Re: [PATCH v2 7/8] drm/mediatek: Add programming flow for unsupported subsys ID hardware

[CK Hu (胡俊光) <ck.hu@xxxxxxxxxxxx>]

Hi, Jason:

On Wed, 2024-12-11 at 11:22 +0800, Jason-JH.Lin wrote:
> To support hardware without subsys IDs on new SoCs, add a programming
> flow that checks whether the subsys ID is valid. If the subsys ID is
> invalid, the flow will call 2 alternative CMDQ APIs:
> cmdq_pkt_assign() and cmdq_pkt_write_s_value() to achieve the same
> functionality.
> 
> Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/mediatek/mtk_ddp_comp.c | 34 ++++++++++++++++++++-----
>  1 file changed, 28 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_ddp_comp.c b/drivers/gpu/drm/mediatek/mtk_ddp_comp.c
> index edc6417639e6..0792c895526f 100644
> --- a/drivers/gpu/drm/mediatek/mtk_ddp_comp.c
> +++ b/drivers/gpu/drm/mediatek/mtk_ddp_comp.c
> @@ -66,14 +66,38 @@ struct mtk_ddp_comp_dev {
>  	struct cmdq_client_reg cmdq_reg;
>  };
>  
> +#if IS_REACHABLE(CONFIG_MTK_CMDQ)
> +static void mtk_ddp_write_cmdq_pkt(struct cmdq_pkt *cmdq_pkt, struct cmdq_client_reg *cmdq_reg,
> +				   unsigned int offset, unsigned int value, unsigned int mask)

Drop this function.

> +{
> +	struct cmdq_client *cl = (struct cmdq_client *)cmdq_pkt->cl;
> +
> +	offset += cmdq_reg->offset;
> +
> +	if (cmdq_subsys_is_valid(cl->chan, cmdq_reg->subsys)) {
> +		if (mask == GENMASK(31, 0))
> +			cmdq_pkt_write(cmdq_pkt, cmdq_reg->subsys, offset, value);
> +		else
> +			cmdq_pkt_write_mask(cmdq_pkt, cmdq_reg->subsys, offset, value, mask);
> +	} else {
> +		/* only MMIO access, no need to check mminfro_offset */
> +		cmdq_pkt_assign(cmdq_pkt, 0, CMDQ_ADDR_HIGH(cmdq_reg->pa_base));
> +		if (mask == GENMASK(31, 0))
> +			cmdq_pkt_write_s_value(cmdq_pkt, 0, CMDQ_ADDR_LOW(offset), value);
> +		else
> +			cmdq_pkt_write_s_mask_value(cmdq_pkt, 0, CMDQ_ADDR_LOW(offset),
> +						    value, mask);
> +	}
> +}
> +#endif
> +
>  void mtk_ddp_write(struct cmdq_pkt *cmdq_pkt, unsigned int value,
>  		   struct cmdq_client_reg *cmdq_reg, void __iomem *regs,
>  		   unsigned int offset)
>  {
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>  	if (cmdq_pkt)
> -		cmdq_pkt_write(cmdq_pkt, cmdq_reg->subsys,
> -			       cmdq_reg->offset + offset, value);
> +		mtk_ddp_write_cmdq_pkt(cmdq_pkt, cmdq_reg, offset, value, GENMASK(31, 0));

/* only MMIO access, no need to check mminfro_offset */
cmdq_pkt_assign(cmdq_pkt, CMDQ_XXXREG_0, CMDQ_ADDR_HIGH(cmdq_reg->pa_base));
cmdq_pkt_write_s_value(cmdq_pkt, CMDQ_XXXREG_0, CMDQ_ADDR_LOW(offset), value);

>  	else
>  #endif
>  		writel(value, regs + offset);
> @@ -85,8 +109,7 @@ void mtk_ddp_write_relaxed(struct cmdq_pkt *cmdq_pkt, unsigned int value,
>  {
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>  	if (cmdq_pkt)
> -		cmdq_pkt_write(cmdq_pkt, cmdq_reg->subsys,
> -			       cmdq_reg->offset + offset, value);
> +		mtk_ddp_write_cmdq_pkt(cmdq_pkt, cmdq_reg, offset, value, GENMASK(31, 0));

/* only MMIO access, no need to check mminfro_offset */
cmdq_pkt_assign(cmdq_pkt, CMDQ_XXXREG_0, CMDQ_ADDR_HIGH(cmdq_reg->pa_base));
cmdq_pkt_write_s_value(cmdq_pkt, CMDQ_XXXREG_0, CMDQ_ADDR_LOW(offset), value);

>  	else
>  #endif
>  		writel_relaxed(value, regs + offset);
> @@ -98,8 +121,7 @@ void mtk_ddp_write_mask(struct cmdq_pkt *cmdq_pkt, unsigned int value,
>  {
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>  	if (cmdq_pkt) {
> -		cmdq_pkt_write_mask(cmdq_pkt, cmdq_reg->subsys,
> -				    cmdq_reg->offset + offset, value, mask);
> +		mtk_ddp_write_cmdq_pkt(cmdq_pkt, cmdq_reg, offset, value, mask);

/* only MMIO access, no need to check mminfro_offset */
cmdq_pkt_assign(cmdq_pkt, CMDQ_XXXREG_0, CMDQ_ADDR_HIGH(cmdq_reg->pa_base));
cmdq_pkt_write_s_mask_value(cmdq_pkt, CMDQ_XXXREG_0, CMDQ_ADDR_LOW(offset),
			    value, mask);

CMDQ_XXXREG_0 is defined in cmdq header file.

Regards,
CK

>  	} else {
>  #endif
>  		u32 tmp = readl(regs + offset);