* found on AT91SAM9263.
*/
+#include <dt-bindings/dma/at91.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
/* prototypes */
static dma_cookie_t atc_tx_submit(struct dma_async_tx_descriptor *tx);
+static void atc_issue_pending(struct dma_chan *chan);
/*----------------------------------------------------------------------*/
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
atc_chain_complete(atchan, desc);
}
-/**
- * atc_cleanup_descriptors - cleanup up finished descriptors in active_list
- * @atchan: channel to be cleaned up
- *
- * Called with atchan->lock held and bh disabled
- */
-static void atc_cleanup_descriptors(struct at_dma_chan *atchan)
-{
- struct at_desc *desc, *_desc;
- struct at_desc *child;
-
- dev_vdbg(chan2dev(&atchan->chan_common), "cleanup descriptors\n");
-
- list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
- if (!(desc->lli.ctrla & ATC_DONE))
- /* This one is currently in progress */
- return;
-
- list_for_each_entry(child, &desc->tx_list, desc_node)
- if (!(child->lli.ctrla & ATC_DONE))
- /* Currently in progress */
- return;
-
- /*
- * No descriptors so far seem to be in progress, i.e.
- * this chain must be done.
- */
- atc_chain_complete(atchan, desc);
- }
-}
-
/**
* atc_advance_work - at the end of a transaction, move forward
* @atchan: channel where the transaction ended
/* 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;
}
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;
}
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);
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");
}
atslave = devm_kzalloc(&dmac_pdev->dev, sizeof(*atslave), GFP_KERNEL);
if (!atslave)
return NULL;
+
+ atslave->cfg = ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW;
/*
* We can fill both SRC_PER and DST_PER, one of these fields will be
* ignored depending on DMA transfer direction.
*/
- per_id = dma_spec->args[1];
- atslave->cfg = ATC_FIFOCFG_HALFFIFO
- | ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW
- | ATC_DST_PER_MSB(per_id) | ATC_DST_PER(per_id)
+ per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK;
+ atslave->cfg |= ATC_DST_PER_MSB(per_id) | ATC_DST_PER(per_id)
| ATC_SRC_PER_MSB(per_id) | ATC_SRC_PER(per_id);
+ /*
+ * We have to translate the value we get from the device tree since
+ * the half FIFO configuration value had to be 0 to keep backward
+ * compatibility.
+ */
+ switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) {
+ case AT91_DMA_CFG_FIFOCFG_ALAP:
+ atslave->cfg |= ATC_FIFOCFG_LARGESTBURST;
+ break;
+ case AT91_DMA_CFG_FIFOCFG_ASAP:
+ atslave->cfg |= ATC_FIFOCFG_ENOUGHSPACE;
+ break;
+ case AT91_DMA_CFG_FIFOCFG_HALF:
+ default:
+ atslave->cfg |= ATC_FIFOCFG_HALFFIFO;
+ }
atslave->dma_dev = &dmac_pdev->dev;
chan = dma_request_channel(mask, at_dma_filter, atslave);
err = PTR_ERR(atdma->clk);
goto err_clk;
}
- clk_enable(atdma->clk);
+ err = clk_prepare_enable(atdma->clk);
+ if (err)
+ goto err_clk_prepare;
/* force dma off, just in case */
at_dma_off(atdma);
dma_async_device_unregister(&atdma->dma_common);
dma_pool_destroy(atdma->dma_desc_pool);
err_pool_create:
- platform_set_drvdata(pdev, NULL);
free_irq(platform_get_irq(pdev, 0), atdma);
err_irq:
- clk_disable(atdma->clk);
+ clk_disable_unprepare(atdma->clk);
+err_clk_prepare:
clk_put(atdma->clk);
err_clk:
iounmap(atdma->regs);
dma_async_device_unregister(&atdma->dma_common);
dma_pool_destroy(atdma->dma_desc_pool);
- platform_set_drvdata(pdev, NULL);
free_irq(platform_get_irq(pdev, 0), atdma);
list_for_each_entry_safe(chan, _chan, &atdma->dma_common.channels,
list_del(&chan->device_node);
}
- clk_disable(atdma->clk);
+ clk_disable_unprepare(atdma->clk);
clk_put(atdma->clk);
iounmap(atdma->regs);
struct at_dma *atdma = platform_get_drvdata(pdev);
at_dma_off(platform_get_drvdata(pdev));
- clk_disable(atdma->clk);
+ clk_disable_unprepare(atdma->clk);
}
static int at_dma_prepare(struct device *dev)
/* disable DMA controller */
at_dma_off(atdma);
- clk_disable(atdma->clk);
+ clk_disable_unprepare(atdma->clk);
return 0;
}
struct dma_chan *chan, *_chan;
/* bring back DMA controller */
- clk_enable(atdma->clk);
+ clk_prepare_enable(atdma->clk);
dma_writel(atdma, EN, AT_DMA_ENABLE);
/* clear any pending interrupt */