1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) ST-Ericsson SA 2010 4 * 5 * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson 6 */ 7 8 #include <linux/init.h> 9 #include <linux/platform_device.h> 10 #include <linux/slab.h> 11 #include <linux/gpio/driver.h> 12 #include <linux/interrupt.h> 13 #include <linux/of.h> 14 #include <linux/mfd/stmpe.h> 15 #include <linux/seq_file.h> 16 #include <linux/bitops.h> 17 18 /* 19 * These registers are modified under the irq bus lock and cached to avoid 20 * unnecessary writes in bus_sync_unlock. 21 */ 22 enum { REG_RE, REG_FE, REG_IE }; 23 24 enum { LSB, CSB, MSB }; 25 26 #define CACHE_NR_REGS 3 27 /* No variant has more than 24 GPIOs */ 28 #define CACHE_NR_BANKS (24 / 8) 29 30 struct stmpe_gpio { 31 struct gpio_chip chip; 32 struct stmpe *stmpe; 33 struct device *dev; 34 struct mutex irq_lock; 35 u32 norequest_mask; 36 /* Caches of interrupt control registers for bus_lock */ 37 u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS]; 38 u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS]; 39 }; 40 41 static int stmpe_gpio_get(struct gpio_chip *chip, unsigned offset) 42 { 43 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip); 44 struct stmpe *stmpe = stmpe_gpio->stmpe; 45 u8 reg = stmpe->regs[STMPE_IDX_GPMR_LSB + (offset / 8)]; 46 u8 mask = BIT(offset % 8); 47 int ret; 48 49 ret = stmpe_reg_read(stmpe, reg); 50 if (ret < 0) 51 return ret; 52 53 return !!(ret & mask); 54 } 55 56 static void stmpe_gpio_set(struct gpio_chip *chip, unsigned offset, int val) 57 { 58 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip); 59 struct stmpe *stmpe = stmpe_gpio->stmpe; 60 int which = val ? STMPE_IDX_GPSR_LSB : STMPE_IDX_GPCR_LSB; 61 u8 reg = stmpe->regs[which + (offset / 8)]; 62 u8 mask = BIT(offset % 8); 63 64 /* 65 * Some variants have single register for gpio set/clear functionality. 66 * For them we need to write 0 to clear and 1 to set. 67 */ 68 if (stmpe->regs[STMPE_IDX_GPSR_LSB] == stmpe->regs[STMPE_IDX_GPCR_LSB]) 69 stmpe_set_bits(stmpe, reg, mask, val ? mask : 0); 70 else 71 stmpe_reg_write(stmpe, reg, mask); 72 } 73 74 static int stmpe_gpio_get_direction(struct gpio_chip *chip, 75 unsigned offset) 76 { 77 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip); 78 struct stmpe *stmpe = stmpe_gpio->stmpe; 79 u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8); 80 u8 mask = BIT(offset % 8); 81 int ret; 82 83 ret = stmpe_reg_read(stmpe, reg); 84 if (ret < 0) 85 return ret; 86 87 return !(ret & mask); 88 } 89 90 static int stmpe_gpio_direction_output(struct gpio_chip *chip, 91 unsigned offset, int val) 92 { 93 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip); 94 struct stmpe *stmpe = stmpe_gpio->stmpe; 95 u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB + (offset / 8)]; 96 u8 mask = BIT(offset % 8); 97 98 stmpe_gpio_set(chip, offset, val); 99 100 return stmpe_set_bits(stmpe, reg, mask, mask); 101 } 102 103 static int stmpe_gpio_direction_input(struct gpio_chip *chip, 104 unsigned offset) 105 { 106 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip); 107 struct stmpe *stmpe = stmpe_gpio->stmpe; 108 u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB + (offset / 8)]; 109 u8 mask = BIT(offset % 8); 110 111 return stmpe_set_bits(stmpe, reg, mask, 0); 112 } 113 114 static int stmpe_gpio_request(struct gpio_chip *chip, unsigned offset) 115 { 116 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip); 117 struct stmpe *stmpe = stmpe_gpio->stmpe; 118 119 if (stmpe_gpio->norequest_mask & BIT(offset)) 120 return -EINVAL; 121 122 return stmpe_set_altfunc(stmpe, BIT(offset), STMPE_BLOCK_GPIO); 123 } 124 125 static const struct gpio_chip template_chip = { 126 .label = "stmpe", 127 .owner = THIS_MODULE, 128 .get_direction = stmpe_gpio_get_direction, 129 .direction_input = stmpe_gpio_direction_input, 130 .get = stmpe_gpio_get, 131 .direction_output = stmpe_gpio_direction_output, 132 .set = stmpe_gpio_set, 133 .request = stmpe_gpio_request, 134 .can_sleep = true, 135 }; 136 137 static int stmpe_gpio_irq_set_type(struct irq_data *d, unsigned int type) 138 { 139 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 140 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc); 141 int offset = d->hwirq; 142 int regoffset = offset / 8; 143 int mask = BIT(offset % 8); 144 145 if (type & IRQ_TYPE_LEVEL_LOW || type & IRQ_TYPE_LEVEL_HIGH) 146 return -EINVAL; 147 148 /* STMPE801 and STMPE 1600 don't have RE and FE registers */ 149 if (stmpe_gpio->stmpe->partnum == STMPE801 || 150 stmpe_gpio->stmpe->partnum == STMPE1600) 151 return 0; 152 153 if (type & IRQ_TYPE_EDGE_RISING) 154 stmpe_gpio->regs[REG_RE][regoffset] |= mask; 155 else 156 stmpe_gpio->regs[REG_RE][regoffset] &= ~mask; 157 158 if (type & IRQ_TYPE_EDGE_FALLING) 159 stmpe_gpio->regs[REG_FE][regoffset] |= mask; 160 else 161 stmpe_gpio->regs[REG_FE][regoffset] &= ~mask; 162 163 return 0; 164 } 165 166 static void stmpe_gpio_irq_lock(struct irq_data *d) 167 { 168 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 169 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc); 170 171 mutex_lock(&stmpe_gpio->irq_lock); 172 } 173 174 static void stmpe_gpio_irq_sync_unlock(struct irq_data *d) 175 { 176 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 177 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc); 178 struct stmpe *stmpe = stmpe_gpio->stmpe; 179 int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8); 180 static const u8 regmap[CACHE_NR_REGS][CACHE_NR_BANKS] = { 181 [REG_RE][LSB] = STMPE_IDX_GPRER_LSB, 182 [REG_RE][CSB] = STMPE_IDX_GPRER_CSB, 183 [REG_RE][MSB] = STMPE_IDX_GPRER_MSB, 184 [REG_FE][LSB] = STMPE_IDX_GPFER_LSB, 185 [REG_FE][CSB] = STMPE_IDX_GPFER_CSB, 186 [REG_FE][MSB] = STMPE_IDX_GPFER_MSB, 187 [REG_IE][LSB] = STMPE_IDX_IEGPIOR_LSB, 188 [REG_IE][CSB] = STMPE_IDX_IEGPIOR_CSB, 189 [REG_IE][MSB] = STMPE_IDX_IEGPIOR_MSB, 190 }; 191 int i, j; 192 193 /* 194 * STMPE1600: to be able to get IRQ from pins, 195 * a read must be done on GPMR register, or a write in 196 * GPSR or GPCR registers 197 */ 198 if (stmpe->partnum == STMPE1600) { 199 stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_LSB]); 200 stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_CSB]); 201 } 202 203 for (i = 0; i < CACHE_NR_REGS; i++) { 204 /* STMPE801 and STMPE1600 don't have RE and FE registers */ 205 if ((stmpe->partnum == STMPE801 || 206 stmpe->partnum == STMPE1600) && 207 (i != REG_IE)) 208 continue; 209 210 for (j = 0; j < num_banks; j++) { 211 u8 old = stmpe_gpio->oldregs[i][j]; 212 u8 new = stmpe_gpio->regs[i][j]; 213 214 if (new == old) 215 continue; 216 217 stmpe_gpio->oldregs[i][j] = new; 218 stmpe_reg_write(stmpe, stmpe->regs[regmap[i][j]], new); 219 } 220 } 221 222 mutex_unlock(&stmpe_gpio->irq_lock); 223 } 224 225 static void stmpe_gpio_irq_mask(struct irq_data *d) 226 { 227 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 228 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc); 229 int offset = d->hwirq; 230 int regoffset = offset / 8; 231 int mask = BIT(offset % 8); 232 233 stmpe_gpio->regs[REG_IE][regoffset] &= ~mask; 234 } 235 236 static void stmpe_gpio_irq_unmask(struct irq_data *d) 237 { 238 struct gpio_chip *gc = irq_data_get_irq_chip_data(d); 239 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc); 240 int offset = d->hwirq; 241 int regoffset = offset / 8; 242 int mask = BIT(offset % 8); 243 244 stmpe_gpio->regs[REG_IE][regoffset] |= mask; 245 } 246 247 static void stmpe_dbg_show_one(struct seq_file *s, 248 struct gpio_chip *gc, 249 unsigned offset, unsigned gpio) 250 { 251 struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc); 252 struct stmpe *stmpe = stmpe_gpio->stmpe; 253 const char *label = gpiochip_is_requested(gc, offset); 254 bool val = !!stmpe_gpio_get(gc, offset); 255 u8 bank = offset / 8; 256 u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB + bank]; 257 u8 mask = BIT(offset % 8); 258 int ret; 259 u8 dir; 260 261 ret = stmpe_reg_read(stmpe, dir_reg); 262 if (ret < 0) 263 return; 264 dir = !!(ret & mask); 265 266 if (dir) { 267 seq_printf(s, " gpio-%-3d (%-20.20s) out %s", 268 gpio, label ?: "(none)", 269 val ? "hi" : "lo"); 270 } else { 271 u8 edge_det_reg; 272 u8 rise_reg; 273 u8 fall_reg; 274 u8 irqen_reg; 275 276 static const char * const edge_det_values[] = { 277 "edge-inactive", 278 "edge-asserted", 279 "not-supported" 280 }; 281 static const char * const rise_values[] = { 282 "no-rising-edge-detection", 283 "rising-edge-detection", 284 "not-supported" 285 }; 286 static const char * const fall_values[] = { 287 "no-falling-edge-detection", 288 "falling-edge-detection", 289 "not-supported" 290 }; 291 #define NOT_SUPPORTED_IDX 2 292 u8 edge_det = NOT_SUPPORTED_IDX; 293 u8 rise = NOT_SUPPORTED_IDX; 294 u8 fall = NOT_SUPPORTED_IDX; 295 bool irqen; 296 297 switch (stmpe->partnum) { 298 case STMPE610: 299 case STMPE811: 300 case STMPE1601: 301 case STMPE2401: 302 case STMPE2403: 303 edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_LSB + bank]; 304 ret = stmpe_reg_read(stmpe, edge_det_reg); 305 if (ret < 0) 306 return; 307 edge_det = !!(ret & mask); 308 /* fall through */ 309 case STMPE1801: 310 rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB + bank]; 311 fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB + bank]; 312 313 ret = stmpe_reg_read(stmpe, rise_reg); 314 if (ret < 0) 315 return; 316 rise = !!(ret & mask); 317 ret = stmpe_reg_read(stmpe, fall_reg); 318 if (ret < 0) 319 return; 320 fall = !!(ret & mask); 321 /* fall through */ 322 case STMPE801: 323 case STMPE1600: 324 irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB + bank]; 325 break; 326 327 default: 328 return; 329 } 330 331 ret = stmpe_reg_read(stmpe, irqen_reg); 332 if (ret < 0) 333 return; 334 irqen = !!(ret & mask); 335 336 seq_printf(s, " gpio-%-3d (%-20.20s) in %s %13s %13s %25s %25s", 337 gpio, label ?: "(none)", 338 val ? "hi" : "lo", 339 edge_det_values[edge_det], 340 irqen ? "IRQ-enabled" : "IRQ-disabled", 341 rise_values[rise], 342 fall_values[fall]); 343 } 344 } 345 346 static void stmpe_dbg_show(struct seq_file *s, struct gpio_chip *gc) 347 { 348 unsigned i; 349 unsigned gpio = gc->base; 350 351 for (i = 0; i < gc->ngpio; i++, gpio++) { 352 stmpe_dbg_show_one(s, gc, i, gpio); 353 seq_putc(s, '\n'); 354 } 355 } 356 357 static struct irq_chip stmpe_gpio_irq_chip = { 358 .name = "stmpe-gpio", 359 .irq_bus_lock = stmpe_gpio_irq_lock, 360 .irq_bus_sync_unlock = stmpe_gpio_irq_sync_unlock, 361 .irq_mask = stmpe_gpio_irq_mask, 362 .irq_unmask = stmpe_gpio_irq_unmask, 363 .irq_set_type = stmpe_gpio_irq_set_type, 364 }; 365 366 #define MAX_GPIOS 24 367 368 static irqreturn_t stmpe_gpio_irq(int irq, void *dev) 369 { 370 struct stmpe_gpio *stmpe_gpio = dev; 371 struct stmpe *stmpe = stmpe_gpio->stmpe; 372 u8 statmsbreg; 373 int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8); 374 u8 status[DIV_ROUND_UP(MAX_GPIOS, 8)]; 375 int ret; 376 int i; 377 378 /* 379 * the stmpe_block_read() call below, imposes to set statmsbreg 380 * with the register located at the lowest address. As STMPE1600 381 * variant is the only one which respect registers address's order 382 * (LSB regs located at lowest address than MSB ones) whereas all 383 * the others have a registers layout with MSB located before the 384 * LSB regs. 385 */ 386 if (stmpe->partnum == STMPE1600) 387 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_LSB]; 388 else 389 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_MSB]; 390 391 ret = stmpe_block_read(stmpe, statmsbreg, num_banks, status); 392 if (ret < 0) 393 return IRQ_NONE; 394 395 for (i = 0; i < num_banks; i++) { 396 int bank = (stmpe_gpio->stmpe->partnum == STMPE1600) ? i : 397 num_banks - i - 1; 398 unsigned int enabled = stmpe_gpio->regs[REG_IE][bank]; 399 unsigned int stat = status[i]; 400 401 stat &= enabled; 402 if (!stat) 403 continue; 404 405 while (stat) { 406 int bit = __ffs(stat); 407 int line = bank * 8 + bit; 408 int child_irq = irq_find_mapping(stmpe_gpio->chip.irq.domain, 409 line); 410 411 handle_nested_irq(child_irq); 412 stat &= ~BIT(bit); 413 } 414 415 /* 416 * interrupt status register write has no effect on 417 * 801/1801/1600, bits are cleared when read. 418 * Edge detect register is not present on 801/1600/1801 419 */ 420 if (stmpe->partnum != STMPE801 && stmpe->partnum != STMPE1600 && 421 stmpe->partnum != STMPE1801) { 422 stmpe_reg_write(stmpe, statmsbreg + i, status[i]); 423 stmpe_reg_write(stmpe, 424 stmpe->regs[STMPE_IDX_GPEDR_MSB] + i, 425 status[i]); 426 } 427 } 428 429 return IRQ_HANDLED; 430 } 431 432 static int stmpe_gpio_probe(struct platform_device *pdev) 433 { 434 struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); 435 struct device_node *np = pdev->dev.of_node; 436 struct stmpe_gpio *stmpe_gpio; 437 int ret, irq; 438 439 if (stmpe->num_gpios > MAX_GPIOS) { 440 dev_err(&pdev->dev, "Need to increase maximum GPIO number\n"); 441 return -EINVAL; 442 } 443 444 stmpe_gpio = kzalloc(sizeof(*stmpe_gpio), GFP_KERNEL); 445 if (!stmpe_gpio) 446 return -ENOMEM; 447 448 mutex_init(&stmpe_gpio->irq_lock); 449 450 stmpe_gpio->dev = &pdev->dev; 451 stmpe_gpio->stmpe = stmpe; 452 stmpe_gpio->chip = template_chip; 453 stmpe_gpio->chip.ngpio = stmpe->num_gpios; 454 stmpe_gpio->chip.parent = &pdev->dev; 455 stmpe_gpio->chip.of_node = np; 456 stmpe_gpio->chip.base = -1; 457 458 if (IS_ENABLED(CONFIG_DEBUG_FS)) 459 stmpe_gpio->chip.dbg_show = stmpe_dbg_show; 460 461 of_property_read_u32(np, "st,norequest-mask", 462 &stmpe_gpio->norequest_mask); 463 if (stmpe_gpio->norequest_mask) 464 stmpe_gpio->chip.irq.need_valid_mask = true; 465 466 irq = platform_get_irq(pdev, 0); 467 if (irq < 0) 468 dev_info(&pdev->dev, 469 "device configured in no-irq mode: " 470 "irqs are not available\n"); 471 472 ret = stmpe_enable(stmpe, STMPE_BLOCK_GPIO); 473 if (ret) 474 goto out_free; 475 476 ret = gpiochip_add_data(&stmpe_gpio->chip, stmpe_gpio); 477 if (ret) { 478 dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret); 479 goto out_disable; 480 } 481 482 if (irq > 0) { 483 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, 484 stmpe_gpio_irq, IRQF_ONESHOT, 485 "stmpe-gpio", stmpe_gpio); 486 if (ret) { 487 dev_err(&pdev->dev, "unable to get irq: %d\n", ret); 488 goto out_disable; 489 } 490 if (stmpe_gpio->norequest_mask) { 491 int i; 492 493 /* Forbid unused lines to be mapped as IRQs */ 494 for (i = 0; i < sizeof(u32); i++) 495 if (stmpe_gpio->norequest_mask & BIT(i)) 496 clear_bit(i, stmpe_gpio->chip.irq.valid_mask); 497 } 498 ret = gpiochip_irqchip_add_nested(&stmpe_gpio->chip, 499 &stmpe_gpio_irq_chip, 500 0, 501 handle_simple_irq, 502 IRQ_TYPE_NONE); 503 if (ret) { 504 dev_err(&pdev->dev, 505 "could not connect irqchip to gpiochip\n"); 506 goto out_disable; 507 } 508 509 gpiochip_set_nested_irqchip(&stmpe_gpio->chip, 510 &stmpe_gpio_irq_chip, 511 irq); 512 } 513 514 platform_set_drvdata(pdev, stmpe_gpio); 515 516 return 0; 517 518 out_disable: 519 stmpe_disable(stmpe, STMPE_BLOCK_GPIO); 520 gpiochip_remove(&stmpe_gpio->chip); 521 out_free: 522 kfree(stmpe_gpio); 523 return ret; 524 } 525 526 static struct platform_driver stmpe_gpio_driver = { 527 .driver = { 528 .suppress_bind_attrs = true, 529 .name = "stmpe-gpio", 530 }, 531 .probe = stmpe_gpio_probe, 532 }; 533 534 static int __init stmpe_gpio_init(void) 535 { 536 return platform_driver_register(&stmpe_gpio_driver); 537 } 538 subsys_initcall(stmpe_gpio_init); 539