[PATCH 1/2] dmaengine: sun4i: Add support for cyclic requests with dedicated DMA

From: Stefan Mavrodiev
Date: Fri Jan 10 2020 - 09:12:14 EST


Currently the cyclic transfers can be used only with normal DMAs. They
can be used by pcm_dmaengine module, which is required for implementing
sound with sun4i-hdmi encoder. This is so because the controller can
accept audio only from a dedicated DMA.

This patch enables them, following the existing style for the
scatter/gather type transfers.

Signed-off-by: Stefan Mavrodiev <stefan@xxxxxxxxxx>
---
drivers/dma/sun4i-dma.c | 45 ++++++++++++++++++++++-------------------
1 file changed, 24 insertions(+), 21 deletions(-)

diff --git a/drivers/dma/sun4i-dma.c b/drivers/dma/sun4i-dma.c
index e397a50058c8..7b41815d86fb 100644
--- a/drivers/dma/sun4i-dma.c
+++ b/drivers/dma/sun4i-dma.c
@@ -669,43 +669,41 @@ sun4i_dma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf, size_t len,
dma_addr_t src, dest;
u32 endpoints;
int nr_periods, offset, plength, i;
+ u8 ram_type, io_mode, linear_mode;

if (!is_slave_direction(dir)) {
dev_err(chan2dev(chan), "Invalid DMA direction\n");
return NULL;
}

- if (vchan->is_dedicated) {
- /*
- * As we are using this just for audio data, we need to use
- * normal DMA. There is nothing stopping us from supporting
- * dedicated DMA here as well, so if a client comes up and
- * requires it, it will be simple to implement it.
- */
- dev_err(chan2dev(chan),
- "Cyclic transfers are only supported on Normal DMA\n");
- return NULL;
- }
-
contract = generate_dma_contract();
if (!contract)
return NULL;

contract->is_cyclic = 1;

- /* Figure out the endpoints and the address we need */
+ if (vchan->is_dedicated) {
+ io_mode = SUN4I_DDMA_ADDR_MODE_IO;
+ linear_mode = SUN4I_DDMA_ADDR_MODE_LINEAR;
+ ram_type = SUN4I_DDMA_DRQ_TYPE_SDRAM;
+ } else {
+ io_mode = SUN4I_NDMA_ADDR_MODE_IO;
+ linear_mode = SUN4I_NDMA_ADDR_MODE_LINEAR;
+ ram_type = SUN4I_NDMA_DRQ_TYPE_SDRAM;
+ }
+
if (dir == DMA_MEM_TO_DEV) {
src = buf;
dest = sconfig->dst_addr;
- endpoints = SUN4I_DMA_CFG_SRC_DRQ_TYPE(SUN4I_NDMA_DRQ_TYPE_SDRAM) |
- SUN4I_DMA_CFG_DST_DRQ_TYPE(vchan->endpoint) |
- SUN4I_DMA_CFG_DST_ADDR_MODE(SUN4I_NDMA_ADDR_MODE_IO);
+ endpoints = SUN4I_DMA_CFG_DST_DRQ_TYPE(vchan->endpoint) |
+ SUN4I_DMA_CFG_DST_ADDR_MODE(io_mode) |
+ SUN4I_DMA_CFG_SRC_DRQ_TYPE(ram_type);
} else {
src = sconfig->src_addr;
dest = buf;
- endpoints = SUN4I_DMA_CFG_SRC_DRQ_TYPE(vchan->endpoint) |
- SUN4I_DMA_CFG_SRC_ADDR_MODE(SUN4I_NDMA_ADDR_MODE_IO) |
- SUN4I_DMA_CFG_DST_DRQ_TYPE(SUN4I_NDMA_DRQ_TYPE_SDRAM);
+ endpoints = SUN4I_DMA_CFG_DST_DRQ_TYPE(ram_type) |
+ SUN4I_DMA_CFG_SRC_DRQ_TYPE(vchan->endpoint) |
+ SUN4I_DMA_CFG_SRC_ADDR_MODE(io_mode);
}

/*
@@ -747,8 +745,13 @@ sun4i_dma_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf, size_t len,
dest = buf + offset;

/* Make the promise */
- promise = generate_ndma_promise(chan, src, dest,
- plength, sconfig, dir);
+ if (vchan->is_dedicated)
+ promise = generate_ddma_promise(chan, src, dest,
+ plength, sconfig);
+ else
+ promise = generate_ndma_promise(chan, src, dest,
+ plength, sconfig, dir);
+
if (!promise) {
/* TODO: should we free everything? */
return NULL;
--
2.17.1