path: root/drivers/net/ethernet/altera/altera_tse_main.c

// SPDX-License-Identifier: GPL-2.0-only
/* Altera Triple-Speed Ethernet MAC driver
 * Copyright (C) 2008-2014 Altera Corporation. All rights reserved
 *
 * Contributors:
 *   Dalon Westergreen
 *   Thomas Chou
 *   Ian Abbott
 *   Yuriy Kozlov
 *   Tobias Klauser
 *   Andriy Smolskyy
 *   Roman Bulgakov
 *   Dmytro Mytarchuk
 *   Matthew Gerlach
 *
 * Original driver contributed by SLS.
 * Major updates contributed by GlobalLogic
 */

#include <linux/atomic.h>
#include <linux/delay.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mii.h>
#include <linux/mdio/mdio-regmap.h>
#include <linux/netdevice.h>
#include <linux/of.h>
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/pcs-lynx.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/skbuff.h>
#include <asm/cacheflush.h>

#include "altera_utils.h"
#include "altera_tse.h"
#include "altera_sgdma.h"
#include "altera_msgdma.h"

static atomic_t instance_count = ATOMIC_INIT(~0);
/* Module parameters */
static int debug = -1;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Message Level (-1: default, 0: no output, 16: all)");

static const u32 default_msg_level = (NETIF_MSG_DRV | NETIF_MSG_PROBE |
					NETIF_MSG_LINK | NETIF_MSG_IFUP |
					NETIF_MSG_IFDOWN);

#define RX_DESCRIPTORS 64
static int dma_rx_num = RX_DESCRIPTORS;
module_param(dma_rx_num, int, 0644);
MODULE_PARM_DESC(dma_rx_num, "Number of descriptors in the RX list");

#define TX_DESCRIPTORS 64
static int dma_tx_num = TX_DESCRIPTORS;
module_param(dma_tx_num, int, 0644);
MODULE_PARM_DESC(dma_tx_num, "Number of descriptors in the TX list");


#define POLL_PHY (-1)

/* Make sure DMA buffer size is larger than the max frame size
 * plus some alignment offset and a VLAN header. If the max frame size is
 * 1518, a VLAN header would be additional 4 bytes and additional
 * headroom for alignment is 2 bytes, 2048 is just fine.
 */
#define ALTERA_RXDMABUFFER_SIZE	2048

/* Allow network stack to resume queuing packets after we've
 * finished transmitting at least 1/4 of the packets in the queue.
 */
#define TSE_TX_THRESH(x)	(x->tx_ring_size / 4)

#define TXQUEUESTOP_THRESHHOLD	2

static inline u32 tse_tx_avail(struct altera_tse_private *priv)
{
	return priv->tx_cons + priv->tx_ring_size - priv->tx_prod - 1;
}

/* MDIO specific functions
 */
static int altera_tse_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
{
	struct net_device *ndev = bus->priv;
	struct altera_tse_private *priv = netdev_priv(ndev);

	/* set MDIO address */
	csrwr32((mii_id & 0x1f), priv->mac_dev,
		tse_csroffs(mdio_phy1_addr));

	/* get the data */
	return csrrd32(priv->mac_dev,
		       tse_csroffs(mdio_phy1) + regnum * 4) & 0xffff;
}

static int altera_tse_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
				 u16 value)
{
	struct net_device *ndev = bus->priv;
	struct altera_tse_private *priv = netdev_priv(ndev);

	/* set MDIO address */
	csrwr32((mii_id & 0x1f), priv->mac_dev,
		tse_csroffs(mdio_phy1_addr));

	/* write the data */
	csrwr32(value, priv->mac_dev, tse_csroffs(mdio_phy1) + regnum * 4);
	return 0;
}

static int altera_tse_mdio_create(struct net_device *dev, unsigned int id)
{
	struct altera_tse_private *priv = netdev_priv(dev);
	struct device_node *mdio_node = NULL;
	struct device_node *child_node = NULL;
	struct mii_bus *mdio = NULL;
	int ret;

	for_each_child_of_node(priv->device->of_node, child_node) {
		if (of_device_is_compatible(child_node, "altr,tse-mdio")) {
			mdio_node = child_node;
			break;
		}
	}

	if (mdio_node) {
		netdev_dbg(dev, "FOUND MDIO subnode\n");
	} else {
		netdev_dbg(dev, "NO MDIO subnode\n");
		return 0;
	}

	mdio = mdiobus_alloc();
	if (mdio == NULL) {
		netdev_err(dev, "Error allocating MDIO bus\n");
		ret = -ENOMEM;
		goto put_node;
	}

	mdio->name = ALTERA_TSE_RESOURCE_NAME;
	mdio->read = &altera_tse_mdio_read;
	mdio->write = &altera_tse_mdio_write;
	snprintf(mdio->id, MII_BUS_ID_SIZE, "%s-%u", mdio->name, id);

	mdio->priv = dev;
	mdio->parent = priv->device;

	ret = of_mdiobus_register(mdio, mdio_node);
	if (ret != 0) {
		netdev_err(dev, "Cannot register MDIO bus %s\n",
			   mdio->id);
		goto out_free_mdio;
	}
	of_node_put(mdio_node);

	if (netif_msg_drv(priv))
		netdev_info(dev, "MDIO bus %s: created\n", mdio->id);

	priv->mdio = mdio;
	return 0;
out_free_mdio:
	mdiobus_free(mdio);
	mdio = NULL;
put_node:
	of_node_put(mdio_node);
	return ret;
}

static void altera_tse_mdio_destroy(struct net_device *dev)
{
	struct altera_tse_private *priv = netdev_priv(dev);

	if (priv->mdio == NULL)
		return;

	if (netif_msg_drv(priv))
		netdev_info(dev, "MDIO bus %s: removed\n",
			    priv->mdio->id);

	mdiobus_unregister(priv->mdio);
	mdiobus_free(priv->mdio);
	priv->mdio = NULL;
}

static int tse_init_rx_buffer(struct altera_tse_private *priv,
			      struct tse_buffer *rxbuffer, int len)
{
	rxbuffer->skb = netdev_alloc_skb_ip_align(priv->dev, len);
	if (!rxbuffer->skb)
		return -ENOMEM;

	rxbuffer->dma_addr = dma_map_single(priv->device, rxbuffer->skb->data,
						len,
						DMA_FROM_DEVICE);

	if (dma_mapping_error(priv->device, rxbuffer->dma_addr)) {
		netdev_err(priv->dev, "%s: DMA mapping error\n", __func__);
		dev_kfree_skb_any(rxbuffer->skb);
		return -EINVAL;
	}
	rxbuffer->dma_addr &= (dma_addr_t)~3;
	rxbuffer->len = len;
	return 0;
}

static void tse_free_rx_buffer(struct altera_tse_private *priv,
			       struct tse_buffer *rxbuffer)
{
	dma_addr_t dma_addr = rxbuffer->dma_addr;
	struct sk_buff *skb = rxbuffer->skb;

	if (skb != NULL) {
		if (dma_addr)
			dma_unmap_single(priv->device, dma_addr,
					 rxbuffer->len,
					 DMA_FROM_DEVICE);
		dev_kfree_skb_any(skb);
		rxbuffer->skb = NULL;
		rxbuffer->dma_addr = 0;
	}
}

/* Unmap and free Tx buffer resources
 */
static void tse_free_tx_buffer(struct altera_tse_private *priv,
			       struct tse_buffer *buffer)
{
	if (buffer->dma_addr) {
		if (buffer->mapped_as_page)
			dma_unmap_page(priv->device, buffer->dma_addr,
				       buffer->len, DMA_TO_DEVICE);
		else
			dma_unmap_single(priv->device, buffer->dma_addr,
					 buffer->len, DMA_TO_DEVICE);
		buffer->dma_addr = 0;
	}
	if (buffer->skb) {
		dev_kfree_skb_any(buffer->skb);
		buffer->skb = NULL;
	}
}

static int alloc_init_skbufs(struct altera_tse_private *priv)
{
	unsigned int rx_descs = priv->rx_ring_size;
	unsigned int tx_descs = priv->tx_ring_size;
	int ret = -ENOMEM;
	int i;

	/* Create Rx ring buffer */
	priv->rx_ring = kcalloc(rx_descs, si