drivers/gpio/gpio-stmpe.c

   1 /*
   2  * Copyright (C) ST-Ericsson SA 2010
   3  *
   4  * License Terms: GNU General Public License, version 2
   5  * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/init.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/slab.h>
  12 #include <linux/gpio.h>
  13 #include <linux/irq.h>
  14 #include <linux/irqdomain.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/of.h>
  17 #include <linux/mfd/stmpe.h>
  18
  19 /*
  20  * These registers are modified under the irq bus lock and cached to avoid
  21  * unnecessary writes in bus_sync_unlock.
  22  */
  23 enum { REG_RE, REG_FE, REG_IE };
  24
  25 #define CACHE_NR_REGS   3
  26 #define CACHE_NR_BANKS  (STMPE_NR_GPIOS / 8)
  27
  28 struct stmpe_gpio {
  29         struct gpio_chip chip;
  30         struct stmpe *stmpe;
  31         struct device *dev;
  32         struct mutex irq_lock;
  33         struct irq_domain *domain;
  34
  35         int irq_base;
  36         unsigned norequest_mask;
  37
  38         /* Caches of interrupt control registers for bus_lock */
  39         u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
  40         u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
  41 };
  42
  43 static inline struct stmpe_gpio *to_stmpe_gpio(struct gpio_chip *chip)
  44 {
  45         return container_of(chip, struct stmpe_gpio, chip);
  46 }
  47
  48 static int stmpe_gpio_get(struct gpio_chip *chip, unsigned offset)
  49 {
  50         struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
  51         struct stmpe *stmpe = stmpe_gpio->stmpe;
  52         u8 reg = stmpe->regs[STMPE_IDX_GPMR_LSB] - (offset / 8);
  53         u8 mask = 1 << (offset % 8);
  54         int ret;
  55
  56         ret = stmpe_reg_read(stmpe, reg);
  57         if (ret < 0)
  58                 return ret;
  59
  60         return !!(ret & mask);
  61 }
  62
  63 static void stmpe_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
  64 {
  65         struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
  66         struct stmpe *stmpe = stmpe_gpio->stmpe;
  67         int which = val ? STMPE_IDX_GPSR_LSB : STMPE_IDX_GPCR_LSB;
  68         u8 reg = stmpe->regs[which] - (offset / 8);
  69         u8 mask = 1 << (offset % 8);
  70
  71         /*
  72          * Some variants have single register for gpio set/clear functionality.
  73          * For them we need to write 0 to clear and 1 to set.
  74          */
  75         if (stmpe->regs[STMPE_IDX_GPSR_LSB] == stmpe->regs[STMPE_IDX_GPCR_LSB])
  76                 stmpe_set_bits(stmpe, reg, mask, val ? mask : 0);
  77         else
  78                 stmpe_reg_write(stmpe, reg, mask);
  79 }
  80
  81 static int stmpe_gpio_direction_output(struct gpio_chip *chip,
  82                                          unsigned offset, int val)
  83 {
  84         struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
  85         struct stmpe *stmpe = stmpe_gpio->stmpe;
  86         u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
  87         u8 mask = 1 << (offset % 8);
  88
  89         stmpe_gpio_set(chip, offset, val);
  90
  91         return stmpe_set_bits(stmpe, reg, mask, mask);
  92 }
  93
  94 static int stmpe_gpio_direction_input(struct gpio_chip *chip,
  95                                         unsigned offset)
  96 {
  97         struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
  98         struct stmpe *stmpe = stmpe_gpio->stmpe;
  99         u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
 100         u8 mask = 1 << (offset % 8);
 101
 102         return stmpe_set_bits(stmpe, reg, mask, 0);
 103 }
 104
 105 static int stmpe_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 106 {
 107         struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
 108
 109         return irq_create_mapping(stmpe_gpio->domain, offset);
 110 }
 111
 112 static int stmpe_gpio_request(struct gpio_chip *chip, unsigned offset)
 113 {
 114         struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
 115         struct stmpe *stmpe = stmpe_gpio->stmpe;
 116
 117         if (stmpe_gpio->norequest_mask & (1 << offset))
 118                 return -EINVAL;
 119
 120         return stmpe_set_altfunc(stmpe, 1 << offset, STMPE_BLOCK_GPIO);
 121 }
 122
 123 static struct gpio_chip template_chip = {
 124         .label                  = "stmpe",
 125         .owner                  = THIS_MODULE,
 126         .direction_input        = stmpe_gpio_direction_input,
 127         .get                    = stmpe_gpio_get,
 128         .direction_output       = stmpe_gpio_direction_output,
 129         .set                    = stmpe_gpio_set,
 130         .to_irq                 = stmpe_gpio_to_irq,
 131         .request                = stmpe_gpio_request,
 132         .can_sleep              = true,
 133 };
 134
 135 static int stmpe_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 136 {
 137         struct stmpe_gpio *stmpe_gpio = irq_data_get_irq_chip_data(d);
 138         int offset = d->hwirq;
 139         int regoffset = offset / 8;
 140         int mask = 1 << (offset % 8);
 141
 142         if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
 143                 return -EINVAL;
 144
 145         /* STMPE801 doesn't have RE and FE registers */
 146         if (stmpe_gpio->stmpe->partnum == STMPE801)
 147                 return 0;
 148
 149         if (type == IRQ_TYPE_EDGE_RISING)
 150                 stmpe_gpio->regs[REG_RE][regoffset] |= mask;
 151         else
 152                 stmpe_gpio->regs[REG_RE][regoffset] &= ~mask;
 153
 154         if (type == IRQ_TYPE_EDGE_FALLING)
 155                 stmpe_gpio->regs[REG_FE][regoffset] |= mask;
 156         else
 157                 stmpe_gpio->regs[REG_FE][regoffset] &= ~mask;
 158
 159         return 0;
 160 }
 161
 162 static void stmpe_gpio_irq_lock(struct irq_data *d)
 163 {
 164         struct stmpe_gpio *stmpe_gpio = irq_data_get_irq_chip_data(d);
 165
 166         mutex_lock(&stmpe_gpio->irq_lock);
 167 }
 168
 169 static void stmpe_gpio_irq_sync_unlock(struct irq_data *d)
 170 {
 171         struct stmpe_gpio *stmpe_gpio = irq_data_get_irq_chip_data(d);
 172         struct stmpe *stmpe = stmpe_gpio->stmpe;
 173         int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
 174         static const u8 regmap[] = {
 175                 [REG_RE]        = STMPE_IDX_GPRER_LSB,
 176                 [REG_FE]        = STMPE_IDX_GPFER_LSB,
 177                 [REG_IE]        = STMPE_IDX_IEGPIOR_LSB,
 178         };
 179         int i, j;
 180
 181         for (i = 0; i < CACHE_NR_REGS; i++) {
 182                 /* STMPE801 doesn't have RE and FE registers */
 183                 if ((stmpe->partnum == STMPE801) &&
 184                                 (i != REG_IE))
 185                         continue;
 186
 187                 for (j = 0; j < num_banks; j++) {
 188                         u8 old = stmpe_gpio->oldregs[i][j];
 189                         u8 new = stmpe_gpio->regs[i][j];
 190
 191                         if (new == old)
 192                                 continue;
 193
 194                         stmpe_gpio->oldregs[i][j] = new;
 195                         stmpe_reg_write(stmpe, stmpe->regs[regmap[i]] - j, new);
 196                 }
 197         }
 198
 199         mutex_unlock(&stmpe_gpio->irq_lock);
 200 }
 201
 202 static void stmpe_gpio_irq_mask(struct irq_data *d)
 203 {
 204         struct stmpe_gpio *stmpe_gpio = irq_data_get_irq_chip_data(d);
 205         int offset = d->hwirq;
 206         int regoffset = offset / 8;
 207         int mask = 1 << (offset % 8);
 208
 209         stmpe_gpio->regs[REG_IE][regoffset] &= ~mask;
 210 }
 211
 212 static void stmpe_gpio_irq_unmask(struct irq_data *d)
 213 {
 214         struct stmpe_gpio *stmpe_gpio = irq_data_get_irq_chip_data(d);
 215         int offset = d->hwirq;
 216         int regoffset = offset / 8;
 217         int mask = 1 << (offset % 8);
 218
 219         stmpe_gpio->regs[REG_IE][regoffset] |= mask;
 220 }
 221
 222 static struct irq_chip stmpe_gpio_irq_chip = {
 223         .name                   = "stmpe-gpio",
 224         .irq_bus_lock           = stmpe_gpio_irq_lock,
 225         .irq_bus_sync_unlock    = stmpe_gpio_irq_sync_unlock,
 226         .irq_mask               = stmpe_gpio_irq_mask,
 227         .irq_unmask             = stmpe_gpio_irq_unmask,
 228         .irq_set_type           = stmpe_gpio_irq_set_type,
 229 };
 230
 231 static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
 232 {
 233         struct stmpe_gpio *stmpe_gpio = dev;
 234         struct stmpe *stmpe = stmpe_gpio->stmpe;
 235         u8 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_MSB];
 236         int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
 237         u8 status[num_banks];
 238         int ret;
 239         int i;
 240
 241         ret = stmpe_block_read(stmpe, statmsbreg, num_banks, status);
 242         if (ret < 0)
 243                 return IRQ_NONE;
 244
 245         for (i = 0; i < num_banks; i++) {
 246                 int bank = num_banks - i - 1;
 247                 unsigned int enabled = stmpe_gpio->regs[REG_IE][bank];
 248                 unsigned int stat = status[i];
 249
 250                 stat &= enabled;
 251                 if (!stat)
 252                         continue;
 253
 254                 while (stat) {
 255                         int bit = __ffs(stat);
 256                         int line = bank * 8 + bit;
 257                         int child_irq = irq_find_mapping(stmpe_gpio->domain,
 258                                                          line);
 259
 260                         handle_nested_irq(child_irq);
 261                         stat &= ~(1 << bit);
 262                 }
 263
 264                 stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
 265
 266                 /* Edge detect register is not present on 801 */
 267                 if (stmpe->partnum != STMPE801)
 268                         stmpe_reg_write(stmpe, stmpe->regs[STMPE_IDX_GPEDR_MSB]
 269                                         + i, status[i]);
 270         }
 271
 272         return IRQ_HANDLED;
 273 }
 274
 275 static int stmpe_gpio_irq_map(struct irq_domain *d, unsigned int irq,
 276                               irq_hw_number_t hwirq)
 277 {
 278         struct stmpe_gpio *stmpe_gpio = d->host_data;
 279
 280         if (!stmpe_gpio)
 281                 return -EINVAL;
 282
 283         irq_set_chip_data(irq, stmpe_gpio);
 284         irq_set_chip_and_handler(irq, &stmpe_gpio_irq_chip,
 285                                  handle_simple_irq);
 286         irq_set_nested_thread(irq, 1);
 287 #ifdef CONFIG_ARM
 288         set_irq_flags(irq, IRQF_VALID);
 289 #else
 290         irq_set_noprobe(irq);
 291 #endif
 292
 293         return 0;
 294 }
 295
 296 static void stmpe_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
 297 {
 298 #ifdef CONFIG_ARM
 299         set_irq_flags(irq, 0);
 300 #endif
 301         irq_set_chip_and_handler(irq, NULL, NULL);
 302         irq_set_chip_data(irq, NULL);
 303 }
 304
 305 static const struct irq_domain_ops stmpe_gpio_irq_simple_ops = {
 306         .unmap = stmpe_gpio_irq_unmap,
 307         .map = stmpe_gpio_irq_map,
 308         .xlate = irq_domain_xlate_twocell,
 309 };
 310
 311 static int stmpe_gpio_irq_init(struct stmpe_gpio *stmpe_gpio,
 312                 struct device_node *np)
 313 {
 314         int base = 0;
 315
 316         if (!np)
 317                 base = stmpe_gpio->irq_base;
 318
 319         stmpe_gpio->domain = irq_domain_add_simple(np,
 320                                 stmpe_gpio->chip.ngpio, base,
 321                                 &stmpe_gpio_irq_simple_ops, stmpe_gpio);
 322         if (!stmpe_gpio->domain) {
 323                 dev_err(stmpe_gpio->dev, "failed to create irqdomain\n");
 324                 return -ENOSYS;
 325         }
 326
 327         return 0;
 328 }
 329
 330 static int stmpe_gpio_probe(struct platform_device *pdev)
 331 {
 332         struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
 333         struct device_node *np = pdev->dev.of_node;
 334         struct stmpe_gpio_platform_data *pdata;
 335         struct stmpe_gpio *stmpe_gpio;
 336         int ret;
 337         int irq = 0;
 338
 339         pdata = stmpe->pdata->gpio;
 340
 341         irq = platform_get_irq(pdev, 0);
 342
 343         stmpe_gpio = kzalloc(sizeof(struct stmpe_gpio), GFP_KERNEL);
 344         if (!stmpe_gpio)
 345                 return -ENOMEM;
 346
 347         mutex_init(&stmpe_gpio->irq_lock);
 348
 349         stmpe_gpio->dev = &pdev->dev;
 350         stmpe_gpio->stmpe = stmpe;
 351         stmpe_gpio->chip = template_chip;
 352         stmpe_gpio->chip.ngpio = stmpe->num_gpios;
 353         stmpe_gpio->chip.dev = &pdev->dev;
 354 #ifdef CONFIG_OF
 355         stmpe_gpio->chip.of_node = np;
 356 #endif
 357         stmpe_gpio->chip.base = pdata ? pdata->gpio_base : -1;
 358
 359         if (pdata)
 360                 stmpe_gpio->norequest_mask = pdata->norequest_mask;
 361         else if (np)
 362                 of_property_read_u32(np, "st,norequest-mask",
 363                                 &stmpe_gpio->norequest_mask);
 364
 365         if (irq >= 0)
 366                 stmpe_gpio->irq_base = stmpe->irq_base + STMPE_INT_GPIO(0);
 367         else
 368                 dev_info(&pdev->dev,
 369                         "device configured in no-irq mode; "
 370                         "irqs are not available\n");
 371
 372         ret = stmpe_enable(stmpe, STMPE_BLOCK_GPIO);
 373         if (ret)
 374                 goto out_free;
 375
 376         if (irq >= 0) {
 377                 ret = stmpe_gpio_irq_init(stmpe_gpio, np);
 378                 if (ret)
 379                         goto out_disable;
 380
 381                 ret = request_threaded_irq(irq, NULL, stmpe_gpio_irq,
 382                                 IRQF_ONESHOT, "stmpe-gpio", stmpe_gpio);
 383                 if (ret) {
 384                         dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
 385                         goto out_disable;
 386                 }
 387         }
 388
 389         ret = gpiochip_add(&stmpe_gpio->chip);
 390         if (ret) {
 391                 dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
 392                 goto out_freeirq;
 393         }
 394
 395         if (pdata && pdata->setup)
 396                 pdata->setup(stmpe, stmpe_gpio->chip.base);
 397
 398         platform_set_drvdata(pdev, stmpe_gpio);
 399
 400         return 0;
 401
 402 out_freeirq:
 403         if (irq >= 0)
 404                 free_irq(irq, stmpe_gpio);
 405 out_disable:
 406         stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
 407 out_free:
 408         kfree(stmpe_gpio);
 409         return ret;
 410 }
 411
 412 static int stmpe_gpio_remove(struct platform_device *pdev)
 413 {
 414         struct stmpe_gpio *stmpe_gpio = platform_get_drvdata(pdev);
 415         struct stmpe *stmpe = stmpe_gpio->stmpe;
 416         struct stmpe_gpio_platform_data *pdata = stmpe->pdata->gpio;
 417         int irq = platform_get_irq(pdev, 0);
 418         int ret;
 419
 420         if (pdata && pdata->remove)
 421                 pdata->remove(stmpe, stmpe_gpio->chip.base);
 422
 423         ret = gpiochip_remove(&stmpe_gpio->chip);
 424         if (ret < 0) {
 425                 dev_err(stmpe_gpio->dev,
 426                         "unable to remove gpiochip: %d\n", ret);
 427                 return ret;
 428         }
 429
 430         stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
 431
 432         if (irq >= 0)
 433                 free_irq(irq, stmpe_gpio);
 434
 435         kfree(stmpe_gpio);
 436
 437         return 0;
 438 }
 439
 440 static struct platform_driver stmpe_gpio_driver = {
 441         .driver.name    = "stmpe-gpio",
 442         .driver.owner   = THIS_MODULE,
 443         .probe          = stmpe_gpio_probe,
 444         .remove         = stmpe_gpio_remove,
 445 };
 446
 447 static int __init stmpe_gpio_init(void)
 448 {
 449         return platform_driver_register(&stmpe_gpio_driver);
 450 }
 451 subsys_initcall(stmpe_gpio_init);
 452
 453 static void __exit stmpe_gpio_exit(void)
 454 {
 455         platform_driver_unregister(&stmpe_gpio_driver);
 456 }
 457 module_exit(stmpe_gpio_exit);
 458
 459 MODULE_LICENSE("GPL v2");
 460 MODULE_DESCRIPTION("STMPExxxx GPIO driver");
 461 MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");