->hw_irq);
 299
 300         if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
 301                 intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, ~bit);
 302                 intc_irqpin_dbg(i, "demux2");
 303                 generic_handle_irq(i->domain_irq);
 304                 return IRQ_HANDLED;
 305         }
 306         return IRQ_NONE;
 307 }
 308
 309 static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
 310 {
 311         struct intc_irqpin_priv *p = dev_id;
 312         unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
 313         irqreturn_t status = IRQ_NONE;
 314         int k;
 315
 316         for (k = 0; k < 8; k++) {
 317                 if (reg_source & BIT(7 - k)) {
 318                         if (BIT(k) & p->shared_irq_mask)
 319                                 continue;
 320
 321                         status |= intc_irqpin_irq_handler(irq, &p->irq[k]);
 322                 }
 323         }
 324
 325         return status;
 326 }
 327
 328 static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
 329                                       irq_hw_number_t hw)
 330 {
 331         struct intc_irqpin_priv *p = h->host_data;
 332
 333         p->irq[hw].domain_irq = virq;
 334         p->irq[hw].hw_irq = hw;
 335
 336         intc_irqpin_dbg(&p->irq[hw], "map");
 337         irq_set_chip_data(virq, h->host_data);
 338         irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
 339         set_irq_flags(virq, IRQF_VALID); /* kill me now */
 340         return 0;
 341 }
 342
 343 static struct irq_domain_ops intc_irqpin_irq_domain_ops = {
 344         .map    = intc_irqpin_irq_domain_map,
 345         .xlate  = irq_domain_xlate_twocell,
 346 };
 347
 348 static int intc_irqpin_probe(struct platform_device *pdev)
 349 {
 350         struct device *dev = &pdev->dev;
 351         struct renesas_intc_irqpin_config *pdata = dev->platform_data;
 352         struct intc_irqpin_priv *p;
 353         struct intc_irqpin_iomem *i;
 354         struct resource *io[INTC_IRQPIN_REG_NR];
 355         struct resource *irq;
 356         struct irq_chip *irq_chip;
 357         void (*enable_fn)(struct irq_data *d);
 358         void (*disable_fn)(struct irq_data *d);
 359         const char *name = dev_name(dev);
 360         int ref_irq;
 361         int ret;
 362         int k;
 363
 364         p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
 365         if (!p) {
 366                 dev_err(dev, "failed to allocate driver data\n");
 367                 return -ENOMEM;
 368         }
 369
 370         /* deal with driver instance configuration */
 371         if (pdata) {
 372                 memcpy(&p->config, pdata, sizeof(*pdata));
 373         } else {
 374                 of_property_read_u32(dev->of_node, "sense-bitfield-width",
 375                                      &p->config.sense_bitfield_width);
 376                 p->config.control_parent = of_property_read_bool(dev->of_node,
 377                                                                  "control-parent");
 378         }
 379         if (!p->config.sense_bitfield_width)
 380                 p->config.sense_bitfield_width = 4; /* default to 4 bits */
 381
 382         p->pdev = pdev;
 383         platform_set_drvdata(pdev, p);
 384
 385         p->clk = devm_clk_get(dev, NULL);
 386         if (IS_ERR(p->clk)) {
 387                 dev_warn(dev, "unable to get clock\n");
 388                 p->clk = NULL;
 389         }
 390
 391         pm_runtime_enable(dev);
 392         pm_runtime_get_sync(dev);
 393
 394         /* get hold of manadatory IOMEM */
 395         for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 396                 io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
 397                 if (!io[k]) {
 398                         dev_err(dev, "not enough IOMEM resources\n");
 399                         ret = -EINVAL;
 400                         goto err0;
 401                 }
 402         }
 403
 404         /* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
 405         for (k = 0; k < INTC_IRQPIN_MAX; k++) {
 406                 irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
 407                 if (!irq)
 408                         break;
 409
 410                 p->irq[k].p = p;
 411                 p->irq[k].requested_irq = irq->start;
 412         }
 413
 414         p->number_of_irqs = k;
 415         if (p->number_of_irqs < 1) {
 416                 dev_err(dev, "not enough IRQ resources\n");
 417                 ret = -EINVAL;
 418                 goto err0;
 419         }
 420
 421         /* ioremap IOMEM and setup read/write callbacks */
 422         for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
 423                 i = &p->iomem[k];
 424
 425                 switch (resource_size(io[k])) {
 426                 case 1:
 427                         i->width = 8;
 428                         i->read = intc_irqpin_read8;
 429                         i->write = intc_irqpin_write8;
 430                         break;
 431                 case 4:
 432                         i->width = 32;
 433                         i->read = intc_irqpin_read32;
 434                         i->write = intc_irqpin_write32;
 435                         break;
 436                 default:
 437                         dev_err(dev, "IOMEM size mismatch\n");
 438                         ret = -EINVAL;
 439                         goto err0;
 440                 }
 441
 442                 i->iomem = devm_ioremap_nocache(dev, io[k]->start,
 443                                                 resource_size(io[k]));
 444                 if (!i->iomem) {
 445                         dev_err(dev, "failed to remap IOMEM\n");
 446                         ret = -ENXIO;
 447                         goto err0;
 448                 }
 449         }
 450
 451         /* mask all interrupts using priority */
 452         for (k = 0; k < p->number_of_irqs; k++)
 453                 intc_irqpin_mask_unmask_prio(p, k, 1);
 454
 455         /* clear all pending interrupts */
 456         intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, 0x0);
 457
 458         /* scan for shared interrupt lines */
 459         ref_irq = p->irq[0].requested_irq;
 460         p->shared_irqs = true;
 461         for (k = 1; k < p->number_of_irqs; k++) {
 462                 if (ref_irq != p->irq[k].requested_irq) {
 463                         p->shared_irqs = false;
 464                         break;
 465                 }
 466         }
 467
 468         /* use more severe masking method if requested */
 469         if (p->config.control_parent) {
 470                 enable_fn = intc_irqpin_irq_enable_force;
 471                 disable_fn = intc_irqpin_irq_disable_force;
 472         } else if (!p->shared_irqs) {
 473                 enable_fn = intc_irqpin_irq_enable;
 474                 disable_fn = intc_irqpin_irq_disable;
 475         } else {
 476                 enable_fn = intc_irqpin_shared_irq_enable;
 477                 disable_fn = intc_irqpin_shared_irq_disable;
 478         }
 479
 480         irq_chip = &p->irq_chip;
 481         irq_chip->name = name;
 482         irq_chip->irq_mask = disable_fn;
 483         irq_chip->irq_unmask = enable_fn;
 484         irq_chip->irq_set_type = intc_irqpin_irq_set_type;
 485         irq_chip->irq_set_wake = intc_irqpin_irq_set_wake;
 486         irq_chip->flags = IRQCHIP_MASK_ON_SUSPEND;
 487
 488         p->irq_domain = irq_domain_add_simple(dev->of_node,
 489                                               p->number_of_irqs,
 490                                               p->config.irq_base,
 491                                               &intc_irqpin_irq_domain_ops, p);
 492         if (!p->irq_domain) {
 493                 ret = -ENXIO;
 494                 dev_err(dev, "cannot initialize irq domain\n");
 495                 goto err0;
 496         }
 497
 498         if (p->shared_irqs) {
 499                 /* request one shared interrupt */
 500                 if (devm_request_irq(dev, p->irq[0].requested_irq,
 501                                 intc_irqpin_shared_irq_handler,
 502                                 IRQF_SHARED, name, p)) {
 503                         dev_err(dev, "failed to request low IRQ\n");
 504                         ret = -ENOENT;
 505                         goto err1;
 506                 }
 507         } else {
 508                 /* request interrupts one by one */
 509                 for (k = 0; k < p->number_of_irqs; k++) {
 510                         if (devm_request_irq(dev, p->irq[k].requested_irq,
 511                                              intc_irqpin_irq_handler, 0, name,
 512                                              &p->irq[k])) {
 513                                 dev_err(dev, "failed to request low IRQ\n");
 514                                 ret = -ENOENT;
 515                                 goto err1;
 516                         }
 517                 }
 518         }
 519
 520         /* unmask all interrupts on prio level */
 521         for (k = 0; k < p->number_of_irqs; k++)
 522                 intc_irqpin_mask_unmask_prio(p, k, 0);
 523
 524         dev_info(dev, "driving %d irqs\n", p->number_of_irqs);
 525
 526         /* warn in case of mismatch if irq base is specified */
 527         if (p->config.irq_base) {
 528                 if (p->config.irq_base != p->irq[0].domain_irq)
 529                         dev_warn(dev, "irq base mismatch (%d/%d)\n",
 530                                  p->config.irq_base, p->irq[0].domain_irq);
 531         }
 532
 533         return 0;
 534
 535 err1:
 536         irq_domain_remove(p->irq_domain);
 537 err0:
 538         pm_runtime_put(dev);
 539         pm_runtime_disable(dev);
 540         return ret;
 541 }
 542
 543 static int intc_irqpin_remove(struct platform_device *pdev)
 544 {
 545         struct intc_irqpin_priv *p = platform_get_drvdata(pdev);
 546
 547         irq_domain_remove(p->irq_domain);
 548         pm_runtime_put(&pdev->dev);
 549         pm_runtime_disable(&pdev->dev);
 550         return 0;
 551 }
 552
 553 static const struct of_device_id intc_irqpin_dt_ids[] = {
 554         { .compatible = "renesas,intc-irqpin", },
 555         {},
 556 };
 557 MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
 558
 559 static struct platform_driver intc_irqpin_device_driver = {
 560         .probe          = intc_irqpin_probe,
 561         .remove         = intc_irqpin_remove,
 562         .driver         = {
 563                 .name   = "renesas_intc_irqpin",
 564                 .of_match_table = intc_irqpin_dt_ids,
 565         }
 566 };
 567
 568 static int __init intc_irqpin_init(void)
 569 {
 570         return platform_driver_register(&intc_irqpin_device_driver);
 571 }
 572 postcore_initcall(intc_irqpin_init);
 573
 574 static void __exit intc_irqpin_exit(void)
 575 {
 576         platform_driver_unregister(&intc_irqpin_device_driver);
 577 }
 578 module_exit(intc_irqpin_exit);
 579
 580 MODULE_AUTHOR("Magnus Damm");
 581 MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
 582 MODULE_LICENSE("GPL v2");