drivers/gpio/gpio-adp5588.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * GPIO Chip driver for Analog Devices
   4  * ADP5588/ADP5587 I/O Expander and QWERTY Keypad Controller
   5  *
   6  * Copyright 2009-2010 Analog Devices Inc.
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/kernel.h>
  11 #include <linux/slab.h>
  12 #include <linux/init.h>
  13 #include <linux/i2c.h>
  14 #include <linux/gpio/driver.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irq.h>
  17 #include <linux/of_device.h>
  18
  19 #include <linux/platform_data/adp5588.h>
  20
  21 #define DRV_NAME        "adp5588-gpio"
  22
  23 /*
  24  * Early pre 4.0 Silicon required to delay readout by at least 25ms,
  25  * since the Event Counter Register updated 25ms after the interrupt
  26  * asserted.
  27  */
  28 #define WA_DELAYED_READOUT_REVID(rev)   ((rev) < 4)
  29
  30 struct adp5588_gpio {
  31         struct i2c_client *client;
  32         struct gpio_chip gpio_chip;
  33         struct mutex lock;      /* protect cached dir, dat_out */
  34         /* protect serialized access to the interrupt controller bus */
  35         struct mutex irq_lock;
  36         uint8_t dat_out[3];
  37         uint8_t dir[3];
  38         uint8_t int_lvl_low[3];
  39         uint8_t int_lvl_high[3];
  40         uint8_t int_en[3];
  41         uint8_t irq_mask[3];
  42         uint8_t int_input_en[3];
  43 };
  44
  45 static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
  46 {
  47         int ret = i2c_smbus_read_byte_data(client, reg);
  48
  49         if (ret < 0)
  50                 dev_err(&client->dev, "Read Error\n");
  51
  52         return ret;
  53 }
  54
  55 static int adp5588_gpio_write(struct i2c_client *client, u8 reg, u8 val)
  56 {
  57         int ret = i2c_smbus_write_byte_data(client, reg, val);
  58
  59         if (ret < 0)
  60                 dev_err(&client->dev, "Write Error\n");
  61
  62         return ret;
  63 }
  64
  65 static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
  66 {
  67         struct adp5588_gpio *dev = gpiochip_get_data(chip);
  68         unsigned bank = ADP5588_BANK(off);
  69         unsigned bit = ADP5588_BIT(off);
  70         int val;
  71
  72         mutex_lock(&dev->lock);
  73
  74         if (dev->dir[bank] & bit)
  75                 val = dev->dat_out[bank];
  76         else
  77                 val = adp5588_gpio_read(dev->client, GPIO_DAT_STAT1 + bank);
  78
  79         mutex_unlock(&dev->lock);
  80
  81         return !!(val & bit);
  82 }
  83
  84 static void adp5588_gpio_set_value(struct gpio_chip *chip,
  85                                    unsigned off, int val)
  86 {
  87         unsigned bank, bit;
  88         struct adp5588_gpio *dev = gpiochip_get_data(chip);
  89
  90         bank = ADP5588_BANK(off);
  91         bit = ADP5588_BIT(off);
  92
  93         mutex_lock(&dev->lock);
  94         if (val)
  95                 dev->dat_out[bank] |= bit;
  96         else
  97                 dev->dat_out[bank] &= ~bit;
  98
  99         adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
 100                            dev->dat_out[bank]);
 101         mutex_unlock(&dev->lock);
 102 }
 103
 104 static int adp5588_gpio_direction_input(struct gpio_chip *chip, unsigned off)
 105 {
 106         int ret;
 107         unsigned bank;
 108         struct adp5588_gpio *dev = gpiochip_get_data(chip);
 109
 110         bank = ADP5588_BANK(off);
 111
 112         mutex_lock(&dev->lock);
 113         dev->dir[bank] &= ~ADP5588_BIT(off);
 114         ret = adp5588_gpio_write(dev->client, GPIO_DIR1 + bank, dev->dir[bank]);
 115         mutex_unlock(&dev->lock);
 116
 117         return ret;
 118 }
 119
 120 static int adp5588_gpio_direction_output(struct gpio_chip *chip,
 121                                          unsigned off, int val)
 122 {
 123         int ret;
 124         unsigned bank, bit;
 125         struct adp5588_gpio *dev = gpiochip_get_data(chip);
 126
 127         bank = ADP5588_BANK(off);
 128         bit = ADP5588_BIT(off);
 129
 130         mutex_lock(&dev->lock);
 131         dev->dir[bank] |= bit;
 132
 133         if (val)
 134                 dev->dat_out[bank] |= bit;
 135         else
 136                 dev->dat_out[bank] &= ~bit;
 137
 138         ret = adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
 139                                  dev->dat_out[bank]);
 140         ret |= adp5588_gpio_write(dev->client, GPIO_DIR1 + bank,
 141                                  dev->dir[bank]);
 142         mutex_unlock(&dev->lock);
 143
 144         return ret;
 145 }
 146
 147 #ifdef CONFIG_GPIO_ADP5588_IRQ
 148
 149 static void adp5588_irq_bus_lock(struct irq_data *d)
 150 {
 151         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 152         struct adp5588_gpio *dev = gpiochip_get_data(gc);
 153
 154         mutex_lock(&dev->irq_lock);
 155 }
 156
 157  /*
 158   * genirq core code can issue chip->mask/unmask from atomic context.
 159   * This doesn't work for slow busses where an access needs to sleep.
 160   * bus_sync_unlock() is therefore called outside the atomic context,
 161   * syncs the current irq mask state with the slow external controller
 162   * and unlocks the bus.
 163   */
 164
 165 static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
 166 {
 167         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 168         struct adp5588_gpio *dev = gpiochip_get_data(gc);
 169         int i;
 170
 171         for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 172                 if (dev->int_input_en[i]) {
 173                         mutex_lock(&dev->lock);
 174                         dev->dir[i] &= ~dev->int_input_en[i];
 175                         dev->int_input_en[i] = 0;
 176                         adp5588_gpio_write(dev->client, GPIO_DIR1 + i,
 177                                            dev->dir[i]);
 178                         mutex_unlock(&dev->lock);
 179                 }
 180
 181                 if (dev->int_en[i] ^ dev->irq_mask[i]) {
 182                         dev->int_en[i] = dev->irq_mask[i];
 183                         adp5588_gpio_write(dev->client, GPI_EM1 + i,
 184                                            dev->int_en[i]);
 185                 }
 186         }
 187
 188         mutex_unlock(&dev->irq_lock);
 189 }
 190
 191 static void adp5588_irq_mask(struct irq_data *d)
 192 {
 193         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 194         struct adp5588_gpio *dev = gpiochip_get_data(gc);
 195
 196         dev->irq_mask[ADP5588_BANK(d->hwirq)] &= ~ADP5588_BIT(d->hwirq);
 197 }
 198
 199 static void adp5588_irq_unmask(struct irq_data *d)
 200 {
 201         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 202         struct adp5588_gpio *dev = gpiochip_get_data(gc);
 203
 204         dev->irq_mask[ADP5588_BANK(d->hwirq)] |= ADP5588_BIT(d->hwirq);
 205 }
 206
 207 static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
 208 {
 209         struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 210         struct adp5588_gpio *dev = gpiochip_get_data(gc);
 211         uint16_t gpio = d->hwirq;
 212         unsigned bank, bit;
 213
 214         bank = ADP5588_BANK(gpio);
 215         bit = ADP5588_BIT(gpio);
 216
 217         dev->int_lvl_low[bank] &= ~bit;
 218         dev->int_lvl_high[bank] &= ~bit;
 219
 220         if (type & IRQ_TYPE_EDGE_BOTH || type & IRQ_TYPE_LEVEL_HIGH)
 221                 dev->int_lvl_high[bank] |= bit;
 222
 223         if (type & IRQ_TYPE_EDGE_BOTH || type & IRQ_TYPE_LEVEL_LOW)
 224                 dev->int_lvl_low[bank] |= bit;
 225
 226         dev->int_input_en[bank] |= bit;
 227
 228         return 0;
 229 }
 230
 231 static struct irq_chip adp5588_irq_chip = {
 232         .name                   = "adp5588",
 233         .irq_mask               = adp5588_irq_mask,
 234         .irq_unmask             = adp5588_irq_unmask,
 235         .irq_bus_lock           = adp5588_irq_bus_lock,
 236         .irq_bus_sync_unlock    = adp5588_irq_bus_sync_unlock,
 237         .irq_set_type           = adp5588_irq_set_type,
 238 };
 239
 240 static irqreturn_t adp5588_irq_handler(int irq, void *devid)
 241 {
 242         struct adp5588_gpio *dev = devid;
 243         int status = adp5588_gpio_read(dev->client, INT_STAT);
 244
 245         if (status & ADP5588_KE_INT) {
 246                 int ev_cnt = adp5588_gpio_read(dev->client, KEY_LCK_EC_STAT);
 247
 248                 if (ev_cnt > 0) {
 249                         int i;
 250
 251                         for (i = 0; i < (ev_cnt & ADP5588_KEC); i++) {
 252                                 int key = adp5588_gpio_read(dev->client,
 253                                                             Key_EVENTA + i);
 254                                 /* GPIN events begin at 97,
 255                                  * bit 7 indicates logic level
 256                                  */
 257                                 int gpio = (key & 0x7f) - 97;
 258                                 int lvl = key & (1 << 7);
 259                                 int bank = ADP5588_BANK(gpio);
 260                                 int bit = ADP5588_BIT(gpio);
 261
 262                                 if ((lvl && dev->int_lvl_high[bank] & bit) ||
 263                                     (!lvl && dev->int_lvl_low[bank] & bit))
 264                                         handle_nested_irq(irq_find_mapping(
 265                                               dev->gpio_chip.irq.domain, gpio));
 266                         }
 267                 }
 268         }
 269
 270         adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */
 271
 272         return IRQ_HANDLED;
 273 }
 274
 275
 276 static int adp5588_irq_init_hw(struct gpio_chip *gc)
 277 {
 278         struct adp5588_gpio *dev = gpiochip_get_data(gc);
 279         /* Enable IRQs after registering chip */
 280         adp5588_gpio_write(dev->client, CFG,
 281                            ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_KE_IEN);
 282
 283         return 0;
 284 }
 285
 286 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 287 {
 288         struct i2c_client *client = dev->client;
 289         int ret;
 290         struct adp5588_gpio_platform_data *pdata =
 291                         dev_get_platdata(&client->dev);
 292         struct gpio_irq_chip *girq;
 293
 294         adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
 295         adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
 296
 297         mutex_init(&dev->irq_lock);
 298
 299         ret = devm_request_threaded_irq(&client->dev, client->irq,
 300                                         NULL, adp5588_irq_handler, IRQF_ONESHOT
 301                                         | IRQF_TRIGGER_FALLING | IRQF_SHARED,
 302                                         dev_name(&client->dev), dev);
 303         if (ret) {
 304                 dev_err(&client->dev, "failed to request irq %d\n",
 305                         client->irq);
 306                 return ret;
 307         }
 308
 309         /* This will be registered in the call to devm_gpiochip_add_data() */
 310         girq = &dev->gpio_chip.irq;
 311         girq->chip = &adp5588_irq_chip;
 312         /* This will let us handle the parent IRQ in the driver */
 313         girq->parent_handler = NULL;
 314         girq->num_parents = 0;
 315         girq->parents = NULL;
 316         girq->first = pdata ? pdata->irq_base : 0;
 317         girq->default_type = IRQ_TYPE_NONE;
 318         girq->handler = handle_simple_irq;
 319         girq->init_hw = adp5588_irq_init_hw;
 320         girq->threaded = true;
 321
 322         return 0;
 323 }
 324
 325 #else
 326 static int adp5588_irq_setup(struct adp5588_gpio *dev)
 327 {
 328         struct i2c_client *client = dev->client;
 329         dev_warn(&client->dev, "interrupt support not compiled in\n");
 330
 331         return 0;
 332 }
 333
 334 #endif /* CONFIG_GPIO_ADP5588_IRQ */
 335
 336 static int adp5588_gpio_probe(struct i2c_client *client)
 337 {
 338         struct adp5588_gpio_platform_data *pdata =
 339                         dev_get_platdata(&client->dev);
 340         struct adp5588_gpio *dev;
 341         struct gpio_chip *gc;
 342         int ret, i, revid;
 343         unsigned int pullup_dis_mask = 0;
 344
 345         if (!i2c_check_functionality(client->adapter,
 346                                         I2C_FUNC_SMBUS_BYTE_DATA)) {
 347                 dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
 348                 return -EIO;
 349         }
 350
 351         dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
 352         if (!dev)
 353                 return -ENOMEM;
 354
 355         dev->client = client;
 356
 357         gc = &dev->gpio_chip;
 358         gc->direction_input = adp5588_gpio_direction_input;
 359         gc->direction_output = adp5588_gpio_direction_output;
 360         gc->get = adp5588_gpio_get_value;
 361         gc->set = adp5588_gpio_set_value;
 362         gc->can_sleep = true;
 363         gc->base = -1;
 364         gc->parent = &client->dev;
 365
 366         if (pdata) {
 367                 gc->base = pdata->gpio_start;
 368                 gc->names = pdata->names;
 369                 pullup_dis_mask = pdata->pullup_dis_mask;
 370         }
 371
 372         gc->ngpio = ADP5588_MAXGPIO;
 373         gc->label = client->name;
 374         gc->owner = THIS_MODULE;
 375
 376         mutex_init(&dev->lock);
 377
 378         ret = adp5588_gpio_read(dev->client, DEV_ID);
 379         if (ret < 0)
 380                 return ret;
 381
 382         revid = ret & ADP5588_DEVICE_ID_MASK;
 383
 384         for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 385                 dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
 386                 dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
 387                 ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
 388                 ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
 389                                 (pullup_dis_mask >> (8 * i)) & 0xFF);
 390                 ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
 391                 if (ret)
 392                         return ret;
 393         }
 394
 395         if (client->irq) {
 396                 if (WA_DELAYED_READOUT_REVID(revid)) {
 397                         dev_warn(&client->dev, "GPIO int not supported\n");
 398                 } else {
 399                         ret = adp5588_irq_setup(dev);
 400                         if (ret)
 401                                 return ret;
 402                 }
 403         }
 404
 405         ret = devm_gpiochip_add_data(&client->dev, &dev->gpio_chip, dev);
 406         if (ret)
 407                 return ret;
 408
 409         if (pdata && pdata->setup) {
 410                 ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
 411                 if (ret < 0)
 412                         dev_warn(&client->dev, "setup failed, %d\n", ret);
 413         }
 414
 415         i2c_set_clientdata(client, dev);
 416
 417         return 0;
 418 }
 419
 420 static int adp5588_gpio_remove(struct i2c_client *client)
 421 {
 422         struct adp5588_gpio_platform_data *pdata =
 423                         dev_get_platdata(&client->dev);
 424         struct adp5588_gpio *dev = i2c_get_clientdata(client);
 425         int ret;
 426
 427         if (pdata && pdata->teardown) {
 428                 ret = pdata->teardown(client,
 429                                       dev->gpio_chip.base, dev->gpio_chip.ngpio,
 430                                       pdata->context);
 431                 if (ret < 0) {
 432                         dev_err(&client->dev, "teardown failed %d\n", ret);
 433                         return ret;
 434                 }
 435         }
 436
 437         if (dev->client->irq)
 438                 free_irq(dev->client->irq, dev);
 439
 440         return 0;
 441 }
 442
 443 static const struct i2c_device_id adp5588_gpio_id[] = {
 444         {DRV_NAME, 0},
 445         {}
 446 };
 447 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
 448
 449 #ifdef CONFIG_OF
 450 static const struct of_device_id adp5588_gpio_of_id[] = {
 451         { .compatible = "adi," DRV_NAME, },
 452         {},
 453 };
 454 MODULE_DEVICE_TABLE(of, adp5588_gpio_of_id);
 455 #endif
 456
 457 static struct i2c_driver adp5588_gpio_driver = {
 458         .driver = {
 459                 .name = DRV_NAME,
 460                 .of_match_table = of_match_ptr(adp5588_gpio_of_id),
 461         },
 462         .probe_new = adp5588_gpio_probe,
 463         .remove = adp5588_gpio_remove,
 464         .id_table = adp5588_gpio_id,
 465 };
 466
 467 module_i2c_driver(adp5588_gpio_driver);
 468
 469 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 470 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
 471 MODULE_LICENSE("GPL");