bcm2835-dma: Advertise the full DMA range

Unless the DMA mask is set wider than 32 bits, DMA mapping will use a
bounce buffer.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>

diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index 84b1009da23b67ae28f5efcc7d75dc3c1f7a069d..d1127b9058a4704b9195cc345140128efbaf326a 100644 (file)
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -41,6 +41,7 @@
 #define BCM2711_DMA_MEMCPY_CHAN 14
 
 struct bcm2835_dma_cfg_data {
+       u64     dma_mask;
        u32     chan_40bit_mask;
 };
 
@@ -300,10 +301,12 @@ DEFINE_SPINLOCK(memcpy_lock);
 
 static const struct bcm2835_dma_cfg_data bcm2835_dma_cfg = {
        .chan_40bit_mask = 0,
+       .dma_mask = DMA_BIT_MASK(32),
 };
 
 static const struct bcm2835_dma_cfg_data bcm2711_dma_cfg = {
        .chan_40bit_mask = BIT(11) | BIT(12) | BIT(13) | BIT(14),
+       .dma_mask = DMA_BIT_MASK(36),
 };
 
 static inline size_t bcm2835_dma_max_frame_length(struct bcm2835_chan *c)
@@ -1180,6 +1183,8 @@ static struct dma_chan *bcm2835_dma_xlate(struct of_phandle_args *spec,
 
 static int bcm2835_dma_probe(struct platform_device *pdev)
 {
+       const struct bcm2835_dma_cfg_data *cfg_data;
+       const struct of_device_id *of_id;
        struct bcm2835_dmadev *od;
        struct resource *res;
        void __iomem *base;
@@ -1189,13 +1194,20 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
        int irq_flags;
        uint32_t chans_available;
        char chan_name[BCM2835_DMA_CHAN_NAME_SIZE];
-       const struct of_device_id *of_id;
        int chan_count, chan_start, chan_end;
 
+       of_id = of_match_node(bcm2835_dma_of_match, pdev->dev.of_node);
+       if (!of_id) {
+               dev_err(&pdev->dev, "Failed to match compatible string\n");
+               return -EINVAL;
+       }
+
+       cfg_data = of_id->data;
+
        if (!pdev->dev.dma_mask)
                pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
 
-       rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+       rc = dma_set_mask_and_coherent(&pdev->dev, cfg_data->dma_mask);
        if (rc) {
                dev_err(&pdev->dev, "Unable to set DMA mask\n");
                return rc;
@@ -1260,7 +1272,7 @@ static int bcm2835_dma_probe(struct platform_device *pdev)
                return -EINVAL;
        }
 
-       od->cfg_data = of_id->data;
+       od->cfg_data = cfg_data;
 
        /* Request DMA channel mask from device tree */
        if (of_property_read_u32(pdev->dev.of_node,