[PATCH 32/32] dma40: cyclic xfer support

From: Linus Walleij
Date: Tue Jan 25 2011 - 05:20:09 EST

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From: Rabin Vincent <rabin.vincent@xxxxxxxxxxxxxx>

Support cyclic transfers, which are useful for ALSA drivers.

Acked-by: Per Forlin <per.forlin@xxxxxxxxxxxxxx>
Acked-by: Jonas Aaberg <jonas.aberg@xxxxxxxxxxxxxx>
Signed-off-by: Rabin Vincent <rabin.vincent@xxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
---
drivers/dma/ste_dma40.c | 172 +++++++++++++++++++++++++++++++++++--------
drivers/dma/ste_dma40_ll.c | 35 ++++++----
drivers/dma/ste_dma40_ll.h | 9 ++-
3 files changed, 167 insertions(+), 49 deletions(-)

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 8fd0bb9..af955de 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -115,6 +115,7 @@ struct d40_desc {
struct list_head node;

bool is_in_client_list;
+ bool cyclic;
};

/**
@@ -527,17 +528,45 @@ static void d40_log_lli_to_lcxa(struct d40_chan *chan, struct d40_desc *desc)
struct d40_log_lli_bidir *lli = &desc->lli_log;
int lli_current = desc->lli_current;
int lli_len = desc->lli_len;
+ bool cyclic = desc->cyclic;
int curr_lcla = -EINVAL;
+ int first_lcla = 0;
+ bool linkback;

- if (lli_len - lli_current > 1)
+ /*
+ * We may have partially running cyclic transfers, in case we did't get
+ * enough LCLA entries.
+ */
+ linkback = cyclic && lli_current == 0;
+
+ /*
+ * For linkback, we need one LCLA even with only one link, because we
+ * can't link back to the one in LCPA space
+ */
+ if (linkback || (lli_len - lli_current > 1)) {
curr_lcla = d40_lcla_alloc_one(chan, desc);
+ first_lcla = curr_lcla;
+ }
+
+ /*
+ * For linkback, we normally load the LCPA in the loop since we need to
+ * link it to the second LCLA and not the first. However, if we
+ * couldn't even get a first LCLA, then we have to run in LCPA and
+ * reload manually.
+ */
+ if (!linkback || curr_lcla == -EINVAL) {
+ unsigned int flags = 0;

- d40_log_lli_lcpa_write(chan->lcpa,
- &lli->dst[lli_current],
- &lli->src[lli_current],
- curr_lcla);
+ if (curr_lcla == -EINVAL)
+ flags |= LLI_TERM_INT;

- lli_current++;
+ d40_log_lli_lcpa_write(chan->lcpa,
+ &lli->dst[lli_current],
+ &lli->src[lli_current],
+ curr_lcla,
+ flags);
+ lli_current++;
+ }

if (curr_lcla < 0)
goto out;
@@ -546,17 +575,33 @@ static void d40_log_lli_to_lcxa(struct d40_chan *chan, struct d40_desc *desc)
unsigned int lcla_offset = chan->phy_chan->num * 1024 +
8 * curr_lcla * 2;
struct d40_log_lli *lcla = pool->base + lcla_offset;
+ unsigned int flags = 0;
int next_lcla;

if (lli_current + 1 < lli_len)
next_lcla = d40_lcla_alloc_one(chan, desc);
else
- next_lcla = -EINVAL;
+ next_lcla = linkback ? first_lcla : -EINVAL;
+
+ if (cyclic || next_lcla == -EINVAL)
+ flags |= LLI_TERM_INT;

+ if (linkback && curr_lcla == first_lcla) {
+ /* First link goes in both LCPA and LCLA */
+ d40_log_lli_lcpa_write(chan->lcpa,
+ &lli->dst[lli_current],
+ &lli->src[lli_current],
+ next_lcla, flags);
+ }
+
+ /*
+ * One unused LCLA in the cyclic case if the very first
+ * next_lcla fails...
+ */
d40_log_lli_lcla_write(lcla,
&lli->dst[lli_current],
&lli->src[lli_current],
- next_lcla);
+ next_lcla, flags);

dma_sync_single_range_for_device(chan->base->dev,
pool->dma_addr, lcla_offset,
@@ -565,7 +610,7 @@ static void d40_log_lli_to_lcxa(struct d40_chan *chan, struct d40_desc *desc)

curr_lcla = next_lcla;

- if (curr_lcla == -EINVAL) {
+ if (curr_lcla == -EINVAL || curr_lcla == first_lcla) {
lli_current++;
break;
}
@@ -1074,17 +1119,36 @@ static void dma_tc_handle(struct d40_chan *d40c)
if (d40d == NULL)
return;

- d40_lcla_free_all(d40c, d40d);
+ if (d40d->cyclic) {
+ /*
+ * If this was a paritially loaded list, we need to reloaded
+ * it, and only when the list is completed. We need to check
+ * for done because the interrupt will hit for every link, and
+ * not just the last one.
+ */
+ if (d40d->lli_current < d40d->lli_len
+ && !d40_tx_is_linked(d40c)
+ && !d40_residue(d40c)) {
+ d40_lcla_free_all(d40c, d40d);
+ d40_desc_load(d40c, d40d);
+ (void) d40_start(d40c);

- if (d40d->lli_current < d40d->lli_len) {
- d40_desc_load(d40c, d40d);
- /* Start dma job */
- (void) d40_start(d40c);
- return;
- }
+ if (d40d->lli_current == d40d->lli_len)
+ d40d->lli_current = 0;
+ }
+ } else {
+ d40_lcla_free_all(d40c, d40d);

- if (d40_queue_start(d40c) == NULL)
- d40c->busy = false;
+ if (d40d->lli_current < d40d->lli_len) {
+ d40_desc_load(d40c, d40d);
+ /* Start dma job */
+ (void) d40_start(d40c);
+ return;
+ }
+
+ if (d40_queue_start(d40c) == NULL)
+ d40c->busy = false;
+ }

d40c->pending_tx++;
tasklet_schedule(&d40c->tasklet);
@@ -1103,11 +1167,11 @@ static void dma_tasklet(unsigned long data)

/* Get first active entry from list */
d40d = d40_first_active_get(d40c);
-
if (d40d == NULL)
goto err;

- d40c->completed = d40d->txd.cookie;
+ if (!d40d->cyclic)
+ d40c->completed = d40d->txd.cookie;

/*
* If terminating a channel pending_tx is set to zero.
@@ -1122,16 +1186,18 @@ static void dma_tasklet(unsigned long data)
callback = d40d->txd.callback;
callback_param = d40d->txd.callback_param;

- if (async_tx_test_ack(&d40d->txd)) {
- d40_pool_lli_free(d40c, d40d);
- d40_desc_remove(d40d);
- d40_desc_free(d40c, d40d);
- } else {
- if (!d40d->is_in_client_list) {
+ if (!d40d->cyclic) {
+ if (async_tx_test_ack(&d40d->txd)) {
+ d40_pool_lli_free(d40c, d40d);
d40_desc_remove(d40d);
- d40_lcla_free_all(d40c, d40d);
- list_add_tail(&d40d->node, &d40c->client);
- d40d->is_in_client_list = true;
+ d40_desc_free(d40c, d40d);
+ } else {
+ if (!d40d->is_in_client_list) {
+ d40_desc_remove(d40d);
+ d40_lcla_free_all(d40c, d40d);
+ list_add_tail(&d40d->node, &d40c->client);
+ d40d->is_in_client_list = true;
+ }
}
}

@@ -1694,19 +1760,23 @@ d40_prep_sg_phy(struct d40_chan *chan, struct d40_desc *desc,
struct stedma40_chan_cfg *cfg = &chan->dma_cfg;
struct stedma40_half_channel_info *src_info = &cfg->src_info;
struct stedma40_half_channel_info *dst_info = &cfg->dst_info;
+ unsigned long flags = 0;
int ret;

+ if (desc->cyclic)
+ flags |= LLI_CYCLIC | LLI_TERM_INT;
+
ret = d40_phy_sg_to_lli(sg_src, sg_len, src_dev_addr,
desc->lli_phy.src,
virt_to_phys(desc->lli_phy.src),
chan->src_def_cfg,
- src_info, dst_info);
+ src_info, dst_info, flags);

ret = d40_phy_sg_to_lli(sg_dst, sg_len, dst_dev_addr,
desc->lli_phy.dst,
virt_to_phys(desc->lli_phy.dst),
chan->dst_def_cfg,
- dst_info, src_info);
+ dst_info, src_info, flags);

dma_sync_single_for_device(chan->base->dev, desc->lli_pool.dma_addr,
desc->lli_pool.size, DMA_TO_DEVICE);
@@ -1789,12 +1859,16 @@ d40_prep_sg(struct dma_chan *dchan, struct scatterlist *sg_src,
return NULL;
}

+
spin_lock_irqsave(&chan->lock, flags);

desc = d40_prep_desc(chan, sg_src, sg_len, dma_flags);
if (desc == NULL)
goto err;

+ if (sg_next(&sg_src[sg_len - 1]) == sg_src)
+ desc->cyclic = true;
+
if (direction != DMA_NONE) {
dma_addr_t dev_addr = d40_get_dev_addr(chan, direction);

@@ -2007,6 +2081,36 @@ static struct dma_async_tx_descriptor *d40_prep_slave_sg(struct dma_chan *chan,
return d40_prep_sg(chan, sgl, sgl, sg_len, direction, dma_flags);
}

+static struct dma_async_tx_descriptor *
+dma40_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t dma_addr,
+ size_t buf_len, size_t period_len,
+ enum dma_data_direction direction)
+{
+ unsigned int periods = buf_len / period_len;
+ struct dma_async_tx_descriptor *txd;
+ struct scatterlist *sg;
+ int i;
+
+ sg = kcalloc(periods + 1, sizeof(struct scatterlist), GFP_KERNEL);
+ for (i = 0; i < periods; i++) {
+ sg_dma_address(&sg[i]) = dma_addr;
+ sg_dma_len(&sg[i]) = period_len;
+ dma_addr += period_len;
+ }
+
+ sg[periods].offset = 0;
+ sg[periods].length = 0;
+ sg[periods].page_link =
+ ((unsigned long)sg | 0x01) & ~0x02;
+
+ txd = d40_prep_sg(chan, sg, sg, periods, direction,
+ DMA_PREP_INTERRUPT);
+
+ kfree(sg);
+
+ return txd;
+}
+
static enum dma_status d40_tx_status(struct dma_chan *chan,
dma_cookie_t cookie,
struct dma_tx_state *txstate)
@@ -2264,6 +2368,9 @@ static void d40_ops_init(struct d40_base *base, struct dma_device *dev)
if (dma_has_cap(DMA_SG, dev->cap_mask))
dev->device_prep_dma_sg = d40_prep_memcpy_sg;

+ if (dma_has_cap(DMA_CYCLIC, dev->cap_mask))
+ dev->device_prep_dma_cyclic = dma40_prep_dma_cyclic;
+
dev->device_alloc_chan_resources = d40_alloc_chan_resources;
dev->device_free_chan_resources = d40_free_chan_resources;
dev->device_issue_pending = d40_issue_pending;
@@ -2282,6 +2389,7 @@ static int __init d40_dmaengine_init(struct d40_base *base,

dma_cap_zero(base->dma_slave.cap_mask);
dma_cap_set(DMA_SLAVE, base->dma_slave.cap_mask);
+ dma_cap_set(DMA_CYCLIC, base->dma_slave.cap_mask);

d40_ops_init(base, &base->dma_slave);

@@ -2316,9 +2424,9 @@ static int __init d40_dmaengine_init(struct d40_base *base,
dma_cap_set(DMA_SLAVE, base->dma_both.cap_mask);
dma_cap_set(DMA_MEMCPY, base->dma_both.cap_mask);
dma_cap_set(DMA_SG, base->dma_both.cap_mask);
+ dma_cap_set(DMA_CYCLIC, base->dma_slave.cap_mask);

d40_ops_init(base, &base->dma_both);
-
err = dma_async_device_register(&base->dma_both);

if (err) {
diff --git a/drivers/dma/ste_dma40_ll.c b/drivers/dma/ste_dma40_ll.c
index 88b9e37..cad9e1d 100644
--- a/drivers/dma/ste_dma40_ll.c
+++ b/drivers/dma/ste_dma40_ll.c
@@ -202,13 +202,15 @@ static int d40_seg_size(int size, int data_width1, int data_width2)

static struct d40_phy_lli *
d40_phy_buf_to_lli(struct d40_phy_lli *lli, dma_addr_t addr, u32 size,
- dma_addr_t lli_phys, u32 reg_cfg,
+ dma_addr_t lli_phys, dma_addr_t first_phys, u32 reg_cfg,
struct stedma40_half_channel_info *info,
struct stedma40_half_channel_info *otherinfo,
unsigned long flags)
{
+ bool lastlink = flags & LLI_LAST_LINK;
bool addr_inc = flags & LLI_ADDR_INC;
bool term_int = flags & LLI_TERM_INT;
+ bool cyclic = flags & LLI_CYCLIC;
int err;
dma_addr_t next = lli_phys;
int size_rest = size;
@@ -226,10 +228,12 @@ d40_phy_buf_to_lli(struct d40_phy_lli *lli, dma_addr_t addr, u32 size,
otherinfo->data_width);
size_rest -= size_seg;

- if (term_int && size_rest == 0) {
- next = 0;
+ if (size_rest == 0 && term_int)
flags |= LLI_TERM_INT;
- } else
+
+ if (size_rest == 0 && lastlink)
+ next = cyclic ? first_phys : 0;
+ else
next = ALIGN(next + sizeof(struct d40_phy_lli),
D40_LLI_ALIGN);

@@ -257,14 +261,14 @@ int d40_phy_sg_to_lli(struct scatterlist *sg,
dma_addr_t lli_phys,
u32 reg_cfg,
struct stedma40_half_channel_info *info,
- struct stedma40_half_channel_info *otherinfo)
+ struct stedma40_half_channel_info *otherinfo,
+ unsigned long flags)
{
int total_size = 0;
int i;
struct scatterlist *current_sg = sg;
struct d40_phy_lli *lli = lli_sg;
dma_addr_t l_phys = lli_phys;
- unsigned long flags = 0;

if (!target)
flags |= LLI_ADDR_INC;
@@ -277,12 +281,12 @@ int d40_phy_sg_to_lli(struct scatterlist *sg,
total_size += sg_dma_len(current_sg);

if (i == sg_len - 1)
- flags |= LLI_TERM_INT;
+ flags |= LLI_TERM_INT | LLI_LAST_LINK;

l_phys = ALIGN(lli_phys + (lli - lli_sg) *
sizeof(struct d40_phy_lli), D40_LLI_ALIGN);

- lli = d40_phy_buf_to_lli(lli, dst, len, l_phys,
+ lli = d40_phy_buf_to_lli(lli, dst, len, l_phys, lli_phys,
reg_cfg, info, otherinfo, flags);

if (lli == NULL)
@@ -297,15 +301,18 @@ int d40_phy_sg_to_lli(struct scatterlist *sg,

static void d40_log_lli_link(struct d40_log_lli *lli_dst,
struct d40_log_lli *lli_src,
- int next)
+ int next, unsigned int flags)
{
+ bool interrupt = flags & LLI_TERM_INT;
u32 slos = 0;
u32 dlos = 0;

if (next != -EINVAL) {
slos = next * 2;
dlos = next * 2 + 1;
- } else {
+ }
+
+ if (interrupt) {
lli_dst->lcsp13 |= D40_MEM_LCSP1_SCFG_TIM_MASK;
lli_dst->lcsp13 |= D40_MEM_LCSP3_DTCP_MASK;
}
@@ -320,9 +327,9 @@ static void d40_log_lli_link(struct d40_log_lli *lli_dst,
void d40_log_lli_lcpa_write(struct d40_log_lli_full *lcpa,
struct d40_log_lli *lli_dst,
struct d40_log_lli *lli_src,
- int next)
+ int next, unsigned int flags)
{
- d40_log_lli_link(lli_dst, lli_src, next);
+ d40_log_lli_link(lli_dst, lli_src, next, flags);

writel(lli_src->lcsp02, &lcpa[0].lcsp0);
writel(lli_src->lcsp13, &lcpa[0].lcsp1);
@@ -333,9 +340,9 @@ void d40_log_lli_lcpa_write(struct d40_log_lli_full *lcpa,
void d40_log_lli_lcla_write(struct d40_log_lli *lcla,
struct d40_log_lli *lli_dst,
struct d40_log_lli *lli_src,
- int next)
+ int next, unsigned int flags)
{
- d40_log_lli_link(lli_dst, lli_src, next);
+ d40_log_lli_link(lli_dst, lli_src, next, flags);

writel(lli_src->lcsp02, &lcla[0].lcsp02);
writel(lli_src->lcsp13, &lcla[0].lcsp13);
diff --git a/drivers/dma/ste_dma40_ll.h b/drivers/dma/ste_dma40_ll.h
index 59e72f0..195ee65 100644
--- a/drivers/dma/ste_dma40_ll.h
+++ b/drivers/dma/ste_dma40_ll.h
@@ -296,6 +296,8 @@ struct d40_def_lcsp {
enum d40_lli_flags {
LLI_ADDR_INC = 1 << 0,
LLI_TERM_INT = 1 << 1,
+ LLI_CYCLIC = 1 << 2,
+ LLI_LAST_LINK = 1 << 3,
};

void d40_phy_cfg(struct stedma40_chan_cfg *cfg,
@@ -314,7 +316,8 @@ int d40_phy_sg_to_lli(struct scatterlist *sg,
dma_addr_t lli_phys,
u32 reg_cfg,
struct stedma40_half_channel_info *info,
- struct stedma40_half_channel_info *otherinfo);
+ struct stedma40_half_channel_info *otherinfo,
+ unsigned long flags);

/* Logical channels */

@@ -328,11 +331,11 @@ int d40_log_sg_to_lli(struct scatterlist *sg,
void d40_log_lli_lcpa_write(struct d40_log_lli_full *lcpa,
struct d40_log_lli *lli_dst,
struct d40_log_lli *lli_src,
- int next);
+ int next, unsigned int flags);

void d40_log_lli_lcla_write(struct d40_log_lli *lcla,
struct d40_log_lli *lli_dst,
struct d40_log_lli *lli_src,
- int next);
+ int next, unsigned int flags);

#endif /* STE_DMA40_LLI_H */
--
1.7.3.2

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Next message: Linus Walleij: "[PATCH 20/32] dma40: combine mem and slave prep_sg functions"
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