drivers: net: xgene-v2: Add base driver

This patch adds,

     - probe, remove, shutdown
     - open, close and stats
     - create and delete ring
     - request and delete irq
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: Keyur Chudgar <kchudgar@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/apm/xgene-v2/main.c

+/*
+ * Applied Micro X-Gene SoC Ethernet v2 Driver
+ *
+ * Copyright (c) 2017, Applied Micro Circuits Corporation
+ * Author(s): Iyappan Subramanian <isubramanian@apm.com>
+ *	      Keyur Chudgar <kchudgar@apm.com>
+ *
+ * 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 "main.h"
+
+static const struct acpi_device_id xge_acpi_match[];
+
+static int xge_get_resources(struct xge_pdata *pdata)
+{
+	struct platform_device *pdev;
+	struct net_device *ndev;
+	struct device *dev;
+	struct resource *res;
+	int phy_mode, ret = 0;
+
+	pdev = pdata->pdev;
+	dev = &pdev->dev;
+	ndev = pdata->ndev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Resource enet_csr not defined\n");
+		return -ENODEV;
+	}
+
+	pdata->resources.base_addr = devm_ioremap(dev, res->start,
+						  resource_size(res));
+	if (!pdata->resources.base_addr) {
+		dev_err(dev, "Unable to retrieve ENET Port CSR region\n");
+		return -ENOMEM;
+	}
+
+	if (!device_get_mac_address(dev, ndev->dev_addr, ETH_ALEN))
+		eth_hw_addr_random(ndev);
+
+	memcpy(ndev->perm_addr, ndev->dev_addr, ndev->addr_len);
+
+	phy_mode = device_get_phy_mode(dev);
+	if (phy_mode < 0) {
+		dev_err(dev, "Unable to get phy-connection-type\n");
+		return phy_mode;
+	}
+	pdata->resources.phy_mode = phy_mode;
+
+	if (pdata->resources.phy_mode != PHY_INTERFACE_MODE_RGMII) {
+		dev_err(dev, "Incorrect phy-connection-type specified\n");
+		return -ENODEV;
+	}
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret <= 0) {
+		dev_err(dev, "Unable to get ENET IRQ\n");
+		ret = ret ? : -ENXIO;
+		return ret;
+	}
+	pdata->resources.irq = ret;
+
+	return 0;
+}
+
+static int xge_refill_buffers(struct net_device *ndev, u32 nbuf)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	struct xge_desc_ring *ring = pdata->rx_ring;
+	const u8 slots = XGENE_ENET_NUM_DESC - 1;
+	struct device *dev = &pdata->pdev->dev;
+	struct xge_raw_desc *raw_desc;
+	u64 addr_lo, addr_hi;
+	u8 tail = ring->tail;
+	struct sk_buff *skb;
+	dma_addr_t dma_addr;
+	u16 len;
+	int i;
+
+	for (i = 0; i < nbuf; i++) {
+		raw_desc = &ring->raw_desc[tail];
+
+		len = XGENE_ENET_STD_MTU;
+		skb = netdev_alloc_skb(ndev, len);
+		if (unlikely(!skb))
+			return -ENOMEM;
+
+		dma_addr = dma_map_single(dev, skb->data, len, DMA_FROM_DEVICE);
+		if (dma_mapping_error(dev, dma_addr)) {
+			netdev_err(ndev, "DMA mapping error\n");
+			dev_kfree_skb_any(skb);
+			return -EINVAL;
+		}
+
+		ring->pkt_info[tail].skb = skb;
+		ring->pkt_info[tail].dma_addr = dma_addr;
+
+		addr_hi = GET_BITS(NEXT_DESC_ADDRH, le64_to_cpu(raw_desc->m1));
+		addr_lo = GET_BITS(NEXT_DESC_ADDRL, le64_to_cpu(raw_desc->m1));
+		raw_desc->m1 = cpu_to_le64(SET_BITS(NEXT_DESC_ADDRL, addr_lo) |
+					   SET_BITS(NEXT_DESC_ADDRH, addr_hi) |
+					   SET_BITS(PKT_ADDRH,
+						    dma_addr >> PKT_ADDRL_LEN));
+
+		dma_wmb();
+		raw_desc->m0 = cpu_to_le64(SET_BITS(PKT_ADDRL, dma_addr) |
+					   SET_BITS(E, 1));
+		tail = (tail + 1) & slots;
+	}
+
+	ring->tail = tail;
+
+	return 0;
+}
+
+static int xge_init_hw(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	int ret;
+
+	ret = xge_port_reset(ndev);
+	if (ret)
+		return ret;
+
+	xge_port_init(ndev);
+	pdata->nbufs = NUM_BUFS;
+
+	return 0;
+}
+
+static irqreturn_t xge_irq(const int irq, void *data)
+{
+	struct xge_pdata *pdata = data;
+
+	if (napi_schedule_prep(&pdata->napi)) {
+		xge_intr_disable(pdata);
+		__napi_schedule(&pdata->napi);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int xge_request_irq(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	struct device *dev = &pdata->pdev->dev;
+	int ret;
+
+	snprintf(pdata->irq_name, IRQ_ID_SIZE, "%s", ndev->name);
+
+	ret = devm_request_irq(dev, pdata->resources.irq, xge_irq,
+			       0, pdata->irq_name, pdata);
+	if (ret)
+		netdev_err(ndev, "Failed to request irq %s\n", pdata->irq_name);
+
+	return ret;
+}
+
+static void xge_free_irq(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	struct device *dev = &pdata->pdev->dev;
+
+	devm_free_irq(dev, pdata->resources.irq, pdata);
+}
+
+static void xge_delete_desc_ring(struct net_device *ndev,
+				 struct xge_desc_ring *ring)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	struct device *dev = &pdata->pdev->dev;
+	u16 size;
+
+	if (!ring)
+		return;
+
+	size = XGENE_ENET_DESC_SIZE * XGENE_ENET_NUM_DESC;
+	if (ring->desc_addr)
+		dma_free_coherent(dev, size, ring->desc_addr, ring->dma_addr);
+
+	kfree(ring->pkt_info);
+	kfree(ring);
+}
+
+static void xge_free_buffers(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	struct xge_desc_ring *ring = pdata->rx_ring;
+	struct device *dev = &pdata->pdev->dev;
+	struct sk_buff *skb;
+	dma_addr_t dma_addr;
+	int i;
+
+	for (i = 0; i < XGENE_ENET_NUM_DESC; i++) {
+		skb = ring->pkt_info[i].skb;
+		dma_addr = ring->pkt_info[i].dma_addr;
+
+		if (!skb)
+			continue;
+
+		dma_unmap_single(dev, dma_addr, XGENE_ENET_STD_MTU,
+				 DMA_FROM_DEVICE);
+		dev_kfree_skb_any(skb);
+	}
+}
+
+static void xge_delete_desc_rings(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+
+	xge_delete_desc_ring(ndev, pdata->tx_ring);
+
+	xge_free_buffers(ndev);
+	xge_delete_desc_ring(ndev, pdata->rx_ring);
+}
+
+static struct xge_desc_ring *xge_create_desc_ring(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	struct device *dev = &pdata->pdev->dev;
+	struct xge_desc_ring *ring;
+	u16 size;
+
+	ring = kzalloc(sizeof(struct xge_desc_ring), GFP_KERNEL);
+	if (!ring)
+		return NULL;
+
+	ring->ndev = ndev;
+
+	size = XGENE_ENET_DESC_SIZE * XGENE_ENET_NUM_DESC;
+	ring->desc_addr = dma_zalloc_coherent(dev, size, &ring->dma_addr,
+					      GFP_KERNEL);
+	if (!ring->desc_addr)
+		goto err;
+
+	ring->pkt_info = kcalloc(XGENE_ENET_NUM_DESC, sizeof(struct pkt_info),
+				 GFP_KERNEL);
+	if (!ring->pkt_info)
+		goto err;
+
+	xge_setup_desc(ring);
+
+	return ring;
+
+err:
+	xge_delete_desc_ring(ndev, ring);
+
+	return NULL;
+}
+
+static int xge_create_desc_rings(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	struct xge_desc_ring *ring;
+	int ret;
+
+	/* create tx ring */
+	ring = xge_create_desc_ring(ndev);
+	if (!ring)
+		goto err;
+
+	pdata->tx_ring = ring;
+	xge_update_tx_desc_addr(pdata);
+
+	/* create rx ring */
+	ring = xge_create_desc_ring(ndev);
+	if (!ring)
+		goto err;
+
+	pdata->rx_ring = ring;
+	xge_update_rx_desc_addr(pdata);
+
+	ret = xge_refill_buffers(ndev, XGENE_ENET_NUM_DESC);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	xge_delete_desc_rings(ndev);
+
+	return -ENOMEM;
+}
+
+static int xge_open(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	int ret;
+
+	ret = xge_create_desc_rings(ndev);
+	if (ret)
+		return ret;
+
+	napi_enable(&pdata->napi);
+	ret = xge_request_irq(ndev);
+	if (ret)
+		return ret;
+
+	xge_intr_enable(pdata);
+	xge_wr_csr(pdata, DMARXCTRL, 1);
+	xge_mac_enable(pdata);
+	netif_start_queue(ndev);
+	netif_carrier_on(ndev);
+
+	return 0;
+}
+
+static int xge_close(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+
+	netif_carrier_off(ndev);
+	netif_stop_queue(ndev);
+	xge_mac_disable(pdata);
+
+	xge_intr_disable(pdata);
+	xge_free_irq(ndev);
+	napi_disable(&pdata->napi);
+	xge_delete_desc_rings(ndev);
+
+	return 0;
+}
+
+static int xge_set_mac_addr(struct net_device *ndev, void *addr)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	int ret;
+
+	ret = eth_mac_addr(ndev, addr);
+	if (ret)
+		return ret;
+
+	xge_mac_set_station_addr(pdata);
+
+	return 0;
+}
+
+static void xge_timeout(struct net_device *ndev)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+
+	rtnl_lock();
+
+	if (netif_running(ndev)) {
+		netif_carrier_off(ndev);
+		netif_stop_queue(ndev);
+		xge_intr_disable(pdata);
+		napi_disable(&pdata->napi);
+
+		xge_wr_csr(pdata, DMATXCTRL, 0);
+		xge_txc_poll(ndev);
+		xge_free_pending_skb(ndev);
+		xge_wr_csr(pdata, DMATXSTATUS, ~0U);
+
+		xge_setup_desc(pdata->tx_ring);
+		xge_update_tx_desc_addr(pdata);
+		xge_mac_init(pdata);
+
+		napi_enable(&pdata->napi);
+		xge_intr_enable(pdata);
+		xge_mac_enable(pdata);
+		netif_start_queue(ndev);
+		netif_carrier_on(ndev);
+	}
+
+	rtnl_unlock();
+}
+
+static void xge_get_stats64(struct net_device *ndev,
+			    struct rtnl_link_stats64 *storage)
+{
+	struct xge_pdata *pdata = netdev_priv(ndev);
+	struct xge_stats *stats = &pdata->stats;
+
+	storage->tx_packets += stats->tx_packets;
+	storage->tx_bytes += stats->tx_bytes;
+
+	storage->rx_packets += stats->rx_packets;
+	storage->rx_bytes += stats->rx_bytes;
+}
+
+static const struct net_device_ops xgene_ndev_ops = {
+	.ndo_open = xge_open,
+	.ndo_stop = xge_close,
+	.ndo_set_mac_address = xge_set_mac_addr,
+	.ndo_tx_timeout = xge_timeout,
+	.ndo_get_stats64 = xge_get_stats64,
+};
+
+static int xge_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct net_device *ndev;
+	struct xge_pdata *pdata;
+	int ret;
+
+	ndev = alloc_etherdev(sizeof(struct xge_pdata));
+	if (!ndev)
+		return -ENOMEM;
+
+	pdata = netdev_priv(ndev);
+
+	pdata->pdev = pdev;
+	pdata->ndev = ndev;
+	SET_NETDEV_DEV(ndev, dev);
+	platform_set_drvdata(pdev, pdata);
+	ndev->netdev_ops = &xgene_ndev_ops;
+
+	ndev->features |= NETIF_F_GSO |
+			  NETIF_F_GRO;
+
+	ret = xge_get_resources(pdata);
+	if (ret)
+		goto err;
+
+	ndev->hw_features = ndev->features;
+
+	ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
+	if (ret) {
+		netdev_err(ndev, "No usable DMA configuration\n");
+		goto err;
+	}
+
+	ret = xge_init_hw(ndev);
+	if (ret)
+		goto err;
+
+	netif_napi_add(ndev, &pdata->napi, xge_napi, NAPI_POLL_WEIGHT);
+
+	netif_carrier_off(ndev);
+	ret = register_netdev(ndev);
+	if (ret) {
+		netdev_err(ndev, "Failed to register netdev\n");
+		goto err;
+	}
+
+	return 0;
+
+err:
+	free_netdev(ndev);
+
+	return ret;
+}
+
+static int xge_remove(struct platform_device *pdev)
+{
+	struct xge_pdata *pdata;
+	struct net_device *ndev;
+
+	pdata = platform_get_drvdata(pdev);
+	ndev = pdata->ndev;
+
+	rtnl_lock();
+	if (netif_running(ndev))
+		dev_close(ndev);
+	rtnl_unlock();
+
+	unregister_netdev(ndev);
+	free_netdev(ndev);
+
+	return 0;
+}
+
+static void xge_shutdown(struct platform_device *pdev)
+{
+	struct xge_pdata *pdata;
+
+	pdata = platform_get_drvdata(pdev);
+	if (!pdata)
+		return;
+
+	if (!pdata->ndev)
+		return;
+
+	xge_remove(pdev);
+}
+
+static const struct acpi_device_id xge_acpi_match[] = {
+	{ "APMC0D80" },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, xge_acpi_match);
+
+static struct platform_driver xge_driver = {
+	.driver = {
+		   .name = "xgene-enet-v2",
+		   .acpi_match_table = ACPI_PTR(xge_acpi_match),
+	},
+	.probe = xge_probe,
+	.remove = xge_remove,
+	.shutdown = xge_shutdown,
+};
+module_platform_driver(xge_driver);
+
+MODULE_DESCRIPTION("APM X-Gene SoC Ethernet v2 driver");
+MODULE_AUTHOR("Iyappan Subramanian <isubramanian@apm.com>");
+MODULE_VERSION(XGENE_ENET_V2_VERSION);
+MODULE_LICENSE("GPL");