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 #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; 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 gpiochip_add_data(&chips->chip, chips); 236 platform_set_drvdata(pdev, chips); 237 davinci_gpio_irq_setup(pdev); 238 return 0; 239 } 240 241 /*--------------------------------------------------------------------------*/ 242 /* 243 * We expect irqs will normally be set up as input pins, but they can also be 244 * used as output pins ... which is convenient for testing. 245 * 246 * NOTE: The first few GPIOs also have direct INTC hookups in addition 247 * to their GPIOBNK0 irq, with a bit less overhead. 248 * 249 * All those INTC hookups (direct, plus several IRQ banks) can also 250 * serve as EDMA event triggers. 251 */ 252 253 static void gpio_irq_disable(struct irq_data *d) 254 { 255 struct davinci_gpio_regs __iomem *g = irq2regs(d); 256 u32 mask = (u32) irq_data_get_irq_handler_data(d); 257 258 writel_relaxed(mask, &g->clr_falling); 259 writel_relaxed(mask, &g->clr_rising); 260 } 261 262 static void gpio_irq_enable(struct irq_data *d) 263 { 264 struct davinci_gpio_regs __iomem *g = irq2regs(d); 265 u32 mask = (u32) irq_data_get_irq_handler_data(d); 266 unsigned status = irqd_get_trigger_type(d); 267 268 status &= IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING; 269 if (!status) 270 status = IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING; 271 272 if (status & IRQ_TYPE_EDGE_FALLING) 273 writel_relaxed(mask, &g->set_falling); 274 if (status & IRQ_TYPE_EDGE_RISING) 275 writel_relaxed(mask, &g->set_rising); 276 } 277 278 static int gpio_irq_type(struct irq_data *d, unsigned trigger) 279 { 280 if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) 281 return -EINVAL; 282 283 return 0; 284 } 285 286 static struct irq_chip gpio_irqchip = { 287 .name = "GPIO", 288 .irq_enable = gpio_irq_enable, 289 .irq_disable = gpio_irq_disable, 290 .irq_set_type = gpio_irq_type, 291 .flags = IRQCHIP_SET_TYPE_MASKED, 292 }; 293 294 static void gpio_irq_handler(struct irq_desc *desc) 295 { 296 struct davinci_gpio_regs __iomem *g; 297 u32 mask = 0xffff; 298 int bank_num; 299 struct davinci_gpio_controller *d; 300 struct davinci_gpio_irq_data *irqdata; 301 302 irqdata = (struct davinci_gpio_irq_data *)irq_desc_get_handler_data(desc); 303 bank_num = irqdata->bank_num; 304 g = irqdata->regs; 305 d = irqdata->chip; 306 307 /* we only care about one bank */ 308 if ((bank_num % 2) == 1) 309 mask <<= 16; 310 311 /* temporarily mask (level sensitive) parent IRQ */ 312 chained_irq_enter(irq_desc_get_chip(desc), desc); 313 while (1) { 314 u32 status; 315 int bit; 316 irq_hw_number_t hw_irq; 317 318 /* ack any irqs */ 319 status = readl_relaxed(&g->intstat) & mask; 320 if (!status) 321 break; 322 writel_relaxed(status, &g->intstat); 323 324 /* now demux them to the right lowlevel handler */ 325 326 while (status) { 327 bit = __ffs(status); 328 status &= ~BIT(bit); 329 /* Max number of gpios per controller is 144 so 330 * hw_irq will be in [0..143] 331 */ 332 hw_irq = (bank_num / 2) * 32 + bit; 333 334 generic_handle_irq( 335 irq_find_mapping(d->irq_domain, hw_irq)); 336 } 337 } 338 chained_irq_exit(irq_desc_get_chip(desc), desc); 339 /* now it may re-trigger */ 340 } 341 342 static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset) 343 { 344 struct davinci_gpio_controller *d = gpiochip_get_data(chip); 345 346 if (d->irq_domain) 347 return irq_create_mapping(d->irq_domain, offset); 348 else 349 return -ENXIO; 350 } 351 352 static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset) 353 { 354 struct davinci_gpio_controller *d = gpiochip_get_data(chip); 355 356 /* 357 * NOTE: we assume for now that only irqs in the first gpio_chip 358 * can provide direct-mapped IRQs to AINTC (up to 32 GPIOs). 359 */ 360 if (offset < d->gpio_unbanked) 361 return d->base_irq + offset; 362 else 363 return -ENODEV; 364 } 365 366 static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger) 367 { 368 struct davinci_gpio_controller *d; 369 struct davinci_gpio_regs __iomem *g; 370 u32 mask; 371 372 d = (struct davinci_gpio_controller *)irq_data_get_irq_handler_data(data); 373 g = (struct davinci_gpio_regs __iomem *)d->regs; 374 mask = __gpio_mask(data->irq - d->base_irq); 375 376 if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) 377 return -EINVAL; 378 379 writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_FALLING) 380 ? &g->set_falling : &g->clr_falling); 381 writel_relaxed(mask, (trigger & IRQ_TYPE_EDGE_RISING) 382 ? &g->set_rising : &g->clr_rising); 383 384 return 0; 385 } 386 387 static int 388 davinci_gpio_irq_map(struct irq_domain *d, unsigned int irq, 389 irq_hw_number_t hw) 390 { 391 struct davinci_gpio_controller *chips = 392 (struct davinci_gpio_controller *)d->host_data; 393 struct davinci_gpio_regs __iomem *g = chips->regs[hw / 32]; 394 395 irq_set_chip_and_handler_name(irq, &gpio_irqchip, handle_simple_irq, 396 "davinci_gpio"); 397 irq_set_irq_type(irq, IRQ_TYPE_NONE); 398 irq_set_chip_data(irq, (__force void *)g); 399 irq_set_handler_data(irq, (void *)__gpio_mask(hw)); 400 401 return 0; 402 } 403 404 static const struct irq_domain_ops davinci_gpio_irq_ops = { 405 .map = davinci_gpio_irq_map, 406 .xlate = irq_domain_xlate_onetwocell, 407 }; 408 409 static struct irq_chip *davinci_gpio_get_irq_chip(unsigned int irq) 410 { 411 static struct irq_chip_type gpio_unbanked; 412 413 gpio_unbanked = *irq_data_get_chip_type(irq_get_irq_data(irq)); 414 415 return &gpio_unbanked.chip; 416 }; 417 418 static struct irq_chip *keystone_gpio_get_irq_chip(unsigned int irq) 419 { 420 static struct irq_chip gpio_unbanked; 421 422 gpio_unbanked = *irq_get_chip(irq); 423 return &gpio_unbanked; 424 }; 425 426 static const struct of_device_id davinci_gpio_ids[]; 427 428 /* 429 * NOTE: for suspend/resume, probably best to make a platform_device with 430 * suspend_late/resume_resume calls hooking into results of the set_wake() 431 * calls ... so if no gpios are wakeup events the clock can be disabled, 432 * with outputs left at previously set levels, and so that VDD3P3V.IOPWDN0 433 * (dm6446) can be set appropriately for GPIOV33 pins. 434 */ 435 436 static int davinci_gpio_irq_setup(struct platform_device *pdev) 437 { 438 unsigned gpio, bank; 439 int irq; 440 struct clk *clk; 441 u32 binten = 0; 442 unsigned ngpio, bank_irq; 443 struct device *dev = &pdev->dev; 444 struct resource *res; 445 struct davinci_gpio_controller *chips = platform_get_drvdata(pdev); 446 struct davinci_gpio_platform_data *pdata = dev->platform_data; 447 struct davinci_gpio_regs __iomem *g; 448 struct irq_domain *irq_domain = NULL; 449 const struct of_device_id *match; 450 struct irq_chip *irq_chip; 451 struct davinci_gpio_irq_data *irqdata; 452 gpio_get_irq_chip_cb_t gpio_get_irq_chip; 453 454 /* 455 * Use davinci_gpio_get_irq_chip by default to handle non DT cases 456 */ 457 gpio_get_irq_chip = davinci_gpio_get_irq_chip; 458 match = of_match_device(of_match_ptr(davinci_gpio_ids), 459 dev); 460 if (match) 461 gpio_get_irq_chip = (gpio_get_irq_chip_cb_t)match->data; 462 463 ngpio = pdata->ngpio; 464 res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 465 if (!res) { 466 dev_err(dev, "Invalid IRQ resource\n"); 467 return -EBUSY; 468 } 469 470 bank_irq = res->start; 471 472 if (!bank_irq) { 473 dev_err(dev, "Invalid IRQ resource\n"); 474 return -ENODEV; 475 } 476 477 clk = devm_clk_get(dev, "gpio"); 478 if (IS_ERR(clk)) { 479 printk(KERN_ERR "Error %ld getting gpio clock?\n", 480 PTR_ERR(clk)); 481 return PTR_ERR(clk); 482 } 483 clk_prepare_enable(clk); 484 485 if (!pdata->gpio_unbanked) { 486 irq = irq_alloc_descs(-1, 0, ngpio, 0); 487 if (irq < 0) { 488 dev_err(dev, "Couldn't allocate IRQ numbers\n"); 489 return irq; 490 } 491 492 irq_domain = irq_domain_add_legacy(dev->of_node, ngpio, irq, 0, 493 &davinci_gpio_irq_ops, 494 chips); 495 if (!irq_domain) { 496 dev_err(dev, "Couldn't register an IRQ domain\n"); 497 return -ENODEV; 498 } 499 } 500 501 /* 502 * Arrange gpio_to_irq() support, handling either direct IRQs or 503 * banked IRQs. Having GPIOs in the first GPIO bank use direct 504 * IRQs, while the others use banked IRQs, would need some setup 505 * tweaks to recognize hardware which can do that. 506 */ 507 chips->chip.to_irq = gpio_to_irq_banked; 508 chips->irq_domain = irq_domain; 509 510 /* 511 * AINTC can handle direct/unbanked IRQs for GPIOs, with the GPIO 512 * controller only handling trigger modes. We currently assume no 513 * IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs. 514 */ 515 if (pdata->gpio_unbanked) { 516 /* pass "bank 0" GPIO IRQs to AINTC */ 517 chips->chip.to_irq = gpio_to_irq_unbanked; 518 chips->base_irq = bank_irq; 519 chips->gpio_unbanked = pdata->gpio_unbanked; 520 binten = GENMASK(pdata->gpio_unbanked / 16, 0); 521 522 /* AINTC handles mask/unmask; GPIO handles triggering */ 523 irq = bank_irq; 524 irq_chip = gpio_get_irq_chip(irq); 525 irq_chip->name = "GPIO-AINTC"; 526 irq_chip->irq_set_type = gpio_irq_type_unbanked; 527 528 /* default trigger: both edges */ 529 g = chips->regs[0]; 530 writel_relaxed(~0, &g->set_falling); 531 writel_relaxed(~0, &g->set_rising); 532 533 /* set the direct IRQs up to use that irqchip */ 534 for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++, irq++) { 535 irq_set_chip(irq, irq_chip); 536 irq_set_handler_data(irq, chips); 537 irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH); 538 } 539 540 goto done; 541 } 542 543 /* 544 * Or, AINTC can handle IRQs for banks of 16 GPIO IRQs, which we 545 * then chain through our own handler. 546 */ 547 for (gpio = 0, bank = 0; gpio < ngpio; bank++, bank_irq++, gpio += 16) { 548 /* disabled by default, enabled only as needed 549 * There are register sets for 32 GPIOs. 2 banks of 16 550 * GPIOs are covered by each set of registers hence divide by 2 551 */ 552 g = chips->regs[bank / 2]; 553 writel_relaxed(~0, &g->clr_falling); 554 writel_relaxed(~0, &g->clr_rising); 555 556 /* 557 * Each chip handles 32 gpios, and each irq bank consists of 16 558 * gpio irqs. Pass the irq bank's corresponding controller to 559 * the chained irq handler. 560 */ 561 irqdata = devm_kzalloc(&pdev->dev, 562 sizeof(struct 563 davinci_gpio_irq_data), 564 GFP_KERNEL); 565 if (!irqdata) 566 return -ENOMEM; 567 568 irqdata->regs = g; 569 irqdata->bank_num = bank; 570 irqdata->chip = chips; 571 572 irq_set_chained_handler_and_data(bank_irq, gpio_irq_handler, 573 irqdata); 574 575 binten |= BIT(bank); 576 } 577 578 done: 579 /* 580 * BINTEN -- per-bank interrupt enable. genirq would also let these 581 * bits be set/cleared dynamically. 582 */ 583 writel_relaxed(binten, gpio_base + BINTEN); 584 585 return 0; 586 } 587 588 #if IS_ENABLED(CONFIG_OF) 589 static const struct of_device_id davinci_gpio_ids[] = { 590 { .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip}, 591 { .compatible = "ti,dm6441-gpio", davinci_gpio_get_irq_chip}, 592 { /* sentinel */ }, 593 }; 594 MODULE_DEVICE_TABLE(of, davinci_gpio_ids); 595 #endif 596 597 static struct platform_driver davinci_gpio_driver = { 598 .probe = davinci_gpio_probe, 599 .driver = { 600 .name = "davinci_gpio", 601 .of_match_table = of_match_ptr(davinci_gpio_ids), 602 }, 603 }; 604 605 /** 606 * GPIO driver registration needs to be done before machine_init functions 607 * access GPIO. Hence davinci_gpio_drv_reg() is a postcore_initcall. 608 */ 609 static int __init davinci_gpio_drv_reg(void) 610 { 611 return platform_driver_register(&davinci_gpio_driver); 612 } 613 postcore_initcall(davinci_gpio_drv_reg); 614