linux/drivers/gpio/gpio-adp5588.c
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   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
  30struct 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
  45static 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
  55static 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
  65static 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
  84static 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
 104static 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
 120static 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
 149static 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
 165static 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
 191static 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
 199static 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
 207static 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
 231static 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
 240static 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
 275static int adp5588_irq_setup(struct adp5588_gpio *dev)
 276{
 277        struct i2c_client *client = dev->client;
 278        int ret;
 279        struct adp5588_gpio_platform_data *pdata =
 280                        dev_get_platdata(&client->dev);
 281        int irq_base = pdata ? pdata->irq_base : 0;
 282
 283        adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
 284        adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
 285
 286        mutex_init(&dev->irq_lock);
 287
 288        ret = devm_request_threaded_irq(&client->dev, client->irq,
 289                                        NULL, adp5588_irq_handler, IRQF_ONESHOT
 290                                        | IRQF_TRIGGER_FALLING | IRQF_SHARED,
 291                                        dev_name(&client->dev), dev);
 292        if (ret) {
 293                dev_err(&client->dev, "failed to request irq %d\n",
 294                        client->irq);
 295                return ret;
 296        }
 297        ret = gpiochip_irqchip_add_nested(&dev->gpio_chip,
 298                                          &adp5588_irq_chip, irq_base,
 299                                          handle_simple_irq,
 300                                          IRQ_TYPE_NONE);
 301        if (ret) {
 302                dev_err(&client->dev,
 303                        "could not connect irqchip to gpiochip\n");
 304                return ret;
 305        }
 306        gpiochip_set_nested_irqchip(&dev->gpio_chip,
 307                                    &adp5588_irq_chip,
 308                                    client->irq);
 309
 310        adp5588_gpio_write(client, CFG,
 311                ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_KE_IEN);
 312
 313        return 0;
 314}
 315
 316#else
 317static int adp5588_irq_setup(struct adp5588_gpio *dev)
 318{
 319        struct i2c_client *client = dev->client;
 320        dev_warn(&client->dev, "interrupt support not compiled in\n");
 321
 322        return 0;
 323}
 324
 325#endif /* CONFIG_GPIO_ADP5588_IRQ */
 326
 327static int adp5588_gpio_probe(struct i2c_client *client)
 328{
 329        struct adp5588_gpio_platform_data *pdata =
 330                        dev_get_platdata(&client->dev);
 331        struct adp5588_gpio *dev;
 332        struct gpio_chip *gc;
 333        int ret, i, revid;
 334        unsigned int pullup_dis_mask = 0;
 335
 336        if (!i2c_check_functionality(client->adapter,
 337                                        I2C_FUNC_SMBUS_BYTE_DATA)) {
 338                dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
 339                return -EIO;
 340        }
 341
 342        dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
 343        if (!dev)
 344                return -ENOMEM;
 345
 346        dev->client = client;
 347
 348        gc = &dev->gpio_chip;
 349        gc->direction_input = adp5588_gpio_direction_input;
 350        gc->direction_output = adp5588_gpio_direction_output;
 351        gc->get = adp5588_gpio_get_value;
 352        gc->set = adp5588_gpio_set_value;
 353        gc->can_sleep = true;
 354        gc->base = -1;
 355        gc->parent = &client->dev;
 356
 357        if (pdata) {
 358                gc->base = pdata->gpio_start;
 359                gc->names = pdata->names;
 360                pullup_dis_mask = pdata->pullup_dis_mask;
 361        }
 362
 363        gc->ngpio = ADP5588_MAXGPIO;
 364        gc->label = client->name;
 365        gc->owner = THIS_MODULE;
 366
 367        mutex_init(&dev->lock);
 368
 369        ret = adp5588_gpio_read(dev->client, DEV_ID);
 370        if (ret < 0)
 371                return ret;
 372
 373        revid = ret & ADP5588_DEVICE_ID_MASK;
 374
 375        for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
 376                dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
 377                dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
 378                ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
 379                ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
 380                                (pullup_dis_mask >> (8 * i)) & 0xFF);
 381                ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
 382                if (ret)
 383                        return ret;
 384        }
 385
 386        if (client->irq) {
 387                if (WA_DELAYED_READOUT_REVID(revid)) {
 388                        dev_warn(&client->dev, "GPIO int not supported\n");
 389                } else {
 390                        ret = adp5588_irq_setup(dev);
 391                        if (ret)
 392                                return ret;
 393                }
 394        }
 395
 396        ret = devm_gpiochip_add_data(&client->dev, &dev->gpio_chip, dev);
 397        if (ret)
 398                return ret;
 399
 400        if (pdata && pdata->setup) {
 401                ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
 402                if (ret < 0)
 403                        dev_warn(&client->dev, "setup failed, %d\n", ret);
 404        }
 405
 406        i2c_set_clientdata(client, dev);
 407
 408        return 0;
 409}
 410
 411static int adp5588_gpio_remove(struct i2c_client *client)
 412{
 413        struct adp5588_gpio_platform_data *pdata =
 414                        dev_get_platdata(&client->dev);
 415        struct adp5588_gpio *dev = i2c_get_clientdata(client);
 416        int ret;
 417
 418        if (pdata && pdata->teardown) {
 419                ret = pdata->teardown(client,
 420                                      dev->gpio_chip.base, dev->gpio_chip.ngpio,
 421                                      pdata->context);
 422                if (ret < 0) {
 423                        dev_err(&client->dev, "teardown failed %d\n", ret);
 424                        return ret;
 425                }
 426        }
 427
 428        if (dev->client->irq)
 429                free_irq(dev->client->irq, dev);
 430
 431        return 0;
 432}
 433
 434static const struct i2c_device_id adp5588_gpio_id[] = {
 435        {DRV_NAME, 0},
 436        {}
 437};
 438MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
 439
 440#ifdef CONFIG_OF
 441static const struct of_device_id adp5588_gpio_of_id[] = {
 442        { .compatible = "adi," DRV_NAME, },
 443        {},
 444};
 445MODULE_DEVICE_TABLE(of, adp5588_gpio_of_id);
 446#endif
 447
 448static struct i2c_driver adp5588_gpio_driver = {
 449        .driver = {
 450                .name = DRV_NAME,
 451                .of_match_table = of_match_ptr(adp5588_gpio_of_id),
 452        },
 453        .probe_new = adp5588_gpio_probe,
 454        .remove = adp5588_gpio_remove,
 455        .id_table = adp5588_gpio_id,
 456};
 457
 458module_i2c_driver(adp5588_gpio_driver);
 459
 460MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 461MODULE_DESCRIPTION("GPIO ADP5588 Driver");
 462MODULE_LICENSE("GPL");
 463