[PATCH 04/10] dmaengine: sun6i: Enable additional burst lengths/widths on H3

Stefan Brüns
2017-09-03T22:42:47Z

The H3 supports bursts lengths of 1, 4, 8 and 16 transfers, each with
a width of 1, 2, 4 or 8 bytes.

The register value for the the width is log2-encoded, change the
conversion function to provide the correct value for width == 8.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
---
drivers/dma/sun6i-dma.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index c5644bd0f91a..335a8ec88b0b 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -263,8 +263,12 @@ static inline s8 convert_burst(u32 maxburst)
switch (maxburst) {
case 1:
return 0;
+ case 4:
+ return 1;
case 8:
return 2;
+ case 16:
+ return 3;
default:
return -EINVAL;
}
@@ -272,7 +276,7 @@ static inline s8 convert_burst(u32 maxburst)

static inline s8 convert_buswidth(enum dma_slave_buswidth addr_width)
{
- return addr_width >> 1;
+ return ilog2(addr_width);
}

static size_t sun6i_get_chan_size(struct sun6i_pchan *pchan)
@@ -1152,6 +1156,12 @@ static int sun6i_dma_probe(struct platform_device *pdev)
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
sdc->src_burst_lengths = BIT(1) | BIT(8);
sdc->dst_burst_lengths = BIT(1) | BIT(8);
+ if (sdc->cfg->dmac_variant == DMAC_VARIANT_H3) {
+ sdc->slave.src_addr_widths |= BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
+ sdc->slave.dst_addr_widths |= BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
+ sdc->src_burst_lengths |= BIT(4) | BIT(16);
+ sdc->dst_burst_lengths |= BIT(4) | BIT(16);
+ }
sdc->slave.directions = BIT(DMA_DEV_TO_MEM) |
BIT(DMA_MEM_TO_DEV);
sdc->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
--
2.14.1