// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018 MediaTek Inc.
 */
#include <linux/bitfield.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_net.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/stmmac.h>

#include "stmmac.h"
#include "stmmac_platform.h"

/* Peri Configuration register for mt2712 */
#define PERI_ETH_PHY_INTF_SEL	0x418
#define PHY_INTF_MII		0
#define PHY_INTF_RGMII		1
#define PHY_INTF_RMII		4
#define RMII_CLK_SRC_RXC	BIT(4)
#define RMII_CLK_SRC_INTERNAL	BIT(5)

#define PERI_ETH_DLY	0x428
#define ETH_DLY_GTXC_INV	BIT(6)
#define ETH_DLY_GTXC_ENABLE	BIT(5)
#define ETH_DLY_GTXC_STAGES	GENMASK(4, 0)
#define ETH_DLY_TXC_INV		BIT(20)
#define ETH_DLY_TXC_ENABLE	BIT(19)
#define ETH_DLY_TXC_STAGES	GENMASK(18, 14)
#define ETH_DLY_RXC_INV		BIT(13)
#define ETH_DLY_RXC_ENABLE	BIT(12)
#define ETH_DLY_RXC_STAGES	GENMASK(11, 7)

#define PERI_ETH_DLY_FINE	0x800
#define ETH_RMII_DLY_TX_INV	BIT(2)
#define ETH_FINE_DLY_GTXC	BIT(1)
#define ETH_FINE_DLY_RXC	BIT(0)

struct mac_delay_struct {
	u32 tx_delay;
	u32 rx_delay;
	bool tx_inv;
	bool rx_inv;
};

struct mediatek_dwmac_plat_data {
	const struct mediatek_dwmac_variant *variant;
	struct mac_delay_struct mac_delay;
	struct clk_bulk_data *clks;
	struct device_node *np;
	struct regmap *peri_regmap;
	struct device *dev;
	int phy_mode;
	bool rmii_rxc;
};

struct mediatek_dwmac_variant {
	int (*dwmac_set_phy_interface)(struct mediatek_dwmac_plat_data *plat);
	int (*dwmac_set_delay)(struct mediatek_dwmac_plat_data *plat);

	/* clock ids to be requested */
	const char * const *clk_list;
	int num_clks;

	u32 dma_bit_mask;
	u32 rx_delay_max;
	u32 tx_delay_max;
};

/* list of clocks required for mac */
static const char * const mt2712_dwmac_clk_l[] = {
	"axi", "apb", "mac_main", "ptp_ref"
};

static int mt2712_set_interface(struct mediatek_dwmac_plat_data *plat)
{
	int rmii_rxc = plat->rmii_rxc ? RMII_CLK_SRC_RXC : 0;
	u32 intf_val = 0;

	/* select phy interface in top control domain */
	switch (plat->phy_mode) {
	case PHY_INTERFACE_MODE_MII:
		intf_val |= PHY_INTF_MII;
		break;
	case PHY_INTERFACE_MODE_RMII:
		intf_val |= (PHY_INTF_RMII | rmii_rxc);
		break;
	case PHY_INTERFACE_MODE_RGMII:
	case PHY_INTERFACE_MODE_RGMII_TXID:
	case PHY_INTERFACE_MODE_RGMII_RXID:
	case PHY_INTERFACE_MODE_RGMII_ID:
		intf_val |= PHY_INTF_RGMII;
		break;
	default:
		dev_err(plat->dev, "phy interface not supported\n");
		return -EINVAL;
	}

	regmap_write(plat->peri_regmap, PERI_ETH_PHY_INTF_SEL, intf_val);

	return 0;
}

static void mt2712_delay_ps2stage(struct mediatek_dwmac_plat_data *plat)
{
	struct mac_delay_struct *mac_delay = &plat->mac_delay;

	switch (plat->phy_mode) {
	case PHY_INTERFACE_MODE_MII:
	case PHY_INTERFACE_MODE_RMII:
		/* 550ps per stage for MII/RMII */
		mac_delay->tx_delay /= 550;
		mac_delay->rx_delay /= 550;
		break;
	case PHY_INTERFACE_MODE_RGMII:
	case PHY_INTERFACE_MODE_RGMII_TXID:
	case PHY_INTERFACE_MODE_RGMII_RXID:
	case PHY_INTERFACE_MODE_RGMII_ID:
		/* 170ps per stage for RGMII */
		mac_delay->tx_delay /= 170;
		mac_delay->rx_delay /= 170;
		break;
	default:
		dev_err(plat->dev, "phy interface not supported\n");
		break;
	}
}

static int mt2712_set_delay(struct mediatek_dwmac_plat_data *plat)
{
	struct mac_delay_struct *mac_delay = &plat->mac_delay;
	u32 delay_val = 0, fine_val = 0;

	mt2712_delay_ps2stage(plat);

	switch (plat->phy_mode) {
	case PHY_INTERFACE_MODE_MII:
		delay_val |= FIELD_PREP(ETH_DLY_TXC_ENABLE, !!mac_delay->tx_delay);
		delay_val |= FIELD_PREP(ETH_DLY_TXC_STAGES, mac_delay->tx_delay);
		delay_val |= FIELD_PREP(ETH_DLY_TXC_INV, mac_delay->tx_inv);

		delay_val |= FIELD_PREP(ETH_DLY_RXC_ENABLE, !!mac_delay->rx_delay);
		delay_val |= FIELD_PREP(ETH_DLY_RXC_STAGES, mac_delay->rx_delay);
		delay_val |= FIELD_PREP(ETH_DLY_RXC_INV, mac_delay->rx_inv);
		break;
	case PHY_INTERFACE_MODE_RMII:
		/* the rmii reference clock is from external phy,
		 * and the property "rmii_rxc" indicates which pin(TXC/RXC)
		 * the reference clk is connected to. The reference clock is a
		 * received signal, so rx_delay/rx_inv are used to indicate
		 * the reference clock timing adjustment
		 */
		if (plat->rmii_rxc) {
			/* the rmii reference clock from outside is connected
			 * to RXC pin, the reference clock will be adjusted
			 * by RXC delay macro circuit.
			 */
			delay_val |= FIELD_PREP(ETH_DLY_RXC_ENABLE, !!mac_delay->rx_delay);
			delay_val |= FIELD_PREP(ETH_DLY_RXC_STAGES, mac_delay->rx_delay);
			delay_val |= FIELD_PREP(ETH_DLY_RXC_INV, mac_delay->rx_inv);
		} else {
			/* the rmii reference clock from outside is connected
			 * to TXC pin, the reference clock will be adjusted
			 * by TXC delay macro circuit.
			 */
			delay_val |= FIELD_PREP(ETH_DLY_TXC_ENABLE, !!mac_delay->rx_delay);
			delay_val |= FIELD_PREP(ETH_DLY_TXC_STAGES, mac_delay->rx_delay);
			delay_val |= FIELD_PREP(ETH_DLY_TXC_INV, mac_delay->rx_inv);
		}
		/* tx_inv will inverse the tx clock inside mac relateive to
		 * reference clock from external phy,
		 * and this bit is located in the same register with fine-tune
		 */
		if (mac_delay->tx_inv)
			fine_val = ETH_RMII_DLY_TX_INV;
		break;
	case PHY_INTERFACE_MODE_RGMII:
	case PHY_INTERFACE_MODE_RGMII_TXID:
	case PHY_INTERFACE_MODE_RGMII_RXID:
	case PHY_INTERFACE_MODE_RGMII_ID:
		fine_val = ETH_FINE_DLY_GTXC | ETH_FINE_DLY_RXC;

		delay_val |= FIELD_PREP(ETH_DLY_GTXC_ENABLE, !!mac_delay->tx_delay);
		delay_val |= FIELD_PREP(ETH_DLY_GTXC_STAGES, mac_delay->tx_delay);
		delay_val |= FIELD_PREP(ETH_DLY_GTXC_INV, mac_delay->tx_inv);

		delay_val |= FIELD_PREP(ETH_DLY_RXC_ENABLE, !!mac_delay->rx_delay);
		delay_val |= FIELD_PREP(ETH_DLY_RXC_STAGES, mac_delay->rx_delay);
		delay_val |= FIELD_PREP(ETH_DLY_RXC_INV, mac_delay->rx_inv);
		break;
	default:
		dev_err(plat->dev, "phy interface not supported\n");
		return -EINVAL;
	}
	regmap_write(plat->peri_regmap, PERI_ETH_DLY, delay_val);
	regmap_write(plat->peri_regmap, PERI_ETH_DLY_FINE, fine_val);

	return 0;
}

static const struct mediatek_dwmac_variant mt2712_gmac_variant = {
		.dwmac_set_phy_interface = mt2712_set_interface,
		.dwmac_set_delay = mt2712_set_delay,
		.clk_list = mt2712_dwmac_clk_l,
		.num_clks = ARRAY_SIZE(mt2712_dwmac_clk_l),
		.dma_bit_mask = 33,
		.rx_delay_max = 17600,
		.tx_delay_max = 17600,
};

static int mediatek_dwmac_config_dt(struct mediatek_dwmac_plat_data *plat)
{
	struct mac_delay_struct *mac_delay = &plat->mac_delay;
	u32 tx_delay_ps, rx_delay_ps;

	plat->peri_regmap = syscon_regmap_lookup_by_phandle(plat->np, "mediatek,pericfg");
	if (IS_ERR(plat->peri_regmap)) {
		dev_err(plat->dev, "Failed to get pericfg syscon\n");
		return PTR_ERR(plat->peri_regmap);
	}

	plat->phy_mode = of_get_phy_mode(plat->np);
	if (plat->phy_mode < 0) {
		dev_err(plat->dev, "not find phy-mode\n");
		return -EINVAL;
	}

	if (!of_property_read_u32(plat->np, "mediatek,tx-delay-ps", &tx_delay_ps)) {
		if (tx_delay_ps < plat->variant->tx_delay_max) {
			mac_delay->tx_delay = tx_delay_ps;
		} else {
			dev_err(plat->dev, "Invalid TX clock delay: %dps\n", tx_delay_ps);
			return -EINVAL;
		}
	}

	if (!of_property_read_u32(plat->np, "mediatek,rx-delay-ps", &rx_delay_ps)) {
		if (rx_delay_ps < plat->variant->rx_delay_max) {
			mac_delay->rx_delay = rx_delay_ps;
		} else {
			dev_err(plat->dev, "Invalid RX clock delay: %dps\n", rx_delay_ps);
			return -EINVAL;
		}
	}

	mac_delay->tx_inv = of_property_read_bool(plat->np, "mediatek,txc-inverse");
	mac_delay->rx_inv = of_property_read_bool(plat->np, "mediatek,rxc-inverse");
	plat->rmii_rxc = of_property_read_bool(plat->np, "mediatek,rmii-rxc");

	return 0;
}

static int mediatek_dwmac_clk_init(struct mediatek_dwmac_plat_data *plat)
{
	const struct mediatek_dwmac_variant *variant = plat->variant;
	int i, num = variant->num_clks;

	plat->clks = devm_kcalloc(plat->dev, num, sizeof(*plat->clks), GFP_KERNEL);
	if (!plat->clks)
		return -ENOMEM;

	for (i = 0; i < num; i++)
		plat->clks[i].id = variant->clk_list[i];

	return devm_clk_bulk_get(plat->dev, num, plat->clks);
}

static int mediatek_dwmac_init(struct platform_device *pdev, void *priv)
{
	struct mediatek_dwmac_plat_data *plat = priv;
	const struct mediatek_dwmac_variant *variant = plat->variant;
	int ret;

	ret = dma_set_mask_and_coherent(plat->dev, DMA_BIT_MASK(variant->dma_bit_mask));
	if (ret) {
		dev_err(plat->dev, "No suitable DMA available, err = %d\n", ret);
		return ret;
	}

	ret = variant->dwmac_set_phy_interface(plat);
	if (ret) {
		dev_err(plat->dev, "failed to set phy interface, err = %d\n", ret);
		return ret;
	}

	ret = variant->dwmac_set_delay(plat);
	if (ret) {
		dev_err(plat->dev, "failed to set delay value, err = %d\n", ret);
		return ret;
	}

	ret = clk_bulk_prepare_enable(variant->num_clks, plat->clks);
	if (ret) {
		dev_err(plat->dev, "failed to enable clks, err = %d\n", ret);
		return ret;
	}

	pm_runtime_enable(&pdev->dev);
	pm_runtime_get_sync(&pdev->dev);

	return 0;
}

static void mediatek_dwmac_exit(struct platform_device *pdev, void *priv)
{
	struct mediatek_dwmac_plat_data *plat = priv;
	const struct mediatek_dwmac_variant *variant = plat->variant;

	clk_bulk_disable_unprepare(variant->num_clks, plat->clks);

	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
}

static int mediatek_dwmac_probe(struct platform_device *pdev)
{
	struct mediatek_dwmac_plat_data *priv_plat;
	struct plat_stmmacenet_data *plat_dat;
	struct stmmac_resources stmmac_res;
	int ret;

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

	priv_plat->variant = of_device_get_match_data(&pdev->dev);
	if (!priv_plat->variant) {
		dev_err(&pdev->dev, "Missing dwmac-mediatek variant\n");
		return -EINVAL;
	}

	priv_plat->dev = &pdev->dev;
	priv_plat->np = pdev->dev.of_node;

	ret = mediatek_dwmac_config_dt(priv_plat);
	if (ret)
		return ret;

	ret = mediatek_dwmac_clk_init(priv_plat);
	if (ret)
		return ret;

	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
	if (ret)
		return ret;

	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
	if (IS_ERR(plat_dat))
		return PTR_ERR(plat_dat);

	plat_dat->interface = priv_plat->phy_mode;
	plat_dat->has_gmac4 = 1;
	plat_dat->has_gmac = 0;
	plat_dat->pmt = 0;
	plat_dat->riwt_off = 1;
	plat_dat->maxmtu = ETH_DATA_LEN;
	plat_dat->bsp_priv = priv_plat;
	plat_dat->init = mediatek_dwmac_init;
	plat_dat->exit = mediatek_dwmac_exit;
	mediatek_dwmac_init(pdev, priv_plat);

	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
	if (ret) {
		stmmac_remove_config_dt(pdev, plat_dat);
		return ret;
	}

	return 0;
}

static const struct of_device_id mediatek_dwmac_match[] = {
	{ .compatible = "mediatek,mt2712-gmac",
	  .data = &mt2712_gmac_variant },
	{ }
};

MODULE_DEVICE_TABLE(of, mediatek_dwmac_match);

static struct platform_driver mediatek_dwmac_driver = {
	.probe  = mediatek_dwmac_probe,
	.remove = stmmac_pltfr_remove,
	.driver = {
		.name           = "dwmac-mediatek",
		.pm		= &stmmac_pltfr_pm_ops,
		.of_match_table = mediatek_dwmac_match,
	},
};
module_platform_driver(mediatek_dwmac_driver);

MODULE_AUTHOR("Biao Huang <biao.huang@mediatek.com>");
MODULE_DESCRIPTION("MediaTek DWMAC specific glue layer");
MODULE_LICENSE("GPL v2");