From 51402ac12be9a0025f16db51fbde7c050a54e5fe Mon Sep 17 00:00:00 2001 From: Peter Tyser Date: Tue, 30 Jun 2009 17:15:43 -0500 Subject: fsl_dma: Add support for arbitrarily large transfers Support DMA transfers larger than the DMA controller's limit of (2 ^ 26 - 1) bytes Signed-off-by: Peter Tyser Signed-off-by: Kumar Gala --- drivers/dma/fsl_dma.c | 40 ++++++++++++++++++++++++++++------------ 1 file changed, 28 insertions(+), 12 deletions(-) (limited to 'drivers/dma') diff --git a/drivers/dma/fsl_dma.c b/drivers/dma/fsl_dma.c index 33ea8285e..f3575af6d 100644 --- a/drivers/dma/fsl_dma.c +++ b/drivers/dma/fsl_dma.c @@ -30,6 +30,9 @@ #include #include +/* Controller can only transfer 2^26 - 1 bytes at a time */ +#define FSL_DMA_MAX_SIZE (0x3ffffff) + #if defined(CONFIG_MPC85xx) ccsr_dma_t *dma_base = (void *)(CONFIG_SYS_MPC85xx_DMA_ADDR); #elif defined(CONFIG_MPC86xx) @@ -77,20 +80,33 @@ void dma_init(void) { int dma_xfer(void *dest, uint count, void *src) { volatile fsl_dma_t *dma = &dma_base->dma[0]; + uint xfer_size; - out_be32(&dma->dar, (uint) dest); - out_be32(&dma->sar, (uint) src); - out_be32(&dma->bcr, count); + while (count) { + xfer_size = MIN(FSL_DMA_MAX_SIZE, count); - /* Disable bandwidth control, use direct transfer mode */ - out_be32(&dma->mr, FSL_DMA_MR_BWC_DIS | FSL_DMA_MR_CTM_DIRECT); - dma_sync(); + out_be32(&dma->dar, (uint) dest); + out_be32(&dma->sar, (uint) src); + out_be32(&dma->bcr, xfer_size); - /* Start the transfer */ - out_be32(&dma->mr, FSL_DMA_MR_BWC_DIS | - FSL_DMA_MR_CTM_DIRECT | - FSL_DMA_MR_CS); - dma_sync(); + /* Disable bandwidth control, use direct transfer mode */ + out_be32(&dma->mr, FSL_DMA_MR_BWC_DIS | FSL_DMA_MR_CTM_DIRECT); + dma_sync(); + + /* Start the transfer */ + out_be32(&dma->mr, FSL_DMA_MR_BWC_DIS | + FSL_DMA_MR_CTM_DIRECT | + FSL_DMA_MR_CS); + + count -= xfer_size; + src += xfer_size; + dest += xfer_size; + + dma_sync(); + + if (dma_check()) + return -1; + } - return dma_check(); + return 0; } -- cgit v1.2.3