From e0ddaab76802d3179013f4864535043e2aea6c69 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Tue, 21 May 2019 09:06:41 +0200 Subject: dmaengine: mxs: Add header file to be shared with gpmi nand driver The mxs dma driver can do PIO transfers. A pointer to the PIO words to transfer is passed in the struct scatterlist * argument of dmaengine_prep_slave_sg(). It's quite ugly and non obvious to cast u32 * to struct scatterlist * each time when calling dmaengine_prep_slave_sg(), so add a static inline wrapper function to be called by the user along with a description what is going on. Signed-off-by: Sascha Hauer Acked-by: Vinod Koul Signed-off-by: Miquel Raynal --- include/linux/dma/mxs-dma.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 include/linux/dma/mxs-dma.h (limited to 'include/linux/dma') diff --git a/include/linux/dma/mxs-dma.h b/include/linux/dma/mxs-dma.h new file mode 100644 index 000000000000..092b2a7b92ac --- /dev/null +++ b/include/linux/dma/mxs-dma.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _MXS_DMA_H_ +#define _MXS_DMA_H_ + +#include + +/* + * The mxs dmaengine can do PIO transfers. We pass a pointer to the PIO words + * in the second argument to dmaengine_prep_slave_sg when the direction is + * set to DMA_TRANS_NONE. To make this clear and to prevent users from doing + * the error prone casting we have this wrapper function + */ +static inline struct dma_async_tx_descriptor *mxs_dmaengine_prep_pio( + struct dma_chan *chan, u32 *pio, unsigned int npio, + enum dma_transfer_direction dir, unsigned long flags) +{ + return dmaengine_prep_slave_sg(chan, (struct scatterlist *)pio, npio, + dir, flags); +} + +#endif /* _MXS_DMA_H_ */ -- cgit v1.2.3