drivers/gpio/gpio-davinci.c

   1 /*
   2  * TI DaVinci GPIO Support
   3  *
   4  * Copyright (c) 2006-2007 David Brownell
   5  * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12 #include <linux/gpio.h>
  13 #include <linux/errno.h>
  14 #include <linux/kernel.h>
  15 #include <linux/clk.h>
  16 #include <linux/err.h>
  17 #include <linux/io.h>
  18 #include <linux/irq.h>
  19 #include <linux/irqdomain.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/of_device.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/platform_data/gpio-davinci.h>
  25 #include <linux/irqchip/chained_irq.h>
  26
  27 struct davinci_gpio_regs {
  28         u32     dir;
  29         u32     out_data;
  30         u32     set_data;
  31         u32     clr_data;
  32         u32     in_data;
  33         u32     set_rising;
  34         u32     clr_rising;
  35         u32     set_falling;
  36         u32     clr_falling;
  37         u32     intstat;
  38 };
  39
  40 typedef struct irq_chip *(*gpio_get_irq_chip_cb_t)(unsigned int irq);
  41
  42 #define BINTEN  0x8 /* GPIO Interrupt Per-Bank Enable Register */
  43
  44 static void __iomem *gpio_base;
  45
  46 static struct davinci_gpio_regs __iomem *gpio2regs(unsigned gpio)
  47 {
  48         void __iomem *ptr;
  49
  50         if (gpio < 32 * 1)
  51                 ptr = gpio_base + 0x10;
  52         else if (gpio < 32 * 2)
  53                 ptr = gpio_base + 0x38;
  54         else if (gpio < 32 * 3)
  55                 ptr = gpio_base + 0x60;
  56         else if (gpio < 32 * 4)
  57                 ptr = gpio_base + 0x88;
  58         else if (gpio < 32 * 5)
  59                 ptr = gpio_base + 0xb0;
  60         else
  61                 ptr = NULL;
  62         return ptr;
  63 }
  64
  65 static inline struct davinci_gpio_regs __iomem *irq2regs(struct irq_data *d)
  66 {
  67         struct davinci_gpio_regs __iomem *g;
  68
  69         g = (__force struct davinci_gpio_regs __iomem *)irq_data_get_irq_chip_data(d);
  70
  71         return g;
  72 }
  73
  74 static int davinci_gpio_irq_setup(struct platform_device *pdev);
  75
  76 /*--------------------------------------------------------------------------*/
  77
  78 /* board setup code *MUST* setup pinmux and enable the GPIO clock. */
  79 static inline int __davinci_direction(struct gpio_chip *chip,
  80                         unsigned offset, bool out, int value)
  81 {
  82         struct davinci_gpio_controller *d = gpiochip_get_data(chip);
  83         struct davinci_gpio_regs __iomem *g = d->regs;
  84         unsigned long flags;
  85         u32 temp;
  86         u32 mask = 1 << offset;
  87
  88         spin_lock_irqsave(&d->lock, flags);
  89         temp = readl_relaxed(&g->dir);
  90         if (out) {
  91                 temp &= ~mask;
  92                 writel_relaxed(mask, value ? &g->set_data : &g->clr_data);
  93         } else {
  94                 temp |= mask;
  95         }
  96         writel_relaxed(temp, &g->dir);
  97         spin_unlock_irqrestore(&d->lock, flags);
  98
  99         return 0;
 100 }
 101
 102 static int davinci_direction_in(struct gpio_chip *chip, unsigned offset)
 103 {
 104         return __davinci_direction(chip, offset, false, 0);
 105 }
 106
 107 static int
 108 davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value)
 109 {
 110         return __davinci_direction(chip, offset, true, value);
 111 }
 112
 113 /*
 114  * Read the pin's value (works even if it's set up as output);
 115  * returns zero/nonzero.
 116  *
 117  * Note that changes are synched to the GPIO clock, so reading values back
 118  * right after you've set them may give old values.
 119  */
 120 static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset)
 121 {
 122         struct davinci_gpio_controller *d = gpiochip_get_data(chip);
 123         struct davinci_gpio_regs __iomem *g = d->regs;
 124
 125         return !!((1 << offset) & readl_relaxed(&g->in_data));
 126 }
 127
 128 /*
 129  * Assuming the pin is muxed as a gpio output, set its output value.
 130  */
 131 static void
 132 davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 133 {
 134         struct davinci_gpio_controller *d = gpiochip_get_data(chip);
 135         struct davinci_gpio_regs __iomem *g = d->regs;
 136
 137         writel_relaxed((1 << offset), value ? &g->set_data : &g->clr_data);
 138 }
 139
 140 static struct davinci_gpio_platform_data *
 141 davinci_gpio_get_pdata(struct platform_device *pdev)
 142 {
 143         struct device_node *dn = pdev->dev.of_node;
 144         struct davinci_gpio_platform_data *pdata;
 145         int ret;
 146         u32 val;
 147
 148         if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)
 149                 return dev_get_platdata(&pdev->dev);
 150
 151         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 152         if (!pdata)
 153                 return NULL;
 154
 155         ret = of_property_read_u32(dn, "ti,ngpio", &val);
 156         if (ret)
 157                 goto of_err;
 158
 159         pdata->ngpio = val;
 160
 161         ret = of_property_read_u32(dn, "ti,davinci-gpio-unbanked", &val);
 162         if (ret)
 163                 goto of_err;
 164
 165         pdata->gpio_unbanked = val;
 166
 167         return pdata;
 168
 169 of_err:
 170         dev_err(&pdev->dev, "Populating pdata from DT failed: err %d\n", ret);
 171         return NULL;
 172 }
 173
 174 #ifdef CONFIG_OF_GPIO
 175 static int davinci_gpio_of_xlate(struct gpio_chip *gc,
 176                              const struct of_phandle_args *gpiospec,
 177                              u32 *flags)
 178 {
 179         struct davinci_gpio_controller *chips = dev_get_drvdata(gc->parent);
 180         struct davinci_gpio_platform_data *pdata = dev_get_platdata(gc->parent);
 181
 182         if (gpiospec->args[0] > pdata->ngpio)
 183                 return -EINVAL;
 184
 185         if (gc != &chips[gpiospec->args[0] / 32].chip)
 186                 return -EINVAL;
 187
 188         if (flags)
 189                 *flags = gpiospec->args[1];
 190
 191         return gpiospec->args[0] % 32;
 192 }
 193 #endif
 194
 195 static int davinci_gpio_probe(struct platform_device *pdev)
 196 {
 197         int i, base;
 198         unsigned ngpio;
 199         struct davinci_gpio_controller *chips;
 200         struct davinci_gpio_platform_data *pdata;
 201         struct davinci_gpio_regs __iomem *regs;
 202         struct device *dev = &pdev->dev;
 203         struct resource *res;
 204
 205         pdata = davinci_gpio_get_pdata(pdev);
 206         if (!pdata) {
 207                 dev_err(dev, "No platform data found\n");
 208                 return -EINVAL;
 209         }
 210
 211         dev->platform_data = pdata;
 212
 213         /*
 214          * The gpio banks conceptually expose a segmented bitmap,
 215          * and "ngpio" is one more than the largest zero-based
 216          * bit index that's valid.
 217          */
 218         ngpio = pdata->ngpio;
 219         if (ngpio == 0) {
 220                 dev_err(dev, "How many GPIOs?\n");
 221                 return -EINVAL;
 222         }
 223
 224         if (WARN_ON(ARCH_NR_GPIOS < ngpio))
 225                 ngpio = ARCH_NR_GPIOS;
 226
 227         chips = devm_kzalloc(dev,
 228                              ngpio * sizeof(struct davinci_gpio_controller),
 229                              GFP_KERNEL);
 230         if (!chips)
 231                 return -ENOMEM;
 232
 233         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 234         gpio_base = devm_ioremap_resource(dev, res);
 235         if (IS_ERR(gpio_base))
 236                 return PTR_ERR(gpio_base);
 237
 238         for (i = 0, base = 0; base < ngpio; i++, base += 32) {
 239                 chips[i].chip.label = "DaVinci";
 240
 241                 chips[i].chip.direction_input = davinci_direction_in;
 242                 chips[i].chip.get = davinci_gpio_get;
 243                 chips[i].chip.direction_output = davinci_direction_out;
 244                 chips[i].chip.set = davinci_gpio_set;
 245
 246                 chips[i].chip.base = base;
 247                 chips[i].chip.ngpio = ngpio - base;
 248                 if (chips[i].chip.ngpio > 32)
 249                         chips[i].chip.ngpio = 32;
 250
 251 #ifdef CONFIG_OF_GPIO
 252                 chips[i].chip.of_gpio_n_cells = 2;
 253                 chips[i].chip.of_xlate = davinci_gpio_of_xlate;
 254                 chips[i].chip.parent = dev;
 255                 chips[i].chip.of_node = dev->of_node;
 256 #endif
 257                 spin_lock_init(&chips[i].lock);
 258
 259                 regs = gpio2regs(base);
 260                 chips[i].regs = regs;
 261                 chips[i].set_data = &regs->set_data;
 262                 chips[i].clr_data = &regs->clr_data;
 263                 chips[i].in_data = &regs->in_data;
 264
 265                 gpiochip_add_data(&chips[i].chip, &chips[i]);
 266         }
 267
 268         platform_set_drvdata(pdev, chips);
 269         davinci_gpio_irq_setup(pdev);
 270         return 0;
 271 }
 272
 273 /*--------------------------------------------------------------------------*/
 274 /*
 275  * We expect irqs will normally be set up as input pins, but they can also be
 276  * used as output pins ... which is convenient for testing.
 277  *
 278  * NOTE:  The first few GPIOs also have direct INTC hookups in addition
 279  * to their GPIOBNK0 irq, with a bit less overhead.
 280  *
 281  * All those INTC hookups (direct, plus several IRQ banks) can also
 282  * serve as EDMA event triggers.
 283  */
 284
 285 static void gpio_irq_disable(struct irq_data *d)
 286 {
 287         struct davinci_gpio_regs __iomem *g = irq2regs(d);
 288         u32 mask = (u32) irq_data_get_irq_handler_data(d);
 289
 290         writel_relaxed(mask, &g->clr_falling);
 291         writel_relaxed(mask, &g->clr_rising);
 292 }
 293
 294 static void gpio_irq_enable(struct irq_data *d)
 295 {
 296         struct davinci_gpio_regs __iomem *g = irq2regs(d);
 297         u32 mask = (u32) irq_data_get_irq_handler_data(d);
 298         unsigned status = irqd_get_trigger_type(d);
 299
 300         status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
 301         if (!status)
 302                 status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING;
 303
 304         if (status & IRQ_TYPE_EDGE_FALLING)
 305                 writel_relaxed(mask, &g->set_falling);
 306         if (status & IRQ_TYPE_EDGE_RISING)
 307                 writel_relaxed(mask, &g->set_rising);
 308 }
 309
 310 static int gpio_irq_type(struct irq_data *d, unsigned trigger)
 311 {
 312         if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
 313                 return -EINVAL;
 314
 315         return 0;
 316 }
 317
 318 static struct irq_chip gpio_irqchip = {
 319         .name           = "GPIO",
 320         .irq_enable     = gpio_irq_enable,
 321         .irq_disable    = gpio_irq_disable,
 322         .irq_set_type   = gpio_irq_type,
 323         .flags          = IRQCHIP_SET_TYPE_MASKED,
 324 };
 325
 326 static void gpio_irq_handler(struct irq_desc *desc)
 327 {
 328         unsigned int irq = irq_desc_get_irq(desc);
 329         struct davinci_gpio_regs __iomem *g;
 330         u32 mask = 0xffff;
 331         struct davinci_gpio_controller *d;
 332
 333         d = (struct davinci_gpio_controller *)irq_desc_get_handler_data(desc);
 334         g = (struct davinci_gpio_regs __iomem *)d->regs;
 335
 336         /* we only care about one bank */
 337         if (irq & 1)
 338                 mask <<= 16;
 339
 340         /* temporarily mask (level sensitive) parent IRQ */
 341         chained_irq_enter(irq_desc_get_chip(desc), desc);
 342         while (1) {
 343                 u32             status;
 344                 int             bit;
 345
 346                 /* ack any irqs */
 347                 status = readl_relaxed(&g->intstat) & mask;
 348                 if (!status)
 349                         break;
 350                 writel_relaxed(status, &g->intstat);
 351
 352                 /* now demux them to the right lowlevel handler */
 353
 354                 while (status) {
 355                         bit = __ffs(status);
 356                         status &= ~BIT(bit);
 357                         generic_handle_irq(
 358                                 irq_find_mapping(d->irq_domain,
 359                                                  d->chip.base + bit));
 360                 }
 361         }
 362         chained_irq_exit(irq_desc_get_chip(desc), desc);
 363         /* now it may re-trigger */
 364 }
 365
 366 static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)
 367 {
 368         struct davinci_gpio_controller *d = gpiochip_get_data(chip);
 369
 370         if (d->irq_domain)
 371                 return irq_create_mapping(d->irq_domain, d->chip.base + offset);
 372         else
 373                 return -ENXIO;
 374 }
 375
 376 static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
 377 {
 378         struct davinci_gpio_controller *d = gpiochip_get_data(chip);
 379
 380         /*
 381          * NOTE:  we assume for now that only irqs in the first gpio_chip
 382          * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
 383          */
 384         if (offset < d->gpio_unbanked)
 385                 return d->gpio_irq + offset;
 386         else
 387                 return -ENODEV;
 388 }
 389
 390 static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
 391 {
 392         struct davinci_gpio_controller *d;
 393         struct davinci_gpio_regs __iomem *g;
 394         u32 mask;
 395
 396         d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data);
 397         g = (struct davinci_gpio_regs __iomem *)d->regs;
 398         mask = __gpio_mask(data->irq - d->gpio_irq);
 399
 400         if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
 401                 return -EINVAL;
 402
 403         writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING)
 404                      ? &g->set_falling : &g->clr_falling);
 405         writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING)
 406                      ? &g->set_rising : &g->clr_rising);
 407
 408         return 0;
 409 }
 410
 411 static int
 412 davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq,
 413                      irq_hw_number_t hw)
 414 {
 415         struct davinci_gpio_regs __iomem *g = gpio2regs(hw);
 416
 417         irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq,
 418                                 "davinci_gpio");
 419         irq_set_irq_type(irq, IRQ_TYPE_NONE);
 420         irq_set_chip_data(irq, (__force void *)g);
 421         irq_set_handler_data(irq, (void *)__gpio_mask(hw));
 422
 423         return 0;
 424 }
 425
 426 static const struct irq_domain_ops davinci_gpio_irq_ops = {
 427         .map = davinci_gpio_irq_map,
 428         .xlate = irq_domain_xlate_onetwocell,
 429 };
 430
 431 static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq)
 432 {
 433         static struct irq_chip_type gpio_unbanked;
 434
 435         gpio_unbanked = *container_of(irq_get_chip(irq),
 436                                       struct irq_chip_type, chip);
 437
 438         return &gpio_unbanked.chip;
 439 };
 440
 441 static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq)
 442 {
 443         static struct irq_chip gpio_unbanked;
 444
 445         gpio_unbanked = *irq_get_chip(irq);
 446         return &gpio_unbanked;
 447 };
 448
 449 static const struct of_device_id davinci_gpio_ids[];
 450
 451 /*
 452  * NOTE:  for suspend/resume, probably best to make a platform_device with
 453  * suspend_late/resume_resume calls hooking into results of the set_wake()
 454  * calls ... so if no gpios are wakeup events the clock can be disabled,
 455  * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0
 456  * (dm6446) can be set appropriately for GPIOV33 pins.
 457  */
 458
 459 static int davinci_gpio_irq_setup(struct platform_device *pdev)
 460 {
 461         unsigned        gpio, bank;
 462         int             irq;
 463         struct clk      *clk;
 464         u32             binten = 0;
 465         unsigned        ngpio, bank_irq;
 466         struct device *dev = &pdev->dev;
 467         struct resource *res;
 468         struct davinci_gpio_controller *chips = platform_get_drvdata(pdev);
 469         struct davinci_gpio_platform_data *pdata = dev->platform_data;
 470         struct davinci_gpio_regs __iomem *g;
 471         struct irq_domain       *irq_domain = NULL;
 472         const struct of_device_id *match;
 473         struct irq_chip *irq_chip;
 474         gpio_get_irq_chip_cb_t gpio_get_irq_chip;
 475
 476         /*
 477          * Use davinci_gpio_get_irq_chip by default to handle non DT cases
 478          */
 479         gpio_get_irq_chip = davinci_gpio_get_irq_chip;
 480         match = of_match_device(of_match_ptr(davinci_gpio_ids),
 481                                 dev);
 482         if (match)
 483                 gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)match->data;
 484
 485         ngpio = pdata->ngpio;
 486         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 487         if (!res) {
 488                 dev_err(dev, "Invalid IRQ resource\n");
 489                 return -EBUSY;
 490         }
 491
 492         bank_irq = res->start;
 493
 494         if (!bank_irq) {
 495                 dev_err(dev, "Invalid IRQ resource\n");
 496                 return -ENODEV;
 497         }
 498
 499         clk = devm_clk_get(dev, "gpio");
 500         if (IS_ERR(clk)) {
 501                 printk(KERN_ERR "Error %ld getting gpio clock?\n",
 502                        PTR_ERR(clk));
 503                 return PTR_ERR(clk);
 504         }
 505         clk_prepare_enable(clk);
 506
 507         if (!pdata->gpio_unbanked) {
 508                 irq = irq_alloc_descs(-1, 0, ngpio, 0);
 509                 if (irq < 0) {
 510                         dev_err(dev, "Couldn't allocate IRQ numbers\n");
 511                         return irq;
 512                 }
 513
 514                 irq_domain = irq_domain_add_legacy(NULL, ngpio, irq, 0,
 515                                                         &davinci_gpio_irq_ops,
 516                                                         chips);
 517                 if (!irq_domain) {
 518                         dev_err(dev, "Couldn't register an IRQ domain\n");
 519                         return -ENODEV;
 520                 }
 521         }
 522
 523         /*
 524          * Arrange gpio_to_irq() support, handling either direct IRQs or
 525          * banked IRQs.  Having GPIOs in the first GPIO bank use direct
 526          * IRQs, while the others use banked IRQs, would need some setup
 527          * tweaks to recognize hardware which can do that.
 528          */
 529         for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) {
 530                 chips[bank].chip.to_irq = gpio_to_irq_banked;
 531                 chips[bank].irq_domain = irq_domain;
 532         }
 533
 534         /*
 535          * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO
 536          * controller only handling trigger modes.  We currently assume no
 537          * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
 538          */
 539         if (pdata->gpio_unbanked) {
 540                 /* pass "bank 0" GPIO IRQs to AINTC */
 541                 chips[0].chip.to_irq = gpio_to_irq_unbanked;
 542                 chips[0].gpio_irq = bank_irq;
 543                 chips[0].gpio_unbanked = pdata->gpio_unbanked;
 544                 binten = GENMASK(pdata->gpio_unbanked / 16, 0);
 545
 546                 /* AINTC handles mask/unmask; GPIO handles triggering */
 547                 irq = bank_irq;
 548                 irq_chip = gpio_get_irq_chip(irq);
 549                 irq_chip->name = "GPIO-AINTC";
 550                 irq_chip->irq_set_type = gpio_irq_type_unbanked;
 551
 552                 /* default trigger: both edges */
 553                 g = gpio2regs(0);
 554                 writel_relaxed(~0, &g->set_falling);
 555                 writel_relaxed(~0, &g->set_rising);
 556
 557                 /* set the direct IRQs up to use that irqchip */
 558                 for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++, irq++) {
 559                         irq_set_chip(irq, irq_chip);
 560                         irq_set_handler_data(irq, &chips[gpio / 32]);
 561                         irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH);
 562                 }
 563
 564                 goto done;
 565         }
 566
 567         /*
 568          * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we
 569          * then chain through our own handler.
 570          */
 571         for (gpio = 0, bank = 0; gpio < ngpio; bank++, bank_irq++, gpio += 16) {
 572                 /* disabled by default, enabled only as needed */
 573                 g = gpio2regs(gpio);
 574                 writel_relaxed(~0, &g->clr_falling);
 575                 writel_relaxed(~0, &g->clr_rising);
 576
 577                 /*
 578                  * Each chip handles 32 gpios, and each irq bank consists of 16
 579                  * gpio irqs. Pass the irq bank's corresponding controller to
 580                  * the chained irq handler.
 581                  */
 582                 irq_set_chained_handler_and_data(bank_irq, gpio_irq_handler,
 583                                                  &chips[gpio / 32]);
 584
 585                 binten |= BIT(bank);
 586         }
 587
 588 done:
 589         /*
 590          * BINTEN -- per-bank interrupt enable. genirq would also let these
 591          * bits be set/cleared dynamically.
 592          */
 593         writel_relaxed(binten, gpio_base + BINTEN);
 594
 595         return 0;
 596 }
 597
 598 #if IS_ENABLED(CONFIG_OF)
 599 static const struct of_device_id davinci_gpio_ids[] = {
 600         { .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip},
 601         { .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip},
 602         { /* sentinel */ },
 603 };
 604 MODULE_DEVICE_TABLE(of, davinci_gpio_ids);
 605 #endif
 606
 607 static struct platform_driver davinci_gpio_driver = {
 608         .probe          = davinci_gpio_probe,
 609         .driver         = {
 610                 .name           = "davinci_gpio",
 611                 .of_match_table = of_match_ptr(davinci_gpio_ids),
 612         },
 613 };
 614
 615 /**
 616  * GPIO driver registration needs to be done before machine_init functions
 617  * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall.
 618  */
 619 static int __init davinci_gpio_drv_reg(void)
 620 {
 621         return platform_driver_register(&davinci_gpio_driver);
 622 }
 623 postcore_initcall(davinci_gpio_drv_reg);