drivers/phy/mediatek/phy-mtk-dp.c

// SPDX-License-Identifier: GPL-2.0
/*
 * MediaTek DisplayPort PHY driver
 *
 * Copyright (c) 2022, BayLibre Inc.
 * Copyright (c) 2022, MediaTek Inc.
 */

#include <linux/delay.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define PHY_OFFSET			0x1000

#define MTK_DP_PHY_DIG_PLL_CTL_1	(PHY_OFFSET + 0x14)
#define TPLL_SSC_EN			BIT(3)

#define MTK_DP_PHY_DIG_BIT_RATE		(PHY_OFFSET + 0x3C)
#define BIT_RATE_RBR			0
#define BIT_RATE_HBR			1
#define BIT_RATE_HBR2			2
#define BIT_RATE_HBR3			3

#define MTK_DP_PHY_DIG_SW_RST		(PHY_OFFSET + 0x38)
#define DP_GLB_SW_RST_PHYD		BIT(0)

#define MTK_DP_LANE0_DRIVING_PARAM_3		(PHY_OFFSET + 0x138)
#define MTK_DP_LANE1_DRIVING_PARAM_3		(PHY_OFFSET + 0x238)
#define MTK_DP_LANE2_DRIVING_PARAM_3		(PHY_OFFSET + 0x338)
#define MTK_DP_LANE3_DRIVING_PARAM_3		(PHY_OFFSET + 0x438)
#define XTP_LN_TX_LCTXC0_SW0_PRE0_DEFAULT	BIT(4)
#define XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT	(BIT(10) | BIT(12))
#define XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT	GENMASK(20, 19)
#define XTP_LN_TX_LCTXC0_SW0_PRE3_DEFAULT	GENMASK(29, 29)
#define DRIVING_PARAM_3_DEFAULT	(XTP_LN_TX_LCTXC0_SW0_PRE0_DEFAULT | \
				 XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT | \
				 XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT | \
				 XTP_LN_TX_LCTXC0_SW0_PRE3_DEFAULT)

#define XTP_LN_TX_LCTXC0_SW1_PRE0_DEFAULT	GENMASK(4, 3)
#define XTP_LN_TX_LCTXC0_SW1_PRE1_DEFAULT	GENMASK(12, 9)
#define XTP_LN_TX_LCTXC0_SW1_PRE2_DEFAULT	(BIT(18) | BIT(21))
#define XTP_LN_TX_LCTXC0_SW2_PRE0_DEFAULT	GENMASK(29, 29)
#define DRIVING_PARAM_4_DEFAULT	(XTP_LN_TX_LCTXC0_SW1_PRE0_DEFAULT | \
				 XTP_LN_TX_LCTXC0_SW1_PRE1_DEFAULT | \
				 XTP_LN_TX_LCTXC0_SW1_PRE2_DEFAULT | \
				 XTP_LN_TX_LCTXC0_SW2_PRE0_DEFAULT)

#define XTP_LN_TX_LCTXC0_SW2_PRE1_DEFAULT	(BIT(3) | BIT(5))
#define XTP_LN_TX_LCTXC0_SW3_PRE0_DEFAULT	GENMASK(13, 12)
#define DRIVING_PARAM_5_DEFAULT	(XTP_LN_TX_LCTXC0_SW2_PRE1_DEFAULT | \
				 XTP_LN_TX_LCTXC0_SW3_PRE0_DEFAULT)

#define XTP_LN_TX_LCTXCP1_SW0_PRE0_DEFAULT	0
#define XTP_LN_TX_LCTXCP1_SW0_PRE1_DEFAULT	GENMASK(10, 10)
#define XTP_LN_TX_LCTXCP1_SW0_PRE2_DEFAULT	GENMASK(19, 19)
#define XTP_LN_TX_LCTXCP1_SW0_PRE3_DEFAULT	GENMASK(28, 28)
#define DRIVING_PARAM_6_DEFAULT	(XTP_LN_TX_LCTXCP1_SW0_PRE0_DEFAULT | \
				 XTP_LN_TX_LCTXCP1_SW0_PRE1_DEFAULT | \
				 XTP_LN_TX_LCTXCP1_SW0_PRE2_DEFAULT | \
				 XTP_LN_TX_LCTXCP1_SW0_PRE3_DEFAULT)

#define XTP_LN_TX_LCTXCP1_SW1_PRE0_DEFAULT	0
#define XTP_LN_TX_LCTXCP1_SW1_PRE1_DEFAULT	GENMASK(10, 9)
#define XTP_LN_TX_LCTXCP1_SW1_PRE2_DEFAULT	GENMASK(19, 18)
#define XTP_LN_TX_LCTXCP1_SW2_PRE0_DEFAULT	0
#define DRIVING_PARAM_7_DEFAULT	(XTP_LN_TX_LCTXCP1_SW1_PRE0_DEFAULT | \
				 XTP_LN_TX_LCTXCP1_SW1_PRE1_DEFAULT | \
				 XTP_LN_TX_LCTXCP1_SW1_PRE2_DEFAULT | \
				 XTP_LN_TX_LCTXCP1_SW2_PRE0_DEFAULT)

#define XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT	GENMASK(3, 3)
#define XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT	0
#define DRIVING_PARAM_8_DEFAULT	(XTP_LN_TX_LCTXCP1_SW2_PRE1_DEFAULT | \
				 XTP_LN_TX_LCTXCP1_SW3_PRE0_DEFAULT)

struct mtk_dp_phy {
	struct regmap *regs;
};

static int mtk_dp_phy_init(struct phy *phy)
{
	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
	static const u32 driving_params[] = {
		DRIVING_PARAM_3_DEFAULT,
		DRIVING_PARAM_4_DEFAULT,
		DRIVING_PARAM_5_DEFAULT,
		DRIVING_PARAM_6_DEFAULT,
		DRIVING_PARAM_7_DEFAULT,
		DRIVING_PARAM_8_DEFAULT
	};

	regmap_bulk_write(dp_phy->regs, MTK_DP_LANE0_DRIVING_PARAM_3,
			  driving_params, ARRAY_SIZE(driving_params));
	regmap_bulk_write(dp_phy->regs, MTK_DP_LANE1_DRIVING_PARAM_3,
			  driving_params, ARRAY_SIZE(driving_params));
	regmap_bulk_write(dp_phy->regs, MTK_DP_LANE2_DRIVING_PARAM_3,
			  driving_params, ARRAY_SIZE(driving_params));
	regmap_bulk_write(dp_phy->regs, MTK_DP_LANE3_DRIVING_PARAM_3,
			  driving_params, ARRAY_SIZE(driving_params));

	return 0;
}

static int mtk_dp_phy_configure(struct phy *phy, union phy_configure_opts *opts)
{
	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
	u32 val;

	if (opts->dp.set_rate) {
		switch (opts->dp.link_rate) {
		default:
			dev_err(&phy->dev,
				"Implementation error, unknown linkrate %x\n",
				opts->dp.link_rate);
			return -EINVAL;
		case 1620:
			val = BIT_RATE_RBR;
			break;
		case 2700:
			val = BIT_RATE_HBR;
			break;
		case 5400:
			val = BIT_RATE_HBR2;
			break;
		case 8100:
			val = BIT_RATE_HBR3;
			break;
		}
		regmap_write(dp_phy->regs, MTK_DP_PHY_DIG_BIT_RATE, val);
	}

	regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_PLL_CTL_1,
			   TPLL_SSC_EN, opts->dp.ssc ? TPLL_SSC_EN : 0);

	return 0;
}

static int mtk_dp_phy_reset(struct phy *phy)
{
	struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);

	regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_SW_RST,
			   DP_GLB_SW_RST_PHYD, 0);
	usleep_range(50, 200);
	regmap_update_bits(dp_phy->regs, MTK_DP_PHY_DIG_SW_RST,
			   DP_GLB_SW_RST_PHYD, 1);

	return 0;
}

static const struct phy_ops mtk_dp_phy_dev_ops = {
	.init = mtk_dp_phy_init,
	.configure = mtk_dp_phy_configure,
	.reset = mtk_dp_phy_reset,
	.owner = THIS_MODULE,
};

static int mtk_dp_phy_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct mtk_dp_phy *dp_phy;
	struct phy *phy;
	struct regmap *regs;

	regs = *(struct regmap **)dev->platform_data;
	if (!regs)
		return dev_err_probe(dev, EINVAL,
				     "No data passed, requires struct regmap**\n");

	dp_phy = devm_kzalloc(dev, sizeof(*dp_phy), GFP_KERNEL);
	if (!dp_phy)
		return -ENOMEM;

	dp_phy->regs = regs;
	phy = devm_phy_create(dev, NULL, &mtk_dp_phy_dev_ops);
	if (IS_ERR(phy))
		return dev_err_probe(dev, PTR_ERR(phy),
				     "Failed to create DP PHY\n");

	phy_set_drvdata(phy, dp_phy);
	if (!dev->of_node)
		phy_create_lookup(phy, "dp", dev_name(dev));

	return 0;
}

static struct platform_driver mtk_dp_phy_driver = {
	.probe = mtk_dp_phy_probe,
	.driver = {
		.name = "mediatek-dp-phy",
	},
};
module_platform_driver(mtk_dp_phy_driver);

MODULE_AUTHOR("Markus Schneider-Pargmann <msp@baylibre.com>");
MODULE_DESCRIPTION("MediaTek DP PHY Driver");
MODULE_LICENSE("GPL");