diff options
author | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-09-24 21:22:33 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-09-24 21:22:33 +0100 |
commit | baea7b946f00a291b166ccae7fcfed6c01530cc6 (patch) | |
tree | 4aa275fbdbec9c7b9b4629e8bee2bbecd3c6a6af /drivers/dma/fsldma.c | |
parent | ae19ffbadc1b2100285a5b5b3d0a4e0a11390904 (diff) | |
parent | 94e0fb086fc5663c38bbc0fe86d698be8314f82f (diff) |
Merge branch 'origin' into for-linus
Conflicts:
MAINTAINERS
Diffstat (limited to 'drivers/dma/fsldma.c')
-rw-r--r-- | drivers/dma/fsldma.c | 288 |
1 files changed, 265 insertions, 23 deletions
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index ef87a898414..296f9e747fa 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -34,6 +34,7 @@ #include <linux/dmapool.h> #include <linux/of_platform.h> +#include <asm/fsldma.h> #include "fsldma.h" static void dma_init(struct fsl_dma_chan *fsl_chan) @@ -280,28 +281,40 @@ static void fsl_chan_set_dest_loop_size(struct fsl_dma_chan *fsl_chan, int size) } /** - * fsl_chan_toggle_ext_pause - Toggle channel external pause status + * fsl_chan_set_request_count - Set DMA Request Count for external control * @fsl_chan : Freescale DMA channel - * @size : Pause control size, 0 for disable external pause control. - * The maximum is 1024. + * @size : Number of bytes to transfer in a single request + * + * The Freescale DMA channel can be controlled by the external signal DREQ#. + * The DMA request count is how many bytes are allowed to transfer before + * pausing the channel, after which a new assertion of DREQ# resumes channel + * operation. * - * The Freescale DMA channel can be controlled by the external - * signal DREQ#. The pause control size is how many bytes are allowed - * to transfer before pausing the channel, after which a new assertion - * of DREQ# resumes channel operation. + * A size of 0 disables external pause control. The maximum size is 1024. */ -static void fsl_chan_toggle_ext_pause(struct fsl_dma_chan *fsl_chan, int size) +static void fsl_chan_set_request_count(struct fsl_dma_chan *fsl_chan, int size) { - if (size > 1024) - return; + BUG_ON(size > 1024); + DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, + DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) + | ((__ilog2(size) << 24) & 0x0f000000), + 32); +} - if (size) { - DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, - DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) - | ((__ilog2(size) << 24) & 0x0f000000), - 32); +/** + * fsl_chan_toggle_ext_pause - Toggle channel external pause status + * @fsl_chan : Freescale DMA channel + * @enable : 0 is disabled, 1 is enabled. + * + * The Freescale DMA channel can be controlled by the external signal DREQ#. + * The DMA Request Count feature should be used in addition to this feature + * to set the number of bytes to transfer before pausing the channel. + */ +static void fsl_chan_toggle_ext_pause(struct fsl_dma_chan *fsl_chan, int enable) +{ + if (enable) fsl_chan->feature |= FSL_DMA_CHAN_PAUSE_EXT; - } else + else fsl_chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT; } @@ -326,7 +339,8 @@ static void fsl_chan_toggle_ext_start(struct fsl_dma_chan *fsl_chan, int enable) static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) { struct fsl_dma_chan *fsl_chan = to_fsl_chan(tx->chan); - struct fsl_desc_sw *desc; + struct fsl_desc_sw *desc = tx_to_fsl_desc(tx); + struct fsl_desc_sw *child; unsigned long flags; dma_cookie_t cookie; @@ -334,7 +348,7 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) spin_lock_irqsave(&fsl_chan->desc_lock, flags); cookie = fsl_chan->common.cookie; - list_for_each_entry(desc, &tx->tx_list, node) { + list_for_each_entry(child, &desc->tx_list, node) { cookie++; if (cookie < 0) cookie = 1; @@ -343,8 +357,8 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) } fsl_chan->common.cookie = cookie; - append_ld_queue(fsl_chan, tx_to_fsl_desc(tx)); - list_splice_init(&tx->tx_list, fsl_chan->ld_queue.prev); + append_ld_queue(fsl_chan, desc); + list_splice_init(&desc->tx_list, fsl_chan->ld_queue.prev); spin_unlock_irqrestore(&fsl_chan->desc_lock, flags); @@ -366,6 +380,7 @@ static struct fsl_desc_sw *fsl_dma_alloc_descriptor( desc_sw = dma_pool_alloc(fsl_chan->desc_pool, GFP_ATOMIC, &pdesc); if (desc_sw) { memset(desc_sw, 0, sizeof(struct fsl_desc_sw)); + INIT_LIST_HEAD(&desc_sw->tx_list); dma_async_tx_descriptor_init(&desc_sw->async_tx, &fsl_chan->common); desc_sw->async_tx.tx_submit = fsl_dma_tx_submit; @@ -455,7 +470,7 @@ fsl_dma_prep_interrupt(struct dma_chan *chan, unsigned long flags) new->async_tx.flags = flags; /* Insert the link descriptor to the LD ring */ - list_add_tail(&new->node, &new->async_tx.tx_list); + list_add_tail(&new->node, &new->tx_list); /* Set End-of-link to the last link descriptor of new list*/ set_ld_eol(fsl_chan, new); @@ -513,7 +528,7 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy( dma_dest += copy; /* Insert the link descriptor to the LD ring */ - list_add_tail(&new->node, &first->async_tx.tx_list); + list_add_tail(&new->node, &first->tx_list); } while (len); new->async_tx.flags = flags; /* client is in control of this ack */ @@ -528,7 +543,7 @@ fail: if (!first) return NULL; - list = &first->async_tx.tx_list; + list = &first->tx_list; list_for_each_entry_safe_reverse(new, prev, list, node) { list_del(&new->node); dma_pool_free(fsl_chan->desc_pool, new, new->async_tx.phys); @@ -538,6 +553,229 @@ fail: } /** + * fsl_dma_prep_slave_sg - 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: DMAEngine flags + * + * Prepare a set of descriptors for a DMA_SLAVE transaction. Following the + * DMA_SLAVE API, this gets the device-specific information from the + * chan->private variable. + */ +static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg( + struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, + enum dma_data_direction direction, unsigned long flags) +{ + struct fsl_dma_chan *fsl_chan; + struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL; + struct fsl_dma_slave *slave; + struct list_head *tx_list; + size_t copy; + + int i; + struct scatterlist *sg; + size_t sg_used; + size_t hw_used; + struct fsl_dma_hw_addr *hw; + dma_addr_t dma_dst, dma_src; + + if (!chan) + return NULL; + + if (!chan->private) + return NULL; + + fsl_chan = to_fsl_chan(chan); + slave = chan->private; + + if (list_empty(&slave->addresses)) + return NULL; + + hw = list_first_entry(&slave->addresses, struct fsl_dma_hw_addr, entry); + hw_used = 0; + + /* + * Build the hardware transaction to copy from the scatterlist to + * the hardware, or from the hardware to the scatterlist + * + * If you are copying from the hardware to the scatterlist and it + * takes two hardware entries to fill an entire page, then both + * hardware entries will be coalesced into the same page + * + * If you are copying from the scatterlist to the hardware and a + * single page can fill two hardware entries, then the data will + * be read out of the page into the first hardware entry, and so on + */ + for_each_sg(sgl, sg, sg_len, i) { + sg_used = 0; + + /* Loop until the entire scatterlist entry is used */ + while (sg_used < sg_dma_len(sg)) { + + /* + * If we've used up the current hardware address/length + * pair, we need to load a new one + * + * This is done in a while loop so that descriptors with + * length == 0 will be skipped + */ + while (hw_used >= hw->length) { + + /* + * If the current hardware entry is the last + * entry in the list, we're finished + */ + if (list_is_last(&hw->entry, &slave->addresses)) + goto finished; + + /* Get the next hardware address/length pair */ + hw = list_entry(hw->entry.next, + struct fsl_dma_hw_addr, entry); + hw_used = 0; + } + + /* Allocate the link descriptor from DMA pool */ + new = fsl_dma_alloc_descriptor(fsl_chan); + if (!new) { + dev_err(fsl_chan->dev, "No free memory for " + "link descriptor\n"); + goto fail; + } +#ifdef FSL_DMA_LD_DEBUG + dev_dbg(fsl_chan->dev, "new link desc alloc %p\n", new); +#endif + + /* + * Calculate the maximum number of bytes to transfer, + * making sure it is less than the DMA controller limit + */ + copy = min_t(size_t, sg_dma_len(sg) - sg_used, + hw->length - hw_used); + copy = min_t(size_t, copy, FSL_DMA_BCR_MAX_CNT); + + /* + * DMA_FROM_DEVICE + * from the hardware to the scatterlist + * + * DMA_TO_DEVICE + * from the scatterlist to the hardware + */ + if (direction == DMA_FROM_DEVICE) { + dma_src = hw->address + hw_used; + dma_dst = sg_dma_address(sg) + sg_used; + } else { + dma_src = sg_dma_address(sg) + sg_used; + dma_dst = hw->address + hw_used; + } + + /* Fill in the descriptor */ + set_desc_cnt(fsl_chan, &new->hw, copy); + set_desc_src(fsl_chan, &new->hw, dma_src); + set_desc_dest(fsl_chan, &new->hw, dma_dst); + + /* + * If this is not the first descriptor, chain the + * current descriptor after the previous descriptor + */ + if (!first) { + first = new; + } else { + set_desc_next(fsl_chan, &prev->hw, + new->async_tx.phys); + } + + new->async_tx.cookie = 0; + async_tx_ack(&new->async_tx); + + prev = new; + sg_used += copy; + hw_used += copy; + + /* Insert the link descriptor into the LD ring */ + list_add_tail(&new->node, &first->tx_list); + } + } + +finished: + + /* All of the hardware address/length pairs had length == 0 */ + if (!first || !new) + return NULL; + + new->async_tx.flags = flags; + new->async_tx.cookie = -EBUSY; + + /* Set End-of-link to the last link descriptor of new list */ + set_ld_eol(fsl_chan, new); + + /* Enable extra controller features */ + if (fsl_chan->set_src_loop_size) + fsl_chan->set_src_loop_size(fsl_chan, slave->src_loop_size); + + if (fsl_chan->set_dest_loop_size) + fsl_chan->set_dest_loop_size(fsl_chan, slave->dst_loop_size); + + if (fsl_chan->toggle_ext_start) + fsl_chan->toggle_ext_start(fsl_chan, slave->external_start); + + if (fsl_chan->toggle_ext_pause) + fsl_chan->toggle_ext_pause(fsl_chan, slave->external_pause); + + if (fsl_chan->set_request_count) + fsl_chan->set_request_count(fsl_chan, slave->request_count); + + return &first->async_tx; + +fail: + /* If first was not set, then we failed to allocate the very first + * descriptor, and we're done */ + if (!first) + return NULL; + + /* + * First is set, so all of the descriptors we allocated have been added + * to first->tx_list, INCLUDING "first" itself. Therefore we + * must traverse the list backwards freeing each descriptor in turn + * + * We're re-using variables for the loop, oh well + */ + tx_list = &first->tx_list; + list_for_each_entry_safe_reverse(new, prev, tx_list, node) { + list_del_init(&new->node); + dma_pool_free(fsl_chan->desc_pool, new, new->async_tx.phys); + } + + return NULL; +} + +static void fsl_dma_device_terminate_all(struct dma_chan *chan) +{ + struct fsl_dma_chan *fsl_chan; + struct fsl_desc_sw *desc, *tmp; + unsigned long flags; + + if (!chan) + return; + + fsl_chan = to_fsl_chan(chan); + + /* Halt the DMA engine */ + dma_halt(fsl_chan); + + spin_lock_irqsave(&fsl_chan->desc_lock, flags); + + /* Remove and free all of the descriptors in the LD queue */ + list_for_each_entry_safe(desc, tmp, &fsl_chan->ld_queue, node) { + list_del(&desc->node); + dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys); + } + + spin_unlock_irqrestore(&fsl_chan->desc_lock, flags); +} + +/** * fsl_dma_update_completed_cookie - Update the completed cookie. * @fsl_chan : Freescale DMA channel */ @@ -883,6 +1121,7 @@ static int __devinit fsl_dma_chan_probe(struct fsl_dma_device *fdev, new_fsl_chan->toggle_ext_start = fsl_chan_toggle_ext_start; new_fsl_chan->set_src_loop_size = fsl_chan_set_src_loop_size; new_fsl_chan->set_dest_loop_size = fsl_chan_set_dest_loop_size; + new_fsl_chan->set_request_count = fsl_chan_set_request_count; } spin_lock_init(&new_fsl_chan->desc_lock); @@ -962,12 +1201,15 @@ static int __devinit of_fsl_dma_probe(struct of_device *dev, dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask); dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask); + dma_cap_set(DMA_SLAVE, fdev->common.cap_mask); fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources; fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources; fdev->common.device_prep_dma_interrupt = fsl_dma_prep_interrupt; fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy; fdev->common.device_is_tx_complete = fsl_dma_is_complete; fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending; + fdev->common.device_prep_slave_sg = fsl_dma_prep_slave_sg; + fdev->common.device_terminate_all = fsl_dma_device_terminate_all; fdev->common.dev = &dev->dev; fdev->irq = irq_of_parse_and_map(dev->node, 0); |