drivers/mfd/intel-lpss.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Intel Sunrisepoint LPSS core support.
   4  *
   5  * Copyright (C) 2015, Intel Corporation
   6  *
   7  * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
   8  *          Mika Westerberg <mika.westerberg@linux.intel.com>
   9  *          Heikki Krogerus <heikki.krogerus@linux.intel.com>
  10  *          Jarkko Nikula <jarkko.nikula@linux.intel.com>
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/clkdev.h>
  15 #include <linux/clk-provider.h>
  16 #include <linux/debugfs.h>
  17 #include <linux/idr.h>
  18 #include <linux/io.h>
  19 #include <linux/ioport.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/mfd/core.h>
  23 #include <linux/pm_qos.h>
  24 #include <linux/pm_runtime.h>
  25 #include <linux/property.h>
  26 #include <linux/seq_file.h>
  27 #include <linux/io-64-nonatomic-lo-hi.h>
  28
  29 #include <linux/dma/idma64.h>
  30
  31 #include "intel-lpss.h"
  32
  33 #define LPSS_DEV_OFFSET         0x000
  34 #define LPSS_DEV_SIZE           0x200
  35 #define LPSS_PRIV_OFFSET        0x200
  36 #define LPSS_PRIV_SIZE          0x100
  37 #define LPSS_PRIV_REG_COUNT     (LPSS_PRIV_SIZE / 4)
  38 #define LPSS_IDMA64_OFFSET      0x800
  39 #define LPSS_IDMA64_SIZE        0x800
  40
  41 /* Offsets from lpss->priv */
  42 #define LPSS_PRIV_RESETS                0x04
  43 #define LPSS_PRIV_RESETS_IDMA           BIT(2)
  44 #define LPSS_PRIV_RESETS_FUNC           0x3
  45
  46 #define LPSS_PRIV_ACTIVELTR             0x10
  47 #define LPSS_PRIV_IDLELTR               0x14
  48
  49 #define LPSS_PRIV_LTR_REQ               BIT(15)
  50 #define LPSS_PRIV_LTR_SCALE_MASK        GENMASK(11, 10)
  51 #define LPSS_PRIV_LTR_SCALE_1US         (2 << 10)
  52 #define LPSS_PRIV_LTR_SCALE_32US        (3 << 10)
  53 #define LPSS_PRIV_LTR_VALUE_MASK        GENMASK(9, 0)
  54
  55 #define LPSS_PRIV_SSP_REG               0x20
  56 #define LPSS_PRIV_SSP_REG_DIS_DMA_FIN   BIT(0)
  57
  58 #define LPSS_PRIV_REMAP_ADDR            0x40
  59
  60 #define LPSS_PRIV_CAPS                  0xfc
  61 #define LPSS_PRIV_CAPS_NO_IDMA          BIT(8)
  62 #define LPSS_PRIV_CAPS_TYPE_MASK        GENMASK(7, 4)
  63 #define LPSS_PRIV_CAPS_TYPE_SHIFT       4
  64
  65 /* This matches the type field in CAPS register */
  66 enum intel_lpss_dev_type {
  67         LPSS_DEV_I2C = 0,
  68         LPSS_DEV_UART,
  69         LPSS_DEV_SPI,
  70 };
  71
  72 struct intel_lpss {
  73         const struct intel_lpss_platform_info *info;
  74         enum intel_lpss_dev_type type;
  75         struct clk *clk;
  76         struct clk_lookup *clock;
  77         struct mfd_cell *cell;
  78         struct device *dev;
  79         void __iomem *priv;
  80         u32 priv_ctx[LPSS_PRIV_REG_COUNT];
  81         int devid;
  82         u32 caps;
  83         u32 active_ltr;
  84         u32 idle_ltr;
  85         struct dentry *debugfs;
  86 };
  87
  88 static const struct resource intel_lpss_dev_resources[] = {
  89         DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
  90         DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
  91         DEFINE_RES_IRQ(0),
  92 };
  93
  94 static const struct resource intel_lpss_idma64_resources[] = {
  95         DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
  96         DEFINE_RES_IRQ(0),
  97 };
  98
  99 /*
 100  * Cells needs to be ordered so that the iDMA is created first. This is
 101  * because we need to be sure the DMA is available when the host controller
 102  * driver is probed.
 103  */
 104 static const struct mfd_cell intel_lpss_idma64_cell = {
 105         .name = LPSS_IDMA64_DRIVER_NAME,
 106         .num_resources = ARRAY_SIZE(intel_lpss_idma64_resources),
 107         .resources = intel_lpss_idma64_resources,
 108 };
 109
 110 static const struct mfd_cell intel_lpss_i2c_cell = {
 111         .name = "i2c_designware",
 112         .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
 113         .resources = intel_lpss_dev_resources,
 114 };
 115
 116 static const struct mfd_cell intel_lpss_uart_cell = {
 117         .name = "dw-apb-uart",
 118         .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
 119         .resources = intel_lpss_dev_resources,
 120 };
 121
 122 static const struct mfd_cell intel_lpss_spi_cell = {
 123         .name = "pxa2xx-spi",
 124         .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
 125         .resources = intel_lpss_dev_resources,
 126 };
 127
 128 static DEFINE_IDA(intel_lpss_devid_ida);
 129 static struct dentry *intel_lpss_debugfs;
 130
 131 static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
 132 {
 133         lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
 134         lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR);
 135 }
 136
 137 static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
 138 {
 139         struct dentry *dir;
 140
 141         dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
 142         if (IS_ERR(dir))
 143                 return PTR_ERR(dir);
 144
 145         /* Cache the values into lpss structure */
 146         intel_lpss_cache_ltr(lpss);
 147
 148         debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps);
 149         debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr);
 150         debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr);
 151
 152         lpss->debugfs = dir;
 153         return 0;
 154 }
 155
 156 static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
 157 {
 158         debugfs_remove_recursive(lpss->debugfs);
 159 }
 160
 161 static void intel_lpss_ltr_set(struct device *dev, s32 val)
 162 {
 163         struct intel_lpss *lpss = dev_get_drvdata(dev);
 164         u32 ltr;
 165
 166         /*
 167          * Program latency tolerance (LTR) accordingly what has been asked
 168          * by the PM QoS layer or disable it in case we were passed
 169          * negative value or PM_QOS_LATENCY_ANY.
 170          */
 171         ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
 172
 173         if (val == PM_QOS_LATENCY_ANY || val < 0) {
 174                 ltr &= ~LPSS_PRIV_LTR_REQ;
 175         } else {
 176                 ltr |= LPSS_PRIV_LTR_REQ;
 177                 ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
 178                 ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;
 179
 180                 if (val > LPSS_PRIV_LTR_VALUE_MASK)
 181                         ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
 182                 else
 183                         ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
 184         }
 185
 186         if (ltr == lpss->active_ltr)
 187                 return;
 188
 189         writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR);
 190         writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR);
 191
 192         /* Cache the values into lpss structure */
 193         intel_lpss_cache_ltr(lpss);
 194 }
 195
 196 static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
 197 {
 198         lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
 199         dev_pm_qos_expose_latency_tolerance(lpss->dev);
 200 }
 201
 202 static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
 203 {
 204         dev_pm_qos_hide_latency_tolerance(lpss->dev);
 205         lpss->dev->power.set_latency_tolerance = NULL;
 206 }
 207
 208 static int intel_lpss_assign_devs(struct intel_lpss *lpss)
 209 {
 210         const struct mfd_cell *cell;
 211         unsigned int type;
 212
 213         type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
 214         type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
 215
 216         switch (type) {
 217         case LPSS_DEV_I2C:
 218                 cell = &intel_lpss_i2c_cell;
 219                 break;
 220         case LPSS_DEV_UART:
 221                 cell = &intel_lpss_uart_cell;
 222                 break;
 223         case LPSS_DEV_SPI:
 224                 cell = &intel_lpss_spi_cell;
 225                 break;
 226         default:
 227                 return -ENODEV;
 228         }
 229
 230         lpss->cell = devm_kmemdup(lpss->dev, cell, sizeof(*cell), GFP_KERNEL);
 231         if (!lpss->cell)
 232                 return -ENOMEM;
 233
 234         lpss->type = type;
 235
 236         return 0;
 237 }
 238
 239 static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
 240 {
 241         return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
 242 }
 243
 244 static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
 245 {
 246         resource_size_t addr = lpss->info->mem->start;
 247
 248         lo_hi_writeq(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR);
 249 }
 250
 251 static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
 252 {
 253         u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;
 254
 255         /* Bring out the device from reset */
 256         writel(value, lpss->priv + LPSS_PRIV_RESETS);
 257 }
 258
 259 static void intel_lpss_init_dev(const struct intel_lpss *lpss)
 260 {
 261         u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
 262
 263         /* Set the device in reset state */
 264         writel(0, lpss->priv + LPSS_PRIV_RESETS);
 265
 266         intel_lpss_deassert_reset(lpss);
 267
 268         intel_lpss_set_remap_addr(lpss);
 269
 270         if (!intel_lpss_has_idma(lpss))
 271                 return;
 272
 273         /* Make sure that SPI multiblock DMA transfers are re-enabled */
 274         if (lpss->type == LPSS_DEV_SPI)
 275                 writel(value, lpss->priv + LPSS_PRIV_SSP_REG);
 276 }
 277
 278 static void intel_lpss_unregister_clock_tree(struct clk *clk)
 279 {
 280         struct clk *parent;
 281
 282         while (clk) {
 283                 parent = clk_get_parent(clk);
 284                 clk_unregister(clk);
 285                 clk = parent;
 286         }
 287 }
 288
 289 static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
 290                                              const char *devname,
 291                                              struct clk **clk)
 292 {
 293         char name[32];
 294         struct clk *tmp = *clk;
 295
 296         snprintf(name, sizeof(name), "%s-enable", devname);
 297         tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
 298                                 lpss->priv, 0, 0, NULL);
 299         if (IS_ERR(tmp))
 300                 return PTR_ERR(tmp);
 301
 302         snprintf(name, sizeof(name), "%s-div", devname);
 303         tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
 304                                               CLK_FRAC_DIVIDER_POWER_OF_TWO_PS,
 305                                               lpss->priv, 1, 15, 16, 15, 0,
 306                                               NULL);
 307         if (IS_ERR(tmp))
 308                 return PTR_ERR(tmp);
 309         *clk = tmp;
 310
 311         snprintf(name, sizeof(name), "%s-update", devname);
 312         tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
 313                                 CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
 314         if (IS_ERR(tmp))
 315                 return PTR_ERR(tmp);
 316         *clk = tmp;
 317
 318         return 0;
 319 }
 320
 321 static int intel_lpss_register_clock(struct intel_lpss *lpss)
 322 {
 323         const struct mfd_cell *cell = lpss->cell;
 324         struct clk *clk;
 325         char devname[24];
 326         int ret;
 327
 328         if (!lpss->info->clk_rate)
 329                 return 0;
 330
 331         /* Root clock */
 332         clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL, 0,
 333                                       lpss->info->clk_rate);
 334         if (IS_ERR(clk))
 335                 return PTR_ERR(clk);
 336
 337         snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);
 338
 339         /*
 340          * Support for clock divider only if it has some preset value.
 341          * Otherwise we assume that the divider is not used.
 342          */
 343         if (lpss->type != LPSS_DEV_I2C) {
 344                 ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
 345                 if (ret)
 346                         goto err_clk_register;
 347         }
 348
 349         ret = -ENOMEM;
 350
 351         /* Clock for the host controller */
 352         lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname);
 353         if (!lpss->clock)
 354                 goto err_clk_register;
 355
 356         lpss->clk = clk;
 357
 358         return 0;
 359
 360 err_clk_register:
 361         intel_lpss_unregister_clock_tree(clk);
 362
 363         return ret;
 364 }
 365
 366 static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
 367 {
 368         if (IS_ERR_OR_NULL(lpss->clk))
 369                 return;
 370
 371         clkdev_drop(lpss->clock);
 372         intel_lpss_unregister_clock_tree(lpss->clk);
 373 }
 374
 375 int intel_lpss_probe(struct device *dev,
 376                      const struct intel_lpss_platform_info *info)
 377 {
 378         struct intel_lpss *lpss;
 379         int ret;
 380
 381         if (!info || !info->mem || info->irq <= 0)
 382                 return -EINVAL;
 383
 384         lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL);
 385         if (!lpss)
 386                 return -ENOMEM;
 387
 388         lpss->priv = devm_ioremap_uc(dev, info->mem->start + LPSS_PRIV_OFFSET,
 389                                   LPSS_PRIV_SIZE);
 390         if (!lpss->priv)
 391                 return -ENOMEM;
 392
 393         lpss->info = info;
 394         lpss->dev = dev;
 395         lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS);
 396
 397         dev_set_drvdata(dev, lpss);
 398
 399         ret = intel_lpss_assign_devs(lpss);
 400         if (ret)
 401                 return ret;
 402
 403         lpss->cell->swnode = info->swnode;
 404
 405         intel_lpss_init_dev(lpss);
 406
 407         lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL);
 408         if (lpss->devid < 0)
 409                 return lpss->devid;
 410
 411         ret = intel_lpss_register_clock(lpss);
 412         if (ret)
 413                 goto err_clk_register;
 414
 415         intel_lpss_ltr_expose(lpss);
 416
 417         ret = intel_lpss_debugfs_add(lpss);
 418         if (ret)
 419                 dev_warn(dev, "Failed to create debugfs entries\n");
 420
 421         if (intel_lpss_has_idma(lpss)) {
 422                 ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell,
 423                                       1, info->mem, info->irq, NULL);
 424                 if (ret)
 425                         dev_warn(dev, "Failed to add %s, fallback to PIO\n",
 426                                  LPSS_IDMA64_DRIVER_NAME);
 427         }
 428
 429         ret = mfd_add_devices(dev, lpss->devid, lpss->cell,
 430                               1, info->mem, info->irq, NULL);
 431         if (ret)
 432                 goto err_remove_ltr;
 433
 434         dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND);
 435
 436         return 0;
 437
 438 err_remove_ltr:
 439         intel_lpss_debugfs_remove(lpss);
 440         intel_lpss_ltr_hide(lpss);
 441         intel_lpss_unregister_clock(lpss);
 442
 443 err_clk_register:
 444         ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
 445
 446         return ret;
 447 }
 448 EXPORT_SYMBOL_GPL(intel_lpss_probe);
 449
 450 void intel_lpss_remove(struct device *dev)
 451 {
 452         struct intel_lpss *lpss = dev_get_drvdata(dev);
 453
 454         mfd_remove_devices(dev);
 455         intel_lpss_debugfs_remove(lpss);
 456         intel_lpss_ltr_hide(lpss);
 457         intel_lpss_unregister_clock(lpss);
 458         ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
 459 }
 460 EXPORT_SYMBOL_GPL(intel_lpss_remove);
 461
 462 static int resume_lpss_device(struct device *dev, void *data)
 463 {
 464         if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND))
 465                 pm_runtime_resume(dev);
 466
 467         return 0;
 468 }
 469
 470 int intel_lpss_prepare(struct device *dev)
 471 {
 472         /*
 473          * Resume both child devices before entering system sleep. This
 474          * ensures that they are in proper state before they get suspended.
 475          */
 476         device_for_each_child_reverse(dev, NULL, resume_lpss_device);
 477         return 0;
 478 }
 479 EXPORT_SYMBOL_GPL(intel_lpss_prepare);
 480
 481 int intel_lpss_suspend(struct device *dev)
 482 {
 483         struct intel_lpss *lpss = dev_get_drvdata(dev);
 484         unsigned int i;
 485
 486         /* Save device context */
 487         for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
 488                 lpss->priv_ctx[i] = readl(lpss->priv + i * 4);
 489
 490         /*
 491          * If the device type is not UART, then put the controller into
 492          * reset. UART cannot be put into reset since S3/S0ix fail when
 493          * no_console_suspend flag is enabled.
 494          */
 495         if (lpss->type != LPSS_DEV_UART)
 496                 writel(0, lpss->priv + LPSS_PRIV_RESETS);
 497
 498         return 0;
 499 }
 500 EXPORT_SYMBOL_GPL(intel_lpss_suspend);
 501
 502 int intel_lpss_resume(struct device *dev)
 503 {
 504         struct intel_lpss *lpss = dev_get_drvdata(dev);
 505         unsigned int i;
 506
 507         intel_lpss_deassert_reset(lpss);
 508
 509         /* Restore device context */
 510         for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
 511                 writel(lpss->priv_ctx[i], lpss->priv + i * 4);
 512
 513         return 0;
 514 }
 515 EXPORT_SYMBOL_GPL(intel_lpss_resume);
 516
 517 static int __init intel_lpss_init(void)
 518 {
 519         intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
 520         return 0;
 521 }
 522 module_init(intel_lpss_init);
 523
 524 static void __exit intel_lpss_exit(void)
 525 {
 526         ida_destroy(&intel_lpss_devid_ida);
 527         debugfs_remove(intel_lpss_debugfs);
 528 }
 529 module_exit(intel_lpss_exit);
 530
 531 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
 532 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
 533 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
 534 MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
 535 MODULE_DESCRIPTION("Intel LPSS core driver");
 536 MODULE_LICENSE("GPL v2");
 537 /*
 538  * Ensure the DMA driver is loaded before the host controller device appears,
 539  * so that the host controller driver can request its DMA channels as early
 540  * as possible.
 541  *
 542  * If the DMA module is not there that's OK as well.
 543  */
 544 MODULE_SOFTDEP("pre: platform:" LPSS_IDMA64_DRIVER_NAME);