Messages in this thread Patch in this message | | | Date | Fri, 12 Feb 2016 12:53:37 +0530 | From | Shraddha Barke <> | Subject | [PATCH] Platform: goldfish: goldfish_pipe.c: Add DMA support using managed version |
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setup_access_params_addr has 2 goals-
-Initialize the access_params field so that it can be used to send and read commands from the device in access_with_param -Get a bus address for the allocated memory to transfer to the device.
Replace the combination of devm_kzalloc and _pa() with dmam_alloc_coherent. Coherent mapping guarantees that the device and CPU are in sync.
Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com> --- drivers/platform/goldfish/goldfish_pipe.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c index e7a29e2..49f877d 100644 --- a/drivers/platform/goldfish/goldfish_pipe.c +++ b/drivers/platform/goldfish/goldfish_pipe.c @@ -57,6 +57,7 @@ #include <linux/slab.h> #include <linux/io.h> #include <linux/goldfish.h> +#include <linux/dma-mapping.h> /* * IMPORTANT: The following constants must match the ones used and defined @@ -217,17 +218,18 @@ static int valid_batchbuffer_addr(struct goldfish_pipe_dev *dev, static int setup_access_params_addr(struct platform_device *pdev, struct goldfish_pipe_dev *dev) { - u64 paddr; + dma_addr_t dma_handle; struct access_params *aps; - aps = devm_kzalloc(&pdev->dev, sizeof(struct access_params), GFP_KERNEL); - if (!aps) - return -1; + aps = dmam_alloc_coherent(&pdev->dev, sizeof(struct access_params), + &dma_handle, GFP_KERNEL); + if (!aps) { + dev_err(&pdev->dev, "allocate buffer failed\n"); + return -ENOMEM; + } - /* FIXME */ - paddr = __pa(aps); - writel((u32)(paddr >> 32), dev->base + PIPE_REG_PARAMS_ADDR_HIGH); - writel((u32)paddr, dev->base + PIPE_REG_PARAMS_ADDR_LOW); + writel(upper_32_bits(dma_handle), dev->base + PIPE_REG_PARAMS_ADDR_HIGH); + writel(lower_32_bits(dma_handle), dev->base + PIPE_REG_PARAMS_ADDR_LOW); if (valid_batchbuffer_addr(dev, aps)) { dev->aps = aps; -- 2.1.4
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