// SPDX-License-Identifier: GPL-2.0
/*
 * phy-zynqmp.c - PHY driver for Xilinx ZynqMP GT.
 *
 * Copyright (C) 2018-2020 Xilinx Inc.
 *
 * Author: Anurag Kumar Vulisha <anuragku@xilinx.com>
 * Author: Subbaraya Sundeep <sundeep.lkml@gmail.com>
 * Author: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *
 * This driver is tested for USB, SGMII, SATA and Display Port currently.
 * PCIe should also work but that is experimental as of now.
 */

#include <linux/clk.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

#include <dt-bindings/phy/phy.h>

/*
 * Lane Registers
 */

/* TX De-emphasis parameters */
#define L0_TX_ANA_TM_18                 0x0048
#define L0_TX_ANA_TM_118                0x01d8
#define L0_TX_ANA_TM_118_FORCE_17_0     BIT(0)

/* DN Resistor calibration code parameters */
#define L0_TXPMA_ST_3                   0x0b0c
#define L0_DN_CALIB_CODE                0x3f

/* PMA control parameters */
#define L0_TXPMD_TM_45                  0x0cb4
#define L0_TXPMD_TM_48                  0x0cc0
#define L0_TXPMD_TM_45_OVER_DP_MAIN     BIT(0)
#define L0_TXPMD_TM_45_ENABLE_DP_MAIN   BIT(1)
#define L0_TXPMD_TM_45_OVER_DP_POST1    BIT(2)
#define L0_TXPMD_TM_45_ENABLE_DP_POST1  BIT(3)
#define L0_TXPMD_TM_45_OVER_DP_POST2    BIT(4)
#define L0_TXPMD_TM_45_ENABLE_DP_POST2  BIT(5)

/* PCS control parameters */
#define L0_TM_DIG_6                     0x106c
#define L0_TM_DIS_DESCRAMBLE_DECODER    0x0f
#define L0_TX_DIG_61                    0x00f4
#define L0_TM_DISABLE_SCRAMBLE_ENCODER  0x0f

/* PLL Test Mode register parameters */
#define L0_TM_PLL_DIG_37                0x2094
#define L0_TM_COARSE_CODE_LIMIT         0x10

/* PLL SSC step size offsets */
#define L0_PLL_SS_STEPS_0_LSB           0x2368
#define L0_PLL_SS_STEPS_1_MSB           0x236c
#define L0_PLL_SS_STEP_SIZE_0_LSB       0x2370
#define L0_PLL_SS_STEP_SIZE_1           0x2374
#define L0_PLL_SS_STEP_SIZE_2           0x2378
#define L0_PLL_SS_STEP_SIZE_3_MSB       0x237c
#define L0_PLL_STATUS_READ_1            0x23e4

/* SSC step size parameters */
#define STEP_SIZE_0_MASK                0xff
#define STEP_SIZE_1_MASK                0xff
#define STEP_SIZE_2_MASK                0xff
#define STEP_SIZE_3_MASK                0x3
#define STEP_SIZE_SHIFT                 8
#define FORCE_STEP_SIZE                 0x10
#define FORCE_STEPS                     0x20
#define STEPS_0_MASK                    0xff
#define STEPS_1_MASK                    0x07

/* Reference clock selection parameters */
#define L0_Ln_REF_CLK_SEL(n)            (0x2860 + (n) * 4)
#define L0_REF_CLK_LCL_SEL              BIT(7)
#define L0_REF_CLK_SEL_MASK             0x9f

/* Calibration digital logic parameters */
#define L3_TM_CALIB_DIG19               0xec4c
#define L3_CALIB_DONE_STATUS            0xef14
#define L3_TM_CALIB_DIG18               0xec48
#define L3_TM_CALIB_DIG19_NSW           0x07
#define L3_TM_CALIB_DIG18_NSW           0xe0
#define L3_TM_OVERRIDE_NSW_CODE         0x20
#define L3_CALIB_DONE                   0x02
#define L3_NSW_SHIFT                    5
#define L3_NSW_PIPE_SHIFT               4
#define L3_NSW_CALIB_SHIFT              3

#define PHY_REG_OFFSET                  0x4000

/*
 * Global Registers
 */

/* Refclk selection parameters */
#define PLL_REF_SEL(n)                  (0x10000 + (n) * 4)
#define PLL_FREQ_MASK                   0x1f
#define PLL_STATUS_LOCKED               0x10

/* Inter Connect Matrix parameters */
#define ICM_CFG0                        0x10010
#define ICM_CFG1                        0x10014
#define ICM_CFG0_L0_MASK                0x07
#define ICM_CFG0_L1_MASK                0x70
#define ICM_CFG1_L2_MASK                0x07
#define ICM_CFG2_L3_MASK                0x70
#define ICM_CFG_SHIFT                   4

/* Inter Connect Matrix allowed protocols */
#define ICM_PROTOCOL_PD                 0x0
#define ICM_PROTOCOL_PCIE               0x1
#define ICM_PROTOCOL_SATA               0x2
#define ICM_PROTOCOL_USB                0x3
#define ICM_PROTOCOL_DP                 0x4
#define ICM_PROTOCOL_SGMII              0x5

static const char *const xpsgtr_icm_str[] = {
        [ICM_PROTOCOL_PD] = "none",
        [ICM_PROTOCOL_PCIE] = "PCIe",
        [ICM_PROTOCOL_SATA] = "SATA",
        [ICM_PROTOCOL_USB] = "USB",
        [ICM_PROTOCOL_DP] = "DisplayPort",
        [ICM_PROTOCOL_SGMII] = "SGMII",
};

/* Test Mode common reset control  parameters */
#define TM_CMN_RST                      0x10018
#define TM_CMN_RST_EN                   0x1
#define TM_CMN_RST_SET                  0x2
#define TM_CMN_RST_MASK                 0x3

/* Bus width parameters */
#define TX_PROT_BUS_WIDTH               0x10040
#define RX_PROT_BUS_WIDTH               0x10044
#define PROT_BUS_WIDTH_10               0x0
#define PROT_BUS_WIDTH_20               0x1
#define PROT_BUS_WIDTH_40               0x2
#define PROT_BUS_WIDTH_SHIFT(n)         ((n) * 2)
#define PROT_BUS_WIDTH_MASK(n)          GENMASK((n) * 2 + 1, (n) * 2)

/* Number of GT lanes */
#define NUM_LANES                       4

/* SIOU SATA control register */
#define SATA_CONTROL_OFFSET             0x0100

/* Total number of controllers */
#define CONTROLLERS_PER_LANE            5

/* Timeout values */
#define TIMEOUT_US                      1000

/* Lane 0/1/2/3 offset */
#define DIG_8(n)                ((0x4000 * (n)) + 0x1074)
#define ILL13(n)                ((0x4000 * (n)) + 0x1994)
#define DIG_10(n)               ((0x4000 * (n)) + 0x107c)
#define RST_DLY(n)              ((0x4000 * (n)) + 0x19a4)
#define BYP_15(n)               ((0x4000 * (n)) + 0x1038)
#define BYP_12(n)               ((0x4000 * (n)) + 0x102c)
#define MISC3(n)                ((0x4000 * (n)) + 0x19ac)
#define EQ11(n)                 ((0x4000 * (n)) + 0x1978)

static u32 save_reg_address[] = {
        /* Lane 0/1/2/3 Register */
        DIG_8(0), ILL13(0), DIG_10(0), RST_DLY(0), BYP_15(0), BYP_12(0), MISC3(0), EQ11(0),
        DIG_8(1), ILL13(1), DIG_10(1), RST_DLY(1), BYP_15(1), BYP_12(1), MISC3(1), EQ11(1),
        DIG_8(2), ILL13(2), DIG_10(2), RST_DLY(2), BYP_15(2), BYP_12(2), MISC3(2), EQ11(2),
        DIG_8(3), ILL13(3), DIG_10(3), RST_DLY(3), BYP_15(3), BYP_12(3), MISC3(3), EQ11(3),
};

struct xpsgtr_dev;

/**
 * struct xpsgtr_ssc - structure to hold SSC settings for a lane
 * @refclk_rate: PLL reference clock frequency
 * @pll_ref_clk: value to be written to register for corresponding ref clk rate
 * @steps: number of steps of SSC (Spread Spectrum Clock)
 * @step_size: step size of each step
 */
struct xpsgtr_ssc {
        u32 refclk_rate;
        u8  pll_ref_clk;
        u32 steps;
        u32 step_size;
};

/**
 * struct xpsgtr_phy - representation of a lane
 * @phy: pointer to the kernel PHY device
 * @instance: instance of the protocol type (such as the lane within a
 *            protocol, or the USB/Ethernet controller)
 * @lane: lane number
 * @protocol: protocol in which the lane operates
 * @skip_phy_init: skip phy_init() if true
 * @dev: pointer to the xpsgtr_dev instance
 * @refclk: reference clock index
 */
struct xpsgtr_phy {
        struct phy *phy;
        u8 instance;
        u8 lane;
        u8 protocol;
        bool skip_phy_init;
        struct xpsgtr_dev *dev;
        unsigned int refclk;
};

/**
 * struct xpsgtr_dev - representation of a ZynMP GT device
 * @dev: pointer to device
 * @serdes: serdes base address
 * @siou: siou base address
 * @gtr_mutex: mutex for locking
 * @phys: PHY lanes
 * @clk: reference clocks
 * @tx_term_fix: fix for GT issue
 * @saved_icm_cfg0: stored value of ICM CFG0 register
 * @saved_icm_cfg1: stored value of ICM CFG1 register
 * @saved_regs: registers to be saved/restored during suspend/resume
 */
struct xpsgtr_dev {
        struct device *dev;
        void __iomem *serdes;
        void __iomem *siou;
        struct mutex gtr_mutex; /* mutex for locking */
        struct xpsgtr_phy phys[NUM_LANES];
        struct clk *clk[NUM_LANES];
        bool tx_term_fix;
        unsigned int saved_icm_cfg0;
        unsigned int saved_icm_cfg1;
        u32 *saved_regs;
};

/*
 * Configuration Data
 */

/* lookup table to hold all settings needed for a ref clock frequency */
static const struct xpsgtr_ssc ssc_lookup[] = {
        {  19200000, 0x05,  608, 264020 },
        {  20000000, 0x06,  634, 243454 },
        {  24000000, 0x07,  760, 168973 },
        {  26000000, 0x08,  824, 143860 },
        {  27000000, 0x09,  856,  86551 },
        {  38400000, 0x0a, 1218,  65896 },
        {  40000000, 0x0b,  634, 243454 },
        {  52000000, 0x0c,  824, 143860 },
        { 100000000, 0x0d, 1058,  87533 },
        { 108000000, 0x0e,  856,  86551 },
        { 125000000, 0x0f,  992, 119497 },
        { 135000000, 0x10, 1070,  55393 },
        { 150000000, 0x11,  792, 187091 }
};

/*
 * I/O Accessors
 */

static inline u32 xpsgtr_read(struct xpsgtr_dev *gtr_dev, u32 reg)
{
        return readl(gtr_dev->serdes + reg);
}

static inline void xpsgtr_write(struct xpsgtr_dev *gtr_dev, u32 reg, u32 value)
{
        writel(value, gtr_dev->serdes + reg);
}

static inline void xpsgtr_clr_set(struct xpsgtr_dev *gtr_dev, u32 reg,
                                  u32 clr, u32 set)
{
        u32 value = xpsgtr_read(gtr_dev, reg);

        value &= ~clr;
        value |= set;
        xpsgtr_write(gtr_dev, reg, value);
}

static inline u32 xpsgtr_read_phy(struct xpsgtr_phy *gtr_phy, u32 reg)
{
        void __iomem *addr = gtr_phy->dev->serdes
                           + gtr_phy->lane * PHY_REG_OFFSET + reg;

        return readl(addr);
}

static inline void xpsgtr_write_phy(struct xpsgtr_phy *gtr_phy,
                                    u32 reg, u32 value)
{
        void __iomem *addr = gtr_phy->dev->serdes
                           + gtr_phy->lane * PHY_REG_OFFSET + reg;

        writel(value, addr);
}

static inline void xpsgtr_clr_set_phy(struct xpsgtr_phy *gtr_phy,
                                      u32 reg, u32 clr, u32 set)
{
        void __iomem *addr = gtr_phy->dev->serdes
                           + gtr_phy->lane * PHY_REG_OFFSET + reg;

        writel((readl(addr) & ~clr) | set, addr);
}

/**
 * xpsgtr_save_lane_regs - Saves registers on suspend
 * @gtr_dev: pointer to phy controller context structure
 */
static void xpsgtr_save_lane_regs(struct xpsgtr_dev *gtr_dev)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(save_reg_address); i++)
                gtr_dev->saved_regs[i] = xpsgtr_read(gtr_dev,
                                                     save_reg_address[i]);
}

/**
 * xpsgtr_restore_lane_regs - Restores registers on resume
 * @gtr_dev: pointer to phy controller context structure
 */
static void xpsgtr_restore_lane_regs(struct xpsgtr_dev *gtr_dev)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(save_reg_address); i++)
                xpsgtr_write(gtr_dev, save_reg_address[i],
                             gtr_dev->saved_regs[i]);
}

/*
 * Hardware Configuration
 */

/* Wait for the PLL to lock (with a timeout). */
static int xpsgtr_wait_pll_lock(struct phy *phy)
{
        struct xpsgtr_phy *gtr_phy = phy_get_drvdata(phy);
        struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
        unsigned int timeout = TIMEOUT_US;
        u8 protocol = gtr_phy->protocol;
        int ret;

        dev_dbg(gtr_dev->dev, "Waiting for PLL lock\n");

        /*
         * For DP and PCIe, only the instance 0 PLL is used. Switch to that phy
         * so we wait on the right PLL.
         */
        if ((protocol == ICM_PROTOCOL_DP || protocol == ICM_PROTOCOL_PCIE) &&
            gtr_phy->instance) {
                int i;

                for (i = 0; i < NUM_LANES; i++) {
                        gtr_phy = &gtr_dev->phys[i];

                        if (gtr_phy->protocol == protocol && !gtr_phy->instance)
                                goto got_phy;
                }

                return -EBUSY;
        }

got_phy:
        while (1) {
                u32 reg = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);

                if ((reg & PLL_STATUS_LOCKED) == PLL_STATUS_LOCKED) {
                        ret = 0;
                        break;
                }

                if (--timeout == 0) {
                        ret = -ETIMEDOUT;
                        break;
                }

                udelay(1);
        }

        if (ret == -ETIMEDOUT)
                dev_err(gtr_dev->dev,
                        "lane %u (protocol %u, instance %u): PLL lock timeout\n",
                        gtr_phy->lane, gtr_phy->protocol, gtr_phy->instance);

        return ret;
}

/* Get the spread spectrum (SSC) settings for the reference clock rate */
static const struct xpsgtr_ssc *xpsgtr_find_sscs(struct xpsgtr_phy *gtr_phy)
{
        unsigned long rate;
        struct clk *clk;
        unsigned int i;

        clk = gtr_phy->dev->clk[gtr_phy->refclk];
        rate = clk_get_rate(clk);

        for (i = 0 ; i < ARRAY_SIZE(ssc_lookup); i++) {
                /* Allow an error of 100 ppm */
                unsigned long error = ssc_lookup[i].refclk_rate / 10000;

                if (abs(rate - ssc_lookup[i].refclk_rate) < error)
                        return &ssc_lookup[i];
        }

        dev_err(gtr_phy->dev->dev, "Invalid rate %lu for reference clock %u\n",
                rate, gtr_phy->refclk);

        return NULL;
}

/* Configure PLL and spread-sprectrum clock. */
static int xpsgtr_configure_pll(struct xpsgtr_phy *gtr_phy)
{
        const struct xpsgtr_ssc *ssc;
        u32 step_size;

        ssc = xpsgtr_find_sscs(gtr_phy);
        if (!ssc)
                return -EINVAL;

        step_size = ssc->step_size;

        xpsgtr_clr_set(gtr_phy->dev, PLL_REF_SEL(gtr_phy->lane),
                       PLL_FREQ_MASK, ssc->pll_ref_clk);

        /* Enable lane clock sharing, if required */
        if (gtr_phy->refclk == gtr_phy->lane)
                xpsgtr_clr_set(gtr_phy->dev, L0_Ln_REF_CLK_SEL(gtr_phy->lane),
                               L0_REF_CLK_SEL_MASK, L0_REF_CLK_LCL_SEL);
        else
                xpsgtr_clr_set(gtr_phy->dev, L0_Ln_REF_CLK_SEL(gtr_phy->lane),
                               L0_REF_CLK_SEL_MASK, 1 << gtr_phy->refclk);

        /* SSC step size [7:0] */
        xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEP_SIZE_0_LSB,
                           STEP_SIZE_0_MASK, step_size & STEP_SIZE_0_MASK);

        /* SSC step size [15:8] */
        step_size >>= STEP_SIZE_SHIFT;
        xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEP_SIZE_1,
                           STEP_SIZE_1_MASK, step_size & STEP_SIZE_1_MASK);

        /* SSC step size [23:16] */
        step_size >>= STEP_SIZE_SHIFT;
        xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEP_SIZE_2,
                           STEP_SIZE_2_MASK, step_size & STEP_SIZE_2_MASK);

        /* SSC steps [7:0] */
        xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEPS_0_LSB,
                           STEPS_0_MASK, ssc->steps & STEPS_0_MASK);

        /* SSC steps [10:8] */
        xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEPS_1_MSB,
                           STEPS_1_MASK,
                           (ssc->steps >> STEP_SIZE_SHIFT) & STEPS_1_MASK);

        /* SSC step size [24:25] */
        step_size >>= STEP_SIZE_SHIFT;
        xpsgtr_clr_set_phy(gtr_phy, L0_PLL_SS_STEP_SIZE_3_MSB,
                           STEP_SIZE_3_MASK, (step_size & STEP_SIZE_3_MASK) |
                           FORCE_STEP_SIZE | FORCE_STEPS);

        return 0;
}

/* Configure the lane protocol. */
static void xpsgtr_lane_set_protocol(struct xpsgtr_phy *gtr_phy)
{
        struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
        u8 protocol = gtr_phy->protocol;

        switch (gtr_phy->lane) {
        case 0:
                xpsgtr_clr_set(gtr_dev, ICM_CFG0, ICM_CFG0_L0_MASK, protocol);
                break;
        case 1:
                xpsgtr_clr_set(gtr_dev, ICM_CFG0, ICM_CFG0_L1_MASK,
                               protocol << ICM_CFG_SHIFT);
                break;
        case 2:
                xpsgtr_clr_set(gtr_dev, ICM_CFG1, ICM_CFG0_L0_MASK, protocol);
                break;
        case 3:
                xpsgtr_clr_set(gtr_dev, ICM_CFG1, ICM_CFG0_L1_MASK,
                               protocol << ICM_CFG_SHIFT);
                break;
        default:
                /* We already checked 0 <= lane <= 3 */
                break;
        }
}

/* Bypass (de)scrambler and 8b/10b decoder and encoder. */
static void xpsgtr_bypass_scrambler_8b10b(struct xpsgtr_phy *gtr_phy)
{
        xpsgtr_write_phy(gtr_phy, L0_TM_DIG_6, L0_TM_DIS_DESCRAMBLE_DECODER);
        xpsgtr_write_phy(gtr_phy, L0_TX_DIG_61, L0_TM_DISABLE_SCRAMBLE_ENCODER);
}

/* DP-specific initialization. */
static void xpsgtr_phy_init_dp(struct xpsgtr_phy *gtr_phy)
{
        xpsgtr_write_phy(gtr_phy, L0_TXPMD_TM_45,
                         L0_TXPMD_TM_45_OVER_DP_MAIN |
                         L0_TXPMD_TM_45_ENABLE_DP_MAIN |
                         L0_TXPMD_TM_45_OVER_DP_POST1 |
                         L0_TXPMD_TM_45_OVER_DP_POST2 |
                         L0_TXPMD_TM_45_ENABLE_DP_POST2);
        xpsgtr_write_phy(gtr_phy, L0_TX_ANA_TM_118,
                         L0_TX_ANA_TM_118_FORCE_17_0);
}

/* SATA-specific initialization. */
static void xpsgtr_phy_init_sata(struct xpsgtr_phy *gtr_phy)
{
        struct xpsgtr_dev *gtr_dev = gtr_phy->dev;

        xpsgtr_bypass_scrambler_8b10b(gtr_phy);

        writel(gtr_phy->lane, gtr_dev->siou + SATA_CONTROL_OFFSET);
}

/* SGMII-specific initialization. */
static void xpsgtr_phy_init_sgmii(struct xpsgtr_phy *gtr_phy)
{
        struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
        u32 mask = PROT_BUS_WIDTH_MASK(gtr_phy->lane);
        u32 val = PROT_BUS_WIDTH_10 << PROT_BUS_WIDTH_SHIFT(gtr_phy->lane);

        /* Set SGMII protocol TX and RX bus width to 10 bits. */
        xpsgtr_clr_set(gtr_dev, TX_PROT_BUS_WIDTH, mask, val);
        xpsgtr_clr_set(gtr_dev, RX_PROT_BUS_WIDTH, mask, val);

        xpsgtr_bypass_scrambler_8b10b(gtr_phy);
}

/* Configure TX de-emphasis and margining for DP. */
static void xpsgtr_phy_configure_dp(struct xpsgtr_phy *gtr_phy, unsigned int pre,
                                    unsigned int voltage)
{
        static const u8 voltage_swing[4][4] = {
                { 0x2a, 0x27, 0x24, 0x20 },
                { 0x27, 0x23, 0x20, 0xff },
                { 0x24, 0x20, 0xff, 0xff },
                { 0xff, 0xff, 0xff, 0xff }
        };
        static const u8 pre_emphasis[4][4] = {
                { 0x02, 0x02, 0x02, 0x02 },
                { 0x01, 0x01, 0x01, 0xff },
                { 0x00, 0x00, 0xff, 0xff },
                { 0xff, 0xff, 0xff, 0xff }
        };

        xpsgtr_write_phy(gtr_phy, L0_TXPMD_TM_48, voltage_swing[pre][voltage]);
        xpsgtr_write_phy(gtr_phy, L0_TX_ANA_TM_18, pre_emphasis[pre][voltage]);
}

/*
 * PHY Operations
 */

static bool xpsgtr_phy_init_required(struct xpsgtr_phy *gtr_phy)
{
        /*
         * As USB may save the snapshot of the states during hibernation, doing
         * phy_init() will put the USB controller into reset, resulting in the
         * losing of the saved snapshot. So try to avoid phy_init() for USB
         * except when gtr_phy->skip_phy_init is false (this happens when FPD is
         * shutdown during suspend or when gt lane is changed from current one)
         */
        if (gtr_phy->protocol == ICM_PROTOCOL_USB && gtr_phy->skip_phy_init)
                return false;
        else
                return true;
}

/*
 * There is a functional issue in the GT. The TX termination resistance can be
 * out of spec due to a issue in the calibration logic. This is the workaround
 * to fix it, required for XCZU9EG silicon.
 */
static int xpsgtr_phy_tx_term_fix(struct xpsgtr_phy *gtr_phy)
{
        struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
        u32 timeout = TIMEOUT_US;
        u32 nsw;

        /* Enabling Test Mode control for CMN Rest */
        xpsgtr_clr_set(gtr_dev, TM_CMN_RST, TM_CMN_RST_MASK, TM_CMN_RST_SET);

        /* Set Test Mode reset */
        xpsgtr_clr_set(gtr_dev, TM_CMN_RST, TM_CMN_RST_MASK, TM_CMN_RST_EN);

        xpsgtr_write(gtr_dev, L3_TM_CALIB_DIG18, 0x00);
        xpsgtr_write(gtr_dev, L3_TM_CALIB_DIG19, L3_TM_OVERRIDE_NSW_CODE);

        /*
         * As a part of work around sequence for PMOS calibration fix,
         * we need to configure any lane ICM_CFG to valid protocol. This
         * will deassert the CMN_Resetn signal.
         */
        xpsgtr_lane_set_protocol(gtr_phy);

        /* Clear Test Mode reset */
        xpsgtr_clr_set(gtr_dev, TM_CMN_RST, TM_CMN_RST_MASK, TM_CMN_RST_SET);

        dev_dbg(gtr_dev->dev, "calibrating...\n");

        do {
                u32 reg = xpsgtr_read(gtr_dev, L3_CALIB_DONE_STATUS);

                if ((reg & L3_CALIB_DONE) == L3_CALIB_DONE)
                        break;

                if (!--timeout) {
                        dev_err(gtr_dev->dev, "calibration time out\n");
                        return -ETIMEDOUT;
                }

                udelay(1);
        } while (timeout > 0);

        dev_dbg(gtr_dev->dev, "calibration done\n");

        /* Reading NMOS Register Code */
        nsw = xpsgtr_read(gtr_dev, L0_TXPMA_ST_3) & L0_DN_CALIB_CODE;

        /* Set Test Mode reset */
        xpsgtr_clr_set(gtr_dev, TM_CMN_RST, TM_CMN_RST_MASK, TM_CMN_RST_EN);

        /* Writing NMOS register values back [5:3] */
        xpsgtr_write(gtr_dev, L3_TM_CALIB_DIG19, nsw >> L3_NSW_CALIB_SHIFT);

        /* Writing NMOS register value [2:0] */
        xpsgtr_write(gtr_dev, L3_TM_CALIB_DIG18,
                     ((nsw & L3_TM_CALIB_DIG19_NSW) << L3_NSW_SHIFT) |
                     (1 << L3_NSW_PIPE_SHIFT));

        /* Clear Test Mode reset */
        xpsgtr_clr_set(gtr_dev, TM_CMN_RST, TM_CMN_RST_MASK, TM_CMN_RST_SET);

        return 0;
}

static int xpsgtr_phy_init(struct phy *phy)
{
        struct xpsgtr_phy *gtr_phy = phy_get_drvdata(phy);
        struct xpsgtr_dev *gtr_dev = gtr_phy->dev;
        int ret = 0;

        mutex_lock(&gtr_dev->gtr_mutex);

        /* Configure and enable the clock when peripheral phy_init call */
        if (clk_prepare_enable(gtr_dev->clk[gtr_phy->refclk]))
                goto out;

        /* Skip initialization if not required. */
        if (!xpsgtr_phy_init_required(gtr_phy))
                goto out;

        if (gtr_dev->tx_term_fix) {
                ret = xpsgtr_phy_tx_term_fix(gtr_phy);
                if (ret < 0)
                        goto out;

                gtr_dev->tx_term_fix = false;
        }

        /* Enable coarse code saturation limiting logic. */
        xpsgtr_write_phy(gtr_phy, L0_TM_PLL_DIG_37, L0_TM_COARSE_CODE_LIMIT);

        /*
         * Configure the PLL, the lane protocol, and perform protocol-specific
         * initialization.
         */
        ret = xpsgtr_configure_pll(gtr_phy);
        if (ret)
                goto out;

        xpsgtr_lane_set_protocol(gtr_phy);

        switch (gtr_phy->protocol) {
        case ICM_PROTOCOL_DP:
                xpsgtr_phy_init_dp(gtr_phy);
                break;

        case ICM_PROTOCOL_SATA:
                xpsgtr_phy_init_sata(gtr_phy);
                break;

        case ICM_PROTOCOL_SGMII:
                xpsgtr_phy_init_sgmii(gtr_phy);
                break;
        }

out:
        mutex_unlock(&gtr_dev->gtr_mutex);
        return ret;
}

static int xpsgtr_phy_exit(struct phy *phy)
{
        struct xpsgtr_phy *gtr_phy = phy_get_drvdata(phy);
        struct xpsgtr_dev *gtr_dev = gtr_phy->dev;

        gtr_phy->skip_phy_init = false;

        /* Ensure that disable clock only, which configure for lane */
        clk_disable_unprepare(gtr_dev->clk[gtr_phy->refclk]);

        return 0;
}

static int xpsgtr_phy_power_on(struct phy *phy)
{
        struct xpsgtr_phy *gtr_phy = phy_get_drvdata(phy);
        int ret = 0;

        /* Skip initialization if not required. */
        if (!xpsgtr_phy_init_required(gtr_phy))
                return ret;
        return xpsgtr_wait_pll_lock(phy);
}

static int xpsgtr_phy_configure(struct phy *phy, union phy_configure_opts *opts)
{
        struct xpsgtr_phy *gtr_phy = phy_get_drvdata(phy);

        if (gtr_phy->protocol != ICM_PROTOCOL_DP)
                return 0;

        xpsgtr_phy_configure_dp(gtr_phy, opts->dp.pre[0], opts->dp.voltage[0]);

        return 0;
}

static const struct phy_ops xpsgtr_phyops = {
        .init           = xpsgtr_phy_init,
        .exit           = xpsgtr_phy_exit,
        .power_on       = xpsgtr_phy_power_on,
        .configure      = xpsgtr_phy_configure,
        .owner          = THIS_MODULE,
};

/*
 * OF Xlate Support
 */

/* Set the lane protocol and instance based on the PHY type and instance number. */
static int xpsgtr_set_lane_type(struct xpsgtr_phy *gtr_phy, u8 phy_type,
                                unsigned int phy_instance)
{
        unsigned int num_phy_types;

        switch (phy_type) {
        case PHY_TYPE_SATA:
                num_phy_types = 2;
                gtr_phy->protocol = ICM_PROTOCOL_SATA;
                break;
        case PHY_TYPE_USB3:
                num_phy_types = 2;
                gtr_phy->protocol = ICM_PROTOCOL_USB;
                break;
        case PHY_TYPE_DP:
                num_phy_types = 2;
                gtr_phy->protocol = ICM_PROTOCOL_DP;
                break;
        case PHY_TYPE_PCIE:
                num_phy_types = 4;
                gtr_phy->protocol = ICM_PROTOCOL_PCIE;
                break;
        case PHY_TYPE_SGMII:
                num_phy_types = 4;
                gtr_phy->protocol = ICM_PROTOCOL_SGMII;
                break;
        default:
                return -EINVAL;
        }

        if (phy_instance >= num_phy_types)
                return -EINVAL;

        gtr_phy->instance = phy_instance;
        return 0;
}

/*
 * Valid combinations of controllers and lanes (Interconnect Matrix). Each
 * "instance" represents one controller for a lane. For PCIe and DP, the
 * "instance" is the logical lane in the link. For SATA, USB, and SGMII,
 * the instance is the index of the controller.
 *
 * This information is only used to validate the devicetree reference, and is
 * not used when programming the hardware.
 */
static const unsigned int icm_matrix[NUM_LANES][CONTROLLERS_PER_LANE] = {
        /* PCIe, SATA, USB, DP, SGMII */
        { 0, 0, 0, 1, 0 }, /* Lane 0 */
        { 1, 1, 0, 0, 1 }, /* Lane 1 */
        { 2, 0, 0, 1, 2 }, /* Lane 2 */
        { 3, 1, 1, 0, 3 }, /* Lane 3 */
};

/* Translate OF phandle and args to PHY instance. */
static struct phy *xpsgtr_xlate(struct device *dev,
                                const struct of_phandle_args *args)
{
        struct xpsgtr_dev *gtr_dev = dev_get_drvdata(dev);
        struct xpsgtr_phy *gtr_phy;
        unsigned int phy_instance;
        unsigned int phy_lane;
        unsigned int phy_type;
        unsigned int refclk;
        unsigned int i;
        int ret;

        if (args->args_count != 4) {
                dev_err(dev, "Invalid number of cells in 'phy' property\n");
                return ERR_PTR(-EINVAL);
        }

        /*
         * Get the PHY parameters from the OF arguments and derive the lane
         * type.
         */
        phy_lane = args->args[0];
        if (phy_lane >= ARRAY_SIZE(gtr_dev->phys)) {
                dev_err(dev, "Invalid lane number %u\n", phy_lane);
                return ERR_PTR(-ENODEV);
        }

        gtr_phy = &gtr_dev->phys[phy_lane];
        phy_type = args->args[1];
        phy_instance = args->args[2];

        guard(mutex)(&gtr_phy->phy->mutex);
        ret = xpsgtr_set_lane_type(gtr_phy, phy_type, phy_instance);
        if (ret < 0) {
                dev_err(gtr_dev->dev, "Invalid PHY type and/or instance\n");
                return ERR_PTR(ret);
        }

        refclk = args->args[3];
        if (refclk >= ARRAY_SIZE(gtr_dev->clk)) {
                dev_err(dev, "Invalid reference clock number %u\n", refclk);
                return ERR_PTR(-EINVAL);
        }

        gtr_phy->refclk = refclk;

        /*
         * Ensure that the Interconnect Matrix is obeyed, i.e a given lane type
         * is allowed to operate on the lane.
         */
        for (i = 0; i < CONTROLLERS_PER_LANE; i++) {
                if (icm_matrix[phy_lane][i] == gtr_phy->instance)
                        return gtr_phy->phy;
        }

        return ERR_PTR(-EINVAL);
}

/*
 * DebugFS
 */

static int xpsgtr_status_read(struct seq_file *seq, void *data)
{
        struct device *dev = seq->private;
        struct xpsgtr_phy *gtr_phy = dev_get_drvdata(dev);
        struct clk *clk;
        u32 pll_status;

        mutex_lock(&gtr_phy->phy->mutex);
        pll_status = xpsgtr_read_phy(gtr_phy, L0_PLL_STATUS_READ_1);
        clk = gtr_phy->dev->clk[gtr_phy->refclk];

        seq_printf(seq, "Lane:            %u\n", gtr_phy->lane);
        seq_printf(seq, "Protocol:        %s\n",
                   xpsgtr_icm_str[gtr_phy->protocol]);
        seq_printf(seq, "Instance:        %u\n", gtr_phy->instance);
        seq_printf(seq, "Reference clock: %u (%pC)\n", gtr_phy->refclk, clk);
        seq_printf(seq, "Reference rate:  %lu\n", clk_get_rate(clk));
        seq_printf(seq, "PLL locked:      %s\n",
                   pll_status & PLL_STATUS_LOCKED ? "yes" : "no");

        mutex_unlock(&gtr_phy->phy->mutex);
        return 0;
}

/*
 * Power Management
 */

static int xpsgtr_runtime_suspend(struct device *dev)
{
        struct xpsgtr_dev *gtr_dev = dev_get_drvdata(dev);

        /* Save the snapshot ICM_CFG registers. */
        gtr_dev->saved_icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
        gtr_dev->saved_icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);

        xpsgtr_save_lane_regs(gtr_dev);

        return 0;
}

static int xpsgtr_runtime_resume(struct device *dev)
{
        struct xpsgtr_dev *gtr_dev = dev_get_drvdata(dev);
        unsigned int icm_cfg0, icm_cfg1;
        unsigned int i;
        bool skip_phy_init;

        xpsgtr_restore_lane_regs(gtr_dev);

        icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
        icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);

        /* Return if no GT lanes got configured before suspend. */
        if (!gtr_dev->saved_icm_cfg0 && !gtr_dev->saved_icm_cfg1)
                return 0;

        /* Check if the ICM configurations changed after suspend. */
        if (icm_cfg0 == gtr_dev->saved_icm_cfg0 &&
            icm_cfg1 == gtr_dev->saved_icm_cfg1)
                skip_phy_init = true;
        else
                skip_phy_init = false;

        /* Update the skip_phy_init for all gtr_phy instances. */
        for (i = 0; i < ARRAY_SIZE(gtr_dev->phys); i++)
                gtr_dev->phys[i].skip_phy_init = skip_phy_init;

        return 0;
}

static DEFINE_RUNTIME_DEV_PM_OPS(xpsgtr_pm_ops, xpsgtr_runtime_suspend,
                                 xpsgtr_runtime_resume, NULL);
/*
 * Probe & Platform Driver
 */

static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
{
        unsigned int refclk;

        for (refclk = 0; refclk < ARRAY_SIZE(gtr_dev->clk); ++refclk) {
                struct clk *clk;
                char name[8];

                snprintf(name, sizeof(name), "ref%u", refclk);
                clk = devm_clk_get_optional(gtr_dev->dev, name);
                if (IS_ERR(clk)) {
                        return dev_err_probe(gtr_dev->dev, PTR_ERR(clk),
                                             "Failed to get ref clock %u\n",
                                             refclk);
                }

                if (!clk)
                        continue;

                gtr_dev->clk[refclk] = clk;
        }

        return 0;
}

static int xpsgtr_probe(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct xpsgtr_dev *gtr_dev;
        struct phy_provider *provider;
        unsigned int port;
        int ret;

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

        gtr_dev->dev = &pdev->dev;
        platform_set_drvdata(pdev, gtr_dev);

        mutex_init(&gtr_dev->gtr_mutex);

        if (of_device_is_compatible(np, "xlnx,zynqmp-psgtr"))
                gtr_dev->tx_term_fix =
                        of_property_read_bool(np, "xlnx,tx-termination-fix");

        /* Acquire resources. */
        gtr_dev->serdes = devm_platform_ioremap_resource_byname(pdev, "serdes");
        if (IS_ERR(gtr_dev->serdes))
                return PTR_ERR(gtr_dev->serdes);

        gtr_dev->siou = devm_platform_ioremap_resource_byname(pdev, "siou");
        if (IS_ERR(gtr_dev->siou))
                return PTR_ERR(gtr_dev->siou);

        ret = xpsgtr_get_ref_clocks(gtr_dev);
        if (ret)
                return ret;

        /* Create PHYs. */
        for (port = 0; port < ARRAY_SIZE(gtr_dev->phys); ++port) {
                struct xpsgtr_phy *gtr_phy = &gtr_dev->phys[port];
                struct phy *phy;

                gtr_phy->lane = port;
                gtr_phy->dev = gtr_dev;

                phy = devm_phy_create(&pdev->dev, np, &xpsgtr_phyops);
                if (IS_ERR(phy)) {
                        dev_err(&pdev->dev, "failed to create PHY\n");
                        return PTR_ERR(phy);
                }

                gtr_phy->phy = phy;
                phy_set_drvdata(phy, gtr_phy);
                debugfs_create_devm_seqfile(&phy->dev, "status", phy->debugfs,
                                            xpsgtr_status_read);
        }

        /* Register the PHY provider. */
        provider = devm_of_phy_provider_register(&pdev->dev, xpsgtr_xlate);
        if (IS_ERR(provider)) {
                dev_err(&pdev->dev, "registering provider failed\n");
                return PTR_ERR(provider);
        }

        pm_runtime_set_active(gtr_dev->dev);
        pm_runtime_enable(gtr_dev->dev);

        ret = pm_runtime_resume_and_get(gtr_dev->dev);
        if (ret < 0) {
                pm_runtime_disable(gtr_dev->dev);
                return ret;
        }

        gtr_dev->saved_regs = devm_kmalloc(gtr_dev->dev,
                                           sizeof(save_reg_address),
                                           GFP_KERNEL);
        if (!gtr_dev->saved_regs)
                return -ENOMEM;

        return 0;
}

static void xpsgtr_remove(struct platform_device *pdev)
{
        struct xpsgtr_dev *gtr_dev = platform_get_drvdata(pdev);

        pm_runtime_disable(gtr_dev->dev);
        pm_runtime_put_noidle(gtr_dev->dev);
        pm_runtime_set_suspended(gtr_dev->dev);
}

static const struct of_device_id xpsgtr_of_match[] = {
        { .compatible = "xlnx,zynqmp-psgtr", },
        { .compatible = "xlnx,zynqmp-psgtr-v1.1", },
        {},
};
MODULE_DEVICE_TABLE(of, xpsgtr_of_match);

static struct platform_driver xpsgtr_driver = {
        .probe = xpsgtr_probe,
        .remove = xpsgtr_remove,
        .driver = {
                .name = "xilinx-psgtr",
                .of_match_table = xpsgtr_of_match,
                .pm =  pm_ptr(&xpsgtr_pm_ops),
        },
};

module_platform_driver(xpsgtr_driver);

MODULE_AUTHOR("Xilinx Inc.");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Xilinx ZynqMP High speed Gigabit Transceiver");