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
 184         { "INT3430", (unsigned long)&lpt_dev_desc },
 185         { "INT3431", (unsigned long)&lpt_dev_desc },
 186         { "INT3432", (unsigned long)&lpt_dev_desc },
 187         { "INT3433", (unsigned long)&lpt_dev_desc },
 188         { "INT3434", (unsigned long)&lpt_uart_dev_desc },
 189         { "INT3435", (unsigned long)&lpt_uart_dev_desc },
 190         { "INT3436", (unsigned long)&lpt_sdio_dev_desc },
 191         { "INT3437", },
 192
 193         { }
 194 };
 195
 196 static int is_memory(struct acpi_resource *res, void *not_used)
 197 {
 198         struct resource r;
 199         return !acpi_dev_resource_memory(res, &r);
 200 }
 201
 202 /* LPSS main clock device. */
 203 static struct platform_device *lpss_clk_dev;
 204
 205 static inline void lpt_register_clock_device(void)
 206 {
 207         lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0);
 208 }
 209
 210 static int register_device_clock(struct acpi_device *adev,
 211                                  struct lpss_private_data *pdata)
 212 {
 213         const struct lpss_device_desc *dev_desc = pdata->dev_desc;
 214         struct lpss_shared_clock *shared_clock = dev_desc->shared_clock;
 215         struct clk *clk = ERR_PTR(-ENODEV);
 216         struct lpss_clk_data *clk_data;
 217         const char *parent;
 218
 219         if (!lpss_clk_dev)
 220                 lpt_register_clock_device();
 221
 222         clk_data = platform_get_drvdata(lpss_clk_dev);
 223         if (!clk_data)
 224                 return -ENODEV;
 225
 226         if (dev_desc->clkdev_name) {
 227                 clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name,
 228                                     dev_name(&adev->dev));
 229                 return 0;
 230         }
 231
 232         if (!pdata->mmio_base
 233             || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE)
 234                 return -ENODATA;
 235
 236         parent = clk_data->name;
 237
 238         if (shared_clock) {
 239                 clk = shared_clock->clk;
 240                 if (!clk) {
 241                         clk = clk_register_fixed_rate(NULL, shared_clock->name,
 242                                                       "lpss_clk", 0,
 243                                                       shared_clock->rate);
 244                         shared_clock->clk = clk;
 245                 }
 246                 parent = shared_clock->name;
 247         }
 248
 249         if (dev_desc->clk_gate) {
 250                 clk = clk_register_gate(NULL, dev_name(&adev->dev), parent, 0,
 251                                         pdata->mmio_base + dev_desc->prv_offset,
 252                                         0, 0, NULL);
 253                 pdata->clk = clk;
 254         }
 255
 256         if (IS_ERR(clk))
 257                 return PTR_ERR(clk);
 258
 259         clk_register_clkdev(clk, NULL, dev_name(&adev->dev));
 260         return 0;
 261 }
 262
 263 static int acpi_lpss_create_device(struct acpi_device *adev,
 264                                    const struct acpi_device_id *id)
 265 {
 266         struct lpss_device_desc *dev_desc;
 267         struct lpss_private_data *pdata;
 268         struct resource_list_entry *rentry;
 269         struct list_head resource_list;
 270         int ret;
 271
 272         dev_desc = (struct lpss_device_desc *)id->driver_data;
 273         if (!dev_desc)
 274                 return acpi_create_platform_device(adev, id);
 275
 276         pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 277         if (!pdata)
 278                 return -ENOMEM;
 279
 280         INIT_LIST_HEAD(&resource_list);
 281         ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL);
 282         if (ret < 0)
 283                 goto err_out;
 284
 285         list_for_each_entry(rentry, &resource_list, node)
 286                 if (resource_type(&rentry->res) == IORESOURCE_MEM) {
 287                         if (dev_desc->prv_size_override)
 288                                 pdata->mmio_size = dev_desc->prv_size_override;
 289                         else
 290                                 pdata->mmio_size = resource_size(&rentry->res);
 291                         pdata->mmio_base = ioremap(rentry->res.start,
 292                                                    pdata->mmio_size);
 293                         break;
 294                 }
 295
 296         acpi_dev_free_resource_list(&resource_list);
 297
 298         pdata->dev_desc = dev_desc;
 299
 300         if (dev_desc->clk_required) {
 301                 ret = register_device_clock(adev, pdata);
 302                 if (ret) {
 303                         /* Skip the device, but continue the namespace scan. */
 304                         ret = 0;
 305                         goto err_out;
 306                 }
 307         }
 308
 309         /*
 310          * This works around a known issue in ACPI tables where LPSS devices
 311          * have _PS0 and _PS3 without _PSC (and no power resources), so
 312          * acpi_bus_init_power() will assume that the BIOS has put them into D0.
 313          */
 314         ret = acpi_device_fix_up_power(adev);
 315         if (ret) {
 316                 /* Skip the device, but continue the namespace scan. */
 317                 ret = 0;
 318                 goto err_out;
 319         }
 320
 321         if (dev_desc->setup)
 322                 dev_desc->setup(pdata);
 323
 324         adev->driver_data = pdata;
 325         ret = acpi_create_platform_device(adev, id);
 326         if (ret > 0)
 327                 return ret;
 328
 329         adev->driver_data = NULL;
 330
 331  err_out:
 332         kfree(pdata);
 333         return ret;
 334 }
 335
 336 static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg)
 337 {
 338         return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 339 }
 340
 341 static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata,
 342                              unsigned int reg)
 343 {
 344         writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg);
 345 }
 346
 347 static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val)
 348 {
 349         struct acpi_device *adev;
 350         struct lpss_private_data *pdata;
 351         unsigned long flags;
 352         int ret;
 353
 354         ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev);
 355         if (WARN_ON(ret))
 356                 return ret;
 357
 358         spin_lock_irqsave(&dev->power.lock, flags);
 359         if (pm_runtime_suspended(dev)) {
 360                 ret = -EAGAIN;
 361                 goto out;
 362         }
 363         pdata = acpi_driver_data(adev);
 364         if (WARN_ON(!pdata || !pdata->mmio_base)) {
 365                 ret = -ENODEV;
 366                 goto out;
 367         }
 368         *val = __lpss_reg_read(pdata, reg);
 369
 370  out:
 371         spin_unlock_irqrestore(&dev->power.lock, flags);
 372         return ret;
 373 }
 374
 375 static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr,
 376                              char *buf)
 377 {
 378         u32 ltr_value = 0;
 379         unsigned int reg;
 380         int ret;
 381
 382         reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR;
 383         ret = lpss_reg_read(dev, reg, &ltr_value);
 384         if (ret)
 385                 return ret;
 386
 387         return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value);
 388 }
 389
 390 static ssize_t lpss_ltr_mode_show(struct device *dev,
 391                                   struct device_attribute *attr, char *buf)
 392 {
 393         u32 ltr_mode = 0;
 394         char *outstr;
 395         int ret;
 396
 397         ret = lpss_reg_read(dev, LPSS_GENERAL, &ltr_mode);
 398         if (ret)
 399                 return ret;
 400
 401         outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto";
 402         return sprintf(buf, "%s\n", outstr);
 403 }
 404
 405 static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL);
 406 static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL);
 407 static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL);
 408
 409 static struct attribute *lpss_attrs[] = {
 410         &dev_attr_auto_ltr.attr,
 411         &dev_attr_sw_ltr.attr,
 412         &dev_attr_ltr_mode.attr,
 413         NULL,
 414 };
 415
 416 static struct attribute_group lpss_attr_group = {
 417         .attrs = lpss_attrs,
 418         .name = "lpss_ltr",
 419 };
 420
 421 static void acpi_lpss_set_ltr(struct device *dev, s32 val)
 422 {
 423         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 424         u32 ltr_mode, ltr_val;
 425
 426         ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL);
 427         if (val < 0) {
 428                 if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) {
 429                         ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW;
 430                         __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 431                 }
 432                 return;
 433         }
 434         ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK;
 435         if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) {
 436                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US;
 437                 val = LPSS_LTR_MAX_VAL;
 438         } else if (val > LPSS_LTR_MAX_VAL) {
 439                 ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ;
 440                 val >>= LPSS_LTR_SNOOP_LAT_SHIFT;
 441         } else {
 442                 ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ;
 443         }
 444         ltr_val |= val;
 445         __lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR);
 446         if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) {
 447                 ltr_mode |= LPSS_GENERAL_LTR_MODE_SW;
 448                 __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL);
 449         }
 450 }
 451
 452 static int acpi_lpss_platform_notify(struct notifier_block *nb,
 453                                      unsigned long action, void *data)
 454 {
 455         struct platform_device *pdev = to_platform_device(data);
 456         struct lpss_private_data *pdata;
 457         struct acpi_device *adev;
 458         const struct acpi_device_id *id;
 459         int ret = 0;
 460
 461         id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev);
 462         if (!id || !id->driver_data)
 463                 return 0;
 464
 465         if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev))
 466                 return 0;
 467
 468         pdata = acpi_driver_data(adev);
 469         if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
 470                 return 0;
 471
 472         if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) {
 473                 dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n");
 474                 return 0;
 475         }
 476
 477         if (action == BUS_NOTIFY_ADD_DEVICE)
 478                 ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group);
 479         else if (action == BUS_NOTIFY_DEL_DEVICE)
 480                 sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
 481
 482         return ret;
 483 }
 484
 485 static struct notifier_block acpi_lpss_nb = {
 486         .notifier_call = acpi_lpss_platform_notify,
 487 };
 488
 489 static void acpi_lpss_bind(struct device *dev)
 490 {
 491         struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 492
 493         if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required)
 494                 return;
 495
 496         if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE)
 497                 dev->power.set_latency_tolerance = acpi_lpss_set_ltr;
 498         else
 499                 dev_err(dev, "MMIO size insufficient to access LTR\n");
 500 }
 501
 502 static void acpi_lpss_unbind(struct device *dev)
 503 {
 504         dev->power.set_latency_tolerance = NULL;
 505 }
 506
 507 static struct acpi_scan_handler lpss_handler = {
 508         .ids = acpi_lpss_device_ids,
 509         .attach = acpi_lpss_create_device,
 510         .bind = acpi_lpss_bind,
 511         .unbind = acpi_lpss_unbind,
 512 };
 513
 514 void __init acpi_lpss_init(void)
 515 {
 516         if (!lpt_clk_init()) {
 517                 bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
 518                 acpi_scan_add_handler(&lpss_handler);
 519         }
 520 }