diff options
Diffstat (limited to 'drivers/dma/at_hdmac.c')
| -rw-r--r-- | drivers/dma/at_hdmac.c | 130 |
1 files changed, 112 insertions, 18 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index 4c101a9..5ce8936 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -54,6 +54,7 @@ MODULE_PARM_DESC(init_nr_desc_per_channel, /* prototypes */ static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx); +static void atc_issue_pending(struct dma_chan *chan); /*----------------------------------------------------------------------*/ @@ -230,6 +231,94 @@ static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first) vdbg_dump_regs(atchan); } +/* + * atc_get_current_descriptors - + * locate the descriptor which equal to physical address in DSCR + * @atchan: the channel we want to start + * @dscr_addr: physical descriptor address in DSCR + */ +static struct at_desc *atc_get_current_descriptors(struct at_dma_chan *atchan, + u32 dscr_addr) +{ + struct at_desc *desc, *_desc, *child, *desc_cur = NULL; + + list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) { + if (desc->lli.dscr == dscr_addr) { + desc_cur = desc; + break; + } + + list_for_each_entry(child, &desc->tx_list, desc_node) { + if (child->lli.dscr == dscr_addr) { + desc_cur = child; + break; + } + } + } + + return desc_cur; +} + +/* + * atc_get_bytes_left - + * Get the number of bytes residue in dma buffer, + * @chan: the channel we want to start + */ +static int atc_get_bytes_left(struct dma_chan *chan) +{ + struct at_dma_chan *atchan = to_at_dma_chan(chan); + struct at_dma *atdma = to_at_dma(chan->device); + int chan_id = atchan->chan_common.chan_id; + struct at_desc *desc_first = atc_first_active(atchan); + struct at_desc *desc_cur; + int ret = 0, count = 0; + + /* + * Initialize necessary values in the first time. + * remain_desc record remain desc length. + */ + if (atchan->remain_desc == 0) + /* First descriptor embedds the transaction length */ + atchan->remain_desc = desc_first->len; + + /* + * This happens when current descriptor transfer complete. + * The residual buffer size should reduce current descriptor length. + */ + if (unlikely(test_bit(ATC_IS_BTC, &atchan->status))) { + clear_bit(ATC_IS_BTC, &atchan->status); + desc_cur = atc_get_current_descriptors(atchan, + channel_readl(atchan, DSCR)); + if (!desc_cur) { + ret = -EINVAL; + goto out; + } + atchan->remain_desc -= (desc_cur->lli.ctrla & ATC_BTSIZE_MAX) + << (desc_first->tx_width); + if (atchan->remain_desc < 0) { + ret = -EINVAL; + goto out; + } else + ret = atchan->remain_desc; + } else { + /* + * Get residual bytes when current + * descriptor transfer in progress. + */ + count = (channel_readl(atchan, CTRLA) & ATC_BTSIZE_MAX) + << (desc_first->tx_width); + ret = atchan->remain_desc - count; + } + /* + * Check fifo empty. + */ + if (!(dma_readl(atdma, CHSR) & AT_DMA_EMPT(chan_id))) + atc_issue_pending(chan); + +out: + return ret; +} + /** * atc_chain_complete - finish work for one transaction chain * @atchan: channel we work on @@ -496,6 +585,8 @@ static irqreturn_t at_dma_interrupt(int irq, void *dev_id) /* Give information to tasklet */ set_bit(ATC_IS_ERROR, &atchan->status); } + if (pending & AT_DMA_BTC(i)) + set_bit(ATC_IS_BTC, &atchan->status); tasklet_schedule(&atchan->tasklet); ret = IRQ_HANDLED; } @@ -1035,34 +1126,35 @@ atc_tx_status(struct dma_chan *chan, struct dma_tx_state *txstate) { struct at_dma_chan *atchan = to_at_dma_chan(chan); - dma_cookie_t last_used; - dma_cookie_t last_complete; unsigned long flags; enum dma_status ret; - - spin_lock_irqsave(&atchan->lock, flags); + int bytes = 0; ret = dma_cookie_status(chan, cookie, txstate); - if (ret != DMA_SUCCESS) { - atc_cleanup_descriptors(atchan); + if (ret == DMA_SUCCESS) + return ret; + /* + * There's no point calculating the residue if there's + * no txstate to store the value. + */ + if (!txstate) + return DMA_ERROR; - ret = dma_cookie_status(chan, cookie, txstate); - } + spin_lock_irqsave(&atchan->lock, flags); - last_complete = chan->completed_cookie; - last_used = chan->cookie; + /* Get number of bytes left in the active transactions */ + bytes = atc_get_bytes_left(chan); spin_unlock_irqrestore(&atchan->lock, flags); - if (ret != DMA_SUCCESS) - dma_set_residue(txstate, atc_first_active(atchan)->len); - - if (atc_chan_is_paused(atchan)) - ret = DMA_PAUSED; + if (unlikely(bytes < 0)) { + dev_vdbg(chan2dev(chan), "get residual bytes error\n"); + return DMA_ERROR; + } else + dma_set_residue(txstate, bytes); - dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d (d%d, u%d)\n", - ret, cookie, last_complete ? last_complete : 0, - last_used ? last_used : 0); + dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %d\n", + ret, cookie, bytes); return ret; } @@ -1146,6 +1238,7 @@ static int atc_alloc_chan_resources(struct dma_chan *chan) spin_lock_irqsave(&atchan->lock, flags); atchan->descs_allocated = i; + atchan->remain_desc = 0; list_splice(&tmp_list, &atchan->free_list); dma_cookie_init(chan); spin_unlock_irqrestore(&atchan->lock, flags); @@ -1188,6 +1281,7 @@ static void atc_free_chan_resources(struct dma_chan *chan) list_splice_init(&atchan->free_list, &list); atchan->descs_allocated = 0; atchan->status = 0; + atchan->remain_desc = 0; dev_vdbg(chan2dev(chan), "free_chan_resources: done\n"); } |
