drivers/gpio/gpio-rcar.c

   1 /*
   2  * Renesas R-Car GPIO Support
   3  *
   4  *  Copyright (C) 2014 Renesas Electronics Corporation
   5  *  Copyright (C) 2013 Magnus Damm
   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
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/clk.h>
  18 #include <linux/err.h>
  19 #include <linux/gpio.h>
  20 #include <linux/init.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/io.h>
  23 #include <linux/ioport.h>
  24 #include <linux/irq.h>
  25 #include <linux/module.h>
  26 #include <linux/of.h>
  27 #include <linux/pinctrl/consumer.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/pm_runtime.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/slab.h>
  32
  33 struct gpio_rcar_priv {
  34         void __iomem *base;
  35         spinlock_t lock;
  36         struct platform_device *pdev;
  37         struct gpio_chip gpio_chip;
  38         struct irq_chip irq_chip;
  39         struct clk *clk;
  40         unsigned int irq_parent;
  41         bool has_both_edge_trigger;
  42         bool needs_clk;
  43 };
  44
  45 #define IOINTSEL 0x00   /* General IO/Interrupt Switching Register */
  46 #define INOUTSEL 0x04   /* General Input/Output Switching Register */
  47 #define OUTDT 0x08      /* General Output Register */
  48 #define INDT 0x0c       /* General Input Register */
  49 #define INTDT 0x10      /* Interrupt Display Register */
  50 #define INTCLR 0x14     /* Interrupt Clear Register */
  51 #define INTMSK 0x18     /* Interrupt Mask Register */
  52 #define MSKCLR 0x1c     /* Interrupt Mask Clear Register */
  53 #define POSNEG 0x20     /* Positive/Negative Logic Select Register */
  54 #define EDGLEVEL 0x24   /* Edge/level Select Register */
  55 #define FILONOFF 0x28   /* Chattering Prevention On/Off Register */
  56 #define BOTHEDGE 0x4c   /* One Edge/Both Edge Select Register */
  57
  58 #define RCAR_MAX_GPIO_PER_BANK          32
  59
  60 static inline u32 gpio_rcar_read(struct gpio_rcar_priv *p, int offs)
  61 {
  62         return ioread32(p->base + offs);
  63 }
  64
  65 static inline void gpio_rcar_write(struct gpio_rcar_priv *p, int offs,
  66                                    u32 value)
  67 {
  68         iowrite32(value, p->base + offs);
  69 }
  70
  71 static void gpio_rcar_modify_bit(struct gpio_rcar_priv *p, int offs,
  72                                  int bit, bool value)
  73 {
  74         u32 tmp = gpio_rcar_read(p, offs);
  75
  76         if (value)
  77                 tmp |= BIT(bit);
  78         else
  79                 tmp &= ~BIT(bit);
  80
  81         gpio_rcar_write(p, offs, tmp);
  82 }
  83
  84 static void gpio_rcar_irq_disable(struct irq_data *d)
  85 {
  86         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  87         struct gpio_rcar_priv *p = gpiochip_get_data(gc);
  88
  89         gpio_rcar_write(p, INTMSK, ~BIT(irqd_to_hwirq(d)));
  90 }
  91
  92 static void gpio_rcar_irq_enable(struct irq_data *d)
  93 {
  94         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
  95         struct gpio_rcar_priv *p = gpiochip_get_data(gc);
  96
  97         gpio_rcar_write(p, MSKCLR, BIT(irqd_to_hwirq(d)));
  98 }
  99
 100 static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p,
 101                                                   unsigned int hwirq,
 102                                                   bool active_high_rising_edge,
 103                                                   bool level_trigger,
 104                                                   bool both)
 105 {
 106         unsigned long flags;
 107
 108         /* follow steps in the GPIO documentation for
 109          * "Setting Edge-Sensitive Interrupt Input Mode" and
 110          * "Setting Level-Sensitive Interrupt Input Mode"
 111          */
 112
 113         spin_lock_irqsave(&p->lock, flags);
 114
 115         /* Configure postive or negative logic in POSNEG */
 116         gpio_rcar_modify_bit(p, POSNEG, hwirq, !active_high_rising_edge);
 117
 118         /* Configure edge or level trigger in EDGLEVEL */
 119         gpio_rcar_modify_bit(p, EDGLEVEL, hwirq, !level_trigger);
 120
 121         /* Select one edge or both edges in BOTHEDGE */
 122         if (p->has_both_edge_trigger)
 123                 gpio_rcar_modify_bit(p, BOTHEDGE, hwirq, both);
 124
 125         /* Select "Interrupt Input Mode" in IOINTSEL */
 126         gpio_rcar_modify_bit(p, IOINTSEL, hwirq, true);
 127
 128         /* Write INTCLR in case of edge trigger */
 129         if (!level_trigger)
 130                 gpio_rcar_write(p, INTCLR, BIT(hwirq));
 131
 132         spin_unlock_irqrestore(&p->lock, flags);
 133 }
 134
 135 static int gpio_rcar_irq_set_type(struct irq_data *d, unsigned int type)
 136 {
 137         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 138         struct gpio_rcar_priv *p = gpiochip_get_data(gc);
 139         unsigned int hwirq = irqd_to_hwirq(d);
 140
 141         dev_dbg(&p->pdev->dev, "sense irq = %d, type = %d\n", hwirq, type);
 142
 143         switch (type & IRQ_TYPE_SENSE_MASK) {
 144         case IRQ_TYPE_LEVEL_HIGH:
 145                 gpio_rcar_config_interrupt_input_mode(p, hwirq, true, true,
 146                                                       false);
 147                 break;
 148         case IRQ_TYPE_LEVEL_LOW:
 149                 gpio_rcar_config_interrupt_input_mode(p, hwirq, false, true,
 150                                                       false);
 151                 break;
 152         case IRQ_TYPE_EDGE_RISING:
 153                 gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
 154                                                       false);
 155                 break;
 156         case IRQ_TYPE_EDGE_FALLING:
 157                 gpio_rcar_config_interrupt_input_mode(p, hwirq, false, false,
 158                                                       false);
 159                 break;
 160         case IRQ_TYPE_EDGE_BOTH:
 161                 if (!p->has_both_edge_trigger)
 162                         return -EINVAL;
 163                 gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false,
 164                                                       true);
 165                 break;
 166         default:
 167                 return -EINVAL;
 168         }
 169         return 0;
 170 }
 171
 172 static int gpio_rcar_irq_set_wake(struct irq_data *d, unsigned int on)
 173 {
 174         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 175         struct gpio_rcar_priv *p = gpiochip_get_data(gc);
 176         int error;
 177
 178         if (p->irq_parent) {
 179                 error = irq_set_irq_wake(p->irq_parent, on);
 180                 if (error) {
 181                         dev_dbg(&p->pdev->dev,
 182                                 "irq %u doesn't support irq_set_wake\n",
 183                                 p->irq_parent);
 184                         p->irq_parent = 0;
 185                 }
 186         }
 187
 188         if (!p->clk)
 189                 return 0;
 190
 191         if (on)
 192                 clk_enable(p->clk);
 193         else
 194                 clk_disable(p->clk);
 195
 196         return 0;
 197 }
 198
 199 static irqreturn_t gpio_rcar_irq_handler(int irq, void *dev_id)
 200 {
 201         struct gpio_rcar_priv *p = dev_id;
 202         u32 pending;
 203         unsigned int offset, irqs_handled = 0;
 204
 205         while ((pending = gpio_rcar_read(p, INTDT) &
 206                           gpio_rcar_read(p, INTMSK))) {
 207                 offset = __ffs(pending);
 208                 gpio_rcar_write(p, INTCLR, BIT(offset));
 209                 generic_handle_irq(irq_find_mapping(p->gpio_chip.irqdomain,
 210                                                     offset));
 211                 irqs_handled++;
 212         }
 213
 214         return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
 215 }
 216
 217 static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip,
 218                                                        unsigned int gpio,
 219                                                        bool output)
 220 {
 221         struct gpio_rcar_priv *p = gpiochip_get_data(chip);
 222         unsigned long flags;
 223
 224         /* follow steps in the GPIO documentation for
 225          * "Setting General Output Mode" and
 226          * "Setting General Input Mode"
 227          */
 228
 229         spin_lock_irqsave(&p->lock, flags);
 230
 231         /* Configure postive logic in POSNEG */
 232         gpio_rcar_modify_bit(p, POSNEG, gpio, false);
 233
 234         /* Select "General Input/Output Mode" in IOINTSEL */
 235         gpio_rcar_modify_bit(p, IOINTSEL, gpio, false);
 236
 237         /* Select Input Mode or Output Mode in INOUTSEL */
 238         gpio_rcar_modify_bit(p, INOUTSEL, gpio, output);
 239
 240         spin_unlock_irqrestore(&p->lock, flags);
 241 }
 242
 243 static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)
 244 {
 245         struct gpio_rcar_priv *p = gpiochip_get_data(chip);
 246         int error;
 247
 248         error = pm_runtime_get_sync(&p->pdev->dev);
 249         if (error < 0)
 250                 return error;
 251
 252         error = pinctrl_request_gpio(chip->base + offset);
 253         if (error)
 254                 pm_runtime_put(&p->pdev->dev);
 255
 256         return error;
 257 }
 258
 259 static void gpio_rcar_free(struct gpio_chip *chip, unsigned offset)
 260 {
 261         struct gpio_rcar_priv *p = gpiochip_get_data(chip);
 262
 263         pinctrl_free_gpio(chip->base + offset);
 264
 265         /* Set the GPIO as an input to ensure that the next GPIO request won't
 266          * drive the GPIO pin as an output.
 267          */
 268         gpio_rcar_config_general_input_output_mode(chip, offset, false);
 269
 270         pm_runtime_put(&p->pdev->dev);
 271 }
 272
 273 static int gpio_rcar_direction_input(struct gpio_chip *chip, unsigned offset)
 274 {
 275         gpio_rcar_config_general_input_output_mode(chip, offset, false);
 276         return 0;
 277 }
 278
 279 static int gpio_rcar_get(struct gpio_chip *chip, unsigned offset)
 280 {
 281         u32 bit = BIT(offset);
 282
 283         /* testing on r8a7790 shows that INDT does not show correct pin state
 284          * when configured as output, so use OUTDT in case of output pins */
 285         if (gpio_rcar_read(gpiochip_get_data(chip), INOUTSEL) & bit)
 286                 return !!(gpio_rcar_read(gpiochip_get_data(chip), OUTDT) & bit);
 287         else
 288                 return !!(gpio_rcar_read(gpiochip_get_data(chip), INDT) & bit);
 289 }
 290
 291 static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int value)
 292 {
 293         struct gpio_rcar_priv *p = gpiochip_get_data(chip);
 294         unsigned long flags;
 295
 296         spin_lock_irqsave(&p->lock, flags);
 297         gpio_rcar_modify_bit(p, OUTDT, offset, value);
 298         spin_unlock_irqrestore(&p->lock, flags);
 299 }
 300
 301 static int gpio_rcar_direction_output(struct gpio_chip *chip, unsigned offset,
 302                                       int value)
 303 {
 304         /* write GPIO value to output before selecting output mode of pin */
 305         gpio_rcar_set(chip, offset, value);
 306         gpio_rcar_config_general_input_output_mode(chip, offset, true);
 307         return 0;
 308 }
 309
 310 struct gpio_rcar_info {
 311         bool has_both_edge_trigger;
 312         bool needs_clk;
 313 };
 314
 315 static const struct gpio_rcar_info gpio_rcar_info_gen1 = {
 316         .has_both_edge_trigger = false,
 317         .needs_clk = false,
 318 };
 319
 320 static const struct gpio_rcar_info gpio_rcar_info_gen2 = {
 321         .has_both_edge_trigger = true,
 322         .needs_clk = true,
 323 };
 324
 325 static const struct of_device_id gpio_rcar_of_table[] = {
 326         {
 327                 .compatible = "renesas,gpio-r8a7790",
 328                 .data = &gpio_rcar_info_gen2,
 329         }, {
 330                 .compatible = "renesas,gpio-r8a7791",
 331                 .data = &gpio_rcar_info_gen2,
 332         }, {
 333                 .compatible = "renesas,gpio-r8a7793",
 334                 .data = &gpio_rcar_info_gen2,
 335         }, {
 336                 .compatible = "renesas,gpio-r8a7794",
 337                 .data = &gpio_rcar_info_gen2,
 338         }, {
 339                 .compatible = "renesas,gpio-r8a7795",
 340                 /* Gen3 GPIO is identical to Gen2. */
 341                 .data = &gpio_rcar_info_gen2,
 342         }, {
 343                 .compatible = "renesas,gpio-rcar",
 344                 .data = &gpio_rcar_info_gen1,
 345         }, {
 346                 /* Terminator */
 347         },
 348 };
 349
 350 MODULE_DEVICE_TABLE(of, gpio_rcar_of_table);
 351
 352 static int gpio_rcar_parse_dt(struct gpio_rcar_priv *p, unsigned int *npins)
 353 {
 354         struct device_node *np = p->pdev->dev.of_node;
 355         const struct of_device_id *match;
 356         const struct gpio_rcar_info *info;
 357         struct of_phandle_args args;
 358         int ret;
 359
 360         match = of_match_node(gpio_rcar_of_table, np);
 361         if (!match)
 362                 return -EINVAL;
 363
 364         info = match->data;
 365
 366         ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0, &args);
 367         *npins = ret == 0 ? args.args[2] : RCAR_MAX_GPIO_PER_BANK;
 368         p->has_both_edge_trigger = info->has_both_edge_trigger;
 369         p->needs_clk = info->needs_clk;
 370
 371         if (*npins == 0 || *npins > RCAR_MAX_GPIO_PER_BANK) {
 372                 dev_warn(&p->pdev->dev,
 373                          "Invalid number of gpio lines %u, using %u\n", *npins,
 374                          RCAR_MAX_GPIO_PER_BANK);
 375                 *npins = RCAR_MAX_GPIO_PER_BANK;
 376         }
 377
 378         return 0;
 379 }
 380
 381 static int gpio_rcar_probe(struct platform_device *pdev)
 382 {
 383         struct gpio_rcar_priv *p;
 384         struct resource *io, *irq;
 385         struct gpio_chip *gpio_chip;
 386         struct irq_chip *irq_chip;
 387         struct device *dev = &pdev->dev;
 388         const char *name = dev_name(dev);
 389         unsigned int npins;
 390         int ret;
 391
 392         p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
 393         if (!p)
 394                 return -ENOMEM;
 395
 396         p->pdev = pdev;
 397         spin_lock_init(&p->lock);
 398
 399         /* Get device configuration from DT node */
 400         ret = gpio_rcar_parse_dt(p, &npins);
 401         if (ret < 0)
 402                 return ret;
 403
 404         platform_set_drvdata(pdev, p);
 405
 406         p->clk = devm_clk_get(dev, NULL);
 407         if (IS_ERR(p->clk)) {
 408                 if (p->needs_clk) {
 409                         dev_err(dev, "unable to get clock\n");
 410                         ret = PTR_ERR(p->clk);
 411                         goto err0;
 412                 }
 413                 p->clk = NULL;
 414         }
 415
 416         pm_runtime_enable(dev);
 417
 418         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 419         irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 420
 421         if (!io || !irq) {
 422                 dev_err(dev, "missing IRQ or IOMEM\n");
 423                 ret = -EINVAL;
 424                 goto err0;
 425         }
 426
 427         p->base = devm_ioremap_nocache(dev, io->start, resource_size(io));
 428         if (!p->base) {
 429                 dev_err(dev, "failed to remap I/O memory\n");
 430                 ret = -ENXIO;
 431                 goto err0;
 432         }
 433
 434         gpio_chip = &p->gpio_chip;
 435         gpio_chip->request = gpio_rcar_request;
 436         gpio_chip->free = gpio_rcar_free;
 437         gpio_chip->direction_input = gpio_rcar_direction_input;
 438         gpio_chip->get = gpio_rcar_get;
 439         gpio_chip->direction_output = gpio_rcar_direction_output;
 440         gpio_chip->set = gpio_rcar_set;
 441         gpio_chip->label = name;
 442         gpio_chip->parent = dev;
 443         gpio_chip->owner = THIS_MODULE;
 444         gpio_chip->base = -1;
 445         gpio_chip->ngpio = npins;
 446
 447         irq_chip = &p->irq_chip;
 448         irq_chip->name = name;
 449         irq_chip->irq_mask = gpio_rcar_irq_disable;
 450         irq_chip->irq_unmask = gpio_rcar_irq_enable;
 451         irq_chip->irq_set_type = gpio_rcar_irq_set_type;
 452         irq_chip->irq_set_wake = gpio_rcar_irq_set_wake;
 453         irq_chip->flags = IRQCHIP_SET_TYPE_MASKED | IRQCHIP_MASK_ON_SUSPEND;
 454
 455         ret = gpiochip_add_data(gpio_chip, p);
 456         if (ret) {
 457                 dev_err(dev, "failed to add GPIO controller\n");
 458                 goto err0;
 459         }
 460
 461         ret = gpiochip_irqchip_add(gpio_chip, irq_chip, 0, handle_level_irq,
 462                                    IRQ_TYPE_NONE);
 463         if (ret) {
 464                 dev_err(dev, "cannot add irqchip\n");
 465                 goto err1;
 466         }
 467
 468         p->irq_parent = irq->start;
 469         if (devm_request_irq(dev, irq->start, gpio_rcar_irq_handler,
 470                              IRQF_SHARED, name, p)) {
 471                 dev_err(dev, "failed to request IRQ\n");
 472                 ret = -ENOENT;
 473                 goto err1;
 474         }
 475
 476         dev_info(dev, "driving %d GPIOs\n", npins);
 477
 478         return 0;
 479
 480 err1:
 481         gpiochip_remove(gpio_chip);
 482 err0:
 483         pm_runtime_disable(dev);
 484         return ret;
 485 }
 486
 487 static int gpio_rcar_remove(struct platform_device *pdev)
 488 {
 489         struct gpio_rcar_priv *p = platform_get_drvdata(pdev);
 490
 491         gpiochip_remove(&p->gpio_chip);
 492
 493         pm_runtime_disable(&pdev->dev);
 494         return 0;
 495 }
 496
 497 static struct platform_driver gpio_rcar_device_driver = {
 498         .probe          = gpio_rcar_probe,
 499         .remove         = gpio_rcar_remove,
 500         .driver         = {
 501                 .name   = "gpio_rcar",
 502                 .of_match_table = of_match_ptr(gpio_rcar_of_table),
 503         }
 504 };
 505
 506 module_platform_driver(gpio_rcar_device_driver);
 507
 508 MODULE_AUTHOR("Magnus Damm");
 509 MODULE_DESCRIPTION("Renesas R-Car GPIO Driver");
 510 MODULE_LICENSE("GPL v2");