dmaengine: bcm2835: Fix dma driver for BCM2835-38

The previous commit broke support on older devices.
Make the breaking parts of patch conditional on
the device being used.

Fixes: 6e1856ac7c39 ("dmaengine: bcm2835: HACK: Support DMA-Lite channels")

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index 5d6ce10..e159f97 100644 (file)
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -102,6 +102,7 @@ struct bcm2835_chan {
 
        bool is_lite_channel;
        bool is_40bit_channel;
+       bool is_2712;
 };
 
 struct bcm2835_desc {
@@ -550,7 +551,11 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
                        control_block->info = info;
                        control_block->src = src;
                        control_block->dst = dst;
-                       control_block->stride = (upper_32_bits(dst) << 8) | upper_32_bits(src);
+                       if (c->is_2712)
+                               control_block->stride = (upper_32_bits(dst) << 8) |
+                                                       upper_32_bits(src);
+                       else
+                               control_block->stride = 0;
                        control_block->next = 0;
                }
 
@@ -575,7 +580,8 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain(
                         d->cb_list[frame - 1].cb)->next_cb =
                                to_40bit_cbaddr(cb_entry->paddr);
                if (frame && !c->is_40bit_channel)
-                       d->cb_list[frame - 1].cb->next = to_40bit_cbaddr(cb_entry->paddr);
+                       d->cb_list[frame - 1].cb->next = c->is_2712 ?
+                       to_40bit_cbaddr(cb_entry->paddr) : cb_entry->paddr;
 
                /* update src and dst and length */
                if (src && (info & BCM2835_DMA_S_INC)) {
@@ -762,7 +768,7 @@ static void bcm2835_dma_start_desc(struct bcm2835_chan *c)
        } else {
                writel(BIT(31), c->chan_base + BCM2835_DMA_CS);
 
-               writel(to_40bit_cbaddr(d->cb_list[0].paddr),
+               writel(c->is_2712 ? to_40bit_cbaddr(d->cb_list[0].paddr) : d->cb_list[0].paddr,
                       c->chan_base + BCM2835_DMA_ADDR);
                writel(BCM2835_DMA_ACTIVE | BCM2835_DMA_CS_FLAGS(c->dreq),
                       c->chan_base + BCM2835_DMA_CS);
@@ -1132,7 +1138,8 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic(
                 d->cb_list[frames - 1].cb)->next_cb =
                        to_40bit_cbaddr(d->cb_list[0].paddr);
        else
-               d->cb_list[d->frames - 1].cb->next = to_40bit_cbaddr(d->cb_list[0].paddr);
+               d->cb_list[d->frames - 1].cb->next = c->is_2712 ?
+               to_40bit_cbaddr(d->cb_list[0].paddr) : d->cb_list[0].paddr;
 
        return vchan_tx_prep(&c->vc, &d->vd, flags);
 }
@@ -1199,6 +1206,8 @@ static int bcm2835_dma_chan_init(struct bcm2835_dmadev *d, int chan_id,
        else if (readl(c->chan_base + BCM2835_DMA_DEBUG) &
                 BCM2835_DMA_DEBUG_LITE)
                c->is_lite_channel = true;
+       if (d->cfg_data->dma_mask == DMA_BIT_MASK(40))
+               c->is_2712 = true;
 
        return 0;
 }