staging: comedi: ni_at_a2150: remove VIRT_TO_BUS dependancy
authorH Hartley Sweeten <hsweeten@visionengravers.com>
Mon, 12 Jan 2015 17:55:51 +0000 (10:55 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 17 Jan 2015 22:25:19 +0000 (14:25 -0800)
Use dma_{alloc,free}_coherent() to allocate and free the DMA buffers.
This removes the dependancy on VIRT_TO_BUS.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/comedi/Kconfig
drivers/staging/comedi/drivers/ni_at_a2150.c

index fe030a3..982b03f 100644 (file)
@@ -462,7 +462,7 @@ config COMEDI_ADQ12B
 
 config COMEDI_NI_AT_A2150
        tristate "NI AT-A2150 ISA card support"
-       depends on VIRT_TO_BUS && ISA_DMA_API
+       depends on ISA_DMA_API
        ---help---
          Enable support for National Instruments AT-A2150 cards
 
index a1300e0..3905097 100644 (file)
@@ -147,7 +147,8 @@ static const struct a2150_board a2150_boards[] = {
 
 struct a2150_dma_desc {
        unsigned int chan;      /* DMA channel */
-       uint16_t *virt_addr;    /* virtual address of DMA buffer */
+       void *virt_addr;        /* virtual address of DMA buffer */
+       dma_addr_t hw_addr;     /* hardware (bus) address of DMA buffer */
        unsigned int size;      /* size of DMA transfer (in bytes) */
 };
 
@@ -170,6 +171,7 @@ static irqreturn_t a2150_interrupt(int irq, void *d)
        struct comedi_subdevice *s = dev->read_subdev;
        struct comedi_async *async;
        struct comedi_cmd *cmd;
+       unsigned short *buf = dma->virt_addr;
        unsigned int max_points, num_points, residue, leftover;
        unsigned short dpnt;
 
@@ -237,7 +239,7 @@ static irqreturn_t a2150_interrupt(int irq, void *d)
 
        for (i = 0; i < num_points; i++) {
                /* write data point to comedi buffer */
-               dpnt = dma->virt_addr[i];
+               dpnt = buf[i];
                /*  convert from 2's complement to unsigned coding */
                dpnt ^= 0x8000;
                comedi_buf_write_samples(s, &dpnt, 1);
@@ -250,7 +252,7 @@ static irqreturn_t a2150_interrupt(int irq, void *d)
        }
        /*  re-enable  dma */
        if (leftover) {
-               set_dma_addr(dma->chan, virt_to_bus(dma->virt_addr));
+               set_dma_addr(dma->chan, dma->hw_addr);
                set_dma_count(dma->chan,
                              comedi_samples_to_bytes(s, leftover));
                enable_dma(dma->chan);
@@ -553,7 +555,7 @@ static int a2150_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
        /* clear flip-flop to make sure 2-byte registers for
         * count and address get set correctly */
        clear_dma_ff(dma->chan);
-       set_dma_addr(dma->chan, virt_to_bus(dma->virt_addr));
+       set_dma_addr(dma->chan, dma->hw_addr);
        /*  set size of transfer to fill in 1/3 second */
 #define ONE_THIRD_SECOND 333333333
        dma->size = comedi_bytes_per_sample(s) * cmd->chanlist_len *
@@ -709,7 +711,8 @@ static void a2150_alloc_irq_dma(struct comedi_device *dev,
                free_irq(irq_num, dev);
                return;
        }
-       dma->virt_addr = kmalloc(A2150_DMA_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
+       dma->virt_addr = dma_alloc_coherent(NULL, A2150_DMA_BUFFER_SIZE,
+                                           &dma->hw_addr, GFP_KERNEL);
        if (!dma->virt_addr) {
                free_dma(dma_chan);
                free_irq(irq_num, dev);
@@ -735,7 +738,9 @@ static void a2150_free_dma(struct comedi_device *dev)
        dma = &devpriv->dma_desc;
        if (dma->chan)
                free_dma(dma->chan);
-       kfree(dma->virt_addr);
+       if (dma->virt_addr)
+               dma_free_coherent(NULL, A2150_DMA_BUFFER_SIZE,
+                                 dma->virt_addr, dma->hw_addr);
 }
 
 /* probes board type, returns offset */