/*
   * 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);
  		priv->oldmode = mode;
  		netdev_dbg(netdev, "speed %u duplex %d, setting mode to 0x%04x
  ",
  			   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, i;
  
  	priv->mdio = mdiobus_alloc();
  	if (!priv->mdio) {
  		netdev_err(dev->net, "Could not allocate MDIO bus
  ");
  		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);
  
  	priv->mdio->irq = kzalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
  	if (!priv->mdio->irq) {
  		ret = -ENOMEM;
  		goto mfree;
  	}
  	for (i = 0; i < PHY_MAX_ADDR; i++)
  		priv->mdio->irq[i] = PHY_POLL;
  
  	ret = mdiobus_register(priv->mdio);
  	if (ret) {
  		netdev_err(dev->net, "Could not register MDIO bus
  ");
  		goto ifree;
  	}
  
  	netdev_info(dev->net, "registered mdio bus %s
  ", priv->mdio->id);
  	return 0;
  
  ifree:
  	kfree(priv->mdio->irq);
  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
  ", priv->mdio->id);
  	mdiobus_unregister(priv->mdio);
  	kfree(priv->mdio->irq);
  	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_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 int ax88172a_get_settings(struct net_device *net,
  				 struct ethtool_cmd *cmd)
  {
  	if (!net->phydev)
  		return -ENODEV;
  
  	return phy_ethtool_gset(net->phydev, cmd);
  }
  
  static int ax88172a_set_settings(struct net_device *net,
  				 struct ethtool_cmd *cmd)
  {
  	if (!net->phydev)
  		return -ENODEV;
  
  	return phy_ethtool_sset(net->phydev, cmd);
  }
  
  static int ax88172a_nway_reset(struct net_device *net)
  {
  	if (!net->phydev)
  		return -ENODEV;
  
  	return phy_start_aneg(net->phydev);
  }
  
  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,
  	.get_settings		= ax88172a_get_settings,
  	.set_settings		= ax88172a_set_settings,
  	.nway_reset		= ax88172a_nway_reset,
  };
  
  static int ax88172a_reset_phy(struct usbnet *dev, int embd_phy)
  {
  	int ret;
  
  	ret = asix_sw_reset(dev, AX_SWRESET_IPPD);
  	if (ret < 0)
  		goto err;
  
  	msleep(150);
  	ret = asix_sw_reset(dev, AX_SWRESET_CLEAR);
  	if (ret < 0)
  		goto err;
  
  	msleep(150);
  
  	ret = asix_sw_reset(dev, embd_phy ? AX_SWRESET_IPRL : AX_SWRESET_IPPD);
  	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;
  
  	usbnet_get_endpoints(dev, intf);
  
  	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);
  	if (ret < 0) {
  		netdev_err(dev->net, "Failed to read MAC address: %d
  ", ret);
  		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);
  	if (ret < 0) {
  		netdev_err(dev->net, "Failed to read software interface selection register: %d
  ",
  			   ret);
  		goto free;
  	}
  
  	netdev_dbg(dev->net, "AX_CMD_SW_PHY_STATUS = 0x%02x
  ", buf[0]);
  	switch (buf[0] & AX_PHY_SELECT_MASK) {
  	case AX_PHY_SELECT_INTERNAL:
  		netdev_dbg(dev->net, "use internal phy
  ");
  		priv->use_embdphy = 1;
  		break;
  	case AX_PHY_SELECT_EXTERNAL:
  		netdev_dbg(dev->net, "use external phy
  ");
  		priv->use_embdphy = 0;
  		break;
  	default:
  		netdev_err(dev->net, "Interface mode not supported by driver
  ");
  		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
  ");
  
  	if (priv->phydev) {
  		netdev_info(dev->net, "Disconnecting from phy %s
  ",
  			    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);
  	netdev_dbg(dev->net, "RX_CTL is 0x%04x after software reset
  ", rx_ctl);
  	ret = asix_write_rx_ctl(dev, 0x0000);
  	if (ret < 0)
  		goto out;
  
  	rx_ctl = asix_read_rx_ctl(dev);
  	netdev_dbg(dev->net, "RX_CTL is 0x%04x setting to 0x0000
  ", rx_ctl);
  
  	msleep(150);
  
  	ret = asix_write_cmd(dev, AX_CMD_WRITE_IPG0,
  			     AX88772_IPG0_DEFAULT | AX88772_IPG1_DEFAULT,
  			     AX88772_IPG2_DEFAULT, 0, NULL);
  	if (ret < 0) {
  		netdev_err(dev->net, "Write IPG,IPG1,IPG2 failed: %d
  ", 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);
  	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);
  	if (ret < 0)
  		goto out;
  
  	rx_ctl = asix_read_rx_ctl(dev);
  	netdev_dbg(dev->net, "RX_CTL is 0x%04x after all initializations
  ",
  		   rx_ctl);
  
  	rx_ctl = asix_read_medium_status(dev);
  	netdev_dbg(dev->net, "Medium Status is 0x%04x after all initializations
  ",
  		   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
  ",
  			   priv->phy_name);
  		ret = PTR_ERR(priv->phydev);
  		goto out;
  	}
  
  	netdev_info(dev->net, "Connected to phy %s
  ", 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,
  };