[v1,2/5] dmaengine: dw: introduce block2bytes() and bytes2block()

Commit Message

Andy Shevchenko Sept. 9, 2016, 7:57 p.m. UTC

The newly introduced helpers prepare driver to support new DMA controller
hardware.

While here, introduce DWC_CTLH_BLOCK_TS() macro as well.

Signed-off-by: Andy Shevchenko <[e-mail]>
---
 drivers/dma/dw/core.c | 60 +++++++++++++++++++++++++++------------------------
 drivers/dma/dw/regs.h |  6 ++++--
 2 files changed, 36 insertions(+), 30 deletions(-)

Patch

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index d06319b..7973682 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -184,6 +184,22 @@  static inline void dwc_chan_disable(struct dw_dma *dw, struct dw_dma_chan *dwc)
 		cpu_relax();
 }
 
+static u32 bytes2block(struct dw_dma_chan *dwc, size_t bytes,
+			  unsigned int width, size_t *len)
+{
+	u32 block;
+
+	block = min_t(u32, bytes >> width, dwc->block_size);
+	*len = block << width;
+
+	return block;
+}
+
+static size_t block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
+{
+	return DWC_CTLH_BLOCK_TS(block) << width;
+}
+
 /*----------------------------------------------------------------------*/
 
 /* Perform single block transfer */
@@ -332,7 +348,7 @@  static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
 	u32 ctlhi = channel_readl(dwc, CTL_HI);
 	u32 ctllo = channel_readl(dwc, CTL_LO);
 
-	return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (ctllo >> 4 & 7));
+	return block2bytes(dwc, ctlhi, ctllo >> 4 & 7);
 }
 
 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
@@ -692,10 +708,7 @@  dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 			| DWC_CTLL_FC_M2M;
 	prev = first = NULL;
 
-	for (offset = 0; offset < len; offset += xfer_count << src_width) {
-		xfer_count = min_t(size_t, (len - offset) >> src_width,
-					   dwc->block_size);
-
+	for (offset = 0; offset < len; offset += xfer_count) {
 		desc = dwc_desc_get(dwc);
 		if (!desc)
 			goto err_desc_get;
@@ -703,8 +716,8 @@  dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 		lli_write(desc, sar, src + offset);
 		lli_write(desc, dar, dest + offset);
 		lli_write(desc, ctllo, ctllo);
-		lli_write(desc, ctlhi, xfer_count);
-		desc->len = xfer_count << src_width;
+		lli_write(desc, ctlhi, bytes2block(dwc, len - offset, src_width, &xfer_count));
+		desc->len = xfer_count;
 
 		if (!first) {
 			first = desc;
@@ -775,7 +788,8 @@  dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 		for_each_sg(sgl, sg, sg_len, i) {
 			struct dw_desc	*desc;
-			u32		len, dlen, mem;
+			u32		len, mem;
+			size_t		dlen;
 
 			mem = sg_dma_address(sg);
 			len = sg_dma_len(sg);
@@ -790,16 +804,7 @@  slave_sg_todev_fill_desc:
 			lli_write(desc, sar, mem);
 			lli_write(desc, dar, reg);
 			lli_write(desc, ctllo, ctllo | DWC_CTLL_SRC_WIDTH(mem_width));
-			if ((len >> mem_width) > dwc->block_size) {
-				dlen = dwc->block_size << mem_width;
-				mem += dlen;
-				len -= dlen;
-			} else {
-				dlen = len;
-				len = 0;
-			}
-
-			lli_write(desc, ctlhi, dlen >> mem_width);
+			lli_write(desc, ctlhi, bytes2block(dwc, len, mem_width, &dlen));
 			desc->len = dlen;
 
 			if (!first) {
@@ -809,6 +814,9 @@  slave_sg_todev_fill_desc:
 				list_add_tail(&desc->desc_node, &first->tx_list);
 			}
 			prev = desc;
+
+			mem += dlen;
+			len -= dlen;
 			total_len += dlen;
 
 			if (len)
@@ -828,7 +836,8 @@  slave_sg_todev_fill_desc:
 
 		for_each_sg(sgl, sg, sg_len, i) {
 			struct dw_desc	*desc;
-			u32		len, dlen, mem;
+			u32		len, mem;
+			size_t		dlen;
 
 			mem = sg_dma_address(sg);
 			len = sg_dma_len(sg);
@@ -843,15 +852,7 @@  slave_sg_fromdev_fill_desc:
 			lli_write(desc, sar, reg);
 			lli_write(desc, dar, mem);
 			lli_write(desc, ctllo, ctllo | DWC_CTLL_DST_WIDTH(mem_width));
-			if ((len >> reg_width) > dwc->block_size) {
-				dlen = dwc->block_size << reg_width;
-				mem += dlen;
-				len -= dlen;
-			} else {
-				dlen = len;
-				len = 0;
-			}
-			lli_write(desc, ctlhi, dlen >> reg_width);
+			lli_write(desc, ctlhi, bytes2block(dwc, len, reg_width, &dlen));
 			desc->len = dlen;
 
 			if (!first) {
@@ -861,6 +862,9 @@  slave_sg_fromdev_fill_desc:
 				list_add_tail(&desc->desc_node, &first->tx_list);
 			}
 			prev = desc;
+
+			mem += dlen;
+			len -= dlen;
 			total_len += dlen;
 
 			if (len)
diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h
index f65dd10..5a44584 100644
--- a/drivers/dma/dw/regs.h
+++ b/drivers/dma/dw/regs.h
@@ -9,6 +9,7 @@ 
  * published by the Free Software Foundation.
  */
 
+#include <linux/bitops.h>
 #include <linux/interrupt.h>
 #include <linux/dmaengine.h>
 
@@ -169,8 +170,9 @@  enum dw_dma_msize {
 #define DWC_CTLL_LLP_S_EN	(1 << 28)	/* src block chain */
 
 /* Bitfields in CTL_HI */
-#define DWC_CTLH_DONE		0x00001000
-#define DWC_CTLH_BLOCK_TS_MASK	0x00000fff
+#define DWC_CTLH_BLOCK_TS_MASK	GENMASK(11, 0)
+#define DWC_CTLH_BLOCK_TS(x)	((x) & DWC_CTLH_BLOCK_TS_MASK)
+#define DWC_CTLH_DONE		(1 << 12)
 
 /* Bitfields in CFG_LO */
 #define DWC_CFGL_CH_PRIOR_MASK	(0x7 << 5)	/* priority mask */