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/mutex.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/platform_data/clk-lpss.h>
  21 #include <linux/platform_data/x86/pmc_atom.h>
  22 #include <linux/pm_domain.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/pwm.h>
  25 #include <linux/delay.h>
  26
  27 #include "internal.h"
  28
  29 ACPI_MODULE_NAME("acpi_lpss");
  30
  31 #ifdef CONFIG_X86_INTEL_LPSS
  32
  33 #include <asm/cpu_device_id.h>
  34 #include <asm/intel-family.h>
  35 #include <asm/iosf_mbi.h>
  36
  37 #define LPSS_ADDR(desc) ((unsigned long)&desc)
  38
  39 #define LPSS_CLK_SIZE   0x04
  40 #define LPSS_LTR_SIZE   0x18
  41
  42 /* Offsets relative to LPSS_PRIVATE_OFFSET */
  43 #define LPSS_CLK_DIVIDER_DEF_MASK       (BIT(1) | BIT(16))
  44 #define LPSS_RESETS                     0x04
  45 #define LPSS_RESETS_RESET_FUNC          BIT(0)
  46 #define LPSS_RESETS_RESET_APB           BIT(1)
  47 #define LPSS_GENERAL                    0x08
  48 #define LPSS_GENERAL_LTR_MODE_SW        BIT(2)
  49 #define LPSS_GENERAL_UART_RTS_OVRD      BIT(3)
  50 #define LPSS_SW_LTR                     0x10
  51 #define LPSS_AUTO_LTR                   0x14
  52 #define LPSS_LTR_SNOOP_REQ              BIT(15)
  53 #define LPSS_LTR_SNOOP_MASK             0x0000FFFF
  54 #define LPSS_LTR_SNOOP_LAT_1US          0x800
  55 #define LPSS_LTR_SNOOP_LAT_32US         0xC00
  56 #define LPSS_LTR_SNOOP_LAT_SHIFT        5
  57 #define LPSS_LTR_SNOOP_LAT_CUTOFF       3000
  58 #define LPSS_LTR_MAX_VAL                0x3FF
  59 #define LPSS_TX_INT                     0x20
  60 #define LPSS_TX_INT_MASK                BIT(1)
  61
  62 #define LPSS_PRV_REG_COUNT              9
  63
  64 /* LPSS Flags */
  65 #define LPSS_CLK                        BIT(0)
  66 #define LPSS_CLK_GATE                   BIT(1)
  67 #define LPSS_CLK_DIVIDER                BIT(2)
  68 #define LPSS_LTR                        BIT(3)
  69 #define LPSS_SAVE_CTX                   BIT(4)
  70 #define LPSS_NO_D3_DELAY                BIT(5)
  71
  72 struct lpss_private_data;
  73
  74 struct lpss_device_desc {
  75         unsigned int flags;
  76         const char *clk_con_id;
  77         unsigned int prv_offset;
  78         size_t prv_size_override;
  79         struct property_entry *properties;
  80         void (*setup)(struct lpss_private_data *pdata);
  81 };
  82
  83 static const struct lpss_device_desc lpss_dma_desc = {
  84         .flags = LPSS_CLK,
  85 };
  86
  87 struct lpss_private_data {
  88         struct acpi_device *adev;
  89         void __iomem *mmio_base;
  90         resource_size_t mmio_size;
  91         unsigned int fixed_clk_rate;
  92         struct clk *clk;
  93         const struct lpss_device_desc *dev_desc;
  94         u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
  95 };
  96
  97 /* LPSS run time quirks */
  98 static unsigned int lpss_quirks;
  99
 100 /*
 101  * LPSS_QUIRK_ALWAYS_POWER_ON: override power state for LPSS DMA device.
 102  *
 103  * The LPSS DMA controller has neither _PS0 nor _PS3 method. Moreover
 104  * it can be powered off automatically whenever the last LPSS device goes down.
 105  * In case of no power any access to the DMA controller will hang the system.
 106  * The behaviour is reproduced on some HP laptops based on Intel BayTrail as
 107  * well as on ASuS T100TA transformer.
 108  *
 109  * This quirk overrides power state of entire LPSS island to keep DMA powered
 110  * on whenever we have at least one other device in use.
 111  */
 112 #define LPSS_QUIRK_ALWAYS_POWER_ON      BIT(0)
 113
 114 /* UART Component Parameter Register */
 115 #define LPSS_UART_CPR                   0xF4
 116 #define LPSS_UART_CPR_AFCE              BIT(4)
 117
 118 static void lpss_uart_setup(struct lpss_private_data *pdata)
 119 {
 120         unsigned int offset;
 121         u32 val;
 122
 123         offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
 124         val = readl(pdata->mmio_base + offset);
 125         writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
 126
 127         val = readl(pdata->mmio_base + LPSS_UART_CPR);
 128         if (!(val & LPSS_UART_CPR_AFCE)) {
 129                 offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
 130                 val = readl(pdata->mmio_base + offset);
 131                 val |= LPSS_GENERAL_UART_RTS_OVRD;
 132                 writel(val, pdata->mmio_base + offset);
 133         }
 134 }
 135
 136 static void lpss_deassert_reset(struct lpss_private_data *pdata)
 137 {
 138         unsigned int offset;
 139         u32 val;
 140
 141         offset = pdata->dev_desc->prv_offset + LPSS_RESETS;
 142         val = readl(pdata->mmio_base + offset);
 143         val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC;
 144         writel(val, pdata->mmio_base + offset);
 145 }
 146
 147 /*
 148  * BYT PWM used for backlight control by the i915 driver on systems without
 149  * the Crystal Cove PMIC.
 150  */
 151 static struct pwm_lookup byt_pwm_lookup[] = {
 152         PWM_LOOKUP_WITH_MODULE("80860F09:00", 0, "0000:00:02.0",
 153                                "pwm_backlight", 0, PWM_POLARITY_NORMAL,
 154                                "pwm-lpss-platform"),
 155 };
 156
 157 static void byt_pwm_setup(struct lpss_private_data *pdata)
 158 {
 159         struct acpi_device *adev = pdata->adev;
 160
 161         /* Only call pwm_add_table for the first PWM controller */
 162         if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
 163                 return;
 164
 165         if (!acpi_dev_present("INT33FD", NULL, -1))
 166                 pwm_add_table(byt_pwm_lookup, ARRAY_SIZE(byt_pwm_lookup));
 167 }
 168
 169 #define LPSS_I2C_ENABLE                 0x6c
 170
 171 static void byt_i2c_setup(struct lpss_private_data *pdata)
 172 {
 173         lpss_deassert_reset(pdata);
 174
 175         if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset))
 176                 pdata->fixed_clk_rate = 133000000;
 177
 178         writel(0, pdata->mmio_base + LPSS_I2C_ENABLE);
 179 }
 180
 181 /* BSW PWM used for backlight control by the i915 driver */
 182 static struct pwm_lookup bsw_pwm_lookup[] = {
 183         PWM_LOOKUP_WITH_MODULE("80862288:00", 0, "0000:00:02.0",
 184                                "pwm_backlight", 0, PWM_POLARITY_NORMAL,
 185                                "pwm-lpss-platform"),
 186 };
 187
 188 static void bsw_pwm_setup(struct lpss_private_data *pdata)
 189 {
 190         struct acpi_device *adev = pdata->adev;
 191
 192         /* Only call pwm_add_table for the first PWM controller */
 193         if (!adev->pnp.unique_id || strcmp(adev->pnp.unique_id, "1"))
 194                 return;
 195
 196         pwm_add_table(bsw_pwm_lookup, ARRAY_SIZE(bsw_pwm_lookup));
 197 }
 198
 199 static const struct lpss_device_desc lpt_dev_desc = {
 200         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
 201         .prv_offset = 0x800,
 202 };
 203
 204 static const struct lpss_device_desc lpt_i2c_dev_desc = {
 205         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR,
 206         .prv_offset = 0x800,
 207 };
 208
 209 static struct property_entry uart_properties[] = {
 210         PROPERTY_ENTRY_U32("reg-io-width", 4),
 211         PROPERTY_ENTRY_U32("reg-shift", 2),
 212         PROPERTY_ENTRY_BOOL("snps,uart-16550-compatible"),
 213         { },
 214 };
 215
 216 static const struct lpss_device_desc lpt_uart_dev_desc = {
 217         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR,
 218         .clk_con_id = "baudclk",
 219         .prv_offset = 0x800,
 220         .setup = lpss_uart_setup,
 221         .properties = uart_properties,
 222 };
 223
 224 static const struct lpss_device_desc lpt_sdio_dev_desc = {
 225         .flags = LPSS_LTR,
 226         .prv_offset = 0x1000,
 227         .prv_size_override = 0x1018,
 228 };
 229
 230 static const struct lpss_device_desc byt_pwm_dev_desc = {
 231         .flags = LPSS_SAVE_CTX,
 232         .setup = byt_pwm_setup,
 233 };
 234
 235 static const struct lpss_device_desc bsw_pwm_dev_desc = {
 236         .flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
 237         .setup = bsw_pwm_setup,
 238 };
 239
 240 static const struct lpss_device_desc byt_uart_dev_desc = {
 241         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
 242         .clk_con_id = "baudclk",
 243         .prv_offset = 0x800,
 244         .setup = lpss_uart_setup,
 245         .properties = uart_properties,
 246 };
 247
 248 static const struct lpss_device_desc bsw_uart_dev_desc = {
 249         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
 250                         | LPSS_NO_D3_DELAY,
 251         .clk_con_id = "baudclk",
 252         .prv_offset = 0x800,
 253         .setup = lpss_uart_setup,
 254         .properties = uart_properties,
 255 };
 256
 257 static const struct lpss_device_desc byt_spi_dev_desc = {
 258         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX,
 259         .prv_offset = 0x400,
 260 };
 261
 262 static const struct lpss_device_desc byt_sdio_dev_desc = {
 263         .flags = LPSS_CLK,
 264 };
 265
 266 static const struct lpss_device_desc byt_i2c_dev_desc = {
 267         .flags = LPSS_CLK | LPSS_SAVE_CTX,
 268         .prv_offset = 0x800,
 269         .setup = byt_i2c_setup,
 270 };
 271
 272 static const struct lpss_device_desc bsw_i2c_dev_desc = {
 273         .flags = LPSS_CLK | LPSS_SAVE_CTX | LPSS_NO_D3_DELAY,
 274         .prv_offset = 0x800,
 275         .setup = byt_i2c_setup,
 276 };
 277
 278 static const struct lpss_device_desc bsw_spi_dev_desc = {
 279         .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
 280                         | LPSS_NO_D3_DELAY,
 281         .prv_offset = 0x400,
 282         .setup = lpss_deassert_reset,
 283 };
 284
 285 #define ICPU(model)     { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }
 286
 287 static const struct x86_cpu_id lpss_cpu_ids[] = {
 288         ICPU(INTEL_FAM6_ATOM_SILVERMONT1),      /* Valleyview, Bay Trail */
 289         ICPU(INTEL_FAM6_ATOM_AIRMONT),  /* Braswell, Cherry Trail */
 290         {}
 291 };
 292
 293 #else
 294
 295 #define LPSS_ADDR(desc) (0UL)
 296
 297 #endif /* CONFIG_X86_INTEL_LPSS */
 298
 299 static const struct acpi_device_id acpi_lpss_device_ids[] = {
 300         /* Generic LPSS devices */
 301         { "INTL9C60", LPSS_ADDR(lpss_dma_desc) },
 302
 303         /* Lynxpoint LPSS devices */
 304         { "INT33C0", LPSS_ADDR(lpt_dev_desc) },
 305         { "INT33C1", LPSS_ADDR(lpt_dev_desc) },
 306         { "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) },
 307         { "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) },
 308         { "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) },
 309         { "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) },
 310         { "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) },
 311         { "INT33C7", },
 312
 313         /* BayTrail LPSS devices */
 314         { "80860F09", LPSS_ADDR(byt_pwm_dev_desc) },
 315         { "80860F0A", LPSS_ADDR(byt_uart_dev_desc) },
 316         { "80860F0E", LPSS_ADDR(byt_spi_dev_desc) },
 317         { "80860F14", LPSS_ADDR(byt_sdio_dev_desc) },
 318         { "80860F41", LPSS_ADDR(byt_i2c_dev_desc) },
 319         { "INT33B2", },
 320         { "INT33FC", },
 321
 322         /* Braswell LPSS devices */
 323         { "80862288", LPSS_ADDR(bsw_pwm_dev_desc) },
 324         { "8086228A", LPSS_ADDR(bsw_uart_dev_desc) },
 325         { "8086228E", LPSS_ADDR(bsw_spi_dev_desc) },
 326         { "808622C1", LPSS_ADDR(bsw_i2c_dev_desc) },
 327
 328         /* Broadwell LPSS devices */
 329         { "INT3430", LPSS_ADDR(lpt_dev_desc) },
 330         { "INT3431", LPSS_ADDR(lpt_dev_desc) },
 331         { "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) },
 332         { "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) },
 333         { "INT3434", LPSS_ADDR(lpt_uart_dev_desc) },
 334         { "INT3435", LPSS_ADDR(lpt_uart_dev_desc) },
 335         { "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) },
 336         { "INT3437", },
 337
 338         /* Wildcat Point LPSS devices */
 339         { "INT3438", LPSS_ADDR(lpt_dev_desc) },
 340
 341         { }
 342 };
 343
 344 #ifdef CONFIG_X86_INTEL_LPSS
 345
 346 static int is_memory(struct acpi_resource *res, void *not_used)
 347 {
 348         struct resource r;
 349         return !acpi_dev_resource_memory(res, &r);
 350 }
 351
 352 /* LPSS main clock device. */
 353 static struct platform_device *lpss_clk_dev;
 354
 355 static inline void lpt_register_clock_device(void)
 356 {
 357         lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
 358 }
 359
 360 static int register_device_clock(struct acpi_device *adev,
 361                                  struct lpss_private_data *pdata)
 362 {
 363         const struct lpss_device_desc *dev_desc = pdata->dev_desc;
 364         const char *devname = dev_name(&adev->dev);
 365         struct clk *clk = ERR_PTR(-ENODEV);
 366         struct lpss_clk_data *clk_data;
 367         const char *parent, *clk_name;
 368         void __iomem *prv_base;
 369
 370         if (!lpss_clk_dev)
 371                 lpt_register_clock_device();
 372
 373         clk_data = platform_get_drvdata(lpss_clk_dev);
 374         if (!clk_data)
 375                 return -ENODEV;
 376         clk = clk_data->clk;
 377
 378         if (!pdata->mmio_base
 379             || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
 380                 return -ENODATA;
 381
 382         parent = clk_data->name;
 383         prv_base = pdata->mmio_base + dev_desc->prv_offset;
 384
 385         if (pdata->fixed_clk_rate) {
 386                 clk = clk_register_fixed_rate(NULL, devname, parent, 0,
 387                                               pdata->fixed_clk_rate);
 388                 goto out;
 389         }
 390
 391         if (dev_desc->flags & LPSS_CLK_GATE) {
 392                 clk = clk_register_gate(NULL, devname, parent, 0,
 393                                         prv_base, 0, 0, NULL);
 394                 parent = devname;
 395         }
 396
 397         if (dev_desc->flags & LPSS_CLK_DIVIDER) {
 398                 /* Prevent division by zero */
 399                 if (!readl(prv_base))
 400                         writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base);
 401
 402                 clk_name = kasprintf(GFP_KERNEL, "%s-div", devname);
 403                 if (!clk_name)
 404                         return -ENOMEM;
 405                 clk = clk_register_fractional_divider(NULL, clk_name, parent,
 406                                                       0, prv_base,
 407                                                       1, 15, 16, 15, 0, NULL);
 408                 parent = clk_name;
 409
 410                 clk_name = kasprintf(GFP_KERNEL, "%s-update", devname);
 411                 if (!clk_name) {
 412                         kfree(parent);
 413                         return -ENOMEM;
 414                 }
 415                 clk = clk_register_gate(NULL, clk_name, parent,
 416                                         CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
 417                                         prv_base, 31, 0, NULL);
 418                 kfree(parent);
 419                 kfree(clk_name);
 420         }
 421 out:
 422         if (IS_ERR(clk))
 423                 return PTR_ERR(clk);
 424
 425         pdata->clk = clk;
 426         clk_register_clkdev(clk, dev_desc->clk_con_id, devname);
 427         return 0;
 428 }
 429
 430 static int acpi_lpss_create_device(struct acpi_device *adev,
 431                                    const struct acpi_device_id *id)
 432 {
 433         const struct lpss_device_desc *dev_desc;
 434         struct lpss_private_data *pdata;
 435         struct resource_entry *rentry;
 436         struct list_head resource_list;
 437         struct platform_device *pdev;
 438         int ret;
 439
 440         dev_desc = (const struct lpss_device_desc *)id->driver_data;
 441         if (!dev_desc) {
 442                 pdev = acpi_create_platform_device(adev, NULL);
 443                 return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
 444         }
 445         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 446         if (!pdata)
 447                 return -ENOMEM;
 448
 449         INIT_LIST_HEAD(&resource_list);
 450         ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
 451         if (ret < 0)
 452                 goto err_out;
 453
 454         list_for_each_entry(rentry, &resource_list, node)
 455                 if (resource_type(rentry->res) == IORESOURCE_MEM) {
 456                         if (dev_desc->prv_size_override)
 457                                 pdata->mmio_size = dev_desc->prv_size_override;
 458                         else
 459                                 pdata->mmio_size = resource_size(rentry->res);
 460                         pdata->mmio_base = ioremap(rentry->res->start,
 461                                                    pdata->mmio_size);
 462                         break;
 463                 }
 464
 465         acpi_dev_free_resource_list(&resource_list);
 466
 467         if (!pdata->mmio_base) {
 468                 ret = -ENOMEM;
 469                 goto err_out;
 470         }
 471
 472         pdata->adev = adev;
 473         pdata->dev_desc = dev_desc;
 474
 475         if (dev_desc->setup)
 476                 dev_desc->setup(pdata);
 477
 478         if (dev_desc->flags & LPSS_CLK) {
 479                 ret = register_device_clock(adev, pdata);
 480                 if (ret) {
 481                         /* Skip the device, but continue the namespace scan. */
 482                         ret = 0;
 483                         goto err_out;
 484                 }
 485         }
 486
 487         /*
 488          * This works around a known issue in ACPI tables where LPSS devices
 489          * have _PS0 and _PS3 without _PSC (and no power resources), so
 490          * acpi_bus_init_power() will assume that the BIOS has put them into D0.
 491          */
 492         ret = acpi_device_fix_up_power(adev);
 493         if (ret) {
 494                 /* Skip the device, but continue the namespace scan. */
 495                 ret = 0;
 496                 goto err_out;
 497         }
 498
 499         adev->driver_data = pdata;
 500         pdev = acpi_create_platform_device(adev, dev_desc->properties);
 501         if (!IS_ERR_OR_NULL(pdev)) {
 502                 return 1;
 503         }
 504
 505         ret = PTR_ERR(pdev);
 506         adev->driver_data = NULL;
 507
 508  err_out:
 509         kfree(pdata);
 510         return ret;
 511 }
 512
 513 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
 514 {
 515         return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 516 }
 517
 518 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
 519                              unsigned int reg)
 520 {
 521         writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 522 }
 523
 524 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
 525 {
 526         struct acpi_device *adev;
 527         struct lpss_private_data *pdata;
 528         unsigned long flags;
 529         int ret;
 530
 531         ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
 532         if (WARN_ON(ret))
 533                 return ret;
 534
 535         spin_lock_irqsave(&dev->power.lock, flags);
 536         if (pm_runtime_suspended(dev)) {
 537                 ret = -EAGAIN;
 538                 goto out;
 539         }
 540         pdata = acpi_driver_data(adev);
 541         if (WARN_ON(!pdata || !pdata->mmio_base)) {
 542                 ret = -ENODEV;
 543                 goto out;
 544         }
 545         *val = __lpss_reg_read(pdata, reg);
 546
 547  out:
 548         spin_unlock_irqrestore(&dev->power.lock, flags);
 549         return ret;
 550 }
 551
 552 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
 553                              char *buf)
 554 {
 555         u32 ltr_value = 0;
 556         unsigned int reg;
 557         int ret;
 558
 559         reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
 560         ret = lpss_reg_read(dev, reg, &ltr_value);
 561         if (ret)
 562                 return ret;
 563
 564         return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
 565 }
 566
 567 static ssize_t lpss_ltr_mode_show(struct device *dev,
 568                                   struct device_attribute *attr, char *buf)
 569 {
 570         u32 ltr_mode = 0;
 571         char *outstr;
 572         int ret;
 573
 574         ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
 575         if (ret)
 576                 return ret;
 577
 578         outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
 579         return sprintf(buf, "%s\n", outstr);
 580 }
 581
 582 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
 583 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
 584 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
 585
 586 static struct attribute *lpss_attrs[] = {
 587         &dev_attr_auto_ltr.attr,
 588         &dev_attr_sw_ltr.attr,
 589         &dev_attr_ltr_mode.attr,
 590         NULL,
 591 };
 592
 593 static const struct attribute_group lpss_attr_group = {
 594         .attrs = lpss_attrs,
 595         .name = "lpss_ltr",
 596 };
 597
 598 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
 599 {
 600         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 601         u32 ltr_mode, ltr_val;
 602
 603         ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
 604         if (val < 0) {
 605                 if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
 606                         ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
 607                         __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 608                 }
 609                 return;
 610         }
 611         ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
 612         if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
 613                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
 614                 val = LPSS_LTR_MAX_VAL;
 615         } else if (val > LPSS_LTR_MAX_VAL) {
 616                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
 617                 val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
 618         } else {
 619                 ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
 620         }
 621         ltr_val |= val;
 622         __lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
 623         if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
 624                 ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
 625                 __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 626         }
 627 }
 628
 629 #ifdef CONFIG_PM
 630 /**
 631  * acpi_lpss_save_ctx() - Save the private registers of LPSS device
 632  * @dev: LPSS device
 633  * @pdata: pointer to the private data of the LPSS device
 634  *
 635  * Most LPSS devices have private registers which may loose their context when
 636  * the device is powered down. acpi_lpss_save_ctx() saves those registers into
 637  * prv_reg_ctx array.
 638  */
 639 static void acpi_lpss_save_ctx(struct device *dev,
 640                                struct lpss_private_data *pdata)
 641 {
 642         unsigned int i;
 643
 644         for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
 645                 unsigned long offset = i * sizeof(u32);
 646
 647                 pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset);
 648                 dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n",
 649                         pdata->prv_reg_ctx[i], offset);
 650         }
 651 }
 652
 653 /**
 654  * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device
 655  * @dev: LPSS device
 656  * @pdata: pointer to the private data of the LPSS device
 657  *
 658  * Restores the registers that were previously stored with acpi_lpss_save_ctx().
 659  */
 660 static void acpi_lpss_restore_ctx(struct device *dev,
 661                                   struct lpss_private_data *pdata)
 662 {
 663         unsigned int i;
 664
 665         for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
 666                 unsigned long offset = i * sizeof(u32);
 667
 668                 __lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
 669                 dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
 670                         pdata->prv_reg_ctx[i], offset);
 671         }
 672 }
 673
 674 static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
 675 {
 676         /*
 677          * The following delay is needed or the subsequent write operations may
 678          * fail. The LPSS devices are actually PCI devices and the PCI spec
 679          * expects 10ms delay before the device can be accessed after D3 to D0
 680          * transition. However some platforms like BSW does not need this delay.
 681          */
 682         unsigned int delay = 10;        /* default 10ms delay */
 683
 684         if (pdata->dev_desc->flags & LPSS_NO_D3_DELAY)
 685                 delay = 0;
 686
 687         msleep(delay);
 688 }
 689
 690 static int acpi_lpss_activate(struct device *dev)
 691 {
 692         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 693         int ret;
 694
 695         ret = acpi_dev_runtime_resume(dev);
 696         if (ret)
 697                 return ret;
 698
 699         acpi_lpss_d3_to_d0_delay(pdata);
 700
 701         /*
 702          * This is called only on ->probe() stage where a device is either in
 703          * known state defined by BIOS or most likely powered off. Due to this
 704          * we have to deassert reset line to be sure that ->probe() will
 705          * recognize the device.
 706          */
 707         if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 708                 lpss_deassert_reset(pdata);
 709
 710         return 0;
 711 }
 712
 713 static void acpi_lpss_dismiss(struct device *dev)
 714 {
 715         acpi_dev_runtime_suspend(dev);
 716 }
 717
 718 #ifdef CONFIG_PM_SLEEP
 719 static int acpi_lpss_suspend_late(struct device *dev)
 720 {
 721         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 722         int ret;
 723
 724         ret = pm_generic_suspend_late(dev);
 725         if (ret)
 726                 return ret;
 727
 728         if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 729                 acpi_lpss_save_ctx(dev, pdata);
 730
 731         return acpi_dev_suspend_late(dev);
 732 }
 733
 734 static int acpi_lpss_resume_early(struct device *dev)
 735 {
 736         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 737         int ret;
 738
 739         ret = acpi_dev_resume_early(dev);
 740         if (ret)
 741                 return ret;
 742
 743         acpi_lpss_d3_to_d0_delay(pdata);
 744
 745         if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 746                 acpi_lpss_restore_ctx(dev, pdata);
 747
 748         return pm_generic_resume_early(dev);
 749 }
 750 #endif /* CONFIG_PM_SLEEP */
 751
 752 /* IOSF SB for LPSS island */
 753 #define LPSS_IOSF_UNIT_LPIOEP           0xA0
 754 #define LPSS_IOSF_UNIT_LPIO1            0xAB
 755 #define LPSS_IOSF_UNIT_LPIO2            0xAC
 756
 757 #define LPSS_IOSF_PMCSR                 0x84
 758 #define LPSS_PMCSR_D0                   0
 759 #define LPSS_PMCSR_D3hot                3
 760 #define LPSS_PMCSR_Dx_MASK              GENMASK(1, 0)
 761
 762 #define LPSS_IOSF_GPIODEF0              0x154
 763 #define LPSS_GPIODEF0_DMA1_D3           BIT(2)
 764 #define LPSS_GPIODEF0_DMA2_D3           BIT(3)
 765 #define LPSS_GPIODEF0_DMA_D3_MASK       GENMASK(3, 2)
 766 #define LPSS_GPIODEF0_DMA_LLP           BIT(13)
 767
 768 static DEFINE_MUTEX(lpss_iosf_mutex);
 769
 770 static void lpss_iosf_enter_d3_state(void)
 771 {
 772         u32 value1 = 0;
 773         u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
 774         u32 value2 = LPSS_PMCSR_D3hot;
 775         u32 mask2 = LPSS_PMCSR_Dx_MASK;
 776         /*
 777          * PMC provides an information about actual status of the LPSS devices.
 778          * Here we read the values related to LPSS power island, i.e. LPSS
 779          * devices, excluding both LPSS DMA controllers, along with SCC domain.
 780          */
 781         u32 func_dis, d3_sts_0, pmc_status, pmc_mask = 0xfe000ffe;
 782         int ret;
 783
 784         ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
 785         if (ret)
 786                 return;
 787
 788         mutex_lock(&lpss_iosf_mutex);
 789
 790         ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
 791         if (ret)
 792                 goto exit;
 793
 794         /*
 795          * Get the status of entire LPSS power island per device basis.
 796          * Shutdown both LPSS DMA controllers if and only if all other devices
 797          * are already in D3hot.
 798          */
 799         pmc_status = (~(d3_sts_0 | func_dis)) & pmc_mask;
 800         if (pmc_status)
 801                 goto exit;
 802
 803         iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
 804                         LPSS_IOSF_PMCSR, value2, mask2);
 805
 806         iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
 807                         LPSS_IOSF_PMCSR, value2, mask2);
 808
 809         iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
 810                         LPSS_IOSF_GPIODEF0, value1, mask1);
 811 exit:
 812         mutex_unlock(&lpss_iosf_mutex);
 813 }
 814
 815 static void lpss_iosf_exit_d3_state(void)
 816 {
 817         u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3 |
 818                      LPSS_GPIODEF0_DMA_LLP;
 819         u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK | LPSS_GPIODEF0_DMA_LLP;
 820         u32 value2 = LPSS_PMCSR_D0;
 821         u32 mask2 = LPSS_PMCSR_Dx_MASK;
 822
 823         mutex_lock(&lpss_iosf_mutex);
 824
 825         iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
 826                         LPSS_IOSF_GPIODEF0, value1, mask1);
 827
 828         iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
 829                         LPSS_IOSF_PMCSR, value2, mask2);
 830
 831         iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
 832                         LPSS_IOSF_PMCSR, value2, mask2);
 833
 834         mutex_unlock(&lpss_iosf_mutex);
 835 }
 836
 837 static int acpi_lpss_runtime_suspend(struct device *dev)
 838 {
 839         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 840         int ret;
 841
 842         ret = pm_generic_runtime_suspend(dev);
 843         if (ret)
 844                 return ret;
 845
 846         if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 847                 acpi_lpss_save_ctx(dev, pdata);
 848
 849         ret = acpi_dev_runtime_suspend(dev);
 850
 851         /*
 852          * This call must be last in the sequence, otherwise PMC will return
 853          * wrong status for devices being about to be powered off. See
 854          * lpss_iosf_enter_d3_state() for further information.
 855          */
 856         if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
 857                 lpss_iosf_enter_d3_state();
 858
 859         return ret;
 860 }
 861
 862 static int acpi_lpss_runtime_resume(struct device *dev)
 863 {
 864         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 865         int ret;
 866
 867         /*
 868          * This call is kept first to be in symmetry with
 869          * acpi_lpss_runtime_suspend() one.
 870          */
 871         if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
 872                 lpss_iosf_exit_d3_state();
 873
 874         ret = acpi_dev_runtime_resume(dev);
 875         if (ret)
 876                 return ret;
 877
 878         acpi_lpss_d3_to_d0_delay(pdata);
 879
 880         if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 881                 acpi_lpss_restore_ctx(dev, pdata);
 882
 883         return pm_generic_runtime_resume(dev);
 884 }
 885 #endif /* CONFIG_PM */
 886
 887 static struct dev_pm_domain acpi_lpss_pm_domain = {
 888 #ifdef CONFIG_PM
 889         .activate = acpi_lpss_activate,
 890         .dismiss = acpi_lpss_dismiss,
 891 #endif
 892         .ops = {
 893 #ifdef CONFIG_PM
 894 #ifdef CONFIG_PM_SLEEP
 895                 .prepare = acpi_subsys_prepare,
 896                 .complete = pm_complete_with_resume_check,
 897                 .suspend = acpi_subsys_suspend,
 898                 .suspend_late = acpi_lpss_suspend_late,
 899                 .resume_early = acpi_lpss_resume_early,
 900                 .freeze = acpi_subsys_freeze,
 901                 .poweroff = acpi_subsys_suspend,
 902                 .poweroff_late = acpi_lpss_suspend_late,
 903                 .restore_early = acpi_lpss_resume_early,
 904 #endif
 905                 .runtime_suspend = acpi_lpss_runtime_suspend,
 906                 .runtime_resume = acpi_lpss_runtime_resume,
 907 #endif
 908         },
 909 };
 910
 911 static int acpi_lpss_platform_notify(struct notifier_block *nb,
 912                                      unsigned long action, void *data)
 913 {
 914         struct platform_device *pdev = to_platform_device(data);
 915         struct lpss_private_data *pdata;
 916         struct acpi_device *adev;
 917         const struct acpi_device_id *id;
 918
 919         id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
 920         if (!id || !id->driver_data)
 921                 return 0;
 922
 923         if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
 924                 return 0;
 925
 926         pdata = acpi_driver_data(adev);
 927         if (!pdata)
 928                 return 0;
 929
 930         if (pdata->mmio_base &&
 931             pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
 932                 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
 933                 return 0;
 934         }
 935
 936         switch (action) {
 937         case BUS_NOTIFY_BIND_DRIVER:
 938                 dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
 939                 break;
 940         case BUS_NOTIFY_DRIVER_NOT_BOUND:
 941         case BUS_NOTIFY_UNBOUND_DRIVER:
 942                 dev_pm_domain_set(&pdev->dev, NULL);
 943                 break;
 944         case BUS_NOTIFY_ADD_DEVICE:
 945                 dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
 946                 if (pdata->dev_desc->flags & LPSS_LTR)
 947                         return sysfs_create_group(&pdev->dev.kobj,
 948                                                   &lpss_attr_group);
 949                 break;
 950         case BUS_NOTIFY_DEL_DEVICE:
 951                 if (pdata->dev_desc->flags & LPSS_LTR)
 952                         sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
 953                 dev_pm_domain_set(&pdev->dev, NULL);
 954                 break;
 955         default:
 956                 break;
 957         }
 958
 959         return 0;
 960 }
 961
 962 static struct notifier_block acpi_lpss_nb = {
 963         .notifier_call = acpi_lpss_platform_notify,
 964 };
 965
 966 static void acpi_lpss_bind(struct device *dev)
 967 {
 968         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 969
 970         if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR))
 971                 return;
 972
 973         if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
 974                 dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
 975         else
 976                 dev_err(dev, "MMIO size insufficient to access LTR\n");
 977 }
 978
 979 static void acpi_lpss_unbind(struct device *dev)
 980 {
 981         dev->power.set_latency_tolerance = NULL;
 982 }
 983
 984 static struct acpi_scan_handler lpss_handler = {
 985         .ids = acpi_lpss_device_ids,
 986         .attach = acpi_lpss_create_device,
 987         .bind = acpi_lpss_bind,
 988         .unbind = acpi_lpss_unbind,
 989 };
 990
 991 void __init acpi_lpss_init(void)
 992 {
 993         const struct x86_cpu_id *id;
 994         int ret;
 995
 996         ret = lpt_clk_init();
 997         if (ret)
 998                 return;
 999
1000         id = x86_match_cpu(lpss_cpu_ids);
1001         if (id)
1002                 lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
1003
1004         bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
1005         acpi_scan_add_handler(&lpss_handler);
1006 }
1007
1008 #else
1009
1010 static struct acpi_scan_handler lpss_handler = {
1011         .ids = acpi_lpss_device_ids,
1012 };
1013
1014 void __init acpi_lpss_init(void)
1015 {
1016         acpi_scan_add_handler(&lpss_handler);
1017 }
1018
1019 #endif /* CONFIG_X86_INTEL_LPSS */