linux/drivers/gpio/gpio-uniphier.c
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   1// SPDX-License-Identifier: GPL-2.0
   2//
   3// Copyright (C) 2017 Socionext Inc.
   4//   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
   5
   6#include <linux/bits.h>
   7#include <linux/gpio/driver.h>
   8#include <linux/irq.h>
   9#include <linux/irqdomain.h>
  10#include <linux/module.h>
  11#include <linux/of.h>
  12#include <linux/of_device.h>
  13#include <linux/of_irq.h>
  14#include <linux/platform_device.h>
  15#include <linux/spinlock.h>
  16#include <dt-bindings/gpio/uniphier-gpio.h>
  17
  18#define UNIPHIER_GPIO_IRQ_MAX_NUM       24
  19
  20#define UNIPHIER_GPIO_PORT_DATA         0x0     /* data */
  21#define UNIPHIER_GPIO_PORT_DIR          0x4     /* direction (1:in, 0:out) */
  22#define UNIPHIER_GPIO_IRQ_EN            0x90    /* irq enable */
  23#define UNIPHIER_GPIO_IRQ_MODE          0x94    /* irq mode (1: both edge) */
  24#define UNIPHIER_GPIO_IRQ_FLT_EN        0x98    /* noise filter enable */
  25#define UNIPHIER_GPIO_IRQ_FLT_CYC       0x9c    /* noise filter clock cycle */
  26
  27struct uniphier_gpio_priv {
  28        struct gpio_chip chip;
  29        struct irq_chip irq_chip;
  30        struct irq_domain *domain;
  31        void __iomem *regs;
  32        spinlock_t lock;
  33        u32 saved_vals[];
  34};
  35
  36static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank)
  37{
  38        unsigned int reg;
  39
  40        reg = (bank + 1) * 8;
  41
  42        /*
  43         * Unfortunately, the GPIO port registers are not contiguous because
  44         * offset 0x90-0x9f is used for IRQ.  Add 0x10 when crossing the region.
  45         */
  46        if (reg >= UNIPHIER_GPIO_IRQ_EN)
  47                reg += 0x10;
  48
  49        return reg;
  50}
  51
  52static void uniphier_gpio_get_bank_and_mask(unsigned int offset,
  53                                            unsigned int *bank, u32 *mask)
  54{
  55        *bank = offset / UNIPHIER_GPIO_LINES_PER_BANK;
  56        *mask = BIT(offset % UNIPHIER_GPIO_LINES_PER_BANK);
  57}
  58
  59static void uniphier_gpio_reg_update(struct uniphier_gpio_priv *priv,
  60                                     unsigned int reg, u32 mask, u32 val)
  61{
  62        unsigned long flags;
  63        u32 tmp;
  64
  65        spin_lock_irqsave(&priv->lock, flags);
  66        tmp = readl(priv->regs + reg);
  67        tmp &= ~mask;
  68        tmp |= mask & val;
  69        writel(tmp, priv->regs + reg);
  70        spin_unlock_irqrestore(&priv->lock, flags);
  71}
  72
  73static void uniphier_gpio_bank_write(struct gpio_chip *chip, unsigned int bank,
  74                                     unsigned int reg, u32 mask, u32 val)
  75{
  76        struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
  77
  78        if (!mask)
  79                return;
  80
  81        uniphier_gpio_reg_update(priv, uniphier_gpio_bank_to_reg(bank) + reg,
  82                                 mask, val);
  83}
  84
  85static void uniphier_gpio_offset_write(struct gpio_chip *chip,
  86                                       unsigned int offset, unsigned int reg,
  87                                       int val)
  88{
  89        unsigned int bank;
  90        u32 mask;
  91
  92        uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
  93
  94        uniphier_gpio_bank_write(chip, bank, reg, mask, val ? mask : 0);
  95}
  96
  97static int uniphier_gpio_offset_read(struct gpio_chip *chip,
  98                                     unsigned int offset, unsigned int reg)
  99{
 100        struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
 101        unsigned int bank, reg_offset;
 102        u32 mask;
 103
 104        uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
 105        reg_offset = uniphier_gpio_bank_to_reg(bank) + reg;
 106
 107        return !!(readl(priv->regs + reg_offset) & mask);
 108}
 109
 110static int uniphier_gpio_get_direction(struct gpio_chip *chip,
 111                                       unsigned int offset)
 112{
 113        if (uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DIR))
 114                return GPIO_LINE_DIRECTION_IN;
 115
 116        return GPIO_LINE_DIRECTION_OUT;
 117}
 118
 119static int uniphier_gpio_direction_input(struct gpio_chip *chip,
 120                                         unsigned int offset)
 121{
 122        uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 1);
 123
 124        return 0;
 125}
 126
 127static int uniphier_gpio_direction_output(struct gpio_chip *chip,
 128                                          unsigned int offset, int val)
 129{
 130        uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
 131        uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 0);
 132
 133        return 0;
 134}
 135
 136static int uniphier_gpio_get(struct gpio_chip *chip, unsigned int offset)
 137{
 138        return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DATA);
 139}
 140
 141static void uniphier_gpio_set(struct gpio_chip *chip,
 142                              unsigned int offset, int val)
 143{
 144        uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
 145}
 146
 147static void uniphier_gpio_set_multiple(struct gpio_chip *chip,
 148                                       unsigned long *mask, unsigned long *bits)
 149{
 150        unsigned long i, bank, bank_mask, bank_bits;
 151
 152        for_each_set_clump8(i, bank_mask, mask, chip->ngpio) {
 153                bank = i / UNIPHIER_GPIO_LINES_PER_BANK;
 154                bank_bits = bitmap_get_value8(bits, i);
 155
 156                uniphier_gpio_bank_write(chip, bank, UNIPHIER_GPIO_PORT_DATA,
 157                                         bank_mask, bank_bits);
 158        }
 159}
 160
 161static int uniphier_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
 162{
 163        struct irq_fwspec fwspec;
 164
 165        if (offset < UNIPHIER_GPIO_IRQ_OFFSET)
 166                return -ENXIO;
 167
 168        fwspec.fwnode = of_node_to_fwnode(chip->parent->of_node);
 169        fwspec.param_count = 2;
 170        fwspec.param[0] = offset - UNIPHIER_GPIO_IRQ_OFFSET;
 171        /*
 172         * IRQ_TYPE_NONE is rejected by the parent irq domain. Set LEVEL_HIGH
 173         * temporarily. Anyway, ->irq_set_type() will override it later.
 174         */
 175        fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
 176
 177        return irq_create_fwspec_mapping(&fwspec);
 178}
 179
 180static void uniphier_gpio_irq_mask(struct irq_data *data)
 181{
 182        struct uniphier_gpio_priv *priv = data->chip_data;
 183        u32 mask = BIT(data->hwirq);
 184
 185        uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, 0);
 186
 187        return irq_chip_mask_parent(data);
 188}
 189
 190static void uniphier_gpio_irq_unmask(struct irq_data *data)
 191{
 192        struct uniphier_gpio_priv *priv = data->chip_data;
 193        u32 mask = BIT(data->hwirq);
 194
 195        uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, mask);
 196
 197        return irq_chip_unmask_parent(data);
 198}
 199
 200static int uniphier_gpio_irq_set_type(struct irq_data *data, unsigned int type)
 201{
 202        struct uniphier_gpio_priv *priv = data->chip_data;
 203        u32 mask = BIT(data->hwirq);
 204        u32 val = 0;
 205
 206        if (type == IRQ_TYPE_EDGE_BOTH) {
 207                val = mask;
 208                type = IRQ_TYPE_EDGE_FALLING;
 209        }
 210
 211        uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_MODE, mask, val);
 212        /* To enable both edge detection, the noise filter must be enabled. */
 213        uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_FLT_EN, mask, val);
 214
 215        return irq_chip_set_type_parent(data, type);
 216}
 217
 218static int uniphier_gpio_irq_get_parent_hwirq(struct uniphier_gpio_priv *priv,
 219                                              unsigned int hwirq)
 220{
 221        struct device_node *np = priv->chip.parent->of_node;
 222        const __be32 *range;
 223        u32 base, parent_base, size;
 224        int len;
 225
 226        range = of_get_property(np, "socionext,interrupt-ranges", &len);
 227        if (!range)
 228                return -EINVAL;
 229
 230        len /= sizeof(*range);
 231
 232        for (; len >= 3; len -= 3) {
 233                base = be32_to_cpu(*range++);
 234                parent_base = be32_to_cpu(*range++);
 235                size = be32_to_cpu(*range++);
 236
 237                if (base <= hwirq && hwirq < base + size)
 238                        return hwirq - base + parent_base;
 239        }
 240
 241        return -ENOENT;
 242}
 243
 244static int uniphier_gpio_irq_domain_translate(struct irq_domain *domain,
 245                                              struct irq_fwspec *fwspec,
 246                                              unsigned long *out_hwirq,
 247                                              unsigned int *out_type)
 248{
 249        if (WARN_ON(fwspec->param_count < 2))
 250                return -EINVAL;
 251
 252        *out_hwirq = fwspec->param[0];
 253        *out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
 254
 255        return 0;
 256}
 257
 258static int uniphier_gpio_irq_domain_alloc(struct irq_domain *domain,
 259                                          unsigned int virq,
 260                                          unsigned int nr_irqs, void *arg)
 261{
 262        struct uniphier_gpio_priv *priv = domain->host_data;
 263        struct irq_fwspec parent_fwspec;
 264        irq_hw_number_t hwirq;
 265        unsigned int type;
 266        int ret;
 267
 268        if (WARN_ON(nr_irqs != 1))
 269                return -EINVAL;
 270
 271        ret = uniphier_gpio_irq_domain_translate(domain, arg, &hwirq, &type);
 272        if (ret)
 273                return ret;
 274
 275        ret = uniphier_gpio_irq_get_parent_hwirq(priv, hwirq);
 276        if (ret < 0)
 277                return ret;
 278
 279        /* parent is UniPhier AIDET */
 280        parent_fwspec.fwnode = domain->parent->fwnode;
 281        parent_fwspec.param_count = 2;
 282        parent_fwspec.param[0] = ret;
 283        parent_fwspec.param[1] = (type == IRQ_TYPE_EDGE_BOTH) ?
 284                                                IRQ_TYPE_EDGE_FALLING : type;
 285
 286        ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
 287                                            &priv->irq_chip, priv);
 288        if (ret)
 289                return ret;
 290
 291        return irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
 292}
 293
 294static int uniphier_gpio_irq_domain_activate(struct irq_domain *domain,
 295                                             struct irq_data *data, bool early)
 296{
 297        struct uniphier_gpio_priv *priv = domain->host_data;
 298        struct gpio_chip *chip = &priv->chip;
 299
 300        return gpiochip_lock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
 301}
 302
 303static void uniphier_gpio_irq_domain_deactivate(struct irq_domain *domain,
 304                                                struct irq_data *data)
 305{
 306        struct uniphier_gpio_priv *priv = domain->host_data;
 307        struct gpio_chip *chip = &priv->chip;
 308
 309        gpiochip_unlock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
 310}
 311
 312static const struct irq_domain_ops uniphier_gpio_irq_domain_ops = {
 313        .alloc = uniphier_gpio_irq_domain_alloc,
 314        .free = irq_domain_free_irqs_common,
 315        .activate = uniphier_gpio_irq_domain_activate,
 316        .deactivate = uniphier_gpio_irq_domain_deactivate,
 317        .translate = uniphier_gpio_irq_domain_translate,
 318};
 319
 320static void uniphier_gpio_hw_init(struct uniphier_gpio_priv *priv)
 321{
 322        /*
 323         * Due to the hardware design, the noise filter must be enabled to
 324         * detect both edge interrupts.  This filter is intended to remove the
 325         * noise from the irq lines.  It does not work for GPIO input, so GPIO
 326         * debounce is not supported.  Unfortunately, the filter period is
 327         * shared among all irq lines.  Just choose a sensible period here.
 328         */
 329        writel(0xff, priv->regs + UNIPHIER_GPIO_IRQ_FLT_CYC);
 330}
 331
 332static unsigned int uniphier_gpio_get_nbanks(unsigned int ngpio)
 333{
 334        return DIV_ROUND_UP(ngpio, UNIPHIER_GPIO_LINES_PER_BANK);
 335}
 336
 337static int uniphier_gpio_probe(struct platform_device *pdev)
 338{
 339        struct device *dev = &pdev->dev;
 340        struct device_node *parent_np;
 341        struct irq_domain *parent_domain;
 342        struct uniphier_gpio_priv *priv;
 343        struct gpio_chip *chip;
 344        struct irq_chip *irq_chip;
 345        unsigned int nregs;
 346        u32 ngpios;
 347        int ret;
 348
 349        parent_np = of_irq_find_parent(dev->of_node);
 350        if (!parent_np)
 351                return -ENXIO;
 352
 353        parent_domain = irq_find_host(parent_np);
 354        of_node_put(parent_np);
 355        if (!parent_domain)
 356                return -EPROBE_DEFER;
 357
 358        ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios);
 359        if (ret)
 360                return ret;
 361
 362        nregs = uniphier_gpio_get_nbanks(ngpios) * 2 + 3;
 363        priv = devm_kzalloc(dev, struct_size(priv, saved_vals, nregs),
 364                            GFP_KERNEL);
 365        if (!priv)
 366                return -ENOMEM;
 367
 368        priv->regs = devm_platform_ioremap_resource(pdev, 0);
 369        if (IS_ERR(priv->regs))
 370                return PTR_ERR(priv->regs);
 371
 372        spin_lock_init(&priv->lock);
 373
 374        chip = &priv->chip;
 375        chip->label = dev_name(dev);
 376        chip->parent = dev;
 377        chip->request = gpiochip_generic_request;
 378        chip->free = gpiochip_generic_free;
 379        chip->get_direction = uniphier_gpio_get_direction;
 380        chip->direction_input = uniphier_gpio_direction_input;
 381        chip->direction_output = uniphier_gpio_direction_output;
 382        chip->get = uniphier_gpio_get;
 383        chip->set = uniphier_gpio_set;
 384        chip->set_multiple = uniphier_gpio_set_multiple;
 385        chip->to_irq = uniphier_gpio_to_irq;
 386        chip->base = -1;
 387        chip->ngpio = ngpios;
 388
 389        irq_chip = &priv->irq_chip;
 390        irq_chip->name = dev_name(dev);
 391        irq_chip->irq_mask = uniphier_gpio_irq_mask;
 392        irq_chip->irq_unmask = uniphier_gpio_irq_unmask;
 393        irq_chip->irq_eoi = irq_chip_eoi_parent;
 394        irq_chip->irq_set_affinity = irq_chip_set_affinity_parent;
 395        irq_chip->irq_set_type = uniphier_gpio_irq_set_type;
 396
 397        uniphier_gpio_hw_init(priv);
 398
 399        ret = devm_gpiochip_add_data(dev, chip, priv);
 400        if (ret)
 401                return ret;
 402
 403        priv->domain = irq_domain_create_hierarchy(
 404                                        parent_domain, 0,
 405                                        UNIPHIER_GPIO_IRQ_MAX_NUM,
 406                                        of_node_to_fwnode(dev->of_node),
 407                                        &uniphier_gpio_irq_domain_ops, priv);
 408        if (!priv->domain)
 409                return -ENOMEM;
 410
 411        platform_set_drvdata(pdev, priv);
 412
 413        return 0;
 414}
 415
 416static int uniphier_gpio_remove(struct platform_device *pdev)
 417{
 418        struct uniphier_gpio_priv *priv = platform_get_drvdata(pdev);
 419
 420        irq_domain_remove(priv->domain);
 421
 422        return 0;
 423}
 424
 425static int __maybe_unused uniphier_gpio_suspend(struct device *dev)
 426{
 427        struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
 428        unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
 429        u32 *val = priv->saved_vals;
 430        unsigned int reg;
 431        int i;
 432
 433        for (i = 0; i < nbanks; i++) {
 434                reg = uniphier_gpio_bank_to_reg(i);
 435
 436                *val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
 437                *val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
 438        }
 439
 440        *val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_EN);
 441        *val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_MODE);
 442        *val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
 443
 444        return 0;
 445}
 446
 447static int __maybe_unused uniphier_gpio_resume(struct device *dev)
 448{
 449        struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
 450        unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
 451        const u32 *val = priv->saved_vals;
 452        unsigned int reg;
 453        int i;
 454
 455        for (i = 0; i < nbanks; i++) {
 456                reg = uniphier_gpio_bank_to_reg(i);
 457
 458                writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
 459                writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
 460        }
 461
 462        writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_EN);
 463        writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_MODE);
 464        writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
 465
 466        uniphier_gpio_hw_init(priv);
 467
 468        return 0;
 469}
 470
 471static const struct dev_pm_ops uniphier_gpio_pm_ops = {
 472        SET_LATE_SYSTEM_SLEEP_PM_OPS(uniphier_gpio_suspend,
 473                                     uniphier_gpio_resume)
 474};
 475
 476static const struct of_device_id uniphier_gpio_match[] = {
 477        { .compatible = "socionext,uniphier-gpio" },
 478        { /* sentinel */ }
 479};
 480MODULE_DEVICE_TABLE(of, uniphier_gpio_match);
 481
 482static struct platform_driver uniphier_gpio_driver = {
 483        .probe = uniphier_gpio_probe,
 484        .remove = uniphier_gpio_remove,
 485        .driver = {
 486                .name = "uniphier-gpio",
 487                .of_match_table = uniphier_gpio_match,
 488                .pm = &uniphier_gpio_pm_ops,
 489        },
 490};
 491module_platform_driver(uniphier_gpio_driver);
 492
 493MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
 494MODULE_DESCRIPTION("UniPhier GPIO driver");
 495MODULE_LICENSE("GPL v2");
 496