From: Alban Bedel alban.bedel@avionic-design.de
Many audio interface drivers require support of cyclic transfers to work correctly, for example Samsung ASoC DMA driver. This patch adds support for cyclic transfers to the amba-pl08x driver.
Signed-off-by: Alban Bedel alban.bedel@avionic-design.de [tfiga: Rebase and slightly beautify the original patch.] Signed-off-by: Tomasz Figa tomasz.figa@gmail.com Acked-by: Linus Walleij linus.walleij@linaro.org --- drivers/dma/amba-pl08x.c | 147 +++++++++++++++++++++++++++++++++++++---------- 1 file changed, 118 insertions(+), 29 deletions(-)
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c index 6b9cba2..cd29434 100644 --- a/drivers/dma/amba-pl08x.c +++ b/drivers/dma/amba-pl08x.c @@ -173,6 +173,7 @@ struct pl08x_sg { * @ccfg: config reg values for current txd * @done: this marks completed descriptors, which should not have their * mux released. + * @cyclic: indicate cyclic transfers */ struct pl08x_txd { struct virt_dma_desc vd; @@ -187,6 +188,7 @@ struct pl08x_txd { */ u32 ccfg; bool done; + bool cyclic; };
/** @@ -574,9 +576,9 @@ static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan) bytes += get_bytes_in_cctl(llis_va[PL080_LLI_CCTL]);
/* - * A LLI pointer of 0 terminates the LLI list + * A LLI pointer going backward terminates the LLI list */ - if (!llis_va[PL080_LLI_LLI]) + if (llis_va[PL080_LLI_LLI] <= clli) break; }
@@ -1125,10 +1127,16 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
llis_va = txd->llis_va; last_lli = llis_va + (num_llis - 1) * pl08x->lli_words; - /* The final LLI terminates the LLI. */ - last_lli[PL080_LLI_LLI] = 0; - /* The final LLI element shall also fire an interrupt. */ - last_lli[PL080_LLI_CCTL] |= PL080_CONTROL_TC_IRQ_EN; + + if (txd->cyclic) { + /* Link back to the first LLI. */ + last_lli[PL080_LLI_LLI] = txd->llis_bus | bd.lli_bus; + } else { + /* The final LLI terminates the LLI. */ + last_lli[PL080_LLI_LLI] = 0; + /* The final LLI element shall also fire an interrupt. */ + last_lli[PL080_LLI_CCTL] |= PL080_CONTROL_TC_IRQ_EN; + }
pl08x_dump_lli(pl08x, llis_va, num_llis);
@@ -1513,25 +1521,19 @@ static struct dma_async_tx_descriptor *pl08x_prep_dma_memcpy( return vchan_tx_prep(&plchan->vc, &txd->vd, flags); }
-static struct dma_async_tx_descriptor *pl08x_prep_slave_sg( - struct dma_chan *chan, struct scatterlist *sgl, - unsigned int sg_len, enum dma_transfer_direction direction, - unsigned long flags, void *context) +static struct pl08x_txd *pl08x_init_txd( + struct dma_chan *chan, + enum dma_transfer_direction direction, + dma_addr_t *slave_addr) { struct pl08x_dma_chan *plchan = to_pl08x_chan(chan); struct pl08x_driver_data *pl08x = plchan->host; struct pl08x_txd *txd; - struct pl08x_sg *dsg; - struct scatterlist *sg; enum dma_slave_buswidth addr_width; - dma_addr_t slave_addr; int ret, tmp; u8 src_buses, dst_buses; u32 maxburst, cctl;
- dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n", - __func__, sg_dma_len(sgl), plchan->name); - txd = pl08x_get_txd(plchan); if (!txd) { dev_err(&pl08x->adev->dev, "%s no txd\n", __func__); @@ -1545,14 +1547,14 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg( */ if (direction == DMA_MEM_TO_DEV) { cctl = PL080_CONTROL_SRC_INCR; - slave_addr = plchan->cfg.dst_addr; + *slave_addr = plchan->cfg.dst_addr; addr_width = plchan->cfg.dst_addr_width; maxburst = plchan->cfg.dst_maxburst; src_buses = pl08x->mem_buses; dst_buses = plchan->cd->periph_buses; } else if (direction == DMA_DEV_TO_MEM) { cctl = PL080_CONTROL_DST_INCR; - slave_addr = plchan->cfg.src_addr; + *slave_addr = plchan->cfg.src_addr; addr_width = plchan->cfg.src_addr_width; maxburst = plchan->cfg.src_maxburst; src_buses = plchan->cd->periph_buses; @@ -1601,24 +1603,107 @@ static struct dma_async_tx_descriptor *pl08x_prep_slave_sg( else txd->ccfg |= plchan->signal << PL080_CONFIG_SRC_SEL_SHIFT;
+ return txd; +} + +static int pl08x_tx_add_sg(struct pl08x_txd *txd, + enum dma_transfer_direction direction, + dma_addr_t slave_addr, + dma_addr_t buf_addr, + unsigned int len) +{ + struct pl08x_sg *dsg; + + dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT); + if (!dsg) + return -ENOMEM; + + list_add_tail(&dsg->node, &txd->dsg_list); + + dsg->len = len; + if (direction == DMA_MEM_TO_DEV) { + dsg->src_addr = buf_addr; + dsg->dst_addr = slave_addr; + } else { + dsg->src_addr = slave_addr; + dsg->dst_addr = buf_addr; + } + + return 0; +} + +static struct dma_async_tx_descriptor *pl08x_prep_slave_sg( + struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction direction, + unsigned long flags, void *context) +{ + struct pl08x_dma_chan *plchan = to_pl08x_chan(chan); + struct pl08x_driver_data *pl08x = plchan->host; + struct pl08x_txd *txd; + struct scatterlist *sg; + int ret, tmp; + dma_addr_t slave_addr; + + dev_dbg(&pl08x->adev->dev, "%s prepare transaction of %d bytes from %s\n", + __func__, sg_dma_len(sgl), plchan->name); + + txd = pl08x_init_txd(chan, direction, &slave_addr); + if (!txd) + return NULL; + for_each_sg(sgl, sg, sg_len, tmp) { - dsg = kzalloc(sizeof(struct pl08x_sg), GFP_NOWAIT); - if (!dsg) { + ret = pl08x_tx_add_sg(txd, direction, slave_addr, + sg_dma_address(sg), + sg_dma_len(sg)); + if (ret) { pl08x_release_mux(plchan); pl08x_free_txd(pl08x, txd); dev_err(&pl08x->adev->dev, "%s no mem for pl080 sg\n", __func__); return NULL; } - list_add_tail(&dsg->node, &txd->dsg_list); + }
- dsg->len = sg_dma_len(sg); - if (direction == DMA_MEM_TO_DEV) { - dsg->src_addr = sg_dma_address(sg); - dsg->dst_addr = slave_addr; - } else { - dsg->src_addr = slave_addr; - dsg->dst_addr = sg_dma_address(sg); + ret = pl08x_fill_llis_for_desc(plchan->host, txd); + if (!ret) { + pl08x_release_mux(plchan); + pl08x_free_txd(pl08x, txd); + return NULL; + } + + return vchan_tx_prep(&plchan->vc, &txd->vd, flags); +} + +static struct dma_async_tx_descriptor *pl08x_prep_dma_cyclic( + struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, + size_t period_len, enum dma_transfer_direction direction, + unsigned long flags, void *context) +{ + struct pl08x_dma_chan *plchan = to_pl08x_chan(chan); + struct pl08x_driver_data *pl08x = plchan->host; + struct pl08x_txd *txd; + int ret, tmp; + dma_addr_t slave_addr; + + dev_dbg(&pl08x->adev->dev, + "%s prepare cyclic transaction of %d/%d bytes %s %s\n", + __func__, period_len, buf_len, + direction == DMA_MEM_TO_DEV ? "to" : "from", + plchan->name); + + txd = pl08x_init_txd(chan, direction, &slave_addr); + if (!txd) + return NULL; + + txd->cyclic = true; + txd->cctl |= PL080_CONTROL_TC_IRQ_EN; + for (tmp = 0; tmp < buf_len; tmp += period_len) { + ret = pl08x_tx_add_sg(txd, direction, slave_addr, + buf_addr + tmp, period_len); + if (ret) { + pl08x_release_mux(plchan); + pl08x_free_txd(pl08x, txd); + return NULL; } }
@@ -1761,7 +1846,9 @@ static irqreturn_t pl08x_irq(int irq, void *dev)
spin_lock(&plchan->vc.lock); tx = plchan->at; - if (tx) { + if (tx && tx->cyclic) { + vchan_cyclic_callback(&tx->vd); + } else if (tx) { plchan->at = NULL; /* * This descriptor is done, release its mux @@ -1983,6 +2070,7 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
/* Initialize slave engine */ dma_cap_set(DMA_SLAVE, pl08x->slave.cap_mask); + dma_cap_set(DMA_CYCLIC, pl08x->slave.cap_mask); pl08x->slave.dev = &adev->dev; pl08x->slave.device_alloc_chan_resources = pl08x_alloc_chan_resources; pl08x->slave.device_free_chan_resources = pl08x_free_chan_resources; @@ -1990,6 +2078,7 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id) pl08x->slave.device_tx_status = pl08x_dma_tx_status; pl08x->slave.device_issue_pending = pl08x_issue_pending; pl08x->slave.device_prep_slave_sg = pl08x_prep_slave_sg; + pl08x->slave.device_prep_dma_cyclic = pl08x_prep_dma_cyclic; pl08x->slave.device_control = pl08x_control;
/* Get the platform data */