[PATCH 16/18] drm/vc4: Use phys addresses for slave DMA config

Dave Stevenson
2024-05-24T18:28:03Z

From: Phil Elwell <phil@raspberrypi.com>

Slave addresses for DMA are meant to be supplied as physical addresses
(contrary to what struct snd_dmaengine_dai_dma_data does).

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index d30f8e8e8967..c2afd72bd96e 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2696,7 +2696,7 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
struct snd_soc_card *card = &vc4_hdmi->audio.card;
struct device *dev = &vc4_hdmi->pdev->dev;
struct platform_device *codec_pdev;
- const __be32 *addr;
+ struct resource *iomem;
int index, len;
int ret;

@@ -2732,22 +2732,15 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi)
}

/*
- * Get the physical address of VC4_HD_MAI_DATA. We need to retrieve
- * the bus address specified in the DT, because the physical address
- * (the one returned by platform_get_resource()) is not appropriate
- * for DMA transfers.
- * This VC/MMU should probably be exposed to avoid this kind of hacks.
+ * Get the physical address of VC4_HD_MAI_DATA.
*/
index = of_property_match_string(dev->of_node, "reg-names", "hd");
/* Before BCM2711, we don't have a named register range */
if (index < 0)
index = 1;
+ iomem = platform_get_resource(vc4_hdmi->pdev, IORESOURCE_MEM, index);

- addr = of_get_address(dev->of_node, index, NULL, NULL);
- if (!addr)
- return -EINVAL;
-
- vc4_hdmi->audio.dma_data.addr = be32_to_cpup(addr) + mai_data->offset;
+ vc4_hdmi->audio.dma_data.addr = iomem->start + mai_data->offset;
vc4_hdmi->audio.dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
vc4_hdmi->audio.dma_data.maxburst = 2;

--
2.34.1