Re: [PATCH v5 1/5] dmaengine: sun6i-dma: Refactor to support A733 interrupt and register handling

[Frank Li]

On Wed, Aug 26, 2026 at 02:40:27AM +0000, Yuanshen Cao wrote:
> The `sun6i-dma` driver currently uses hardcoded logic for interrupt
> handling (reading/writing interrupt enable and status registers) and
> register dumping.
>
> To support the Allwinner A733, which has a different register layout and
> interrupt handling logic, add `irq_stride`, `irq_en_offset`, and
> `irq_stat_offset` to `struct sun6i_dma_config`. Implement generic
> `sun6i_read/write_irq_*` functions using these new configuration fields
> to accommodate different hardware revisions.
>
> Signed-off-by: Yuanshen Cao <alex.caoys@xxxxxxxxx>
> ---

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>

>  drivers/dma/sun6i-dma.c | 87 +++++++++++++++++++++++++++++++++++++------------
>  1 file changed, 67 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> index f47a326dd7ff..f305fbfb3545 100644
> --- a/drivers/dma/sun6i-dma.c
> +++ b/drivers/dma/sun6i-dma.c
> @@ -27,7 +27,6 @@
>  /*
>   * Common registers
>   */
> -#define DMA_IRQ_EN(x)		((x) * 0x04)
>  #define DMA_IRQ_HALF			BIT(0)
>  #define DMA_IRQ_PKG			BIT(1)
>  #define DMA_IRQ_QUEUE			BIT(2)
> @@ -36,8 +35,6 @@
>  #define DMA_IRQ_CHAN_WIDTH		4
>
>
> -#define DMA_IRQ_STAT(x)		((x) * 0x04 + 0x10)
> -
>  #define DMA_STAT		0x30
>
>  /* Offset between DMA_IRQ_EN and DMA_IRQ_STAT limits number of channels */
> @@ -52,6 +49,14 @@
>  #define SUNXI_H3_SECURE_REG		0x20
>  #define SUNXI_H3_DMA_GATE		0x28
>  #define SUNXI_H3_DMA_GATE_ENABLE	0x4
> +
> +/*
> + * Interrupts specific registers
> + */
> +#define DMA_IRQ_STRIDE_A31		0x04
> +#define DMA_IRQ_EN_OFFSET_A31		0x00
> +#define DMA_IRQ_STAT_OFFSET_A31		0x10
> +
>  /*
>   * Channels specific registers
>   */
> @@ -144,6 +149,9 @@ struct sun6i_dma_config {
>  	u32 dst_addr_widths;
>  	bool has_high_addr;
>  	bool has_mbus_clk;
> +	u32 irq_stride;
> +	u32 irq_en_offset;
> +	u32 irq_stat_offset;
>  };
>
>  /*
> @@ -234,19 +242,43 @@ to_sun6i_desc(struct dma_async_tx_descriptor *tx)
>  	return container_of(tx, struct sun6i_desc, vd.tx);
>  }
>
> +static u32 sun6i_read_irq_en(struct sun6i_dma_dev *sdev, u32 irq_reg)
> +{
> +	return readl(sdev->base + irq_reg * sdev->cfg->irq_stride + sdev->cfg->irq_en_offset);
> +}
> +
> +static void sun6i_write_irq_en(struct sun6i_dma_dev *sdev, u32 irq_reg, u32 irq_val)
> +{
> +	writel(irq_val, sdev->base + irq_reg * sdev->cfg->irq_stride + sdev->cfg->irq_en_offset);
> +}
> +
> +static u32 sun6i_read_irq_stat(struct sun6i_dma_dev *sdev, u32 irq_reg)
> +{
> +	return readl(sdev->base + irq_reg * sdev->cfg->irq_stride + sdev->cfg->irq_stat_offset);
> +}
> +
> +static void sun6i_write_irq_stat(struct sun6i_dma_dev *sdev, u32 irq_reg, u32 status)
> +{
> +	writel(status, sdev->base + irq_reg * sdev->cfg->irq_stride + sdev->cfg->irq_stat_offset);
> +}
> +
>  static inline void sun6i_dma_dump_com_regs(struct sun6i_dma_dev *sdev)
>  {
> -	dev_dbg(sdev->slave.dev, "Common register:\n"
> -		"\tmask0(%04x): 0x%08x\n"
> -		"\tmask1(%04x): 0x%08x\n"
> -		"\tpend0(%04x): 0x%08x\n"
> -		"\tpend1(%04x): 0x%08x\n"
> -		"\tstats(%04x): 0x%08x\n",
> -		DMA_IRQ_EN(0), readl(sdev->base + DMA_IRQ_EN(0)),
> -		DMA_IRQ_EN(1), readl(sdev->base + DMA_IRQ_EN(1)),
> -		DMA_IRQ_STAT(0), readl(sdev->base + DMA_IRQ_STAT(0)),
> -		DMA_IRQ_STAT(1), readl(sdev->base + DMA_IRQ_STAT(1)),
> -		DMA_STAT, readl(sdev->base + DMA_STAT));
> +	int i;
> +
> +	for (i = 0; i < 2; i++) {
> +		dev_dbg(sdev->slave.dev, "Common register:\n"
> +			"chan num %d\n"
> +			"\tmask(%04x): 0x%08x\n"
> +			"\tpend(%04x): 0x%08x\n"
> +			"\tstats(%04x): 0x%08x\n",
> +			i,
> +			i * sdev->cfg->irq_stride + sdev->cfg->irq_en_offset,
> +			sun6i_read_irq_en(sdev, i),
> +			i * sdev->cfg->irq_stride + sdev->cfg->irq_stat_offset,
> +			sun6i_read_irq_stat(sdev, i),
> +			DMA_STAT, readl(sdev->base + DMA_STAT));
> +	}
>  }
>
>  static inline void sun6i_dma_dump_chan_regs(struct sun6i_dma_dev *sdev,
> @@ -460,11 +492,11 @@ static int sun6i_dma_start_desc(struct sun6i_vchan *vchan)
>
>  	vchan->irq_type = vchan->cyclic ? DMA_IRQ_PKG : DMA_IRQ_QUEUE;
>
> -	irq_val = readl(sdev->base + DMA_IRQ_EN(irq_reg));
> +	irq_val = sun6i_read_irq_en(sdev, irq_reg);
>  	irq_val &= ~((DMA_IRQ_HALF | DMA_IRQ_PKG | DMA_IRQ_QUEUE) <<
>  			(irq_offset * DMA_IRQ_CHAN_WIDTH));
>  	irq_val |= vchan->irq_type << (irq_offset * DMA_IRQ_CHAN_WIDTH);
> -	writel(irq_val, sdev->base + DMA_IRQ_EN(irq_reg));
> +	sun6i_write_irq_en(sdev, irq_reg, irq_val);
>
>  	writel(pchan->desc->p_lli, pchan->base + DMA_CHAN_LLI_ADDR);
>  	writel(DMA_CHAN_ENABLE_START, pchan->base + DMA_CHAN_ENABLE);
> @@ -549,14 +581,14 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
>  	u32 status;
>
>  	for (i = 0; i < sdev->num_pchans / DMA_IRQ_CHAN_NR; i++) {
> -		status = readl(sdev->base + DMA_IRQ_STAT(i));
> +		status = sun6i_read_irq_stat(sdev, i);
>  		if (!status)
>  			continue;
>
>  		dev_dbg(sdev->slave.dev, "DMA irq status %s: 0x%x\n",
>  			str_high_low(i), status);
>
> -		writel(status, sdev->base + DMA_IRQ_STAT(i));
> +		sun6i_write_irq_stat(sdev, i, status);
>
>  		for (j = 0; (j < DMA_IRQ_CHAN_NR) && status; j++) {
>  			pchan = sdev->pchans + j;
> @@ -1072,9 +1104,11 @@ 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 < 2; i++)
> +		sun6i_write_irq_en(sdev, i, 0);
>
>  	/* Prevent spurious interrupts from scheduling the tasklet */
>  	atomic_inc(&sdev->tasklet_shutdown);
> @@ -1098,6 +1132,11 @@ static inline void sun6i_dma_free(struct sun6i_dma_dev *sdev)
>  	}
>  }
>
> +#define SUN6I_DMA_IRQ_A31_COMMON_CFG	\
> +	.irq_stride      = DMA_IRQ_STRIDE_A31,	\
> +	.irq_en_offset   = DMA_IRQ_EN_OFFSET_A31,	\
> +	.irq_stat_offset = DMA_IRQ_STAT_OFFSET_A31,
> +
>  /*
>   * For A31:
>   *
> @@ -1129,6 +1168,7 @@ 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),
> +	SUN6I_DMA_IRQ_A31_COMMON_CFG
>  };
>
>  /*
> @@ -1152,6 +1192,7 @@ 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),
> +	SUN6I_DMA_IRQ_A31_COMMON_CFG
>  };
>
>  static struct sun6i_dma_config sun8i_a83t_dma_cfg = {
> @@ -1170,6 +1211,7 @@ 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),
> +	SUN6I_DMA_IRQ_A31_COMMON_CFG
>  };
>
>  /*
> @@ -1197,6 +1239,7 @@ 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),
> +	SUN6I_DMA_IRQ_A31_COMMON_CFG
>  };
>
>  /*
> @@ -1218,6 +1261,7 @@ 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),
> +	SUN6I_DMA_IRQ_A31_COMMON_CFG
>  };
>
>  /*
> @@ -1241,6 +1285,7 @@ static struct sun6i_dma_config sun50i_a100_dma_cfg = {
>  			     BIT(DMA_SLAVE_BUSWIDTH_8_BYTES),
>  	.has_high_addr = true,
>  	.has_mbus_clk = true,
> +	SUN6I_DMA_IRQ_A31_COMMON_CFG
>  };
>
>  /*
> @@ -1263,6 +1308,7 @@ static struct sun6i_dma_config sun50i_h6_dma_cfg = {
>  			     BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
>  			     BIT(DMA_SLAVE_BUSWIDTH_8_BYTES),
>  	.has_mbus_clk = true,
> +	SUN6I_DMA_IRQ_A31_COMMON_CFG
>  };
>
>  /*
> @@ -1286,6 +1332,7 @@ 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),
> +	SUN6I_DMA_IRQ_A31_COMMON_CFG
>  };
>
>  static const struct of_device_id sun6i_dma_match[] = {
>
> --
> 2.55.0
>