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/seq_file.h>
  28
  29 #include "intel-lpss.h"
  30
  31 #define LPSS_DEV_OFFSET         0x000
  32 #define LPSS_DEV_SIZE           0x200
  33 #define LPSS_PRIV_OFFSET        0x200
  34 #define LPSS_PRIV_SIZE          0x100
  35 #define LPSS_IDMA64_OFFSET      0x800
  36 #define LPSS_IDMA64_SIZE        0x800
  37
  38 /* Offsets from lpss->priv */
  39 #define LPSS_PRIV_RESETS                0x04
  40 #define LPSS_PRIV_RESETS_FUNC           BIT(2)
  41 #define LPSS_PRIV_RESETS_IDMA           0x3
  42
  43 #define LPSS_PRIV_ACTIVELTR             0x10
  44 #define LPSS_PRIV_IDLELTR               0x14
  45
  46 #define LPSS_PRIV_LTR_REQ               BIT(15)
  47 #define LPSS_PRIV_LTR_SCALE_MASK        0xc00
  48 #define LPSS_PRIV_LTR_SCALE_1US         0x800
  49 #define LPSS_PRIV_LTR_SCALE_32US        0xc00
  50 #define LPSS_PRIV_LTR_VALUE_MASK        0x3ff
  51
  52 #define LPSS_PRIV_SSP_REG               0x20
  53 #define LPSS_PRIV_SSP_REG_DIS_DMA_FIN   BIT(0)
  54
  55 #define LPSS_PRIV_REMAP_ADDR_LO         0x40
  56 #define LPSS_PRIV_REMAP_ADDR_HI         0x44
  57
  58 #define LPSS_PRIV_CAPS                  0xfc
  59 #define LPSS_PRIV_CAPS_NO_IDMA          BIT(8)
  60 #define LPSS_PRIV_CAPS_TYPE_SHIFT       4
  61 #define LPSS_PRIV_CAPS_TYPE_MASK        (0xf << LPSS_PRIV_CAPS_TYPE_SHIFT)
  62
  63 /* This matches the type field in CAPS register */
  64 enum intel_lpss_dev_type {
  65         LPSS_DEV_I2C = 0,
  66         LPSS_DEV_UART,
  67         LPSS_DEV_SPI,
  68 };
  69
  70 struct intel_lpss {
  71         const struct intel_lpss_platform_info *info;
  72         enum intel_lpss_dev_type type;
  73         struct clk *clk;
  74         struct clk_lookup *clock;
  75         const struct mfd_cell *cell;
  76         struct device *dev;
  77         void __iomem *priv;
  78         int devid;
  79         u32 caps;
  80         u32 active_ltr;
  81         u32 idle_ltr;
  82         struct dentry *debugfs;
  83 };
  84
  85 static const struct resource intel_lpss_dev_resources[] = {
  86         DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
  87         DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
  88         DEFINE_RES_IRQ(0),
  89 };
  90
  91 static const struct resource intel_lpss_idma64_resources[] = {
  92         DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
  93         DEFINE_RES_IRQ(0),
  94 };
  95
  96 #define LPSS_IDMA64_DRIVER_NAME         "idma64"
  97
  98 /*
  99  * Cells needs to be ordered so that the iDMA is created first. This is
 100  * because we need to be sure the DMA is available when the host controller
 101  * driver is probed.
 102  */
 103 static const struct mfd_cell intel_lpss_idma64_cell = {
 104         .name = LPSS_IDMA64_DRIVER_NAME,
 105         .num_resources = ARRAY_SIZE(intel_lpss_idma64_resources),
 106         .resources = intel_lpss_idma64_resources,
 107 };
 108
 109 static const struct mfd_cell intel_lpss_i2c_cell = {
 110         .name = "i2c_designware",
 111         .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
 112         .resources = intel_lpss_dev_resources,
 113 };
 114
 115 static const struct mfd_cell intel_lpss_uart_cell = {
 116         .name = "dw-apb-uart",
 117         .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
 118         .resources = intel_lpss_dev_resources,
 119 };
 120
 121 static const struct mfd_cell intel_lpss_spi_cell = {
 122         .name = "pxa2xx-spi",
 123         .num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
 124         .resources = intel_lpss_dev_resources,
 125 };
 126
 127 static DEFINE_IDA(intel_lpss_devid_ida);
 128 static struct dentry *intel_lpss_debugfs;
 129
 130 static int intel_lpss_request_dma_module(const char *name)
 131 {
 132         static bool intel_lpss_dma_requested;
 133
 134         if (intel_lpss_dma_requested)
 135                 return 0;
 136
 137         intel_lpss_dma_requested = true;
 138         return request_module("%s", name);
 139 }
 140
 141 static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
 142 {
 143         lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
 144         lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR);
 145 }
 146
 147 static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
 148 {
 149         struct dentry *dir;
 150
 151         dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
 152         if (IS_ERR(dir))
 153                 return PTR_ERR(dir);
 154
 155         /* Cache the values into lpss structure */
 156         intel_lpss_cache_ltr(lpss);
 157
 158         debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps);
 159         debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr);
 160         debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr);
 161
 162         lpss->debugfs = dir;
 163         return 0;
 164 }
 165
 166 static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
 167 {
 168         debugfs_remove_recursive(lpss->debugfs);
 169 }
 170
 171 static void intel_lpss_ltr_set(struct device *dev, s32 val)
 172 {
 173         struct intel_lpss *lpss = dev_get_drvdata(dev);
 174         u32 ltr;
 175
 176         /*
 177          * Program latency tolerance (LTR) accordingly what has been asked
 178          * by the PM QoS layer or disable it in case we were passed
 179          * negative value or PM_QOS_LATENCY_ANY.
 180          */
 181         ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
 182
 183         if (val == PM_QOS_LATENCY_ANY || val < 0) {
 184                 ltr &= ~LPSS_PRIV_LTR_REQ;
 185         } else {
 186                 ltr |= LPSS_PRIV_LTR_REQ;
 187                 ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
 188                 ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;
 189
 190                 if (val > LPSS_PRIV_LTR_VALUE_MASK)
 191                         ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
 192                 else
 193                         ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
 194         }
 195
 196         if (ltr == lpss->active_ltr)
 197                 return;
 198
 199         writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR);
 200         writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR);
 201
 202         /* Cache the values into lpss structure */
 203         intel_lpss_cache_ltr(lpss);
 204 }
 205
 206 static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
 207 {
 208         lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
 209         dev_pm_qos_expose_latency_tolerance(lpss->dev);
 210 }
 211
 212 static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
 213 {
 214         dev_pm_qos_hide_latency_tolerance(lpss->dev);
 215         lpss->dev->power.set_latency_tolerance = NULL;
 216 }
 217
 218 static int intel_lpss_assign_devs(struct intel_lpss *lpss)
 219 {
 220         unsigned int type;
 221
 222         type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
 223         type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
 224
 225         switch (type) {
 226         case LPSS_DEV_I2C:
 227                 lpss->cell = &intel_lpss_i2c_cell;
 228                 break;
 229         case LPSS_DEV_UART:
 230                 lpss->cell = &intel_lpss_uart_cell;
 231                 break;
 232         case LPSS_DEV_SPI:
 233                 lpss->cell = &intel_lpss_spi_cell;
 234                 break;
 235         default:
 236                 return -ENODEV;
 237         }
 238
 239         lpss->type = type;
 240
 241         return 0;
 242 }
 243
 244 static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
 245 {
 246         return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
 247 }
 248
 249 static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
 250 {
 251         resource_size_t addr = lpss->info->mem->start;
 252
 253         writel(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR_LO);
 254 #if BITS_PER_LONG > 32
 255         writel(addr >> 32, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI);
 256 #else
 257         writel(0, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI);
 258 #endif
 259 }
 260
 261 static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
 262 {
 263         u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;
 264
 265         /* Bring out the device from reset */
 266         writel(value, lpss->priv + LPSS_PRIV_RESETS);
 267 }
 268
 269 static void intel_lpss_init_dev(const struct intel_lpss *lpss)
 270 {
 271         u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
 272
 273         intel_lpss_deassert_reset(lpss);
 274
 275         if (!intel_lpss_has_idma(lpss))
 276                 return;
 277
 278         intel_lpss_set_remap_addr(lpss);
 279
 280         /* Make sure that SPI multiblock DMA transfers are re-enabled */
 281         if (lpss->type == LPSS_DEV_SPI)
 282                 writel(value, lpss->priv + LPSS_PRIV_SSP_REG);
 283 }
 284
 285 static void intel_lpss_unregister_clock_tree(struct clk *clk)
 286 {
 287         struct clk *parent;
 288
 289         while (clk) {
 290                 parent = clk_get_parent(clk);
 291                 clk_unregister(clk);
 292                 clk = parent;
 293         }
 294 }
 295
 296 static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
 297                                              const char *devname,
 298                                              struct clk **clk)
 299 {
 300         char name[32];
 301         struct clk *tmp = *clk;
 302
 303         snprintf(name, sizeof(name), "%s-enable", devname);
 304         tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
 305                                 lpss->priv, 0, 0, NULL);
 306         if (IS_ERR(tmp))
 307                 return PTR_ERR(tmp);
 308
 309         snprintf(name, sizeof(name), "%s-div", devname);
 310         tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
 311                                               0, lpss->priv, 1, 15, 16, 15, 0,
 312                                               NULL);
 313         if (IS_ERR(tmp))
 314                 return PTR_ERR(tmp);
 315         *clk = tmp;
 316
 317         snprintf(name, sizeof(name), "%s-update", devname);
 318         tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
 319                                 CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
 320         if (IS_ERR(tmp))
 321                 return PTR_ERR(tmp);
 322         *clk = tmp;
 323
 324         return 0;
 325 }
 326
 327 static int intel_lpss_register_clock(struct intel_lpss *lpss)
 328 {
 329         const struct mfd_cell *cell = lpss->cell;
 330         struct clk *clk;
 331         char devname[24];
 332         int ret;
 333
 334         if (!lpss->info->clk_rate)
 335                 return 0;
 336
 337         /* Root clock */
 338         clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL,
 339                                       CLK_IS_ROOT, lpss->info->clk_rate);
 340         if (IS_ERR(clk))
 341                 return PTR_ERR(clk);
 342
 343         snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);
 344
 345         /*
 346          * Support for clock divider only if it has some preset value.
 347          * Otherwise we assume that the divider is not used.
 348          */
 349         if (lpss->type != LPSS_DEV_I2C) {
 350                 ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
 351                 if (ret)
 352                         goto err_clk_register;
 353         }
 354
 355         ret = -ENOMEM;
 356
 357         /* Clock for the host controller */
 358         lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname);
 359         if (!lpss->clock)
 360                 goto err_clk_register;
 361
 362         lpss->clk = clk;
 363
 364         return 0;
 365
 366 err_clk_register:
 367         intel_lpss_unregister_clock_tree(clk);
 368
 369         return ret;
 370 }
 371
 372 static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
 373 {
 374         if (IS_ERR_OR_NULL(lpss->clk))
 375                 return;
 376
 377         clkdev_drop(lpss->clock);
 378         intel_lpss_unregister_clock_tree(lpss->clk);
 379 }
 380
 381 int intel_lpss_probe(struct device *dev,
 382                      const struct intel_lpss_platform_info *info)
 383 {
 384         struct intel_lpss *lpss;
 385         int ret;
 386
 387         if (!info || !info->mem || info->irq <= 0)
 388                 return -EINVAL;
 389
 390         lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL);
 391         if (!lpss)
 392                 return -ENOMEM;
 393
 394         lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
 395                                   LPSS_PRIV_SIZE);
 396         if (!lpss->priv)
 397                 return -ENOMEM;
 398
 399         lpss->info = info;
 400         lpss->dev = dev;
 401         lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS);
 402
 403         dev_set_drvdata(dev, lpss);
 404
 405         ret = intel_lpss_assign_devs(lpss);
 406         if (ret)
 407                 return ret;
 408
 409         intel_lpss_init_dev(lpss);
 410
 411         lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL);
 412         if (lpss->devid < 0)
 413                 return lpss->devid;
 414
 415         ret = intel_lpss_register_clock(lpss);
 416         if (ret)
 417                 goto err_clk_register;
 418
 419         intel_lpss_ltr_expose(lpss);
 420
 421         ret = intel_lpss_debugfs_add(lpss);
 422         if (ret)
 423                 dev_warn(dev, "Failed to create debugfs entries\n");
 424
 425         if (intel_lpss_has_idma(lpss)) {
 426                 /*
 427                  * Ensure the DMA driver is loaded before the host
 428                  * controller device appears, so that the host controller
 429                  * driver can request its DMA channels as early as
 430                  * possible.
 431                  *
 432                  * If the DMA module is not there that's OK as well.
 433                  */
 434                 intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME);
 435
 436                 ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell,
 437                                       1, info->mem, info->irq, NULL);
 438                 if (ret)
 439                         dev_warn(dev, "Failed to add %s, fallback to PIO\n",
 440                                  LPSS_IDMA64_DRIVER_NAME);
 441         }
 442
 443         ret = mfd_add_devices(dev, lpss->devid, lpss->cell,
 444                               1, info->mem, info->irq, NULL);
 445         if (ret)
 446                 goto err_remove_ltr;
 447
 448         return 0;
 449
 450 err_remove_ltr:
 451         intel_lpss_debugfs_remove(lpss);
 452         intel_lpss_ltr_hide(lpss);
 453
 454 err_clk_register:
 455         ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
 456
 457         return ret;
 458 }
 459 EXPORT_SYMBOL_GPL(intel_lpss_probe);
 460
 461 void intel_lpss_remove(struct device *dev)
 462 {
 463         struct intel_lpss *lpss = dev_get_drvdata(dev);
 464
 465         mfd_remove_devices(dev);
 466         intel_lpss_debugfs_remove(lpss);
 467         intel_lpss_ltr_hide(lpss);
 468         intel_lpss_unregister_clock(lpss);
 469         ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
 470 }
 471 EXPORT_SYMBOL_GPL(intel_lpss_remove);
 472
 473 static int resume_lpss_device(struct device *dev, void *data)
 474 {
 475         pm_runtime_resume(dev);
 476         return 0;
 477 }
 478
 479 int intel_lpss_prepare(struct device *dev)
 480 {
 481         /*
 482          * Resume both child devices before entering system sleep. This
 483          * ensures that they are in proper state before they get suspended.
 484          */
 485         device_for_each_child_reverse(dev, NULL, resume_lpss_device);
 486         return 0;
 487 }
 488 EXPORT_SYMBOL_GPL(intel_lpss_prepare);
 489
 490 int intel_lpss_suspend(struct device *dev)
 491 {
 492         return 0;
 493 }
 494 EXPORT_SYMBOL_GPL(intel_lpss_suspend);
 495
 496 int intel_lpss_resume(struct device *dev)
 497 {
 498         struct intel_lpss *lpss = dev_get_drvdata(dev);
 499
 500         intel_lpss_init_dev(lpss);
 501
 502         return 0;
 503 }
 504 EXPORT_SYMBOL_GPL(intel_lpss_resume);
 505
 506 static int __init intel_lpss_init(void)
 507 {
 508         intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
 509         return 0;
 510 }
 511 module_init(intel_lpss_init);
 512
 513 static void __exit intel_lpss_exit(void)
 514 {
 515         debugfs_remove(intel_lpss_debugfs);
 516 }
 517 module_exit(intel_lpss_exit);
 518
 519 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
 520 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
 521 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
 522 MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
 523 MODULE_DESCRIPTION("Intel LPSS core driver");
 524 MODULE_LICENSE("GPL v2");