/*
 * net/dsa/dsa.c - Hardware switch handling
 * Copyright (c) 2008-2009 Marvell Semiconductor
 * Copyright (c) 2013 Florian Fainelli <florian@openwrt.org>
 *
 * 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/device.h>
#include <linux/list.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_mdio.h>
#include <linux/of_platform.h>
#include <linux/of_net.h>
#include <linux/of_gpio.h>
#include <linux/netdevice.h>
#include <linux/sysfs.h>
#include <linux/phy_fixed.h>
#include <linux/gpio/consumer.h>
#include <linux/etherdevice.h>
#include <net/dsa.h>
#include "dsa_priv.h"

static struct sk_buff *dsa_slave_notag_xmit(struct sk_buff *skb,
					    struct net_device *dev)
{
	/* Just return the original SKB */
	return skb;
}

static const struct dsa_device_ops none_ops = {
	.xmit	= dsa_slave_notag_xmit,
	.rcv	= NULL,
};

const struct dsa_device_ops *dsa_device_ops[DSA_TAG_LAST] = {
#ifdef CONFIG_NET_DSA_TAG_DSA
	[DSA_TAG_PROTO_DSA] = &dsa_netdev_ops,
#endif
#ifdef CONFIG_NET_DSA_TAG_EDSA
	[DSA_TAG_PROTO_EDSA] = &edsa_netdev_ops,
#endif
#ifdef CONFIG_NET_DSA_TAG_TRAILER
	[DSA_TAG_PROTO_TRAILER] = &trailer_netdev_ops,
#endif
#ifdef CONFIG_NET_DSA_TAG_BRCM
	[DSA_TAG_PROTO_BRCM] = &brcm_netdev_ops,
#endif
#ifdef CONFIG_NET_DSA_TAG_QCA
	[DSA_TAG_PROTO_QCA] = &qca_netdev_ops,
#endif
#ifdef CONFIG_NET_DSA_TAG_MTK
	[DSA_TAG_PROTO_MTK] = &mtk_netdev_ops,
#endif
	[DSA_TAG_PROTO_NONE] = &none_ops,
};

int dsa_cpu_dsa_setup(struct dsa_switch *ds, struct device *dev,
		      struct dsa_port *dport, int port)
{
	struct device_node *port_dn = dport->dn;
	struct phy_device *phydev;
	int ret, mode;

	if (of_phy_is_fixed_link(port_dn)) {
		ret = of_phy_register_fixed_link(port_dn);
		if (ret) {
			dev_err(dev, "failed to register fixed PHY\n");
			return ret;
		}
		phydev = of_phy_find_device(port_dn);

		mode = of_get_phy_mode(port_dn);
		if (mode < 0)
			mode = PHY_INTERFACE_MODE_NA;
		phydev->interface = mode;

		genphy_config_init(phydev);
		genphy_read_status(phydev);
		if (ds->ops->adjust_link)
			ds->ops->adjust_link(ds, port, phydev);

		put_device(&phydev->mdio.dev);
	}

	return 0;
}

const struct dsa_device_ops *dsa_resolve_tag_protocol(int tag_protocol)
{
	const struct dsa_device_ops *ops;

	if (tag_protocol >= DSA_TAG_LAST)
		return ERR_PTR(-EINVAL);
	ops = dsa_device_ops[tag_protocol];

	if (!ops)
		return ERR_PTR(-ENOPROTOOPT);

	return ops;
}

int dsa_cpu_port_ethtool_setup(struct dsa_switch *ds)
{
	struct net_device *master;
	struct ethtool_ops *cpu_ops;

	master = ds->dst->master_netdev;
	if (ds->master_netdev)
		master = ds->master_netdev;

	cpu_ops = devm_kzalloc(ds->dev, sizeof(*cpu_ops), GFP_KERNEL);
	if (!cpu_ops)
		return -ENOMEM;

	memcpy(&ds->dst->master_ethtool_ops, master->ethtool_ops,
	       sizeof(struct ethtool_ops));
	ds->dst->master_orig_ethtool_ops = master->ethtool_ops;
	memcpy(cpu_ops, &ds->dst->master_ethtool_ops,
	       sizeof(struct ethtool_ops));
	dsa_cpu_port_ethtool_init(cpu_ops);
	master->ethtool_ops = cpu_ops;

	return 0;
}

void dsa_cpu_port_ethtool_restore(struct dsa_switch *ds)
{
	struct net_device *master;

	master = ds->dst->master_netdev;
	if (ds->master_netdev)
		master = ds->master_netdev;

	master->ethtool_ops = ds->dst->master_orig_ethtool_ops;
}

void dsa_cpu_dsa_destroy(struct dsa_port *port)
{
	struct device_node *port_dn = port->dn;

	if (of_phy_is_fixed_link(port_dn))
		of_phy_deregister_fixed_link(port_dn);
}

static int dev_is_class(struct device *dev, void *class)
{
	if (dev->class != NULL && !strcmp(dev->class->name, class))
		return 1;

	return 0;
}

static struct device *dev_find_class(struct device *parent, char *class)
{
	if (dev_is_class(parent, class)) {
		get_device(parent);
		return parent;
	}

	return device_find_child(parent, class, dev_is_class);
}

struct net_device *dsa_dev_to_net_device(struct device *dev)
{
	struct device *d;

	d = dev_find_class(dev, "net");
	if (d != NULL) {
		struct net_device *nd;

		nd = to_net_dev(d);
		dev_hold(nd);
		put_device(d);

		return nd;
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(dsa_dev_to_net_device);

static int dsa_switch_rcv(struct sk_buff *skb, struct net_device *dev,
			  struct packet_type *pt, struct net_device *orig_dev)
{
	struct dsa_switch_tree *dst = dev->dsa_ptr;
	struct sk_buff *nskb = NULL;

	if (unlikely(dst == NULL)) {
		kfree_skb(skb);
		return 0;
	}

	skb = skb_unshare(skb, GFP_ATOMIC);
	if (!skb)
		return 0;

	nskb = dst->rcv(skb, dev, pt, orig_dev);
	if (!nskb) {
		kfree_skb(skb);
		return 0;
	}

	skb = nskb;
	skb_push(skb, ETH_HLEN);
	skb->pkt_type = PACKET_HOST;
	skb->protocol = eth_type_trans(skb, skb->dev);

	skb->dev->stats.rx_packets++;
	skb->dev->stats.rx_bytes += skb->len;

	netif_receive_skb(skb);

	return 0;
}

static struct packet_type dsa_pack_type __read_mostly = {
	.type	= cpu_to_be16(ETH_P_XDSA),
	.func	= dsa_switch_rcv,
};

static int __init dsa_init_module(void)
{
	int rc;

	rc = dsa_slave_register_notifier();
	if (rc)
		return rc;

	rc = dsa_legacy_register();
	if (rc)
		return rc;

	dev_add_pack(&dsa_pack_type);

	return 0;
}
module_init(dsa_init_module);

static void __exit dsa_cleanup_module(void)
{
	dsa_slave_unregister_notifier();
	dev_remove_pack(&dsa_pack_type);
	dsa_legacy_unregister();
}
module_exit(dsa_cleanup_module);

MODULE_AUTHOR("Lennert Buytenhek <buytenh@wantstofly.org>");
MODULE_DESCRIPTION("Driver for Distributed Switch Architecture switch chips");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:dsa");