drivers/gpio/gpio-ljca.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Intel La Jolla Cove Adapter USB-GPIO driver
   4  *
   5  * Copyright (c) 2023, Intel Corporation.
   6  */
   7
   8 #include <linux/acpi.h>
   9 #include <linux/auxiliary_bus.h>
  10 #include <linux/bitfield.h>
  11 #include <linux/bitops.h>
  12 #include <linux/dev_printk.h>
  13 #include <linux/gpio/driver.h>
  14 #include <linux/irq.h>
  15 #include <linux/kernel.h>
  16 #include <linux/kref.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19 #include <linux/types.h>
  20 #include <linux/usb/ljca.h>
  21
  22 /* GPIO commands */
  23 #define LJCA_GPIO_CONFIG                1
  24 #define LJCA_GPIO_READ                  2
  25 #define LJCA_GPIO_WRITE                 3
  26 #define LJCA_GPIO_INT_EVENT             4
  27 #define LJCA_GPIO_INT_MASK              5
  28 #define LJCA_GPIO_INT_UNMASK            6
  29
  30 #define LJCA_GPIO_CONF_DISABLE          BIT(0)
  31 #define LJCA_GPIO_CONF_INPUT            BIT(1)
  32 #define LJCA_GPIO_CONF_OUTPUT           BIT(2)
  33 #define LJCA_GPIO_CONF_PULLUP           BIT(3)
  34 #define LJCA_GPIO_CONF_PULLDOWN         BIT(4)
  35 #define LJCA_GPIO_CONF_DEFAULT          BIT(5)
  36 #define LJCA_GPIO_CONF_INTERRUPT        BIT(6)
  37 #define LJCA_GPIO_INT_TYPE              BIT(7)
  38
  39 #define LJCA_GPIO_CONF_EDGE             FIELD_PREP(LJCA_GPIO_INT_TYPE, 1)
  40 #define LJCA_GPIO_CONF_LEVEL            FIELD_PREP(LJCA_GPIO_INT_TYPE, 0)
  41
  42 /* Intentional overlap with PULLUP / PULLDOWN */
  43 #define LJCA_GPIO_CONF_SET              BIT(3)
  44 #define LJCA_GPIO_CONF_CLR              BIT(4)
  45
  46 #define LJCA_GPIO_BUF_SIZE              60u
  47
  48 struct ljca_gpio_op {
  49         u8 index;
  50         u8 value;
  51 } __packed;
  52
  53 struct ljca_gpio_packet {
  54         u8 num;
  55         struct ljca_gpio_op item[] __counted_by(num);
  56 } __packed;
  57
  58 struct ljca_gpio_dev {
  59         struct ljca_client *ljca;
  60         struct gpio_chip gc;
  61         struct ljca_gpio_info *gpio_info;
  62         DECLARE_BITMAP(unmasked_irqs, LJCA_MAX_GPIO_NUM);
  63         DECLARE_BITMAP(enabled_irqs, LJCA_MAX_GPIO_NUM);
  64         DECLARE_BITMAP(reenable_irqs, LJCA_MAX_GPIO_NUM);
  65         DECLARE_BITMAP(output_enabled, LJCA_MAX_GPIO_NUM);
  66         u8 *connect_mode;
  67         /* protect irq bus */
  68         struct mutex irq_lock;
  69         struct work_struct work;
  70         /* protect package transfer to hardware */
  71         struct mutex trans_lock;
  72
  73         u8 obuf[LJCA_GPIO_BUF_SIZE];
  74         u8 ibuf[LJCA_GPIO_BUF_SIZE];
  75 };
  76
  77 static int ljca_gpio_config(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id,
  78                             u8 config)
  79 {
  80         struct ljca_gpio_packet *packet =
  81                                 (struct ljca_gpio_packet *)ljca_gpio->obuf;
  82         int ret;
  83
  84         mutex_lock(&ljca_gpio->trans_lock);
  85         packet->item[0].index = gpio_id;
  86         packet->item[0].value = config | ljca_gpio->connect_mode[gpio_id];
  87         packet->num = 1;
  88
  89         ret = ljca_transfer(ljca_gpio->ljca, LJCA_GPIO_CONFIG, (u8 *)packet,
  90                             struct_size(packet, item, packet->num), NULL, 0);
  91         mutex_unlock(&ljca_gpio->trans_lock);
  92
  93         return ret < 0 ? ret : 0;
  94 }
  95
  96 static int ljca_gpio_read(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id)
  97 {
  98         struct ljca_gpio_packet *ack_packet =
  99                                 (struct ljca_gpio_packet *)ljca_gpio->ibuf;
 100         struct ljca_gpio_packet *packet =
 101                                 (struct ljca_gpio_packet *)ljca_gpio->obuf;
 102         int ret;
 103
 104         mutex_lock(&ljca_gpio->trans_lock);
 105         packet->num = 1;
 106         packet->item[0].index = gpio_id;
 107         ret = ljca_transfer(ljca_gpio->ljca, LJCA_GPIO_READ, (u8 *)packet,
 108                             struct_size(packet, item, packet->num),
 109                             ljca_gpio->ibuf, LJCA_GPIO_BUF_SIZE);
 110
 111         if (ret <= 0 || ack_packet->num != packet->num) {
 112                 dev_err(&ljca_gpio->ljca->auxdev.dev,
 113                         "read package error, gpio_id: %u num: %u ret: %d\n",
 114                         gpio_id, ack_packet->num, ret);
 115                 ret = ret < 0 ? ret : -EIO;
 116         }
 117         mutex_unlock(&ljca_gpio->trans_lock);
 118
 119         return ret < 0 ? ret : ack_packet->item[0].value > 0;
 120 }
 121
 122 static int ljca_gpio_write(struct ljca_gpio_dev *ljca_gpio, u8 gpio_id, int value)
 123 {
 124         struct ljca_gpio_packet *packet =
 125                         (struct ljca_gpio_packet *)ljca_gpio->obuf;
 126         int ret;
 127
 128         mutex_lock(&ljca_gpio->trans_lock);
 129         packet->num = 1;
 130         packet->item[0].index = gpio_id;
 131         packet->item[0].value = value & 1;
 132
 133         ret = ljca_transfer(ljca_gpio->ljca, LJCA_GPIO_WRITE, (u8 *)packet,
 134                             struct_size(packet, item, packet->num), NULL, 0);
 135         mutex_unlock(&ljca_gpio->trans_lock);
 136
 137         return ret < 0 ? ret : 0;
 138 }
 139
 140 static int ljca_gpio_get_value(struct gpio_chip *chip, unsigned int offset)
 141 {
 142         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 143
 144         return ljca_gpio_read(ljca_gpio, offset);
 145 }
 146
 147 static void ljca_gpio_set_value(struct gpio_chip *chip, unsigned int offset,
 148                                 int val)
 149 {
 150         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 151         int ret;
 152
 153         ret = ljca_gpio_write(ljca_gpio, offset, val);
 154         if (ret)
 155                 dev_err(chip->parent,
 156                         "set value failed offset: %u val: %d ret: %d\n",
 157                         offset, val, ret);
 158 }
 159
 160 static int ljca_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
 161 {
 162         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 163         u8 config = LJCA_GPIO_CONF_INPUT | LJCA_GPIO_CONF_CLR;
 164         int ret;
 165
 166         ret = ljca_gpio_config(ljca_gpio, offset, config);
 167         if (ret)
 168                 return ret;
 169
 170         clear_bit(offset, ljca_gpio->output_enabled);
 171
 172         return 0;
 173 }
 174
 175 static int ljca_gpio_direction_output(struct gpio_chip *chip,
 176                                       unsigned int offset, int val)
 177 {
 178         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 179         u8 config = LJCA_GPIO_CONF_OUTPUT | LJCA_GPIO_CONF_CLR;
 180         int ret;
 181
 182         ret = ljca_gpio_config(ljca_gpio, offset, config);
 183         if (ret)
 184                 return ret;
 185
 186         ljca_gpio_set_value(chip, offset, val);
 187         set_bit(offset, ljca_gpio->output_enabled);
 188
 189         return 0;
 190 }
 191
 192 static int ljca_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
 193 {
 194         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 195
 196         if (test_bit(offset, ljca_gpio->output_enabled))
 197                 return GPIO_LINE_DIRECTION_OUT;
 198
 199         return GPIO_LINE_DIRECTION_IN;
 200 }
 201
 202 static int ljca_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
 203                                 unsigned long config)
 204 {
 205         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 206
 207         ljca_gpio->connect_mode[offset] = 0;
 208         switch (pinconf_to_config_param(config)) {
 209         case PIN_CONFIG_BIAS_PULL_UP:
 210                 ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLUP;
 211                 break;
 212         case PIN_CONFIG_BIAS_PULL_DOWN:
 213                 ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLDOWN;
 214                 break;
 215         case PIN_CONFIG_DRIVE_PUSH_PULL:
 216         case PIN_CONFIG_PERSIST_STATE:
 217                 break;
 218         default:
 219                 return -ENOTSUPP;
 220         }
 221
 222         return 0;
 223 }
 224
 225 static int ljca_gpio_init_valid_mask(struct gpio_chip *chip,
 226                                      unsigned long *valid_mask,
 227                                      unsigned int ngpios)
 228 {
 229         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip);
 230
 231         WARN_ON_ONCE(ngpios != ljca_gpio->gpio_info->num);
 232         bitmap_copy(valid_mask, ljca_gpio->gpio_info->valid_pin_map, ngpios);
 233
 234         return 0;
 235 }
 236
 237 static void ljca_gpio_irq_init_valid_mask(struct gpio_chip *chip,
 238                                           unsigned long *valid_mask,
 239                                           unsigned int ngpios)
 240 {
 241         ljca_gpio_init_valid_mask(chip, valid_mask, ngpios);
 242 }
 243
 244 static int ljca_enable_irq(struct ljca_gpio_dev *ljca_gpio, int gpio_id,
 245                            bool enable)
 246 {
 247         struct ljca_gpio_packet *packet =
 248                         (struct ljca_gpio_packet *)ljca_gpio->obuf;
 249         int ret;
 250
 251         mutex_lock(&ljca_gpio->trans_lock);
 252         packet->num = 1;
 253         packet->item[0].index = gpio_id;
 254         packet->item[0].value = 0;
 255
 256         ret = ljca_transfer(ljca_gpio->ljca,
 257                             enable ? LJCA_GPIO_INT_UNMASK : LJCA_GPIO_INT_MASK,
 258                             (u8 *)packet, struct_size(packet, item, packet->num),
 259                             NULL, 0);
 260         mutex_unlock(&ljca_gpio->trans_lock);
 261
 262         return ret < 0 ? ret : 0;
 263 }
 264
 265 static void ljca_gpio_async(struct work_struct *work)
 266 {
 267         struct ljca_gpio_dev *ljca_gpio =
 268                         container_of(work, struct ljca_gpio_dev, work);
 269         int gpio_id, unmasked;
 270
 271         for_each_set_bit(gpio_id, ljca_gpio->reenable_irqs, ljca_gpio->gc.ngpio) {
 272                 clear_bit(gpio_id, ljca_gpio->reenable_irqs);
 273                 unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
 274                 if (unmasked)
 275                         ljca_enable_irq(ljca_gpio, gpio_id, true);
 276         }
 277 }
 278
 279 static void ljca_gpio_event_cb(void *context, u8 cmd, const void *evt_data,
 280                                int len)
 281 {
 282         const struct ljca_gpio_packet *packet = evt_data;
 283         struct ljca_gpio_dev *ljca_gpio = context;
 284         int i, irq;
 285
 286         if (cmd != LJCA_GPIO_INT_EVENT)
 287                 return;
 288
 289         for (i = 0; i < packet->num; i++) {
 290                 irq = irq_find_mapping(ljca_gpio->gc.irq.domain,
 291                                        packet->item[i].index);
 292                 if (!irq) {
 293                         dev_err(ljca_gpio->gc.parent,
 294                                 "gpio_id %u does not mapped to IRQ yet\n",
 295                                 packet->item[i].index);
 296                         return;
 297                 }
 298
 299                 generic_handle_domain_irq(ljca_gpio->gc.irq.domain, irq);
 300                 set_bit(packet->item[i].index, ljca_gpio->reenable_irqs);
 301         }
 302
 303         schedule_work(&ljca_gpio->work);
 304 }
 305
 306 static void ljca_irq_unmask(struct irq_data *irqd)
 307 {
 308         struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 309         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
 310         int gpio_id = irqd_to_hwirq(irqd);
 311
 312         gpiochip_enable_irq(gc, gpio_id);
 313         set_bit(gpio_id, ljca_gpio->unmasked_irqs);
 314 }
 315
 316 static void ljca_irq_mask(struct irq_data *irqd)
 317 {
 318         struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 319         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
 320         int gpio_id = irqd_to_hwirq(irqd);
 321
 322         clear_bit(gpio_id, ljca_gpio->unmasked_irqs);
 323         gpiochip_disable_irq(gc, gpio_id);
 324 }
 325
 326 static int ljca_irq_set_type(struct irq_data *irqd, unsigned int type)
 327 {
 328         struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 329         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
 330         int gpio_id = irqd_to_hwirq(irqd);
 331
 332         ljca_gpio->connect_mode[gpio_id] = LJCA_GPIO_CONF_INTERRUPT;
 333         switch (type) {
 334         case IRQ_TYPE_LEVEL_HIGH:
 335                 ljca_gpio->connect_mode[gpio_id] |=
 336                         (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLUP);
 337                 break;
 338         case IRQ_TYPE_LEVEL_LOW:
 339                 ljca_gpio->connect_mode[gpio_id] |=
 340                         (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLDOWN);
 341                 break;
 342         case IRQ_TYPE_EDGE_BOTH:
 343                 break;
 344         case IRQ_TYPE_EDGE_RISING:
 345                 ljca_gpio->connect_mode[gpio_id] |=
 346                         (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLUP);
 347                 break;
 348         case IRQ_TYPE_EDGE_FALLING:
 349                 ljca_gpio->connect_mode[gpio_id] |=
 350                         (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLDOWN);
 351                 break;
 352         default:
 353                 return -EINVAL;
 354         }
 355
 356         return 0;
 357 }
 358
 359 static void ljca_irq_bus_lock(struct irq_data *irqd)
 360 {
 361         struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 362         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
 363
 364         mutex_lock(&ljca_gpio->irq_lock);
 365 }
 366
 367 static void ljca_irq_bus_unlock(struct irq_data *irqd)
 368 {
 369         struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
 370         struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc);
 371         int gpio_id = irqd_to_hwirq(irqd);
 372         int enabled, unmasked;
 373
 374         enabled = test_bit(gpio_id, ljca_gpio->enabled_irqs);
 375         unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs);
 376
 377         if (enabled != unmasked) {
 378                 if (unmasked) {
 379                         ljca_gpio_config(ljca_gpio, gpio_id, 0);
 380                         ljca_enable_irq(ljca_gpio, gpio_id, true);
 381                         set_bit(gpio_id, ljca_gpio->enabled_irqs);
 382                 } else {
 383                         ljca_enable_irq(ljca_gpio, gpio_id, false);
 384                         clear_bit(gpio_id, ljca_gpio->enabled_irqs);
 385                 }
 386         }
 387
 388         mutex_unlock(&ljca_gpio->irq_lock);
 389 }
 390
 391 static const struct irq_chip ljca_gpio_irqchip = {
 392         .name = "ljca-irq",
 393         .irq_mask = ljca_irq_mask,
 394         .irq_unmask = ljca_irq_unmask,
 395         .irq_set_type = ljca_irq_set_type,
 396         .irq_bus_lock = ljca_irq_bus_lock,
 397         .irq_bus_sync_unlock = ljca_irq_bus_unlock,
 398         .flags = IRQCHIP_IMMUTABLE,
 399         GPIOCHIP_IRQ_RESOURCE_HELPERS,
 400 };
 401
 402 static int ljca_gpio_probe(struct auxiliary_device *auxdev,
 403                            const struct auxiliary_device_id *aux_dev_id)
 404 {
 405         struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
 406         struct ljca_gpio_dev *ljca_gpio;
 407         struct gpio_irq_chip *girq;
 408         int ret;
 409
 410         ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL);
 411         if (!ljca_gpio)
 412                 return -ENOMEM;
 413
 414         ljca_gpio->ljca = ljca;
 415         ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev);
 416         ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev,
 417                                                ljca_gpio->gpio_info->num,
 418                                                sizeof(*ljca_gpio->connect_mode),
 419                                                GFP_KERNEL);
 420         if (!ljca_gpio->connect_mode)
 421                 return -ENOMEM;
 422
 423         ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock);
 424         if (ret)
 425                 return ret;
 426
 427         ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->trans_lock);
 428         if (ret)
 429                 return ret;
 430
 431         ljca_gpio->gc.direction_input = ljca_gpio_direction_input;
 432         ljca_gpio->gc.direction_output = ljca_gpio_direction_output;
 433         ljca_gpio->gc.get_direction = ljca_gpio_get_direction;
 434         ljca_gpio->gc.get = ljca_gpio_get_value;
 435         ljca_gpio->gc.set = ljca_gpio_set_value;
 436         ljca_gpio->gc.set_config = ljca_gpio_set_config;
 437         ljca_gpio->gc.init_valid_mask = ljca_gpio_init_valid_mask;
 438         ljca_gpio->gc.can_sleep = true;
 439         ljca_gpio->gc.parent = &auxdev->dev;
 440
 441         ljca_gpio->gc.base = -1;
 442         ljca_gpio->gc.ngpio = ljca_gpio->gpio_info->num;
 443         ljca_gpio->gc.label = ACPI_COMPANION(&auxdev->dev) ?
 444                               acpi_dev_name(ACPI_COMPANION(&auxdev->dev)) :
 445                               dev_name(&auxdev->dev);
 446         ljca_gpio->gc.owner = THIS_MODULE;
 447
 448         auxiliary_set_drvdata(auxdev, ljca_gpio);
 449         ljca_register_event_cb(ljca, ljca_gpio_event_cb, ljca_gpio);
 450
 451         girq = &ljca_gpio->gc.irq;
 452         gpio_irq_chip_set_chip(girq, &ljca_gpio_irqchip);
 453         girq->parent_handler = NULL;
 454         girq->num_parents = 0;
 455         girq->parents = NULL;
 456         girq->default_type = IRQ_TYPE_NONE;
 457         girq->handler = handle_simple_irq;
 458         girq->init_valid_mask = ljca_gpio_irq_init_valid_mask;
 459
 460         INIT_WORK(&ljca_gpio->work, ljca_gpio_async);
 461         ret = gpiochip_add_data(&ljca_gpio->gc, ljca_gpio);
 462         if (ret)
 463                 ljca_unregister_event_cb(ljca);
 464
 465         return ret;
 466 }
 467
 468 static void ljca_gpio_remove(struct auxiliary_device *auxdev)
 469 {
 470         struct ljca_gpio_dev *ljca_gpio = auxiliary_get_drvdata(auxdev);
 471
 472         gpiochip_remove(&ljca_gpio->gc);
 473         ljca_unregister_event_cb(ljca_gpio->ljca);
 474         cancel_work_sync(&ljca_gpio->work);
 475 }
 476
 477 static const struct auxiliary_device_id ljca_gpio_id_table[] = {
 478         { "usb_ljca.ljca-gpio", 0 },
 479         { /* sentinel */ },
 480 };
 481 MODULE_DEVICE_TABLE(auxiliary, ljca_gpio_id_table);
 482
 483 static struct auxiliary_driver ljca_gpio_driver = {
 484         .probe = ljca_gpio_probe,
 485         .remove = ljca_gpio_remove,
 486         .id_table = ljca_gpio_id_table,
 487 };
 488 module_auxiliary_driver(ljca_gpio_driver);
 489
 490 MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
 491 MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
 492 MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>");
 493 MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-GPIO driver");
 494 MODULE_LICENSE("GPL");
 495 MODULE_IMPORT_NS("LJCA");