diff options
| -rw-r--r-- | drivers/dma/bcm2835-dma.c | 78 |
1 files changed, 54 insertions, 24 deletions
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index c92d6a70ccf3..996c4b00d323 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -31,6 +31,7 @@ */ #include <linux/dmaengine.h> #include <linux/dma-mapping.h> +#include <linux/dmapool.h> #include <linux/err.h> #include <linux/init.h> #include <linux/interrupt.h> @@ -62,6 +63,11 @@ struct bcm2835_dma_cb { uint32_t pad[2]; }; +struct bcm2835_cb_entry { + struct bcm2835_dma_cb *cb; + dma_addr_t paddr; +}; + struct bcm2835_chan { struct virt_dma_chan vc; struct list_head node; @@ -72,18 +78,18 @@ struct bcm2835_chan { int ch; struct bcm2835_desc *desc; + struct dma_pool *cb_pool; void __iomem *chan_base; int irq_number; }; struct bcm2835_desc { + struct bcm2835_chan *c; struct virt_dma_desc vd; enum dma_transfer_direction dir; - unsigned int control_block_size; - struct bcm2835_dma_cb *control_block_base; - dma_addr_t control_block_base_phys; + struct bcm2835_cb_entry *cb_list; unsigned int frames; size_t size; @@ -143,10 +149,13 @@ static inline struct bcm2835_desc *to_bcm2835_dma_desc( static void bcm2835_dma_desc_free(struct virt_dma_desc *vd) { struct bcm2835_desc *desc = container_of(vd, struct bcm2835_desc, vd); - dma_free_coherent(desc->vd.tx.chan->device->dev, - desc->control_block_size, - desc->control_block_base, - desc->control_block_base_phys); + int i; + + for (i = 0; i < desc->frames; i++) + dma_pool_free(desc->c->cb_pool, desc->cb_list[i].cb, + desc->cb_list[i].paddr); + + kfree(desc->cb_list); kfree(desc); } @@ -199,7 +208,7 @@ static void bcm2835_dma_start_desc(struct bcm2835_chan *c) c->desc = d = to_bcm2835_dma_desc(&vd->tx); - writel(d->control_block_base_phys, c->chan_base + BCM2835_DMA_ADDR); + writel(d->cb_list[0].paddr, c->chan_base + BCM2835_DMA_ADDR); writel(BCM2835_DMA_ACTIVE, c->chan_base + BCM2835_DMA_CS); } @@ -232,9 +241,16 @@ static irqreturn_t bcm2835_dma_callback(int irq, void *data) static int bcm2835_dma_alloc_chan_resources(struct dma_chan *chan) { struct bcm2835_chan *c = to_bcm2835_dma_chan(chan); + struct device *dev = c->vc.chan.device->dev; + + dev_dbg(dev, "Allocating DMA channel %d\n", c->ch); - dev_dbg(c->vc.chan.device->dev, - "Allocating DMA channel %d\n", c->ch); + c->cb_pool = dma_pool_create(dev_name(dev), dev, + sizeof(struct bcm2835_dma_cb), 0, 0); + if (!c->cb_pool) { + dev_err(dev, "unable to allocate descriptor pool\n"); + return -ENOMEM; + } return request_irq(c->irq_number, bcm2835_dma_callback, 0, "DMA IRQ", c); @@ -246,6 +262,7 @@ static void bcm2835_dma_free_chan_resources(struct dma_chan *chan) vchan_free_chan_resources(&c->vc); free_irq(c->irq_number, c); + dma_pool_destroy(c->cb_pool); dev_dbg(c->vc.chan.device->dev, "Freeing DMA channel %u\n", c->ch); } @@ -261,8 +278,7 @@ static size_t bcm2835_dma_desc_size_pos(struct bcm2835_desc *d, dma_addr_t addr) size_t size; for (size = i = 0; i < d->frames; i++) { - struct bcm2835_dma_cb *control_block = - &d->control_block_base[i]; + struct bcm2835_dma_cb *control_block = d->cb_list[i].cb; size_t this_size = control_block->length; dma_addr_t dma; @@ -343,6 +359,7 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( dma_addr_t dev_addr; unsigned int es, sync_type; unsigned int frame; + int i; /* Grab configuration */ if (!is_slave_direction(direction)) { @@ -374,27 +391,31 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( if (!d) return NULL; + d->c = c; d->dir = direction; d->frames = buf_len / period_len; - /* Allocate memory for control blocks */ - d->control_block_size = d->frames * sizeof(struct bcm2835_dma_cb); - d->control_block_base = dma_zalloc_coherent(chan->device->dev, - d->control_block_size, &d->control_block_base_phys, - GFP_NOWAIT); - - if (!d->control_block_base) { + d->cb_list = kcalloc(d->frames, sizeof(*d->cb_list), GFP_KERNEL); + if (!d->cb_list) { kfree(d); return NULL; } + /* Allocate memory for control blocks */ + for (i = 0; i < d->frames; i++) { + struct bcm2835_cb_entry *cb_entry = &d->cb_list[i]; + + cb_entry->cb = dma_pool_zalloc(c->cb_pool, GFP_ATOMIC, + &cb_entry->paddr); + if (!cb_entry->cb) + goto error_cb; + } /* * Iterate over all frames, create a control block * for each frame and link them together. */ for (frame = 0; frame < d->frames; frame++) { - struct bcm2835_dma_cb *control_block = - &d->control_block_base[frame]; + struct bcm2835_dma_cb *control_block = d->cb_list[frame].cb; /* Setup adresses */ if (d->dir == DMA_DEV_TO_MEM) { @@ -428,12 +449,21 @@ static struct dma_async_tx_descriptor *bcm2835_dma_prep_dma_cyclic( * This DMA engine driver currently only supports cyclic DMA. * Therefore, wrap around at number of frames. */ - control_block->next = d->control_block_base_phys + - sizeof(struct bcm2835_dma_cb) - * ((frame + 1) % d->frames); + control_block->next = d->cb_list[((frame + 1) % d->frames)].paddr; } return vchan_tx_prep(&c->vc, &d->vd, flags); +error_cb: + i--; + for (; i >= 0; i--) { + struct bcm2835_cb_entry *cb_entry = &d->cb_list[i]; + + dma_pool_free(c->cb_pool, cb_entry->cb, cb_entry->paddr); + } + + kfree(d->cb_list); + kfree(d); + return NULL; } static int bcm2835_dma_slave_config(struct dma_chan *chan, |