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_RESETS                     0x04
  38 #define LPSS_RESETS_RESET_FUNC          BIT(0)
  39 #define LPSS_RESETS_RESET_APB           BIT(1)
  40 #define LPSS_GENERAL                    0x08
  41 #define LPSS_GENERAL_LTR_MODE_SW        BIT(2)
  42 #define LPSS_GENERAL_UART_RTS_OVRD      BIT(3)
  43 #define LPSS_SW_LTR                     0x10
  44 #define LPSS_AUTO_LTR                   0x14
  45 #define LPSS_LTR_SNOOP_REQ              BIT(15)
  46 #define LPSS_LTR_SNOOP_MASK             0x0000FFFF
  47 #define LPSS_LTR_SNOOP_LAT_1US          0x800
  48 #define LPSS_LTR_SNOOP_LAT_32US         0xC00
  49 #define LPSS_LTR_SNOOP_LAT_SHIFT        5
  50 #define LPSS_LTR_SNOOP_LAT_CUTOFF       3000
  51 #define LPSS_LTR_MAX_VAL                0x3FF
  52 #define LPSS_TX_INT                     0x20
  53 #define LPSS_TX_INT_MASK                BIT(1)
  54
  55 #define LPSS_PRV_REG_COUNT              9
  56
  57 struct lpss_shared_clock {
  58         const char *name;
  59         unsigned long rate;
  60         struct clk *clk;
  61 };
  62
  63 struct lpss_private_data;
  64
  65 struct lpss_device_desc {
  66         bool clk_required;
  67         const char *clkdev_name;
  68         bool ltr_required;
  69         unsigned int prv_offset;
  70         size_t prv_size_override;
  71         bool clk_divider;
  72         bool clk_gate;
  73         bool save_ctx;
  74         struct lpss_shared_clock *shared_clock;
  75         void (*setup)(struct lpss_private_data *pdata);
  76 };
  77
  78 static struct lpss_device_desc lpss_dma_desc = {
  79         .clk_required = true,
  80         .clkdev_name = "hclk",
  81 };
  82
  83 struct lpss_private_data {
  84         void __iomem *mmio_base;
  85         resource_size_t mmio_size;
  86         struct clk *clk;
  87         const struct lpss_device_desc *dev_desc;
  88         u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
  89 };
  90
  91 static void lpss_uart_setup(struct lpss_private_data *pdata)
  92 {
  93         unsigned int offset;
  94         u32 reg;
  95
  96         offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
  97         reg = readl(pdata->mmio_base + offset);
  98         writel(reg | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
  99
 100         offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
 101         reg = readl(pdata->mmio_base + offset);
 102         writel(reg | LPSS_GENERAL_UART_RTS_OVRD, pdata->mmio_base + offset);
 103 }
 104
 105 static void lpss_i2c_setup(struct lpss_private_data *pdata)
 106 {
 107         unsigned int offset;
 108         u32 val;
 109
 110         offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
 111         val = readl(pdata->mmio_base + offset);
 112         val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
 113         writel(val, pdata->mmio_base + offset);
 114 }
 115
 116 static struct lpss_device_desc lpt_dev_desc = {
 117         .clk_required = true,
 118         .prv_offset = 0x800,
 119         .ltr_required = true,
 120         .clk_divider = true,
 121         .clk_gate = true,
 122 };
 123
 124 static struct lpss_device_desc lpt_i2c_dev_desc = {
 125         .clk_required = true,
 126         .prv_offset = 0x800,
 127         .ltr_required = true,
 128         .clk_gate = true,
 129 };
 130
 131 static struct lpss_device_desc lpt_uart_dev_desc = {
 132         .clk_required = true,
 133         .prv_offset = 0x800,
 134         .ltr_required = true,
 135         .clk_divider = true,
 136         .clk_gate = true,
 137         .setup = lpss_uart_setup,
 138 };
 139
 140 static struct lpss_device_desc lpt_sdio_dev_desc = {
 141         .prv_offset = 0x1000,
 142         .prv_size_override = 0x1018,
 143         .ltr_required = true,
 144 };
 145
 146 static struct lpss_shared_clock pwm_clock = {
 147         .name = "pwm_clk",
 148         .rate = 25000000,
 149 };
 150
 151 static struct lpss_device_desc byt_pwm_dev_desc = {
 152         .clk_required = true,
 153         .save_ctx = true,
 154         .shared_clock = &pwm_clock,
 155 };
 156
 157 static struct lpss_device_desc byt_uart_dev_desc = {
 158         .clk_required = true,
 159         .prv_offset = 0x800,
 160         .clk_divider = true,
 161         .clk_gate = true,
 162         .save_ctx = true,
 163         .setup = lpss_uart_setup,
 164 };
 165
 166 static struct lpss_device_desc byt_spi_dev_desc = {
 167         .clk_required = true,
 168         .prv_offset = 0x400,
 169         .clk_divider = true,
 170         .clk_gate = true,
 171         .save_ctx = true,
 172 };
 173
 174 static struct lpss_device_desc byt_sdio_dev_desc = {
 175         .clk_required = true,
 176 };
 177
 178 static struct lpss_shared_clock i2c_clock = {
 179         .name = "i2c_clk",
 180         .rate = 100000000,
 181 };
 182
 183 static struct lpss_device_desc byt_i2c_dev_desc = {
 184         .clk_required = true,
 185         .prv_offset = 0x800,
 186         .save_ctx = true,
 187         .shared_clock = &i2c_clock,
 188         .setup = lpss_i2c_setup,
 189 };
 190
 191 #else
 192
 193 #define LPSS_ADDR(desc) (0UL)
 194
 195 #endif /* CONFIG_X86_INTEL_LPSS */
 196
 197 static const struct acpi_device_id acpi_lpss_device_ids[] = {
 198         /* Generic LPSS devices */
 199         { "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
 200
 201         /* Lynxpoint LPSS devices */
 202         { "INT33C0", LPSS_ADDR(lpt_dev_desc) },
 203         { "INT33C1", LPSS_ADDR(lpt_dev_desc) },
 204         { "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
 205         { "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
 206         { "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
 207         { "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
 208         { "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
 209         { "INT33C7", },
 210
 211         /* BayTrail LPSS devices */
 212         { "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
 213         { "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
 214         { "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
 215         { "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
 216         { "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
 217         { "INT33B2", },
 218         { "INT33FC", },
 219
 220         { "INT3430", LPSS_ADDR(lpt_dev_desc) },
 221         { "INT3431", LPSS_ADDR(lpt_dev_desc) },
 222         { "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
 223         { "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
 224         { "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
 225         { "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
 226         { "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
 227         { "INT3437", },
 228
 229         { }
 230 };
 231
 232 #ifdef CONFIG_X86_INTEL_LPSS
 233
 234 static int is_memory(struct acpi_resource *res, void *not_used)
 235 {
 236         struct resource r;
 237         return !acpi_dev_resource_memory(res, &r);
 238 }
 239
 240 /* LPSS main clock device. */
 241 static struct platform_device *lpss_clk_dev;
 242
 243 static inline void lpt_register_clock_device(void)
 244 {
 245         lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
 246 }
 247
 248 static int register_device_clock(struct acpi_device *adev,
 249                                  struct lpss_private_data *pdata)
 250 {
 251         const struct lpss_device_desc *dev_desc = pdata->dev_desc;
 252         struct lpss_shared_clock *shared_clock = dev_desc->shared_clock;
 253         const char *devname = dev_name(&adev->dev);
 254         struct clk *clk = ERR_PTR(-ENODEV);
 255         struct lpss_clk_data *clk_data;
 256         const char *parent, *clk_name;
 257         void __iomem *prv_base;
 258
 259         if (!lpss_clk_dev)
 260                 lpt_register_clock_device();
 261
 262         clk_data = platform_get_drvdata(lpss_clk_dev);
 263         if (!clk_data)
 264                 return -ENODEV;
 265
 266         if (dev_desc->clkdev_name) {
 267                 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
 268                                     devname);
 269                 return 0;
 270         }
 271
 272         if (!pdata->mmio_base
 273             || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
 274                 return -ENODATA;
 275
 276         parent = clk_data->name;
 277         prv_base = pdata->mmio_base + dev_desc->prv_offset;
 278
 279         if (shared_clock) {
 280                 clk = shared_clock->clk;
 281                 if (!clk) {
 282                         clk = clk_register_fixed_rate(NULL, shared_clock->name,
 283                                                       "lpss_clk", 0,
 284                                                       shared_clock->rate);
 285                         shared_clock->clk = clk;
 286                 }
 287                 parent = shared_clock->name;
 288         }
 289
 290         if (dev_desc->clk_gate) {
 291                 clk = clk_register_gate(NULL, devname, parent, 0,
 292                                         prv_base, 0, 0, NULL);
 293                 parent = devname;
 294         }
 295
 296         if (dev_desc->clk_divider) {
 297                 /* Prevent division by zero */
 298                 if (!readl(prv_base))
 299                         writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
 300
 301                 clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
 302                 if (!clk_name)
 303                         return -ENOMEM;
 304                 clk = clk_register_fractional_divider(NULL, clk_name, parent,
 305                                                       0, prv_base,
 306                                                       1, 15, 16, 15, 0, NULL);
 307                 parent = clk_name;
 308
 309                 clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
 310                 if (!clk_name) {
 311                         kfree(parent);
 312                         return -ENOMEM;
 313                 }
 314                 clk = clk_register_gate(NULL, clk_name, parent,
 315                                         CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
 316                                         prv_base, 31, 0, NULL);
 317                 kfree(parent);
 318                 kfree(clk_name);
 319         }
 320
 321         if (IS_ERR(clk))
 322                 return PTR_ERR(clk);
 323
 324         pdata->clk = clk;
 325         clk_register_clkdev(clk, NULL, devname);
 326         return 0;
 327 }
 328
 329 static int acpi_lpss_create_device(struct acpi_device *adev,
 330                                    const struct acpi_device_id *id)
 331 {
 332         struct lpss_device_desc *dev_desc;
 333         struct lpss_private_data *pdata;
 334         struct resource_list_entry *rentry;
 335         struct list_head resource_list;
 336         struct platform_device *pdev;
 337         int ret;
 338
 339         dev_desc = (struct lpss_device_desc *)id->driver_data;
 340         if (!dev_desc) {
 341                 pdev = acpi_create_platform_device(adev);
 342                 return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
 343         }
 344         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 345         if (!pdata)
 346                 return -ENOMEM;
 347
 348         INIT_LIST_HEAD(&resource_list);
 349         ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
 350         if (ret < 0)
 351                 goto err_out;
 352
 353         list_for_each_entry(rentry, &resource_list, node)
 354                 if (resource_type(&rentry->res) == IORESOURCE_MEM) {
 355                         if (dev_desc->prv_size_override)
 356                                 pdata->mmio_size = dev_desc->prv_size_override;
 357                         else
 358                                 pdata->mmio_size = resource_size(&rentry->res);
 359                         pdata->mmio_base = ioremap(rentry->res.start,
 360                                                    pdata->mmio_size);
 361                         break;
 362                 }
 363
 364         acpi_dev_free_resource_list(&resource_list);
 365
 366         pdata->dev_desc = dev_desc;
 367
 368         if (dev_desc->clk_required) {
 369                 ret = register_device_clock(adev, pdata);
 370                 if (ret) {
 371                         /* Skip the device, but continue the namespace scan. */
 372                         ret = 0;
 373                         goto err_out;
 374                 }
 375         }
 376
 377         /*
 378          * This works around a known issue in ACPI tables where LPSS devices
 379          * have _PS0 and _PS3 without _PSC (and no power resources), so
 380          * acpi_bus_init_power() will assume that the BIOS has put them into D0.
 381          */
 382         ret = acpi_device_fix_up_power(adev);
 383         if (ret) {
 384                 /* Skip the device, but continue the namespace scan. */
 385                 ret = 0;
 386                 goto err_out;
 387         }
 388
 389         if (dev_desc->setup)
 390                 dev_desc->setup(pdata);
 391
 392         adev->driver_data = pdata;
 393         pdev = acpi_create_platform_device(adev);
 394         if (!IS_ERR_OR_NULL(pdev)) {
 395                 device_enable_async_suspend(&pdev->dev);
 396                 return 1;
 397         }
 398
 399         ret = PTR_ERR(pdev);
 400         adev->driver_data = NULL;
 401
 402  err_out:
 403         kfree(pdata);
 404         return ret;
 405 }
 406
 407 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
 408 {
 409         return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 410 }
 411
 412 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
 413                              unsigned int reg)
 414 {
 415         writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 416 }
 417
 418 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
 419 {
 420         struct acpi_device *adev;
 421         struct lpss_private_data *pdata;
 422         unsigned long flags;
 423         int ret;
 424
 425         ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
 426         if (WARN_ON(ret))
 427                 return ret;
 428
 429         spin_lock_irqsave(&dev->power.lock, flags);
 430         if (pm_runtime_suspended(dev)) {
 431                 ret = -EAGAIN;
 432                 goto out;
 433         }
 434         pdata = acpi_driver_data(adev);
 435         if (WARN_ON(!pdata || !pdata->mmio_base)) {
 436                 ret = -ENODEV;
 437                 goto out;
 438         }
 439         *val = __lpss_reg_read(pdata, reg);
 440
 441  out:
 442         spin_unlock_irqrestore(&dev->power.lock, flags);
 443         return ret;
 444 }
 445
 446 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
 447                              char *buf)
 448 {
 449         u32 ltr_value = 0;
 450         unsigned int reg;
 451         int ret;
 452
 453         reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
 454         ret = lpss_reg_read(dev, reg, &ltr_value);
 455         if (ret)
 456                 return ret;
 457
 458         return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
 459 }
 460
 461 static ssize_t lpss_ltr_mode_show(struct device *dev,
 462                                   struct device_attribute *attr, char *buf)
 463 {
 464         u32 ltr_mode = 0;
 465         char *outstr;
 466         int ret;
 467
 468         ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
 469         if (ret)
 470                 return ret;
 471
 472         outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
 473         return sprintf(buf, "%s\n", outstr);
 474 }
 475
 476 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
 477 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
 478 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
 479
 480 static struct attribute *lpss_attrs[] = {
 481         &dev_attr_auto_ltr.attr,
 482         &dev_attr_sw_ltr.attr,
 483         &dev_attr_ltr_mode.attr,
 484         NULL,
 485 };
 486
 487 static struct attribute_group lpss_attr_group = {
 488         .attrs = lpss_attrs,
 489         .name = "lpss_ltr",
 490 };
 491
 492 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
 493 {
 494         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 495         u32 ltr_mode, ltr_val;
 496
 497         ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
 498         if (val < 0) {
 499                 if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
 500                         ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
 501                         __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 502                 }
 503                 return;
 504         }
 505         ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
 506         if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
 507                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
 508                 val = LPSS_LTR_MAX_VAL;
 509         } else if (val > LPSS_LTR_MAX_VAL) {
 510                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
 511                 val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
 512         } else {
 513                 ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
 514         }
 515         ltr_val |= val;
 516         __lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
 517         if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
 518                 ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
 519                 __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 520         }
 521 }
 522
 523 #ifdef CONFIG_PM
 524 /**
 525  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
 526  * @dev: LPSS device
 527  *
 528  * Most LPSS devices have private registers which may loose their context when
 529  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
 530  * prv_reg_ctx array.
 531  */
 532 static void acpi_lpss_save_ctx(struct device *dev)
 533 {
 534         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 535         unsigned int i;
 536
 537         for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
 538                 unsigned long offset = i * sizeof(u32);
 539
 540                 pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
 541                 dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
 542                         pdata->prv_reg_ctx[i], offset);
 543         }
 544 }
 545
 546 /**
 547  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
 548  * @dev: LPSS device
 549  *
 550  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
 551  */
 552 static void acpi_lpss_restore_ctx(struct device *dev)
 553 {
 554         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 555         unsigned int i;
 556
 557         /*
 558          * The following delay is needed or the subsequent write operations may
 559          * fail. The LPSS devices are actually PCI devices and the PCI spec
 560          * expects 10ms delay before the device can be accessed after D3 to D0
 561          * transition.
 562          */
 563         msleep(10);
 564
 565         for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
 566                 unsigned long offset = i * sizeof(u32);
 567
 568                 __lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
 569                 dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
 570                         pdata->prv_reg_ctx[i], offset);
 571         }
 572 }
 573
 574 #ifdef CONFIG_PM_SLEEP
 575 static int acpi_lpss_suspend_late(struct device *dev)
 576 {
 577         int ret = pm_generic_suspend_late(dev);
 578
 579         if (ret)
 580                 return ret;
 581
 582         acpi_lpss_save_ctx(dev);
 583         return acpi_dev_suspend_late(dev);
 584 }
 585
 586 static int acpi_lpss_restore_early(struct device *dev)
 587 {
 588         int ret = acpi_dev_resume_early(dev);
 589
 590         if (ret)
 591                 return ret;
 592
 593         acpi_lpss_restore_ctx(dev);
 594         return pm_generic_resume_early(dev);
 595 }
 596 #endif /* CONFIG_PM_SLEEP */
 597
 598 #ifdef CONFIG_PM_RUNTIME
 599 static int acpi_lpss_runtime_suspend(struct device *dev)
 600 {
 601         int ret = pm_generic_runtime_suspend(dev);
 602
 603         if (ret)
 604                 return ret;
 605
 606         acpi_lpss_save_ctx(dev);
 607         return acpi_dev_runtime_suspend(dev);
 608 }
 609
 610 static int acpi_lpss_runtime_resume(struct device *dev)
 611 {
 612         int ret = acpi_dev_runtime_resume(dev);
 613
 614         if (ret)
 615                 return ret;
 616
 617         acpi_lpss_restore_ctx(dev);
 618         return pm_generic_runtime_resume(dev);
 619 }
 620 #endif /* CONFIG_PM_RUNTIME */
 621 #endif /* CONFIG_PM */
 622
 623 static struct dev_pm_domain acpi_lpss_pm_domain = {
 624         .ops = {
 625 #ifdef CONFIG_PM_SLEEP
 626                 .suspend_late = acpi_lpss_suspend_late,
 627                 .restore_early = acpi_lpss_restore_early,
 628                 .prepare = acpi_subsys_prepare,
 629                 .complete = acpi_subsys_complete,
 630                 .suspend = acpi_subsys_suspend,
 631                 .resume_early = acpi_subsys_resume_early,
 632                 .freeze = acpi_subsys_freeze,
 633                 .poweroff = acpi_subsys_suspend,
 634                 .poweroff_late = acpi_subsys_suspend_late,
 635 #endif
 636 #ifdef CONFIG_PM_RUNTIME
 637                 .runtime_suspend = acpi_lpss_runtime_suspend,
 638                 .runtime_resume = acpi_lpss_runtime_resume,
 639 #endif
 640         },
 641 };
 642
 643 static int acpi_lpss_platform_notify(struct notifier_block *nb,
 644                                      unsigned long action, void *data)
 645 {
 646         struct platform_device *pdev = to_platform_device(data);
 647         struct lpss_private_data *pdata;
 648         struct acpi_device *adev;
 649         const struct acpi_device_id *id;
 650
 651         id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
 652         if (!id || !id->driver_data)
 653                 return 0;
 654
 655         if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
 656                 return 0;
 657
 658         pdata = acpi_driver_data(adev);
 659         if (!pdata || !pdata->mmio_base)
 660                 return 0;
 661
 662         if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
 663                 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
 664                 return 0;
 665         }
 666
 667         switch (action) {
 668         case BUS_NOTIFY_BOUND_DRIVER:
 669                 if (pdata->dev_desc->save_ctx)
 670                         pdev->dev.pm_domain = &acpi_lpss_pm_domain;
 671                 break;
 672         case BUS_NOTIFY_UNBOUND_DRIVER:
 673                 if (pdata->dev_desc->save_ctx)
 674                         pdev->dev.pm_domain = NULL;
 675                 break;
 676         case BUS_NOTIFY_ADD_DEVICE:
 677                 if (pdata->dev_desc->ltr_required)
 678                         return sysfs_create_group(&pdev->dev.kobj,
 679                                                   &lpss_attr_group);
 680         case BUS_NOTIFY_DEL_DEVICE:
 681                 if (pdata->dev_desc->ltr_required)
 682                         sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
 683         default:
 684                 break;
 685         }
 686
 687         return 0;
 688 }
 689
 690 static struct notifier_block acpi_lpss_nb = {
 691         .notifier_call = acpi_lpss_platform_notify,
 692 };
 693
 694 static void acpi_lpss_bind(struct device *dev)
 695 {
 696         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 697
 698         if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
 699                 return;
 700
 701         if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
 702                 dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
 703         else
 704                 dev_err(dev, "MMIO size insufficient to access LTR\n");
 705 }
 706
 707 static void acpi_lpss_unbind(struct device *dev)
 708 {
 709         dev->power.set_latency_tolerance = NULL;
 710 }
 711
 712 static struct acpi_scan_handler lpss_handler = {
 713         .ids = acpi_lpss_device_ids,
 714         .attach = acpi_lpss_create_device,
 715         .bind = acpi_lpss_bind,
 716         .unbind = acpi_lpss_unbind,
 717 };
 718
 719 void __init acpi_lpss_init(void)
 720 {
 721         if (!lpt_clk_init()) {
 722                 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
 723                 acpi_scan_add_handler(&lpss_handler);
 724         }
 725 }
 726
 727 #else
 728
 729 static struct acpi_scan_handler lpss_handler = {
 730         .ids = acpi_lpss_device_ids,
 731 };
 732
 733 void __init acpi_lpss_init(void)
 734 {
 735         acpi_scan_add_handler(&lpss_handler);
 736 }
 737
 738 #endif /* CONFIG_X86_INTEL_LPSS */