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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.c376
1 files changed, 291 insertions, 85 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 235f53bf494e..36144f88d718 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -37,8 +37,8 @@
#define ATC_DEFAULT_CFG (ATC_FIFOCFG_HALFFIFO)
#define ATC_DEFAULT_CTRLA (0)
-#define ATC_DEFAULT_CTRLB (ATC_SIF(0) \
- |ATC_DIF(1))
+#define ATC_DEFAULT_CTRLB (ATC_SIF(AT_DMA_MEM_IF) \
+ |ATC_DIF(AT_DMA_MEM_IF))
/*
* Initial number of descriptors to allocate for each channel. This could
@@ -165,6 +165,29 @@ static void atc_desc_put(struct at_dma_chan *atchan, struct at_desc *desc)
}
/**
+ * atc_desc_chain - build chain adding a descripor
+ * @first: address of first descripor of the chain
+ * @prev: address of previous descripor of the chain
+ * @desc: descriptor to queue
+ *
+ * Called from prep_* functions
+ */
+static void atc_desc_chain(struct at_desc **first, struct at_desc **prev,
+ struct at_desc *desc)
+{
+ if (!(*first)) {
+ *first = desc;
+ } else {
+ /* inform the HW lli about chaining */
+ (*prev)->lli.dscr = desc->txd.phys;
+ /* insert the link descriptor to the LD ring */
+ list_add_tail(&desc->desc_node,
+ &(*first)->tx_list);
+ }
+ *prev = desc;
+}
+
+/**
* atc_assign_cookie - compute and assign new cookie
* @atchan: channel we work on
* @desc: descriptor to assign cookie for
@@ -237,16 +260,12 @@ static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
static void
atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
{
- dma_async_tx_callback callback;
- void *param;
struct dma_async_tx_descriptor *txd = &desc->txd;
dev_vdbg(chan2dev(&atchan->chan_common),
"descriptor %u complete\n", txd->cookie);
atchan->completed_cookie = txd->cookie;
- callback = txd->callback;
- param = txd->callback_param;
/* move children to free_list */
list_splice_init(&desc->tx_list, &atchan->free_list);
@@ -278,12 +297,19 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
}
}
- /*
- * The API requires that no submissions are done from a
- * callback, so we don't need to drop the lock here
- */
- if (callback)
- callback(param);
+ /* for cyclic transfers,
+ * no need to replay callback function while stopping */
+ if (!test_bit(ATC_IS_CYCLIC, &atchan->status)) {
+ dma_async_tx_callback callback = txd->callback;
+ void *param = txd->callback_param;
+
+ /*
+ * The API requires that no submissions are done from a
+ * callback, so we don't need to drop the lock here
+ */
+ if (callback)
+ callback(param);
+ }
dma_run_dependencies(txd);
}
@@ -419,6 +445,26 @@ static void atc_handle_error(struct at_dma_chan *atchan)
atc_chain_complete(atchan, bad_desc);
}
+/**
+ * atc_handle_cyclic - at the end of a period, run callback function
+ * @atchan: channel used for cyclic operations
+ *
+ * Called with atchan->lock held and bh disabled
+ */
+static void atc_handle_cyclic(struct at_dma_chan *atchan)
+{
+ struct at_desc *first = atc_first_active(atchan);
+ struct dma_async_tx_descriptor *txd = &first->txd;
+ dma_async_tx_callback callback = txd->callback;
+ void *param = txd->callback_param;
+
+ dev_vdbg(chan2dev(&atchan->chan_common),
+ "new cyclic period llp 0x%08x\n",
+ channel_readl(atchan, DSCR));
+
+ if (callback)
+ callback(param);
+}
/*-- IRQ & Tasklet ---------------------------------------------------*/
@@ -426,16 +472,11 @@ static void atc_tasklet(unsigned long data)
{
struct at_dma_chan *atchan = (struct at_dma_chan *)data;
- /* Channel cannot be enabled here */
- if (atc_chan_is_enabled(atchan)) {
- dev_err(chan2dev(&atchan->chan_common),
- "BUG: channel enabled in tasklet\n");
- return;
- }
-
spin_lock(&atchan->lock);
- if (test_and_clear_bit(0, &atchan->error_status))
+ if (test_and_clear_bit(ATC_IS_ERROR, &atchan->status))
atc_handle_error(atchan);
+ else if (test_bit(ATC_IS_CYCLIC, &atchan->status))
+ atc_handle_cyclic(atchan);
else
atc_advance_work(atchan);
@@ -464,12 +505,13 @@ static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
for (i = 0; i < atdma->dma_common.chancnt; i++) {
atchan = &atdma->chan[i];
- if (pending & (AT_DMA_CBTC(i) | AT_DMA_ERR(i))) {
+ if (pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i))) {
if (pending & AT_DMA_ERR(i)) {
/* Disable channel on AHB error */
- dma_writel(atdma, CHDR, atchan->mask);
+ dma_writel(atdma, CHDR,
+ AT_DMA_RES(i) | atchan->mask);
/* Give information to tasklet */
- set_bit(0, &atchan->error_status);
+ set_bit(ATC_IS_ERROR, &atchan->status);
}
tasklet_schedule(&atchan->tasklet);
ret = IRQ_HANDLED;
@@ -549,7 +591,7 @@ atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
}
ctrla = ATC_DEFAULT_CTRLA;
- ctrlb = ATC_DEFAULT_CTRLB
+ ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN
| ATC_SRC_ADDR_MODE_INCR
| ATC_DST_ADDR_MODE_INCR
| ATC_FC_MEM2MEM;
@@ -584,16 +626,7 @@ atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
desc->txd.cookie = 0;
- if (!first) {
- first = desc;
- } else {
- /* inform the HW lli about chaining */
- prev->lli.dscr = desc->txd.phys;
- /* insert the link descriptor to the LD ring */
- list_add_tail(&desc->desc_node,
- &first->tx_list);
- }
- prev = desc;
+ atc_desc_chain(&first, &prev, desc);
}
/* First descriptor of the chain embedds additional information */
@@ -639,7 +672,8 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
struct scatterlist *sg;
size_t total_len = 0;
- dev_vdbg(chan2dev(chan), "prep_slave_sg: %s f0x%lx\n",
+ dev_vdbg(chan2dev(chan), "prep_slave_sg (%d): %s f0x%lx\n",
+ sg_len,
direction == DMA_TO_DEVICE ? "TO DEVICE" : "FROM DEVICE",
flags);
@@ -651,14 +685,15 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
reg_width = atslave->reg_width;
ctrla = ATC_DEFAULT_CTRLA | atslave->ctrla;
- ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN;
+ ctrlb = ATC_IEN;
switch (direction) {
case DMA_TO_DEVICE:
ctrla |= ATC_DST_WIDTH(reg_width);
ctrlb |= ATC_DST_ADDR_MODE_FIXED
| ATC_SRC_ADDR_MODE_INCR
- | ATC_FC_MEM2PER;
+ | ATC_FC_MEM2PER
+ | ATC_SIF(AT_DMA_MEM_IF) | ATC_DIF(AT_DMA_PER_IF);
reg = atslave->tx_reg;
for_each_sg(sgl, sg, sg_len, i) {
struct at_desc *desc;
@@ -682,16 +717,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
| len >> mem_width;
desc->lli.ctrlb = ctrlb;
- if (!first) {
- first = desc;
- } else {
- /* inform the HW lli about chaining */
- prev->lli.dscr = desc->txd.phys;
- /* insert the link descriptor to the LD ring */
- list_add_tail(&desc->desc_node,
- &first->tx_list);
- }
- prev = desc;
+ atc_desc_chain(&first, &prev, desc);
total_len += len;
}
break;
@@ -699,7 +725,8 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
ctrla |= ATC_SRC_WIDTH(reg_width);
ctrlb |= ATC_DST_ADDR_MODE_INCR
| ATC_SRC_ADDR_MODE_FIXED
- | ATC_FC_PER2MEM;
+ | ATC_FC_PER2MEM
+ | ATC_SIF(AT_DMA_PER_IF) | ATC_DIF(AT_DMA_MEM_IF);
reg = atslave->rx_reg;
for_each_sg(sgl, sg, sg_len, i) {
@@ -724,16 +751,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
| len >> reg_width;
desc->lli.ctrlb = ctrlb;
- if (!first) {
- first = desc;
- } else {
- /* inform the HW lli about chaining */
- prev->lli.dscr = desc->txd.phys;
- /* insert the link descriptor to the LD ring */
- list_add_tail(&desc->desc_node,
- &first->tx_list);
- }
- prev = desc;
+ atc_desc_chain(&first, &prev, desc);
total_len += len;
}
break;
@@ -759,41 +777,211 @@ err_desc_get:
return NULL;
}
+/**
+ * atc_dma_cyclic_check_values
+ * Check for too big/unaligned periods and unaligned DMA buffer
+ */
+static int
+atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr,
+ size_t period_len, enum dma_data_direction direction)
+{
+ if (period_len > (ATC_BTSIZE_MAX << reg_width))
+ goto err_out;
+ if (unlikely(period_len & ((1 << reg_width) - 1)))
+ goto err_out;
+ if (unlikely(buf_addr & ((1 << reg_width) - 1)))
+ goto err_out;
+ if (unlikely(!(direction & (DMA_TO_DEVICE | DMA_FROM_DEVICE))))
+ goto err_out;
+
+ return 0;
+
+err_out:
+ return -EINVAL;
+}
+
+/**
+ * atc_dma_cyclic_fill_desc - Fill one period decriptor
+ */
+static int
+atc_dma_cyclic_fill_desc(struct at_dma_slave *atslave, struct at_desc *desc,
+ unsigned int period_index, dma_addr_t buf_addr,
+ size_t period_len, enum dma_data_direction direction)
+{
+ u32 ctrla;
+ unsigned int reg_width = atslave->reg_width;
+
+ /* prepare common CRTLA value */
+ ctrla = ATC_DEFAULT_CTRLA | atslave->ctrla
+ | ATC_DST_WIDTH(reg_width)
+ | ATC_SRC_WIDTH(reg_width)
+ | period_len >> reg_width;
+
+ switch (direction) {
+ case DMA_TO_DEVICE:
+ desc->lli.saddr = buf_addr + (period_len * period_index);
+ desc->lli.daddr = atslave->tx_reg;
+ desc->lli.ctrla = ctrla;
+ 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);
+ break;
+
+ case DMA_FROM_DEVICE:
+ desc->lli.saddr = atslave->rx_reg;
+ desc->lli.daddr = buf_addr + (period_len * period_index);
+ desc->lli.ctrla = ctrla;
+ 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);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * atc_prep_dma_cyclic - prepare the cyclic DMA transfer
+ * @chan: the DMA channel to prepare
+ * @buf_addr: physical DMA address where the buffer starts
+ * @buf_len: total number of bytes for the entire buffer
+ * @period_len: number of bytes for each period
+ * @direction: transfer direction, to or from device
+ */
+static struct dma_async_tx_descriptor *
+atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_data_direction direction)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_dma_slave *atslave = chan->private;
+ struct at_desc *first = NULL;
+ struct at_desc *prev = NULL;
+ unsigned long was_cyclic;
+ unsigned int periods = buf_len / period_len;
+ unsigned int i;
+
+ dev_vdbg(chan2dev(chan), "prep_dma_cyclic: %s buf@0x%08x - %d (%d/%d)\n",
+ direction == DMA_TO_DEVICE ? "TO DEVICE" : "FROM DEVICE",
+ buf_addr,
+ periods, buf_len, period_len);
+
+ if (unlikely(!atslave || !buf_len || !period_len)) {
+ dev_dbg(chan2dev(chan), "prep_dma_cyclic: length is zero!\n");
+ return NULL;
+ }
+
+ was_cyclic = test_and_set_bit(ATC_IS_CYCLIC, &atchan->status);
+ if (was_cyclic) {
+ dev_dbg(chan2dev(chan), "prep_dma_cyclic: channel in use!\n");
+ return NULL;
+ }
+
+ /* Check for too big/unaligned periods and unaligned DMA buffer */
+ if (atc_dma_cyclic_check_values(atslave->reg_width, buf_addr,
+ period_len, direction))
+ goto err_out;
+
+ /* build cyclic linked list */
+ for (i = 0; i < periods; i++) {
+ struct at_desc *desc;
+
+ desc = atc_desc_get(atchan);
+ if (!desc)
+ goto err_desc_get;
+
+ if (atc_dma_cyclic_fill_desc(atslave, desc, i, buf_addr,
+ period_len, direction))
+ goto err_desc_get;
+
+ atc_desc_chain(&first, &prev, desc);
+ }
+
+ /* lets make a cyclic list */
+ prev->lli.dscr = first->txd.phys;
+
+ /* First descriptor of the chain embedds additional information */
+ first->txd.cookie = -EBUSY;
+ first->len = buf_len;
+
+ return &first->txd;
+
+err_desc_get:
+ dev_err(chan2dev(chan), "not enough descriptors available\n");
+ atc_desc_put(atchan, first);
+err_out:
+ clear_bit(ATC_IS_CYCLIC, &atchan->status);
+ return NULL;
+}
+
+
static int atc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma *atdma = to_at_dma(chan->device);
- struct at_desc *desc, *_desc;
+ int chan_id = atchan->chan_common.chan_id;
+
LIST_HEAD(list);
- /* Only supports DMA_TERMINATE_ALL */
- if (cmd != DMA_TERMINATE_ALL)
- return -ENXIO;
+ dev_vdbg(chan2dev(chan), "atc_control (%d)\n", cmd);
- /*
- * This is only called when something went wrong elsewhere, so
- * we don't really care about the data. Just disable the
- * channel. We still have to poll the channel enable bit due
- * to AHB/HSB limitations.
- */
- spin_lock_bh(&atchan->lock);
+ if (cmd == DMA_PAUSE) {
+ spin_lock_bh(&atchan->lock);
- dma_writel(atdma, CHDR, atchan->mask);
+ dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id));
+ set_bit(ATC_IS_PAUSED, &atchan->status);
- /* confirm that this channel is disabled */
- while (dma_readl(atdma, CHSR) & atchan->mask)
- cpu_relax();
+ spin_unlock_bh(&atchan->lock);
+ } else if (cmd == DMA_RESUME) {
+ if (!test_bit(ATC_IS_PAUSED, &atchan->status))
+ return 0;
- /* active_list entries will end up before queued entries */
- list_splice_init(&atchan->queue, &list);
- list_splice_init(&atchan->active_list, &list);
+ spin_lock_bh(&atchan->lock);
- /* Flush all pending and queued descriptors */
- list_for_each_entry_safe(desc, _desc, &list, desc_node)
- atc_chain_complete(atchan, desc);
+ dma_writel(atdma, CHDR, AT_DMA_RES(chan_id));
+ clear_bit(ATC_IS_PAUSED, &atchan->status);
- spin_unlock_bh(&atchan->lock);
+ spin_unlock_bh(&atchan->lock);
+ } else if (cmd == DMA_TERMINATE_ALL) {
+ struct at_desc *desc, *_desc;
+ /*
+ * This is only called when something went wrong elsewhere, so
+ * we don't really care about the data. Just disable the
+ * channel. We still have to poll the channel enable bit due
+ * to AHB/HSB limitations.
+ */
+ spin_lock_bh(&atchan->lock);
+
+ /* disabling channel: must also remove suspend state */
+ dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask);
+
+ /* confirm that this channel is disabled */
+ while (dma_readl(atdma, CHSR) & atchan->mask)
+ cpu_relax();
+
+ /* active_list entries will end up before queued entries */
+ list_splice_init(&atchan->queue, &list);
+ list_splice_init(&atchan->active_list, &list);
+
+ /* Flush all pending and queued descriptors */
+ list_for_each_entry_safe(desc, _desc, &list, desc_node)
+ atc_chain_complete(atchan, desc);
+
+ clear_bit(ATC_IS_PAUSED, &atchan->status);
+ /* if channel dedicated to cyclic operations, free it */
+ clear_bit(ATC_IS_CYCLIC, &atchan->status);
+
+ spin_unlock_bh(&atchan->lock);
+ } else {
+ return -ENXIO;
+ }
return 0;
}
@@ -835,9 +1023,17 @@ atc_tx_status(struct dma_chan *chan,
spin_unlock_bh(&atchan->lock);
- dma_set_tx_state(txstate, last_complete, last_used, 0);
- dev_vdbg(chan2dev(chan), "tx_status: %d (d%d, u%d)\n",
- cookie, last_complete ? last_complete : 0,
+ if (ret != DMA_SUCCESS)
+ dma_set_tx_state(txstate, last_complete, last_used,
+ atc_first_active(atchan)->len);
+ else
+ dma_set_tx_state(txstate, last_complete, last_used, 0);
+
+ if (test_bit(ATC_IS_PAUSED, &atchan->status))
+ ret = DMA_PAUSED;
+
+ 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);
return ret;
@@ -853,6 +1049,10 @@ static void atc_issue_pending(struct dma_chan *chan)
dev_vdbg(chan2dev(chan), "issue_pending\n");
+ /* Not needed for cyclic transfers */
+ if (test_bit(ATC_IS_CYCLIC, &atchan->status))
+ return;
+
spin_lock_bh(&atchan->lock);
if (!atc_chan_is_enabled(atchan)) {
atc_advance_work(atchan);
@@ -959,6 +1159,7 @@ static void atc_free_chan_resources(struct dma_chan *chan)
}
list_splice_init(&atchan->free_list, &list);
atchan->descs_allocated = 0;
+ atchan->status = 0;
dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
}
@@ -1092,10 +1293,15 @@ static int __init at_dma_probe(struct platform_device *pdev)
if (dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask))
atdma->dma_common.device_prep_dma_memcpy = atc_prep_dma_memcpy;
- if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)) {
+ if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask))
atdma->dma_common.device_prep_slave_sg = atc_prep_slave_sg;
+
+ if (dma_has_cap(DMA_CYCLIC, atdma->dma_common.cap_mask))
+ atdma->dma_common.device_prep_dma_cyclic = atc_prep_dma_cyclic;
+
+ if (dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask) ||
+ dma_has_cap(DMA_CYCLIC, atdma->dma_common.cap_mask))
atdma->dma_common.device_control = atc_control;
- }
dma_writel(atdma, EN, AT_DMA_ENABLE);