Re: [PATCH v8] drm/mediatek: dsi: Add dsi per-frame lp code for mt8188

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

Hi, Shuijing:

On Mon, 2024-08-26 at 14:06 +0800, Shuijing Li wrote:
> Adding the per-frame lp function of mt8188, which can keep HFP in HS and
> reduce the time required for each line to enter and exit low power.
> Per Frame LP:
>   |<----------One Active Frame-------->|
> --______________________________________----___________________
>   ^HSA+HBP^^RGB^^HFP^^HSA+HBP^^RGB^^HFP^    ^HSA+HBP^^RGB^^HFP^
> 
> Per Line LP:
>   |<---------------One Active Frame----------->|
> --______________--______________--______________----______________
>   ^HSA+HBP^^RGB^  ^HSA+HBP^^RGB^  ^HSA+HBP^^RGB^    ^HSA+HBP^^RGB^

Reviewed-by: CK Hu <ck.hu@mediatek.com>

> 
> Signed-off-by: Shuijing Li <shuijing.li@mediatek.com>
> ---
> Changes in v8:
> Directly write value into DSI_HSTX_CKL_WC without check per suggestion from previous thread:
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20240819061333.26069-1-shuijing.li@mediatek.com/__;!!CTRNKA9wMg0ARbw!jAEUeH9B73jMpvAylYO1skZQ9OG6PXO_PpvPhxISZQXRpIbti7zVD240hC95XuUyth0YaP_HhDdOV1Lyl5qaWQ$ 
> Changes in v7:
> Fix code style and simplify the code per suggestion from previous thread:
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20240813022315.18502-1-shuijing.li@mediatek.com/__;!!CTRNKA9wMg0ARbw!jAEUeH9B73jMpvAylYO1skZQ9OG6PXO_PpvPhxISZQXRpIbti7zVD240hC95XuUyth0YaP_HhDdOV1KhAo9kRw$ 
> Changes in v6:
> Simplify the code per suggestion from previous thread:
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20240812070341.26053-1-shuijing.li@mediatek.com/__;!!CTRNKA9wMg0ARbw!jAEUeH9B73jMpvAylYO1skZQ9OG6PXO_PpvPhxISZQXRpIbti7zVD240hC95XuUyth0YaP_HhDdOV1IM8B4mGA$ 
> Changes in v5:
> Fix code style issue and add per-line-lp function to be symmetrical with per-frame-lp.
> per suggestion from previous thread:
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20240801081144.22372-1-shuijing.li@mediatek.com/__;!!CTRNKA9wMg0ARbw!jAEUeH9B73jMpvAylYO1skZQ9OG6PXO_PpvPhxISZQXRpIbti7zVD240hC95XuUyth0YaP_HhDdOV1IMJlFxbw$ 
> Changes in v4:
> Drop the code related to bllp_en and bllp_wc, adjust ps_wc to dsi->vm.hactive *
> dsi_buf_bpp.
> Changes in v3:
> Use function in bitfield.h and get value from phy timing, per suggestion
> from previous thread:
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20240424091639.22759-1-shuijing.li@mediatek.com/__;!!CTRNKA9wMg0ARbw!jAEUeH9B73jMpvAylYO1skZQ9OG6PXO_PpvPhxISZQXRpIbti7zVD240hC95XuUyth0YaP_HhDdOV1J6CfbWXQ$ 
> Changes in v2:
> Use bitfield macros and add new function for per prame lp and improve
> the format, per suggestion from previous thread:
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20240314094238.3315-1-shuijing.li@mediatek.com/__;!!CTRNKA9wMg0ARbw!jAEUeH9B73jMpvAylYO1skZQ9OG6PXO_PpvPhxISZQXRpIbti7zVD240hC95XuUyth0YaP_HhDdOV1JKA7KU2w$ 
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 106 +++++++++++++++++++++++++----
>  1 file changed, 94 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index b6e3c011a12d..eeec641cab60 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -88,12 +88,15 @@
>  #define DSI_HSA_WC		0x50
>  #define DSI_HBP_WC		0x54
>  #define DSI_HFP_WC		0x58
> +#define HFP_HS_VB_PS_WC		GENMASK(30, 16)
> +#define HFP_HS_EN			BIT(31)
>  
>  #define DSI_CMDQ_SIZE		0x60
>  #define CMDQ_SIZE			0x3f
>  #define CMDQ_SIZE_SEL		BIT(15)
>  
>  #define DSI_HSTX_CKL_WC		0x64
> +#define HSTX_CKL_WC			GENMASK(15, 2)
>  
>  #define DSI_RX_DATA0		0x74
>  #define DSI_RX_DATA1		0x78
> @@ -187,6 +190,7 @@ struct mtk_dsi_driver_data {
>  	bool has_shadow_ctl;
>  	bool has_size_ctl;
>  	bool cmdq_long_packet_ctl;
> +	bool support_per_frame_lp;
>  };
>  
>  struct mtk_dsi {
> @@ -426,7 +430,75 @@ static void mtk_dsi_ps_control(struct mtk_dsi *dsi, bool config_vact)
>  	writel(ps_val, dsi->regs + DSI_PSCTRL);
>  }
>  
> -static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
> +static void mtk_dsi_config_vdo_timing_per_frame_lp(struct mtk_dsi *dsi)
> +{
> +	u32 horizontal_sync_active_byte;
> +	u32 horizontal_backporch_byte;
> +	u32 horizontal_frontporch_byte;
> +	u32 hfp_byte_adjust, v_active_adjust;
> +	u32 cklp_wc_min_adjust, cklp_wc_max_adjust;
> +	u32 dsi_tmp_buf_bpp;
> +	unsigned int da_hs_trail;
> +	unsigned int ps_wc, hs_vb_ps_wc;
> +	u32 v_active_roundup, hstx_cklp_wc;
> +	u32 hstx_cklp_wc_max, hstx_cklp_wc_min;
> +	struct videomode *vm = &dsi->vm;
> +
> +	if (dsi->format == MIPI_DSI_FMT_RGB565)
> +		dsi_tmp_buf_bpp = 2;
> +	else
> +		dsi_tmp_buf_bpp = 3;
> +
> +	da_hs_trail = dsi->phy_timing.da_hs_trail;
> +	ps_wc = vm->hactive * dsi_tmp_buf_bpp;
> +
> +	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
> +		horizontal_sync_active_byte =
> +			vm->hsync_len * dsi_tmp_buf_bpp - 10;
> +		horizontal_backporch_byte =
> +			vm->hback_porch * dsi_tmp_buf_bpp - 10;
> +		hfp_byte_adjust = 12;
> +		v_active_adjust = 32 + horizontal_sync_active_byte;
> +		cklp_wc_min_adjust = 12 + 2 + 4 + horizontal_sync_active_byte;
> +		cklp_wc_max_adjust = 20 + 6 + 4 + horizontal_sync_active_byte;
> +	} else {
> +		horizontal_sync_active_byte = vm->hsync_len * dsi_tmp_buf_bpp - 4;
> +		horizontal_backporch_byte = (vm->hback_porch + vm->hsync_len) *
> +			dsi_tmp_buf_bpp - 10;
> +		cklp_wc_min_adjust = 4;
> +		cklp_wc_max_adjust = 12 + 4 + 4;
> +		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) {
> +			hfp_byte_adjust = 18;
> +			v_active_adjust = 28;
> +		} else {
> +			hfp_byte_adjust = 12;
> +			v_active_adjust = 22;
> +		}
> +	}
> +	horizontal_frontporch_byte = vm->hfront_porch * dsi_tmp_buf_bpp - hfp_byte_adjust;
> +	v_active_roundup = (v_active_adjust + horizontal_backporch_byte + ps_wc +
> +			   horizontal_frontporch_byte) % dsi->lanes;
> +	if (v_active_roundup)
> +		horizontal_backporch_byte += dsi->lanes - v_active_roundup;
> +	hstx_cklp_wc_min = (DIV_ROUND_UP(cklp_wc_min_adjust, dsi->lanes) + da_hs_trail + 1)
> +			   * dsi->lanes / 6 - 1;
> +	hstx_cklp_wc_max = (DIV_ROUND_UP((cklp_wc_max_adjust + horizontal_backporch_byte +
> +			   ps_wc), dsi->lanes) + da_hs_trail + 1) * dsi->lanes / 6 - 1;
> +
> +	hstx_cklp_wc = FIELD_PREP(HSTX_CKL_WC, (hstx_cklp_wc_min + hstx_cklp_wc_max) / 2);
> +	writel(hstx_cklp_wc, dsi->regs + DSI_HSTX_CKL_WC);
> +
> +	hs_vb_ps_wc = ps_wc - (dsi->phy_timing.lpx + dsi->phy_timing.da_hs_exit +
> +		      dsi->phy_timing.da_hs_prepare + dsi->phy_timing.da_hs_zero + 2) * dsi->lanes;
> +	horizontal_frontporch_byte |= FIELD_PREP(HFP_HS_EN, 1) |
> +				      FIELD_PREP(HFP_HS_VB_PS_WC, hs_vb_ps_wc);
> +
> +	writel(horizontal_sync_active_byte, dsi->regs + DSI_HSA_WC);
> +	writel(horizontal_backporch_byte, dsi->regs + DSI_HBP_WC);
> +	writel(horizontal_frontporch_byte, dsi->regs + DSI_HFP_WC);
> +}
> +
> +static void mtk_dsi_config_vdo_timing_per_line_lp(struct mtk_dsi *dsi)
>  {
>  	u32 horizontal_sync_active_byte;
>  	u32 horizontal_backporch_byte;
> @@ -436,7 +508,6 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
>  	u32 dsi_tmp_buf_bpp, data_phy_cycles;
>  	u32 delta;
>  	struct mtk_phy_timing *timing = &dsi->phy_timing;
> -
>  	struct videomode *vm = &dsi->vm;
>  
>  	if (dsi->format == MIPI_DSI_FMT_RGB565)
> @@ -444,16 +515,6 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
>  	else
>  		dsi_tmp_buf_bpp = 3;
>  
> -	writel(vm->vsync_len, dsi->regs + DSI_VSA_NL);
> -	writel(vm->vback_porch, dsi->regs + DSI_VBP_NL);
> -	writel(vm->vfront_porch, dsi->regs + DSI_VFP_NL);
> -	writel(vm->vactive, dsi->regs + DSI_VACT_NL);
> -
> -	if (dsi->driver_data->has_size_ctl)
> -		writel(FIELD_PREP(DSI_HEIGHT, vm->vactive) |
> -		       FIELD_PREP(DSI_WIDTH, vm->hactive),
> -		       dsi->regs + DSI_SIZE_CON);
> -
>  	horizontal_sync_active_byte = (vm->hsync_len * dsi_tmp_buf_bpp - 10);
>  
>  	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
> @@ -499,6 +560,26 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
>  	writel(horizontal_sync_active_byte, dsi->regs + DSI_HSA_WC);
>  	writel(horizontal_backporch_byte, dsi->regs + DSI_HBP_WC);
>  	writel(horizontal_frontporch_byte, dsi->regs + DSI_HFP_WC);
> +}
> +
> +static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
> +{
> +	struct videomode *vm = &dsi->vm;
> +
> +	writel(vm->vsync_len, dsi->regs + DSI_VSA_NL);
> +	writel(vm->vback_porch, dsi->regs + DSI_VBP_NL);
> +	writel(vm->vfront_porch, dsi->regs + DSI_VFP_NL);
> +	writel(vm->vactive, dsi->regs + DSI_VACT_NL);
> +
> +	if (dsi->driver_data->has_size_ctl)
> +		writel(FIELD_PREP(DSI_HEIGHT, vm->vactive) |
> +			FIELD_PREP(DSI_WIDTH, vm->hactive),
> +			dsi->regs + DSI_SIZE_CON);
> +
> +	if (dsi->driver_data->support_per_frame_lp)
> +		mtk_dsi_config_vdo_timing_per_frame_lp(dsi);
> +	else
> +		mtk_dsi_config_vdo_timing_per_line_lp(dsi);
>  
>  	mtk_dsi_ps_control(dsi, false);
>  }
> @@ -1197,6 +1278,7 @@ static const struct mtk_dsi_driver_data mt8188_dsi_driver_data = {
>  	.has_shadow_ctl = true,
>  	.has_size_ctl = true,
>  	.cmdq_long_packet_ctl = true,
> +	.support_per_frame_lp = true,
>  };
>  
>  static const struct of_device_id mtk_dsi_of_match[] = {