[RESEND PATCH 0/3] Convert mtk-dpi to drm_bridge API

[RESEND PATCH 0/3] Convert mtk-dpi to drm_bridge API

[Enric Balletbo i Serra]

The reason for this resend is because I forget to add some bridge
maintainers. So adding them and collect the actual tags.

The mtk-dpi driver still uses the drm_encoder API which is now somewhat
deprecated. We started to move all the Mediatek drivers to the drm_bridge API,
like we did for the mtk-dsi driver [1], this is another small step to be able to
fully convert the DRM Mediatek drivers to the drm_bridge API. A dummy
drm_encoder is maintained in the mtk-dpi driver but the end goal is move all the
dummy drm_encoder (mtk-dsi, mtk-dpi, etc) to the main mtk_drm_drv driver.

[1] https://lore.kernel.org/patchwork/project/lkml/list/?series=441559


Enric Balletbo i Serra (3):
  drm/mediatek: mtk_dpi: Rename bridge to next_bridge
  drm/mediatek: mtk_dpi: Convert to bridge driver
  drm/mediatek: mtk_dpi: Use simple encoder

 drivers/gpu/drm/mediatek/mtk_dpi.c | 84 ++++++++++++++----------------
 1 file changed, 39 insertions(+), 45 deletions(-)

-- 
2.26.2

[RESEND PATCH 1/3] drm/mediatek: mtk_dpi: Rename bridge to next_bridge

[Enric Balletbo i Serra]

This is really a cosmetic change just to make a bit more readable the
code after convert the driver to drm_bridge. The bridge variable name
will be used by the encoder drm_bridge, and the chained bridge will be
named next_bridge.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
---

 drivers/gpu/drm/mediatek/mtk_dpi.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 7fbfa95bab09..7112125dc3d1 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -61,7 +61,7 @@ enum mtk_dpi_out_color_format {
 struct mtk_dpi {
 	struct mtk_ddp_comp ddp_comp;
 	struct drm_encoder encoder;
-	struct drm_bridge *bridge;
+	struct drm_bridge *next_bridge;
 	void __iomem *regs;
 	struct device *dev;
 	struct clk *engine_clk;
@@ -607,7 +607,7 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
 	/* Currently DPI0 is fixed to be driven by OVL1 */
 	dpi->encoder.possible_crtcs = BIT(1);
 
-	ret = drm_bridge_attach(&dpi->encoder, dpi->bridge, NULL, 0);
+	ret = drm_bridge_attach(&dpi->encoder, dpi->next_bridge, NULL, 0);
 	if (ret) {
 		dev_err(dev, "Failed to attach bridge: %d\n", ret);
 		goto err_cleanup;
@@ -747,11 +747,11 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 	}
 
 	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
-					  NULL, &dpi->bridge);
+					  NULL, &dpi->next_bridge);
 	if (ret)
 		return ret;
 
-	dev_info(dev, "Found bridge node: %pOF\n", dpi->bridge->of_node);
+	dev_info(dev, "Found bridge node: %pOF\n", dpi->next_bridge->of_node);
 
 	comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DPI);
 	if (comp_id < 0) {
-- 
2.26.2

[RESEND PATCH 2/3] drm/mediatek: mtk_dpi: Convert to bridge driver

[Enric Balletbo i Serra]

Convert mtk_dpi to a bridge driver with built-in encoder support for
compatibility with existing component drivers.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
---

 drivers/gpu/drm/mediatek/mtk_dpi.c | 66 +++++++++++++++---------------
 1 file changed, 34 insertions(+), 32 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 7112125dc3d1..baad198c69eb 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -61,6 +61,7 @@ enum mtk_dpi_out_color_format {
 struct mtk_dpi {
 	struct mtk_ddp_comp ddp_comp;
 	struct drm_encoder encoder;
+	struct drm_bridge bridge;
 	struct drm_bridge *next_bridge;
 	void __iomem *regs;
 	struct device *dev;
@@ -77,9 +78,9 @@ struct mtk_dpi {
 	int refcount;
 };
 
-static inline struct mtk_dpi *mtk_dpi_from_encoder(struct drm_encoder *e)
+static inline struct mtk_dpi *bridge_to_dpi(struct drm_bridge *b)
 {
-	return container_of(e, struct mtk_dpi, encoder);
+	return container_of(b, struct mtk_dpi, bridge);
 }
 
 enum mtk_dpi_polarity {
@@ -518,50 +519,44 @@ static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = {
 	.destroy = mtk_dpi_encoder_destroy,
 };
 
-static bool mtk_dpi_encoder_mode_fixup(struct drm_encoder *encoder,
-				       const struct drm_display_mode *mode,
-				       struct drm_display_mode *adjusted_mode)
+static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,
+				 enum drm_bridge_attach_flags flags)
 {
-	return true;
+	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
+
+	return drm_bridge_attach(bridge->encoder, dpi->next_bridge,
+				 &dpi->bridge, flags);
 }
 
-static void mtk_dpi_encoder_mode_set(struct drm_encoder *encoder,
-				     struct drm_display_mode *mode,
-				     struct drm_display_mode *adjusted_mode)
+static void mtk_dpi_bridge_mode_set(struct drm_bridge *bridge,
+				const struct drm_display_mode *mode,
+				const struct drm_display_mode *adjusted_mode)
 {
-	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);
+	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
 
 	drm_mode_copy(&dpi->mode, adjusted_mode);
 }
 
-static void mtk_dpi_encoder_disable(struct drm_encoder *encoder)
+static void mtk_dpi_bridge_disable(struct drm_bridge *bridge)
 {
-	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);
+	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
 
 	mtk_dpi_power_off(dpi);
 }
 
-static void mtk_dpi_encoder_enable(struct drm_encoder *encoder)
+static void mtk_dpi_bridge_enable(struct drm_bridge *bridge)
 {
-	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);
+	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
 
 	mtk_dpi_power_on(dpi);
 	mtk_dpi_set_display_mode(dpi, &dpi->mode);
 }
 
-static int mtk_dpi_atomic_check(struct drm_encoder *encoder,
-				struct drm_crtc_state *crtc_state,
-				struct drm_connector_state *conn_state)
-{
-	return 0;
-}
-
-static const struct drm_encoder_helper_funcs mtk_dpi_encoder_helper_funcs = {
-	.mode_fixup = mtk_dpi_encoder_mode_fixup,
-	.mode_set = mtk_dpi_encoder_mode_set,
-	.disable = mtk_dpi_encoder_disable,
-	.enable = mtk_dpi_encoder_enable,
-	.atomic_check = mtk_dpi_atomic_check,
+static const struct drm_bridge_funcs mtk_dpi_bridge_funcs = {
+	.attach = mtk_dpi_bridge_attach,
+	.mode_set = mtk_dpi_bridge_mode_set,
+	.disable = mtk_dpi_bridge_disable,
+	.enable = mtk_dpi_bridge_enable,
 };
 
 static void mtk_dpi_start(struct mtk_ddp_comp *comp)
@@ -602,16 +597,13 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
 		dev_err(dev, "Failed to initialize decoder: %d\n", ret);
 		goto err_unregister;
 	}
-	drm_encoder_helper_add(&dpi->encoder, &mtk_dpi_encoder_helper_funcs);
 
 	/* Currently DPI0 is fixed to be driven by OVL1 */
 	dpi->encoder.possible_crtcs = BIT(1);
 
-	ret = drm_bridge_attach(&dpi->encoder, dpi->next_bridge, NULL, 0);
-	if (ret) {
-		dev_err(dev, "Failed to attach bridge: %d\n", ret);
+	ret = drm_bridge_attach(&dpi->encoder, &dpi->bridge, NULL, 0);
+	if (ret)
 		goto err_cleanup;
-	}
 
 	dpi->bit_num = MTK_DPI_OUT_BIT_NUM_8BITS;
 	dpi->channel_swap = MTK_DPI_OUT_CHANNEL_SWAP_RGB;
@@ -768,8 +760,15 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, dpi);
 
+	dpi->bridge.funcs = &mtk_dpi_bridge_funcs;
+	dpi->bridge.of_node = dev->of_node;
+	dpi->bridge.type = DRM_MODE_CONNECTOR_DPI;
+
+	drm_bridge_add(&dpi->bridge);
+
 	ret = component_add(dev, &mtk_dpi_component_ops);
 	if (ret) {
+		drm_bridge_remove(&dpi->bridge);
 		dev_err(dev, "Failed to add component: %d\n", ret);
 		return ret;
 	}
@@ -779,7 +778,10 @@ static int mtk_dpi_probe(struct platform_device *pdev)
 
 static int mtk_dpi_remove(struct platform_device *pdev)
 {
+	struct mtk_dpi *dpi = platform_get_drvdata(pdev);
+
 	component_del(&pdev->dev, &mtk_dpi_component_ops);
+	drm_bridge_remove(&dpi->bridge);
 
 	return 0;
 }
-- 
2.26.2

[RESEND PATCH 3/3] drm/mediatek: mtk_dpi: Use simple encoder

[Enric Balletbo i Serra]

The mtk_dpi driver uses an empty implementation for its encoder. Replace
the code with the generic simple encoder.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
---

 drivers/gpu/drm/mediatek/mtk_dpi.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index baad198c69eb..80778b2aac2a 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -20,6 +20,7 @@
 #include <drm/drm_bridge.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_of.h>
+#include <drm/drm_simple_kms_helper.h>
 
 #include "mtk_dpi_regs.h"
 #include "mtk_drm_ddp_comp.h"
@@ -510,15 +511,6 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
 	return 0;
 }
 
-static void mtk_dpi_encoder_destroy(struct drm_encoder *encoder)
-{
-	drm_encoder_cleanup(encoder);
-}
-
-static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = {
-	.destroy = mtk_dpi_encoder_destroy,
-};
-
 static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,
 				 enum drm_bridge_attach_flags flags)
 {
@@ -591,8 +583,8 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 	}
 
-	ret = drm_encoder_init(drm_dev, &dpi->encoder, &mtk_dpi_encoder_funcs,
-			       DRM_MODE_ENCODER_TMDS, NULL);
+	ret = drm_simple_encoder_init(drm_dev, &dpi->encoder,
+				      DRM_MODE_ENCODER_TMDS);
 	if (ret) {
 		dev_err(dev, "Failed to initialize decoder: %d\n", ret);
 		goto err_unregister;
-- 
2.26.2

Re: [RESEND PATCH 0/3] Convert mtk-dpi to drm_bridge API

[Enric Balletbo i Serra]

Hi,

On 18/5/20 19:39, Enric Balletbo i Serra wrote:
> The reason for this resend is because I forget to add some bridge
> maintainers. So adding them and collect the actual tags.
> 
> The mtk-dpi driver still uses the drm_encoder API which is now somewhat
> deprecated. We started to move all the Mediatek drivers to the drm_bridge API,
> like we did for the mtk-dsi driver [1], this is another small step to be able to
> fully convert the DRM Mediatek drivers to the drm_bridge API. A dummy
> drm_encoder is maintained in the mtk-dpi driver but the end goal is move all the
> dummy drm_encoder (mtk-dsi, mtk-dpi, etc) to the main mtk_drm_drv driver.
> 
> [1] https://lore.kernel.org/patchwork/project/lkml/list/?series=441559
> 
> 
> Enric Balletbo i Serra (3):
>   drm/mediatek: mtk_dpi: Rename bridge to next_bridge
>   drm/mediatek: mtk_dpi: Convert to bridge driver
>   drm/mediatek: mtk_dpi: Use simple encoder
> 
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 84 ++++++++++++++----------------

A gentle ping, I think this patchset still is missing a reviewed tag from bridge
maintainers if is fine.

Thanks,
 Enric


>  1 file changed, 39 insertions(+), 45 deletions(-)
> 

Re: [RESEND PATCH 1/3] drm/mediatek: mtk_dpi: Rename bridge to next_bridge

[Boris Brezillon]

On Mon, 18 May 2020 19:39:07 +0200
Enric Balletbo i Serra <enric.balletbo@collabora.com> wrote:

> This is really a cosmetic change just to make a bit more readable the
> code after convert the driver to drm_bridge. The bridge variable name
> will be used by the encoder drm_bridge, and the chained bridge will be
> named next_bridge.
> 
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> ---
> 
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index 7fbfa95bab09..7112125dc3d1 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -61,7 +61,7 @@ enum mtk_dpi_out_color_format {
>  struct mtk_dpi {
>  	struct mtk_ddp_comp ddp_comp;
>  	struct drm_encoder encoder;
> -	struct drm_bridge *bridge;
> +	struct drm_bridge *next_bridge;

Did you consider moving the drm_of_find_panel_or_bridge() call to
mtk_dpi_bind() so you can get rid of this field?

This makes we realize there's no refcounting on bridges, which means
the bridge can vanish between the drm_of_find_panel_or_bridge() and
drm_bridge_attach() calls :-/.

>  	void __iomem *regs;
>  	struct device *dev;
>  	struct clk *engine_clk;
> @@ -607,7 +607,7 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
>  	/* Currently DPI0 is fixed to be driven by OVL1 */
>  	dpi->encoder.possible_crtcs = BIT(1);
>  
> -	ret = drm_bridge_attach(&dpi->encoder, dpi->bridge, NULL, 0);
> +	ret = drm_bridge_attach(&dpi->encoder, dpi->next_bridge, NULL, 0);
>  	if (ret) {
>  		dev_err(dev, "Failed to attach bridge: %d\n", ret);
>  		goto err_cleanup;
> @@ -747,11 +747,11 @@ static int mtk_dpi_probe(struct platform_device *pdev)
>  	}
>  
>  	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> -					  NULL, &dpi->bridge);
> +					  NULL, &dpi->next_bridge);
>  	if (ret)
>  		return ret;
>  
> -	dev_info(dev, "Found bridge node: %pOF\n", dpi->bridge->of_node);
> +	dev_info(dev, "Found bridge node: %pOF\n", dpi->next_bridge->of_node);
>  
>  	comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DPI);
>  	if (comp_id < 0) {

Re: [RESEND PATCH 1/3] drm/mediatek: mtk_dpi: Rename bridge to next_bridge

[Boris Brezillon]

On Wed, 1 Jul 2020 13:23:03 +0200
Boris Brezillon <boris.brezillon@collabora.com> wrote:

> On Mon, 18 May 2020 19:39:07 +0200
> Enric Balletbo i Serra <enric.balletbo@collabora.com> wrote:
> 
> > This is really a cosmetic change just to make a bit more readable the
> > code after convert the driver to drm_bridge. The bridge variable name
> > will be used by the encoder drm_bridge, and the chained bridge will be
> > named next_bridge.
> > 
> > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> > Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> > ---
> > 
> >  drivers/gpu/drm/mediatek/mtk_dpi.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > index 7fbfa95bab09..7112125dc3d1 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> > @@ -61,7 +61,7 @@ enum mtk_dpi_out_color_format {
> >  struct mtk_dpi {
> >  	struct mtk_ddp_comp ddp_comp;
> >  	struct drm_encoder encoder;
> > -	struct drm_bridge *bridge;
> > +	struct drm_bridge *next_bridge;  
> 
> Did you consider moving the drm_of_find_panel_or_bridge() call to
> mtk_dpi_bind() so you can get rid of this field?

Nevermind, you need it in patch 2 for the recursive call to
drm_bridge_attach().

> 
> This makes we realize there's no refcounting on bridges, which means
> the bridge can vanish between the drm_of_find_panel_or_bridge() and
> drm_bridge_attach() calls :-/.
> 
> >  	void __iomem *regs;
> >  	struct device *dev;
> >  	struct clk *engine_clk;
> > @@ -607,7 +607,7 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
> >  	/* Currently DPI0 is fixed to be driven by OVL1 */
> >  	dpi->encoder.possible_crtcs = BIT(1);
> >  
> > -	ret = drm_bridge_attach(&dpi->encoder, dpi->bridge, NULL, 0);
> > +	ret = drm_bridge_attach(&dpi->encoder, dpi->next_bridge, NULL, 0);
> >  	if (ret) {
> >  		dev_err(dev, "Failed to attach bridge: %d\n", ret);
> >  		goto err_cleanup;
> > @@ -747,11 +747,11 @@ static int mtk_dpi_probe(struct platform_device *pdev)
> >  	}
> >  
> >  	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> > -					  NULL, &dpi->bridge);
> > +					  NULL, &dpi->next_bridge);
> >  	if (ret)
> >  		return ret;
> >  
> > -	dev_info(dev, "Found bridge node: %pOF\n", dpi->bridge->of_node);
> > +	dev_info(dev, "Found bridge node: %pOF\n", dpi->next_bridge->of_node);
> >  
> >  	comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DPI);
> >  	if (comp_id < 0) {  
> 

Re: [RESEND PATCH 3/3] drm/mediatek: mtk_dpi: Use simple encoder

[Boris Brezillon]

On Mon, 18 May 2020 19:39:09 +0200
Enric Balletbo i Serra <enric.balletbo@collabora.com> wrote:

> The mtk_dpi driver uses an empty implementation for its encoder. Replace
> the code with the generic simple encoder.
> 
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> ---
> 
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 14 +++-----------
>  1 file changed, 3 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index baad198c69eb..80778b2aac2a 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -20,6 +20,7 @@
>  #include <drm/drm_bridge.h>
>  #include <drm/drm_crtc.h>
>  #include <drm/drm_of.h>
> +#include <drm/drm_simple_kms_helper.h>
>  
>  #include "mtk_dpi_regs.h"
>  #include "mtk_drm_ddp_comp.h"
> @@ -510,15 +511,6 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
>  	return 0;
>  }
>  
> -static void mtk_dpi_encoder_destroy(struct drm_encoder *encoder)
> -{
> -	drm_encoder_cleanup(encoder);
> -}
> -
> -static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = {
> -	.destroy = mtk_dpi_encoder_destroy,
> -};
> -
>  static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,
>  				 enum drm_bridge_attach_flags flags)
>  {
> @@ -591,8 +583,8 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
>  		return ret;
>  	}
>  
> -	ret = drm_encoder_init(drm_dev, &dpi->encoder, &mtk_dpi_encoder_funcs,
> -			       DRM_MODE_ENCODER_TMDS, NULL);
> +	ret = drm_simple_encoder_init(drm_dev, &dpi->encoder,
> +				      DRM_MODE_ENCODER_TMDS);

Not related to this change, but shouldn't we have DRM_MODE_ENCODER_DPI
here?

>  	if (ret) {
>  		dev_err(dev, "Failed to initialize decoder: %d\n", ret);
>  		goto err_unregister;

Re: [RESEND PATCH 2/3] drm/mediatek: mtk_dpi: Convert to bridge driver

[Boris Brezillon]

On Mon, 18 May 2020 19:39:08 +0200
Enric Balletbo i Serra <enric.balletbo@collabora.com> wrote:

> Convert mtk_dpi to a bridge driver with built-in encoder support for
> compatibility with existing component drivers.
> 
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> ---
> 
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 66 +++++++++++++++---------------
>  1 file changed, 34 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index 7112125dc3d1..baad198c69eb 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -61,6 +61,7 @@ enum mtk_dpi_out_color_format {
>  struct mtk_dpi {
>  	struct mtk_ddp_comp ddp_comp;
>  	struct drm_encoder encoder;
> +	struct drm_bridge bridge;
>  	struct drm_bridge *next_bridge;
>  	void __iomem *regs;
>  	struct device *dev;
> @@ -77,9 +78,9 @@ struct mtk_dpi {
>  	int refcount;
>  };
>  
> -static inline struct mtk_dpi *mtk_dpi_from_encoder(struct drm_encoder *e)
> +static inline struct mtk_dpi *bridge_to_dpi(struct drm_bridge *b)
>  {
> -	return container_of(e, struct mtk_dpi, encoder);
> +	return container_of(b, struct mtk_dpi, bridge);
>  }
>  
>  enum mtk_dpi_polarity {
> @@ -518,50 +519,44 @@ static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = {
>  	.destroy = mtk_dpi_encoder_destroy,
>  };
>  
> -static bool mtk_dpi_encoder_mode_fixup(struct drm_encoder *encoder,
> -				       const struct drm_display_mode *mode,
> -				       struct drm_display_mode *adjusted_mode)
> +static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,
> +				 enum drm_bridge_attach_flags flags)
>  {
> -	return true;
> +	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
> +
> +	return drm_bridge_attach(bridge->encoder, dpi->next_bridge,
> +				 &dpi->bridge, flags);
>  }
>  
> -static void mtk_dpi_encoder_mode_set(struct drm_encoder *encoder,
> -				     struct drm_display_mode *mode,
> -				     struct drm_display_mode *adjusted_mode)
> +static void mtk_dpi_bridge_mode_set(struct drm_bridge *bridge,
> +				const struct drm_display_mode *mode,
> +				const struct drm_display_mode *adjusted_mode)
>  {
> -	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);
> +	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
>  
>  	drm_mode_copy(&dpi->mode, adjusted_mode);
>  }
>  
> -static void mtk_dpi_encoder_disable(struct drm_encoder *encoder)
> +static void mtk_dpi_bridge_disable(struct drm_bridge *bridge)
>  {
> -	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);
> +	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
>  
>  	mtk_dpi_power_off(dpi);
>  }
>  
> -static void mtk_dpi_encoder_enable(struct drm_encoder *encoder)
> +static void mtk_dpi_bridge_enable(struct drm_bridge *bridge)
>  {
> -	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);
> +	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
>  
>  	mtk_dpi_power_on(dpi);
>  	mtk_dpi_set_display_mode(dpi, &dpi->mode);
>  }
>  
> -static int mtk_dpi_atomic_check(struct drm_encoder *encoder,
> -				struct drm_crtc_state *crtc_state,
> -				struct drm_connector_state *conn_state)
> -{
> -	return 0;
> -}
> -
> -static const struct drm_encoder_helper_funcs mtk_dpi_encoder_helper_funcs = {
> -	.mode_fixup = mtk_dpi_encoder_mode_fixup,
> -	.mode_set = mtk_dpi_encoder_mode_set,
> -	.disable = mtk_dpi_encoder_disable,
> -	.enable = mtk_dpi_encoder_enable,
> -	.atomic_check = mtk_dpi_atomic_check,
> +static const struct drm_bridge_funcs mtk_dpi_bridge_funcs = {
> +	.attach = mtk_dpi_bridge_attach,
> +	.mode_set = mtk_dpi_bridge_mode_set,
> +	.disable = mtk_dpi_bridge_disable,
> +	.enable = mtk_dpi_bridge_enable,
>  };
>  
>  static void mtk_dpi_start(struct mtk_ddp_comp *comp)
> @@ -602,16 +597,13 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
>  		dev_err(dev, "Failed to initialize decoder: %d\n", ret);
>  		goto err_unregister;
>  	}
> -	drm_encoder_helper_add(&dpi->encoder, &mtk_dpi_encoder_helper_funcs);
>  
>  	/* Currently DPI0 is fixed to be driven by OVL1 */
>  	dpi->encoder.possible_crtcs = BIT(1);
>  
> -	ret = drm_bridge_attach(&dpi->encoder, dpi->next_bridge, NULL, 0);
> -	if (ret) {
> -		dev_err(dev, "Failed to attach bridge: %d\n", ret);

Any reason your decided to drop this error message? If there's one,
this should probably happen in a separate patch.

> +	ret = drm_bridge_attach(&dpi->encoder, &dpi->bridge, NULL, 0);
> +	if (ret)
>  		goto err_cleanup;
> -	}
>  
>  	dpi->bit_num = MTK_DPI_OUT_BIT_NUM_8BITS;
>  	dpi->channel_swap = MTK_DPI_OUT_CHANNEL_SWAP_RGB;
> @@ -768,8 +760,15 @@ static int mtk_dpi_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, dpi);
>  
> +	dpi->bridge.funcs = &mtk_dpi_bridge_funcs;
> +	dpi->bridge.of_node = dev->of_node;
> +	dpi->bridge.type = DRM_MODE_CONNECTOR_DPI;
> +
> +	drm_bridge_add(&dpi->bridge);

I wonder if it's really useful to add the bridge when it's private (you
don't want this bridge to be added to external bridge chains).

> +
>  	ret = component_add(dev, &mtk_dpi_component_ops);
>  	if (ret) {
> +		drm_bridge_remove(&dpi->bridge);
>  		dev_err(dev, "Failed to add component: %d\n", ret);
>  		return ret;
>  	}
> @@ -779,7 +778,10 @@ static int mtk_dpi_probe(struct platform_device *pdev)
>  
>  static int mtk_dpi_remove(struct platform_device *pdev)
>  {
> +	struct mtk_dpi *dpi = platform_get_drvdata(pdev);
> +
>  	component_del(&pdev->dev, &mtk_dpi_component_ops);
> +	drm_bridge_remove(&dpi->bridge);
>  
>  	return 0;
>  }

Re: [RESEND PATCH 3/3] drm/mediatek: mtk_dpi: Use simple encoder

[Enric Balletbo i Serra]

Hi Boris,

Thank you to spend some time to review the patches.

On 1/7/20 13:41, Boris Brezillon wrote:
> On Mon, 18 May 2020 19:39:09 +0200
> Enric Balletbo i Serra <enric.balletbo@collabora.com> wrote:
> 
>> The mtk_dpi driver uses an empty implementation for its encoder. Replace
>> the code with the generic simple encoder.
>>
>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
>> Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
>> ---
>>
>>  drivers/gpu/drm/mediatek/mtk_dpi.c | 14 +++-----------
>>  1 file changed, 3 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
>> index baad198c69eb..80778b2aac2a 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
>> @@ -20,6 +20,7 @@
>>  #include <drm/drm_bridge.h>
>>  #include <drm/drm_crtc.h>
>>  #include <drm/drm_of.h>
>> +#include <drm/drm_simple_kms_helper.h>
>>  
>>  #include "mtk_dpi_regs.h"
>>  #include "mtk_drm_ddp_comp.h"
>> @@ -510,15 +511,6 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
>>  	return 0;
>>  }
>>  
>> -static void mtk_dpi_encoder_destroy(struct drm_encoder *encoder)
>> -{
>> -	drm_encoder_cleanup(encoder);
>> -}
>> -
>> -static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = {
>> -	.destroy = mtk_dpi_encoder_destroy,
>> -};
>> -
>>  static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,
>>  				 enum drm_bridge_attach_flags flags)
>>  {
>> @@ -591,8 +583,8 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
>>  		return ret;
>>  	}
>>  
>> -	ret = drm_encoder_init(drm_dev, &dpi->encoder, &mtk_dpi_encoder_funcs,
>> -			       DRM_MODE_ENCODER_TMDS, NULL);
>> +	ret = drm_simple_encoder_init(drm_dev, &dpi->encoder,
>> +				      DRM_MODE_ENCODER_TMDS);
> 
> Not related to this change, but shouldn't we have DRM_MODE_ENCODER_DPI
> here?
> 

Right, I'll add a patch to fix this.

>>  	if (ret) {
>>  		dev_err(dev, "Failed to initialize decoder: %d\n", ret);
>>  		goto err_unregister;
> 

Re: [RESEND PATCH 2/3] drm/mediatek: mtk_dpi: Convert to bridge driver

[Enric Balletbo i Serra]

Hi Boris,

Thank you for review the patch.

On 1/7/20 13:51, Boris Brezillon wrote:
> On Mon, 18 May 2020 19:39:08 +0200
> Enric Balletbo i Serra <enric.balletbo@collabora.com> wrote:
> 
>> Convert mtk_dpi to a bridge driver with built-in encoder support for
>> compatibility with existing component drivers.
>>
>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
>> Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
>> ---
>>
>>  drivers/gpu/drm/mediatek/mtk_dpi.c | 66 +++++++++++++++---------------
>>  1 file changed, 34 insertions(+), 32 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
>> index 7112125dc3d1..baad198c69eb 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
>> @@ -61,6 +61,7 @@ enum mtk_dpi_out_color_format {
>>  struct mtk_dpi {
>>  	struct mtk_ddp_comp ddp_comp;
>>  	struct drm_encoder encoder;
>> +	struct drm_bridge bridge;
>>  	struct drm_bridge *next_bridge;
>>  	void __iomem *regs;
>>  	struct device *dev;
>> @@ -77,9 +78,9 @@ struct mtk_dpi {
>>  	int refcount;
>>  };
>>  
>> -static inline struct mtk_dpi *mtk_dpi_from_encoder(struct drm_encoder *e)
>> +static inline struct mtk_dpi *bridge_to_dpi(struct drm_bridge *b)
>>  {
>> -	return container_of(e, struct mtk_dpi, encoder);
>> +	return container_of(b, struct mtk_dpi, bridge);
>>  }
>>  
>>  enum mtk_dpi_polarity {
>> @@ -518,50 +519,44 @@ static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = {
>>  	.destroy = mtk_dpi_encoder_destroy,
>>  };
>>  
>> -static bool mtk_dpi_encoder_mode_fixup(struct drm_encoder *encoder,
>> -				       const struct drm_display_mode *mode,
>> -				       struct drm_display_mode *adjusted_mode)
>> +static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,
>> +				 enum drm_bridge_attach_flags flags)
>>  {
>> -	return true;
>> +	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
>> +
>> +	return drm_bridge_attach(bridge->encoder, dpi->next_bridge,
>> +				 &dpi->bridge, flags);
>>  }
>>  
>> -static void mtk_dpi_encoder_mode_set(struct drm_encoder *encoder,
>> -				     struct drm_display_mode *mode,
>> -				     struct drm_display_mode *adjusted_mode)
>> +static void mtk_dpi_bridge_mode_set(struct drm_bridge *bridge,
>> +				const struct drm_display_mode *mode,
>> +				const struct drm_display_mode *adjusted_mode)
>>  {
>> -	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);
>> +	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
>>  
>>  	drm_mode_copy(&dpi->mode, adjusted_mode);
>>  }
>>  
>> -static void mtk_dpi_encoder_disable(struct drm_encoder *encoder)
>> +static void mtk_dpi_bridge_disable(struct drm_bridge *bridge)
>>  {
>> -	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);
>> +	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
>>  
>>  	mtk_dpi_power_off(dpi);
>>  }
>>  
>> -static void mtk_dpi_encoder_enable(struct drm_encoder *encoder)
>> +static void mtk_dpi_bridge_enable(struct drm_bridge *bridge)
>>  {
>> -	struct mtk_dpi *dpi = mtk_dpi_from_encoder(encoder);
>> +	struct mtk_dpi *dpi = bridge_to_dpi(bridge);
>>  
>>  	mtk_dpi_power_on(dpi);
>>  	mtk_dpi_set_display_mode(dpi, &dpi->mode);
>>  }
>>  
>> -static int mtk_dpi_atomic_check(struct drm_encoder *encoder,
>> -				struct drm_crtc_state *crtc_state,
>> -				struct drm_connector_state *conn_state)
>> -{
>> -	return 0;
>> -}
>> -
>> -static const struct drm_encoder_helper_funcs mtk_dpi_encoder_helper_funcs = {
>> -	.mode_fixup = mtk_dpi_encoder_mode_fixup,
>> -	.mode_set = mtk_dpi_encoder_mode_set,
>> -	.disable = mtk_dpi_encoder_disable,
>> -	.enable = mtk_dpi_encoder_enable,
>> -	.atomic_check = mtk_dpi_atomic_check,
>> +static const struct drm_bridge_funcs mtk_dpi_bridge_funcs = {
>> +	.attach = mtk_dpi_bridge_attach,
>> +	.mode_set = mtk_dpi_bridge_mode_set,
>> +	.disable = mtk_dpi_bridge_disable,
>> +	.enable = mtk_dpi_bridge_enable,
>>  };
>>  
>>  static void mtk_dpi_start(struct mtk_ddp_comp *comp)
>> @@ -602,16 +597,13 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
>>  		dev_err(dev, "Failed to initialize decoder: %d\n", ret);
>>  		goto err_unregister;
>>  	}
>> -	drm_encoder_helper_add(&dpi->encoder, &mtk_dpi_encoder_helper_funcs);
>>  
>>  	/* Currently DPI0 is fixed to be driven by OVL1 */
>>  	dpi->encoder.possible_crtcs = BIT(1);
>>  
>> -	ret = drm_bridge_attach(&dpi->encoder, dpi->next_bridge, NULL, 0);
>> -	if (ret) {
>> -		dev_err(dev, "Failed to attach bridge: %d\n", ret);
> 
> Any reason your decided to drop this error message? If there's one,
> this should probably happen in a separate patch.
> 

Right, I'll maintain the error in next version.

>> +	ret = drm_bridge_attach(&dpi->encoder, &dpi->bridge, NULL, 0);
>> +	if (ret)
>>  		goto err_cleanup;
>> -	}
>>  
>>  	dpi->bit_num = MTK_DPI_OUT_BIT_NUM_8BITS;
>>  	dpi->channel_swap = MTK_DPI_OUT_CHANNEL_SWAP_RGB;
>> @@ -768,8 +760,15 @@ static int mtk_dpi_probe(struct platform_device *pdev)
>>  
>>  	platform_set_drvdata(pdev, dpi);
>>  
>> +	dpi->bridge.funcs = &mtk_dpi_bridge_funcs;
>> +	dpi->bridge.of_node = dev->of_node;
>> +	dpi->bridge.type = DRM_MODE_CONNECTOR_DPI;
>> +
>> +	drm_bridge_add(&dpi->bridge);
> 
> I wonder if it's really useful to add the bridge when it's private (you
> don't want this bridge to be added to external bridge chains).
> 
>> +
>>  	ret = component_add(dev, &mtk_dpi_component_ops);
>>  	if (ret) {
>> +		drm_bridge_remove(&dpi->bridge);
>>  		dev_err(dev, "Failed to add component: %d\n", ret);
>>  		return ret;
>>  	}
>> @@ -779,7 +778,10 @@ static int mtk_dpi_probe(struct platform_device *pdev)
>>  
>>  static int mtk_dpi_remove(struct platform_device *pdev)
>>  {
>> +	struct mtk_dpi *dpi = platform_get_drvdata(pdev);
>> +
>>  	component_del(&pdev->dev, &mtk_dpi_component_ops);
>> +	drm_bridge_remove(&dpi->bridge);
>>  
>>  	return 0;
>>  }
> 
> 

Re: [RESEND PATCH 3/3] drm/mediatek: mtk_dpi: Use simple encoder

[Enric Balletbo i Serra]

Hi again,

On 8/7/20 17:12, Enric Balletbo i Serra wrote:
> Hi Boris,
> 
> Thank you to spend some time to review the patches.
> 
> On 1/7/20 13:41, Boris Brezillon wrote:
>> On Mon, 18 May 2020 19:39:09 +0200
>> Enric Balletbo i Serra <enric.balletbo@collabora.com> wrote:
>>
>>> The mtk_dpi driver uses an empty implementation for its encoder. Replace
>>> the code with the generic simple encoder.
>>>
>>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
>>> Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
>>> ---
>>>
>>>  drivers/gpu/drm/mediatek/mtk_dpi.c | 14 +++-----------
>>>  1 file changed, 3 insertions(+), 11 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
>>> index baad198c69eb..80778b2aac2a 100644
>>> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
>>> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
>>> @@ -20,6 +20,7 @@
>>>  #include <drm/drm_bridge.h>
>>>  #include <drm/drm_crtc.h>
>>>  #include <drm/drm_of.h>
>>> +#include <drm/drm_simple_kms_helper.h>
>>>  
>>>  #include "mtk_dpi_regs.h"
>>>  #include "mtk_drm_ddp_comp.h"
>>> @@ -510,15 +511,6 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
>>>  	return 0;
>>>  }
>>>  
>>> -static void mtk_dpi_encoder_destroy(struct drm_encoder *encoder)
>>> -{
>>> -	drm_encoder_cleanup(encoder);
>>> -}
>>> -
>>> -static const struct drm_encoder_funcs mtk_dpi_encoder_funcs = {
>>> -	.destroy = mtk_dpi_encoder_destroy,
>>> -};
>>> -
>>>  static int mtk_dpi_bridge_attach(struct drm_bridge *bridge,
>>>  				 enum drm_bridge_attach_flags flags)
>>>  {
>>> @@ -591,8 +583,8 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
>>>  		return ret;
>>>  	}
>>>  
>>> -	ret = drm_encoder_init(drm_dev, &dpi->encoder, &mtk_dpi_encoder_funcs,
>>> -			       DRM_MODE_ENCODER_TMDS, NULL);
>>> +	ret = drm_simple_encoder_init(drm_dev, &dpi->encoder,
>>> +				      DRM_MODE_ENCODER_TMDS);
>>
>> Not related to this change, but shouldn't we have DRM_MODE_ENCODER_DPI
>> here?
>>
> 

Thinking a bit more about this and this patchset in general, I think I'll drop
this patch from the series, at the end, all the encoder creation stuff should be
moved to mtk_drm_drv.


> Right, I'll add a patch to fix this.
> 
>>>  	if (ret) {
>>>  		dev_err(dev, "Failed to initialize decoder: %d\n", ret);
>>>  		goto err_unregister;
>>
>