From dfbb85cab5f0819d0424a3637b03e7892704fa42 Mon Sep 17 00:00:00 2001 From: Kuninori Morimoto Date: Wed, 2 Apr 2014 20:17:00 -0700 Subject: [PATCH] DMA: shdma: add cyclic transfer support This patch add cyclic transfer support and enables dmaengine_prep_dma_cyclic() Signed-off-by: Kuninori Morimoto [reflown changelog for readablity] Signed-off-by: Vinod Koul --- drivers/dma/sh/shdma-base.c | 72 +++++++++++++++++++++++++++++++++---- include/linux/shdma-base.h | 1 + 2 files changed, 66 insertions(+), 7 deletions(-) diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c index 6786ecbd5ed4..974794cdb6ed 100644 --- a/drivers/dma/sh/shdma-base.c +++ b/drivers/dma/sh/shdma-base.c @@ -304,6 +304,7 @@ static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all) dma_async_tx_callback callback = NULL; void *param = NULL; unsigned long flags; + LIST_HEAD(cyclic_list); spin_lock_irqsave(&schan->chan_lock, flags); list_for_each_entry_safe(desc, _desc, &schan->ld_queue, node) { @@ -369,10 +370,16 @@ static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all) if (((desc->mark == DESC_COMPLETED || desc->mark == DESC_WAITING) && async_tx_test_ack(&desc->async_tx)) || all) { - /* Remove from ld_queue list */ - desc->mark = DESC_IDLE; - list_move(&desc->node, &schan->ld_free); + if (all || !desc->cyclic) { + /* Remove from ld_queue list */ + desc->mark = DESC_IDLE; + list_move(&desc->node, &schan->ld_free); + } else { + /* reuse as cyclic */ + desc->mark = DESC_SUBMITTED; + list_move_tail(&desc->node, &cyclic_list); + } if (list_empty(&schan->ld_queue)) { dev_dbg(schan->dev, "Bring down channel %d\n", schan->id); @@ -389,6 +396,8 @@ static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all) */ schan->dma_chan.completed_cookie = schan->dma_chan.cookie; + list_splice_tail(&cyclic_list, &schan->ld_queue); + spin_unlock_irqrestore(&schan->chan_lock, flags); if (callback) @@ -521,7 +530,7 @@ static struct shdma_desc *shdma_add_desc(struct shdma_chan *schan, */ static struct dma_async_tx_descriptor *shdma_prep_sg(struct shdma_chan *schan, struct scatterlist *sgl, unsigned int sg_len, dma_addr_t *addr, - enum dma_transfer_direction direction, unsigned long flags) + enum dma_transfer_direction direction, unsigned long flags, bool cyclic) { struct scatterlist *sg; struct shdma_desc *first = NULL, *new = NULL /* compiler... */; @@ -569,7 +578,11 @@ static struct dma_async_tx_descriptor *shdma_prep_sg(struct shdma_chan *schan, if (!new) goto err_get_desc; - new->chunks = chunks--; + new->cyclic = cyclic; + if (cyclic) + new->chunks = 1; + else + new->chunks = chunks--; list_add_tail(&new->node, &tx_list); } while (len); } @@ -612,7 +625,8 @@ static struct dma_async_tx_descriptor *shdma_prep_memcpy( sg_dma_address(&sg) = dma_src; sg_dma_len(&sg) = len; - return shdma_prep_sg(schan, &sg, 1, &dma_dest, DMA_MEM_TO_MEM, flags); + return shdma_prep_sg(schan, &sg, 1, &dma_dest, DMA_MEM_TO_MEM, + flags, false); } static struct dma_async_tx_descriptor *shdma_prep_slave_sg( @@ -640,7 +654,50 @@ static struct dma_async_tx_descriptor *shdma_prep_slave_sg( slave_addr = ops->slave_addr(schan); return shdma_prep_sg(schan, sgl, sg_len, &slave_addr, - direction, flags); + direction, flags, false); +} + +struct dma_async_tx_descriptor *shdma_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 shdma_chan *schan = to_shdma_chan(chan); + struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); + const struct shdma_ops *ops = sdev->ops; + unsigned int sg_len = buf_len / period_len; + int slave_id = schan->slave_id; + dma_addr_t slave_addr; + struct scatterlist sgl[sg_len]; + int i; + + if (!chan) + return NULL; + + BUG_ON(!schan->desc_num); + + /* Someone calling slave DMA on a generic channel? */ + if (slave_id < 0 || (buf_len < period_len)) { + dev_warn(schan->dev, + "%s: bad parameter: buf_len=%d, period_len=%d, id=%d\n", + __func__, buf_len, period_len, slave_id); + return NULL; + } + + slave_addr = ops->slave_addr(schan); + + sg_init_table(sgl, sg_len); + for (i = 0; i < sg_len; i++) { + dma_addr_t src = buf_addr + (period_len * i); + + sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len, + offset_in_page(src)); + sg_dma_address(&sgl[i]) = src; + sg_dma_len(&sgl[i]) = period_len; + } + + return shdma_prep_sg(schan, sgl, sg_len, &slave_addr, + direction, flags, true); } static int shdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, @@ -915,6 +972,7 @@ int shdma_init(struct device *dev, struct shdma_dev *sdev, /* Compulsory for DMA_SLAVE fields */ dma_dev->device_prep_slave_sg = shdma_prep_slave_sg; + dma_dev->device_prep_dma_cyclic = shdma_prep_dma_cyclic; dma_dev->device_control = shdma_control; dma_dev->dev = dev; diff --git a/include/linux/shdma-base.h b/include/linux/shdma-base.h index f92c0a43c54c..abdf1f229dc3 100644 --- a/include/linux/shdma-base.h +++ b/include/linux/shdma-base.h @@ -54,6 +54,7 @@ struct shdma_desc { dma_cookie_t cookie; int chunks; int mark; + bool cyclic; /* used as cyclic transfer */ }; struct shdma_chan { -- 2.20.1