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/clkdev.h>
  15 #include <linux/clk-provider.h>
  16 #include <linux/err.h>
  17 #include <linux/io.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/platform_data/clk-lpss.h>
  20 #include <linux/pm_runtime.h>
  21 #include <linux/delay.h>
  22
  23 #include "internal.h"
  24
  25 ACPI_MODULE_NAME("acpi_lpss");
  26
  27 #ifdef CONFIG_X86_INTEL_LPSS
  28
  29 #define LPSS_ADDR(desc) ((unsigned long)&desc)
  30
  31 #define LPSS_CLK_SIZE   0x04
  32 #define LPSS_LTR_SIZE   0x18
  33
  34 /* Offsets relative to LPSS_PRIVATE_OFFSET */
  35 #define LPSS_CLK_DIVIDER_DEF_MASK       (BIT(1) | BIT(16))
  36 #define LPSS_RESETS                     0x04
  37 #define LPSS_RESETS_RESET_FUNC          BIT(0)
  38 #define LPSS_RESETS_RESET_APB           BIT(1)
  39 #define LPSS_GENERAL                    0x08
  40 #define LPSS_GENERAL_LTR_MODE_SW        BIT(2)
  41 #define LPSS_GENERAL_UART_RTS_OVRD      BIT(3)
  42 #define LPSS_SW_LTR                     0x10
  43 #define LPSS_AUTO_LTR                   0x14
  44 #define LPSS_LTR_SNOOP_REQ              BIT(15)
  45 #define LPSS_LTR_SNOOP_MASK             0x0000FFFF
  46 #define LPSS_LTR_SNOOP_LAT_1US          0x800
  47 #define LPSS_LTR_SNOOP_LAT_32US         0xC00
  48 #define LPSS_LTR_SNOOP_LAT_SHIFT        5
  49 #define LPSS_LTR_SNOOP_LAT_CUTOFF       3000
  50 #define LPSS_LTR_MAX_VAL                0x3FF
  51 #define LPSS_TX_INT                     0x20
  52 #define LPSS_TX_INT_MASK                BIT(1)
  53
  54 #define LPSS_PRV_REG_COUNT              9
  55
  56 /* LPSS Flags */
  57 #define LPSS_CLK                        BIT(0)
  58 #define LPSS_CLK_GATE                   BIT(1)
  59 #define LPSS_CLK_DIVIDER                BIT(2)
  60 #define LPSS_LTR                        BIT(3)
  61 #define LPSS_SAVE_CTX                   BIT(4)
  62
  63 struct lpss_private_data;
  64
  65 struct lpss_device_desc {
  66         unsigned int flags;
  67         const char *clk_con_id;
  68         unsigned int prv_offset;
  69         size_t prv_size_override;
  70         void (*setup)(struct lpss_private_data *pdata);
  71 };
  72
  73 static struct lpss_device_desc lpss_dma_desc = {
  74         .flags = LPSS_CLK,
  75 };
  76
  77 struct lpss_private_data {
  78         void __iomem *mmio_base;
  79         resource_size_t mmio_size;
  80         unsigned int fixed_clk_rate;
  81         struct clk *clk;
  82         const struct lpss_device_desc *dev_desc;
  83         u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
  84 };
  85
  86 /* UART Component Parameter Register */
  87 #define LPSS_UART_CPR                   0xF4
  88 #define LPSS_UART_CPR_AFCE              BIT(4)
  89
  90 static void lpss_uart_setup(struct lpss_private_data *pdata)
  91 {
  92         unsigned int offset;
  93         u32 val;
  94
  95         offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
  96         val = readl(pdata->mmio_base + offset);
  97         writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
  98
  99         val = readl(pdata->mmio_base + LPSS_UART_CPR);
 100         if (!(val & LPSS_UART_CPR_AFCE)) {
 101                 offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
 102                 val = readl(pdata->mmio_base + offset);
 103                 val |= LPSS_GENERAL_UART_RTS_OVRD;
 104                 writel(val, pdata->mmio_base + offset);
 105         }
 106 }
 107
 108 static void lpss_deassert_reset(struct lpss_private_data *pdata)
 109 {
 110         unsigned int offset;
 111         u32 val;
 112
 113         offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
 114         val = readl(pdata->mmio_base + offset);
 115         val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
 116         writel(val, pdata->mmio_base + offset);
 117 }
 118
 119 #define LPSS_I2C_ENABLE                 0x6c
 120
 121 static void byt_i2c_setup(struct lpss_private_data *pdata)
 122 {
 123         lpss_deassert_reset(pdata);
 124
 125         if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
 126                 pdata->fixed_clk_rate = 133000000;
 127
 128         writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
 129 }
 130
 131 static const struct lpss_device_desc lpt_dev_desc = {
 132         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
 133         .prv_offset = 0x800,
 134 };
 135
 136 static const struct lpss_device_desc lpt_i2c_dev_desc = {
 137         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR,
 138         .prv_offset = 0x800,
 139 };
 140
 141 static const struct lpss_device_desc lpt_uart_dev_desc = {
 142         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
 143         .clk_con_id = "baudclk",
 144         .prv_offset = 0x800,
 145         .setup = lpss_uart_setup,
 146 };
 147
 148 static const struct lpss_device_desc lpt_sdio_dev_desc = {
 149         .flags = LPSS_LTR,
 150         .prv_offset = 0x1000,
 151         .prv_size_override = 0x1018,
 152 };
 153
 154 static const struct lpss_device_desc byt_pwm_dev_desc = {
 155         .flags = LPSS_SAVE_CTX,
 156 };
 157
 158 static const struct lpss_device_desc byt_uart_dev_desc = {
 159         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
 160         .clk_con_id = "baudclk",
 161         .prv_offset = 0x800,
 162         .setup = lpss_uart_setup,
 163 };
 164
 165 static const struct lpss_device_desc byt_spi_dev_desc = {
 166         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
 167         .prv_offset = 0x400,
 168 };
 169
 170 static const struct lpss_device_desc byt_sdio_dev_desc = {
 171         .flags = LPSS_CLK,
 172 };
 173
 174 static const struct lpss_device_desc byt_i2c_dev_desc = {
 175         .flags = LPSS_CLK | LPSS_SAVE_CTX,
 176         .prv_offset = 0x800,
 177         .setup = byt_i2c_setup,
 178 };
 179
 180 static struct lpss_device_desc bsw_spi_dev_desc = {
 181         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
 182         .prv_offset = 0x400,
 183         .setup = lpss_deassert_reset,
 184 };
 185
 186 #else
 187
 188 #define LPSS_ADDR(desc) (0UL)
 189
 190 #endif /* CONFIG_X86_INTEL_LPSS */
 191
 192 static const struct acpi_device_id acpi_lpss_device_ids[] = {
 193         /* Generic LPSS devices */
 194         { "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
 195
 196         /* Lynxpoint LPSS devices */
 197         { "INT33C0", LPSS_ADDR(lpt_dev_desc) },
 198         { "INT33C1", LPSS_ADDR(lpt_dev_desc) },
 199         { "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
 200         { "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
 201         { "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
 202         { "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
 203         { "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
 204         { "INT33C7", },
 205
 206         /* BayTrail LPSS devices */
 207         { "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
 208         { "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
 209         { "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
 210         { "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
 211         { "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
 212         { "INT33B2", },
 213         { "INT33FC", },
 214
 215         /* Braswell LPSS devices */
 216         { "80862288", LPSS_ADDR(byt_pwm_dev_desc) },
 217         { "8086228A", LPSS_ADDR(byt_uart_dev_desc) },
 218         { "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
 219         { "808622C1", LPSS_ADDR(byt_i2c_dev_desc) },
 220
 221         { "INT3430", LPSS_ADDR(lpt_dev_desc) },
 222         { "INT3431", LPSS_ADDR(lpt_dev_desc) },
 223         { "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
 224         { "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
 225         { "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
 226         { "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
 227         { "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
 228         { "INT3437", },
 229
 230         /* Wildcat Point LPSS devices */
 231         { "INT3438", LPSS_ADDR(lpt_dev_desc) },
 232
 233         { }
 234 };
 235
 236 #ifdef CONFIG_X86_INTEL_LPSS
 237
 238 static int is_memory(struct acpi_resource *res, void *not_used)
 239 {
 240         struct resource r;
 241         return !acpi_dev_resource_memory(res, &r);
 242 }
 243
 244 /* LPSS main clock device. */
 245 static struct platform_device *lpss_clk_dev;
 246
 247 static inline void lpt_register_clock_device(void)
 248 {
 249         lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
 250 }
 251
 252 static int register_device_clock(struct acpi_device *adev,
 253                                  struct lpss_private_data *pdata)
 254 {
 255         const struct lpss_device_desc *dev_desc = pdata->dev_desc;
 256         const char *devname = dev_name(&adev->dev);
 257         struct clk *clk = ERR_PTR(-ENODEV);
 258         struct lpss_clk_data *clk_data;
 259         const char *parent, *clk_name;
 260         void __iomem *prv_base;
 261
 262         if (!lpss_clk_dev)
 263                 lpt_register_clock_device();
 264
 265         clk_data = platform_get_drvdata(lpss_clk_dev);
 266         if (!clk_data)
 267                 return -ENODEV;
 268         clk = clk_data->clk;
 269
 270         if (!pdata->mmio_base
 271             || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
 272                 return -ENODATA;
 273
 274         parent = clk_data->name;
 275         prv_base = pdata->mmio_base + dev_desc->prv_offset;
 276
 277         if (pdata->fixed_clk_rate) {
 278                 clk = clk_register_fixed_rate(NULL, devname, parent, 0,
 279                                               pdata->fixed_clk_rate);
 280                 goto out;
 281         }
 282
 283         if (dev_desc->flags & LPSS_CLK_GATE) {
 284                 clk = clk_register_gate(NULL, devname, parent, 0,
 285                                         prv_base, 0, 0, NULL);
 286                 parent = devname;
 287         }
 288
 289         if (dev_desc->flags & LPSS_CLK_DIVIDER) {
 290                 /* Prevent division by zero */
 291                 if (!readl(prv_base))
 292                         writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
 293
 294                 clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
 295                 if (!clk_name)
 296                         return -ENOMEM;
 297                 clk = clk_register_fractional_divider(NULL, clk_name, parent,
 298                                                       0, prv_base,
 299                                                       1, 15, 16, 15, 0, NULL);
 300                 parent = clk_name;
 301
 302                 clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
 303                 if (!clk_name) {
 304                         kfree(parent);
 305                         return -ENOMEM;
 306                 }
 307                 clk = clk_register_gate(NULL, clk_name, parent,
 308                                         CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
 309                                         prv_base, 31, 0, NULL);
 310                 kfree(parent);
 311                 kfree(clk_name);
 312         }
 313 out:
 314         if (IS_ERR(clk))
 315                 return PTR_ERR(clk);
 316
 317         pdata->clk = clk;
 318         clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
 319         return 0;
 320 }
 321
 322 static int acpi_lpss_create_device(struct acpi_device *adev,
 323                                    const struct acpi_device_id *id)
 324 {
 325         const struct lpss_device_desc *dev_desc;
 326         struct lpss_private_data *pdata;
 327         struct resource_entry *rentry;
 328         struct list_head resource_list;
 329         struct platform_device *pdev;
 330         int ret;
 331
 332         dev_desc = (const struct lpss_device_desc *)id->driver_data;
 333         if (!dev_desc) {
 334                 pdev = acpi_create_platform_device(adev);
 335                 return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
 336         }
 337         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 338         if (!pdata)
 339                 return -ENOMEM;
 340
 341         INIT_LIST_HEAD(&resource_list);
 342         ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
 343         if (ret < 0)
 344                 goto err_out;
 345
 346         list_for_each_entry(rentry, &resource_list, node)
 347                 if (resource_type(rentry->res) == IORESOURCE_MEM) {
 348                         if (dev_desc->prv_size_override)
 349                                 pdata->mmio_size = dev_desc->prv_size_override;
 350                         else
 351                                 pdata->mmio_size = resource_size(rentry->res);
 352                         pdata->mmio_base = ioremap(rentry->res->start,
 353                                                    pdata->mmio_size);
 354                         break;
 355                 }
 356
 357         acpi_dev_free_resource_list(&resource_list);
 358
 359         if (!pdata->mmio_base) {
 360                 ret = -ENOMEM;
 361                 goto err_out;
 362         }
 363
 364         pdata->dev_desc = dev_desc;
 365
 366         if (dev_desc->setup)
 367                 dev_desc->setup(pdata);
 368
 369         if (dev_desc->flags & LPSS_CLK) {
 370                 ret = register_device_clock(adev, pdata);
 371                 if (ret) {
 372                         /* Skip the device, but continue the namespace scan. */
 373                         ret = 0;
 374                         goto err_out;
 375                 }
 376         }
 377
 378         /*
 379          * This works around a known issue in ACPI tables where LPSS devices
 380          * have _PS0 and _PS3 without _PSC (and no power resources), so
 381          * acpi_bus_init_power() will assume that the BIOS has put them into D0.
 382          */
 383         ret = acpi_device_fix_up_power(adev);
 384         if (ret) {
 385                 /* Skip the device, but continue the namespace scan. */
 386                 ret = 0;
 387                 goto err_out;
 388         }
 389
 390         adev->driver_data = pdata;
 391         pdev = acpi_create_platform_device(adev);
 392         if (!IS_ERR_OR_NULL(pdev)) {
 393                 return 1;
 394         }
 395
 396         ret = PTR_ERR(pdev);
 397         adev->driver_data = NULL;
 398
 399  err_out:
 400         kfree(pdata);
 401         return ret;
 402 }
 403
 404 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
 405 {
 406         return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 407 }
 408
 409 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
 410                              unsigned int reg)
 411 {
 412         writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 413 }
 414
 415 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
 416 {
 417         struct acpi_device *adev;
 418         struct lpss_private_data *pdata;
 419         unsigned long flags;
 420         int ret;
 421
 422         ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
 423         if (WARN_ON(ret))
 424                 return ret;
 425
 426         spin_lock_irqsave(&dev->power.lock, flags);
 427         if (pm_runtime_suspended(dev)) {
 428                 ret = -EAGAIN;
 429                 goto out;
 430         }
 431         pdata = acpi_driver_data(adev);
 432         if (WARN_ON(!pdata || !pdata->mmio_base)) {
 433                 ret = -ENODEV;
 434                 goto out;
 435         }
 436         *val = __lpss_reg_read(pdata, reg);
 437
 438  out:
 439         spin_unlock_irqrestore(&dev->power.lock, flags);
 440         return ret;
 441 }
 442
 443 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
 444                              char *buf)
 445 {
 446         u32 ltr_value = 0;
 447         unsigned int reg;
 448         int ret;
 449
 450         reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
 451         ret = lpss_reg_read(dev, reg, &ltr_value);
 452         if (ret)
 453                 return ret;
 454
 455         return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
 456 }
 457
 458 static ssize_t lpss_ltr_mode_show(struct device *dev,
 459                                   struct device_attribute *attr, char *buf)
 460 {
 461         u32 ltr_mode = 0;
 462         char *outstr;
 463         int ret;
 464
 465         ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
 466         if (ret)
 467                 return ret;
 468
 469         outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
 470         return sprintf(buf, "%s\n", outstr);
 471 }
 472
 473 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
 474 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
 475 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
 476
 477 static struct attribute *lpss_attrs[] = {
 478         &dev_attr_auto_ltr.attr,
 479         &dev_attr_sw_ltr.attr,
 480         &dev_attr_ltr_mode.attr,
 481         NULL,
 482 };
 483
 484 static struct attribute_group lpss_attr_group = {
 485         .attrs = lpss_attrs,
 486         .name = "lpss_ltr",
 487 };
 488
 489 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
 490 {
 491         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 492         u32 ltr_mode, ltr_val;
 493
 494         ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
 495         if (val < 0) {
 496                 if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
 497                         ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
 498                         __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 499                 }
 500                 return;
 501         }
 502         ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
 503         if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
 504                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
 505                 val = LPSS_LTR_MAX_VAL;
 506         } else if (val > LPSS_LTR_MAX_VAL) {
 507                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
 508                 val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
 509         } else {
 510                 ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
 511         }
 512         ltr_val |= val;
 513         __lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
 514         if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
 515                 ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
 516                 __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 517         }
 518 }
 519
 520 #ifdef CONFIG_PM
 521 /**
 522  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
 523  * @dev: LPSS device
 524  * @pdata: pointer to the private data of the LPSS device
 525  *
 526  * Most LPSS devices have private registers which may loose their context when
 527  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
 528  * prv_reg_ctx array.
 529  */
 530 static void acpi_lpss_save_ctx(struct device *dev,
 531                                struct lpss_private_data *pdata)
 532 {
 533         unsigned int i;
 534
 535         for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
 536                 unsigned long offset = i * sizeof(u32);
 537
 538                 pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
 539                 dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
 540                         pdata->prv_reg_ctx[i], offset);
 541         }
 542 }
 543
 544 /**
 545  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
 546  * @dev: LPSS device
 547  * @pdata: pointer to the private data of the LPSS device
 548  *
 549  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
 550  */
 551 static void acpi_lpss_restore_ctx(struct device *dev,
 552                                   struct lpss_private_data *pdata)
 553 {
 554         unsigned int i;
 555
 556         /*
 557          * The following delay is needed or the subsequent write operations may
 558          * fail. The LPSS devices are actually PCI devices and the PCI spec
 559          * expects 10ms delay before the device can be accessed after D3 to D0
 560          * transition.
 561          */
 562         msleep(10);
 563
 564         for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
 565                 unsigned long offset = i * sizeof(u32);
 566
 567                 __lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
 568                 dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
 569                         pdata->prv_reg_ctx[i], offset);
 570         }
 571 }
 572
 573 #ifdef CONFIG_PM_SLEEP
 574 static int acpi_lpss_suspend_late(struct device *dev)
 575 {
 576         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 577         int ret;
 578
 579         ret = pm_generic_suspend_late(dev);
 580         if (ret)
 581                 return ret;
 582
 583         if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 584                 acpi_lpss_save_ctx(dev, pdata);
 585
 586         return acpi_dev_suspend_late(dev);
 587 }
 588
 589 static int acpi_lpss_resume_early(struct device *dev)
 590 {
 591         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 592         int ret;
 593
 594         ret = acpi_dev_resume_early(dev);
 595         if (ret)
 596                 return ret;
 597
 598         if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 599                 acpi_lpss_restore_ctx(dev, pdata);
 600
 601         return pm_generic_resume_early(dev);
 602 }
 603 #endif /* CONFIG_PM_SLEEP */
 604
 605 static int acpi_lpss_runtime_suspend(struct device *dev)
 606 {
 607         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 608         int ret;
 609
 610         ret = pm_generic_runtime_suspend(dev);
 611         if (ret)
 612                 return ret;
 613
 614         if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 615                 acpi_lpss_save_ctx(dev, pdata);
 616
 617         return acpi_dev_runtime_suspend(dev);
 618 }
 619
 620 static int acpi_lpss_runtime_resume(struct device *dev)
 621 {
 622         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 623         int ret;
 624
 625         ret = acpi_dev_runtime_resume(dev);
 626         if (ret)
 627                 return ret;
 628
 629         if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 630                 acpi_lpss_restore_ctx(dev, pdata);
 631
 632         return pm_generic_runtime_resume(dev);
 633 }
 634 #endif /* CONFIG_PM */
 635
 636 static struct dev_pm_domain acpi_lpss_pm_domain = {
 637         .ops = {
 638 #ifdef CONFIG_PM
 639 #ifdef CONFIG_PM_SLEEP
 640                 .prepare = acpi_subsys_prepare,
 641                 .complete = acpi_subsys_complete,
 642                 .suspend = acpi_subsys_suspend,
 643                 .suspend_late = acpi_lpss_suspend_late,
 644                 .resume_early = acpi_lpss_resume_early,
 645                 .freeze = acpi_subsys_freeze,
 646                 .poweroff = acpi_subsys_suspend,
 647                 .poweroff_late = acpi_lpss_suspend_late,
 648                 .restore_early = acpi_lpss_resume_early,
 649 #endif
 650                 .runtime_suspend = acpi_lpss_runtime_suspend,
 651                 .runtime_resume = acpi_lpss_runtime_resume,
 652 #endif
 653         },
 654 };
 655
 656 static int acpi_lpss_platform_notify(struct notifier_block *nb,
 657                                      unsigned long action, void *data)
 658 {
 659         struct platform_device *pdev = to_platform_device(data);
 660         struct lpss_private_data *pdata;
 661         struct acpi_device *adev;
 662         const struct acpi_device_id *id;
 663
 664         id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
 665         if (!id || !id->driver_data)
 666                 return 0;
 667
 668         if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
 669                 return 0;
 670
 671         pdata = acpi_driver_data(adev);
 672         if (!pdata)
 673                 return 0;
 674
 675         if (pdata->mmio_base &&
 676             pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
 677                 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
 678                 return 0;
 679         }
 680
 681         switch (action) {
 682         case BUS_NOTIFY_ADD_DEVICE:
 683                 pdev->dev.pm_domain = &acpi_lpss_pm_domain;
 684                 if (pdata->dev_desc->flags & LPSS_LTR)
 685                         return sysfs_create_group(&pdev->dev.kobj,
 686                                                   &lpss_attr_group);
 687                 break;
 688         case BUS_NOTIFY_DEL_DEVICE:
 689                 if (pdata->dev_desc->flags & LPSS_LTR)
 690                         sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
 691                 pdev->dev.pm_domain = NULL;
 692                 break;
 693         default:
 694                 break;
 695         }
 696
 697         return 0;
 698 }
 699
 700 static struct notifier_block acpi_lpss_nb = {
 701         .notifier_call = acpi_lpss_platform_notify,
 702 };
 703
 704 static void acpi_lpss_bind(struct device *dev)
 705 {
 706         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 707
 708         if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
 709                 return;
 710
 711         if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
 712                 dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
 713         else
 714                 dev_err(dev, "MMIO size insufficient to access LTR\n");
 715 }
 716
 717 static void acpi_lpss_unbind(struct device *dev)
 718 {
 719         dev->power.set_latency_tolerance = NULL;
 720 }
 721
 722 static struct acpi_scan_handler lpss_handler = {
 723         .ids = acpi_lpss_device_ids,
 724         .attach = acpi_lpss_create_device,
 725         .bind = acpi_lpss_bind,
 726         .unbind = acpi_lpss_unbind,
 727 };
 728
 729 void __init acpi_lpss_init(void)
 730 {
 731         if (!lpt_clk_init()) {
 732                 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
 733                 acpi_scan_add_handler(&lpss_handler);
 734         }
 735 }
 736
 737 #else
 738
 739 static struct acpi_scan_handler lpss_handler = {
 740         .ids = acpi_lpss_device_ids,
 741 };
 742
 743 void __init acpi_lpss_init(void)
 744 {
 745         acpi_scan_add_handler(&lpss_handler);
 746 }
 747
 748 #endif /* CONFIG_X86_INTEL_LPSS */