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/pinctrl/consumer.h>
  26 #include <linux/platform_data/gpio-rcar.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/slab.h>
  30
  31 struct gpio_rcar_priv {
  32         void __iomem *base;
  33         spinlock_t lock;
  34         struct gpio_rcar_config config;
  35         struct platform_device *pdev;
  36         struct gpio_chip gpio_chip;
  37         struct irq_chip irq_chip;
  38         struct irq_domain *irq_domain;
  39 };
  40
  41 #define IOINTSEL 0x00
  42 #define INOUTSEL 0x04
  43 #define OUTDT 0x08
  44 #define INDT 0x0c
  45 #define INTDT 0x10
  46 #define INTCLR 0x14
  47 #define INTMSK 0x18
  48 #define MSKCLR 0x1c
  49 #define POSNEG 0x20
  50 #define EDGLEVEL 0x24
  51 #define FILONOFF 0x28
  52
  53 static inline u32 gpio_rcar_read(struct gpio_rcar_priv *p, int offs)
  54 {
  55         return ioread32(p->base + offs);
  56 }
  57
  58 static inline void gpio_rcar_write(struct gpio_rcar_priv *p, int offs,
  59                                    u32 value)
  60 {
  61         iowrite32(value, p->base + offs);
  62 }
  63
  64 static void gpio_rcar_modify_bit(struct gpio_rcar_priv *p, int offs,
  65                                  int bit, bool value)
  66 {
  67         u32 tmp = gpio_rcar_read(p, offs);
  68
  69         if (value)
  70                 tmp |= BIT(bit);
  71         else
  72                 tmp &= ~BIT(bit);
  73
  74         gpio_rcar_write(p, offs, tmp);
  75 }
  76
  77 static void gpio_rcar_irq_disable(struct irq_data *d)
  78 {
  79         struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
  80
  81         gpio_rcar_write(p, INTMSK, ~BIT(irqd_to_hwirq(d)));
  82 }
  83
  84 static void gpio_rcar_irq_enable(struct irq_data *d)
  85 {
  86         struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
  87
  88         gpio_rcar_write(p, MSKCLR, BIT(irqd_to_hwirq(d)));
  89 }
  90
  91 static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p,
  92                                                   unsigned int hwirq,
  93                                                   bool active_high_rising_edge,
  94                                                   bool level_trigger)
  95 {
  96         unsigned long flags;
  97
  98         /* follow steps in the GPIO documentation for
  99          * "Setting Edge-Sensitive Interrupt Input Mode" and
 100          * "Setting Level-Sensitive Interrupt Input Mode"
 101          */
 102
 103         spin_lock_irqsave(&p->lock, flags);
 104
 105         /* Configure postive or negative logic in POSNEG */
 106         gpio_rcar_modify_bit(p, POSNEG, hwirq, !active_high_rising_edge);
 107
 108         /* Configure edge or level trigger in EDGLEVEL */
 109         gpio_rcar_modify_bit(p, EDGLEVEL, hwirq, !level_trigger);
 110
 111         /* Select "Interrupt Input Mode" in IOINTSEL */
 112         gpio_rcar_modify_bit(p, IOINTSEL, hwirq, true);
 113
 114         /* Write INTCLR in case of edge trigger */
 115         if (!level_trigger)
 116                 gpio_rcar_write(p, INTCLR, BIT(hwirq));
 117
 118         spin_unlock_irqrestore(&p->lock, flags);
 119 }
 120
 121 static int gpio_rcar_irq_set_type(struct irq_data *d, unsigned int type)
 122 {
 123         struct gpio_rcar_priv *p = irq_data_get_irq_chip_data(d);
 124         unsigned int hwirq = irqd_to_hwirq(d);
 125
 126         dev_dbg(&p->pdev->dev, "sense irq = %d, type = %d\n", hwirq, type);
 127
 128         switch (type & IRQ_TYPE_SENSE_MASK) {
 129         case IRQ_TYPE_LEVEL_HIGH:
 130                 gpio_rcar_config_interrupt_input_mode(p, hwirq, true, true);
 131                 break;
 132         case IRQ_TYPE_LEVEL_LOW:
 133                 gpio_rcar_config_interrupt_input_mode(p, hwirq, false, true);
 134                 break;
 135         case IRQ_TYPE_EDGE_RISING:
 136                 gpio_rcar_config_interrupt_input_mode(p, hwirq, true, false);
 137                 break;
 138         case IRQ_TYPE_EDGE_FALLING:
 139                 gpio_rcar_config_interrupt_input_mode(p, hwirq, false, false);
 140                 break;
 141         default:
 142                 return -EINVAL;
 143         }
 144         return 0;
 145 }
 146
 147 static irqreturn_t gpio_rcar_irq_handler(int irq, void *dev_id)
 148 {
 149         struct gpio_rcar_priv *p = dev_id;
 150         u32 pending;
 151         unsigned int offset, irqs_handled = 0;
 152
 153         while ((pending = gpio_rcar_read(p, INTDT))) {
 154                 offset = __ffs(pending);
 155                 gpio_rcar_write(p, INTCLR, BIT(offset));
 156                 generic_handle_irq(irq_find_mapping(p->irq_domain, offset));
 157                 irqs_handled++;
 158         }
 159
 160         return irqs_handled ? IRQ_HANDLED : IRQ_NONE;
 161 }
 162
 163 static inline struct gpio_rcar_priv *gpio_to_priv(struct gpio_chip *chip)
 164 {
 165         return container_of(chip, struct gpio_rcar_priv, gpio_chip);
 166 }
 167
 168 static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip,
 169                                                        unsigned int gpio,
 170                                                        bool output)
 171 {
 172         struct gpio_rcar_priv *p = gpio_to_priv(chip);
 173         unsigned long flags;
 174
 175         /* follow steps in the GPIO documentation for
 176          * "Setting General Output Mode" and
 177          * "Setting General Input Mode"
 178          */
 179
 180         spin_lock_irqsave(&p->lock, flags);
 181
 182         /* Configure postive logic in POSNEG */
 183         gpio_rcar_modify_bit(p, POSNEG, gpio, false);
 184
 185         /* Select "General Input/Output Mode" in IOINTSEL */
 186         gpio_rcar_modify_bit(p, IOINTSEL, gpio, false);
 187
 188         /* Select Input Mode or Output Mode in INOUTSEL */
 189         gpio_rcar_modify_bit(p, INOUTSEL, gpio, output);
 190
 191         spin_unlock_irqrestore(&p->lock, flags);
 192 }
 193
 194 static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset)
 195 {
 196         return pinctrl_request_gpio(chip->base + offset);
 197 }
 198
 199 static void gpio_rcar_free(struct gpio_chip *chip, unsigned offset)
 200 {
 201         pinctrl_free_gpio(chip->base + offset);
 202
 203         /* Set the GPIO as an input to ensure that the next GPIO request won't
 204          * drive the GPIO pin as an output.
 205          */
 206         gpio_rcar_config_general_input_output_mode(chip, offset, false);
 207 }
 208
 209 static int gpio_rcar_direction_input(struct gpio_chip *chip, unsigned offset)
 210 {
 211         gpio_rcar_config_general_input_output_mode(chip, offset, false);
 212         return 0;
 213 }
 214
 215 static int gpio_rcar_get(struct gpio_chip *chip, unsigned offset)
 216 {
 217         return (int)(gpio_rcar_read(gpio_to_priv(chip), INDT) & BIT(offset));
 218 }
 219
 220 static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int value)
 221 {
 222         struct gpio_rcar_priv *p = gpio_to_priv(chip);
 223         unsigned long flags;
 224
 225         spin_lock_irqsave(&p->lock, flags);
 226         gpio_rcar_modify_bit(p, OUTDT, offset, value);
 227         spin_unlock_irqrestore(&p->lock, flags);
 228 }
 229
 230 static int gpio_rcar_direction_output(struct gpio_chip *chip, unsigned offset,
 231                                       int value)
 232 {
 233         /* write GPIO value to output before selecting output mode of pin */
 234         gpio_rcar_set(chip, offset, value);
 235         gpio_rcar_config_general_input_output_mode(chip, offset, true);
 236         return 0;
 237 }
 238
 239 static int gpio_rcar_to_irq(struct gpio_chip *chip, unsigned offset)
 240 {
 241         return irq_create_mapping(gpio_to_priv(chip)->irq_domain, offset);
 242 }
 243
 244 static int gpio_rcar_irq_domain_map(struct irq_domain *h, unsigned int virq,
 245                                  irq_hw_number_t hw)
 246 {
 247         struct gpio_rcar_priv *p = h->host_data;
 248
 249         dev_dbg(&p->pdev->dev, "map hw irq = %d, virq = %d\n", (int)hw, virq);
 250
 251         irq_set_chip_data(virq, h->host_data);
 252         irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
 253         set_irq_flags(virq, IRQF_VALID); /* kill me now */
 254         return 0;
 255 }
 256
 257 static struct irq_domain_ops gpio_rcar_irq_domain_ops = {
 258         .map    = gpio_rcar_irq_domain_map,
 259 };
 260
 261 static int gpio_rcar_probe(struct platform_device *pdev)
 262 {
 263         struct gpio_rcar_config *pdata = pdev->dev.platform_data;
 264         struct gpio_rcar_priv *p;
 265         struct resource *io, *irq;
 266         struct gpio_chip *gpio_chip;
 267         struct irq_chip *irq_chip;
 268         const char *name = dev_name(&pdev->dev);
 269         int ret;
 270
 271         p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
 272         if (!p) {
 273                 dev_err(&pdev->dev, "failed to allocate driver data\n");
 274                 ret = -ENOMEM;
 275                 goto err0;
 276         }
 277
 278         /* deal with driver instance configuration */
 279         if (pdata)
 280                 p->config = *pdata;
 281
 282         p->pdev = pdev;
 283         platform_set_drvdata(pdev, p);
 284         spin_lock_init(&p->lock);
 285
 286         io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 287         irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 288
 289         if (!io || !irq) {
 290                 dev_err(&pdev->dev, "missing IRQ or IOMEM\n");
 291                 ret = -EINVAL;
 292                 goto err0;
 293         }
 294
 295         p->base = devm_ioremap_nocache(&pdev->dev, io->start,
 296                                        resource_size(io));
 297         if (!p->base) {
 298                 dev_err(&pdev->dev, "failed to remap I/O memory\n");
 299                 ret = -ENXIO;
 300                 goto err0;
 301         }
 302
 303         gpio_chip = &p->gpio_chip;
 304         gpio_chip->request = gpio_rcar_request;
 305         gpio_chip->free = gpio_rcar_free;
 306         gpio_chip->direction_input = gpio_rcar_direction_input;
 307         gpio_chip->get = gpio_rcar_get;
 308         gpio_chip->direction_output = gpio_rcar_direction_output;
 309         gpio_chip->set = gpio_rcar_set;
 310         gpio_chip->to_irq = gpio_rcar_to_irq;
 311         gpio_chip->label = name;
 312         gpio_chip->owner = THIS_MODULE;
 313         gpio_chip->base = p->config.gpio_base;
 314         gpio_chip->ngpio = p->config.number_of_pins;
 315
 316         irq_chip = &p->irq_chip;
 317         irq_chip->name = name;
 318         irq_chip->irq_mask = gpio_rcar_irq_disable;
 319         irq_chip->irq_unmask = gpio_rcar_irq_enable;
 320         irq_chip->irq_enable = gpio_rcar_irq_enable;
 321         irq_chip->irq_disable = gpio_rcar_irq_disable;
 322         irq_chip->irq_set_type = gpio_rcar_irq_set_type;
 323         irq_chip->flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_SET_TYPE_MASKED;
 324
 325         p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
 326                                               p->config.number_of_pins,
 327                                               p->config.irq_base,
 328                                               &gpio_rcar_irq_domain_ops, p);
 329         if (!p->irq_domain) {
 330                 ret = -ENXIO;
 331                 dev_err(&pdev->dev, "cannot initialize irq domain\n");
 332                 goto err1;
 333         }
 334
 335         if (devm_request_irq(&pdev->dev, irq->start,
 336                              gpio_rcar_irq_handler, 0, name, p)) {
 337                 dev_err(&pdev->dev, "failed to request IRQ\n");
 338                 ret = -ENOENT;
 339                 goto err1;
 340         }
 341
 342         ret = gpiochip_add(gpio_chip);
 343         if (ret) {
 344                 dev_err(&pdev->dev, "failed to add GPIO controller\n");
 345                 goto err1;
 346         }
 347
 348         dev_info(&pdev->dev, "driving %d GPIOs\n", p->config.number_of_pins);
 349
 350         /* warn in case of mismatch if irq base is specified */
 351         if (p->config.irq_base) {
 352                 ret = irq_find_mapping(p->irq_domain, 0);
 353                 if (p->config.irq_base != ret)
 354                         dev_warn(&pdev->dev, "irq base mismatch (%u/%u)\n",
 355                                  p->config.irq_base, ret);
 356         }
 357
 358         ret = gpiochip_add_pin_range(gpio_chip, p->config.pctl_name, 0,
 359                                      gpio_chip->base, gpio_chip->ngpio);
 360         if (ret < 0)
 361                 dev_warn(&pdev->dev, "failed to add pin range\n");
 362
 363         return 0;
 364
 365 err1:
 366         irq_domain_remove(p->irq_domain);
 367 err0:
 368         return ret;
 369 }
 370
 371 static int gpio_rcar_remove(struct platform_device *pdev)
 372 {
 373         struct gpio_rcar_priv *p = platform_get_drvdata(pdev);
 374         int ret;
 375
 376         ret = gpiochip_remove(&p->gpio_chip);
 377         if (ret)
 378                 return ret;
 379
 380         irq_domain_remove(p->irq_domain);
 381         return 0;
 382 }
 383
 384 static struct platform_driver gpio_rcar_device_driver = {
 385         .probe          = gpio_rcar_probe,
 386         .remove         = gpio_rcar_remove,
 387         .driver         = {
 388                 .name   = "gpio_rcar",
 389         }
 390 };
 391
 392 module_platform_driver(gpio_rcar_device_driver);
 393
 394 MODULE_AUTHOR("Magnus Damm");
 395 MODULE_DESCRIPTION("Renesas R-Car GPIO Driver");
 396 MODULE_LICENSE("GPL v2");