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 #define chip2controller(chip) \ 45 container_of(chip, struct davinci_gpio_controller, chip) 46 47 static void __iomem *gpio_base; 48 49 static struct davinci_gpio_regs __iomem *gpio2regs(unsigned gpio) 50 { 51 void __iomem *ptr; 52 53 if (gpio < 32 * 1) 54 ptr = gpio_base + 0x10; 55 else if (gpio < 32 * 2) 56 ptr = gpio_base + 0x38; 57 else if (gpio < 32 * 3) 58 ptr = gpio_base + 0x60; 59 else if (gpio < 32 * 4) 60 ptr = gpio_base + 0x88; 61 else if (gpio < 32 * 5) 62 ptr = gpio_base + 0xb0; 63 else 64 ptr = NULL; 65 return ptr; 66 } 67 68 static inline struct davinci_gpio_regs __iomem *irq2regs(struct irq_data *d) 69 { 70 struct davinci_gpio_regs __iomem *g; 71 72 g = (__force struct davinci_gpio_regs __iomem *)irq_data_get_irq_chip_data(d); 73 74 return g; 75 } 76 77 static int davinci_gpio_irq_setup(struct platform_device *pdev); 78 79 /*--------------------------------------------------------------------------*/ 80 81 /* board setup code *MUST* setup pinmux and enable the GPIO clock. */ 82 static inline int __davinci_direction(struct gpio_chip *chip, 83 unsigned offset, bool out, int value) 84 { 85 struct davinci_gpio_controller *d = chip2controller(chip); 86 struct davinci_gpio_regs __iomem *g = d->regs; 87 unsigned long flags; 88 u32 temp; 89 u32 mask = 1 << offset; 90 91 spin_lock_irqsave(&d->lock, flags); 92 temp = readl_relaxed(&g->dir); 93 if (out) { 94 temp &= ~mask; 95 writel_relaxed(mask, value ? &g->set_data : &g->clr_data); 96 } else { 97 temp |= mask; 98 } 99 writel_relaxed(temp, &g->dir); 100 spin_unlock_irqrestore(&d->lock, flags); 101 102 return 0; 103 } 104 105 static int davinci_direction_in(struct gpio_chip *chip, unsigned offset) 106 { 107 return __davinci_direction(chip, offset, false, 0); 108 } 109 110 static int 111 davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value) 112 { 113 return __davinci_direction(chip, offset, true, value); 114 } 115 116 /* 117 * Read the pin's value (works even if it's set up as output); 118 * returns zero/nonzero. 119 * 120 * Note that changes are synched to the GPIO clock, so reading values back 121 * right after you've set them may give old values. 122 */ 123 static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset) 124 { 125 struct davinci_gpio_controller *d = chip2controller(chip); 126 struct davinci_gpio_regs __iomem *g = d->regs; 127 128 return (1 << offset) & readl_relaxed(&g->in_data); 129 } 130 131 /* 132 * Assuming the pin is muxed as a gpio output, set its output value. 133 */ 134 static void 135 davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 136 { 137 struct davinci_gpio_controller *d = chip2controller(chip); 138 struct davinci_gpio_regs __iomem *g = d->regs; 139 140 writel_relaxed((1 << offset), value ? &g->set_data : &g->clr_data); 141 } 142 143 static struct davinci_gpio_platform_data * 144 davinci_gpio_get_pdata(struct platform_device *pdev) 145 { 146 struct device_node *dn = pdev->dev.of_node; 147 struct davinci_gpio_platform_data *pdata; 148 int ret; 149 u32 val; 150 151 if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node) 152 return pdev->dev.platform_data; 153 154 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 155 if (!pdata) 156 return NULL; 157 158 ret = of_property_read_u32(dn, "ti,ngpio", &val); 159 if (ret) 160 goto of_err; 161 162 pdata->ngpio = val; 163 164 ret = of_property_read_u32(dn, "ti,davinci-gpio-unbanked", &val); 165 if (ret) 166 goto of_err; 167 168 pdata->gpio_unbanked = val; 169 170 return pdata; 171 172 of_err: 173 dev_err(&pdev->dev, "Populating pdata from DT failed: err %d\n", ret); 174 return NULL; 175 } 176 177 #ifdef CONFIG_OF_GPIO 178 static int davinci_gpio_of_xlate(struct gpio_chip *gc, 179 const struct of_phandle_args *gpiospec, 180 u32 *flags) 181 { 182 struct davinci_gpio_controller *chips = dev_get_drvdata(gc->dev); 183 struct davinci_gpio_platform_data *pdata = dev_get_platdata(gc->dev); 184 185 if (gpiospec->args[0] > pdata->ngpio) 186 return -EINVAL; 187 188 if (gc != &chips[gpiospec->args[0] / 32].chip) 189 return -EINVAL; 190 191 if (flags) 192 *flags = gpiospec->args[1]; 193 194 return gpiospec->args[0] % 32; 195 } 196 #endif 197 198 static int davinci_gpio_probe(struct platform_device *pdev) 199 { 200 int i, base; 201 unsigned ngpio; 202 struct davinci_gpio_controller *chips; 203 struct davinci_gpio_platform_data *pdata; 204 struct davinci_gpio_regs __iomem *regs; 205 struct device *dev = &pdev->dev; 206 struct resource *res; 207 208 pdata = davinci_gpio_get_pdata(pdev); 209 if (!pdata) { 210 dev_err(dev, "No platform data found\n"); 211 return -EINVAL; 212 } 213 214 dev->platform_data = pdata; 215 216 /* 217 * The gpio banks conceptually expose a segmented bitmap, 218 * and "ngpio" is one more than the largest zero-based 219 * bit index that's valid. 220 */ 221 ngpio = pdata->ngpio; 222 if (ngpio == 0) { 223 dev_err(dev, "How many GPIOs?\n"); 224 return -EINVAL; 225 } 226 227 if (WARN_ON(ARCH_NR_GPIOS < ngpio)) 228 ngpio = ARCH_NR_GPIOS; 229 230 chips = devm_kzalloc(dev, 231 ngpio * sizeof(struct davinci_gpio_controller), 232 GFP_KERNEL); 233 if (!chips) 234 return -ENOMEM; 235 236 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 237 gpio_base = devm_ioremap_resource(dev, res); 238 if (IS_ERR(gpio_base)) 239 return PTR_ERR(gpio_base); 240 241 for (i = 0, base = 0; base < ngpio; i++, base += 32) { 242 chips[i].chip.label = "DaVinci"; 243 244 chips[i].chip.direction_input = davinci_direction_in; 245 chips[i].chip.get = davinci_gpio_get; 246 chips[i].chip.direction_output = davinci_direction_out; 247 chips[i].chip.set = davinci_gpio_set; 248 249 chips[i].chip.base = base; 250 chips[i].chip.ngpio = ngpio - base; 251 if (chips[i].chip.ngpio > 32) 252 chips[i].chip.ngpio = 32; 253 254 #ifdef CONFIG_OF_GPIO 255 chips[i].chip.of_gpio_n_cells = 2; 256 chips[i].chip.of_xlate = davinci_gpio_of_xlate; 257 chips[i].chip.dev = dev; 258 chips[i].chip.of_node = dev->of_node; 259 #endif 260 spin_lock_init(&chips[i].lock); 261 262 regs = gpio2regs(base); 263 chips[i].regs = regs; 264 chips[i].set_data = ®s->set_data; 265 chips[i].clr_data = ®s->clr_data; 266 chips[i].in_data = ®s->in_data; 267 268 gpiochip_add(&chips[i].chip); 269 } 270 271 platform_set_drvdata(pdev, chips); 272 davinci_gpio_irq_setup(pdev); 273 return 0; 274 } 275 276 /*--------------------------------------------------------------------------*/ 277 /* 278 * We expect irqs will normally be set up as input pins, but they can also be 279 * used as output pins ... which is convenient for testing. 280 * 281 * NOTE: The first few GPIOs also have direct INTC hookups in addition 282 * to their GPIOBNK0 irq, with a bit less overhead. 283 * 284 * All those INTC hookups (direct, plus several IRQ banks) can also 285 * serve as EDMA event triggers. 286 */ 287 288 static void gpio_irq_disable(struct irq_data *d) 289 { 290 struct davinci_gpio_regs __iomem *g = irq2regs(d); 291 u32 mask = (u32) irq_data_get_irq_handler_data(d); 292 293 writel_relaxed(mask, &g->clr_falling); 294 writel_relaxed(mask, &g->clr_rising); 295 } 296 297 static void gpio_irq_enable(struct irq_data *d) 298 { 299 struct davinci_gpio_regs __iomem *g = irq2regs(d); 300 u32 mask = (u32) irq_data_get_irq_handler_data(d); 301 unsigned status = irqd_get_trigger_type(d); 302 303 status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING; 304 if (!status) 305 status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING; 306 307 if (status & IRQ_TYPE_EDGE_FALLING) 308 writel_relaxed(mask, &g->set_falling); 309 if (status & IRQ_TYPE_EDGE_RISING) 310 writel_relaxed(mask, &g->set_rising); 311 } 312 313 static int gpio_irq_type(struct irq_data *d, unsigned trigger) 314 { 315 if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) 316 return -EINVAL; 317 318 return 0; 319 } 320 321 static struct irq_chip gpio_irqchip = { 322 .name = "GPIO", 323 .irq_enable = gpio_irq_enable, 324 .irq_disable = gpio_irq_disable, 325 .irq_set_type = gpio_irq_type, 326 .flags = IRQCHIP_SET_TYPE_MASKED, 327 }; 328 329 static void gpio_irq_handler(struct irq_desc *desc) 330 { 331 unsigned int irq = irq_desc_get_irq(desc); 332 struct davinci_gpio_regs __iomem *g; 333 u32 mask = 0xffff; 334 struct davinci_gpio_controller *d; 335 336 d = (struct davinci_gpio_controller *)irq_desc_get_handler_data(desc); 337 g = (struct davinci_gpio_regs __iomem *)d->regs; 338 339 /* we only care about one bank */ 340 if (irq & 1) 341 mask <<= 16; 342 343 /* temporarily mask (level sensitive) parent IRQ */ 344 chained_irq_enter(irq_desc_get_chip(desc), desc); 345 while (1) { 346 u32 status; 347 int bit; 348 349 /* ack any irqs */ 350 status = readl_relaxed(&g->intstat) & mask; 351 if (!status) 352 break; 353 writel_relaxed(status, &g->intstat); 354 355 /* now demux them to the right lowlevel handler */ 356 357 while (status) { 358 bit = __ffs(status); 359 status &= ~BIT(bit); 360 generic_handle_irq( 361 irq_find_mapping(d->irq_domain, 362 d->chip.base + bit)); 363 } 364 } 365 chained_irq_exit(irq_desc_get_chip(desc), desc); 366 /* now it may re-trigger */ 367 } 368 369 static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset) 370 { 371 struct davinci_gpio_controller *d = chip2controller(chip); 372 373 if (d->irq_domain) 374 return irq_create_mapping(d->irq_domain, d->chip.base + offset); 375 else 376 return -ENXIO; 377 } 378 379 static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset) 380 { 381 struct davinci_gpio_controller *d = chip2controller(chip); 382 383 /* 384 * NOTE: we assume for now that only irqs in the first gpio_chip 385 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs). 386 */ 387 if (offset < d->gpio_unbanked) 388 return d->gpio_irq + offset; 389 else 390 return -ENODEV; 391 } 392 393 static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger) 394 { 395 struct davinci_gpio_controller *d; 396 struct davinci_gpio_regs __iomem *g; 397 u32 mask; 398 399 d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data); 400 g = (struct davinci_gpio_regs __iomem *)d->regs; 401 mask = __gpio_mask(data->irq - d->gpio_irq); 402 403 if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) 404 return -EINVAL; 405 406 writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING) 407 ? &g->set_falling : &g->clr_falling); 408 writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING) 409 ? &g->set_rising : &g->clr_rising); 410 411 return 0; 412 } 413 414 static int 415 davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq, 416 irq_hw_number_t hw) 417 { 418 struct davinci_gpio_regs __iomem *g = gpio2regs(hw); 419 420 irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq, 421 "davinci_gpio"); 422 irq_set_irq_type(irq, IRQ_TYPE_NONE); 423 irq_set_chip_data(irq, (__force void *)g); 424 irq_set_handler_data(irq, (void *)__gpio_mask(hw)); 425 426 return 0; 427 } 428 429 static const struct irq_domain_ops davinci_gpio_irq_ops = { 430 .map = davinci_gpio_irq_map, 431 .xlate = irq_domain_xlate_onetwocell, 432 }; 433 434 static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq) 435 { 436 static struct irq_chip_type gpio_unbanked; 437 438 gpio_unbanked = *container_of(irq_get_chip(irq), 439 struct irq_chip_type, chip); 440 441 return &gpio_unbanked.chip; 442 }; 443 444 static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq) 445 { 446 static struct irq_chip gpio_unbanked; 447 448 gpio_unbanked = *irq_get_chip(irq); 449 return &gpio_unbanked; 450 }; 451 452 static const struct of_device_id davinci_gpio_ids[]; 453 454 /* 455 * NOTE: for suspend/resume, probably best to make a platform_device with 456 * suspend_late/resume_resume calls hooking into results of the set_wake() 457 * calls ... so if no gpios are wakeup events the clock can be disabled, 458 * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0 459 * (dm6446) can be set appropriately for GPIOV33 pins. 460 */ 461 462 static int davinci_gpio_irq_setup(struct platform_device *pdev) 463 { 464 unsigned gpio, bank; 465 int irq; 466 struct clk *clk; 467 u32 binten = 0; 468 unsigned ngpio, bank_irq; 469 struct device *dev = &pdev->dev; 470 struct resource *res; 471 struct davinci_gpio_controller *chips = platform_get_drvdata(pdev); 472 struct davinci_gpio_platform_data *pdata = dev->platform_data; 473 struct davinci_gpio_regs __iomem *g; 474 struct irq_domain *irq_domain = NULL; 475 const struct of_device_id *match; 476 struct irq_chip *irq_chip; 477 gpio_get_irq_chip_cb_t gpio_get_irq_chip; 478 479 /* 480 * Use davinci_gpio_get_irq_chip by default to handle non DT cases 481 */ 482 gpio_get_irq_chip = davinci_gpio_get_irq_chip; 483 match = of_match_device(of_match_ptr(davinci_gpio_ids), 484 dev); 485 if (match) 486 gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)match->data; 487 488 ngpio = pdata->ngpio; 489 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 490 if (!res) { 491 dev_err(dev, "Invalid IRQ resource\n"); 492 return -EBUSY; 493 } 494 495 bank_irq = res->start; 496 497 if (!bank_irq) { 498 dev_err(dev, "Invalid IRQ resource\n"); 499 return -ENODEV; 500 } 501 502 clk = devm_clk_get(dev, "gpio"); 503 if (IS_ERR(clk)) { 504 printk(KERN_ERR "Error %ld getting gpio clock?\n", 505 PTR_ERR(clk)); 506 return PTR_ERR(clk); 507 } 508 clk_prepare_enable(clk); 509 510 if (!pdata->gpio_unbanked) { 511 irq = irq_alloc_descs(-1, 0, ngpio, 0); 512 if (irq < 0) { 513 dev_err(dev, "Couldn't allocate IRQ numbers\n"); 514 return irq; 515 } 516 517 irq_domain = irq_domain_add_legacy(NULL, ngpio, irq, 0, 518 &davinci_gpio_irq_ops, 519 chips); 520 if (!irq_domain) { 521 dev_err(dev, "Couldn't register an IRQ domain\n"); 522 return -ENODEV; 523 } 524 } 525 526 /* 527 * Arrange gpio_to_irq() support, handling either direct IRQs or 528 * banked IRQs. Having GPIOs in the first GPIO bank use direct 529 * IRQs, while the others use banked IRQs, would need some setup 530 * tweaks to recognize hardware which can do that. 531 */ 532 for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) { 533 chips[bank].chip.to_irq = gpio_to_irq_banked; 534 chips[bank].irq_domain = irq_domain; 535 } 536 537 /* 538 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO 539 * controller only handling trigger modes. We currently assume no 540 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs. 541 */ 542 if (pdata->gpio_unbanked) { 543 /* pass "bank 0" GPIO IRQs to AINTC */ 544 chips[0].chip.to_irq = gpio_to_irq_unbanked; 545 chips[0].gpio_irq = bank_irq; 546 chips[0].gpio_unbanked = pdata->gpio_unbanked; 547 binten = GENMASK(pdata->gpio_unbanked / 16, 0); 548 549 /* AINTC handles mask/unmask; GPIO handles triggering */ 550 irq = bank_irq; 551 irq_chip = gpio_get_irq_chip(irq); 552 irq_chip->name = "GPIO-AINTC"; 553 irq_chip->irq_set_type = gpio_irq_type_unbanked; 554 555 /* default trigger: both edges */ 556 g = gpio2regs(0); 557 writel_relaxed(~0, &g->set_falling); 558 writel_relaxed(~0, &g->set_rising); 559 560 /* set the direct IRQs up to use that irqchip */ 561 for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++, irq++) { 562 irq_set_chip(irq, irq_chip); 563 irq_set_handler_data(irq, &chips[gpio / 32]); 564 irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH); 565 } 566 567 goto done; 568 } 569 570 /* 571 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we 572 * then chain through our own handler. 573 */ 574 for (gpio = 0, bank = 0; gpio < ngpio; bank++, bank_irq++, gpio += 16) { 575 /* disabled by default, enabled only as needed */ 576 g = gpio2regs(gpio); 577 writel_relaxed(~0, &g->clr_falling); 578 writel_relaxed(~0, &g->clr_rising); 579 580 /* 581 * Each chip handles 32 gpios, and each irq bank consists of 16 582 * gpio irqs. Pass the irq bank's corresponding controller to 583 * the chained irq handler. 584 */ 585 irq_set_chained_handler_and_data(bank_irq, gpio_irq_handler, 586 &chips[gpio / 32]); 587 588 binten |= BIT(bank); 589 } 590 591 done: 592 /* 593 * BINTEN -- per-bank interrupt enable. genirq would also let these 594 * bits be set/cleared dynamically. 595 */ 596 writel_relaxed(binten, gpio_base + BINTEN); 597 598 return 0; 599 } 600 601 #if IS_ENABLED(CONFIG_OF) 602 static const struct of_device_id davinci_gpio_ids[] = { 603 { .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip}, 604 { .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip}, 605 { /* sentinel */ }, 606 }; 607 MODULE_DEVICE_TABLE(of, davinci_gpio_ids); 608 #endif 609 610 static struct platform_driver davinci_gpio_driver = { 611 .probe = davinci_gpio_probe, 612 .driver = { 613 .name = "davinci_gpio", 614 .of_match_table = of_match_ptr(davinci_gpio_ids), 615 }, 616 }; 617 618 /** 619 * GPIO driver registration needs to be done before machine_init functions 620 * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall. 621 */ 622 static int __init davinci_gpio_drv_reg(void) 623 { 624 return platform_driver_register(&davinci_gpio_driver); 625 } 626 postcore_initcall(davinci_gpio_drv_reg); 627