// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
 *
 * Author:
 *      Mikko Perttunen <mperttunen@nvidia.com>
 */

#include <linux/clk-provider.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clk/tegra.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/interconnect-provider.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/sort.h>
#include <linux/string.h>

#include <soc/tegra/fuse.h>
#include <soc/tegra/mc.h>

#include "mc.h"

#define EMC_FBIO_CFG5                           0x104
#define EMC_FBIO_CFG5_DRAM_TYPE_MASK            0x3
#define EMC_FBIO_CFG5_DRAM_TYPE_SHIFT           0
#define EMC_FBIO_CFG5_DRAM_WIDTH_X64            BIT(4)

#define EMC_INTSTATUS                           0x0
#define EMC_INTSTATUS_CLKCHANGE_COMPLETE        BIT(4)

#define EMC_CFG                                 0xc
#define EMC_CFG_DRAM_CLKSTOP_PD                 BIT(31)
#define EMC_CFG_DRAM_CLKSTOP_SR                 BIT(30)
#define EMC_CFG_DRAM_ACPD                       BIT(29)
#define EMC_CFG_DYN_SREF                        BIT(28)
#define EMC_CFG_PWR_MASK                        ((0xF << 28) | BIT(18))
#define EMC_CFG_DSR_VTTGEN_DRV_EN               BIT(18)

#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_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_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_MODE_SHIFT                    0
#define EMC_CFG_2_DIS_STP_OB_CLK_DURING_NON_WR  BIT(6)

#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_XM2VTTGENPADCTRL3                   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 EMC_XM2CMDPADCTRL5                      0x488
#define EMC_DLL_XFORM_DQS8                      0x4a0
#define EMC_DLL_XFORM_DQS9                      0x4a4
#define EMC_DLL_XFORM_DQS10                     0x4a8
#define EMC_DLL_XFORM_DQS11                     0x4ac
#define EMC_DLL_XFORM_DQS12                     0x4b0
#define EMC_DLL_XFORM_DQS13                     0x4b4
#define EMC_DLL_XFORM_DQS14                     0x4b8
#define EMC_DLL_XFORM_DQS15                     0x4bc
#define EMC_DLL_XFORM_QUSE8                     0x4c0
#define EMC_DLL_XFORM_QUSE9                     0x4c4
#define EMC_DLL_XFORM_QUSE10                    0x4c8
#define EMC_DLL_XFORM_QUSE11                    0x4cc
#define EMC_DLL_XFORM_QUSE12                    0x4d0
#define EMC_DLL_XFORM_QUSE13                    0x4d4
#define EMC_DLL_XFORM_QUSE14                    0x4d8
#define EMC_DLL_XFORM_QUSE15                    0x4dc
#define EMC_DLL_XFORM_DQ4                       0x4e0
#define EMC_DLL_XFORM_DQ5                       0x4e4
#define EMC_DLL_XFORM_DQ6                       0x4e8
#define EMC_DLL_XFORM_DQ7                       0x4ec
#define EMC_DLI_TRIM_TXDQS8                     0x520
#define EMC_DLI_TRIM_TXDQS9                     0x524
#define EMC_DLI_TRIM_TXDQS10                    0x528
#define EMC_DLI_TRIM_TXDQS11                    0x52c
#define EMC_DLI_TRIM_TXDQS12                    0x530
#define EMC_DLI_TRIM_TXDQS13                    0x534
#define EMC_DLI_TRIM_TXDQS14                    0x538
#define EMC_DLI_TRIM_TXDQS15                    0x53c
#define EMC_CDB_CNTL_3                          0x540
#define EMC_XM2DQSPADCTRL5                      0x544
#define EMC_XM2DQSPADCTRL6                      0x548
#define EMC_XM2DQPADCTRL3                       0x54c
#define EMC_DLL_XFORM_ADDR3                     0x550
#define EMC_DLL_XFORM_ADDR4                     0x554
#define EMC_DLL_XFORM_ADDR5                     0x558
#define EMC_CFG_PIPE                            0x560
#define EMC_QPOP                                0x564
#define EMC_QUSE_WIDTH                          0x568
#define EMC_PUTERM_WIDTH                        0x56c
#define EMC_BGBIAS_CTL0                         0x570
#define EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX BIT(3)
#define EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_VTTGEN BIT(2)
#define EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD        BIT(1)
#define EMC_PUTERM_ADJ                          0x574

#define DRAM_DEV_SEL_ALL                        0
#define DRAM_DEV_SEL_0                          (2 << 30)
#define DRAM_DEV_SEL_1                          (1 << 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 = 0,
        DRAM_TYPE_DDR1 = 1,
        DRAM_TYPE_LPDDR3 = 2,
        DRAM_TYPE_DDR2 = 3
};

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_RFC_SLR,
        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_QUSE_WIDTH,
        EMC_IBDLY,
        EMC_EINPUT,
        EMC_EINPUT_DURATION,
        EMC_PUTERM_EXTRA,
        EMC_PUTERM_WIDTH,
        EMC_PUTERM_ADJ,
        EMC_CDB_CNTL_1,
        EMC_CDB_CNTL_2,
        EMC_CDB_CNTL_3,
        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_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_DQS8,
        EMC_DLL_XFORM_DQS9,
        EMC_DLL_XFORM_DQS10,
        EMC_DLL_XFORM_DQS11,
        EMC_DLL_XFORM_DQS12,
        EMC_DLL_XFORM_DQS13,
        EMC_DLL_XFORM_DQS14,
        EMC_DLL_XFORM_DQS15,
        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_DLL_XFORM_ADDR0,
        EMC_DLL_XFORM_ADDR1,
        EMC_DLL_XFORM_ADDR2,
        EMC_DLL_XFORM_ADDR3,
        EMC_DLL_XFORM_ADDR4,
        EMC_DLL_XFORM_ADDR5,
        EMC_DLL_XFORM_QUSE8,
        EMC_DLL_XFORM_QUSE9,
        EMC_DLL_XFORM_QUSE10,
        EMC_DLL_XFORM_QUSE11,
        EMC_DLL_XFORM_QUSE12,
        EMC_DLL_XFORM_QUSE13,
        EMC_DLL_XFORM_QUSE14,
        EMC_DLL_XFORM_QUSE15,
        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_DLI_TRIM_TXDQS8,
        EMC_DLI_TRIM_TXDQS9,
        EMC_DLI_TRIM_TXDQS10,
        EMC_DLI_TRIM_TXDQS11,
        EMC_DLI_TRIM_TXDQS12,
        EMC_DLI_TRIM_TXDQS13,
        EMC_DLI_TRIM_TXDQS14,
        EMC_DLI_TRIM_TXDQS15,
        EMC_DLL_XFORM_DQ0,
        EMC_DLL_XFORM_DQ1,
        EMC_DLL_XFORM_DQ2,
        EMC_DLL_XFORM_DQ3,
        EMC_DLL_XFORM_DQ4,
        EMC_DLL_XFORM_DQ5,
        EMC_DLL_XFORM_DQ6,
        EMC_DLL_XFORM_DQ7,
        EMC_XM2CMDPADCTRL,
        EMC_XM2CMDPADCTRL4,
        EMC_XM2CMDPADCTRL5,
        EMC_XM2DQPADCTRL2,
        EMC_XM2DQPADCTRL3,
        EMC_XM2CLKPADCTRL,
        EMC_XM2CLKPADCTRL2,
        EMC_XM2COMPPADCTRL,
        EMC_XM2VTTGENPADCTRL,
        EMC_XM2VTTGENPADCTRL2,
        EMC_XM2VTTGENPADCTRL3,
        EMC_XM2DQSPADCTRL3,
        EMC_XM2DQSPADCTRL4,
        EMC_XM2DQSPADCTRL5,
        EMC_XM2DQSPADCTRL6,
        EMC_DSR_VTTGEN_DRV,
        EMC_TXDSRVTTGEN,
        EMC_FBIO_SPARE,
        EMC_ZCAL_WAIT_CNT,
        EMC_MRS_WAIT_CNT2,
        EMC_CTT,
        EMC_CTT_DURATION,
        EMC_CFG_PIPE,
        EMC_DYN_SELF_REF_CONTROL,
        EMC_QPOP
};

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_bgbias_ctl0;
        u32 emc_cfg;
        u32 emc_cfg_2;
        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;
};

enum emc_rate_request_type {
        EMC_RATE_DEBUG,
        EMC_RATE_ICC,
        EMC_RATE_TYPE_MAX,
};

struct emc_rate_request {
        unsigned long min_rate;
        unsigned long max_rate;
};

struct tegra_emc {
        struct device *dev;

        struct tegra_mc *mc;

        void __iomem *regs;

        struct clk *clk;

        enum emc_dram_type dram_type;
        unsigned int dram_bus_width;
        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;

        /*
         * There are multiple sources in the EMC driver which could request
         * a min/max clock rate, these rates are contained in this array.
         */
        struct emc_rate_request requested_rate[EMC_RATE_TYPE_MAX];

        /* protect shared rate-change code path */
        struct mutex rate_lock;
};

/* 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)
{
        unsigned int i;
        u32 value;

        writel(1, emc->regs + EMC_TIMING_CONTROL);

        for (i = 0; i < EMC_STATUS_UPDATE_TIMEOUT; ++i) {
                value = readl(emc->regs + EMC_STATUS);
                if ((value & EMC_STATUS_TIMING_UPDATE_STALLED) == 0)
                        return;
                udelay(1);
        }

        dev_err(emc->dev, "timing update timed out\n");
}

static void emc_seq_disable_auto_cal(struct tegra_emc *emc)
{
        unsigned int i;
        u32 value;

        writel(0, emc->regs + EMC_AUTO_CAL_INTERVAL);

        for (i = 0; i < EMC_STATUS_UPDATE_TIMEOUT; ++i) {
                value = readl(emc->regs + EMC_AUTO_CAL_STATUS);
                if ((value & EMC_AUTO_CAL_STATUS_ACTIVE) == 0)
                        return;
                udelay(1);
        }

        dev_err(emc->dev, "auto cal disable timed out\n");
}

static void emc_seq_wait_clkchange(struct tegra_emc *emc)
{
        unsigned int i;
        u32 value;

        for (i = 0; i < EMC_STATUS_UPDATE_TIMEOUT; ++i) {
                value = readl(emc->regs + EMC_INTSTATUS);
                if (value & EMC_INTSTATUS_CLKCHANGE_COMPLETE)
                        return;
                udelay(1);
        }

        dev_err(emc->dev, "clock change timed out\n");
}

static struct emc_timing *tegra_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 tegra_emc_prepare_timing_change(struct tegra_emc *emc,
                                           unsigned long rate)
{
        struct emc_timing *timing = tegra_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, val2, mask;
        bool update = false;
        unsigned int i;

        if (!timing)
                return -ENOENT;

        if ((last->emc_mode_1 & 0x1) == (timing->emc_mode_1 & 0x1))
                dll_change = DLL_CHANGE_NONE;
        else if (timing->emc_mode_1 & 0x1)
                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_BGBIAS_CTL0);
        val2 = last->emc_bgbias_ctl0;
        if (!(timing->emc_bgbias_ctl0 &
              EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX) &&
            (val & EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX)) {
                val2 &= ~EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX;
                update = true;
        }

        if ((val & EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD) ||
            (val & EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_VTTGEN)) {
                update = true;
        }

        if (update) {
                writel(val2, emc->regs + EMC_BGBIAS_CTL0);
                if (pre_wait < 5)
                        pre_wait = 5;
        }

        update = false;
        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);
        }

        val = timing->emc_cfg_2;
        val &= ~EMC_CFG_2_DIS_STP_OB_CLK_DURING_NON_WR;
        emc_ccfifo_writel(emc, val, EMC_CFG_2);

        /* 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);

        if (timing->emc_cfg_2 & EMC_CFG_2_DIS_STP_OB_CLK_DURING_NON_WR)
                emc_ccfifo_writel(emc, timing->emc_cfg_2, EMC_CFG_2);

        /* Disable AUTO_CAL for clock change */
        emc_seq_disable_auto_cal(emc);

        /* Read register to wait until programming has settled */
        readl(emc->regs + EMC_INTSTATUS);

        return 0;
}

static void tegra_emc_complete_timing_change(struct tegra_emc *emc,
                                             unsigned long rate)
{
        struct emc_timing *timing = tegra_emc_find_timing(emc, rate);
        struct emc_timing *last = &emc->last_timing;
        u32 val;

        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);

        /* LPDDR3: Turn off BGBIAS if low frequency */
        if (emc->dram_type == DRAM_TYPE_LPDDR3 &&
            timing->emc_bgbias_ctl0 &
              EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_RX) {
                val = timing->emc_bgbias_ctl0;
                val |= EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD_IBIAS_VTTGEN;
                val |= EMC_BGBIAS_CTL0_BIAS0_DSC_E_PWRD;
                writel(val, emc->regs + EMC_BGBIAS_CTL0);
        } else {
                if (emc->dram_type == DRAM_TYPE_DDR3 &&
                    readl(emc->regs + EMC_BGBIAS_CTL0) !=
                      timing->emc_bgbias_ctl0) {
                        writel(timing->emc_bgbias_ctl0,
                               emc->regs + EMC_BGBIAS_CTL0);
                }

                writel(timing->emc_auto_cal_interval,
                       emc->regs + EMC_AUTO_CAL_INTERVAL);
        }

        /* 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 int emc_init(struct tegra_emc *emc)
{
        emc->dram_type = readl(emc->regs + EMC_FBIO_CFG5);

        if (emc->dram_type & EMC_FBIO_CFG5_DRAM_WIDTH_X64)
                emc->dram_bus_width = 64;
        else
                emc->dram_bus_width = 32;

        dev_info(emc->dev, "%ubit DRAM bus\n", emc->dram_bus_width);

        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_read_current_timing(emc, &emc->last_timing);

        return 0;
}

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_bgbias_ctl0, "nvidia,emc-bgbias-ctl0")
        EMC_READ_PROP(emc_cfg, "nvidia,emc-cfg")
        EMC_READ_PROP(emc_cfg_2, "nvidia,emc-cfg-2")
        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 tegra_emc_load_timings_from_dt(struct tegra_emc *emc,
                                          struct device_node *node)
{
        int child_count = of_get_child_count(node);
        struct device_node *child;
        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(node, child) {
                timing = &emc->timings[i++];

                err = load_one_timing_from_dt(emc, timing, child);
                if (err) {
                        of_node_put(child);
                        return err;
                }
        }

        sort(emc->timings, emc->num_timings, sizeof(*timing), cmp_timings,
             NULL);

        return 0;
}

static const struct of_device_id tegra_emc_of_match[] = {
        { .compatible = "nvidia,tegra124-emc" },
        { .compatible = "nvidia,tegra132-emc" },
        {}
};
MODULE_DEVICE_TABLE(of, tegra_emc_of_match);

static struct device_node *
tegra_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;
}

static void tegra_emc_rate_requests_init(struct tegra_emc *emc)
{
        unsigned int i;

        for (i = 0; i < EMC_RATE_TYPE_MAX; i++) {
                emc->requested_rate[i].min_rate = 0;
                emc->requested_rate[i].max_rate = ULONG_MAX;
        }
}

static int emc_request_rate(struct tegra_emc *emc,
                            unsigned long new_min_rate,
                            unsigned long new_max_rate,
                            enum emc_rate_request_type type)
{
        struct emc_rate_request *req = emc->requested_rate;
        unsigned long min_rate = 0, max_rate = ULONG_MAX;
        unsigned int i;
        int err;

        /* select minimum and maximum rates among the requested rates */
        for (i = 0; i < EMC_RATE_TYPE_MAX; i++, req++) {
                if (i == type) {
                        min_rate = max(new_min_rate, min_rate);
                        max_rate = min(new_max_rate, max_rate);
                } else {
                        min_rate = max(req->min_rate, min_rate);
                        max_rate = min(req->max_rate, max_rate);
                }
        }

        if (min_rate > max_rate) {
                dev_err_ratelimited(emc->dev, "%s: type %u: out of range: %lu %lu\n",
                                    __func__, type, min_rate, max_rate);
                return -ERANGE;
        }

        /*
         * EMC rate-changes should go via OPP API because it manages voltage
         * changes.
         */
        err = dev_pm_opp_set_rate(emc->dev, min_rate);
        if (err)
                return err;

        emc->requested_rate[type].min_rate = new_min_rate;
        emc->requested_rate[type].max_rate = new_max_rate;

        return 0;
}

static int emc_set_min_rate(struct tegra_emc *emc, unsigned long rate,
                            enum emc_rate_request_type type)
{
        struct emc_rate_request *req = &emc->requested_rate[type];
        int ret;

        mutex_lock(&emc->rate_lock);
        ret = emc_request_rate(emc, rate, req->max_rate, type);
        mutex_unlock(&emc->rate_lock);

        return ret;
}

static int emc_set_max_rate(struct tegra_emc *emc, unsigned long rate,
                            enum emc_rate_request_type type)
{
        struct emc_rate_request *req = &emc->requested_rate[type];
        int ret;

        mutex_lock(&emc->rate_lock);
        ret = emc_request_rate(emc, req->min_rate, rate, type);
        mutex_unlock(&emc->rate_lock);

        return ret;
}

/*
 * 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: Similarily 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 tegra_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 tegra_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(tegra_emc_debug_available_rates);

static int tegra_emc_debug_min_rate_get(void *data, u64 *rate)
{
        struct tegra_emc *emc = data;

        *rate = emc->debugfs.min_rate;

        return 0;
}

static int tegra_emc_debug_min_rate_set(void *data, u64 rate)
{
        struct tegra_emc *emc = data;
        int err;

        if (!tegra_emc_validate_rate(emc, rate))
                return -EINVAL;

        err = emc_set_min_rate(emc, rate, EMC_RATE_DEBUG);
        if (err < 0)
                return err;

        emc->debugfs.min_rate = rate;

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(tegra_emc_debug_min_rate_fops,
                        tegra_emc_debug_min_rate_get,
                        tegra_emc_debug_min_rate_set, "%llu\n");

static int tegra_emc_debug_max_rate_get(void *data, u64 *rate)
{
        struct tegra_emc *emc = data;

        *rate = emc->debugfs.max_rate;

        return 0;
}

static int tegra_emc_debug_max_rate_set(void *data, u64 rate)
{
        struct tegra_emc *emc = data;
        int err;

        if (!tegra_emc_validate_rate(emc, rate))
                return -EINVAL;

        err = emc_set_max_rate(emc, rate, EMC_RATE_DEBUG);
        if (err < 0)
                return err;

        emc->debugfs.max_rate = rate;

        return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(tegra_emc_debug_max_rate_fops,
                        tegra_emc_debug_max_rate_get,
                        tegra_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);
        if (!emc->debugfs.root) {
                dev_err(dev, "failed to create debugfs directory\n");
                return;
        }

        debugfs_create_file("available_rates", 0444, emc->debugfs.root, emc,
                            &tegra_emc_debug_available_rates_fops);
        debugfs_create_file("min_rate", 0644, emc->debugfs.root,
                            emc, &tegra_emc_debug_min_rate_fops);
        debugfs_create_file("max_rate", 0644, emc->debugfs.root,
                            emc, &tegra_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(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(sizeof(*ndata), GFP_KERNEL);
                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;
        const unsigned int ddr = 2;
        int err;

        /*
         * Tegra124 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.
         */
        dram_data_bus_width_bytes = emc->dram_bus_width / 8;
        do_div(rate, ddr * dram_data_bus_width_bytes);
        rate = min_t(u64, rate, U32_MAX);

        err = emc_set_min_rate(emc, rate, EMC_RATE_ICC);
        if (err)
                return err;

        return 0;
}

static int tegra_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;

        err = icc_provider_add(&emc->provider);
        if (err)
                goto err_msg;

        /* create External Memory Controller node */
        node = icc_node_create(TEGRA_ICC_EMC);
        if (IS_ERR(node)) {
                err = PTR_ERR(node);
                goto del_provider;
        }

        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);

        return 0;

remove_nodes:
        icc_nodes_remove(&emc->provider);
del_provider:
        icc_provider_del(&emc->provider);
err_msg:
        dev_err(emc->dev, "failed to initialize ICC: %d\n", err);

        return err;
}

static int tegra_emc_opp_table_init(struct tegra_emc *emc)
{
        u32 hw_version = BIT(tegra_sku_info.soc_speedo_id);
        struct opp_table *hw_opp_table;
        int err;

        hw_opp_table = dev_pm_opp_set_supported_hw(emc->dev, &hw_version, 1);
        err = PTR_ERR_OR_ZERO(hw_opp_table);
        if (err) {
                dev_err(emc->dev, "failed to set OPP supported HW: %d\n", err);
                return err;
        }

        err = dev_pm_opp_of_add_table(emc->dev);
        if (err) {
                if (err == -ENODEV)
                        dev_err(emc->dev, "OPP table not found, please update your device tree\n");
                else
                        dev_err(emc->dev, "failed to add OPP table: %d\n", err);

                goto put_hw_table;
        }

        dev_info(emc->dev, "OPP HW ver. 0x%x, current clock rate %lu MHz\n",
                 hw_version, clk_get_rate(emc->clk) / 1000000);

        /* first dummy rate-set initializes voltage state */
        err = dev_pm_opp_set_rate(emc->dev, clk_get_rate(emc->clk));
        if (err) {
                dev_err(emc->dev, "failed to initialize OPP clock: %d\n", err);
                goto remove_table;
        }

        return 0;

remove_table:
        dev_pm_opp_of_remove_table(emc->dev);
put_hw_table:
        dev_pm_opp_put_supported_hw(hw_opp_table);

        return err;
}

static void devm_tegra_emc_unset_callback(void *data)
{
        tegra124_clk_set_emc_callbacks(NULL, NULL);
}

static int tegra_emc_probe(struct platform_device *pdev)
{
        struct device_node *np;
        struct tegra_emc *emc;
        u32 ram_code;
        int err;

        emc = devm_kzalloc(&pdev->dev, sizeof(*emc), GFP_KERNEL);
        if (!emc)
                return -ENOMEM;

        mutex_init(&emc->rate_lock);
        emc->dev = &pdev->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(&pdev->dev);
        if (IS_ERR(emc->mc))
                return PTR_ERR(emc->mc);

        ram_code = tegra_read_ram_code();

        np = tegra_emc_find_node_by_ram_code(pdev->dev.of_node, ram_code);
        if (np) {
                err = tegra_emc_load_timings_from_dt(emc, np);
                of_node_put(np);
                if (err)
                        return err;
        } else {
                dev_info(&pdev->dev,
                         "no memory timings for RAM code %u found in DT\n",
                         ram_code);
        }

        err = emc_init(emc);
        if (err) {
                dev_err(&pdev->dev, "EMC initialization failed: %d\n", err);
                return err;
        }

        platform_set_drvdata(pdev, emc);

        tegra124_clk_set_emc_callbacks(tegra_emc_prepare_timing_change,
                                       tegra_emc_complete_timing_change);

        err = devm_add_action_or_reset(&pdev->dev, devm_tegra_emc_unset_callback,
                                       NULL);
        if (err)
                return err;

        emc->clk = devm_clk_get(&pdev->dev, "emc");
        if (IS_ERR(emc->clk)) {
                err = PTR_ERR(emc->clk);
                dev_err(&pdev->dev, "failed to get EMC clock: %d\n", err);
                return err;
        }

        err = tegra_emc_opp_table_init(emc);
        if (err)
                return err;

        tegra_emc_rate_requests_init(emc);

        if (IS_ENABLED(CONFIG_DEBUG_FS))
                emc_debugfs_init(&pdev->dev, emc);

        tegra_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 struct platform_driver tegra_emc_driver = {
        .probe = tegra_emc_probe,
        .driver = {
                .name = "tegra-emc",
                .of_match_table = tegra_emc_of_match,
                .suppress_bind_attrs = true,
                .sync_state = icc_sync_state,
        },
};
module_platform_driver(tegra_emc_driver);

MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
MODULE_DESCRIPTION("NVIDIA Tegra124 EMC driver");
MODULE_LICENSE("GPL v2");