[v2,PATCH 0/3] mt8183 dpi supports dual edge

[v2,PATCH 0/3] mt8183 dpi supports dual edge

[Rex-BC Chen]

v2:
modify unused code

v1:
DPI can sample on falling, rising or both edge.
When DPI sample the data both rising and falling edge.
It can reduce half data io pins.

Rex-BC Chen (3):
  drm/mediatek: dpi dual edge sample mode support
  drm/mediatek: config mt8183 driver data to support dual edge sample
  drm/mediatek: dpi: add bus format negotiation

 drivers/gpu/drm/mediatek/mtk_dpi.c | 102 +++++++++++++++++++++++++++--
 1 file changed, 97 insertions(+), 5 deletions(-)

-- 
2.18.0

[v2,PATCH 1/3] drm/mediatek: dpi dual edge sample mode support

[Rex-BC Chen]

DPI can sample on falling, rising or both edge.
When DPI sample the data both rising and falling edge.
It can reduce half data io pins.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index b05f900d9322..21a3a7b78835 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -83,6 +83,7 @@ struct mtk_dpi {
 	struct pinctrl *pinctrl;
 	struct pinctrl_state *pins_gpio;
 	struct pinctrl_state *pins_dpi;
+	bool ddr_edge_sel;
 	int refcount;
 };
 
@@ -121,6 +122,7 @@ struct mtk_dpi_conf {
 	unsigned int (*cal_factor)(int clock);
 	u32 reg_h_fre_con;
 	bool edge_sel_en;
+	bool dual_edge;
 };
 
 static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
@@ -380,6 +382,15 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
 	}
 }
 
+static void mtk_dpi_dual_edge(struct mtk_dpi *dpi)
+{
+	if (dpi->conf->dual_edge) {
+		mtk_dpi_mask(dpi, DPI_DDR_SETTING, DDR_EN | DDR_4PHASE,
+			     DDR_EN | DDR_4PHASE);
+		mtk_dpi_mask(dpi, DPI_OUTPUT_SETTING, dpi->ddr_edge_sel ? EDGE_SEL : 0, EDGE_SEL);
+	}
+}
+
 static void mtk_dpi_power_off(struct mtk_dpi *dpi)
 {
 	if (WARN_ON(dpi->refcount == 0))
@@ -518,6 +529,7 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
 	mtk_dpi_config_yc_map(dpi, dpi->yc_map);
 	mtk_dpi_config_color_format(dpi, dpi->color_format);
 	mtk_dpi_config_2n_h_fre(dpi);
+	mtk_dpi_dual_edge(dpi);
 	mtk_dpi_config_disable_edge(dpi);
 	mtk_dpi_sw_reset(dpi, false);
 
-- 
2.18.0

[v2,PATCH 2/3] drm/mediatek: config mt8183 driver data to support dual edge sample

[Rex-BC Chen]

add dual_edge value for mt8183_conf

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 21a3a7b78835..76431fe849b8 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -691,6 +691,7 @@ static const struct mtk_dpi_conf mt2701_conf = {
 static const struct mtk_dpi_conf mt8183_conf = {
 	.cal_factor = mt8183_calculate_factor,
 	.reg_h_fre_con = 0xe0,
+	.dual_edge = true,
 };
 
 static int mtk_dpi_probe(struct platform_device *pdev)
-- 
2.18.0

[v2,PATCH 3/3] drm/mediatek: dpi: add bus format negotiation

[Rex-BC Chen]

Add the atomic_get_output_bus_fmts, atomic_get_input_bus_fmts to negotiate
the possible output and input formats for the current mode and monitor,
and use the negotiated formats in a basic atomic_check callback.

Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 89 ++++++++++++++++++++++++++++--
 1 file changed, 84 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 76431fe849b8..b4e9c6c8d706 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -536,6 +536,87 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
 	return 0;
 }
 
+#define MAX_OUTPUT_SEL_FORMATS	2
+
+static u32 *mtk_dpi_bridge_atomic_get_output_bus_fmts(struct drm_bridge *bridge,
+					struct drm_bridge_state *bridge_state,
+					struct drm_crtc_state *crtc_state,
+					struct drm_connector_state *conn_state,
+					unsigned int *num_output_fmts)
+{
+	struct drm_display_mode *mode = &crtc_state->mode;
+	u32 *output_fmts;
+	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
+
+	*num_output_fmts = 0;
+
+	output_fmts = kcalloc(MAX_OUTPUT_SEL_FORMATS, sizeof(*output_fmts),
+			      GFP_KERNEL);
+	if (!output_fmts)
+		return NULL;
+
+	/* Default 8bit RGB fallback */
+	if (dpi->conf->dual_edge) {
+		output_fmts[0] =  MEDIA_BUS_FMT_RGB888_2X12_LE;
+		output_fmts[1] =  MEDIA_BUS_FMT_RGB888_2X12_BE;
+		*num_output_fmts = 2;
+	} else {
+		output_fmts[0] =  MEDIA_BUS_FMT_RGB888_1X24;
+		*num_output_fmts = 1;
+	}
+
+	return output_fmts;
+}
+
+#define MAX_INPUT_SEL_FORMATS	1
+
+static u32 *mtk_dpi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+					struct drm_bridge_state *bridge_state,
+					struct drm_crtc_state *crtc_state,
+					struct drm_connector_state *conn_state,
+					u32 output_fmt,
+					unsigned int *num_input_fmts)
+{
+	u32 *input_fmts;
+
+	*num_input_fmts = 0;
+
+	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
+			     GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	*num_input_fmts = 1;
+	input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
+
+	return input_fmts;
+}
+
+static int mtk_dpi_bridge_atomic_check(struct drm_bridge *bridge,
+				       struct drm_bridge_state *bridge_state,
+				       struct drm_crtc_state *crtc_state,
+				       struct drm_connector_state *conn_state)
+{
+	struct mtk_dpi *dpi = bridge->driver_private;
+	unsigned int out_bus_format;
+
+	out_bus_format = bridge_state->output_bus_cfg.format;
+
+	dev_dbg(dpi->dev, "input format 0x%04x, output format 0x%04x\n",
+		bridge_state->input_bus_cfg.format,
+		bridge_state->output_bus_cfg.format);
+
+	dpi->ddr_edge_sel = (out_bus_format == MEDIA_BUS_FMT_RGB888_2X12_LE) ?
+		 		true : false;
+
+	dpi->bit_num = MTK_DPI_OUT_BIT_NUM_8BITS;
+	dpi->channel_swap = MTK_DPI_OUT_CHANNEL_SWAP_RGB;
+	dpi->yc_map = MTK_DPI_OUT_YC_MAP_RGB;
+	dpi->color_format = MTK_DPI_COLOR_FORMAT_RGB;
+
+	return 0;
+}
+
 static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,
 				 enum drm_bridge_attach_flags flags)
 {
@@ -574,6 +655,9 @@ static const struct drm_bridge_funcs mtk_dpi_bridge_funcs = {
 	.mode_set = mtk_dpi_bridge_mode_set,
 	.disable = mtk_dpi_bridge_disable,
 	.enable = mtk_dpi_bridge_enable,
+	.atomic_check = mtk_dpi_bridge_atomic_check,
+	.atomic_get_output_bus_fmts = mtk_dpi_bridge_atomic_get_output_bus_fmts,
+	.atomic_get_input_bus_fmts = mtk_dpi_bridge_atomic_get_input_bus_fmts,
 };
 
 void mtk_dpi_start(struct device *dev)
@@ -620,11 +704,6 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
 	}
 	drm_connector_attach_encoder(dpi->connector, &dpi->encoder);
 
-	dpi->bit_num = MTK_DPI_OUT_BIT_NUM_8BITS;
-	dpi->channel_swap = MTK_DPI_OUT_CHANNEL_SWAP_RGB;
-	dpi->yc_map = MTK_DPI_OUT_YC_MAP_RGB;
-	dpi->color_format = MTK_DPI_COLOR_FORMAT_RGB;
-
 	return 0;
 
 err_cleanup:
-- 
2.18.0

Re: [v2,PATCH 1/3] drm/mediatek: dpi dual edge sample mode support

[Neil Armstrong]

Hi,

On 14/04/2021 15:35, Rex-BC Chen wrote:
> DPI can sample on falling, rising or both edge.
> When DPI sample the data both rising and falling edge.
> It can reduce half data io pins.
> 
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index b05f900d9322..21a3a7b78835 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -83,6 +83,7 @@ struct mtk_dpi {
>  	struct pinctrl *pinctrl;
>  	struct pinctrl_state *pins_gpio;
>  	struct pinctrl_state *pins_dpi;
> +	bool ddr_edge_sel;
>  	int refcount;
>  };
>  
> @@ -121,6 +122,7 @@ struct mtk_dpi_conf {
>  	unsigned int (*cal_factor)(int clock);
>  	u32 reg_h_fre_con;
>  	bool edge_sel_en;
> +	bool dual_edge;
>  };
>  
>  static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val, u32 mask)
> @@ -380,6 +382,15 @@ static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
>  	}
>  }
>  
> +static void mtk_dpi_dual_edge(struct mtk_dpi *dpi)
> +{
> +	if (dpi->conf->dual_edge) {
> +		mtk_dpi_mask(dpi, DPI_DDR_SETTING, DDR_EN | DDR_4PHASE,
> +			     DDR_EN | DDR_4PHASE);
> +		mtk_dpi_mask(dpi, DPI_OUTPUT_SETTING, dpi->ddr_edge_sel ? EDGE_SEL : 0, EDGE_SEL);
> +	}
> +}
> +

By using the downstream code as reference:

-       clk_set_rate(dpi->pixel_clk, vm.pixelclock);
+       clk_set_rate(dpi->pixel_clk, vm.pixelclock * (dpi->conf->dual_edge ? 2 : 1));

is missing in mtk_dpi_set_display_mode()

>  static void mtk_dpi_power_off(struct mtk_dpi *dpi)
>  {
>  	if (WARN_ON(dpi->refcount == 0))
> @@ -518,6 +529,7 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
>  	mtk_dpi_config_yc_map(dpi, dpi->yc_map);
>  	mtk_dpi_config_color_format(dpi, dpi->color_format);
>  	mtk_dpi_config_2n_h_fre(dpi);
> +	mtk_dpi_dual_edge(dpi);
>  	mtk_dpi_config_disable_edge(dpi);
>  	mtk_dpi_sw_reset(dpi, false);
>  
> 

Neil

Re: [v2,PATCH 1/3] drm/mediatek: dpi dual edge sample mode support

[Rex-BC Chen]

On Mon, 2021-04-19 at 09:36 +0200, Neil Armstrong wrote:
> Hi,
> 
> On 14/04/2021 15:35, Rex-BC Chen wrote:
> > DPI can sample on falling, rising or both edge.
> > When DPI sample the data both rising and falling edge.
> > It can reduce half data io pins.
> > 
> > Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> > Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_dpi.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > index b05f900d9322..21a3a7b78835 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > @@ -83,6 +83,7 @@ struct mtk_dpi {
> >  	struct pinctrl *pinctrl;
> >  	struct pinctrl_state *pins_gpio;
> >  	struct pinctrl_state *pins_dpi;
> > +	bool ddr_edge_sel;
> >  	int refcount;
> >  };
> >  
> > @@ -121,6 +122,7 @@ struct mtk_dpi_conf {
> >  	unsigned int (*cal_factor)(int clock);
> >  	u32 reg_h_fre_con;
> >  	bool edge_sel_en;
> > +	bool dual_edge;
> >  };
> >  
> >  static void mtk_dpi_mask(struct mtk_dpi *dpi, u32 offset, u32 val,
> > u32 mask)
> > @@ -380,6 +382,15 @@ static void mtk_dpi_config_color_format(struct
> > mtk_dpi *dpi,
> >  	}
> >  }
> >  
> > +static void mtk_dpi_dual_edge(struct mtk_dpi *dpi)
> > +{
> > +	if (dpi->conf->dual_edge) {
> > +		mtk_dpi_mask(dpi, DPI_DDR_SETTING, DDR_EN | DDR_4PHASE,
> > +			     DDR_EN | DDR_4PHASE);
> > +		mtk_dpi_mask(dpi, DPI_OUTPUT_SETTING, dpi->ddr_edge_sel 
> > ? EDGE_SEL : 0, EDGE_SEL);
> > +	}
> > +}
> > +
> 
> By using the downstream code as reference:
> 
> -       clk_set_rate(dpi->pixel_clk, vm.pixelclock);
> +       clk_set_rate(dpi->pixel_clk, vm.pixelclock * (dpi->conf-
> >dual_edge ? 2 : 1));
> 
> is missing in mtk_dpi_set_display_mode()
> 
Hello Neil,

Thanks for helping checking this.
I will add this modification for next patch.

BRs,
Rex-BC Chen
> >  static void mtk_dpi_power_off(struct mtk_dpi *dpi)
> >  {
> >  	if (WARN_ON(dpi->refcount == 0))
> > @@ -518,6 +529,7 @@ static int mtk_dpi_set_display_mode(struct
> > mtk_dpi *dpi,
> >  	mtk_dpi_config_yc_map(dpi, dpi->yc_map);
> >  	mtk_dpi_config_color_format(dpi, dpi->color_format);
> >  	mtk_dpi_config_2n_h_fre(dpi);
> > +	mtk_dpi_dual_edge(dpi);
> >  	mtk_dpi_config_disable_edge(dpi);
> >  	mtk_dpi_sw_reset(dpi, false);
> >  
> > 
> 
> Neil