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| author | Sascha Hauer <s.hauer@pengutronix.de> | 2019-05-21 10:06:41 +0300 |
|---|---|---|
| committer | Miquel Raynal <miquel.raynal@bootlin.com> | 2019-06-27 21:05:29 +0300 |
| commit | e0ddaab76802d3179013f4864535043e2aea6c69 (patch) | |
| tree | 992fba574f07acb858f55e728b3f566f8bde2ab1 /include/linux/dma | |
| parent | 475345e89ced298afbeefed6c86122bb8415593d (diff) | |
| download | linux-e0ddaab76802d3179013f4864535043e2aea6c69.tar.xz | |
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 <s.hauer@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Diffstat (limited to 'include/linux/dma')
| -rw-r--r-- | include/linux/dma/mxs-dma.h | 21 |
1 files changed, 21 insertions, 0 deletions
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 <linux/dmaengine.h> + +/* + * 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_ */ |