// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * MediaTek 10GE SerDes XFI T-PHY driver
 *
 * Copyright (c) 2024 Daniel Golle <daniel@makrotopia.org>
 *                    Bc-bocun Chen <bc-bocun.chen@mediatek.com>
 * based on mtk_usxgmii.c and mtk_sgmii.c found in MediaTek's SDK (GPL-2.0)
 * Copyright (c) 2022 MediaTek Inc.
 * Author: Henry Yen <henry.yen@mediatek.com>
 */

#include <linux/module.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/reset.h>
#include <linux/phy.h>
#include <linux/phy/phy.h>

#include "phy-mtk-io.h"

#define MTK_XFI_TPHY_NUM_CLOCKS         2

#define REG_DIG_GLB_70                  0x0070
#define  XTP_PCS_RX_EQ_IN_PROGRESS(x)   FIELD_PREP(GENMASK(25, 24), (x))
#define  XTP_PCS_MODE_MASK              GENMASK(17, 16)
#define  XTP_PCS_MODE(x)                FIELD_PREP(GENMASK(17, 16), (x))
#define  XTP_PCS_RST_B                  BIT(15)
#define  XTP_FRC_PCS_RST_B              BIT(14)
#define  XTP_PCS_PWD_SYNC_MASK          GENMASK(13, 12)
#define  XTP_PCS_PWD_SYNC(x)            FIELD_PREP(XTP_PCS_PWD_SYNC_MASK, (x))
#define  XTP_PCS_PWD_ASYNC_MASK         GENMASK(11, 10)
#define  XTP_PCS_PWD_ASYNC(x)           FIELD_PREP(XTP_PCS_PWD_ASYNC_MASK, (x))
#define  XTP_FRC_PCS_PWD_ASYNC          BIT(8)
#define  XTP_PCS_UPDT                   BIT(4)
#define  XTP_PCS_IN_FR_RG               BIT(0)

#define REG_DIG_GLB_F4                  0x00f4
#define  XFI_DPHY_PCS_SEL               BIT(0)
#define   XFI_DPHY_PCS_SEL_SGMII        FIELD_PREP(XFI_DPHY_PCS_SEL, 1)
#define   XFI_DPHY_PCS_SEL_USXGMII      FIELD_PREP(XFI_DPHY_PCS_SEL, 0)
#define  XFI_DPHY_AD_SGDT_FRC_EN        BIT(5)

#define REG_DIG_LN_TRX_40               0x3040
#define  XTP_LN_FRC_TX_DATA_EN          BIT(29)
#define  XTP_LN_TX_DATA_EN              BIT(28)

#define REG_DIG_LN_TRX_B0               0x30b0
#define  XTP_LN_FRC_TX_MACCK_EN         BIT(5)
#define  XTP_LN_TX_MACCK_EN             BIT(4)

#define REG_ANA_GLB_D0                  0x90d0
#define  XTP_GLB_USXGMII_SEL_MASK       GENMASK(3, 1)
#define  XTP_GLB_USXGMII_SEL(x)         FIELD_PREP(GENMASK(3, 1), (x))
#define  XTP_GLB_USXGMII_EN             BIT(0)

/**
 * struct mtk_xfi_tphy - run-time data of the XFI phy instance
 * @base: IO memory area to access phy registers.
 * @dev: Kernel device used to output prefixed debug info.
 * @reset: Reset control corresponding to the phy instance.
 * @clocks: All clocks required for the phy to operate.
 * @da_war: Enables work-around for 10GBase-R mode.
 */
struct mtk_xfi_tphy {
        void __iomem            *base;
        struct device           *dev;
        struct reset_control    *reset;
        struct clk_bulk_data    clocks[MTK_XFI_TPHY_NUM_CLOCKS];
        bool                    da_war;
};

/**
 * mtk_xfi_tphy_setup() - Setup phy for specified interface mode.
 * @xfi_tphy: XFI phy instance.
 * @interface: Ethernet interface mode
 *
 * The setup function is the condensed result of combining the 5 functions which
 * setup the phy in MediaTek's GPL licensed public SDK sources. They can be found
 * in mtk_sgmii.c[1] as well as mtk_usxgmii.c[2].
 *
 * Many magic values have been replaced by register and bit definitions, however,
 * that has not been possible in all cases. While the vendor driver uses a
 * sequence of 32-bit writes, here we try to only modify the actually required
 * bits.
 *
 * [1]: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/b72d6cba92bf9e29fb035c03052fa1e86664a25b/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_sgmii.c
 *
 * [2]: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/dec96a1d9b82cdcda4a56453fd0b453d4cab4b85/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_eth_soc.c
 */
static void mtk_xfi_tphy_setup(struct mtk_xfi_tphy *xfi_tphy,
                               phy_interface_t interface)
{
        bool is_1g, is_2p5g, is_5g, is_10g, da_war, use_lynxi_pcs;

        /* shorthands for specific clock speeds depending on interface mode */
        is_1g = interface == PHY_INTERFACE_MODE_1000BASEX ||
                interface == PHY_INTERFACE_MODE_SGMII;
        is_2p5g = interface == PHY_INTERFACE_MODE_2500BASEX;
        is_5g = interface == PHY_INTERFACE_MODE_5GBASER;
        is_10g = interface == PHY_INTERFACE_MODE_10GBASER ||
                 interface == PHY_INTERFACE_MODE_USXGMII;

        /* Is overriding 10GBase-R tuning value required? */
        da_war = xfi_tphy->da_war && (interface == PHY_INTERFACE_MODE_10GBASER);

        /* configure input mux to either
         *  - USXGMII PCS (64b/66b coding) for 5G/10G
         *  - LynxI PCS (8b/10b coding) for 1G/2.5G
         */
        use_lynxi_pcs = is_1g || is_2p5g;

        dev_dbg(xfi_tphy->dev, "setting up for mode %s\n", phy_modes(interface));

        /* Setup PLL setting */
        mtk_phy_update_bits(xfi_tphy->base + 0x9024, 0x100000, is_10g ? 0x0 : 0x100000);
        mtk_phy_update_bits(xfi_tphy->base + 0x2020, 0x202000, is_5g ? 0x202000 : 0x0);
        mtk_phy_update_bits(xfi_tphy->base + 0x2030, 0x500, is_1g ? 0x0 : 0x500);
        mtk_phy_update_bits(xfi_tphy->base + 0x2034, 0xa00, is_1g ? 0x0 : 0xa00);
        mtk_phy_update_bits(xfi_tphy->base + 0x2040, 0x340000, is_1g ? 0x200000 : 0x140000);

        /* Setup RXFE BW setting */
        mtk_phy_update_bits(xfi_tphy->base + 0x50f0, 0xc10, is_1g ? 0x410 : is_5g ? 0x800 : 0x400);
        mtk_phy_update_bits(xfi_tphy->base + 0x50e0, 0x4000, is_5g ? 0x0 : 0x4000);

        /* Setup RX CDR setting */
        mtk_phy_update_bits(xfi_tphy->base + 0x506c, 0x30000, is_5g ? 0x0 : 0x30000);
        mtk_phy_update_bits(xfi_tphy->base + 0x5070, 0x670000, is_5g ? 0x620000 : 0x50000);
        mtk_phy_update_bits(xfi_tphy->base + 0x5074, 0x180000, is_5g ? 0x180000 : 0x0);
        mtk_phy_update_bits(xfi_tphy->base + 0x5078, 0xf000400, is_5g ? 0x8000000 :
                                                                        0x7000400);
        mtk_phy_update_bits(xfi_tphy->base + 0x507c, 0x5000500, is_5g ? 0x4000400 :
                                                                        0x1000100);
        mtk_phy_update_bits(xfi_tphy->base + 0x5080, 0x1410, is_1g ? 0x400 : is_5g ? 0x1010 : 0x0);
        mtk_phy_update_bits(xfi_tphy->base + 0x5084, 0x30300, is_1g ? 0x30300 :
                                                              is_5g ? 0x30100 :
                                                                      0x100);
        mtk_phy_update_bits(xfi_tphy->base + 0x5088, 0x60200, is_1g ? 0x20200 :
                                                              is_5g ? 0x40000 :
                                                                      0x20000);

        /* Setting RXFE adaptation range setting */
        mtk_phy_update_bits(xfi_tphy->base + 0x50e4, 0xc0000, is_5g ? 0x0 : 0xc0000);
        mtk_phy_update_bits(xfi_tphy->base + 0x50e8, 0x40000, is_5g ? 0x0 : 0x40000);
        mtk_phy_update_bits(xfi_tphy->base + 0x50ec, 0xa00, is_1g ? 0x200 : 0x800);
        mtk_phy_update_bits(xfi_tphy->base + 0x50a8, 0xee0000, is_5g ? 0x800000 :
                                                                       0x6e0000);
        mtk_phy_update_bits(xfi_tphy->base + 0x6004, 0x190000, is_5g ? 0x0 : 0x190000);

        if (is_10g)
                writel(0x01423342, xfi_tphy->base + 0x00f8);
        else if (is_5g)
                writel(0x00a132a1, xfi_tphy->base + 0x00f8);
        else if (is_2p5g)
                writel(0x009c329c, xfi_tphy->base + 0x00f8);
        else
                writel(0x00fa32fa, xfi_tphy->base + 0x00f8);

        /* Force SGDT_OUT off and select PCS */
        mtk_phy_update_bits(xfi_tphy->base + REG_DIG_GLB_F4,
                            XFI_DPHY_AD_SGDT_FRC_EN | XFI_DPHY_PCS_SEL,
                            XFI_DPHY_AD_SGDT_FRC_EN |
                            (use_lynxi_pcs ? XFI_DPHY_PCS_SEL_SGMII :
                                             XFI_DPHY_PCS_SEL_USXGMII));

        /* Force GLB_CKDET_OUT */
        mtk_phy_set_bits(xfi_tphy->base + 0x0030, 0xc00);

        /* Force AEQ on */
        writel(XTP_PCS_RX_EQ_IN_PROGRESS(2) | XTP_PCS_PWD_SYNC(2) | XTP_PCS_PWD_ASYNC(2),
               xfi_tphy->base + REG_DIG_GLB_70);

        usleep_range(1, 5);
        writel(XTP_LN_FRC_TX_DATA_EN, xfi_tphy->base + REG_DIG_LN_TRX_40);

        /* Setup TX DA default value */
        mtk_phy_update_bits(xfi_tphy->base + 0x30b0, 0x30, 0x20);
        writel(0x00008a01, xfi_tphy->base + 0x3028);
        writel(0x0000a884, xfi_tphy->base + 0x302c);
        writel(0x00083002, xfi_tphy->base + 0x3024);

        /* Setup RG default value */
        if (use_lynxi_pcs) {
                writel(0x00011110, xfi_tphy->base + 0x3010);
                writel(0x40704000, xfi_tphy->base + 0x3048);
        } else {
                writel(0x00022220, xfi_tphy->base + 0x3010);
                writel(0x0f020a01, xfi_tphy->base + 0x5064);
                writel(0x06100600, xfi_tphy->base + 0x50b4);
                if (interface == PHY_INTERFACE_MODE_USXGMII)
                        writel(0x40704000, xfi_tphy->base + 0x3048);
                else
                        writel(0x47684100, xfi_tphy->base + 0x3048);
        }

        if (is_1g)
                writel(0x0000c000, xfi_tphy->base + 0x3064);

        /* Setup RX EQ initial value */
        mtk_phy_update_bits(xfi_tphy->base + 0x3050, 0xa8000000,
                            (interface != PHY_INTERFACE_MODE_10GBASER) ? 0xa8000000 : 0x0);
        mtk_phy_update_bits(xfi_tphy->base + 0x3054, 0xaa,
                            (interface != PHY_INTERFACE_MODE_10GBASER) ? 0xaa : 0x0);

        if (!use_lynxi_pcs)
                writel(0x00000f00, xfi_tphy->base + 0x306c);
        else if (is_2p5g)
                writel(0x22000f00, xfi_tphy->base + 0x306c);
        else
                writel(0x20200f00, xfi_tphy->base + 0x306c);

        mtk_phy_update_bits(xfi_tphy->base + 0xa008, 0x10000, da_war ? 0x10000 : 0x0);

        mtk_phy_update_bits(xfi_tphy->base + 0xa060, 0x50000, use_lynxi_pcs ? 0x50000 : 0x40000);

        /* Setup PHYA speed */
        mtk_phy_update_bits(xfi_tphy->base + REG_ANA_GLB_D0,
                            XTP_GLB_USXGMII_SEL_MASK | XTP_GLB_USXGMII_EN,
                            is_10g ?  XTP_GLB_USXGMII_SEL(0) :
                            is_5g ?   XTP_GLB_USXGMII_SEL(1) :
                            is_2p5g ? XTP_GLB_USXGMII_SEL(2) :
                                      XTP_GLB_USXGMII_SEL(3));
        mtk_phy_set_bits(xfi_tphy->base + REG_ANA_GLB_D0, XTP_GLB_USXGMII_EN);

        /* Release reset */
        mtk_phy_set_bits(xfi_tphy->base + REG_DIG_GLB_70,
                         XTP_PCS_RST_B | XTP_FRC_PCS_RST_B);
        usleep_range(150, 500);

        /* Switch to P0 */
        mtk_phy_update_bits(xfi_tphy->base + REG_DIG_GLB_70,
                            XTP_PCS_IN_FR_RG |
                            XTP_FRC_PCS_PWD_ASYNC |
                            XTP_PCS_PWD_ASYNC_MASK |
                            XTP_PCS_PWD_SYNC_MASK |
                            XTP_PCS_UPDT,
                            XTP_PCS_IN_FR_RG |
                            XTP_FRC_PCS_PWD_ASYNC |
                            XTP_PCS_UPDT);
        usleep_range(1, 5);

        mtk_phy_clear_bits(xfi_tphy->base + REG_DIG_GLB_70, XTP_PCS_UPDT);
        usleep_range(15, 50);

        if (use_lynxi_pcs) {
                /* Switch to Gen2 */
                mtk_phy_update_bits(xfi_tphy->base + REG_DIG_GLB_70,
                                    XTP_PCS_MODE_MASK | XTP_PCS_UPDT,
                                    XTP_PCS_MODE(1) | XTP_PCS_UPDT);
        } else {
                /* Switch to Gen3 */
                mtk_phy_update_bits(xfi_tphy->base + REG_DIG_GLB_70,
                                    XTP_PCS_MODE_MASK | XTP_PCS_UPDT,
                                    XTP_PCS_MODE(2) | XTP_PCS_UPDT);
        }
        usleep_range(1, 5);

        mtk_phy_clear_bits(xfi_tphy->base + REG_DIG_GLB_70, XTP_PCS_UPDT);

        usleep_range(100, 500);

        /* Enable MAC CK */
        mtk_phy_set_bits(xfi_tphy->base + REG_DIG_LN_TRX_B0, XTP_LN_TX_MACCK_EN);
        mtk_phy_clear_bits(xfi_tphy->base + REG_DIG_GLB_F4, XFI_DPHY_AD_SGDT_FRC_EN);

        /* Enable TX data */
        mtk_phy_set_bits(xfi_tphy->base + REG_DIG_LN_TRX_40,
                         XTP_LN_FRC_TX_DATA_EN | XTP_LN_TX_DATA_EN);
        usleep_range(400, 1000);
}

/**
 * mtk_xfi_tphy_set_mode() - Setup phy for specified interface mode.
 *
 * @phy: Phy instance.
 * @mode: Only PHY_MODE_ETHERNET is supported.
 * @submode: An Ethernet interface mode.
 *
 * Validate selected mode and call function mtk_xfi_tphy_setup().
 *
 * Return:
 * * %0 - OK
 * * %-EINVAL - invalid mode
 */
static int mtk_xfi_tphy_set_mode(struct phy *phy, enum phy_mode mode, int
                                 submode)
{
        struct mtk_xfi_tphy *xfi_tphy = phy_get_drvdata(phy);

        if (mode != PHY_MODE_ETHERNET)
                return -EINVAL;

        switch (submode) {
        case PHY_INTERFACE_MODE_1000BASEX:
        case PHY_INTERFACE_MODE_2500BASEX:
        case PHY_INTERFACE_MODE_SGMII:
        case PHY_INTERFACE_MODE_5GBASER:
        case PHY_INTERFACE_MODE_10GBASER:
        case PHY_INTERFACE_MODE_USXGMII:
                mtk_xfi_tphy_setup(xfi_tphy, submode);
                return 0;
        default:
                return -EINVAL;
        }
}

/**
 * mtk_xfi_tphy_reset() - Reset the phy.
 *
 * @phy: Phy instance.
 *
 * Reset the phy using the external reset controller.
 *
 * Return:
 * %0 - OK
 */
static int mtk_xfi_tphy_reset(struct phy *phy)
{
        struct mtk_xfi_tphy *xfi_tphy = phy_get_drvdata(phy);

        reset_control_assert(xfi_tphy->reset);
        usleep_range(100, 500);
        reset_control_deassert(xfi_tphy->reset);
        usleep_range(1, 10);

        return 0;
}

/**
 * mtk_xfi_tphy_power_on() - Power-on the phy.
 *
 * @phy: Phy instance.
 *
 * Prepare and enable all clocks required for the phy to operate.
 *
 * Return:
 * See clk_bulk_prepare_enable().
 */
static int mtk_xfi_tphy_power_on(struct phy *phy)
{
        struct mtk_xfi_tphy *xfi_tphy = phy_get_drvdata(phy);

        return clk_bulk_prepare_enable(MTK_XFI_TPHY_NUM_CLOCKS, xfi_tphy->clocks);
}

/**
 * mtk_xfi_tphy_power_off() - Power-off the phy.
 *
 * @phy: Phy instance.
 *
 * Disable and unprepare all clocks previously enabled.
 *
 * Return:
 * See clk_bulk_disable_unprepare().
 */
static int mtk_xfi_tphy_power_off(struct phy *phy)
{
        struct mtk_xfi_tphy *xfi_tphy = phy_get_drvdata(phy);

        clk_bulk_disable_unprepare(MTK_XFI_TPHY_NUM_CLOCKS, xfi_tphy->clocks);

        return 0;
}

static const struct phy_ops mtk_xfi_tphy_ops = {
        .power_on       = mtk_xfi_tphy_power_on,
        .power_off      = mtk_xfi_tphy_power_off,
        .set_mode       = mtk_xfi_tphy_set_mode,
        .reset          = mtk_xfi_tphy_reset,
        .owner          = THIS_MODULE,
};

/**
 * mtk_xfi_tphy_probe() - Probe phy instance from Device Tree.
 * @pdev: Matching platform device.
 *
 * The probe function gets IO resource, clocks, reset controller and
 * whether the DA work-around for 10GBase-R is required from Device Tree and
 * allocates memory for holding that information in a struct mtk_xfi_tphy.
 *
 * Return:
 * * %0       - OK
 * * %-ENODEV - Missing associated Device Tree node (should never happen).
 * * %-ENOMEM - Out of memory.
 * * Any error value which devm_platform_ioremap_resource(),
 *   devm_clk_bulk_get(), devm_reset_control_get_exclusive(),
 *   devm_phy_create() or devm_of_phy_provider_register() may return.
 */
static int mtk_xfi_tphy_probe(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct phy_provider *phy_provider;
        struct mtk_xfi_tphy *xfi_tphy;
        struct phy *phy;
        int ret;

        if (!np)
                return -ENODEV;

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

        xfi_tphy->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(xfi_tphy->base))
                return PTR_ERR(xfi_tphy->base);

        xfi_tphy->dev = &pdev->dev;
        xfi_tphy->clocks[0].id = "topxtal";
        xfi_tphy->clocks[1].id = "xfipll";
        ret = devm_clk_bulk_get(&pdev->dev, MTK_XFI_TPHY_NUM_CLOCKS, xfi_tphy->clocks);
        if (ret)
                return ret;

        xfi_tphy->reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
        if (IS_ERR(xfi_tphy->reset))
                return PTR_ERR(xfi_tphy->reset);

        xfi_tphy->da_war = of_property_read_bool(np, "mediatek,usxgmii-performance-errata");

        phy = devm_phy_create(&pdev->dev, NULL, &mtk_xfi_tphy_ops);
        if (IS_ERR(phy))
                return PTR_ERR(phy);

        phy_set_drvdata(phy, xfi_tphy);
        phy_provider = devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate);

        return PTR_ERR_OR_ZERO(phy_provider);
}

static const struct of_device_id mtk_xfi_tphy_match[] = {
        { .compatible = "mediatek,mt7988-xfi-tphy", },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mtk_xfi_tphy_match);

static struct platform_driver mtk_xfi_tphy_driver = {
        .probe = mtk_xfi_tphy_probe,
        .driver = {
                .name = "mtk-xfi-tphy",
                .of_match_table = mtk_xfi_tphy_match,
        },
};
module_platform_driver(mtk_xfi_tphy_driver);

MODULE_DESCRIPTION("MediaTek 10GE SerDes XFI T-PHY driver");
MODULE_AUTHOR("Daniel Golle <daniel@makrotopia.org>");
MODULE_AUTHOR("Bc-bocun Chen <bc-bocun.chen@mediatek.com>");
MODULE_LICENSE("GPL");