]> git.ipfire.org Git - thirdparty/linux.git/commitdiff
memory: tegra: Add Tegra114 EMC driver
authorSvyatoslav Ryhel <clamor95@gmail.com>
Mon, 27 Apr 2026 07:03:09 +0000 (10:03 +0300)
committerKrzysztof Kozlowski <krzk@kernel.org>
Mon, 4 May 2026 18:47:18 +0000 (20:47 +0200)
Introduce driver for the External Memory Controller (EMC) found in
Tegra114 SoC. It controls the external DRAM on the board. The purpose of
this driver is to program memory timing for external memory on the EMC
clock rate change.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Link: https://patch.msgid.link/20260427070312.81679-5-clamor95@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
drivers/memory/tegra/Kconfig
drivers/memory/tegra/Makefile
drivers/memory/tegra/tegra114-emc.c [new file with mode: 0644]

index 92671f9df672139da8b96a3c046e0da380d3a7a3..cf0bfead8c456fcb59992aec29816f4791db75bb 100644 (file)
@@ -37,6 +37,19 @@ config TEGRA30_EMC
          This driver is required to change memory timings / clock rate for
          external memory.
 
+config TEGRA114_EMC
+       tristate "NVIDIA Tegra114 External Memory Controller driver"
+       default ARCH_TEGRA_114_SOC
+       depends on ARCH_TEGRA_114_SOC || COMPILE_TEST
+       select TEGRA124_CLK_EMC if ARCH_TEGRA
+       select PM_OPP
+       select TEGRA_EMC_COMMON
+       help
+         This driver is for the External Memory Controller (EMC) found on
+         Tegra114 chips. The EMC controls the external DRAM on the board.
+         This driver is required to change memory timings / clock rate for
+         external memory.
+
 config TEGRA124_EMC
        tristate "NVIDIA Tegra124 External Memory Controller driver"
        default ARCH_TEGRA_124_SOC
index 218361cdaf2d7c28474b10908c67be80c12292b9..908a5046454f61838a0adb8e90b3d994fcd33fd2 100644 (file)
@@ -18,6 +18,7 @@ obj-$(CONFIG_TEGRA_MC) += tegra-mc.o
 obj-$(CONFIG_TEGRA_EMC_COMMON) += tegra-emc-common.o
 obj-$(CONFIG_TEGRA20_EMC)  += tegra20-emc.o
 obj-$(CONFIG_TEGRA30_EMC)  += tegra30-emc.o
+obj-$(CONFIG_TEGRA114_EMC) += tegra114-emc.o
 obj-$(CONFIG_TEGRA124_EMC) += tegra124-emc.o
 obj-$(CONFIG_TEGRA210_EMC_TABLE) += tegra210-emc-table.o
 obj-$(CONFIG_TEGRA210_EMC) += tegra210-emc.o
diff --git a/drivers/memory/tegra/tegra114-emc.c b/drivers/memory/tegra/tegra114-emc.c
new file mode 100644 (file)
index 0000000..be6c699
--- /dev/null
@@ -0,0 +1,1353 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Tegra114 External Memory Controller driver
+ *
+ * Based on downstream driver from NVIDIA and tegra124-emc.c
+ * Copyright (C) 2011-2014 NVIDIA Corporation
+ *
+ * Copyright (C) 2024 Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/clk/tegra.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/sort.h>
+#include <linux/string.h>
+
+#include <soc/tegra/common.h>
+#include <soc/tegra/fuse.h>
+#include <soc/tegra/mc.h>
+
+#include "mc.h"
+#include "tegra-emc-common.h"
+
+#define EMC_INTSTATUS                          0x0
+#define EMC_INTSTATUS_REFRESH_OVERFLOW         BIT(3)
+#define EMC_INTSTATUS_CLKCHANGE_COMPLETE       BIT(4)
+
+#define EMC_INTMASK                            0x4
+
+#define EMC_DBG                                        0x8
+#define EMC_DBG_READ_MUX_ASSEMBLY              BIT(0)
+#define EMC_DBG_WRITE_MUX_ACTIVE               BIT(1)
+#define EMC_DBG_FORCE_UPDATE                   BIT(2)
+#define EMC_DBG_CFG_PRIORITY                   BIT(24)
+
+#define EMC_CFG                                        0xc
+#define EMC_CFG_DSR_VTTGEN_DRV_EN              BIT(18)
+#define EMC_CFG_PWR_MASK                       ((0xF << 28) | BIT(18))
+#define EMC_CFG_DYN_SREF                       BIT(28)
+#define EMC_CFG_DRAM_ACPD                      BIT(29)
+#define EMC_CFG_DRAM_CLKSTOP_SR                        BIT(30)
+#define EMC_CFG_DRAM_CLKSTOP_PD                        BIT(31)
+
+#define EMC_ADR_CFG                            0x10
+#define EMC_ADR_CFG_EMEM_NUMDEV                        BIT(0)
+
+#define EMC_REFCTRL                            0x20
+#define EMC_REFCTRL_DEV_SEL_SHIFT              0
+#define EMC_REFCTRL_ENABLE                     BIT(31)
+
+#define EMC_TIMING_CONTROL                     0x28
+#define EMC_RC                                 0x2c
+#define EMC_RFC                                        0x30
+#define EMC_RAS                                        0x34
+#define EMC_RP                                 0x38
+#define EMC_R2W                                        0x3c
+#define EMC_W2R                                        0x40
+#define EMC_R2P                                        0x44
+#define EMC_W2P                                        0x48
+#define EMC_RD_RCD                             0x4c
+#define EMC_WR_RCD                             0x50
+#define EMC_RRD                                        0x54
+#define EMC_REXT                               0x58
+#define EMC_WDV                                        0x5c
+#define EMC_QUSE                               0x60
+#define EMC_QRST                               0x64
+#define EMC_QSAFE                              0x68
+#define EMC_RDV                                        0x6c
+#define EMC_REFRESH                            0x70
+#define EMC_BURST_REFRESH_NUM                  0x74
+#define EMC_PDEX2WR                            0x78
+#define EMC_PDEX2RD                            0x7c
+#define EMC_PCHG2PDEN                          0x80
+#define EMC_ACT2PDEN                           0x84
+#define EMC_AR2PDEN                            0x88
+#define EMC_RW2PDEN                            0x8c
+#define EMC_TXSR                               0x90
+#define EMC_TCKE                               0x94
+#define EMC_TFAW                               0x98
+#define EMC_TRPAB                              0x9c
+#define EMC_TCLKSTABLE                         0xa0
+#define EMC_TCLKSTOP                           0xa4
+#define EMC_TREFBW                             0xa8
+#define EMC_QUSE_EXTRA                         0xac
+#define EMC_ODT_WRITE                          0xb0
+#define EMC_ODT_READ                           0xb4
+#define EMC_WEXT                               0xb8
+#define EMC_CTT                                        0xbc
+#define EMC_RFC_SLR                            0xc0
+#define EMC_MRS_WAIT_CNT2                      0xc4
+
+#define EMC_MRS_WAIT_CNT                       0xc8
+#define EMC_MRS_WAIT_CNT_SHORT_WAIT_SHIFT      0
+#define EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK       \
+       (0x3FF << EMC_MRS_WAIT_CNT_SHORT_WAIT_SHIFT)
+#define EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT       16
+#define EMC_MRS_WAIT_CNT_LONG_WAIT_MASK                \
+       (0x3FF << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT)
+
+#define EMC_MRS                                        0xcc
+#define EMC_MODE_SET_DLL_RESET                 BIT(8)
+#define EMC_MODE_SET_LONG_CNT                  BIT(26)
+#define EMC_EMRS                               0xd0
+#define EMC_REF                                        0xd4
+#define EMC_PRE                                        0xd8
+
+#define EMC_SELF_REF                           0xe0
+#define EMC_SELF_REF_CMD_ENABLED               BIT(0)
+#define EMC_SELF_REF_DEV_SEL_SHIFT             30
+
+#define EMC_MRW                                        0xe8
+
+#define EMC_MRR                                        0xec
+#define EMC_MRR_MA_SHIFT                       16
+#define LPDDR2_MR4_TEMP_SHIFT                  0
+
+#define EMC_XM2DQSPADCTRL3                     0xf8
+#define EMC_FBIO_SPARE                         0x100
+
+#define EMC_FBIO_CFG5                          0x104
+#define EMC_FBIO_CFG5_DRAM_TYPE_MASK           0x3
+#define EMC_FBIO_CFG5_DRAM_TYPE_SHIFT          0
+
+#define EMC_FBIO_CFG6                          0x114
+#define EMC_EMRS2                              0x12c
+#define EMC_MRW2                               0x134
+#define EMC_MRW4                               0x13c
+#define EMC_EINPUT                             0x14c
+#define EMC_EINPUT_DURATION                    0x150
+#define EMC_PUTERM_EXTRA                       0x154
+#define EMC_TCKESR                             0x158
+#define EMC_TPD                                        0x15c
+
+#define EMC_AUTO_CAL_CONFIG                    0x2a4
+#define EMC_AUTO_CAL_CONFIG_AUTO_CAL_START     BIT(31)
+#define EMC_AUTO_CAL_INTERVAL                  0x2a8
+#define EMC_AUTO_CAL_STATUS                    0x2ac
+#define EMC_AUTO_CAL_STATUS_ACTIVE             BIT(31)
+#define EMC_STATUS                             0x2b4
+#define EMC_STATUS_TIMING_UPDATE_STALLED       BIT(23)
+
+#define EMC_CFG_2                              0x2b8
+#define EMC_CFG_2_CLKCHANGE_REQ_ENABLE         BIT(0)
+#define EMC_CFG_2_CLKCHANGE_PD_ENABLE          BIT(1)
+#define EMC_CFG_2_CLKCHANGE_SR_ENABLE          BIT(2)
+
+#define EMC_CFG_DIG_DLL                                0x2bc
+#define EMC_CFG_DIG_DLL_PERIOD                 0x2c0
+#define EMC_RDV_MASK                           0x2cc
+#define EMC_WDV_MASK                           0x2d0
+#define EMC_CTT_DURATION                       0x2d8
+#define EMC_CTT_TERM_CTRL                      0x2dc
+#define EMC_ZCAL_INTERVAL                      0x2e0
+#define EMC_ZCAL_WAIT_CNT                      0x2e4
+
+#define EMC_ZQ_CAL                             0x2ec
+#define EMC_ZQ_CAL_CMD                         BIT(0)
+#define EMC_ZQ_CAL_LONG                                BIT(4)
+#define EMC_ZQ_CAL_LONG_CMD_DEV0               \
+       (DRAM_DEV_SEL_0 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
+#define EMC_ZQ_CAL_LONG_CMD_DEV1               \
+       (DRAM_DEV_SEL_1 | EMC_ZQ_CAL_LONG | EMC_ZQ_CAL_CMD)
+
+#define EMC_XM2CMDPADCTRL                      0x2f0
+#define EMC_XM2DQSPADCTRL                      0x2f8
+#define EMC_XM2DQSPADCTRL2                     0x2fc
+#define EMC_XM2DQSPADCTRL2_RX_FT_REC_ENABLE    BIT(0)
+#define EMC_XM2DQSPADCTRL2_VREF_ENABLE         BIT(5)
+#define EMC_XM2DQPADCTRL                       0x300
+#define EMC_XM2DQPADCTRL2                      0x304
+#define EMC_XM2CLKPADCTRL                      0x308
+#define EMC_XM2COMPPADCTRL                     0x30c
+#define EMC_XM2VTTGENPADCTRL                   0x310
+#define EMC_XM2VTTGENPADCTRL2                  0x314
+#define EMC_XM2QUSEPADCTRL                     0x318
+#define EMC_XM2DQSPADCTRL4                     0x320
+#define EMC_DLL_XFORM_DQS0                     0x328
+#define EMC_DLL_XFORM_DQS1                     0x32c
+#define EMC_DLL_XFORM_DQS2                     0x330
+#define EMC_DLL_XFORM_DQS3                     0x334
+#define EMC_DLL_XFORM_DQS4                     0x338
+#define EMC_DLL_XFORM_DQS5                     0x33c
+#define EMC_DLL_XFORM_DQS6                     0x340
+#define EMC_DLL_XFORM_DQS7                     0x344
+#define EMC_DLL_XFORM_QUSE0                    0x348
+#define EMC_DLL_XFORM_QUSE1                    0x34c
+#define EMC_DLL_XFORM_QUSE2                    0x350
+#define EMC_DLL_XFORM_QUSE3                    0x354
+#define EMC_DLL_XFORM_QUSE4                    0x358
+#define EMC_DLL_XFORM_QUSE5                    0x35c
+#define EMC_DLL_XFORM_QUSE6                    0x360
+#define EMC_DLL_XFORM_QUSE7                    0x364
+#define EMC_DLL_XFORM_DQ0                      0x368
+#define EMC_DLL_XFORM_DQ1                      0x36c
+#define EMC_DLL_XFORM_DQ2                      0x370
+#define EMC_DLL_XFORM_DQ3                      0x374
+#define EMC_DLI_TRIM_TXDQS0                    0x3a8
+#define EMC_DLI_TRIM_TXDQS1                    0x3ac
+#define EMC_DLI_TRIM_TXDQS2                    0x3b0
+#define EMC_DLI_TRIM_TXDQS3                    0x3b4
+#define EMC_DLI_TRIM_TXDQS4                    0x3b8
+#define EMC_DLI_TRIM_TXDQS5                    0x3bc
+#define EMC_DLI_TRIM_TXDQS6                    0x3c0
+#define EMC_DLI_TRIM_TXDQS7                    0x3c4
+#define EMC_STALL_THEN_EXE_AFTER_CLKCHANGE     0x3cc
+#define EMC_SEL_DPD_CTRL                       0x3d8
+#define EMC_SEL_DPD_CTRL_DATA_SEL_DPD          BIT(8)
+#define EMC_SEL_DPD_CTRL_ODT_SEL_DPD           BIT(5)
+#define EMC_SEL_DPD_CTRL_RESET_SEL_DPD         BIT(4)
+#define EMC_SEL_DPD_CTRL_CA_SEL_DPD            BIT(3)
+#define EMC_SEL_DPD_CTRL_CLK_SEL_DPD           BIT(2)
+#define EMC_SEL_DPD_CTRL_DDR3_MASK     \
+       ((0xf << 2) | BIT(8))
+#define EMC_SEL_DPD_CTRL_MASK \
+       ((0x3 << 2) | BIT(5) | BIT(8))
+#define EMC_PRE_REFRESH_REQ_CNT                        0x3dc
+#define EMC_DYN_SELF_REF_CONTROL               0x3e0
+#define EMC_TXSRDLL                            0x3e4
+#define EMC_CCFIFO_ADDR                                0x3e8
+#define EMC_CCFIFO_DATA                                0x3ec
+#define EMC_CCFIFO_STATUS                      0x3f0
+#define EMC_CDB_CNTL_1                         0x3f4
+#define EMC_CDB_CNTL_2                         0x3f8
+#define EMC_XM2CLKPADCTRL2                     0x3fc
+#define EMC_AUTO_CAL_CONFIG2                   0x458
+#define EMC_AUTO_CAL_CONFIG3                   0x45c
+#define EMC_IBDLY                              0x468
+#define EMC_DLL_XFORM_ADDR0                    0x46c
+#define EMC_DLL_XFORM_ADDR1                    0x470
+#define EMC_DLL_XFORM_ADDR2                    0x474
+#define EMC_DSR_VTTGEN_DRV                     0x47c
+#define EMC_TXDSRVTTGEN                                0x480
+#define EMC_XM2CMDPADCTRL4                     0x484
+
+#define DRAM_DEV_SEL_ALL                       0
+#define DRAM_DEV_SEL_0                         BIT(31)
+#define DRAM_DEV_SEL_1                         BIT(30)
+
+#define EMC_CFG_POWER_FEATURES_MASK            \
+       (EMC_CFG_DYN_SREF | EMC_CFG_DRAM_ACPD | EMC_CFG_DRAM_CLKSTOP_SR | \
+       EMC_CFG_DRAM_CLKSTOP_PD | EMC_CFG_DSR_VTTGEN_DRV_EN)
+#define EMC_REFCTRL_DEV_SEL(n) ((((n) > 1) ? 0 : 2) << EMC_REFCTRL_DEV_SEL_SHIFT)
+#define EMC_DRAM_DEV_SEL(n) (((n) > 1) ? DRAM_DEV_SEL_ALL : DRAM_DEV_SEL_0)
+
+/* Maximum amount of time in us. to wait for changes to become effective */
+#define EMC_STATUS_UPDATE_TIMEOUT              1000
+
+enum emc_dram_type {
+       DRAM_TYPE_DDR3,
+       DRAM_TYPE_DDR1,
+       DRAM_TYPE_LPDDR2,
+       DRAM_TYPE_DDR2
+};
+
+enum emc_dll_change {
+       DLL_CHANGE_NONE,
+       DLL_CHANGE_ON,
+       DLL_CHANGE_OFF
+};
+
+static const unsigned long emc_burst_regs[] = {
+       EMC_RC,
+       EMC_RFC,
+       EMC_RAS,
+       EMC_RP,
+       EMC_R2W,
+       EMC_W2R,
+       EMC_R2P,
+       EMC_W2P,
+       EMC_RD_RCD,
+       EMC_WR_RCD,
+       EMC_RRD,
+       EMC_REXT,
+       EMC_WEXT,
+       EMC_WDV,
+       EMC_WDV_MASK,
+       EMC_QUSE,
+       EMC_IBDLY,
+       EMC_EINPUT,
+       EMC_EINPUT_DURATION,
+       EMC_PUTERM_EXTRA,
+       EMC_CDB_CNTL_1,
+       EMC_CDB_CNTL_2,
+       EMC_QRST,
+       EMC_QSAFE,
+       EMC_RDV,
+       EMC_RDV_MASK,
+       EMC_REFRESH,
+       EMC_BURST_REFRESH_NUM,
+       EMC_PRE_REFRESH_REQ_CNT,
+       EMC_PDEX2WR,
+       EMC_PDEX2RD,
+       EMC_PCHG2PDEN,
+       EMC_ACT2PDEN,
+       EMC_AR2PDEN,
+       EMC_RW2PDEN,
+       EMC_TXSR,
+       EMC_TXSRDLL,
+       EMC_TCKE,
+       EMC_TCKESR,
+       EMC_TPD,
+       EMC_TFAW,
+       EMC_TRPAB,
+       EMC_TCLKSTABLE,
+       EMC_TCLKSTOP,
+       EMC_TREFBW,
+       EMC_QUSE_EXTRA,
+       EMC_FBIO_CFG6,
+       EMC_ODT_WRITE,
+       EMC_ODT_READ,
+       EMC_FBIO_CFG5,
+       EMC_CFG_DIG_DLL,
+       EMC_CFG_DIG_DLL_PERIOD,
+       EMC_DLL_XFORM_DQS0,
+       EMC_DLL_XFORM_DQS1,
+       EMC_DLL_XFORM_DQS2,
+       EMC_DLL_XFORM_DQS3,
+       EMC_DLL_XFORM_DQS4,
+       EMC_DLL_XFORM_DQS5,
+       EMC_DLL_XFORM_DQS6,
+       EMC_DLL_XFORM_DQS7,
+       EMC_DLL_XFORM_QUSE0,
+       EMC_DLL_XFORM_QUSE1,
+       EMC_DLL_XFORM_QUSE2,
+       EMC_DLL_XFORM_QUSE3,
+       EMC_DLL_XFORM_QUSE4,
+       EMC_DLL_XFORM_QUSE5,
+       EMC_DLL_XFORM_QUSE6,
+       EMC_DLL_XFORM_QUSE7,
+       EMC_DLI_TRIM_TXDQS0,
+       EMC_DLI_TRIM_TXDQS1,
+       EMC_DLI_TRIM_TXDQS2,
+       EMC_DLI_TRIM_TXDQS3,
+       EMC_DLI_TRIM_TXDQS4,
+       EMC_DLI_TRIM_TXDQS5,
+       EMC_DLI_TRIM_TXDQS6,
+       EMC_DLI_TRIM_TXDQS7,
+       EMC_DLL_XFORM_DQ0,
+       EMC_DLL_XFORM_DQ1,
+       EMC_DLL_XFORM_DQ2,
+       EMC_DLL_XFORM_DQ3,
+       EMC_XM2CMDPADCTRL,
+       EMC_XM2CMDPADCTRL4,
+       EMC_XM2DQPADCTRL2,
+       EMC_XM2CLKPADCTRL,
+       EMC_XM2COMPPADCTRL,
+       EMC_XM2VTTGENPADCTRL,
+       EMC_XM2VTTGENPADCTRL2,
+       EMC_XM2DQSPADCTRL3,
+       EMC_XM2DQSPADCTRL4,
+       EMC_DSR_VTTGEN_DRV,
+       EMC_TXDSRVTTGEN,
+       EMC_FBIO_SPARE,
+       EMC_ZCAL_WAIT_CNT,
+       EMC_MRS_WAIT_CNT2,
+       EMC_CTT,
+       EMC_CTT_DURATION,
+       EMC_DYN_SELF_REF_CONTROL,
+};
+
+struct emc_timing {
+       unsigned long rate;
+
+       u32 emc_burst_data[ARRAY_SIZE(emc_burst_regs)];
+
+       u32 emc_auto_cal_config;
+       u32 emc_auto_cal_config2;
+       u32 emc_auto_cal_config3;
+       u32 emc_auto_cal_interval;
+       u32 emc_cfg;
+       u32 emc_ctt_term_ctrl;
+       u32 emc_mode_1;
+       u32 emc_mode_2;
+       u32 emc_mode_4;
+       u32 emc_mode_reset;
+       u32 emc_mrs_wait_cnt;
+       u32 emc_sel_dpd_ctrl;
+       u32 emc_xm2dqspadctrl2;
+       u32 emc_zcal_cnt_long;
+       u32 emc_zcal_interval;
+};
+
+struct tegra_emc {
+       struct device *dev;
+       struct tegra_mc *mc;
+       void __iomem *regs;
+       unsigned int irq;
+       struct clk *clk;
+
+       enum emc_dram_type dram_type;
+       unsigned int dram_num;
+
+       struct emc_timing last_timing;
+       struct emc_timing *timings;
+       unsigned int num_timings;
+
+       struct {
+               struct dentry *root;
+               unsigned long min_rate;
+               unsigned long max_rate;
+       } debugfs;
+
+       struct icc_provider provider;
+       struct tegra_emc_rate_requests reqs;
+};
+
+static irqreturn_t tegra114_emc_isr(int irq, void *data)
+{
+       struct tegra_emc *emc = data;
+       u32 intmask = EMC_INTSTATUS_REFRESH_OVERFLOW;
+       u32 status;
+
+       status = readl_relaxed(emc->regs + EMC_INTSTATUS) & intmask;
+       if (!status)
+               return IRQ_NONE;
+
+       /* notify about HW problem */
+       if (status & EMC_INTSTATUS_REFRESH_OVERFLOW)
+               dev_err_ratelimited(emc->dev,
+                                   "refresh request overflow timeout\n");
+
+       /* clear interrupts */
+       writel_relaxed(status, emc->regs + EMC_INTSTATUS);
+
+       return IRQ_HANDLED;
+}
+
+/* Timing change sequence functions */
+
+static void emc_ccfifo_writel(struct tegra_emc *emc, u32 value,
+                             unsigned long offset)
+{
+       writel(value, emc->regs + EMC_CCFIFO_DATA);
+       writel(offset, emc->regs + EMC_CCFIFO_ADDR);
+}
+
+static void emc_seq_update_timing(struct tegra_emc *emc)
+{
+       int ret;
+       u32 value;
+
+       writel(1, emc->regs + EMC_TIMING_CONTROL);
+
+       ret = readl_poll_timeout_atomic(emc->regs + EMC_STATUS, value,
+                                       !(value & EMC_STATUS_TIMING_UPDATE_STALLED),
+                                       1, EMC_STATUS_UPDATE_TIMEOUT);
+       if (ret)
+               dev_err(emc->dev, "timing update timed out\n");
+}
+
+static void emc_seq_disable_auto_cal(struct tegra_emc *emc)
+{
+       int ret;
+       u32 value;
+
+       writel(0, emc->regs + EMC_AUTO_CAL_INTERVAL);
+
+       ret = readl_poll_timeout_atomic(emc->regs + EMC_AUTO_CAL_STATUS, value,
+                                       !(value & EMC_AUTO_CAL_STATUS_ACTIVE),
+                                       1, EMC_STATUS_UPDATE_TIMEOUT);
+       if (ret)
+               dev_err(emc->dev, "auto cal disable timed out\n");
+}
+
+static void emc_seq_wait_clkchange(struct tegra_emc *emc)
+{
+       int ret;
+       u32 value;
+
+       ret = readl_poll_timeout_atomic(emc->regs + EMC_INTSTATUS, value,
+                                       value & EMC_INTSTATUS_CLKCHANGE_COMPLETE,
+                                       1, EMC_STATUS_UPDATE_TIMEOUT);
+       if (ret)
+               dev_err(emc->dev, "clock change timed out\n");
+}
+
+static struct emc_timing *tegra114_emc_find_timing(struct tegra_emc *emc,
+                                                  unsigned long rate)
+{
+       struct emc_timing *timing = NULL;
+       unsigned int i;
+
+       for (i = 0; i < emc->num_timings; i++) {
+               if (emc->timings[i].rate == rate) {
+                       timing = &emc->timings[i];
+                       break;
+               }
+       }
+
+       if (!timing) {
+               dev_err(emc->dev, "no timing for rate %lu\n", rate);
+               return NULL;
+       }
+
+       return timing;
+}
+
+static int tegra114_emc_prepare_timing_change(struct tegra_emc *emc,
+                                             unsigned long rate)
+{
+       struct emc_timing *timing = tegra114_emc_find_timing(emc, rate);
+       struct emc_timing *last = &emc->last_timing;
+       enum emc_dll_change dll_change;
+       unsigned int pre_wait = 0;
+       u32 val, mask;
+       bool next_dll_enabled = !(timing->emc_mode_1 & 0x1);
+       bool last_dll_enabled = !(last->emc_mode_1 & 0x1);
+       bool update = false;
+       unsigned int i;
+
+       if (!timing)
+               return -ENOENT;
+
+       if (next_dll_enabled == last_dll_enabled)
+               dll_change = DLL_CHANGE_NONE;
+       else if (next_dll_enabled)
+               dll_change = DLL_CHANGE_ON;
+       else
+               dll_change = DLL_CHANGE_OFF;
+
+       /* Clear CLKCHANGE_COMPLETE interrupts */
+       writel(EMC_INTSTATUS_CLKCHANGE_COMPLETE, emc->regs + EMC_INTSTATUS);
+
+       /* Disable dynamic self-refresh */
+       val = readl(emc->regs + EMC_CFG);
+       if (val & EMC_CFG_PWR_MASK) {
+               val &= ~EMC_CFG_POWER_FEATURES_MASK;
+               writel(val, emc->regs + EMC_CFG);
+
+               pre_wait = 5;
+       }
+
+       /* Disable SEL_DPD_CTRL for clock change */
+       if (emc->dram_type == DRAM_TYPE_DDR3)
+               mask = EMC_SEL_DPD_CTRL_DDR3_MASK;
+       else
+               mask = EMC_SEL_DPD_CTRL_MASK;
+
+       val = readl(emc->regs + EMC_SEL_DPD_CTRL);
+       if (val & mask) {
+               val &= ~mask;
+               writel(val, emc->regs + EMC_SEL_DPD_CTRL);
+       }
+
+       /* Prepare DQ/DQS for clock change */
+       val = readl(emc->regs + EMC_XM2DQSPADCTRL2);
+       if (timing->emc_xm2dqspadctrl2 & EMC_XM2DQSPADCTRL2_VREF_ENABLE &&
+           !(val & EMC_XM2DQSPADCTRL2_VREF_ENABLE)) {
+               val |= EMC_XM2DQSPADCTRL2_VREF_ENABLE;
+               update = true;
+       }
+
+       if (timing->emc_xm2dqspadctrl2 & EMC_XM2DQSPADCTRL2_RX_FT_REC_ENABLE &&
+           !(val & EMC_XM2DQSPADCTRL2_RX_FT_REC_ENABLE)) {
+               val |= EMC_XM2DQSPADCTRL2_RX_FT_REC_ENABLE;
+               update = true;
+       }
+
+       if (update) {
+               writel(val, emc->regs + EMC_XM2DQSPADCTRL2);
+               if (pre_wait < 30)
+                       pre_wait = 30;
+       }
+
+       /* Wait to settle */
+       if (pre_wait) {
+               emc_seq_update_timing(emc);
+               udelay(pre_wait);
+       }
+
+       /* Program CTT_TERM control */
+       if (last->emc_ctt_term_ctrl != timing->emc_ctt_term_ctrl) {
+               emc_seq_disable_auto_cal(emc);
+               writel(timing->emc_ctt_term_ctrl,
+                      emc->regs + EMC_CTT_TERM_CTRL);
+               emc_seq_update_timing(emc);
+       }
+
+       /* Program burst shadow registers */
+       for (i = 0; i < ARRAY_SIZE(timing->emc_burst_data); ++i)
+               writel(timing->emc_burst_data[i],
+                      emc->regs + emc_burst_regs[i]);
+
+       writel(timing->emc_xm2dqspadctrl2, emc->regs + EMC_XM2DQSPADCTRL2);
+       writel(timing->emc_zcal_interval, emc->regs + EMC_ZCAL_INTERVAL);
+
+       tegra_mc_write_emem_configuration(emc->mc, timing->rate);
+
+       val = timing->emc_cfg & ~EMC_CFG_POWER_FEATURES_MASK;
+       emc_ccfifo_writel(emc, val, EMC_CFG);
+
+       /* Program AUTO_CAL_CONFIG */
+       if (timing->emc_auto_cal_config2 != last->emc_auto_cal_config2)
+               emc_ccfifo_writel(emc, timing->emc_auto_cal_config2,
+                                 EMC_AUTO_CAL_CONFIG2);
+
+       if (timing->emc_auto_cal_config3 != last->emc_auto_cal_config3)
+               emc_ccfifo_writel(emc, timing->emc_auto_cal_config3,
+                                 EMC_AUTO_CAL_CONFIG3);
+
+       if (timing->emc_auto_cal_config != last->emc_auto_cal_config) {
+               val = timing->emc_auto_cal_config;
+               val &= EMC_AUTO_CAL_CONFIG_AUTO_CAL_START;
+               emc_ccfifo_writel(emc, val, EMC_AUTO_CAL_CONFIG);
+       }
+
+       /* DDR3: predict MRS long wait count */
+       if (emc->dram_type == DRAM_TYPE_DDR3 &&
+           dll_change == DLL_CHANGE_ON) {
+               u32 cnt = 512;
+
+               if (timing->emc_zcal_interval != 0 &&
+                   last->emc_zcal_interval == 0)
+                       cnt -= emc->dram_num * 256;
+
+               val = (timing->emc_mrs_wait_cnt
+                       & EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK)
+                       >> EMC_MRS_WAIT_CNT_SHORT_WAIT_SHIFT;
+               if (cnt < val)
+                       cnt = val;
+
+               val = timing->emc_mrs_wait_cnt
+                       & ~EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
+               val |= (cnt << EMC_MRS_WAIT_CNT_LONG_WAIT_SHIFT)
+                       & EMC_MRS_WAIT_CNT_LONG_WAIT_MASK;
+
+               writel(val, emc->regs + EMC_MRS_WAIT_CNT);
+       }
+
+       /* DDR3: Turn off DLL and enter self-refresh */
+       if (emc->dram_type == DRAM_TYPE_DDR3 && dll_change == DLL_CHANGE_OFF)
+               emc_ccfifo_writel(emc, timing->emc_mode_1, EMC_EMRS);
+
+       /* Disable refresh controller */
+       emc_ccfifo_writel(emc, EMC_REFCTRL_DEV_SEL(emc->dram_num),
+                         EMC_REFCTRL);
+       if (emc->dram_type == DRAM_TYPE_DDR3)
+               emc_ccfifo_writel(emc, EMC_DRAM_DEV_SEL(emc->dram_num) |
+                                      EMC_SELF_REF_CMD_ENABLED,
+                                 EMC_SELF_REF);
+
+       /* Flow control marker */
+       emc_ccfifo_writel(emc, 1, EMC_STALL_THEN_EXE_AFTER_CLKCHANGE);
+
+       /* DDR3: Exit self-refresh */
+       if (emc->dram_type == DRAM_TYPE_DDR3)
+               emc_ccfifo_writel(emc, EMC_DRAM_DEV_SEL(emc->dram_num),
+                                 EMC_SELF_REF);
+       emc_ccfifo_writel(emc, EMC_REFCTRL_DEV_SEL(emc->dram_num) |
+                              EMC_REFCTRL_ENABLE,
+                         EMC_REFCTRL);
+
+       /* Set DRAM mode registers */
+       if (emc->dram_type == DRAM_TYPE_DDR3) {
+               if (timing->emc_mode_1 != last->emc_mode_1)
+                       emc_ccfifo_writel(emc, timing->emc_mode_1, EMC_EMRS);
+               if (timing->emc_mode_2 != last->emc_mode_2)
+                       emc_ccfifo_writel(emc, timing->emc_mode_2, EMC_EMRS2);
+
+               if (timing->emc_mode_reset != last->emc_mode_reset ||
+                   dll_change == DLL_CHANGE_ON) {
+                       val = timing->emc_mode_reset;
+                       if (dll_change == DLL_CHANGE_ON) {
+                               val |= EMC_MODE_SET_DLL_RESET;
+                               val |= EMC_MODE_SET_LONG_CNT;
+                       } else {
+                               val &= ~EMC_MODE_SET_DLL_RESET;
+                       }
+                       emc_ccfifo_writel(emc, val, EMC_MRS);
+               }
+       } else {
+               if (timing->emc_mode_2 != last->emc_mode_2)
+                       emc_ccfifo_writel(emc, timing->emc_mode_2, EMC_MRW2);
+               if (timing->emc_mode_1 != last->emc_mode_1)
+                       emc_ccfifo_writel(emc, timing->emc_mode_1, EMC_MRW);
+               if (timing->emc_mode_4 != last->emc_mode_4)
+                       emc_ccfifo_writel(emc, timing->emc_mode_4, EMC_MRW4);
+       }
+
+       /*  Issue ZCAL command if turning ZCAL on */
+       if (timing->emc_zcal_interval != 0 && last->emc_zcal_interval == 0) {
+               emc_ccfifo_writel(emc, EMC_ZQ_CAL_LONG_CMD_DEV0, EMC_ZQ_CAL);
+               if (emc->dram_num > 1)
+                       emc_ccfifo_writel(emc, EMC_ZQ_CAL_LONG_CMD_DEV1,
+                                         EMC_ZQ_CAL);
+       }
+
+       /*  Write to RO register to remove stall after change */
+       emc_ccfifo_writel(emc, 0, EMC_CCFIFO_STATUS);
+
+       /* Disable AUTO_CAL for clock change */
+       emc_seq_disable_auto_cal(emc);
+
+       /* Read register to wait until programming has settled */
+       mc_readl(emc->mc, MC_EMEM_ADR_CFG);
+
+       return 0;
+}
+
+static void tegra114_emc_complete_timing_change(struct tegra_emc *emc,
+                                               unsigned long rate)
+{
+       struct emc_timing *timing = tegra114_emc_find_timing(emc, rate);
+       struct emc_timing *last = &emc->last_timing;
+
+       if (!timing)
+               return;
+
+       /* Wait until the state machine has settled */
+       emc_seq_wait_clkchange(emc);
+
+       /* Restore AUTO_CAL */
+       if (timing->emc_ctt_term_ctrl != last->emc_ctt_term_ctrl)
+               writel(timing->emc_auto_cal_interval,
+                      emc->regs + EMC_AUTO_CAL_INTERVAL);
+
+       /* Restore dynamic self-refresh */
+       if (timing->emc_cfg & EMC_CFG_PWR_MASK)
+               writel(timing->emc_cfg, emc->regs + EMC_CFG);
+
+       /* Set ZCAL wait count */
+       writel(timing->emc_zcal_cnt_long, emc->regs + EMC_ZCAL_WAIT_CNT);
+
+       /* Wait for timing to settle */
+       udelay(2);
+
+       /* Reprogram SEL_DPD_CTRL */
+       writel(timing->emc_sel_dpd_ctrl, emc->regs + EMC_SEL_DPD_CTRL);
+       emc_seq_update_timing(emc);
+
+       emc->last_timing = *timing;
+}
+
+/* Initialization and deinitialization */
+
+static void emc_read_current_timing(struct tegra_emc *emc,
+                                   struct emc_timing *timing)
+{
+       unsigned int i;
+
+       for (i = 0; i < ARRAY_SIZE(emc_burst_regs); ++i)
+               timing->emc_burst_data[i] =
+                       readl(emc->regs + emc_burst_regs[i]);
+
+       timing->emc_cfg = readl(emc->regs + EMC_CFG);
+
+       timing->emc_auto_cal_interval = 0;
+       timing->emc_zcal_cnt_long = 0;
+       timing->emc_mode_1 = 0;
+       timing->emc_mode_2 = 0;
+       timing->emc_mode_4 = 0;
+       timing->emc_mode_reset = 0;
+}
+
+static void emc_init(struct tegra_emc *emc)
+{
+       u32 emc_cfg, emc_dbg;
+       u32 intmask = EMC_INTSTATUS_REFRESH_OVERFLOW;
+       const char *dram_type_str;
+
+       emc->dram_type = readl(emc->regs + EMC_FBIO_CFG5);
+
+       emc->dram_type &= EMC_FBIO_CFG5_DRAM_TYPE_MASK;
+       emc->dram_type >>= EMC_FBIO_CFG5_DRAM_TYPE_SHIFT;
+
+       emc->dram_num = tegra_mc_get_emem_device_count(emc->mc);
+
+       emc_cfg = readl_relaxed(emc->regs + EMC_CFG_2);
+
+       /* enable EMC and CAR to handshake on PLL divider/source changes */
+       emc_cfg |= EMC_CFG_2_CLKCHANGE_REQ_ENABLE;
+
+       /* configure clock change mode accordingly to DRAM type */
+       if (emc->dram_type == DRAM_TYPE_LPDDR2)
+               emc_cfg |= EMC_CFG_2_CLKCHANGE_PD_ENABLE;
+       else
+               emc_cfg &= ~EMC_CFG_2_CLKCHANGE_PD_ENABLE;
+
+       writel_relaxed(emc_cfg, emc->regs + EMC_CFG_2);
+
+       /* initialize interrupt */
+       writel_relaxed(intmask, emc->regs + EMC_INTMASK);
+       writel_relaxed(0xffffffff, emc->regs + EMC_INTSTATUS);
+
+       /* ensure that unwanted debug features are disabled */
+       emc_dbg = readl_relaxed(emc->regs + EMC_DBG);
+       emc_dbg |= EMC_DBG_CFG_PRIORITY;
+       emc_dbg &= ~EMC_DBG_READ_MUX_ASSEMBLY;
+       emc_dbg &= ~EMC_DBG_WRITE_MUX_ACTIVE;
+       emc_dbg &= ~EMC_DBG_FORCE_UPDATE;
+       writel_relaxed(emc_dbg, emc->regs + EMC_DBG);
+
+       switch (emc->dram_type) {
+       case DRAM_TYPE_DDR1:
+               dram_type_str = "DDR1";
+               break;
+       case DRAM_TYPE_LPDDR2:
+               dram_type_str = "LPDDR2";
+               break;
+       case DRAM_TYPE_DDR2:
+               dram_type_str = "DDR2";
+               break;
+       case DRAM_TYPE_DDR3:
+               dram_type_str = "DDR3";
+               break;
+       }
+
+       dev_info_once(emc->dev, "%u %s %s attached\n", emc->dram_num,
+                     dram_type_str, emc->dram_num == 2 ? "devices" : "device");
+
+       emc_read_current_timing(emc, &emc->last_timing);
+}
+
+static int load_one_timing_from_dt(struct tegra_emc *emc,
+                                  struct emc_timing *timing,
+                                  struct device_node *node)
+{
+       u32 value;
+       int err;
+
+       err = of_property_read_u32(node, "clock-frequency", &value);
+       if (err) {
+               dev_err(emc->dev, "timing %pOFn: failed to read rate: %d\n",
+                       node, err);
+               return err;
+       }
+
+       timing->rate = value;
+
+       err = of_property_read_u32_array(node, "nvidia,emc-configuration",
+                                        timing->emc_burst_data,
+                                        ARRAY_SIZE(timing->emc_burst_data));
+       if (err) {
+               dev_err(emc->dev,
+                       "timing %pOFn: failed to read emc burst data: %d\n",
+                       node, err);
+               return err;
+       }
+
+#define EMC_READ_PROP(prop, dtprop) { \
+       err = of_property_read_u32(node, dtprop, &timing->prop); \
+       if (err) { \
+               dev_err(emc->dev, "timing %pOFn: failed to read " #prop ": %d\n", \
+                       node, err); \
+               return err; \
+       } \
+}
+
+       EMC_READ_PROP(emc_auto_cal_config, "nvidia,emc-auto-cal-config")
+       EMC_READ_PROP(emc_auto_cal_config2, "nvidia,emc-auto-cal-config2")
+       EMC_READ_PROP(emc_auto_cal_config3, "nvidia,emc-auto-cal-config3")
+       EMC_READ_PROP(emc_auto_cal_interval, "nvidia,emc-auto-cal-interval")
+       EMC_READ_PROP(emc_cfg, "nvidia,emc-cfg")
+       EMC_READ_PROP(emc_ctt_term_ctrl, "nvidia,emc-ctt-term-ctrl")
+       EMC_READ_PROP(emc_mode_1, "nvidia,emc-mode-1")
+       EMC_READ_PROP(emc_mode_2, "nvidia,emc-mode-2")
+       EMC_READ_PROP(emc_mode_4, "nvidia,emc-mode-4")
+       EMC_READ_PROP(emc_mode_reset, "nvidia,emc-mode-reset")
+       EMC_READ_PROP(emc_mrs_wait_cnt, "nvidia,emc-mrs-wait-cnt")
+       EMC_READ_PROP(emc_sel_dpd_ctrl, "nvidia,emc-sel-dpd-ctrl")
+       EMC_READ_PROP(emc_xm2dqspadctrl2, "nvidia,emc-xm2dqspadctrl2")
+       EMC_READ_PROP(emc_zcal_cnt_long, "nvidia,emc-zcal-cnt-long")
+       EMC_READ_PROP(emc_zcal_interval, "nvidia,emc-zcal-interval")
+
+#undef EMC_READ_PROP
+
+       return 0;
+}
+
+static int cmp_timings(const void *_a, const void *_b)
+{
+       const struct emc_timing *a = _a;
+       const struct emc_timing *b = _b;
+
+       if (a->rate < b->rate)
+               return -1;
+       else if (a->rate == b->rate)
+               return 0;
+       else
+               return 1;
+}
+
+static int emc_check_mc_timings(struct tegra_emc *emc)
+{
+       struct tegra_mc *mc = emc->mc;
+       unsigned int i;
+
+       if (emc->num_timings != mc->num_timings) {
+               dev_err(emc->dev, "emc/mc timings number mismatch: %u %u\n",
+                       emc->num_timings, mc->num_timings);
+               return -EINVAL;
+       }
+
+       for (i = 0; i < mc->num_timings; i++) {
+               if (emc->timings[i].rate != mc->timings[i].rate) {
+                       dev_err(emc->dev,
+                               "emc/mc timing rate mismatch: %lu %lu\n",
+                               emc->timings[i].rate, mc->timings[i].rate);
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+
+static int tegra114_emc_load_timings_from_dt(struct tegra_emc *emc,
+                                            struct device_node *node)
+{
+       int child_count = of_get_child_count(node);
+       struct emc_timing *timing;
+       unsigned int i = 0;
+       int err;
+
+       emc->timings = devm_kcalloc(emc->dev, child_count, sizeof(*timing),
+                                   GFP_KERNEL);
+       if (!emc->timings)
+               return -ENOMEM;
+
+       emc->num_timings = child_count;
+
+       for_each_child_of_node_scoped(node, child) {
+               timing = &emc->timings[i++];
+
+               err = load_one_timing_from_dt(emc, timing, child);
+               if (err)
+                       return err;
+       }
+
+       sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings,
+            NULL);
+
+       err = emc_check_mc_timings(emc);
+       if (err)
+               return err;
+
+       dev_info_once(emc->dev,
+                     "got %u timings for RAM code %u (min %luMHz max %luMHz)\n",
+                     emc->num_timings,
+                     tegra_read_ram_code(),
+                     emc->timings[0].rate / 1000000,
+                     emc->timings[emc->num_timings - 1].rate / 1000000);
+
+       return 0;
+}
+
+static struct device_node *
+tegra114_emc_find_node_by_ram_code(struct device_node *node, u32 ram_code)
+{
+       struct device_node *np;
+       int err;
+
+       for_each_child_of_node(node, np) {
+               u32 value;
+
+               err = of_property_read_u32(np, "nvidia,ram-code", &value);
+               if (err || value != ram_code)
+                       continue;
+
+               return np;
+       }
+
+       return NULL;
+}
+
+/*
+ * debugfs interface
+ *
+ * The memory controller driver exposes some files in debugfs that can be used
+ * to control the EMC frequency. The top-level directory can be found here:
+ *
+ *   /sys/kernel/debug/emc
+ *
+ * It contains the following files:
+ *
+ *   - available_rates: This file contains a list of valid, space-separated
+ *     EMC frequencies.
+ *
+ *   - min_rate: Writing a value to this file sets the given frequency as the
+ *       floor of the permitted range. If this is higher than the currently
+ *       configured EMC frequency, this will cause the frequency to be
+ *       increased so that it stays within the valid range.
+ *
+ *   - max_rate: Similarly to the min_rate file, writing a value to this file
+ *       sets the given frequency as the ceiling of the permitted range. If
+ *       the value is lower than the currently configured EMC frequency, this
+ *       will cause the frequency to be decreased so that it stays within the
+ *       valid range.
+ */
+
+static bool tegra114_emc_validate_rate(struct tegra_emc *emc, unsigned long rate)
+{
+       unsigned int i;
+
+       for (i = 0; i < emc->num_timings; i++)
+               if (rate == emc->timings[i].rate)
+                       return true;
+
+       return false;
+}
+
+static int tegra114_emc_debug_available_rates_show(struct seq_file *s,
+                                                  void *data)
+{
+       struct tegra_emc *emc = s->private;
+       const char *prefix = "";
+       unsigned int i;
+
+       for (i = 0; i < emc->num_timings; i++) {
+               seq_printf(s, "%s%lu", prefix, emc->timings[i].rate);
+               prefix = " ";
+       }
+
+       seq_puts(s, "\n");
+
+       return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(tegra114_emc_debug_available_rates);
+
+static int tegra114_emc_debug_min_rate_get(void *data, u64 *rate)
+{
+       struct tegra_emc *emc = data;
+
+       *rate = emc->debugfs.min_rate;
+
+       return 0;
+}
+
+static int tegra114_emc_debug_min_rate_set(void *data, u64 rate)
+{
+       struct tegra_emc *emc = data;
+       int err;
+
+       if (!tegra114_emc_validate_rate(emc, rate))
+               return -EINVAL;
+
+       err = tegra_emc_set_min_rate(&emc->reqs, rate, TEGRA_EMC_RATE_DEBUG);
+       if (err < 0)
+               return err;
+
+       emc->debugfs.min_rate = rate;
+
+       return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(tegra114_emc_debug_min_rate_fops,
+                        tegra114_emc_debug_min_rate_get,
+                        tegra114_emc_debug_min_rate_set, "%llu\n");
+
+static int tegra114_emc_debug_max_rate_get(void *data, u64 *rate)
+{
+       struct tegra_emc *emc = data;
+
+       *rate = emc->debugfs.max_rate;
+
+       return 0;
+}
+
+static int tegra114_emc_debug_max_rate_set(void *data, u64 rate)
+{
+       struct tegra_emc *emc = data;
+       int err;
+
+       if (!tegra114_emc_validate_rate(emc, rate))
+               return -EINVAL;
+
+       err = tegra_emc_set_max_rate(&emc->reqs, rate, TEGRA_EMC_RATE_DEBUG);
+       if (err < 0)
+               return err;
+
+       emc->debugfs.max_rate = rate;
+
+       return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(tegra114_emc_debug_max_rate_fops,
+                        tegra114_emc_debug_max_rate_get,
+                        tegra114_emc_debug_max_rate_set, "%llu\n");
+
+static void emc_debugfs_init(struct device *dev, struct tegra_emc *emc)
+{
+       unsigned int i;
+       int err;
+
+       emc->debugfs.min_rate = ULONG_MAX;
+       emc->debugfs.max_rate = 0;
+
+       for (i = 0; i < emc->num_timings; i++) {
+               if (emc->timings[i].rate < emc->debugfs.min_rate)
+                       emc->debugfs.min_rate = emc->timings[i].rate;
+
+               if (emc->timings[i].rate > emc->debugfs.max_rate)
+                       emc->debugfs.max_rate = emc->timings[i].rate;
+       }
+
+       if (!emc->num_timings) {
+               emc->debugfs.min_rate = clk_get_rate(emc->clk);
+               emc->debugfs.max_rate = emc->debugfs.min_rate;
+       }
+
+       err = clk_set_rate_range(emc->clk, emc->debugfs.min_rate,
+                                emc->debugfs.max_rate);
+       if (err < 0) {
+               dev_err(dev, "failed to set rate range [%lu-%lu] for %pC\n",
+                       emc->debugfs.min_rate, emc->debugfs.max_rate,
+                       emc->clk);
+               return;
+       }
+
+       emc->debugfs.root = debugfs_create_dir("emc", NULL);
+
+       debugfs_create_file("available_rates", 0444, emc->debugfs.root, emc,
+                           &tegra114_emc_debug_available_rates_fops);
+       debugfs_create_file("min_rate", 0644, emc->debugfs.root,
+                           emc, &tegra114_emc_debug_min_rate_fops);
+       debugfs_create_file("max_rate", 0644, emc->debugfs.root,
+                           emc, &tegra114_emc_debug_max_rate_fops);
+}
+
+static inline struct tegra_emc *
+to_tegra_emc_provider(struct icc_provider *provider)
+{
+       return container_of(provider, struct tegra_emc, provider);
+}
+
+static struct icc_node_data *
+emc_of_icc_xlate_extended(const struct of_phandle_args *spec, void *data)
+{
+       struct icc_provider *provider = data;
+       struct icc_node_data *ndata;
+       struct icc_node *node;
+
+       /* External Memory is the only possible ICC route */
+       list_for_each_entry(node, &provider->nodes, node_list) {
+               if (node->id != TEGRA_ICC_EMEM)
+                       continue;
+
+               ndata = kzalloc_obj(*ndata);
+               if (!ndata)
+                       return ERR_PTR(-ENOMEM);
+
+               /*
+                * SRC and DST nodes should have matching TAG in order to have
+                * it set by default for a requested path.
+                */
+               ndata->tag = TEGRA_MC_ICC_TAG_ISO;
+               ndata->node = node;
+
+               return ndata;
+       }
+
+       return ERR_PTR(-EPROBE_DEFER);
+}
+
+static int emc_icc_set(struct icc_node *src, struct icc_node *dst)
+{
+       struct tegra_emc *emc = to_tegra_emc_provider(dst->provider);
+       unsigned long long peak_bw = icc_units_to_bps(dst->peak_bw);
+       unsigned long long avg_bw = icc_units_to_bps(dst->avg_bw);
+       unsigned long long rate = max(avg_bw, peak_bw);
+       unsigned int dram_data_bus_width_bytes = 4;
+       const unsigned int ddr = 2;
+       int err;
+
+       /*
+        * Tegra114 EMC runs on a clock rate of SDRAM bus. This means that
+        * EMC clock rate is twice smaller than the peak data rate because
+        * data is sampled on both EMC clock edges.
+        */
+       do_div(rate, ddr * dram_data_bus_width_bytes);
+       rate = min_t(u64, rate, U32_MAX);
+
+       err = tegra_emc_set_min_rate(&emc->reqs, rate, TEGRA_EMC_RATE_ICC);
+       if (err)
+               return err;
+
+       return 0;
+}
+
+static int tegra114_emc_interconnect_init(struct tegra_emc *emc)
+{
+       const struct tegra_mc_soc *soc = emc->mc->soc;
+       struct icc_node *node;
+       int err;
+
+       emc->provider.dev = emc->dev;
+       emc->provider.set = emc_icc_set;
+       emc->provider.data = &emc->provider;
+       emc->provider.aggregate = soc->icc_ops->aggregate;
+       emc->provider.xlate_extended = emc_of_icc_xlate_extended;
+
+       icc_provider_init(&emc->provider);
+
+       /* create External Memory Controller node */
+       node = icc_node_create(TEGRA_ICC_EMC);
+       if (IS_ERR(node)) {
+               err = PTR_ERR(node);
+               goto err_msg;
+       }
+
+       node->name = "External Memory Controller";
+       icc_node_add(node, &emc->provider);
+
+       /* link External Memory Controller to External Memory (DRAM) */
+       err = icc_link_create(node, TEGRA_ICC_EMEM);
+       if (err)
+               goto remove_nodes;
+
+       /* create External Memory node */
+       node = icc_node_create(TEGRA_ICC_EMEM);
+       if (IS_ERR(node)) {
+               err = PTR_ERR(node);
+               goto remove_nodes;
+       }
+
+       node->name = "External Memory (DRAM)";
+       icc_node_add(node, &emc->provider);
+
+       err = icc_provider_register(&emc->provider);
+       if (err)
+               goto remove_nodes;
+
+       return 0;
+
+remove_nodes:
+       icc_nodes_remove(&emc->provider);
+err_msg:
+       dev_err(emc->dev, "failed to initialize ICC: %d\n", err);
+
+       return err;
+}
+
+static void devm_tegra114_emc_unset_callback(void *data)
+{
+       tegra124_clk_set_emc_callbacks(NULL, NULL);
+}
+
+static int tegra114_emc_probe(struct platform_device *pdev)
+{
+       struct tegra_core_opp_params opp_params = {};
+       struct device *dev = &pdev->dev;
+       struct device_node *np;
+       struct tegra_emc *emc;
+       u32 ram_code;
+       int err;
+
+       emc = devm_kzalloc(dev, sizeof(*emc), GFP_KERNEL);
+       if (!emc)
+               return -ENOMEM;
+
+       emc->dev = dev;
+
+       emc->regs = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(emc->regs))
+               return PTR_ERR(emc->regs);
+
+       emc->mc = devm_tegra_memory_controller_get(dev);
+       if (IS_ERR(emc->mc))
+               return PTR_ERR(emc->mc);
+
+       ram_code = tegra_read_ram_code();
+
+       np = tegra114_emc_find_node_by_ram_code(dev->of_node, ram_code);
+       if (np) {
+               err = tegra114_emc_load_timings_from_dt(emc, np);
+               of_node_put(np);
+               if (err)
+                       return err;
+       } else {
+               dev_info_once(dev, "no memory timings for RAM code %u found in DT\n",
+                             ram_code);
+       }
+
+       emc_init(emc);
+
+       platform_set_drvdata(pdev, emc);
+
+       tegra124_clk_set_emc_callbacks(tegra114_emc_prepare_timing_change,
+                                      tegra114_emc_complete_timing_change);
+
+       err = devm_add_action_or_reset(dev, devm_tegra114_emc_unset_callback,
+                                      NULL);
+       if (err)
+               return err;
+
+       err = platform_get_irq(pdev, 0);
+       if (err < 0)
+               return err;
+
+       emc->irq = err;
+
+       err = devm_request_irq(dev, emc->irq, tegra114_emc_isr, 0,
+                              dev_name(dev), emc);
+       if (err)
+               return dev_err_probe(dev, err, "failed to request irq\n");
+
+       emc->clk = devm_clk_get(dev, "emc");
+       if (IS_ERR(emc->clk))
+               return dev_err_probe(dev, PTR_ERR(emc->clk),
+                                    "failed to get EMC clock\n");
+
+       opp_params.init_state = true;
+
+       err = devm_tegra_core_dev_init_opp_table(dev, &opp_params);
+       if (err)
+               return err;
+
+       tegra_emc_rate_requests_init(&emc->reqs, dev);
+
+       if (IS_ENABLED(CONFIG_DEBUG_FS))
+               emc_debugfs_init(dev, emc);
+
+       tegra114_emc_interconnect_init(emc);
+
+       /*
+        * Don't allow the kernel module to be unloaded. Unloading adds some
+        * extra complexity which doesn't really worth the effort in a case of
+        * this driver.
+        */
+       try_module_get(THIS_MODULE);
+
+       return 0;
+};
+
+static const struct of_device_id tegra114_emc_of_match[] = {
+       { .compatible = "nvidia,tegra114-emc" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, tegra114_emc_of_match);
+
+static struct platform_driver tegra114_emc_driver = {
+       .probe = tegra114_emc_probe,
+       .driver = {
+               .name = "tegra114-emc",
+               .of_match_table = tegra114_emc_of_match,
+               .suppress_bind_attrs = true,
+               .sync_state = icc_sync_state,
+       },
+};
+module_platform_driver(tegra114_emc_driver);
+
+MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra114 EMC driver");
+MODULE_LICENSE("GPL");