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

[Frank Li]

On Fri, Jun 19, 2026 at 04:53:30AM +0000, Yuanshen Cao wrote:
>
> This patch is the first step in a refactoring effort to support the

avoid use "this patch/commit", Just

Refactor ... to support Allwinner A733 DMA controller.

> 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.
> - 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>
> ---
>  drivers/dma/sun6i-dma.c | 74 +++++++++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 69 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> index a9a254dbf8cb..d92e702320d9 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 chan_num);
> +       void (*write_irq_en)(struct sun6i_dma_dev *sdev, u32 chan_num, u32 irq_val);
> +       u32 (*read_irq_stat)(struct sun6i_dma_dev *sdev, u32 chan_num);
> +       void (*write_irq_stat)(struct sun6i_dma_dev *sdev, u32 chan_num, u32 status);
>         u32 src_burst_lengths;
>         u32 dst_burst_lengths;
>         u32 src_addr_widths;
> @@ -347,6 +352,25 @@ 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 chan_num)
> +{
> +       return readl(sdev->base + DMA_IRQ_EN(chan_num));
> +}
> +
> +static void sun6i_write_irq_en(struct sun6i_dma_dev *sdev, u32 chan_num, u32 irq_val)
> +{
> +       writel(irq_val, sdev->base + DMA_IRQ_EN(chan_num));
> +}
> +static u32 sun6i_read_irq_stat(struct sun6i_dma_dev *sdev, u32 chan_num)
> +{
> +       return readl(sdev->base + DMA_IRQ_STAT(chan_num));
> +}
> +
> +static void sun6i_write_irq_stat(struct sun6i_dma_dev *sdev, u32 chan_num, u32 status)
> +{
> +       writel(status, sdev->base + DMA_IRQ_STAT(chan_num));
> +}
> +
>  static size_t sun6i_get_chan_size(struct sun6i_pchan *pchan)
>  {
>         struct sun6i_desc *txd = pchan->desc;
> @@ -460,16 +484,16 @@ 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 +573,14 @@ 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;
> @@ -1124,6 +1148,11 @@ static struct sun6i_dma_config sun6i_a31_dma_cfg = {
>         .set_burst_length = sun6i_set_burst_length_a31,
>         .set_drq          = sun6i_set_drq_a31,
>         .set_mode         = sun6i_set_mode_a31,
> +       .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,

Can you define macro like to avoid duplicate these init code. Or set it at
probe if it is NULL.

Frank

>         .src_burst_lengths = BIT(1) | BIT(8),
>         .dst_burst_lengths = BIT(1) | BIT(8),
>         .src_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> @@ -1147,6 +1176,11 @@ static struct sun6i_dma_config sun8i_a23_dma_cfg = {
>         .set_burst_length = sun6i_set_burst_length_a31,
>         .set_drq          = sun6i_set_drq_a31,
>         .set_mode         = sun6i_set_mode_a31,
> +       .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,
>         .src_burst_lengths = BIT(1) | BIT(8),
>         .dst_burst_lengths = BIT(1) | BIT(8),
>         .src_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> @@ -1165,6 +1199,11 @@ static struct sun6i_dma_config sun8i_a83t_dma_cfg = {
>         .set_burst_length = sun6i_set_burst_length_a31,
>         .set_drq          = sun6i_set_drq_a31,
>         .set_mode         = sun6i_set_mode_a31,
> +       .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,
>         .src_burst_lengths = BIT(1) | BIT(8),
>         .dst_burst_lengths = BIT(1) | BIT(8),
>         .src_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> @@ -1190,6 +1229,11 @@ static struct sun6i_dma_config sun8i_h3_dma_cfg = {
>         .set_burst_length = sun6i_set_burst_length_h3,
>         .set_drq          = sun6i_set_drq_a31,
>         .set_mode         = sun6i_set_mode_a31,
> +       .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,
>         .src_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
>         .dst_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
>         .src_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> @@ -1211,6 +1255,11 @@ static struct sun6i_dma_config sun50i_a64_dma_cfg = {
>         .set_burst_length = sun6i_set_burst_length_h3,
>         .set_drq          = sun6i_set_drq_a31,
>         .set_mode         = sun6i_set_mode_a31,
> +       .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,
>         .src_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
>         .dst_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
>         .src_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> @@ -1232,6 +1281,11 @@ static struct sun6i_dma_config sun50i_a100_dma_cfg = {
>         .set_burst_length = sun6i_set_burst_length_h3,
>         .set_drq          = sun6i_set_drq_h6,
>         .set_mode         = sun6i_set_mode_h6,
> +       .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,
>         .src_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
>         .dst_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
>         .src_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> @@ -1255,6 +1309,11 @@ static struct sun6i_dma_config sun50i_h6_dma_cfg = {
>         .set_burst_length = sun6i_set_burst_length_h3,
>         .set_drq          = sun6i_set_drq_h6,
>         .set_mode         = sun6i_set_mode_h6,
> +       .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,
>         .src_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
>         .dst_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
>         .src_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> @@ -1281,6 +1340,11 @@ static struct sun6i_dma_config sun8i_v3s_dma_cfg = {
>         .set_burst_length = sun6i_set_burst_length_a31,
>         .set_drq          = sun6i_set_drq_a31,
>         .set_mode         = sun6i_set_mode_a31,
> +       .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,
>         .src_burst_lengths = BIT(1) | BIT(8),
>         .dst_burst_lengths = BIT(1) | BIT(8),
>         .src_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
>
> --
> 2.54.0
>