linux/drivers/phy/eswin/phy-eic7700-sata.c

// SPDX-License-Identifier: GPL-2.0
/*
 * ESWIN SATA PHY driver
 *
 * Copyright 2026, Beijing ESWIN Computing Technology Co., Ltd..
 * All rights reserved.
 *
 * Authors: Yulin Lu <luyulin@eswincomputing.com>
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset.h>

#define SATA_AXI_LP_CTRL			0x08
#define SATA_MPLL_CTRL				0x20
#define SATA_P0_PHY_STAT			0x24
#define SATA_PHY_CTRL0				0x28
#define SATA_PHY_CTRL1				0x2c
#define SATA_REF_CTRL				0x34
#define SATA_REF_CTRL1				0x38
#define SATA_LOS_IDEN				0x3c

#define SATA_CLK_RST_SOURCE_PHY			BIT(0)
#define SATA_P0_PHY_TX_AMPLITUDE_GEN1_MASK	GENMASK(6, 0)
#define SATA_P0_PHY_TX_AMPLITUDE_GEN1_DEFAULT	0x42
#define SATA_P0_PHY_TX_AMPLITUDE_GEN2_MASK	GENMASK(14, 8)
#define SATA_P0_PHY_TX_AMPLITUDE_GEN2_DEFAULT	0x46
#define SATA_P0_PHY_TX_AMPLITUDE_GEN3_MASK	GENMASK(22, 16)
#define SATA_P0_PHY_TX_AMPLITUDE_GEN3_DEFAULT	0x73
#define SATA_P0_PHY_TX_PREEMPH_GEN1_MASK	GENMASK(5, 0)
#define SATA_P0_PHY_TX_PREEMPH_GEN1_DEFAULT	0x5
#define SATA_P0_PHY_TX_PREEMPH_GEN2_MASK	GENMASK(13, 8)
#define SATA_P0_PHY_TX_PREEMPH_GEN2_DEFAULT	0x5
#define SATA_P0_PHY_TX_PREEMPH_GEN3_MASK	GENMASK(21, 16)
#define SATA_P0_PHY_TX_PREEMPH_GEN3_DEFAULT	0x23
#define SATA_LOS_LEVEL_MASK			GENMASK(4, 0)
#define SATA_LOS_BIAS_MASK			GENMASK(18, 16)
#define SATA_M_CSYSREQ				BIT(0)
#define SATA_S_CSYSREQ				BIT(16)
#define SATA_REF_REPEATCLK_EN			BIT(0)
#define SATA_REF_USE_PAD			BIT(20)
#define SATA_MPLL_MULTIPLIER_MASK		GENMASK(22, 16)
#define SATA_P0_PHY_READY			BIT(0)

#define PLL_LOCK_SLEEP_US			10
#define PLL_LOCK_TIMEOUT_US			1000

struct eic7700_sata_phy {
	u32 tx_amplitude_tuning_val[3];
	u32 tx_preemph_tuning_val[3];
	struct reset_control *rst;
	struct regmap *regmap;
	struct clk *clk;
	struct phy *phy;
};

static const struct regmap_config eic7700_sata_phy_regmap_config = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = 4,
	.max_register = SATA_LOS_IDEN,
};

static int wait_for_phy_ready(struct regmap *regmap, u32 reg, u32 checkbit,
			      u32 status)
{
	u32 val;
	int ret;

	ret = regmap_read_poll_timeout(regmap, reg, val,
				       (val & checkbit) == status,
				       PLL_LOCK_SLEEP_US, PLL_LOCK_TIMEOUT_US);

	return ret;
}

static int eic7700_sata_phy_init(struct phy *phy)
{
	struct eic7700_sata_phy *sata_phy = phy_get_drvdata(phy);
	u32 val;
	int ret;

	ret = clk_prepare_enable(sata_phy->clk);
	if (ret)
		return ret;

	regmap_write(sata_phy->regmap, SATA_REF_CTRL1, SATA_CLK_RST_SOURCE_PHY);

	val = FIELD_PREP(SATA_P0_PHY_TX_AMPLITUDE_GEN1_MASK,
			 sata_phy->tx_amplitude_tuning_val[0]) |
	      FIELD_PREP(SATA_P0_PHY_TX_AMPLITUDE_GEN2_MASK,
			 sata_phy->tx_amplitude_tuning_val[1]) |
	      FIELD_PREP(SATA_P0_PHY_TX_AMPLITUDE_GEN3_MASK,
			 sata_phy->tx_amplitude_tuning_val[2]);
	regmap_write(sata_phy->regmap, SATA_PHY_CTRL0, val);

	val = FIELD_PREP(SATA_P0_PHY_TX_PREEMPH_GEN1_MASK,
			 sata_phy->tx_preemph_tuning_val[0]) |
	      FIELD_PREP(SATA_P0_PHY_TX_PREEMPH_GEN2_MASK,
			 sata_phy->tx_preemph_tuning_val[1]) |
	      FIELD_PREP(SATA_P0_PHY_TX_PREEMPH_GEN3_MASK,
			 sata_phy->tx_preemph_tuning_val[2]);
	regmap_write(sata_phy->regmap, SATA_PHY_CTRL1, val);

	val = FIELD_PREP(SATA_LOS_LEVEL_MASK, 0x9) |
	      FIELD_PREP(SATA_LOS_BIAS_MASK, 0x2);
	regmap_write(sata_phy->regmap, SATA_LOS_IDEN, val);

	val = SATA_M_CSYSREQ | SATA_S_CSYSREQ;
	regmap_write(sata_phy->regmap, SATA_AXI_LP_CTRL, val);

	val = SATA_REF_REPEATCLK_EN | SATA_REF_USE_PAD;
	regmap_write(sata_phy->regmap, SATA_REF_CTRL, val);

	val = FIELD_PREP(SATA_MPLL_MULTIPLIER_MASK, 0x3c);
	regmap_write(sata_phy->regmap, SATA_MPLL_CTRL, val);

	usleep_range(15, 20);

	ret = reset_control_deassert(sata_phy->rst);
	if (ret)
		goto disable_clk;

	ret = wait_for_phy_ready(sata_phy->regmap, SATA_P0_PHY_STAT,
				 SATA_P0_PHY_READY, 1);
	if (ret < 0) {
		dev_err(&sata_phy->phy->dev, "PHY READY check failed\n");
		goto disable_clk;
	}

	return 0;

disable_clk:
	clk_disable_unprepare(sata_phy->clk);
	return ret;
}

static int eic7700_sata_phy_exit(struct phy *phy)
{
	struct eic7700_sata_phy *sata_phy = phy_get_drvdata(phy);
	int ret;

	ret = reset_control_assert(sata_phy->rst);
	if (ret)
		return ret;

	clk_disable_unprepare(sata_phy->clk);

	return 0;
}

static const struct phy_ops eic7700_sata_phy_ops = {
	.init		= eic7700_sata_phy_init,
	.exit		= eic7700_sata_phy_exit,
	.owner		= THIS_MODULE,
};

static void eic7700_get_tuning_param(struct device_node *np,
				     struct eic7700_sata_phy *sata_phy)
{
	if (of_property_read_u32_array
		(np, "eswin,tx-amplitude-tuning",
		sata_phy->tx_amplitude_tuning_val,
		ARRAY_SIZE(sata_phy->tx_amplitude_tuning_val))) {
		sata_phy->tx_amplitude_tuning_val[0] =
			SATA_P0_PHY_TX_AMPLITUDE_GEN1_DEFAULT;
		sata_phy->tx_amplitude_tuning_val[1] =
			SATA_P0_PHY_TX_AMPLITUDE_GEN2_DEFAULT;
		sata_phy->tx_amplitude_tuning_val[2] =
			SATA_P0_PHY_TX_AMPLITUDE_GEN3_DEFAULT;
	}

	if (of_property_read_u32_array
		(np, "eswin,tx-preemph-tuning",
		sata_phy->tx_preemph_tuning_val,
		ARRAY_SIZE(sata_phy->tx_preemph_tuning_val))) {
		sata_phy->tx_preemph_tuning_val[0] =
			SATA_P0_PHY_TX_PREEMPH_GEN1_DEFAULT;
		sata_phy->tx_preemph_tuning_val[1] =
			SATA_P0_PHY_TX_PREEMPH_GEN2_DEFAULT;
		sata_phy->tx_preemph_tuning_val[2] =
			SATA_P0_PHY_TX_PREEMPH_GEN3_DEFAULT;
	}
}

static int eic7700_sata_phy_probe(struct platform_device *pdev)
{
	struct eic7700_sata_phy *sata_phy;
	struct phy_provider *phy_provider;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct resource *res;
	void __iomem *regs;

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

	/*
	 * Map the I/O resource with platform_get_resource and devm_ioremap
	 * instead of the devm_platform_ioremap_resource API, because the
	 * address region of the SATA-PHY falls into the region of the HSP
	 * clock & reset that has already been obtained by the HSP
	 * clock-and-reset driver.
	 */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENOENT;

	regs = devm_ioremap(dev, res->start, resource_size(res));
	if (IS_ERR(regs))
		return PTR_ERR(regs);

	sata_phy->regmap = devm_regmap_init_mmio
			   (dev, regs, &eic7700_sata_phy_regmap_config);
	if (IS_ERR(sata_phy->regmap))
		return dev_err_probe(dev, PTR_ERR(sata_phy->regmap),
				     "failed to init regmap\n");

	dev_set_drvdata(dev, sata_phy);

	eic7700_get_tuning_param(np, sata_phy);

	sata_phy->clk = devm_clk_get(dev, "phy");
	if (IS_ERR(sata_phy->clk))
		return PTR_ERR(sata_phy->clk);

	sata_phy->rst = devm_reset_control_array_get_exclusive(dev);
	if (IS_ERR(sata_phy->rst))
		return dev_err_probe(dev, PTR_ERR(sata_phy->rst),
				     "failed to get reset control\n");

	sata_phy->phy = devm_phy_create(dev, NULL, &eic7700_sata_phy_ops);
	if (IS_ERR(sata_phy->phy))
		return dev_err_probe(dev, PTR_ERR(sata_phy->phy),
				     "failed to create PHY\n");

	phy_set_drvdata(sata_phy->phy, sata_phy);

	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
	if (IS_ERR(phy_provider))
		return dev_err_probe(dev, PTR_ERR(phy_provider),
				     "failed to register PHY provider\n");

	return 0;
}

static const struct of_device_id eic7700_sata_phy_of_match[] = {
	{ .compatible = "eswin,eic7700-sata-phy" },
	{ },
};
MODULE_DEVICE_TABLE(of, eic7700_sata_phy_of_match);

static struct platform_driver eic7700_sata_phy_driver = {
	.probe	= eic7700_sata_phy_probe,
	.driver = {
		.of_match_table	= eic7700_sata_phy_of_match,
		.name  = "eic7700-sata-phy",
	}
};
module_platform_driver(eic7700_sata_phy_driver);

MODULE_DESCRIPTION("SATA PHY driver for the ESWIN EIC7700 SoC");
MODULE_AUTHOR("Yulin Lu <luyulin@eswincomputing.com>");
MODULE_LICENSE("GPL");