[PATCH v2] drm/mediatek: dsi: Add dsi per-frame lp code for mt8188

CK Hu (胡俊光) ck.hu at mediatek.com
Wed May 22 00:30:27 PDT 2024


Hi, Shuijing:

On Wed, 2024-04-24 at 17:16 +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 v2:
> Use bitfield macros and add new function for per prame lp and improve
> the format, per suggestion frome previous thread:
> https://urldefense.com/v3/__https://patchwork.kernel.org/project/linux-mediatek/patch/20240314094238.3315-1-shuijing.li@mediatek.com/__;!!CTRNKA9wMg0ARbw!iJrqnLwBi80AYshU8-sTvs0LiPH_URRrjTLsXFQLyUyAWZW0x5B0lCgIKTXl-wS9NmkTBcIdyncDMxDio1jk8w$ 
> ---
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 143 +++++++++++++++++++++++++++++
>  1 file changed, 143 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 9501f4019199..75719b0535f7 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -68,6 +68,8 @@
>  #define EXT_TE_EDGE			BIT(10)
>  #define MAX_RTN_SIZE			GENMASK(15, 12)
>  #define HSTX_CKLP_EN			BIT(16)
> +#define HSTX_BLLP_EN_SHIFT 7
> +#define HSTX_BLLP_EN_MASK  0x1
>  
>  #define DSI_PSCTRL		0x1c
>  #define DSI_PS_WC			GENMASK(13, 0)
> @@ -76,6 +78,8 @@
>  #define PACKED_PS_18BIT_RGB666		1
>  #define LOOSELY_PS_24BIT_RGB666		2
>  #define PACKED_PS_24BIT_RGB888		3
> +#define PS_WC_SHIFT 0
> +#define PS_WC_MASK  0x7fff
>  
>  #define DSI_VSA_NL		0x20
>  #define DSI_VBP_NL		0x24
> @@ -88,12 +92,20 @@
>  #define DSI_HSA_WC		0x50
>  #define DSI_HBP_WC		0x54
>  #define DSI_HFP_WC		0x58
> +#define HFP_HS_EN		31
> +#define HFP_HS_VB_PS_WC_SHIFT 16
> +
> +#define DSI_BLLP_WC		0x5C
> +#define BLLP_WC_SHIFT 0
> +#define BLLP_WC_MASK  0xfff
>  
>  #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_SHIFT 2
> +#define HSTX_CKL_WC_MASK  0x3fff
>  
>  #define DSI_RX_DATA0		0x74
>  #define DSI_RX_DATA1		0x78
> @@ -118,12 +130,22 @@
>  #define HS_PREP				GENMASK(15, 8)
>  #define HS_ZERO				GENMASK(23, 16)
>  #define HS_TRAIL			GENMASK(31, 24)
> +#define LPX_SHIFT 0
> +#define LPX_MASK  0xff
> +#define DA_HS_PREP_SHIFT 8
> +#define DA_HS_PREP_MASK  0xff
> +#define DA_HS_ZERO_SHIFT 16
> +#define DA_HS_ZERO_MASK  0xff
> +#define DA_HS_TRAIL_SHIFT 24
> +#define DA_HS_TRAIL_MASK  0xff
>  
>  #define DSI_PHY_TIMECON1	0x114
>  #define TA_GO				GENMASK(7, 0)
>  #define TA_SURE				GENMASK(15, 8)
>  #define TA_GET				GENMASK(23, 16)
>  #define DA_HS_EXIT			GENMASK(31, 24)
> +#define DA_HS_EXIT_SHIFT 24
> +#define DA_HS_EXIT_MASK  0xff
>  
>  #define DSI_PHY_TIMECON2	0x118
>  #define CONT_DET			GENMASK(7, 0)
> @@ -154,6 +176,7 @@
>  #define DATA_1				GENMASK(31, 24)
>  
>  #define NS_TO_CYCLE(n, c)    ((n) / (c) + (((n) % (c)) ? 1 : 0))
> +#define REG_FIELD_VALUE(reg, field) (((reg) >> (field##_SHIFT)) & (field##_MASK))

Use function in bitfield.h instead of re-inventing it.

>  
>  #define MTK_DSI_HOST_IS_READ(type) \
>  	((type == MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM) || \
> @@ -187,6 +210,7 @@ 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 {
> @@ -425,6 +449,121 @@ 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_per_frame_lp(struct mtk_dsi *dsi)
> +{
> +	u32 horizontal_sync_active_byte;
> +	u32 horizontal_backporch_byte;
> +	u32 horizontal_frontporch_byte;
> +	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 bllp_wc, bllp_en, 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 = REG_FIELD_VALUE(readl(dsi->regs + DSI_PHY_TIMECON0),
> +		DA_HS_TRAIL);

da_hs_trail = dsi->phy_timing.clk_hs_trail;

> +	bllp_en = REG_FIELD_VALUE(readl(dsi->regs + DSI_TXRX_CTRL),
> +		HSTX_BLLP_EN);

Where do you define HSTX_BLLP_EN?
DSI_TXRX_CTRL is written in mtk_dsi_txrx_control() and I guess that bllp_en is zero, right?
If bllp_en is zero, drop the code related to bllp_en.

> +	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;
> +		horizontal_frontporch_byte =
> +			vm->hfront_porch * dsi_tmp_buf_bpp - 12;
> +
> +		ps_wc = REG_FIELD_VALUE(readl(dsi->regs + DSI_PSCTRL), PS_WC);

ps_wc = dsi->vm.hactive * dsi_buf_bpp;

> +		v_active_roundup = (32 + horizontal_sync_active_byte +
> +			horizontal_backporch_byte + ps_wc +
> +			horizontal_frontporch_byte) % dsi->lanes;
> +		if (v_active_roundup)
> +			horizontal_backporch_byte = horizontal_backporch_byte +
> +				dsi->lanes - v_active_roundup;

Is this roundup the same as the one in mtk_dsi_config_vdo_timing()? If the same, merge these two.

> +		hstx_cklp_wc_min = (DIV_ROUND_UP((12 + 2 + 4 +
> +			horizontal_sync_active_byte), dsi->lanes) + da_hs_trail + 1)
> +			* dsi->lanes / 6 - 1;
> +		hstx_cklp_wc_max = (DIV_ROUND_UP((20 + 6 + 4 +
> +			horizontal_sync_active_byte + horizontal_backporch_byte +
> +			ps_wc), dsi->lanes) + da_hs_trail + 1) * dsi->lanes / 6 - 1;
> +	} 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;
> +		hstx_cklp_wc_min = (DIV_ROUND_UP(4, dsi->lanes) + da_hs_trail + 1)
> +			* dsi->lanes / 6 - 1;
> +
> +		if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) {
> +			ps_wc = REG_FIELD_VALUE(readl(dsi->regs + DSI_PSCTRL), PS_WC);
> +			bllp_wc = REG_FIELD_VALUE(readl(dsi->regs + DSI_BLLP_WC), BLLP_WC);

This register is never written. Which setting would influence this value? Before dsi configuration finish, is this value stable?

> +			horizontal_frontporch_byte = (vm->hfront_porch *
> +				dsi_tmp_buf_bpp - 18);
> +
> +			v_active_roundup = (28 + horizontal_backporch_byte + ps_wc +
> +				horizontal_frontporch_byte + bllp_wc) % dsi->lanes;
> +			if (v_active_roundup)
> +				horizontal_backporch_byte = horizontal_backporch_byte +
> +				dsi->lanes - v_active_roundup;
> +			if (bllp_en) {
> +				hstx_cklp_wc_max = (DIV_ROUND_UP((16 + 6 + 4 +
> +					horizontal_backporch_byte + bllp_wc + ps_wc),
> +					dsi->lanes) + da_hs_trail + 1) * dsi->lanes / 6 - 1;
> +			} else {
> +				hstx_cklp_wc_max = (DIV_ROUND_UP((12 + 4 + 4 +
> +					horizontal_backporch_byte + bllp_wc + ps_wc),
> +					dsi->lanes) + da_hs_trail + 1) * dsi->lanes / 6 - 1;
> +			}
> +		} else {
> +			ps_wc = REG_FIELD_VALUE(readl(dsi->regs + DSI_PSCTRL), PS_WC);
> +			horizontal_frontporch_byte = (vm->hfront_porch *
> +				dsi_tmp_buf_bpp - 12);
> +
> +			v_active_roundup = (22 + horizontal_backporch_byte + ps_wc +
> +				horizontal_frontporch_byte) % dsi->lanes;
> +			if (v_active_roundup)
> +				horizontal_backporch_byte = horizontal_backporch_byte +
> +				dsi->lanes - v_active_roundup;
> +
> +			hstx_cklp_wc_max = (DIV_ROUND_UP((12 + 4 + 4 +
> +				horizontal_backporch_byte + ps_wc),
> +				dsi->lanes) + da_hs_trail + 1) * dsi->lanes / 6 - 1;
> +		}
> +	}
> +	hstx_cklp_wc = REG_FIELD_VALUE(ps_wc, HSTX_CKL_WC);

hstx_cklp_wc = REG_FIELD_VALUE(dsi->vm.hactive * dsi_buf_bpp, HSTX_CKL_WC);

But this looks a little weird.

> +	if (hstx_cklp_wc <= hstx_cklp_wc_min ||
> +		hstx_cklp_wc >= hstx_cklp_wc_max) {
> +		hstx_cklp_wc = (hstx_cklp_wc_max / 2) << HSTX_CKL_WC_SHIFT;

You choose the new setting with a risk that has a warning, why not let hstx_cklp_wc = (hstx_cklp_wc_min + hstx_cklp_wc_max) / 2 ?

> +		writel(hstx_cklp_wc, dsi->regs + DSI_HSTX_CKL_WC);
> +	}
> +	hstx_cklp_wc = hstx_cklp_wc >> HSTX_CKL_WC_SHIFT;
> +	if (hstx_cklp_wc <= hstx_cklp_wc_min ||
> +		hstx_cklp_wc >= hstx_cklp_wc_max) {
> +		DRM_WARN("Wrong setting of hstx_ckl_wc\n");
> +	}
> +
> +	lpx = REG_FIELD_VALUE(readl(dsi->regs + DSI_PHY_TIMECON0), LPX);

lpx = dsi->phy_timing.lpx;

> +	da_hs_exit = REG_FIELD_VALUE(readl(dsi->regs + DSI_PHY_TIMECON1), DA_HS_EXIT);

da_hs_exit = dsi->phy_timing.da_hs_exit;

> +	da_hs_prep = REG_FIELD_VALUE(readl(dsi->regs + DSI_PHY_TIMECON0), DA_HS_PREP);

da_hs_prep = dsi->phy_timing.da_hs_prepare;

> +	da_hs_zero = REG_FIELD_VALUE(readl(dsi->regs + DSI_PHY_TIMECON0), DA_HS_ZERO);

da_hs_zero = dsi->phy_timing.da_hs_zero;

> +	ps_wc = REG_FIELD_VALUE(readl(dsi->regs + DSI_PSCTRL), PS_WC);

This value is assigned?

> +	hs_vb_ps_wc = ps_wc -
> +		(lpx + da_hs_exit + da_hs_prep + da_hs_zero + 2)
> +		* dsi->lanes;
> +	horizontal_frontporch_byte = (1 << HFP_HS_EN)
> +		| (hs_vb_ps_wc << HFP_HS_VB_PS_WC_SHIFT)
> +		| (horizontal_frontporch_byte);
> +
> +	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)
>  {
>  	u32 horizontal_sync_active_byte;
> @@ -499,6 +638,9 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
>  	writel(horizontal_backporch_byte, dsi->regs + DSI_HBP_WC);
>  	writel(horizontal_frontporch_byte, dsi->regs + DSI_HFP_WC);
>  

If dsi->driver_data->support_per_frame_lp is false, the calculation before this is redundant. It's worth to move previous calculation to a function and call that function when dsi->driver_data-
>support_per_frame_lp is false.

> +	if (dsi->driver_data->support_per_frame_lp)
> +		mtk_dsi_config_vdo_timing_per_frame_lp(dsi);
> +
>  	mtk_dsi_ps_control(dsi, false);
>  }
>  
> @@ -1193,6 +1335,7 @@ 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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