Re: [PATCH v2 1/7] drm/bridge: Refactor out the panel wrapper from the lvds-encoder bridge.

Hi,

On 05/12/2017 12:01 AM, Eric Anholt wrote:

Many DRM drivers have common code to make a stub connector implementation that wraps a drm_panel. By wrapping the panel in a DRM bridge, all of the connector code (including calls during encoder enable/disable) goes away.

v2: Fix build with CONFIG_DRM=m, drop "dev" argument that should just be the panel's dev, move kerneldoc up a level and document _remove().

Signed-off-by: Eric Anholt eric@anholt.net Acked-by: Daniel Vetter daniel.vetter@ffwll.ch

---

Documentation/gpu/drm-kms-helpers.rst | 6 ++ drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/bridge/Kconfig | 11 +- drivers/gpu/drm/bridge/lvds-encoder.c | 157 ++++----------------------- drivers/gpu/drm/bridge/panel.c | 197 ++++++++++++++++++++++++++++++++++ include/drm/drm_bridge.h | 7 ++ 6 files changed, 238 insertions(+), 141 deletions(-) create mode 100644 drivers/gpu/drm/bridge/panel.c

diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst index c075aadd7078..7c5e2549a58a 100644 --- a/Documentation/gpu/drm-kms-helpers.rst +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -143,6 +143,12 @@ Bridge Helper Reference .. kernel-doc:: drivers/gpu/drm/drm_bridge.c :export:

+Panel-Bridge Helper Reference +-----------------------------

+.. kernel-doc:: drivers/gpu/drm/bridge/panel.c

• :export:

.. _drm_panel_helper:

Panel Helper Reference diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index c156fecfb362..4cc9c02cc3f2 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -24,6 +24,7 @@ drm-$(CONFIG_COMPAT) += drm_ioc32.o drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o drm-$(CONFIG_PCI) += ati_pcigart.o drm-$(CONFIG_DRM_PANEL) += drm_panel.o +drm-$(CONFIG_DRM_PANEL_BRIDGE) += bridge/panel.o drm-$(CONFIG_OF) += drm_of.o drm-$(CONFIG_AGP) += drm_agpsupport.o drm-$(CONFIG_DEBUG_FS) += drm_debugfs.o drm_debugfs_crc.o diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index f6968d3b4b41..c4daca38743c 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -4,6 +4,14 @@ config DRM_BRIDGE help Bridge registration and lookup framework.

+config DRM_PANEL_BRIDGE

• def_bool y
• depends on DRM_BRIDGE
• select DRM_KMS_HELPER
• select DRM_PANEL
• help

•  DRM bridge wrapper of DRM panels
  

menu "Display Interface Bridges" depends on DRM && DRM_BRIDGE

@@ -27,8 +35,7 @@ config DRM_DUMB_VGA_DAC config DRM_LVDS_ENCODER tristate "Transparent parallel to LVDS encoder support" depends on OF

• select DRM_KMS_HELPER
• select DRM_PANEL

• select DRM_PANEL_BRIDGE help Support for transparent parallel to LVDS encoders that don't require any configuration.

diff --git a/drivers/gpu/drm/bridge/lvds-encoder.c b/drivers/gpu/drm/bridge/lvds-encoder.c index f1f67a279426..0903ba574f61 100644 --- a/drivers/gpu/drm/bridge/lvds-encoder.c +++ b/drivers/gpu/drm/bridge/lvds-encoder.c @@ -8,144 +8,18 @@ */

#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 <drm/drm_bridge.h> #include <drm/drm_panel.h>

#include <linux/of_graph.h>

-struct lvds_encoder {

• struct device *dev;
• struct drm_bridge bridge;
• struct drm_connector connector;
• struct drm_panel *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);
• return drm_panel_get_modes(lvds->panel);

-}

-static const struct drm_connector_helper_funcs lvds_connector_helper_funcs = {

• .get_modes = lvds_connector_get_modes,

-};

-static const struct drm_connector_funcs lvds_connector_funcs = {

• .dpms = drm_atomic_helper_connector_dpms,
• .reset = drm_atomic_helper_connector_reset,
• .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;
  

• }
• 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);
• ret = drm_panel_attach(lvds->panel, &lvds->connector);
• if (ret < 0)

• return ret;
  

• return 0;

-}

-static void lvds_encoder_detach(struct drm_bridge *bridge) -{

• struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
• drm_panel_detach(lvds->panel);

-}

-static void lvds_encoder_pre_enable(struct drm_bridge *bridge) -{

• struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
• drm_panel_prepare(lvds->panel);

-}

-static void lvds_encoder_enable(struct drm_bridge *bridge) -{

• struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
• drm_panel_enable(lvds->panel);

-}

-static void lvds_encoder_disable(struct drm_bridge *bridge) -{

• struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
• drm_panel_disable(lvds->panel);

-}

-static void lvds_encoder_post_disable(struct drm_bridge *bridge) -{

• struct lvds_encoder *lvds = drm_bridge_to_lvds_encoder(bridge);
• drm_panel_unprepare(lvds->panel);

-}

-static const struct drm_bridge_funcs lvds_encoder_bridge_funcs = {

• .attach = lvds_encoder_attach,
• .detach = lvds_encoder_detach,
• .pre_enable = lvds_encoder_pre_enable,
• .enable = lvds_encoder_enable,
• .disable = lvds_encoder_disable,
• .post_disable = lvds_encoder_post_disable,

-};

static int lvds_encoder_probe(struct platform_device *pdev) {

• struct lvds_encoder *lvds; struct device_node *port; struct device_node *endpoint;
• struct device_node *panel;
• 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;

• struct device_node *panel_node;

• struct drm_panel *panel;

• struct drm_bridge *bridge;

  /* Locate the panel DT node. */ port = of_graph_get_port_by_id(pdev->dev.of_node, 1);

@@ -161,29 +35,34 @@ static int lvds_encoder_probe(struct platform_device *pdev) return -ENXIO; }

• panel = of_graph_get_remote_port_parent(endpoint);

• panel_node = of_graph_get_remote_port_parent(endpoint); of_node_put(endpoint);

• if (!panel) {

• if (!panel_node) { dev_dbg(&pdev->dev, "no remote endpoint for port 1\n"); return -ENXIO; }

• lvds->panel = of_drm_find_panel(panel);
• of_node_put(panel);
• if (!lvds->panel) {

• panel = of_drm_find_panel(panel_node);
• of_node_put(panel_node);
• if (!panel) { dev_dbg(&pdev->dev, "panel not found, deferring probe\n"); return -EPROBE_DEFER; }

• /* Register the bridge. */
• return drm_bridge_add(&lvds->bridge);

• bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_LVDS);
• if (IS_ERR(bridge))

• return PTR_ERR(bridge);
  

• platform_set_drvdata(pdev, bridge);
• return 0;

}

static int lvds_encoder_remove(struct platform_device *pdev) {

• struct lvds_encoder *encoder = platform_get_drvdata(pdev);

• struct drm_bridge *bridge = platform_get_drvdata(pdev);

• drm_bridge_remove(&encoder->bridge);

• drm_bridge_remove(bridge);

  return 0;

} diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c new file mode 100644 index 000000000000..fd1a78cb1205 --- /dev/null +++ b/drivers/gpu/drm/bridge/panel.c @@ -0,0 +1,197 @@ +/*

• • Copyright (C) 2016 Laurent Pinchart laurent.pinchart@ideasonboard.com
• • Copyright (C) 2017 Broadcom
• • 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_panel.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 <drm/drm_panel.h>

+struct panel_bridge {

• struct drm_bridge bridge;
• struct drm_connector connector;
• struct drm_panel *panel;
• u32 connector_type;

+};

+static inline struct panel_bridge * +drm_bridge_to_panel_bridge(struct drm_bridge *bridge) +{

• return container_of(bridge, struct panel_bridge, bridge);

+}

+static inline struct panel_bridge * +drm_connector_to_panel_bridge(struct drm_connector *connector) +{

• return container_of(connector, struct panel_bridge, connector);

+}

+static int panel_bridge_connector_get_modes(struct drm_connector *connector) +{

• struct panel_bridge *panel_bridge =

• drm_connector_to_panel_bridge(connector);
  

• return drm_panel_get_modes(panel_bridge->panel);

+}

+static const struct drm_connector_helper_funcs panel_bridge_connector_helper_funcs = {

This can be wrapped to 80 lines to prevent checkpatch warnings.

• .get_modes = panel_bridge_connector_get_modes,

+};

+static const struct drm_connector_funcs panel_bridge_connector_funcs = {

• .dpms = drm_atomic_helper_connector_dpms,
• .reset = drm_atomic_helper_connector_reset,
• .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 panel_bridge_attach(struct drm_bridge *bridge) +{

• struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
• struct drm_connector *connector = &panel_bridge->connector;
• int ret;
• if (!bridge->encoder) {

• DRM_ERROR("Missing encoder\n");
  

• return -ENODEV;
  

• }
• drm_connector_helper_add(connector,

• 		 &panel_bridge_connector_helper_funcs);
  

• ret = drm_connector_init(bridge->dev, connector,

• 		 &panel_bridge_connector_funcs,
  

• 		 panel_bridge->connector_type);
  

• if (ret) {

• DRM_ERROR("Failed to initialize connector\n");
  

• return ret;
  

• }
• drm_mode_connector_attach_encoder(&panel_bridge->connector,

• 			  bridge->encoder);
  

• ret = drm_panel_attach(panel_bridge->panel, &panel_bridge->connector);
• if (ret < 0)

• return ret;
  

• return 0;

+}

+static void panel_bridge_detach(struct drm_bridge *bridge) +{

• struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
• drm_panel_detach(panel_bridge->panel);

+}

+static void panel_bridge_pre_enable(struct drm_bridge *bridge) +{

• struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
• drm_panel_prepare(panel_bridge->panel);

+}

+static void panel_bridge_enable(struct drm_bridge *bridge) +{

• struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
• drm_panel_enable(panel_bridge->panel);

+}

+static void panel_bridge_disable(struct drm_bridge *bridge) +{

• struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
• drm_panel_disable(panel_bridge->panel);

+}

+static void panel_bridge_post_disable(struct drm_bridge *bridge) +{

• struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
• drm_panel_unprepare(panel_bridge->panel);

+}

+static const struct drm_bridge_funcs panel_bridge_bridge_funcs = {

• .attach = panel_bridge_attach,
• .detach = panel_bridge_detach,
• .pre_enable = panel_bridge_pre_enable,
• .enable = panel_bridge_enable,
• .disable = panel_bridge_disable,
• .post_disable = panel_bridge_post_disable,

+};

+/**

• • drm_panel_bridge_add - Creates a drm_bridge and drm_connector that
• • just calls the appropriate functions from drm_panel.
• • @panel: The drm_panel being wrapped. Must be non-NULL.
• • @connector_type: The DRM_MODE_CONNECTOR_* for the connector to be
• • created.
• • For drivers converting from directly using drm_panel: The expected
• • usage pattern is that during either encoder module probe or DSI
• • host attach, a drm_panel will be looked up through
• • drm_of_find_panel_or_bridge(). drm_panel_bridge_add() is used to
• • wrap that panel in the new bridge, and the result can then be
• • passed to drm_bridge_attach(). The drm_panel_prepare() and related
• • functions can be dropped from the encoder driver (they're now
• • called by the KMS helpers before calling into the encoder), along
• • with connector creation. When done with the bridge,
• • drm_bridge_detach() should be called as normal, then
• • drm_panel_bridge_remove() to free it.
• */

+struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,

• 			u32 connector_type)
  

There are more arguments besides the connector_type that we may require to create the connector correctly. Things like connector's 'bus_formats' and 'polled' fields need to come from the caller. I guess they don't matter as much for simple panels, but we'd probably want to wrap them all in a struct in the future.

+{

• struct panel_bridge *panel_bridge;
• int ret;
• if (!panel)

• return ERR_PTR(EINVAL);
  

• panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge),

• 		    GFP_KERNEL);
  

• if (!panel_bridge)

• return ERR_PTR(-ENOMEM);
  

• panel_bridge->connector_type = connector_type;
• panel_bridge->panel = panel;
• panel_bridge->bridge.funcs = &panel_bridge_bridge_funcs;
• panel_bridge->bridge.of_node = panel->dev->of_node;
• ret = drm_bridge_add(&panel_bridge->bridge);
• if (ret)

• return ERR_PTR(ret);
  

• return &panel_bridge->bridge;

+} +EXPORT_SYMBOL(drm_panel_bridge_add);

+/**

• • drm_panel_bridge_remove - Unregisters and frees a drm_bridge
• • created by drm_panel_bridge_add().
• • @bridge: The drm_bridge being freed.
• */

+void drm_panel_bridge_remove(struct drm_bridge *bridge) +{

• struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge);
• drm_bridge_remove(bridge);
• devm_kfree(panel_bridge->panel->dev, bridge);

+} +EXPORT_SYMBOL(drm_panel_bridge_remove); diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index fdd82fcbf168..bad2178ea3e0 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -29,6 +29,7 @@ #include <drm/drm_modes.h>

struct drm_bridge; +struct drm_panel;

/**

• struct drm_bridge_funcs - drm_bridge control functions

@@ -221,4 +222,10 @@ void drm_bridge_mode_set(struct drm_bridge *bridge, void drm_bridge_pre_enable(struct drm_bridge *bridge); void drm_bridge_enable(struct drm_bridge *bridge);

+#ifdef CONFIG_DRM_PANEL +struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel,

• 			u32 connector_type);
  

+void drm_panel_bridge_remove(struct drm_bridge *bridge); +#endif

Shouldn't this be CONFIG_DRM_PANEL_BRIDGE?

As I mentioned on irc, I was facing some build issues with this patch applied. Once we sort that out:

Acked-by: Archit Taneja architt@codeaurora.org

Thanks, Archit