From 72a1179ed41e0fc6bd5eb58e02e8d230eba10e24 Mon Sep 17 00:00:00 2001 From: Samu Onkalo Date: Mon, 2 Aug 2010 14:21:40 +0300 Subject: [PATCH] omap: dma: Support for prefetch in destination synchronizedtransfer Omap DMA controller can prefetch data in advance in case of destination synchronized data transfer. This may increase performance when target HW block doesn't have fifo. Data is waiting for transfer request in DMA fifo instead of read from memory. Signed-off-by: Samu Onkalo Signed-off-by: Tony Lindgren --- arch/arm/plat-omap/dma.c | 11 +++++++---- arch/arm/plat-omap/include/plat/dma.h | 1 + 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index f7f571e7987..ec7eddf9e52 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -290,7 +290,7 @@ void omap_set_dma_transfer_params(int lch, int data_type, int elem_count, val = dma_read(CCR(lch)); /* DMA_SYNCHRO_CONTROL_UPPER depends on the channel number */ - val &= ~((3 << 19) | 0x1f); + val &= ~((1 << 23) | (3 << 19) | 0x1f); val |= (dma_trigger & ~0x1f) << 14; val |= dma_trigger & 0x1f; @@ -304,11 +304,14 @@ void omap_set_dma_transfer_params(int lch, int data_type, int elem_count, else val &= ~(1 << 18); - if (src_or_dst_synch) + if (src_or_dst_synch == OMAP_DMA_DST_SYNC_PREFETCH) { + val &= ~(1 << 24); /* dest synch */ + val |= (1 << 23); /* Prefetch */ + } else if (src_or_dst_synch) { val |= 1 << 24; /* source synch */ - else + } else { val &= ~(1 << 24); /* dest synch */ - + } dma_write(val, CCR(lch)); } diff --git a/arch/arm/plat-omap/include/plat/dma.h b/arch/arm/plat-omap/include/plat/dma.h index 02232ca2c37..af3a03941ad 100644 --- a/arch/arm/plat-omap/include/plat/dma.h +++ b/arch/arm/plat-omap/include/plat/dma.h @@ -345,6 +345,7 @@ #define OMAP_DMA_SYNC_BLOCK 0x02 #define OMAP_DMA_SYNC_PACKET 0x03 +#define OMAP_DMA_DST_SYNC_PREFETCH 0x02 #define OMAP_DMA_SRC_SYNC 0x01 #define OMAP_DMA_DST_SYNC 0x00 -- 2.20.1