drivers/acpi/acpi_lpss.c

   1 /*
   2  * ACPI support for Intel Lynxpoint LPSS.
   3  *
   4  * Copyright (C) 2013, Intel Corporation
   5  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
   6  *          Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/acpi.h>
  14 #include <linux/clk.h>
  15 #include <linux/clkdev.h>
  16 #include <linux/clk-provider.h>
  17 #include <linux/err.h>
  18 #include <linux/io.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/platform_data/clk-lpss.h>
  21 #include <linux/pm_runtime.h>
  22 #include <linux/delay.h>
  23
  24 #include "internal.h"
  25
  26 ACPI_MODULE_NAME("acpi_lpss");
  27
  28 #ifdef CONFIG_X86_INTEL_LPSS
  29
  30 #define LPSS_ADDR(desc) ((unsigned long)&desc)
  31
  32 #define LPSS_CLK_SIZE   0x04
  33 #define LPSS_LTR_SIZE   0x18
  34
  35 /* Offsets relative to LPSS_PRIVATE_OFFSET */
  36 #define LPSS_CLK_DIVIDER_DEF_MASK       (BIT(1) | BIT(16))
  37 #define LPSS_GENERAL                    0x08
  38 #define LPSS_GENERAL_LTR_MODE_SW        BIT(2)
  39 #define LPSS_GENERAL_UART_RTS_OVRD      BIT(3)
  40 #define LPSS_SW_LTR                     0x10
  41 #define LPSS_AUTO_LTR                   0x14
  42 #define LPSS_LTR_SNOOP_REQ              BIT(15)
  43 #define LPSS_LTR_SNOOP_MASK             0x0000FFFF
  44 #define LPSS_LTR_SNOOP_LAT_1US          0x800
  45 #define LPSS_LTR_SNOOP_LAT_32US         0xC00
  46 #define LPSS_LTR_SNOOP_LAT_SHIFT        5
  47 #define LPSS_LTR_SNOOP_LAT_CUTOFF       3000
  48 #define LPSS_LTR_MAX_VAL                0x3FF
  49 #define LPSS_TX_INT                     0x20
  50 #define LPSS_TX_INT_MASK                BIT(1)
  51
  52 #define LPSS_PRV_REG_COUNT              9
  53
  54 struct lpss_shared_clock {
  55         const char *name;
  56         unsigned long rate;
  57         struct clk *clk;
  58 };
  59
  60 struct lpss_private_data;
  61
  62 struct lpss_device_desc {
  63         bool clk_required;
  64         const char *clkdev_name;
  65         bool ltr_required;
  66         unsigned int prv_offset;
  67         size_t prv_size_override;
  68         bool clk_divider;
  69         bool clk_gate;
  70         bool save_ctx;
  71         struct lpss_shared_clock *shared_clock;
  72         void (*setup)(struct lpss_private_data *pdata);
  73 };
  74
  75 static struct lpss_device_desc lpss_dma_desc = {
  76         .clk_required = true,
  77         .clkdev_name = "hclk",
  78 };
  79
  80 struct lpss_private_data {
  81         void __iomem *mmio_base;
  82         resource_size_t mmio_size;
  83         struct clk *clk;
  84         const struct lpss_device_desc *dev_desc;
  85         u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
  86 };
  87
  88 static void lpss_uart_setup(struct lpss_private_data *pdata)
  89 {
  90         unsigned int offset;
  91         u32 reg;
  92
  93         offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
  94         reg = readl(pdata->mmio_base + offset);
  95         writel(reg | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
  96
  97         offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
  98         reg = readl(pdata->mmio_base + offset);
  99         writel(reg | LPSS_GENERAL_UART_RTS_OVRD, pdata->mmio_base + offset);
 100 }
 101
 102 static struct lpss_device_desc lpt_dev_desc = {
 103         .clk_required = true,
 104         .prv_offset = 0x800,
 105         .ltr_required = true,
 106         .clk_divider = true,
 107         .clk_gate = true,
 108 };
 109
 110 static struct lpss_device_desc lpt_i2c_dev_desc = {
 111         .clk_required = true,
 112         .prv_offset = 0x800,
 113         .ltr_required = true,
 114         .clk_gate = true,
 115 };
 116
 117 static struct lpss_device_desc lpt_uart_dev_desc = {
 118         .clk_required = true,
 119         .prv_offset = 0x800,
 120         .ltr_required = true,
 121         .clk_divider = true,
 122         .clk_gate = true,
 123         .setup = lpss_uart_setup,
 124 };
 125
 126 static struct lpss_device_desc lpt_sdio_dev_desc = {
 127         .prv_offset = 0x1000,
 128         .prv_size_override = 0x1018,
 129         .ltr_required = true,
 130 };
 131
 132 static struct lpss_shared_clock pwm_clock = {
 133         .name = "pwm_clk",
 134         .rate = 25000000,
 135 };
 136
 137 static struct lpss_device_desc byt_pwm_dev_desc = {
 138         .clk_required = true,
 139         .save_ctx = true,
 140         .shared_clock = &pwm_clock,
 141 };
 142
 143 static struct lpss_device_desc byt_uart_dev_desc = {
 144         .clk_required = true,
 145         .prv_offset = 0x800,
 146         .clk_divider = true,
 147         .clk_gate = true,
 148         .save_ctx = true,
 149         .setup = lpss_uart_setup,
 150 };
 151
 152 static struct lpss_device_desc byt_spi_dev_desc = {
 153         .clk_required = true,
 154         .prv_offset = 0x400,
 155         .clk_divider = true,
 156         .clk_gate = true,
 157         .save_ctx = true,
 158 };
 159
 160 static struct lpss_device_desc byt_sdio_dev_desc = {
 161         .clk_required = true,
 162 };
 163
 164 static struct lpss_shared_clock i2c_clock = {
 165         .name = "i2c_clk",
 166         .rate = 100000000,
 167 };
 168
 169 static struct lpss_device_desc byt_i2c_dev_desc = {
 170         .clk_required = true,
 171         .prv_offset = 0x800,
 172         .save_ctx = true,
 173         .shared_clock = &i2c_clock,
 174 };
 175
 176 #else
 177
 178 #define LPSS_ADDR(desc) (0UL)
 179
 180 #endif /* CONFIG_X86_INTEL_LPSS */
 181
 182 static const struct acpi_device_id acpi_lpss_device_ids[] = {
 183         /* Generic LPSS devices */
 184         { "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
 185
 186         /* Lynxpoint LPSS devices */
 187         { "INT33C0", LPSS_ADDR(lpt_dev_desc) },
 188         { "INT33C1", LPSS_ADDR(lpt_dev_desc) },
 189         { "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
 190         { "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
 191         { "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
 192         { "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
 193         { "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
 194         { "INT33C7", },
 195
 196         /* BayTrail LPSS devices */
 197         { "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
 198         { "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
 199         { "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
 200         { "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
 201         { "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
 202         { "INT33B2", },
 203         { "INT33FC", },
 204
 205         { "INT3430", LPSS_ADDR(lpt_dev_desc) },
 206         { "INT3431", LPSS_ADDR(lpt_dev_desc) },
 207         { "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
 208         { "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
 209         { "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
 210         { "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
 211         { "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
 212         { "INT3437", },
 213
 214         { }
 215 };
 216
 217 #ifdef CONFIG_X86_INTEL_LPSS
 218
 219 static int is_memory(struct acpi_resource *res, void *not_used)
 220 {
 221         struct resource r;
 222         return !acpi_dev_resource_memory(res, &r);
 223 }
 224
 225 /* LPSS main clock device. */
 226 static struct platform_device *lpss_clk_dev;
 227
 228 static inline void lpt_register_clock_device(void)
 229 {
 230         lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
 231 }
 232
 233 static int register_device_clock(struct acpi_device *adev,
 234                                  struct lpss_private_data *pdata)
 235 {
 236         const struct lpss_device_desc *dev_desc = pdata->dev_desc;
 237         struct lpss_shared_clock *shared_clock = dev_desc->shared_clock;
 238         const char *devname = dev_name(&adev->dev);
 239         struct clk *clk = ERR_PTR(-ENODEV);
 240         struct lpss_clk_data *clk_data;
 241         const char *parent, *clk_name;
 242         void __iomem *prv_base;
 243
 244         if (!lpss_clk_dev)
 245                 lpt_register_clock_device();
 246
 247         clk_data = platform_get_drvdata(lpss_clk_dev);
 248         if (!clk_data)
 249                 return -ENODEV;
 250
 251         if (dev_desc->clkdev_name) {
 252                 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
 253                                     devname);
 254                 return 0;
 255         }
 256
 257         if (!pdata->mmio_base
 258             || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
 259                 return -ENODATA;
 260
 261         parent = clk_data->name;
 262         prv_base = pdata->mmio_base + dev_desc->prv_offset;
 263
 264         if (shared_clock) {
 265                 clk = shared_clock->clk;
 266                 if (!clk) {
 267                         clk = clk_register_fixed_rate(NULL, shared_clock->name,
 268                                                       "lpss_clk", 0,
 269                                                       shared_clock->rate);
 270                         shared_clock->clk = clk;
 271                 }
 272                 parent = shared_clock->name;
 273         }
 274
 275         if (dev_desc->clk_gate) {
 276                 clk = clk_register_gate(NULL, devname, parent, 0,
 277                                         prv_base, 0, 0, NULL);
 278                 parent = devname;
 279         }
 280
 281         if (dev_desc->clk_divider) {
 282                 /* Prevent division by zero */
 283                 if (!readl(prv_base))
 284                         writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
 285
 286                 clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
 287                 if (!clk_name)
 288                         return -ENOMEM;
 289                 clk = clk_register_fractional_divider(NULL, clk_name, parent,
 290                                                       0, prv_base,
 291                                                       1, 15, 16, 15, 0, NULL);
 292                 parent = clk_name;
 293
 294                 clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
 295                 if (!clk_name) {
 296                         kfree(parent);
 297                         return -ENOMEM;
 298                 }
 299                 clk = clk_register_gate(NULL, clk_name, parent,
 300                                         CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
 301                                         prv_base, 31, 0, NULL);
 302                 kfree(parent);
 303                 kfree(clk_name);
 304         }
 305
 306         if (IS_ERR(clk))
 307                 return PTR_ERR(clk);
 308
 309         pdata->clk = clk;
 310         clk_register_clkdev(clk, NULL, devname);
 311         return 0;
 312 }
 313
 314 static int acpi_lpss_create_device(struct acpi_device *adev,
 315                                    const struct acpi_device_id *id)
 316 {
 317         struct lpss_device_desc *dev_desc;
 318         struct lpss_private_data *pdata;
 319         struct resource_list_entry *rentry;
 320         struct list_head resource_list;
 321         struct platform_device *pdev;
 322         int ret;
 323
 324         dev_desc = (struct lpss_device_desc *)id->driver_data;
 325         if (!dev_desc) {
 326                 pdev = acpi_create_platform_device(adev);
 327                 return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
 328         }
 329         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 330         if (!pdata)
 331                 return -ENOMEM;
 332
 333         INIT_LIST_HEAD(&resource_list);
 334         ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
 335         if (ret < 0)
 336                 goto err_out;
 337
 338         list_for_each_entry(rentry, &resource_list, node)
 339                 if (resource_type(&rentry->res) == IORESOURCE_MEM) {
 340                         if (dev_desc->prv_size_override)
 341                                 pdata->mmio_size = dev_desc->prv_size_override;
 342                         else
 343                                 pdata->mmio_size = resource_size(&rentry->res);
 344                         pdata->mmio_base = ioremap(rentry->res.start,
 345                                                    pdata->mmio_size);
 346                         break;
 347                 }
 348
 349         acpi_dev_free_resource_list(&resource_list);
 350
 351         pdata->dev_desc = dev_desc;
 352
 353         if (dev_desc->clk_required) {
 354                 ret = register_device_clock(adev, pdata);
 355                 if (ret) {
 356                         /* Skip the device, but continue the namespace scan. */
 357                         ret = 0;
 358                         goto err_out;
 359                 }
 360         }
 361
 362         /*
 363          * This works around a known issue in ACPI tables where LPSS devices
 364          * have _PS0 and _PS3 without _PSC (and no power resources), so
 365          * acpi_bus_init_power() will assume that the BIOS has put them into D0.
 366          */
 367         ret = acpi_device_fix_up_power(adev);
 368         if (ret) {
 369                 /* Skip the device, but continue the namespace scan. */
 370                 ret = 0;
 371                 goto err_out;
 372         }
 373
 374         if (dev_desc->setup)
 375                 dev_desc->setup(pdata);
 376
 377         adev->driver_data = pdata;
 378         pdev = acpi_create_platform_device(adev);
 379         if (!IS_ERR_OR_NULL(pdev)) {
 380                 device_enable_async_suspend(&pdev->dev);
 381                 return 1;
 382         }
 383
 384         ret = PTR_ERR(pdev);
 385         adev->driver_data = NULL;
 386
 387  err_out:
 388         kfree(pdata);
 389         return ret;
 390 }
 391
 392 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
 393 {
 394         return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 395 }
 396
 397 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
 398                              unsigned int reg)
 399 {
 400         writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 401 }
 402
 403 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
 404 {
 405         struct acpi_device *adev;
 406         struct lpss_private_data *pdata;
 407         unsigned long flags;
 408         int ret;
 409
 410         ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
 411         if (WARN_ON(ret))
 412                 return ret;
 413
 414         spin_lock_irqsave(&dev->power.lock, flags);
 415         if (pm_runtime_suspended(dev)) {
 416                 ret = -EAGAIN;
 417                 goto out;
 418         }
 419         pdata = acpi_driver_data(adev);
 420         if (WARN_ON(!pdata || !pdata->mmio_base)) {
 421                 ret = -ENODEV;
 422                 goto out;
 423         }
 424         *val = __lpss_reg_read(pdata, reg);
 425
 426  out:
 427         spin_unlock_irqrestore(&dev->power.lock, flags);
 428         return ret;
 429 }
 430
 431 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
 432                              char *buf)
 433 {
 434         u32 ltr_value = 0;
 435         unsigned int reg;
 436         int ret;
 437
 438         reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
 439         ret = lpss_reg_read(dev, reg, &ltr_value);
 440         if (ret)
 441                 return ret;
 442
 443         return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
 444 }
 445
 446 static ssize_t lpss_ltr_mode_show(struct device *dev,
 447                                   struct device_attribute *attr, char *buf)
 448 {
 449         u32 ltr_mode = 0;
 450         char *outstr;
 451         int ret;
 452
 453         ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
 454         if (ret)
 455                 return ret;
 456
 457         outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
 458         return sprintf(buf, "%s\n", outstr);
 459 }
 460
 461 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
 462 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
 463 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
 464
 465 static struct attribute *lpss_attrs[] = {
 466         &dev_attr_auto_ltr.attr,
 467         &dev_attr_sw_ltr.attr,
 468         &dev_attr_ltr_mode.attr,
 469         NULL,
 470 };
 471
 472 static struct attribute_group lpss_attr_group = {
 473         .attrs = lpss_attrs,
 474         .name = "lpss_ltr",
 475 };
 476
 477 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
 478 {
 479         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 480         u32 ltr_mode, ltr_val;
 481
 482         ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
 483         if (val < 0) {
 484                 if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
 485                         ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
 486                         __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 487                 }
 488                 return;
 489         }
 490         ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
 491         if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
 492                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
 493                 val = LPSS_LTR_MAX_VAL;
 494         } else if (val > LPSS_LTR_MAX_VAL) {
 495                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
 496                 val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
 497         } else {
 498                 ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
 499         }
 500         ltr_val |= val;
 501         __lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
 502         if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
 503                 ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
 504                 __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 505         }
 506 }
 507
 508 #ifdef CONFIG_PM
 509 /**
 510  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
 511  * @dev: LPSS device
 512  *
 513  * Most LPSS devices have private registers which may loose their context when
 514  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
 515  * prv_reg_ctx array.
 516  */
 517 static void acpi_lpss_save_ctx(struct device *dev)
 518 {
 519         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 520         unsigned int i;
 521
 522         for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
 523                 unsigned long offset = i * sizeof(u32);
 524
 525                 pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
 526                 dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
 527                         pdata->prv_reg_ctx[i], offset);
 528         }
 529 }
 530
 531 /**
 532  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
 533  * @dev: LPSS device
 534  *
 535  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
 536  */
 537 static void acpi_lpss_restore_ctx(struct device *dev)
 538 {
 539         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 540         unsigned int i;
 541
 542         /*
 543          * The following delay is needed or the subsequent write operations may
 544          * fail. The LPSS devices are actually PCI devices and the PCI spec
 545          * expects 10ms delay before the device can be accessed after D3 to D0
 546          * transition.
 547          */
 548         msleep(10);
 549
 550         for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
 551                 unsigned long offset = i * sizeof(u32);
 552
 553                 __lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
 554                 dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
 555                         pdata->prv_reg_ctx[i], offset);
 556         }
 557 }
 558
 559 #ifdef CONFIG_PM_SLEEP
 560 static int acpi_lpss_suspend_late(struct device *dev)
 561 {
 562         int ret = pm_generic_suspend_late(dev);
 563
 564         if (ret)
 565                 return ret;
 566
 567         acpi_lpss_save_ctx(dev);
 568         return acpi_dev_suspend_late(dev);
 569 }
 570
 571 static int acpi_lpss_restore_early(struct device *dev)
 572 {
 573         int ret = acpi_dev_resume_early(dev);
 574
 575         if (ret)
 576                 return ret;
 577
 578         acpi_lpss_restore_ctx(dev);
 579         return pm_generic_resume_early(dev);
 580 }
 581 #endif /* CONFIG_PM_SLEEP */
 582
 583 #ifdef CONFIG_PM_RUNTIME
 584 static int acpi_lpss_runtime_suspend(struct device *dev)
 585 {
 586         int ret = pm_generic_runtime_suspend(dev);
 587
 588         if (ret)
 589                 return ret;
 590
 591         acpi_lpss_save_ctx(dev);
 592         return acpi_dev_runtime_suspend(dev);
 593 }
 594
 595 static int acpi_lpss_runtime_resume(struct device *dev)
 596 {
 597         int ret = acpi_dev_runtime_resume(dev);
 598
 599         if (ret)
 600                 return ret;
 601
 602         acpi_lpss_restore_ctx(dev);
 603         return pm_generic_runtime_resume(dev);
 604 }
 605 #endif /* CONFIG_PM_RUNTIME */
 606 #endif /* CONFIG_PM */
 607
 608 static struct dev_pm_domain acpi_lpss_pm_domain = {
 609         .ops = {
 610 #ifdef CONFIG_PM_SLEEP
 611                 .suspend_late = acpi_lpss_suspend_late,
 612                 .restore_early = acpi_lpss_restore_early,
 613                 .prepare = acpi_subsys_prepare,
 614                 .complete = acpi_subsys_complete,
 615                 .suspend = acpi_subsys_suspend,
 616                 .resume_early = acpi_subsys_resume_early,
 617                 .freeze = acpi_subsys_freeze,
 618                 .poweroff = acpi_subsys_suspend,
 619                 .poweroff_late = acpi_subsys_suspend_late,
 620 #endif
 621 #ifdef CONFIG_PM_RUNTIME
 622                 .runtime_suspend = acpi_lpss_runtime_suspend,
 623                 .runtime_resume = acpi_lpss_runtime_resume,
 624 #endif
 625         },
 626 };
 627
 628 static int acpi_lpss_platform_notify(struct notifier_block *nb,
 629                                      unsigned long action, void *data)
 630 {
 631         struct platform_device *pdev = to_platform_device(data);
 632         struct lpss_private_data *pdata;
 633         struct acpi_device *adev;
 634         const struct acpi_device_id *id;
 635
 636         id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
 637         if (!id || !id->driver_data)
 638                 return 0;
 639
 640         if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
 641                 return 0;
 642
 643         pdata = acpi_driver_data(adev);
 644         if (!pdata || !pdata->mmio_base)
 645                 return 0;
 646
 647         if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
 648                 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
 649                 return 0;
 650         }
 651
 652         switch (action) {
 653         case BUS_NOTIFY_BOUND_DRIVER:
 654                 if (pdata->dev_desc->save_ctx)
 655                         pdev->dev.pm_domain = &acpi_lpss_pm_domain;
 656                 break;
 657         case BUS_NOTIFY_UNBOUND_DRIVER:
 658                 if (pdata->dev_desc->save_ctx)
 659                         pdev->dev.pm_domain = NULL;
 660                 break;
 661         case BUS_NOTIFY_ADD_DEVICE:
 662                 if (pdata->dev_desc->ltr_required)
 663                         return sysfs_create_group(&pdev->dev.kobj,
 664                                                   &lpss_attr_group);
 665         case BUS_NOTIFY_DEL_DEVICE:
 666                 if (pdata->dev_desc->ltr_required)
 667                         sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
 668         default:
 669                 break;
 670         }
 671
 672         return 0;
 673 }
 674
 675 static struct notifier_block acpi_lpss_nb = {
 676         .notifier_call = acpi_lpss_platform_notify,
 677 };
 678
 679 static void acpi_lpss_bind(struct device *dev)
 680 {
 681         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 682
 683         if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
 684                 return;
 685
 686         if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
 687                 dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
 688         else
 689                 dev_err(dev, "MMIO size insufficient to access LTR\n");
 690 }
 691
 692 static void acpi_lpss_unbind(struct device *dev)
 693 {
 694         dev->power.set_latency_tolerance = NULL;
 695 }
 696
 697 static struct acpi_scan_handler lpss_handler = {
 698         .ids = acpi_lpss_device_ids,
 699         .attach = acpi_lpss_create_device,
 700         .bind = acpi_lpss_bind,
 701         .unbind = acpi_lpss_unbind,
 702 };
 703
 704 void __init acpi_lpss_init(void)
 705 {
 706         if (!lpt_clk_init()) {
 707                 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
 708                 acpi_scan_add_handler(&lpss_handler);
 709         }
 710 }
 711
 712 #else
 713
 714 static struct acpi_scan_handler lpss_handler = {
 715         .ids = acpi_lpss_device_ids,
 716 };
 717
 718 void __init acpi_lpss_init(void)
 719 {
 720         acpi_scan_add_handler(&lpss_handler);
 721 }
 722
 723 #endif /* CONFIG_X86_INTEL_LPSS */