/*
 * ASIX AX88172A based USB 2.0 Ethernet Devices
 * Copyright (C) 2012 OMICRON electronics GmbH
 *
 * Supports external PHYs via phylib. Based on the driver for the
 * AX88772. Original copyrights follow:
 *
 * Copyright (C) 2003-2006 David Hollis <dhollis@davehollis.com>
 * Copyright (C) 2005 Phil Chang <pchang23@sbcglobal.net>
 * Copyright (C) 2006 James Painter <jamie.painter@iname.com>
 * Copyright (c) 2002-2003 TiVo Inc.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "asix.h"
#include <linux/phy.h>

struct ax88172a_private {
	struct mii_bus *mdio;
	struct phy_device *phydev;
	char phy_name[20];
	u16 phy_addr;
	u16 oldmode;
	int use_embdphy;
	struct asix_rx_fixup_info rx_fixup_info;
};

/* MDIO read and write wrappers for phylib */
static int asix_mdio_bus_read(struct mii_bus *bus, int phy_id, int regnum)
{
	return asix_mdio_read(((struct usbnet *)bus->priv)->net, phy_id,
			      regnum);
}

static int asix_mdio_bus_write(struct mii_bus *bus, int phy_id, int regnum,
			       u16 val)
{
	asix_mdio_write(((struct usbnet *)bus->priv)->net, phy_id, regnum, val);
	return 0;
}

static int ax88172a_ioctl(struct net_device *net, struct ifreq *rq, int cmd)
{
	if (!netif_running(net))
		return -EINVAL;

	if (!net->phydev)
		return -ENODEV;

	return phy_mii_ioctl(net->phydev, rq, cmd);
}

/* set MAC link settings according to information from phylib */
static void ax88172a_adjust_link(struct net_device *netdev)
{
	struct phy_device *phydev = netdev->phydev;
	struct usbnet *dev = netdev_priv(netdev);
	struct ax88172a_private *priv = dev->driver_priv;
	u16 mode = 0;

	if (phydev->link) {
		mode = AX88772_MEDIUM_DEFAULT;

		if (phydev->duplex == DUPLEX_HALF)
			mode &= ~AX_MEDIUM_FD;

		if (phydev->speed != SPEED_100)
			mode &= ~AX_MEDIUM_PS;
	}

	if (mode != priv->oldmode) {
		asix_write_medium_mode(dev, mode, 0);
		priv->oldmode = mode;
		netdev_dbg(netdev, "speed %u duplex %d, setting mode to 0x%04x\n",
			   phydev->speed, phydev->duplex, mode);
		phy_print_status(phydev);
	}
}

static void ax88172a_status(struct usbnet *dev, struct urb *urb)
{
	/* link changes are detected by polling the phy */
}

/* use phylib infrastructure */
static int ax88172a_init_mdio(struct usbnet *dev)
{
	struct ax88172a_private *priv = dev->driver_priv;
	int ret;

	priv->mdio = mdiobus_alloc();
	if (!priv->mdio) {
		netdev_err(dev->net, "Could not allocate MDIO bus\n");
		return -ENOMEM;
	}

	priv->mdio->priv = (void *)dev;
	priv->mdio->read = &asix_mdio_bus_read;
	priv->mdio->write = &asix_mdio_bus_write;
	priv->mdio->name = "Asix MDIO Bus";
	/* mii bus name is usb-<usb bus number>-<usb device number> */
	snprintf(priv->mdio->id, MII_BUS_ID_SIZE, "usb-%03d:%03d",
		 dev->udev->bus->busnum, dev->udev->devnum);

	ret = mdiobus_register(priv->mdio);
	if (ret) {
		netdev_err(dev->net, "Could not register MDIO bus\n");
		goto mfree;
	}

	netdev_info(dev->net, "registered mdio bus %s\n", priv->mdio->id);
	return 0;

mfree:
	mdiobus_free(priv->mdio);
	return ret;
}

static void ax88172a_remove_mdio(struct usbnet *dev)
{
	struct ax88172a_private *priv = dev->driver_priv;

	netdev_info(dev->net, "deregistering mdio bus %s\n", priv->mdio->id);
	mdiobus_unregister(priv->mdio);
	mdiobus_free(priv->mdio);
}

static const struct net_device_ops ax88172a_netdev_ops = {
	.ndo_open		= usbnet_open,
	.ndo_stop		= usbnet_stop,
	.ndo_start_xmit		= usbnet_start_xmit,
	.ndo_tx_timeout		= usbnet_tx_timeout,
	.ndo_change_mtu		= usbnet_change_mtu,
	.ndo_get_stats64	= usbnet_get_stats64,
	.ndo_set_mac_address	= asix_set_mac_address,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_do_ioctl		= ax88172a_ioctl,
	.ndo_set_rx_mode        = asix_set_multicast,
};

static const struct ethtool_ops ax88172a_ethtool_ops = {
	.get_drvinfo		= asix_get_drvinfo,
	.get_link		= usbnet_get_link,
	.get_msglevel		= usbnet_get_msglevel,
	.set_msglevel		= usbnet_set_msglevel,
	.get_wol		= asix_get_wol,
	.set_wol		= asix_set_wol,
	.get_eeprom_len		= asix_get_eeprom_len,
	.get_eeprom		= asix_get_eeprom,
	.set_eeprom		= asix_set_eeprom,
	.nway_reset		= phy_ethtool_nway_reset,
	.get_link_ksettings	= phy_ethtool_get_link_ksettings,
	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
};

static int ax88172a_reset_phy(struct usbnet *dev, int embd_phy)
{
	int ret;

	ret = asix_sw_reset(dev, AX_SWRESET_IPPD, 0);
	if (ret < 0)
		goto err;

	msleep(150);
	ret = asix_sw_reset(dev, AX_SWRESET_CLEAR, 0);
	if (ret < 0)
		goto err;

	msleep(150);

	ret = asix_sw_reset(dev, embd_phy ? AX_SWRESET_IPRL : AX_SWRESET_IPPD,
			    0);
	if (ret < 0)
		goto err;

	return 0;

err:
	return ret;
}


static int ax88172a_bind(struct usbnet *dev, struct usb_interface *intf)
{
	int ret;
	u8 buf[ETH_ALEN];
	struct ax88172a_private *priv;

	ret = usbnet_get_endpoints(dev, intf);
	if (ret)
		return ret;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	dev->driver_priv = priv;

	/* Get the MAC address */
	ret = asix_read_cmd(dev, AX_CMD_READ_NODE_ID, 0, 0, ETH_ALEN, buf, 0);
	if (ret < ETH_ALEN) {
		netdev_err(dev->net, "Failed to read MAC address: %d\n", ret);
		ret = -EIO;
		goto free;
	}
	memcpy(dev->net->dev_addr, buf, ETH_ALEN);

	dev->net->netdev_ops = &ax88172a_netdev_ops;
	dev->net->ethtool_ops = &ax88172a_ethtool_ops;

	/* are we using the internal or the external phy? */
	ret = asix_read_cmd(dev, AX_CMD_SW_PHY_STATUS, 0, 0, 1, buf, 0);
	if (ret < 0) {
		netdev_err(dev->net, "Failed to read software interface selection register: %d\n",
			   ret);
		goto free;
	}

	netdev_dbg(dev->net, "AX_CMD_SW_PHY_STATUS = 0x%02x\n", buf[0]);
	switch (buf[0] & AX_PHY_SELECT_MASK) {
	case AX_PHY_SELECT_INTERNAL:
		netdev_dbg(dev->net, "use internal phy\n");
		priv->use_embdphy = 1;
		break;
	case AX_PHY_SELECT_EXTERNAL:
		netdev_dbg(dev->net, "use external phy\n");
		priv->use_embdphy = 0;
		break;
	default:
		netdev_err(dev->net, "Interface mode not supported by driver\n");
		ret = -ENOTSUPP;
		goto free;
	}

	priv->phy_addr = asix_read_phy_addr(dev, priv->use_embdphy);
	ax88172a_reset_phy(dev, priv->use_embdphy);

	/* Asix framing packs multiple eth frames into a 2K usb bulk transfer */
	if (dev->driver_info->flags & FLAG_FRAMING_AX) {
		/* hard_mtu  is still the default - the device does not support
		   jumbo eth frames */
		dev->rx_urb_size = 2048;
	}

	/* init MDIO bus */
	ret = ax88172a_init_mdio(dev);
	if (ret)
		goto free;

	return 0;

free:
	kfree(priv);
	return ret;
}

static int ax88172a_stop(struct usbnet *dev)
{
	struct ax88172a_private *priv = dev->driver_priv;

	netdev_dbg(dev->net, "Stopping interface\n");

	if (priv->phydev) {
		netdev_info(dev->net, "Disconnecting from phy %s\n",
			    priv->phy_name);
		phy_stop(priv->phydev);
		phy_disconnect(priv->phydev);
	}

	return 0;
}

static void ax88172a_unbind(struct usbnet *dev, struct usb_interface *intf)
{
	struct ax88172a_private *priv = dev->driver_priv;

	ax88172a_remove_mdio(dev);
	kfree(priv);
}

static int ax88172a_reset(struct usbnet *dev)
{
	struct asix_data *data = (struct asix_data *)&dev->data;
	struct ax88172a_private *priv = dev->driver_priv;
	int ret;
	u16 rx_ctl;

	ax88172a_reset_phy(dev, priv->use_embdphy);

	msleep(150);
	rx_ctl = asix_read_rx_ctl(dev, 0);
	netdev_dbg(dev->net, "RX_CTL is 0x%04x after software reset\n", rx_ctl);
	ret = asix_write_rx_ctl(dev, 0x0000, 0);
	if (ret < 0)
		goto out;

	rx_ctl = asix_read_rx_ctl(dev, 0);
	netdev_dbg(dev->net, "RX_CTL is 0x%04x setting to 0x0000\n", rx_ctl);

	msleep(150);

	ret = asix_write_cmd(dev, AX_CMD_WRITE_IPG0,
			     AX88772_IPG0_DEFAULT | AX88772_IPG1_DEFAULT,
			     AX88772_IPG2_DEFAULT, 0, NULL, 0);
	if (ret < 0) {
		netdev_err(dev->net, "Write IPG,IPG1,IPG2 failed: %d\n", ret);
		goto out;
	}

	/* Rewrite MAC address */
	memcpy(data->mac_addr, dev->net->dev_addr, ETH_ALEN);
	ret = asix_write_cmd(dev, AX_CMD_WRITE_NODE_ID, 0, 0, ETH_ALEN,
			     data->mac_addr, 0);
	if (ret < 0)
		goto out;

	/* Set RX_CTL to default values with 2k buffer, and enable cactus */
	ret = asix_write_rx_ctl(dev, AX_DEFAULT_RX_CTL, 0);
	if (ret < 0)
		goto out;

	rx_ctl = asix_read_rx_ctl(dev, 0);
	netdev_dbg(dev->net, "RX_CTL is 0x%04x after all initializations\n",
		   rx_ctl);

	rx_ctl = asix_read_medium_status(dev, 0);
	netdev_dbg(dev->net, "Medium Status is 0x%04x after all initializations\n",
		   rx_ctl);

	/* Connect to PHY */
	snprintf(priv->phy_name, 20, PHY_ID_FMT,
		 priv->mdio->id, priv->phy_addr);

	priv->phydev = phy_connect(dev->net, priv->phy_name,
				   &ax88172a_adjust_link,
				   PHY_INTERFACE_MODE_MII);
	if (IS_ERR(priv->phydev)) {
		netdev_err(dev->net, "Could not connect to PHY device %s\n",
			   priv->phy_name);
		ret = PTR_ERR(priv->phydev);
		goto out;
	}

	netdev_info(dev->net, "Connected to phy %s\n", priv->phy_name);

	/* During power-up, the AX88172A set the power down (BMCR_PDOWN)
	 * bit of the PHY. Bring the PHY up again.
	 */
	genphy_resume(priv->phydev);
	phy_start(priv->phydev);

	return 0;

out:
	return ret;

}

static int ax88172a_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
{
	struct ax88172a_private *dp = dev->driver_priv;
	struct asix_rx_fixup_info *rx = &dp->rx_fixup_info;

	return asix_rx_fixup_internal(dev, skb, rx);
}

const struct driver_info ax88172a_info = {
	.description = "ASIX AX88172A USB 2.0 Ethernet",
	.bind = ax88172a_bind,
	.reset = ax88172a_reset,
	.stop = ax88172a_stop,
	.unbind = ax88172a_unbind,
	.status = ax88172a_status,
	.flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_LINK_INTR |
		 FLAG_MULTI_PACKET,
	.rx_fixup = ax88172a_rx_fixup,
	.tx_fixup = asix_tx_fixup,
};