From c8acd6aa6bed3c0fd7898202f4ebc534db9085f2 Mon Sep 17 00:00:00 2001 From: Zhangfei Gao Date: Mon, 3 Sep 2012 11:03:45 +0800 Subject: dmaengine: mmp-pdma support 1. virtual channel vs. physical channel Virtual channel is managed by dmaengine Physical channel handling resource, such as irq Physical channel is alloced dynamically as descending priority, freed immediately when irq done. The availble highest priority physically channel will alwayes be alloced Issue pending list -> alloc highest dma physically channel available -> dma done -> free physically channel 2. list: running list & pending list submit: desc list -> pending list issue_pending_list: if (IDLE) pending list -> running list; free pending list (RUN) irq: free running list (IDLE) check pendlist -> pending list -> running list; free pending list (RUN) 3. irq: Each list generate one irq, calling callback One list may contain several desc chain, in such case, make sure only the last desc list generate irq. 4. async Submit will add desc chain to pending list, which can be multi-called If multi desc chain is submitted, only the last desc would generate irq -> call back If IDLE, issue_pending_list start pending_list, transforming pendlist to running list If RUN, irq will start pending list 5. test 5.1 pxa3xx_nand on pxa910 5.2 insmod dmatest.ko (threads_per_chan=y) By default drivers/dma/dmatest.c test every channel and test memcpy with 1 threads per channel Signed-off-by: Zhangfei Gao Acked-by: Arnd Bergmann Signed-off-by: Vinod Koul --- include/linux/platform_data/mmp_dma.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) create mode 100644 include/linux/platform_data/mmp_dma.h (limited to 'include/linux/platform_data/mmp_dma.h') diff --git a/include/linux/platform_data/mmp_dma.h b/include/linux/platform_data/mmp_dma.h new file mode 100644 index 000000000000..2a330ec9e2af --- /dev/null +++ b/include/linux/platform_data/mmp_dma.h @@ -0,0 +1,19 @@ +/* + * MMP Platform DMA Management + * + * Copyright (c) 2011 Marvell Semiconductors Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#ifndef MMP_DMA_H +#define MMP_DMA_H + +struct mmp_dma_platdata { + int dma_channels; +}; + +#endif /* MMP_DMA_H */ -- cgit v1.2.3