Re: [PATCH v2 1/5] dmaengine: sun6i-dma: Refactor to support A733 interrupt and register handling

[Frank Li]

On Sun, Jun 21, 2026 at 09:40:54PM +0000, Yuanshen Cao wrote:
> Refactor to support the Allwinner A733 DMA controller. Currently, the
> `sun6i-dma` driver has several functions related to interrupt handling
> (reading/writing interrupt enable and status registers) and register
> dumping that are hardcoded.
>
> To support the A733, which has different register layouts and interrupt
> handling logic, these functions are being moved into the
> `sun6i_dma_config` structure as function pointers. This allows the
> driver to use a polymorphic approach where the specific implementation
> is determined by the hardware configuration assigned during device
> probing.
>
> Changes:
> - Added function pointers to `struct sun6i_dma_config` for:
>     - `dump_com_regs`
>     - `read_irq_en`
>     - `write_irq_en`
>     - `read_irq_stat`
>     - `write_irq_stat`
> - Implemented generic `sun6i_read/write_irq_*` functions for existing
>   hardware.
> - Added a macro and updated existing `sun6i_dma_config` instances (A31,
>   A23, H3, A64, A100, H6, V3S) to use these new function pointers.
>
> Signed-off-by: Yuanshen Cao <alex.caoys@xxxxxxxxx>
> ---

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

>  drivers/dma/sun6i-dma.c | 50 ++++++++++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 45 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> index a9a254dbf8cb..ef3052c4ab36 100644
> --- a/drivers/dma/sun6i-dma.c
> +++ b/drivers/dma/sun6i-dma.c
> @@ -138,6 +138,11 @@ struct sun6i_dma_config {
>  	void (*set_burst_length)(u32 *p_cfg, s8 src_burst, s8 dst_burst);
>  	void (*set_drq)(u32 *p_cfg, s8 src_drq, s8 dst_drq);
>  	void (*set_mode)(u32 *p_cfg, s8 src_mode, s8 dst_mode);
> +	void (*dump_com_regs)(struct sun6i_dma_dev *sdev);
> +	u32 (*read_irq_en)(struct sun6i_dma_dev *sdev, u32 irq_reg);
> +	void (*write_irq_en)(struct sun6i_dma_dev *sdev, u32 irq_reg, u32 irq_val);
> +	u32 (*read_irq_stat)(struct sun6i_dma_dev *sdev, u32 irq_reg);
> +	void (*write_irq_stat)(struct sun6i_dma_dev *sdev, u32 irq_reg, u32 status);
>  	u32 src_burst_lengths;
>  	u32 dst_burst_lengths;
>  	u32 src_addr_widths;
> @@ -347,6 +352,26 @@ static void sun6i_set_mode_h6(u32 *p_cfg, s8 src_mode, s8 dst_mode)
>  		  DMA_CHAN_CFG_DST_MODE_H6(dst_mode);
>  }
>
> +static u32 sun6i_read_irq_en(struct sun6i_dma_dev *sdev, u32 irq_reg)
> +{
> +	return readl(sdev->base + DMA_IRQ_EN(irq_reg));
> +}
> +
> +static void sun6i_write_irq_en(struct sun6i_dma_dev *sdev, u32 irq_reg, u32 irq_val)
> +{
> +	writel(irq_val, sdev->base + DMA_IRQ_EN(irq_reg));
> +}
> +
> +static u32 sun6i_read_irq_stat(struct sun6i_dma_dev *sdev, u32 irq_reg)
> +{
> +	return readl(sdev->base + DMA_IRQ_STAT(irq_reg));
> +}
> +
> +static void sun6i_write_irq_stat(struct sun6i_dma_dev *sdev, u32 irq_reg, u32 status)
> +{
> +	writel(status, sdev->base + DMA_IRQ_STAT(irq_reg));
> +}
> +
>  static size_t sun6i_get_chan_size(struct sun6i_pchan *pchan)
>  {
>  	struct sun6i_desc *txd = pchan->desc;
> @@ -460,16 +485,16 @@ 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 = sdev->cfg->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));
> +	sdev->cfg->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);
>
> -	sun6i_dma_dump_com_regs(sdev);
> +	sdev->cfg->dump_com_regs(sdev);
>  	sun6i_dma_dump_chan_regs(sdev, pchan);
>
>  	return 0;
> @@ -549,14 +574,14 @@ 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 = sdev->cfg->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));
> +		sdev->cfg->write_irq_stat(sdev, i, status);
>
>  		for (j = 0; (j < DMA_IRQ_CHAN_NR) && status; j++) {
>  			pchan = sdev->pchans + j;
> @@ -1101,6 +1126,13 @@ static inline void sun6i_dma_free(struct sun6i_dma_dev *sdev)
>  	}
>  }
>
> +#define SUN6I_DMA_IRQ_A31_COMMON_OPS	\
> +	.dump_com_regs    = sun6i_dma_dump_com_regs,	\
> +	.read_irq_en      = sun6i_read_irq_en,	\
> +	.write_irq_en     = sun6i_write_irq_en,	\
> +	.read_irq_stat    = sun6i_read_irq_stat,	\
> +	.write_irq_stat   = sun6i_write_irq_stat,
> +
>  /*
>   * For A31:
>   *
> @@ -1132,6 +1164,7 @@ 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_OPS
>  };
>
>  /*
> @@ -1155,6 +1188,7 @@ 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_OPS
>  };
>
>  static struct sun6i_dma_config sun8i_a83t_dma_cfg = {
> @@ -1173,6 +1207,7 @@ 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_OPS
>  };
>
>  /*
> @@ -1200,6 +1235,7 @@ 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_OPS
>  };
>
>  /*
> @@ -1221,6 +1257,7 @@ 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_OPS
>  };
>
>  /*
> @@ -1244,6 +1281,7 @@ 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_OPS
>  };
>
>  /*
> @@ -1266,6 +1304,7 @@ 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_OPS
>  };
>
>  /*
> @@ -1289,6 +1328,7 @@ 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_OPS
>  };
>
>  static const struct of_device_id sun6i_dma_match[] = {
>
> --
> 2.54.0
>