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