X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=drivers%2Fnet%2Fks8842.c;h=928b2b83cef509080c30eccd6c4d1c4cfe76fd58;hb=48d3ff82698cb0094684aed70446e0a5cbb1a4d0;hp=f852ab3ae9cf2aaa86ff6ac9718d8b839bea6bdb;hpb=1c62c72b1a3c4478fb9069503d20c41b1f385ca1;p=karo-tx-linux.git

diff --git a/drivers/net/ks8842.c b/drivers/net/ks8842.c
index f852ab3ae9cf..928b2b83cef5 100644
--- a/drivers/net/ks8842.c
+++ b/drivers/net/ks8842.c
@@ -18,6 +18,7 @@
 
 /* Supports:
  * The Micrel KS8842 behind the timberdale FPGA
+ * The genuine Micrel KS8841/42 device with ISA 16/32bit bus interface
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -29,11 +30,19 @@
 #include <linux/etherdevice.h>
 #include <linux/ethtool.h>
 #include <linux/ks8842.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
 
 #define DRV_NAME "ks8842"
 
 /* Timberdale specific Registers */
-#define REG_TIMB_RST	0x1c
+#define REG_TIMB_RST		0x1c
+#define REG_TIMB_FIFO		0x20
+#define REG_TIMB_ISR		0x24
+#define REG_TIMB_IER		0x28
+#define REG_TIMB_IAR		0x2C
+#define REQ_TIMB_DMA_RESUME	0x30
 
 /* KS8842 registers */
 
@@ -76,6 +85,15 @@
 #define IRQ_RX_ERROR	0x0080
 #define ENABLED_IRQS	(IRQ_LINK_CHANGE | IRQ_TX | IRQ_RX | IRQ_RX_STOPPED | \
 		IRQ_TX_STOPPED | IRQ_RX_OVERRUN | IRQ_RX_ERROR)
+/* When running via timberdale in DMA mode, the RX interrupt should be
+   enabled in the KS8842, but not in the FPGA IP, since the IP handles
+   RX DMA internally.
+   TX interrupts are not needed it is handled by the FPGA the driver is
+   notified via DMA callbacks.
+*/
+#define ENABLED_IRQS_DMA_IP	(IRQ_LINK_CHANGE | IRQ_RX_STOPPED | \
+	IRQ_TX_STOPPED | IRQ_RX_OVERRUN | IRQ_RX_ERROR)
+#define ENABLED_IRQS_DMA	(ENABLED_IRQS_DMA_IP | IRQ_RX)
 #define REG_ISR		0x02
 #define REG_RXSR	0x04
 #define RXSR_VALID	0x8000
@@ -114,14 +132,53 @@
 #define REG_P1CR4		0x02
 #define REG_P1SR		0x04
 
+/* flags passed by platform_device for configuration */
+#define	MICREL_KS884X		0x01	/* 0=Timeberdale(FPGA), 1=Micrel */
+#define	KS884X_16BIT		0x02	/*  1=16bit, 0=32bit */
+
+#define DMA_BUFFER_SIZE		2048
+
+struct ks8842_tx_dma_ctl {
+	struct dma_chan *chan;
+	struct dma_async_tx_descriptor *adesc;
+	void *buf;
+	struct scatterlist sg;
+	int channel;
+};
+
+struct ks8842_rx_dma_ctl {
+	struct dma_chan *chan;
+	struct dma_async_tx_descriptor *adesc;
+	struct sk_buff  *skb;
+	struct scatterlist sg;
+	struct tasklet_struct tasklet;
+	int channel;
+};
+
+#define KS8842_USE_DMA(adapter) (((adapter)->dma_tx.channel != -1) && \
+	 ((adapter)->dma_rx.channel != -1))
+
 struct ks8842_adapter {
 	void __iomem	*hw_addr;
 	int		irq;
+	unsigned long	conf_flags;	/* copy of platform_device config */
 	struct tasklet_struct	tasklet;
 	spinlock_t	lock; /* spinlock to be interrupt safe */
-	struct platform_device *pdev;
+	struct work_struct timeout_work;
+	struct net_device *netdev;
+	struct device *dev;
+	struct ks8842_tx_dma_ctl	dma_tx;
+	struct ks8842_rx_dma_ctl	dma_rx;
 };
 
+static void ks8842_dma_rx_cb(void *data);
+static void ks8842_dma_tx_cb(void *data);
+
+static inline void ks8842_resume_dma(struct ks8842_adapter *adapter)
+{
+	iowrite32(1, adapter->hw_addr + REQ_TIMB_DMA_RESUME);
+}
+
 static inline void ks8842_select_bank(struct ks8842_adapter *adapter, u16 bank)
 {
 	iowrite16(bank, adapter->hw_addr + REG_SELECT_BANK);
@@ -191,16 +248,21 @@ static inline u32 ks8842_read32(struct ks8842_adapter *adapter, u16 bank,
 
 static void ks8842_reset(struct ks8842_adapter *adapter)
 {
-	/* The KS8842 goes haywire when doing softare reset
-	 * a work around in the timberdale IP is implemented to
-	 * do a hardware reset instead
-	ks8842_write16(adapter, 3, 1, REG_GRR);
-	msleep(10);
-	iowrite16(0, adapter->hw_addr + REG_GRR);
-	*/
-	iowrite16(32, adapter->hw_addr + REG_SELECT_BANK);
-	iowrite32(0x1, adapter->hw_addr + REG_TIMB_RST);
-	msleep(20);
+	if (adapter->conf_flags & MICREL_KS884X) {
+		ks8842_write16(adapter, 3, 1, REG_GRR);
+		msleep(10);
+		iowrite16(0, adapter->hw_addr + REG_GRR);
+	} else {
+		/* The KS8842 goes haywire when doing softare reset
+		* a work around in the timberdale IP is implemented to
+		* do a hardware reset instead
+		ks8842_write16(adapter, 3, 1, REG_GRR);
+		msleep(10);
+		iowrite16(0, adapter->hw_addr + REG_GRR);
+		*/
+		iowrite32(0x1, adapter->hw_addr + REG_TIMB_RST);
+		msleep(20);
+	}
 }
 
 static void ks8842_update_link_status(struct net_device *netdev,
@@ -269,8 +331,6 @@ static void ks8842_reset_hw(struct ks8842_adapter *adapter)
 
 	/* restart port auto-negotiation */
 	ks8842_enable_bits(adapter, 49, 1 << 13, REG_P1CR4);
-	/* only advertise 10Mbps */
-	ks8842_clear_bits(adapter, 49, 3 << 2, REG_P1CR4);
 
 	/* Enable the transmitter */
 	ks8842_enable_tx(adapter);
@@ -282,8 +342,19 @@ static void ks8842_reset_hw(struct ks8842_adapter *adapter)
 	ks8842_write16(adapter, 18, 0xffff, REG_ISR);
 
 	/* enable interrupts */
-	ks8842_write16(adapter, 18, ENABLED_IRQS, REG_IER);
-
+	if (KS8842_USE_DMA(adapter)) {
+		/* When running in DMA Mode the RX interrupt is not enabled in
+		   timberdale because RX data is received by DMA callbacks
+		   it must still be enabled in the KS8842 because it indicates
+		   to timberdale when there is RX data for it's DMA FIFOs */
+		iowrite16(ENABLED_IRQS_DMA_IP, adapter->hw_addr + REG_TIMB_IER);
+		ks8842_write16(adapter, 18, ENABLED_IRQS_DMA, REG_IER);
+	} else {
+		if (!(adapter->conf_flags & MICREL_KS884X))
+			iowrite16(ENABLED_IRQS,
+				adapter->hw_addr + REG_TIMB_IER);
+		ks8842_write16(adapter, 18, ENABLED_IRQS, REG_IER);
+	}
 	/* enable the switch */
 	ks8842_write16(adapter, 32, 0x1, REG_SW_ID_AND_ENABLE);
 }
@@ -296,13 +367,28 @@ static void ks8842_read_mac_addr(struct ks8842_adapter *adapter, u8 *dest)
 	for (i = 0; i < ETH_ALEN; i++)
 		dest[ETH_ALEN - i - 1] = ks8842_read8(adapter, 2, REG_MARL + i);
 
-	/* make sure the switch port uses the same MAC as the QMU */
-	mac = ks8842_read16(adapter, 2, REG_MARL);
-	ks8842_write16(adapter, 39, mac, REG_MACAR1);
-	mac = ks8842_read16(adapter, 2, REG_MARM);
-	ks8842_write16(adapter, 39, mac, REG_MACAR2);
-	mac = ks8842_read16(adapter, 2, REG_MARH);
-	ks8842_write16(adapter, 39, mac, REG_MACAR3);
+	if (adapter->conf_flags & MICREL_KS884X) {
+		/*
+		the sequence of saving mac addr between MAC and Switch is
+		different.
+		*/
+
+		mac = ks8842_read16(adapter, 2, REG_MARL);
+		ks8842_write16(adapter, 39, mac, REG_MACAR3);
+		mac = ks8842_read16(adapter, 2, REG_MARM);
+		ks8842_write16(adapter, 39, mac, REG_MACAR2);
+		mac = ks8842_read16(adapter, 2, REG_MARH);
+		ks8842_write16(adapter, 39, mac, REG_MACAR1);
+	} else {
+
+		/* make sure the switch port uses the same MAC as the QMU */
+		mac = ks8842_read16(adapter, 2, REG_MARL);
+		ks8842_write16(adapter, 39, mac, REG_MACAR1);
+		mac = ks8842_read16(adapter, 2, REG_MARM);
+		ks8842_write16(adapter, 39, mac, REG_MACAR2);
+		mac = ks8842_read16(adapter, 2, REG_MARH);
+		ks8842_write16(adapter, 39, mac, REG_MACAR3);
+	}
 }
 
 static void ks8842_write_mac_addr(struct ks8842_adapter *adapter, u8 *mac)
@@ -313,8 +399,25 @@ static void ks8842_write_mac_addr(struct ks8842_adapter *adapter, u8 *mac)
 	spin_lock_irqsave(&adapter->lock, flags);
 	for (i = 0; i < ETH_ALEN; i++) {
 		ks8842_write8(adapter, 2, mac[ETH_ALEN - i - 1], REG_MARL + i);
-		ks8842_write8(adapter, 39, mac[ETH_ALEN - i - 1],
-			REG_MACAR1 + i);
+		if (!(adapter->conf_flags & MICREL_KS884X))
+			ks8842_write8(adapter, 39, mac[ETH_ALEN - i - 1],
+				REG_MACAR1 + i);
+	}
+
+	if (adapter->conf_flags & MICREL_KS884X) {
+		/*
+		the sequence of saving mac addr between MAC and Switch is
+		different.
+		*/
+
+		u16 mac;
+
+		mac = ks8842_read16(adapter, 2, REG_MARL);
+		ks8842_write16(adapter, 39, mac, REG_MACAR3);
+		mac = ks8842_read16(adapter, 2, REG_MARM);
+		ks8842_write16(adapter, 39, mac, REG_MACAR2);
+		mac = ks8842_read16(adapter, 2, REG_MARH);
+		ks8842_write16(adapter, 39, mac, REG_MACAR1);
 	}
 	spin_unlock_irqrestore(&adapter->lock, flags);
 }
@@ -324,15 +427,59 @@ static inline u16 ks8842_tx_fifo_space(struct ks8842_adapter *adapter)
 	return ks8842_read16(adapter, 16, REG_TXMIR) & 0x1fff;
 }
 
+static int ks8842_tx_frame_dma(struct sk_buff *skb, struct net_device *netdev)
+{
+	struct ks8842_adapter *adapter = netdev_priv(netdev);
+	struct ks8842_tx_dma_ctl *ctl = &adapter->dma_tx;
+	u8 *buf = ctl->buf;
+
+	if (ctl->adesc) {
+		netdev_dbg(netdev, "%s: TX ongoing\n", __func__);
+		/* transfer ongoing */
+		return NETDEV_TX_BUSY;
+	}
+
+	sg_dma_len(&ctl->sg) = skb->len + sizeof(u32);
+
+	/* copy data to the TX buffer */
+	/* the control word, enable IRQ, port 1 and the length */
+	*buf++ = 0x00;
+	*buf++ = 0x01; /* Port 1 */
+	*buf++ = skb->len & 0xff;
+	*buf++ = (skb->len >> 8) & 0xff;
+	skb_copy_from_linear_data(skb, buf, skb->len);
+
+	dma_sync_single_range_for_device(adapter->dev,
+		sg_dma_address(&ctl->sg), 0, sg_dma_len(&ctl->sg),
+		DMA_TO_DEVICE);
+
+	/* make sure the length is a multiple of 4 */
+	if (sg_dma_len(&ctl->sg) % 4)
+		sg_dma_len(&ctl->sg) += 4 - sg_dma_len(&ctl->sg) % 4;
+
+	ctl->adesc = ctl->chan->device->device_prep_slave_sg(ctl->chan,
+		&ctl->sg, 1, DMA_TO_DEVICE,
+		DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_SRC_UNMAP);
+	if (!ctl->adesc)
+		return NETDEV_TX_BUSY;
+
+	ctl->adesc->callback_param = netdev;
+	ctl->adesc->callback = ks8842_dma_tx_cb;
+	ctl->adesc->tx_submit(ctl->adesc);
+
+	netdev->stats.tx_bytes += skb->len;
+
+	dev_kfree_skb(skb);
+
+	return NETDEV_TX_OK;
+}
+
 static int ks8842_tx_frame(struct sk_buff *skb, struct net_device *netdev)
 {
 	struct ks8842_adapter *adapter = netdev_priv(netdev);
 	int len = skb->len;
-	u32 *ptr = (u32 *)skb->data;
-	u32 ctrl;
 
-	dev_dbg(&adapter->pdev->dev,
-		"%s: len %u head %p data %p tail %p end %p\n",
+	netdev_dbg(netdev, "%s: len %u head %p data %p tail %p end %p\n",
 		__func__, skb->len, skb->head, skb->data,
 		skb_tail_pointer(skb), skb_end_pointer(skb));
 
@@ -340,17 +487,34 @@ static int ks8842_tx_frame(struct sk_buff *skb, struct net_device *netdev)
 	if (ks8842_tx_fifo_space(adapter) < len + 8)
 		return NETDEV_TX_BUSY;
 
-	/* the control word, enable IRQ, port 1 and the length */
-	ctrl = 0x8000 | 0x100 | (len << 16);
-	ks8842_write32(adapter, 17, ctrl, REG_QMU_DATA_LO);
+	if (adapter->conf_flags & KS884X_16BIT) {
+		u16 *ptr16 = (u16 *)skb->data;
+		ks8842_write16(adapter, 17, 0x8000 | 0x100, REG_QMU_DATA_LO);
+		ks8842_write16(adapter, 17, (u16)len, REG_QMU_DATA_HI);
+		netdev->stats.tx_bytes += len;
+
+		/* copy buffer */
+		while (len > 0) {
+			iowrite16(*ptr16++, adapter->hw_addr + REG_QMU_DATA_LO);
+			iowrite16(*ptr16++, adapter->hw_addr + REG_QMU_DATA_HI);
+			len -= sizeof(u32);
+		}
+	} else {
 
-	netdev->stats.tx_bytes += len;
+		u32 *ptr = (u32 *)skb->data;
+		u32 ctrl;
+		/* the control word, enable IRQ, port 1 and the length */
+		ctrl = 0x8000 | 0x100 | (len << 16);
+		ks8842_write32(adapter, 17, ctrl, REG_QMU_DATA_LO);
 
-	/* copy buffer */
-	while (len > 0) {
-		iowrite32(*ptr, adapter->hw_addr + REG_QMU_DATA_LO);
-		len -= sizeof(u32);
-		ptr++;
+		netdev->stats.tx_bytes += len;
+
+		/* copy buffer */
+		while (len > 0) {
+			iowrite32(*ptr, adapter->hw_addr + REG_QMU_DATA_LO);
+			len -= sizeof(u32);
+			ptr++;
+		}
 	}
 
 	/* enqueue packet */
@@ -361,54 +525,174 @@ static int ks8842_tx_frame(struct sk_buff *skb, struct net_device *netdev)
 	return NETDEV_TX_OK;
 }
 
-static void ks8842_rx_frame(struct net_device *netdev,
-	struct ks8842_adapter *adapter)
+static void ks8842_update_rx_err_counters(struct net_device *netdev, u32 status)
+{
+	netdev_dbg(netdev, "RX error, status: %x\n", status);
+
+	netdev->stats.rx_errors++;
+	if (status & RXSR_TOO_LONG)
+		netdev->stats.rx_length_errors++;
+	if (status & RXSR_CRC_ERROR)
+		netdev->stats.rx_crc_errors++;
+	if (status & RXSR_RUNT)
+		netdev->stats.rx_frame_errors++;
+}
+
+static void ks8842_update_rx_counters(struct net_device *netdev, u32 status,
+	int len)
+{
+	netdev_dbg(netdev, "RX packet, len: %d\n", len);
+
+	netdev->stats.rx_packets++;
+	netdev->stats.rx_bytes += len;
+	if (status & RXSR_MULTICAST)
+		netdev->stats.multicast++;
+}
+
+static int __ks8842_start_new_rx_dma(struct net_device *netdev)
 {
-	u32 status = ks8842_read32(adapter, 17, REG_QMU_DATA_LO);
-	int len = (status >> 16) & 0x7ff;
+	struct ks8842_adapter *adapter = netdev_priv(netdev);
+	struct ks8842_rx_dma_ctl *ctl = &adapter->dma_rx;
+	struct scatterlist *sg = &ctl->sg;
+	int err;
 
-	status &= 0xffff;
+	ctl->skb = netdev_alloc_skb(netdev, DMA_BUFFER_SIZE);
+	if (ctl->skb) {
+		sg_init_table(sg, 1);
+		sg_dma_address(sg) = dma_map_single(adapter->dev,
+			ctl->skb->data, DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
+		err = dma_mapping_error(adapter->dev, sg_dma_address(sg));
+		if (unlikely(err)) {
+			sg_dma_address(sg) = 0;
+			goto out;
+		}
+
+		sg_dma_len(sg) = DMA_BUFFER_SIZE;
+
+		ctl->adesc = ctl->chan->device->device_prep_slave_sg(ctl->chan,
+			sg, 1, DMA_FROM_DEVICE,
+			DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_SRC_UNMAP);
+
+		if (!ctl->adesc)
+			goto out;
+
+		ctl->adesc->callback_param = netdev;
+		ctl->adesc->callback = ks8842_dma_rx_cb;
+		ctl->adesc->tx_submit(ctl->adesc);
+	} else {
+		err = -ENOMEM;
+		sg_dma_address(sg) = 0;
+		goto out;
+	}
 
-	dev_dbg(&adapter->pdev->dev, "%s - rx_data: status: %x\n",
-		__func__, status);
+	return err;
+out:
+	if (sg_dma_address(sg))
+		dma_unmap_single(adapter->dev, sg_dma_address(sg),
+			DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
+	sg_dma_address(sg) = 0;
+	if (ctl->skb)
+		dev_kfree_skb(ctl->skb);
+
+	ctl->skb = NULL;
+
+	printk(KERN_ERR DRV_NAME": Failed to start RX DMA: %d\n", err);
+	return err;
+}
+
+static void ks8842_rx_frame_dma_tasklet(unsigned long arg)
+{
+	struct net_device *netdev = (struct net_device *)arg;
+	struct ks8842_adapter *adapter = netdev_priv(netdev);
+	struct ks8842_rx_dma_ctl *ctl = &adapter->dma_rx;
+	struct sk_buff *skb = ctl->skb;
+	dma_addr_t addr = sg_dma_address(&ctl->sg);
+	u32 status;
+
+	ctl->adesc = NULL;
+
+	/* kick next transfer going */
+	__ks8842_start_new_rx_dma(netdev);
+
+	/* now handle the data we got */
+	dma_unmap_single(adapter->dev, addr, DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
+
+	status = *((u32 *)skb->data);
+
+	netdev_dbg(netdev, "%s - rx_data: status: %x\n",
+		__func__, status & 0xffff);
 
 	/* check the status */
 	if ((status & RXSR_VALID) && !(status & RXSR_ERROR)) {
-		struct sk_buff *skb = netdev_alloc_skb_ip_align(netdev, len);
+		int len = (status >> 16) & 0x7ff;
 
-		dev_dbg(&adapter->pdev->dev, "%s, got package, len: %d\n",
-			__func__, len);
-		if (skb) {
-			u32 *data;
+		ks8842_update_rx_counters(netdev, status, len);
 
-			netdev->stats.rx_packets++;
-			netdev->stats.rx_bytes += len;
-			if (status & RXSR_MULTICAST)
-				netdev->stats.multicast++;
+		/* reserve 4 bytes which is the status word */
+		skb_reserve(skb, 4);
+		skb_put(skb, len);
 
-			data = (u32 *)skb_put(skb, len);
+		skb->protocol = eth_type_trans(skb, netdev);
+		netif_rx(skb);
+	} else {
+		ks8842_update_rx_err_counters(netdev, status);
+		dev_kfree_skb(skb);
+	}
+}
 
-			ks8842_select_bank(adapter, 17);
-			while (len > 0) {
-				*data++ = ioread32(adapter->hw_addr +
-					REG_QMU_DATA_LO);
-				len -= sizeof(u32);
-			}
+static void ks8842_rx_frame(struct net_device *netdev,
+	struct ks8842_adapter *adapter)
+{
+	u32 status;
+	int len;
+
+	if (adapter->conf_flags & KS884X_16BIT) {
+		status = ks8842_read16(adapter, 17, REG_QMU_DATA_LO);
+		len = ks8842_read16(adapter, 17, REG_QMU_DATA_HI);
+		netdev_dbg(netdev, "%s - rx_data: status: %x\n",
+			   __func__, status);
+	} else {
+		status = ks8842_read32(adapter, 17, REG_QMU_DATA_LO);
+		len = (status >> 16) & 0x7ff;
+		status &= 0xffff;
+		netdev_dbg(netdev, "%s - rx_data: status: %x\n",
+			   __func__, status);
+	}
 
+	/* check the status */
+	if ((status & RXSR_VALID) && !(status & RXSR_ERROR)) {
+		struct sk_buff *skb = netdev_alloc_skb_ip_align(netdev, len);
+
+		if (skb) {
+
+			ks8842_update_rx_counters(netdev, status, len);
+
+			if (adapter->conf_flags & KS884X_16BIT) {
+				u16 *data16 = (u16 *)skb_put(skb, len);
+				ks8842_select_bank(adapter, 17);
+				while (len > 0) {
+					*data16++ = ioread16(adapter->hw_addr +
+						REG_QMU_DATA_LO);
+					*data16++ = ioread16(adapter->hw_addr +
+						REG_QMU_DATA_HI);
+					len -= sizeof(u32);
+				}
+			} else {
+				u32 *data = (u32 *)skb_put(skb, len);
+
+				ks8842_select_bank(adapter, 17);
+				while (len > 0) {
+					*data++ = ioread32(adapter->hw_addr +
+						REG_QMU_DATA_LO);
+					len -= sizeof(u32);
+				}
+			}
 			skb->protocol = eth_type_trans(skb, netdev);
 			netif_rx(skb);
 		} else
 			netdev->stats.rx_dropped++;
-	} else {
-		dev_dbg(&adapter->pdev->dev, "RX error, status: %x\n", status);
-		netdev->stats.rx_errors++;
-		if (status & RXSR_TOO_LONG)
-			netdev->stats.rx_length_errors++;
-		if (status & RXSR_CRC_ERROR)
-			netdev->stats.rx_crc_errors++;
-		if (status & RXSR_RUNT)
-			netdev->stats.rx_frame_errors++;
-	}
+	} else
+		ks8842_update_rx_err_counters(netdev, status);
 
 	/* set high watermark to 3K */
 	ks8842_clear_bits(adapter, 0, 1 << 12, REG_QRFCR);
@@ -423,8 +707,7 @@ static void ks8842_rx_frame(struct net_device *netdev,
 void ks8842_handle_rx(struct net_device *netdev, struct ks8842_adapter *adapter)
 {
 	u16 rx_data = ks8842_read16(adapter, 16, REG_RXMIR) & 0x1fff;
-	dev_dbg(&adapter->pdev->dev, "%s Entry - rx_data: %d\n",
-		__func__, rx_data);
+	netdev_dbg(netdev, "%s Entry - rx_data: %d\n", __func__, rx_data);
 	while (rx_data) {
 		ks8842_rx_frame(netdev, adapter);
 		rx_data = ks8842_read16(adapter, 16, REG_RXMIR) & 0x1fff;
@@ -434,7 +717,7 @@ void ks8842_handle_rx(struct net_device *netdev, struct ks8842_adapter *adapter)
 void ks8842_handle_tx(struct net_device *netdev, struct ks8842_adapter *adapter)
 {
 	u16 sr = ks8842_read16(adapter, 16, REG_TXSR);
-	dev_dbg(&adapter->pdev->dev, "%s - entry, sr: %x\n", __func__, sr);
+	netdev_dbg(netdev, "%s - entry, sr: %x\n", __func__, sr);
 	netdev->stats.tx_packets++;
 	if (netif_queue_stopped(netdev))
 		netif_wake_queue(netdev);
@@ -443,7 +726,7 @@ void ks8842_handle_tx(struct net_device *netdev, struct ks8842_adapter *adapter)
 void ks8842_handle_rx_overrun(struct net_device *netdev,
 	struct ks8842_adapter *adapter)
 {
-	dev_dbg(&adapter->pdev->dev, "%s: entry\n", __func__);
+	netdev_dbg(netdev, "%s: entry\n", __func__);
 	netdev->stats.rx_errors++;
 	netdev->stats.rx_fifo_errors++;
 }
@@ -462,20 +745,32 @@ void ks8842_tasklet(unsigned long arg)
 	spin_unlock_irqrestore(&adapter->lock, flags);
 
 	isr = ks8842_read16(adapter, 18, REG_ISR);
-	dev_dbg(&adapter->pdev->dev, "%s - ISR: 0x%x\n", __func__, isr);
+	netdev_dbg(netdev, "%s - ISR: 0x%x\n", __func__, isr);
+
+	/* when running in DMA mode, do not ack RX interrupts, it is handled
+	   internally by timberdale, otherwise it's DMA FIFO:s would stop
+	*/
+	if (KS8842_USE_DMA(adapter))
+		isr &= ~IRQ_RX;
 
 	/* Ack */
 	ks8842_write16(adapter, 18, isr, REG_ISR);
 
+	if (!(adapter->conf_flags & MICREL_KS884X))
+		/* Ack in the timberdale IP as well */
+		iowrite32(0x1, adapter->hw_addr + REG_TIMB_IAR);
+
 	if (!netif_running(netdev))
 		return;
 
 	if (isr & IRQ_LINK_CHANGE)
 		ks8842_update_link_status(netdev, adapter);
 
-	if (isr & (IRQ_RX | IRQ_RX_ERROR))
+	/* should not get IRQ_RX when running DMA mode */
+	if (isr & (IRQ_RX | IRQ_RX_ERROR) && !KS8842_USE_DMA(adapter))
 		ks8842_handle_rx(netdev, adapter);
 
+	/* should only happen when in PIO mode */
 	if (isr & IRQ_TX)
 		ks8842_handle_tx(netdev, adapter);
 
@@ -494,24 +789,38 @@ void ks8842_tasklet(unsigned long arg)
 
 	/* re-enable interrupts, put back the bank selection register */
 	spin_lock_irqsave(&adapter->lock, flags);
-	ks8842_write16(adapter, 18, ENABLED_IRQS, REG_IER);
+	if (KS8842_USE_DMA(adapter))
+		ks8842_write16(adapter, 18, ENABLED_IRQS_DMA, REG_IER);
+	else
+		ks8842_write16(adapter, 18, ENABLED_IRQS, REG_IER);
 	iowrite16(entry_bank, adapter->hw_addr + REG_SELECT_BANK);
+
+	/* Make sure timberdale continues DMA operations, they are stopped while
+	   we are handling the ks8842 because we might change bank */
+	if (KS8842_USE_DMA(adapter))
+		ks8842_resume_dma(adapter);
+
 	spin_unlock_irqrestore(&adapter->lock, flags);
 }
 
 static irqreturn_t ks8842_irq(int irq, void *devid)
 {
-	struct ks8842_adapter *adapter = devid;
+	struct net_device *netdev = devid;
+	struct ks8842_adapter *adapter = netdev_priv(netdev);
 	u16 isr;
 	u16 entry_bank = ioread16(adapter->hw_addr + REG_SELECT_BANK);
 	irqreturn_t ret = IRQ_NONE;
 
 	isr = ks8842_read16(adapter, 18, REG_ISR);
-	dev_dbg(&adapter->pdev->dev, "%s - ISR: 0x%x\n", __func__, isr);
+	netdev_dbg(netdev, "%s - ISR: 0x%x\n", __func__, isr);
 
 	if (isr) {
-		/* disable IRQ */
-		ks8842_write16(adapter, 18, 0x00, REG_IER);
+		if (KS8842_USE_DMA(adapter))
+			/* disable all but RX IRQ, since the FPGA relies on it*/
+			ks8842_write16(adapter, 18, IRQ_RX, REG_IER);
+		else
+			/* disable IRQ */
+			ks8842_write16(adapter, 18, 0x00, REG_IER);
 
 		/* schedule tasklet */
 		tasklet_schedule(&adapter->tasklet);
@@ -521,9 +830,151 @@ static irqreturn_t ks8842_irq(int irq, void *devid)
 
 	iowrite16(entry_bank, adapter->hw_addr + REG_SELECT_BANK);
 
+	/* After an interrupt, tell timberdale to continue DMA operations.
+	   DMA is disabled while we are handling the ks8842 because we might
+	   change bank */
+	ks8842_resume_dma(adapter);
+
 	return ret;
 }
 
+static void ks8842_dma_rx_cb(void *data)
+{
+	struct net_device	*netdev = data;
+	struct ks8842_adapter	*adapter = netdev_priv(netdev);
+
+	netdev_dbg(netdev, "RX DMA finished\n");
+	/* schedule tasklet */
+	if (adapter->dma_rx.adesc)
+		tasklet_schedule(&adapter->dma_rx.tasklet);
+}
+
+static void ks8842_dma_tx_cb(void *data)
+{
+	struct net_device		*netdev = data;
+	struct ks8842_adapter		*adapter = netdev_priv(netdev);
+	struct ks8842_tx_dma_ctl	*ctl = &adapter->dma_tx;
+
+	netdev_dbg(netdev, "TX DMA finished\n");
+
+	if (!ctl->adesc)
+		return;
+
+	netdev->stats.tx_packets++;
+	ctl->adesc = NULL;
+
+	if (netif_queue_stopped(netdev))
+		netif_wake_queue(netdev);
+}
+
+static void ks8842_stop_dma(struct ks8842_adapter *adapter)
+{
+	struct ks8842_tx_dma_ctl *tx_ctl = &adapter->dma_tx;
+	struct ks8842_rx_dma_ctl *rx_ctl = &adapter->dma_rx;
+
+	tx_ctl->adesc = NULL;
+	if (tx_ctl->chan)
+		tx_ctl->chan->device->device_control(tx_ctl->chan,
+			DMA_TERMINATE_ALL, 0);
+
+	rx_ctl->adesc = NULL;
+	if (rx_ctl->chan)
+		rx_ctl->chan->device->device_control(rx_ctl->chan,
+			DMA_TERMINATE_ALL, 0);
+
+	if (sg_dma_address(&rx_ctl->sg))
+		dma_unmap_single(adapter->dev, sg_dma_address(&rx_ctl->sg),
+			DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
+	sg_dma_address(&rx_ctl->sg) = 0;
+
+	dev_kfree_skb(rx_ctl->skb);
+	rx_ctl->skb = NULL;
+}
+
+static void ks8842_dealloc_dma_bufs(struct ks8842_adapter *adapter)
+{
+	struct ks8842_tx_dma_ctl *tx_ctl = &adapter->dma_tx;
+	struct ks8842_rx_dma_ctl *rx_ctl = &adapter->dma_rx;
+
+	ks8842_stop_dma(adapter);
+
+	if (tx_ctl->chan)
+		dma_release_channel(tx_ctl->chan);
+	tx_ctl->chan = NULL;
+
+	if (rx_ctl->chan)
+		dma_release_channel(rx_ctl->chan);
+	rx_ctl->chan = NULL;
+
+	tasklet_kill(&rx_ctl->tasklet);
+
+	if (sg_dma_address(&tx_ctl->sg))
+		dma_unmap_single(adapter->dev, sg_dma_address(&tx_ctl->sg),
+			DMA_BUFFER_SIZE, DMA_TO_DEVICE);
+	sg_dma_address(&tx_ctl->sg) = 0;
+
+	kfree(tx_ctl->buf);
+	tx_ctl->buf = NULL;
+}
+
+static bool ks8842_dma_filter_fn(struct dma_chan *chan, void *filter_param)
+{
+	return chan->chan_id == (long)filter_param;
+}
+
+static int ks8842_alloc_dma_bufs(struct net_device *netdev)
+{
+	struct ks8842_adapter *adapter = netdev_priv(netdev);
+	struct ks8842_tx_dma_ctl *tx_ctl = &adapter->dma_tx;
+	struct ks8842_rx_dma_ctl *rx_ctl = &adapter->dma_rx;
+	int err;
+
+	dma_cap_mask_t mask;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+	dma_cap_set(DMA_PRIVATE, mask);
+
+	sg_init_table(&tx_ctl->sg, 1);
+
+	tx_ctl->chan = dma_request_channel(mask, ks8842_dma_filter_fn,
+					   (void *)(long)tx_ctl->channel);
+	if (!tx_ctl->chan) {
+		err = -ENODEV;
+		goto err;
+	}
+
+	/* allocate DMA buffer */
+	tx_ctl->buf = kmalloc(DMA_BUFFER_SIZE, GFP_KERNEL);
+	if (!tx_ctl->buf) {
+		err = -ENOMEM;
+		goto err;
+	}
+
+	sg_dma_address(&tx_ctl->sg) = dma_map_single(adapter->dev,
+		tx_ctl->buf, DMA_BUFFER_SIZE, DMA_TO_DEVICE);
+	err = dma_mapping_error(adapter->dev,
+		sg_dma_address(&tx_ctl->sg));
+	if (err) {
+		sg_dma_address(&tx_ctl->sg) = 0;
+		goto err;
+	}
+
+	rx_ctl->chan = dma_request_channel(mask, ks8842_dma_filter_fn,
+					   (void *)(long)rx_ctl->channel);
+	if (!rx_ctl->chan) {
+		err = -ENODEV;
+		goto err;
+	}
+
+	tasklet_init(&rx_ctl->tasklet, ks8842_rx_frame_dma_tasklet,
+		(unsigned long)netdev);
+
+	return 0;
+err:
+	ks8842_dealloc_dma_bufs(adapter);
+	return err;
+}
 
 /* Netdevice operations */
 
@@ -532,7 +983,26 @@ static int ks8842_open(struct net_device *netdev)
 	struct ks8842_adapter *adapter = netdev_priv(netdev);
 	int err;
 
-	dev_dbg(&adapter->pdev->dev, "%s - entry\n", __func__);
+	netdev_dbg(netdev, "%s - entry\n", __func__);
+
+	if (KS8842_USE_DMA(adapter)) {
+		err = ks8842_alloc_dma_bufs(netdev);
+
+		if (!err) {
+			/* start RX dma */
+			err = __ks8842_start_new_rx_dma(netdev);
+			if (err)
+				ks8842_dealloc_dma_bufs(adapter);
+		}
+
+		if (err) {
+			printk(KERN_WARNING DRV_NAME
+				": Failed to initiate DMA, running PIO\n");
+			ks8842_dealloc_dma_bufs(adapter);
+			adapter->dma_rx.channel = -1;
+			adapter->dma_tx.channel = -1;
+		}
+	}
 
 	/* reset the HW */
 	ks8842_reset_hw(adapter);
@@ -542,7 +1012,7 @@ static int ks8842_open(struct net_device *netdev)
 	ks8842_update_link_status(netdev, adapter);
 
 	err = request_irq(adapter->irq, ks8842_irq, IRQF_SHARED, DRV_NAME,
-		adapter);
+		netdev);
 	if (err) {
 		pr_err("Failed to request IRQ: %d: %d\n", adapter->irq, err);
 		return err;
@@ -555,10 +1025,15 @@ static int ks8842_close(struct net_device *netdev)
 {
 	struct ks8842_adapter *adapter = netdev_priv(netdev);
 
-	dev_dbg(&adapter->pdev->dev, "%s - entry\n", __func__);
+	netdev_dbg(netdev, "%s - entry\n", __func__);
+
+	cancel_work_sync(&adapter->timeout_work);
+
+	if (KS8842_USE_DMA(adapter))
+		ks8842_dealloc_dma_bufs(adapter);
 
 	/* free the irq */
-	free_irq(adapter->irq, adapter);
+	free_irq(adapter->irq, netdev);
 
 	/* disable the switch */
 	ks8842_write16(adapter, 32, 0x0, REG_SW_ID_AND_ENABLE);
@@ -572,7 +1047,18 @@ static netdev_tx_t ks8842_xmit_frame(struct sk_buff *skb,
 	int ret;
 	struct ks8842_adapter *adapter = netdev_priv(netdev);
 
-	dev_dbg(&adapter->pdev->dev, "%s: entry\n", __func__);
+	netdev_dbg(netdev, "%s: entry\n", __func__);
+
+	if (KS8842_USE_DMA(adapter)) {
+		unsigned long flags;
+		ret = ks8842_tx_frame_dma(skb, netdev);
+		/* for now only allow one transfer at the time */
+		spin_lock_irqsave(&adapter->lock, flags);
+		if (adapter->dma_tx.adesc)
+			netif_stop_queue(netdev);
+		spin_unlock_irqrestore(&adapter->lock, flags);
+		return ret;
+	}
 
 	ret = ks8842_tx_frame(skb, netdev);
 
@@ -588,7 +1074,7 @@ static int ks8842_set_mac(struct net_device *netdev, void *p)
 	struct sockaddr *addr = p;
 	char *mac = (u8 *)addr->sa_data;
 
-	dev_dbg(&adapter->pdev->dev, "%s: entry\n", __func__);
+	netdev_dbg(netdev, "%s: entry\n", __func__);
 
 	if (!is_valid_ether_addr(addr->sa_data))
 		return -EADDRNOTAVAIL;
@@ -599,17 +1085,26 @@ static int ks8842_set_mac(struct net_device *netdev, void *p)
 	return 0;
 }
 
-static void ks8842_tx_timeout(struct net_device *netdev)
+static void ks8842_tx_timeout_work(struct work_struct *work)
 {
-	struct ks8842_adapter *adapter = netdev_priv(netdev);
+	struct ks8842_adapter *adapter =
+		container_of(work, struct ks8842_adapter, timeout_work);
+	struct net_device *netdev = adapter->netdev;
 	unsigned long flags;
 
-	dev_dbg(&adapter->pdev->dev, "%s: entry\n", __func__);
+	netdev_dbg(netdev, "%s: entry\n", __func__);
 
 	spin_lock_irqsave(&adapter->lock, flags);
+
+	if (KS8842_USE_DMA(adapter))
+		ks8842_stop_dma(adapter);
+
 	/* disable interrupts */
 	ks8842_write16(adapter, 18, 0, REG_IER);
 	ks8842_write16(adapter, 18, 0xFFFF, REG_ISR);
+
+	netif_stop_queue(netdev);
+
 	spin_unlock_irqrestore(&adapter->lock, flags);
 
 	ks8842_reset_hw(adapter);
@@ -617,6 +1112,18 @@ static void ks8842_tx_timeout(struct net_device *netdev)
 	ks8842_write_mac_addr(adapter, netdev->dev_addr);
 
 	ks8842_update_link_status(netdev, adapter);
+
+	if (KS8842_USE_DMA(adapter))
+		__ks8842_start_new_rx_dma(netdev);
+}
+
+static void ks8842_tx_timeout(struct net_device *netdev)
+{
+	struct ks8842_adapter *adapter = netdev_priv(netdev);
+
+	netdev_dbg(netdev, "%s: entry\n", __func__);
+
+	schedule_work(&adapter->timeout_work);
 }
 
 static const struct net_device_ops ks8842_netdev_ops = {
@@ -653,7 +1160,11 @@ static int __devinit ks8842_probe(struct platform_device *pdev)
 	SET_NETDEV_DEV(netdev, &pdev->dev);
 
 	adapter = netdev_priv(netdev);
+	adapter->netdev = netdev;
+	INIT_WORK(&adapter->timeout_work, ks8842_tx_timeout_work);
 	adapter->hw_addr = ioremap(iomem->start, resource_size(iomem));
+	adapter->conf_flags = iomem->flags;
+
 	if (!adapter->hw_addr)
 		goto err_ioremap;
 
@@ -663,7 +1174,18 @@ static int __devinit ks8842_probe(struct platform_device *pdev)
 		goto err_get_irq;
 	}
 
-	adapter->pdev = pdev;
+	adapter->dev = (pdev->dev.parent) ? pdev->dev.parent : &pdev->dev;
+
+	/* DMA is only supported when accessed via timberdale */
+	if (!(adapter->conf_flags & MICREL_KS884X) && pdata &&
+		(pdata->tx_dma_channel != -1) &&
+		(pdata->rx_dma_channel != -1)) {
+		adapter->dma_rx.channel = pdata->rx_dma_channel;
+		adapter->dma_tx.channel = pdata->tx_dma_channel;
+	} else {
+		adapter->dma_rx.channel = -1;
+		adapter->dma_tx.channel = -1;
+	}
 
 	tasklet_init(&adapter->tasklet, ks8842_tasklet, (unsigned long)netdev);
 	spin_lock_init(&adapter->lock);