kernel/drivers/phy/broadcom/phy-bcm-ns-usb3.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Broadcom Northstar USB 3.0 PHY Driver
 *
 * Copyright (C) 2016 Rafał Miłecki <rafal@milecki.pl>
 * Copyright (C) 2016 Broadcom
 *
 * All magic values used for initialization (and related comments) were obtained
 * from Broadcom's SDK:
 * Copyright (c) Broadcom Corp, 2012
 */

#include <linux/bcma/bcma.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/iopoll.h>
#include <linux/mdio.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/phy/phy.h>
#include <linux/slab.h>

#define BCM_NS_USB3_PHY_BASE_ADDR_REG	0x1f
#define BCM_NS_USB3_PHY_PLL30_BLOCK	0x8000
#define BCM_NS_USB3_PHY_TX_PMD_BLOCK	0x8040
#define BCM_NS_USB3_PHY_PIPE_BLOCK	0x8060

/* Registers of PLL30 block */
#define BCM_NS_USB3_PLL_CONTROL		0x01
#define BCM_NS_USB3_PLLA_CONTROL0	0x0a
#define BCM_NS_USB3_PLLA_CONTROL1	0x0b

/* Registers of TX PMD block */
#define BCM_NS_USB3_TX_PMD_CONTROL1	0x01

/* Registers of PIPE block */
#define BCM_NS_USB3_LFPS_CMP		0x02
#define BCM_NS_USB3_LFPS_DEGLITCH	0x03

enum bcm_ns_family {
	BCM_NS_UNKNOWN,
	BCM_NS_AX,
	BCM_NS_BX,
};

struct bcm_ns_usb3 {
	struct device *dev;
	enum bcm_ns_family family;
	void __iomem *dmp;
	struct mdio_device *mdiodev;
	struct phy *phy;
};

static const struct of_device_id bcm_ns_usb3_id_table[] = {
	{
		.compatible = "brcm,ns-ax-usb3-phy",
		.data = (int *)BCM_NS_AX,
	},
	{
		.compatible = "brcm,ns-bx-usb3-phy",
		.data = (int *)BCM_NS_BX,
	},
	{},
};

static int bcm_ns_usb3_mdio_phy_write(struct bcm_ns_usb3 *usb3, u16 reg,
				      u16 value);

static int bcm_ns_usb3_phy_init_ns_bx(struct bcm_ns_usb3 *usb3)
{
	int err;

	/* USB3 PLL Block */
	err = bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
					 BCM_NS_USB3_PHY_PLL30_BLOCK);
	if (err < 0)
		return err;

	/* Assert Ana_Pllseq start */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLL_CONTROL, 0x1000);

	/* Assert CML Divider ratio to 26 */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLLA_CONTROL0, 0x6400);

	/* Asserting PLL Reset */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLLA_CONTROL1, 0xc000);

	/* Deaaserting PLL Reset */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLLA_CONTROL1, 0x8000);

	/* Deasserting USB3 system reset */
	writel(0, usb3->dmp + BCMA_RESET_CTL);

	/* PLL frequency monitor enable */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLL_CONTROL, 0x9000);

	/* PIPE Block */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
				   BCM_NS_USB3_PHY_PIPE_BLOCK);

	/* CMPMAX & CMPMINTH setting */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_LFPS_CMP, 0xf30d);

	/* DEGLITCH MIN & MAX setting */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_LFPS_DEGLITCH, 0x6302);

	/* TXPMD block */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
				   BCM_NS_USB3_PHY_TX_PMD_BLOCK);

	/* Enabling SSC */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_TX_PMD_CONTROL1, 0x1003);

	return 0;
}

static int bcm_ns_usb3_phy_init_ns_ax(struct bcm_ns_usb3 *usb3)
{
	int err;

	/* PLL30 block */
	err = bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
					 BCM_NS_USB3_PHY_PLL30_BLOCK);
	if (err < 0)
		return err;

	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLLA_CONTROL0, 0x6400);

	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG, 0x80e0);

	bcm_ns_usb3_mdio_phy_write(usb3, 0x02, 0x009c);

	/* Enable SSC */
	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
				   BCM_NS_USB3_PHY_TX_PMD_BLOCK);

	bcm_ns_usb3_mdio_phy_write(usb3, 0x02, 0x21d3);

	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_TX_PMD_CONTROL1, 0x1003);

	/* Deasserting USB3 system reset */
	writel(0, usb3->dmp + BCMA_RESET_CTL);

	return 0;
}

static int bcm_ns_usb3_phy_init(struct phy *phy)
{
	struct bcm_ns_usb3 *usb3 = phy_get_drvdata(phy);
	int err;

	/* Perform USB3 system soft reset */
	writel(BCMA_RESET_CTL_RESET, usb3->dmp + BCMA_RESET_CTL);

	switch (usb3->family) {
	case BCM_NS_AX:
		err = bcm_ns_usb3_phy_init_ns_ax(usb3);
		break;
	case BCM_NS_BX:
		err = bcm_ns_usb3_phy_init_ns_bx(usb3);
		break;
	default:
		WARN_ON(1);
		err = -ENOTSUPP;
	}

	return err;
}

static const struct phy_ops ops = {
	.init		= bcm_ns_usb3_phy_init,
	.owner		= THIS_MODULE,
};

/**************************************************
 * MDIO driver code
 **************************************************/

static int bcm_ns_usb3_mdio_phy_write(struct bcm_ns_usb3 *usb3, u16 reg,
				      u16 value)
{
	struct mdio_device *mdiodev = usb3->mdiodev;

	return mdiobus_write(mdiodev->bus, mdiodev->addr, reg, value);
}

static int bcm_ns_usb3_mdio_probe(struct mdio_device *mdiodev)
{
	struct device *dev = &mdiodev->dev;
	const struct of_device_id *of_id;
	struct phy_provider *phy_provider;
	struct device_node *syscon_np;
	struct bcm_ns_usb3 *usb3;
	struct resource res;
	int err;

	usb3 = devm_kzalloc(dev, sizeof(*usb3), GFP_KERNEL);
	if (!usb3)
		return -ENOMEM;

	usb3->dev = dev;
	usb3->mdiodev = mdiodev;

	of_id = of_match_device(bcm_ns_usb3_id_table, dev);
	if (!of_id)
		return -EINVAL;
	usb3->family = (enum bcm_ns_family)of_id->data;

	syscon_np = of_parse_phandle(dev->of_node, "usb3-dmp-syscon", 0);
	err = of_address_to_resource(syscon_np, 0, &res);
	of_node_put(syscon_np);
	if (err)
		return err;

	usb3->dmp = devm_ioremap_resource(dev, &res);
	if (IS_ERR(usb3->dmp))
		return PTR_ERR(usb3->dmp);

	usb3->phy = devm_phy_create(dev, NULL, &ops);
	if (IS_ERR(usb3->phy)) {
		dev_err(dev, "Failed to create PHY\n");
		return PTR_ERR(usb3->phy);
	}

	phy_set_drvdata(usb3->phy, usb3);

	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);

	return PTR_ERR_OR_ZERO(phy_provider);
}

static struct mdio_driver bcm_ns_usb3_mdio_driver = {
	.mdiodrv = {
		.driver = {
			.name = "bcm_ns_mdio_usb3",
			.of_match_table = bcm_ns_usb3_id_table,
		},
	},
	.probe = bcm_ns_usb3_mdio_probe,
};

mdio_module_driver(bcm_ns_usb3_mdio_driver);

MODULE_LICENSE("GPL v2");
MODULE_DEVICE_TABLE(of, bcm_ns_usb3_id_table);