drivers/gpio/gpio-pmic-eic-sprd.c

   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  */
  40 enum {
  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  * @regmap: 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  */
  57 struct 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
  67 static 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
  77 static 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
  91 static 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
  97 static 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
 102 static 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
 107 static 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
 114 static 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
 120 static 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
 138 static 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
 150 static 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
 159 static 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
 168 static 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
 196 static 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
 204 static 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
 234 static 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);
 244 retry:
 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
 263 static 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
 295 static 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                 dev_err(&pdev->dev, "Failed to get PMIC EIC interrupt.\n");
 310                 return pmic_eic->irq;
 311         }
 312
 313         pmic_eic->map = dev_get_regmap(pdev->dev.parent, NULL);
 314         if (!pmic_eic->map)
 315                 return -ENODEV;
 316
 317         ret = of_property_read_u32(pdev->dev.of_node, "reg", &pmic_eic->offset);
 318         if (ret) {
 319                 dev_err(&pdev->dev, "Failed to get PMIC EIC base address.\n");
 320                 return ret;
 321         }
 322
 323         ret = devm_request_threaded_irq(&pdev->dev, pmic_eic->irq, NULL,
 324                                         sprd_pmic_eic_irq_handler,
 325                                         IRQF_TRIGGER_LOW |
 326                                         IRQF_ONESHOT | IRQF_NO_SUSPEND,
 327                                         dev_name(&pdev->dev), pmic_eic);
 328         if (ret) {
 329                 dev_err(&pdev->dev, "Failed to request PMIC EIC IRQ.\n");
 330                 return ret;
 331         }
 332
 333         pmic_eic->chip.label = dev_name(&pdev->dev);
 334         pmic_eic->chip.ngpio = SPRD_PMIC_EIC_NR;
 335         pmic_eic->chip.base = -1;
 336         pmic_eic->chip.parent = &pdev->dev;
 337         pmic_eic->chip.of_node = pdev->dev.of_node;
 338         pmic_eic->chip.direction_input = sprd_pmic_eic_direction_input;
 339         pmic_eic->chip.request = sprd_pmic_eic_request;
 340         pmic_eic->chip.free = sprd_pmic_eic_free;
 341         pmic_eic->chip.set_config = sprd_pmic_eic_set_config;
 342         pmic_eic->chip.set = sprd_pmic_eic_set;
 343         pmic_eic->chip.get = sprd_pmic_eic_get;
 344
 345         pmic_eic->intc.name = dev_name(&pdev->dev);
 346         pmic_eic->intc.irq_mask = sprd_pmic_eic_irq_mask;
 347         pmic_eic->intc.irq_unmask = sprd_pmic_eic_irq_unmask;
 348         pmic_eic->intc.irq_set_type = sprd_pmic_eic_irq_set_type;
 349         pmic_eic->intc.irq_bus_lock = sprd_pmic_eic_bus_lock;
 350         pmic_eic->intc.irq_bus_sync_unlock = sprd_pmic_eic_bus_sync_unlock;
 351         pmic_eic->intc.flags = IRQCHIP_SKIP_SET_WAKE;
 352
 353         irq = &pmic_eic->chip.irq;
 354         irq->chip = &pmic_eic->intc;
 355         irq->threaded = true;
 356
 357         ret = devm_gpiochip_add_data(&pdev->dev, &pmic_eic->chip, pmic_eic);
 358         if (ret < 0) {
 359                 dev_err(&pdev->dev, "Could not register gpiochip %d.\n", ret);
 360                 return ret;
 361         }
 362
 363         platform_set_drvdata(pdev, pmic_eic);
 364         return 0;
 365 }
 366
 367 static const struct of_device_id sprd_pmic_eic_of_match[] = {
 368         { .compatible = "sprd,sc27xx-eic", },
 369         { /* end of list */ }
 370 };
 371 MODULE_DEVICE_TABLE(of, sprd_pmic_eic_of_match);
 372
 373 static struct platform_driver sprd_pmic_eic_driver = {
 374         .probe = sprd_pmic_eic_probe,
 375         .driver = {
 376                 .name = "sprd-pmic-eic",
 377                 .of_match_table = sprd_pmic_eic_of_match,
 378         },
 379 };
 380
 381 module_platform_driver(sprd_pmic_eic_driver);
 382
 383 MODULE_DESCRIPTION("Spreadtrum PMIC EIC driver");
 384 MODULE_LICENSE("GPL v2");