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path: root/drivers/dma/at_hdmac.c
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Diffstat (limited to 'drivers/dma/at_hdmac.c')
-rw-r--r--drivers/dma/at_hdmac.c346
1 files changed, 244 insertions, 102 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 13a02f4425b..c13a3bb0f59 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -14,6 +14,7 @@
* found on AT91SAM9263.
*/
+#include <dt-bindings/dma/at91.h>
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
@@ -24,6 +25,7 @@
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/of_dma.h>
#include "at_hdmac_regs.h"
#include "dmaengine.h"
@@ -53,6 +55,7 @@ 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);
/*----------------------------------------------------------------------*/
@@ -229,6 +232,95 @@ 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
@@ -252,31 +344,7 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
/* move myself to free_list */
list_move(&desc->desc_node, &atchan->free_list);
- /* unmap dma addresses (not on slave channels) */
- if (!atchan->chan_common.private) {
- struct device *parent = chan2parent(&atchan->chan_common);
- if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
- if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
- dma_unmap_single(parent,
- desc->lli.daddr,
- desc->len, DMA_FROM_DEVICE);
- else
- dma_unmap_page(parent,
- desc->lli.daddr,
- desc->len, DMA_FROM_DEVICE);
- }
- if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
- if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
- dma_unmap_single(parent,
- desc->lli.saddr,
- desc->len, DMA_TO_DEVICE);
- else
- dma_unmap_page(parent,
- desc->lli.saddr,
- desc->len, DMA_TO_DEVICE);
- }
- }
-
+ dma_descriptor_unmap(txd);
/* for cyclic transfers,
* no need to replay callback function while stopping */
if (!atc_chan_is_cyclic(atchan)) {
@@ -310,8 +378,6 @@ static void atc_complete_all(struct at_dma_chan *atchan)
dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
- BUG_ON(atc_chan_is_enabled(atchan));
-
/*
* Submit queued descriptors ASAP, i.e. before we go through
* the completed ones.
@@ -328,37 +394,6 @@ static void atc_complete_all(struct at_dma_chan *atchan)
}
/**
- * 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
*
@@ -368,6 +403,9 @@ static void atc_advance_work(struct at_dma_chan *atchan)
{
dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
+ if (atc_chan_is_enabled(atchan))
+ return;
+
if (list_empty(&atchan->active_list) ||
list_is_singular(&atchan->active_list)) {
atc_complete_all(atchan);
@@ -494,6 +532,8 @@ 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;
}
@@ -613,6 +653,7 @@ atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
/* First descriptor of the chain embedds additional information */
first->txd.cookie = -EBUSY;
first->len = len;
+ first->tx_width = src_width;
/* set end-of-link to the last link descriptor of list*/
set_desc_eol(desc);
@@ -676,7 +717,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
ctrlb |= ATC_DST_ADDR_MODE_FIXED
| ATC_SRC_ADDR_MODE_INCR
| ATC_FC_MEM2PER
- | ATC_SIF(AT_DMA_MEM_IF) | ATC_DIF(AT_DMA_PER_IF);
+ | ATC_SIF(atchan->mem_if) | ATC_DIF(atchan->per_if);
reg = sconfig->dst_addr;
for_each_sg(sgl, sg, sg_len, i) {
struct at_desc *desc;
@@ -715,7 +756,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
ctrlb |= ATC_DST_ADDR_MODE_INCR
| ATC_SRC_ADDR_MODE_FIXED
| ATC_FC_PER2MEM
- | ATC_SIF(AT_DMA_PER_IF) | ATC_DIF(AT_DMA_MEM_IF);
+ | ATC_SIF(atchan->per_if) | ATC_DIF(atchan->mem_if);
reg = sconfig->src_addr;
for_each_sg(sgl, sg, sg_len, i) {
@@ -759,6 +800,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
/* First descriptor of the chain embedds additional information */
first->txd.cookie = -EBUSY;
first->len = total_len;
+ first->tx_width = reg_width;
/* first link descriptor of list is responsible of flags */
first->txd.flags = flags; /* client is in control of this ack */
@@ -778,7 +820,7 @@ err:
*/
static int
atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr,
- size_t period_len, enum dma_transfer_direction direction)
+ size_t period_len)
{
if (period_len > (ATC_BTSIZE_MAX << reg_width))
goto err_out;
@@ -786,8 +828,6 @@ atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr,
goto err_out;
if (unlikely(buf_addr & ((1 << reg_width) - 1)))
goto err_out;
- if (unlikely(!(direction & (DMA_DEV_TO_MEM | DMA_MEM_TO_DEV))))
- goto err_out;
return 0;
@@ -823,8 +863,8 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED
| ATC_SRC_ADDR_MODE_INCR
| ATC_FC_MEM2PER
- | ATC_SIF(AT_DMA_MEM_IF)
- | ATC_DIF(AT_DMA_PER_IF);
+ | ATC_SIF(atchan->mem_if)
+ | ATC_DIF(atchan->per_if);
break;
case DMA_DEV_TO_MEM:
@@ -834,8 +874,8 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR
| ATC_SRC_ADDR_MODE_FIXED
| ATC_FC_PER2MEM
- | ATC_SIF(AT_DMA_PER_IF)
- | ATC_DIF(AT_DMA_MEM_IF);
+ | ATC_SIF(atchan->per_if)
+ | ATC_DIF(atchan->mem_if);
break;
default:
@@ -886,14 +926,16 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
return NULL;
}
+ if (unlikely(!is_slave_direction(direction)))
+ goto err_out;
+
if (sconfig->direction == DMA_MEM_TO_DEV)
reg_width = convert_buswidth(sconfig->dst_addr_width);
else
reg_width = convert_buswidth(sconfig->src_addr_width);
/* Check for too big/unaligned periods and unaligned DMA buffer */
- if (atc_dma_cyclic_check_values(reg_width, buf_addr,
- period_len, direction))
+ if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len))
goto err_out;
/* build cyclic linked list */
@@ -917,6 +959,7 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
/* First descriptor of the chain embedds additional information */
first->txd.cookie = -EBUSY;
first->len = buf_len;
+ first->tx_width = reg_width;
return &first->txd;
@@ -1030,34 +1073,36 @@ 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_COMPLETE)
+ 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;
}
@@ -1078,9 +1123,7 @@ static void atc_issue_pending(struct dma_chan *chan)
return;
spin_lock_irqsave(&atchan->lock, flags);
- if (!atc_chan_is_enabled(atchan)) {
- atc_advance_work(atchan);
- }
+ atc_advance_work(atchan);
spin_unlock_irqrestore(&atchan->lock, flags);
}
@@ -1120,7 +1163,7 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
*/
BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_common.dev);
- /* if cfg configuration specified take it instad of default */
+ /* if cfg configuration specified take it instead of default */
if (atslave->cfg)
cfg = atslave->cfg;
}
@@ -1143,6 +1186,7 @@ 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);
@@ -1185,10 +1229,89 @@ 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");
}
+#ifdef CONFIG_OF
+static bool at_dma_filter(struct dma_chan *chan, void *slave)
+{
+ struct at_dma_slave *atslave = slave;
+
+ if (atslave->dma_dev == chan->device->dev) {
+ chan->private = atslave;
+ return true;
+ } else {
+ return false;
+ }
+}
+
+static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *of_dma)
+{
+ struct dma_chan *chan;
+ struct at_dma_chan *atchan;
+ struct at_dma_slave *atslave;
+ dma_cap_mask_t mask;
+ unsigned int per_id;
+ struct platform_device *dmac_pdev;
+
+ if (dma_spec->args_count != 2)
+ return NULL;
+
+ dmac_pdev = of_find_device_by_node(dma_spec->np);
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ 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] & 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);
+ if (!chan)
+ return NULL;
+
+ atchan = to_at_dma_chan(chan);
+ atchan->per_if = dma_spec->args[0] & 0xff;
+ atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff;
+
+ return chan;
+}
+#else
+static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *of_dma)
+{
+ return NULL;
+}
+#endif
/*-- Module Management -----------------------------------------------*/
@@ -1313,7 +1436,9 @@ static int __init at_dma_probe(struct platform_device *pdev)
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);
@@ -1343,6 +1468,8 @@ static int __init at_dma_probe(struct platform_device *pdev)
for (i = 0; i < plat_dat->nr_channels; i++) {
struct at_dma_chan *atchan = &atdma->chan[i];
+ atchan->mem_if = AT_DMA_MEM_IF;
+ atchan->per_if = AT_DMA_PER_IF;
atchan->chan_common.device = &atdma->dma_common;
dma_cookie_init(&atchan->chan_common);
list_add_tail(&atchan->chan_common.device_node,
@@ -1389,13 +1516,30 @@ static int __init at_dma_probe(struct platform_device *pdev)
dma_async_device_register(&atdma->dma_common);
+ /*
+ * Do not return an error if the dmac node is not present in order to
+ * not break the existing way of requesting channel with
+ * dma_request_channel().
+ */
+ if (pdev->dev.of_node) {
+ err = of_dma_controller_register(pdev->dev.of_node,
+ at_dma_xlate, atdma);
+ if (err) {
+ dev_err(&pdev->dev, "could not register of_dma_controller\n");
+ goto err_of_dma_controller_register;
+ }
+ }
+
return 0;
+err_of_dma_controller_register:
+ 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);
@@ -1407,7 +1551,7 @@ err_kfree:
return err;
}
-static int __exit at_dma_remove(struct platform_device *pdev)
+static int at_dma_remove(struct platform_device *pdev)
{
struct at_dma *atdma = platform_get_drvdata(pdev);
struct dma_chan *chan, *_chan;
@@ -1417,7 +1561,6 @@ static int __exit at_dma_remove(struct platform_device *pdev)
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,
@@ -1426,13 +1569,12 @@ static int __exit at_dma_remove(struct platform_device *pdev)
/* Disable interrupts */
atc_disable_chan_irq(atdma, chan->chan_id);
- tasklet_disable(&atchan->tasklet);
tasklet_kill(&atchan->tasklet);
list_del(&chan->device_node);
}
- clk_disable(atdma->clk);
+ clk_disable_unprepare(atdma->clk);
clk_put(atdma->clk);
iounmap(atdma->regs);
@@ -1451,7 +1593,7 @@ static void at_dma_shutdown(struct platform_device *pdev)
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)
@@ -1508,7 +1650,7 @@ static int at_dma_suspend_noirq(struct device *dev)
/* disable DMA controller */
at_dma_off(atdma);
- clk_disable(atdma->clk);
+ clk_disable_unprepare(atdma->clk);
return 0;
}
@@ -1538,7 +1680,7 @@ static int at_dma_resume_noirq(struct device *dev)
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 */
@@ -1565,7 +1707,7 @@ static const struct dev_pm_ops at_dma_dev_pm_ops = {
};
static struct platform_driver at_dma_driver = {
- .remove = __exit_p(at_dma_remove),
+ .remove = at_dma_remove,
.shutdown = at_dma_shutdown,
.id_table = atdma_devtypes,
.driver = {