diff mbox

[1/8] drm: bridge: Add LVDS encoder driver

Message ID 1476887143-24831-2-git-send-email-laurent.pinchart+renesas@ideasonboard.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Laurent Pinchart Oct. 19, 2016, 2:25 p.m. UTC
The LVDS encoder driver is a DRM bridge driver that supports the
parallel to LVDS encoders that don't require any configuration. The
driver thus doesn't interact with the device, but creates an LVDS
connector for the panel and exposes its size and timing based on
information retrieved from DT.

Cc: devicetree@vger.kernel.org
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 .../bindings/display/bridge/lvds-transmitter.txt   |  64 +++++++
 drivers/gpu/drm/bridge/Kconfig                     |   8 +
 drivers/gpu/drm/bridge/Makefile                    |   1 +
 drivers/gpu/drm/bridge/lvds-encoder.c              | 203 +++++++++++++++++++++
 4 files changed, 276 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
 create mode 100644 drivers/gpu/drm/bridge/lvds-encoder.c

Comments

Archit Taneja Oct. 21, 2016, 5:21 a.m. UTC | #1
On 10/19/2016 07:55 PM, Laurent Pinchart wrote:
> The LVDS encoder driver is a DRM bridge driver that supports the
> parallel to LVDS encoders that don't require any configuration. The
> driver thus doesn't interact with the device, but creates an LVDS
> connector for the panel and exposes its size and timing based on
> information retrieved from DT.
>
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> ---
>  .../bindings/display/bridge/lvds-transmitter.txt   |  64 +++++++
>  drivers/gpu/drm/bridge/Kconfig                     |   8 +
>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>  drivers/gpu/drm/bridge/lvds-encoder.c              | 203 +++++++++++++++++++++
>  4 files changed, 276 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
>  create mode 100644 drivers/gpu/drm/bridge/lvds-encoder.c
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> new file mode 100644
> index 000000000000..fd39ad34c383
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> @@ -0,0 +1,64 @@
> +Parallel to LVDS Encoder
> +------------------------
> +
> +This binding supports the parallel to LVDS encoders that don't require any
> +configuration.
> +
> +LVDS is a physical layer specification defined in ANSI/TIA/EIA-644-A. Multiple
> +incompatible data link layers have been used over time to transmit image data
> +to LVDS panels. This binding targets devices compatible with the following
> +specifications only.
> +
> +[JEIDA] "Digital Interface Standards for Monitor", JEIDA-59-1999, February
> +1999 (Version 1.0), Japan Electronic Industry Development Association (JEIDA)
> +[LDI] "Open LVDS Display Interface", May 1999 (Version 0.95), National
> +Semiconductor
> +[VESA] "VESA Notebook Panel Standard", October 2007 (Version 1.0), Video
> +Electronics Standards Association (VESA)
> +
> +Those devices have been marketed under the FPD-Link and FlatLink brand names
> +among others.
> +
> +
> +Required properties:
> +
> +- compatible: Must be "lvds-encoder"
> +
> +Required nodes:
> +
> +This device has two video ports. Their connections are modeled using the OF
> +graph bindings specified in Documentation/devicetree/bindings/graph.txt.
> +
> +- Video port 0 for parallel input
> +- Video port 1 for LVDS output
> +
> +
> +Example
> +-------
> +
> +lvds-encoder {
> +	compatible = "lvds-encoder";
> +	#address-cells = <1>;
> +	#size-cells = <0>;
> +
> +	ports {
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		port@0 {
> +			reg = <0>;
> +
> +			lvds_enc_in: endpoint {
> +				remote-endpoint = <&display_out_rgb>;
> +			};
> +		};
> +
> +		port@1 {
> +			reg = <1>;
> +
> +			lvds_enc_out: endpoint {
> +				remote-endpoint = <&lvds_panel_in>;
> +			};
> +		};
> +	};
> +};
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index 10e12e74fc9f..5dafad7817ad 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -24,6 +24,14 @@ config DRM_DUMB_VGA_DAC
>  	help
>  	  Support for RGB to VGA DAC based bridges
>
> +config DRM_LVDS_ENCODER
> +	tristate "Transparent parallel to LVDS encoder support"
> +	depends on OF
> +	select DRM_KMS_HELPER
> +	help
> +	  Support for transparent parallel to LVDS encoders that don't require
> +	  any configuration.
> +
>  config DRM_DW_HDMI
>  	tristate
>  	select DRM_KMS_HELPER
> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> index cdf3a3cf765d..bbaf583581ac 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -2,6 +2,7 @@ ccflags-y := -Iinclude/drm
>
>  obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
>  obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o
> +obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o
>  obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
>  obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
>  obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
> diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c b/drivers/gpu/drm/bridge/lvds-encoder.c
> new file mode 100644
> index 000000000000..33e8025c8a6d
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/lvds-encoder.c
> @@ -0,0 +1,203 @@
> +/*
> + * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + */
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_connector.h>
> +#include <drm/drm_crtc_helper.h>
> +#include <drm/drm_encoder.h>
> +#include <drm/drm_modeset_helper_vtables.h>
> +
> +#include <linux/of_graph.h>
> +
> +#include <video/display_timing.h>
> +#include <video/of_display_timing.h>
> +#include <video/videomode.h>
> +
> +struct lvds_encoder {
> +	struct device *dev;
> +
> +	struct drm_bridge bridge;
> +	struct drm_connector connector;
> +
> +	struct {
> +		unsigned int width_mm;
> +		unsigned int height_mm;
> +		struct videomode mode;
> +	} panel;

I don't see why we need create our own panel instance
in the encoder driver. We should use the drm_panel
API here rather than managing panel specific stuff in
this driver.

The parade-ps8622 and nxp-ptn3460 bridge drivers already
do this.

Thanks,
Archit

> +};
> +
> +static inline struct lvds_encoder *
> +drm_bridge_to_lvds_encoder(struct drm_bridge *bridge)
> +{
> +	return container_of(bridge, struct lvds_encoder, bridge);
> +}
> +
> +static inline struct lvds_encoder *
> +drm_connector_to_lvds_encoder(struct drm_connector *connector)
> +{
> +	return container_of(connector, struct lvds_encoder, connector);
> +}
> +
> +static int lvds_connector_get_modes(struct drm_connector *connector)
> +{
> +	struct lvds_encoder *lvds = drm_connector_to_lvds_encoder(connector);
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_create(connector->dev);
> +	if (mode == NULL)
> +		return 0;
> +
> +	mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
> +
> +	drm_display_mode_from_videomode(&lvds->panel.mode, mode);
> +
> +	drm_mode_probed_add(connector, mode);
> +
> +	return 1;
> +}
> +
> +static const struct drm_connector_helper_funcs lvds_connector_helper_funcs = {
> +	.get_modes = lvds_connector_get_modes,
> +};
> +
> +static enum drm_connector_status
> +lvds_connector_detect(struct drm_connector *connector, bool force)
> +{
> +	return connector_status_connected;
> +}
> +
> +static const struct drm_connector_funcs lvds_connector_funcs = {
> +	.dpms = drm_atomic_helper_connector_dpms,
> +	.reset = drm_atomic_helper_connector_reset,
> +	.detect = lvds_connector_detect,
> +	.fill_modes = drm_helper_probe_single_connector_modes,
> +	.destroy = drm_connector_cleanup,
> +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +};
> +
> +static int lvds_encoder_attach(struct drm_bridge *bridge)
> +{
> +	struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
> +	struct drm_connector *connector = &lvds->connector;
> +	int ret;
> +
> +	if (!bridge->encoder) {
> +		DRM_ERROR("Missing encoder\n");
> +		return -ENODEV;
> +	}
> +
> +	connector->display_info.width_mm = lvds->panel.width_mm;
> +	connector->display_info.height_mm = lvds->panel.height_mm;
> +
> +	drm_connector_helper_add(connector, &lvds_connector_helper_funcs);
> +
> +	ret = drm_connector_init(bridge->dev, connector, &lvds_connector_funcs,
> +				 DRM_MODE_CONNECTOR_LVDS);
> +	if (ret) {
> +		DRM_ERROR("Failed to initialize connector\n");
> +		return ret;
> +	}
> +
> +	drm_mode_connector_attach_encoder(&lvds->connector, bridge->encoder);
> +
> +	return 0;
> +}
> +
> +static const struct drm_bridge_funcs lvds_encoder_bridge_funcs = {
> +	.attach = lvds_encoder_attach,
> +};
> +
> +static int lvds_encoder_probe(struct platform_device *pdev)
> +{
> +	struct lvds_encoder *lvds;
> +	struct display_timing timing;
> +	struct device_node *port;
> +	struct device_node *endpoint;
> +	struct device_node *panel;
> +	int ret;
> +
> +	lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
> +	if (!lvds)
> +		return -ENOMEM;
> +
> +	lvds->dev = &pdev->dev;
> +	platform_set_drvdata(pdev, lvds);
> +
> +	lvds->bridge.funcs = &lvds_encoder_bridge_funcs;
> +	lvds->bridge.of_node = pdev->dev.of_node;
> +	lvds->bridge.encoder_type = DRM_MODE_ENCODER_LVDS;
> +
> +	/* Locate the panel DT node. */
> +	port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
> +	if (!port) {
> +		dev_dbg(&pdev->dev, "port 1 not found\n");
> +		return -ENXIO;
> +	}
> +
> +	endpoint = of_get_child_by_name(port, "endpoint");
> +	of_node_put(port);
> +	if (!endpoint) {
> +		dev_dbg(&pdev->dev, "no endpoint for port 1\n");
> +		return -ENXIO;
> +	}
> +
> +	panel = of_graph_get_remote_port_parent(endpoint);
> +	of_node_put(endpoint);
> +	if (!panel) {
> +		dev_dbg(&pdev->dev, "no remote endpoint for port 1\n");
> +		return -ENXIO;
> +	}
> +
> +	/* Parse and store panel information. */
> +	ret = of_get_display_timing(panel, "panel-timing", &timing);
> +	of_node_put(panel);
> +	if (ret < 0) {
> +		dev_dbg(&pdev->dev, "unable to parse panel timings\n");
> +		return ret;
> +	}
> +
> +	videomode_from_timing(&timing, &lvds->panel.mode);
> +
> +	of_property_read_u32(panel, "width-mm", &lvds->panel.width_mm);
> +	of_property_read_u32(panel, "height-mm", &lvds->panel.height_mm);
> +
> +	/* Register the bridge. */
> +	return drm_bridge_add(&lvds->bridge);
> +}
> +
> +static int lvds_encoder_remove(struct platform_device *pdev)
> +{
> +	struct lvds_encoder *encoder = platform_get_drvdata(pdev);
> +
> +	drm_bridge_remove(&encoder->bridge);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id lvds_encoder_match[] = {
> +	{ .compatible = "lvds-encoder" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, lvds_encoder_match);
> +
> +struct platform_driver lvds_encoder_driver = {
> +	.probe	= lvds_encoder_probe,
> +	.remove	= lvds_encoder_remove,
> +	.driver		= {
> +		.name		= "lvds-encoder",
> +		.of_match_table	= lvds_encoder_match,
> +	},
> +};
> +module_platform_driver(lvds_encoder_driver);
> +
> +MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
> +MODULE_DESCRIPTION("Transparent parallel to LVDS encoder");
> +MODULE_LICENSE("GPL");
>
Laurent Pinchart Oct. 21, 2016, 10:21 a.m. UTC | #2
Hi Archit,

On Friday 21 Oct 2016 10:51:59 Archit Taneja wrote:
> On 10/19/2016 07:55 PM, Laurent Pinchart wrote:
> > The LVDS encoder driver is a DRM bridge driver that supports the
> > parallel to LVDS encoders that don't require any configuration. The
> > driver thus doesn't interact with the device, but creates an LVDS
> > connector for the panel and exposes its size and timing based on
> > information retrieved from DT.
> > 
> > Cc: devicetree@vger.kernel.org
> > Signed-off-by: Laurent Pinchart
> > <laurent.pinchart+renesas@ideasonboard.com>
> > ---
> > 
> >  .../bindings/display/bridge/lvds-transmitter.txt   |  64 +++++++
> >  drivers/gpu/drm/bridge/Kconfig                     |   8 +
> >  drivers/gpu/drm/bridge/Makefile                    |   1 +
> >  drivers/gpu/drm/bridge/lvds-encoder.c              | 203 ++++++++++++++++
> >  4 files changed, 276 insertions(+)
> >  create mode 100644
> >  Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> >  create mode 100644 drivers/gpu/drm/bridge/lvds-encoder.c
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> > b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> > new file mode 100644
> > index 000000000000..fd39ad34c383
> > --- /dev/null
> > +++
> > b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
> > @@ -0,0 +1,64 @@
> > +Parallel to LVDS Encoder
> > +------------------------
> > +
> > +This binding supports the parallel to LVDS encoders that don't require
> > any
> > +configuration.
> > +
> > +LVDS is a physical layer specification defined in ANSI/TIA/EIA-644-A.
> > Multiple +incompatible data link layers have been used over time to
> > transmit image data +to LVDS panels. This binding targets devices
> > compatible with the following +specifications only.
> > +
> > +[JEIDA] "Digital Interface Standards for Monitor", JEIDA-59-1999,
> > February
> > +1999 (Version 1.0), Japan Electronic Industry Development Association
> > (JEIDA) +[LDI] "Open LVDS Display Interface", May 1999 (Version 0.95),
> > National +Semiconductor
> > +[VESA] "VESA Notebook Panel Standard", October 2007 (Version 1.0), Video
> > +Electronics Standards Association (VESA)
> > +
> > +Those devices have been marketed under the FPD-Link and FlatLink brand
> > names +among others.
> > +
> > +
> > +Required properties:
> > +
> > +- compatible: Must be "lvds-encoder"
> > +
> > +Required nodes:
> > +
> > +This device has two video ports. Their connections are modeled using the
> > OF +graph bindings specified in
> > Documentation/devicetree/bindings/graph.txt. +
> > +- Video port 0 for parallel input
> > +- Video port 1 for LVDS output
> > +
> > +
> > +Example
> > +-------
> > +
> > +lvds-encoder {
> > +	compatible = "lvds-encoder";
> > +	#address-cells = <1>;
> > +	#size-cells = <0>;
> > +
> > +	ports {
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +
> > +		port@0 {
> > +			reg = <0>;
> > +
> > +			lvds_enc_in: endpoint {
> > +				remote-endpoint = <&display_out_rgb>;
> > +			};
> > +		};
> > +
> > +		port@1 {
> > +			reg = <1>;
> > +
> > +			lvds_enc_out: endpoint {
> > +				remote-endpoint = <&lvds_panel_in>;
> > +			};
> > +		};
> > +	};
> > +};
> > diff --git a/drivers/gpu/drm/bridge/Kconfig
> > b/drivers/gpu/drm/bridge/Kconfig index 10e12e74fc9f..5dafad7817ad 100644
> > --- a/drivers/gpu/drm/bridge/Kconfig
> > +++ b/drivers/gpu/drm/bridge/Kconfig
> > @@ -24,6 +24,14 @@ config DRM_DUMB_VGA_DAC
> > 
> >  	help
> >  	
> >  	  Support for RGB to VGA DAC based bridges
> > 
> > +config DRM_LVDS_ENCODER
> > +	tristate "Transparent parallel to LVDS encoder support"
> > +	depends on OF
> > +	select DRM_KMS_HELPER
> > +	help
> > +	  Support for transparent parallel to LVDS encoders that don't require
> > +	  any configuration.
> > +
> > 
> >  config DRM_DW_HDMI
> >  
> >  	tristate
> >  	select DRM_KMS_HELPER
> > 
> > diff --git a/drivers/gpu/drm/bridge/Makefile
> > b/drivers/gpu/drm/bridge/Makefile index cdf3a3cf765d..bbaf583581ac 100644
> > --- a/drivers/gpu/drm/bridge/Makefile
> > +++ b/drivers/gpu/drm/bridge/Makefile
> > @@ -2,6 +2,7 @@ ccflags-y := -Iinclude/drm
> > 
> >  obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
> >  obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o
> > 
> > +obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o
> > 
> >  obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
> >  obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
> >  obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
> > 
> > diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c
> > b/drivers/gpu/drm/bridge/lvds-encoder.c new file mode 100644
> > index 000000000000..33e8025c8a6d
> > --- /dev/null
> > +++ b/drivers/gpu/drm/bridge/lvds-encoder.c
> > @@ -0,0 +1,203 @@
> > +/*
> > + * Copyright (C) 2016 Laurent Pinchart
> > <laurent.pinchart@ideasonboard.com>
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License as
> > + * published by the Free Software Foundation; either version 2 of
> > + * the License, or (at your option) any later version.
> > + */
> > +
> > +#include <drm/drmP.h>
> > +#include <drm/drm_atomic_helper.h>
> > +#include <drm/drm_connector.h>
> > +#include <drm/drm_crtc_helper.h>
> > +#include <drm/drm_encoder.h>
> > +#include <drm/drm_modeset_helper_vtables.h>
> > +
> > +#include <linux/of_graph.h>
> > +
> > +#include <video/display_timing.h>
> > +#include <video/of_display_timing.h>
> > +#include <video/videomode.h>
> > +
> > +struct lvds_encoder {
> > +	struct device *dev;
> > +
> > +	struct drm_bridge bridge;
> > +	struct drm_connector connector;
> > +
> > +	struct {
> > +		unsigned int width_mm;
> > +		unsigned int height_mm;
> > +		struct videomode mode;
> > +	} panel;
> 
> I don't see why we need create our own panel instance
> in the encoder driver. We should use the drm_panel
> API here rather than managing panel specific stuff in
> this driver.

It's not a panel instance but a structure that holds information about the 
connected panel. This is temporary until the LVDS panel DT bindings I've 
submitted get accepted.

> The parade-ps8622 and nxp-ptn3460 bridge drivers already
> do this.
> 
> Thanks,
> Archit
> 
> > +};
> > +
> > +static inline struct lvds_encoder *
> > +drm_bridge_to_lvds_encoder(struct drm_bridge *bridge)
> > +{
> > +	return container_of(bridge, struct lvds_encoder, bridge);
> > +}
> > +
> > +static inline struct lvds_encoder *
> > +drm_connector_to_lvds_encoder(struct drm_connector *connector)
> > +{
> > +	return container_of(connector, struct lvds_encoder, connector);
> > +}
> > +
> > +static int lvds_connector_get_modes(struct drm_connector *connector)
> > +{
> > +	struct lvds_encoder *lvds = drm_connector_to_lvds_encoder(connector);
> > +	struct drm_display_mode *mode;
> > +
> > +	mode = drm_mode_create(connector->dev);
> > +	if (mode == NULL)
> > +		return 0;
> > +
> > +	mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
> > +
> > +	drm_display_mode_from_videomode(&lvds->panel.mode, mode);
> > +
> > +	drm_mode_probed_add(connector, mode);
> > +
> > +	return 1;
> > +}
> > +
> > +static const struct drm_connector_helper_funcs
> > lvds_connector_helper_funcs = { +	.get_modes = lvds_connector_get_modes,
> > +};
> > +
> > +static enum drm_connector_status
> > +lvds_connector_detect(struct drm_connector *connector, bool force)
> > +{
> > +	return connector_status_connected;
> > +}
> > +
> > +static const struct drm_connector_funcs lvds_connector_funcs = {
> > +	.dpms = drm_atomic_helper_connector_dpms,
> > +	.reset = drm_atomic_helper_connector_reset,
> > +	.detect = lvds_connector_detect,
> > +	.fill_modes = drm_helper_probe_single_connector_modes,
> > +	.destroy = drm_connector_cleanup,
> > +	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> > +	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> > +};
> > +
> > +static int lvds_encoder_attach(struct drm_bridge *bridge)
> > +{
> > +	struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
> > +	struct drm_connector *connector = &lvds->connector;
> > +	int ret;
> > +
> > +	if (!bridge->encoder) {
> > +		DRM_ERROR("Missing encoder\n");
> > +		return -ENODEV;
> > +	}
> > +
> > +	connector->display_info.width_mm = lvds->panel.width_mm;
> > +	connector->display_info.height_mm = lvds->panel.height_mm;
> > +
> > +	drm_connector_helper_add(connector, &lvds_connector_helper_funcs);
> > +
> > +	ret = drm_connector_init(bridge->dev, connector, 
&lvds_connector_funcs,
> > +				 DRM_MODE_CONNECTOR_LVDS);
> > +	if (ret) {
> > +		DRM_ERROR("Failed to initialize connector\n");
> > +		return ret;
> > +	}
> > +
> > +	drm_mode_connector_attach_encoder(&lvds->connector, bridge->encoder);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct drm_bridge_funcs lvds_encoder_bridge_funcs = {
> > +	.attach = lvds_encoder_attach,
> > +};
> > +
> > +static int lvds_encoder_probe(struct platform_device *pdev)
> > +{
> > +	struct lvds_encoder *lvds;
> > +	struct display_timing timing;
> > +	struct device_node *port;
> > +	struct device_node *endpoint;
> > +	struct device_node *panel;
> > +	int ret;
> > +
> > +	lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
> > +	if (!lvds)
> > +		return -ENOMEM;
> > +
> > +	lvds->dev = &pdev->dev;
> > +	platform_set_drvdata(pdev, lvds);
> > +
> > +	lvds->bridge.funcs = &lvds_encoder_bridge_funcs;
> > +	lvds->bridge.of_node = pdev->dev.of_node;
> > +	lvds->bridge.encoder_type = DRM_MODE_ENCODER_LVDS;
> > +
> > +	/* Locate the panel DT node. */
> > +	port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
> > +	if (!port) {
> > +		dev_dbg(&pdev->dev, "port 1 not found\n");
> > +		return -ENXIO;
> > +	}
> > +
> > +	endpoint = of_get_child_by_name(port, "endpoint");
> > +	of_node_put(port);
> > +	if (!endpoint) {
> > +		dev_dbg(&pdev->dev, "no endpoint for port 1\n");
> > +		return -ENXIO;
> > +	}
> > +
> > +	panel = of_graph_get_remote_port_parent(endpoint);
> > +	of_node_put(endpoint);
> > +	if (!panel) {
> > +		dev_dbg(&pdev->dev, "no remote endpoint for port 1\n");
> > +		return -ENXIO;
> > +	}
> > +
> > +	/* Parse and store panel information. */
> > +	ret = of_get_display_timing(panel, "panel-timing", &timing);
> > +	of_node_put(panel);
> > +	if (ret < 0) {
> > +		dev_dbg(&pdev->dev, "unable to parse panel timings\n");
> > +		return ret;
> > +	}
> > +
> > +	videomode_from_timing(&timing, &lvds->panel.mode);
> > +
> > +	of_property_read_u32(panel, "width-mm", &lvds->panel.width_mm);
> > +	of_property_read_u32(panel, "height-mm", &lvds->panel.height_mm);
> > +
> > +	/* Register the bridge. */
> > +	return drm_bridge_add(&lvds->bridge);
> > +}
> > +
> > +static int lvds_encoder_remove(struct platform_device *pdev)
> > +{
> > +	struct lvds_encoder *encoder = platform_get_drvdata(pdev);
> > +
> > +	drm_bridge_remove(&encoder->bridge);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id lvds_encoder_match[] = {
> > +	{ .compatible = "lvds-encoder" },
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, lvds_encoder_match);
> > +
> > +struct platform_driver lvds_encoder_driver = {
> > +	.probe	= lvds_encoder_probe,
> > +	.remove	= lvds_encoder_remove,
> > +	.driver		= {
> > +		.name		= "lvds-encoder",
> > +		.of_match_table	= lvds_encoder_match,
> > +	},
> > +};
> > +module_platform_driver(lvds_encoder_driver);
> > +
> > +MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
> > +MODULE_DESCRIPTION("Transparent parallel to LVDS encoder");
> > +MODULE_LICENSE("GPL");
Rob Herring (Arm) Oct. 26, 2016, 9:32 p.m. UTC | #3
On Wed, Oct 19, 2016 at 05:25:36PM +0300, Laurent Pinchart wrote:
> The LVDS encoder driver is a DRM bridge driver that supports the
> parallel to LVDS encoders that don't require any configuration. The
> driver thus doesn't interact with the device, but creates an LVDS
> connector for the panel and exposes its size and timing based on
> information retrieved from DT.
> 
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> ---
>  .../bindings/display/bridge/lvds-transmitter.txt   |  64 +++++++

It's preferred that bindings are separate patches. That makes the 
filtered DT only repo commits more sane.

Acked-by: Rob Herring <robh@kernel.org>

>  drivers/gpu/drm/bridge/Kconfig                     |   8 +
>  drivers/gpu/drm/bridge/Makefile                    |   1 +
>  drivers/gpu/drm/bridge/lvds-encoder.c              | 203 +++++++++++++++++++++
>  4 files changed, 276 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
>  create mode 100644 drivers/gpu/drm/bridge/lvds-encoder.c
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
new file mode 100644
index 000000000000..fd39ad34c383
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
@@ -0,0 +1,64 @@ 
+Parallel to LVDS Encoder
+------------------------
+
+This binding supports the parallel to LVDS encoders that don't require any
+configuration.
+
+LVDS is a physical layer specification defined in ANSI/TIA/EIA-644-A. Multiple
+incompatible data link layers have been used over time to transmit image data
+to LVDS panels. This binding targets devices compatible with the following
+specifications only.
+
+[JEIDA] "Digital Interface Standards for Monitor", JEIDA-59-1999, February
+1999 (Version 1.0), Japan Electronic Industry Development Association (JEIDA)
+[LDI] "Open LVDS Display Interface", May 1999 (Version 0.95), National
+Semiconductor
+[VESA] "VESA Notebook Panel Standard", October 2007 (Version 1.0), Video
+Electronics Standards Association (VESA)
+
+Those devices have been marketed under the FPD-Link and FlatLink brand names
+among others.
+
+
+Required properties:
+
+- compatible: Must be "lvds-encoder"
+
+Required nodes:
+
+This device has two video ports. Their connections are modeled using the OF
+graph bindings specified in Documentation/devicetree/bindings/graph.txt.
+
+- Video port 0 for parallel input
+- Video port 1 for LVDS output
+
+
+Example
+-------
+
+lvds-encoder {
+	compatible = "lvds-encoder";
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	ports {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		port@0 {
+			reg = <0>;
+
+			lvds_enc_in: endpoint {
+				remote-endpoint = <&display_out_rgb>;
+			};
+		};
+
+		port@1 {
+			reg = <1>;
+
+			lvds_enc_out: endpoint {
+				remote-endpoint = <&lvds_panel_in>;
+			};
+		};
+	};
+};
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index 10e12e74fc9f..5dafad7817ad 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -24,6 +24,14 @@  config DRM_DUMB_VGA_DAC
 	help
 	  Support for RGB to VGA DAC based bridges
 
+config DRM_LVDS_ENCODER
+	tristate "Transparent parallel to LVDS encoder support"
+	depends on OF
+	select DRM_KMS_HELPER
+	help
+	  Support for transparent parallel to LVDS encoders that don't require
+	  any configuration.
+
 config DRM_DW_HDMI
 	tristate
 	select DRM_KMS_HELPER
diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
index cdf3a3cf765d..bbaf583581ac 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -2,6 +2,7 @@  ccflags-y := -Iinclude/drm
 
 obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
 obj-$(CONFIG_DRM_DUMB_VGA_DAC) += dumb-vga-dac.o
+obj-$(CONFIG_DRM_LVDS_ENCODER) += lvds-encoder.o
 obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
 obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
 obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o
diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c b/drivers/gpu/drm/bridge/lvds-encoder.c
new file mode 100644
index 000000000000..33e8025c8a6d
--- /dev/null
+++ b/drivers/gpu/drm/bridge/lvds-encoder.c
@@ -0,0 +1,203 @@ 
+/*
+ * Copyright (C) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_connector.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_modeset_helper_vtables.h>
+
+#include <linux/of_graph.h>
+
+#include <video/display_timing.h>
+#include <video/of_display_timing.h>
+#include <video/videomode.h>
+
+struct lvds_encoder {
+	struct device *dev;
+
+	struct drm_bridge bridge;
+	struct drm_connector connector;
+
+	struct {
+		unsigned int width_mm;
+		unsigned int height_mm;
+		struct videomode mode;
+	} panel;
+};
+
+static inline struct lvds_encoder *
+drm_bridge_to_lvds_encoder(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct lvds_encoder, bridge);
+}
+
+static inline struct lvds_encoder *
+drm_connector_to_lvds_encoder(struct drm_connector *connector)
+{
+	return container_of(connector, struct lvds_encoder, connector);
+}
+
+static int lvds_connector_get_modes(struct drm_connector *connector)
+{
+	struct lvds_encoder *lvds = drm_connector_to_lvds_encoder(connector);
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_create(connector->dev);
+	if (mode == NULL)
+		return 0;
+
+	mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
+
+	drm_display_mode_from_videomode(&lvds->panel.mode, mode);
+
+	drm_mode_probed_add(connector, mode);
+
+	return 1;
+}
+
+static const struct drm_connector_helper_funcs lvds_connector_helper_funcs = {
+	.get_modes = lvds_connector_get_modes,
+};
+
+static enum drm_connector_status
+lvds_connector_detect(struct drm_connector *connector, bool force)
+{
+	return connector_status_connected;
+}
+
+static const struct drm_connector_funcs lvds_connector_funcs = {
+	.dpms = drm_atomic_helper_connector_dpms,
+	.reset = drm_atomic_helper_connector_reset,
+	.detect = lvds_connector_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = drm_connector_cleanup,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static int lvds_encoder_attach(struct drm_bridge *bridge)
+{
+	struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
+	struct drm_connector *connector = &lvds->connector;
+	int ret;
+
+	if (!bridge->encoder) {
+		DRM_ERROR("Missing encoder\n");
+		return -ENODEV;
+	}
+
+	connector->display_info.width_mm = lvds->panel.width_mm;
+	connector->display_info.height_mm = lvds->panel.height_mm;
+
+	drm_connector_helper_add(connector, &lvds_connector_helper_funcs);
+
+	ret = drm_connector_init(bridge->dev, connector, &lvds_connector_funcs,
+				 DRM_MODE_CONNECTOR_LVDS);
+	if (ret) {
+		DRM_ERROR("Failed to initialize connector\n");
+		return ret;
+	}
+
+	drm_mode_connector_attach_encoder(&lvds->connector, bridge->encoder);
+
+	return 0;
+}
+
+static const struct drm_bridge_funcs lvds_encoder_bridge_funcs = {
+	.attach = lvds_encoder_attach,
+};
+
+static int lvds_encoder_probe(struct platform_device *pdev)
+{
+	struct lvds_encoder *lvds;
+	struct display_timing timing;
+	struct device_node *port;
+	struct device_node *endpoint;
+	struct device_node *panel;
+	int ret;
+
+	lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
+	if (!lvds)
+		return -ENOMEM;
+
+	lvds->dev = &pdev->dev;
+	platform_set_drvdata(pdev, lvds);
+
+	lvds->bridge.funcs = &lvds_encoder_bridge_funcs;
+	lvds->bridge.of_node = pdev->dev.of_node;
+	lvds->bridge.encoder_type = DRM_MODE_ENCODER_LVDS;
+
+	/* Locate the panel DT node. */
+	port = of_graph_get_port_by_id(pdev->dev.of_node, 1);
+	if (!port) {
+		dev_dbg(&pdev->dev, "port 1 not found\n");
+		return -ENXIO;
+	}
+
+	endpoint = of_get_child_by_name(port, "endpoint");
+	of_node_put(port);
+	if (!endpoint) {
+		dev_dbg(&pdev->dev, "no endpoint for port 1\n");
+		return -ENXIO;
+	}
+
+	panel = of_graph_get_remote_port_parent(endpoint);
+	of_node_put(endpoint);
+	if (!panel) {
+		dev_dbg(&pdev->dev, "no remote endpoint for port 1\n");
+		return -ENXIO;
+	}
+
+	/* Parse and store panel information. */
+	ret = of_get_display_timing(panel, "panel-timing", &timing);
+	of_node_put(panel);
+	if (ret < 0) {
+		dev_dbg(&pdev->dev, "unable to parse panel timings\n");
+		return ret;
+	}
+
+	videomode_from_timing(&timing, &lvds->panel.mode);
+
+	of_property_read_u32(panel, "width-mm", &lvds->panel.width_mm);
+	of_property_read_u32(panel, "height-mm", &lvds->panel.height_mm);
+
+	/* Register the bridge. */
+	return drm_bridge_add(&lvds->bridge);
+}
+
+static int lvds_encoder_remove(struct platform_device *pdev)
+{
+	struct lvds_encoder *encoder = platform_get_drvdata(pdev);
+
+	drm_bridge_remove(&encoder->bridge);
+
+	return 0;
+}
+
+static const struct of_device_id lvds_encoder_match[] = {
+	{ .compatible = "lvds-encoder" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, lvds_encoder_match);
+
+struct platform_driver lvds_encoder_driver = {
+	.probe	= lvds_encoder_probe,
+	.remove	= lvds_encoder_remove,
+	.driver		= {
+		.name		= "lvds-encoder",
+		.of_match_table	= lvds_encoder_match,
+	},
+};
+module_platform_driver(lvds_encoder_driver);
+
+MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
+MODULE_DESCRIPTION("Transparent parallel to LVDS encoder");
+MODULE_LICENSE("GPL");