drivers/gpio/gpio-uniphier.c

   1 /*
   2  * Copyright (C) 2017 Socionext Inc.
   3  *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/bitops.h>
  16 #include <linux/gpio/driver.h>
  17 #include <linux/irq.h>
  18 #include <linux/irqdomain.h>
  19 #include <linux/module.h>
  20 #include <linux/of.h>
  21 #include <linux/of_device.h>
  22 #include <linux/of_irq.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/spinlock.h>
  25 #include <dt-bindings/gpio/uniphier-gpio.h>
  26
  27 #define UNIPHIER_GPIO_BANK_MASK         \
  28                                 GENMASK((UNIPHIER_GPIO_LINES_PER_BANK) - 1, 0)
  29
  30 #define UNIPHIER_GPIO_IRQ_MAX_NUM       24
  31
  32 #define UNIPHIER_GPIO_PORT_DATA         0x0     /* data */
  33 #define UNIPHIER_GPIO_PORT_DIR          0x4     /* direction (1:in, 0:out) */
  34 #define UNIPHIER_GPIO_IRQ_EN            0x90    /* irq enable */
  35 #define UNIPHIER_GPIO_IRQ_MODE          0x94    /* irq mode (1: both edge) */
  36 #define UNIPHIER_GPIO_IRQ_FLT_EN        0x98    /* noise filter enable */
  37 #define UNIPHIER_GPIO_IRQ_FLT_CYC       0x9c    /* noise filter clock cycle */
  38
  39 struct uniphier_gpio_priv {
  40         struct gpio_chip chip;
  41         struct irq_chip irq_chip;
  42         struct irq_domain *domain;
  43         void __iomem *regs;
  44         spinlock_t lock;
  45         u32 saved_vals[0];
  46 };
  47
  48 static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank)
  49 {
  50         unsigned int reg;
  51
  52         reg = (bank + 1) * 8;
  53
  54         /*
  55          * Unfortunately, the GPIO port registers are not contiguous because
  56          * offset 0x90-0x9f is used for IRQ.  Add 0x10 when crossing the region.
  57          */
  58         if (reg >= UNIPHIER_GPIO_IRQ_EN)
  59                 reg += 0x10;
  60
  61         return reg;
  62 }
  63
  64 static void uniphier_gpio_get_bank_and_mask(unsigned int offset,
  65                                             unsigned int *bank, u32 *mask)
  66 {
  67         *bank = offset / UNIPHIER_GPIO_LINES_PER_BANK;
  68         *mask = BIT(offset % UNIPHIER_GPIO_LINES_PER_BANK);
  69 }
  70
  71 static void uniphier_gpio_reg_update(struct uniphier_gpio_priv *priv,
  72                                      unsigned int reg, u32 mask, u32 val)
  73 {
  74         unsigned long flags;
  75         u32 tmp;
  76
  77         spin_lock_irqsave(&priv->lock, flags);
  78         tmp = readl(priv->regs + reg);
  79         tmp &= ~mask;
  80         tmp |= mask & val;
  81         writel(tmp, priv->regs + reg);
  82         spin_unlock_irqrestore(&priv->lock, flags);
  83 }
  84
  85 static void uniphier_gpio_bank_write(struct gpio_chip *chip, unsigned int bank,
  86                                      unsigned int reg, u32 mask, u32 val)
  87 {
  88         struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
  89
  90         if (!mask)
  91                 return;
  92
  93         uniphier_gpio_reg_update(priv, uniphier_gpio_bank_to_reg(bank) + reg,
  94                                  mask, val);
  95 }
  96
  97 static void uniphier_gpio_offset_write(struct gpio_chip *chip,
  98                                        unsigned int offset, unsigned int reg,
  99                                        int val)
 100 {
 101         unsigned int bank;
 102         u32 mask;
 103
 104         uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
 105
 106         uniphier_gpio_bank_write(chip, bank, reg, mask, val ? mask : 0);
 107 }
 108
 109 static int uniphier_gpio_offset_read(struct gpio_chip *chip,
 110                                      unsigned int offset, unsigned int reg)
 111 {
 112         struct uniphier_gpio_priv *priv = gpiochip_get_data(chip);
 113         unsigned int bank, reg_offset;
 114         u32 mask;
 115
 116         uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
 117         reg_offset = uniphier_gpio_bank_to_reg(bank) + reg;
 118
 119         return !!(readl(priv->regs + reg_offset) & mask);
 120 }
 121
 122 static int uniphier_gpio_get_direction(struct gpio_chip *chip,
 123                                        unsigned int offset)
 124 {
 125         return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DIR);
 126 }
 127
 128 static int uniphier_gpio_direction_input(struct gpio_chip *chip,
 129                                          unsigned int offset)
 130 {
 131         uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 1);
 132
 133         return 0;
 134 }
 135
 136 static int uniphier_gpio_direction_output(struct gpio_chip *chip,
 137                                           unsigned int offset, int val)
 138 {
 139         uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
 140         uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DIR, 0);
 141
 142         return 0;
 143 }
 144
 145 static int uniphier_gpio_get(struct gpio_chip *chip, unsigned int offset)
 146 {
 147         return uniphier_gpio_offset_read(chip, offset, UNIPHIER_GPIO_PORT_DATA);
 148 }
 149
 150 static void uniphier_gpio_set(struct gpio_chip *chip,
 151                               unsigned int offset, int val)
 152 {
 153         uniphier_gpio_offset_write(chip, offset, UNIPHIER_GPIO_PORT_DATA, val);
 154 }
 155
 156 static void uniphier_gpio_set_multiple(struct gpio_chip *chip,
 157                                        unsigned long *mask, unsigned long *bits)
 158 {
 159         unsigned int bank, shift, bank_mask, bank_bits;
 160         int i;
 161
 162         for (i = 0; i < chip->ngpio; i += UNIPHIER_GPIO_LINES_PER_BANK) {
 163                 bank = i / UNIPHIER_GPIO_LINES_PER_BANK;
 164                 shift = i % BITS_PER_LONG;
 165                 bank_mask = (mask[BIT_WORD(i)] >> shift) &
 166                                                 UNIPHIER_GPIO_BANK_MASK;
 167                 bank_bits = bits[BIT_WORD(i)] >> shift;
 168
 169                 uniphier_gpio_bank_write(chip, bank, UNIPHIER_GPIO_PORT_DATA,
 170                                          bank_mask, bank_bits);
 171         }
 172 }
 173
 174 static int uniphier_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
 175 {
 176         struct irq_fwspec fwspec;
 177
 178         if (offset < UNIPHIER_GPIO_IRQ_OFFSET)
 179                 return -ENXIO;
 180
 181         fwspec.fwnode = of_node_to_fwnode(chip->parent->of_node);
 182         fwspec.param_count = 2;
 183         fwspec.param[0] = offset - UNIPHIER_GPIO_IRQ_OFFSET;
 184         /*
 185          * IRQ_TYPE_NONE is rejected by the parent irq domain. Set LEVEL_HIGH
 186          * temporarily. Anyway, ->irq_set_type() will override it later.
 187          */
 188         fwspec.param[1] = IRQ_TYPE_LEVEL_HIGH;
 189
 190         return irq_create_fwspec_mapping(&fwspec);
 191 }
 192
 193 static void uniphier_gpio_irq_mask(struct irq_data *data)
 194 {
 195         struct uniphier_gpio_priv *priv = data->chip_data;
 196         u32 mask = BIT(data->hwirq);
 197
 198         uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, 0);
 199
 200         return irq_chip_mask_parent(data);
 201 }
 202
 203 static void uniphier_gpio_irq_unmask(struct irq_data *data)
 204 {
 205         struct uniphier_gpio_priv *priv = data->chip_data;
 206         u32 mask = BIT(data->hwirq);
 207
 208         uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_EN, mask, mask);
 209
 210         return irq_chip_unmask_parent(data);
 211 }
 212
 213 static int uniphier_gpio_irq_set_type(struct irq_data *data, unsigned int type)
 214 {
 215         struct uniphier_gpio_priv *priv = data->chip_data;
 216         u32 mask = BIT(data->hwirq);
 217         u32 val = 0;
 218
 219         if (type == IRQ_TYPE_EDGE_BOTH) {
 220                 val = mask;
 221                 type = IRQ_TYPE_EDGE_FALLING;
 222         }
 223
 224         uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_MODE, mask, val);
 225         /* To enable both edge detection, the noise filter must be enabled. */
 226         uniphier_gpio_reg_update(priv, UNIPHIER_GPIO_IRQ_FLT_EN, mask, val);
 227
 228         return irq_chip_set_type_parent(data, type);
 229 }
 230
 231 static int uniphier_gpio_irq_get_parent_hwirq(struct uniphier_gpio_priv *priv,
 232                                               unsigned int hwirq)
 233 {
 234         struct device_node *np = priv->chip.parent->of_node;
 235         const __be32 *range;
 236         u32 base, parent_base, size;
 237         int len;
 238
 239         range = of_get_property(np, "socionext,interrupt-ranges", &len);
 240         if (!range)
 241                 return -EINVAL;
 242
 243         len /= sizeof(*range);
 244
 245         for (; len >= 3; len -= 3) {
 246                 base = be32_to_cpu(*range++);
 247                 parent_base = be32_to_cpu(*range++);
 248                 size = be32_to_cpu(*range++);
 249
 250                 if (base <= hwirq && hwirq < base + size)
 251                         return hwirq - base + parent_base;
 252         }
 253
 254         return -ENOENT;
 255 }
 256
 257 static int uniphier_gpio_irq_domain_translate(struct irq_domain *domain,
 258                                               struct irq_fwspec *fwspec,
 259                                               unsigned long *out_hwirq,
 260                                               unsigned int *out_type)
 261 {
 262         if (WARN_ON(fwspec->param_count < 2))
 263                 return -EINVAL;
 264
 265         *out_hwirq = fwspec->param[0];
 266         *out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
 267
 268         return 0;
 269 }
 270
 271 static int uniphier_gpio_irq_domain_alloc(struct irq_domain *domain,
 272                                           unsigned int virq,
 273                                           unsigned int nr_irqs, void *arg)
 274 {
 275         struct uniphier_gpio_priv *priv = domain->host_data;
 276         struct irq_fwspec parent_fwspec;
 277         irq_hw_number_t hwirq;
 278         unsigned int type;
 279         int ret;
 280
 281         if (WARN_ON(nr_irqs != 1))
 282                 return -EINVAL;
 283
 284         ret = uniphier_gpio_irq_domain_translate(domain, arg, &hwirq, &type);
 285         if (ret)
 286                 return ret;
 287
 288         ret = uniphier_gpio_irq_get_parent_hwirq(priv, hwirq);
 289         if (ret < 0)
 290                 return ret;
 291
 292         /* parent is UniPhier AIDET */
 293         parent_fwspec.fwnode = domain->parent->fwnode;
 294         parent_fwspec.param_count = 2;
 295         parent_fwspec.param[0] = ret;
 296         parent_fwspec.param[1] = (type == IRQ_TYPE_EDGE_BOTH) ?
 297                                                 IRQ_TYPE_EDGE_FALLING : type;
 298
 299         ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
 300                                             &priv->irq_chip, priv);
 301         if (ret)
 302                 return ret;
 303
 304         return irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
 305 }
 306
 307 static int uniphier_gpio_irq_domain_activate(struct irq_domain *domain,
 308                                              struct irq_data *data, bool early)
 309 {
 310         struct uniphier_gpio_priv *priv = domain->host_data;
 311         struct gpio_chip *chip = &priv->chip;
 312
 313         gpiochip_lock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
 314         return 0;
 315 }
 316
 317 static void uniphier_gpio_irq_domain_deactivate(struct irq_domain *domain,
 318                                                 struct irq_data *data)
 319 {
 320         struct uniphier_gpio_priv *priv = domain->host_data;
 321         struct gpio_chip *chip = &priv->chip;
 322
 323         gpiochip_unlock_as_irq(chip, data->hwirq + UNIPHIER_GPIO_IRQ_OFFSET);
 324 }
 325
 326 static const struct irq_domain_ops uniphier_gpio_irq_domain_ops = {
 327         .alloc = uniphier_gpio_irq_domain_alloc,
 328         .free = irq_domain_free_irqs_common,
 329         .activate = uniphier_gpio_irq_domain_activate,
 330         .deactivate = uniphier_gpio_irq_domain_deactivate,
 331         .translate = uniphier_gpio_irq_domain_translate,
 332 };
 333
 334 static void uniphier_gpio_hw_init(struct uniphier_gpio_priv *priv)
 335 {
 336         /*
 337          * Due to the hardware design, the noise filter must be enabled to
 338          * detect both edge interrupts.  This filter is intended to remove the
 339          * noise from the irq lines.  It does not work for GPIO input, so GPIO
 340          * debounce is not supported.  Unfortunately, the filter period is
 341          * shared among all irq lines.  Just choose a sensible period here.
 342          */
 343         writel(0xff, priv->regs + UNIPHIER_GPIO_IRQ_FLT_CYC);
 344 }
 345
 346 static unsigned int uniphier_gpio_get_nbanks(unsigned int ngpio)
 347 {
 348         return DIV_ROUND_UP(ngpio, UNIPHIER_GPIO_LINES_PER_BANK);
 349 }
 350
 351 static int uniphier_gpio_probe(struct platform_device *pdev)
 352 {
 353         struct device *dev = &pdev->dev;
 354         struct device_node *parent_np;
 355         struct irq_domain *parent_domain;
 356         struct uniphier_gpio_priv *priv;
 357         struct gpio_chip *chip;
 358         struct irq_chip *irq_chip;
 359         struct resource *regs;
 360         unsigned int nregs;
 361         u32 ngpios;
 362         int ret;
 363
 364         parent_np = of_irq_find_parent(dev->of_node);
 365         if (!parent_np)
 366                 return -ENXIO;
 367
 368         parent_domain = irq_find_host(parent_np);
 369         of_node_put(parent_np);
 370         if (!parent_domain)
 371                 return -EPROBE_DEFER;
 372
 373         ret = of_property_read_u32(dev->of_node, "ngpios", &ngpios);
 374         if (ret)
 375                 return ret;
 376
 377         nregs = uniphier_gpio_get_nbanks(ngpios) * 2 + 3;
 378         priv = devm_kzalloc(dev,
 379                             sizeof(*priv) + sizeof(priv->saved_vals[0]) * nregs,
 380                             GFP_KERNEL);
 381         if (!priv)
 382                 return -ENOMEM;
 383
 384         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 385         priv->regs = devm_ioremap_resource(dev, regs);
 386         if (IS_ERR(priv->regs))
 387                 return PTR_ERR(priv->regs);
 388
 389         spin_lock_init(&priv->lock);
 390
 391         chip = &priv->chip;
 392         chip->label = dev_name(dev);
 393         chip->parent = dev;
 394         chip->request = gpiochip_generic_request;
 395         chip->free = gpiochip_generic_free;
 396         chip->get_direction = uniphier_gpio_get_direction;
 397         chip->direction_input = uniphier_gpio_direction_input;
 398         chip->direction_output = uniphier_gpio_direction_output;
 399         chip->get = uniphier_gpio_get;
 400         chip->set = uniphier_gpio_set;
 401         chip->set_multiple = uniphier_gpio_set_multiple;
 402         chip->to_irq = uniphier_gpio_to_irq;
 403         chip->base = -1;
 404         chip->ngpio = ngpios;
 405
 406         irq_chip = &priv->irq_chip;
 407         irq_chip->name = dev_name(dev);
 408         irq_chip->irq_mask = uniphier_gpio_irq_mask;
 409         irq_chip->irq_unmask = uniphier_gpio_irq_unmask;
 410         irq_chip->irq_eoi = irq_chip_eoi_parent;
 411         irq_chip->irq_set_affinity = irq_chip_set_affinity_parent;
 412         irq_chip->irq_set_type = uniphier_gpio_irq_set_type;
 413
 414         uniphier_gpio_hw_init(priv);
 415
 416         ret = devm_gpiochip_add_data(dev, chip, priv);
 417         if (ret)
 418                 return ret;
 419
 420         priv->domain = irq_domain_create_hierarchy(
 421                                         parent_domain, 0,
 422                                         UNIPHIER_GPIO_IRQ_MAX_NUM,
 423                                         of_node_to_fwnode(dev->of_node),
 424                                         &uniphier_gpio_irq_domain_ops, priv);
 425         if (!priv->domain)
 426                 return -ENOMEM;
 427
 428         platform_set_drvdata(pdev, priv);
 429
 430         return 0;
 431 }
 432
 433 static int uniphier_gpio_remove(struct platform_device *pdev)
 434 {
 435         struct uniphier_gpio_priv *priv = platform_get_drvdata(pdev);
 436
 437         irq_domain_remove(priv->domain);
 438
 439         return 0;
 440 }
 441
 442 static int __maybe_unused uniphier_gpio_suspend(struct device *dev)
 443 {
 444         struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
 445         unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
 446         u32 *val = priv->saved_vals;
 447         unsigned int reg;
 448         int i;
 449
 450         for (i = 0; i < nbanks; i++) {
 451                 reg = uniphier_gpio_bank_to_reg(i);
 452
 453                 *val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
 454                 *val++ = readl(priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
 455         }
 456
 457         *val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_EN);
 458         *val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_MODE);
 459         *val++ = readl(priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
 460
 461         return 0;
 462 }
 463
 464 static int __maybe_unused uniphier_gpio_resume(struct device *dev)
 465 {
 466         struct uniphier_gpio_priv *priv = dev_get_drvdata(dev);
 467         unsigned int nbanks = uniphier_gpio_get_nbanks(priv->chip.ngpio);
 468         const u32 *val = priv->saved_vals;
 469         unsigned int reg;
 470         int i;
 471
 472         for (i = 0; i < nbanks; i++) {
 473                 reg = uniphier_gpio_bank_to_reg(i);
 474
 475                 writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DATA);
 476                 writel(*val++, priv->regs + reg + UNIPHIER_GPIO_PORT_DIR);
 477         }
 478
 479         writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_EN);
 480         writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_MODE);
 481         writel(*val++, priv->regs + UNIPHIER_GPIO_IRQ_FLT_EN);
 482
 483         uniphier_gpio_hw_init(priv);
 484
 485         return 0;
 486 }
 487
 488 static const struct dev_pm_ops uniphier_gpio_pm_ops = {
 489         SET_LATE_SYSTEM_SLEEP_PM_OPS(uniphier_gpio_suspend,
 490                                      uniphier_gpio_resume)
 491 };
 492
 493 static const struct of_device_id uniphier_gpio_match[] = {
 494         { .compatible = "socionext,uniphier-gpio" },
 495         { /* sentinel */ }
 496 };
 497 MODULE_DEVICE_TABLE(of, uniphier_gpio_match);
 498
 499 static struct platform_driver uniphier_gpio_driver = {
 500         .probe = uniphier_gpio_probe,
 501         .remove = uniphier_gpio_remove,
 502         .driver = {
 503                 .name = "uniphier-gpio",
 504                 .of_match_table = uniphier_gpio_match,
 505                 .pm = &uniphier_gpio_pm_ops,
 506         },
 507 };
 508 module_platform_driver(uniphier_gpio_driver);
 509
 510 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
 511 MODULE_DESCRIPTION("UniPhier GPIO driver");
 512 MODULE_LICENSE("GPL v2");