linux/drivers/gpio/gpio-wcove.c
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   1/*
   2 * Intel Whiskey Cove PMIC GPIO Driver
   3 *
   4 * This driver is written based on gpio-crystalcove.c
   5 *
   6 * Copyright (C) 2016 Intel Corporation. All rights reserved.
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License version
  10 * 2 as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 */
  17
  18#include <linux/bitops.h>
  19#include <linux/module.h>
  20#include <linux/interrupt.h>
  21#include <linux/gpio/driver.h>
  22#include <linux/mfd/intel_soc_pmic.h>
  23#include <linux/platform_device.h>
  24#include <linux/regmap.h>
  25#include <linux/seq_file.h>
  26
  27/*
  28 * Whiskey Cove PMIC has 13 physical GPIO pins divided into 3 banks:
  29 * Bank 0: Pin 0 - 6
  30 * Bank 1: Pin 7 - 10
  31 * Bank 2: Pin 11 -12
  32 * Each pin has one output control register and one input control register.
  33 */
  34#define BANK0_NR_PINS           7
  35#define BANK1_NR_PINS           4
  36#define BANK2_NR_PINS           2
  37#define WCOVE_GPIO_NUM          (BANK0_NR_PINS + BANK1_NR_PINS + BANK2_NR_PINS)
  38#define WCOVE_VGPIO_NUM         94
  39/* GPIO output control registers (one per pin): 0x4e44 - 0x4e50 */
  40#define GPIO_OUT_CTRL_BASE      0x4e44
  41/* GPIO input control registers (one per pin): 0x4e51 - 0x4e5d */
  42#define GPIO_IN_CTRL_BASE       0x4e51
  43
  44/*
  45 * GPIO interrupts are organized in two groups:
  46 * Group 0: Bank 0 pins (Pin 0 - 6)
  47 * Group 1: Bank 1 and Bank 2 pins (Pin 7 - 12)
  48 * Each group has two registers (one bit per pin): status and mask.
  49 */
  50#define GROUP0_NR_IRQS          7
  51#define GROUP1_NR_IRQS          6
  52#define IRQ_MASK_BASE           0x4e19
  53#define IRQ_STATUS_BASE         0x4e0b
  54#define GPIO_IRQ0_MASK          GENMASK(6, 0)
  55#define GPIO_IRQ1_MASK          GENMASK(5, 0)
  56#define UPDATE_IRQ_TYPE         BIT(0)
  57#define UPDATE_IRQ_MASK         BIT(1)
  58
  59#define CTLI_INTCNT_DIS         (0 << 1)
  60#define CTLI_INTCNT_NE          (1 << 1)
  61#define CTLI_INTCNT_PE          (2 << 1)
  62#define CTLI_INTCNT_BE          (3 << 1)
  63
  64#define CTLO_DIR_IN             (0 << 5)
  65#define CTLO_DIR_OUT            (1 << 5)
  66
  67#define CTLO_DRV_MASK           (1 << 4)
  68#define CTLO_DRV_OD             (0 << 4)
  69#define CTLO_DRV_CMOS           (1 << 4)
  70
  71#define CTLO_DRV_REN            (1 << 3)
  72
  73#define CTLO_RVAL_2KDOWN        (0 << 1)
  74#define CTLO_RVAL_2KUP          (1 << 1)
  75#define CTLO_RVAL_50KDOWN       (2 << 1)
  76#define CTLO_RVAL_50KUP         (3 << 1)
  77
  78#define CTLO_INPUT_SET  (CTLO_DRV_CMOS | CTLO_DRV_REN | CTLO_RVAL_2KUP)
  79#define CTLO_OUTPUT_SET (CTLO_DIR_OUT | CTLO_INPUT_SET)
  80
  81enum ctrl_register {
  82        CTRL_IN,
  83        CTRL_OUT,
  84};
  85
  86/*
  87 * struct wcove_gpio - Whiskey Cove GPIO controller
  88 * @buslock: for bus lock/sync and unlock.
  89 * @chip: the abstract gpio_chip structure.
  90 * @dev: the gpio device
  91 * @regmap: the regmap from the parent device.
  92 * @regmap_irq_chip: the regmap of the gpio irq chip.
  93 * @update: pending IRQ setting update, to be written to the chip upon unlock.
  94 * @intcnt: the Interrupt Detect value to be written.
  95 * @set_irq_mask: true if the IRQ mask needs to be set, false to clear.
  96 */
  97struct wcove_gpio {
  98        struct mutex buslock;
  99        struct gpio_chip chip;
 100        struct device *dev;
 101        struct regmap *regmap;
 102        struct regmap_irq_chip_data *regmap_irq_chip;
 103        int update;
 104        int intcnt;
 105        bool set_irq_mask;
 106};
 107
 108static inline unsigned int to_reg(int gpio, enum ctrl_register reg_type)
 109{
 110        unsigned int reg;
 111
 112        if (gpio >= WCOVE_GPIO_NUM)
 113                return -EOPNOTSUPP;
 114
 115        if (reg_type == CTRL_IN)
 116                reg = GPIO_IN_CTRL_BASE + gpio;
 117        else
 118                reg = GPIO_OUT_CTRL_BASE + gpio;
 119
 120        return reg;
 121}
 122
 123static void wcove_update_irq_mask(struct wcove_gpio *wg, int gpio)
 124{
 125        unsigned int reg, mask;
 126
 127        if (gpio < GROUP0_NR_IRQS) {
 128                reg = IRQ_MASK_BASE;
 129                mask = BIT(gpio % GROUP0_NR_IRQS);
 130        } else {
 131                reg = IRQ_MASK_BASE + 1;
 132                mask = BIT((gpio - GROUP0_NR_IRQS) % GROUP1_NR_IRQS);
 133        }
 134
 135        if (wg->set_irq_mask)
 136                regmap_update_bits(wg->regmap, reg, mask, mask);
 137        else
 138                regmap_update_bits(wg->regmap, reg, mask, 0);
 139}
 140
 141static void wcove_update_irq_ctrl(struct wcove_gpio *wg, int gpio)
 142{
 143        int reg = to_reg(gpio, CTRL_IN);
 144
 145        if (reg < 0)
 146                return;
 147
 148        regmap_update_bits(wg->regmap, reg, CTLI_INTCNT_BE, wg->intcnt);
 149}
 150
 151static int wcove_gpio_dir_in(struct gpio_chip *chip, unsigned int gpio)
 152{
 153        struct wcove_gpio *wg = gpiochip_get_data(chip);
 154        int reg = to_reg(gpio, CTRL_OUT);
 155
 156        if (reg < 0)
 157                return 0;
 158
 159        return regmap_write(wg->regmap, reg, CTLO_INPUT_SET);
 160}
 161
 162static int wcove_gpio_dir_out(struct gpio_chip *chip, unsigned int gpio,
 163                                    int value)
 164{
 165        struct wcove_gpio *wg = gpiochip_get_data(chip);
 166        int reg = to_reg(gpio, CTRL_OUT);
 167
 168        if (reg < 0)
 169                return 0;
 170
 171        return regmap_write(wg->regmap, reg, CTLO_OUTPUT_SET | value);
 172}
 173
 174static int wcove_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
 175{
 176        struct wcove_gpio *wg = gpiochip_get_data(chip);
 177        unsigned int val;
 178        int ret, reg = to_reg(gpio, CTRL_OUT);
 179
 180        if (reg < 0)
 181                return 0;
 182
 183        ret = regmap_read(wg->regmap, reg, &val);
 184        if (ret)
 185                return ret;
 186
 187        return !(val & CTLO_DIR_OUT);
 188}
 189
 190static int wcove_gpio_get(struct gpio_chip *chip, unsigned int gpio)
 191{
 192        struct wcove_gpio *wg = gpiochip_get_data(chip);
 193        unsigned int val;
 194        int ret, reg = to_reg(gpio, CTRL_IN);
 195
 196        if (reg < 0)
 197                return 0;
 198
 199        ret = regmap_read(wg->regmap, reg, &val);
 200        if (ret)
 201                return ret;
 202
 203        return val & 0x1;
 204}
 205
 206static void wcove_gpio_set(struct gpio_chip *chip,
 207                                 unsigned int gpio, int value)
 208{
 209        struct wcove_gpio *wg = gpiochip_get_data(chip);
 210        int reg = to_reg(gpio, CTRL_OUT);
 211
 212        if (reg < 0)
 213                return;
 214
 215        if (value)
 216                regmap_update_bits(wg->regmap, reg, 1, 1);
 217        else
 218                regmap_update_bits(wg->regmap, reg, 1, 0);
 219}
 220
 221static int wcove_gpio_set_config(struct gpio_chip *chip, unsigned int gpio,
 222                                 unsigned long config)
 223{
 224        struct wcove_gpio *wg = gpiochip_get_data(chip);
 225        int reg = to_reg(gpio, CTRL_OUT);
 226
 227        if (reg < 0)
 228                return 0;
 229
 230        switch (pinconf_to_config_param(config)) {
 231        case PIN_CONFIG_DRIVE_OPEN_DRAIN:
 232                return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
 233                                          CTLO_DRV_OD);
 234        case PIN_CONFIG_DRIVE_PUSH_PULL:
 235                return regmap_update_bits(wg->regmap, reg, CTLO_DRV_MASK,
 236                                          CTLO_DRV_CMOS);
 237        default:
 238                break;
 239        }
 240
 241        return -ENOTSUPP;
 242}
 243
 244static int wcove_irq_type(struct irq_data *data, unsigned int type)
 245{
 246        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 247        struct wcove_gpio *wg = gpiochip_get_data(chip);
 248
 249        if (data->hwirq >= WCOVE_GPIO_NUM)
 250                return 0;
 251
 252        switch (type) {
 253        case IRQ_TYPE_NONE:
 254                wg->intcnt = CTLI_INTCNT_DIS;
 255                break;
 256        case IRQ_TYPE_EDGE_BOTH:
 257                wg->intcnt = CTLI_INTCNT_BE;
 258                break;
 259        case IRQ_TYPE_EDGE_RISING:
 260                wg->intcnt = CTLI_INTCNT_PE;
 261                break;
 262        case IRQ_TYPE_EDGE_FALLING:
 263                wg->intcnt = CTLI_INTCNT_NE;
 264                break;
 265        default:
 266                return -EINVAL;
 267        }
 268
 269        wg->update |= UPDATE_IRQ_TYPE;
 270
 271        return 0;
 272}
 273
 274static void wcove_bus_lock(struct irq_data *data)
 275{
 276        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 277        struct wcove_gpio *wg = gpiochip_get_data(chip);
 278
 279        mutex_lock(&wg->buslock);
 280}
 281
 282static void wcove_bus_sync_unlock(struct irq_data *data)
 283{
 284        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 285        struct wcove_gpio *wg = gpiochip_get_data(chip);
 286        int gpio = data->hwirq;
 287
 288        if (wg->update & UPDATE_IRQ_TYPE)
 289                wcove_update_irq_ctrl(wg, gpio);
 290        if (wg->update & UPDATE_IRQ_MASK)
 291                wcove_update_irq_mask(wg, gpio);
 292        wg->update = 0;
 293
 294        mutex_unlock(&wg->buslock);
 295}
 296
 297static void wcove_irq_unmask(struct irq_data *data)
 298{
 299        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 300        struct wcove_gpio *wg = gpiochip_get_data(chip);
 301
 302        if (data->hwirq >= WCOVE_GPIO_NUM)
 303                return;
 304
 305        wg->set_irq_mask = false;
 306        wg->update |= UPDATE_IRQ_MASK;
 307}
 308
 309static void wcove_irq_mask(struct irq_data *data)
 310{
 311        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 312        struct wcove_gpio *wg = gpiochip_get_data(chip);
 313
 314        if (data->hwirq >= WCOVE_GPIO_NUM)
 315                return;
 316
 317        wg->set_irq_mask = true;
 318        wg->update |= UPDATE_IRQ_MASK;
 319}
 320
 321static struct irq_chip wcove_irqchip = {
 322        .name                   = "Whiskey Cove",
 323        .irq_mask               = wcove_irq_mask,
 324        .irq_unmask             = wcove_irq_unmask,
 325        .irq_set_type           = wcove_irq_type,
 326        .irq_bus_lock           = wcove_bus_lock,
 327        .irq_bus_sync_unlock    = wcove_bus_sync_unlock,
 328};
 329
 330static irqreturn_t wcove_gpio_irq_handler(int irq, void *data)
 331{
 332        struct wcove_gpio *wg = (struct wcove_gpio *)data;
 333        unsigned int pending, virq, gpio, mask, offset;
 334        u8 p[2];
 335
 336        if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
 337                dev_err(wg->dev, "Failed to read irq status register\n");
 338                return IRQ_NONE;
 339        }
 340
 341        pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
 342        if (!pending)
 343                return IRQ_NONE;
 344
 345        /* Iterate until no interrupt is pending */
 346        while (pending) {
 347                /* One iteration is for all pending bits */
 348                for_each_set_bit(gpio, (const unsigned long *)&pending,
 349                                                 WCOVE_GPIO_NUM) {
 350                        offset = (gpio > GROUP0_NR_IRQS) ? 1 : 0;
 351                        mask = (offset == 1) ? BIT(gpio - GROUP0_NR_IRQS) :
 352                                                                BIT(gpio);
 353                        virq = irq_find_mapping(wg->chip.irq.domain, gpio);
 354                        handle_nested_irq(virq);
 355                        regmap_update_bits(wg->regmap, IRQ_STATUS_BASE + offset,
 356                                                                mask, mask);
 357                }
 358
 359                /* Next iteration */
 360                if (regmap_bulk_read(wg->regmap, IRQ_STATUS_BASE, p, 2)) {
 361                        dev_err(wg->dev, "Failed to read irq status\n");
 362                        break;
 363                }
 364
 365                pending = (p[0] & GPIO_IRQ0_MASK) | ((p[1] & GPIO_IRQ1_MASK) << 7);
 366        }
 367
 368        return IRQ_HANDLED;
 369}
 370
 371static void wcove_gpio_dbg_show(struct seq_file *s,
 372                                      struct gpio_chip *chip)
 373{
 374        unsigned int ctlo, ctli, irq_mask, irq_status;
 375        struct wcove_gpio *wg = gpiochip_get_data(chip);
 376        int gpio, offset, group, ret = 0;
 377
 378        for (gpio = 0; gpio < WCOVE_GPIO_NUM; gpio++) {
 379                group = gpio < GROUP0_NR_IRQS ? 0 : 1;
 380                ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_OUT), &ctlo);
 381                ret += regmap_read(wg->regmap, to_reg(gpio, CTRL_IN), &ctli);
 382                ret += regmap_read(wg->regmap, IRQ_MASK_BASE + group,
 383                                                        &irq_mask);
 384                ret += regmap_read(wg->regmap, IRQ_STATUS_BASE + group,
 385                                                        &irq_status);
 386                if (ret) {
 387                        pr_err("Failed to read registers: ctrl out/in or irq status/mask\n");
 388                        break;
 389                }
 390
 391                offset = gpio % 8;
 392                seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s\n",
 393                           gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
 394                           ctli & 0x1 ? "hi" : "lo",
 395                           ctli & CTLI_INTCNT_NE ? "fall" : "    ",
 396                           ctli & CTLI_INTCNT_PE ? "rise" : "    ",
 397                           ctlo,
 398                           irq_mask & BIT(offset) ? "mask  " : "unmask",
 399                           irq_status & BIT(offset) ? "pending" : "       ");
 400        }
 401}
 402
 403static int wcove_gpio_probe(struct platform_device *pdev)
 404{
 405        struct intel_soc_pmic *pmic;
 406        struct wcove_gpio *wg;
 407        int virq, ret, irq;
 408        struct device *dev;
 409
 410        /*
 411         * This gpio platform device is created by a mfd device (see
 412         * drivers/mfd/intel_soc_pmic_bxtwc.c for details). Information
 413         * shared by all sub-devices created by the mfd device, the regmap
 414         * pointer for instance, is stored as driver data of the mfd device
 415         * driver.
 416         */
 417        pmic = dev_get_drvdata(pdev->dev.parent);
 418        if (!pmic)
 419                return -ENODEV;
 420
 421        irq = platform_get_irq(pdev, 0);
 422        if (irq < 0)
 423                return irq;
 424
 425        dev = &pdev->dev;
 426
 427        wg = devm_kzalloc(dev, sizeof(*wg), GFP_KERNEL);
 428        if (!wg)
 429                return -ENOMEM;
 430
 431        wg->regmap_irq_chip = pmic->irq_chip_data;
 432
 433        platform_set_drvdata(pdev, wg);
 434
 435        mutex_init(&wg->buslock);
 436        wg->chip.label = KBUILD_MODNAME;
 437        wg->chip.direction_input = wcove_gpio_dir_in;
 438        wg->chip.direction_output = wcove_gpio_dir_out;
 439        wg->chip.get_direction = wcove_gpio_get_direction;
 440        wg->chip.get = wcove_gpio_get;
 441        wg->chip.set = wcove_gpio_set;
 442        wg->chip.set_config = wcove_gpio_set_config,
 443        wg->chip.base = -1;
 444        wg->chip.ngpio = WCOVE_VGPIO_NUM;
 445        wg->chip.can_sleep = true;
 446        wg->chip.parent = pdev->dev.parent;
 447        wg->chip.dbg_show = wcove_gpio_dbg_show;
 448        wg->dev = dev;
 449        wg->regmap = pmic->regmap;
 450
 451        ret = devm_gpiochip_add_data(dev, &wg->chip, wg);
 452        if (ret) {
 453                dev_err(dev, "Failed to add gpiochip: %d\n", ret);
 454                return ret;
 455        }
 456
 457        ret = gpiochip_irqchip_add_nested(&wg->chip, &wcove_irqchip, 0,
 458                                          handle_simple_irq, IRQ_TYPE_NONE);
 459        if (ret) {
 460                dev_err(dev, "Failed to add irqchip: %d\n", ret);
 461                return ret;
 462        }
 463
 464        virq = regmap_irq_get_virq(wg->regmap_irq_chip, irq);
 465        if (virq < 0) {
 466                dev_err(dev, "Failed to get virq by irq %d\n", irq);
 467                return virq;
 468        }
 469
 470        ret = devm_request_threaded_irq(dev, virq, NULL,
 471                wcove_gpio_irq_handler, IRQF_ONESHOT, pdev->name, wg);
 472        if (ret) {
 473                dev_err(dev, "Failed to request irq %d\n", virq);
 474                return ret;
 475        }
 476
 477        gpiochip_set_nested_irqchip(&wg->chip, &wcove_irqchip, virq);
 478
 479        /* Enable GPIO0 interrupts */
 480        ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE, GPIO_IRQ0_MASK,
 481                                 0x00);
 482        if (ret)
 483                return ret;
 484
 485        /* Enable GPIO1 interrupts */
 486        ret = regmap_update_bits(wg->regmap, IRQ_MASK_BASE + 1, GPIO_IRQ1_MASK,
 487                                 0x00);
 488        if (ret)
 489                return ret;
 490
 491        return 0;
 492}
 493
 494/*
 495 * Whiskey Cove PMIC itself is a analog device(but with digital control
 496 * interface) providing power management support for other devices in
 497 * the accompanied SoC, so we have no .pm for Whiskey Cove GPIO driver.
 498 */
 499static struct platform_driver wcove_gpio_driver = {
 500        .driver = {
 501                .name = "bxt_wcove_gpio",
 502        },
 503        .probe = wcove_gpio_probe,
 504};
 505
 506module_platform_driver(wcove_gpio_driver);
 507
 508MODULE_AUTHOR("Ajay Thomas <ajay.thomas.david.rajamanickam@intel.com>");
 509MODULE_AUTHOR("Bin Gao <bin.gao@intel.com>");
 510MODULE_DESCRIPTION("Intel Whiskey Cove GPIO Driver");
 511MODULE_LICENSE("GPL v2");
 512MODULE_ALIAS("platform:bxt_wcove_gpio");
 513