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        IRQ_STATUS,
  77        IRQ_MASK,
  78};
  79
  80/*
  81 * struct wcove_gpio - Whiskey Cove GPIO controller
  82 * @buslock: for bus lock/sync and unlock.
  83 * @chip: the abstract gpio_chip structure.
  84 * @dev: the gpio device
  85 * @regmap: the regmap from the parent device.
  86 * @regmap_irq_chip: the regmap of the gpio irq chip.
  87 * @update: pending IRQ setting update, to be written to the chip upon unlock.
  88 * @intcnt: the Interrupt Detect value to be written.
  89 * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
  90 */
  91struct wcove_gpio {
  92        struct mutex buslock;
  93        struct gpio_chip chip;
  94        struct device *dev;
  95        struct regmap *regmap;
  96        struct regmap_irq_chip_data *regmap_irq_chip;
  97        int update;
  98        int intcnt;
  99        bool set_irq_mask;
 100};
 101
 102static inline int to_reg(int gpio, enum ctrl_register type)
 103{
 104        unsigned int reg = type == CTRL_IN ? GPIO_IN_CTRL_BASE : GPIO_OUT_CTRL_BASE;
 105
 106        if (gpio >= WCOVE_GPIO_NUM)
 107                return -EOPNOTSUPP;
 108
 109        return reg + gpio;
 110}
 111
 112static inline int to_ireg(int gpio, enum ctrl_register type, unsigned int *mask)
 113{
 114        unsigned int reg = type == IRQ_STATUS ? IRQ_STATUS_BASE : IRQ_MASK_BASE;
 115
 116        if (gpio < GROUP0_NR_IRQS) {
 117                reg += 0;
 118                *mask = BIT(gpio);
 119        } else {
 120                reg += 1;
 121                *mask = BIT(gpio - GROUP0_NR_IRQS);
 122        }
 123
 124        return reg;
 125}
 126
 127static void wcove_update_irq_mask(struct wcove_gpio *wg, irq_hw_number_t gpio)
 128{
 129        unsigned int mask, reg = to_ireg(gpio, IRQ_MASK, &mask);
 130
 131        if (wg->set_irq_mask)
 132                regmap_set_bits(wg->regmap, reg, mask);
 133        else
 134                regmap_clear_bits(wg->regmap, reg, mask);
 135}
 136
 137static void wcove_update_irq_ctrl(struct wcove_gpio *wg, irq_hw_number_t gpio)
 138{
 139        int reg = to_reg(gpio, CTRL_IN);
 140
 141        regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
 142}
 143
 144static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
 145{
 146        struct wcove_gpio *wg = gpiochip_get_data(chip);
 147        int reg = to_reg(gpio, CTRL_OUT);
 148
 149        if (reg < 0)
 150                return 0;
 151
 152        return regmap_write(wg->regmap, reg, CTLO_INPUT_SET);
 153}
 154
 155static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
 156                                    int value)
 157{
 158        struct wcove_gpio *wg = gpiochip_get_data(chip);
 159        int reg = to_reg(gpio, CTRL_OUT);
 160
 161        if (reg < 0)
 162                return 0;
 163
 164        return regmap_write(wg->regmap, reg, CTLO_OUTPUT_SET | value);
 165}
 166
 167static int wcove_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
 168{
 169        struct wcove_gpio *wg = gpiochip_get_data(chip);
 170        unsigned int val;
 171        int ret, reg = to_reg(gpio, CTRL_OUT);
 172
 173        if (reg < 0)
 174                return GPIO_LINE_DIRECTION_OUT;
 175
 176        ret = regmap_read(wg->regmap, reg, &val);
 177        if (ret)
 178                return ret;
 179
 180        if (val & CTLO_DIR_OUT)
 181                return GPIO_LINE_DIRECTION_OUT;
 182
 183        return GPIO_LINE_DIRECTION_IN;
 184}
 185
 186static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
 187{
 188        struct wcove_gpio *wg = gpiochip_get_data(chip);
 189        unsigned int val;
 190        int ret, reg = to_reg(gpio, CTRL_IN);
 191
 192        if (reg < 0)
 193                return 0;
 194
 195        ret = regmap_read(wg->regmap, reg, &val);
 196        if (ret)
 197                return ret;
 198
 199        return val & 0x1;
 200}
 201
 202static void wcove_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
 203{
 204        struct wcove_gpio *wg = gpiochip_get_data(chip);
 205        int reg = to_reg(gpio, CTRL_OUT);
 206
 207        if (reg < 0)
 208                return;
 209
 210        if (value)
 211                regmap_set_bits(wg->regmap, reg, 1);
 212        else
 213                regmap_clear_bits(wg->regmap, reg, 1);
 214}
 215
 216static int wcove_gpio_set_config(struct gpio_chip *chip, unsigned int gpio,
 217                                 unsigned long config)
 218{
 219        struct wcove_gpio *wg = gpiochip_get_data(chip);
 220        int reg = to_reg(gpio, CTRL_OUT);
 221
 222        if (reg < 0)
 223                return 0;
 224
 225        switch (pinconf_to_config_param(config)) {
 226        case PIN_CONFIG_DRIVE_OPEN_DRAIN:
 227                return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
 228                                          CTLO_DRV_OD);
 229        case PIN_CONFIG_DRIVE_PUSH_PULL:
 230                return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
 231                                          CTLO_DRV_CMOS);
 232        default:
 233                break;
 234        }
 235
 236        return -ENOTSUPP;
 237}
 238
 239static int wcove_irq_type(struct irq_data *data, unsigned int type)
 240{
 241        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 242        struct wcove_gpio *wg = gpiochip_get_data(chip);
 243        irq_hw_number_t gpio = irqd_to_hwirq(data);
 244
 245        if (gpio >= WCOVE_GPIO_NUM)
 246                return 0;
 247
 248        switch (type) {
 249        case IRQ_TYPE_NONE:
 250                wg->intcnt = CTLI_INTCNT_DIS;
 251                break;
 252        case IRQ_TYPE_EDGE_BOTH:
 253                wg->intcnt = CTLI_INTCNT_BE;
 254                break;
 255        case IRQ_TYPE_EDGE_RISING:
 256                wg->intcnt = CTLI_INTCNT_PE;
 257                break;
 258        case IRQ_TYPE_EDGE_FALLING:
 259                wg->intcnt = CTLI_INTCNT_NE;
 260                break;
 261        default:
 262                return -EINVAL;
 263        }
 264
 265        wg->update |= UPDATE_IRQ_TYPE;
 266
 267        return 0;
 268}
 269
 270static void wcove_bus_lock(struct irq_data *data)
 271{
 272        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 273        struct wcove_gpio *wg = gpiochip_get_data(chip);
 274
 275        mutex_lock(&wg->buslock);
 276}
 277
 278static void wcove_bus_sync_unlock(struct irq_data *data)
 279{
 280        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 281        struct wcove_gpio *wg = gpiochip_get_data(chip);
 282        irq_hw_number_t gpio = irqd_to_hwirq(data);
 283
 284        if (wg->update & UPDATE_IRQ_TYPE)
 285                wcove_update_irq_ctrl(wg, gpio);
 286        if (wg->update & UPDATE_IRQ_MASK)
 287                wcove_update_irq_mask(wg, gpio);
 288        wg->update = 0;
 289
 290        mutex_unlock(&wg->buslock);
 291}
 292
 293static void wcove_irq_unmask(struct irq_data *data)
 294{
 295        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 296        struct wcove_gpio *wg = gpiochip_get_data(chip);
 297        irq_hw_number_t gpio = irqd_to_hwirq(data);
 298
 299        if (gpio >= WCOVE_GPIO_NUM)
 300                return;
 301
 302        wg->set_irq_mask = false;
 303        wg->update |= UPDATE_IRQ_MASK;
 304}
 305
 306static void wcove_irq_mask(struct irq_data *data)
 307{
 308        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 309        struct wcove_gpio *wg = gpiochip_get_data(chip);
 310        irq_hw_number_t gpio = irqd_to_hwirq(data);
 311
 312        if (gpio >= WCOVE_GPIO_NUM)
 313                return;
 314
 315        wg->set_irq_mask = true;
 316        wg->update |= UPDATE_IRQ_MASK;
 317}
 318
 319static struct irq_chip wcove_irqchip = {
 320        .name                   = "Whiskey Cove",
 321        .irq_mask               = wcove_irq_mask,
 322        .irq_unmask             = wcove_irq_unmask,
 323        .irq_set_type           = wcove_irq_type,
 324        .irq_bus_lock           = wcove_bus_lock,
 325        .irq_bus_sync_unlock    = wcove_bus_sync_unlock,
 326};
 327
 328static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
 329{
 330        struct wcove_gpio *wg = (struct wcove_gpio *)data;
 331        unsigned int virq, gpio;
 332        unsigned long pending;
 333        u8 p[2];
 334
 335        if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
 336                dev_err(wg->dev, "Failed to read irq status register\n");
 337                return IRQ_NONE;
 338        }
 339
 340        pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
 341        if (!pending)
 342                return IRQ_NONE;
 343
 344        /* Iterate until no interrupt is pending */
 345        while (pending) {
 346                /* One iteration is for all pending bits */
 347                for_each_set_bit(gpio, &pending, WCOVE_GPIO_NUM) {
 348                        unsigned int mask, reg = to_ireg(gpio, IRQ_STATUS, &mask);
 349
 350                        virq = irq_find_mapping(wg->chip.irq.domain, gpio);
 351                        handle_nested_irq(virq);
 352                        regmap_set_bits(wg->regmap, reg, mask);
 353                }
 354
 355                /* Next iteration */
 356                if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
 357                        dev_err(wg->dev, "Failed to read irq status\n");
 358                        break;
 359                }
 360
 361                pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
 362        }
 363
 364        return IRQ_HANDLED;
 365}
 366
 367static void wcove_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
 368{
 369        unsigned int ctlo, ctli, irq_mask, irq_status;
 370        struct wcove_gpio *wg = gpiochip_get_data(chip);
 371        int gpio, mask, ret = 0;
 372
 373        for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
 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                if (ret) {
 377                        dev_err(wg->dev, "Failed to read registers: CTRL out/in\n");
 378                        break;
 379                }
 380
 381                ret += regmap_read(wg->regmap, to_ireg(gpio, IRQ_MASK, &mask), &irq_mask);
 382                ret += regmap_read(wg->regmap, to_ireg(gpio, IRQ_STATUS, &mask), &irq_status);
 383                if (ret) {
 384                        dev_err(wg->dev, "Failed to read registers: IRQ status/mask\n");
 385                        break;
 386                }
 387
 388                seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
 389                           gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
 390                           ctli & 0x1 ? "hi" : "lo",
 391                           ctli & CTLI_INTCNT_NE ? "fall" : "    ",
 392                           ctli & CTLI_INTCNT_PE ? "rise" : "    ",
 393                           ctlo,
 394                           irq_mask & mask ? "mask  " : "unmask",
 395                           irq_status & mask ? "pending" : "       ");
 396        }
 397}
 398
 399static int wcove_gpio_probe(struct platform_device *pdev)
 400{
 401        struct intel_soc_pmic *pmic;
 402        struct wcove_gpio *wg;
 403        int virq, ret, irq;
 404        struct device *dev;
 405        struct gpio_irq_chip *girq;
 406
 407        /*
 408         * This gpio platform device is created by a mfd device (see
 409         * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
 410         * shared by all sub-devices created by the mfd device, the regmap
 411         * pointer for instance, is stored as driver data of the mfd device
 412         * driver.
 413         */
 414        pmic = dev_get_drvdata(pdev->dev.parent);
 415        if (!pmic)
 416                return -ENODEV;
 417
 418        irq = platform_get_irq(pdev, 0);
 419        if (irq < 0)
 420                return irq;
 421
 422        dev = &pdev->dev;
 423
 424        wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
 425        if (!wg)
 426                return -ENOMEM;
 427
 428        wg->regmap_irq_chip = pmic->irq_chip_data;
 429
 430        platform_set_drvdata(pdev, wg);
 431
 432        mutex_init(&wg->buslock);
 433        wg->chip.label = KBUILD_MODNAME;
 434        wg->chip.direction_input = wcove_gpio_dir_in;
 435        wg->chip.direction_output = wcove_gpio_dir_out;
 436        wg->chip.get_direction = wcove_gpio_get_direction;
 437        wg->chip.get = wcove_gpio_get;
 438        wg->chip.set = wcove_gpio_set;
 439        wg->chip.set_config = wcove_gpio_set_config;
 440        wg->chip.base = -1;
 441        wg->chip.ngpio = WCOVE_VGPIO_NUM;
 442        wg->chip.can_sleep = true;
 443        wg->chip.parent = pdev->dev.parent;
 444        wg->chip.dbg_show = wcove_gpio_dbg_show;
 445        wg->dev = dev;
 446        wg->regmap = pmic->regmap;
 447
 448        virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
 449        if (virq < 0) {
 450                dev_err(dev, "Failed to get virq by irq %d\n", irq);
 451                return virq;
 452        }
 453
 454        girq = &wg->chip.irq;
 455        girq->chip = &wcove_irqchip;
 456        /* This will let us handle the parent IRQ in the driver */
 457        girq->parent_handler = NULL;
 458        girq->num_parents = 0;
 459        girq->parents = NULL;
 460        girq->default_type = IRQ_TYPE_NONE;
 461        girq->handler = handle_simple_irq;
 462        girq->threaded = true;
 463
 464        ret = devm_request_threaded_irq(dev, virq, NULL, wcove_gpio_irq_handler,
 465                                        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        ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
 472        if (ret) {
 473                dev_err(dev, "Failed to add gpiochip: %d\n", ret);
 474                return ret;
 475        }
 476
 477        /* Enable GPIO0 interrupts */
 478        ret = regmap_clear_bits(wg->regmap, IRQ_MASK_BASE + 0, GPIO_IRQ0_MASK);
 479        if (ret)
 480                return ret;
 481
 482        /* Enable GPIO1 interrupts */
 483        ret = regmap_clear_bits(wg->regmap, IRQ_MASK_BASE + 1, GPIO_IRQ1_MASK);
 484        if (ret)
 485                return ret;
 486
 487        return 0;
 488}
 489
 490/*
 491 * Whiskey Cove PMIC itself is a analog device(but with digital control
 492 * interface) providing power management support for other devices in
 493 * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
 494 */
 495static struct platform_driver wcove_gpio_driver = {
 496        .driver = {
 497                .name = "bxt_wcove_gpio",
 498        },
 499        .probe = wcove_gpio_probe,
 500};
 501
 502module_platform_driver(wcove_gpio_driver);
 503
 504MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
 505MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
 506MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
 507MODULE_LICENSE("GPL v2");
 508MODULE_ALIAS("platform:bxt_wcove_gpio");
 509