[PATCH v2 3/5] dmaengine: sun6i-dma: Add num_channels_per_reg for flexible interrupt mapping
From: Yuanshen Cao
Date: Sun Jun 21 2026 - 17:44:40 EST
The previous implementation of `sun6i-dma` had some implicit assumptions
about the number of channels per interrupt register. Specifically,
functions like `sun6i_kill_tasklet` were hardcoded to only disable
interrupts for IRQ 0 and 1. `DMA_MAX_CHANNELS` is also not in used in
the past, and the old SoCs never has more than 16 channels.
The A733 has a different interrupt structure where the number of
channels per register may differ. This patch introduces
`num_channels_per_reg` to the `sun6i_dma_config`, similar to BSP, to
make the interrupt handling logic hardware-agnostic. It also sets
`DMA_MAX_CHANNELS` to 16 to align with the new BSP code and ensure loops
over interrupts are correctly bounded.
Changes:
- Change `DMA_MAX_CHANNELS` definition to 16.
- Added `num_channels_per_reg` to `struct sun6i_dma_config`.
- Replaced hardcoded IRQ register calculations with values from
`sdev->cfg->num_channels_per_reg`.
- Updated `sun6i_kill_tasklet` to loop through all possible interrupt
registers based on `DMA_MAX_CHANNELS` and the configuration.
Signed-off-by: Yuanshen Cao <alex.caoys@xxxxxxxxx>
---
drivers/dma/sun6i-dma.c | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)
diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index 9984b9033cbb..196a0d73b221 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -41,7 +41,7 @@
#define DMA_STAT 0x30
/* Offset between DMA_IRQ_EN and DMA_IRQ_STAT limits number of channels */
-#define DMA_MAX_CHANNELS (DMA_IRQ_CHAN_NR * 0x10 / 4)
+#define DMA_MAX_CHANNELS 16
/*
* sun8i specific registers
@@ -151,6 +151,7 @@ struct sun6i_dma_config {
u32 src_addr_widths;
u32 dst_addr_widths;
bool has_mbus_clk;
+ u32 num_channels_per_reg;
};
/*
@@ -482,8 +483,8 @@ static int sun6i_dma_start_desc(struct sun6i_vchan *vchan)
sun6i_dma_dump_lli(vchan, pchan->desc->v_lli, pchan->desc->p_lli);
- irq_reg = pchan->idx / DMA_IRQ_CHAN_NR;
- irq_offset = pchan->idx % DMA_IRQ_CHAN_NR;
+ irq_reg = pchan->idx / sdev->cfg->num_channels_per_reg;
+ irq_offset = pchan->idx % sdev->cfg->num_channels_per_reg;
vchan->irq_type = vchan->cyclic ? DMA_IRQ_PKG : DMA_IRQ_QUEUE;
@@ -575,7 +576,7 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
int i, j, ret = IRQ_NONE;
u32 status;
- for (i = 0; i < sdev->num_pchans / DMA_IRQ_CHAN_NR; i++) {
+ for (i = 0; i < sdev->num_pchans / sdev->cfg->num_channels_per_reg; i++) {
status = sdev->cfg->read_irq_stat(sdev, i);
if (!status)
continue;
@@ -585,7 +586,7 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
sdev->cfg->write_irq_stat(sdev, i, status);
- for (j = 0; (j < DMA_IRQ_CHAN_NR) && status; j++) {
+ for (j = 0; (j < sdev->cfg->num_channels_per_reg) && status; j++) {
pchan = sdev->pchans + j;
vchan = pchan->vchan;
if (vchan && (status & vchan->irq_type)) {
@@ -1116,9 +1117,11 @@ static struct dma_chan *sun6i_dma_of_xlate(struct of_phandle_args *dma_spec,
static inline void sun6i_kill_tasklet(struct sun6i_dma_dev *sdev)
{
+ int i;
+
/* Disable all interrupts from DMA */
- writel(0, sdev->base + DMA_IRQ_EN(0));
- writel(0, sdev->base + DMA_IRQ_EN(1));
+ for (i = 0; i < DMA_MAX_CHANNELS / sdev->cfg->num_channels_per_reg; i++)
+ sdev->cfg->write_irq_en(sdev, i, 0);
/* Prevent spurious interrupts from scheduling the tasklet */
atomic_inc(&sdev->tasklet_shutdown);
@@ -1181,6 +1184,7 @@ static struct sun6i_dma_config sun6i_a31_dma_cfg = {
.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES),
+ .num_channels_per_reg = DMA_IRQ_CHAN_NR,
SUN6I_DMA_IRQ_A31_COMMON_OPS
};
@@ -1206,6 +1210,7 @@ static struct sun6i_dma_config sun8i_a23_dma_cfg = {
.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES),
+ .num_channels_per_reg = DMA_IRQ_CHAN_NR,
SUN6I_DMA_IRQ_A31_COMMON_OPS
};
@@ -1226,6 +1231,7 @@ static struct sun6i_dma_config sun8i_a83t_dma_cfg = {
.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES),
+ .num_channels_per_reg = DMA_IRQ_CHAN_NR,
SUN6I_DMA_IRQ_A31_COMMON_OPS
};
@@ -1255,6 +1261,7 @@ static struct sun6i_dma_config sun8i_h3_dma_cfg = {
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES),
+ .num_channels_per_reg = DMA_IRQ_CHAN_NR,
SUN6I_DMA_IRQ_A31_COMMON_OPS
};
@@ -1278,6 +1285,7 @@ static struct sun6i_dma_config sun50i_a64_dma_cfg = {
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES),
+ .num_channels_per_reg = DMA_IRQ_CHAN_NR,
SUN6I_DMA_IRQ_A31_COMMON_OPS
};
@@ -1301,6 +1309,7 @@ static struct sun6i_dma_config sun50i_a100_dma_cfg = {
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES),
+ .num_channels_per_reg = DMA_IRQ_CHAN_NR,
.has_mbus_clk = true,
SUN6I_DMA_IRQ_A31_COMMON_OPS
};
@@ -1325,6 +1334,7 @@ static struct sun6i_dma_config sun50i_h6_dma_cfg = {
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_8_BYTES),
+ .num_channels_per_reg = DMA_IRQ_CHAN_NR,
.has_mbus_clk = true,
SUN6I_DMA_IRQ_A31_COMMON_OPS
};
@@ -1351,6 +1361,7 @@ static struct sun6i_dma_config sun8i_v3s_dma_cfg = {
.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES),
+ .num_channels_per_reg = DMA_IRQ_CHAN_NR,
SUN6I_DMA_IRQ_A31_COMMON_OPS
};
--
2.54.0