diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0398-dmaengine-bcm2835-add-slave_sg-support-to-bcm2835-dm.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0398-dmaengine-bcm2835-add-slave_sg-support-to-bcm2835-dm.patch | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0398-dmaengine-bcm2835-add-slave_sg-support-to-bcm2835-dm.patch b/target/linux/brcm2708/patches-4.4/0398-dmaengine-bcm2835-add-slave_sg-support-to-bcm2835-dm.patch new file mode 100644 index 0000000000..ef1b43357e --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0398-dmaengine-bcm2835-add-slave_sg-support-to-bcm2835-dm.patch @@ -0,0 +1,182 @@ +From 9026efd53eae4b320941e581f141ddc87f2adc20 Mon Sep 17 00:00:00 2001 +From: Martin Sperl <kernel@martin.sperl.org> +Date: Wed, 16 Mar 2016 12:25:01 -0700 +Subject: [PATCH] dmaengine: bcm2835: add slave_sg support to bcm2835-dma + +Add slave_sg support to bcm2835-dma using shared allocation +code for bcm2835_desc and DMA-control blocks already used by +dma_cyclic. + +Note that bcm2835_dma_callback had to get modified to support +both modes of operation (cyclic and non-cyclic). + +Tested using: +* Hifiberry I2S card (using cyclic DMA) +* fb_st7735r SPI-framebuffer (using slave_sg DMA via spi-bcm2835) +playing BigBuckBunny for audio and video. + +Signed-off-by: Martin Sperl <kernel@martin.sperl.org> +Reviewed-by: Eric Anholt <eric@anholt.net> +Signed-off-by: Eric Anholt <eric@anholt.net> +Signed-off-by: Vinod Koul <vinod.koul@intel.com> +--- + drivers/dma/bcm2835-dma.c | 113 ++++++++++++++++++++++++++++++++++++++++++++-- + 1 file changed, 108 insertions(+), 5 deletions(-) + +--- a/drivers/dma/bcm2835-dma.c ++++ b/drivers/dma/bcm2835-dma.c +@@ -260,6 +260,23 @@ static void bcm2835_dma_create_cb_set_le + control_block->info |= finalextrainfo; + } + ++static inline size_t bcm2835_dma_count_frames_for_sg( ++ struct bcm2835_chan *c, ++ struct scatterlist *sgl, ++ unsigned int sg_len) ++{ ++ size_t frames = 0; ++ struct scatterlist *sgent; ++ unsigned int i; ++ size_t plength = bcm2835_dma_max_frame_length(c); ++ ++ for_each_sg(sgl, sgent, sg_len, i) ++ frames += bcm2835_dma_frames_for_length( ++ sg_dma_len(sgent), plength); ++ ++ return frames; ++} ++ + /** + * bcm2835_dma_create_cb_chain - create a control block and fills data in + * +@@ -361,6 +378,32 @@ error_cb: + return NULL; + } + ++static void bcm2835_dma_fill_cb_chain_with_sg( ++ struct dma_chan *chan, ++ enum dma_transfer_direction direction, ++ struct bcm2835_cb_entry *cb, ++ struct scatterlist *sgl, ++ unsigned int sg_len) ++{ ++ struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); ++ size_t max_len = bcm2835_dma_max_frame_length(c); ++ unsigned int i, len; ++ dma_addr_t addr; ++ struct scatterlist *sgent; ++ ++ for_each_sg(sgl, sgent, sg_len, i) { ++ for (addr = sg_dma_address(sgent), len = sg_dma_len(sgent); ++ len > 0; ++ addr += cb->cb->length, len -= cb->cb->length, cb++) { ++ if (direction == DMA_DEV_TO_MEM) ++ cb->cb->dst = addr; ++ else ++ cb->cb->src = addr; ++ cb->cb->length = min(len, max_len); ++ } ++ } ++} ++ + static int bcm2835_dma_abort(void __iomem *chan_base) + { + unsigned long cs; +@@ -428,13 +471,19 @@ static irqreturn_t bcm2835_dma_callback( + d = c->desc; + + if (d) { +- /* TODO Only works for cyclic DMA */ +- vchan_cyclic_callback(&d->vd); ++ if (d->cyclic) { ++ /* call the cyclic callback */ ++ vchan_cyclic_callback(&d->vd); ++ ++ /* Keep the DMA engine running */ ++ writel(BCM2835_DMA_ACTIVE, ++ c->chan_base + BCM2835_DMA_CS); ++ } else { ++ vchan_cookie_complete(&c->desc->vd); ++ bcm2835_dma_start_desc(c); ++ } + } + +- /* Keep the DMA engine running */ +- writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS); +- + spin_unlock_irqrestore(&c->vc.lock, flags); + + return IRQ_HANDLED; +@@ -548,6 +597,58 @@ static void bcm2835_dma_issue_pending(st + spin_unlock_irqrestore(&c->vc.lock, flags); + } + ++static struct dma_async_tx_descriptor *bcm2835_dma_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 bcm2835_chan *c = to_bcm2835_dma_chan(chan); ++ struct bcm2835_desc *d; ++ dma_addr_t src = 0, dst = 0; ++ u32 info = BCM2835_DMA_WAIT_RESP; ++ u32 extra = BCM2835_DMA_INT_EN; ++ size_t frames; ++ ++ if (!is_slave_direction(direction)) { ++ dev_err(chan->device->dev, ++ "%s: bad direction?\n", __func__); ++ return NULL; ++ } ++ ++ if (c->dreq != 0) ++ info |= BCM2835_DMA_PER_MAP(c->dreq); ++ ++ if (direction == DMA_DEV_TO_MEM) { ++ if (c->cfg.src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ++ return NULL; ++ src = c->cfg.src_addr; ++ info |= BCM2835_DMA_S_DREQ | BCM2835_DMA_D_INC; ++ } else { ++ if (c->cfg.dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ++ return NULL; ++ dst = c->cfg.dst_addr; ++ info |= BCM2835_DMA_D_DREQ | BCM2835_DMA_S_INC; ++ } ++ ++ /* count frames in sg list */ ++ frames = bcm2835_dma_count_frames_for_sg(c, sgl, sg_len); ++ ++ /* allocate the CB chain */ ++ d = bcm2835_dma_create_cb_chain(chan, direction, false, ++ info, extra, ++ frames, src, dst, 0, 0, ++ GFP_KERNEL); ++ if (!d) ++ return NULL; ++ ++ /* fill in frames with scatterlist pointers */ ++ bcm2835_dma_fill_cb_chain_with_sg(chan, direction, d->cb_list, ++ sgl, sg_len); ++ ++ return vchan_tx_prep(&c->vc, &d->vd, flags); ++} ++ + static struct dma_async_tx_descriptor *bcm2835_dma_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, +@@ -778,11 +879,13 @@ static int bcm2835_dma_probe(struct plat + dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); + dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask); + dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask); ++ dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); + od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources; + od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources; + od->ddev.device_tx_status = bcm2835_dma_tx_status; + od->ddev.device_issue_pending = bcm2835_dma_issue_pending; + od->ddev.device_prep_dma_cyclic = bcm2835_dma_prep_dma_cyclic; ++ od->ddev.device_prep_slave_sg = bcm2835_dma_prep_slave_sg; + od->ddev.device_config = bcm2835_dma_slave_config; + od->ddev.device_terminate_all = bcm2835_dma_terminate_all; + od->ddev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); |