The XDMAC supports memset transfers, both over contiguous areas, and over discontiguous areas through a LLI. The current memset operation only supports contiguous memset for now, add some support for it. Scatter-gathered memset will come eventually. Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> --- drivers/dma/at_xdmac.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index 3c40c5ef043d..950debf99111 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -1097,6 +1097,93 @@ at_xdmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, return &first->tx_dma_desc; } +static struct at_xdmac_desc *at_xdmac_memset_create_desc(struct dma_chan *chan, + struct at_xdmac_chan *atchan, + dma_addr_t dst_addr, + size_t len, + int value) +{ + struct at_xdmac_desc *desc; + unsigned long flags; + size_t ublen; + u32 dwidth; + /* + * WARNING: The channel configuration is set here since there is no + * dmaengine_slave_config call in this case. Moreover we don't know the + * direction, it involves we can't dynamically set the source and dest + * interface so we have to use the same one. Only interface 0 allows EBI + * access. Hopefully we can access DDR through both ports (at least on + * SAMA5D4x), so we can use the same interface for source and dest, + * that solves the fact we don't know the direction. + */ + u32 chan_cc = AT_XDMAC_CC_DAM_INCREMENTED_AM + | AT_XDMAC_CC_SAM_INCREMENTED_AM + | AT_XDMAC_CC_DIF(0) + | AT_XDMAC_CC_SIF(0) + | AT_XDMAC_CC_MBSIZE_SIXTEEN + | AT_XDMAC_CC_MEMSET_HW_MODE + | AT_XDMAC_CC_TYPE_MEM_TRAN; + + dwidth = at_xdmac_align_width(chan, dst_addr); + + if (len >= (AT_XDMAC_MBR_UBC_UBLEN_MAX << dwidth)) { + dev_err(chan2dev(chan), + "%s: Transfer too large, aborting...\n", + __func__); + return NULL; + } + + spin_lock_irqsave(&atchan->lock, flags); + desc = at_xdmac_get_desc(atchan); + spin_unlock_irqrestore(&atchan->lock, flags); + if (!desc) { + dev_err(chan2dev(chan), "can't get descriptor\n"); + return NULL; + } + + chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth); + + ublen = len >> dwidth; + + desc->lld.mbr_da = dst_addr; + desc->lld.mbr_ds = value; + desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV3 + | AT_XDMAC_MBR_UBC_NDEN + | AT_XDMAC_MBR_UBC_NSEN + | ublen; + desc->lld.mbr_cfg = chan_cc; + + dev_dbg(chan2dev(chan), + "%s: lld: mbr_da=0x%08x, mbr_ds=0x%08x, mbr_ubc=0x%08x, mbr_cfg=0x%08x\n", + __func__, desc->lld.mbr_da, desc->lld.mbr_ds, desc->lld.mbr_ubc, + desc->lld.mbr_cfg); + + return desc; +} + +struct dma_async_tx_descriptor * +at_xdmac_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value, + size_t len, unsigned long flags) +{ + struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan); + struct at_xdmac_desc *desc; + + dev_dbg(chan2dev(chan), "%s: dest=0x%08x, len=%d, pattern=0x%x, flags=0x%lx\n", + __func__, dest, len, value, flags); + + if (unlikely(!len)) + return NULL; + + desc = at_xdmac_memset_create_desc(chan, atchan, dest, len, value); + list_add_tail(&desc->desc_node, &desc->descs_list); + + desc->tx_dma_desc.cookie = -EBUSY; + desc->tx_dma_desc.flags = flags; + desc->xfer_size = len; + + return &desc->tx_dma_desc; +} + static enum dma_status at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate) @@ -1623,6 +1710,7 @@ static int at_xdmac_probe(struct platform_device *pdev) dma_cap_set(DMA_CYCLIC, atxdmac->dma.cap_mask); dma_cap_set(DMA_INTERLEAVE, atxdmac->dma.cap_mask); dma_cap_set(DMA_MEMCPY, atxdmac->dma.cap_mask); + dma_cap_set(DMA_MEMSET, atxdmac->dma.cap_mask); dma_cap_set(DMA_SLAVE, atxdmac->dma.cap_mask); /* * Without DMA_PRIVATE the driver is not able to allocate more than @@ -1637,6 +1725,7 @@ static int at_xdmac_probe(struct platform_device *pdev) atxdmac->dma.device_prep_dma_cyclic = at_xdmac_prep_dma_cyclic; atxdmac->dma.device_prep_interleaved_dma = at_xdmac_prep_interleaved; atxdmac->dma.device_prep_dma_memcpy = at_xdmac_prep_dma_memcpy; + atxdmac->dma.device_prep_dma_memset = at_xdmac_prep_dma_memset; atxdmac->dma.device_prep_slave_sg = at_xdmac_prep_slave_sg; atxdmac->dma.device_config = at_xdmac_device_config; atxdmac->dma.device_pause = at_xdmac_device_pause; -- 2.3.6 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html