Re: [PATCH 2/5] dmaengine: sun6i-dma: Add set_addr function pointer for variable address widths

[Frank Li]

On Fri, Jun 19, 2026 at 04:53:31AM +0000, Yuanshen Cao wrote:
>
> The A733 DMA controller supports higher address (up to 32G) compared to
> previous generations. The existing `sun6i_dma_set_addr` function uses a
> hardcoded logic for setting the high-address bits in the LLI parameters.
>
> By moving `set_addr` into the `sun6i_dma_config` structure, we can
> provide specialized implementations for different hardware. This allows
> the A733 to use a version of `set_addr` that correctly handles its
> specific `SRC_HIGH_ADDR_32G` and `DST_HIGH_ADDR_32G` in the `set_addr`
> register later in the series.
>
> Changes:
> - Added `set_addr` function pointer to `struct sun6i_dma_config`.
> - Refactored `sun6i_dma_set_addr` and introduced
>   `sun6i_dma_set_addr_a100` (keeping the logic for high address
>   support).
> - Updated all existing configuration structs to include the new
>   `set_addr` pointer.
> - Removed `has_high_addr` since the logic is replaced by
>   `sun6i_dma_set_addr_a100`.
>
> Signed-off-by: Yuanshen Cao <alex.caoys@xxxxxxxxx>
> ---
>  drivers/dma/sun6i-dma.c | 36 ++++++++++++++++++++++++++----------
>  1 file changed, 26 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> index d92e702320d9..059455425e19 100644
> --- a/drivers/dma/sun6i-dma.c
> +++ b/drivers/dma/sun6i-dma.c
> @@ -112,6 +112,7 @@
>
>  /* forward declaration */
>  struct sun6i_dma_dev;
> +struct sun6i_dma_lli;
>
>  /*
>   * Hardware channels / ports representation
> @@ -138,6 +139,8 @@ 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 (*set_addr)(struct sun6i_dma_dev *sdev, struct sun6i_dma_lli *v_lli,
> +               dma_addr_t src, dma_addr_t dst);
>         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);
> @@ -147,7 +150,6 @@ struct sun6i_dma_config {
>         u32 dst_burst_lengths;
>         u32 src_addr_widths;
>         u32 dst_addr_widths;
> -       bool has_high_addr;
>         bool has_mbus_clk;
>  };
>
> @@ -675,13 +677,20 @@ static int set_config(struct sun6i_dma_dev *sdev,
>  static inline void sun6i_dma_set_addr(struct sun6i_dma_dev *sdev,
>                                       struct sun6i_dma_lli *v_lli,
>                                       dma_addr_t src, dma_addr_t dst)
> +{
> +       v_lli->src = lower_32_bits(src);
> +       v_lli->dst = lower_32_bits(dst);
> +}
> +
> +static inline void sun6i_dma_set_addr_a100(struct sun6i_dma_dev *sdev,
> +                                     struct sun6i_dma_lli *v_lli,
> +                                     dma_addr_t src, dma_addr_t dst)
>  {
>         v_lli->src = lower_32_bits(src);
>         v_lli->dst = lower_32_bits(dst);
>
> -       if (sdev->cfg->has_high_addr)
> -               v_lli->para |= SRC_HIGH_ADDR(upper_32_bits(src)) |
> -                              DST_HIGH_ADDR(upper_32_bits(dst));
> +       v_lli->para |= SRC_HIGH_ADDR(upper_32_bits(src)) |
> +                               DST_HIGH_ADDR(upper_32_bits(dst));
>  }
>
>  static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy(
> @@ -714,7 +723,7 @@ static struct dma_async_tx_descriptor *sun6i_dma_prep_dma_memcpy(
>
>         v_lli->len = len;
>         v_lli->para = NORMAL_WAIT;
> -       sun6i_dma_set_addr(sdev, v_lli, src, dest);
> +       sdev->cfg->set_addr(sdev, v_lli, src, dest);

can you move sdev->cfg->set_addr into helper function  sun6i_dma_set_addr())
so need't change other place.

Old sun6i_dma_set_addr() rename sun6i_dma_set_addr_<name>()

sun6i_dma_set_addr()
{
	sdev->cfg->set_addr(sdev, v_lli, src, dest)
}

Frank