intel_mid_dma: add support for single item scatter-gather list
Current driver's device_prep_slave_sg can't be used by DMAC2 even
the sg list contains one item, this patch will enable DMAC2 to
use this API.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dma/intel_mid_dma.c b/drivers/dma/intel_mid_dma.c
index 41941d0..0c0feb8 100644
--- a/drivers/dma/intel_mid_dma.c
+++ b/drivers/dma/intel_mid_dma.c
@@ -664,11 +664,20 @@
/*calculate CTL_LO*/
ctl_lo.ctl_lo = 0;
ctl_lo.ctlx.int_en = 1;
- ctl_lo.ctlx.dst_tr_width = mids->dma_slave.dst_addr_width;
- ctl_lo.ctlx.src_tr_width = mids->dma_slave.src_addr_width;
ctl_lo.ctlx.dst_msize = mids->dma_slave.src_maxburst;
ctl_lo.ctlx.src_msize = mids->dma_slave.dst_maxburst;
+ /*
+ * Here we need some translation from "enum dma_slave_buswidth"
+ * to the format for our dma controller
+ * standard intel_mid_dmac's format
+ * 1 Byte 0b000
+ * 2 Bytes 0b001
+ * 4 Bytes 0b010
+ */
+ ctl_lo.ctlx.dst_tr_width = mids->dma_slave.dst_addr_width / 2;
+ ctl_lo.ctlx.src_tr_width = mids->dma_slave.src_addr_width / 2;
+
if (mids->cfg_mode == LNW_DMA_MEM_TO_MEM) {
ctl_lo.ctlx.tt_fc = 0;
ctl_lo.ctlx.sinc = 0;
@@ -746,8 +755,18 @@
BUG_ON(!mids);
if (!midc->dma->pimr_mask) {
- pr_debug("MDMA: SG list is not supported by this controller\n");
- return NULL;
+ /* We can still handle sg list with only one item */
+ if (sg_len == 1) {
+ txd = intel_mid_dma_prep_memcpy(chan,
+ mids->dma_slave.dst_addr,
+ mids->dma_slave.src_addr,
+ sgl->length,
+ flags);
+ return txd;
+ } else {
+ pr_warn("MDMA: SG list is not supported by this controller\n");
+ return NULL;
+ }
}
pr_debug("MDMA: SG Length = %d, direction = %d, Flags = %#lx\n",
@@ -758,6 +777,7 @@
pr_err("MDMA: Prep memcpy failed\n");
return NULL;
}
+
desc = to_intel_mid_dma_desc(txd);
desc->dirn = direction;
ctl_lo.ctl_lo = desc->ctl_lo;