gpio-tegra.c 14.5 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593
/*
 * arch/arm/mach-tegra/gpio.c
 *
 * Copyright (c) 2010 Google, Inc
 *
 * Author:
 *	Erik Gilling <konkers@google.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/err.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/irqdomain.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pm.h>

#define GPIO_BANK(x)		((x) >> 5)
#define GPIO_PORT(x)		(((x) >> 3) & 0x3)
#define GPIO_BIT(x)		((x) & 0x7)

#define GPIO_REG(x)		(GPIO_BANK(x) * tegra_gpio_bank_stride + \
					GPIO_PORT(x) * 4)

#define GPIO_CNF(x)		(GPIO_REG(x) + 0x00)
#define GPIO_OE(x)		(GPIO_REG(x) + 0x10)
#define GPIO_OUT(x)		(GPIO_REG(x) + 0X20)
#define GPIO_IN(x)		(GPIO_REG(x) + 0x30)
#define GPIO_INT_STA(x)		(GPIO_REG(x) + 0x40)
#define GPIO_INT_ENB(x)		(GPIO_REG(x) + 0x50)
#define GPIO_INT_LVL(x)		(GPIO_REG(x) + 0x60)
#define GPIO_INT_CLR(x)		(GPIO_REG(x) + 0x70)

#define GPIO_MSK_CNF(x)		(GPIO_REG(x) + tegra_gpio_upper_offset + 0x00)
#define GPIO_MSK_OE(x)		(GPIO_REG(x) + tegra_gpio_upper_offset + 0x10)
#define GPIO_MSK_OUT(x)		(GPIO_REG(x) + tegra_gpio_upper_offset + 0X20)
#define GPIO_MSK_INT_STA(x)	(GPIO_REG(x) + tegra_gpio_upper_offset + 0x40)
#define GPIO_MSK_INT_ENB(x)	(GPIO_REG(x) + tegra_gpio_upper_offset + 0x50)
#define GPIO_MSK_INT_LVL(x)	(GPIO_REG(x) + tegra_gpio_upper_offset + 0x60)

#define GPIO_INT_LVL_MASK		0x010101
#define GPIO_INT_LVL_EDGE_RISING	0x000101
#define GPIO_INT_LVL_EDGE_FALLING	0x000100
#define GPIO_INT_LVL_EDGE_BOTH		0x010100
#define GPIO_INT_LVL_LEVEL_HIGH		0x000001
#define GPIO_INT_LVL_LEVEL_LOW		0x000000

struct tegra_gpio_bank {
	int bank;
	int irq;
	spinlock_t lvl_lock[4];
#ifdef CONFIG_PM_SLEEP
	u32 cnf[4];
	u32 out[4];
	u32 oe[4];
	u32 int_enb[4];
	u32 int_lvl[4];
	u32 wake_enb[4];
#endif
};

static struct device *dev;
static struct irq_domain *irq_domain;
static void __iomem *regs;
static u32 tegra_gpio_bank_count;
static u32 tegra_gpio_bank_stride;
static u32 tegra_gpio_upper_offset;
static struct tegra_gpio_bank *tegra_gpio_banks;

static inline void tegra_gpio_writel(u32 val, u32 reg)
{
	__raw_writel(val, regs + reg);
}

static inline u32 tegra_gpio_readl(u32 reg)
{
	return __raw_readl(regs + reg);
}

static int tegra_gpio_compose(int bank, int port, int bit)
{
	return (bank << 5) | ((port & 0x3) << 3) | (bit & 0x7);
}

static void tegra_gpio_mask_write(u32 reg, int gpio, int value)
{
	u32 val;

	val = 0x100 << GPIO_BIT(gpio);
	if (value)
		val |= 1 << GPIO_BIT(gpio);
	tegra_gpio_writel(val, reg);
}

static void tegra_gpio_enable(int gpio)
{
	tegra_gpio_mask_write(GPIO_MSK_CNF(gpio), gpio, 1);
}

static void tegra_gpio_disable(int gpio)
{
	tegra_gpio_mask_write(GPIO_MSK_CNF(gpio), gpio, 0);
}

static int tegra_gpio_request(struct gpio_chip *chip, unsigned offset)
{
	return pinctrl_request_gpio(offset);
}

static void tegra_gpio_free(struct gpio_chip *chip, unsigned offset)
{
	pinctrl_free_gpio(offset);
	tegra_gpio_disable(offset);
}

static void tegra_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	tegra_gpio_mask_write(GPIO_MSK_OUT(offset), offset, value);
}

static int tegra_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	/* If gpio is in output mode then read from the out value */
	if ((tegra_gpio_readl(GPIO_OE(offset)) >> GPIO_BIT(offset)) & 1)
		return (tegra_gpio_readl(GPIO_OUT(offset)) >>
				GPIO_BIT(offset)) & 0x1;

	return (tegra_gpio_readl(GPIO_IN(offset)) >> GPIO_BIT(offset)) & 0x1;
}

static int tegra_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
	tegra_gpio_mask_write(GPIO_MSK_OE(offset), offset, 0);
	tegra_gpio_enable(offset);
	return 0;
}

static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
					int value)
{
	tegra_gpio_set(chip, offset, value);
	tegra_gpio_mask_write(GPIO_MSK_OE(offset), offset, 1);
	tegra_gpio_enable(offset);
	return 0;
}

static int tegra_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
	return irq_find_mapping(irq_domain, offset);
}

static struct gpio_chip tegra_gpio_chip = {
	.label			= "tegra-gpio",
	.request		= tegra_gpio_request,
	.free			= tegra_gpio_free,
	.direction_input	= tegra_gpio_direction_input,
	.get			= tegra_gpio_get,
	.direction_output	= tegra_gpio_direction_output,
	.set			= tegra_gpio_set,
	.to_irq			= tegra_gpio_to_irq,
	.base			= 0,
};

static void tegra_gpio_irq_ack(struct irq_data *d)
{
	int gpio = d->hwirq;

	tegra_gpio_writel(1 << GPIO_BIT(gpio), GPIO_INT_CLR(gpio));
}

static void tegra_gpio_irq_mask(struct irq_data *d)
{
	int gpio = d->hwirq;

	tegra_gpio_mask_write(GPIO_MSK_INT_ENB(gpio), gpio, 0);
}

static void tegra_gpio_irq_unmask(struct irq_data *d)
{
	int gpio = d->hwirq;

	tegra_gpio_mask_write(GPIO_MSK_INT_ENB(gpio), gpio, 1);
}

static int tegra_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
	int gpio = d->hwirq;
	struct tegra_gpio_bank *bank = irq_data_get_irq_chip_data(d);
	int port = GPIO_PORT(gpio);
	int lvl_type;
	int val;
	unsigned long flags;
	int ret;

	switch (type & IRQ_TYPE_SENSE_MASK) {
	case IRQ_TYPE_EDGE_RISING:
		lvl_type = GPIO_INT_LVL_EDGE_RISING;
		break;

	case IRQ_TYPE_EDGE_FALLING:
		lvl_type = GPIO_INT_LVL_EDGE_FALLING;
		break;

	case IRQ_TYPE_EDGE_BOTH:
		lvl_type = GPIO_INT_LVL_EDGE_BOTH;
		break;

	case IRQ_TYPE_LEVEL_HIGH:
		lvl_type = GPIO_INT_LVL_LEVEL_HIGH;
		break;

	case IRQ_TYPE_LEVEL_LOW:
		lvl_type = GPIO_INT_LVL_LEVEL_LOW;
		break;

	default:
		return -EINVAL;
	}

	ret = gpio_lock_as_irq(&tegra_gpio_chip, gpio);
	if (ret) {
		dev_err(dev, "unable to lock Tegra GPIO %d as IRQ\n", gpio);
		return ret;
	}

	spin_lock_irqsave(&bank->lvl_lock[port], flags);

	val = tegra_gpio_readl(GPIO_INT_LVL(gpio));
	val &= ~(GPIO_INT_LVL_MASK << GPIO_BIT(gpio));
	val |= lvl_type << GPIO_BIT(gpio);
	tegra_gpio_writel(val, GPIO_INT_LVL(gpio));

	spin_unlock_irqrestore(&bank->lvl_lock[port], flags);

	tegra_gpio_mask_write(GPIO_MSK_OE(gpio), gpio, 0);
	tegra_gpio_enable(gpio);

	if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
		__irq_set_handler_locked(d->irq, handle_level_irq);
	else if (type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
		__irq_set_handler_locked(d->irq, handle_edge_irq);

	return 0;
}

static void tegra_gpio_irq_shutdown(struct irq_data *d)
{
	int gpio = d->hwirq;

	gpio_unlock_as_irq(&tegra_gpio_chip, gpio);
}

static void tegra_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
{
	struct tegra_gpio_bank *bank;
	int port;
	int pin;
	int unmasked = 0;
	struct irq_chip *chip = irq_desc_get_chip(desc);

	chained_irq_enter(chip, desc);

	bank = irq_get_handler_data(irq);

	for (port = 0; port < 4; port++) {
		int gpio = tegra_gpio_compose(bank->bank, port, 0);
		unsigned long sta = tegra_gpio_readl(GPIO_INT_STA(gpio)) &
			tegra_gpio_readl(GPIO_INT_ENB(gpio));
		u32 lvl = tegra_gpio_readl(GPIO_INT_LVL(gpio));

		for_each_set_bit(pin, &sta, 8) {
			tegra_gpio_writel(1 << pin, GPIO_INT_CLR(gpio));

			/* if gpio is edge triggered, clear condition
			 * before executing the hander so that we don't
			 * miss edges
			 */
			if (lvl & (0x100 << pin)) {
				unmasked = 1;
				chained_irq_exit(chip, desc);
			}

			generic_handle_irq(gpio_to_irq(gpio + pin));
		}
	}

	if (!unmasked)
		chained_irq_exit(chip, desc);

}

#ifdef CONFIG_PM_SLEEP
static int tegra_gpio_resume(struct device *dev)
{
	unsigned long flags;
	int b;
	int p;

	local_irq_save(flags);

	for (b = 0; b < tegra_gpio_bank_count; b++) {
		struct tegra_gpio_bank *bank = &tegra_gpio_banks[b];

		for (p = 0; p < ARRAY_SIZE(bank->oe); p++) {
			unsigned int gpio = (b<<5) | (p<<3);
			tegra_gpio_writel(bank->cnf[p], GPIO_CNF(gpio));
			tegra_gpio_writel(bank->out[p], GPIO_OUT(gpio));
			tegra_gpio_writel(bank->oe[p], GPIO_OE(gpio));
			tegra_gpio_writel(bank->int_lvl[p], GPIO_INT_LVL(gpio));
			tegra_gpio_writel(bank->int_enb[p], GPIO_INT_ENB(gpio));
		}
	}

	local_irq_restore(flags);
	return 0;
}

static int tegra_gpio_suspend(struct device *dev)
{
	unsigned long flags;
	int b;
	int p;

	local_irq_save(flags);
	for (b = 0; b < tegra_gpio_bank_count; b++) {
		struct tegra_gpio_bank *bank = &tegra_gpio_banks[b];

		for (p = 0; p < ARRAY_SIZE(bank->oe); p++) {
			unsigned int gpio = (b<<5) | (p<<3);
			bank->cnf[p] = tegra_gpio_readl(GPIO_CNF(gpio));
			bank->out[p] = tegra_gpio_readl(GPIO_OUT(gpio));
			bank->oe[p] = tegra_gpio_readl(GPIO_OE(gpio));
			bank->int_enb[p] = tegra_gpio_readl(GPIO_INT_ENB(gpio));
			bank->int_lvl[p] = tegra_gpio_readl(GPIO_INT_LVL(gpio));

			/* Enable gpio irq for wake up source */
			tegra_gpio_writel(bank->wake_enb[p],
					  GPIO_INT_ENB(gpio));
		}
	}
	local_irq_restore(flags);
	return 0;
}

static int tegra_gpio_irq_set_wake(struct irq_data *d, unsigned int enable)
{
	struct tegra_gpio_bank *bank = irq_data_get_irq_chip_data(d);
	int gpio = d->hwirq;
	u32 port, bit, mask;

	port = GPIO_PORT(gpio);
	bit = GPIO_BIT(gpio);
	mask = BIT(bit);

	if (enable)
		bank->wake_enb[port] |= mask;
	else
		bank->wake_enb[port] &= ~mask;

	return irq_set_irq_wake(bank->irq, enable);
}
#endif

static struct irq_chip tegra_gpio_irq_chip = {
	.name		= "GPIO",
	.irq_ack	= tegra_gpio_irq_ack,
	.irq_mask	= tegra_gpio_irq_mask,
	.irq_unmask	= tegra_gpio_irq_unmask,
	.irq_set_type	= tegra_gpio_irq_set_type,
	.irq_shutdown	= tegra_gpio_irq_shutdown,
#ifdef CONFIG_PM_SLEEP
	.irq_set_wake	= tegra_gpio_irq_set_wake,
#endif
};

static const struct dev_pm_ops tegra_gpio_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(tegra_gpio_suspend, tegra_gpio_resume)
};

struct tegra_gpio_soc_config {
	u32 bank_stride;
	u32 upper_offset;
};

static struct tegra_gpio_soc_config tegra20_gpio_config = {
	.bank_stride = 0x80,
	.upper_offset = 0x800,
};

static struct tegra_gpio_soc_config tegra30_gpio_config = {
	.bank_stride = 0x100,
	.upper_offset = 0x80,
};

static struct of_device_id tegra_gpio_of_match[] = {
	{ .compatible = "nvidia,tegra30-gpio", .data = &tegra30_gpio_config },
	{ .compatible = "nvidia,tegra20-gpio", .data = &tegra20_gpio_config },
	{ },
};

/* This lock class tells lockdep that GPIO irqs are in a different
 * category than their parents, so it won't report false recursion.
 */
static struct lock_class_key gpio_lock_class;

static int tegra_gpio_probe(struct platform_device *pdev)
{
	const struct of_device_id *match;
	struct tegra_gpio_soc_config *config;
	struct resource *res;
	struct tegra_gpio_bank *bank;
	int ret;
	int gpio;
	int i;
	int j;

	dev = &pdev->dev;

	match = of_match_device(tegra_gpio_of_match, &pdev->dev);
	if (!match) {
		dev_err(&pdev->dev, "Error: No device match found\n");
		return -ENODEV;
	}
	config = (struct tegra_gpio_soc_config *)match->data;

	tegra_gpio_bank_stride = config->bank_stride;
	tegra_gpio_upper_offset = config->upper_offset;

	for (;;) {
		res = platform_get_resource(pdev, IORESOURCE_IRQ, tegra_gpio_bank_count);
		if (!res)
			break;
		tegra_gpio_bank_count++;
	}
	if (!tegra_gpio_bank_count) {
		dev_err(&pdev->dev, "Missing IRQ resource\n");
		return -ENODEV;
	}

	tegra_gpio_chip.ngpio = tegra_gpio_bank_count * 32;

	tegra_gpio_banks = devm_kzalloc(&pdev->dev,
			tegra_gpio_bank_count * sizeof(*tegra_gpio_banks),
			GFP_KERNEL);
	if (!tegra_gpio_banks) {
		dev_err(&pdev->dev, "Couldn't allocate bank structure\n");
		return -ENODEV;
	}

	irq_domain = irq_domain_add_linear(pdev->dev.of_node,
					   tegra_gpio_chip.ngpio,
					   &irq_domain_simple_ops, NULL);
	if (!irq_domain)
		return -ENODEV;

	for (i = 0; i < tegra_gpio_bank_count; i++) {
		res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
		if (!res) {
			dev_err(&pdev->dev, "Missing IRQ resource\n");
			return -ENODEV;
		}

		bank = &tegra_gpio_banks[i];
		bank->bank = i;
		bank->irq = res->start;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(regs))
		return PTR_ERR(regs);

	for (i = 0; i < tegra_gpio_bank_count; i++) {
		for (j = 0; j < 4; j++) {
			int gpio = tegra_gpio_compose(i, j, 0);
			tegra_gpio_writel(0x00, GPIO_INT_ENB(gpio));
		}
	}

	tegra_gpio_chip.of_node = pdev->dev.of_node;

	ret = gpiochip_add(&tegra_gpio_chip);
	if (ret < 0) {
		irq_domain_remove(irq_domain);
		return ret;
	}

	for (gpio = 0; gpio < tegra_gpio_chip.ngpio; gpio++) {
		int irq = irq_create_mapping(irq_domain, gpio);
		/* No validity check; all Tegra GPIOs are valid IRQs */

		bank = &tegra_gpio_banks[GPIO_BANK(gpio)];

		irq_set_lockdep_class(irq, &gpio_lock_class);
		irq_set_chip_data(irq, bank);
		irq_set_chip_and_handler(irq, &tegra_gpio_irq_chip,
					 handle_simple_irq);
		set_irq_flags(irq, IRQF_VALID);
	}

	for (i = 0; i < tegra_gpio_bank_count; i++) {
		bank = &tegra_gpio_banks[i];

		irq_set_chained_handler(bank->irq, tegra_gpio_irq_handler);
		irq_set_handler_data(bank->irq, bank);

		for (j = 0; j < 4; j++)
			spin_lock_init(&bank->lvl_lock[j]);
	}

	return 0;
}

static struct platform_driver tegra_gpio_driver = {
	.driver		= {
		.name	= "tegra-gpio",
		.owner	= THIS_MODULE,
		.pm	= &tegra_gpio_pm_ops,
		.of_match_table = tegra_gpio_of_match,
	},
	.probe		= tegra_gpio_probe,
};

static int __init tegra_gpio_init(void)
{
	return platform_driver_register(&tegra_gpio_driver);
}
postcore_initcall(tegra_gpio_init);

#ifdef	CONFIG_DEBUG_FS

#include <linux/debugfs.h>
#include <linux/seq_file.h>

static int dbg_gpio_show(struct seq_file *s, void *unused)
{
	int i;
	int j;

	for (i = 0; i < tegra_gpio_bank_count; i++) {
		for (j = 0; j < 4; j++) {
			int gpio = tegra_gpio_compose(i, j, 0);
			seq_printf(s,
				"%d:%d %02x %02x %02x %02x %02x %02x %06x\n",
				i, j,
				tegra_gpio_readl(GPIO_CNF(gpio)),
				tegra_gpio_readl(GPIO_OE(gpio)),
				tegra_gpio_readl(GPIO_OUT(gpio)),
				tegra_gpio_readl(GPIO_IN(gpio)),
				tegra_gpio_readl(GPIO_INT_STA(gpio)),
				tegra_gpio_readl(GPIO_INT_ENB(gpio)),
				tegra_gpio_readl(GPIO_INT_LVL(gpio)));
		}
	}
	return 0;
}

static int dbg_gpio_open(struct inode *inode, struct file *file)
{
	return single_open(file, dbg_gpio_show, &inode->i_private);
}

static const struct file_operations debug_fops = {
	.open		= dbg_gpio_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int __init tegra_gpio_debuginit(void)
{
	(void) debugfs_create_file("tegra_gpio", S_IRUGO,
					NULL, NULL, &debug_fops);
	return 0;
}
late_initcall(tegra_gpio_debuginit);
#endif