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