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