@@ -67,12 +67,21 @@ static size_t dw_dma_block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
static u32 dw_dma_prepare_ctllo(struct dw_dma_chan *dwc)
{
struct dma_slave_config *sconfig = &dwc->dma_sconfig;
- u8 smsize = (dwc->direction == DMA_DEV_TO_MEM) ? sconfig->src_maxburst : 0;
- u8 dmsize = (dwc->direction == DMA_MEM_TO_DEV) ? sconfig->dst_maxburst : 0;
- u8 p_master = dwc->dws.p_master;
- u8 m_master = dwc->dws.m_master;
- u8 dms = (dwc->direction == DMA_MEM_TO_DEV) ? p_master : m_master;
- u8 sms = (dwc->direction == DMA_DEV_TO_MEM) ? p_master : m_master;
+ u8 smsize = 0, dmsize = 0;
+ u8 sms, dms;
+
+ if (dwc->direction == DMA_MEM_TO_DEV) {
+ sms = dwc->dws.m_master;
+ dms = dwc->dws.p_master;
+ dmsize = sconfig->dst_maxburst;
+ } else if (dwc->direction == DMA_DEV_TO_MEM) {
+ sms = dwc->dws.p_master;
+ dms = dwc->dws.m_master;
+ smsize = sconfig->src_maxburst;
+ } else /* DMA_MEM_TO_MEM */ {
+ sms = dwc->dws.m_master;
+ dms = dwc->dws.m_master;
+ }
return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN |
DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize) |
@@ -202,8 +202,12 @@ static size_t idma32_block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
static u32 idma32_prepare_ctllo(struct dw_dma_chan *dwc)
{
struct dma_slave_config *sconfig = &dwc->dma_sconfig;
- u8 smsize = (dwc->direction == DMA_DEV_TO_MEM) ? sconfig->src_maxburst : 0;
- u8 dmsize = (dwc->direction == DMA_MEM_TO_DEV) ? sconfig->dst_maxburst : 0;
+ u8 smsize = 0, dmsize = 0;
+
+ if (dwc->direction == DMA_MEM_TO_DEV)
+ dmsize = sconfig->dst_maxburst;
+ else if (dwc->direction == DMA_DEV_TO_MEM)
+ smsize = sconfig->src_maxburst;
return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN |
DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize);
Currently the CTL LO fields are calculated on the platform-specific basis. It's implemented by means of the prepare_ctllo() callbacks using the ternary operator within the local variables init block at the beginning of the block scope. The functions code currently is relatively hard to comprehend and isn't that optimal since implies four conditional statements executed and two additional local variables defined. Let's simplify the DW AHB DMA prepare_ctllo() method by unrolling the ternary operators into the normal if-else statement, dropping redundant master-interface ID variables and initializing the local variables based on the singly evaluated DMA-transfer direction check. Thus the method will look much more readable since now the fields content can be easily inferred right from the if-else branch. Provide the same update in the Intel DMA32 core driver for the sake of the driver code unification. Note besides of the effects described above this update is basically a preparation before dropping the max burst encoding callback. The dropping will require to call the burst fields calculation methods right in the prepare_ctllo() callbacks. It would have made the later functions code even more complex should they were left in the original state. Signed-off-by: Serge Semin <fancer.lancer@gmail.com> --- Changelog v2: - Group sms+dms and smsize+dmsize variables initializations up. (Andy) - Move the zero initializations out to the variables init block. (Andy) --- drivers/dma/dw/dw.c | 21 +++++++++++++++------ drivers/dma/dw/idma32.c | 8 ++++++-- 2 files changed, 21 insertions(+), 8 deletions(-)