diff options
| -rw-r--r-- | drivers/dma/xilinx/xilinx_vdma.c | 178 |
1 files changed, 173 insertions, 5 deletions
diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c index df9118540b91..3edd4544478a 100644 --- a/drivers/dma/xilinx/xilinx_vdma.c +++ b/drivers/dma/xilinx/xilinx_vdma.c @@ -157,6 +157,7 @@ /* AXI DMA Specific Masks/Bit fields */ #define XILINX_DMA_MAX_TRANS_LEN GENMASK(22, 0) #define XILINX_DMA_CR_COALESCE_MAX GENMASK(23, 16) +#define XILINX_DMA_CR_CYCLIC_BD_EN_MASK BIT(4) #define XILINX_DMA_CR_COALESCE_SHIFT 16 #define XILINX_DMA_BD_SOP BIT(27) #define XILINX_DMA_BD_EOP BIT(26) @@ -278,11 +279,13 @@ struct xilinx_cdma_tx_segment { * @async_tx: Async transaction descriptor * @segments: TX segments list * @node: Node in the channel descriptors list + * @cyclic: Check for cyclic transfers. */ struct xilinx_dma_tx_descriptor { struct dma_async_tx_descriptor async_tx; struct list_head segments; struct list_head node; + bool cyclic; }; /** @@ -302,6 +305,7 @@ struct xilinx_dma_tx_descriptor { * @direction: Transfer direction * @num_frms: Number of frames * @has_sg: Support scatter transfers + * @cyclic: Check for cyclic transfers. * @genlock: Support genlock mode * @err: Channel has errors * @tasklet: Cleanup work after irq @@ -312,6 +316,7 @@ struct xilinx_dma_tx_descriptor { * @desc_submitcount: Descriptor h/w submitted count * @residue: Residue for AXI DMA * @seg_v: Statically allocated segments base + * @cyclic_seg_v: Statically allocated segment base for cyclic transfers * @start_transfer: Differentiate b/w DMA IP's transfer */ struct xilinx_dma_chan { @@ -330,6 +335,7 @@ struct xilinx_dma_chan { enum dma_transfer_direction direction; int num_frms; bool has_sg; + bool cyclic; bool genlock; bool err; struct tasklet_struct tasklet; @@ -340,6 +346,7 @@ struct xilinx_dma_chan { u32 desc_submitcount; u32 residue; struct xilinx_axidma_tx_segment *seg_v; + struct xilinx_axidma_tx_segment *cyclic_seg_v; void (*start_transfer)(struct xilinx_dma_chan *chan); }; @@ -660,13 +667,37 @@ static void xilinx_dma_free_chan_resources(struct dma_chan *dchan) dev_dbg(chan->dev, "Free all channel resources.\n"); xilinx_dma_free_descriptors(chan); - if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) + if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) { + xilinx_dma_free_tx_segment(chan, chan->cyclic_seg_v); xilinx_dma_free_tx_segment(chan, chan->seg_v); + } dma_pool_destroy(chan->desc_pool); chan->desc_pool = NULL; } /** + * xilinx_dma_chan_handle_cyclic - Cyclic dma callback + * @chan: Driver specific dma channel + * @desc: dma transaction descriptor + * @flags: flags for spin lock + */ +static void xilinx_dma_chan_handle_cyclic(struct xilinx_dma_chan *chan, + struct xilinx_dma_tx_descriptor *desc, + unsigned long *flags) +{ + dma_async_tx_callback callback; + void *callback_param; + + callback = desc->async_tx.callback; + callback_param = desc->async_tx.callback_param; + if (callback) { + spin_unlock_irqrestore(&chan->lock, *flags); + callback(callback_param); + spin_lock_irqsave(&chan->lock, *flags); + } +} + +/** * xilinx_dma_chan_desc_cleanup - Clean channel descriptors * @chan: Driver specific DMA channel */ @@ -681,6 +712,11 @@ static void xilinx_dma_chan_desc_cleanup(struct xilinx_dma_chan *chan) dma_async_tx_callback callback; void *callback_param; + if (desc->cyclic) { + xilinx_dma_chan_handle_cyclic(chan, desc, &flags); + break; + } + /* Remove from the list of running transactions */ list_del(&desc->node); @@ -757,7 +793,7 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan) return -ENOMEM; } - if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) + if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) { /* * For AXI DMA case after submitting a pending_list, keep * an extra segment allocated so that the "next descriptor" @@ -768,6 +804,15 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan) */ chan->seg_v = xilinx_axidma_alloc_tx_segment(chan); + /* + * For cyclic DMA mode we need to program the tail Descriptor + * register with a value which is not a part of the BD chain + * so allocating a desc segment during channel allocation for + * programming tail descriptor. + */ + chan->cyclic_seg_v = xilinx_axidma_alloc_tx_segment(chan); + } + dma_cookie_init(dchan); if (chan->xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) { @@ -1157,8 +1202,12 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan) /* Start the transfer */ if (chan->has_sg) { - dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC, - tail_segment->phys); + if (chan->cyclic) + dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC, + chan->cyclic_seg_v->phys); + else + dma_ctrl_write(chan, XILINX_DMA_REG_TAILDESC, + tail_segment->phys); } else { struct xilinx_axidma_tx_segment *segment; struct xilinx_axidma_desc_hw *hw; @@ -1209,7 +1258,8 @@ static void xilinx_dma_complete_descriptor(struct xilinx_dma_chan *chan) list_for_each_entry_safe(desc, next, &chan->active_list, node) { list_del(&desc->node); - dma_cookie_complete(&desc->async_tx); + if (!desc->cyclic) + dma_cookie_complete(&desc->async_tx); list_add_tail(&desc->node, &chan->done_list); } } @@ -1397,6 +1447,11 @@ static dma_cookie_t xilinx_dma_tx_submit(struct dma_async_tx_descriptor *tx) unsigned long flags; int err; + if (chan->cyclic) { + xilinx_dma_free_tx_descriptor(chan, desc); + return -EBUSY; + } + if (chan->err) { /* * If reset fails, need to hard reset the system. @@ -1414,6 +1469,9 @@ static dma_cookie_t xilinx_dma_tx_submit(struct dma_async_tx_descriptor *tx) /* Put this transaction onto the tail of the pending queue */ append_desc_queue(chan, desc); + if (desc->cyclic) + chan->cyclic = true; + spin_unlock_irqrestore(&chan->lock, flags); return cookie; @@ -1669,12 +1727,112 @@ error: } /** + * xilinx_dma_prep_dma_cyclic - prepare descriptors for a DMA_SLAVE transaction + * @chan: DMA channel + * @sgl: scatterlist to transfer to/from + * @sg_len: number of entries in @scatterlist + * @direction: DMA direction + * @flags: transfer ack flags + */ +static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic( + struct dma_chan *dchan, dma_addr_t buf_addr, size_t buf_len, + size_t period_len, enum dma_transfer_direction direction, + unsigned long flags) +{ + struct xilinx_dma_chan *chan = to_xilinx_chan(dchan); + struct xilinx_dma_tx_descriptor *desc; + struct xilinx_axidma_tx_segment *segment, *head_segment, *prev = NULL; + size_t copy, sg_used; + unsigned int num_periods; + int i; + u32 reg; + + num_periods = buf_len / period_len; + + if (!is_slave_direction(direction)) + return NULL; + + /* Allocate a transaction descriptor. */ + desc = xilinx_dma_alloc_tx_descriptor(chan); + if (!desc) + return NULL; + + chan->direction = direction; + dma_async_tx_descriptor_init(&desc->async_tx, &chan->common); + desc->async_tx.tx_submit = xilinx_dma_tx_submit; + + for (i = 0; i < num_periods; ++i) { + sg_used = 0; + + while (sg_used < period_len) { + struct xilinx_axidma_desc_hw *hw; + + /* Get a free segment */ + segment = xilinx_axidma_alloc_tx_segment(chan); + if (!segment) + goto error; + + /* + * Calculate the maximum number of bytes to transfer, + * making sure it is less than the hw limit + */ + copy = min_t(size_t, period_len - sg_used, + XILINX_DMA_MAX_TRANS_LEN); + hw = &segment->hw; + hw->buf_addr = buf_addr + sg_used + (period_len * i); + hw->control = copy; + + if (prev) + prev->hw.next_desc = segment->phys; + + prev = segment; + sg_used += copy; + + /* + * Insert the segment into the descriptor segments + * list. + */ + list_add_tail(&segment->node, &desc->segments); + } + } + + head_segment = list_first_entry(&desc->segments, + struct xilinx_axidma_tx_segment, node); + desc->async_tx.phys = head_segment->phys; + + desc->cyclic = true; + reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR); + reg |= XILINX_DMA_CR_CYCLIC_BD_EN_MASK; + dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg); + + /* For the last DMA_MEM_TO_DEV transfer, set EOP */ + if (direction == DMA_MEM_TO_DEV) { + segment->hw.control |= XILINX_DMA_BD_SOP; + segment = list_last_entry(&desc->segments, + struct xilinx_axidma_tx_segment, + node); + segment->hw.control |= XILINX_DMA_BD_EOP; + segment->hw.next_desc = (u32) head_segment->phys; + } + + return &desc->async_tx; + +error: + xilinx_dma_free_tx_descriptor(chan, desc); + return NULL; +} + +/** * xilinx_dma_terminate_all - Halt the channel and free descriptors * @chan: Driver specific DMA Channel pointer */ static int xilinx_dma_terminate_all(struct dma_chan *dchan) { struct xilinx_dma_chan *chan = to_xilinx_chan(dchan); + u32 reg; + + if (chan->cyclic) + xilinx_dma_chan_reset(chan); /* Halt the DMA engine */ xilinx_dma_halt(chan); @@ -1682,6 +1840,13 @@ static int xilinx_dma_terminate_all(struct dma_chan *dchan) /* Remove and free all of the descriptors in the lists */ xilinx_dma_free_descriptors(chan); + if (chan->cyclic) { + reg = dma_ctrl_read(chan, XILINX_DMA_REG_DMACR); + reg &= ~XILINX_DMA_CR_CYCLIC_BD_EN_MASK; + dma_ctrl_write(chan, XILINX_DMA_REG_DMACR, reg); + chan->cyclic = false; + } + return 0; } @@ -2218,7 +2383,10 @@ static int xilinx_dma_probe(struct platform_device *pdev) xdev->common.device_tx_status = xilinx_dma_tx_status; xdev->common.device_issue_pending = xilinx_dma_issue_pending; if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA) { + dma_cap_set(DMA_CYCLIC, xdev->common.cap_mask); xdev->common.device_prep_slave_sg = xilinx_dma_prep_slave_sg; + xdev->common.device_prep_dma_cyclic = + xilinx_dma_prep_dma_cyclic; /* Residue calculation is supported by only AXI DMA */ xdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT; 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