/*
 * 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
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/bcma/bcma.h>
#include <linux/delay.h>
#include <linux/err.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_MII_MNG_TIMEOUT_US	1000	/* usecs */

#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;
	void __iomem *ccb_mii;
	struct mdio_device *mdiodev;
	struct phy *phy;

	int (*phy_write)(struct bcm_ns_usb3 *usb3, u16 reg, u16 value);
};

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,
	},
	{},
};
MODULE_DEVICE_TABLE(of, bcm_ns_usb3_id_table);

static int bcm_ns_usb3_mdio_phy_write(struct bcm_ns_usb3 *usb3, u16 reg,
				      u16 value)
{
	return usb3->phy_write(usb3, reg, 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_mdiodev_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)) {
		dev_err(dev, "Failed to map DMP regs\n");
		return PTR_ERR(usb3->dmp);
	}

	usb3->phy_write = bcm_ns_usb3_mdiodev_phy_write;

	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,
};

/**************************************************
 * Platform driver code
 **************************************************/

static int bcm_ns_usb3_wait_reg(struct bcm_ns_usb3 *usb3, void __iomem *addr,
				u32 mask, u32 value, unsigned long timeout)
{
	unsigned long deadline = jiffies + timeout;
	u32 val;

	do {
		val = readl(addr);
		if ((val & mask) == value)
			return 0;
		cpu_relax();
		udelay(10);
	} while (!time_after_eq(jiffies, deadline));

	dev_err(usb3->dev, "Timeout waiting for register %p\n", addr);

	return -EBUSY;
}

static inline int bcm_ns_usb3_mii_mng_wait_idle(struct bcm_ns_usb3 *usb3)
{
	return bcm_ns_usb3_wait_reg(usb3, usb3->ccb_mii + BCMA_CCB_MII_MNG_CTL,
				    0x0100, 0x0000,
				    usecs_to_jiffies(BCM_NS_USB3_MII_MNG_TIMEOUT_US));
}

static int bcm_ns_usb3_platform_phy_write(struct bcm_ns_usb3 *usb3, u16 reg,
					  u16 value)
{
	u32 tmp = 0;
	int err;

	err = bcm_ns_usb3_mii_mng_wait_idle(usb3);
	if (err < 0) {
		dev_err(usb3->dev, "Couldn't write 0x%08x value\n", value);
		return err;
	}

	/* TODO: Use a proper MDIO bus layer */
	tmp |= 0x58020000; /* Magic value for MDIO PHY write */
	tmp |= reg << 18;
	tmp |= value;
	writel(tmp, usb3->ccb_mii + BCMA_CCB_MII_MNG_CMD_DATA);

	return bcm_ns_usb3_mii_mng_wait_idle(usb3);
}

static int bcm_ns_usb3_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	const struct of_device_id *of_id;
	struct bcm_ns_usb3 *usb3;
	struct resource *res;
	struct phy_provider *phy_provider;

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

	usb3->dev = dev;

	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;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dmp");
	usb3->dmp = devm_ioremap_resource(dev, res);
	if (IS_ERR(usb3->dmp)) {
		dev_err(dev, "Failed to map DMP regs\n");
		return PTR_ERR(usb3->dmp);
	}

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ccb-mii");
	usb3->ccb_mii = devm_ioremap_resource(dev, res);
	if (IS_ERR(usb3->ccb_mii)) {
		dev_err(dev, "Failed to map ChipCommon B MII regs\n");
		return PTR_ERR(usb3->ccb_mii);
	}

	/* Enable MDIO. Setting MDCDIV as 26  */
	writel(0x0000009a, usb3->ccb_mii + BCMA_CCB_MII_MNG_CTL);

	/* Wait for MDIO? */
	udelay(2);

	usb3->phy_write = bcm_ns_usb3_platform_phy_write;

	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);
	platform_set_drvdata(pdev, usb3);

	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
	if (!IS_ERR(phy_provider))
		dev_info(dev, "Registered Broadcom Northstar USB 3.0 PHY driver\n");

	return PTR_ERR_OR_ZERO(phy_provider);
}

static struct platform_driver bcm_ns_usb3_driver = {
	.probe		= bcm_ns_usb3_probe,
	.driver = {
		.name = "bcm_ns_usb3",
		.of_match_table = bcm_ns_usb3_id_table,
	},
};

static int __init bcm_ns_usb3_module_init(void)
{
	int err;

	/*
	 * For backward compatibility we register as MDIO and platform driver.
	 * After getting MDIO binding commonly used (e.g. switching all DT files
	 * to use it) we should deprecate the old binding and eventually drop
	 * support for it.
	 */

	err = mdio_driver_register(&bcm_ns_usb3_mdio_driver);
	if (err)
		return err;

	err = platform_driver_register(&bcm_ns_usb3_driver);
	if (err)
		mdio_driver_unregister(&bcm_ns_usb3_mdio_driver);

	return err;
}
module_init(bcm_ns_usb3_module_init);

static void __exit bcm_ns_usb3_module_exit(void)
{
	platform_driver_unregister(&bcm_ns_usb3_driver);
	mdio_driver_unregister(&bcm_ns_usb3_mdio_driver);
}
module_exit(bcm_ns_usb3_module_exit)

MODULE_LICENSE("GPL v2");