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->num = 1; 86 packet->item[0].index = gpio_id; 87 packet->item[0].value = config | ljca_gpio->connect_mode[gpio_id]; 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 int 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 return ret; 160 } 161 162 static int ljca_gpio_direction_input(struct gpio_chip *chip, unsigned int offset) 163 { 164 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip); 165 u8 config = LJCA_GPIO_CONF_INPUT | LJCA_GPIO_CONF_CLR; 166 int ret; 167 168 ret = ljca_gpio_config(ljca_gpio, offset, config); 169 if (ret) 170 return ret; 171 172 clear_bit(offset, ljca_gpio->output_enabled); 173 174 return 0; 175 } 176 177 static int ljca_gpio_direction_output(struct gpio_chip *chip, 178 unsigned int offset, int val) 179 { 180 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip); 181 u8 config = LJCA_GPIO_CONF_OUTPUT | LJCA_GPIO_CONF_CLR; 182 int ret; 183 184 ret = ljca_gpio_config(ljca_gpio, offset, config); 185 if (ret) 186 return ret; 187 188 ret = ljca_gpio_set_value(chip, offset, val); 189 if (ret) 190 return ret; 191 192 set_bit(offset, ljca_gpio->output_enabled); 193 194 return 0; 195 } 196 197 static int ljca_gpio_get_direction(struct gpio_chip *chip, unsigned int offset) 198 { 199 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip); 200 201 if (test_bit(offset, ljca_gpio->output_enabled)) 202 return GPIO_LINE_DIRECTION_OUT; 203 204 return GPIO_LINE_DIRECTION_IN; 205 } 206 207 static int ljca_gpio_set_config(struct gpio_chip *chip, unsigned int offset, 208 unsigned long config) 209 { 210 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip); 211 212 ljca_gpio->connect_mode[offset] = 0; 213 switch (pinconf_to_config_param(config)) { 214 case PIN_CONFIG_BIAS_PULL_UP: 215 ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLUP; 216 break; 217 case PIN_CONFIG_BIAS_PULL_DOWN: 218 ljca_gpio->connect_mode[offset] |= LJCA_GPIO_CONF_PULLDOWN; 219 break; 220 case PIN_CONFIG_DRIVE_PUSH_PULL: 221 case PIN_CONFIG_PERSIST_STATE: 222 break; 223 default: 224 return -ENOTSUPP; 225 } 226 227 return 0; 228 } 229 230 static int ljca_gpio_init_valid_mask(struct gpio_chip *chip, 231 unsigned long *valid_mask, 232 unsigned int ngpios) 233 { 234 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(chip); 235 236 WARN_ON_ONCE(ngpios != ljca_gpio->gpio_info->num); 237 bitmap_copy(valid_mask, ljca_gpio->gpio_info->valid_pin_map, ngpios); 238 239 return 0; 240 } 241 242 static void ljca_gpio_irq_init_valid_mask(struct gpio_chip *chip, 243 unsigned long *valid_mask, 244 unsigned int ngpios) 245 { 246 ljca_gpio_init_valid_mask(chip, valid_mask, ngpios); 247 } 248 249 static int ljca_enable_irq(struct ljca_gpio_dev *ljca_gpio, int gpio_id, 250 bool enable) 251 { 252 struct ljca_gpio_packet *packet = 253 (struct ljca_gpio_packet *)ljca_gpio->obuf; 254 int ret; 255 256 mutex_lock(&ljca_gpio->trans_lock); 257 packet->num = 1; 258 packet->item[0].index = gpio_id; 259 packet->item[0].value = 0; 260 261 ret = ljca_transfer(ljca_gpio->ljca, 262 enable ? LJCA_GPIO_INT_UNMASK : LJCA_GPIO_INT_MASK, 263 (u8 *)packet, struct_size(packet, item, packet->num), 264 NULL, 0); 265 mutex_unlock(&ljca_gpio->trans_lock); 266 267 return ret < 0 ? ret : 0; 268 } 269 270 static void ljca_gpio_async(struct work_struct *work) 271 { 272 struct ljca_gpio_dev *ljca_gpio = 273 container_of(work, struct ljca_gpio_dev, work); 274 int gpio_id, unmasked; 275 276 for_each_set_bit(gpio_id, ljca_gpio->reenable_irqs, ljca_gpio->gc.ngpio) { 277 clear_bit(gpio_id, ljca_gpio->reenable_irqs); 278 unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs); 279 if (unmasked) 280 ljca_enable_irq(ljca_gpio, gpio_id, true); 281 } 282 } 283 284 static void ljca_gpio_event_cb(void *context, u8 cmd, const void *evt_data, 285 int len) 286 { 287 const struct ljca_gpio_packet *packet = evt_data; 288 struct ljca_gpio_dev *ljca_gpio = context; 289 int i, irq; 290 291 if (cmd != LJCA_GPIO_INT_EVENT) 292 return; 293 294 for (i = 0; i < packet->num; i++) { 295 irq = irq_find_mapping(ljca_gpio->gc.irq.domain, 296 packet->item[i].index); 297 if (!irq) { 298 dev_err(ljca_gpio->gc.parent, 299 "gpio_id %u does not mapped to IRQ yet\n", 300 packet->item[i].index); 301 return; 302 } 303 304 generic_handle_domain_irq(ljca_gpio->gc.irq.domain, irq); 305 set_bit(packet->item[i].index, ljca_gpio->reenable_irqs); 306 } 307 308 schedule_work(&ljca_gpio->work); 309 } 310 311 static void ljca_irq_unmask(struct irq_data *irqd) 312 { 313 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 314 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc); 315 int gpio_id = irqd_to_hwirq(irqd); 316 317 gpiochip_enable_irq(gc, gpio_id); 318 set_bit(gpio_id, ljca_gpio->unmasked_irqs); 319 } 320 321 static void ljca_irq_mask(struct irq_data *irqd) 322 { 323 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 324 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc); 325 int gpio_id = irqd_to_hwirq(irqd); 326 327 clear_bit(gpio_id, ljca_gpio->unmasked_irqs); 328 gpiochip_disable_irq(gc, gpio_id); 329 } 330 331 static int ljca_irq_set_type(struct irq_data *irqd, unsigned int type) 332 { 333 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 334 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc); 335 int gpio_id = irqd_to_hwirq(irqd); 336 337 ljca_gpio->connect_mode[gpio_id] = LJCA_GPIO_CONF_INTERRUPT; 338 switch (type) { 339 case IRQ_TYPE_LEVEL_HIGH: 340 ljca_gpio->connect_mode[gpio_id] |= 341 (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLUP); 342 break; 343 case IRQ_TYPE_LEVEL_LOW: 344 ljca_gpio->connect_mode[gpio_id] |= 345 (LJCA_GPIO_CONF_LEVEL | LJCA_GPIO_CONF_PULLDOWN); 346 break; 347 case IRQ_TYPE_EDGE_BOTH: 348 break; 349 case IRQ_TYPE_EDGE_RISING: 350 ljca_gpio->connect_mode[gpio_id] |= 351 (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLUP); 352 break; 353 case IRQ_TYPE_EDGE_FALLING: 354 ljca_gpio->connect_mode[gpio_id] |= 355 (LJCA_GPIO_CONF_EDGE | LJCA_GPIO_CONF_PULLDOWN); 356 break; 357 default: 358 return -EINVAL; 359 } 360 361 return 0; 362 } 363 364 static void ljca_irq_bus_lock(struct irq_data *irqd) 365 { 366 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 367 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc); 368 369 mutex_lock(&ljca_gpio->irq_lock); 370 } 371 372 static void ljca_irq_bus_unlock(struct irq_data *irqd) 373 { 374 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 375 struct ljca_gpio_dev *ljca_gpio = gpiochip_get_data(gc); 376 int gpio_id = irqd_to_hwirq(irqd); 377 int enabled, unmasked; 378 379 enabled = test_bit(gpio_id, ljca_gpio->enabled_irqs); 380 unmasked = test_bit(gpio_id, ljca_gpio->unmasked_irqs); 381 382 if (enabled != unmasked) { 383 if (unmasked) { 384 ljca_gpio_config(ljca_gpio, gpio_id, 0); 385 ljca_enable_irq(ljca_gpio, gpio_id, true); 386 set_bit(gpio_id, ljca_gpio->enabled_irqs); 387 } else { 388 ljca_enable_irq(ljca_gpio, gpio_id, false); 389 clear_bit(gpio_id, ljca_gpio->enabled_irqs); 390 } 391 } 392 393 mutex_unlock(&ljca_gpio->irq_lock); 394 } 395 396 static const struct irq_chip ljca_gpio_irqchip = { 397 .name = "ljca-irq", 398 .irq_mask = ljca_irq_mask, 399 .irq_unmask = ljca_irq_unmask, 400 .irq_set_type = ljca_irq_set_type, 401 .irq_bus_lock = ljca_irq_bus_lock, 402 .irq_bus_sync_unlock = ljca_irq_bus_unlock, 403 .flags = IRQCHIP_IMMUTABLE, 404 GPIOCHIP_IRQ_RESOURCE_HELPERS, 405 }; 406 407 static int ljca_gpio_probe(struct auxiliary_device *auxdev, 408 const struct auxiliary_device_id *aux_dev_id) 409 { 410 struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev); 411 struct ljca_gpio_dev *ljca_gpio; 412 struct gpio_irq_chip *girq; 413 int ret; 414 415 ljca_gpio = devm_kzalloc(&auxdev->dev, sizeof(*ljca_gpio), GFP_KERNEL); 416 if (!ljca_gpio) 417 return -ENOMEM; 418 419 ljca_gpio->ljca = ljca; 420 ljca_gpio->gpio_info = dev_get_platdata(&auxdev->dev); 421 ljca_gpio->connect_mode = devm_kcalloc(&auxdev->dev, 422 ljca_gpio->gpio_info->num, 423 sizeof(*ljca_gpio->connect_mode), 424 GFP_KERNEL); 425 if (!ljca_gpio->connect_mode) 426 return -ENOMEM; 427 428 ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->irq_lock); 429 if (ret) 430 return ret; 431 432 ret = devm_mutex_init(&auxdev->dev, &ljca_gpio->trans_lock); 433 if (ret) 434 return ret; 435 436 ljca_gpio->gc.direction_input = ljca_gpio_direction_input; 437 ljca_gpio->gc.direction_output = ljca_gpio_direction_output; 438 ljca_gpio->gc.get_direction = ljca_gpio_get_direction; 439 ljca_gpio->gc.get = ljca_gpio_get_value; 440 ljca_gpio->gc.set = ljca_gpio_set_value; 441 ljca_gpio->gc.set_config = ljca_gpio_set_config; 442 ljca_gpio->gc.init_valid_mask = ljca_gpio_init_valid_mask; 443 ljca_gpio->gc.can_sleep = true; 444 ljca_gpio->gc.parent = &auxdev->dev; 445 446 ljca_gpio->gc.base = -1; 447 ljca_gpio->gc.ngpio = ljca_gpio->gpio_info->num; 448 ljca_gpio->gc.label = ACPI_COMPANION(&auxdev->dev) ? 449 acpi_dev_name(ACPI_COMPANION(&auxdev->dev)) : 450 dev_name(&auxdev->dev); 451 ljca_gpio->gc.owner = THIS_MODULE; 452 453 auxiliary_set_drvdata(auxdev, ljca_gpio); 454 ljca_register_event_cb(ljca, ljca_gpio_event_cb, ljca_gpio); 455 456 girq = &ljca_gpio->gc.irq; 457 gpio_irq_chip_set_chip(girq, &ljca_gpio_irqchip); 458 girq->parent_handler = NULL; 459 girq->num_parents = 0; 460 girq->parents = NULL; 461 girq->default_type = IRQ_TYPE_NONE; 462 girq->handler = handle_simple_irq; 463 girq->init_valid_mask = ljca_gpio_irq_init_valid_mask; 464 465 INIT_WORK(&ljca_gpio->work, ljca_gpio_async); 466 ret = gpiochip_add_data(&ljca_gpio->gc, ljca_gpio); 467 if (ret) 468 ljca_unregister_event_cb(ljca); 469 470 return ret; 471 } 472 473 static void ljca_gpio_remove(struct auxiliary_device *auxdev) 474 { 475 struct ljca_gpio_dev *ljca_gpio = auxiliary_get_drvdata(auxdev); 476 477 gpiochip_remove(&ljca_gpio->gc); 478 ljca_unregister_event_cb(ljca_gpio->ljca); 479 cancel_work_sync(&ljca_gpio->work); 480 } 481 482 static const struct auxiliary_device_id ljca_gpio_id_table[] = { 483 { "usb_ljca.ljca-gpio", 0 }, 484 { /* sentinel */ }, 485 }; 486 MODULE_DEVICE_TABLE(auxiliary, ljca_gpio_id_table); 487 488 static struct auxiliary_driver ljca_gpio_driver = { 489 .probe = ljca_gpio_probe, 490 .remove = ljca_gpio_remove, 491 .id_table = ljca_gpio_id_table, 492 }; 493 module_auxiliary_driver(ljca_gpio_driver); 494 495 MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>"); 496 MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>"); 497 MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>"); 498 MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-GPIO driver"); 499 MODULE_LICENSE("GPL"); 500 MODULE_IMPORT_NS("LJCA"); 501