linux/drivers/memory/tegra/tegra30-emc.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Tegra30 External Memory Controller driver
   4 *
   5 * Based on downstream driver from NVIDIA and tegra124-emc.c
   6 * Copyright (C) 2011-2014 NVIDIA Corporation
   7 *
   8 * Author: Dmitry Osipenko <digetx@gmail.com>
   9 * Copyright (C) 2019 GRATE-DRIVER project
  10 */
  11
  12#include <linux/bitfield.h>
  13#include <linux/clk.h>
  14#include <linux/clk/tegra.h>
  15#include <linux/debugfs.h>
  16#include <linux/delay.h>
  17#include <linux/err.h>
  18#include <linux/interconnect-provider.h>
  19#include <linux/interrupt.h>
  20#include <linux/io.h>
  21#include <linux/iopoll.h>
  22#include <linux/kernel.h>
  23#include <linux/module.h>
  24#include <linux/mutex.h>
  25#include <linux/of_platform.h>
  26#include <linux/platform_device.h>
  27#include <linux/pm_opp.h>
  28#include <linux/slab.h>
  29#include <linux/sort.h>
  30#include <linux/types.h>
  31
  32#include <soc/tegra/common.h>
  33#include <soc/tegra/fuse.h>
  34
  35#include "../jedec_ddr.h"
  36#include "../of_memory.h"
  37
  38#include "mc.h"
  39
  40#define EMC_INTSTATUS                           0x000
  41#define EMC_INTMASK                             0x004
  42#define EMC_DBG                                 0x008
  43#define EMC_ADR_CFG                             0x010
  44#define EMC_CFG                                 0x00c
  45#define EMC_REFCTRL                             0x020
  46#define EMC_TIMING_CONTROL                      0x028
  47#define EMC_RC                                  0x02c
  48#define EMC_RFC                                 0x030
  49#define EMC_RAS                                 0x034
  50#define EMC_RP                                  0x038
  51#define EMC_R2W                                 0x03c
  52#define EMC_W2R                                 0x040
  53#define EMC_R2P                                 0x044
  54#define EMC_W2P                                 0x048
  55#define EMC_RD_RCD                              0x04c
  56#define EMC_WR_RCD                              0x050
  57#define EMC_RRD                                 0x054
  58#define EMC_REXT                                0x058
  59#define EMC_WDV                                 0x05c
  60#define EMC_QUSE                                0x060
  61#define EMC_QRST                                0x064
  62#define EMC_QSAFE                               0x068
  63#define EMC_RDV                                 0x06c
  64#define EMC_REFRESH                             0x070
  65#define EMC_BURST_REFRESH_NUM                   0x074
  66#define EMC_PDEX2WR                             0x078
  67#define EMC_PDEX2RD                             0x07c
  68#define EMC_PCHG2PDEN                           0x080
  69#define EMC_ACT2PDEN                            0x084
  70#define EMC_AR2PDEN                             0x088
  71#define EMC_RW2PDEN                             0x08c
  72#define EMC_TXSR                                0x090
  73#define EMC_TCKE                                0x094
  74#define EMC_TFAW                                0x098
  75#define EMC_TRPAB                               0x09c
  76#define EMC_TCLKSTABLE                          0x0a0
  77#define EMC_TCLKSTOP                            0x0a4
  78#define EMC_TREFBW                              0x0a8
  79#define EMC_QUSE_EXTRA                          0x0ac
  80#define EMC_ODT_WRITE                           0x0b0
  81#define EMC_ODT_READ                            0x0b4
  82#define EMC_WEXT                                0x0b8
  83#define EMC_CTT                                 0x0bc
  84#define EMC_MRS_WAIT_CNT                        0x0c8
  85#define EMC_MRS                                 0x0cc
  86#define EMC_EMRS                                0x0d0
  87#define EMC_SELF_REF                            0x0e0
  88#define EMC_MRW                                 0x0e8
  89#define EMC_MRR                                 0x0ec
  90#define EMC_XM2DQSPADCTRL3                      0x0f8
  91#define EMC_FBIO_SPARE                          0x100
  92#define EMC_FBIO_CFG5                           0x104
  93#define EMC_FBIO_CFG6                           0x114
  94#define EMC_CFG_RSV                             0x120
  95#define EMC_AUTO_CAL_CONFIG                     0x2a4
  96#define EMC_AUTO_CAL_INTERVAL                   0x2a8
  97#define EMC_AUTO_CAL_STATUS                     0x2ac
  98#define EMC_STATUS                              0x2b4
  99#define EMC_CFG_2                               0x2b8
 100#define EMC_CFG_DIG_DLL                         0x2bc
 101#define EMC_CFG_DIG_DLL_PERIOD                  0x2c0
 102#define EMC_CTT_DURATION                        0x2d8
 103#define EMC_CTT_TERM_CTRL                       0x2dc
 104#define EMC_ZCAL_INTERVAL                       0x2e0
 105#define EMC_ZCAL_WAIT_CNT                       0x2e4
 106#define EMC_ZQ_CAL                              0x2ec
 107#define EMC_XM2CMDPADCTRL                       0x2f0
 108#define EMC_XM2DQSPADCTRL2                      0x2fc
 109#define EMC_XM2DQPADCTRL2                       0x304
 110#define EMC_XM2CLKPADCTRL                       0x308
 111#define EMC_XM2COMPPADCTRL                      0x30c
 112#define EMC_XM2VTTGENPADCTRL                    0x310
 113#define EMC_XM2VTTGENPADCTRL2                   0x314
 114#define EMC_XM2QUSEPADCTRL                      0x318
 115#define EMC_DLL_XFORM_DQS0                      0x328
 116#define EMC_DLL_XFORM_DQS1                      0x32c
 117#define EMC_DLL_XFORM_DQS2                      0x330
 118#define EMC_DLL_XFORM_DQS3                      0x334
 119#define EMC_DLL_XFORM_DQS4                      0x338
 120#define EMC_DLL_XFORM_DQS5                      0x33c
 121#define EMC_DLL_XFORM_DQS6                      0x340
 122#define EMC_DLL_XFORM_DQS7                      0x344
 123#define EMC_DLL_XFORM_QUSE0                     0x348
 124#define EMC_DLL_XFORM_QUSE1                     0x34c
 125#define EMC_DLL_XFORM_QUSE2                     0x350
 126#define EMC_DLL_XFORM_QUSE3                     0x354
 127#define EMC_DLL_XFORM_QUSE4                     0x358
 128#define EMC_DLL_XFORM_QUSE5                     0x35c
 129#define EMC_DLL_XFORM_QUSE6                     0x360
 130#define EMC_DLL_XFORM_QUSE7                     0x364
 131#define EMC_DLL_XFORM_DQ0                       0x368
 132#define EMC_DLL_XFORM_DQ1                       0x36c
 133#define EMC_DLL_XFORM_DQ2                       0x370
 134#define EMC_DLL_XFORM_DQ3                       0x374
 135#define EMC_DLI_TRIM_TXDQS0                     0x3a8
 136#define EMC_DLI_TRIM_TXDQS1                     0x3ac
 137#define EMC_DLI_TRIM_TXDQS2                     0x3b0
 138#define EMC_DLI_TRIM_TXDQS3                     0x3b4
 139#define EMC_DLI_TRIM_TXDQS4                     0x3b8
 140#define EMC_DLI_TRIM_TXDQS5                     0x3bc
 141#define EMC_DLI_TRIM_TXDQS6                     0x3c0
 142#define EMC_DLI_TRIM_TXDQS7                     0x3c4
 143#define EMC_STALL_THEN_EXE_BEFORE_CLKCHANGE     0x3c8
 144#define EMC_STALL_THEN_EXE_AFTER_CLKCHANGE      0x3cc
 145#define EMC_UNSTALL_RW_AFTER_CLKCHANGE          0x3d0
 146#define EMC_SEL_DPD_CTRL                        0x3d8
 147#define EMC_PRE_REFRESH_REQ_CNT                 0x3dc
 148#define EMC_DYN_SELF_REF_CONTROL                0x3e0
 149#define EMC_TXSRDLL                             0x3e4
 150
 151#define EMC_STATUS_TIMING_UPDATE_STALLED        BIT(23)
 152
 153#define EMC_MODE_SET_DLL_RESET                  BIT(8)
 154#define EMC_MODE_SET_LONG_CNT                   BIT(26)
 155
 156#define EMC_SELF_REF_CMD_ENABLED                BIT(0)
 157
 158#define DRAM_DEV_SEL_ALL                        (0 << 30)
 159#define DRAM_DEV_SEL_0                          BIT(31)
 160#define DRAM_DEV_SEL_1                          BIT(30)
 161#define DRAM_BROADCAST(num) \
 162        ((num) > 1 ? DRAM_DEV_SEL_ALL : DRAM_DEV_SEL_0)
 163
 164#define EMC_ZQ_CAL_CMD                          BIT(0)
 165#define EMC_ZQ_CAL_LONG                         BIT(4)
 166#define EMC_ZQ_CAL_LONG_CMD_DEV0 \
 167        (DRAM_DEV_SEL_0 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
 168#define EMC_ZQ_CAL_LONG_CMD_DEV1 \
 169        (DRAM_DEV_SEL_1 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
 170
 171#define EMC_DBG_READ_MUX_ASSEMBLY               BIT(0)
 172#define EMC_DBG_WRITE_MUX_ACTIVE                BIT(1)
 173#define EMC_DBG_FORCE_UPDATE                    BIT(2)
 174#define EMC_DBG_CFG_PRIORITY                    BIT(24)
 175
 176#define EMC_CFG5_QUSE_MODE_SHIFT                13
 177#define EMC_CFG5_QUSE_MODE_MASK                 (7 << EMC_CFG5_QUSE_MODE_SHIFT)
 178
 179#define EMC_CFG5_QUSE_MODE_INTERNAL_LPBK        2
 180#define EMC_CFG5_QUSE_MODE_PULSE_INTERN         3
 181
 182#define EMC_SEL_DPD_CTRL_QUSE_DPD_ENABLE        BIT(9)
 183
 184#define EMC_XM2COMPPADCTRL_VREF_CAL_ENABLE      BIT(10)
 185
 186#define EMC_XM2QUSEPADCTRL_IVREF_ENABLE         BIT(4)
 187
 188#define EMC_XM2DQSPADCTRL2_VREF_ENABLE          BIT(5)
 189#define EMC_XM2DQSPADCTRL3_VREF_ENABLE          BIT(5)
 190
 191#define EMC_AUTO_CAL_STATUS_ACTIVE              BIT(31)
 192
 193#define EMC_FBIO_CFG5_DRAM_TYPE_MASK            0x3
 194
 195#define EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK        0x3ff
 196#define EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT        16
 197#define EMC_MRS_WAIT_CNT_LONG_WAIT_MASK \
 198        (0x3ff << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT)
 199
 200#define EMC_REFCTRL_DEV_SEL_MASK                0x3
 201#define EMC_REFCTRL_ENABLE                      BIT(31)
 202#define EMC_REFCTRL_ENABLE_ALL(num) \
 203        (((num) > 1 ? 0 : 2) | EMC_REFCTRL_ENABLE)
 204#define EMC_REFCTRL_DISABLE_ALL(num)            ((num) > 1 ? 0 : 2)
 205
 206#define EMC_CFG_PERIODIC_QRST                   BIT(21)
 207#define EMC_CFG_DYN_SREF_ENABLE                 BIT(28)
 208
 209#define EMC_CLKCHANGE_REQ_ENABLE                BIT(0)
 210#define EMC_CLKCHANGE_PD_ENABLE                 BIT(1)
 211#define EMC_CLKCHANGE_SR_ENABLE                 BIT(2)
 212
 213#define EMC_TIMING_UPDATE                       BIT(0)
 214
 215#define EMC_REFRESH_OVERFLOW_INT                BIT(3)
 216#define EMC_CLKCHANGE_COMPLETE_INT              BIT(4)
 217#define EMC_MRR_DIVLD_INT                       BIT(5)
 218
 219#define EMC_MRR_DEV_SELECTN                     GENMASK(31, 30)
 220#define EMC_MRR_MRR_MA                          GENMASK(23, 16)
 221#define EMC_MRR_MRR_DATA                        GENMASK(15, 0)
 222
 223#define EMC_ADR_CFG_EMEM_NUMDEV                 BIT(0)
 224
 225enum emc_dram_type {
 226        DRAM_TYPE_DDR3,
 227        DRAM_TYPE_DDR1,
 228        DRAM_TYPE_LPDDR2,
 229        DRAM_TYPE_DDR2,
 230};
 231
 232enum emc_dll_change {
 233        DLL_CHANGE_NONE,
 234        DLL_CHANGE_ON,
 235        DLL_CHANGE_OFF
 236};
 237
 238static const u16 emc_timing_registers[] = {
 239        [0] = EMC_RC,
 240        [1] = EMC_RFC,
 241        [2] = EMC_RAS,
 242        [3] = EMC_RP,
 243        [4] = EMC_R2W,
 244        [5] = EMC_W2R,
 245        [6] = EMC_R2P,
 246        [7] = EMC_W2P,
 247        [8] = EMC_RD_RCD,
 248        [9] = EMC_WR_RCD,
 249        [10] = EMC_RRD,
 250        [11] = EMC_REXT,
 251        [12] = EMC_WEXT,
 252        [13] = EMC_WDV,
 253        [14] = EMC_QUSE,
 254        [15] = EMC_QRST,
 255        [16] = EMC_QSAFE,
 256        [17] = EMC_RDV,
 257        [18] = EMC_REFRESH,
 258        [19] = EMC_BURST_REFRESH_NUM,
 259        [20] = EMC_PRE_REFRESH_REQ_CNT,
 260        [21] = EMC_PDEX2WR,
 261        [22] = EMC_PDEX2RD,
 262        [23] = EMC_PCHG2PDEN,
 263        [24] = EMC_ACT2PDEN,
 264        [25] = EMC_AR2PDEN,
 265        [26] = EMC_RW2PDEN,
 266        [27] = EMC_TXSR,
 267        [28] = EMC_TXSRDLL,
 268        [29] = EMC_TCKE,
 269        [30] = EMC_TFAW,
 270        [31] = EMC_TRPAB,
 271        [32] = EMC_TCLKSTABLE,
 272        [33] = EMC_TCLKSTOP,
 273        [34] = EMC_TREFBW,
 274        [35] = EMC_QUSE_EXTRA,
 275        [36] = EMC_FBIO_CFG6,
 276        [37] = EMC_ODT_WRITE,
 277        [38] = EMC_ODT_READ,
 278        [39] = EMC_FBIO_CFG5,
 279        [40] = EMC_CFG_DIG_DLL,
 280        [41] = EMC_CFG_DIG_DLL_PERIOD,
 281        [42] = EMC_DLL_XFORM_DQS0,
 282        [43] = EMC_DLL_XFORM_DQS1,
 283        [44] = EMC_DLL_XFORM_DQS2,
 284        [45] = EMC_DLL_XFORM_DQS3,
 285        [46] = EMC_DLL_XFORM_DQS4,
 286        [47] = EMC_DLL_XFORM_DQS5,
 287        [48] = EMC_DLL_XFORM_DQS6,
 288        [49] = EMC_DLL_XFORM_DQS7,
 289        [50] = EMC_DLL_XFORM_QUSE0,
 290        [51] = EMC_DLL_XFORM_QUSE1,
 291        [52] = EMC_DLL_XFORM_QUSE2,
 292        [53] = EMC_DLL_XFORM_QUSE3,
 293        [54] = EMC_DLL_XFORM_QUSE4,
 294        [55] = EMC_DLL_XFORM_QUSE5,
 295        [56] = EMC_DLL_XFORM_QUSE6,
 296        [57] = EMC_DLL_XFORM_QUSE7,
 297        [58] = EMC_DLI_TRIM_TXDQS0,
 298        [59] = EMC_DLI_TRIM_TXDQS1,
 299        [60] = EMC_DLI_TRIM_TXDQS2,
 300        [61] = EMC_DLI_TRIM_TXDQS3,
 301        [62] = EMC_DLI_TRIM_TXDQS4,
 302        [63] = EMC_DLI_TRIM_TXDQS5,
 303        [64] = EMC_DLI_TRIM_TXDQS6,
 304        [65] = EMC_DLI_TRIM_TXDQS7,
 305        [66] = EMC_DLL_XFORM_DQ0,
 306        [67] = EMC_DLL_XFORM_DQ1,
 307        [68] = EMC_DLL_XFORM_DQ2,
 308        [69] = EMC_DLL_XFORM_DQ3,
 309        [70] = EMC_XM2CMDPADCTRL,
 310        [71] = EMC_XM2DQSPADCTRL2,
 311        [72] = EMC_XM2DQPADCTRL2,
 312        [73] = EMC_XM2CLKPADCTRL,
 313        [74] = EMC_XM2COMPPADCTRL,
 314        [75] = EMC_XM2VTTGENPADCTRL,
 315        [76] = EMC_XM2VTTGENPADCTRL2,
 316        [77] = EMC_XM2QUSEPADCTRL,
 317        [78] = EMC_XM2DQSPADCTRL3,
 318        [79] = EMC_CTT_TERM_CTRL,
 319        [80] = EMC_ZCAL_INTERVAL,
 320        [81] = EMC_ZCAL_WAIT_CNT,
 321        [82] = EMC_MRS_WAIT_CNT,
 322        [83] = EMC_AUTO_CAL_CONFIG,
 323        [84] = EMC_CTT,
 324        [85] = EMC_CTT_DURATION,
 325        [86] = EMC_DYN_SELF_REF_CONTROL,
 326        [87] = EMC_FBIO_SPARE,
 327        [88] = EMC_CFG_RSV,
 328};
 329
 330struct emc_timing {
 331        unsigned long rate;
 332
 333        u32 data[ARRAY_SIZE(emc_timing_registers)];
 334
 335        u32 emc_auto_cal_interval;
 336        u32 emc_mode_1;
 337        u32 emc_mode_2;
 338        u32 emc_mode_reset;
 339        u32 emc_zcal_cnt_long;
 340        bool emc_cfg_periodic_qrst;
 341        bool emc_cfg_dyn_self_ref;
 342};
 343
 344enum emc_rate_request_type {
 345        EMC_RATE_DEBUG,
 346        EMC_RATE_ICC,
 347        EMC_RATE_TYPE_MAX,
 348};
 349
 350struct emc_rate_request {
 351        unsigned long min_rate;
 352        unsigned long max_rate;
 353};
 354
 355struct tegra_emc {
 356        struct device *dev;
 357        struct tegra_mc *mc;
 358        struct icc_provider provider;
 359        struct notifier_block clk_nb;
 360        struct clk *clk;
 361        void __iomem *regs;
 362        unsigned int irq;
 363        bool bad_state;
 364
 365        struct emc_timing *new_timing;
 366        struct emc_timing *timings;
 367        unsigned int num_timings;
 368
 369        u32 mc_override;
 370        u32 emc_cfg;
 371
 372        u32 emc_mode_1;
 373        u32 emc_mode_2;
 374        u32 emc_mode_reset;
 375
 376        bool vref_cal_toggle : 1;
 377        bool zcal_long : 1;
 378        bool dll_on : 1;
 379
 380        struct {
 381                struct dentry *root;
 382                unsigned long min_rate;
 383                unsigned long max_rate;
 384        } debugfs;
 385
 386        /*
 387         * There are multiple sources in the EMC driver which could request
 388         * a min/max clock rate, these rates are contained in this array.
 389         */
 390        struct emc_rate_request requested_rate[EMC_RATE_TYPE_MAX];
 391
 392        /* protect shared rate-change code path */
 393        struct mutex rate_lock;
 394
 395        bool mrr_error;
 396};
 397
 398static int emc_seq_update_timing(struct tegra_emc *emc)
 399{
 400        u32 val;
 401        int err;
 402
 403        writel_relaxed(EMC_TIMING_UPDATE, emc->regs + EMC_TIMING_CONTROL);
 404
 405        err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_STATUS, val,
 406                                !(val & EMC_STATUS_TIMING_UPDATE_STALLED),
 407                                1, 200);
 408        if (err) {
 409                dev_err(emc->dev, "failed to update timing: %d\n", err);
 410                return err;
 411        }
 412
 413        return 0;
 414}
 415
 416static irqreturn_t tegra_emc_isr(int irq, void *data)
 417{
 418        struct tegra_emc *emc = data;
 419        u32 intmask = EMC_REFRESH_OVERFLOW_INT;
 420        u32 status;
 421
 422        status = readl_relaxed(emc->regs + EMC_INTSTATUS) & intmask;
 423        if (!status)
 424                return IRQ_NONE;
 425
 426        /* notify about HW problem */
 427        if (status & EMC_REFRESH_OVERFLOW_INT)
 428                dev_err_ratelimited(emc->dev,
 429                                    "refresh request overflow timeout\n");
 430
 431        /* clear interrupts */
 432        writel_relaxed(status, emc->regs + EMC_INTSTATUS);
 433
 434        return IRQ_HANDLED;
 435}
 436
 437static struct emc_timing *emc_find_timing(struct tegra_emc *emc,
 438                                          unsigned long rate)
 439{
 440        struct emc_timing *timing = NULL;
 441        unsigned int i;
 442
 443        for (i = 0; i < emc->num_timings; i++) {
 444                if (emc->timings[i].rate >= rate) {
 445                        timing = &emc->timings[i];
 446                        break;
 447                }
 448        }
 449
 450        if (!timing) {
 451                dev_err(emc->dev, "no timing for rate %lu\n", rate);
 452                return NULL;
 453        }
 454
 455        return timing;
 456}
 457
 458static bool emc_dqs_preset(struct tegra_emc *emc, struct emc_timing *timing,
 459                           bool *schmitt_to_vref)
 460{
 461        bool preset = false;
 462        u32 val;
 463
 464        if (timing->data[71] & EMC_XM2DQSPADCTRL2_VREF_ENABLE) {
 465                val = readl_relaxed(emc->regs + EMC_XM2DQSPADCTRL2);
 466
 467                if (!(val & EMC_XM2DQSPADCTRL2_VREF_ENABLE)) {
 468                        val |= EMC_XM2DQSPADCTRL2_VREF_ENABLE;
 469                        writel_relaxed(val, emc->regs + EMC_XM2DQSPADCTRL2);
 470
 471                        preset = true;
 472                }
 473        }
 474
 475        if (timing->data[78] & EMC_XM2DQSPADCTRL3_VREF_ENABLE) {
 476                val = readl_relaxed(emc->regs + EMC_XM2DQSPADCTRL3);
 477
 478                if (!(val & EMC_XM2DQSPADCTRL3_VREF_ENABLE)) {
 479                        val |= EMC_XM2DQSPADCTRL3_VREF_ENABLE;
 480                        writel_relaxed(val, emc->regs + EMC_XM2DQSPADCTRL3);
 481
 482                        preset = true;
 483                }
 484        }
 485
 486        if (timing->data[77] & EMC_XM2QUSEPADCTRL_IVREF_ENABLE) {
 487                val = readl_relaxed(emc->regs + EMC_XM2QUSEPADCTRL);
 488
 489                if (!(val & EMC_XM2QUSEPADCTRL_IVREF_ENABLE)) {
 490                        val |= EMC_XM2QUSEPADCTRL_IVREF_ENABLE;
 491                        writel_relaxed(val, emc->regs + EMC_XM2QUSEPADCTRL);
 492
 493                        *schmitt_to_vref = true;
 494                        preset = true;
 495                }
 496        }
 497
 498        return preset;
 499}
 500
 501static int emc_prepare_mc_clk_cfg(struct tegra_emc *emc, unsigned long rate)
 502{
 503        struct tegra_mc *mc = emc->mc;
 504        unsigned int misc0_index = 16;
 505        unsigned int i;
 506        bool same;
 507
 508        for (i = 0; i < mc->num_timings; i++) {
 509                if (mc->timings[i].rate != rate)
 510                        continue;
 511
 512                if (mc->timings[i].emem_data[misc0_index] & BIT(27))
 513                        same = true;
 514                else
 515                        same = false;
 516
 517                return tegra20_clk_prepare_emc_mc_same_freq(emc->clk, same);
 518        }
 519
 520        return -EINVAL;
 521}
 522
 523static int emc_prepare_timing_change(struct tegra_emc *emc, unsigned long rate)
 524{
 525        struct emc_timing *timing = emc_find_timing(emc, rate);
 526        enum emc_dll_change dll_change;
 527        enum emc_dram_type dram_type;
 528        bool schmitt_to_vref = false;
 529        unsigned int pre_wait = 0;
 530        bool qrst_used = false;
 531        unsigned int dram_num;
 532        unsigned int i;
 533        u32 fbio_cfg5;
 534        u32 emc_dbg;
 535        u32 val;
 536        int err;
 537
 538        if (!timing || emc->bad_state)
 539                return -EINVAL;
 540
 541        dev_dbg(emc->dev, "%s: using timing rate %lu for requested rate %lu\n",
 542                __func__, timing->rate, rate);
 543
 544        emc->bad_state = true;
 545
 546        err = emc_prepare_mc_clk_cfg(emc, rate);
 547        if (err) {
 548                dev_err(emc->dev, "mc clock preparation failed: %d\n", err);
 549                return err;
 550        }
 551
 552        emc->vref_cal_toggle = false;
 553        emc->mc_override = mc_readl(emc->mc, MC_EMEM_ARB_OVERRIDE);
 554        emc->emc_cfg = readl_relaxed(emc->regs + EMC_CFG);
 555        emc_dbg = readl_relaxed(emc->regs + EMC_DBG);
 556
 557        if (emc->dll_on == !!(timing->emc_mode_1 & 0x1))
 558                dll_change = DLL_CHANGE_NONE;
 559        else if (timing->emc_mode_1 & 0x1)
 560                dll_change = DLL_CHANGE_ON;
 561        else
 562                dll_change = DLL_CHANGE_OFF;
 563
 564        emc->dll_on = !!(timing->emc_mode_1 & 0x1);
 565
 566        if (timing->data[80] && !readl_relaxed(emc->regs + EMC_ZCAL_INTERVAL))
 567                emc->zcal_long = true;
 568        else
 569                emc->zcal_long = false;
 570
 571        fbio_cfg5 = readl_relaxed(emc->regs + EMC_FBIO_CFG5);
 572        dram_type = fbio_cfg5 & EMC_FBIO_CFG5_DRAM_TYPE_MASK;
 573
 574        dram_num = tegra_mc_get_emem_device_count(emc->mc);
 575
 576        /* disable dynamic self-refresh */
 577        if (emc->emc_cfg & EMC_CFG_DYN_SREF_ENABLE) {
 578                emc->emc_cfg &= ~EMC_CFG_DYN_SREF_ENABLE;
 579                writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
 580
 581                pre_wait = 5;
 582        }
 583
 584        /* update MC arbiter settings */
 585        val = mc_readl(emc->mc, MC_EMEM_ARB_OUTSTANDING_REQ);
 586        if (!(val & MC_EMEM_ARB_OUTSTANDING_REQ_HOLDOFF_OVERRIDE) ||
 587            ((val & MC_EMEM_ARB_OUTSTANDING_REQ_MAX_MASK) > 0x50)) {
 588
 589                val = MC_EMEM_ARB_OUTSTANDING_REQ_LIMIT_ENABLE |
 590                      MC_EMEM_ARB_OUTSTANDING_REQ_HOLDOFF_OVERRIDE | 0x50;
 591                mc_writel(emc->mc, val, MC_EMEM_ARB_OUTSTANDING_REQ);
 592                mc_writel(emc->mc, MC_TIMING_UPDATE, MC_TIMING_CONTROL);
 593        }
 594
 595        if (emc->mc_override & MC_EMEM_ARB_OVERRIDE_EACK_MASK)
 596                mc_writel(emc->mc,
 597                          emc->mc_override & ~MC_EMEM_ARB_OVERRIDE_EACK_MASK,
 598                          MC_EMEM_ARB_OVERRIDE);
 599
 600        /* check DQ/DQS VREF delay */
 601        if (emc_dqs_preset(emc, timing, &schmitt_to_vref)) {
 602                if (pre_wait < 3)
 603                        pre_wait = 3;
 604        }
 605
 606        if (pre_wait) {
 607                err = emc_seq_update_timing(emc);
 608                if (err)
 609                        return err;
 610
 611                udelay(pre_wait);
 612        }
 613
 614        /* disable auto-calibration if VREF mode is switching */
 615        if (timing->emc_auto_cal_interval) {
 616                val = readl_relaxed(emc->regs + EMC_XM2COMPPADCTRL);
 617                val ^= timing->data[74];
 618
 619                if (val & EMC_XM2COMPPADCTRL_VREF_CAL_ENABLE) {
 620                        writel_relaxed(0, emc->regs + EMC_AUTO_CAL_INTERVAL);
 621
 622                        err = readl_relaxed_poll_timeout_atomic(
 623                                emc->regs + EMC_AUTO_CAL_STATUS, val,
 624                                !(val & EMC_AUTO_CAL_STATUS_ACTIVE), 1, 300);
 625                        if (err) {
 626                                dev_err(emc->dev,
 627                                        "auto-cal finish timeout: %d\n", err);
 628                                return err;
 629                        }
 630
 631                        emc->vref_cal_toggle = true;
 632                }
 633        }
 634
 635        /* program shadow registers */
 636        for (i = 0; i < ARRAY_SIZE(timing->data); i++) {
 637                /* EMC_XM2CLKPADCTRL should be programmed separately */
 638                if (i != 73)
 639                        writel_relaxed(timing->data[i],
 640                                       emc->regs + emc_timing_registers[i]);
 641        }
 642
 643        err = tegra_mc_write_emem_configuration(emc->mc, timing->rate);
 644        if (err)
 645                return err;
 646
 647        /* DDR3: predict MRS long wait count */
 648        if (dram_type == DRAM_TYPE_DDR3 && dll_change == DLL_CHANGE_ON) {
 649                u32 cnt = 512;
 650
 651                if (emc->zcal_long)
 652                        cnt -= dram_num * 256;
 653
 654                val = timing->data[82] & EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK;
 655                if (cnt < val)
 656                        cnt = val;
 657
 658                val = timing->data[82] & ~EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
 659                val |= (cnt << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT) &
 660                        EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
 661
 662                writel_relaxed(val, emc->regs + EMC_MRS_WAIT_CNT);
 663        }
 664
 665        /* this read also completes the writes */
 666        val = readl_relaxed(emc->regs + EMC_SEL_DPD_CTRL);
 667
 668        if (!(val & EMC_SEL_DPD_CTRL_QUSE_DPD_ENABLE) && schmitt_to_vref) {
 669                u32 cur_mode, new_mode;
 670
 671                cur_mode = fbio_cfg5 & EMC_CFG5_QUSE_MODE_MASK;
 672                cur_mode >>= EMC_CFG5_QUSE_MODE_SHIFT;
 673
 674                new_mode = timing->data[39] & EMC_CFG5_QUSE_MODE_MASK;
 675                new_mode >>= EMC_CFG5_QUSE_MODE_SHIFT;
 676
 677                if ((cur_mode != EMC_CFG5_QUSE_MODE_PULSE_INTERN &&
 678                     cur_mode != EMC_CFG5_QUSE_MODE_INTERNAL_LPBK) ||
 679                    (new_mode != EMC_CFG5_QUSE_MODE_PULSE_INTERN &&
 680                     new_mode != EMC_CFG5_QUSE_MODE_INTERNAL_LPBK))
 681                        qrst_used = true;
 682        }
 683
 684        /* flow control marker 1 */
 685        writel_relaxed(0x1, emc->regs + EMC_STALL_THEN_EXE_BEFORE_CLKCHANGE);
 686
 687        /* enable periodic reset */
 688        if (qrst_used) {
 689                writel_relaxed(emc_dbg | EMC_DBG_WRITE_MUX_ACTIVE,
 690                               emc->regs + EMC_DBG);
 691                writel_relaxed(emc->emc_cfg | EMC_CFG_PERIODIC_QRST,
 692                               emc->regs + EMC_CFG);
 693                writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
 694        }
 695
 696        /* disable auto-refresh to save time after clock change */
 697        writel_relaxed(EMC_REFCTRL_DISABLE_ALL(dram_num),
 698                       emc->regs + EMC_REFCTRL);
 699
 700        /* turn off DLL and enter self-refresh on DDR3 */
 701        if (dram_type == DRAM_TYPE_DDR3) {
 702                if (dll_change == DLL_CHANGE_OFF)
 703                        writel_relaxed(timing->emc_mode_1,
 704                                       emc->regs + EMC_EMRS);
 705
 706                writel_relaxed(DRAM_BROADCAST(dram_num) |
 707                               EMC_SELF_REF_CMD_ENABLED,
 708                               emc->regs + EMC_SELF_REF);
 709        }
 710
 711        /* flow control marker 2 */
 712        writel_relaxed(0x1, emc->regs + EMC_STALL_THEN_EXE_AFTER_CLKCHANGE);
 713
 714        /* enable write-active MUX, update unshadowed pad control */
 715        writel_relaxed(emc_dbg | EMC_DBG_WRITE_MUX_ACTIVE, emc->regs + EMC_DBG);
 716        writel_relaxed(timing->data[73], emc->regs + EMC_XM2CLKPADCTRL);
 717
 718        /* restore periodic QRST and disable write-active MUX */
 719        val = !!(emc->emc_cfg & EMC_CFG_PERIODIC_QRST);
 720        if (qrst_used || timing->emc_cfg_periodic_qrst != val) {
 721                if (timing->emc_cfg_periodic_qrst)
 722                        emc->emc_cfg |= EMC_CFG_PERIODIC_QRST;
 723                else
 724                        emc->emc_cfg &= ~EMC_CFG_PERIODIC_QRST;
 725
 726                writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
 727        }
 728        writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
 729
 730        /* exit self-refresh on DDR3 */
 731        if (dram_type == DRAM_TYPE_DDR3)
 732                writel_relaxed(DRAM_BROADCAST(dram_num),
 733                               emc->regs + EMC_SELF_REF);
 734
 735        /* set DRAM-mode registers */
 736        if (dram_type == DRAM_TYPE_DDR3) {
 737                if (timing->emc_mode_1 != emc->emc_mode_1)
 738                        writel_relaxed(timing->emc_mode_1,
 739                                       emc->regs + EMC_EMRS);
 740
 741                if (timing->emc_mode_2 != emc->emc_mode_2)
 742                        writel_relaxed(timing->emc_mode_2,
 743                                       emc->regs + EMC_EMRS);
 744
 745                if (timing->emc_mode_reset != emc->emc_mode_reset ||
 746                    dll_change == DLL_CHANGE_ON) {
 747                        val = timing->emc_mode_reset;
 748                        if (dll_change == DLL_CHANGE_ON) {
 749                                val |= EMC_MODE_SET_DLL_RESET;
 750                                val |= EMC_MODE_SET_LONG_CNT;
 751                        } else {
 752                                val &= ~EMC_MODE_SET_DLL_RESET;
 753                        }
 754                        writel_relaxed(val, emc->regs + EMC_MRS);
 755                }
 756        } else {
 757                if (timing->emc_mode_2 != emc->emc_mode_2)
 758                        writel_relaxed(timing->emc_mode_2,
 759                                       emc->regs + EMC_MRW);
 760
 761                if (timing->emc_mode_1 != emc->emc_mode_1)
 762                        writel_relaxed(timing->emc_mode_1,
 763                                       emc->regs + EMC_MRW);
 764        }
 765
 766        emc->emc_mode_1 = timing->emc_mode_1;
 767        emc->emc_mode_2 = timing->emc_mode_2;
 768        emc->emc_mode_reset = timing->emc_mode_reset;
 769
 770        /* issue ZCAL command if turning ZCAL on */
 771        if (emc->zcal_long) {
 772                writel_relaxed(EMC_ZQ_CAL_LONG_CMD_DEV0,
 773                               emc->regs + EMC_ZQ_CAL);
 774
 775                if (dram_num > 1)
 776                        writel_relaxed(EMC_ZQ_CAL_LONG_CMD_DEV1,
 777                                       emc->regs + EMC_ZQ_CAL);
 778        }
 779
 780        /* flow control marker 3 */
 781        writel_relaxed(0x1, emc->regs + EMC_UNSTALL_RW_AFTER_CLKCHANGE);
 782
 783        /*
 784         * Read and discard an arbitrary MC register (Note: EMC registers
 785         * can't be used) to ensure the register writes are completed.
 786         */
 787        mc_readl(emc->mc, MC_EMEM_ARB_OVERRIDE);
 788
 789        return 0;
 790}
 791
 792static int emc_complete_timing_change(struct tegra_emc *emc,
 793                                      unsigned long rate)
 794{
 795        struct emc_timing *timing = emc_find_timing(emc, rate);
 796        unsigned int dram_num;
 797        int err;
 798        u32 v;
 799
 800        err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_INTSTATUS, v,
 801                                                v & EMC_CLKCHANGE_COMPLETE_INT,
 802                                                1, 100);
 803        if (err) {
 804                dev_err(emc->dev, "emc-car handshake timeout: %d\n", err);
 805                return err;
 806        }
 807
 808        /* re-enable auto-refresh */
 809        dram_num = tegra_mc_get_emem_device_count(emc->mc);
 810        writel_relaxed(EMC_REFCTRL_ENABLE_ALL(dram_num),
 811                       emc->regs + EMC_REFCTRL);
 812
 813        /* restore auto-calibration */
 814        if (emc->vref_cal_toggle)
 815                writel_relaxed(timing->emc_auto_cal_interval,
 816                               emc->regs + EMC_AUTO_CAL_INTERVAL);
 817
 818        /* restore dynamic self-refresh */
 819        if (timing->emc_cfg_dyn_self_ref) {
 820                emc->emc_cfg |= EMC_CFG_DYN_SREF_ENABLE;
 821                writel_relaxed(emc->emc_cfg, emc->regs + EMC_CFG);
 822        }
 823
 824        /* set number of clocks to wait after each ZQ command */
 825        if (emc->zcal_long)
 826                writel_relaxed(timing->emc_zcal_cnt_long,
 827                               emc->regs + EMC_ZCAL_WAIT_CNT);
 828
 829        /* wait for writes to settle */
 830        udelay(2);
 831
 832        /* update restored timing */
 833        err = emc_seq_update_timing(emc);
 834        if (!err)
 835                emc->bad_state = false;
 836
 837        /* restore early ACK */
 838        mc_writel(emc->mc, emc->mc_override, MC_EMEM_ARB_OVERRIDE);
 839
 840        return err;
 841}
 842
 843static int emc_unprepare_timing_change(struct tegra_emc *emc,
 844                                       unsigned long rate)
 845{
 846        if (!emc->bad_state) {
 847                /* shouldn't ever happen in practice */
 848                dev_err(emc->dev, "timing configuration can't be reverted\n");
 849                emc->bad_state = true;
 850        }
 851
 852        return 0;
 853}
 854
 855static int emc_clk_change_notify(struct notifier_block *nb,
 856                                 unsigned long msg, void *data)
 857{
 858        struct tegra_emc *emc = container_of(nb, struct tegra_emc, clk_nb);
 859        struct clk_notifier_data *cnd = data;
 860        int err;
 861
 862        switch (msg) {
 863        case PRE_RATE_CHANGE:
 864                /*
 865                 * Disable interrupt since read accesses are prohibited after
 866                 * stalling.
 867                 */
 868                disable_irq(emc->irq);
 869                err = emc_prepare_timing_change(emc, cnd->new_rate);
 870                enable_irq(emc->irq);
 871                break;
 872
 873        case ABORT_RATE_CHANGE:
 874                err = emc_unprepare_timing_change(emc, cnd->old_rate);
 875                break;
 876
 877        case POST_RATE_CHANGE:
 878                err = emc_complete_timing_change(emc, cnd->new_rate);
 879                break;
 880
 881        default:
 882                return NOTIFY_DONE;
 883        }
 884
 885        return notifier_from_errno(err);
 886}
 887
 888static int load_one_timing_from_dt(struct tegra_emc *emc,
 889                                   struct emc_timing *timing,
 890                                   struct device_node *node)
 891{
 892        u32 value;
 893        int err;
 894
 895        err = of_property_read_u32(node, "clock-frequency", &value);
 896        if (err) {
 897                dev_err(emc->dev, "timing %pOF: failed to read rate: %d\n",
 898                        node, err);
 899                return err;
 900        }
 901
 902        timing->rate = value;
 903
 904        err = of_property_read_u32_array(node, "nvidia,emc-configuration",
 905                                         timing->data,
 906                                         ARRAY_SIZE(emc_timing_registers));
 907        if (err) {
 908                dev_err(emc->dev,
 909                        "timing %pOF: failed to read emc timing data: %d\n",
 910                        node, err);
 911                return err;
 912        }
 913
 914#define EMC_READ_BOOL(prop, dtprop) \
 915        timing->prop = of_property_read_bool(node, dtprop);
 916
 917#define EMC_READ_U32(prop, dtprop) \
 918        err = of_property_read_u32(node, dtprop, &timing->prop); \
 919        if (err) { \
 920                dev_err(emc->dev, \
 921                        "timing %pOFn: failed to read " #prop ": %d\n", \
 922                        node, err); \
 923                return err; \
 924        }
 925
 926        EMC_READ_U32(emc_auto_cal_interval, "nvidia,emc-auto-cal-interval")
 927        EMC_READ_U32(emc_mode_1, "nvidia,emc-mode-1")
 928        EMC_READ_U32(emc_mode_2, "nvidia,emc-mode-2")
 929        EMC_READ_U32(emc_mode_reset, "nvidia,emc-mode-reset")
 930        EMC_READ_U32(emc_zcal_cnt_long, "nvidia,emc-zcal-cnt-long")
 931        EMC_READ_BOOL(emc_cfg_dyn_self_ref, "nvidia,emc-cfg-dyn-self-ref")
 932        EMC_READ_BOOL(emc_cfg_periodic_qrst, "nvidia,emc-cfg-periodic-qrst")
 933
 934#undef EMC_READ_U32
 935#undef EMC_READ_BOOL
 936
 937        dev_dbg(emc->dev, "%s: %pOF: rate %lu\n", __func__, node, timing->rate);
 938
 939        return 0;
 940}
 941
 942static int cmp_timings(const void *_a, const void *_b)
 943{
 944        const struct emc_timing *a = _a;
 945        const struct emc_timing *b = _b;
 946
 947        if (a->rate < b->rate)
 948                return -1;
 949
 950        if (a->rate > b->rate)
 951                return 1;
 952
 953        return 0;
 954}
 955
 956static int emc_check_mc_timings(struct tegra_emc *emc)
 957{
 958        struct tegra_mc *mc = emc->mc;
 959        unsigned int i;
 960
 961        if (emc->num_timings != mc->num_timings) {
 962                dev_err(emc->dev, "emc/mc timings number mismatch: %u %u\n",
 963                        emc->num_timings, mc->num_timings);
 964                return -EINVAL;
 965        }
 966
 967        for (i = 0; i < mc->num_timings; i++) {
 968                if (emc->timings[i].rate != mc->timings[i].rate) {
 969                        dev_err(emc->dev,
 970                                "emc/mc timing rate mismatch: %lu %lu\n",
 971                                emc->timings[i].rate, mc->timings[i].rate);
 972                        return -EINVAL;
 973                }
 974        }
 975
 976        return 0;
 977}
 978
 979static int emc_load_timings_from_dt(struct tegra_emc *emc,
 980                                    struct device_node *node)
 981{
 982        struct device_node *child;
 983        struct emc_timing *timing;
 984        int child_count;
 985        int err;
 986
 987        child_count = of_get_child_count(node);
 988        if (!child_count) {
 989                dev_err(emc->dev, "no memory timings in: %pOF\n", node);
 990                return -EINVAL;
 991        }
 992
 993        emc->timings = devm_kcalloc(emc->dev, child_count, sizeof(*timing),
 994                                    GFP_KERNEL);
 995        if (!emc->timings)
 996                return -ENOMEM;
 997
 998        emc->num_timings = child_count;
 999        timing = emc->timings;
1000
1001        for_each_child_of_node(node, child) {
1002                err = load_one_timing_from_dt(emc, timing++, child);
1003                if (err) {
1004                        of_node_put(child);
1005                        return err;
1006                }
1007        }
1008
1009        sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings,
1010             NULL);
1011
1012        err = emc_check_mc_timings(emc);
1013        if (err)
1014                return err;
1015
1016        dev_info_once(emc->dev,
1017                      "got %u timings for RAM code %u (min %luMHz max %luMHz)\n",
1018                      emc->num_timings,
1019                      tegra_read_ram_code(),
1020                      emc->timings[0].rate / 1000000,
1021                      emc->timings[emc->num_timings - 1].rate / 1000000);
1022
1023        return 0;
1024}
1025
1026static struct device_node *emc_find_node_by_ram_code(struct tegra_emc *emc)
1027{
1028        struct device *dev = emc->dev;
1029        struct device_node *np;
1030        u32 value, ram_code;
1031        int err;
1032
1033        if (emc->mrr_error) {
1034                dev_warn(dev, "memory timings skipped due to MRR error\n");
1035                return NULL;
1036        }
1037
1038        if (of_get_child_count(dev->of_node) == 0) {
1039                dev_info_once(dev, "device-tree doesn't have memory timings\n");
1040                return NULL;
1041        }
1042
1043        ram_code = tegra_read_ram_code();
1044
1045        for_each_child_of_node(dev->of_node, np) {
1046                err = of_property_read_u32(np, "nvidia,ram-code", &value);
1047                if (err || value != ram_code)
1048                        continue;
1049
1050                return np;
1051        }
1052
1053        dev_err(dev, "no memory timings for RAM code %u found in device-tree\n",
1054                ram_code);
1055
1056        return NULL;
1057}
1058
1059static int emc_read_lpddr_mode_register(struct tegra_emc *emc,
1060                                        unsigned int emem_dev,
1061                                        unsigned int register_addr,
1062                                        unsigned int *register_data)
1063{
1064        u32 memory_dev = emem_dev ? 1 : 2;
1065        u32 val, mr_mask = 0xff;
1066        int err;
1067
1068        /* clear data-valid interrupt status */
1069        writel_relaxed(EMC_MRR_DIVLD_INT, emc->regs + EMC_INTSTATUS);
1070
1071        /* issue mode register read request */
1072        val  = FIELD_PREP(EMC_MRR_DEV_SELECTN, memory_dev);
1073        val |= FIELD_PREP(EMC_MRR_MRR_MA, register_addr);
1074
1075        writel_relaxed(val, emc->regs + EMC_MRR);
1076
1077        /* wait for the LPDDR2 data-valid interrupt */
1078        err = readl_relaxed_poll_timeout_atomic(emc->regs + EMC_INTSTATUS, val,
1079                                                val & EMC_MRR_DIVLD_INT,
1080                                                1, 100);
1081        if (err) {
1082                dev_err(emc->dev, "mode register %u read failed: %d\n",
1083                        register_addr, err);
1084                emc->mrr_error = true;
1085                return err;
1086        }
1087
1088        /* read out mode register data */
1089        val = readl_relaxed(emc->regs + EMC_MRR);
1090        *register_data = FIELD_GET(EMC_MRR_MRR_DATA, val) & mr_mask;
1091
1092        return 0;
1093}
1094
1095static void emc_read_lpddr_sdram_info(struct tegra_emc *emc,
1096                                      unsigned int emem_dev)
1097{
1098        union lpddr2_basic_config4 basic_conf4;
1099        unsigned int manufacturer_id;
1100        unsigned int revision_id1;
1101        unsigned int revision_id2;
1102
1103        /* these registers are standard for all LPDDR JEDEC memory chips */
1104        emc_read_lpddr_mode_register(emc, emem_dev, 5, &manufacturer_id);
1105        emc_read_lpddr_mode_register(emc, emem_dev, 6, &revision_id1);
1106        emc_read_lpddr_mode_register(emc, emem_dev, 7, &revision_id2);
1107        emc_read_lpddr_mode_register(emc, emem_dev, 8, &basic_conf4.value);
1108
1109        dev_info(emc->dev, "SDRAM[dev%u]: manufacturer: 0x%x (%s) rev1: 0x%x rev2: 0x%x prefetch: S%u density: %uMbit iowidth: %ubit\n",
1110                 emem_dev, manufacturer_id,
1111                 lpddr2_jedec_manufacturer(manufacturer_id),
1112                 revision_id1, revision_id2,
1113                 4 >> basic_conf4.arch_type,
1114                 64 << basic_conf4.density,
1115                 32 >> basic_conf4.io_width);
1116}
1117
1118static int emc_setup_hw(struct tegra_emc *emc)
1119{
1120        u32 fbio_cfg5, emc_cfg, emc_dbg, emc_adr_cfg;
1121        u32 intmask = EMC_REFRESH_OVERFLOW_INT;
1122        static bool print_sdram_info_once;
1123        enum emc_dram_type dram_type;
1124        const char *dram_type_str;
1125        unsigned int emem_numdev;
1126
1127        fbio_cfg5 = readl_relaxed(emc->regs + EMC_FBIO_CFG5);
1128        dram_type = fbio_cfg5 & EMC_FBIO_CFG5_DRAM_TYPE_MASK;
1129
1130        emc_cfg = readl_relaxed(emc->regs + EMC_CFG_2);
1131
1132        /* enable EMC and CAR to handshake on PLL divider/source changes */
1133        emc_cfg |= EMC_CLKCHANGE_REQ_ENABLE;
1134
1135        /* configure clock change mode accordingly to DRAM type */
1136        switch (dram_type) {
1137        case DRAM_TYPE_LPDDR2:
1138                emc_cfg |= EMC_CLKCHANGE_PD_ENABLE;
1139                emc_cfg &= ~EMC_CLKCHANGE_SR_ENABLE;
1140                break;
1141
1142        default:
1143                emc_cfg &= ~EMC_CLKCHANGE_SR_ENABLE;
1144                emc_cfg &= ~EMC_CLKCHANGE_PD_ENABLE;
1145                break;
1146        }
1147
1148        writel_relaxed(emc_cfg, emc->regs + EMC_CFG_2);
1149
1150        /* initialize interrupt */
1151        writel_relaxed(intmask, emc->regs + EMC_INTMASK);
1152        writel_relaxed(0xffffffff, emc->regs + EMC_INTSTATUS);
1153
1154        /* ensure that unwanted debug features are disabled */
1155        emc_dbg = readl_relaxed(emc->regs + EMC_DBG);
1156        emc_dbg |= EMC_DBG_CFG_PRIORITY;
1157        emc_dbg &= ~EMC_DBG_READ_MUX_ASSEMBLY;
1158        emc_dbg &= ~EMC_DBG_WRITE_MUX_ACTIVE;
1159        emc_dbg &= ~EMC_DBG_FORCE_UPDATE;
1160        writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
1161
1162        switch (dram_type) {
1163        case DRAM_TYPE_DDR1:
1164                dram_type_str = "DDR1";
1165                break;
1166        case DRAM_TYPE_LPDDR2:
1167                dram_type_str = "LPDDR2";
1168                break;
1169        case DRAM_TYPE_DDR2:
1170                dram_type_str = "DDR2";
1171                break;
1172        case DRAM_TYPE_DDR3:
1173                dram_type_str = "DDR3";
1174                break;
1175        }
1176
1177        emc_adr_cfg = readl_relaxed(emc->regs + EMC_ADR_CFG);
1178        emem_numdev = FIELD_GET(EMC_ADR_CFG_EMEM_NUMDEV, emc_adr_cfg) + 1;
1179
1180        dev_info_once(emc->dev, "%u %s %s attached\n", emem_numdev,
1181                      dram_type_str, emem_numdev == 2 ? "devices" : "device");
1182
1183        if (dram_type == DRAM_TYPE_LPDDR2 && !print_sdram_info_once) {
1184                while (emem_numdev--)
1185                        emc_read_lpddr_sdram_info(emc, emem_numdev);
1186
1187                print_sdram_info_once = true;
1188        }
1189
1190        return 0;
1191}
1192
1193static long emc_round_rate(unsigned long rate,
1194                           unsigned long min_rate,
1195                           unsigned long max_rate,
1196                           void *arg)
1197{
1198        struct emc_timing *timing = NULL;
1199        struct tegra_emc *emc = arg;
1200        unsigned int i;
1201
1202        if (!emc->num_timings)
1203                return clk_get_rate(emc->clk);
1204
1205        min_rate = min(min_rate, emc->timings[emc->num_timings - 1].rate);
1206
1207        for (i = 0; i < emc->num_timings; i++) {
1208                if (emc->timings[i].rate < rate && i != emc->num_timings - 1)
1209                        continue;
1210
1211                if (emc->timings[i].rate > max_rate) {
1212                        i = max(i, 1u) - 1;
1213
1214                        if (emc->timings[i].rate < min_rate)
1215                                break;
1216                }
1217
1218                if (emc->timings[i].rate < min_rate)
1219                        continue;
1220
1221                timing = &emc->timings[i];
1222                break;
1223        }
1224
1225        if (!timing) {
1226                dev_err(emc->dev, "no timing for rate %lu min %lu max %lu\n",
1227                        rate, min_rate, max_rate);
1228                return -EINVAL;
1229        }
1230
1231        return timing->rate;
1232}
1233
1234static void tegra_emc_rate_requests_init(struct tegra_emc *emc)
1235{
1236        unsigned int i;
1237
1238        for (i = 0; i < EMC_RATE_TYPE_MAX; i++) {
1239                emc->requested_rate[i].min_rate = 0;
1240                emc->requested_rate[i].max_rate = ULONG_MAX;
1241        }
1242}
1243
1244static int emc_request_rate(struct tegra_emc *emc,
1245                            unsigned long new_min_rate,
1246                            unsigned long new_max_rate,
1247                            enum emc_rate_request_type type)
1248{
1249        struct emc_rate_request *req = emc->requested_rate;
1250        unsigned long min_rate = 0, max_rate = ULONG_MAX;
1251        unsigned int i;
1252        int err;
1253
1254        /* select minimum and maximum rates among the requested rates */
1255        for (i = 0; i < EMC_RATE_TYPE_MAX; i++, req++) {
1256                if (i == type) {
1257                        min_rate = max(new_min_rate, min_rate);
1258                        max_rate = min(new_max_rate, max_rate);
1259                } else {
1260                        min_rate = max(req->min_rate, min_rate);
1261                        max_rate = min(req->max_rate, max_rate);
1262                }
1263        }
1264
1265        if (min_rate > max_rate) {
1266                dev_err_ratelimited(emc->dev, "%s: type %u: out of range: %lu %lu\n",
1267                                    __func__, type, min_rate, max_rate);
1268                return -ERANGE;
1269        }
1270
1271        /*
1272         * EMC rate-changes should go via OPP API because it manages voltage
1273         * changes.
1274         */
1275        err = dev_pm_opp_set_rate(emc->dev, min_rate);
1276        if (err)
1277                return err;
1278
1279        emc->requested_rate[type].min_rate = new_min_rate;
1280        emc->requested_rate[type].max_rate = new_max_rate;
1281
1282        return 0;
1283}
1284
1285static int emc_set_min_rate(struct tegra_emc *emc, unsigned long rate,
1286                            enum emc_rate_request_type type)
1287{
1288        struct emc_rate_request *req = &emc->requested_rate[type];
1289        int ret;
1290
1291        mutex_lock(&emc->rate_lock);
1292        ret = emc_request_rate(emc, rate, req->max_rate, type);
1293        mutex_unlock(&emc->rate_lock);
1294
1295        return ret;
1296}
1297
1298static int emc_set_max_rate(struct tegra_emc *emc, unsigned long rate,
1299                            enum emc_rate_request_type type)
1300{
1301        struct emc_rate_request *req = &emc->requested_rate[type];
1302        int ret;
1303
1304        mutex_lock(&emc->rate_lock);
1305        ret = emc_request_rate(emc, req->min_rate, rate, type);
1306        mutex_unlock(&emc->rate_lock);
1307
1308        return ret;
1309}
1310
1311/*
1312 * debugfs interface
1313 *
1314 * The memory controller driver exposes some files in debugfs that can be used
1315 * to control the EMC frequency. The top-level directory can be found here:
1316 *
1317 *   /sys/kernel/debug/emc
1318 *
1319 * It contains the following files:
1320 *
1321 *   - available_rates: This file contains a list of valid, space-separated
1322 *     EMC frequencies.
1323 *
1324 *   - min_rate: Writing a value to this file sets the given frequency as the
1325 *       floor of the permitted range. If this is higher than the currently
1326 *       configured EMC frequency, this will cause the frequency to be
1327 *       increased so that it stays within the valid range.
1328 *
1329 *   - max_rate: Similarily to the min_rate file, writing a value to this file
1330 *       sets the given frequency as the ceiling of the permitted range. If
1331 *       the value is lower than the currently configured EMC frequency, this
1332 *       will cause the frequency to be decreased so that it stays within the
1333 *       valid range.
1334 */
1335
1336static bool tegra_emc_validate_rate(struct tegra_emc *emc, unsigned long rate)
1337{
1338        unsigned int i;
1339
1340        for (i = 0; i < emc->num_timings; i++)
1341                if (rate == emc->timings[i].rate)
1342                        return true;
1343
1344        return false;
1345}
1346
1347static int tegra_emc_debug_available_rates_show(struct seq_file *s, void *data)
1348{
1349        struct tegra_emc *emc = s->private;
1350        const char *prefix = "";
1351        unsigned int i;
1352
1353        for (i = 0; i < emc->num_timings; i++) {
1354                seq_printf(s, "%s%lu", prefix, emc->timings[i].rate);
1355                prefix = " ";
1356        }
1357
1358        seq_puts(s, "\n");
1359
1360        return 0;
1361}
1362
1363static int tegra_emc_debug_available_rates_open(struct inode *inode,
1364                                                struct file *file)
1365{
1366        return single_open(file, tegra_emc_debug_available_rates_show,
1367                           inode->i_private);
1368}
1369
1370static const struct file_operations tegra_emc_debug_available_rates_fops = {
1371        .open = tegra_emc_debug_available_rates_open,
1372        .read = seq_read,
1373        .llseek = seq_lseek,
1374        .release = single_release,
1375};
1376
1377static int tegra_emc_debug_min_rate_get(void *data, u64 *rate)
1378{
1379        struct tegra_emc *emc = data;
1380
1381        *rate = emc->debugfs.min_rate;
1382
1383        return 0;
1384}
1385
1386static int tegra_emc_debug_min_rate_set(void *data, u64 rate)
1387{
1388        struct tegra_emc *emc = data;
1389        int err;
1390
1391        if (!tegra_emc_validate_rate(emc, rate))
1392                return -EINVAL;
1393
1394        err = emc_set_min_rate(emc, rate, EMC_RATE_DEBUG);
1395        if (err < 0)
1396                return err;
1397
1398        emc->debugfs.min_rate = rate;
1399
1400        return 0;
1401}
1402
1403DEFINE_DEBUGFS_ATTRIBUTE(tegra_emc_debug_min_rate_fops,
1404                        tegra_emc_debug_min_rate_get,
1405                        tegra_emc_debug_min_rate_set, "%llu\n");
1406
1407static int tegra_emc_debug_max_rate_get(void *data, u64 *rate)
1408{
1409        struct tegra_emc *emc = data;
1410
1411        *rate = emc->debugfs.max_rate;
1412
1413        return 0;
1414}
1415
1416static int tegra_emc_debug_max_rate_set(void *data, u64 rate)
1417{
1418        struct tegra_emc *emc = data;
1419        int err;
1420
1421        if (!tegra_emc_validate_rate(emc, rate))
1422                return -EINVAL;
1423
1424        err = emc_set_max_rate(emc, rate, EMC_RATE_DEBUG);
1425        if (err < 0)
1426                return err;
1427
1428        emc->debugfs.max_rate = rate;
1429
1430        return 0;
1431}
1432
1433DEFINE_DEBUGFS_ATTRIBUTE(tegra_emc_debug_max_rate_fops,
1434                        tegra_emc_debug_max_rate_get,
1435                        tegra_emc_debug_max_rate_set, "%llu\n");
1436
1437static void tegra_emc_debugfs_init(struct tegra_emc *emc)
1438{
1439        struct device *dev = emc->dev;
1440        unsigned int i;
1441        int err;
1442
1443        emc->debugfs.min_rate = ULONG_MAX;
1444        emc->debugfs.max_rate = 0;
1445
1446        for (i = 0; i < emc->num_timings; i++) {
1447                if (emc->timings[i].rate < emc->debugfs.min_rate)
1448                        emc->debugfs.min_rate = emc->timings[i].rate;
1449
1450                if (emc->timings[i].rate > emc->debugfs.max_rate)
1451                        emc->debugfs.max_rate = emc->timings[i].rate;
1452        }
1453
1454        if (!emc->num_timings) {
1455                emc->debugfs.min_rate = clk_get_rate(emc->clk);
1456                emc->debugfs.max_rate = emc->debugfs.min_rate;
1457        }
1458
1459        err = clk_set_rate_range(emc->clk, emc->debugfs.min_rate,
1460                                 emc->debugfs.max_rate);
1461        if (err < 0) {
1462                dev_err(dev, "failed to set rate range [%lu-%lu] for %pC\n",
1463                        emc->debugfs.min_rate, emc->debugfs.max_rate,
1464                        emc->clk);
1465        }
1466
1467        emc->debugfs.root = debugfs_create_dir("emc", NULL);
1468
1469        debugfs_create_file("available_rates", 0444, emc->debugfs.root,
1470                            emc, &tegra_emc_debug_available_rates_fops);
1471        debugfs_create_file("min_rate", 0644, emc->debugfs.root,
1472                            emc, &tegra_emc_debug_min_rate_fops);
1473        debugfs_create_file("max_rate", 0644, emc->debugfs.root,
1474                            emc, &tegra_emc_debug_max_rate_fops);
1475}
1476
1477static inline struct tegra_emc *
1478to_tegra_emc_provider(struct icc_provider *provider)
1479{
1480        return container_of(provider, struct tegra_emc, provider);
1481}
1482
1483static struct icc_node_data *
1484emc_of_icc_xlate_extended(struct of_phandle_args *spec, void *data)
1485{
1486        struct icc_provider *provider = data;
1487        struct icc_node_data *ndata;
1488        struct icc_node *node;
1489
1490        /* External Memory is the only possible ICC route */
1491        list_for_each_entry(node, &provider->nodes, node_list) {
1492                if (node->id != TEGRA_ICC_EMEM)
1493                        continue;
1494
1495                ndata = kzalloc(sizeof(*ndata), GFP_KERNEL);
1496                if (!ndata)
1497                        return ERR_PTR(-ENOMEM);
1498
1499                /*
1500                 * SRC and DST nodes should have matching TAG in order to have
1501                 * it set by default for a requested path.
1502                 */
1503                ndata->tag = TEGRA_MC_ICC_TAG_ISO;
1504                ndata->node = node;
1505
1506                return ndata;
1507        }
1508
1509        return ERR_PTR(-EPROBE_DEFER);
1510}
1511
1512static int emc_icc_set(struct icc_node *src, struct icc_node *dst)
1513{
1514        struct tegra_emc *emc = to_tegra_emc_provider(dst->provider);
1515        unsigned long long peak_bw = icc_units_to_bps(dst->peak_bw);
1516        unsigned long long avg_bw = icc_units_to_bps(dst->avg_bw);
1517        unsigned long long rate = max(avg_bw, peak_bw);
1518        const unsigned int dram_data_bus_width_bytes = 4;
1519        const unsigned int ddr = 2;
1520        int err;
1521
1522        /*
1523         * Tegra30 EMC runs on a clock rate of SDRAM bus.  This means that
1524         * EMC clock rate is twice smaller than the peak data rate because
1525         * data is sampled on both EMC clock edges.
1526         */
1527        do_div(rate, ddr * dram_data_bus_width_bytes);
1528        rate = min_t(u64, rate, U32_MAX);
1529
1530        err = emc_set_min_rate(emc, rate, EMC_RATE_ICC);
1531        if (err)
1532                return err;
1533
1534        return 0;
1535}
1536
1537static int tegra_emc_interconnect_init(struct tegra_emc *emc)
1538{
1539        const struct tegra_mc_soc *soc = emc->mc->soc;
1540        struct icc_node *node;
1541        int err;
1542
1543        emc->provider.dev = emc->dev;
1544        emc->provider.set = emc_icc_set;
1545        emc->provider.data = &emc->provider;
1546        emc->provider.aggregate = soc->icc_ops->aggregate;
1547        emc->provider.xlate_extended = emc_of_icc_xlate_extended;
1548
1549        err = icc_provider_add(&emc->provider);
1550        if (err)
1551                goto err_msg;
1552
1553        /* create External Memory Controller node */
1554        node = icc_node_create(TEGRA_ICC_EMC);
1555        if (IS_ERR(node)) {
1556                err = PTR_ERR(node);
1557                goto del_provider;
1558        }
1559
1560        node->name = "External Memory Controller";
1561        icc_node_add(node, &emc->provider);
1562
1563        /* link External Memory Controller to External Memory (DRAM) */
1564        err = icc_link_create(node, TEGRA_ICC_EMEM);
1565        if (err)
1566                goto remove_nodes;
1567
1568        /* create External Memory node */
1569        node = icc_node_create(TEGRA_ICC_EMEM);
1570        if (IS_ERR(node)) {
1571                err = PTR_ERR(node);
1572                goto remove_nodes;
1573        }
1574
1575        node->name = "External Memory (DRAM)";
1576        icc_node_add(node, &emc->provider);
1577
1578        return 0;
1579
1580remove_nodes:
1581        icc_nodes_remove(&emc->provider);
1582del_provider:
1583        icc_provider_del(&emc->provider);
1584err_msg:
1585        dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
1586
1587        return err;
1588}
1589
1590static void devm_tegra_emc_unset_callback(void *data)
1591{
1592        tegra20_clk_set_emc_round_callback(NULL, NULL);
1593}
1594
1595static void devm_tegra_emc_unreg_clk_notifier(void *data)
1596{
1597        struct tegra_emc *emc = data;
1598
1599        clk_notifier_unregister(emc->clk, &emc->clk_nb);
1600}
1601
1602static int tegra_emc_init_clk(struct tegra_emc *emc)
1603{
1604        int err;
1605
1606        tegra20_clk_set_emc_round_callback(emc_round_rate, emc);
1607
1608        err = devm_add_action_or_reset(emc->dev, devm_tegra_emc_unset_callback,
1609                                       NULL);
1610        if (err)
1611                return err;
1612
1613        emc->clk = devm_clk_get(emc->dev, NULL);
1614        if (IS_ERR(emc->clk)) {
1615                dev_err(emc->dev, "failed to get EMC clock: %pe\n", emc->clk);
1616                return PTR_ERR(emc->clk);
1617        }
1618
1619        err = clk_notifier_register(emc->clk, &emc->clk_nb);
1620        if (err) {
1621                dev_err(emc->dev, "failed to register clk notifier: %d\n", err);
1622                return err;
1623        }
1624
1625        err = devm_add_action_or_reset(emc->dev,
1626                                       devm_tegra_emc_unreg_clk_notifier, emc);
1627        if (err)
1628                return err;
1629
1630        return 0;
1631}
1632
1633static int tegra_emc_probe(struct platform_device *pdev)
1634{
1635        struct tegra_core_opp_params opp_params = {};
1636        struct device_node *np;
1637        struct tegra_emc *emc;
1638        int err;
1639
1640        emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
1641        if (!emc)
1642                return -ENOMEM;
1643
1644        emc->mc = devm_tegra_memory_controller_get(&pdev->dev);
1645        if (IS_ERR(emc->mc))
1646                return PTR_ERR(emc->mc);
1647
1648        mutex_init(&emc->rate_lock);
1649        emc->clk_nb.notifier_call = emc_clk_change_notify;
1650        emc->dev = &pdev->dev;
1651
1652        emc->regs = devm_platform_ioremap_resource(pdev, 0);
1653        if (IS_ERR(emc->regs))
1654                return PTR_ERR(emc->regs);
1655
1656        err = emc_setup_hw(emc);
1657        if (err)
1658                return err;
1659
1660        np = emc_find_node_by_ram_code(emc);
1661        if (np) {
1662                err = emc_load_timings_from_dt(emc, np);
1663                of_node_put(np);
1664                if (err)
1665                        return err;
1666        }
1667
1668        err = platform_get_irq(pdev, 0);
1669        if (err < 0)
1670                return err;
1671
1672        emc->irq = err;
1673
1674        err = devm_request_irq(&pdev->dev, emc->irq, tegra_emc_isr, 0,
1675                               dev_name(&pdev->dev), emc);
1676        if (err) {
1677                dev_err(&pdev->dev, "failed to request irq: %d\n", err);
1678                return err;
1679        }
1680
1681        err = tegra_emc_init_clk(emc);
1682        if (err)
1683                return err;
1684
1685        opp_params.init_state = true;
1686
1687        err = devm_tegra_core_dev_init_opp_table(&pdev->dev, &opp_params);
1688        if (err)
1689                return err;
1690
1691        platform_set_drvdata(pdev, emc);
1692        tegra_emc_rate_requests_init(emc);
1693        tegra_emc_debugfs_init(emc);
1694        tegra_emc_interconnect_init(emc);
1695
1696        /*
1697         * Don't allow the kernel module to be unloaded. Unloading adds some
1698         * extra complexity which doesn't really worth the effort in a case of
1699         * this driver.
1700         */
1701        try_module_get(THIS_MODULE);
1702
1703        return 0;
1704}
1705
1706static int tegra_emc_suspend(struct device *dev)
1707{
1708        struct tegra_emc *emc = dev_get_drvdata(dev);
1709        int err;
1710
1711        /* take exclusive control over the clock's rate */
1712        err = clk_rate_exclusive_get(emc->clk);
1713        if (err) {
1714                dev_err(emc->dev, "failed to acquire clk: %d\n", err);
1715                return err;
1716        }
1717
1718        /* suspending in a bad state will hang machine */
1719        if (WARN(emc->bad_state, "hardware in a bad state\n"))
1720                return -EINVAL;
1721
1722        emc->bad_state = true;
1723
1724        return 0;
1725}
1726
1727static int tegra_emc_resume(struct device *dev)
1728{
1729        struct tegra_emc *emc = dev_get_drvdata(dev);
1730
1731        emc_setup_hw(emc);
1732        emc->bad_state = false;
1733
1734        clk_rate_exclusive_put(emc->clk);
1735
1736        return 0;
1737}
1738
1739static const struct dev_pm_ops tegra_emc_pm_ops = {
1740        .suspend = tegra_emc_suspend,
1741        .resume = tegra_emc_resume,
1742};
1743
1744static const struct of_device_id tegra_emc_of_match[] = {
1745        { .compatible = "nvidia,tegra30-emc", },
1746        {},
1747};
1748MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
1749
1750static struct platform_driver tegra_emc_driver = {
1751        .probe = tegra_emc_probe,
1752        .driver = {
1753                .name = "tegra30-emc",
1754                .of_match_table = tegra_emc_of_match,
1755                .pm = &tegra_emc_pm_ops,
1756                .suppress_bind_attrs = true,
1757                .sync_state = icc_sync_state,
1758        },
1759};
1760module_platform_driver(tegra_emc_driver);
1761
1762MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
1763MODULE_DESCRIPTION("NVIDIA Tegra30 EMC driver");
1764MODULE_LICENSE("GPL v2");
1765