1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Intel Sunrisepoint LPSS core support. 4 * 5 * Copyright (C) 2015, Intel Corporation 6 * 7 * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com> 8 * Mika Westerberg <mika.westerberg@linux.intel.com> 9 * Heikki Krogerus <heikki.krogerus@linux.intel.com> 10 * Jarkko Nikula <jarkko.nikula@linux.intel.com> 11 */ 12 13 #include <linux/clk.h> 14 #include <linux/clkdev.h> 15 #include <linux/clk-provider.h> 16 #include <linux/debugfs.h> 17 #include <linux/idr.h> 18 #include <linux/io.h> 19 #include <linux/ioport.h> 20 #include <linux/kernel.h> 21 #include <linux/module.h> 22 #include <linux/mfd/core.h> 23 #include <linux/pm_qos.h> 24 #include <linux/pm_runtime.h> 25 #include <linux/property.h> 26 #include <linux/seq_file.h> 27 #include <linux/io-64-nonatomic-lo-hi.h> 28 29 #include <linux/dma/idma64.h> 30 31 #include "intel-lpss.h" 32 33 #define LPSS_DEV_OFFSET 0x000 34 #define LPSS_DEV_SIZE 0x200 35 #define LPSS_PRIV_OFFSET 0x200 36 #define LPSS_PRIV_SIZE 0x100 37 #define LPSS_PRIV_REG_COUNT (LPSS_PRIV_SIZE / 4) 38 #define LPSS_IDMA64_OFFSET 0x800 39 #define LPSS_IDMA64_SIZE 0x800 40 41 /* Offsets from lpss->priv */ 42 #define LPSS_PRIV_RESETS 0x04 43 #define LPSS_PRIV_RESETS_IDMA BIT(2) 44 #define LPSS_PRIV_RESETS_FUNC 0x3 45 46 #define LPSS_PRIV_ACTIVELTR 0x10 47 #define LPSS_PRIV_IDLELTR 0x14 48 49 #define LPSS_PRIV_LTR_REQ BIT(15) 50 #define LPSS_PRIV_LTR_SCALE_MASK GENMASK(11, 10) 51 #define LPSS_PRIV_LTR_SCALE_1US (2 << 10) 52 #define LPSS_PRIV_LTR_SCALE_32US (3 << 10) 53 #define LPSS_PRIV_LTR_VALUE_MASK GENMASK(9, 0) 54 55 #define LPSS_PRIV_SSP_REG 0x20 56 #define LPSS_PRIV_SSP_REG_DIS_DMA_FIN BIT(0) 57 58 #define LPSS_PRIV_REMAP_ADDR 0x40 59 60 #define LPSS_PRIV_CAPS 0xfc 61 #define LPSS_PRIV_CAPS_NO_IDMA BIT(8) 62 #define LPSS_PRIV_CAPS_TYPE_MASK GENMASK(7, 4) 63 #define LPSS_PRIV_CAPS_TYPE_SHIFT 4 64 65 /* This matches the type field in CAPS register */ 66 enum intel_lpss_dev_type { 67 LPSS_DEV_I2C = 0, 68 LPSS_DEV_UART, 69 LPSS_DEV_SPI, 70 }; 71 72 struct intel_lpss { 73 const struct intel_lpss_platform_info *info; 74 enum intel_lpss_dev_type type; 75 struct clk *clk; 76 struct clk_lookup *clock; 77 struct mfd_cell *cell; 78 struct device *dev; 79 void __iomem *priv; 80 u32 priv_ctx[LPSS_PRIV_REG_COUNT]; 81 int devid; 82 u32 caps; 83 u32 active_ltr; 84 u32 idle_ltr; 85 struct dentry *debugfs; 86 }; 87 88 static const struct resource intel_lpss_dev_resources[] = { 89 DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"), 90 DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"), 91 DEFINE_RES_IRQ(0), 92 }; 93 94 static const struct resource intel_lpss_idma64_resources[] = { 95 DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE), 96 DEFINE_RES_IRQ(0), 97 }; 98 99 /* 100 * Cells needs to be ordered so that the iDMA is created first. This is 101 * because we need to be sure the DMA is available when the host controller 102 * driver is probed. 103 */ 104 static const struct mfd_cell intel_lpss_idma64_cell = { 105 .name = LPSS_IDMA64_DRIVER_NAME, 106 .num_resources = ARRAY_SIZE(intel_lpss_idma64_resources), 107 .resources = intel_lpss_idma64_resources, 108 }; 109 110 static const struct mfd_cell intel_lpss_i2c_cell = { 111 .name = "i2c_designware", 112 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources), 113 .resources = intel_lpss_dev_resources, 114 }; 115 116 static const struct mfd_cell intel_lpss_uart_cell = { 117 .name = "dw-apb-uart", 118 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources), 119 .resources = intel_lpss_dev_resources, 120 }; 121 122 static const struct mfd_cell intel_lpss_spi_cell = { 123 .name = "pxa2xx-spi", 124 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources), 125 .resources = intel_lpss_dev_resources, 126 }; 127 128 static DEFINE_IDA(intel_lpss_devid_ida); 129 static struct dentry *intel_lpss_debugfs; 130 131 static void intel_lpss_cache_ltr(struct intel_lpss *lpss) 132 { 133 lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR); 134 lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR); 135 } 136 137 static int intel_lpss_debugfs_add(struct intel_lpss *lpss) 138 { 139 struct dentry *dir; 140 141 dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs); 142 if (IS_ERR(dir)) 143 return PTR_ERR(dir); 144 145 /* Cache the values into lpss structure */ 146 intel_lpss_cache_ltr(lpss); 147 148 debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps); 149 debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr); 150 debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr); 151 152 lpss->debugfs = dir; 153 return 0; 154 } 155 156 static void intel_lpss_debugfs_remove(struct intel_lpss *lpss) 157 { 158 debugfs_remove_recursive(lpss->debugfs); 159 } 160 161 static void intel_lpss_ltr_set(struct device *dev, s32 val) 162 { 163 struct intel_lpss *lpss = dev_get_drvdata(dev); 164 u32 ltr; 165 166 /* 167 * Program latency tolerance (LTR) accordingly what has been asked 168 * by the PM QoS layer or disable it in case we were passed 169 * negative value or PM_QOS_LATENCY_ANY. 170 */ 171 ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR); 172 173 if (val == PM_QOS_LATENCY_ANY || val < 0) { 174 ltr &= ~LPSS_PRIV_LTR_REQ; 175 } else { 176 ltr |= LPSS_PRIV_LTR_REQ; 177 ltr &= ~LPSS_PRIV_LTR_SCALE_MASK; 178 ltr &= ~LPSS_PRIV_LTR_VALUE_MASK; 179 180 if (val > LPSS_PRIV_LTR_VALUE_MASK) 181 ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5; 182 else 183 ltr |= LPSS_PRIV_LTR_SCALE_1US | val; 184 } 185 186 if (ltr == lpss->active_ltr) 187 return; 188 189 writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR); 190 writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR); 191 192 /* Cache the values into lpss structure */ 193 intel_lpss_cache_ltr(lpss); 194 } 195 196 static void intel_lpss_ltr_expose(struct intel_lpss *lpss) 197 { 198 lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set; 199 dev_pm_qos_expose_latency_tolerance(lpss->dev); 200 } 201 202 static void intel_lpss_ltr_hide(struct intel_lpss *lpss) 203 { 204 dev_pm_qos_hide_latency_tolerance(lpss->dev); 205 lpss->dev->power.set_latency_tolerance = NULL; 206 } 207 208 static int intel_lpss_assign_devs(struct intel_lpss *lpss) 209 { 210 const struct mfd_cell *cell; 211 unsigned int type; 212 213 type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK; 214 type >>= LPSS_PRIV_CAPS_TYPE_SHIFT; 215 216 switch (type) { 217 case LPSS_DEV_I2C: 218 cell = &intel_lpss_i2c_cell; 219 break; 220 case LPSS_DEV_UART: 221 cell = &intel_lpss_uart_cell; 222 break; 223 case LPSS_DEV_SPI: 224 cell = &intel_lpss_spi_cell; 225 break; 226 default: 227 return -ENODEV; 228 } 229 230 lpss->cell = devm_kmemdup(lpss->dev, cell, sizeof(*cell), GFP_KERNEL); 231 if (!lpss->cell) 232 return -ENOMEM; 233 234 lpss->type = type; 235 236 return 0; 237 } 238 239 static bool intel_lpss_has_idma(const struct intel_lpss *lpss) 240 { 241 return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0; 242 } 243 244 static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss) 245 { 246 resource_size_t addr = lpss->info->mem->start; 247 248 lo_hi_writeq(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR); 249 } 250 251 static void intel_lpss_deassert_reset(const struct intel_lpss *lpss) 252 { 253 u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA; 254 255 /* Bring out the device from reset */ 256 writel(value, lpss->priv + LPSS_PRIV_RESETS); 257 } 258 259 static void intel_lpss_init_dev(const struct intel_lpss *lpss) 260 { 261 u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN; 262 263 /* Set the device in reset state */ 264 writel(0, lpss->priv + LPSS_PRIV_RESETS); 265 266 intel_lpss_deassert_reset(lpss); 267 268 intel_lpss_set_remap_addr(lpss); 269 270 if (!intel_lpss_has_idma(lpss)) 271 return; 272 273 /* Make sure that SPI multiblock DMA transfers are re-enabled */ 274 if (lpss->type == LPSS_DEV_SPI) 275 writel(value, lpss->priv + LPSS_PRIV_SSP_REG); 276 } 277 278 static void intel_lpss_unregister_clock_tree(struct clk *clk) 279 { 280 struct clk *parent; 281 282 while (clk) { 283 parent = clk_get_parent(clk); 284 clk_unregister(clk); 285 clk = parent; 286 } 287 } 288 289 static int intel_lpss_register_clock_divider(struct intel_lpss *lpss, 290 const char *devname, 291 struct clk **clk) 292 { 293 char name[32]; 294 struct clk *tmp = *clk; 295 296 snprintf(name, sizeof(name), "%s-enable", devname); 297 tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0, 298 lpss->priv, 0, 0, NULL); 299 if (IS_ERR(tmp)) 300 return PTR_ERR(tmp); 301 302 snprintf(name, sizeof(name), "%s-div", devname); 303 tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp), 304 CLK_FRAC_DIVIDER_POWER_OF_TWO_PS, 305 lpss->priv, 1, 15, 16, 15, 0, 306 NULL); 307 if (IS_ERR(tmp)) 308 return PTR_ERR(tmp); 309 *clk = tmp; 310 311 snprintf(name, sizeof(name), "%s-update", devname); 312 tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 313 CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL); 314 if (IS_ERR(tmp)) 315 return PTR_ERR(tmp); 316 *clk = tmp; 317 318 return 0; 319 } 320 321 static int intel_lpss_register_clock(struct intel_lpss *lpss) 322 { 323 const struct mfd_cell *cell = lpss->cell; 324 struct clk *clk; 325 char devname[24]; 326 int ret; 327 328 if (!lpss->info->clk_rate) 329 return 0; 330 331 /* Root clock */ 332 clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL, 0, 333 lpss->info->clk_rate); 334 if (IS_ERR(clk)) 335 return PTR_ERR(clk); 336 337 snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid); 338 339 /* 340 * Support for clock divider only if it has some preset value. 341 * Otherwise we assume that the divider is not used. 342 */ 343 if (lpss->type != LPSS_DEV_I2C) { 344 ret = intel_lpss_register_clock_divider(lpss, devname, &clk); 345 if (ret) 346 goto err_clk_register; 347 } 348 349 ret = -ENOMEM; 350 351 /* Clock for the host controller */ 352 lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname); 353 if (!lpss->clock) 354 goto err_clk_register; 355 356 lpss->clk = clk; 357 358 return 0; 359 360 err_clk_register: 361 intel_lpss_unregister_clock_tree(clk); 362 363 return ret; 364 } 365 366 static void intel_lpss_unregister_clock(struct intel_lpss *lpss) 367 { 368 if (IS_ERR_OR_NULL(lpss->clk)) 369 return; 370 371 clkdev_drop(lpss->clock); 372 intel_lpss_unregister_clock_tree(lpss->clk); 373 } 374 375 int intel_lpss_probe(struct device *dev, 376 const struct intel_lpss_platform_info *info) 377 { 378 struct intel_lpss *lpss; 379 int ret; 380 381 if (!info || !info->mem || info->irq <= 0) 382 return -EINVAL; 383 384 lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL); 385 if (!lpss) 386 return -ENOMEM; 387 388 lpss->priv = devm_ioremap_uc(dev, info->mem->start + LPSS_PRIV_OFFSET, 389 LPSS_PRIV_SIZE); 390 if (!lpss->priv) 391 return -ENOMEM; 392 393 lpss->info = info; 394 lpss->dev = dev; 395 lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS); 396 397 dev_set_drvdata(dev, lpss); 398 399 ret = intel_lpss_assign_devs(lpss); 400 if (ret) 401 return ret; 402 403 lpss->cell->swnode = info->swnode; 404 lpss->cell->ignore_resource_conflicts = info->ignore_resource_conflicts; 405 406 intel_lpss_init_dev(lpss); 407 408 lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL); 409 if (lpss->devid < 0) 410 return lpss->devid; 411 412 ret = intel_lpss_register_clock(lpss); 413 if (ret) 414 goto err_clk_register; 415 416 intel_lpss_ltr_expose(lpss); 417 418 ret = intel_lpss_debugfs_add(lpss); 419 if (ret) 420 dev_warn(dev, "Failed to create debugfs entries\n"); 421 422 if (intel_lpss_has_idma(lpss)) { 423 ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell, 424 1, info->mem, info->irq, NULL); 425 if (ret) 426 dev_warn(dev, "Failed to add %s, fallback to PIO\n", 427 LPSS_IDMA64_DRIVER_NAME); 428 } 429 430 ret = mfd_add_devices(dev, lpss->devid, lpss->cell, 431 1, info->mem, info->irq, NULL); 432 if (ret) 433 goto err_remove_ltr; 434 435 dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND); 436 437 return 0; 438 439 err_remove_ltr: 440 intel_lpss_debugfs_remove(lpss); 441 intel_lpss_ltr_hide(lpss); 442 intel_lpss_unregister_clock(lpss); 443 444 err_clk_register: 445 ida_simple_remove(&intel_lpss_devid_ida, lpss->devid); 446 447 return ret; 448 } 449 EXPORT_SYMBOL_GPL(intel_lpss_probe); 450 451 void intel_lpss_remove(struct device *dev) 452 { 453 struct intel_lpss *lpss = dev_get_drvdata(dev); 454 455 mfd_remove_devices(dev); 456 intel_lpss_debugfs_remove(lpss); 457 intel_lpss_ltr_hide(lpss); 458 intel_lpss_unregister_clock(lpss); 459 ida_simple_remove(&intel_lpss_devid_ida, lpss->devid); 460 } 461 EXPORT_SYMBOL_GPL(intel_lpss_remove); 462 463 #ifdef CONFIG_PM 464 static int resume_lpss_device(struct device *dev, void *data) 465 { 466 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND)) 467 pm_runtime_resume(dev); 468 469 return 0; 470 } 471 472 int intel_lpss_prepare(struct device *dev) 473 { 474 /* 475 * Resume both child devices before entering system sleep. This 476 * ensures that they are in proper state before they get suspended. 477 */ 478 device_for_each_child_reverse(dev, NULL, resume_lpss_device); 479 return 0; 480 } 481 EXPORT_SYMBOL_GPL(intel_lpss_prepare); 482 483 int intel_lpss_suspend(struct device *dev) 484 { 485 struct intel_lpss *lpss = dev_get_drvdata(dev); 486 unsigned int i; 487 488 /* Save device context */ 489 for (i = 0; i < LPSS_PRIV_REG_COUNT; i++) 490 lpss->priv_ctx[i] = readl(lpss->priv + i * 4); 491 492 /* 493 * If the device type is not UART, then put the controller into 494 * reset. UART cannot be put into reset since S3/S0ix fail when 495 * no_console_suspend flag is enabled. 496 */ 497 if (lpss->type != LPSS_DEV_UART) 498 writel(0, lpss->priv + LPSS_PRIV_RESETS); 499 500 return 0; 501 } 502 EXPORT_SYMBOL_GPL(intel_lpss_suspend); 503 504 int intel_lpss_resume(struct device *dev) 505 { 506 struct intel_lpss *lpss = dev_get_drvdata(dev); 507 unsigned int i; 508 509 intel_lpss_deassert_reset(lpss); 510 511 /* Restore device context */ 512 for (i = 0; i < LPSS_PRIV_REG_COUNT; i++) 513 writel(lpss->priv_ctx[i], lpss->priv + i * 4); 514 515 return 0; 516 } 517 EXPORT_SYMBOL_GPL(intel_lpss_resume); 518 #endif 519 520 static int __init intel_lpss_init(void) 521 { 522 intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL); 523 return 0; 524 } 525 module_init(intel_lpss_init); 526 527 static void __exit intel_lpss_exit(void) 528 { 529 ida_destroy(&intel_lpss_devid_ida); 530 debugfs_remove(intel_lpss_debugfs); 531 } 532 module_exit(intel_lpss_exit); 533 534 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>"); 535 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>"); 536 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>"); 537 MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>"); 538 MODULE_DESCRIPTION("Intel LPSS core driver"); 539 MODULE_LICENSE("GPL v2"); 540 /* 541 * Ensure the DMA driver is loaded before the host controller device appears, 542 * so that the host controller driver can request its DMA channels as early 543 * as possible. 544 * 545 * If the DMA module is not there that's OK as well. 546 */ 547 MODULE_SOFTDEP("pre: platform:" LPSS_IDMA64_DRIVER_NAME); 548