drivers/mfd/intel-lpss.c

   1 /*
   2  * Intel Sunrisepoint LPSS core support.
   3  *
   4  * Copyright (C) 2015, Intel Corporation
   5  *
   6  * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
   7  *          Mika Westerberg <mika.westerberg@linux.intel.com>
   8  *          Heikki Krogerus <heikki.krogerus@linux.intel.com>
   9  *          Jarkko Nikula <jarkko.nikula@linux.intel.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  */
  15
  16 #include <linux/clk.h>
  17 #include <linux/clkdev.h>
  18 #include <linux/clk-provider.h>
  19 #include <linux/debugfs.h>
  20 #include <linux/idr.h>
  21 #include <linux/ioport.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/mfd/core.h>
  25 #include <linux/pm_qos.h>
  26 #include <linux/pm_runtime.h>
  27 #include <linux/property.h>
  28 #include <linux/seq_file.h>
  29 #include <linux/io-64-nonatomic-lo-hi.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_IDMA64_OFFSET      0x800
  38 #define LPSS_IDMA64_SIZE        0x800
  39
  40 /* Offsets from lpss->priv */
  41 #define LPSS_PRIV_RESETS                0x04
  42 #define LPSS_PRIV_RESETS_FUNC           BIT(2)
  43 #define LPSS_PRIV_RESETS_IDMA           0x3
  44
  45 #define LPSS_PRIV_ACTIVELTR             0x10
  46 #define LPSS_PRIV_IDLELTR               0x14
  47
  48 #define LPSS_PRIV_LTR_REQ               BIT(15)
  49 #define LPSS_PRIV_LTR_SCALE_MASK        0xc00
  50 #define LPSS_PRIV_LTR_SCALE_1US         0x800
  51 #define LPSS_PRIV_LTR_SCALE_32US        0xc00
  52 #define LPSS_PRIV_LTR_VALUE_MASK        0x3ff
  53
  54 #define LPSS_PRIV_SSP_REG               0x20
  55 #define LPSS_PRIV_SSP_REG_DIS_DMA_FIN   BIT(0)
  56
  57 #define LPSS_PRIV_REMAP_ADDR            0x40
  58
  59 #define LPSS_PRIV_CAPS                  0xfc
  60 #define LPSS_PRIV_CAPS_NO_IDMA          BIT(8)
  61 #define LPSS_PRIV_CAPS_TYPE_SHIFT       4
  62 #define LPSS_PRIV_CAPS_TYPE_MASK        (0xf << LPSS_PRIV_CAPS_TYPE_SHIFT)
  63
  64 /* This matches the type field in CAPS register */
  65 enum intel_lpss_dev_type {
  66         LPSS_DEV_I2C = 0,
  67         LPSS_DEV_UART,
  68         LPSS_DEV_SPI,
  69 };
  70
  71 struct intel_lpss {
  72         const struct intel_lpss_platform_info *info;
  73         enum intel_lpss_dev_type type;
  74         struct clk *clk;
  75         struct clk_lookup *clock;
  76         struct mfd_cell *cell;
  77         struct device *dev;
  78         void __iomem *priv;
  79         int devid;
  80         u32 caps;
  81         u32 active_ltr;
  82         u32 idle_ltr;
  83         struct dentry *debugfs;
  84 };
  85
  86 static const struct resource intel_lpss_dev_resources[] = {
  87         DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
  88         DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
  89         DEFINE_RES_IRQ(0),
  90 };
  91
  92 static const struct resource intel_lpss_idma64_resources[] = {
  93         DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
  94         DEFINE_RES_IRQ(0),
  95 };
  96
  97 #define LPSS_IDMA64_DRIVER_NAME         "idma64"
  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 int intel_lpss_request_dma_module(const char *name)
 132 {
 133         static bool intel_lpss_dma_requested;
 134
 135         if (intel_lpss_dma_requested)
 136                 return 0;
 137
 138         intel_lpss_dma_requested = true;
 139         return request_module("%s", name);
 140 }
 141
 142 static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
 143 {
 144         lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
 145         lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR);
 146 }
 147
 148 static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
 149 {
 150         struct dentry *dir;
 151
 152         dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
 153         if (IS_ERR(dir))
 154                 return PTR_ERR(dir);
 155
 156         /* Cache the values into lpss structure */
 157         intel_lpss_cache_ltr(lpss);
 158
 159         debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps);
 160         debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr);
 161         debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr);
 162
 163         lpss->debugfs = dir;
 164         return 0;
 165 }
 166
 167 static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
 168 {
 169         debugfs_remove_recursive(lpss->debugfs);
 170 }
 171
 172 static void intel_lpss_ltr_set(struct device *dev, s32 val)
 173 {
 174         struct intel_lpss *lpss = dev_get_drvdata(dev);
 175         u32 ltr;
 176
 177         /*
 178          * Program latency tolerance (LTR) accordingly what has been asked
 179          * by the PM QoS layer or disable it in case we were passed
 180          * negative value or PM_QOS_LATENCY_ANY.
 181          */
 182         ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
 183
 184         if (val == PM_QOS_LATENCY_ANY || val < 0) {
 185                 ltr &= ~LPSS_PRIV_LTR_REQ;
 186         } else {
 187                 ltr |= LPSS_PRIV_LTR_REQ;
 188                 ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
 189                 ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;
 190
 191                 if (val > LPSS_PRIV_LTR_VALUE_MASK)
 192                         ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
 193                 else
 194                         ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
 195         }
 196
 197         if (ltr == lpss->active_ltr)
 198                 return;
 199
 200         writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR);
 201         writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR);
 202
 203         /* Cache the values into lpss structure */
 204         intel_lpss_cache_ltr(lpss);
 205 }
 206
 207 static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
 208 {
 209         lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
 210         dev_pm_qos_expose_latency_tolerance(lpss->dev);
 211 }
 212
 213 static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
 214 {
 215         dev_pm_qos_hide_latency_tolerance(lpss->dev);
 216         lpss->dev->power.set_latency_tolerance = NULL;
 217 }
 218
 219 static int intel_lpss_assign_devs(struct intel_lpss *lpss)
 220 {
 221         const struct mfd_cell *cell;
 222         unsigned int type;
 223
 224         type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
 225         type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
 226
 227         switch (type) {
 228         case LPSS_DEV_I2C:
 229                 cell = &intel_lpss_i2c_cell;
 230                 break;
 231         case LPSS_DEV_UART:
 232                 cell = &intel_lpss_uart_cell;
 233                 break;
 234         case LPSS_DEV_SPI:
 235                 cell = &intel_lpss_spi_cell;
 236                 break;
 237         default:
 238                 return -ENODEV;
 239         }
 240
 241         lpss->cell = devm_kmemdup(lpss->dev, cell, sizeof(*cell), GFP_KERNEL);
 242         if (!lpss->cell)
 243                 return -ENOMEM;
 244
 245         lpss->type = type;
 246
 247         return 0;
 248 }
 249
 250 static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
 251 {
 252         return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
 253 }
 254
 255 static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
 256 {
 257         resource_size_t addr = lpss->info->mem->start;
 258
 259         lo_hi_writeq(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR);
 260 }
 261
 262 static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
 263 {
 264         u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;
 265
 266         /* Bring out the device from reset */
 267         writel(value, lpss->priv + LPSS_PRIV_RESETS);
 268 }
 269
 270 static void intel_lpss_init_dev(const struct intel_lpss *lpss)
 271 {
 272         u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
 273
 274         intel_lpss_deassert_reset(lpss);
 275
 276         if (!intel_lpss_has_idma(lpss))
 277                 return;
 278
 279         intel_lpss_set_remap_addr(lpss);
 280
 281         /* Make sure that SPI multiblock DMA transfers are re-enabled */
 282         if (lpss->type == LPSS_DEV_SPI)
 283                 writel(value, lpss->priv + LPSS_PRIV_SSP_REG);
 284 }
 285
 286 static void intel_lpss_unregister_clock_tree(struct clk *clk)
 287 {
 288         struct clk *parent;
 289
 290         while (clk) {
 291                 parent = clk_get_parent(clk);
 292                 clk_unregister(clk);
 293                 clk = parent;
 294         }
 295 }
 296
 297 static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
 298                                              const char *devname,
 299                                              struct clk **clk)
 300 {
 301         char name[32];
 302         struct clk *tmp = *clk;
 303
 304         snprintf(name, sizeof(name), "%s-enable", devname);
 305         tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
 306                                 lpss->priv, 0, 0, NULL);
 307         if (IS_ERR(tmp))
 308                 return PTR_ERR(tmp);
 309
 310         snprintf(name, sizeof(name), "%s-div", devname);
 311         tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
 312                                               0, lpss->priv, 1, 15, 16, 15, 0,
 313                                               NULL);
 314         if (IS_ERR(tmp))
 315                 return PTR_ERR(tmp);
 316         *clk = tmp;
 317
 318         snprintf(name, sizeof(name), "%s-update", devname);
 319         tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
 320                                 CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
 321         if (IS_ERR(tmp))
 322                 return PTR_ERR(tmp);
 323         *clk = tmp;
 324
 325         return 0;
 326 }
 327
 328 static int intel_lpss_register_clock(struct intel_lpss *lpss)
 329 {
 330         const struct mfd_cell *cell = lpss->cell;
 331         struct clk *clk;
 332         char devname[24];
 333         int ret;
 334
 335         if (!lpss->info->clk_rate)
 336                 return 0;
 337
 338         /* Root clock */
 339         clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL,
 340                                       CLK_IS_ROOT, lpss->info->clk_rate);
 341         if (IS_ERR(clk))
 342                 return PTR_ERR(clk);
 343
 344         snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);
 345
 346         /*
 347          * Support for clock divider only if it has some preset value.
 348          * Otherwise we assume that the divider is not used.
 349          */
 350         if (lpss->type != LPSS_DEV_I2C) {
 351                 ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
 352                 if (ret)
 353                         goto err_clk_register;
 354         }
 355
 356         ret = -ENOMEM;
 357
 358         /* Clock for the host controller */
 359         lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname);
 360         if (!lpss->clock)
 361                 goto err_clk_register;
 362
 363         lpss->clk = clk;
 364
 365         return 0;
 366
 367 err_clk_register:
 368         intel_lpss_unregister_clock_tree(clk);
 369
 370         return ret;
 371 }
 372
 373 static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
 374 {
 375         if (IS_ERR_OR_NULL(lpss->clk))
 376                 return;
 377
 378         clkdev_drop(lpss->clock);
 379         intel_lpss_unregister_clock_tree(lpss->clk);
 380 }
 381
 382 int intel_lpss_probe(struct device *dev,
 383                      const struct intel_lpss_platform_info *info)
 384 {
 385         struct intel_lpss *lpss;
 386         int ret;
 387
 388         if (!info || !info->mem || info->irq <= 0)
 389                 return -EINVAL;
 390
 391         lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL);
 392         if (!lpss)
 393                 return -ENOMEM;
 394
 395         lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
 396                                   LPSS_PRIV_SIZE);
 397         if (!lpss->priv)
 398                 return -ENOMEM;
 399
 400         lpss->info = info;
 401         lpss->dev = dev;
 402         lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS);
 403
 404         dev_set_drvdata(dev, lpss);
 405
 406         ret = intel_lpss_assign_devs(lpss);
 407         if (ret)
 408                 return ret;
 409
 410         lpss->cell->pset = info->pset;
 411
 412         intel_lpss_init_dev(lpss);
 413
 414         lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL);
 415         if (lpss->devid < 0)
 416                 return lpss->devid;
 417
 418         ret = intel_lpss_register_clock(lpss);
 419         if (ret)
 420                 goto err_clk_register;
 421
 422         intel_lpss_ltr_expose(lpss);
 423
 424         ret = intel_lpss_debugfs_add(lpss);
 425         if (ret)
 426                 dev_warn(dev, "Failed to create debugfs entries\n");
 427
 428         if (intel_lpss_has_idma(lpss)) {
 429                 /*
 430                  * Ensure the DMA driver is loaded before the host
 431                  * controller device appears, so that the host controller
 432                  * driver can request its DMA channels as early as
 433                  * possible.
 434                  *
 435                  * If the DMA module is not there that's OK as well.
 436                  */
 437                 intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME);
 438
 439                 ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell,
 440                                       1, info->mem, info->irq, NULL);
 441                 if (ret)
 442                         dev_warn(dev, "Failed to add %s, fallback to PIO\n",
 443                                  LPSS_IDMA64_DRIVER_NAME);
 444         }
 445
 446         ret = mfd_add_devices(dev, lpss->devid, lpss->cell,
 447                               1, info->mem, info->irq, NULL);
 448         if (ret)
 449                 goto err_remove_ltr;
 450
 451         return 0;
 452
 453 err_remove_ltr:
 454         intel_lpss_debugfs_remove(lpss);
 455         intel_lpss_ltr_hide(lpss);
 456         intel_lpss_unregister_clock(lpss);
 457
 458 err_clk_register:
 459         ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
 460
 461         return ret;
 462 }
 463 EXPORT_SYMBOL_GPL(intel_lpss_probe);
 464
 465 void intel_lpss_remove(struct device *dev)
 466 {
 467         struct intel_lpss *lpss = dev_get_drvdata(dev);
 468
 469         mfd_remove_devices(dev);
 470         intel_lpss_debugfs_remove(lpss);
 471         intel_lpss_ltr_hide(lpss);
 472         intel_lpss_unregister_clock(lpss);
 473         ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
 474 }
 475 EXPORT_SYMBOL_GPL(intel_lpss_remove);
 476
 477 static int resume_lpss_device(struct device *dev, void *data)
 478 {
 479         pm_runtime_resume(dev);
 480         return 0;
 481 }
 482
 483 int intel_lpss_prepare(struct device *dev)
 484 {
 485         /*
 486          * Resume both child devices before entering system sleep. This
 487          * ensures that they are in proper state before they get suspended.
 488          */
 489         device_for_each_child_reverse(dev, NULL, resume_lpss_device);
 490         return 0;
 491 }
 492 EXPORT_SYMBOL_GPL(intel_lpss_prepare);
 493
 494 int intel_lpss_suspend(struct device *dev)
 495 {
 496         return 0;
 497 }
 498 EXPORT_SYMBOL_GPL(intel_lpss_suspend);
 499
 500 int intel_lpss_resume(struct device *dev)
 501 {
 502         struct intel_lpss *lpss = dev_get_drvdata(dev);
 503
 504         intel_lpss_init_dev(lpss);
 505
 506         return 0;
 507 }
 508 EXPORT_SYMBOL_GPL(intel_lpss_resume);
 509
 510 static int __init intel_lpss_init(void)
 511 {
 512         intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
 513         return 0;
 514 }
 515 module_init(intel_lpss_init);
 516
 517 static void __exit intel_lpss_exit(void)
 518 {
 519         debugfs_remove(intel_lpss_debugfs);
 520 }
 521 module_exit(intel_lpss_exit);
 522
 523 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
 524 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
 525 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
 526 MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
 527 MODULE_DESCRIPTION("Intel LPSS core driver");
 528 MODULE_LICENSE("GPL v2");