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
  23 #include "internal.h"
  24
  25 ACPI_MODULE_NAME("acpi_lpss");
  26
  27 #define LPSS_CLK_SIZE   0x04
  28 #define LPSS_LTR_SIZE   0x18
  29
  30 /* Offsets relative to LPSS_PRIVATE_OFFSET */
  31 #define LPSS_GENERAL                    0x08
  32 #define LPSS_GENERAL_LTR_MODE_SW        BIT(2)
  33 #define LPSS_GENERAL_UART_RTS_OVRD      BIT(3)
  34 #define LPSS_SW_LTR                     0x10
  35 #define LPSS_AUTO_LTR                   0x14
  36 #define LPSS_LTR_SNOOP_REQ              BIT(15)
  37 #define LPSS_LTR_SNOOP_MASK             0x0000FFFF
  38 #define LPSS_LTR_SNOOP_LAT_1US          0x800
  39 #define LPSS_LTR_SNOOP_LAT_32US         0xC00
  40 #define LPSS_LTR_SNOOP_LAT_SHIFT        5
  41 #define LPSS_LTR_SNOOP_LAT_CUTOFF       3000
  42 #define LPSS_LTR_MAX_VAL                0x3FF
  43 #define LPSS_TX_INT                     0x20
  44 #define LPSS_TX_INT_MASK                BIT(1)
  45
  46 struct lpss_shared_clock {
  47         const char *name;
  48         unsigned long rate;
  49         struct clk *clk;
  50 };
  51
  52 struct lpss_private_data;
  53
  54 struct lpss_device_desc {
  55         bool clk_required;
  56         const char *clkdev_name;
  57         bool ltr_required;
  58         unsigned int prv_offset;
  59         size_t prv_size_override;
  60         bool clk_gate;
  61         struct lpss_shared_clock *shared_clock;
  62         void (*setup)(struct lpss_private_data *pdata);
  63 };
  64
  65 static struct lpss_device_desc lpss_dma_desc = {
  66         .clk_required = true,
  67         .clkdev_name = "hclk",
  68 };
  69
  70 struct lpss_private_data {
  71         void __iomem *mmio_base;
  72         resource_size_t mmio_size;
  73         struct clk *clk;
  74         const struct lpss_device_desc *dev_desc;
  75 };
  76
  77 static void lpss_uart_setup(struct lpss_private_data *pdata)
  78 {
  79         unsigned int offset;
  80         u32 reg;
  81
  82         offset = pdata->dev_desc->prv_offset + LPSS_TX_INT;
  83         reg = readl(pdata->mmio_base + offset);
  84         writel(reg | LPSS_TX_INT_MASK, pdata->mmio_base + offset);
  85
  86         offset = pdata->dev_desc->prv_offset + LPSS_GENERAL;
  87         reg = readl(pdata->mmio_base + offset);
  88         writel(reg | LPSS_GENERAL_UART_RTS_OVRD, pdata->mmio_base + offset);
  89 }
  90
  91 static struct lpss_device_desc lpt_dev_desc = {
  92         .clk_required = true,
  93         .prv_offset = 0x800,
  94         .ltr_required = true,
  95         .clk_gate = true,
  96 };
  97
  98 static struct lpss_device_desc lpt_uart_dev_desc = {
  99         .clk_required = true,
 100         .prv_offset = 0x800,
 101         .ltr_required = true,
 102         .clk_gate = true,
 103         .setup = lpss_uart_setup,
 104 };
 105
 106 static struct lpss_device_desc lpt_sdio_dev_desc = {
 107         .prv_offset = 0x1000,
 108         .prv_size_override = 0x1018,
 109         .ltr_required = true,
 110 };
 111
 112 static struct lpss_shared_clock pwm_clock = {
 113         .name = "pwm_clk",
 114         .rate = 25000000,
 115 };
 116
 117 static struct lpss_device_desc byt_pwm_dev_desc = {
 118         .clk_required = true,
 119         .shared_clock = &pwm_clock,
 120 };
 121
 122 static struct lpss_shared_clock uart_clock = {
 123         .name = "uart_clk",
 124         .rate = 44236800,
 125 };
 126
 127 static struct lpss_device_desc byt_uart_dev_desc = {
 128         .clk_required = true,
 129         .prv_offset = 0x800,
 130         .clk_gate = true,
 131         .shared_clock = &uart_clock,
 132         .setup = lpss_uart_setup,
 133 };
 134
 135 static struct lpss_shared_clock spi_clock = {
 136         .name = "spi_clk",
 137         .rate = 50000000,
 138 };
 139
 140 static struct lpss_device_desc byt_spi_dev_desc = {
 141         .clk_required = true,
 142         .prv_offset = 0x400,
 143         .clk_gate = true,
 144         .shared_clock = &spi_clock,
 145 };
 146
 147 static struct lpss_device_desc byt_sdio_dev_desc = {
 148         .clk_required = true,
 149 };
 150
 151 static struct lpss_shared_clock i2c_clock = {
 152         .name = "i2c_clk",
 153         .rate = 100000000,
 154 };
 155
 156 static struct lpss_device_desc byt_i2c_dev_desc = {
 157         .clk_required = true,
 158         .prv_offset = 0x800,
 159         .shared_clock = &i2c_clock,
 160 };
 161
 162 static const struct acpi_device_id acpi_lpss_device_ids[] = {
 163         /* Generic LPSS devices */
 164         { "INTL9C60", (unsigned long)&lpss_dma_desc },
 165
 166         /* Lynxpoint LPSS devices */
 167         { "INT33C0", (unsigned long)&lpt_dev_desc },
 168         { "INT33C1", (unsigned long)&lpt_dev_desc },
 169         { "INT33C2", (unsigned long)&lpt_dev_desc },
 170         { "INT33C3", (unsigned long)&lpt_dev_desc },
 171         { "INT33C4", (unsigned long)&lpt_uart_dev_desc },
 172         { "INT33C5", (unsigned long)&lpt_uart_dev_desc },
 173         { "INT33C6", (unsigned long)&lpt_sdio_dev_desc },
 174         { "INT33C7", },
 175
 176         /* BayTrail LPSS devices */
 177         { "80860F09", (unsigned long)&byt_pwm_dev_desc },
 178         { "80860F0A", (unsigned long)&byt_uart_dev_desc },
 179         { "80860F0E", (unsigned long)&byt_spi_dev_desc },
 180         { "80860F14", (unsigned long)&byt_sdio_dev_desc },
 181         { "80860F41", (unsigned long)&byt_i2c_dev_desc },
 182         { "INT33B2", },
 183         { "INT33FC", },
 184
 185         { "INT3430", (unsigned long)&lpt_dev_desc },
 186         { "INT3431", (unsigned long)&lpt_dev_desc },
 187         { "INT3432", (unsigned long)&lpt_dev_desc },
 188         { "INT3433", (unsigned long)&lpt_dev_desc },
 189         { "INT3434", (unsigned long)&lpt_uart_dev_desc },
 190         { "INT3435", (unsigned long)&lpt_uart_dev_desc },
 191         { "INT3436", (unsigned long)&lpt_sdio_dev_desc },
 192         { "INT3437", },
 193
 194         { }
 195 };
 196
 197 static int is_memory(struct acpi_resource *res, void *not_used)
 198 {
 199         struct resource r;
 200         return !acpi_dev_resource_memory(res, &r);
 201 }
 202
 203 /* LPSS main clock device. */
 204 static struct platform_device *lpss_clk_dev;
 205
 206 static inline void lpt_register_clock_device(void)
 207 {
 208         lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
 209 }
 210
 211 static int register_device_clock(struct acpi_device *adev,
 212                                  struct lpss_private_data *pdata)
 213 {
 214         const struct lpss_device_desc *dev_desc = pdata->dev_desc;
 215         struct lpss_shared_clock *shared_clock = dev_desc->shared_clock;
 216         struct clk *clk = ERR_PTR(-ENODEV);
 217         struct lpss_clk_data *clk_data;
 218         const char *parent;
 219
 220         if (!lpss_clk_dev)
 221                 lpt_register_clock_device();
 222
 223         clk_data = platform_get_drvdata(lpss_clk_dev);
 224         if (!clk_data)
 225                 return -ENODEV;
 226
 227         if (dev_desc->clkdev_name) {
 228                 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
 229                                     dev_name(&adev->dev));
 230                 return 0;
 231         }
 232
 233         if (!pdata->mmio_base
 234             || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
 235                 return -ENODATA;
 236
 237         parent = clk_data->name;
 238
 239         if (shared_clock) {
 240                 clk = shared_clock->clk;
 241                 if (!clk) {
 242                         clk = clk_register_fixed_rate(NULL, shared_clock->name,
 243                                                       "lpss_clk", 0,
 244                                                       shared_clock->rate);
 245                         shared_clock->clk = clk;
 246                 }
 247                 parent = shared_clock->name;
 248         }
 249
 250         if (dev_desc->clk_gate) {
 251                 clk = clk_register_gate(NULL, dev_name(&adev->dev), parent, 0,
 252                                         pdata->mmio_base + dev_desc->prv_offset,
 253                                         0, 0, NULL);
 254                 pdata->clk = clk;
 255         }
 256
 257         if (IS_ERR(clk))
 258                 return PTR_ERR(clk);
 259
 260         clk_register_clkdev(clk, NULL, dev_name(&adev->dev));
 261         return 0;
 262 }
 263
 264 static int acpi_lpss_create_device(struct acpi_device *adev,
 265                                    const struct acpi_device_id *id)
 266 {
 267         struct lpss_device_desc *dev_desc;
 268         struct lpss_private_data *pdata;
 269         struct resource_list_entry *rentry;
 270         struct list_head resource_list;
 271         int ret;
 272
 273         dev_desc = (struct lpss_device_desc *)id->driver_data;
 274         if (!dev_desc)
 275                 return acpi_create_platform_device(adev, id);
 276
 277         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 278         if (!pdata)
 279                 return -ENOMEM;
 280
 281         INIT_LIST_HEAD(&resource_list);
 282         ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
 283         if (ret < 0)
 284                 goto err_out;
 285
 286         list_for_each_entry(rentry, &resource_list, node)
 287                 if (resource_type(&rentry->res) == IORESOURCE_MEM) {
 288                         if (dev_desc->prv_size_override)
 289                                 pdata->mmio_size = dev_desc->prv_size_override;
 290                         else
 291                                 pdata->mmio_size = resource_size(&rentry->res);
 292                         pdata->mmio_base = ioremap(rentry->res.start,
 293                                                    pdata->mmio_size);
 294                         break;
 295                 }
 296
 297         acpi_dev_free_resource_list(&resource_list);
 298
 299         pdata->dev_desc = dev_desc;
 300
 301         if (dev_desc->clk_required) {
 302                 ret = register_device_clock(adev, pdata);
 303                 if (ret) {
 304                         /* Skip the device, but continue the namespace scan. */
 305                         ret = 0;
 306                         goto err_out;
 307                 }
 308         }
 309
 310         /*
 311          * This works around a known issue in ACPI tables where LPSS devices
 312          * have _PS0 and _PS3 without _PSC (and no power resources), so
 313          * acpi_bus_init_power() will assume that the BIOS has put them into D0.
 314          */
 315         ret = acpi_device_fix_up_power(adev);
 316         if (ret) {
 317                 /* Skip the device, but continue the namespace scan. */
 318                 ret = 0;
 319                 goto err_out;
 320         }
 321
 322         if (dev_desc->setup)
 323                 dev_desc->setup(pdata);
 324
 325         adev->driver_data = pdata;
 326         ret = acpi_create_platform_device(adev, id);
 327         if (ret > 0)
 328                 return ret;
 329
 330         adev->driver_data = NULL;
 331
 332  err_out:
 333         kfree(pdata);
 334         return ret;
 335 }
 336
 337 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
 338 {
 339         return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 340 }
 341
 342 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
 343                              unsigned int reg)
 344 {
 345         writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 346 }
 347
 348 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
 349 {
 350         struct acpi_device *adev;
 351         struct lpss_private_data *pdata;
 352         unsigned long flags;
 353         int ret;
 354
 355         ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
 356         if (WARN_ON(ret))
 357                 return ret;
 358
 359         spin_lock_irqsave(&dev->power.lock, flags);
 360         if (pm_runtime_suspended(dev)) {
 361                 ret = -EAGAIN;
 362                 goto out;
 363         }
 364         pdata = acpi_driver_data(adev);
 365         if (WARN_ON(!pdata || !pdata->mmio_base)) {
 366                 ret = -ENODEV;
 367                 goto out;
 368         }
 369         *val = __lpss_reg_read(pdata, reg);
 370
 371  out:
 372         spin_unlock_irqrestore(&dev->power.lock, flags);
 373         return ret;
 374 }
 375
 376 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
 377                              char *buf)
 378 {
 379         u32 ltr_value = 0;
 380         unsigned int reg;
 381         int ret;
 382
 383         reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
 384         ret = lpss_reg_read(dev, reg, &ltr_value);
 385         if (ret)
 386                 return ret;
 387
 388         return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
 389 }
 390
 391 static ssize_t lpss_ltr_mode_show(struct device *dev,
 392                                   struct device_attribute *attr, char *buf)
 393 {
 394         u32 ltr_mode = 0;
 395         char *outstr;
 396         int ret;
 397
 398         ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
 399         if (ret)
 400                 return ret;
 401
 402         outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
 403         return sprintf(buf, "%s\n", outstr);
 404 }
 405
 406 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
 407 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
 408 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
 409
 410 static struct attribute *lpss_attrs[] = {
 411         &dev_attr_auto_ltr.attr,
 412         &dev_attr_sw_ltr.attr,
 413         &dev_attr_ltr_mode.attr,
 414         NULL,
 415 };
 416
 417 static struct attribute_group lpss_attr_group = {
 418         .attrs = lpss_attrs,
 419         .name = "lpss_ltr",
 420 };
 421
 422 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
 423 {
 424         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 425         u32 ltr_mode, ltr_val;
 426
 427         ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
 428         if (val < 0) {
 429                 if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
 430                         ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
 431                         __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 432                 }
 433                 return;
 434         }
 435         ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
 436         if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
 437                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
 438                 val = LPSS_LTR_MAX_VAL;
 439         } else if (val > LPSS_LTR_MAX_VAL) {
 440                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
 441                 val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
 442         } else {
 443                 ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
 444         }
 445         ltr_val |= val;
 446         __lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
 447         if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
 448                 ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
 449                 __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 450         }
 451 }
 452
 453 static int acpi_lpss_platform_notify(struct notifier_block *nb,
 454                                      unsigned long action, void *data)
 455 {
 456         struct platform_device *pdev = to_platform_device(data);
 457         struct lpss_private_data *pdata;
 458         struct acpi_device *adev;
 459         const struct acpi_device_id *id;
 460         int ret = 0;
 461
 462         id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
 463         if (!id || !id->driver_data)
 464                 return 0;
 465
 466         if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
 467                 return 0;
 468
 469         pdata = acpi_driver_data(adev);
 470         if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
 471                 return 0;
 472
 473         if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
 474                 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
 475                 return 0;
 476         }
 477
 478         if (action == BUS_NOTIFY_ADD_DEVICE)
 479                 ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
 480         else if (action == BUS_NOTIFY_DEL_DEVICE)
 481                 sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
 482
 483         return ret;
 484 }
 485
 486 static struct notifier_block acpi_lpss_nb = {
 487         .notifier_call = acpi_lpss_platform_notify,
 488 };
 489
 490 static void acpi_lpss_bind(struct device *dev)
 491 {
 492         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 493
 494         if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
 495                 return;
 496
 497         if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
 498                 dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
 499         else
 500                 dev_err(dev, "MMIO size insufficient to access LTR\n");
 501 }
 502
 503 static void acpi_lpss_unbind(struct device *dev)
 504 {
 505         dev->power.set_latency_tolerance = NULL;
 506 }
 507
 508 static struct acpi_scan_handler lpss_handler = {
 509         .ids = acpi_lpss_device_ids,
 510         .attach = acpi_lpss_create_device,
 511         .bind = acpi_lpss_bind,
 512         .unbind = acpi_lpss_unbind,
 513 };
 514
 515 void __init acpi_lpss_init(void)
 516 {
 517         if (!lpt_clk_init()) {
 518                 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
 519                 acpi_scan_add_handler(&lpss_handler);
 520         }
 521 }