kernel/drivers/irqchip/irq-imgpdc.c

   1 /*
   2  * IMG PowerDown Controller (PDC)
   3  *
   4  * Copyright 2010-2013 Imagination Technologies Ltd.
   5  *
   6  * Exposes the syswake and PDC peripheral wake interrupts to the system.
   7  *
   8  */
   9
  10 #include <linux/bitops.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/irqdomain.h>
  13 #include <linux/io.h>
  14 #include <linux/kernel.h>
  15 #include <linux/of.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/spinlock.h>
  18
  19 /* PDC interrupt register numbers */
  20
  21 #define PDC_IRQ_STATUS                  0x310
  22 #define PDC_IRQ_ENABLE                  0x314
  23 #define PDC_IRQ_CLEAR                   0x318
  24 #define PDC_IRQ_ROUTE                   0x31c
  25 #define PDC_SYS_WAKE_BASE               0x330
  26 #define PDC_SYS_WAKE_STRIDE             0x8
  27 #define PDC_SYS_WAKE_CONFIG_BASE        0x334
  28 #define PDC_SYS_WAKE_CONFIG_STRIDE      0x8
  29
  30 /* PDC interrupt register field masks */
  31
  32 #define PDC_IRQ_SYS3                    0x08
  33 #define PDC_IRQ_SYS2                    0x04
  34 #define PDC_IRQ_SYS1                    0x02
  35 #define PDC_IRQ_SYS0                    0x01
  36 #define PDC_IRQ_ROUTE_WU_EN_SYS3        0x08000000
  37 #define PDC_IRQ_ROUTE_WU_EN_SYS2        0x04000000
  38 #define PDC_IRQ_ROUTE_WU_EN_SYS1        0x02000000
  39 #define PDC_IRQ_ROUTE_WU_EN_SYS0        0x01000000
  40 #define PDC_IRQ_ROUTE_WU_EN_WD          0x00040000
  41 #define PDC_IRQ_ROUTE_WU_EN_IR          0x00020000
  42 #define PDC_IRQ_ROUTE_WU_EN_RTC         0x00010000
  43 #define PDC_IRQ_ROUTE_EXT_EN_SYS3       0x00000800
  44 #define PDC_IRQ_ROUTE_EXT_EN_SYS2       0x00000400
  45 #define PDC_IRQ_ROUTE_EXT_EN_SYS1       0x00000200
  46 #define PDC_IRQ_ROUTE_EXT_EN_SYS0       0x00000100
  47 #define PDC_IRQ_ROUTE_EXT_EN_WD         0x00000004
  48 #define PDC_IRQ_ROUTE_EXT_EN_IR         0x00000002
  49 #define PDC_IRQ_ROUTE_EXT_EN_RTC        0x00000001
  50 #define PDC_SYS_WAKE_RESET              0x00000010
  51 #define PDC_SYS_WAKE_INT_MODE           0x0000000e
  52 #define PDC_SYS_WAKE_INT_MODE_SHIFT     1
  53 #define PDC_SYS_WAKE_PIN_VAL            0x00000001
  54
  55 /* PDC interrupt constants */
  56
  57 #define PDC_SYS_WAKE_INT_LOW            0x0
  58 #define PDC_SYS_WAKE_INT_HIGH           0x1
  59 #define PDC_SYS_WAKE_INT_DOWN           0x2
  60 #define PDC_SYS_WAKE_INT_UP             0x3
  61 #define PDC_SYS_WAKE_INT_CHANGE         0x6
  62 #define PDC_SYS_WAKE_INT_NONE           0x4
  63
  64 /**
  65  * struct pdc_intc_priv - private pdc interrupt data.
  66  * @nr_perips:          Number of peripheral interrupt signals.
  67  * @nr_syswakes:        Number of syswake signals.
  68  * @perip_irqs:         List of peripheral IRQ numbers handled.
  69  * @syswake_irq:        Shared PDC syswake IRQ number.
  70  * @domain:             IRQ domain for PDC peripheral and syswake IRQs.
  71  * @pdc_base:           Base of PDC registers.
  72  * @irq_route:          Cached version of PDC_IRQ_ROUTE register.
  73  * @lock:               Lock to protect the PDC syswake registers and the cached
  74  *                      values of those registers in this struct.
  75  */
  76 struct pdc_intc_priv {
  77         unsigned int            nr_perips;
  78         unsigned int            nr_syswakes;
  79         unsigned int            *perip_irqs;
  80         unsigned int            syswake_irq;
  81         struct irq_domain       *domain;
  82         void __iomem            *pdc_base;
  83
  84         u32                     irq_route;
  85         raw_spinlock_t          lock;
  86 };
  87
  88 static void pdc_write(struct pdc_intc_priv *priv, unsigned int reg_offs,
  89                       unsigned int data)
  90 {
  91         iowrite32(data, priv->pdc_base + reg_offs);
  92 }
  93
  94 static unsigned int pdc_read(struct pdc_intc_priv *priv,
  95                              unsigned int reg_offs)
  96 {
  97         return ioread32(priv->pdc_base + reg_offs);
  98 }
  99
 100 /* Generic IRQ callbacks */
 101
 102 #define SYS0_HWIRQ      8
 103
 104 static unsigned int hwirq_is_syswake(irq_hw_number_t hw)
 105 {
 106         return hw >= SYS0_HWIRQ;
 107 }
 108
 109 static unsigned int hwirq_to_syswake(irq_hw_number_t hw)
 110 {
 111         return hw - SYS0_HWIRQ;
 112 }
 113
 114 static irq_hw_number_t syswake_to_hwirq(unsigned int syswake)
 115 {
 116         return SYS0_HWIRQ + syswake;
 117 }
 118
 119 static struct pdc_intc_priv *irqd_to_priv(struct irq_data *data)
 120 {
 121         return (struct pdc_intc_priv *)data->domain->host_data;
 122 }
 123
 124 /*
 125  * perip_irq_mask() and perip_irq_unmask() use IRQ_ROUTE which also contains
 126  * wake bits, therefore we cannot use the generic irqchip mask callbacks as they
 127  * cache the mask.
 128  */
 129
 130 static void perip_irq_mask(struct irq_data *data)
 131 {
 132         struct pdc_intc_priv *priv = irqd_to_priv(data);
 133
 134         raw_spin_lock(&priv->lock);
 135         priv->irq_route &= ~data->mask;
 136         pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
 137         raw_spin_unlock(&priv->lock);
 138 }
 139
 140 static void perip_irq_unmask(struct irq_data *data)
 141 {
 142         struct pdc_intc_priv *priv = irqd_to_priv(data);
 143
 144         raw_spin_lock(&priv->lock);
 145         priv->irq_route |= data->mask;
 146         pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
 147         raw_spin_unlock(&priv->lock);
 148 }
 149
 150 static int syswake_irq_set_type(struct irq_data *data, unsigned int flow_type)
 151 {
 152         struct pdc_intc_priv *priv = irqd_to_priv(data);
 153         unsigned int syswake = hwirq_to_syswake(data->hwirq);
 154         unsigned int irq_mode;
 155         unsigned int soc_sys_wake_regoff, soc_sys_wake;
 156
 157         /* translate to syswake IRQ mode */
 158         switch (flow_type) {
 159         case IRQ_TYPE_EDGE_BOTH:
 160                 irq_mode = PDC_SYS_WAKE_INT_CHANGE;
 161                 break;
 162         case IRQ_TYPE_EDGE_RISING:
 163                 irq_mode = PDC_SYS_WAKE_INT_UP;
 164                 break;
 165         case IRQ_TYPE_EDGE_FALLING:
 166                 irq_mode = PDC_SYS_WAKE_INT_DOWN;
 167                 break;
 168         case IRQ_TYPE_LEVEL_HIGH:
 169                 irq_mode = PDC_SYS_WAKE_INT_HIGH;
 170                 break;
 171         case IRQ_TYPE_LEVEL_LOW:
 172                 irq_mode = PDC_SYS_WAKE_INT_LOW;
 173                 break;
 174         default:
 175                 return -EINVAL;
 176         }
 177
 178         raw_spin_lock(&priv->lock);
 179
 180         /* set the IRQ mode */
 181         soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + syswake*PDC_SYS_WAKE_STRIDE;
 182         soc_sys_wake = pdc_read(priv, soc_sys_wake_regoff);
 183         soc_sys_wake &= ~PDC_SYS_WAKE_INT_MODE;
 184         soc_sys_wake |= irq_mode << PDC_SYS_WAKE_INT_MODE_SHIFT;
 185         pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
 186
 187         /* and update the handler */
 188         irq_setup_alt_chip(data, flow_type);
 189
 190         raw_spin_unlock(&priv->lock);
 191
 192         return 0;
 193 }
 194
 195 /* applies to both peripheral and syswake interrupts */
 196 static int pdc_irq_set_wake(struct irq_data *data, unsigned int on)
 197 {
 198         struct pdc_intc_priv *priv = irqd_to_priv(data);
 199         irq_hw_number_t hw = data->hwirq;
 200         unsigned int mask = (1 << 16) << hw;
 201         unsigned int dst_irq;
 202
 203         raw_spin_lock(&priv->lock);
 204         if (on)
 205                 priv->irq_route |= mask;
 206         else
 207                 priv->irq_route &= ~mask;
 208         pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
 209         raw_spin_unlock(&priv->lock);
 210
 211         /* control the destination IRQ wakeup too for standby mode */
 212         if (hwirq_is_syswake(hw))
 213                 dst_irq = priv->syswake_irq;
 214         else
 215                 dst_irq = priv->perip_irqs[hw];
 216         irq_set_irq_wake(dst_irq, on);
 217
 218         return 0;
 219 }
 220
 221 static void pdc_intc_perip_isr(unsigned int irq, struct irq_desc *desc)
 222 {
 223         struct pdc_intc_priv *priv;
 224         unsigned int i, irq_no;
 225
 226         priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);
 227
 228         /* find the peripheral number */
 229         for (i = 0; i < priv->nr_perips; ++i)
 230                 if (irq == priv->perip_irqs[i])
 231                         goto found;
 232
 233         /* should never get here */
 234         return;
 235 found:
 236
 237         /* pass on the interrupt */
 238         irq_no = irq_linear_revmap(priv->domain, i);
 239         generic_handle_irq(irq_no);
 240 }
 241
 242 static void pdc_intc_syswake_isr(unsigned int irq, struct irq_desc *desc)
 243 {
 244         struct pdc_intc_priv *priv;
 245         unsigned int syswake, irq_no;
 246         unsigned int status;
 247
 248         priv = (struct pdc_intc_priv *)irq_desc_get_handler_data(desc);
 249
 250         status = pdc_read(priv, PDC_IRQ_STATUS) &
 251                  pdc_read(priv, PDC_IRQ_ENABLE);
 252         status &= (1 << priv->nr_syswakes) - 1;
 253
 254         for (syswake = 0; status; status >>= 1, ++syswake) {
 255                 /* Has this sys_wake triggered? */
 256                 if (!(status & 1))
 257                         continue;
 258
 259                 irq_no = irq_linear_revmap(priv->domain,
 260                                            syswake_to_hwirq(syswake));
 261                 generic_handle_irq(irq_no);
 262         }
 263 }
 264
 265 static void pdc_intc_setup(struct pdc_intc_priv *priv)
 266 {
 267         int i;
 268         unsigned int soc_sys_wake_regoff;
 269         unsigned int soc_sys_wake;
 270
 271         /*
 272          * Mask all syswake interrupts before routing, or we could receive an
 273          * interrupt before we're ready to handle it.
 274          */
 275         pdc_write(priv, PDC_IRQ_ENABLE, 0);
 276
 277         /*
 278          * Enable routing of all syswakes
 279          * Disable all wake sources
 280          */
 281         priv->irq_route = ((PDC_IRQ_ROUTE_EXT_EN_SYS0 << priv->nr_syswakes) -
 282                                 PDC_IRQ_ROUTE_EXT_EN_SYS0);
 283         pdc_write(priv, PDC_IRQ_ROUTE, priv->irq_route);
 284
 285         /* Initialise syswake IRQ */
 286         for (i = 0; i < priv->nr_syswakes; ++i) {
 287                 /* set the IRQ mode to none */
 288                 soc_sys_wake_regoff = PDC_SYS_WAKE_BASE + i*PDC_SYS_WAKE_STRIDE;
 289                 soc_sys_wake = PDC_SYS_WAKE_INT_NONE
 290                                 << PDC_SYS_WAKE_INT_MODE_SHIFT;
 291                 pdc_write(priv, soc_sys_wake_regoff, soc_sys_wake);
 292         }
 293 }
 294
 295 static int pdc_intc_probe(struct platform_device *pdev)
 296 {
 297         struct pdc_intc_priv *priv;
 298         struct device_node *node = pdev->dev.of_node;
 299         struct resource *res_regs;
 300         struct irq_chip_generic *gc;
 301         unsigned int i;
 302         int irq, ret;
 303         u32 val;
 304
 305         if (!node)
 306                 return -ENOENT;
 307
 308         /* Get registers */
 309         res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 310         if (res_regs == NULL) {
 311                 dev_err(&pdev->dev, "cannot find registers resource\n");
 312                 return -ENOENT;
 313         }
 314
 315         /* Allocate driver data */
 316         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 317         if (!priv) {
 318                 dev_err(&pdev->dev, "cannot allocate device data\n");
 319                 return -ENOMEM;
 320         }
 321         raw_spin_lock_init(&priv->lock);
 322         platform_set_drvdata(pdev, priv);
 323
 324         /* Ioremap the registers */
 325         priv->pdc_base = devm_ioremap(&pdev->dev, res_regs->start,
 326                                       res_regs->end - res_regs->start);
 327         if (!priv->pdc_base)
 328                 return -EIO;
 329
 330         /* Get number of peripherals */
 331         ret = of_property_read_u32(node, "num-perips", &val);
 332         if (ret) {
 333                 dev_err(&pdev->dev, "No num-perips node property found\n");
 334                 return -EINVAL;
 335         }
 336         if (val > SYS0_HWIRQ) {
 337                 dev_err(&pdev->dev, "num-perips (%u) out of range\n", val);
 338                 return -EINVAL;
 339         }
 340         priv->nr_perips = val;
 341
 342         /* Get number of syswakes */
 343         ret = of_property_read_u32(node, "num-syswakes", &val);
 344         if (ret) {
 345                 dev_err(&pdev->dev, "No num-syswakes node property found\n");
 346                 return -EINVAL;
 347         }
 348         if (val > SYS0_HWIRQ) {
 349                 dev_err(&pdev->dev, "num-syswakes (%u) out of range\n", val);
 350                 return -EINVAL;
 351         }
 352         priv->nr_syswakes = val;
 353
 354         /* Get peripheral IRQ numbers */
 355         priv->perip_irqs = devm_kzalloc(&pdev->dev, 4 * priv->nr_perips,
 356                                         GFP_KERNEL);
 357         if (!priv->perip_irqs) {
 358                 dev_err(&pdev->dev, "cannot allocate perip IRQ list\n");
 359                 return -ENOMEM;
 360         }
 361         for (i = 0; i < priv->nr_perips; ++i) {
 362                 irq = platform_get_irq(pdev, 1 + i);
 363                 if (irq < 0) {
 364                         dev_err(&pdev->dev, "cannot find perip IRQ #%u\n", i);
 365                         return irq;
 366                 }
 367                 priv->perip_irqs[i] = irq;
 368         }
 369         /* check if too many were provided */
 370         if (platform_get_irq(pdev, 1 + i) >= 0) {
 371                 dev_err(&pdev->dev, "surplus perip IRQs detected\n");
 372                 return -EINVAL;
 373         }
 374
 375         /* Get syswake IRQ number */
 376         irq = platform_get_irq(pdev, 0);
 377         if (irq < 0) {
 378                 dev_err(&pdev->dev, "cannot find syswake IRQ\n");
 379                 return irq;
 380         }
 381         priv->syswake_irq = irq;
 382
 383         /* Set up an IRQ domain */
 384         priv->domain = irq_domain_add_linear(node, 16, &irq_generic_chip_ops,
 385                                              priv);
 386         if (unlikely(!priv->domain)) {
 387                 dev_err(&pdev->dev, "cannot add IRQ domain\n");
 388                 return -ENOMEM;
 389         }
 390
 391         /*
 392          * Set up 2 generic irq chips with 2 chip types.
 393          * The first one for peripheral irqs (only 1 chip type used)
 394          * The second one for syswake irqs (edge and level chip types)
 395          */
 396         ret = irq_alloc_domain_generic_chips(priv->domain, 8, 2, "pdc",
 397                                              handle_level_irq, 0, 0,
 398                                              IRQ_GC_INIT_NESTED_LOCK);
 399         if (ret)
 400                 goto err_generic;
 401
 402         /* peripheral interrupt chip */
 403
 404         gc = irq_get_domain_generic_chip(priv->domain, 0);
 405         gc->unused      = ~(BIT(priv->nr_perips) - 1);
 406         gc->reg_base    = priv->pdc_base;
 407         /*
 408          * IRQ_ROUTE contains wake bits, so we can't use the generic versions as
 409          * they cache the mask
 410          */
 411         gc->chip_types[0].regs.mask             = PDC_IRQ_ROUTE;
 412         gc->chip_types[0].chip.irq_mask         = perip_irq_mask;
 413         gc->chip_types[0].chip.irq_unmask       = perip_irq_unmask;
 414         gc->chip_types[0].chip.irq_set_wake     = pdc_irq_set_wake;
 415
 416         /* syswake interrupt chip */
 417
 418         gc = irq_get_domain_generic_chip(priv->domain, 8);
 419         gc->unused      = ~(BIT(priv->nr_syswakes) - 1);
 420         gc->reg_base    = priv->pdc_base;
 421
 422         /* edge interrupts */
 423         gc->chip_types[0].type                  = IRQ_TYPE_EDGE_BOTH;
 424         gc->chip_types[0].handler               = handle_edge_irq;
 425         gc->chip_types[0].regs.ack              = PDC_IRQ_CLEAR;
 426         gc->chip_types[0].regs.mask             = PDC_IRQ_ENABLE;
 427         gc->chip_types[0].chip.irq_ack          = irq_gc_ack_set_bit;
 428         gc->chip_types[0].chip.irq_mask         = irq_gc_mask_clr_bit;
 429         gc->chip_types[0].chip.irq_unmask       = irq_gc_mask_set_bit;
 430         gc->chip_types[0].chip.irq_set_type     = syswake_irq_set_type;
 431         gc->chip_types[0].chip.irq_set_wake     = pdc_irq_set_wake;
 432         /* for standby we pass on to the shared syswake IRQ */
 433         gc->chip_types[0].chip.flags            = IRQCHIP_MASK_ON_SUSPEND;
 434
 435         /* level interrupts */
 436         gc->chip_types[1].type                  = IRQ_TYPE_LEVEL_MASK;
 437         gc->chip_types[1].handler               = handle_level_irq;
 438         gc->chip_types[1].regs.ack              = PDC_IRQ_CLEAR;
 439         gc->chip_types[1].regs.mask             = PDC_IRQ_ENABLE;
 440         gc->chip_types[1].chip.irq_ack          = irq_gc_ack_set_bit;
 441         gc->chip_types[1].chip.irq_mask         = irq_gc_mask_clr_bit;
 442         gc->chip_types[1].chip.irq_unmask       = irq_gc_mask_set_bit;
 443         gc->chip_types[1].chip.irq_set_type     = syswake_irq_set_type;
 444         gc->chip_types[1].chip.irq_set_wake     = pdc_irq_set_wake;
 445         /* for standby we pass on to the shared syswake IRQ */
 446         gc->chip_types[1].chip.flags            = IRQCHIP_MASK_ON_SUSPEND;
 447
 448         /* Set up the hardware to enable interrupt routing */
 449         pdc_intc_setup(priv);
 450
 451         /* Setup chained handlers for the peripheral IRQs */
 452         for (i = 0; i < priv->nr_perips; ++i) {
 453                 irq = priv->perip_irqs[i];
 454                 irq_set_handler_data(irq, priv);
 455                 irq_set_chained_handler(irq, pdc_intc_perip_isr);
 456         }
 457
 458         /* Setup chained handler for the syswake IRQ */
 459         irq_set_handler_data(priv->syswake_irq, priv);
 460         irq_set_chained_handler(priv->syswake_irq, pdc_intc_syswake_isr);
 461
 462         dev_info(&pdev->dev,
 463                  "PDC IRQ controller initialised (%u perip IRQs, %u syswake IRQs)\n",
 464                  priv->nr_perips,
 465                  priv->nr_syswakes);
 466
 467         return 0;
 468 err_generic:
 469         irq_domain_remove(priv->domain);
 470         return ret;
 471 }
 472
 473 static int pdc_intc_remove(struct platform_device *pdev)
 474 {
 475         struct pdc_intc_priv *priv = platform_get_drvdata(pdev);
 476
 477         irq_domain_remove(priv->domain);
 478         return 0;
 479 }
 480
 481 static const struct of_device_id pdc_intc_match[] = {
 482         { .compatible = "img,pdc-intc" },
 483         {}
 484 };
 485
 486 static struct platform_driver pdc_intc_driver = {
 487         .driver = {
 488                 .name           = "pdc-intc",
 489                 .of_match_table = pdc_intc_match,
 490         },
 491         .probe = pdc_intc_probe,
 492         .remove = pdc_intc_remove,
 493 };
 494
 495 static int __init pdc_intc_init(void)
 496 {
 497         return platform_driver_register(&pdc_intc_driver);
 498 }
 499 core_initcall(pdc_intc_init);