1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for the Diolan DLN-2 USB-GPIO adapter 4 * 5 * Copyright (c) 2014 Intel Corporation 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/slab.h> 11 #include <linux/types.h> 12 #include <linux/irqdomain.h> 13 #include <linux/irq.h> 14 #include <linux/irqchip/chained_irq.h> 15 #include <linux/gpio/driver.h> 16 #include <linux/platform_device.h> 17 #include <linux/mfd/dln2.h> 18 19 #define DLN2_GPIO_ID 0x01 20 21 #define DLN2_GPIO_GET_PIN_COUNT DLN2_CMD(0x01, DLN2_GPIO_ID) 22 #define DLN2_GPIO_SET_DEBOUNCE DLN2_CMD(0x04, DLN2_GPIO_ID) 23 #define DLN2_GPIO_GET_DEBOUNCE DLN2_CMD(0x05, DLN2_GPIO_ID) 24 #define DLN2_GPIO_PORT_GET_VAL DLN2_CMD(0x06, DLN2_GPIO_ID) 25 #define DLN2_GPIO_PIN_GET_VAL DLN2_CMD(0x0B, DLN2_GPIO_ID) 26 #define DLN2_GPIO_PIN_SET_OUT_VAL DLN2_CMD(0x0C, DLN2_GPIO_ID) 27 #define DLN2_GPIO_PIN_GET_OUT_VAL DLN2_CMD(0x0D, DLN2_GPIO_ID) 28 #define DLN2_GPIO_CONDITION_MET_EV DLN2_CMD(0x0F, DLN2_GPIO_ID) 29 #define DLN2_GPIO_PIN_ENABLE DLN2_CMD(0x10, DLN2_GPIO_ID) 30 #define DLN2_GPIO_PIN_DISABLE DLN2_CMD(0x11, DLN2_GPIO_ID) 31 #define DLN2_GPIO_PIN_SET_DIRECTION DLN2_CMD(0x13, DLN2_GPIO_ID) 32 #define DLN2_GPIO_PIN_GET_DIRECTION DLN2_CMD(0x14, DLN2_GPIO_ID) 33 #define DLN2_GPIO_PIN_SET_EVENT_CFG DLN2_CMD(0x1E, DLN2_GPIO_ID) 34 #define DLN2_GPIO_PIN_GET_EVENT_CFG DLN2_CMD(0x1F, DLN2_GPIO_ID) 35 36 #define DLN2_GPIO_EVENT_NONE 0 37 #define DLN2_GPIO_EVENT_CHANGE 1 38 #define DLN2_GPIO_EVENT_LVL_HIGH 2 39 #define DLN2_GPIO_EVENT_LVL_LOW 3 40 #define DLN2_GPIO_EVENT_CHANGE_RISING 0x11 41 #define DLN2_GPIO_EVENT_CHANGE_FALLING 0x21 42 #define DLN2_GPIO_EVENT_MASK 0x0F 43 44 #define DLN2_GPIO_MAX_PINS 32 45 46 struct dln2_gpio { 47 struct platform_device *pdev; 48 struct gpio_chip gpio; 49 50 /* 51 * Cache pin direction to save us one transfer, since the hardware has 52 * separate commands to read the in and out values. 53 */ 54 DECLARE_BITMAP(output_enabled, DLN2_GPIO_MAX_PINS); 55 56 /* active IRQs - not synced to hardware */ 57 DECLARE_BITMAP(unmasked_irqs, DLN2_GPIO_MAX_PINS); 58 /* active IRQS - synced to hardware */ 59 DECLARE_BITMAP(enabled_irqs, DLN2_GPIO_MAX_PINS); 60 int irq_type[DLN2_GPIO_MAX_PINS]; 61 struct mutex irq_lock; 62 }; 63 64 struct dln2_gpio_pin { 65 __le16 pin; 66 }; 67 68 struct dln2_gpio_pin_val { 69 __le16 pin __packed; 70 u8 value; 71 }; 72 73 static int dln2_gpio_get_pin_count(struct platform_device *pdev) 74 { 75 int ret; 76 __le16 count; 77 int len = sizeof(count); 78 79 ret = dln2_transfer_rx(pdev, DLN2_GPIO_GET_PIN_COUNT, &count, &len); 80 if (ret < 0) 81 return ret; 82 if (len < sizeof(count)) 83 return -EPROTO; 84 85 return le16_to_cpu(count); 86 } 87 88 static int dln2_gpio_pin_cmd(struct dln2_gpio *dln2, int cmd, unsigned pin) 89 { 90 struct dln2_gpio_pin req = { 91 .pin = cpu_to_le16(pin), 92 }; 93 94 return dln2_transfer_tx(dln2->pdev, cmd, &req, sizeof(req)); 95 } 96 97 static int dln2_gpio_pin_val(struct dln2_gpio *dln2, int cmd, unsigned int pin) 98 { 99 int ret; 100 struct dln2_gpio_pin req = { 101 .pin = cpu_to_le16(pin), 102 }; 103 struct dln2_gpio_pin_val rsp; 104 int len = sizeof(rsp); 105 106 ret = dln2_transfer(dln2->pdev, cmd, &req, sizeof(req), &rsp, &len); 107 if (ret < 0) 108 return ret; 109 if (len < sizeof(rsp) || req.pin != rsp.pin) 110 return -EPROTO; 111 112 return rsp.value; 113 } 114 115 static int dln2_gpio_pin_get_in_val(struct dln2_gpio *dln2, unsigned int pin) 116 { 117 int ret; 118 119 ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_VAL, pin); 120 if (ret < 0) 121 return ret; 122 return !!ret; 123 } 124 125 static int dln2_gpio_pin_get_out_val(struct dln2_gpio *dln2, unsigned int pin) 126 { 127 int ret; 128 129 ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_OUT_VAL, pin); 130 if (ret < 0) 131 return ret; 132 return !!ret; 133 } 134 135 static int dln2_gpio_pin_set_out_val(struct dln2_gpio *dln2, 136 unsigned int pin, int value) 137 { 138 struct dln2_gpio_pin_val req = { 139 .pin = cpu_to_le16(pin), 140 .value = value, 141 }; 142 143 return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_OUT_VAL, &req, 144 sizeof(req)); 145 } 146 147 #define DLN2_GPIO_DIRECTION_IN 0 148 #define DLN2_GPIO_DIRECTION_OUT 1 149 150 static int dln2_gpio_request(struct gpio_chip *chip, unsigned offset) 151 { 152 struct dln2_gpio *dln2 = gpiochip_get_data(chip); 153 struct dln2_gpio_pin req = { 154 .pin = cpu_to_le16(offset), 155 }; 156 struct dln2_gpio_pin_val rsp; 157 int len = sizeof(rsp); 158 int ret; 159 160 ret = dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_ENABLE, offset); 161 if (ret < 0) 162 return ret; 163 164 /* cache the pin direction */ 165 ret = dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_GET_DIRECTION, 166 &req, sizeof(req), &rsp, &len); 167 if (ret < 0) 168 return ret; 169 if (len < sizeof(rsp) || req.pin != rsp.pin) { 170 ret = -EPROTO; 171 goto out_disable; 172 } 173 174 switch (rsp.value) { 175 case DLN2_GPIO_DIRECTION_IN: 176 clear_bit(offset, dln2->output_enabled); 177 return 0; 178 case DLN2_GPIO_DIRECTION_OUT: 179 set_bit(offset, dln2->output_enabled); 180 return 0; 181 default: 182 ret = -EPROTO; 183 goto out_disable; 184 } 185 186 out_disable: 187 dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset); 188 return ret; 189 } 190 191 static void dln2_gpio_free(struct gpio_chip *chip, unsigned offset) 192 { 193 struct dln2_gpio *dln2 = gpiochip_get_data(chip); 194 195 dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset); 196 } 197 198 static int dln2_gpio_get_direction(struct gpio_chip *chip, unsigned offset) 199 { 200 struct dln2_gpio *dln2 = gpiochip_get_data(chip); 201 202 if (test_bit(offset, dln2->output_enabled)) 203 return GPIO_LINE_DIRECTION_OUT; 204 205 return GPIO_LINE_DIRECTION_IN; 206 } 207 208 static int dln2_gpio_get(struct gpio_chip *chip, unsigned int offset) 209 { 210 struct dln2_gpio *dln2 = gpiochip_get_data(chip); 211 int dir; 212 213 dir = dln2_gpio_get_direction(chip, offset); 214 if (dir < 0) 215 return dir; 216 217 if (dir == GPIO_LINE_DIRECTION_IN) 218 return dln2_gpio_pin_get_in_val(dln2, offset); 219 220 return dln2_gpio_pin_get_out_val(dln2, offset); 221 } 222 223 static void dln2_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 224 { 225 struct dln2_gpio *dln2 = gpiochip_get_data(chip); 226 227 dln2_gpio_pin_set_out_val(dln2, offset, value); 228 } 229 230 static int dln2_gpio_set_direction(struct gpio_chip *chip, unsigned offset, 231 unsigned dir) 232 { 233 struct dln2_gpio *dln2 = gpiochip_get_data(chip); 234 struct dln2_gpio_pin_val req = { 235 .pin = cpu_to_le16(offset), 236 .value = dir, 237 }; 238 int ret; 239 240 ret = dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_DIRECTION, 241 &req, sizeof(req)); 242 if (ret < 0) 243 return ret; 244 245 if (dir == DLN2_GPIO_DIRECTION_OUT) 246 set_bit(offset, dln2->output_enabled); 247 else 248 clear_bit(offset, dln2->output_enabled); 249 250 return ret; 251 } 252 253 static int dln2_gpio_direction_input(struct gpio_chip *chip, unsigned offset) 254 { 255 return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_IN); 256 } 257 258 static int dln2_gpio_direction_output(struct gpio_chip *chip, unsigned offset, 259 int value) 260 { 261 struct dln2_gpio *dln2 = gpiochip_get_data(chip); 262 int ret; 263 264 ret = dln2_gpio_pin_set_out_val(dln2, offset, value); 265 if (ret < 0) 266 return ret; 267 268 return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_OUT); 269 } 270 271 static int dln2_gpio_set_config(struct gpio_chip *chip, unsigned offset, 272 unsigned long config) 273 { 274 struct dln2_gpio *dln2 = gpiochip_get_data(chip); 275 __le32 duration; 276 277 if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE) 278 return -ENOTSUPP; 279 280 duration = cpu_to_le32(pinconf_to_config_argument(config)); 281 return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_SET_DEBOUNCE, 282 &duration, sizeof(duration)); 283 } 284 285 static int dln2_gpio_set_event_cfg(struct dln2_gpio *dln2, unsigned pin, 286 unsigned type, unsigned period) 287 { 288 struct { 289 __le16 pin; 290 u8 type; 291 __le16 period; 292 } __packed req = { 293 .pin = cpu_to_le16(pin), 294 .type = type, 295 .period = cpu_to_le16(period), 296 }; 297 298 return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_EVENT_CFG, 299 &req, sizeof(req)); 300 } 301 302 static void dln2_irq_unmask(struct irq_data *irqd) 303 { 304 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 305 struct dln2_gpio *dln2 = gpiochip_get_data(gc); 306 int pin = irqd_to_hwirq(irqd); 307 308 gpiochip_enable_irq(gc, pin); 309 set_bit(pin, dln2->unmasked_irqs); 310 } 311 312 static void dln2_irq_mask(struct irq_data *irqd) 313 { 314 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 315 struct dln2_gpio *dln2 = gpiochip_get_data(gc); 316 int pin = irqd_to_hwirq(irqd); 317 318 clear_bit(pin, dln2->unmasked_irqs); 319 gpiochip_disable_irq(gc, pin); 320 } 321 322 static int dln2_irq_set_type(struct irq_data *irqd, unsigned type) 323 { 324 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 325 struct dln2_gpio *dln2 = gpiochip_get_data(gc); 326 int pin = irqd_to_hwirq(irqd); 327 328 switch (type) { 329 case IRQ_TYPE_LEVEL_HIGH: 330 dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_HIGH; 331 break; 332 case IRQ_TYPE_LEVEL_LOW: 333 dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_LOW; 334 break; 335 case IRQ_TYPE_EDGE_BOTH: 336 dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE; 337 break; 338 case IRQ_TYPE_EDGE_RISING: 339 dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_RISING; 340 break; 341 case IRQ_TYPE_EDGE_FALLING: 342 dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_FALLING; 343 break; 344 default: 345 return -EINVAL; 346 } 347 348 return 0; 349 } 350 351 static void dln2_irq_bus_lock(struct irq_data *irqd) 352 { 353 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 354 struct dln2_gpio *dln2 = gpiochip_get_data(gc); 355 356 mutex_lock(&dln2->irq_lock); 357 } 358 359 static void dln2_irq_bus_unlock(struct irq_data *irqd) 360 { 361 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 362 struct dln2_gpio *dln2 = gpiochip_get_data(gc); 363 int pin = irqd_to_hwirq(irqd); 364 int enabled, unmasked; 365 unsigned type; 366 int ret; 367 368 enabled = test_bit(pin, dln2->enabled_irqs); 369 unmasked = test_bit(pin, dln2->unmasked_irqs); 370 371 if (enabled != unmasked) { 372 if (unmasked) { 373 type = dln2->irq_type[pin] & DLN2_GPIO_EVENT_MASK; 374 set_bit(pin, dln2->enabled_irqs); 375 } else { 376 type = DLN2_GPIO_EVENT_NONE; 377 clear_bit(pin, dln2->enabled_irqs); 378 } 379 380 ret = dln2_gpio_set_event_cfg(dln2, pin, type, 0); 381 if (ret) 382 dev_err(dln2->gpio.parent, "failed to set event\n"); 383 } 384 385 mutex_unlock(&dln2->irq_lock); 386 } 387 388 static const struct irq_chip dln2_irqchip = { 389 .name = "dln2-irq", 390 .irq_mask = dln2_irq_mask, 391 .irq_unmask = dln2_irq_unmask, 392 .irq_set_type = dln2_irq_set_type, 393 .irq_bus_lock = dln2_irq_bus_lock, 394 .irq_bus_sync_unlock = dln2_irq_bus_unlock, 395 .flags = IRQCHIP_IMMUTABLE, 396 GPIOCHIP_IRQ_RESOURCE_HELPERS, 397 }; 398 399 static void dln2_gpio_event(struct platform_device *pdev, u16 echo, 400 const void *data, int len) 401 { 402 int pin, ret; 403 404 const struct { 405 __le16 count; 406 __u8 type; 407 __le16 pin; 408 __u8 value; 409 } __packed *event = data; 410 struct dln2_gpio *dln2 = platform_get_drvdata(pdev); 411 412 if (len < sizeof(*event)) { 413 dev_err(dln2->gpio.parent, "short event message\n"); 414 return; 415 } 416 417 pin = le16_to_cpu(event->pin); 418 if (pin >= dln2->gpio.ngpio) { 419 dev_err(dln2->gpio.parent, "out of bounds pin %d\n", pin); 420 return; 421 } 422 423 switch (dln2->irq_type[pin]) { 424 case DLN2_GPIO_EVENT_CHANGE_RISING: 425 if (!event->value) 426 return; 427 break; 428 case DLN2_GPIO_EVENT_CHANGE_FALLING: 429 if (event->value) 430 return; 431 break; 432 } 433 434 ret = generic_handle_domain_irq(dln2->gpio.irq.domain, pin); 435 if (unlikely(ret)) 436 dev_err(dln2->gpio.parent, "pin %d not mapped to IRQ\n", pin); 437 } 438 439 static int dln2_gpio_probe(struct platform_device *pdev) 440 { 441 struct dln2_gpio *dln2; 442 struct device *dev = &pdev->dev; 443 struct gpio_irq_chip *girq; 444 int pins; 445 int ret; 446 447 pins = dln2_gpio_get_pin_count(pdev); 448 if (pins < 0) { 449 dev_err(dev, "failed to get pin count: %d\n", pins); 450 return pins; 451 } 452 if (pins > DLN2_GPIO_MAX_PINS) { 453 pins = DLN2_GPIO_MAX_PINS; 454 dev_warn(dev, "clamping pins to %d\n", DLN2_GPIO_MAX_PINS); 455 } 456 457 dln2 = devm_kzalloc(&pdev->dev, sizeof(*dln2), GFP_KERNEL); 458 if (!dln2) 459 return -ENOMEM; 460 461 mutex_init(&dln2->irq_lock); 462 463 dln2->pdev = pdev; 464 465 dln2->gpio.label = "dln2"; 466 dln2->gpio.parent = dev; 467 dln2->gpio.owner = THIS_MODULE; 468 dln2->gpio.base = -1; 469 dln2->gpio.ngpio = pins; 470 dln2->gpio.can_sleep = true; 471 dln2->gpio.set = dln2_gpio_set; 472 dln2->gpio.get = dln2_gpio_get; 473 dln2->gpio.request = dln2_gpio_request; 474 dln2->gpio.free = dln2_gpio_free; 475 dln2->gpio.get_direction = dln2_gpio_get_direction; 476 dln2->gpio.direction_input = dln2_gpio_direction_input; 477 dln2->gpio.direction_output = dln2_gpio_direction_output; 478 dln2->gpio.set_config = dln2_gpio_set_config; 479 480 girq = &dln2->gpio.irq; 481 gpio_irq_chip_set_chip(girq, &dln2_irqchip); 482 /* The event comes from the outside so no parent handler */ 483 girq->parent_handler = NULL; 484 girq->num_parents = 0; 485 girq->parents = NULL; 486 girq->default_type = IRQ_TYPE_NONE; 487 girq->handler = handle_simple_irq; 488 489 platform_set_drvdata(pdev, dln2); 490 491 ret = devm_gpiochip_add_data(dev, &dln2->gpio, dln2); 492 if (ret < 0) { 493 dev_err(dev, "failed to add gpio chip: %d\n", ret); 494 return ret; 495 } 496 497 ret = dln2_register_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV, 498 dln2_gpio_event); 499 if (ret) { 500 dev_err(dev, "failed to register event cb: %d\n", ret); 501 return ret; 502 } 503 504 return 0; 505 } 506 507 static int dln2_gpio_remove(struct platform_device *pdev) 508 { 509 dln2_unregister_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV); 510 511 return 0; 512 } 513 514 static struct platform_driver dln2_gpio_driver = { 515 .driver.name = "dln2-gpio", 516 .probe = dln2_gpio_probe, 517 .remove = dln2_gpio_remove, 518 }; 519 520 module_platform_driver(dln2_gpio_driver); 521 522 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com"); 523 MODULE_DESCRIPTION("Driver for the Diolan DLN2 GPIO interface"); 524 MODULE_LICENSE("GPL v2"); 525 MODULE_ALIAS("platform:dln2-gpio"); 526