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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.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}
1362DEFINE_SHOW_ATTRIBUTE(tegra_emc_debug_available_rates);
1363
1364static int tegra_emc_debug_min_rate_get(void *data, u64 *rate)
1365{
1366	struct tegra_emc *emc = data;
1367
1368	*rate = emc->debugfs.min_rate;
1369
1370	return 0;
1371}
1372
1373static int tegra_emc_debug_min_rate_set(void *data, u64 rate)
1374{
1375	struct tegra_emc *emc = data;
1376	int err;
1377
1378	if (!tegra_emc_validate_rate(emc, rate))
1379		return -EINVAL;
1380
1381	err = emc_set_min_rate(emc, rate, EMC_RATE_DEBUG);
1382	if (err < 0)
1383		return err;
1384
1385	emc->debugfs.min_rate = rate;
1386
1387	return 0;
1388}
1389
1390DEFINE_DEBUGFS_ATTRIBUTE(tegra_emc_debug_min_rate_fops,
1391			tegra_emc_debug_min_rate_get,
1392			tegra_emc_debug_min_rate_set, "%llu\n");
1393
1394static int tegra_emc_debug_max_rate_get(void *data, u64 *rate)
1395{
1396	struct tegra_emc *emc = data;
1397
1398	*rate = emc->debugfs.max_rate;
1399
1400	return 0;
1401}
1402
1403static int tegra_emc_debug_max_rate_set(void *data, u64 rate)
1404{
1405	struct tegra_emc *emc = data;
1406	int err;
1407
1408	if (!tegra_emc_validate_rate(emc, rate))
1409		return -EINVAL;
1410
1411	err = emc_set_max_rate(emc, rate, EMC_RATE_DEBUG);
1412	if (err < 0)
1413		return err;
1414
1415	emc->debugfs.max_rate = rate;
1416
1417	return 0;
1418}
1419
1420DEFINE_DEBUGFS_ATTRIBUTE(tegra_emc_debug_max_rate_fops,
1421			tegra_emc_debug_max_rate_get,
1422			tegra_emc_debug_max_rate_set, "%llu\n");
1423
1424static void tegra_emc_debugfs_init(struct tegra_emc *emc)
1425{
1426	struct device *dev = emc->dev;
1427	unsigned int i;
1428	int err;
1429
1430	emc->debugfs.min_rate = ULONG_MAX;
1431	emc->debugfs.max_rate = 0;
1432
1433	for (i = 0; i < emc->num_timings; i++) {
1434		if (emc->timings[i].rate < emc->debugfs.min_rate)
1435			emc->debugfs.min_rate = emc->timings[i].rate;
1436
1437		if (emc->timings[i].rate > emc->debugfs.max_rate)
1438			emc->debugfs.max_rate = emc->timings[i].rate;
1439	}
1440
1441	if (!emc->num_timings) {
1442		emc->debugfs.min_rate = clk_get_rate(emc->clk);
1443		emc->debugfs.max_rate = emc->debugfs.min_rate;
1444	}
1445
1446	err = clk_set_rate_range(emc->clk, emc->debugfs.min_rate,
1447				 emc->debugfs.max_rate);
1448	if (err < 0) {
1449		dev_err(dev, "failed to set rate range [%lu-%lu] for %pC\n",
1450			emc->debugfs.min_rate, emc->debugfs.max_rate,
1451			emc->clk);
1452	}
1453
1454	emc->debugfs.root = debugfs_create_dir("emc", NULL);
1455
1456	debugfs_create_file("available_rates", 0444, emc->debugfs.root,
1457			    emc, &tegra_emc_debug_available_rates_fops);
1458	debugfs_create_file("min_rate", 0644, emc->debugfs.root,
1459			    emc, &tegra_emc_debug_min_rate_fops);
1460	debugfs_create_file("max_rate", 0644, emc->debugfs.root,
1461			    emc, &tegra_emc_debug_max_rate_fops);
1462}
1463
1464static inline struct tegra_emc *
1465to_tegra_emc_provider(struct icc_provider *provider)
1466{
1467	return container_of(provider, struct tegra_emc, provider);
1468}
1469
1470static struct icc_node_data *
1471emc_of_icc_xlate_extended(struct of_phandle_args *spec, void *data)
1472{
1473	struct icc_provider *provider = data;
1474	struct icc_node_data *ndata;
1475	struct icc_node *node;
1476
1477	/* External Memory is the only possible ICC route */
1478	list_for_each_entry(node, &provider->nodes, node_list) {
1479		if (node->id != TEGRA_ICC_EMEM)
1480			continue;
1481
1482		ndata = kzalloc(sizeof(*ndata), GFP_KERNEL);
1483		if (!ndata)
1484			return ERR_PTR(-ENOMEM);
1485
1486		/*
1487		 * SRC and DST nodes should have matching TAG in order to have
1488		 * it set by default for a requested path.
1489		 */
1490		ndata->tag = TEGRA_MC_ICC_TAG_ISO;
1491		ndata->node = node;
1492
1493		return ndata;
1494	}
1495
1496	return ERR_PTR(-EPROBE_DEFER);
1497}
1498
1499static int emc_icc_set(struct icc_node *src, struct icc_node *dst)
1500{
1501	struct tegra_emc *emc = to_tegra_emc_provider(dst->provider);
1502	unsigned long long peak_bw = icc_units_to_bps(dst->peak_bw);
1503	unsigned long long avg_bw = icc_units_to_bps(dst->avg_bw);
1504	unsigned long long rate = max(avg_bw, peak_bw);
1505	const unsigned int dram_data_bus_width_bytes = 4;
1506	const unsigned int ddr = 2;
1507	int err;
1508
1509	/*
1510	 * Tegra30 EMC runs on a clock rate of SDRAM bus.  This means that
1511	 * EMC clock rate is twice smaller than the peak data rate because
1512	 * data is sampled on both EMC clock edges.
1513	 */
1514	do_div(rate, ddr * dram_data_bus_width_bytes);
1515	rate = min_t(u64, rate, U32_MAX);
1516
1517	err = emc_set_min_rate(emc, rate, EMC_RATE_ICC);
1518	if (err)
1519		return err;
1520
1521	return 0;
1522}
1523
1524static int tegra_emc_interconnect_init(struct tegra_emc *emc)
1525{
1526	const struct tegra_mc_soc *soc = emc->mc->soc;
1527	struct icc_node *node;
1528	int err;
1529
1530	emc->provider.dev = emc->dev;
1531	emc->provider.set = emc_icc_set;
1532	emc->provider.data = &emc->provider;
1533	emc->provider.aggregate = soc->icc_ops->aggregate;
1534	emc->provider.xlate_extended = emc_of_icc_xlate_extended;
1535
1536	icc_provider_init(&emc->provider);
1537
1538	/* create External Memory Controller node */
1539	node = icc_node_create(TEGRA_ICC_EMC);
1540	if (IS_ERR(node)) {
1541		err = PTR_ERR(node);
1542		goto err_msg;
1543	}
1544
1545	node->name = "External Memory Controller";
1546	icc_node_add(node, &emc->provider);
1547
1548	/* link External Memory Controller to External Memory (DRAM) */
1549	err = icc_link_create(node, TEGRA_ICC_EMEM);
1550	if (err)
1551		goto remove_nodes;
1552
1553	/* create External Memory node */
1554	node = icc_node_create(TEGRA_ICC_EMEM);
1555	if (IS_ERR(node)) {
1556		err = PTR_ERR(node);
1557		goto remove_nodes;
1558	}
1559
1560	node->name = "External Memory (DRAM)";
1561	icc_node_add(node, &emc->provider);
1562
1563	err = icc_provider_register(&emc->provider);
1564	if (err)
1565		goto remove_nodes;
1566
1567	return 0;
1568
1569remove_nodes:
1570	icc_nodes_remove(&emc->provider);
1571err_msg:
1572	dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
1573
1574	return err;
1575}
1576
1577static void devm_tegra_emc_unset_callback(void *data)
1578{
1579	tegra20_clk_set_emc_round_callback(NULL, NULL);
1580}
1581
1582static void devm_tegra_emc_unreg_clk_notifier(void *data)
1583{
1584	struct tegra_emc *emc = data;
1585
1586	clk_notifier_unregister(emc->clk, &emc->clk_nb);
1587}
1588
1589static int tegra_emc_init_clk(struct tegra_emc *emc)
1590{
1591	int err;
1592
1593	tegra20_clk_set_emc_round_callback(emc_round_rate, emc);
1594
1595	err = devm_add_action_or_reset(emc->dev, devm_tegra_emc_unset_callback,
1596				       NULL);
1597	if (err)
1598		return err;
1599
1600	emc->clk = devm_clk_get(emc->dev, NULL);
1601	if (IS_ERR(emc->clk)) {
1602		dev_err(emc->dev, "failed to get EMC clock: %pe\n", emc->clk);
1603		return PTR_ERR(emc->clk);
1604	}
1605
1606	err = clk_notifier_register(emc->clk, &emc->clk_nb);
1607	if (err) {
1608		dev_err(emc->dev, "failed to register clk notifier: %d\n", err);
1609		return err;
1610	}
1611
1612	err = devm_add_action_or_reset(emc->dev,
1613				       devm_tegra_emc_unreg_clk_notifier, emc);
1614	if (err)
1615		return err;
1616
1617	return 0;
1618}
1619
1620static int tegra_emc_probe(struct platform_device *pdev)
1621{
1622	struct tegra_core_opp_params opp_params = {};
1623	struct device_node *np;
1624	struct tegra_emc *emc;
1625	int err;
1626
1627	emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
1628	if (!emc)
1629		return -ENOMEM;
1630
1631	emc->mc = devm_tegra_memory_controller_get(&pdev->dev);
1632	if (IS_ERR(emc->mc))
1633		return PTR_ERR(emc->mc);
1634
1635	mutex_init(&emc->rate_lock);
1636	emc->clk_nb.notifier_call = emc_clk_change_notify;
1637	emc->dev = &pdev->dev;
1638
1639	emc->regs = devm_platform_ioremap_resource(pdev, 0);
1640	if (IS_ERR(emc->regs))
1641		return PTR_ERR(emc->regs);
1642
1643	err = emc_setup_hw(emc);
1644	if (err)
1645		return err;
1646
1647	np = emc_find_node_by_ram_code(emc);
1648	if (np) {
1649		err = emc_load_timings_from_dt(emc, np);
1650		of_node_put(np);
1651		if (err)
1652			return err;
1653	}
1654
1655	err = platform_get_irq(pdev, 0);
1656	if (err < 0)
1657		return err;
1658
1659	emc->irq = err;
1660
1661	err = devm_request_irq(&pdev->dev, emc->irq, tegra_emc_isr, 0,
1662			       dev_name(&pdev->dev), emc);
1663	if (err) {
1664		dev_err(&pdev->dev, "failed to request irq: %d\n", err);
1665		return err;
1666	}
1667
1668	err = tegra_emc_init_clk(emc);
1669	if (err)
1670		return err;
1671
1672	opp_params.init_state = true;
1673
1674	err = devm_tegra_core_dev_init_opp_table(&pdev->dev, &opp_params);
1675	if (err)
1676		return err;
1677
1678	platform_set_drvdata(pdev, emc);
1679	tegra_emc_rate_requests_init(emc);
1680	tegra_emc_debugfs_init(emc);
1681	tegra_emc_interconnect_init(emc);
1682
1683	/*
1684	 * Don't allow the kernel module to be unloaded. Unloading adds some
1685	 * extra complexity which doesn't really worth the effort in a case of
1686	 * this driver.
1687	 */
1688	try_module_get(THIS_MODULE);
1689
1690	return 0;
1691}
1692
1693static int tegra_emc_suspend(struct device *dev)
1694{
1695	struct tegra_emc *emc = dev_get_drvdata(dev);
1696	int err;
1697
1698	/* take exclusive control over the clock's rate */
1699	err = clk_rate_exclusive_get(emc->clk);
1700	if (err) {
1701		dev_err(emc->dev, "failed to acquire clk: %d\n", err);
1702		return err;
1703	}
1704
1705	/* suspending in a bad state will hang machine */
1706	if (WARN(emc->bad_state, "hardware in a bad state\n"))
1707		return -EINVAL;
1708
1709	emc->bad_state = true;
1710
1711	return 0;
1712}
1713
1714static int tegra_emc_resume(struct device *dev)
1715{
1716	struct tegra_emc *emc = dev_get_drvdata(dev);
1717
1718	emc_setup_hw(emc);
1719	emc->bad_state = false;
1720
1721	clk_rate_exclusive_put(emc->clk);
1722
1723	return 0;
1724}
1725
1726static const struct dev_pm_ops tegra_emc_pm_ops = {
1727	.suspend = tegra_emc_suspend,
1728	.resume = tegra_emc_resume,
1729};
1730
1731static const struct of_device_id tegra_emc_of_match[] = {
1732	{ .compatible = "nvidia,tegra30-emc", },
1733	{},
1734};
1735MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
1736
1737static struct platform_driver tegra_emc_driver = {
1738	.probe = tegra_emc_probe,
1739	.driver = {
1740		.name = "tegra30-emc",
1741		.of_match_table = tegra_emc_of_match,
1742		.pm = &tegra_emc_pm_ops,
1743		.suppress_bind_attrs = true,
1744		.sync_state = icc_sync_state,
1745	},
1746};
1747module_platform_driver(tegra_emc_driver);
1748
1749MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
1750MODULE_DESCRIPTION("NVIDIA Tegra30 EMC driver");
1751MODULE_LICENSE("GPL v2");