[PATCH v6] drm/mediatek: dsi: Add dsi per-frame lp code for mt8188

CK Hu (胡俊光) ck.hu at mediatek.com
Mon Aug 12 23:25:35 PDT 2024


Hi, Shuijing:

On Tue, 2024-08-13 at 10:22 +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^
> 
> Signed-off-by: Shuijing Li <shuijing.li at mediatek.com>
> ---
> 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!kHNi5p7BRvby5bDcHumAIC5tuDhYaUcG9IybmOwHIO6Enm7yTsu9okLOjCkzJXjAACVGrs-Vxvy_8tjwTK5rcg$ 
> 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!kHNi5p7BRvby5bDcHumAIC5tuDhYaUcG9IybmOwHIO6Enm7yTsu9okLOjCkzJXjAACVGrs-Vxvy_8tgEaxz7Eg$ 
> 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!kHNi5p7BRvby5bDcHumAIC5tuDhYaUcG9IybmOwHIO6Enm7yTsu9okLOjCkzJXjAACVGrs-Vxvy_8tiCeNP2ow$ 
> 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!kHNi5p7BRvby5bDcHumAIC5tuDhYaUcG9IybmOwHIO6Enm7yTsu9okLOjCkzJXjAACVGrs-Vxvy_8tjbRym5yQ$ 
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 158 +++++++++++++++++++++++++----
>  1 file changed, 139 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index b6e3c011a12d..940fc99cc87d 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)

One more 'tab' for bitwise definition.

>  
>  #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 +430,92 @@ 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 lpx, da_hs_exit, da_hs_prep, da_hs_trail;
> +	unsigned int da_hs_zero, 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 = dsi->vm.hactive * dsi_tmp_buf_bpp;

vm->hactive

> +
> +	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;

Align to the right of '=' in previous line.

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;

Ditto.

> +	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;

Ditto.

> +
> +	hstx_cklp_wc = FIELD_GET(HSTX_CKL_WC, readl(dsi->regs + DSI_HSTX_CKL_WC));
> +
> +	if (hstx_cklp_wc <= hstx_cklp_wc_min || hstx_cklp_wc >= hstx_cklp_wc_max) {
> +		hstx_cklp_wc = ((hstx_cklp_wc_min + hstx_cklp_wc_max) / 2);
> +
> +		/* Check if the new setting is valid */
> +		if (hstx_cklp_wc <= hstx_cklp_wc_min ||	hstx_cklp_wc >= hstx_cklp_wc_max)

I think this would not happen.

> +			DRM_WARN("Wrong setting of hstx_ckl_wc\n");
> +
> +		hstx_cklp_wc = FIELD_PREP(HSTX_CKL_WC, hstx_cklp_wc);
> +		writel(hstx_cklp_wc, dsi->regs + DSI_HSTX_CKL_WC);

Why not just calculate an accurate value to set and prevent adjustment?
Is hstx_cklp_wc = ((hstx_cklp_wc_min + hstx_cklp_wc_max) / 2) accurate value?
If so, directly write it into DSI_HSTX_CKL_WC.

> +	}
> +
> +	lpx = dsi->phy_timing.lpx;
> +	da_hs_exit = dsi->phy_timing.da_hs_exit;
> +	da_hs_prep = dsi->phy_timing.da_hs_prepare;
> +	da_hs_zero = dsi->phy_timing.da_hs_zero;

lpx, da_hs_exit, da_hs_prep, da_hs_zero are used only once, so drop them.

> +
> +	hs_vb_ps_wc = ps_wc -
> +		(lpx + da_hs_exit + da_hs_prep + 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) |
> +		horizontal_frontporch_byte;

horizontal_frontporch_byte |= FIELD_PREP(HFP_HS_EN, 1) |
			      FIELD_PREP(HFP_HS_VB_PS_WC, hs_vb_ps_wc);

Regards,
CK

> +
> +	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 +525,6 @@ 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 +532,6 @@ 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 +577,26 @@ 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 +1295,7 @@ 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[] = {


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