From: Li Yu <liyu65@xxxxxxxxxxxxx>
On k3 series of SoC, DMA controller reserves some channels for
other on-chip coprocessors. By reading property "hisilicon,dma-min-chan"
from dts node, kernel will not use these reserved channels.
As an example, on Hi3660, channel 0 is reserved for lpm3.
Refer to Documentation/devicetree/bindings/dma/k3dma.txt for more
information.
Signed-off-by: Li Yu <liyu65@xxxxxxxxxxxxx>
Signed-off-by: Guodong Xu <guodong.xu@xxxxxxxxxx>
---
drivers/dma/k3dma.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c
index fa31cccbe04f..33efb541acb2 100644
--- a/drivers/dma/k3dma.c
+++ b/drivers/dma/k3dma.c
@@ -113,6 +113,7 @@ struct k3_dma_dev {
struct dma_pool *pool;
u32 dma_channels;
u32 dma_requests;
+ u32 dma_min_chan;
unsigned int irq;
};
@@ -309,7 +310,7 @@ static void k3_dma_tasklet(unsigned long arg)
/* check new channel request in d->chan_pending */
spin_lock_irq(&d->lock);
- for (pch = 0; pch < d->dma_channels; pch++) {
+ for (pch = d->dma_min_chan; pch < d->dma_channels; pch++) {
p = &d->phy[pch];
if (p->vchan == NULL && !list_empty(&d->chan_pending)) {
@@ -326,7 +327,7 @@ static void k3_dma_tasklet(unsigned long arg)
}
spin_unlock_irq(&d->lock);
- for (pch = 0; pch < d->dma_channels; pch++) {
+ for (pch = d->dma_min_chan; pch < d->dma_channels; pch++) {
if (pch_alloc & (1 << pch)) {
p = &d->phy[pch];
c = p->vchan;
@@ -825,6 +826,8 @@ static int k3_dma_probe(struct platform_device *op)
"dma-channels", &d->dma_channels);
of_property_read_u32((&op->dev)->of_node,
"dma-requests", &d->dma_requests);
+ of_property_read_u32((&op->dev)->of_node,
+ "hisilicon,dma-min-chan", &d->dma_min_chan);
}
d->clk = devm_clk_get(&op->dev, NULL);
@@ -848,12 +851,12 @@ static int k3_dma_probe(struct platform_device *op)
return -ENOMEM;
/* init phy channel */
- d->phy = devm_kcalloc(&op->dev,
- d->dma_channels, sizeof(struct k3_dma_phy), GFP_KERNEL);
+ d->phy = devm_kcalloc(&op->dev, (d->dma_channels - d->dma_min_chan),
+ sizeof(struct k3_dma_phy), GFP_KERNEL);
if (d->phy == NULL)
return -ENOMEM;
- for (i = 0; i < d->dma_channels; i++) {
+ for (i = d->dma_min_chan; i < d->dma_channels; i++) {
struct k3_dma_phy *p = &d->phy[i];
p->idx = i;
--
2.17.1
--
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