linux/drivers/gpio/gpio-wcove.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Intel Whiskey Cove PMIC GPIO Driver
   4 *
   5 * This driver is written based on gpio-crystalcove.c
   6 *
   7 * Copyright (C) 2016 Intel Corporation. All rights reserved.
   8 */
   9
  10#include <linux/bitops.h>
  11#include <linux/gpio/driver.h>
  12#include <linux/interrupt.h>
  13#include <linux/mfd/intel_soc_pmic.h>
  14#include <linux/module.h>
  15#include <linux/platform_device.h>
  16#include <linux/regmap.h>
  17#include <linux/seq_file.h>
  18
  19/*
  20 * Whiskey Cove PMIC has 13 physical GPIO pins divided into 3 banks:
  21 * Bank 0: Pin  0 - 6
  22 * Bank 1: Pin  7 - 10
  23 * Bank 2: Pin 11 - 12
  24 * Each pin has one output control register and one input control register.
  25 */
  26#define BANK0_NR_PINS           7
  27#define BANK1_NR_PINS           4
  28#define BANK2_NR_PINS           2
  29#define WCOVE_GPIO_NUM          (BANK0_NR_PINS + BANK1_NR_PINS + BANK2_NR_PINS)
  30#define WCOVE_VGPIO_NUM         94
  31/* GPIO output control registers (one per pin): 0x4e44 - 0x4e50 */
  32#define GPIO_OUT_CTRL_BASE      0x4e44
  33/* GPIO input control registers (one per pin): 0x4e51 - 0x4e5d */
  34#define GPIO_IN_CTRL_BASE       0x4e51
  35
  36/*
  37 * GPIO interrupts are organized in two groups:
  38 * Group 0: Bank 0 pins (Pin 0 - 6)
  39 * Group 1: Bank 1 and Bank 2 pins (Pin 7 - 12)
  40 * Each group has two registers (one bit per pin): status and mask.
  41 */
  42#define GROUP0_NR_IRQS          7
  43#define GROUP1_NR_IRQS          6
  44#define IRQ_MASK_BASE           0x4e19
  45#define IRQ_STATUS_BASE         0x4e0b
  46#define GPIO_IRQ0_MASK          GENMASK(6, 0)
  47#define GPIO_IRQ1_MASK          GENMASK(5, 0)
  48#define UPDATE_IRQ_TYPE         BIT(0)
  49#define UPDATE_IRQ_MASK         BIT(1)
  50
  51#define CTLI_INTCNT_DIS         (0 << 1)
  52#define CTLI_INTCNT_NE          (1 << 1)
  53#define CTLI_INTCNT_PE          (2 << 1)
  54#define CTLI_INTCNT_BE          (3 << 1)
  55
  56#define CTLO_DIR_IN             (0 << 5)
  57#define CTLO_DIR_OUT            (1 << 5)
  58
  59#define CTLO_DRV_MASK           (1 << 4)
  60#define CTLO_DRV_OD             (0 << 4)
  61#define CTLO_DRV_CMOS           (1 << 4)
  62
  63#define CTLO_DRV_REN            (1 << 3)
  64
  65#define CTLO_RVAL_2KDOWN        (0 << 1)
  66#define CTLO_RVAL_2KUP          (1 << 1)
  67#define CTLO_RVAL_50KDOWN       (2 << 1)
  68#define CTLO_RVAL_50KUP         (3 << 1)
  69
  70#define CTLO_INPUT_SET          (CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
  71#define CTLO_OUTPUT_SET         (CTLO_DIR_OUT | CTLO_INPUT_SET)
  72
  73enum ctrl_register {
  74        CTRL_IN,
  75        CTRL_OUT,
  76};
  77
  78/*
  79 * struct wcove_gpio - Whiskey Cove GPIO controller
  80 * @buslock: for bus lock/sync and unlock.
  81 * @chip: the abstract gpio_chip structure.
  82 * @dev: the gpio device
  83 * @regmap: the regmap from the parent device.
  84 * @regmap_irq_chip: the regmap of the gpio irq chip.
  85 * @update: pending IRQ setting update, to be written to the chip upon unlock.
  86 * @intcnt: the Interrupt Detect value to be written.
  87 * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
  88 */
  89struct wcove_gpio {
  90        struct mutex buslock;
  91        struct gpio_chip chip;
  92        struct device *dev;
  93        struct regmap *regmap;
  94        struct regmap_irq_chip_data *regmap_irq_chip;
  95        int update;
  96        int intcnt;
  97        bool set_irq_mask;
  98};
  99
 100static inline int to_reg(int gpio, enum ctrl_register reg_type)
 101{
 102        unsigned int reg;
 103
 104        if (gpio >= WCOVE_GPIO_NUM)
 105                return -EOPNOTSUPP;
 106
 107        if (reg_type == CTRL_IN)
 108                reg = GPIO_IN_CTRL_BASE + gpio;
 109        else
 110                reg = GPIO_OUT_CTRL_BASE + gpio;
 111
 112        return reg;
 113}
 114
 115static void wcove_update_irq_mask(struct wcove_gpio *wg, int gpio)
 116{
 117        unsigned int reg, mask;
 118
 119        if (gpio < GROUP0_NR_IRQS) {
 120                reg = IRQ_MASK_BASE;
 121                mask = BIT(gpio % GROUP0_NR_IRQS);
 122        } else {
 123                reg = IRQ_MASK_BASE + 1;
 124                mask = BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
 125        }
 126
 127        if (wg->set_irq_mask)
 128                regmap_update_bits(wg->regmap, reg, mask, mask);
 129        else
 130                regmap_update_bits(wg->regmap, reg, mask, 0);
 131}
 132
 133static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
 134{
 135        int reg = to_reg(gpio, CTRL_IN);
 136
 137        if (reg < 0)
 138                return;
 139
 140        regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
 141}
 142
 143static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
 144{
 145        struct wcove_gpio *wg = gpiochip_get_data(chip);
 146        int reg = to_reg(gpio, CTRL_OUT);
 147
 148        if (reg < 0)
 149                return 0;
 150
 151        return regmap_write(wg->regmap, reg, CTLO_INPUT_SET);
 152}
 153
 154static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
 155                                    int value)
 156{
 157        struct wcove_gpio *wg = gpiochip_get_data(chip);
 158        int reg = to_reg(gpio, CTRL_OUT);
 159
 160        if (reg < 0)
 161                return 0;
 162
 163        return regmap_write(wg->regmap, reg, CTLO_OUTPUT_SET | value);
 164}
 165
 166static int wcove_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
 167{
 168        struct wcove_gpio *wg = gpiochip_get_data(chip);
 169        unsigned int val;
 170        int ret, reg = to_reg(gpio, CTRL_OUT);
 171
 172        if (reg < 0)
 173                return GPIO_LINE_DIRECTION_OUT;
 174
 175        ret = regmap_read(wg->regmap, reg, &val);
 176        if (ret)
 177                return ret;
 178
 179        if (val & CTLO_DIR_OUT)
 180                return GPIO_LINE_DIRECTION_OUT;
 181
 182        return GPIO_LINE_DIRECTION_IN;
 183}
 184
 185static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
 186{
 187        struct wcove_gpio *wg = gpiochip_get_data(chip);
 188        unsigned int val;
 189        int ret, reg = to_reg(gpio, CTRL_IN);
 190
 191        if (reg < 0)
 192                return 0;
 193
 194        ret = regmap_read(wg->regmap, reg, &val);
 195        if (ret)
 196                return ret;
 197
 198        return val & 0x1;
 199}
 200
 201static void wcove_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
 202{
 203        struct wcove_gpio *wg = gpiochip_get_data(chip);
 204        int reg = to_reg(gpio, CTRL_OUT);
 205
 206        if (reg < 0)
 207                return;
 208
 209        if (value)
 210                regmap_update_bits(wg->regmap, reg, 1, 1);
 211        else
 212                regmap_update_bits(wg->regmap, reg, 1, 0);
 213}
 214
 215static int wcove_gpio_set_config(struct gpio_chip *chip, unsigned int gpio,
 216                                 unsigned long config)
 217{
 218        struct wcove_gpio *wg = gpiochip_get_data(chip);
 219        int reg = to_reg(gpio, CTRL_OUT);
 220
 221        if (reg < 0)
 222                return 0;
 223
 224        switch (pinconf_to_config_param(config)) {
 225        case PIN_CONFIG_DRIVE_OPEN_DRAIN:
 226                return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
 227                                          CTLO_DRV_OD);
 228        case PIN_CONFIG_DRIVE_PUSH_PULL:
 229                return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
 230                                          CTLO_DRV_CMOS);
 231        default:
 232                break;
 233        }
 234
 235        return -ENOTSUPP;
 236}
 237
 238static int wcove_irq_type(struct irq_data *data, unsigned int type)
 239{
 240        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 241        struct wcove_gpio *wg = gpiochip_get_data(chip);
 242
 243        if (data->hwirq >= WCOVE_GPIO_NUM)
 244                return 0;
 245
 246        switch (type) {
 247        case IRQ_TYPE_NONE:
 248                wg->intcnt = CTLI_INTCNT_DIS;
 249                break;
 250        case IRQ_TYPE_EDGE_BOTH:
 251                wg->intcnt = CTLI_INTCNT_BE;
 252                break;
 253        case IRQ_TYPE_EDGE_RISING:
 254                wg->intcnt = CTLI_INTCNT_PE;
 255                break;
 256        case IRQ_TYPE_EDGE_FALLING:
 257                wg->intcnt = CTLI_INTCNT_NE;
 258                break;
 259        default:
 260                return -EINVAL;
 261        }
 262
 263        wg->update |= UPDATE_IRQ_TYPE;
 264
 265        return 0;
 266}
 267
 268static void wcove_bus_lock(struct irq_data *data)
 269{
 270        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 271        struct wcove_gpio *wg = gpiochip_get_data(chip);
 272
 273        mutex_lock(&wg->buslock);
 274}
 275
 276static void wcove_bus_sync_unlock(struct irq_data *data)
 277{
 278        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 279        struct wcove_gpio *wg = gpiochip_get_data(chip);
 280        int gpio = data->hwirq;
 281
 282        if (wg->update & UPDATE_IRQ_TYPE)
 283                wcove_update_irq_ctrl(wg, gpio);
 284        if (wg->update & UPDATE_IRQ_MASK)
 285                wcove_update_irq_mask(wg, gpio);
 286        wg->update = 0;
 287
 288        mutex_unlock(&wg->buslock);
 289}
 290
 291static void wcove_irq_unmask(struct irq_data *data)
 292{
 293        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 294        struct wcove_gpio *wg = gpiochip_get_data(chip);
 295
 296        if (data->hwirq >= WCOVE_GPIO_NUM)
 297                return;
 298
 299        wg->set_irq_mask = false;
 300        wg->update |= UPDATE_IRQ_MASK;
 301}
 302
 303static void wcove_irq_mask(struct irq_data *data)
 304{
 305        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 306        struct wcove_gpio *wg = gpiochip_get_data(chip);
 307
 308        if (data->hwirq >= WCOVE_GPIO_NUM)
 309                return;
 310
 311        wg->set_irq_mask = true;
 312        wg->update |= UPDATE_IRQ_MASK;
 313}
 314
 315static struct irq_chip wcove_irqchip = {
 316        .name                   = "Whiskey Cove",
 317        .irq_mask               = wcove_irq_mask,
 318        .irq_unmask             = wcove_irq_unmask,
 319        .irq_set_type           = wcove_irq_type,
 320        .irq_bus_lock           = wcove_bus_lock,
 321        .irq_bus_sync_unlock    = wcove_bus_sync_unlock,
 322};
 323
 324static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
 325{
 326        struct wcove_gpio *wg = (struct wcove_gpio *)data;
 327        unsigned int pending, virq, gpio, mask, offset;
 328        u8 p[2];
 329
 330        if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
 331                dev_err(wg->dev, "Failed to read irq status register\n");
 332                return IRQ_NONE;
 333        }
 334
 335        pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
 336        if (!pending)
 337                return IRQ_NONE;
 338
 339        /* Iterate until no interrupt is pending */
 340        while (pending) {
 341                /* One iteration is for all pending bits */
 342                for_each_set_bit(gpio, (const unsigned long *)&pending,
 343                                                 WCOVE_GPIO_NUM) {
 344                        offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
 345                        mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
 346                                                                BIT(gpio);
 347                        virq = irq_find_mapping(wg->chip.irq.domain, gpio);
 348                        handle_nested_irq(virq);
 349                        regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
 350                                                                mask, mask);
 351                }
 352
 353                /* Next iteration */
 354                if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
 355                        dev_err(wg->dev, "Failed to read irq status\n");
 356                        break;
 357                }
 358
 359                pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
 360        }
 361
 362        return IRQ_HANDLED;
 363}
 364
 365static void wcove_gpio_dbg_show(struct seq_file *s,
 366                                      struct gpio_chip *chip)
 367{
 368        unsigned int ctlo, ctli, irq_mask, irq_status;
 369        struct wcove_gpio *wg = gpiochip_get_data(chip);
 370        int gpio, offset, group, ret = 0;
 371
 372        for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
 373                group = gpio < GROUP0_NR_IRQS ? 0 : 1;
 374                ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
 375                ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
 376                ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
 377                                                        &irq_mask);
 378                ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
 379                                                        &irq_status);
 380                if (ret) {
 381                        pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
 382                        break;
 383                }
 384
 385                offset = gpio % 8;
 386                seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
 387                           gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
 388                           ctli & 0x1 ? "hi" : "lo",
 389                           ctli & CTLI_INTCNT_NE ? "fall" : "    ",
 390                           ctli & CTLI_INTCNT_PE ? "rise" : "    ",
 391                           ctlo,
 392                           irq_mask & BIT(offset) ? "mask  " : "unmask",
 393                           irq_status & BIT(offset) ? "pending" : "       ");
 394        }
 395}
 396
 397static int wcove_gpio_probe(struct platform_device *pdev)
 398{
 399        struct intel_soc_pmic *pmic;
 400        struct wcove_gpio *wg;
 401        int virq, ret, irq;
 402        struct device *dev;
 403
 404        /*
 405         * This gpio platform device is created by a mfd device (see
 406         * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
 407         * shared by all sub-devices created by the mfd device, the regmap
 408         * pointer for instance, is stored as driver data of the mfd device
 409         * driver.
 410         */
 411        pmic = dev_get_drvdata(pdev->dev.parent);
 412        if (!pmic)
 413                return -ENODEV;
 414
 415        irq = platform_get_irq(pdev, 0);
 416        if (irq < 0)
 417                return irq;
 418
 419        dev = &pdev->dev;
 420
 421        wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
 422        if (!wg)
 423                return -ENOMEM;
 424
 425        wg->regmap_irq_chip = pmic->irq_chip_data;
 426
 427        platform_set_drvdata(pdev, wg);
 428
 429        mutex_init(&wg->buslock);
 430        wg->chip.label = KBUILD_MODNAME;
 431        wg->chip.direction_input = wcove_gpio_dir_in;
 432        wg->chip.direction_output = wcove_gpio_dir_out;
 433        wg->chip.get_direction = wcove_gpio_get_direction;
 434        wg->chip.get = wcove_gpio_get;
 435        wg->chip.set = wcove_gpio_set;
 436        wg->chip.set_config = wcove_gpio_set_config,
 437        wg->chip.base = -1;
 438        wg->chip.ngpio = WCOVE_VGPIO_NUM;
 439        wg->chip.can_sleep = true;
 440        wg->chip.parent = pdev->dev.parent;
 441        wg->chip.dbg_show = wcove_gpio_dbg_show;
 442        wg->dev = dev;
 443        wg->regmap = pmic->regmap;
 444
 445        ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
 446        if (ret) {
 447                dev_err(dev, "Failed to add gpiochip: %d\n", ret);
 448                return ret;
 449        }
 450
 451        ret = gpiochip_irqchip_add_nested(&wg->chip, &wcove_irqchip, 0,
 452                                          handle_simple_irq, IRQ_TYPE_NONE);
 453        if (ret) {
 454                dev_err(dev, "Failed to add irqchip: %d\n", ret);
 455                return ret;
 456        }
 457
 458        virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
 459        if (virq < 0) {
 460                dev_err(dev, "Failed to get virq by irq %d\n", irq);
 461                return virq;
 462        }
 463
 464        ret = devm_request_threaded_irq(dev, virq, NULL,
 465                wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
 466        if (ret) {
 467                dev_err(dev, "Failed to request irq %d\n", virq);
 468                return ret;
 469        }
 470
 471        gpiochip_set_nested_irqchip(&wg->chip, &wcove_irqchip, virq);
 472
 473        /* Enable GPIO0 interrupts */
 474        ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE, GPIO_IRQ0_MASK,
 475                                 0x00);
 476        if (ret)
 477                return ret;
 478
 479        /* Enable GPIO1 interrupts */
 480        ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE + 1, GPIO_IRQ1_MASK,
 481                                 0x00);
 482        if (ret)
 483                return ret;
 484
 485        return 0;
 486}
 487
 488/*
 489 * Whiskey Cove PMIC itself is a analog device(but with digital control
 490 * interface) providing power management support for other devices in
 491 * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
 492 */
 493static struct platform_driver wcove_gpio_driver = {
 494        .driver = {
 495                .name = "bxt_wcove_gpio",
 496        },
 497        .probe = wcove_gpio_probe,
 498};
 499
 500module_platform_driver(wcove_gpio_driver);
 501
 502MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
 503MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
 504MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
 505MODULE_LICENSE("GPL v2");
 506MODULE_ALIAS("platform:bxt_wcove_gpio");
 507