/*
 * Driver for the Renesas PHY uPD60620.
 *
 * Copyright (C) 2015 Softing Industrial Automation GmbH
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/phy.h>

#define UPD60620_PHY_ID    0xb8242824

/* Extended Registers and values */
/* PHY Special Control/Status    */
#define PHY_PHYSCR         0x1F      /* PHY.31 */
#define PHY_PHYSCR_10MB    0x0004    /* PHY speed = 10mb */
#define PHY_PHYSCR_100MB   0x0008    /* PHY speed = 100mb */
#define PHY_PHYSCR_DUPLEX  0x0010    /* PHY Duplex */

/* PHY Special Modes */
#define PHY_SPM            0x12      /* PHY.18 */

/* Init PHY */

static int upd60620_config_init(struct phy_device *phydev)
{
	/* Enable support for passive HUBs (could be a strap option) */
	/* PHYMODE: All speeds, HD in parallel detect */
	return phy_write(phydev, PHY_SPM, 0x0180 | phydev->mdio.addr);
}

/* Get PHY status from common registers */

static int upd60620_read_status(struct phy_device *phydev)
{
	int phy_state;

	/* Read negotiated state */
	phy_state = phy_read(phydev, MII_BMSR);
	if (phy_state < 0)
		return phy_state;

	phydev->link = 0;
	phydev->lp_advertising = 0;
	phydev->pause = 0;
	phydev->asym_pause = 0;

	if (phy_state & (BMSR_ANEGCOMPLETE | BMSR_LSTATUS)) {
		phy_state = phy_read(phydev, PHY_PHYSCR);
		if (phy_state < 0)
			return phy_state;

		if (phy_state & (PHY_PHYSCR_10MB | PHY_PHYSCR_100MB)) {
			phydev->link = 1;
			phydev->speed = SPEED_10;
			phydev->duplex = DUPLEX_HALF;

			if (phy_state & PHY_PHYSCR_100MB)
				phydev->speed = SPEED_100;
			if (phy_state & PHY_PHYSCR_DUPLEX)
				phydev->duplex = DUPLEX_FULL;

			phy_state = phy_read(phydev, MII_LPA);
			if (phy_state < 0)
				return phy_state;

			phydev->lp_advertising
				= mii_lpa_to_ethtool_lpa_t(phy_state);

			if (phydev->duplex == DUPLEX_FULL) {
				if (phy_state & LPA_PAUSE_CAP)
					phydev->pause = 1;
				if (phy_state & LPA_PAUSE_ASYM)
					phydev->asym_pause = 1;
			}
		}
	}
	return 0;
}

MODULE_DESCRIPTION("Renesas uPD60620 PHY driver");
MODULE_AUTHOR("Bernd Edlinger <bernd.edlinger@hotmail.de>");
MODULE_LICENSE("GPL");

static struct phy_driver upd60620_driver[1] = { {
	.phy_id         = UPD60620_PHY_ID,
	.phy_id_mask    = 0xfffffffe,
	.name           = "Renesas uPD60620",
	.features       = PHY_BASIC_FEATURES,
	.flags          = 0,
	.config_init    = upd60620_config_init,
	.read_status    = upd60620_read_status,
} };

module_phy_driver(upd60620_driver);

static struct mdio_device_id __maybe_unused upd60620_tbl[] = {
	{ UPD60620_PHY_ID, 0xfffffffe },
	{ }
};

MODULE_DEVICE_TABLE(mdio, upd60620_tbl);