NET: sa11x0-ir: convert sa11x0-ir driver to use DMA engine API
authorRussell King <rmk+kernel@arm.linux.org.uk>
Fri, 13 Jan 2012 11:48:13 +0000 (11:48 +0000)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Wed, 7 Mar 2012 11:46:17 +0000 (11:46 +0000)
Convert the sa11x0 IrDA driver to use the sa11x0 DMA engine driver
rather than our own platform specific DMA API.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
drivers/net/irda/Kconfig
drivers/net/irda/sa1100_ir.c

index e535137..4680478 100644 (file)
@@ -356,7 +356,7 @@ config VLSI_FIR
 
 config SA1100_FIR
        tristate "SA1100 Internal IR"
-       depends on ARCH_SA1100 && IRDA
+       depends on ARCH_SA1100 && IRDA && DMA_SA11X0
 
 config VIA_FIR
        tristate "VIA VT8231/VT1211 SIR/MIR/FIR"
index 9c748f3..620a48d 100644 (file)
 #include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/sa11x0-dma.h>
 
 #include <net/irda/irda.h>
 #include <net/irda/wrapper.h>
 #include <net/irda/irda_device.h>
 
-#include <mach/dma.h>
 #include <mach/hardware.h>
 #include <asm/mach/irda.h>
 
@@ -47,7 +48,8 @@ struct sa1100_buf {
        struct device           *dev;
        struct sk_buff          *skb;
        struct scatterlist      sg;
-       dma_regs_t              *regs;
+       struct dma_chan         *chan;
+       dma_cookie_t            cookie;
 };
 
 struct sa1100_irda {
@@ -79,6 +81,75 @@ static int sa1100_irda_set_speed(struct sa1100_irda *, int);
 
 #define HPSIR_MAX_RXLEN                2047
 
+static struct dma_slave_config sa1100_irda_fir_rx = {
+       .direction      = DMA_FROM_DEVICE,
+       .src_addr       = __PREG(Ser2HSDR),
+       .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+       .src_maxburst   = 8,
+};
+
+static struct dma_slave_config sa1100_irda_fir_tx = {
+       .direction      = DMA_TO_DEVICE,
+       .dst_addr       = __PREG(Ser2HSDR),
+       .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+       .dst_maxburst   = 8,
+};
+
+static unsigned sa1100_irda_dma_xferred(struct sa1100_buf *buf)
+{
+       struct dma_chan *chan = buf->chan;
+       struct dma_tx_state state;
+       enum dma_status status;
+
+       status = chan->device->device_tx_status(chan, buf->cookie, &state);
+       if (status != DMA_PAUSED)
+               return 0;
+
+       return sg_dma_len(&buf->sg) - state.residue;
+}
+
+static int sa1100_irda_dma_request(struct device *dev, struct sa1100_buf *buf,
+       const char *name, struct dma_slave_config *cfg)
+{
+       dma_cap_mask_t m;
+       int ret;
+
+       dma_cap_zero(m);
+       dma_cap_set(DMA_SLAVE, m);
+
+       buf->chan = dma_request_channel(m, sa11x0_dma_filter_fn, (void *)name);
+       if (!buf->chan) {
+               dev_err(dev, "unable to request DMA channel for %s\n",
+                       name);
+               return -ENOENT;
+       }
+
+       ret = dmaengine_slave_config(buf->chan, cfg);
+       if (ret)
+               dev_warn(dev, "DMA slave_config for %s returned %d\n",
+                       name, ret);
+
+       buf->dev = buf->chan->device->dev;
+
+       return 0;
+}
+
+static void sa1100_irda_dma_start(struct sa1100_buf *buf,
+       enum dma_transfer_direction dir, dma_async_tx_callback cb, void *cb_p)
+{
+       struct dma_async_tx_descriptor *desc;
+       struct dma_chan *chan = buf->chan;
+
+       desc = chan->device->device_prep_slave_sg(chan, &buf->sg, 1, dir,
+                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+       if (desc) {
+               desc->callback = cb;
+               desc->callback_param = cb_p;
+               buf->cookie = dmaengine_submit(desc);
+               dma_async_issue_pending(chan);
+       }
+}
+
 /*
  * Allocate and map the receive buffer, unless it is already allocated.
  */
@@ -127,9 +198,9 @@ 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, sg_dma_address(&si->dma_rx.sg),
-                        sg_dma_len(&si->dma_rx.sg));
+       dmaengine_terminate_all(si->dma_rx.chan);
+       sa1100_irda_dma_start(&si->dma_rx, DMA_DEV_TO_MEM, NULL, NULL);
+
        Ser2HSCR0 = HSCR0_HSSP | HSCR0_RXE;
 }
 
@@ -326,8 +397,7 @@ 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, sg_dma_address(&si->dma_tx.sg),
-                        sg_dma_len(&si->dma_tx.sg));
+       sa1100_irda_dma_start(&si->dma_tx, DMA_MEM_TO_DEV, sa1100_irda_firtxdma_irq, dev);
 
        /*
         * If we have a mean turn-around time, impose the specified
@@ -345,7 +415,6 @@ static int sa1100_irda_fir_tx_start(struct sk_buff *skb, struct net_device *dev,
 static void sa1100_irda_fir_error(struct sa1100_irda *si, struct net_device *dev)
 {
        struct sk_buff *skb = si->dma_rx.skb;
-       dma_addr_t dma_addr;
        unsigned int len, stat, data;
 
        if (!skb) {
@@ -356,8 +425,7 @@ 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 - sg_dma_address(&si->dma_rx.sg);
+       len = sa1100_irda_dma_xferred(&si->dma_rx);
        if (len > HPSIR_MAX_RXLEN)
                len = HPSIR_MAX_RXLEN;
        dma_unmap_sg(si->dma_rx.dev, &si->dma_rx.sg, 1, DMA_FROM_DEVICE);
@@ -421,7 +489,7 @@ static irqreturn_t sa1100_irda_fir_irq(struct net_device *dev, struct sa1100_ird
        /*
         * Stop RX DMA
         */
-       sa1100_stop_dma(si->dma_rx.regs);
+       dmaengine_pause(si->dma_rx.chan);
 
        /*
         * Framing error - we throw away the packet completely.
@@ -476,11 +544,9 @@ static int sa1100_irda_set_speed(struct sa1100_irda *si, int speed)
        case 57600:     case 115200:
                brd = 3686400 / (16 * speed) - 1;
 
-               /*
-                * Stop the receive DMA.
-                */
+               /* Stop the receive DMA, and configure transmit. */
                if (IS_FIR(si))
-                       sa1100_stop_dma(si->dma_rx.regs);
+                       dmaengine_terminate_all(si->dma_rx.chan);
 
                local_irq_save(flags);
 
@@ -698,8 +764,8 @@ static void sa1100_irda_shutdown(struct sa1100_irda *si)
        /*
         * Stop all DMA activity.
         */
-       sa1100_stop_dma(si->dma_rx.regs);
-       sa1100_stop_dma(si->dma_tx.regs);
+       dmaengine_terminate_all(si->dma_rx.chan);
+       dmaengine_terminate_all(si->dma_tx.chan);
 
        /* Disable the port. */
        Ser2UTCR3 = 0;
@@ -716,20 +782,16 @@ static int sa1100_irda_start(struct net_device *dev)
 
        si->speed = 9600;
 
-       err = sa1100_request_dma(DMA_Ser2HSSPRd, "IrDA receive",
-                                NULL, NULL, &si->dma_rx.regs);
+       err = sa1100_irda_dma_request(si->dev, &si->dma_rx, "Ser2ICPRc",
+                               &sa1100_irda_fir_rx);
        if (err)
                goto err_rx_dma;
 
-       err = sa1100_request_dma(DMA_Ser2HSSPWr, "IrDA transmit",
-                                sa1100_irda_firtxdma_irq, dev,
-                                &si->dma_tx.regs);
+       err = sa1100_irda_dma_request(si->dev, &si->dma_tx, "Ser2ICPTr",
+                               &sa1100_irda_sir_tx);
        if (err)
                goto err_tx_dma;
 
-       si->dma_rx.dev = si->dev;
-       si->dma_tx.dev = si->dev;
-
        /*
         * Setup the serial port for the specified speed.
         */
@@ -764,9 +826,9 @@ err_irlap:
        si->open = 0;
        sa1100_irda_shutdown(si);
 err_startup:
-       sa1100_free_dma(si->dma_tx.regs);
+       dma_release_channel(si->dma_tx.chan);
 err_tx_dma:
-       sa1100_free_dma(si->dma_rx.regs);
+       dma_release_channel(si->dma_rx.chan);
 err_rx_dma:
        return err;
 }
@@ -810,8 +872,8 @@ static int sa1100_irda_stop(struct net_device *dev)
        /*
         * Free resources
         */
-       sa1100_free_dma(si->dma_tx.regs);
-       sa1100_free_dma(si->dma_rx.regs);
+       dma_release_channel(si->dma_tx.chan);
+       dma_release_channel(si->dma_rx.chan);
        free_irq(dev->irq, dev);
 
        sa1100_set_power(si, 0);