linux/drivers/gpio/gpio-pmic-eic-sprd.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2018 Spreadtrum Communications Inc.
   4 * Copyright (C) 2018 Linaro Ltd.
   5 */
   6
   7#include <linux/gpio/driver.h>
   8#include <linux/interrupt.h>
   9#include <linux/kernel.h>
  10#include <linux/module.h>
  11#include <linux/of_device.h>
  12#include <linux/platform_device.h>
  13#include <linux/regmap.h>
  14
  15/* EIC registers definition */
  16#define SPRD_PMIC_EIC_DATA              0x0
  17#define SPRD_PMIC_EIC_DMSK              0x4
  18#define SPRD_PMIC_EIC_IEV               0x14
  19#define SPRD_PMIC_EIC_IE                0x18
  20#define SPRD_PMIC_EIC_RIS               0x1c
  21#define SPRD_PMIC_EIC_MIS               0x20
  22#define SPRD_PMIC_EIC_IC                0x24
  23#define SPRD_PMIC_EIC_TRIG              0x28
  24#define SPRD_PMIC_EIC_CTRL0             0x40
  25
  26/*
  27 * The PMIC EIC controller only has one bank, and each bank now can contain
  28 * 16 EICs.
  29 */
  30#define SPRD_PMIC_EIC_PER_BANK_NR       16
  31#define SPRD_PMIC_EIC_NR                SPRD_PMIC_EIC_PER_BANK_NR
  32#define SPRD_PMIC_EIC_DATA_MASK         GENMASK(15, 0)
  33#define SPRD_PMIC_EIC_BIT(x)            ((x) & (SPRD_PMIC_EIC_PER_BANK_NR - 1))
  34#define SPRD_PMIC_EIC_DBNC_MASK         GENMASK(11, 0)
  35
  36/*
  37 * These registers are modified under the irq bus lock and cached to avoid
  38 * unnecessary writes in bus_sync_unlock.
  39 */
  40enum {
  41        REG_IEV,
  42        REG_IE,
  43        REG_TRIG,
  44        CACHE_NR_REGS
  45};
  46
  47/**
  48 * struct sprd_pmic_eic - PMIC EIC controller
  49 * @chip: the gpio_chip structure.
  50 * @intc: the irq_chip structure.
  51 * @map:  the regmap from the parent device.
  52 * @offset: the EIC controller's offset address of the PMIC.
  53 * @reg: the array to cache the EIC registers.
  54 * @buslock: for bus lock/sync and unlock.
  55 * @irq: the interrupt number of the PMIC EIC conteroller.
  56 */
  57struct sprd_pmic_eic {
  58        struct gpio_chip chip;
  59        struct irq_chip intc;
  60        struct regmap *map;
  61        u32 offset;
  62        u8 reg[CACHE_NR_REGS];
  63        struct mutex buslock;
  64        int irq;
  65};
  66
  67static void sprd_pmic_eic_update(struct gpio_chip *chip, unsigned int offset,
  68                                 u16 reg, unsigned int val)
  69{
  70        struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
  71        u32 shift = SPRD_PMIC_EIC_BIT(offset);
  72
  73        regmap_update_bits(pmic_eic->map, pmic_eic->offset + reg,
  74                           BIT(shift), val << shift);
  75}
  76
  77static int sprd_pmic_eic_read(struct gpio_chip *chip, unsigned int offset,
  78                              u16 reg)
  79{
  80        struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
  81        u32 value;
  82        int ret;
  83
  84        ret = regmap_read(pmic_eic->map, pmic_eic->offset + reg, &value);
  85        if (ret)
  86                return ret;
  87
  88        return !!(value & BIT(SPRD_PMIC_EIC_BIT(offset)));
  89}
  90
  91static int sprd_pmic_eic_request(struct gpio_chip *chip, unsigned int offset)
  92{
  93        sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_DMSK, 1);
  94        return 0;
  95}
  96
  97static void sprd_pmic_eic_free(struct gpio_chip *chip, unsigned int offset)
  98{
  99        sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_DMSK, 0);
 100}
 101
 102static int sprd_pmic_eic_get(struct gpio_chip *chip, unsigned int offset)
 103{
 104        return sprd_pmic_eic_read(chip, offset, SPRD_PMIC_EIC_DATA);
 105}
 106
 107static int sprd_pmic_eic_direction_input(struct gpio_chip *chip,
 108                                         unsigned int offset)
 109{
 110        /* EICs are always input, nothing need to do here. */
 111        return 0;
 112}
 113
 114static void sprd_pmic_eic_set(struct gpio_chip *chip, unsigned int offset,
 115                              int value)
 116{
 117        /* EICs are always input, nothing need to do here. */
 118}
 119
 120static int sprd_pmic_eic_set_debounce(struct gpio_chip *chip,
 121                                      unsigned int offset,
 122                                      unsigned int debounce)
 123{
 124        struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
 125        u32 reg, value;
 126        int ret;
 127
 128        reg = SPRD_PMIC_EIC_CTRL0 + SPRD_PMIC_EIC_BIT(offset) * 0x4;
 129        ret = regmap_read(pmic_eic->map, pmic_eic->offset + reg, &value);
 130        if (ret)
 131                return ret;
 132
 133        value &= ~SPRD_PMIC_EIC_DBNC_MASK;
 134        value |= (debounce / 1000) & SPRD_PMIC_EIC_DBNC_MASK;
 135        return regmap_write(pmic_eic->map, pmic_eic->offset + reg, value);
 136}
 137
 138static int sprd_pmic_eic_set_config(struct gpio_chip *chip, unsigned int offset,
 139                                    unsigned long config)
 140{
 141        unsigned long param = pinconf_to_config_param(config);
 142        u32 arg = pinconf_to_config_argument(config);
 143
 144        if (param == PIN_CONFIG_INPUT_DEBOUNCE)
 145                return sprd_pmic_eic_set_debounce(chip, offset, arg);
 146
 147        return -ENOTSUPP;
 148}
 149
 150static void sprd_pmic_eic_irq_mask(struct irq_data *data)
 151{
 152        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 153        struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
 154
 155        pmic_eic->reg[REG_IE] = 0;
 156        pmic_eic->reg[REG_TRIG] = 0;
 157}
 158
 159static void sprd_pmic_eic_irq_unmask(struct irq_data *data)
 160{
 161        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 162        struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
 163
 164        pmic_eic->reg[REG_IE] = 1;
 165        pmic_eic->reg[REG_TRIG] = 1;
 166}
 167
 168static int sprd_pmic_eic_irq_set_type(struct irq_data *data,
 169                                      unsigned int flow_type)
 170{
 171        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 172        struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
 173
 174        switch (flow_type) {
 175        case IRQ_TYPE_LEVEL_HIGH:
 176                pmic_eic->reg[REG_IEV] = 1;
 177                break;
 178        case IRQ_TYPE_LEVEL_LOW:
 179                pmic_eic->reg[REG_IEV] = 0;
 180                break;
 181        case IRQ_TYPE_EDGE_RISING:
 182        case IRQ_TYPE_EDGE_FALLING:
 183        case IRQ_TYPE_EDGE_BOTH:
 184                /*
 185                 * Will set the trigger level according to current EIC level
 186                 * in irq_bus_sync_unlock() interface, so here nothing to do.
 187                 */
 188                break;
 189        default:
 190                return -ENOTSUPP;
 191        }
 192
 193        return 0;
 194}
 195
 196static void sprd_pmic_eic_bus_lock(struct irq_data *data)
 197{
 198        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 199        struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
 200
 201        mutex_lock(&pmic_eic->buslock);
 202}
 203
 204static void sprd_pmic_eic_bus_sync_unlock(struct irq_data *data)
 205{
 206        struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
 207        struct sprd_pmic_eic *pmic_eic = gpiochip_get_data(chip);
 208        u32 trigger = irqd_get_trigger_type(data);
 209        u32 offset = irqd_to_hwirq(data);
 210        int state;
 211
 212        /* Set irq type */
 213        if (trigger & IRQ_TYPE_EDGE_BOTH) {
 214                state = sprd_pmic_eic_get(chip, offset);
 215                if (state)
 216                        sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV, 0);
 217                else
 218                        sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV, 1);
 219        } else {
 220                sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV,
 221                                     pmic_eic->reg[REG_IEV]);
 222        }
 223
 224        /* Set irq unmask */
 225        sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IE,
 226                             pmic_eic->reg[REG_IE]);
 227        /* Generate trigger start pulse for debounce EIC */
 228        sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_TRIG,
 229                             pmic_eic->reg[REG_TRIG]);
 230
 231        mutex_unlock(&pmic_eic->buslock);
 232}
 233
 234static void sprd_pmic_eic_toggle_trigger(struct gpio_chip *chip,
 235                                         unsigned int irq, unsigned int offset)
 236{
 237        u32 trigger = irq_get_trigger_type(irq);
 238        int state, post_state;
 239
 240        if (!(trigger & IRQ_TYPE_EDGE_BOTH))
 241                return;
 242
 243        state = sprd_pmic_eic_get(chip, offset);
 244retry:
 245        if (state)
 246                sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV, 0);
 247        else
 248                sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IEV, 1);
 249
 250        post_state = sprd_pmic_eic_get(chip, offset);
 251        if (state != post_state) {
 252                dev_warn(chip->parent, "PMIC EIC level was changed.\n");
 253                state = post_state;
 254                goto retry;
 255        }
 256
 257        /* Set irq unmask */
 258        sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_IE, 1);
 259        /* Generate trigger start pulse for debounce EIC */
 260        sprd_pmic_eic_update(chip, offset, SPRD_PMIC_EIC_TRIG, 1);
 261}
 262
 263static irqreturn_t sprd_pmic_eic_irq_handler(int irq, void *data)
 264{
 265        struct sprd_pmic_eic *pmic_eic = data;
 266        struct gpio_chip *chip = &pmic_eic->chip;
 267        unsigned long status;
 268        u32 n, girq, val;
 269        int ret;
 270
 271        ret = regmap_read(pmic_eic->map, pmic_eic->offset + SPRD_PMIC_EIC_MIS,
 272                          &val);
 273        if (ret)
 274                return IRQ_RETVAL(ret);
 275
 276        status = val & SPRD_PMIC_EIC_DATA_MASK;
 277
 278        for_each_set_bit(n, &status, chip->ngpio) {
 279                /* Clear the interrupt */
 280                sprd_pmic_eic_update(chip, n, SPRD_PMIC_EIC_IC, 1);
 281
 282                girq = irq_find_mapping(chip->irq.domain, n);
 283                handle_nested_irq(girq);
 284
 285                /*
 286                 * The PMIC EIC can only support level trigger, so we can
 287                 * toggle the level trigger to emulate the edge trigger.
 288                 */
 289                sprd_pmic_eic_toggle_trigger(chip, girq, n);
 290        }
 291
 292        return IRQ_HANDLED;
 293}
 294
 295static int sprd_pmic_eic_probe(struct platform_device *pdev)
 296{
 297        struct gpio_irq_chip *irq;
 298        struct sprd_pmic_eic *pmic_eic;
 299        int ret;
 300
 301        pmic_eic = devm_kzalloc(&pdev->dev, sizeof(*pmic_eic), GFP_KERNEL);
 302        if (!pmic_eic)
 303                return -ENOMEM;
 304
 305        mutex_init(&pmic_eic->buslock);
 306
 307        pmic_eic->irq = platform_get_irq(pdev, 0);
 308        if (pmic_eic->irq < 0)
 309                return pmic_eic->irq;
 310
 311        pmic_eic->map = dev_get_regmap(pdev->dev.parent, NULL);
 312        if (!pmic_eic->map)
 313                return -ENODEV;
 314
 315        ret = of_property_read_u32(pdev->dev.of_node, "reg", &pmic_eic->offset);
 316        if (ret) {
 317                dev_err(&pdev->dev, "Failed to get PMIC EIC base address.\n");
 318                return ret;
 319        }
 320
 321        ret = devm_request_threaded_irq(&pdev->dev, pmic_eic->irq, NULL,
 322                                        sprd_pmic_eic_irq_handler,
 323                                        IRQF_ONESHOT | IRQF_NO_SUSPEND,
 324                                        dev_name(&pdev->dev), pmic_eic);
 325        if (ret) {
 326                dev_err(&pdev->dev, "Failed to request PMIC EIC IRQ.\n");
 327                return ret;
 328        }
 329
 330        pmic_eic->chip.label = dev_name(&pdev->dev);
 331        pmic_eic->chip.ngpio = SPRD_PMIC_EIC_NR;
 332        pmic_eic->chip.base = -1;
 333        pmic_eic->chip.parent = &pdev->dev;
 334        pmic_eic->chip.of_node = pdev->dev.of_node;
 335        pmic_eic->chip.direction_input = sprd_pmic_eic_direction_input;
 336        pmic_eic->chip.request = sprd_pmic_eic_request;
 337        pmic_eic->chip.free = sprd_pmic_eic_free;
 338        pmic_eic->chip.set_config = sprd_pmic_eic_set_config;
 339        pmic_eic->chip.set = sprd_pmic_eic_set;
 340        pmic_eic->chip.get = sprd_pmic_eic_get;
 341
 342        pmic_eic->intc.name = dev_name(&pdev->dev);
 343        pmic_eic->intc.irq_mask = sprd_pmic_eic_irq_mask;
 344        pmic_eic->intc.irq_unmask = sprd_pmic_eic_irq_unmask;
 345        pmic_eic->intc.irq_set_type = sprd_pmic_eic_irq_set_type;
 346        pmic_eic->intc.irq_bus_lock = sprd_pmic_eic_bus_lock;
 347        pmic_eic->intc.irq_bus_sync_unlock = sprd_pmic_eic_bus_sync_unlock;
 348        pmic_eic->intc.flags = IRQCHIP_SKIP_SET_WAKE;
 349
 350        irq = &pmic_eic->chip.irq;
 351        irq->chip = &pmic_eic->intc;
 352        irq->threaded = true;
 353
 354        ret = devm_gpiochip_add_data(&pdev->dev, &pmic_eic->chip, pmic_eic);
 355        if (ret < 0) {
 356                dev_err(&pdev->dev, "Could not register gpiochip %d.\n", ret);
 357                return ret;
 358        }
 359
 360        platform_set_drvdata(pdev, pmic_eic);
 361        return 0;
 362}
 363
 364static const struct of_device_id sprd_pmic_eic_of_match[] = {
 365        { .compatible = "sprd,sc2731-eic", },
 366        { /* end of list */ }
 367};
 368MODULE_DEVICE_TABLE(of, sprd_pmic_eic_of_match);
 369
 370static struct platform_driver sprd_pmic_eic_driver = {
 371        .probe = sprd_pmic_eic_probe,
 372        .driver = {
 373                .name = "sprd-pmic-eic",
 374                .of_match_table = sprd_pmic_eic_of_match,
 375        },
 376};
 377
 378module_platform_driver(sprd_pmic_eic_driver);
 379
 380MODULE_DESCRIPTION("Spreadtrum PMIC EIC driver");
 381MODULE_LICENSE("GPL v2");
 382