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/driver.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 #define MAX_LABEL_SIZE 20 44 45 static void __iomem *gpio_base; 46 static unsigned int offset_array[5] = {0x10, 0x38, 0x60, 0x88, 0xb0}; 47 48 static inline struct davinci_gpio_regs __iomem *irq2regs(struct irq_data *d) 49 { 50 struct davinci_gpio_regs __iomem *g; 51 52 g = (__force struct davinci_gpio_regs __iomem *)irq_data_get_irq_chip_data(d); 53 54 return g; 55 } 56 57 static int davinci_gpio_irq_setup(struct platform_device *pdev); 58 59 /*--------------------------------------------------------------------------*/ 60 61 /* board setup code *MUST* setup pinmux and enable the GPIO clock. */ 62 static inline int __davinci_direction(struct gpio_chip *chip, 63 unsigned offset, bool out, int value) 64 { 65 struct davinci_gpio_controller *d = gpiochip_get_data(chip); 66 struct davinci_gpio_regs __iomem *g; 67 unsigned long flags; 68 u32 temp; 69 int bank = offset / 32; 70 u32 mask = __gpio_mask(offset); 71 72 g = d->regs[bank]; 73 spin_lock_irqsave(&d->lock, flags); 74 temp = readl_relaxed(&g->dir); 75 if (out) { 76 temp &= ~mask; 77 writel_relaxed(mask, value ? &g->set_data : &g->clr_data); 78 } else { 79 temp |= mask; 80 } 81 writel_relaxed(temp, &g->dir); 82 spin_unlock_irqrestore(&d->lock, flags); 83 84 return 0; 85 } 86 87 static int davinci_direction_in(struct gpio_chip *chip, unsigned offset) 88 { 89 return __davinci_direction(chip, offset, false, 0); 90 } 91 92 static int 93 davinci_direction_out(struct gpio_chip *chip, unsigned offset, int value) 94 { 95 return __davinci_direction(chip, offset, true, value); 96 } 97 98 /* 99 * Read the pin's value (works even if it's set up as output); 100 * returns zero/nonzero. 101 * 102 * Note that changes are synched to the GPIO clock, so reading values back 103 * right after you've set them may give old values. 104 */ 105 static int davinci_gpio_get(struct gpio_chip *chip, unsigned offset) 106 { 107 struct davinci_gpio_controller *d = gpiochip_get_data(chip); 108 struct davinci_gpio_regs __iomem *g; 109 int bank = offset / 32; 110 111 g = d->regs[bank]; 112 113 return !!(__gpio_mask(offset) & readl_relaxed(&g->in_data)); 114 } 115 116 /* 117 * Assuming the pin is muxed as a gpio output, set its output value. 118 */ 119 static void 120 davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 121 { 122 struct davinci_gpio_controller *d = gpiochip_get_data(chip); 123 struct davinci_gpio_regs __iomem *g; 124 int bank = offset / 32; 125 126 g = d->regs[bank]; 127 128 writel_relaxed(__gpio_mask(offset), 129 value ? &g->set_data : &g->clr_data); 130 } 131 132 static struct davinci_gpio_platform_data * 133 davinci_gpio_get_pdata(struct platform_device *pdev) 134 { 135 struct device_node *dn = pdev->dev.of_node; 136 struct davinci_gpio_platform_data *pdata; 137 int ret; 138 u32 val; 139 140 if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node) 141 return dev_get_platdata(&pdev->dev); 142 143 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); 144 if (!pdata) 145 return NULL; 146 147 ret = of_property_read_u32(dn, "ti,ngpio", &val); 148 if (ret) 149 goto of_err; 150 151 pdata->ngpio = val; 152 153 ret = of_property_read_u32(dn, "ti,davinci-gpio-unbanked", &val); 154 if (ret) 155 goto of_err; 156 157 pdata->gpio_unbanked = val; 158 159 return pdata; 160 161 of_err: 162 dev_err(&pdev->dev, "Populating pdata from DT failed: err %d\n", ret); 163 return NULL; 164 } 165 166 static int davinci_gpio_probe(struct platform_device *pdev) 167 { 168 static int ctrl_num, bank_base; 169 int gpio, bank, ret = 0; 170 unsigned ngpio, nbank; 171 struct davinci_gpio_controller *chips; 172 struct davinci_gpio_platform_data *pdata; 173 struct device *dev = &pdev->dev; 174 struct resource *res; 175 char label[MAX_LABEL_SIZE]; 176 177 pdata = davinci_gpio_get_pdata(pdev); 178 if (!pdata) { 179 dev_err(dev, "No platform data found\n"); 180 return -EINVAL; 181 } 182 183 dev->platform_data = pdata; 184 185 /* 186 * The gpio banks conceptually expose a segmented bitmap, 187 * and "ngpio" is one more than the largest zero-based 188 * bit index that's valid. 189 */ 190 ngpio = pdata->ngpio; 191 if (ngpio == 0) { 192 dev_err(dev, "How many GPIOs?\n"); 193 return -EINVAL; 194 } 195 196 if (WARN_ON(ARCH_NR_GPIOS < ngpio)) 197 ngpio = ARCH_NR_GPIOS; 198 199 nbank = DIV_ROUND_UP(ngpio, 32); 200 chips = devm_kzalloc(dev, 201 nbank * sizeof(struct davinci_gpio_controller), 202 GFP_KERNEL); 203 if (!chips) 204 return -ENOMEM; 205 206 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 207 gpio_base = devm_ioremap_resource(dev, res); 208 if (IS_ERR(gpio_base)) 209 return PTR_ERR(gpio_base); 210 211 snprintf(label, MAX_LABEL_SIZE, "davinci_gpio.%d", ctrl_num++); 212 chips->chip.label = devm_kstrdup(dev, label, GFP_KERNEL); 213 if (!chips->chip.label) 214 return -ENOMEM; 215 216 chips->chip.direction_input = davinci_direction_in; 217 chips->chip.get = davinci_gpio_get; 218 chips->chip.direction_output = davinci_direction_out; 219 chips->chip.set = davinci_gpio_set; 220 221 chips->chip.ngpio = ngpio; 222 chips->chip.base = bank_base; 223 224 #ifdef CONFIG_OF_GPIO 225 chips->chip.of_gpio_n_cells = 2; 226 chips->chip.parent = dev; 227 chips->chip.of_node = dev->of_node; 228 #endif 229 spin_lock_init(&chips->lock); 230 bank_base += ngpio; 231 232 for (gpio = 0, bank = 0; gpio < ngpio; gpio += 32, bank++) 233 chips->regs[bank] = gpio_base + offset_array[bank]; 234 235 ret = devm_gpiochip_add_data(dev, &chips->chip, chips); 236 if (ret) 237 goto err; 238 239 platform_set_drvdata(pdev, chips); 240 ret = davinci_gpio_irq_setup(pdev); 241 if (ret) 242 goto err; 243 244 return 0; 245 246 err: 247 /* Revert the static variable increments */ 248 ctrl_num--; 249 bank_base -= ngpio; 250 251 return ret; 252 } 253 254 /*--------------------------------------------------------------------------*/ 255 /* 256 * We expect irqs will normally be set up as input pins, but they can also be 257 * used as output pins ... which is convenient for testing. 258 * 259 * NOTE: The first few GPIOs also have direct INTC hookups in addition 260 * to their GPIOBNK0 irq, with a bit less overhead. 261 * 262 * All those INTC hookups (direct, plus several IRQ banks) can also 263 * serve as EDMA event triggers. 264 */ 265 266 static void gpio_irq_disable(struct irq_data *d) 267 { 268 struct davinci_gpio_regs __iomem *g = irq2regs(d); 269 u32 mask = (u32) irq_data_get_irq_handler_data(d); 270 271 writel_relaxed(mask, &g->clr_falling); 272 writel_relaxed(mask, &g->clr_rising); 273 } 274 275 static void gpio_irq_enable(struct irq_data *d) 276 { 277 struct davinci_gpio_regs __iomem *g = irq2regs(d); 278 u32 mask = (u32) irq_data_get_irq_handler_data(d); 279 unsigned status = irqd_get_trigger_type(d); 280 281 status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING; 282 if (!status) 283 status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING; 284 285 if (status & IRQ_TYPE_EDGE_FALLING) 286 writel_relaxed(mask, &g->set_falling); 287 if (status & IRQ_TYPE_EDGE_RISING) 288 writel_relaxed(mask, &g->set_rising); 289 } 290 291 static int gpio_irq_type(struct irq_data *d, unsigned trigger) 292 { 293 if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) 294 return -EINVAL; 295 296 return 0; 297 } 298 299 static struct irq_chip gpio_irqchip = { 300 .name = "GPIO", 301 .irq_enable = gpio_irq_enable, 302 .irq_disable = gpio_irq_disable, 303 .irq_set_type = gpio_irq_type, 304 .flags = IRQCHIP_SET_TYPE_MASKED, 305 }; 306 307 static void gpio_irq_handler(struct irq_desc *desc) 308 { 309 struct davinci_gpio_regs __iomem *g; 310 u32 mask = 0xffff; 311 int bank_num; 312 struct davinci_gpio_controller *d; 313 struct davinci_gpio_irq_data *irqdata; 314 315 irqdata = (struct davinci_gpio_irq_data *)irq_desc_get_handler_data(desc); 316 bank_num = irqdata->bank_num; 317 g = irqdata->regs; 318 d = irqdata->chip; 319 320 /* we only care about one bank */ 321 if ((bank_num % 2) == 1) 322 mask <<= 16; 323 324 /* temporarily mask (level sensitive) parent IRQ */ 325 chained_irq_enter(irq_desc_get_chip(desc), desc); 326 while (1) { 327 u32 status; 328 int bit; 329 irq_hw_number_t hw_irq; 330 331 /* ack any irqs */ 332 status = readl_relaxed(&g->intstat) & mask; 333 if (!status) 334 break; 335 writel_relaxed(status, &g->intstat); 336 337 /* now demux them to the right lowlevel handler */ 338 339 while (status) { 340 bit = __ffs(status); 341 status &= ~BIT(bit); 342 /* Max number of gpios per controller is 144 so 343 * hw_irq will be in [0..143] 344 */ 345 hw_irq = (bank_num / 2) * 32 + bit; 346 347 generic_handle_irq( 348 irq_find_mapping(d->irq_domain, hw_irq)); 349 } 350 } 351 chained_irq_exit(irq_desc_get_chip(desc), desc); 352 /* now it may re-trigger */ 353 } 354 355 static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset) 356 { 357 struct davinci_gpio_controller *d = gpiochip_get_data(chip); 358 359 if (d->irq_domain) 360 return irq_create_mapping(d->irq_domain, offset); 361 else 362 return -ENXIO; 363 } 364 365 static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset) 366 { 367 struct davinci_gpio_controller *d = gpiochip_get_data(chip); 368 369 /* 370 * NOTE: we assume for now that only irqs in the first gpio_chip 371 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs). 372 */ 373 if (offset < d->gpio_unbanked) 374 return d->base_irq + offset; 375 else 376 return -ENODEV; 377 } 378 379 static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger) 380 { 381 struct davinci_gpio_controller *d; 382 struct davinci_gpio_regs __iomem *g; 383 u32 mask; 384 385 d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data); 386 g = (struct davinci_gpio_regs __iomem *)d->regs[0]; 387 mask = __gpio_mask(data->irq - d->base_irq); 388 389 if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) 390 return -EINVAL; 391 392 writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING) 393 ? &g->set_falling : &g->clr_falling); 394 writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING) 395 ? &g->set_rising : &g->clr_rising); 396 397 return 0; 398 } 399 400 static int 401 davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq, 402 irq_hw_number_t hw) 403 { 404 struct davinci_gpio_controller *chips = 405 (struct davinci_gpio_controller *)d->host_data; 406 struct davinci_gpio_regs __iomem *g = chips->regs[hw / 32]; 407 408 irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq, 409 "davinci_gpio"); 410 irq_set_irq_type(irq, IRQ_TYPE_NONE); 411 irq_set_chip_data(irq, (__force void *)g); 412 irq_set_handler_data(irq, (void *)__gpio_mask(hw)); 413 414 return 0; 415 } 416 417 static const struct irq_domain_ops davinci_gpio_irq_ops = { 418 .map = davinci_gpio_irq_map, 419 .xlate = irq_domain_xlate_onetwocell, 420 }; 421 422 static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq) 423 { 424 static struct irq_chip_type gpio_unbanked; 425 426 gpio_unbanked = *irq_data_get_chip_type(irq_get_irq_data(irq)); 427 428 return &gpio_unbanked.chip; 429 }; 430 431 static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq) 432 { 433 static struct irq_chip gpio_unbanked; 434 435 gpio_unbanked = *irq_get_chip(irq); 436 return &gpio_unbanked; 437 }; 438 439 static const struct of_device_id davinci_gpio_ids[]; 440 441 /* 442 * NOTE: for suspend/resume, probably best to make a platform_device with 443 * suspend_late/resume_resume calls hooking into results of the set_wake() 444 * calls ... so if no gpios are wakeup events the clock can be disabled, 445 * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0 446 * (dm6446) can be set appropriately for GPIOV33 pins. 447 */ 448 449 static int davinci_gpio_irq_setup(struct platform_device *pdev) 450 { 451 unsigned gpio, bank; 452 int irq; 453 int ret; 454 struct clk *clk; 455 u32 binten = 0; 456 unsigned ngpio, bank_irq; 457 struct device *dev = &pdev->dev; 458 struct resource *res; 459 struct davinci_gpio_controller *chips = platform_get_drvdata(pdev); 460 struct davinci_gpio_platform_data *pdata = dev->platform_data; 461 struct davinci_gpio_regs __iomem *g; 462 struct irq_domain *irq_domain = NULL; 463 const struct of_device_id *match; 464 struct irq_chip *irq_chip; 465 struct davinci_gpio_irq_data *irqdata; 466 gpio_get_irq_chip_cb_t gpio_get_irq_chip; 467 468 /* 469 * Use davinci_gpio_get_irq_chip by default to handle non DT cases 470 */ 471 gpio_get_irq_chip = davinci_gpio_get_irq_chip; 472 match = of_match_device(of_match_ptr(davinci_gpio_ids), 473 dev); 474 if (match) 475 gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)match->data; 476 477 ngpio = pdata->ngpio; 478 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 479 if (!res) { 480 dev_err(dev, "Invalid IRQ resource\n"); 481 return -EBUSY; 482 } 483 484 bank_irq = res->start; 485 486 if (!bank_irq) { 487 dev_err(dev, "Invalid IRQ resource\n"); 488 return -ENODEV; 489 } 490 491 clk = devm_clk_get(dev, "gpio"); 492 if (IS_ERR(clk)) { 493 dev_err(dev, "Error %ld getting gpio clock\n", PTR_ERR(clk)); 494 return PTR_ERR(clk); 495 } 496 ret = clk_prepare_enable(clk); 497 if (ret) 498 return ret; 499 500 if (!pdata->gpio_unbanked) { 501 irq = devm_irq_alloc_descs(dev, -1, 0, ngpio, 0); 502 if (irq < 0) { 503 dev_err(dev, "Couldn't allocate IRQ numbers\n"); 504 clk_disable_unprepare(clk); 505 return irq; 506 } 507 508 irq_domain = irq_domain_add_legacy(dev->of_node, ngpio, irq, 0, 509 &davinci_gpio_irq_ops, 510 chips); 511 if (!irq_domain) { 512 dev_err(dev, "Couldn't register an IRQ domain\n"); 513 clk_disable_unprepare(clk); 514 return -ENODEV; 515 } 516 } 517 518 /* 519 * Arrange gpio_to_irq() support, handling either direct IRQs or 520 * banked IRQs. Having GPIOs in the first GPIO bank use direct 521 * IRQs, while the others use banked IRQs, would need some setup 522 * tweaks to recognize hardware which can do that. 523 */ 524 chips->chip.to_irq = gpio_to_irq_banked; 525 chips->irq_domain = irq_domain; 526 527 /* 528 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO 529 * controller only handling trigger modes. We currently assume no 530 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs. 531 */ 532 if (pdata->gpio_unbanked) { 533 /* pass "bank 0" GPIO IRQs to AINTC */ 534 chips->chip.to_irq = gpio_to_irq_unbanked; 535 chips->base_irq = bank_irq; 536 chips->gpio_unbanked = pdata->gpio_unbanked; 537 binten = GENMASK(pdata->gpio_unbanked / 16, 0); 538 539 /* AINTC handles mask/unmask; GPIO handles triggering */ 540 irq = bank_irq; 541 irq_chip = gpio_get_irq_chip(irq); 542 irq_chip->name = "GPIO-AINTC"; 543 irq_chip->irq_set_type = gpio_irq_type_unbanked; 544 545 /* default trigger: both edges */ 546 g = chips->regs[0]; 547 writel_relaxed(~0, &g->set_falling); 548 writel_relaxed(~0, &g->set_rising); 549 550 /* set the direct IRQs up to use that irqchip */ 551 for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++, irq++) { 552 irq_set_chip(irq, irq_chip); 553 irq_set_handler_data(irq, chips); 554 irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH); 555 } 556 557 goto done; 558 } 559 560 /* 561 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we 562 * then chain through our own handler. 563 */ 564 for (gpio = 0, bank = 0; gpio < ngpio; bank++, bank_irq++, gpio += 16) { 565 /* disabled by default, enabled only as needed 566 * There are register sets for 32 GPIOs. 2 banks of 16 567 * GPIOs are covered by each set of registers hence divide by 2 568 */ 569 g = chips->regs[bank / 2]; 570 writel_relaxed(~0, &g->clr_falling); 571 writel_relaxed(~0, &g->clr_rising); 572 573 /* 574 * Each chip handles 32 gpios, and each irq bank consists of 16 575 * gpio irqs. Pass the irq bank's corresponding controller to 576 * the chained irq handler. 577 */ 578 irqdata = devm_kzalloc(&pdev->dev, 579 sizeof(struct 580 davinci_gpio_irq_data), 581 GFP_KERNEL); 582 if (!irqdata) { 583 clk_disable_unprepare(clk); 584 return -ENOMEM; 585 } 586 587 irqdata->regs = g; 588 irqdata->bank_num = bank; 589 irqdata->chip = chips; 590 591 irq_set_chained_handler_and_data(bank_irq, gpio_irq_handler, 592 irqdata); 593 594 binten |= BIT(bank); 595 } 596 597 done: 598 /* 599 * BINTEN -- per-bank interrupt enable. genirq would also let these 600 * bits be set/cleared dynamically. 601 */ 602 writel_relaxed(binten, gpio_base + BINTEN); 603 604 return 0; 605 } 606 607 #if IS_ENABLED(CONFIG_OF) 608 static const struct of_device_id davinci_gpio_ids[] = { 609 { .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip}, 610 { .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip}, 611 { /* sentinel */ }, 612 }; 613 MODULE_DEVICE_TABLE(of, davinci_gpio_ids); 614 #endif 615 616 static struct platform_driver davinci_gpio_driver = { 617 .probe = davinci_gpio_probe, 618 .driver = { 619 .name = "davinci_gpio", 620 .of_match_table = of_match_ptr(davinci_gpio_ids), 621 }, 622 }; 623 624 /** 625 * GPIO driver registration needs to be done before machine_init functions 626 * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall. 627 */ 628 static int __init davinci_gpio_drv_reg(void) 629 { 630 return platform_driver_register(&davinci_gpio_driver); 631 } 632 postcore_initcall(davinci_gpio_drv_reg); 633