From 3a774ea91a5d05e7af58db6ae1ba298263c4a3d3 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 21 Jun 2012 10:40:15 +0100 Subject: dmaengine: omap: add support for cyclic DMA Add support for cyclic DMA to the OMAP DMA engine driver. Signed-off-by: Russell King --- drivers/dma/omap-dma.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 89 insertions(+), 4 deletions(-) diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c index f2e919fcea3..ae056182613 100644 --- a/drivers/dma/omap-dma.c +++ b/drivers/dma/omap-dma.c @@ -33,6 +33,7 @@ struct omap_chan { struct dma_slave_config cfg; unsigned dma_sig; + bool cyclic; int dma_ch; struct omap_desc *desc; @@ -138,11 +139,15 @@ static void omap_dma_callback(int ch, u16 status, void *data) spin_lock_irqsave(&c->vc.lock, flags); d = c->desc; if (d) { - if (++c->sgidx < d->sglen) { - omap_dma_start_sg(c, d, c->sgidx); + if (!c->cyclic) { + if (++c->sgidx < d->sglen) { + omap_dma_start_sg(c, d, c->sgidx); + } else { + omap_dma_start_desc(c); + vchan_cookie_complete(&d->vd); + } } else { - omap_dma_start_desc(c); - vchan_cookie_complete(&d->vd); + vchan_cyclic_callback(&d->vd); } } spin_unlock_irqrestore(&c->vc.lock, flags); @@ -358,6 +363,79 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg( return vchan_tx_prep(&c->vc, &d->vd, tx_flags); } +static struct dma_async_tx_descriptor *omap_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 dir, void *context) +{ + struct omap_chan *c = to_omap_dma_chan(chan); + enum dma_slave_buswidth dev_width; + struct omap_desc *d; + dma_addr_t dev_addr; + unsigned es, sync_type; + u32 burst; + + if (dir == DMA_DEV_TO_MEM) { + dev_addr = c->cfg.src_addr; + dev_width = c->cfg.src_addr_width; + burst = c->cfg.src_maxburst; + sync_type = OMAP_DMA_SRC_SYNC; + } else if (dir == DMA_MEM_TO_DEV) { + dev_addr = c->cfg.dst_addr; + dev_width = c->cfg.dst_addr_width; + burst = c->cfg.dst_maxburst; + sync_type = OMAP_DMA_DST_SYNC; + } else { + dev_err(chan->device->dev, "%s: bad direction?\n", __func__); + return NULL; + } + + /* Bus width translates to the element size (ES) */ + switch (dev_width) { + case DMA_SLAVE_BUSWIDTH_1_BYTE: + es = OMAP_DMA_DATA_TYPE_S8; + break; + case DMA_SLAVE_BUSWIDTH_2_BYTES: + es = OMAP_DMA_DATA_TYPE_S16; + break; + case DMA_SLAVE_BUSWIDTH_4_BYTES: + es = OMAP_DMA_DATA_TYPE_S32; + break; + default: /* not reached */ + return NULL; + } + + /* Now allocate and setup the descriptor. */ + d = kzalloc(sizeof(*d) + sizeof(d->sg[0]), GFP_ATOMIC); + if (!d) + return NULL; + + d->dir = dir; + d->dev_addr = dev_addr; + d->fi = burst; + d->es = es; + d->sync_mode = OMAP_DMA_SYNC_PACKET; + d->sync_type = sync_type; + d->periph_port = OMAP_DMA_PORT_MPUI; + d->sg[0].addr = buf_addr; + d->sg[0].en = period_len / es_bytes[es]; + d->sg[0].fn = buf_len / period_len; + d->sglen = 1; + + if (!c->cyclic) { + c->cyclic = true; + omap_dma_link_lch(c->dma_ch, c->dma_ch); + omap_enable_dma_irq(c->dma_ch, OMAP_DMA_FRAME_IRQ); + omap_disable_dma_irq(c->dma_ch, OMAP_DMA_BLOCK_IRQ); + } + + if (!cpu_class_is_omap1()) { + omap_set_dma_src_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16); + omap_set_dma_dest_burst_mode(c->dma_ch, OMAP_DMA_DATA_BURST_16); + } + + return vchan_tx_prep(&c->vc, &d->vd, DMA_CTRL_ACK | DMA_PREP_INTERRUPT); +} + static int omap_dma_slave_config(struct omap_chan *c, struct dma_slave_config *cfg) { if (cfg->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES || @@ -392,6 +470,11 @@ static int omap_dma_terminate_all(struct omap_chan *c) omap_stop_dma(c->dma_ch); } + if (c->cyclic) { + c->cyclic = false; + omap_dma_unlink_lch(c->dma_ch, c->dma_ch); + } + vchan_get_all_descriptors(&c->vc, &head); spin_unlock_irqrestore(&c->vc.lock, flags); vchan_dma_desc_free_list(&c->vc, &head); @@ -484,11 +567,13 @@ static int omap_dma_probe(struct platform_device *pdev) return -ENOMEM; dma_cap_set(DMA_SLAVE, od->ddev.cap_mask); + dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask); od->ddev.device_alloc_chan_resources = omap_dma_alloc_chan_resources; od->ddev.device_free_chan_resources = omap_dma_free_chan_resources; od->ddev.device_tx_status = omap_dma_tx_status; od->ddev.device_issue_pending = omap_dma_issue_pending; od->ddev.device_prep_slave_sg = omap_dma_prep_slave_sg; + od->ddev.device_prep_dma_cyclic = omap_dma_prep_dma_cyclic; od->ddev.device_control = omap_dma_control; od->ddev.dev = &pdev->dev; INIT_LIST_HEAD(&od->ddev.channels); -- cgit v1.2.3