drivers/gpio/gpio-rcar.c

   1 /*
   2  * Renesas R-Car GPIO Support
   3  *
   4  *  Copyright (C) 2013 Magnus Damm
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/err.h>
  17 #include <linux/gpio.h>
  18 #include <linux/init.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/io.h>
  21 #include <linux/ioport.h>
  22 #include <linux/irq.h>
  23 #include <linux/irqdomain.h>
  24 #include <linux/module.h>
  25 #include <linux/of.h>
  26 #include <linux/pinctrl/consumer.h>
  27 #include <linux/platform_data/gpio-rcar.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/slab.h>
  31
  32 struct gpio_rcar_priv {
  33         void __iomem *base;
  34         spinlock_t lock;
  35         struct gpio_rcar_config config;
  36         struct platform_device *pdev;
  37         struct gpio_chip gpio_chip;
  38         struct irq_chip irq_chip;
  39         struct irq_domain *irq_domain;
  40 };
  41
  42 #define IOINTSEL 0x00
  43 #define INOUTSEL 0x04
  44 #define OUTDT 0x08
  45 #define INDT 0x0c
  46 #define INTDT 0x10
  47 #define INTCLR 0x14
  48 #define INTMSK 0x18
  49 #define MSKCLR 0x1c
  50 #define POSNEG 0x20
  51 #define EDGLEVEL 0x24
  52 #define FILONOFF 0x28
  53 #define BOTHEDGE 0x4c
  54
  55 #define RCAR_MAX_GPIO_PER_BANK          32
  56
  57 static inline u32 gpio_rcar_read(struct gpio_rcar_priv *p, int offs)
  58 {
  59         return ioread32(p->base + offs);
  60 }
  61
  62 static inline void gpio_rcar_write(struct gpio_rcar_priv *p, int offs,
  63                                    u32 value)
  64 {
  65         iowrite32(value, p->base + offs);
  66 }
  67
  68 static void gpio_rcar_modify_bit(struct gpio_rcar_priv *p, int offs,
  69                                  int bit, bool value)
  70 {
  71         u32 tmp = gpio_rcar_read(p, offs);
  72
  73         if (value)
  74                 tmp |= BIT(bit);
  75         else
  76                 tmp &= ~BIT(bit);
  77
  78         gpio_rcar_write(p, offs, tmp);
  79 }
  80
  81 static void gpio_rcar_irq_disable(struct irq_data *d)
  82 {
  83         struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
  84
  85         gpio_rcar_write(p, INTMSK, ~BIT(irqd_to_hwirq(d)));
  86 }
  87
  88 static void gpio_rcar_irq_enable(struct irq_data *d)
  89 {
  90         struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
  91
  92         gpio_rcar_write(p, MSKCLR, BIT(irqd_to_hwirq(d)));
  93 }
  94
  95 static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p,
  96                                                   unsigned int hwirq,
  97                                                   bool active_high_rising_edge,
  98                                                   bool level_trigger,
  99                                                   bool both)
 100 {
 101         unsigned long flags;
 102
 103         /* follow steps in the GPIO documentation for
 104          * "Setting Edge-Sensitive Interrupt Input Mode" and
 105          * "Setting Level-Sensitive Interrupt Input Mode"
 106          */
 107
 108         spin_lock_irqsave(&p->lock, flags);
 109
 110         /* Configure postive or negative logic in POSNEG */
 111         gpio_rcar_modify_bit(p, POSNEG, hwirq, !active_high_rising_edge);
 112
 113         /* Configure edge or level trigger in EDGLEVEL */
 114         gpio_rcar_modify_bit(p, EDGLEVEL, hwirq, !level_trigger);
 115
 116         /* Select one edge or both edges in BOTHEDGE */
 117         if (p->config.has_both_edge_trigger)
 118                 gpio_rcar_modify_bit(p, BOTHEDGE, hwirq, both);
 119
 120         /* Select "Interrupt Input Mode" in IOINTSEL */
 121         gpio_rcar_modify_bit(p, IOINTSEL, hwirq, true);
 122
 123         /* Write INTCLR in case of edge trigger */
 124         if (!level_trigger)
 125                 gpio_rcar_write(p, INTCLR, BIT(hwirq));
 126
 127         spin_unlock_irqrestore(&p->lock, flags);
 128 }
 129
 130 static int gpio_rcar_irq_set_type(struct irq_data *d, unsigned int type)
 131 {
 132         struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
 133         unsigned int hwirq = irqd_to_hwirq(d);
 134
 135         dev_dbg(&p->pdev->dev, "sense irq = %d, type = %d\n", hwirq, type);
 136
 137         switch (type & IRQ_TYPE_SENSE_MASK) {
 138         case IRQ_TYPE_LEVEL_HIGH:
 139                 gpio_rcar_config_interrupt_input_mode(p, hwirq, true, true,
 140                                                       false);
 141                 break;
 142         case IRQ_TYPE_LEVEL_LOW:
 143                 gpio_rcar_config_interrupt_input_mode(p, hwirq, false, true,
 144                                                       false);
 145                 break;
 146         case IRQ_TYPE_EDGE_RISING:
 147                 gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
 148                                                       false);
 149                 break;
 150         case IRQ_TYPE_EDGE_FALLING:
 151                 gpio_rcar_config_interrupt_input_mode(p, hwirq, false, false,
 152                                                       false);
 153                 break;
 154         case IRQ_TYPE_EDGE_BOTH:
 155                 if (!p->config.has_both_edge_trigger)
 156                         return -EINVAL;
 157                 gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
 158                                                       true);
 159                 break;
 160         default:
 161                 return -EINVAL;
 162         }
 163         return 0;
 164 }
 165
 166 static irqreturn_t gpio_rcar_irq_handler(int irq, void *dev_id)
 167 {
 168         struct gpio_rcar_priv *p = dev_id;
 169         u32 pending;
 170         unsigned int offset, irqs_handled = 0;
 171
 172         while ((pending = gpio_rcar_read(p, INTDT) &
 173                           gpio_rcar_read(p, INTMSK))) {
 174                 offset = __ffs(pending);
 175                 gpio_rcar_write(p, INTCLR, BIT(offset));
 176                 generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
 177                 irqs_handled++;
 178         }
 179
 180         return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
 181 }
 182
 183 static inline struct gpio_rcar_priv *gpio_to_priv(struct gpio_chip *chip)
 184 {
 185         return container_of(chip, struct gpio_rcar_priv, gpio_chip);
 186 }
 187
 188 static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip,
 189                                                        unsigned int gpio,
 190                                                        bool output)
 191 {
 192         struct gpio_rcar_priv *p = gpio_to_priv(chip);
 193         unsigned long flags;
 194
 195         /* follow steps in the GPIO documentation for
 196          * "Setting General Output Mode" and
 197          * "Setting General Input Mode"
 198          */
 199
 200         spin_lock_irqsave(&p->lock, flags);
 201
 202         /* Configure postive logic in POSNEG */
 203         gpio_rcar_modify_bit(p, POSNEG, gpio, false);
 204
 205         /* Select "General Input/Output Mode" in IOINTSEL */
 206         gpio_rcar_modify_bit(p, IOINTSEL, gpio, false);
 207
 208         /* Select Input Mode or Output Mode in INOUTSEL */
 209         gpio_rcar_modify_bit(p, INOUTSEL, gpio, output);
 210
 211         spin_unlock_irqrestore(&p->lock, flags);
 212 }
 213
 214 static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)
 215 {
 216         return pinctrl_request_gpio(chip->base + offset);
 217 }
 218
 219 static void gpio_rcar_free(struct gpio_chip *chip, unsigned offset)
 220 {
 221         pinctrl_free_gpio(chip->base + offset);
 222
 223         /* Set the GPIO as an input to ensure that the next GPIO request won't
 224          * drive the GPIO pin as an output.
 225          */
 226         gpio_rcar_config_general_input_output_mode(chip, offset, false);
 227 }
 228
 229 static int gpio_rcar_direction_input(struct gpio_chip *chip, unsigned offset)
 230 {
 231         gpio_rcar_config_general_input_output_mode(chip, offset, false);
 232         return 0;
 233 }
 234
 235 static int gpio_rcar_get(struct gpio_chip *chip, unsigned offset)
 236 {
 237         u32 bit = BIT(offset);
 238
 239         /* testing on r8a7790 shows that INDT does not show correct pin state
 240          * when configured as output, so use OUTDT in case of output pins */
 241         if (gpio_rcar_read(gpio_to_priv(chip), INOUTSEL) & bit)
 242                 return (int)(gpio_rcar_read(gpio_to_priv(chip), OUTDT) & bit);
 243         else
 244                 return (int)(gpio_rcar_read(gpio_to_priv(chip), INDT) & bit);
 245 }
 246
 247 static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int value)
 248 {
 249         struct gpio_rcar_priv *p = gpio_to_priv(chip);
 250         unsigned long flags;
 251
 252         spin_lock_irqsave(&p->lock, flags);
 253         gpio_rcar_modify_bit(p, OUTDT, offset, value);
 254         spin_unlock_irqrestore(&p->lock, flags);
 255 }
 256
 257 static int gpio_rcar_direction_output(struct gpio_chip *chip, unsigned offset,
 258                                       int value)
 259 {
 260         /* write GPIO value to output before selecting output mode of pin */
 261         gpio_rcar_set(chip, offset, value);
 262         gpio_rcar_config_general_input_output_mode(chip, offset, true);
 263         return 0;
 264 }
 265
 266 static int gpio_rcar_to_irq(struct gpio_chip *chip, unsigned offset)
 267 {
 268         return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
 269 }
 270
 271 static int gpio_rcar_irq_domain_map(struct irq_domain *h, unsigned int irq,
 272                                  irq_hw_number_t hwirq)
 273 {
 274         struct gpio_rcar_priv *p = h->host_data;
 275
 276         dev_dbg(&p->pdev->dev, "map hw irq = %d, irq = %d\n", (int)hwirq, irq);
 277
 278         irq_set_chip_data(irq, h->host_data);
 279         irq_set_chip_and_handler(irq, &p->irq_chip, handle_level_irq);
 280         set_irq_flags(irq, IRQF_VALID); /* kill me now */
 281         return 0;
 282 }
 283
 284 static struct irq_domain_ops gpio_rcar_irq_domain_ops = {
 285         .map    = gpio_rcar_irq_domain_map,
 286 };
 287
 288 struct gpio_rcar_info {
 289         bool has_both_edge_trigger;
 290 };
 291
 292 static const struct of_device_id gpio_rcar_of_table[] = {
 293         {
 294                 .compatible = "renesas,gpio-r8a7790",
 295                 .data = (void *)&(const struct gpio_rcar_info) {
 296                         .has_both_edge_trigger = true,
 297                 },
 298         }, {
 299                 .compatible = "renesas,gpio-r8a7791",
 300                 .data = (void *)&(const struct gpio_rcar_info) {
 301                         .has_both_edge_trigger = true,
 302                 },
 303         }, {
 304                 .compatible = "renesas,gpio-rcar",
 305                 .data = (void *)&(const struct gpio_rcar_info) {
 306                         .has_both_edge_trigger = false,
 307                 },
 308         }, {
 309                 /* Terminator */
 310         },
 311 };
 312
 313 MODULE_DEVICE_TABLE(of, gpio_rcar_of_table);
 314
 315 static int gpio_rcar_parse_pdata(struct gpio_rcar_priv *p)
 316 {
 317         struct gpio_rcar_config *pdata = dev_get_platdata(&p->pdev->dev);
 318         struct device_node *np = p->pdev->dev.of_node;
 319         struct of_phandle_args args;
 320         int ret;
 321
 322         if (pdata) {
 323                 p->config = *pdata;
 324         } else if (IS_ENABLED(CONFIG_OF) && np) {
 325                 const struct of_device_id *match;
 326                 const struct gpio_rcar_info *info;
 327
 328                 match = of_match_node(gpio_rcar_of_table, np);
 329                 if (!match)
 330                         return -EINVAL;
 331
 332                 info = match->data;
 333
 334                 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0,
 335                                                        &args);
 336                 p->config.number_of_pins = ret == 0 ? args.args[2]
 337                                          : RCAR_MAX_GPIO_PER_BANK;
 338                 p->config.gpio_base = -1;
 339                 p->config.has_both_edge_trigger = info->has_both_edge_trigger;
 340         }
 341
 342         if (p->config.number_of_pins == 0 ||
 343             p->config.number_of_pins > RCAR_MAX_GPIO_PER_BANK) {
 344                 dev_warn(&p->pdev->dev,
 345                          "Invalid number of gpio lines %u, using %u\n",
 346                          p->config.number_of_pins, RCAR_MAX_GPIO_PER_BANK);
 347                 p->config.number_of_pins = RCAR_MAX_GPIO_PER_BANK;
 348         }
 349
 350         return 0;
 351 }
 352
 353 static int gpio_rcar_probe(struct platform_device *pdev)
 354 {
 355         struct gpio_rcar_priv *p;
 356         struct resource *io, *irq;
 357         struct gpio_chip *gpio_chip;
 358         struct irq_chip *irq_chip;
 359         struct device *dev = &pdev->dev;
 360         const char *name = dev_name(dev);
 361         int ret;
 362
 363         p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
 364         if (!p) {
 365                 dev_err(dev, "failed to allocate driver data\n");
 366                 ret = -ENOMEM;
 367                 goto err0;
 368         }
 369
 370         p->pdev = pdev;
 371         spin_lock_init(&p->lock);
 372
 373         /* Get device configuration from DT node or platform data. */
 374         ret = gpio_rcar_parse_pdata(p);
 375         if (ret < 0)
 376                 return ret;
 377
 378         platform_set_drvdata(pdev, p);
 379
 380         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 381         irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 382
 383         if (!io || !irq) {
 384                 dev_err(dev, "missing IRQ or IOMEM\n");
 385                 ret = -EINVAL;
 386                 goto err0;
 387         }
 388
 389         p->base = devm_ioremap_nocache(dev, io->start, resource_size(io));
 390         if (!p->base) {
 391                 dev_err(dev, "failed to remap I/O memory\n");
 392                 ret = -ENXIO;
 393                 goto err0;
 394         }
 395
 396         gpio_chip = &p->gpio_chip;
 397         gpio_chip->request = gpio_rcar_request;
 398         gpio_chip->free = gpio_rcar_free;
 399         gpio_chip->direction_input = gpio_rcar_direction_input;
 400         gpio_chip->get = gpio_rcar_get;
 401         gpio_chip->direction_output = gpio_rcar_direction_output;
 402         gpio_chip->set = gpio_rcar_set;
 403         gpio_chip->to_irq = gpio_rcar_to_irq;
 404         gpio_chip->label = name;
 405         gpio_chip->dev = dev;
 406         gpio_chip->owner = THIS_MODULE;
 407         gpio_chip->base = p->config.gpio_base;
 408         gpio_chip->ngpio = p->config.number_of_pins;
 409
 410         irq_chip = &p->irq_chip;
 411         irq_chip->name = name;
 412         irq_chip->irq_mask = gpio_rcar_irq_disable;
 413         irq_chip->irq_unmask = gpio_rcar_irq_enable;
 414         irq_chip->irq_set_type = gpio_rcar_irq_set_type;
 415         irq_chip->flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_SET_TYPE_MASKED
 416                          | IRQCHIP_MASK_ON_SUSPEND;
 417
 418         p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
 419                                               p->config.number_of_pins,
 420                                               p->config.irq_base,
 421                                               &gpio_rcar_irq_domain_ops, p);
 422         if (!p->irq_domain) {
 423                 ret = -ENXIO;
 424                 dev_err(dev, "cannot initialize irq domain\n");
 425                 goto err0;
 426         }
 427
 428         if (devm_request_irq(dev, irq->start, gpio_rcar_irq_handler,
 429                              IRQF_SHARED, name, p)) {
 430                 dev_err(dev, "failed to request IRQ\n");
 431                 ret = -ENOENT;
 432                 goto err1;
 433         }
 434
 435         ret = gpiochip_add(gpio_chip);
 436         if (ret) {
 437                 dev_err(dev, "failed to add GPIO controller\n");
 438                 goto err1;
 439         }
 440
 441         dev_info(dev, "driving %d GPIOs\n", p->config.number_of_pins);
 442
 443         /* warn in case of mismatch if irq base is specified */
 444         if (p->config.irq_base) {
 445                 ret = irq_find_mapping(p->irq_domain, 0);
 446                 if (p->config.irq_base != ret)
 447                         dev_warn(dev, "irq base mismatch (%u/%u)\n",
 448                                  p->config.irq_base, ret);
 449         }
 450
 451         if (p->config.pctl_name) {
 452                 ret = gpiochip_add_pin_range(gpio_chip, p->config.pctl_name, 0,
 453                                              gpio_chip->base, gpio_chip->ngpio);
 454                 if (ret < 0)
 455                         dev_warn(dev, "failed to add pin range\n");
 456         }
 457
 458         return 0;
 459
 460 err1:
 461         irq_domain_remove(p->irq_domain);
 462 err0:
 463         return ret;
 464 }
 465
 466 static int gpio_rcar_remove(struct platform_device *pdev)
 467 {
 468         struct gpio_rcar_priv *p = platform_get_drvdata(pdev);
 469         int ret;
 470
 471         ret = gpiochip_remove(&p->gpio_chip);
 472         if (ret)
 473                 return ret;
 474
 475         irq_domain_remove(p->irq_domain);
 476         return 0;
 477 }
 478
 479 static struct platform_driver gpio_rcar_device_driver = {
 480         .probe          = gpio_rcar_probe,
 481         .remove         = gpio_rcar_remove,
 482         .driver         = {
 483                 .name   = "gpio_rcar",
 484                 .of_match_table = of_match_ptr(gpio_rcar_of_table),
 485         }
 486 };
 487
 488 module_platform_driver(gpio_rcar_device_driver);
 489
 490 MODULE_AUTHOR("Magnus Damm");
 491 MODULE_DESCRIPTION("Renesas R-Car GPIO Driver");
 492 MODULE_LICENSE("GPL v2");