1 /* 2 * Intel Sunrisepoint LPSS core support. 3 * 4 * Copyright (C) 2015, Intel Corporation 5 * 6 * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com> 7 * Mika Westerberg <mika.westerberg@linux.intel.com> 8 * Heikki Krogerus <heikki.krogerus@linux.intel.com> 9 * Jarkko Nikula <jarkko.nikula@linux.intel.com> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License version 2 as 13 * published by the Free Software Foundation. 14 */ 15 16 #include <linux/clk.h> 17 #include <linux/clkdev.h> 18 #include <linux/clk-provider.h> 19 #include <linux/debugfs.h> 20 #include <linux/idr.h> 21 #include <linux/io.h> 22 #include <linux/ioport.h> 23 #include <linux/kernel.h> 24 #include <linux/module.h> 25 #include <linux/mfd/core.h> 26 #include <linux/pm_qos.h> 27 #include <linux/pm_runtime.h> 28 #include <linux/property.h> 29 #include <linux/seq_file.h> 30 #include <linux/io-64-nonatomic-lo-hi.h> 31 32 #include "intel-lpss.h" 33 34 #define LPSS_DEV_OFFSET 0x000 35 #define LPSS_DEV_SIZE 0x200 36 #define LPSS_PRIV_OFFSET 0x200 37 #define LPSS_PRIV_SIZE 0x100 38 #define LPSS_PRIV_REG_COUNT (LPSS_PRIV_SIZE / 4) 39 #define LPSS_IDMA64_OFFSET 0x800 40 #define LPSS_IDMA64_SIZE 0x800 41 42 /* Offsets from lpss->priv */ 43 #define LPSS_PRIV_RESETS 0x04 44 #define LPSS_PRIV_RESETS_IDMA BIT(2) 45 #define LPSS_PRIV_RESETS_FUNC 0x3 46 47 #define LPSS_PRIV_ACTIVELTR 0x10 48 #define LPSS_PRIV_IDLELTR 0x14 49 50 #define LPSS_PRIV_LTR_REQ BIT(15) 51 #define LPSS_PRIV_LTR_SCALE_MASK 0xc00 52 #define LPSS_PRIV_LTR_SCALE_1US 0x800 53 #define LPSS_PRIV_LTR_SCALE_32US 0xc00 54 #define LPSS_PRIV_LTR_VALUE_MASK 0x3ff 55 56 #define LPSS_PRIV_SSP_REG 0x20 57 #define LPSS_PRIV_SSP_REG_DIS_DMA_FIN BIT(0) 58 59 #define LPSS_PRIV_REMAP_ADDR 0x40 60 61 #define LPSS_PRIV_CAPS 0xfc 62 #define LPSS_PRIV_CAPS_NO_IDMA BIT(8) 63 #define LPSS_PRIV_CAPS_TYPE_SHIFT 4 64 #define LPSS_PRIV_CAPS_TYPE_MASK (0xf << LPSS_PRIV_CAPS_TYPE_SHIFT) 65 66 /* This matches the type field in CAPS register */ 67 enum intel_lpss_dev_type { 68 LPSS_DEV_I2C = 0, 69 LPSS_DEV_UART, 70 LPSS_DEV_SPI, 71 }; 72 73 struct intel_lpss { 74 const struct intel_lpss_platform_info *info; 75 enum intel_lpss_dev_type type; 76 struct clk *clk; 77 struct clk_lookup *clock; 78 struct mfd_cell *cell; 79 struct device *dev; 80 void __iomem *priv; 81 u32 priv_ctx[LPSS_PRIV_REG_COUNT]; 82 int devid; 83 u32 caps; 84 u32 active_ltr; 85 u32 idle_ltr; 86 struct dentry *debugfs; 87 }; 88 89 static const struct resource intel_lpss_dev_resources[] = { 90 DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"), 91 DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"), 92 DEFINE_RES_IRQ(0), 93 }; 94 95 static const struct resource intel_lpss_idma64_resources[] = { 96 DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE), 97 DEFINE_RES_IRQ(0), 98 }; 99 100 #define LPSS_IDMA64_DRIVER_NAME "idma64" 101 102 /* 103 * Cells needs to be ordered so that the iDMA is created first. This is 104 * because we need to be sure the DMA is available when the host controller 105 * driver is probed. 106 */ 107 static const struct mfd_cell intel_lpss_idma64_cell = { 108 .name = LPSS_IDMA64_DRIVER_NAME, 109 .num_resources = ARRAY_SIZE(intel_lpss_idma64_resources), 110 .resources = intel_lpss_idma64_resources, 111 }; 112 113 static const struct mfd_cell intel_lpss_i2c_cell = { 114 .name = "i2c_designware", 115 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources), 116 .resources = intel_lpss_dev_resources, 117 }; 118 119 static const struct mfd_cell intel_lpss_uart_cell = { 120 .name = "dw-apb-uart", 121 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources), 122 .resources = intel_lpss_dev_resources, 123 }; 124 125 static const struct mfd_cell intel_lpss_spi_cell = { 126 .name = "pxa2xx-spi", 127 .num_resources = ARRAY_SIZE(intel_lpss_dev_resources), 128 .resources = intel_lpss_dev_resources, 129 }; 130 131 static DEFINE_IDA(intel_lpss_devid_ida); 132 static struct dentry *intel_lpss_debugfs; 133 134 static int intel_lpss_request_dma_module(const char *name) 135 { 136 static bool intel_lpss_dma_requested; 137 138 if (intel_lpss_dma_requested) 139 return 0; 140 141 intel_lpss_dma_requested = true; 142 return request_module("%s", name); 143 } 144 145 static void intel_lpss_cache_ltr(struct intel_lpss *lpss) 146 { 147 lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR); 148 lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR); 149 } 150 151 static int intel_lpss_debugfs_add(struct intel_lpss *lpss) 152 { 153 struct dentry *dir; 154 155 dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs); 156 if (IS_ERR(dir)) 157 return PTR_ERR(dir); 158 159 /* Cache the values into lpss structure */ 160 intel_lpss_cache_ltr(lpss); 161 162 debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps); 163 debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr); 164 debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr); 165 166 lpss->debugfs = dir; 167 return 0; 168 } 169 170 static void intel_lpss_debugfs_remove(struct intel_lpss *lpss) 171 { 172 debugfs_remove_recursive(lpss->debugfs); 173 } 174 175 static void intel_lpss_ltr_set(struct device *dev, s32 val) 176 { 177 struct intel_lpss *lpss = dev_get_drvdata(dev); 178 u32 ltr; 179 180 /* 181 * Program latency tolerance (LTR) accordingly what has been asked 182 * by the PM QoS layer or disable it in case we were passed 183 * negative value or PM_QOS_LATENCY_ANY. 184 */ 185 ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR); 186 187 if (val == PM_QOS_LATENCY_ANY || val < 0) { 188 ltr &= ~LPSS_PRIV_LTR_REQ; 189 } else { 190 ltr |= LPSS_PRIV_LTR_REQ; 191 ltr &= ~LPSS_PRIV_LTR_SCALE_MASK; 192 ltr &= ~LPSS_PRIV_LTR_VALUE_MASK; 193 194 if (val > LPSS_PRIV_LTR_VALUE_MASK) 195 ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5; 196 else 197 ltr |= LPSS_PRIV_LTR_SCALE_1US | val; 198 } 199 200 if (ltr == lpss->active_ltr) 201 return; 202 203 writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR); 204 writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR); 205 206 /* Cache the values into lpss structure */ 207 intel_lpss_cache_ltr(lpss); 208 } 209 210 static void intel_lpss_ltr_expose(struct intel_lpss *lpss) 211 { 212 lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set; 213 dev_pm_qos_expose_latency_tolerance(lpss->dev); 214 } 215 216 static void intel_lpss_ltr_hide(struct intel_lpss *lpss) 217 { 218 dev_pm_qos_hide_latency_tolerance(lpss->dev); 219 lpss->dev->power.set_latency_tolerance = NULL; 220 } 221 222 static int intel_lpss_assign_devs(struct intel_lpss *lpss) 223 { 224 const struct mfd_cell *cell; 225 unsigned int type; 226 227 type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK; 228 type >>= LPSS_PRIV_CAPS_TYPE_SHIFT; 229 230 switch (type) { 231 case LPSS_DEV_I2C: 232 cell = &intel_lpss_i2c_cell; 233 break; 234 case LPSS_DEV_UART: 235 cell = &intel_lpss_uart_cell; 236 break; 237 case LPSS_DEV_SPI: 238 cell = &intel_lpss_spi_cell; 239 break; 240 default: 241 return -ENODEV; 242 } 243 244 lpss->cell = devm_kmemdup(lpss->dev, cell, sizeof(*cell), GFP_KERNEL); 245 if (!lpss->cell) 246 return -ENOMEM; 247 248 lpss->type = type; 249 250 return 0; 251 } 252 253 static bool intel_lpss_has_idma(const struct intel_lpss *lpss) 254 { 255 return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0; 256 } 257 258 static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss) 259 { 260 resource_size_t addr = lpss->info->mem->start; 261 262 lo_hi_writeq(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR); 263 } 264 265 static void intel_lpss_deassert_reset(const struct intel_lpss *lpss) 266 { 267 u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA; 268 269 /* Bring out the device from reset */ 270 writel(value, lpss->priv + LPSS_PRIV_RESETS); 271 } 272 273 static void intel_lpss_init_dev(const struct intel_lpss *lpss) 274 { 275 u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN; 276 277 intel_lpss_deassert_reset(lpss); 278 279 intel_lpss_set_remap_addr(lpss); 280 281 if (!intel_lpss_has_idma(lpss)) 282 return; 283 284 /* Make sure that SPI multiblock DMA transfers are re-enabled */ 285 if (lpss->type == LPSS_DEV_SPI) 286 writel(value, lpss->priv + LPSS_PRIV_SSP_REG); 287 } 288 289 static void intel_lpss_unregister_clock_tree(struct clk *clk) 290 { 291 struct clk *parent; 292 293 while (clk) { 294 parent = clk_get_parent(clk); 295 clk_unregister(clk); 296 clk = parent; 297 } 298 } 299 300 static int intel_lpss_register_clock_divider(struct intel_lpss *lpss, 301 const char *devname, 302 struct clk **clk) 303 { 304 char name[32]; 305 struct clk *tmp = *clk; 306 307 snprintf(name, sizeof(name), "%s-enable", devname); 308 tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0, 309 lpss->priv, 0, 0, NULL); 310 if (IS_ERR(tmp)) 311 return PTR_ERR(tmp); 312 313 snprintf(name, sizeof(name), "%s-div", devname); 314 tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp), 315 0, lpss->priv, 1, 15, 16, 15, 0, 316 NULL); 317 if (IS_ERR(tmp)) 318 return PTR_ERR(tmp); 319 *clk = tmp; 320 321 snprintf(name, sizeof(name), "%s-update", devname); 322 tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 323 CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL); 324 if (IS_ERR(tmp)) 325 return PTR_ERR(tmp); 326 *clk = tmp; 327 328 return 0; 329 } 330 331 static int intel_lpss_register_clock(struct intel_lpss *lpss) 332 { 333 const struct mfd_cell *cell = lpss->cell; 334 struct clk *clk; 335 char devname[24]; 336 int ret; 337 338 if (!lpss->info->clk_rate) 339 return 0; 340 341 /* Root clock */ 342 clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL, 0, 343 lpss->info->clk_rate); 344 if (IS_ERR(clk)) 345 return PTR_ERR(clk); 346 347 snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid); 348 349 /* 350 * Support for clock divider only if it has some preset value. 351 * Otherwise we assume that the divider is not used. 352 */ 353 if (lpss->type != LPSS_DEV_I2C) { 354 ret = intel_lpss_register_clock_divider(lpss, devname, &clk); 355 if (ret) 356 goto err_clk_register; 357 } 358 359 ret = -ENOMEM; 360 361 /* Clock for the host controller */ 362 lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname); 363 if (!lpss->clock) 364 goto err_clk_register; 365 366 lpss->clk = clk; 367 368 return 0; 369 370 err_clk_register: 371 intel_lpss_unregister_clock_tree(clk); 372 373 return ret; 374 } 375 376 static void intel_lpss_unregister_clock(struct intel_lpss *lpss) 377 { 378 if (IS_ERR_OR_NULL(lpss->clk)) 379 return; 380 381 clkdev_drop(lpss->clock); 382 intel_lpss_unregister_clock_tree(lpss->clk); 383 } 384 385 int intel_lpss_probe(struct device *dev, 386 const struct intel_lpss_platform_info *info) 387 { 388 struct intel_lpss *lpss; 389 int ret; 390 391 if (!info || !info->mem || info->irq <= 0) 392 return -EINVAL; 393 394 lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL); 395 if (!lpss) 396 return -ENOMEM; 397 398 lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET, 399 LPSS_PRIV_SIZE); 400 if (!lpss->priv) 401 return -ENOMEM; 402 403 lpss->info = info; 404 lpss->dev = dev; 405 lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS); 406 407 dev_set_drvdata(dev, lpss); 408 409 ret = intel_lpss_assign_devs(lpss); 410 if (ret) 411 return ret; 412 413 lpss->cell->properties = info->properties; 414 415 intel_lpss_init_dev(lpss); 416 417 lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL); 418 if (lpss->devid < 0) 419 return lpss->devid; 420 421 ret = intel_lpss_register_clock(lpss); 422 if (ret) 423 goto err_clk_register; 424 425 intel_lpss_ltr_expose(lpss); 426 427 ret = intel_lpss_debugfs_add(lpss); 428 if (ret) 429 dev_warn(dev, "Failed to create debugfs entries\n"); 430 431 if (intel_lpss_has_idma(lpss)) { 432 /* 433 * Ensure the DMA driver is loaded before the host 434 * controller device appears, so that the host controller 435 * driver can request its DMA channels as early as 436 * possible. 437 * 438 * If the DMA module is not there that's OK as well. 439 */ 440 intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME); 441 442 ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell, 443 1, info->mem, info->irq, NULL); 444 if (ret) 445 dev_warn(dev, "Failed to add %s, fallback to PIO\n", 446 LPSS_IDMA64_DRIVER_NAME); 447 } 448 449 ret = mfd_add_devices(dev, lpss->devid, lpss->cell, 450 1, info->mem, info->irq, NULL); 451 if (ret) 452 goto err_remove_ltr; 453 454 dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND); 455 456 return 0; 457 458 err_remove_ltr: 459 intel_lpss_debugfs_remove(lpss); 460 intel_lpss_ltr_hide(lpss); 461 intel_lpss_unregister_clock(lpss); 462 463 err_clk_register: 464 ida_simple_remove(&intel_lpss_devid_ida, lpss->devid); 465 466 return ret; 467 } 468 EXPORT_SYMBOL_GPL(intel_lpss_probe); 469 470 void intel_lpss_remove(struct device *dev) 471 { 472 struct intel_lpss *lpss = dev_get_drvdata(dev); 473 474 mfd_remove_devices(dev); 475 intel_lpss_debugfs_remove(lpss); 476 intel_lpss_ltr_hide(lpss); 477 intel_lpss_unregister_clock(lpss); 478 ida_simple_remove(&intel_lpss_devid_ida, lpss->devid); 479 } 480 EXPORT_SYMBOL_GPL(intel_lpss_remove); 481 482 static int resume_lpss_device(struct device *dev, void *data) 483 { 484 if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND)) 485 pm_runtime_resume(dev); 486 487 return 0; 488 } 489 490 int intel_lpss_prepare(struct device *dev) 491 { 492 /* 493 * Resume both child devices before entering system sleep. This 494 * ensures that they are in proper state before they get suspended. 495 */ 496 device_for_each_child_reverse(dev, NULL, resume_lpss_device); 497 return 0; 498 } 499 EXPORT_SYMBOL_GPL(intel_lpss_prepare); 500 501 int intel_lpss_suspend(struct device *dev) 502 { 503 struct intel_lpss *lpss = dev_get_drvdata(dev); 504 unsigned int i; 505 506 /* Save device context */ 507 for (i = 0; i < LPSS_PRIV_REG_COUNT; i++) 508 lpss->priv_ctx[i] = readl(lpss->priv + i * 4); 509 510 /* 511 * If the device type is not UART, then put the controller into 512 * reset. UART cannot be put into reset since S3/S0ix fail when 513 * no_console_suspend flag is enabled. 514 */ 515 if (lpss->type != LPSS_DEV_UART) 516 writel(0, lpss->priv + LPSS_PRIV_RESETS); 517 518 return 0; 519 } 520 EXPORT_SYMBOL_GPL(intel_lpss_suspend); 521 522 int intel_lpss_resume(struct device *dev) 523 { 524 struct intel_lpss *lpss = dev_get_drvdata(dev); 525 unsigned int i; 526 527 intel_lpss_deassert_reset(lpss); 528 529 /* Restore device context */ 530 for (i = 0; i < LPSS_PRIV_REG_COUNT; i++) 531 writel(lpss->priv_ctx[i], lpss->priv + i * 4); 532 533 return 0; 534 } 535 EXPORT_SYMBOL_GPL(intel_lpss_resume); 536 537 static int __init intel_lpss_init(void) 538 { 539 intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL); 540 return 0; 541 } 542 module_init(intel_lpss_init); 543 544 static void __exit intel_lpss_exit(void) 545 { 546 debugfs_remove(intel_lpss_debugfs); 547 } 548 module_exit(intel_lpss_exit); 549 550 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>"); 551 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>"); 552 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>"); 553 MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>"); 554 MODULE_DESCRIPTION("Intel LPSS core driver"); 555 MODULE_LICENSE("GPL v2"); 556