NET: sa11x0-ir: convert to use scatterlist DMA API

Convert the sa11x0 IrDA driver to use the scatterlist DMA API.  This
is a preparatory patch for converting the driver to use the DMA engine
API, which requires a struct scatterlist for every transfer.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/drivers/net/irda/sa1100_ir.c b/drivers/net/irda/sa1100_ir.c
index d428dd0a8bcee838b735eeb8aa7e6ce7b9b68ab6..86d296ed69a7e1d7609385d58c53bbc006be723a 100644 (file)
--- a/drivers/net/irda/sa1100_ir.c
+++ b/drivers/net/irda/sa1100_ir.c
@@ -45,7 +45,7 @@ static int max_rate = 4000000;
 
 struct sa1100_buf {
        struct sk_buff          *skb;
-       dma_addr_t              dma;
+       struct scatterlist      sg;
        dma_regs_t              *regs;
 };
 
@@ -98,10 +98,8 @@ static int sa1100_irda_rx_alloc(struct sa1100_irda *si)
         */
        skb_reserve(si->dma_rx.skb, 1);
 
-       si->dma_rx.dma = dma_map_single(si->dev, si->dma_rx.skb->data,
-                                       HPSIR_MAX_RXLEN,
-                                       DMA_FROM_DEVICE);
-       if (dma_mapping_error(si->dev, si->dma_rx.dma)) {
+       sg_set_buf(&si->dma_rx.sg, si->dma_rx.skb->data, HPSIR_MAX_RXLEN);
+       if (dma_map_sg(si->dev, &si->dma_rx.sg, 1, DMA_FROM_DEVICE) == 0) {
                dev_kfree_skb_any(si->dma_rx.skb);
                return -ENOMEM;
        }
@@ -129,7 +127,8 @@ static void sa1100_irda_rx_dma_start(struct sa1100_irda *si)
         * Enable the DMA, receiver and receive interrupt.
         */
        sa1100_clear_dma(si->dma_rx.regs);
-       sa1100_start_dma(si->dma_rx.regs, si->dma_rx.dma, HPSIR_MAX_RXLEN);
+       sa1100_start_dma(si->dma_rx.regs, sg_dma_address(&si->dma_rx.sg),
+                        sg_dma_len(&si->dma_rx.sg));
        Ser2HSCR0 = HSCR0_HSSP | HSCR0_RXE;
 }
 
@@ -296,8 +295,8 @@ static void sa1100_irda_firtxdma_irq(void *id)
        /* Account and free the packet. */
        skb = si->dma_tx.skb;
        if (skb) {
-               dma_unmap_single(si->dev, si->dma_tx.dma, skb->len,
-                                DMA_TO_DEVICE);
+               dma_unmap_sg(si->dev, &si->dma_tx.sg, 1,
+                            DMA_TO_DEVICE);
                dev->stats.tx_packets ++;
                dev->stats.tx_bytes += skb->len;
                dev_kfree_skb_irq(skb);
@@ -317,9 +316,8 @@ static int sa1100_irda_fir_tx_start(struct sk_buff *skb, struct net_device *dev,
        int mtt = irda_get_mtt(skb);
 
        si->dma_tx.skb = skb;
-       si->dma_tx.dma = dma_map_single(si->dev, skb->data, skb->len,
-                                       DMA_TO_DEVICE);
-       if (dma_mapping_error(si->dev, si->dma_tx.dma)) {
+       sg_set_buf(&si->dma_tx.sg, skb->data, skb->len);
+       if (dma_map_sg(si->dev, &si->dma_tx.sg, 1, DMA_TO_DEVICE) == 0) {
                si->dma_tx.skb = NULL;
                netif_wake_queue(dev);
                dev->stats.tx_dropped++;
@@ -327,7 +325,8 @@ static int sa1100_irda_fir_tx_start(struct sk_buff *skb, struct net_device *dev,
                return NETDEV_TX_OK;
        }
 
-       sa1100_start_dma(si->dma_tx.regs, si->dma_tx.dma, skb->len);
+       sa1100_start_dma(si->dma_tx.regs, sg_dma_address(&si->dma_tx.sg),
+                        sg_dma_len(&si->dma_tx.sg));
 
        /*
         * If we have a mean turn-around time, impose the specified
@@ -357,10 +356,10 @@ static void sa1100_irda_fir_error(struct sa1100_irda *si, struct net_device *dev
         * Get the current data position.
         */
        dma_addr = sa1100_get_dma_pos(si->dma_rx.regs);
-       len = dma_addr - si->dma_rx.dma;
+       len = dma_addr - sg_dma_address(&si->dma_rx.sg);
        if (len > HPSIR_MAX_RXLEN)
                len = HPSIR_MAX_RXLEN;
-       dma_unmap_single(si->dev, si->dma_rx.dma, len, DMA_FROM_DEVICE);
+       dma_unmap_sg(si->dev, &si->dma_rx.sg, 1, DMA_FROM_DEVICE);
 
        do {
                /*
@@ -408,9 +407,7 @@ static void sa1100_irda_fir_error(struct sa1100_irda *si, struct net_device *dev
                 * Remap the buffer - it was previously mapped, and we
                 * hope that this succeeds.
                 */
-               si->dma_rx.dma = dma_map_single(si->dev, si->dma_rx.skb->data,
-                                               HPSIR_MAX_RXLEN,
-                                               DMA_FROM_DEVICE);
+               dma_map_sg(si->dev, &si->dma_rx.sg, 1, DMA_FROM_DEVICE);
        }
 }
 
@@ -786,16 +783,16 @@ static int sa1100_irda_stop(struct net_device *dev)
         */
        skb = si->dma_rx.skb;
        if (skb) {
-               dma_unmap_single(si->dev, si->dma_rx.dma, HPSIR_MAX_RXLEN,
-                                DMA_FROM_DEVICE);
+               dma_unmap_sg(si->dev, &si->dma_rx.sg, 1,
+                            DMA_FROM_DEVICE);
                dev_kfree_skb(skb);
                si->dma_rx.skb = NULL;
        }
 
        skb = si->dma_tx.skb;
        if (skb) {
-               dma_unmap_single(si->dev, si->dma_tx.dma, skb->len,
-                                DMA_TO_DEVICE);
+               dma_unmap_sg(si->dev, &si->dma_tx.sg, 1,
+                            DMA_TO_DEVICE);
                dev_kfree_skb(skb);
                si->dma_tx.skb = NULL;
        }
@@ -871,6 +868,9 @@ static int sa1100_irda_probe(struct platform_device *pdev)
        si->dev = &pdev->dev;
        si->pdata = pdev->dev.platform_data;
 
+       sg_init_table(&si->dma_rx.sg, 1);
+       sg_init_table(&si->dma_tx.sg, 1);
+
        /*
         * Initialise the HP-SIR buffers
         */