1 /* 2 * Driver for the Diolan DLN-2 USB-GPIO adapter 3 * 4 * Copyright (c) 2014 Intel Corporation 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation, version 2. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <linux/types.h> 15 #include <linux/irqdomain.h> 16 #include <linux/irq.h> 17 #include <linux/irqchip/chained_irq.h> 18 #include <linux/gpio.h> 19 #include <linux/gpio/driver.h> 20 #include <linux/platform_device.h> 21 #include <linux/mfd/dln2.h> 22 23 #define DLN2_GPIO_ID 0x01 24 25 #define DLN2_GPIO_GET_PIN_COUNT DLN2_CMD(0x01, DLN2_GPIO_ID) 26 #define DLN2_GPIO_SET_DEBOUNCE DLN2_CMD(0x04, DLN2_GPIO_ID) 27 #define DLN2_GPIO_GET_DEBOUNCE DLN2_CMD(0x05, DLN2_GPIO_ID) 28 #define DLN2_GPIO_PORT_GET_VAL DLN2_CMD(0x06, DLN2_GPIO_ID) 29 #define DLN2_GPIO_PIN_GET_VAL DLN2_CMD(0x0B, DLN2_GPIO_ID) 30 #define DLN2_GPIO_PIN_SET_OUT_VAL DLN2_CMD(0x0C, DLN2_GPIO_ID) 31 #define DLN2_GPIO_PIN_GET_OUT_VAL DLN2_CMD(0x0D, DLN2_GPIO_ID) 32 #define DLN2_GPIO_CONDITION_MET_EV DLN2_CMD(0x0F, DLN2_GPIO_ID) 33 #define DLN2_GPIO_PIN_ENABLE DLN2_CMD(0x10, DLN2_GPIO_ID) 34 #define DLN2_GPIO_PIN_DISABLE DLN2_CMD(0x11, DLN2_GPIO_ID) 35 #define DLN2_GPIO_PIN_SET_DIRECTION DLN2_CMD(0x13, DLN2_GPIO_ID) 36 #define DLN2_GPIO_PIN_GET_DIRECTION DLN2_CMD(0x14, DLN2_GPIO_ID) 37 #define DLN2_GPIO_PIN_SET_EVENT_CFG DLN2_CMD(0x1E, DLN2_GPIO_ID) 38 #define DLN2_GPIO_PIN_GET_EVENT_CFG DLN2_CMD(0x1F, DLN2_GPIO_ID) 39 40 #define DLN2_GPIO_EVENT_NONE 0 41 #define DLN2_GPIO_EVENT_CHANGE 1 42 #define DLN2_GPIO_EVENT_LVL_HIGH 2 43 #define DLN2_GPIO_EVENT_LVL_LOW 3 44 #define DLN2_GPIO_EVENT_CHANGE_RISING 0x11 45 #define DLN2_GPIO_EVENT_CHANGE_FALLING 0x21 46 #define DLN2_GPIO_EVENT_MASK 0x0F 47 48 #define DLN2_GPIO_MAX_PINS 32 49 50 struct dln2_gpio { 51 struct platform_device *pdev; 52 struct gpio_chip gpio; 53 54 /* 55 * Cache pin direction to save us one transfer, since the hardware has 56 * separate commands to read the in and out values. 57 */ 58 DECLARE_BITMAP(output_enabled, DLN2_GPIO_MAX_PINS); 59 60 /* active IRQs - not synced to hardware */ 61 DECLARE_BITMAP(unmasked_irqs, DLN2_GPIO_MAX_PINS); 62 /* active IRQS - synced to hardware */ 63 DECLARE_BITMAP(enabled_irqs, DLN2_GPIO_MAX_PINS); 64 int irq_type[DLN2_GPIO_MAX_PINS]; 65 struct mutex irq_lock; 66 }; 67 68 struct dln2_gpio_pin { 69 __le16 pin; 70 }; 71 72 struct dln2_gpio_pin_val { 73 __le16 pin __packed; 74 u8 value; 75 }; 76 77 static int dln2_gpio_get_pin_count(struct platform_device *pdev) 78 { 79 int ret; 80 __le16 count; 81 int len = sizeof(count); 82 83 ret = dln2_transfer_rx(pdev, DLN2_GPIO_GET_PIN_COUNT, &count, &len); 84 if (ret < 0) 85 return ret; 86 if (len < sizeof(count)) 87 return -EPROTO; 88 89 return le16_to_cpu(count); 90 } 91 92 static int dln2_gpio_pin_cmd(struct dln2_gpio *dln2, int cmd, unsigned pin) 93 { 94 struct dln2_gpio_pin req = { 95 .pin = cpu_to_le16(pin), 96 }; 97 98 return dln2_transfer_tx(dln2->pdev, cmd, &req, sizeof(req)); 99 } 100 101 static int dln2_gpio_pin_val(struct dln2_gpio *dln2, int cmd, unsigned int pin) 102 { 103 int ret; 104 struct dln2_gpio_pin req = { 105 .pin = cpu_to_le16(pin), 106 }; 107 struct dln2_gpio_pin_val rsp; 108 int len = sizeof(rsp); 109 110 ret = dln2_transfer(dln2->pdev, cmd, &req, sizeof(req), &rsp, &len); 111 if (ret < 0) 112 return ret; 113 if (len < sizeof(rsp) || req.pin != rsp.pin) 114 return -EPROTO; 115 116 return rsp.value; 117 } 118 119 static int dln2_gpio_pin_get_in_val(struct dln2_gpio *dln2, unsigned int pin) 120 { 121 int ret; 122 123 ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_VAL, pin); 124 if (ret < 0) 125 return ret; 126 return !!ret; 127 } 128 129 static int dln2_gpio_pin_get_out_val(struct dln2_gpio *dln2, unsigned int pin) 130 { 131 int ret; 132 133 ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_OUT_VAL, pin); 134 if (ret < 0) 135 return ret; 136 return !!ret; 137 } 138 139 static int dln2_gpio_pin_set_out_val(struct dln2_gpio *dln2, 140 unsigned int pin, int value) 141 { 142 struct dln2_gpio_pin_val req = { 143 .pin = cpu_to_le16(pin), 144 .value = value, 145 }; 146 147 return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_OUT_VAL, &req, 148 sizeof(req)); 149 } 150 151 #define DLN2_GPIO_DIRECTION_IN 0 152 #define DLN2_GPIO_DIRECTION_OUT 1 153 154 static int dln2_gpio_request(struct gpio_chip *chip, unsigned offset) 155 { 156 struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio); 157 struct dln2_gpio_pin req = { 158 .pin = cpu_to_le16(offset), 159 }; 160 struct dln2_gpio_pin_val rsp; 161 int len = sizeof(rsp); 162 int ret; 163 164 ret = dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_ENABLE, offset); 165 if (ret < 0) 166 return ret; 167 168 /* cache the pin direction */ 169 ret = dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_GET_DIRECTION, 170 &req, sizeof(req), &rsp, &len); 171 if (ret < 0) 172 return ret; 173 if (len < sizeof(rsp) || req.pin != rsp.pin) { 174 ret = -EPROTO; 175 goto out_disable; 176 } 177 178 switch (rsp.value) { 179 case DLN2_GPIO_DIRECTION_IN: 180 clear_bit(offset, dln2->output_enabled); 181 return 0; 182 case DLN2_GPIO_DIRECTION_OUT: 183 set_bit(offset, dln2->output_enabled); 184 return 0; 185 default: 186 ret = -EPROTO; 187 goto out_disable; 188 } 189 190 out_disable: 191 dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset); 192 return ret; 193 } 194 195 static void dln2_gpio_free(struct gpio_chip *chip, unsigned offset) 196 { 197 struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio); 198 199 dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset); 200 } 201 202 static int dln2_gpio_get_direction(struct gpio_chip *chip, unsigned offset) 203 { 204 struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio); 205 206 if (test_bit(offset, dln2->output_enabled)) 207 return GPIOF_DIR_OUT; 208 209 return GPIOF_DIR_IN; 210 } 211 212 static int dln2_gpio_get(struct gpio_chip *chip, unsigned int offset) 213 { 214 struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio); 215 int dir; 216 217 dir = dln2_gpio_get_direction(chip, offset); 218 if (dir < 0) 219 return dir; 220 221 if (dir == GPIOF_DIR_IN) 222 return dln2_gpio_pin_get_in_val(dln2, offset); 223 224 return dln2_gpio_pin_get_out_val(dln2, offset); 225 } 226 227 static void dln2_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 228 { 229 struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio); 230 231 dln2_gpio_pin_set_out_val(dln2, offset, value); 232 } 233 234 static int dln2_gpio_set_direction(struct gpio_chip *chip, unsigned offset, 235 unsigned dir) 236 { 237 struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio); 238 struct dln2_gpio_pin_val req = { 239 .pin = cpu_to_le16(offset), 240 .value = dir, 241 }; 242 int ret; 243 244 ret = dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_DIRECTION, 245 &req, sizeof(req)); 246 if (ret < 0) 247 return ret; 248 249 if (dir == DLN2_GPIO_DIRECTION_OUT) 250 set_bit(offset, dln2->output_enabled); 251 else 252 clear_bit(offset, dln2->output_enabled); 253 254 return ret; 255 } 256 257 static int dln2_gpio_direction_input(struct gpio_chip *chip, unsigned offset) 258 { 259 return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_IN); 260 } 261 262 static int dln2_gpio_direction_output(struct gpio_chip *chip, unsigned offset, 263 int value) 264 { 265 struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio); 266 int ret; 267 268 ret = dln2_gpio_pin_set_out_val(dln2, offset, value); 269 if (ret < 0) 270 return ret; 271 272 return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_OUT); 273 } 274 275 static int dln2_gpio_set_debounce(struct gpio_chip *chip, unsigned offset, 276 unsigned debounce) 277 { 278 struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio); 279 __le32 duration = cpu_to_le32(debounce); 280 281 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 = container_of(gc, struct dln2_gpio, gpio); 306 int pin = irqd_to_hwirq(irqd); 307 308 set_bit(pin, dln2->unmasked_irqs); 309 } 310 311 static void dln2_irq_mask(struct irq_data *irqd) 312 { 313 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 314 struct dln2_gpio *dln2 = container_of(gc, struct dln2_gpio, gpio); 315 int pin = irqd_to_hwirq(irqd); 316 317 clear_bit(pin, dln2->unmasked_irqs); 318 } 319 320 static int dln2_irq_set_type(struct irq_data *irqd, unsigned type) 321 { 322 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 323 struct dln2_gpio *dln2 = container_of(gc, struct dln2_gpio, gpio); 324 int pin = irqd_to_hwirq(irqd); 325 326 switch (type) { 327 case IRQ_TYPE_LEVEL_HIGH: 328 dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_HIGH; 329 break; 330 case IRQ_TYPE_LEVEL_LOW: 331 dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_LOW; 332 break; 333 case IRQ_TYPE_EDGE_BOTH: 334 dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE; 335 break; 336 case IRQ_TYPE_EDGE_RISING: 337 dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_RISING; 338 break; 339 case IRQ_TYPE_EDGE_FALLING: 340 dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_FALLING; 341 break; 342 default: 343 return -EINVAL; 344 } 345 346 return 0; 347 } 348 349 static void dln2_irq_bus_lock(struct irq_data *irqd) 350 { 351 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 352 struct dln2_gpio *dln2 = container_of(gc, struct dln2_gpio, gpio); 353 354 mutex_lock(&dln2->irq_lock); 355 } 356 357 static void dln2_irq_bus_unlock(struct irq_data *irqd) 358 { 359 struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd); 360 struct dln2_gpio *dln2 = container_of(gc, struct dln2_gpio, gpio); 361 int pin = irqd_to_hwirq(irqd); 362 int enabled, unmasked; 363 unsigned type; 364 int ret; 365 366 enabled = test_bit(pin, dln2->enabled_irqs); 367 unmasked = test_bit(pin, dln2->unmasked_irqs); 368 369 if (enabled != unmasked) { 370 if (unmasked) { 371 type = dln2->irq_type[pin] & DLN2_GPIO_EVENT_MASK; 372 set_bit(pin, dln2->enabled_irqs); 373 } else { 374 type = DLN2_GPIO_EVENT_NONE; 375 clear_bit(pin, dln2->enabled_irqs); 376 } 377 378 ret = dln2_gpio_set_event_cfg(dln2, pin, type, 0); 379 if (ret) 380 dev_err(dln2->gpio.dev, "failed to set event\n"); 381 } 382 383 mutex_unlock(&dln2->irq_lock); 384 } 385 386 static struct irq_chip dln2_gpio_irqchip = { 387 .name = "dln2-irq", 388 .irq_mask = dln2_irq_mask, 389 .irq_unmask = dln2_irq_unmask, 390 .irq_set_type = dln2_irq_set_type, 391 .irq_bus_lock = dln2_irq_bus_lock, 392 .irq_bus_sync_unlock = dln2_irq_bus_unlock, 393 }; 394 395 static void dln2_gpio_event(struct platform_device *pdev, u16 echo, 396 const void *data, int len) 397 { 398 int pin, irq; 399 400 const struct { 401 __le16 count; 402 __u8 type; 403 __le16 pin; 404 __u8 value; 405 } __packed *event = data; 406 struct dln2_gpio *dln2 = platform_get_drvdata(pdev); 407 408 if (len < sizeof(*event)) { 409 dev_err(dln2->gpio.dev, "short event message\n"); 410 return; 411 } 412 413 pin = le16_to_cpu(event->pin); 414 if (pin >= dln2->gpio.ngpio) { 415 dev_err(dln2->gpio.dev, "out of bounds pin %d\n", pin); 416 return; 417 } 418 419 irq = irq_find_mapping(dln2->gpio.irqdomain, pin); 420 if (!irq) { 421 dev_err(dln2->gpio.dev, "pin %d not mapped to IRQ\n", pin); 422 return; 423 } 424 425 switch (dln2->irq_type[pin]) { 426 case DLN2_GPIO_EVENT_CHANGE_RISING: 427 if (event->value) 428 generic_handle_irq(irq); 429 break; 430 case DLN2_GPIO_EVENT_CHANGE_FALLING: 431 if (!event->value) 432 generic_handle_irq(irq); 433 break; 434 default: 435 generic_handle_irq(irq); 436 } 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 int pins; 444 int ret; 445 446 pins = dln2_gpio_get_pin_count(pdev); 447 if (pins < 0) { 448 dev_err(dev, "failed to get pin count: %d\n", pins); 449 return pins; 450 } 451 if (pins > DLN2_GPIO_MAX_PINS) { 452 pins = DLN2_GPIO_MAX_PINS; 453 dev_warn(dev, "clamping pins to %d\n", DLN2_GPIO_MAX_PINS); 454 } 455 456 dln2 = devm_kzalloc(&pdev->dev, sizeof(*dln2), GFP_KERNEL); 457 if (!dln2) 458 return -ENOMEM; 459 460 mutex_init(&dln2->irq_lock); 461 462 dln2->pdev = pdev; 463 464 dln2->gpio.label = "dln2"; 465 dln2->gpio.dev = dev; 466 dln2->gpio.owner = THIS_MODULE; 467 dln2->gpio.base = -1; 468 dln2->gpio.ngpio = pins; 469 dln2->gpio.can_sleep = true; 470 dln2->gpio.irq_not_threaded = 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_debounce = dln2_gpio_set_debounce; 479 480 platform_set_drvdata(pdev, dln2); 481 482 ret = gpiochip_add(&dln2->gpio); 483 if (ret < 0) { 484 dev_err(dev, "failed to add gpio chip: %d\n", ret); 485 goto out; 486 } 487 488 ret = gpiochip_irqchip_add(&dln2->gpio, &dln2_gpio_irqchip, 0, 489 handle_simple_irq, IRQ_TYPE_NONE); 490 if (ret < 0) { 491 dev_err(dev, "failed to add irq chip: %d\n", ret); 492 goto out_gpiochip_remove; 493 } 494 495 ret = dln2_register_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV, 496 dln2_gpio_event); 497 if (ret) { 498 dev_err(dev, "failed to register event cb: %d\n", ret); 499 goto out_gpiochip_remove; 500 } 501 502 return 0; 503 504 out_gpiochip_remove: 505 gpiochip_remove(&dln2->gpio); 506 out: 507 return ret; 508 } 509 510 static int dln2_gpio_remove(struct platform_device *pdev) 511 { 512 struct dln2_gpio *dln2 = platform_get_drvdata(pdev); 513 514 dln2_unregister_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV); 515 gpiochip_remove(&dln2->gpio); 516 517 return 0; 518 } 519 520 static struct platform_driver dln2_gpio_driver = { 521 .driver.name = "dln2-gpio", 522 .probe = dln2_gpio_probe, 523 .remove = dln2_gpio_remove, 524 }; 525 526 module_platform_driver(dln2_gpio_driver); 527 528 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com"); 529 MODULE_DESCRIPTION("Driver for the Diolan DLN2 GPIO interface"); 530 MODULE_LICENSE("GPL v2"); 531 MODULE_ALIAS("platform:dln2-gpio"); 532