net: smc911x: convert pxa dma to dmaengine

Convert the dma transfers to be dmaengine based, now pxa has a dmaengine
slave driver. This makes this driver a bit more PXA agnostic.

The driver was only compile tested. The risk is quite small as no
current PXA platform I'm aware of is using smc911x driver.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Tested-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/smsc/smc911x.c

@@ -73,6 +73,9 @@ static const char version[] =
 #include <linux/etherdevice.h>
 #include <linux/skbuff.h>
 
+#include <linux/dmaengine.h>
+#include <linux/dma/pxa-dma.h>
+
 #include <asm/io.h>
 
 #include "smc911x.h"
@@ -1174,18 +1177,16 @@ static irqreturn_t smc911x_interrupt(int irq, void *dev_id)
 
 #ifdef SMC_USE_DMA
 static void
-smc911x_tx_dma_irq(int dma, void *data)
+smc911x_tx_dma_irq(void *data)
 {
-	struct net_device *dev = (struct net_device *)data;
-	struct smc911x_local *lp = netdev_priv(dev);
+	struct smc911x_local *lp = data;
+	struct net_device *dev = lp->netdev;
 	struct sk_buff *skb = lp->current_tx_skb;
 	unsigned long flags;
 
 	DBG(SMC_DEBUG_FUNC, dev, "--> %s\n", __func__);
 
 	DBG(SMC_DEBUG_TX | SMC_DEBUG_DMA, dev, "TX DMA irq handler\n");
-	/* Clear the DMA interrupt sources */
-	SMC_DMA_ACK_IRQ(dev, dma);
 	BUG_ON(skb == NULL);
 	dma_unmap_single(NULL, tx_dmabuf, tx_dmalen, DMA_TO_DEVICE);
 	dev->trans_start = jiffies;
@@ -1208,18 +1209,16 @@ smc911x_tx_dma_irq(int dma, void *data)
 	    "TX DMA irq completed\n");
 }
 static void
-smc911x_rx_dma_irq(int dma, void *data)
+smc911x_rx_dma_irq(void *data)
 {
-	struct net_device *dev = (struct net_device *)data;
-	struct smc911x_local *lp = netdev_priv(dev);
+	struct smc911x_local *lp = data;
+	struct net_device *dev = lp->netdev;
 	struct sk_buff *skb = lp->current_rx_skb;
 	unsigned long flags;
 	unsigned int pkts;
 
 	DBG(SMC_DEBUG_FUNC, dev, "--> %s\n", __func__);
 	DBG(SMC_DEBUG_RX | SMC_DEBUG_DMA, dev, "RX DMA irq handler\n");
-	/* Clear the DMA interrupt sources */
-	SMC_DMA_ACK_IRQ(dev, dma);
 	dma_unmap_single(NULL, rx_dmabuf, rx_dmalen, DMA_FROM_DEVICE);
 	BUG_ON(skb == NULL);
 	lp->current_rx_skb = NULL;
@@ -1792,6 +1791,9 @@ static int smc911x_probe(struct net_device *dev)
 	unsigned int val, chip_id, revision;
 	const char *version_string;
 	unsigned long irq_flags;
+	struct dma_slave_config	config;
+	dma_cap_mask_t mask;
+	struct pxad_param param;
 
 	DBG(SMC_DEBUG_FUNC, dev, "--> %s\n", __func__);
 
@@ -1963,11 +1965,40 @@ static int smc911x_probe(struct net_device *dev)
 		goto err_out;
 
 #ifdef SMC_USE_DMA
-	lp->rxdma = SMC_DMA_REQUEST(dev, smc911x_rx_dma_irq);
-	lp->txdma = SMC_DMA_REQUEST(dev, smc911x_tx_dma_irq);
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+	param.prio = PXAD_PRIO_LOWEST;
+	param.drcmr = -1UL;
+
+	lp->rxdma =
+		dma_request_slave_channel_compat(mask, pxad_filter_fn,
+						 &param, &dev->dev, "rx");
+	lp->txdma =
+		dma_request_slave_channel_compat(mask, pxad_filter_fn,
+						 &param, &dev->dev, "tx");
 	lp->rxdma_active = 0;
 	lp->txdma_active = 0;
-	dev->dma = lp->rxdma;
+
+	memset(&config, 0, sizeof(config));
+	config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	config.src_addr = lp->physaddr + RX_DATA_FIFO;
+	config.dst_addr = lp->physaddr + TX_DATA_FIFO;
+	config.src_maxburst = 32;
+	config.dst_maxburst = 32;
+	retval = dmaengine_slave_config(lp->rxdma, &config);
+	if (retval) {
+		dev_err(lp->dev, "dma rx channel configuration failed: %d\n",
+			retval);
+		goto err_out;
+	}
+	retval = dmaengine_slave_config(lp->txdma, &config);
+	if (retval) {
+		dev_err(lp->dev, "dma tx channel configuration failed: %d\n",
+			retval);
+		goto err_out;
+	}
 #endif
 
 	retval = register_netdev(dev);
@@ -1978,11 +2009,11 @@ static int smc911x_probe(struct net_device *dev)
 			    dev->base_addr, dev->irq);
 
 #ifdef SMC_USE_DMA
-		if (lp->rxdma != -1)
-			pr_cont(" RXDMA %d", lp->rxdma);
+		if (lp->rxdma)
+			pr_cont(" RXDMA %p", lp->rxdma);
 
-		if (lp->txdma != -1)
-			pr_cont(" TXDMA %d", lp->txdma);
+		if (lp->txdma)
+			pr_cont(" TXDMA %p", lp->txdma);
 #endif
 		pr_cont("\n");
 		if (!is_valid_ether_addr(dev->dev_addr)) {
@@ -2005,12 +2036,10 @@ static int smc911x_probe(struct net_device *dev)
 err_out:
 #ifdef SMC_USE_DMA
 	if (retval) {
-		if (lp->rxdma != -1) {
-			SMC_DMA_FREE(dev, lp->rxdma);
-		}
-		if (lp->txdma != -1) {
-			SMC_DMA_FREE(dev, lp->txdma);
-		}
+		if (lp->rxdma)
+			dma_release_channel(lp->rxdma);
+		if (lp->txdma)
+			dma_release_channel(lp->txdma);
 	}
 #endif
 	return retval;
@@ -2112,12 +2141,10 @@ static int smc911x_drv_remove(struct platform_device *pdev)
 
 #ifdef SMC_USE_DMA
 	{
-		if (lp->rxdma != -1) {
-			SMC_DMA_FREE(dev, lp->rxdma);
-		}
-		if (lp->txdma != -1) {
-			SMC_DMA_FREE(dev, lp->txdma);
-		}
+		if (lp->rxdma)
+			dma_release_channel(lp->rxdma);
+		if (lp->txdma)
+			dma_release_channel(lp->txdma);
 	}
 #endif
 	iounmap(lp->base);

drivers/net/ethernet/smsc/smc911x.h

@@ -101,8 +101,8 @@ struct smc911x_local {
 #ifdef SMC_USE_DMA
 	/* DMA needs the physical address of the chip */
 	u_long physaddr;
-	int rxdma;
-	int txdma;
+	struct dma_chan *rxdma;
+	struct dma_chan *txdma;
 	int rxdma_active;
 	int txdma_active;
 	struct sk_buff *current_rx_skb;
@@ -210,27 +210,6 @@ static inline void SMC_outsl(struct smc911x_local *lp, int reg,
 
 #ifdef SMC_USE_PXA_DMA
 
-#include <mach/dma.h>
-
-/*
- * Define the request and free functions
- * These are unfortunately architecture specific as no generic allocation
- * mechanism exits
- */
-#define SMC_DMA_REQUEST(dev, handler) \
-	 pxa_request_dma(dev->name, DMA_PRIO_LOW, handler, dev)
-
-#define SMC_DMA_FREE(dev, dma) \
-	 pxa_free_dma(dma)
-
-#define SMC_DMA_ACK_IRQ(dev, dma)					\
-{									\
-	if (DCSR(dma) & DCSR_BUSERR) {					\
-		netdev_err(dev, "DMA %d bus error!\n", dma);		\
-	}								\
-	DCSR(dma) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;		\
-}
-
 /*
  * Use a DMA for RX and TX packets.
  */
@@ -238,6 +217,8 @@ static inline void SMC_outsl(struct smc911x_local *lp, int reg,
 
 static dma_addr_t rx_dmabuf, tx_dmabuf;
 static int rx_dmalen, tx_dmalen;
+static void smc911x_rx_dma_irq(void *data);
+static void smc911x_tx_dma_irq(void *data);
 
 #ifdef SMC_insl
 #undef SMC_insl
@@ -246,8 +227,10 @@ static int rx_dmalen, tx_dmalen;
 
 static inline void
 smc_pxa_dma_insl(struct smc911x_local *lp, u_long physaddr,
-		int reg, int dma, u_char *buf, int len)
+		int reg, struct dma_chan *dma, u_char *buf, int len)
 {
+	struct dma_async_tx_descriptor *tx;
+
 	/* 64 bit alignment is required for memory to memory DMA */
 	if ((long)buf & 4) {
 		*((u32 *)buf) = SMC_inl(lp, reg);
@@ -258,12 +241,14 @@ smc_pxa_dma_insl(struct smc911x_local *lp, u_long physaddr,
 	len *= 4;
 	rx_dmabuf = dma_map_single(lp->dev, buf, len, DMA_FROM_DEVICE);
 	rx_dmalen = len;
-	DCSR(dma) = DCSR_NODESC;
-	DTADR(dma) = rx_dmabuf;
-	DSADR(dma) = physaddr + reg;
-	DCMD(dma) = (DCMD_INCTRGADDR | DCMD_BURST32 |
-		DCMD_WIDTH4 | DCMD_ENDIRQEN | (DCMD_LENGTH & rx_dmalen));
-	DCSR(dma) = DCSR_NODESC | DCSR_RUN;
+	tx = dmaengine_prep_slave_single(dma, rx_dmabuf, rx_dmalen,
+					 DMA_DEV_TO_MEM, 0);
+	if (tx) {
+		tx->callback = smc911x_rx_dma_irq;
+		tx->callback_param = lp;
+		dmaengine_submit(tx);
+		dma_async_issue_pending(dma);
+	}
 }
 #endif
 
@@ -274,8 +259,10 @@ smc_pxa_dma_insl(struct smc911x_local *lp, u_long physaddr,
 
 static inline void
 smc_pxa_dma_outsl(struct smc911x_local *lp, u_long physaddr,
-		int reg, int dma, u_char *buf, int len)
+		int reg, struct dma_chan *dma, u_char *buf, int len)
 {
+	struct dma_async_tx_descriptor *tx;
+
 	/* 64 bit alignment is required for memory to memory DMA */
 	if ((long)buf & 4) {
 		SMC_outl(*((u32 *)buf), lp, reg);
@@ -286,12 +273,14 @@ smc_pxa_dma_outsl(struct smc911x_local *lp, u_long physaddr,
 	len *= 4;
 	tx_dmabuf = dma_map_single(lp->dev, buf, len, DMA_TO_DEVICE);
 	tx_dmalen = len;
-	DCSR(dma) = DCSR_NODESC;
-	DSADR(dma) = tx_dmabuf;
-	DTADR(dma) = physaddr + reg;
-	DCMD(dma) = (DCMD_INCSRCADDR | DCMD_BURST32 |
-		DCMD_WIDTH4 | DCMD_ENDIRQEN | (DCMD_LENGTH & tx_dmalen));
-	DCSR(dma) = DCSR_NODESC | DCSR_RUN;
+	tx = dmaengine_prep_slave_single(dma, tx_dmabuf, tx_dmalen,
+					 DMA_DEV_TO_MEM, 0);
+	if (tx) {
+		tx->callback = smc911x_tx_dma_irq;
+		tx->callback_param = lp;
+		dmaengine_submit(tx);
+		dma_async_issue_pending(dma);
+	}
 }
 #endif
 #endif	 /* SMC_USE_PXA_DMA */