drivers/mfd/stmfx.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for STMicroelectronics Multi-Function eXpander (STMFX) core
   4  *
   5  * Copyright (C) 2019 STMicroelectronics
   6  * Author(s): Amelie Delaunay <amelie.delaunay@st.com>.
   7  */
   8 #include <linux/bitfield.h>
   9 #include <linux/i2c.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/irq.h>
  12 #include <linux/mfd/core.h>
  13 #include <linux/mfd/stmfx.h>
  14 #include <linux/module.h>
  15 #include <linux/regulator/consumer.h>
  16
  17 static bool stmfx_reg_volatile(struct device *dev, unsigned int reg)
  18 {
  19         switch (reg) {
  20         case STMFX_REG_SYS_CTRL:
  21         case STMFX_REG_IRQ_SRC_EN:
  22         case STMFX_REG_IRQ_PENDING:
  23         case STMFX_REG_IRQ_GPI_PENDING1:
  24         case STMFX_REG_IRQ_GPI_PENDING2:
  25         case STMFX_REG_IRQ_GPI_PENDING3:
  26         case STMFX_REG_GPIO_STATE1:
  27         case STMFX_REG_GPIO_STATE2:
  28         case STMFX_REG_GPIO_STATE3:
  29         case STMFX_REG_IRQ_GPI_SRC1:
  30         case STMFX_REG_IRQ_GPI_SRC2:
  31         case STMFX_REG_IRQ_GPI_SRC3:
  32         case STMFX_REG_GPO_SET1:
  33         case STMFX_REG_GPO_SET2:
  34         case STMFX_REG_GPO_SET3:
  35         case STMFX_REG_GPO_CLR1:
  36         case STMFX_REG_GPO_CLR2:
  37         case STMFX_REG_GPO_CLR3:
  38                 return true;
  39         default:
  40                 return false;
  41         }
  42 }
  43
  44 static bool stmfx_reg_writeable(struct device *dev, unsigned int reg)
  45 {
  46         return (reg >= STMFX_REG_SYS_CTRL);
  47 }
  48
  49 static const struct regmap_config stmfx_regmap_config = {
  50         .reg_bits       = 8,
  51         .reg_stride     = 1,
  52         .val_bits       = 8,
  53         .max_register   = STMFX_REG_MAX,
  54         .volatile_reg   = stmfx_reg_volatile,
  55         .writeable_reg  = stmfx_reg_writeable,
  56         .cache_type     = REGCACHE_RBTREE,
  57 };
  58
  59 static const struct resource stmfx_pinctrl_resources[] = {
  60         DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_GPIO),
  61 };
  62
  63 static const struct resource stmfx_idd_resources[] = {
  64         DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_IDD),
  65         DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_ERROR),
  66 };
  67
  68 static const struct resource stmfx_ts_resources[] = {
  69         DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_DET),
  70         DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_NE),
  71         DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_TH),
  72         DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_FULL),
  73         DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_OVF),
  74 };
  75
  76 static struct mfd_cell stmfx_cells[] = {
  77         {
  78                 .of_compatible = "st,stmfx-0300-pinctrl",
  79                 .name = "stmfx-pinctrl",
  80                 .resources = stmfx_pinctrl_resources,
  81                 .num_resources = ARRAY_SIZE(stmfx_pinctrl_resources),
  82         },
  83         {
  84                 .of_compatible = "st,stmfx-0300-idd",
  85                 .name = "stmfx-idd",
  86                 .resources = stmfx_idd_resources,
  87                 .num_resources = ARRAY_SIZE(stmfx_idd_resources),
  88         },
  89         {
  90                 .of_compatible = "st,stmfx-0300-ts",
  91                 .name = "stmfx-ts",
  92                 .resources = stmfx_ts_resources,
  93                 .num_resources = ARRAY_SIZE(stmfx_ts_resources),
  94         },
  95 };
  96
  97 static u8 stmfx_func_to_mask(u32 func)
  98 {
  99         u8 mask = 0;
 100
 101         if (func & STMFX_FUNC_GPIO)
 102                 mask |= STMFX_REG_SYS_CTRL_GPIO_EN;
 103
 104         if ((func & STMFX_FUNC_ALTGPIO_LOW) || (func & STMFX_FUNC_ALTGPIO_HIGH))
 105                 mask |= STMFX_REG_SYS_CTRL_ALTGPIO_EN;
 106
 107         if (func & STMFX_FUNC_TS)
 108                 mask |= STMFX_REG_SYS_CTRL_TS_EN;
 109
 110         if (func & STMFX_FUNC_IDD)
 111                 mask |= STMFX_REG_SYS_CTRL_IDD_EN;
 112
 113         return mask;
 114 }
 115
 116 int stmfx_function_enable(struct stmfx *stmfx, u32 func)
 117 {
 118         u32 sys_ctrl;
 119         u8 mask;
 120         int ret;
 121
 122         ret = regmap_read(stmfx->map, STMFX_REG_SYS_CTRL, &sys_ctrl);
 123         if (ret)
 124                 return ret;
 125
 126         /*
 127          * IDD and TS have priority in STMFX FW, so if IDD and TS are enabled,
 128          * ALTGPIO function is disabled by STMFX FW. If IDD or TS is enabled,
 129          * the number of aGPIO available decreases. To avoid GPIO management
 130          * disturbance, abort IDD or TS function enable in this case.
 131          */
 132         if (((func & STMFX_FUNC_IDD) || (func & STMFX_FUNC_TS)) &&
 133             (sys_ctrl & STMFX_REG_SYS_CTRL_ALTGPIO_EN)) {
 134                 dev_err(stmfx->dev, "ALTGPIO function already enabled\n");
 135                 return -EBUSY;
 136         }
 137
 138         /* If TS is enabled, aGPIO[3:0] cannot be used */
 139         if ((func & STMFX_FUNC_ALTGPIO_LOW) &&
 140             (sys_ctrl & STMFX_REG_SYS_CTRL_TS_EN)) {
 141                 dev_err(stmfx->dev, "TS in use, aGPIO[3:0] unavailable\n");
 142                 return -EBUSY;
 143         }
 144
 145         /* If IDD is enabled, aGPIO[7:4] cannot be used */
 146         if ((func & STMFX_FUNC_ALTGPIO_HIGH) &&
 147             (sys_ctrl & STMFX_REG_SYS_CTRL_IDD_EN)) {
 148                 dev_err(stmfx->dev, "IDD in use, aGPIO[7:4] unavailable\n");
 149                 return -EBUSY;
 150         }
 151
 152         mask = stmfx_func_to_mask(func);
 153
 154         return regmap_update_bits(stmfx->map, STMFX_REG_SYS_CTRL, mask, mask);
 155 }
 156 EXPORT_SYMBOL_GPL(stmfx_function_enable);
 157
 158 int stmfx_function_disable(struct stmfx *stmfx, u32 func)
 159 {
 160         u8 mask = stmfx_func_to_mask(func);
 161
 162         return regmap_update_bits(stmfx->map, STMFX_REG_SYS_CTRL, mask, 0);
 163 }
 164 EXPORT_SYMBOL_GPL(stmfx_function_disable);
 165
 166 static void stmfx_irq_bus_lock(struct irq_data *data)
 167 {
 168         struct stmfx *stmfx = irq_data_get_irq_chip_data(data);
 169
 170         mutex_lock(&stmfx->lock);
 171 }
 172
 173 static void stmfx_irq_bus_sync_unlock(struct irq_data *data)
 174 {
 175         struct stmfx *stmfx = irq_data_get_irq_chip_data(data);
 176
 177         regmap_write(stmfx->map, STMFX_REG_IRQ_SRC_EN, stmfx->irq_src);
 178
 179         mutex_unlock(&stmfx->lock);
 180 }
 181
 182 static void stmfx_irq_mask(struct irq_data *data)
 183 {
 184         struct stmfx *stmfx = irq_data_get_irq_chip_data(data);
 185
 186         stmfx->irq_src &= ~BIT(data->hwirq % 8);
 187 }
 188
 189 static void stmfx_irq_unmask(struct irq_data *data)
 190 {
 191         struct stmfx *stmfx = irq_data_get_irq_chip_data(data);
 192
 193         stmfx->irq_src |= BIT(data->hwirq % 8);
 194 }
 195
 196 static struct irq_chip stmfx_irq_chip = {
 197         .name                   = "stmfx-core",
 198         .irq_bus_lock           = stmfx_irq_bus_lock,
 199         .irq_bus_sync_unlock    = stmfx_irq_bus_sync_unlock,
 200         .irq_mask               = stmfx_irq_mask,
 201         .irq_unmask             = stmfx_irq_unmask,
 202 };
 203
 204 static irqreturn_t stmfx_irq_handler(int irq, void *data)
 205 {
 206         struct stmfx *stmfx = data;
 207         unsigned long bits;
 208         u32 pending, ack;
 209         int n, ret;
 210
 211         ret = regmap_read(stmfx->map, STMFX_REG_IRQ_PENDING, &pending);
 212         if (ret)
 213                 return IRQ_NONE;
 214
 215         /*
 216          * There is no ACK for GPIO, MFX_REG_IRQ_PENDING_GPIO is a logical OR
 217          * of MFX_REG_IRQ_GPI _PENDING1/_PENDING2/_PENDING3
 218          */
 219         ack = pending & ~BIT(STMFX_REG_IRQ_SRC_EN_GPIO);
 220         if (ack) {
 221                 ret = regmap_write(stmfx->map, STMFX_REG_IRQ_ACK, ack);
 222                 if (ret)
 223                         return IRQ_NONE;
 224         }
 225
 226         bits = pending;
 227         for_each_set_bit(n, &bits, STMFX_REG_IRQ_SRC_MAX)
 228                 handle_nested_irq(irq_find_mapping(stmfx->irq_domain, n));
 229
 230         return IRQ_HANDLED;
 231 }
 232
 233 static int stmfx_irq_map(struct irq_domain *d, unsigned int virq,
 234                          irq_hw_number_t hwirq)
 235 {
 236         irq_set_chip_data(virq, d->host_data);
 237         irq_set_chip_and_handler(virq, &stmfx_irq_chip, handle_simple_irq);
 238         irq_set_nested_thread(virq, 1);
 239         irq_set_noprobe(virq);
 240
 241         return 0;
 242 }
 243
 244 static void stmfx_irq_unmap(struct irq_domain *d, unsigned int virq)
 245 {
 246         irq_set_chip_and_handler(virq, NULL, NULL);
 247         irq_set_chip_data(virq, NULL);
 248 }
 249
 250 static const struct irq_domain_ops stmfx_irq_ops = {
 251         .map    = stmfx_irq_map,
 252         .unmap  = stmfx_irq_unmap,
 253 };
 254
 255 static void stmfx_irq_exit(struct i2c_client *client)
 256 {
 257         struct stmfx *stmfx = i2c_get_clientdata(client);
 258         int hwirq;
 259
 260         for (hwirq = 0; hwirq < STMFX_REG_IRQ_SRC_MAX; hwirq++)
 261                 irq_dispose_mapping(irq_find_mapping(stmfx->irq_domain, hwirq));
 262
 263         irq_domain_remove(stmfx->irq_domain);
 264 }
 265
 266 static int stmfx_irq_init(struct i2c_client *client)
 267 {
 268         struct stmfx *stmfx = i2c_get_clientdata(client);
 269         u32 irqoutpin = 0, irqtrigger;
 270         int ret;
 271
 272         stmfx->irq_domain = irq_domain_add_simple(stmfx->dev->of_node,
 273                                                   STMFX_REG_IRQ_SRC_MAX, 0,
 274                                                   &stmfx_irq_ops, stmfx);
 275         if (!stmfx->irq_domain) {
 276                 dev_err(stmfx->dev, "Failed to create IRQ domain\n");
 277                 return -EINVAL;
 278         }
 279
 280         if (!of_property_read_bool(stmfx->dev->of_node, "drive-open-drain"))
 281                 irqoutpin |= STMFX_REG_IRQ_OUT_PIN_TYPE;
 282
 283         irqtrigger = irq_get_trigger_type(client->irq);
 284         if ((irqtrigger & IRQ_TYPE_EDGE_RISING) ||
 285             (irqtrigger & IRQ_TYPE_LEVEL_HIGH))
 286                 irqoutpin |= STMFX_REG_IRQ_OUT_PIN_POL;
 287
 288         ret = regmap_write(stmfx->map, STMFX_REG_IRQ_OUT_PIN, irqoutpin);
 289         if (ret)
 290                 return ret;
 291
 292         ret = devm_request_threaded_irq(stmfx->dev, client->irq,
 293                                         NULL, stmfx_irq_handler,
 294                                         irqtrigger | IRQF_ONESHOT,
 295                                         "stmfx", stmfx);
 296         if (ret)
 297                 stmfx_irq_exit(client);
 298
 299         return ret;
 300 }
 301
 302 static int stmfx_chip_reset(struct stmfx *stmfx)
 303 {
 304         int ret;
 305
 306         ret = regmap_write(stmfx->map, STMFX_REG_SYS_CTRL,
 307                            STMFX_REG_SYS_CTRL_SWRST);
 308         if (ret)
 309                 return ret;
 310
 311         msleep(STMFX_BOOT_TIME_MS);
 312
 313         return ret;
 314 }
 315
 316 static int stmfx_chip_init(struct i2c_client *client)
 317 {
 318         struct stmfx *stmfx = i2c_get_clientdata(client);
 319         u32 id;
 320         u8 version[2];
 321         int ret;
 322
 323         stmfx->vdd = devm_regulator_get_optional(&client->dev, "vdd");
 324         ret = PTR_ERR_OR_ZERO(stmfx->vdd);
 325         if (ret == -ENODEV) {
 326                 stmfx->vdd = NULL;
 327         } else if (ret == -EPROBE_DEFER) {
 328                 return ret;
 329         } else if (ret) {
 330                 dev_err(&client->dev, "Failed to get VDD regulator: %d\n", ret);
 331                 return ret;
 332         }
 333
 334         if (stmfx->vdd) {
 335                 ret = regulator_enable(stmfx->vdd);
 336                 if (ret) {
 337                         dev_err(&client->dev, "VDD enable failed: %d\n", ret);
 338                         return ret;
 339                 }
 340         }
 341
 342         ret = regmap_read(stmfx->map, STMFX_REG_CHIP_ID, &id);
 343         if (ret) {
 344                 dev_err(&client->dev, "Error reading chip ID: %d\n", ret);
 345                 goto err;
 346         }
 347
 348         /*
 349          * Check that ID is the complement of the I2C address:
 350          * STMFX I2C address follows the 7-bit format (MSB), that's why
 351          * client->addr is shifted.
 352          *
 353          * STMFX_I2C_ADDR|       STMFX         |        Linux
 354          *   input pin   | I2C device address  | I2C device address
 355          *---------------------------------------------------------
 356          *       0       | b: 1000 010x h:0x84 |       0x42
 357          *       1       | b: 1000 011x h:0x86 |       0x43
 358          */
 359         if (FIELD_GET(STMFX_REG_CHIP_ID_MASK, ~id) != (client->addr << 1)) {
 360                 dev_err(&client->dev, "Unknown chip ID: %#x\n", id);
 361                 ret = -EINVAL;
 362                 goto err;
 363         }
 364
 365         ret = regmap_bulk_read(stmfx->map, STMFX_REG_FW_VERSION_MSB,
 366                                version, ARRAY_SIZE(version));
 367         if (ret) {
 368                 dev_err(&client->dev, "Error reading FW version: %d\n", ret);
 369                 goto err;
 370         }
 371
 372         dev_info(&client->dev, "STMFX id: %#x, fw version: %x.%02x\n",
 373                  id, version[0], version[1]);
 374
 375         ret = stmfx_chip_reset(stmfx);
 376         if (ret) {
 377                 dev_err(&client->dev, "Failed to reset chip: %d\n", ret);
 378                 goto err;
 379         }
 380
 381         return 0;
 382
 383 err:
 384         if (stmfx->vdd)
 385                 return regulator_disable(stmfx->vdd);
 386
 387         return ret;
 388 }
 389
 390 static int stmfx_chip_exit(struct i2c_client *client)
 391 {
 392         struct stmfx *stmfx = i2c_get_clientdata(client);
 393
 394         regmap_write(stmfx->map, STMFX_REG_IRQ_SRC_EN, 0);
 395         regmap_write(stmfx->map, STMFX_REG_SYS_CTRL, 0);
 396
 397         if (stmfx->vdd)
 398                 return regulator_disable(stmfx->vdd);
 399
 400         return 0;
 401 }
 402
 403 static int stmfx_probe(struct i2c_client *client,
 404                        const struct i2c_device_id *id)
 405 {
 406         struct device *dev = &client->dev;
 407         struct stmfx *stmfx;
 408         int ret;
 409
 410         stmfx = devm_kzalloc(dev, sizeof(*stmfx), GFP_KERNEL);
 411         if (!stmfx)
 412                 return -ENOMEM;
 413
 414         i2c_set_clientdata(client, stmfx);
 415
 416         stmfx->dev = dev;
 417
 418         stmfx->map = devm_regmap_init_i2c(client, &stmfx_regmap_config);
 419         if (IS_ERR(stmfx->map)) {
 420                 ret = PTR_ERR(stmfx->map);
 421                 dev_err(dev, "Failed to allocate register map: %d\n", ret);
 422                 return ret;
 423         }
 424
 425         mutex_init(&stmfx->lock);
 426
 427         ret = stmfx_chip_init(client);
 428         if (ret) {
 429                 if (ret == -ETIMEDOUT)
 430                         return -EPROBE_DEFER;
 431                 return ret;
 432         }
 433
 434         if (client->irq < 0) {
 435                 dev_err(dev, "Failed to get IRQ: %d\n", client->irq);
 436                 ret = client->irq;
 437                 goto err_chip_exit;
 438         }
 439
 440         ret = stmfx_irq_init(client);
 441         if (ret)
 442                 goto err_chip_exit;
 443
 444         ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
 445                                    stmfx_cells, ARRAY_SIZE(stmfx_cells), NULL,
 446                                    0, stmfx->irq_domain);
 447         if (ret)
 448                 goto err_irq_exit;
 449
 450         return 0;
 451
 452 err_irq_exit:
 453         stmfx_irq_exit(client);
 454 err_chip_exit:
 455         stmfx_chip_exit(client);
 456
 457         return ret;
 458 }
 459
 460 static int stmfx_remove(struct i2c_client *client)
 461 {
 462         stmfx_irq_exit(client);
 463
 464         return stmfx_chip_exit(client);
 465 }
 466
 467 #ifdef CONFIG_PM_SLEEP
 468 static int stmfx_suspend(struct device *dev)
 469 {
 470         struct stmfx *stmfx = dev_get_drvdata(dev);
 471         int ret;
 472
 473         ret = regmap_raw_read(stmfx->map, STMFX_REG_SYS_CTRL,
 474                               &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
 475         if (ret)
 476                 return ret;
 477
 478         ret = regmap_raw_read(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
 479                               &stmfx->bkp_irqoutpin,
 480                               sizeof(stmfx->bkp_irqoutpin));
 481         if (ret)
 482                 return ret;
 483
 484         if (stmfx->vdd)
 485                 return regulator_disable(stmfx->vdd);
 486
 487         return 0;
 488 }
 489
 490 static int stmfx_resume(struct device *dev)
 491 {
 492         struct stmfx *stmfx = dev_get_drvdata(dev);
 493         int ret;
 494
 495         if (stmfx->vdd) {
 496                 ret = regulator_enable(stmfx->vdd);
 497                 if (ret) {
 498                         dev_err(stmfx->dev,
 499                                 "VDD enable failed: %d\n", ret);
 500                         return ret;
 501                 }
 502         }
 503
 504         ret = regmap_raw_write(stmfx->map, STMFX_REG_SYS_CTRL,
 505                                &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
 506         if (ret)
 507                 return ret;
 508
 509         ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
 510                                &stmfx->bkp_irqoutpin,
 511                                sizeof(stmfx->bkp_irqoutpin));
 512         if (ret)
 513                 return ret;
 514
 515         ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_SRC_EN,
 516                                &stmfx->irq_src, sizeof(stmfx->irq_src));
 517         if (ret)
 518                 return ret;
 519
 520         return 0;
 521 }
 522 #endif
 523
 524 static SIMPLE_DEV_PM_OPS(stmfx_dev_pm_ops, stmfx_suspend, stmfx_resume);
 525
 526 static const struct of_device_id stmfx_of_match[] = {
 527         { .compatible = "st,stmfx-0300", },
 528         {},
 529 };
 530 MODULE_DEVICE_TABLE(of, stmfx_of_match);
 531
 532 static struct i2c_driver stmfx_driver = {
 533         .driver = {
 534                 .name = "stmfx-core",
 535                 .of_match_table = of_match_ptr(stmfx_of_match),
 536                 .pm = &stmfx_dev_pm_ops,
 537         },
 538         .probe = stmfx_probe,
 539         .remove = stmfx_remove,
 540 };
 541 module_i2c_driver(stmfx_driver);
 542
 543 MODULE_DESCRIPTION("STMFX core driver");
 544 MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
 545 MODULE_LICENSE("GPL v2");