[PATCH 06/10] MXS-DMA : add more flags for MXS-DMA
From: Huang Shijie <hidden>
Date: 2012-01-19 09:30:01
Also in:
alsa-devel, linux-mmc, lkml
From: Huang Shijie <hidden>
Date: 2012-01-19 09:30:01
Also in:
alsa-devel, linux-mmc, lkml
hi,
Err, the 'flags' argument to device_prep_slave_sg() is supposed to be from the set of enum dma_ctrl_flags. What this means is that your MXS_DMA_F_APPEND is equivalent to DMA_PREP_INTERRUPT, and MXS_DMA_F_WAIT4END is equivalent to DMA_CTRL_ACK.
thanks a lot. I will reuse the dma_ctrl_flags in the next version.
What this does is make your drivers completely dependent on your DMA engine implementation. That's not a good idea when devices get reused in different SoCs.
Frankly speaking, the APBH-DMA is more coupled with the GPMI then any
other modules.
In the MX6Q, the GPMI is the ONLY user of APBH-DMA.
You even can see the NAND_LOCK bit in the DMA command structure which is
only used by the GPMI
NAND controller,.
To Shawn & Wolfram:
thanks very much for your comments.
Best Regards
Huang Shijie
If you need to supply extra flags which aren't in the dma_ctrl_flags, at least make sure that they're using different bits. For bonus points, also have your driver_check_ the DMA engine it's connected to before it passes these flags.