dmaengine: ste_dma40: Convert data_width from register bit format to value

When a DMA client requests and configures a DMA channel, it requests
data_width in Bytes. The DMA40 driver then swiftly converts it over to
the necessary register bit value. Unfortunately, for any subsequent
calculations we have to shift '1' by the bit pattern (1 << data_width)
times to make any sense of it.

This patch flips the semantics on its head and only converts the value
to its respective register bit pattern when writing to registers. This
way we can use the true data_width (in Bytes) value.

Cc: Dan Williams <djbw@fb.com>
Cc: Per Forlin <per.forlin@stericsson.com>
Cc: Rabin Vincent <rabin@rab.in>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 29 insertions, 14 deletions

diff --git a/drivers/dma/ste_dma40_ll.c b/drivers/dma/ste_dma40_ll.c
index 5ddd724dcdc5..a035dfeab6cb 100644
--- a/drivers/dma/ste_dma40_ll.c
+++ b/drivers/dma/ste_dma40_ll.c
@@ -10,6 +10,18 @@
 
 #include "ste_dma40_ll.h"
 
+u8 d40_width_to_bits(enum dma_slave_buswidth width)
+{
+	if (width == DMA_SLAVE_BUSWIDTH_1_BYTE)
+		return STEDMA40_ESIZE_8_BIT;
+	else if (width == DMA_SLAVE_BUSWIDTH_2_BYTES)
+		return STEDMA40_ESIZE_16_BIT;
+	else if (width == DMA_SLAVE_BUSWIDTH_8_BYTES)
+		return STEDMA40_ESIZE_64_BIT;
+	else
+		return STEDMA40_ESIZE_32_BIT;
+}
+
 /* Sets up proper LCSP1 and LCSP3 register for a logical channel */
 void d40_log_cfg(struct stedma40_chan_cfg *cfg,
 		 u32 *lcsp1, u32 *lcsp3)
@@ -39,11 +51,13 @@ void d40_log_cfg(struct stedma40_chan_cfg *cfg,
 
 	l3 |= BIT(D40_MEM_LCSP3_DCFG_EIM_POS);
 	l3 |= cfg->dst_info.psize << D40_MEM_LCSP3_DCFG_PSIZE_POS;
-	l3 |= cfg->dst_info.data_width << D40_MEM_LCSP3_DCFG_ESIZE_POS;
+	l3 |= d40_width_to_bits(cfg->dst_info.data_width)
+		<< D40_MEM_LCSP3_DCFG_ESIZE_POS;
 
 	l1 |= BIT(D40_MEM_LCSP1_SCFG_EIM_POS);
 	l1 |= cfg->src_info.psize << D40_MEM_LCSP1_SCFG_PSIZE_POS;
-	l1 |= cfg->src_info.data_width << D40_MEM_LCSP1_SCFG_ESIZE_POS;
+	l1 |= d40_width_to_bits(cfg->src_info.data_width)
+		<< D40_MEM_LCSP1_SCFG_ESIZE_POS;
 
 	*lcsp1 = l1;
 	*lcsp3 = l3;
@@ -95,8 +109,10 @@ void d40_phy_cfg(struct stedma40_chan_cfg *cfg, u32 *src_cfg, u32 *dst_cfg)
 	}
 
 	/* Element size */
-	src |= cfg->src_info.data_width << D40_SREG_CFG_ESIZE_POS;
-	dst |= cfg->dst_info.data_width << D40_SREG_CFG_ESIZE_POS;
+	src |= d40_width_to_bits(cfg->src_info.data_width)
+		<< D40_SREG_CFG_ESIZE_POS;
+	dst |= d40_width_to_bits(cfg->dst_info.data_width)
+		<< D40_SREG_CFG_ESIZE_POS;
 
 	/* Set the priority bit to high for the physical channel */
 	if (cfg->high_priority) {
@@ -133,23 +149,22 @@ static int d40_phy_fill_lli(struct d40_phy_lli *lli,
 		num_elems = 2 << psize;
 
 	/* Must be aligned */
-	if (!IS_ALIGNED(data, 0x1 << data_width))
+	if (!IS_ALIGNED(data, data_width))
 		return -EINVAL;
 
 	/* Transfer size can't be smaller than (num_elms * elem_size) */
-	if (data_size < num_elems * (0x1 << data_width))
+	if (data_size < num_elems * data_width)
 		return -EINVAL;
 
 	/* The number of elements. IE now many chunks */
-	lli->reg_elt = (data_size >> data_width) << D40_SREG_ELEM_PHY_ECNT_POS;
+	lli->reg_elt = (data_size / data_width) << D40_SREG_ELEM_PHY_ECNT_POS;
 
 	/*
 	 * Distance to next element sized entry.
 	 * Usually the size of the element unless you want gaps.
 	 */
 	if (addr_inc)
-		lli->reg_elt |= (0x1 << data_width) <<
-			D40_SREG_ELEM_PHY_EIDX_POS;
+		lli->reg_elt |= data_width << D40_SREG_ELEM_PHY_EIDX_POS;
 
 	/* Where the data is */
 	lli->reg_ptr = data;
@@ -177,16 +192,16 @@ static int d40_seg_size(int size, int data_width1, int data_width2)
 {
 	u32 max_w = max(data_width1, data_width2);
 	u32 min_w = min(data_width1, data_width2);
-	u32 seg_max = ALIGN(STEDMA40_MAX_SEG_SIZE << min_w, 1 << max_w);
+	u32 seg_max = ALIGN(STEDMA40_MAX_SEG_SIZE * min_w, max_w);
 
 	if (seg_max > STEDMA40_MAX_SEG_SIZE)
-		seg_max -= (1 << max_w);
+		seg_max -= max_w;
 
 	if (size <= seg_max)
 		return size;
 
 	if (size <= 2 * seg_max)
-		return ALIGN(size / 2, 1 << max_w);
+		return ALIGN(size / 2, max_w);
 
 	return seg_max;
 }
@@ -352,10 +367,10 @@ static void d40_log_fill_lli(struct d40_log_lli *lli,
 	lli->lcsp13 = reg_cfg;
 
 	/* The number of elements to transfer */
-	lli->lcsp02 = ((data_size >> data_width) <<
+	lli->lcsp02 = ((data_size / data_width) <<
 		       D40_MEM_LCSP0_ECNT_POS) & D40_MEM_LCSP0_ECNT_MASK;
 
-	BUG_ON((data_size >> data_width) > STEDMA40_MAX_SEG_SIZE);
+	BUG_ON((data_size / data_width) > STEDMA40_MAX_SEG_SIZE);
 
 	/* 16 LSBs address of the current element */
 	lli->lcsp02 |= data & D40_MEM_LCSP0_SPTR_MASK;